JP2000356907A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect attachment of a cartridge and inherent information by means of a non-contact system by magnetic connection without being affected by contact failure due to stain with toner and so on and wear or the like. SOLUTION: A device main body 10 is provided with a magnetic induction circuit 17 in which a wire is wound round an E-type ferrite core. A developing cartridge 21 is provided with an I-type ferrite core 26 disposed to form a magnetic path opposite the magnetic induction circuit 17 when the developing cartridge 21 is attached to the device main body 10. The magnetic induction circuit 17 and the I-type ferrite core 26 are brought into close contact with each other with a gap member 27, made of a magnetic substance, between them. This changes inductance of the magnetic induction circuit 17 two to three times or more by the formation of the magnetic path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, a printer, and the like, and more particularly to an image forming apparatus having a cartridge which is detachable from an apparatus main body and stores at least one supply consumable. is there.

[0002]

2. Description of the Related Art Conventionally, a toner cartridge as a developer supply container is mounted on a toner supply section of a developing device in an image forming apparatus such as a copying machine, a facsimile, a printer, or the like. As a mechanism for preventing erroneous mounting when mounting the toner cartridge, a bar code reader as information reading means is provided in the toner replenishing unit, and the bar code information displayed on the toner cartridge is read by the bird reader, and the reading result is obtained. In some cases, erroneous mounting is determined by the following. Then, the erroneous insertion prevention shutter is operated to prevent erroneous mounting of the toner cartridge.
-1682).

As another erroneous mounting prevention mechanism, there is a mechanism having a plurality of developing units as in a color image forming apparatus. That is, a plurality of developing units having different colors of developer and a color image forming apparatus main body to which the developing unit is mounted are provided with resistors having different sizes, respectively, and the developing unit is mounted on the image forming apparatus. Then, the corresponding resistors are configured to be in parallel. Then, erroneous mounting of a plurality of developing units is prevented by a change in the combined resistance value (JP-A-8-31427).
No. 6).

[0004]

In any of the erroneous mounting prevention mechanisms described above, since the presence or absence of the mounting of the developing unit is electrically detected, no complicated mechanical mechanism is required. But,
Bar code information and optical reading means of a bar code reader are susceptible to contamination of toner and the like, and may not be able to read correct information. Further, even in the configuration having the electrodes and reading the change in the resistance value, there is also a problem that a contact failure is likely to occur due to contamination or abrasion of the toner or the like, and the change in the resistance value cannot be read accurately. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of detecting mounting and unique information on a cartridge side without being affected by poor contact due to contamination or wear of toner or the like by a non-contact method by magnetic coupling. It is to provide.

[0006]

According to a first aspect of the present invention, there is provided an image forming apparatus having a cartridge detachably mountable to an apparatus main body, wherein the first magnetic induction is provided on the apparatus main body side and has a coil for generating magnetic induction. A second magnetic guiding means disposed on the cartridge side and arranged near the first magnetic guiding means to generate magnetic induction when the cartridge is mounted on the apparatus main body side; By the value of the inductance of the first magnetic induction means, which changes according to the mounting state of the cartridge to the apparatus main body,
Detecting means for detecting information on the cartridge side.

According to a second aspect of the present invention, the first magnetic guiding means is wound around a core having a coil made of a magnetic material, and the second magnetic guiding means is provided when the cartridge is mounted. It is a magnetic member arranged so as to face the core.

According to a third aspect of the present invention, a gap member made of a non-magnetic material for controlling an inductance value is provided so as to be disposed between the core and the magnetic member when the cartridge is mounted. Features.

In a fourth aspect of the present invention, a thickness G of the gap member is set.
s (mm) satisfies the relational expression of Gs ≦ 0.5−0.1 × Le / Se when the effective sectional area is Se (mm ² ) and the effective magnetic path length is Le (mm). And

In a fifth aspect of the present invention, the first magnetic induction means has a gap, and the second magnetic induction means has
It is characterized by having a protruding portion inserted into the gap when the cartridge is mounted.

In a sixth aspect of the present invention, the first magnetic induction means comprises an air core coil in which the air gap is an air core portion,
The protrusion of the second magnetic guiding means is made of a magnetic material.

In a seventh aspect, the second magnetic induction means has a coil, and the coil of the second magnetic induction means is
It is arranged so as to link with the coil of the first magnetic induction means, and is further connected to an information adding means for adding information on the cartridge side.

An eighth invention is characterized in that the information adding means is a capacitor connected in parallel with the coil of the second magnetic induction means.

A ninth aspect of the present invention is characterized in that one of the coils of the first and second magnetic induction means is an air-core coil.

In a tenth aspect, the detecting means includes an oscillation circuit whose oscillation frequency changes by a change in inductance of the first magnetic induction means, and an oscillation frequency or oscillation cycle of a signal output from the oscillation circuit. It is characterized by comprising a measuring means for measuring, and a judging means for judging information on the cartridge side from an output from the measuring means.

An eleventh invention is a Colpitts oscillation circuit in which the oscillation circuit includes a first magnetic induction section for stabilization and a second magnetic induction section for determining an oscillation frequency. The two magnetic induction portions constitute the first magnetic induction means.

A twelfth invention is characterized in that the oscillating circuit is a multivibrator type oscillating circuit including a coil of the first magnetic induction means.

According to a thirteenth aspect, the detecting means includes a filter circuit for generating a phase difference due to a change in inductance of the first magnetic induction means, and a phase difference detecting means for detecting a phase difference between input and output signals of the filter circuit. Means for detecting mounting information on the cartridge side from the output of the phase difference detecting means.

According to a fourteenth aspect, the filter circuit includes:
It is a low-pass filter having a zero point in its transfer function.

In a fifteenth aspect, the detection means generates a resonance circuit whose resonance frequency changes by a change in inductance of the magnetic induction means, and a signal set near the resonance frequency of the resonance circuit. A signal generating circuit to be input to a circuit, a rectifying circuit for rectifying a signal output from the signal generating circuit, a smoothing circuit for smoothing the output signal and converting the output signal into a DC voltage, and an output signal from the smoothing circuit And a comparator for comparing with the desired signal level,
Determining means for determining information on the cartridge side from an output result from the comparator.

A sixteenth invention is characterized in that the signal generating circuit has sweep means for sequentially switching and outputting a plurality of frequencies.

In a seventeenth aspect, the sweep means comprises a frequency dividing circuit for dividing a reference clock, and a control circuit for controlling a frequency dividing ratio of the frequency dividing circuit. It is characterized in that rectangular waves having different periods are sequentially output.

An eighteenth invention is characterized in that the resonance circuit is a band-pass filter circuit comprising a series resonance or a parallel resonance.

A nineteenth aspect of the present invention is a display device for detecting, based on a signal detected by the detecting means, whether or not the cartridge is mounted on the apparatus main body, or for displaying the detected mounted state. It is characterized by having.

According to a twentieth aspect of the present invention, a normal copy operation is performed when the mounted state of the cartridge and the apparatus main body is detected based on a signal detected by the detecting means, and when the mounted state or the mounted state is detected. Is prohibited.

A twenty-first invention is characterized in that, when the detecting means detects the unique information of the cartridge, it performs an initialization process according to the unique information.

In the present invention, the information on the removable cartridge is stored in the first magnetic induction means provided on the main assembly side of the apparatus and the first magnetic induction means provided on the cartridge side by electromagnetic induction between the first magnetic induction means. The inductance of the magnetic induction means is detected. Therefore, it is not necessary for the cartridge to directly contact the apparatus main body in order to detect the cartridge information. Even if the cartridge is contaminated with, for example, toner, the inductance detection is not affected by the contamination. Therefore, highly reliable information can be easily detected.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings, taking a monochrome laser printer using a non-magnetic one-component toner as a developer as an example.

<First Embodiment> A first embodiment of the image forming apparatus according to the present invention will be described. FIG. 1 is a schematic configuration diagram illustrating a configuration of an image forming apparatus main body side according to the first embodiment, FIG. 2 is a schematic configuration diagram illustrating a configuration of a developing cartridge that is detachable from the apparatus main body side, and FIG. FIG. 2 is a schematic configuration diagram illustrating a configuration when the device is mounted on a device.

As shown in FIG. 1, the photosensitive drum 11 having the surface coated with the OPC photosensitive layer is driven and rotated at a constant speed in one direction (clockwise in the figure). It is uniformly charged. Then, a laser scanning unit (not shown) irradiates the surface of the photosensitive drum 11 with a laser beam based on the image signal subjected to the image processing, thereby forming an electrostatic latent image. A magnetic induction circuit 17 as first magnetic induction means in which a winding is wound around an E-type ferrite core (magnetic member) is provided on the device body 10 side.

As shown in FIG. 2, the developing cartridge 21 is a laser printer in which a developer container and a developing means are integrated. The supply roller 24 is driven to rotate in one direction (counterclockwise in the figure), and the non-magnetic one-component toner 28 in the developing cartridge 21 is also driven to rotate in one direction (counterclockwise in the figure). To supply. Next, the non-magnetic one-component toner 28 on the developing roller 22 is sufficiently charged by the blade 23 to form a thin layer of the toner 28, and supplies the toner 28 to the surface of the photosensitive drum 11 on which the electrostatic latent image is formed. And is visualized. The developing cartridge 21 includes a magnetic induction circuit 1 when the developing cartridge 21 is mounted on the apparatus main body 10.
7, a magnetic member disposed to form a magnetic path, that is, an I-type ferrite core 26 is provided (see FIGS. 2 and 3). This I-type ferrite core 26
Is a second type which causes the magnetic induction circuit 17 to generate magnetic induction.
Magnetic induction means. That is, the ferrite core 26
Is arranged close to the first magnetic guiding means when the cartridge is mounted on the apparatus main body side, and causes magnetic induction.

The visualized toner image is transferred to a sheet 16 by the transfer charger 13 shown in FIG. 1, and furthermore, the heat and pressure of the upper fixing roller 14 and the lower fixing roller 15
The toner image transferred to the sheet 16 is fixed on the sheet 16 and discharged outside the image forming apparatus.

A gap material 2 made of a non-magnetic material is provided between the magnetic induction circuit 17 and the I-type ferrite core 26.
7 are in close contact. This is to change the inductance (hereinafter abbreviated as L value) of the magnetic induction circuit 17 by two to three times or more by forming a magnetic path. 2 mm. The magnetic induction circuit 17 is provided with a mounting position so as to escape the thickness (about 1 mm) of the resin of the developing cartridge 21, and further, by a pressing member 25 such as a spring, the magnetic induction circuit 17 and the I-type ferrite core 26 are connected to each other. To improve adhesion.

Next, the developing cartridge 21 and the apparatus main body 1
The specific configuration of the detecting means for detecting the quality of the attachment with the 0 side will be described. FIG. 4 is a block diagram illustrating an example of a specific configuration of the detection unit. This detection circuit has a configuration including an oscillation circuit 31, a measurement circuit 32, and a determination circuit 33. First, the oscillation frequency of the oscillation circuit 31 changes due to a change in the L value due to the attachment / detachment between the developing cartridge 21 and the apparatus main body 10 side. An output signal of the oscillation circuit 31 is input to a measurement circuit 32 that measures an oscillation frequency or an oscillation cycle, and an output of the measurement circuit 32 is input to a determination circuit 33. The determination circuit 33 determines the mounting state of the cartridge by comparing the oscillation frequency or the oscillation cycle with a predetermined reference value. Here, the measurement circuit 32 is, for example, a frequency counter that measures the oscillation signal from the oscillation circuit 31 for a certain period, or from the rise to the next rise of the oscillation signal from the oscillation circuit 31, or from the fall to the next fall. Can be easily realized by a period counter that counts the period of time with a constant clock signal serving as a reference (not shown).

Next, a specific configuration of the oscillation circuit 31 will be described. The oscillation circuit 31 includes a magnetic induction circuit 17 therein.
First, the magnetic induction circuit 17 will be described. FIG. 5 shows a magnetic induction circuit 1 used for an oscillation circuit.
7 is a circuit diagram showing a detailed configuration of FIG. The magnetic induction circuit 17 in the present embodiment has a relative permeability μ as a magnetic member.
r is about 2300, the effective sectional area Se is about 19 mm ² , and the effective magnetic path length Le is about 35 mm.
Use The E-type ferrite core 17a
And a center tap wound with 15 turns each. That is, the magnetic induction circuit 17 includes a first magnetic induction section Ls configured by a winding having a terminal 17s and a terminal 17c, and a second magnetic induction section Lc configured by a winding having a terminal 17c and a terminal 17e. Consists of The L value of the first magnetic guide Ls is set to be substantially equal to the L value of the second magnetic guide Lc.
Therefore, here, the L value of Ls and Lc is L1.

The thickness Gs (mm) of the gap material 27
As a result, when experiments were performed using ferrite cores having various sizes, it was found that it was necessary to satisfy Gs ≦ 0.5−0.1 × Le ÷ Se. More desirably, it was found that it was necessary to satisfy Gs ≦ 0.4−0.1 × Le ÷ Se.

FIG. 6 shows the size L of the ferrite core 17a.
FIG. 4 is a characteristic diagram illustrating a relationship between e / Se and a gap length Gs (mm). The black triangles in the figure show the measurement results under the condition that the L value changes about twice. It can be seen that it is sufficient to satisfy the above inequality.

In this embodiment, the ferrite core 17
When the core size of a is substituted into the above equation, Gs ≦ 0.4−0.1 × 35 ÷ 19 ÷ 0.22 (mm), and the thickness Gs of the gap material 27 is 0.2 mm.
It is better to do the following. In the present embodiment, Gs is set to about 0.1 mm in order to take a larger change in the L value.

As shown in FIG. 1, the developing cartridge 21
Is not attached to the apparatus main body 10, the L value (L1) of the first magnetic induction section Ls and the second magnetic induction section Lc is about 8
μH. On the other hand, as shown in FIG. 3, when the developing cartridge 21 is mounted on the apparatus main body 10, a magnetic path is formed across the gap material 27 by the I-type ferrite core 26 in the developing cartridge 21. , The first magnetic induction part Ls and the second magnetic induction part Lc on the device body 10 side
(L1) increases to about 24 μH.

FIG. 7 is a circuit diagram showing an example of an oscillation circuit using this magnetic induction circuit. The oscillating circuit 31a is a Colpitts oscillating circuit, and includes first and second magnetic induction units Ls and Lc which are coils constituting the magnetic induction circuit 17, capacitors C1 and C2, an NPN transistor Tr1,
It consists of resistors R1, R2, Re. 1st magnetic induction part Ls
And the second magnetic induction part Lc are connected in series. The capacitors C1 and C2 connected in series are connected in parallel with the second magnetic induction section Lc. Second magnetic induction section L
The power supply Vcc is applied to one end of the first magnetic induction section Ls on the side opposite to the c side and to the collector of the transistor Tr1. The power supply Vcc is applied to R1 of the voltage dividing resistors R1 and R2 connected in series, R2 is grounded, and the base of the transistor Tr1 is connected between R1 and R2. Thus, the power supply Vcc is divided by the resistors R1 and R2 and applied to the base of the transistor Tr1. Transistor Tr
One emitter is connected to an emitter resistor Re having one end grounded. The voltage divided by the voltage dividing resistors R1 and R2 is
The voltage is applied to one end of the second magnetic induction portion Lc, not on the side of the magnetic induction portion Ls, to connect between the emitter of the transistor Tr1 and the capacitors C1 and C2. The output terminal 18 of the oscillation circuit 31a is provided at the emitter of the transistor Tr1.

In this oscillation circuit 31a, the capacitances of the capacitors C1 and C2 are both Cs. This oscillation circuit 31
The oscillation frequency fr of a can be obtained from the following equation. fr = 1 {[2π ｛L1 × C1 × C2 ÷ (C1 + C2)｝ ^1/2 ] = 1 = 1 ÷ ｛2π × (L1 × Cs / 2) ^1/2 ｝

That is, an oscillation frequency inversely proportional to the change in the value L1 ^{/ 2} can be obtained from the emitter follow output terminal 18 of the NPN transistor Tr1. In the present embodiment, the L value when the developing cartridge 21 is not mounted on the apparatus main body 10 is about 8 μH, and the L value when the developing cartridge 21 is mounted is about 2 μH.
Since the set 4MyuH, the oscillation frequency changes by 3 ^1/2 times.

FIG. 8 shows actual operation waveforms of the Colpitts oscillation circuit. FIG. 8A illustrates an oscillation circuit 31 a in a state where the developing cartridge 21 is not mounted on the apparatus main body 10.
8B shows a signal waveform of the output terminal 18 of the oscillation circuit 31a in a state where the developing cartridge 21 is mounted on the apparatus main body 10. FIG. FIG.
In (a), the signal oscillating at about 480 KHz changes to L
As shown in FIG. 8B, with the change of the value three times, about 29
It can be seen that the frequency is changed to 0 KHz and 1/3 ^1/2 times.

The L value of the first magnetic induction section Ls for stabilization and the L value of the second magnetic induction section Lc for determining the oscillation frequency of the Colpitts oscillation circuit are not necessarily required to be equal. The first magnetic induction section Ls may be set so as to satisfy the following relational expression between the capacitors C1 and C2 and the second magnetic induction section Lc (the L value of each magnetic induction section and the capacitance of each capacitor are: , The corresponding code is used). Ls = Lc × C2 ÷ C1 ...

The output signal from the oscillation circuit 31 is measured by the measurement circuit 3
2, the oscillation frequency is counted by a counter or the like, and the measurement result is input to the discrimination circuit 33. The determination circuit 33 calculates the value (fc) measured by the measurement circuit 32 as
If the value is equal to or less than a certain desired value (fd), it is determined that the developing cartridge 21 is mounted on the apparatus main body 10 side. Also,
If the value is equal to or more than the desired value (fd), it is determined that the developing cartridge 21 is not mounted on the apparatus main body 10 side. Desired value f
d is, for example, about 3 from the experimental results in FIG.
The frequency is preferably set to 80 KHz. Through the processing by the detection means described above, it is possible to easily determine whether or not the mounting of the developing cartridge 21 to the apparatus main body 10 is good or not.

Next, another embodiment of the oscillation circuit according to the present invention will be described. FIG. 9 is a circuit diagram showing another example of the oscillation circuit. In this oscillation circuit 31b,
One coil is sufficient, and the magnetic induction circuit 17 does not need to be provided with a center tap. That is, the oscillation circuit 31b
Multi-vibrator type oscillation circuit, magnetic induction circuit 1
Coil R11 and resistors R11, R12, R
e, an NPN transistor Tr11, and a comparator 35.

The power Vcc is applied to the collector of the transistor Tr11 via the coil L11, and the emitter is connected to the emitter resistor Re. The output of the comparator 35 is
The voltage is input to the base of the transistor Tr11, and the output of the comparator 35 is divided by the voltage dividing resistors R11 and R12, and is input to one input terminal of the comparator 35. An output from the emitter of the transistor Tr11 is input to the other input terminal of the comparator 35.

The NPN transistor Tr11 is ON, O
It functions as a switching element that performs only FF. When the transistor Tr11 is ON, a current flows from the power supply Vcc through the coil L11, the NPN transistor Tr11, the emitter resistor Re, and the ground. At this time, the potential rise Ve generated in the emitter resistance Re is caused by the transistor Tr
When the saturation voltage of 1 is expressed as a function of time t, where Vce is Vce, it is expressed by the following equation. Ve = (Vc−Vce) × {1-Exp (−Re / L1 × t)}

That is, when the voltage generated at the emitter resistance Re rises at a speed determined by the time constant of L1 / Re, and becomes larger than the threshold value of Vcc × R2 ÷ (R1 + R2) in the comparator 35, the comparator 35 It changes to 0V. When the comparator 35 changes to 0V, the transistor Tr
Although the reference numeral 11 is turned off, the current accumulated in the coil L11 continues to flow only slightly during the carrier accumulation time of the transistor Tr11. Therefore, the potential generated at the emitter resistor Re does not instantaneously decrease but gradually decreases to 0V. . Therefore, when the potential generated at the emitter resistance Re becomes 0 V, the output of the comparator 35 is inverted from 0 V to Vcc, and the NPN transistor Tr11 is turned on again. By repeating the above operation, the multivibrator type oscillation circuit operates stably, and the oscillation frequency becomes a value almost proportional to the L value. Therefore, the mounting state of the cartridge is determined based on the oscillation frequency in the same manner as described above.
3 can be determined.

Next, another example of the detecting means will be described. FIG. 10 is a block diagram showing another detecting means of the first embodiment. This detection means includes a filter circuit 42, a phase difference detection circuit 43, and a determination circuit 44. A rectangular wave signal is input to an input terminal 41 of the filter circuit 42, and the rectangular wave signal and an output signal of the filter circuit 42 are input to a phase difference detection circuit 43, and an output signal of the phase difference detection circuit 43 is input to a discrimination circuit 44. Is done. The phase difference detection circuit 43
For example, a pulse width corresponding to the phase difference can be easily created by a logic circuit such as an exclusive OR. The pulse width can be accurately measured by a counter that counts a reference clock only during a period corresponding to the pulse width.

FIG. 11 is a circuit diagram showing a specific configuration of the filter circuit. Magnetic induction circuit 17 (coil L2
One end of 1) is an input terminal 45, the other end 46 is connected to one end of a capacitor C21, the other end of the capacitor C21 is connected to one end of a resistor R21, and the other end of the resistor R21 is connected to ground. . That is, the filter circuit 42 includes the terminal 45 as an input terminal and the terminal 46 as an output terminal.

Here, the capacitance of the capacitor C21 of the filter circuit 42 is 0.1 μF, and the resistance of the resistor R21 is 10 μF.
It is set to 0Ω. When the developing cartridge 21 is not mounted on the apparatus main body 10, the L value of the coil L21 is about 8 μH, and when the developing cartridge 21 is mounted on the apparatus main body 10, the L value of the coil L21 is about 24 μH.

FIG. 12 shows the transfer characteristic between the input terminal 45 and the output terminal 46 of the filter circuit 42.
ain1 represents the relationship between the frequency and the amplitude when the developing cartridge 21 is not mounted (when the L value is 8 μH);
e1 indicates the relationship between the frequency and the phase, and Gai in FIG.
n2 is when the developing cartridge 21 is mounted (L value is 24 μH
2) shows the relationship between the amplitude and the frequency, and Phase 2 shows the relationship between the phase and the frequency.

FIG. 13 shows a waveform of an output signal waveform when a rectangular wave signal of a frequency, for example, 500 KHz, at which the amplitude changes little in the frequency characteristic of FIG. The simulation result is shown. Vout 1 in FIG.
1 is a filter circuit 42 when not attached to the apparatus main body 10
Vout2 indicates the output signal of the developing cartridge 21.
Indicates an output signal of the filter circuit 42 when the filter circuit 42 is mounted on the apparatus main body 10.

FIG. 14 shows a filter circuit 4 from the rectangular wave signal input to the input terminal 45 of the filter circuit 42.
9 is a timing chart showing a time relationship until a pulse signal S4 having a time width corresponding to the amount of phase delay between input and output of the second pulse signal is generated. In the figure, a signal S1 represents a rectangular wave signal input to the filter circuit 42, and signals S2 and S3 are rectangular by comparing the output signals (Vout1, Vout2) of the filter circuit 42 with a threshold Th by a comparator (not shown). This shows a signal that has been shaped into a wave.

Here, time t1 indicates the rise time of signal S1, time t2 indicates the rise time of signal S2, and time t3 indicates the rise time of signal S3. t1
The pulse signal S4 having a pulse width of -t2 is the signal S1
And the signal S2, and an exclusive OR of the output signal of the exclusive OR and the signal S1. Similarly, a pulse signal S4 having a pulse width of t1-t3 is an exclusive OR of the signal S1 and the signal S3, and further, the output signal of the exclusive OR and the signal S3 are obtained.
This is realized by taking a logical product with 1.

In the phase difference detection circuit 43, the pulse width of the pulse signal S4 is measured by a counter, and the measurement result is input to the discrimination circuit 44. In the determination circuit 44, if the measured value of the pulse width of the pulse signal S4 is equal to or more than a desired value (tr), the developing cartridge 21
Is determined to be attached to the apparatus body 10 side. If it is equal to or less than the desired value (tr), it is determined that the developing cartridge 71 is not mounted on the apparatus main body 10 side. However, the desired value (t
r) satisfies the following relational expression. t2 ≦ tr ≦ t3

By measuring the pulse width of the pulse signal (S4) by the above-described detection means, it is possible to determine whether or not the developing cartridge 21 is mounted or whether or not the developing cartridge 21 is mounted properly.

It should be noted that the filter circuit is not shown with L, C
When the filter is constituted by a secondary low-pass filter consisting of the following, the phase has a steep phase characteristic of changing by 180 ° in the vicinity of the resonance frequency, so that it is difficult to detect the above-mentioned phase difference. In this case, a resistor R is connected in series with the LC filter,
By giving the secondary low-pass filter a damping effect, the phase change can be made more gradual. Even in this case, when the L value changes at most about three times due to the operation of attaching and detaching the developing cartridge 21 to and from the apparatus main body 10, the change in the resonance frequency is suppressed by the damping effect, and the accurate detection based on the above-described phase difference can be performed. It will be difficult. When this filter circuit is used, a method of sweeping the frequency of a signal input to the filter circuit and detecting a change in the resonance frequency of the filter circuit that changes with a change in the L value is suitable.

Further, L, R (not shown)
Even if it is composed of a first-order low-pass filter consisting of, the phase change with respect to the frequency is gradual, so that the detection based on the above-mentioned phase difference is possible. However, in the configuration using the first-order low-pass filter including the L and R, the current flowing through the coil is detected by the resistor R in principle.
A coil drive circuit for supplying a current to the coil is required, which causes an increase in cost.

Accordingly, this filter circuit does not need to sweep the frequency of the input signal, and does not require the special coil drive circuit as described above, and can detect the presence or absence of the unit accurately at the simplest and inexpensive. Things.

<Second Embodiment> Next, a second embodiment of the image forming apparatus according to the present invention will be described. FIG.
FIG. 9 is a cross-sectional view illustrating a configuration when a developing cartridge according to a second embodiment is mounted on an apparatus main body. The basic configuration of FIG. 15 is almost the same as that of FIG.
The same reference numerals are given and the description is omitted. The difference from FIG.
The device main body 50 does not include the magnetic induction circuit 17 having the image E-type ferrite core, and the developing cartridge 51 does not include the I-type ferrite core 26. Instead, as will be described later, an air-core coil 52
However, the projecting portion 53 is provided on the developing cartridge 51.

FIG. 16 is an enlarged side view showing a state where the apparatus main body and the developing cartridge in the second embodiment are mounted. An air core coil 52 corresponding to the first magnetic guiding means is provided on the apparatus main body 50 side, while a projecting portion 53 which is a second magnetic guiding means made of a magnetic material is provided on the detachable developing cartridge 51. Is provided. The projection 53 is inserted into a substantially central portion of the air-core coil 52 at the time of attachment to the apparatus main body 50.
The air-core coil 52 has, for example, a winding composed of 20 turns and has a diameter of about 8 mm and a thickness of about 4 mm. The protrusion 53 made of the magnetic material has an effective cross-sectional area of about 7 mm ² . Use a length of about 12 mm.

As shown in FIG. 16A, when the developing cartridge 51 is not mounted on the apparatus main body 50, the inductance value (hereinafter abbreviated as L value) of the air-core coil 52 is about 2.5 μH. Become. On the other hand, as shown in FIG. 16B, when the developing cartridge 51 is moved in the direction of arrow A and mounted on the main body 50, the image forming apparatus is such that the protrusion 53 passes through substantially the center of the air-core coil 52. Is configured. For this reason, the L value of the air-core coil 52 increases, and is about 7.5 μH in the present embodiment. From the change in the L value, it is possible to detect whether or not the developing cartridge 51 is mounted.

Next, the specific structure of the detecting means for detecting whether or not the developing cartridge 51 and the apparatus main body 50 are properly mounted will be described in detail. FIG. 17 is a block diagram illustrating an example of a specific configuration of the detection unit. This detection means has a configuration including an oscillation circuit 61, a measurement circuit 62, and a determination circuit 63, and is the same as that in FIG. Since the operation is the same, the description is omitted.

Next, an example of the oscillation circuit 61 will be described. A part of the oscillation circuit 61a is constituted by an air core coil 52 provided in the apparatus main body. FIG. 18 is a configuration diagram illustrating the air core coil 11. The air core coil 52 is
The first magnetic induction section Ls ₂ has a terminal 52s and a center terminal 52c, and the second magnetic induction coil Lc ₂ has a center terminal 52c and a terminal 52e.

FIG. 19 is a circuit diagram showing an oscillation circuit 61a, and the same parts as those in FIG. 7 are denoted by the same reference numerals. This oscillating circuit is a Colpitts oscillating circuit, as in FIG. 7, where L values of Ls and Lc are L1 and capacitances of C1 and C2 are Cs.
The oscillation frequency fr can be obtained from:

That is, an oscillation frequency that is inversely proportional to the change in the L1 ^{/ 2} value can be obtained from the emitter follow output terminal 18 of the NPN transistor Trl. In this embodiment, the L value when the developing cartridge 51 is not attached to the apparatus main body 50 is set to about 2.5 μH, and the L value when the developing cartridge 51 is attached is set to about 7.5 μH. 3
^It changes by a factor of ^1/2 , making it easy to determine the presence or absence of wearing.

FIG. 20 is a specific circuit diagram showing another example of the oscillation circuit, and the same parts as those in FIG. 9 are denoted by the same reference numerals.
The oscillation circuit 61b forms a multivibrator type oscillation circuit. In this case, it is not necessary to provide a center tap in the air-core coil 52. The operation of the oscillation circuit 61b is the same as that of FIG.

Next, another detecting means will be described. FIG. 21 is a block diagram illustrating an example of another configuration of the detection unit. This detection means has a configuration including a filter circuit 72, a phase difference detection circuit 73, and a discrimination circuit 74.
This is the same configuration as FIG. The operation is also the same as that in FIG.

FIG. 22 shows a specific configuration of the filter circuit. This filter circuit 72 is substantially the same as that of FIG. 11 except that a coil L31 corresponding to a magnetic induction circuit is connected. The value of each constant of the filter circuit 72 is, for example, 0.1 μF for the capacitor and 10 μF for the resistance.
Since the value is determined to be 0Ω and the L value of the coil is changed in accordance with whether or not the cartridge 51 is mounted, the frequency characteristic of the filter 72 changes according to the change in the L value.

FIG. 23 is a simulation result showing a frequency characteristic of transmission between the input terminal 45 and the output terminal 46 of the filter circuit 72 due to the change in the L value. FIG.
FIG. 23A shows the relationship between the frequency (Bz) and the amplitude (dB) when the cartridge 51 is not yet mounted on the apparatus main body 50 (condition 1: L1 = 2.5 μH), and FIG.
(B) shows the phase (de) for the frequency under the same condition 1.
g) shows the relationship. Similarly, FIG. 23C shows the state when the cartridge 51 is mounted on the apparatus main body 50 (condition 2: Ll
= 7.5 μH), showing the relationship of amplitude to frequency.
FIG. 23D shows the relationship between the frequency and the phase under the same condition 2.

FIG. 24 shows the phase difference when a frequency, for example, a 2 MHz rectangular wave signal whose amplitude hardly changes and whose phase changes greatly, is input to the detecting means shown in FIG. 9 is a simulation result of a pulse signal output from the detection circuit 73. FIG. 24 (a)
FIG. 24B shows the pulse signal when the cartridge 51 is not mounted on the apparatus main body 50, that is, when L31 = 2.5 μH. FIG. 24B shows the pulse signal when the cartridge 51 is mounted on the apparatus main body 50, The pulse signal when L31 = 7.5 μH is shown. From the simulation result, the width of the pulse signal in FIG.
The pulse signal width in FIG. 24B is about 0.05 μsec, which is about three times different from 5 μsec.

That is, the width of the pulse signal is measured by a counter or the like, and if the measured value is equal to or greater than a desired value (tr), it can be determined that the cartridge is mounted on the image forming apparatus main body. In this case, the desired value (tr) may be, for example, about 0.033 μsec.

The width of the pulse signal is measured by the above-described processing by the detection means, and it is possible to determine whether or not the cartridge is mounted or whether or not the cartridge is mounted properly based on the magnitude of the pulse width.

<Third Embodiment> Next, a third embodiment of the image forming apparatus according to the present invention will be described. FIG.
FIG. 13 is a cross-sectional view illustrating a configuration when a developing cartridge according to a third embodiment is mounted on an apparatus main body. Since the basic configuration of FIG. 25 is almost the same as that of FIG.
The same reference numerals are given and the description is omitted. What is different from FIG.
The magnetic induction circuit 77 is provided. This magnetic induction circuit 77 is shown in FIG. FIG. 26A is a configuration diagram of a magnetic induction circuit, and FIG. 26B is a combination diagram of forming a magnetic path between a magnetic induction circuit and a magnetic body.

The magnetic induction circuit 77 as the first magnetic induction means has a relative permeability μr of about 230 as a magnetic member.
0, an E-shaped ferrite core 77a having an effective area Se of about 19 mm ² and an effective magnetic path length Le of about 35 mm is used.
Then, a winding is applied to this E-type ferrite core 77a by 15
It has a configuration having a coil 77b wound by turns. The developing cartridge 21 has an I-type ferrite core, which is a second magnetic induction means, disposed so as to form a magnetic path facing the magnetic induction circuit 77 when the developing cartridge 21 is mounted on the apparatus main body 10. 26 are provided.

A gap member 27 made of a non-magnetic material is disposed between the magnetic induction circuit 77 and the I-type ferrite core 26.
The ferrite core 26 is in close contact with the mold ferrite core 26. This is because the magnetic induction circuit 7 is formed by forming a magnetic path.
This is for changing the inductance (hereinafter abbreviated as L-value) of No. 7 by a factor of 2 to 3 or more, and the thickness of the gap material 27 is, for example, 0.1 to 0.2 mm. The magnetic induction circuit 77
A mounting position is provided so as to escape the thickness (about 1 mm) of the resin of the developing cartridge, and further, the adhesion between the magnetic induction circuit 77 and the I-type ferrite core 26 is enhanced by the pressing member 25 such as a spring. .

FIG. 27 is a block diagram showing an example of the detecting means. The detecting means includes a signal generating circuit 80, a resonance circuit 81 having a magnetic induction circuit 77, and a rectifier for rectifying an output signal from the resonance circuit 81. A circuit 82, a smoothing circuit 83 for converting an output signal from the rectifier circuit 82 into a DC signal, a comparator 84 for comparing the output signal from the smoothing circuit 83 with a predetermined reference value, and an output result of the comparator 84. And a determination circuit 85 for determining whether or not the removable cartridge is mounted.

Next, the specific configuration of each part of the detecting means will be described in detail. FIG. 28 is a block diagram illustrating an example of the signal generation circuit. The signal generating circuit 80 includes a reference clock generating circuit 86 that generates a clock signal having a reference frequency, and a frequency dividing circuit 87 that divides the frequency of the reference clock signal.
And a control circuit 88 for controlling the frequency division ratio of the frequency dividing circuit 87. The frequency dividing circuit 87 and the control circuit 88 are sweep means for sequentially switching and outputting a plurality of frequencies,
According to the frequency division ratio specified by control circuit 88, frequency dividing circuit 87
Divides the reference clock signal.

FIG. 29 is a circuit diagram showing a specific configuration of the resonance circuit. The resonance circuit 81 includes the magnetic induction coil 7
7 is an input terminal 89, and the other end is a capacitor C31.
The other end of the capacitor C31 is connected to one end of the resistor R31 and the output terminal 91.
The other end of 31 is connected to the ground, forming a band-pass filter.

FIG. 30 shows a specific circuit configuration of a rectifier circuit and a smoothing circuit in the detection means. Rectifier circuit 82
Comprises a diode 92 and a resistor R32, and the smoothing circuit 83 comprises a capacitor C32. The resonance circuit 81 is connected to the anode side of the diode 92, and the resistor R32 whose one end is grounded is connected to the cathode side. Capacitor C3
2 is connected in parallel with the resistor R32. The output of the resonance circuit 81 is rectified by the diode 92 and the resistor R32, and is smoothed by the capacitor C32.

FIG. 31 shows the gain characteristics with respect to the input frequency when the resistance R31 is 2Ω and the capacitor C31 is 0.1 μF. FIG. 31A shows the developing cartridge 21.
FIG. 31B shows a gain characteristic when the image forming apparatus is not attached to the image forming apparatus main body 10, that is, when the L value is about 8 μH.
Is a gain characteristic when the developing cartridge 21 is mounted on the image forming apparatus main body 10, that is, when the L value changes to about 24 μH. The resonance frequency having a peak in gain with respect to the frequency is approximately 180
KHz (FIG. 31A) to about 105 KHz (FIG. 31A).
(B)). In order to use the difference in gain at the resonance frequency, the signal output from the signal generation circuit is converted to a signal having a frequency of 180 KHz or 105 KH.
The signal may be a rectangular wave signal set in any vicinity of z. Here, a rectangular wave signal near 105 KHz is used, and a detection method at that time will be described below.

FIG. 32 (a) shows an output waveform from a resonance circuit 81 which is a band-pass filter when the cartridge 21 is not mounted on the image forming apparatus main body 10, and FIG. 32 (b) shows the output waveform. 9 is a simulation result showing a waveform when an output waveform passes through a smoothing circuit 83 and is smoothed. At this time, the resonance frequency of the band pass filter (resonance circuit 81) is about 18 as described above.
Since the frequency is 0 KHz, the gain is small, and the DC level when the gain is smoothed is around 0 V. On the other hand, FIG.
FIG. 32D shows a signal waveform output from the band-pass filter in a state where the cartridge is mounted on the image forming apparatus main body. FIG. 32D shows the output waveform passing through the smoothing circuit and being smoothed. It is a simulation result showing a waveform at the time. The resonance frequency of the band-pass filter (resonance circuit 81) at this time is about 1 as described above.
Since the frequency is changed to 05 Hz, the gain is large, and it can be seen that the DC level when the gain is smoothed rises to around 2.5 V.

The DC level is converted into a desired reference level (0 according to the present embodiment) by a comparator 84 which is a signal processing in the subsequent stage.
If the DC level is higher than the reference level, it can be determined that the cartridge 21 is mounted on the main body 10.

Even if the resonance circuit 81 is constituted by a notch filter whose gain is greatly reduced at a predetermined resonance frequency, information on the cartridge side can be detected by detecting a decrease in gain that changes with the attachment / detachment of the cartridge. However, in the configuration using the notch filter, as can be seen from the gain characteristic with respect to the frequency in FIG. 33, since all frequency components other than the resonance frequency pass, when a rectangular wave signal having a plurality of harmonic components is input from the signal generation circuit. However, only a specific frequency component is removed, and it is difficult to accurately detect a change in the amplitude value. Therefore, in this case, the signal output from the signal generation circuit needs to be a sinusoidal signal having a single frequency.

<Fourth Embodiment> Next, a fourth embodiment of the image forming apparatus according to the present invention will be described. The structure of the magnetic induction circuit on the apparatus main body side and the structure of the magnetic substance on the developing cartridge side when the developing cartridge is mounted on the apparatus main body are shown in FIG.
Same as 6. That is, the air-core coil 52 is provided as a magnetic induction circuit, and the protrusion 53 made of a magnetic material is provided.

The detection means for detecting the attachment of the developing cartridge to the apparatus main body will be described below. The block diagram showing the configuration of this detecting means is the same as FIG. 27, and the specific configuration is also the same as FIGS. 28 to 30. However, in the resonance circuit 81, the coil 90 in FIG. 29 is an air-core coil.

FIG. 34 shows the gain characteristics with respect to the input frequency when the resistance R31 is 2Ω and the capacitor C31 is 0.2 μF. FIG. 34A shows the developing cartridge 51.
FIG. 34 shows the gain characteristics when not attached to the image forming apparatus main body 50, that is, when the L value is about 2.5 μH.
(B), the developing cartridge 51 is the image forming apparatus main body 5
This is a gain characteristic when mounted at 0, that is, when the L value changes to about 7.5 μH. The resonance frequency having a peak in the gain with respect to the frequency, with the mounting of the cartridge 51,
About 225KHz (Fig. 34 (a)) to about 130KHz
(FIG. 34B). In order to use the difference in gain at the resonance frequency, the signal output from the signal generation circuit is converted to a signal having a frequency of 225 KHz or 1 KHz.
The signal may be a rectangular wave signal set near 30 kHz. Here, a rectangular wave signal near 225 KHz is used, and a detection method at that time will be described below.

FIG. 35A shows an output waveform from the band-pass filter (resonance circuit) 81 in a state where the cartridge is not mounted on the image forming apparatus main body. FIG. 35B shows an output waveform. Is a simulation result showing a waveform when the signal passes through the smoothing circuit 83 and is smoothed. Since the resonance frequency of the band-pass filter 81 at this time is about 225 KHz as described above, the gain is large, and the DC level when this is smoothed is about 2.5 V
Near.

FIG. 36A shows a signal waveform output from the band pass filter in a state where the cartridge is mounted on the main body of the image forming apparatus.
(B) is a simulation result showing a waveform when the output waveform passes through the smoothing circuit and is smoothed.
Since the resonance frequency of the band-pass filter 81 at this time has changed to about 130 KHz as described above, the gain of the signal generation circuit at the frequency of 225 KHz is small, and the DC level when this is smoothed is It can be seen that the voltage has dropped to around 0V.

The DC level is converted to a desired reference level (according to the present embodiment, 0%) by a comparator 84 which is a signal processing in the subsequent stage.
If the DC level is smaller than the reference level, it can be determined that the cartridge 51 has been mounted on the main body 50. Conversely, when the frequency of the signal generating circuit is set to 130 KHz, the gain of the band-pass filter 81 increases when the cartridge 51 is mounted on the image forming apparatus main body 50, so that the DC level is lower than the reference level. If it gets bigger, cartridge 5
1 can be determined to be attached to the main body 50.

Even if the resonance circuit 81 is constituted by a notch filter whose gain is greatly reduced at a predetermined resonance frequency, if a decrease in the gain that changes with the attachment / detachment of the cartridge is detected, the resonance of the cartridge is similarly performed. Information can be detected. However, in the configuration using the notch filter, FIG.
As can be seen from the gain characteristics for the frequency of 3, all frequency components other than the resonance frequency pass, so when a rectangular wave signal having a plurality of harmonic components is input from the signal generation circuit, only a specific frequency component is removed. However, accurate detection is difficult from the change in the amplitude value. Therefore, in this case, the signal output from the signal generation circuit needs to be a sinusoidal signal having a single frequency.

<Fifth Embodiment> Next, a fifth embodiment of the image forming apparatus according to the present invention will be described. FIG.
FIG. 2 is a side view schematically showing a place where a main body side 100 and a developing cartridge 101 of the image forming apparatus according to the present invention are mounted. An air core coil 102 corresponding to the first magnetic induction means is provided on the image forming apparatus main body 100 side, while an air core coil 103 corresponding to the second magnetic induction means is provided on the detachable developing cartridge 101. Projecting portion 10 having a configuration in which capacitor 104 as an information adding device is connected in parallel
5 are provided. As shown in FIG.
By sliding in the direction of the arrow A shown in FIG.
Attached to. In conjunction with this mounting operation, the projecting portion 105 is configured to be inserted into a substantially central portion of the air core coil 102 provided on the image forming apparatus main body 100 side.

In the fifth embodiment, the air-core coil 102 is
For example, a winding consisting of 10 turns has an inner diameter of about 16 mm,
It has a thickness of about 4 mm. The air-core coil 103 built in the protruding portion 105 uses a winding having 20 turns and an inner diameter of about 8 mm and a thickness of about 4 mm. At this time, the air-core coil 102
And the inductance value (hereinafter abbreviated as L value) of the air core coil 103 is about 2.5 μH.

On the other hand, as shown in FIG. 37B, when the developing cartridge 101 is mounted on the image forming apparatus main body 100 side, the air-core coil 102 and the air-core coil 103 are magnetically coupled, so that The frequency characteristic of the coil 102 changes. That is, by detecting the state of parallel resonance between the capacitor 104 and the inductance as the information adding device, it is possible to detect whether the phenomenon cartridge 101 is properly mounted. In order to detect the parallel resonance state, in the present embodiment, a series filter circuit including a resistor and a coil including the air-core coil 102 is formed, and the filter circuit is changed from a high-pass filter to a band-pass filter with the mounting of the developing cartridge 101. It is realized from changing to.

FIG. 38 is a block diagram showing an example of a specific configuration of the detecting means. A signal generation circuit 110 for generating a signal set near the resonance frequency of the resonance circuit, a filter circuit 111 to which an output signal from the signal generation circuit 110 is input, and a rectification circuit 112 for rectifying an output signal from the filter circuit. , A smoothing circuit 113 for converting an output signal from the rectifier circuit 112 into a DC signal,
The comparator 114 includes a comparator 114 for comparing an output signal from the comparator with a predetermined reference value, and a discriminating circuit 115 for judging whether or not a detachable cartridge is properly mounted based on an output result of the comparator 114.

Next, a specific configuration of the detection means will be described in detail. FIG. 39 shows a specific circuit diagram of the detection means. One end of the resistor R41 is used as the input terminal 114, the other end is connected to one end of the air-core coil L41 (102), and the other end is connected to the ground.
Is input to the rectifier circuit 112 and the rectifier circuit 1
The 12 output signals are further input to the smoothing circuit 113.

The rectifier circuit 112 is a half-wave rectifier circuit in which a diode D42 and a resistor R43 are connected in series, and the smoothing circuit 113 has a simple configuration in which a capacitor C44 is connected in parallel with the resistor R43. .

FIG. 40 shows, for example, that the resistance R41 is 50Ω,
The resistance R43 is 2 KΩ, and the rectifying capacitor C44 is 0.1
μF, the capacitor 104 as information adding means is set to 0.1
10 is a simulation result showing a signal output from the filter circuit 111 when a rectangular wave signal of 300 KHz is input to the filter circuit 111 with μF. FIG.
(A) shows a 300 KHz rectangular wave signal output from the signal generation circuit, and (b) of FIG. 40 is output from the filter circuit 111 when the developing cartridge 101 is not mounted on the image forming apparatus main body 100. 3 shows a signal waveform. In this case, since the filter circuit 111 is a high-pass filter including the resistor R41 and the air-core coil 102 (L41), the filter circuit 111 has a waveform obtained by differentiating the rectangular wave signal shown in FIG. On the other hand, FIG. 40C shows a signal waveform output from the filter circuit 111 when the developing cartridge 101 is mounted on the image forming apparatus main body 100.
In this case, the air-core coil 102 is magnetically coupled to the air-core coil 103, causing a resonance phenomenon by the capacitor 104 connected in parallel with the air-core coil 103, and the filter circuit 111 changes from a high-pass filter to a band-pass filter. Therefore, in FIG. 40C, a sine wave which is a fundamental wave of 300 KHz is output from the rectangular wave signal.

FIG. 41 shows a simulation waveform when the output waveform is rectified and smoothed. FIG. 41A shows an output waveform from the smoothing circuit 113 when the signal of FIG. 40B is smoothed, that is, when the developing cartridge is not mounted, and the DC level is about 0.5 V. ing. On the other hand, FIG. 41 (b) shows an output waveform from the smoothing circuit 113 when the signal of FIG. 40 (c) is smoothed, that is, when the developing cartridge is in the mounted state. You can see that it is rising.

The DC level is converted into a desired reference level (an appropriate value in the range of 0.5 V to 1.5 V, for example, 1.OV according to the present embodiment) by a comparator 114 which is a signal processing in the subsequent stage. If the DC level is higher than the reference level, the cartridge 101
0 can be determined.

Even if the filter circuit 111 is constituted by a notch filter whose gain is greatly reduced at a predetermined resonance frequency, the information on the cartridge 101 side can be similarly obtained by detecting a decrease in the gain that changes as the cartridge 101 is attached or detached. Can be detected. However, in the configuration using the notch filter, as can be seen from the gain characteristic with respect to the frequency in FIG. 33, all frequency components other than the resonance frequency pass,
When a rectangular wave signal having a plurality of harmonic components is input from the signal generation circuit 110, only a specific frequency component is removed, and it is difficult to accurately detect a change in amplitude value. Therefore, in this case, the signal output from the signal generation circuit 110 needs to be a sine wave signal having a single frequency.

The case where both the first magnetic induction means and the second magnetic induction means are constituted by air core coils has been described. However, a magnetic induction coil including a core may be used.
3 is shown. FIG. 42 shows a case where a winding is wound around an E-shaped core 122 of the EI-shaped core around the first magnetic induction coil, and a gap 1 is formed.
An I-shaped core 125 is provided so as to form a magnetic path with the 24 interposed therebetween. On the other hand, an air-core coil 126 is used as the second magnetic induction coil, and when the developing cartridge 121 is mounted, the projecting portion 128 is linked to the magnetic flux generated by the first magnetic induction coil. Built inside.

The basic structure of the image forming apparatus main body 100 and the developing cartridge 101 in FIG. 43 is the same as that in FIG. 37, and therefore, the same portions are denoted by the same reference numerals. Image forming apparatus main body 1
The air-core coil 101 is used as the first magnetic induction coil on the 00 side, and the winding 103 and the core 132 longer than the thickness of the winding 103 are used as the second magnetic induction coil on the developing cartridge 101 side. That is, the second magnetic induction coil has a configuration in which one end of the core 132 is inserted into the protruding portion 105, and the winding 103 is wound around the other end of the core 132 projecting inward from the developing cartridge 131. By mounting the developing cartridge 131, the core 132 is inserted into the air core coil 102, and a magnetic path is formed.

As described above, an example has been described in which one of the first magnetic induction coil and the second magnetic induction coil is a coil having a core, but both may be coils having a core. Although the resonance circuit has been described here, an oscillation circuit or a filter circuit can be applied to the detection unit as in the second embodiment.

<Others> In the image forming apparatuses according to the first to fifth embodiments, a display device (not shown) is provided in the apparatus main body to indicate whether or not the cartridge is mounted and whether or not the cartridge is mounted. It is possible to give a warning to the user. Further, depending on the user, it is conceivable that the warning displayed on the display device is ignored or overlooked, and the copying operation is performed in spite of the fact that the cartridge is not mounted or is improperly mounted. In this case, a failure of the image forming apparatus due to erroneous mounting of the cartridge may occur. Therefore, when the cartridge is not mounted or is improperly mounted, the normal copying operation is prohibited, so that the failure of the image forming apparatus can be prevented.

In the electrophotographic apparatus, when the developing cartridge or the toner cartridge is replaced, if the charge amount differs between the new and old developers, the density of the recorded image is significantly different before and after the cartridge 21 is replaced, or the recorded image is not replaced. It is known that fogging, blurring, and the like occur, and the quality of a recorded image is greatly deteriorated. Therefore, the gap material 2
7, the thickness of the magnetic induction circuit 17 and the thickness of the I
Two types of information can be provided by one set of the mold ferrite core 26. By increasing the number of sets, it is possible to increase the amount of information. For example, the first set has information on the charge polarity of the developer sealed in the cartridge, and the second and subsequent sets have the charge of the developer. For example, it is possible to have information on the amount. The main body of the apparatus detects the information on the cartridge side and performs initialization processing such as setting the level of the developing bias to an optimum value based on the read information unique to the developer, thereby obtaining the above-described recorded image. Various problems such as fogging and blurring can be prevented.

Next, a description will be given of the processing contents on the apparatus main body side when the cartridge is mounted. FIG. 44 is a flowchart illustrating an example of the flow of processing from cartridge installation to copy permission or device stoppage. First, the cartridge is mounted on the apparatus main body (STEP
1), the main body reads information on the cartridge side based on the change in the L value (STEP 2). If the oscillation frequency or the resonance frequency is lower than a desired value, it is determined that the mounting is good. Judge as defective (STEP
3). If it is determined that the cartridge is improperly mounted, a warning is displayed on the display device indicating that the cartridge is not mounted or is incorrectly mounted (STEP 4), the operation of the image forming apparatus is prohibited, and no copy processing or the like is accepted. (STEP 5).
When it is determined that the mounting is good, information specific to the developer such as the charge amount is read (STEP 6), and initialization processing such as setting the level of the developing bias to an optimum value is performed (STEP 6).
7), permit the copy operation (STEP 8). But,
If there is no developer-specific information in STEP 6, STEP 7
Without performing the above processing, the flow proceeds to STEP 8 to enable the copy operation.

Although the description has been given by taking the monochrome laser printer as an example, a color laser printer may be used. In such a case, a developer cartridge or a toner cartridge containing yellow, magenta, cyan, and black developers is generally provided. Therefore, when these cartridges are replaced, information specific to the developer is stored in the cartridge. By providing color information as described above, it is also possible to prevent color mixing due to erroneous mounting of the cartridge.

In addition to the above-mentioned developing cartridge and toner cartridge, the present invention is also applicable to a toner bottle, a process cartridge integrated with main process parts such as a photosensitive member, a charging means, a cleaner, and a container for storing ink. It is possible. Further, the developer is not limited to a non-magnetic one-component developer, and can be similarly applied to a two-component developer composed of a carrier and a toner, even with a magnetic one-component developer.

[0112]

According to the first aspect of the invention, the information of the detachable cartridge is stored in the electromagnetic field between the first magnetic guiding means provided on the apparatus main body side and the second magnetic guiding means provided on the cartridge side. Since the inductance of the first magnetic induction means generated by the induction is detected, there is no place directly in contact with the apparatus main body side. Even if the cartridge is contaminated with, for example, toner, the influence of the contamination on the inductance detection is eliminated. And highly reliable information can be easily detected.

According to the second invention, the cartridge information is detected by detecting the inductance of the first magnetic induction means due to the magnetic coupling between the core of the first magnetic induction means and the magnetic member of the second magnetic induction means. Since detection is performed, highly reliable information can be detected with a simple structure.

According to the third aspect of the invention, by providing the gap member made of a non-magnetic material, the amount of change in inductance due to electromagnetic induction can be adjusted, and a large amount of information on the cartridge side can be provided. Further, by providing the gap member, a stable inductance value which is not affected by the tolerance of the magnetic member can be obtained, and the malfunction of the detecting means can be prevented.

According to the fourth aspect, by setting the thickness of the gap material to be equal to or less than the length determined by the effective sectional area and the effective magnetic path length of the magnetic material to be used, a stable change in inductance can be obtained. It becomes possible.

According to the fifth aspect, when the cartridge is mounted, the protrusion of the second magnetic induction means is inserted into the gap of the first magnetic induction means, so that the inductance of the first magnetic induction means can be detected. This is more reliable and can prevent malfunction of the detecting means.

According to the sixth aspect, since the air-core coil is used as the magnetic induction coil, accurate information on the cartridge can be detected at low cost and at low cost.

According to the seventh aspect, since the coil of the second magnetic induction means is disposed so as to link with the coil of the first magnetic induction means, the inductance of the first magnetic induction means is detected. And the malfunction of the detection means can be prevented.

According to the eighth aspect, since the capacitor is used as the information adding means, the resonance frequency can be set arbitrarily, and much information on the cartridge side can be detected easily and at low cost. .

According to the ninth aspect, since the air-core coil is used as the magnetic induction coil, accurate information on the cartridge side can be detected at low cost and at low cost.

According to the tenth aspect, since a change in inductance due to electromagnetic induction is detected as a change in the oscillation frequency of the oscillation circuit, there is no need to sweep the frequency of the input signal. Accurate information on the cartridge side can be detected.

According to the eleventh aspect, the first magnetic induction unit for stabilization and the second magnetic induction unit for determining the oscillation frequency change the L value by the same amount according to the attachment / detachment of the cartridge to / from the apparatus main body. By using the Colpitts oscillation circuit configured as described above, even if the inductance varies widely,
Stable oscillation becomes possible.

According to the twelfth aspect, by forming the oscillation circuit with a multivibrator type oscillation circuit, an oscillation frequency almost proportional to a change in inductance can be obtained, and more reliable detection can be performed.

According to the thirteenth aspect, a change in inductance due to electromagnetic induction is captured as a change in a constant of a filter circuit composed of a coil, a capacitor, and a resistor. Since the detection does not require a coil driving circuit for supplying a large power to the coil, and it is not necessary to sweep the frequency of the input signal, it is possible to reduce the cost and cost.

According to the fourteenth aspect, by using a low-pass filter having a zero point in the transfer function of the filter in the filter circuit, a stable phase can be obtained without being affected by noise at a high frequency. , It is possible to accurately detect whether or not the unit device is mounted on the image forming apparatus main body side.

According to the fifteenth aspect, the change in the inductance value due to the magnetic coupling of the first magnetic induction means is configured to be the change in the resonance frequency of the resonance circuit, and the signal output from the resonance circuit is changed. Since the information on the removable cartridge is determined from the amplitude value, accurate information on the cartridge side can be easily detected at low cost at low cost.

According to the sixteenth aspect, since the signal generation circuit for inputting a signal to the resonance circuit has the sweep means for sequentially switching and outputting a plurality of frequencies, a wide range of the resonance frequency accompanying a change in inductance is obtained. For change,
Accurate detection is possible.

According to the seventeenth aspect, the sweeping means comprises:
Since it is composed of a frequency dividing circuit that divides the reference clock and a control circuit that controls the frequency dividing ratio of the frequency dividing circuit, no special circuit is required, and inexpensive and reliable detection is possible. Become.

According to the eighteenth aspect, since the resonance circuit uses a band-pass filter circuit composed of series resonance or parallel resonance, the signal generation circuit may be a rectangular wave signal, and the information on the cartridge side can be used. Inexpensive and accurate detection is possible.

According to the nineteenth aspect of the present invention, by providing a display device for indicating whether or not the detachable member is mounted properly, even a beginner can easily know the problem caused by the detachment of the member. Maintenance of the detachable member in the image forming apparatus can be reliably performed.

According to the twentieth aspect of the present invention, when a detachable member is not mounted or is improperly mounted, or when it is erroneously mounted, a normal copying operation is prohibited, so that an image accompanying erroneous mounting or the like can be prevented. Failure of the forming apparatus can be prevented beforehand.

According to the twenty-first aspect of the present invention, the detachable member has information unique to the cartridge which is a supply consumable such as a developer, a photoreceptor, or ink, and the unique information of the cartridge is provided on the apparatus body side. By detecting information and performing initialization means according to the characteristics, a high-quality image can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of an image forming apparatus according to a first embodiment of the present invention on an apparatus main body side.

FIG. 2 is a schematic configuration diagram illustrating a configuration of a developing cartridge that can be attached to and detached from the apparatus main body in the first embodiment of the image forming apparatus according to the present invention.

FIG. 3 is a schematic configuration diagram showing a configuration when a developing cartridge in the first embodiment of the image forming apparatus according to the present invention is mounted on the apparatus main body.

FIG. 4 is a block diagram illustrating an example of a detection unit according to the first embodiment.

FIG. 5 is a circuit diagram illustrating a configuration of a magnetic induction circuit according to the first embodiment.

FIG. 6 is a characteristic diagram showing a relationship between a size Le / Se of a ferrite core and a gap length Gs.

FIG. 7 is a circuit diagram illustrating an example of an oscillation circuit according to the first embodiment.

FIG. 8 is a characteristic diagram showing operation waveforms of the Colpitts oscillation circuit according to the first embodiment.

FIG. 9 is a circuit diagram showing another example of the oscillation circuit of the first embodiment.

FIG. 10 is a configuration diagram showing another example of the detection means of the first embodiment.

FIG. 11 is a circuit diagram illustrating an example of a filter circuit according to the first embodiment.

FIG. 12 is a characteristic diagram showing a transfer characteristic between an input terminal and an output terminal of the filter circuit.

FIG. 13 is a characteristic diagram illustrating a simulation result of an output signal waveform when a 500 KHz rectangular wave signal is input to an input terminal of a filter circuit.

FIG. 14 is a timing chart showing a time relationship until a pulse signal is created from the rectangular wave signal input to the input terminal of the filter circuit.

FIG. 15 is a schematic configuration diagram illustrating a configuration of a second embodiment of an image forming apparatus according to the present invention when a developing cartridge is mounted on an apparatus main body.

FIG. 16 is an enlarged cross-sectional view illustrating a portion where a developing cartridge is mounted on an apparatus main body according to a second embodiment of the present invention.

FIG. 17 is a block diagram illustrating an example of a detection unit according to the second embodiment.

FIG. 18 is a configuration diagram illustrating an example of an air-core coil according to the second embodiment.

FIG. 19 is a circuit diagram illustrating an example of an oscillation circuit according to a second embodiment.

FIG. 20 is a specific circuit diagram showing another example of the oscillation circuit of the second embodiment.

FIG. 21 is a block diagram illustrating another example of the detection unit of the second embodiment.

FIG. 22 is a circuit diagram illustrating an example of a filter circuit according to the second embodiment.

FIG. 23 is an explanatory diagram of a simulation result showing a frequency characteristic of transmission between an input terminal and an output terminal of a filter circuit due to a change in an L value.

FIG. 24 is an explanatory diagram showing a simulation result of a pulse signal output from a phase difference detection circuit when a rectangular wave signal of 2 MHz is input to the detection means.

FIG. 25 is a schematic configuration diagram illustrating a configuration when a developing cartridge in the third embodiment of the image forming apparatus according to the invention is mounted on the apparatus main body.

FIG. 26 is an enlarged cross-sectional view illustrating a portion where a developing cartridge is mounted on an apparatus main body according to a third embodiment of the present invention.

FIG. 27 is a block diagram illustrating an example of a detection unit according to the third embodiment.

FIG. 28 is a block diagram illustrating an example of a signal generation circuit according to a third embodiment.

FIG. 29 is a circuit diagram illustrating an example of a resonance circuit according to a third embodiment.

FIG. 30 is a circuit diagram showing an example of a rectifier circuit and a smoothing circuit in the detection means of the third embodiment.

FIG. 31 is a characteristic diagram illustrating a gain characteristic with respect to an input frequency of the resonance circuit according to the third embodiment.

FIG. 32 is a waveform diagram of signals output from the resonance circuit and the smoothing circuit according to the third embodiment.

FIG. 33 is a characteristic diagram showing gain characteristics with respect to frequency in a notch filter.

FIG. 34 is a characteristic diagram illustrating characteristics of a gain with respect to an input frequency of the resonance circuit according to the fourth embodiment.

FIG. 35 is a waveform diagram of signals output from the resonance circuit and the smoothing circuit of the fourth embodiment when a cartridge is not mounted.

FIG. 36 is a waveform diagram of signals output from the resonance circuit and the smoothing circuit in the cartridge mounted state according to the fourth embodiment.

FIG. 37 is a cross-sectional view illustrating a configuration of the image forming apparatus according to the fifth embodiment of the present invention when a developing cartridge is attached to the apparatus main body.

FIG. 38 is a block diagram illustrating an example of a detection unit according to the fifth embodiment.

FIG. 39 is a circuit diagram illustrating an example of a detection unit according to the fifth embodiment.

FIG. 40 is a waveform diagram of a rectangular wave signal input to the filter circuit of the fifth embodiment and a signal output from the filter circuit.

FIG. 41 is a waveform diagram of a signal output from the smoothing circuit according to the fifth embodiment.

FIG. 42 is a cross-sectional view showing another configuration of the image forming apparatus according to the fifth embodiment of the present invention when the developing cartridge is mounted on the apparatus main body.

FIG. 43 is a sectional view showing still another configuration of a portion where the developing cartridge is mounted on the apparatus main body in the fifth embodiment of the image forming apparatus according to the present invention.

FIG. 44 is a flowchart illustrating an example of a process flow from mounting of a cartridge to permitting copying or stopping the apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Apparatus main body 11 Photoreceptor drum 12 Charger 13 Transfer charger 14, 15 Fixing roller 16 Paper 17 Magnetic induction circuit 21 Developing cartridge 22 Developing roller 24 Supply roller 25 Spring 26 I-type ferrite core 27 Gap

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Atsushi Inoue 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 2H071 BA03 BA13 BA17 DA08 DA32 2H077 AC04 AD06 AD13 AD17 AE03 BA08 BA09 DA24 DA52 DA86 EA14

Claims (21)

[Claims] 1. An image forming apparatus having a cartridge detachably mountable to an apparatus main body, a first magnetic guiding means provided on the apparatus main body side and having a coil for generating magnetic induction, and provided on the cartridge side. A second magnetic guiding unit which is arranged close to the first magnetic guiding unit and generates magnetic induction when the cartridge is mounted on the apparatus main body side, and according to a mounting state of the cartridge to the apparatus main body. An image forming apparatus, comprising: detecting means for detecting information on the cartridge side based on the value of the inductance of the first magnetic induction means that changes. 2. The first magnetic induction means has a configuration in which the coil is wound around a core made of a magnetic material, and the second magnetic induction means faces the core when the cartridge is mounted. 2. The image forming apparatus according to claim 1, wherein the magnetic member is arranged as described above. 3. A gap member made of a non-magnetic material for controlling an inductance value so as to be arranged between the core and the magnetic material member when the cartridge is mounted. Item 3. The image forming apparatus according to Item 2. 4. The thickness Gs (mm) of the gap member
Indicates that the effective area is Se (mm ² ) and the effective magnetic path length is Le.
The image forming apparatus according to claim 3, wherein a relational expression of Gs ≦ 0.5−0.1 × Le / Se is satisfied when (mm). 5. The apparatus according to claim 1, wherein the first magnetic guiding means has a gap, and the second magnetic guiding means has a protrusion inserted into the gap when the cartridge is mounted. The image forming apparatus according to claim 1. 6. A method according to claim 1, wherein said first magnetic induction means comprises an air core coil in which said air gap portion is an air core portion, and said projecting portion of said second magnetic induction means is made of a magnetic material. The image forming apparatus according to claim 5. 7. The second magnetic induction means has a coil, and the coil of the second magnetic induction means is disposed so as to interlink with the coil of the first magnetic induction means. 7. The image forming apparatus according to claim 6, wherein the image forming apparatus is connected to an information adding unit that adds information on a cartridge. 8. The image forming apparatus according to claim 7, wherein the information adding unit is a capacitor connected in parallel with a coil of the second magnetic induction unit. 9. The image forming apparatus according to claim 7, wherein one of the coils of the first and second magnetic induction means is an air-core coil. 10. An oscillating circuit in which an oscillating frequency changes due to a change in inductance of the first magnetic induction means, and a measuring means for measuring an oscillating frequency or an oscillating cycle of a signal output from the oscillating circuit. The image forming apparatus according to claim 1, further comprising: a determination unit configured to determine information on the cartridge based on an output from the measurement unit. 11. The Colpitts oscillation circuit comprising a first magnetic induction section for stabilization and a second magnetic induction section for determining an oscillation frequency, wherein the first magnetic induction section and the second magnetic induction section. The image forming apparatus according to claim 10, wherein the first magnetic induction unit constitutes the first magnetic induction unit. 12. The image forming apparatus according to claim 10, wherein said oscillation circuit is a multivibrator type oscillation circuit including a coil of said first magnetic induction means. 13. A filter circuit for generating a phase difference due to a change in inductance of the first magnetic induction means; a phase difference detection means for detecting a phase difference between input and output signals of the filter circuit; The image forming apparatus according to claim 1, further comprising: a detecting unit configured to detect mounting information on the cartridge side from an output of the phase difference detecting unit. 14. The image forming apparatus according to claim 13, wherein the filter circuit is a low-pass filter having a transfer function having a zero point. 15. A detection circuit comprising: a resonance circuit whose resonance frequency changes due to a change in inductance of the magnetic induction unit; and a signal set near a resonance frequency of the resonance circuit, and the signal is input to the resonance circuit. A signal generation circuit; a rectification circuit for rectifying a signal output from the signal generation circuit; a smoothing circuit for smoothing the output signal from the rectification circuit and converting it to a DC voltage; an output signal from the smoothing circuit and a desired signal The image forming apparatus according to claim 1, further comprising: a comparator that compares the level with a level; and a determination unit configured to determine information on the cartridge side from an output result from the comparator. . 16. The image forming apparatus according to claim 15, wherein said signal generating circuit includes a sweep unit for sequentially switching and outputting a plurality of frequencies. 17. The sweeping means includes a frequency dividing circuit for dividing a reference clock, and a control circuit for controlling a frequency dividing ratio of the frequency dividing circuit. The image forming apparatus according to claim 15, wherein the waves are sequentially output. 18. The image forming apparatus according to claim 15, wherein the resonance circuit is a band-pass filter circuit including a series resonance or a parallel resonance. 19. A display device for detecting whether or not the cartridge is mounted on the apparatus main body side based on a signal detected by the detecting means, or displaying the detected mounted state of the mounted state. The image forming apparatus according to claim 1, wherein: 20. The apparatus according to claim 1, wherein a signal detected by said detection means detects whether or not the cartridge and the apparatus main body are properly mounted, and prohibits a normal copying operation when a non-mounted state or a poorly mounted state is detected. The image forming apparatus according to claim 1, wherein: 21. The image forming apparatus according to claim 1, wherein when the detecting unit detects the unique information of the cartridge, the detecting unit performs an initialization process according to the unique information.