JP3025896B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which forms a toner image on an image carrier by an electrophotographic method and transfers the toner image onto a transfer material to obtain an image. . In particular, the present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile, and the like, in which a process cartridge in which an image carrier and at least one of a developing unit and a cleaning unit are integrated is detachably provided.

[Background of the Invention]

2. Description of the Related Art As image forming apparatuses such as printers and copiers have become smaller, lighter, and more sophisticated, the density and complexity of image forming apparatuses have been increasing.

By the way, in the transfer type image forming apparatus, the transfer material conveyance performance has been remarkably improved and improved, but the occurrence of jams has not yet been eliminated. Therefore, it is necessary to remove the transfer material that caused the jam (hereinafter, referred to as jam paper). Therefore, the external door of the image forming apparatus is opened, and a part of the transfer material transport path or All the movable parts have to be moved to secure a working space inside the complicated image forming apparatus so that the user can access the jammed paper. Since this jam processing operation is performed by an operator who is a general user, the manufacturer must take care so that the operation can be performed easily and easily without requiring specialized knowledge.

As a maker's consideration, opening the exterior itself divides the transport path as represented by a Chatrex type, clamshell type (for example, JP-A-61-279870),
Alternatively, the handle of the movable section is colored so that the operator can easily recognize the movable section of the transfer path of the transfer material, or the position where the jam has occurred is displayed on the display section. For example, various means have been devised in order to increase the working space, for example, by unitizing a part of the image forming means to release the transport path collectively.

[Problems to be solved by the invention]

However, in each case, the operator himself / herself moves the movable part so as to release the transfer material transfer path, thereby securing a work space for jam processing on the transfer path, and the work is troublesome. In addition, the work space for jam clearance is surprisingly small, and there is not enough space for hands to freely remove jam material. Further, the operator has judged the position display where the jam has occurred and searched the place where the jammed paper exists to release the transport path. However, when the transport path is complicated (especially for color, double-sided, high-speed, high-performance images). Since there are a plurality of movable parts and a plurality of movable parts must be moved at a time to release the transport path, the operator is not only lost, wasting time, but also causing various operations due to erroneous operations. It was causing trouble. By the way, since the image forming apparatus is generally installed at a height near the waist position of the operator, the operator has to check the jam material in an unreasonable posture such as being in a middle waist or bending down. In any case, since the operator moves the movable part to release the transport path, not only is the workability not good, but also there is the danger of injury such as when applying force or putting hands in a narrow place. There was a risk of damaging the image carrier.

On the other hand, when exchanging process cartridges and cassettes, conventionally, it is necessary to pull them out of the main body of the apparatus, which is not only very troublesome, but also because the process cartridges are heavy or the cassettes cannot be used with paper feed rollers. Due to the contact, the operator required considerable power and could even accidentally drop. In other words, the work of clearing or replacing these jams is troublesome, and has the disadvantage that the work cannot be performed easily and safely.

SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, an object of the present invention is to secure a large work space for jam processing, to enable jam processing and replacement of a process cartridge by a simple operation, and to improve maintenance. An object of the present invention is to provide an image forming apparatus excellent in the above. It is another object of the present invention to provide an image forming apparatus that can safely and easily perform jam processing and replacement even when a relatively heavy process cartridge such as a process cartridge for a color image forming apparatus is used.

[Means for solving the problem]

The object is to provide an image carrier, an image exposing unit for forming a latent image on the image carrier, a developing unit for developing the latent image, a transfer unit for transferring the developed toner image onto a transfer material, and the transfer. An image forming apparatus having a cassette for feeding a material to the transfer unit; and a process cartridge having at least the image carrier and the sheet feeding cassette are detachably provided to the image forming apparatus main body. A process cartridge moving means for moving from a first position where an image can be formed to a second position where a process cartridge can be replaced and a jam can be removed; and taking out a cassette from a first position where the cassette can be fed. And a cassette moving means for moving the transfer material to a second position at which jam processing is possible; Jam detection means for outputting a jam signal for notifying the occurrence of the jam and the position of the jam, and control means for outputting a movement signal to the process cartridge movement means and / or the cassette movement means in response to the jam signal. This is achieved by an image forming apparatus having:

〔Example〕

Next, the present invention will be described based on an embodiment shown in the accompanying drawings.

FIG. 1 is a left side view showing a main cross section of a color printer to which the present invention is applied. The apparatus body 10 is surrounded by an operation panel 11, a top cover 12 that can be freely opened and closed, a toner supply cover 13, a front cover 14, and the like, and a process cartridge 15 and a paper cassette that are detachable inside.
16 are provided.

In FIG. 1, a photoreceptor belt 17 as an image carrier is
A photosensitive layer is provided on the surface of a flexible belt, and is stretched between a driving roller 18 and a driven roller 19. The drive roller 18 rotates (to be described later) via a drive gear meshing with a gear provided on the apparatus main body 10, and conveys the photosensitive belt 17 clockwise. Further, the distance between the developing devices 23a to 23d and the photoreceptor belt 17 is kept constant by the spacing member 20, so that a good image can be stably formed. In the present embodiment, the photoreceptor belt 17 is used as the image carrier, but the present invention is not limited to this.
The present invention can be applied to an existing image carrier having a photosensitive layer such as a photosensitive drum.

Around the photoreceptor belt 17, charging means 21, exposure means 2
2. Developing means 23a to 23d, transfer means 24 and cleaning means 25 are provided.

The charging means is provided to uniformly charge the photosensitive layer on the surface of the photoreceptor belt 17 with a predetermined polarity, and is an existing charger 21 such as a corona charger, a scorotron charger, and the like. In this case, a scorotron charger is preferably used.

The exposing means is a semiconductor laser writing system unit 22, which exposes the surface of the photoreceptor belt 17 charged by the charger 21 to form an electrostatic latent image.

The developing means is a developer of a different color, for example, a toner of each color of yellow, magenta, cyan and black (developer)
Are contained in each of the plurality of developing units 23a to 23d. Each of these developing units 23a to 23d includes developing sleeves 231a to 231d for keeping a predetermined gap from the photoreceptor belt 17 and stirring screws 232a to 232d for stirring the toner of each color. It has a function of visualizing an image by a non-contact development method. Unlike the contact developing method, the non-contact developing method does not impair the previous toner image formed on the photoreceptor belt 17 and does not hinder the movement of the photoreceptor belt 17, so that a good color image can be obtained. Can be. The developing means is not limited to color development using four different color toners as in the present embodiment, but may use single color, two color or three color toner. In this case, the number of developing means is equal to the number of toner colors. May be disposed around the photoreceptor belt 17.

The transfer unit transfers the toner image formed on the photoreceptor belt 17 onto a transfer material by a transfer unit 24 such as a transfer corona discharger. As this transfer means, an existing transfer member such as a transfer drum may be used instead of the transfer device 24.

The cleaning means 25 has a cleaning blade 251 which is maintained at a position separated from the surface of the photoreceptor belt 17 during the image forming process, and is used only for cleaning after transferring the toner image onto the transfer material. The photosensitive belt 17 is provided so as to be pressed against the photosensitive member 17 to clean the photosensitive belt 17.

The collection box 26 is for collecting and storing the residual toner on the photoreceptor belt 17 removed by the cleaning unit 25 via the toner collection pipe 262 by the waste toner screw 261.

In the present embodiment, the respective process units of the photoreceptor belt 17, the charging unit 21, the developing units 23a to 23d containing the toners of the respective colors, the cleaning unit 25, and the toner collection box 26 constituting the image forming unit of the printer described above are integrated. Of the apparatus main body 10
Can be attached and detached at once. However, the process unit formed in the process cartridge 15 is not limited to this, and at least the photosensitive belt
It is sufficient that the unit 17 and the developing units 23a to 23d or the photosensitive belt 17 and the cleaning unit 25 are unitized, and other process units may be unitized together.

The process of forming a color image by the color image forming apparatus having the above configuration is performed as follows.

First, the process cartridge 15 is loaded at the first position, and is ready for image formation. The first image output from an image reading device separate from the device main body 10
Is input to the laser writing unit 22, a laser beam is generated by a semiconductor laser (not shown) in the laser writing unit 22. The laser beam is rotationally scanned by a polygon mirror 221 rotated by a drive motor (not shown),
Through the fθ lens 222, the cylindrical lens 224, and the three mirrors 223, the light is projected onto the peripheral surface of the photoreceptor belt 17 which has been uniformly charged to a predetermined charge by the charger 21 in advance to form a bright line.

On the other hand, in the sub-scanning direction, a belt index (not shown) corresponding to a specific position of the photosensitive belt is detected or a print command signal is received, and the semiconductor laser is modulated by an image signal based on the detection or command signal. Is determined, the main scanning line at which the operation starts. When scanning is started, a laser beam is detected by an index sensor (not shown) in the main scanning direction, and modulation of the semiconductor laser by a first color image signal is started based on the detected signal. The modulated laser beam scans the surface of the photoreceptor belt 17. Therefore, a latent image corresponding to the first color is formed on the surface of the photosensitive belt 17 uniformly charged by the main scanning by the laser beam and the sub-scanning by the conveyance of the photosensitive belt 17. This latent image is developed by a developing unit 23a containing yellow toner corresponding to the first color in the developing unit, and a yellow toner image is formed on the surface of the photoreceptor belt 17. Then photoreceptor belt 17
After passing under the cleaning blade 251 which is separated from the surface of the photoreceptor belt 17 while holding the yellow toner image on the surface thereof, the second color image is formed.

That is, the photoreceptor belt 17 on which the yellow toner image has been formed is charged again by the charger 21, and a second color image signal is input to the laser writing system unit 22, and the first color image is output. As in the case of the signal, writing is performed on the surface of the photoreceptor belt 17 to form a latent image. The latent image is developed by a developing device 23b containing magenta toner as the second color. The magenta toner image is formed in the presence of the already formed yellow toner image.

Similarly, the latent image formed by the image signal of the third color is developed by the developing device 23c containing cyan toner to form a cyan toner image, and the latent image formed by the image signal of the fourth color is formed. Developing unit 23 containing image with black toner
By developing in step d, the black toner image is superimposed on the surface of the photoreceptor belt 17, and a color toner image is formed on the surface of the photoreceptor belt 17.

A DC or AC bias is applied to the developing sleeves 231a to 231d of these developing units 23a to 23d so that reversal development (jumping development) is performed without contact with the photoreceptor belt 17 whose base is grounded. Has become. In addition,
For the non-contact development, either a one-component developer or a two-component developer can be used. When a one-component developer is used, there is no need to provide a toner hopper separately from the developing unit, and the size can be reduced. However, the development method using a two-component developer is superior in terms of development stability. Therefore, it is preferable in color reproduction.

The color toner image formed on the surface of the photoreceptor belt 17 as described above is supplied from the paper supply cassette 16 by the paper supply roller 27 and is transferred by the timing roller 28 to a transfer material synchronized with the color toner image. . The transfer unit 24 performs transfer by applying a high-voltage power supply having a polarity opposite to that of the toner.

The transfer material on which the color toner image has been transferred in this manner is surely separated by the photoreceptor belt 17 that changes direction rapidly (small diameter curvature) along the drive roller 18, and the transfer belt 29
Is transported upward. Note that the transport belt 29 is provided with a suction unit 291 to reliably transport the belt upward while sucking. Then, the transfer material is melted and fixed with the toner by the fixing roller 30, and then discharged by the discharge roller 31 onto the upper surface of the upper cover 11 also serving as a discharge tray.

On the other hand, the photoreceptor belt 17 after the transfer of the color toner image to the transfer material is further conveyed clockwise, and the remaining toner is removed and cleaned by the cleaning unit 25 in which the cleaning blade 251 is pressed. After the cleaning is completed, the cleaning blade 251 is separated from the photoreceptor belt 17 again, and a new image forming process is started.

 Next, the jam detection sensor will be described.

In FIG. 1, jam detection sensors S ₁ , S ₂ , S ₃ , S
₄ is provided on the conveying path of the transfer material, the presence or absence of the transfer material, or a photo-sensor for detecting the passage, presence or absence of the transfer material detected by these jam detecting sensor S ₁ to S ₄ For example, a jam is detected by the jam determination unit. The jam determination unit detects a jam by an existing method that determines that a transfer material has not been detected within a predetermined time or that a transfer material has been detected for a predetermined time or more. Each of the jam detection sensors S _{1 to} S ₄ determines whether the transfer material is fed from the cassette 16, whether the transfer material is reliably fed by the timing roller 28, and whether the toner image is reliably separated after the transfer. And whether the sheet is reliably discharged by the sheet discharging roller 31. Note that the arrangement of the jam detection sensor is not limited to this embodiment, and a jam detection sensor for detecting whether or not the transfer material is wound around the fixing roller may be provided. Also,
No paper sensor S _0, when the cassette 16 is loaded in the apparatus body 10, a sensor for detecting the presence or absence of the transfer material in the cassette 16. These jam detecting sensors S ₁ to S ₄ and Kaminashi sensor S _0, not only the reflection type photo coupler as illustrated in this example, may be a transmission type photo-couplers, further non-contact type read An existing sensor such as a switch or a contact type microswitch may be used.

Next, the drive system of the process cartridge 15, the drive system for moving the process cartridge, and the drive system for moving the cassette will be described with reference to FIGS.

FIG. 2 is a right side view showing a drive system of the process cartridge 15, a drive system for moving the process cartridge, and a drive system for moving the cassette. The drive system for the process cartridge 15, the drive system for moving the process cartridge, and the drive system for moving the cassette shown in the present embodiment are driven using two motors M1 and M2.

First, a driving force from the motor M1 is used for a driving system of the photosensitive belt 17. The gear G12 is disposed so as to mesh with the gear G11 of the shaft of the motor M1. When the process cartridge 15 is in a position where an image can be formed, the photosensitive belt
Drive gear provided coaxially with drive roller 18 for transporting 17
G14 meshes with a gear G13 that rotates integrally with the gear G12. That is, the rotation of the motor M1 is controlled by the gear G11 and the gear G1.
2, transmitted to the drive gear G14 via the gear G13, adjusted to an appropriate rotational speed, and further rotated the drive roller 18 integrally with the drive gear G14 in the counterclockwise direction in FIG. The belt 17 is conveyed.

Next, the drive systems of the developing units 23a to 23d, the waste toner screw 261, the toner hopper 35, the process cartridge moving means and the cassette moving means will be described with reference to FIGS.

The motor M2 is used for this drive system. The rotating power of the motor M2 is transmitted to the gear G22 via the gear G21 of the shaft of the motor M2. Further, the driving force is transmitted to a gear G23 provided coaxially with and integrally with the gear G22 to drive the drive system of the developing devices 23a to 23d.

 First, a drive system of the developing units 23a to 23d will be described.

The rotating power of the motor M2 transmitted to the gear G23 is the gear G24b
And gear G24c, and also gear G25a and gear G2
Via 5b, it is transmitted to the gear G24a and the gear G24d. Further, in order to transmit only one-way rotation, the process cartridge 15 is coaxial with the gears G24a to G24d via the open type spring clutches C21a to C21d, and is located at a position where the process cartridge 15 can form an image. The gears G26a to G26a mesh with the provided developing device drive gears G27a to G27d.
G26d is provided. Then, the developing device drive gear G27a ~
The rotational force transmitted to G27d is transmitted to developing sleeves 231a to 231d and stirring screws 232a to 232d via a gear provided on process cartridge 15 to drive the developing device. That is, the rotation of the motor M2 is controlled by the gear G21, the gear G22, and the gear G2.
3 to the gears G24b and G24c, and further to the gears G24a and G24b via the gears G25a and G25b, and if necessary, connect the clutch to the developing device drive gears G27a to G27d. The developer is transmitted to drive the developing devices 23a to 23d. The driving of the developing units 23a to 23d during image formation drives only the developing units corresponding to each color of image formation, and the developing units 23a to 23d are used when the process cartridge 15 and the cassette 16 described later are moved. 23d should not be driven. For this purpose, the respective cams (not shown) having claws abutting on the ratchets (not shown) of the clutches C21a to C21d are provided with a phase difference, and five cams including positions where none of the clutches are connected are provided. A selection position may be provided and controlled by a step motor (not shown). For example, by providing four cam claws corresponding to each clutch with a phase difference of 72 degrees on the same axis and rotating the step motor by 72 degrees, only one of the developing units 23a to 23d is driven or Control can be performed so that neither of them is driven.

Next, the process cartridge moving means will be described.

The rotational power of the motor M2 transmitted to the gear G22 is transmitted to the pulley P21 and the timing belt TB1 which rotate integrally with the gear G22.
And transmitted to the gear G29 meshing with the gear G28 that rotates integrally with the pulley P22. Further, the rotational power of the motor M2 transmitted to the gear G29 is further transmitted to the gear G30 meshing with the gear G29. And the turning power is controlled by an electromagnetic clutch if necessary.
It is transmitted to gear G31 via C22. The gear G31 and the gear G32 are cross-shaft gears, and transmit the rotational power transmitted to the gear G31 to the pinion P1 (see FIG. 4). This pinion P1
Is a rack provided on the side of the process cartridge 15.
The process cartridge 15 can be engaged with R1, and the process cartridge 15 is moved in the left-right direction by the rotation of the pinion P1 and the slide of the rack R2. The movement of the process cartridge 15 will be described later in detail.

 Next, the cassette moving means will be described.

The rotating power of the motor M2 transmitted to the gear G29 is transmitted to the gear G33 meshing with the gear G29. Then, the rotating power is supplied to the pulley P22 via the electromagnetic clutch C23 as necessary.
To the pulley P24 via the timing belt TB2.
Then, the power is further transmitted to a gear G34 which rotates integrally with the pulley P24. Gear G34 and gear G35 are cross shaft gears,
The turning power transmitted to the gear G34 is transmitted to the pinion P2 (see FIG. 5). The pinion P2 can mesh with a rack R2 provided on a side surface of the cassette 16, and moves the cassette 16 in the left-right direction by rotating the pinion P2 and sliding the rack R2. The movement of the cassette 16 will be described later in detail.

 Next, a drive system for collecting waste toner will be described.

The rotating power of the motor M2 transmitted to the pulley P22 is transmitted to the pulley P25 via an open-type spring clutch C24 as needed, and drives the drive system of the waste toner screw 261.

Regarding the drive system of the waste toner screw 261, the pulley P
A gear G36 that rotates integrally with 25 and a waste toner screw drive gear provided on the side of the process cartridge 15.
G37 meshes, and the rotational force transmitted to pulley P25 drives waste toner screw 261. Waste toner screw 261
Supplies the toner remaining on the photoreceptor belt 17 removed by the cleaning unit 25 to the toner collection box 26 through a toner collection pipe 262 having a built-in coil spring that rotates.

Next, a drive system of the toner hoppers 25a to 35d will be described.

The torque of the motor M2 transmitted to the pulley P25 is transmitted to the pulley P26 via the timing belt TB3, and if necessary, to the gear G38 via the spring clutch C25 and further to the gear G38.
The power is transmitted to the gear G39 meshing with G38. If necessary, connect the spring clutches C26a to C26d to connect the gear G39.
The gears G41a to G41d meshing with the gears G40a to G40d that rotate together with the gears G40a to G40d rotate. Then, the toner hopper stirring members 351a to 351d rotate together with the gears G41a to G41d to stir the supply toner in the toner hoppers 35a to 35d, and are coaxial with the gears G42a to G42d meshed with the gears G41a to G41d. The supply toner screws 352a to 352d provided in the printer cartridge rotate to convey the supply toner to the developing devices 23a to 23d in the process cartridge 15. The toner hoppers 35a to 35d
Are driven in correspondence with the driving of the developing units 23a to 23d.
In other words, if the developing device corresponding to the color for which an image is being formed is being driven, only the toner hopper containing the supply toner of the same color can be driven. The drive control uses spring clutches C26a to C26d, and can be performed using a step motor and a cam (both not shown), similarly to the control of the developing device drive.

In this embodiment, the drive system of the photoreceptor belt 17 and the drive systems of the developing units 23a to 23d, the waste toner screw 261, the toner hopper 35, the process cartridge moving unit and the cassette moving unit use two motors M1 and M2. However, it goes without saying that these motors may be driven by a single motor, or dedicated motors may be provided for the process cartridge moving means and the cassette moving means.

Next, the movement of the process cartridge 15 will be described with reference to FIG. 6, which is a sectional view taken along the line AA of FIG. 1, and FIG. 7, which schematically shows the movement of the process cartridge 15.

The process cartridge 15 is provided with a protruding member 36 and a rack R1 for movement on the side surface thereof, and is provided with a driving gear G14 for image formation, developing device driving gears G27a to G27d, and a waste toner screw driving gear G37. ing. The projecting member 36 may be provided with a roller or the like so as to be easily moved.

On the other hand, in the process cartridge accommodating chamber of the apparatus main body 10, a guide member 37 for guiding the insertion and removal of the process cartridge 15 (in this embodiment, the guide member 37 The cartridge 15 is suspended and guided), the driving gear G14 of the process cartridge 15 and the developing device driving gear G27.
Gears G13, G26a to G26d, and a gear G36 corresponding to a to G27d and a waste toner screw drive gear G34 are provided. Further, the pinion P1 is provided to be able to mesh with the rack R1 provided in the process cartridge 15. Further, the guide member 37 is provided with first and second micro switches MS1, MS2. This first and second
Micro switch MS1, MS2, process cartridge
This is a detection means for detecting the 15 positions. Here, the first and second micro switches MS1 and MS2 are provided with a drive gear G14 provided in the process cartridge 15, developing device drive gears G27a to G27d, a waste toner screw drive gear G37, and a gear provided in the apparatus main body 10. G13, gears G26a-G26d, gear G
A first position at which image formation is possible by meshing with the first position, and a position further away from the transfer unit 24 than the first position, that is, retracted from the first position in a direction opposite to the direction in which the process cartridge 15 is inserted. The detected second position is detected, and the position signal is output to the control unit. However, the second position is preferably such that the center of gravity of the process cartridge 15 does not fall outside the apparatus 10. This is because if the center of gravity of the process cartridge 15 is outside the apparatus, the engagement between the rack R1 and the pinion P1 becomes poor, and it becomes difficult to remove and insert the process cartridge 15. The position detection sensors for detecting the first and second positions are not limited to the micro switches, and various existing sensors using a photoelectric switch, a magnetic switch, or the like may be used. Further, the first and second microswitches MS1 and MS2 do not need to be provided on the guide member 37 and may be provided on the apparatus main body 10 as long as the first and second positions can be detected.

First, when removing the process cartridge 15, the seventh
As shown in FIG. 5A, the process cartridge 15 is at the first position. That is, the photosensitive belt 17 on the drive roller 18
And a transfer device 24 with a desired distance (in the case where the transfer member is a transfer drum, having an appropriate pressing force), a driving gear G14 provided in the process cartridge 15, and developing device driving gears G27a to G27.
27d, a waste toner screw driving gear G37 and a gear G13, a gear G26a for driving each provided on the apparatus body 10.
G26d and the gear G36 are in mesh with each other, so that image formation can be performed optimally. The rack R1 provided on the process cartridge 15 and the pinion P1 provided on the apparatus main body 10 are engaged with each other.

Therefore, a control unit, which will be described later, issues a process cartridge movement signal to the process cartridge movement unit. That is, the control unit issues a signal to the motor M2 and the electromagnetic clutch C22, which are drive units of the process cartridge movement unit, to cause the process cartridge 15 to move to the first position. Then, the pinion P1 is rotated to move the process cartridge 15 from the position to the second position, and the process cartridge 15 is moved in the direction of the second position along the guide member 37 (see FIG. 7B).

When the process cartridge 15 moves as shown in FIG. 7C, the second micro switch MS2 detects that the process cartridge 15 has moved to the second position, and sends a signal to the control unit. . Upon receiving the signal, the control unit releases the electromagnetic clutch C22 to stop the moving process cartridge 15, and if not necessary, stops the rotation of the motor M2. That is, the process cartridge 15 stops at the second position with the rack R1 and the pinion P1 engaged with each other, and retreats from the first position to the second position. When performing the jam clearance, this state, that is, the state where the process cartridge 15 is placed at the second position may be maintained. In addition, since the process cartridge 15 is detachable at the second position, the process cartridge 15 can be removed from the apparatus main body 10 by slightly pulling it out of the second position, and the process cartridge 15 can be replaced. it can. The front cover 14
Are configured so as not to hinder the movement of the process cartridge 15 as described later.

Conversely, when the process cartridge 15 is to be inserted into the apparatus main body 10 after replacement, the projecting portion 36 of the process cartridge 15 is inserted along the guide member 37 in the process cartridge storage chamber, and the rack R1 and the pinion P1 are engaged with each other. The process cartridge 15 is inserted until it reaches the second position (FIG. 6C). That is, the process cartridge 15 is in the second position (this state is after the jam clearance).

Then, in order to move the process cartridge 15 from the second position to the first position where image formation is possible, the process cartridge 15 at the second position is further inserted, or a control unit described later is used. When the movement signal is input from the controller, a signal is sent to the motor M2 and the electromagnetic clutch C22 to rotate the pinion P1 to move the process cartridge 15 from the second position to the first position. (Reverse rotation) to move the process cartridge 15 in the direction of the first position along the guide member 37 (FIG. 6 (b)).

Further, when the process cartridge 15 moves, the sixth
As shown in FIG. 3A, the first micro switch MS1 detects that the process cartridge 15 has moved to the first position, and sends a signal to the control unit. Upon receiving the signal, the control unit releases the electromagnetic clutch C22 to stop the process cartridge 15 at the first position, and stops the rotation of the motor M2 if unnecessary. That is, the process cartridge 15 stops at the first position, and the drive gear G14, the developing device drive gears G27a to G27d, the waste toner screw drive gear G37 provided on the process cartridge 15 and the gear G13 provided on the apparatus main body 10 are provided. , Gear G26a-G26d, gear G
By engaging with 36, an image can be formed. At this time,
The corresponding toner hoppers 35a to 35d correspond to the toner supply ports 38a to 38d of the respective developing units 23a to 23d in the process cartridge 15.
The toner supply pipes 353a to 353d of 5d are automatically brought into contact with each other to supply toner.

By the way, when the process cartridge 15 is moved, the front cover 14 is spring-biased in the closing direction, so that the movement of the process cartridge 15 is not hindered. That is, the front cover is moved by the movement of the process cartridge 15.
14 is pushed and released. The spring-biased front cover 14 is latched by a solenoid, and at the same time that a signal to move the process cartridge 15 is issued from the control unit, a signal is sent to the solenoid to stop the latching and the restoring force of the spring is used. The front cover may be released. When the process cartridge 15 is released by the motor and the gear, not only does the front cover 14 release when the process cartridge 15 moves from the first position to the second position, but also from the second position to the first position. When the first micro switch MS1 detects that the process cartridge 15 has moved to the first position, the front cover 14 can be automatically closed.

Next, the movement of the cassette 16 will be described with reference to FIG.

The cassette 16 has on its side a rack R2 for movement and a projection 161 on the front side in the insertion direction, and a rotatable bottom plate 162 for loading a transfer material and a slidable separation claw 163 inside. ing.

On the other hand, a paper feed roller 27, a pinion P2 for moving the cassette 16, a bottom plate
A push-up lever 32 for pushing up 162, a photoelectric switch MS3 composed of a photocoupler, and a microswitch MS4 are provided.

The push-up lever 32 is pivotally supported by a push-up mechanism 321 provided on the apparatus main body 10, and has a roller 322 at its tip.
Is provided. The push-up mechanism may use an existing method such as a spring, a lever principle, or a motor, and may be provided inside the cassette 16 together with the push-up lever 32.

The photoelectric switch MS3 and the micro switch MS4 are detection means for detecting the position of the cassette 16. Here, the photoelectric switch MS3 and the micro switch MS4 are respectively moved to the first position where the uppermost surface of the transfer material in the cassette 16 can be pressed against the separation claw 163 by the push-up lever 32 to enable paper feeding, and A second position retracted from the first position in the direction opposite to the insertion direction is detected, and the position signal is output to the control unit. However, the second position is preferably such that the center of gravity of the cassette 16 does not fall outside the apparatus 10 as in the case of the process cartridge 15. In addition, these first
The position detection sensor that detects the second position is not limited to the present embodiment, and various types of existing sensors using a micro switch, a photoelectric switch, a magnetic switch, and the like may be used.

First, when the cassette 16 is taken out, the cassette 16 is at the first position as shown in FIG. 8A, and the transfer roller 27 is in a state where the transfer material can be optimally fed. The rack R2 and the pinion P2 are meshed.

Therefore, the control unit, which will be described later, issues a cassette movement signal to the cassette movement means, that is, the control unit emits a signal to the motor M2 and the electromagnetic clutch C23, which are drive units of the cassette movement means, to move the cassette 16 from the first position to the first position. Rotate pinion P2 to move to position 2. At this time,
The push-up lever 32 retracts below the movement path of the cassette 16 so as not to hinder the movement of the cassette 16 (see FIG. 8B).

When the cassette 16 moves as shown in FIG. 8 (c), the cassette 16 is moved to the second position by the microswitch MS4.
And sends a signal to the control unit. When the control unit receives the signal, the electromagnetic clutch C2
3 is released to stop the moving cassette 16, and if unnecessary, the rotation of the motor M2 is stopped. That is, the cassette 16 is retracted from the first position to the second position by stopping at the second position with the rack R2 and the pinion P2 engaged. In the second position, the cassette 16 becomes detachable, and when jam clearance, replacement of the cassette 16 and replenishment of the transfer material in the cassette 16 are performed, the cassette 16 can be removed by slightly withdrawing the cassette 16 from the apparatus main body 10. .

Conversely, when the cassette 16 is inserted into the apparatus main body 10, such as after the completion of the jam processing, after the replacement of the cassette 16, and after the replenishment of the transfer material in the cassette 16, the cassette 16 is moved along the cassette storage chamber or It is inserted along a member (not shown), the rack R2 and the pinion P2 are engaged with each other, and the cassette 16 is inserted until it reaches the second position (FIG. 8 (c)).

Then, in order to move the cassette 16 at the second position to the first position at which paper can be fed, the cassette 16 at the second position is further inserted, or a movement signal is sent from a control unit described later. When input, the motor M2 and electromagnetic clutch
A signal is sent to C23, and the pinion P2 is rotated (rotated in a direction opposite to the rotation direction when taking out) to move the cassette 16 from the second position to the first position, and the first position is moved along the guide member 37. (FIG. 8 (b)).

When the cassette 16 further moves, the photoelectric switch MS3 is moved by the projection 161 as shown in FIG.
Detects that it has moved to the first position and sends a signal to the control unit. Upon receiving the signal, the control unit releases the electromagnetic clutch C23 to stop the cassette 16 at the first position, and stops the rotation of the motor M2 if unnecessary.
That is, the cassette 16 is stopped at the first position, and the push-up mechanism 321 rotates the push-up lever 32 clockwise to push up the bottom plate 162 inside the cassette 16 with the roller 322, and the cassette 16 is loaded on the bottom plate 162. The uppermost surface of the transfer material is pressed against the separation claw 163, and the paper can be fed by the paper feed roller 27 which is a half-moon roller.

Next, the upper cover releasing means will be described with reference to FIG.

The upper cover 12 is rotatably supported by an upper cover shaft 39. Further, an upper cover opening / closing gear G51 that rotates integrally with the upper cover 12 is provided on the upper cover shaft 39, and a gear G52 that meshes with the gear G51 is provided on the motor M3 disposed in the apparatus body 10. It is made. Further, micro switches MS5 and M which are position detection sensors for detecting that the upper cover 12 is closed and opened.
Has S6.

By the upper cover releasing means having the above-described configuration, the upper cover 12 during the image forming process is in a closed state,
The upper cover 12 also serves as a discharge plate for the transferred transfer material discharged by the discharge roller 31 (FIG. 9A). Then, an upper cover release signal is input to the upper cover release means from a control unit described later, that is, when a signal is input to the motor M3, the motor M3 rotates clockwise in FIG. The gear G51 is rotated counterclockwise via G52. Therefore the upper cover axis 3
The upper cover 12 is released by rotating counterclockwise around the center 9. Then, the microswitch MS6 detects that the upper cover 12 has been released, and outputs an opening signal to the control unit. Upon receiving the opening signal, the control unit stops the rotation of the motor M3.
That is, the upper cover 12 is released as shown in FIG. 9 (b). The transfer material causing the jam can be easily found from the release opening of the upper cover 12 thus released, and can be easily removed.

Conversely, when closing the upper cover 12, the operator may turn the upper cover 12 in the released state to close,
Alternatively, when a closing signal is input from a control unit described later, the motor M3 is rotated (counterclockwise in the figure) to rotate the upper cover clockwise. Then, when the micro switch MS5 detects that the upper cover 12 is closed, the control unit stops the rotation of the motor M3. That is, the upper cover 12 is closed (FIG. 9A). The upper cover releasing means is not limited to the present embodiment, and a member for urging the upper cover 12 in the releasing direction by a spring and engaging the cover 12 is provided on the upper cover 12, and a release signal from the control unit is provided. The upper cover 12 by the member
May be stopped and released. Furthermore, in the present embodiment, the description is made using the image forming apparatus provided with the upper cover 12, but the present invention is not limited to this. In a so-called clamshell type image forming apparatus, the upper cover Instead of the releasing means, a releasing means may be provided in the upper housing.

Next, the fixing roller pressure releasing means will be described with reference to FIG.

In this embodiment, the pressure release of the fixing roller 30 is performed by:
The opening and closing of the upper cover 12 described above is used. That is, the protrusion 43 is provided near the upper cover shaft 39 and rotates integrally with the upper cover 12 to act as a cam. On the other hand, the fixing roller 30 includes a pressure roller 301 and a heating roller 302, and a separating member and a cleaning member (not shown) are arranged around the periphery of the heating roller 302, and are rotated clockwise by a driving system (not shown). The pressure roller 301 can rotate counterclockwise following the heating roller 302, and the pressure roller shaft 30
3 is pivotally supported by the pressure release member 304. Crimping release member 30
4 has its one end rotatably supported by the apparatus main body 10 by a pressure release shaft 305, and is urged clockwise by a spring 306. Accordingly, as shown in FIG. 9A, during the image forming process, the fixing roller 30 is rotated by the pressing roller 301 pressing the heating roller 302 and the heating roller 302 being heated by heating means (not shown). The transfer material can be conveyed to the paper discharge roller 31 by fusing and fixing the toner image on the transfer material.

When the protrusion 43 rotates counterclockwise with the release of the upper cover 12 by the pressure release mechanism of the fixing roller 30 having the above-described configuration, the pressure release member 304 rotates counterclockwise around the pressure release shaft 305 as a fulcrum. Then, the pressure roller 301 pivotally supported by the pressure release member 304 releases the pressure on the heating roller 302. Fixing roller released in this way
Since a gap is formed between the pressure roller 301 and the heating roller 302, which is 30, the jammed paper in the fixing unit can be easily removed.

Conversely, when pressing the fixing roller 30, the upper cover 12
Is closed, the protrusion 43 rotates clockwise, and the pressure release member 304 is pressed by the spring 306 clockwise about the pressure release shaft 305 as a fulcrum, so that the pressure roller 301 presses against the heating roller 302. Therefore, the pressing and releasing of the fixing roller 30 can be performed by a simple mechanism.

In the present embodiment, the pressure roller 301 is moved to release the pressure of the fixing roller 30.
Needless to say, the pressure contact of the fixing roller 30 may be released by moving the fixing roller 30. Further, although the press release mechanism of the present embodiment is provided with the cam provided on the upper cover 12, the press release of the fixing roller 30 may be directly performed by a signal of the control unit using a motor and a gear or a solenoid. .

As described above, the control of the process cartridge moving means, the cassette moving means, and the upper cover releasing means is described with reference to FIG.
As shown in the figure. That is, the jam detection sensors S ₁ to
A signal of the presence or absence of the transfer material from S ₄ to determine whether a jam in the jam determination unit, if it is determined that the jam jam determination unit emits a jamming signal indicating the occurrence and location of the jam in the control unit. Then, the control unit stops driving units related to image formation, such as the photoreceptor belt driving unit, the developing unit driving unit, and the fixing driving unit, and displays on the display unit (not shown) of the operation panel 11 that a jam has occurred. Further, it controls the process cartridge moving means, the cassette moving means, and the upper cover releasing means according to the position where the jam has occurred. Here, the control unit, as shown in FIG.
A movement signal is issued to the means marked with a circle in the figure according to the position where the jam has occurred. In other words, the control unit
Occurs in the cassette moving means when it occurs at the paper feed location (S ₁ ), and occurs at the transfer station (S ₃ ) when it occurs at the timing (S ₂ ). When this occurs, a movement signal is issued to the process cartridge 15 and the upper cover 12 and to the upper cover releasing means when it occurs at the paper discharge location (S ₄ ). Accordingly, the process cartridge moving means, which has received the process cartridge moving signal from the control unit, controls the process cartridge moving drive system to move the process cartridge 15 from the first position to the second position.
When the position detection signal for detecting that the device has moved to the second position is obtained, the process cartridge movement drive system is stopped. On the other hand, the cassette moving means which receives the cassette driving signal from the control unit also moves the cassette 16 from the first position to the second position. Further, the upper cover releasing means receiving the release signal from the control unit releases the upper cover. That is,
When a jam occurs, as shown in FIG. 12 (FIG. 12 shows a case where both the process cartridge 15 and the cassette 16 have been moved to the second position and the upper cover 12 has been released), Automatically retracts and releases the parts necessary for jam processing without any action, so the operator can easily check the jam paper without misidentifying the location of the jam occurrence, and there is no jam paper left behind. Can be removed. Further, after the jam has been cleared, the process cartridge 15 at the second position is slightly inserted in the direction of the first position, or the cassette 16 at the second position is slightly inserted, or is in the released state. The control unit controls the process cartridge moving means, the cassette moving means, and the upper cover releasing means, regardless of the action of rotating the upper cover 12 to close. At this time, the process cartridge 15 or the cassette 16 is
Are moved to the first position only when they are in the first position (if they are in the first position, they are left as they are), and the upper cover 12 is closed only when the upper cover 12 is in the released state ( If closed, leave it as is). Therefore, the image can be formed only by a simple operation, that is, the setting of the process cartridge 15 and the cassette 16 to the first position and the closing of the upper cover 12 are automatically performed. Not only is greatly reduced, but also the process cartridge 15 and the cassette 16 can be set at optimal positions.

Furthermore, other than when a jam occurs, such as when replacing the process cartridge 15, or when replacing the cassette 16,
Process cartridge 15 and cassette at operator's will
Each of them can be moved by pressing an eject button provided on the operation panel 11 to move the 16 and release the upper cover 12. That is, by pressing the take-out button on the operation panel 11, a take-out signal is input to the control unit. At this time, a print signal from the print button of the operation unit and the photoreceptor belt drive unit,
If there is no image forming process signal such as a photoreceptor belt drive signal, a fixing / discharge drive signal, or a paper feed drive signal indicating that the image forming process of the paper discharge unit and the paper feed unit is operating, Even if the jam signal is not input to the control unit, the process cartridge moving means, the cassette moving means,
A process cartridge movement signal, a cassette movement signal, and an upper cover release signal are issued to the upper cover release means, respectively.
16 can be moved from the first position to the second position and the top cover 12 can be released. Conversely, also when the process cartridge 15 and the cassette 16 are moved from the second position to the first position and the upper cover 12 is closed, a set button provided on the operation panel 11 other than the above is pressed, and
When the process cartridge 15 or the cassette 16 is in the second position or when the upper cover 12 is in the released state, the control unit transfers the process cartridge 15 or the cassette 16 in the second position to the process cartridge moving means or the cassette moving means. A movement signal for moving the first position or a closing signal is issued to the upper cover 12 in the released state to move the process cartridge 15 or the cassette 16 to the first position and close the upper cover 12 in the released state. . That is, after the set button on the operation panel 11 is pressed, the process cartridge 15 and the cassette 16 are at the first position, the upper cover 12 is closed, and the image forming apparatus is set in a state where image formation is possible. it can.
The eject button and the set button provided on the operation panel 11 correspond to the process cartridge 15, the cassette 16
The upper cover 12 and the upper cover 12 may be moved all at once, but a take-out button and a set button for moving the process cartridge, moving the cassette, and opening and closing the upper cassette may be provided independently so as to move each independently. In addition, except when a jam occurs, the paper-out sensor S ₀
When it is detected that the transfer material in the cassette 16 has run out, only the cassette 16 can be moved.

Further, in this embodiment, as the image forming process, an image forming method in which a color toner image is formed on a photoreceptor belt and then transferred to a transfer material once is described. A color image forming method of transferring an image may be used. Further, the present invention can be applied to a normal monochrome printer using a monochrome process. Although the non-contact developing method has been described as a developing method, the present invention is not limited to this non-contact developing method, but can be applied to contact developing. Further, the drive system shown in the present embodiment is only an example, and it goes without saying that the drive system is not limited to the combination of these gears, clutches, belts and the like. Further, the protruding member, guide member, rack, pinion, and the like for moving the process cartridge described in the present embodiment are not limited to these. For example, the process cartridge is placed on the tray, and the tray is moved to the first position. And the second position.

FIG. 13 shows a transfer drum type image forming apparatus as another embodiment to which the present invention is applied. The process cartridge 15 is substantially the same as the previous embodiment, except that the toner hopper 35a is unitized in the process cartridge 15. In the image forming apparatus of the transfer drum type, the transfer drum 50 is brought into contact with the transfer portion of the photoreceptor belt 17, and the transfer drum 50 rotates counterclockwise in synchronization with the photoreceptor belt 17. With the transfer material wound around the transfer drum 50, the toner images of each color formed on the photoreceptor belt 17 were transferred onto the wound transfer material, and the toner images of each color were superimposed on the transfer material. Thereafter, it is separated from the transfer drum 50 and discharged to the upper part of the apparatus main body 10 after fixing.

The peripheral portion of the transfer drum 50 is provided with a charger 501 provided to electrostatically attract the transfer material, and a winding member 502 for mechanically winding the transfer material around the transfer drum 50. Reference numeral 502 has a roller at the leading end, and comes into contact only when the transfer material first winds around the transfer drum 50. A gripper 503 is provided on the peripheral surface of the transfer drum 50, and functions to hold the leading end of the transfer material conveyed in synchronization. The transfer device 504 is provided for the photosensitive belt 17
The upper toner image is electrostatically transferred onto a transfer material. The separation / elimination electrode 505 and the separation claw 506 separate the transfer material after transfer from the transfer drum 50. The detachable cleaner 507 is for removing adhered toner remaining on the transfer drum 50 after the transfer material is separated.

The transfer material fed from the cassette 16 enters the transfer drum 50 charged by the charger 501 while maintaining synchronization, and is wound around the winding member 502, and the transfer material tip is held by the gripper 503, and the transfer unit is closed. The transfer unit 504 rotates and transfers the yellow toner image formed on the photoreceptor belt 17 by the transfer unit 504 to the transfer material at the transfer unit. After the first transfer, the transfer drum 50 continues to rotate and is cleaned by the cleaner 507 to transfer the next toner image. That is, 2
The magenta toner image is transferred in the third rotation, the cyan toner image is transferred in the third rotation, and the black toner image is transferred in the fourth rotation. When the transfer of the four color toner images is completed, the transfer material is neutralized by the separation and removal electrode 505, the separation claw 506 releases the holding of the transfer material front end, is separated, and is conveyed to the fixing roller 30.

In the image forming apparatus of this embodiment, the transfer drum 50 is located on the side of the apparatus main body 10 and the movable process cartridge 15
Has a structure that is not included. Therefore, the movement of the process cartridge 15 is performed in the same manner as in the above embodiment.

〔The invention's effect〕

As described in detail above, the present invention provides an image forming apparatus in which when a jam occurs, the process cartridge automatically retreats from a position where an image can be formed, and retreats from a position where a cassette can be fed.

As a result, in the image forming apparatus of the present invention, when a jam is detected, only the indispensable portions of the process cartridge and the cassette need to be moved, so that the operator can easily and without a large force perform the jam processing without hesitation. it can.

Further, since the process cartridge is mechanically moved, the process cartridge can be replaced or jam-treated without giving any extra vibration to the process cartridge and causing almost no scattering of the developer, thereby achieving an effect of improving maintainability. is there.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main cross section of a color printer to which the present invention is applied, as viewed from the left side. FIG. 2 is a right side view of a drive system according to the present invention. FIG. 3 is a diagram showing a drive system for moving a process cartridge and a cassette from above. FIG. 4 is a diagram showing a main part of a drive system for moving the process cartridge. FIG. 5 is a diagram showing a main part of a drive system for moving the cassette. FIG. 6 is a sectional view taken along the line AA in FIG. FIG. 7 is a schematic diagram schematically showing the movement of the process cartridge. FIG. 8 is a schematic diagram schematically showing movement of the cassette.
FIG. 9 is a view showing a release mechanism of an upper cover. FIG.
FIG. 3 is a diagram illustrating a control system for moving a process cartridge and a cassette. FIG. 11 is a diagram showing control of the process cartridge moving means and the cassette moving means based on the position where the jam has occurred.
FIG. 12 is a main sectional view showing the color printer from the left side when the process cartridge and the cassette are at the second position and the upper cover is released. FIG. 13 is a main sectional view of a transfer drum type image forming apparatus to which the present invention is applied. 10: Main unit, 11: Operation panel 12: Top cover 15: Process cartridge 16: Cassette, 17: Photoreceptor belt 18: Drive roller, 21: Charger 22: Laser writing unit 23 developing unit 24 transfer unit 25 cleaning unit 26 toner collecting box 36 projecting member 37 guide member 27 paper feed roller 28 timing roller 29 transporting unit , 30 ...... fixing roller 31 ...... discharge roller, 39 ...... upper cover axis 50 ...... transfer drum, S ₀ ...... no paper sensor _{S 1, S 2, S 3} , S 4 ...... jam detecting sensor M1, M2, M3 Motor G14 Drive gear G27a to G27d Developing device drive gear G13, G26a to G26d Gear G51, G52 Gear for releasing upper cover P1, P2 Pinion R1, R2 Racks MS1, MS2: Process cartridge position detection sensors MS3, MS4 ... Cassette position detection sensors MS5, MS6 …… Top cover position detection sensor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tadayoshi Ikeda 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Co., Ltd. Examiner Jika Higashi (56) Reference JP-A-61-226757 (JP, A) JP-A Sho 60-205563 (JP, A) JP-A-2-117526 (JP, A) JP-A-61-64638 (JP, A) JP-A-63-174353 (JP, U) (58) Fields investigated (Int. Cl. ^7, DB name) G03G 15/00 G03G 21/00 B65H 1/26

Claims (2)

(57) [Claims] An image carrier, an image exposure device for forming a latent image on the image carrier, a developing device for developing the latent image, a transfer device for transferring the developed toner image onto a transfer material, An image forming apparatus having a cassette for feeding a transfer material to the transfer means, wherein at least a process cartridge having the image carrier and the paper feed cassette are detachably provided to the image forming apparatus main body; From a first position where image formation can be performed to a second position where process cartridge exchange and jam clearance can be performed; and a first position where the cassette can be fed. A cassette moving means for moving the transfer material to a second position at which the transfer material can be removed and jammed; Jam detection means for outputting a jam signal for notifying occurrence of jam and the position of the jam, and control for outputting a movement signal to the process cartridge moving means and / or the cassette moving means in response to the jam signal. And an image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the moving direction of the process cartridge is the same as the moving direction of the cassette.