JP2008116801A - Waste toner sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect presence/absence of a waste toner box and the situation of waste toner in the waste toner box with a small number of components. <P>SOLUTION: A photosensor 73 is disposed in the waste toner box 61 partly formed of a transparent or translucent container, and configured to store the waste toner removed from the surface of a conveyer belt or a photoreceptor drum, and the presence/absence of the waste toner box 61 and the full state of the waste toner in the waste toner box 61 are decided on the basis of the combination of a signal output from an output port and the value of an input port with respect to the output signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a waste toner detection device that detects the presence or absence of a waste toner box that accumulates waste toner that has become unnecessary in an image forming apparatus that uses toner, and the state of waste toner in the waste toner box.

  In the image forming apparatus, after the waste toner remaining on the photosensitive drum is collected by the cleaning device, the waste toner is stored in a waste toner box separate from the cleaning device, and the waste toner box is almost full. There is something that was exchanged for another.

  In the conventional image forming apparatus of such a type, a protruding portion made of a permeable material is provided in a part of the waste toner box, and when the waste toner box is almost full, Waste toner can enter the printer. When the waste toner box is mounted from the outside of the machine body and is in a stationary state, the projecting portion is received in a detection groove of an interrupter type photosensor provided in the machine body. Then, it is configured to detect whether or not the waste toner in the waste toner box is full depending on whether or not the waste toner exists in the protruding portion.

  On the other hand, below the waste toner box is a micro switch fixed in the machine body, and the operation lever of the micro switch is configured to be pressed by the low wall of the waste toner box. Can be detected.

  However, the output signal lines of photo sensors, micro switches or other parts that detect the state of other parts are individually introduced into the input ports, which can interfere with the presence of many wires in the machine, It is also necessary to use a device having a large number of poles, which has the disadvantage that the work efficiency is reduced.

Therefore, as shown in FIG. 7, the transistor Q ₁ and the transistor Q ₂ constitute an astable multivibrator. When the waste toner box is mounted, a flashing signal is generated by the multivibrator, when the waste toner box is not mounted, a lighting signal is displayed, and when the waste toner box is full It has been proposed to emit a turn-off signal and discriminate between three types of states. (For example, see Patent Document 1)
Japanese Utility Model Laid-Open No. 2-134666

  However, it is necessary to use an astable multivibrator to discriminate various states in the conventional image forming apparatus, and as a result, the work efficiency is lowered by building a complicated circuit, resulting in an increase in cost. There was inconvenience such as.

  In order to achieve the above object, the invention described in claim 1 includes at least a part of a light emitting element, output means for changing the presence or absence of light emission of the light emitting element, a light receiving element for detecting light emitted by the light emitting element. Is formed of a transparent or translucent container, and a part of the waste toner box that accumulates waste toner removed from the photoreceptor surface or transfer body is placed between the light emitting element and the light receiving element, and the waste toner box exceeds a certain level A light-blocking unit that blocks light when the waste toner is accumulated, an input unit that receives a light-receiving signal from the light-receiving element, and a light-receiving element that is not emitting light when the waste toner box is not installed. And a means for making it appear as if it has received light.

  According to a second aspect of the present invention, there is provided a light-emitting diode, output means for changing the presence or absence of light emission of the light-emitting diode, a phototransistor for detecting light emitted from the light-emitting diode, and at least partly transparent or translucent A part of the waste toner box, which is formed in a container and accumulates waste toner removed from the photoreceptor surface and transfer body, is placed between the light emitting diode and phototransistor, and a certain amount or more of waste toner is accumulated in the waste toner box. A light-shielding means for making a light-shielded state when the phototransistor is connected, an input means for receiving a light-receiving signal from the phototransistor, and a normally closed switch connected between the collector of the phototransistor and the ground. The closed switch is opened, and the normally closed switch is closed when the waste toner box is not mounted.

  According to a third aspect of the present invention, there is provided a light emitting device, an output means for changing the presence or absence of light emission of the light emitting device, a light receiving device for detecting light emitted from the light emitting device, and at least partly transparent or translucent. A part of the waste toner box, which is formed in a container and accumulates waste toner removed from the photoreceptor surface and transfer body, is placed between the light emitting element and the light receiving element, and a certain amount or more of waste toner is accumulated in the waste toner box. A light-shielding means for making a light-shielded state when the light-receiving element is received, an input means for receiving a light-receiving signal from the light-receiving element, and a means for causing the light-emitting element to always emit light regardless of the output means when the waste toner box is not attached. It is characterized by that.

  According to the invention of claim 4, the light emitting diode, the output means for changing the presence or absence of light emission of the light emitting diode, the transistor provided between the output means and the light emitting diode, the light emitted by the light emitting diode A phototransistor to be detected and a part of a waste toner box which accumulates waste toner removed from the surface of the photosensitive member or the transfer body, which is formed at least partially from a transparent or translucent container, are arranged between the light emitting diode and the phototransistor. And a normally closed connection connected between the power source and the light emitting diode, a light shielding means for blocking light when a certain amount or more of waste toner is accumulated in the waste toner box, a light receiving signal input from the light receiving diode. With a switch, the normally closed switch opens when the waste toner box is installed, and the normally closed switch closes when the waste toner box is not installed. It is an feature.

  According to the first aspect of the present invention, at least a part of the light emitting element, the output means for changing the presence or absence of light emission of the light emitting element, the light receiving element for detecting the light emitted from the light emitting element, are transparent or translucent. A part of the waste toner box, which is formed in a container and accumulates waste toner removed from the photoreceptor surface and transfer body, is placed between the light emitting element and the light receiving element, and a certain amount or more of waste toner is accumulated in the waste toner box. A light-blocking means for setting a light-blocking state when the light-receiving element is received, an input means for receiving a light-receiving signal from the light-receiving element, and a means for making the light-receiving element appear to receive light even when the light-emitting element is not emitting light when the waste toner box is not mounted Since the number of parts can be reduced, it is economically advantageous and the work efficiency is improved.

  According to the second aspect of the present invention, the light-emitting diode as the light-emitting element, the phototransistor as the light-receiving element, and the normally-closed switch as a masquerade means are provided. The effect similar to that of the first aspect of the invention can be expected by closing the normally closed switch when the toner box is not attached.

According to the invention described in claim 3, at least a part of the light emitting element, the output means for changing the presence or absence of light emission of the light emitting element, the light receiving element for detecting the light emitted from the light emitting element, is transparent or translucent. A part of the waste toner box, which is formed in a container and accumulates waste toner removed from the photoreceptor surface and transfer body, is placed between the light emitting element and the light receiving element, and a certain amount or more of waste toner is accumulated in the waste toner box. A light-shielding means for making the light-shielded state when the light-receiving element is received, an input means for receiving a light-receiving signal from the light-receiving element, and a means for causing the light-emitting element to always emit light regardless of the output means when the waste toner box is not attached. This reduces the number of parts, which is economically advantageous and improves work efficiency.

  According to the fourth aspect of the present invention, the light emitting diode as the light emitting element, the phototransistor as the light receiving element, and the normally closed switch connected between the power source and the light emitting diode are provided. The same effect as that of the third aspect of the invention can be expected by opening the closing switch and closing the normally closing switch when the waste toner box is not attached.

  First, a mechanical mechanism common to both the first and second embodiments of the present invention will be described with reference to FIGS.

(Whole structure of laser printer)
FIG. 1 is a side sectional view showing a schematic configuration of a laser printer 1 as an image forming apparatus of the present embodiment. In the following description, the right side in FIG.

  The laser printer 1 is a direct transfer tandem color laser printer, and includes a substantially box-shaped main body casing 2 (an example of an apparatus main body) as shown in FIG. In the main casing 2, as will be described later, an image forming unit 20 for printing an image on a sheet (recording medium) 4 is provided. On the upper surface of the main casing 2, a paper discharge tray 5 on which the paper 4 after image formation is stacked is formed.

  A paper feed tray 7 on which paper 4 for forming an image is loaded is attached to the lower portion of the main body casing 2 so as to be drawn forward. A paper pressing plate (not shown) that can tilt to lift the front end side of the paper 4 is provided at the bottom of the paper feed tray 7. A pickup roller 10, a separation roller 11, and a separation pad 12 that presses against the separation roller 11 by urging of a spring (not shown) are provided at a position above the front end of the paper feed tray 7. Further, a pair of paper dust removing rollers 13 is provided obliquely in front of the pickup roller 10 and a pair of registration rollers 14 is provided thereabove.

  The uppermost sheet 4 in the sheet feeding tray 7 is pressed toward the pickup roller 10 by the sheet pressing plate, and is one sheet when sandwiched between the separation roller 11 and the separation pad 12 by the rotation of the pickup roller 10. Separated. The paper 4 sent out between the separation roller 11 and the separation pad 12 is sent to the registration roller 14 by the paper dust removing roller 13. The registration roller 14 feeds the paper 4 onto the rear belt unit 15 at a predetermined timing.

  The belt unit 15 is detachable from the main casing 2 and includes a transport belt 18 that is a transfer member that is horizontally installed between a pair of belt support rollers 16 and 17 that are spaced apart from each other in the front-rear direction. ing. The conveyor belt 18 is an endless belt made of a resin material such as polycarbonate, and is circulated and moved counterclockwise in FIG. 1 when the rear belt support roller 17 is driven to rotate, and is placed on the upper surface thereof. The paper 4 is conveyed backward. Inside the conveyor belt 18, four transfer rollers 19 arranged to be opposed to respective photosensitive drums 31 that are photosensitive members of a process unit 25 described later are provided at regular intervals in the front-rear direction. The conveyance belt 18 is sandwiched between the corresponding transfer roller 19. At the time of transfer, a transfer bias is applied between the transfer roller 19 and the photosensitive drum 31.

  Below the belt unit 15, a cleaning device 50 for removing toner, paper dust, and the like attached to the conveyance belt 18 is disposed.

  Toner adheres to the surface of the conveyor belt 18 (for example, when a mark is printed on the conveyor belt 18 and color misregistration is adjusted based on the mark), or paper dust is generated from the paper 4. The cleaning device 50 collects the toner or the like on the transport belt 18 in some cases.

  The cleaning roller 55 and the collection roller 56 are rotatably provided in a state where they are pressed against each other. The cleaning roller 55 has a structure in which a foam material made of silicon is provided around a metal shaft member, and is opposed to the metal backup roller 57 provided in the belt unit 15 with the conveyance belt 18 interposed therebetween. Yes. The cleaning roller 55 is driven in a direction opposite to the moving direction of the conveying belt 18 and a predetermined bias is applied between the cleaning roller 55 and the backup roller 57, so that the toner on the conveying belt 18 is removed. It is physically scraped to the cleaning roller 55 side and electrically sucked.

  The collection roller 56 is made of metal, and adsorbs toner or the like attached to the surface of the cleaning roller 55 by applying a predetermined bias to the cleaning roller 55. Further, a rubber scraping blade 58 is pressed against the lower side of the collection roller 56 by its elastic force. The toner or the like adhering to the surface of the collection roller 56 is scraped off by the scraping blade 58 and enters the auger 60. Waste toner collected by the auger 60 in the front direction of FIG. 1 enters a waste toner box 61. It is sufficient that at least a part of the waste toner box 61 is transparent or translucent. However, all of the waste toner box 61 may be transparent or translucent.

  The image forming unit 20 (an example of an image forming unit) includes a scanner unit 27, a process unit 25, the transfer roller 19, the fixing device 43, and the like.

  The scanner unit 27 is provided at an upper portion in the main body casing 2 and irradiates the surface of the corresponding photosensitive drum 31 with laser light for each color based on predetermined image data by high-speed scanning.

  The process unit 25 is provided below the scanner unit 27 in the main body casing 2 so as to be able to be drawn forward. The process unit 25 includes a frame 26, and the frame 26 is provided with four sets of a photosensitive drum 31, a scorotron charger 32 as a charging unit, a developing cartridge 34 as a developer, and the like. Yes.

  The photosensitive drum 31 includes a grounded metal drum main body, and is configured by covering the surface layer with a positively chargeable photosensitive layer.

  The scorotron charger 32 uniformly charges the surface of the photosensitive drum 31 to positive polarity by generating corona discharge from a charging wire (not shown) such as tungsten.

  Each developing cartridge 34 is detachably attached to the frame 26 and corresponds to each color of black, cyan, magenta, and yellow. Each developing cartridge 34 has a substantially box shape, and a toner storage chamber 38 is provided in the upper portion thereof, and a supply roller 39, a developing roller 40, and a layer thickness regulating blade 41 are provided therebelow. Each toner storage chamber 38 stores positively chargeable nonmagnetic one-component toner of each color of yellow, magenta, cyan, and black as a developer. Each toner storage chamber 38 is provided with an agitator 42 for stirring the toner.

The supply roller 39 is configured by coating a metal roller shaft with a conductive foam material, and the developing roller 40 is configured by coating the metal roller shaft with a conductive rubber material. Yes. The toner discharged from the toner storage chamber 38 is supplied to the developing roller 40 by the rotation of the supply roller 39 and is positively frictionally charged between the supply roller 39 and the developing roller 40. Further, the toner supplied onto the developing roller 40 enters between the layer thickness regulating blade 41 and the developing roller 40 with the rotation of the developing roller 40, where it is further sufficiently frictionally charged to have a constant thickness. It is carried on the developing roller 40 as a thin layer.

  The surface of the photosensitive drum 31 is uniformly positively charged by the scorotron charger 32 when rotating. Thereafter, exposure is performed by high-speed scanning of laser light from the scanner unit 27, and an electrostatic latent image corresponding to an image to be formed on the paper 4 is formed.

  Next, the electrostatic latent toner formed on the surface of the photosensitive drum 31 when the positively charged toner carried on the developing roller 40 comes into contact with the photosensitive drum 31 by rotation of the developing roller 40. Supplied to the image. As a result, the electrostatic latent image on the photosensitive drum 31 is visualized, and the surface of the photosensitive drum 31 carries a toner image with toner attached only to the exposed portion.

Thereafter, the toner image carried on the surface of each photosensitive drum 31 is transferred to the transfer roller 19 while the paper 4 conveyed by the conveyance belt 18 passes through each transfer position between the photosensitive drum 31 and the transfer roller 19. Are sequentially transferred onto the paper 4 by a negative transfer bias applied to the sheet 4. At this time, the toner that is not transferred onto the sheet and remains on the surface of the photosensitive drum 31 is also transferred onto the conveying belt 18 at an appropriate timing and then collected by the cleaning device 50.
The sheet 4 having the toner image transferred thereon is then conveyed to the fixing device 43.

  The fixing device 43 is disposed behind the conveyance belt 18 in the main body casing 2. The fixing device 43 includes a heating roller 44 that is rotationally driven with a heat source such as a halogen lamp, and a pressure roller 45 that is disposed below the heating roller 44 so as to face the heating roller 44 and is driven to rotate. It has. The fixing device 43 fixes the toner image on the paper 4 by heating the paper 4 carrying the four color toner images while nipping and conveying the paper 4 by the heating roller 44 and the pressure roller 45. The heat-fixed paper 4 is transported to a paper discharge roller 47 provided on the upper portion of the main body casing 2 by a transport roller 46 disposed obliquely above and rearward of the fixing device 43, and the paper discharge roller 47 performs the above-described operation. The paper is discharged onto the paper discharge tray 5.

(Basic configuration of the cleaning device)
FIG. 2 is a side sectional view of the cleaning device 50. In the figure, a protruding portion 71 made of a permeable material is provided above the side wall of the waste toner box 61, and when the waste toner box 61 is almost full, the waste toner box 61 is disposed in the protruding portion 71. Toner can enter. When the waste toner box 61 is mounted from the outside of the machine body and is in a stationary state, the protrusion 71 is received in a detection groove of an interrupter type photosensor 73 provided in the machine body. Then, whether or not the waste toner in the waste toner box 61 is full can be detected based on whether or not the waste toner is present in the protruding portion 71.

  On the other hand, below the waste toner box 61 is a normally closed switch 74 that is fixed in the machine body and functions as a sensor for detecting the presence or absence of the waste toner box 61. It is configured to be pressed by a wall, and the presence / absence of the waste toner box 61 can be detected by turning on and off the normally closed switch 74. When the waste toner box 61 is not present, the normally closed switch 74 is turned on (contact is closed), and when the waste toner box 61 is present, the normally closed switch 74 is turned off (contact is opened).

(Electronic circuit configuration of the first embodiment)
3 and 4 are diagrams showing the configuration of an electronic circuit diagram according to the first embodiment of the present invention.

In FIG. 3, the control circuit 80 as output means (also serving as input means) is an ASIC including a CPU.
It is configured as (Application Specific Integrated Circuit), and selectively outputs “HIGH” and “LOW” signals to turn on or off the light emitting diode D which is a light emitting element. The output port OUT, the base of the transistor Q ₁ is being connected to the collector of the transistor Q ₁ is connected the base of the transistor Q ₂ through a resistor. With power to the emitter of the transistor Q ₂ is is connected, the power supply to the base of the transistor Q ₂ through a resistor is connected. Emitting diode D is connected through the collector and the resistance of the transistor Q _2, is provided between the light emitting diode D and the detection grooves of the light receiving element phototransistor Q ₃ Metropolitan from consisting interrupter type photo sensor 73 is, waste A protrusion 71 of the toner box 61 is disposed. If the waste to reach the projecting portion 71 the toner is accumulated, emission light emitted from the diode D is blocked by the waste toner, the phototransistor Q ₃ are not able to receive the light (which by the light shielding means configured ) The emitter of the phototransistor Q ₃ are grounded connection, the collector of the phototransistor Q ₃ which is connected to the power supply through a resistor is connected to the input port IN of the control circuit 80 is an input unit. Further, the normally closed switch 74 is connected between the collector and ground of the phototransistor Q _3.

  FIG. 4 is a diagram showing a logic table referred to in the circuit diagram of FIG. 3 for the relationship between the signal output from the output port OUT and the value of the input port IN with respect to the signal output from the output port OUT. .

In the light-emitting diode D, and photo state the protrusion 71 of the waste toner box 61 to detect a groove of the transistor Q ₃ and the photo sensor 73, which is constituted by the absence (when the waste toner box unattached) (see FIG. 4 (a)) The normally closed switch 74 is turned on (contact is closed). In a state where the output "HIGH" signal from the output port OUT, the light emitting diode D is turned, the values of the input port IN Since phototransistor Q ₃ which is received in the conducting state indicates "LOW". Also,
In the state of not outputting a "HIGH" signal from the output port OUT (i.e. "LOW" state of output signal), since the light emitting diode D is turned off, the phototransistor Q ₃ does not become conductive. Therefore it should detect the value "HIGH" input port IN by a power source connected to the collector of the phototransistor Q ₃ would otherwise, but normally closed switch 74 between the collector and ground of the phototransistor Q ₃ is Since it is connected and the normally closed switch 74 is closed, the value of the input port IN detects “LOW”. In this manner, by dropping forcibly ground the output signal of the phototransistor Q ₃ connected to the input port IN, even when the phototransistor Q ₃ is not received from the light emitting diode D, disguised as received And the value of the input port IN is set to “LOW”.

When the protruding portion 71 of the waste toner box 61 exists in the detection groove of the photo sensor 73 (when the waste toner box is mounted), the normally closed switch 74 pressed on the bottom surface of the waste toner box 61 is turned off (the contact is opened). State). In a state where waste toner is present in the protrusion 71 of the waste toner box 61 (see FIG. 4B), when a “HIGH” signal is output from the output port OUT, the light emitting diode D is lit, but the protrusion 71 The light is blocked by waste toner present in the toner. Since this phototransistor Q ₃ by the not conductive, the output signal of the phototransistor Q ₃ connected to the input port IN, that is, the value of the input port IN indicates the value of "HIGH". Further, in the state where the “HIGH” signal is not output from the output port OUT (that is, the state where the “LOW” signal is output), since the light emitting diode D is turned off, whether or not waste toner exists in the protruding portion 71 is determined. not that the photo-transistor Q ₃ in the conducting state regardless of the. Therefore, the value of the input port IN indicates “HIGH”.

Further, the protruding portion 71 of the waste toner box 61 exists in the detection groove in the photosensor 73 (when the waste toner box is mounted), and no waste toner exists in the protruding portion 71 of the waste toner box 61 (FIG. 4 ( c))) When a “HIGH” signal is output from the output port OUT,
Since the phototransistor Q ₃ is turned on, the value of the input port IN shows the "LOW". Further, in the state where the “HIGH” signal is not output from the output port OUT (that is, the state where the “LOW” signal is output), the light emitting diode D is extinguished, so that no waste toner exists in the protruding portion 71. photo transistor Q ₃ is not in the conductive state. Therefore, the value of the input port IN indicates “HIGH”.

  As described above, the combination of the signal output from the output port OUT and the value of the input port IN corresponding to the signal output from the output port OUT indicates that the waste toner box 61 is not attached and the waste toner box is full when the waste toner box is attached. It is possible to discriminate between three states: a state and a state where the waste toner box is full when the waste toner box is mounted. That is, the control circuit 80 can accurately determine the above three states by executing a determination process based on the logic table shown in FIG.

(Electronic circuit configuration of the second embodiment)
5 and 6 are diagrams illustrating the configuration of the electronic circuit according to the second embodiment. In FIG. 5, the control circuit 80 serving as an output unit (also serving as an input unit) includes a CPU as in the first embodiment. It is configured as an ASIC and selectively outputs "HIGH" and "LOW" signals to turn on or off the light emitting diode D, which is a light emitting element. The output port OUT, the base of the transistor Q ₄ is connected via a resistor to the collector of the transistor Q ₄ are connected the base of the transistor Q ₅ through a resistor. With power to the emitter of the transistor Q ₅ is is connected, it is also connected to the base through a resistor. Emitting diode D is connected through the collector and the resistance of the transistor Q _5, between the base of the phototransistor Q ₆ is a light emitting diode D and the light receiving element is disposed projecting portion 71 of the waste toner box 61 Yes. When the waste toner in the inside protruding portion 71 is accumulated, emission light emitted from the diode D is blocked by the waste toner, the phototransistor Q ₆ can not receive light (composed light shielding means by which ). The emitter of the phototransistor Q ₆ are grounded connection, the collector of the phototransistor Q ₆ connected to the power supply is connected to the input port IN of the control circuit 80 is an input unit. Further, the normally closed switch 74 is connected between the collector of the emitter and the phototransistor Q ₅ of the phototransistor Q _6.

  FIG. 6 is a diagram illustrating a logic table referred to in the circuit diagram of FIG. 5 for the relationship between the signal output from the output port OUT and the value of the input port IN with respect to the signal output from the output port OUT. .

In the circuit diagram of FIG. 5, the light emitting diode D, and photo state the detection grooves of the photosensor 73, which is composed of the transistor Q ₆ is the projection 71 of the waste toner box 61 is not present (when the waste toner box unattached) ( 6), the normally closed switch is turned on (contacts are closed). In a state where the output "HIGH" signal from the output port OUT, the light emitting diode D is turned, the values of the input port IN Since phototransistor Q ₆ that has received is turned on indicates the "LOW". Even in a state where a “HIGH” signal is not output from the output port OUT (that is, a state where a “LOW” signal is output), the power supply connected to the emitter of the transistor Q ₅ is connected via the normally closed switch 74. since current is supplied, the light emitting diode D emits light, the phototransistor Q ₆ is received. Therefore, the value of the input port IN is detected as “LOW”. Thus, even though the phototransistor Q ₅ is not conducting, the current is supplied to the light emitting diode D through a normally closed switch 74, the phototransistor Q ₆ receives the light from the light emitting diode D Set the input port IN value to “LOW”.

When the protruding portion 71 of the waste toner box 61 exists in the detection groove of the photo sensor 73 (when the waste toner box is mounted), the normally closed switch 74 pressed on the bottom surface of the waste toner box 61 is turned off (the contact is opened). State). In a state where waste toner is present in the protrusion 71 of the waste toner box 61 (see FIG. 6B), when a “HIGH” signal is output from the output port OUT, the light emitting diode D is lit, but the protrusion Light is blocked by the waste toner present in 71. Since this phototransistor Q ₆ are not conductive, and the value of the input port IN shows the "HIGH". In addition, the output port OUT does not output a “HIGH” signal (
That is, in "LOW" state signal is output), since the light emitting diode D is turned off, regardless of whether the waste toner is present in the projection 71, the phototransistor Q ₆ is turned on the Absent. Therefore, the value of the input port IN indicates “HIGH”.

Further, the protruding portion 71 of the waste toner box 61 exists in the detection groove in the photo sensor 73 (when the waste toner box is mounted), and no waste toner exists in the protruding portion 71 of the waste toner box 61 (FIG. 6). (c) refer), when outputting the signal of "HIGH" from the output port OUT, since the phototransistor Q ₆ is turned on, the value of the input port iN shows the "LOW". Further, in a state in which a “HIGH” signal is not output from the output port OUT (that is, a state in which a “LOW” signal is output), the light emitting diode D is turned off. photo transistor Q ₆ is not in a conductive state. Therefore, the value of the input port IN indicates “HIGH”.

  As described above, the combination of the signal output from the output port OUT and the value of the input port IN with respect to the signal output from the output port OUT indicates that the waste toner box 61 is not attached and the waste toner box is full when the waste toner box is attached. And a state where the waste toner box is less than the full state when the waste toner box is mounted. That is, the control circuit 80 can accurately determine the above three states by executing a determination process based on the logic table shown in FIG.

1 is a side view of an image forming apparatus illustrating an embodiment of the present invention. It is a side view which expands and shows the principal part of a cleaning apparatus. 1 is a circuit diagram of a waste toner detection device illustrating a first embodiment of the present invention. It is a figure which shows the logic in the 1st Embodiment of this invention. FIG. 6 is a circuit diagram of a waste toner detection device showing a second embodiment of the present invention. It is a figure which shows the logic in the 2nd Embodiment of this invention. It is a circuit diagram of a conventional waste toner detection device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 50 Cleaning apparatus 55 Cleaning roller 56 Recovery roller 60 Auger 61 Waste toner box 71 Protruding part 73 Photo sensor 74 Normally closed switch 80 Control circuit
D Light emitting diode
Q _3, Q ₆ phototransistor
OUT output port
IN input port

Claims (4)

  A light emitting element, output means for changing the presence or absence of light emission of the light emitting element, a light receiving element for detecting light emitted from the light emitting element, and at least a part of a transparent or translucent container, A part of the waste toner box for accumulating the waste toner removed from the transfer member is disposed between the light emitting element and the light receiving element, and is in a light-shielding state when a certain amount or more of waste toner is accumulated in the waste toner box. Light shielding means, input means for receiving a light reception signal from the light receiving element, and means for making the light receiving element appear to receive light even when the waste toner box is not attached, even when the light emitting element is not emitting light. A waste toner detection device comprising: A light-emitting diode, output means for changing the presence or absence of light emission of the light-emitting diode, a phototransistor for detecting light emitted from the light-emitting diode, and at least a part of a transparent or translucent container, A part of the waste toner box for accumulating the waste toner removed from the transfer body is disposed between the light emitting diode and the phototransistor so as to be in a light-shielded state when a certain amount or more of the waste toner is accumulated in the waste toner box. A light shielding means, an input means for receiving a light reception signal from the phototransistor, and a normally closed switch connected between the collector of the phototransistor and the ground,
The waste toner detection device, wherein the normally closed switch is opened when the waste toner box is mounted, and the normally closed switch is closed when the waste toner box is not mounted.   A light emitting element, output means for changing the presence or absence of light emission of the light emitting element, a light receiving element for detecting light emitted from the light emitting element, and at least a part of a transparent or translucent container, A part of the waste toner box for accumulating the waste toner removed from the transfer member is disposed between the light emitting element and the light receiving element, and is in a light-shielding state when a certain amount or more of waste toner is accumulated in the waste toner box. A light shielding means; an input means for receiving a light reception signal from the light receiving element; and a means for causing the light emitting element to always emit light regardless of the output means when the waste toner box is not attached. A waste toner detection device. A light emitting diode, an output means for changing the presence or absence of light emission of the light emitting diode, a transistor provided between the output means and the light emitting diode, a phototransistor for detecting light emitted by the light emitting diode, and at least A part of a waste toner box, which is partly formed of a transparent or translucent container and accumulates waste toner removed from the surface of the photoreceptor or the transfer body, is disposed between the light emitting diode and the phototransistor, and the waste toner A light blocking means for blocking light when a certain amount or more of waste toner is accumulated in the box; an input means for receiving a light reception signal from the light receiving diode; a normally closed switch connected between a power source and the light emitting diode; With
The waste toner detection device, wherein the normally closed switch is opened when the waste toner box is mounted, and the normally closed switch is closed when the waste toner box is not mounted.