JPH04119363A - Image forming device - Google Patents

Abstract

PURPOSE:To always stably drive to rotate a photosensitive body by moving the rotary shaft of an image carrier so that it may be connected to and separated from a driving shaft provided on a device main body side when a process cartridge is loaded/unloaded. CONSTITUTION:A photosensitive belt 1, an electrostatic charger 6, respective developing devices 8-11, and a cleaning device 13 are assembled in the process cartridge 30, and the cartridge 30 is placed on a frame 50 to be housed in the device. Before the movement of the frame 50, the rotary shaft of the image carrier 1 on the cartridge 30 side, that means, the rotary shaft of a turning roller 2 automatically retreats to the shaft direction to be separated from the driving shaft on the device main body side, so that the process cartridge 3 is in a state where it is to be unloaded. Meanwhile, in the case that the frame 50 on which the process cartridge 30 is placed is restored, the rotary shaft automatically advances to the shaft direction and is connected to the driving shaft on the device main body side, so that the photosensitive belt 1 is set in a carrying performable state. Thus, the image carrier 1 is always stably actuated and a high-quality image is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image forming apparatus in which process materials for image forming, including an image bearing member, are integrated into and removed from a cartridge.

[Background of the invention]

As one of the devices for obtaining color images by electrophotography, a latent image is formed on a photoreceptor drum or belt according to the number of separated colors of the original image, and development with color toner is repeated. This is a method of superimposing color toner images and then transferring them to obtain a color image. The basic process of forming a multicolor image was published in Japanese Patent Application Laid-open No. 1989-1981 by the applicant.
-75850, 60-76766, 60-95
No. 456, No. 60-95458, No. 60-15847
This is disclosed in Publication No. 5, etc.

In a multicolor image forming apparatus that obtains a color image through such superimposition, a plurality of developing units containing different colored toners are arranged around the periphery of the photoreceptor, and generally the photoreceptor is The body is rotated multiple times to develop the latent image on the photoreceptor to obtain a color image.

Regarding such an image forming apparatus, a part of the image forming means is made into a cartridge in order to replenish and replace various photoreceptors, developer carriers, cleaning members, and developer toner that have a useful life when they are exhausted. A device has been proposed in which a member that integrates the main parts of the device is taken out of the device for maintenance or replacement. Furthermore, various configurations have been proposed in which the conveyance path of the transfer material on which an image is formed by the image forming means is opened to make it easier to take out the transfer material when clearing a jam.

[Problem that the invention seeks to solve]

By stably rotating or transporting each of the photoreceptors, the accuracy of image overlay is maintained at a high level, thereby forming a high quality color image.

Generally, a method is used in which the rotation shaft of the cartridge is connected to the drive shaft of the device by the meshing of gears when the cartridge is installed, but with this method, slight unevenness in rotation or transportation of the photoreceptor may occur. is unavoidable.

As a result of solving and improving this problem, the present invention aims to provide an image forming apparatus that can transmit power to a photoreceptor by engaging a clutch, thereby driving and rotating the photoreceptor in a stable manner at all times. It is.

[Means for solving problems]

The above purpose is to provide an image forming apparatus in which a process cartridge including an image carrier can be attached and detached in a direction perpendicular to the rotation axis of the image carrier, and when the process cartridge is attached or detached, a drive shaft provided on the apparatus main body side is used. On the other hand, this is achieved by an image forming apparatus characterized in that the rotation shaft of the image carrier moves to connect and disconnect.

〔Example〕

An embodiment of the image forming apparatus of the present invention is shown in FIGS. 1 to 5.

In FIG. 1, l is a visible photoreceptor belt that is a belt-like image carrier, and the photoreceptor belt l is installed between rotating rollers 2 and 3, and is rotated clockwise by the drive of rotating roller 2. transported.

Reference numeral 4 denotes a support member or guide member fixed to the main body of the apparatus so as to be inscribed in the photoreceptor belt l-1, and the photoreceptor belt l is kept under tension by the outward biasing action of the rotary roller 3. This causes the guide member 4 to rub against its inner circumferential surface.

Therefore, the photoreceptors on the outer circumferential surface of the photoreceptor belt l are always maintained at a constant position relative to the surface of the guide member 4 even during conveyance, making it possible to form a stable image forming surface.

Reference numeral 6 denotes a scorotron charger as a charging means, 7 a laser writing system unit as an image exposure means, and 8 to 11 a plurality of developing means, that is, developing devices, each containing a developer of a specific color. The means is disposed facing the outer peripheral surface of the photoreceptor belt l with the guide member 4 on the back side.

In addition to the optical system shown in the drawings, the laser writing system unit 7 may also include an optical system that integrates a light emitting section and a convergent light transmission body.

Each of the developing units 8.9, 10, 11 accommodates, for example, yellow magenta, cyan, and black developers, respectively, and is equipped with a respective developing sleeve that maintains a predetermined gap with the photosensitive belt l. -1 has the function of visualizing the latent image on 1 by a non-contact development method. Unlike contact development, this non-contact development has the advantage of not interfering with the movement of the photoreceptor belt.

12 is a transfer device, 12A is a static eliminator, 13 is a cleaning device, and a blade 13A and a toner conveying roller 13B of the cleaning device 13 are connected to the photoconductor bell l-1 during image formation.
The photoreceptor belt 1 is kept in a position apart from the surface of the photoreceptor belt 1, and is pressed against the surface of the photoreceptor belt 1 as shown in the figure only during cleaning after image transfer.

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

First, the formation of a multicolor image according to this embodiment is performed according to the following image forming system. That is, data obtained by a color image data input section in which an image sensor scans an original image is subjected to arithmetic processing in an image data processing section to create image data, which is then stored in an image memory. The image memory is then taken out during recording and inputted into a recording section, for example, the color image forming apparatus shown in the embodiment of FIG.
.

That is, when a color signal output from an image reading device separate from the printer is input to the laser writing system unit 7, a laser beam generated by a semiconductor laser (not shown) is transmitted to the laser writing system unit 7. It is rotated and scanned by a polygon mirror 7B rotated by a drive motor 7A, and then mirrors 7D and 7E pass through an fθ lens 7C.
, 7F, the optical path is bent, and the light is projected onto the circumferential surface of the photoreceptor belt 1, which has been charged in advance by the charger 6, which is a charging means, to form a bright line.

On the other hand, when scanning is started, the beam is detected by the index sensor, modulation of the beam by the first color signal is started, and the modulated beam scans the circumferential surface of the photoreceptor belt l. Therefore, a latent image corresponding to the first color is formed on the circumferential surface of the photoreceptor belt 1 by main scanning by the laser beam and sub-scanning by the conveyance of the photoreceptor belt 1. This latent image is developed by a developing device 8 loaded with yellow (Y) toner (developing medium) of the developing means, and a toner image is formed on the drum surface. The obtained toner image, while being held on the drum surface, passes under a cleaning device 13, which is a cleaning means, which is separated from the circumferential surface of the photoreceptor belt 1, and enters the next copy cycle.

That is, the photoreceptor belt 1 is charged again by the charger 6, and then the second color signal output from the signal processing section is input to the writing system unit 7, and the second color signal is inputted to the writing system unit 7, and the second color signal is inputted to the writing system unit 7. In the same manner, writing is performed on the drum surface to form a latent image. The latent image is developed by a developer 9 loaded with magenta (M) toner as a second color.

This magenta (M) toner image is formed in the presence of the previously formed yellow (Y) toner image.

IO is a developing device having cyan (C) toner, which forms a cyan (C) toner image on the drum surface based on a control signal generated by a signal processing section.

Furthermore, 11 is a developing device having black toner, and forms a black toner image superimposed on the belt surface by the same process. These developing units 8.9°10 and 11
A direct current or even alternating current bias is applied to each sleeve, and jumping development is performed using a two-component developer, which is a developing means, and development is performed without contact on the photoreceptor belt l whose base is grounded. It has become. Incidentally, as the development, non-contact development using a -component developer can also be used.

The color toner image thus formed on the circumferential surface of the photoreceptor belt 10 is transferred to a transfer material fed from the paper feed cassette 14 via the paper feed guide 15 at the transfer section.

That is, the top layer of the transfer material stored in the paper feed cassette 14 is carried out by the rotation of the paper feed roller 16, and transferred to the transfer device 12 via the timing roller 17 in synchronization with the image formation on the photoreceptor belt 1. supplied to.

The transfer material that has undergone image transfer and static electricity removal is transferred to the rotating roller 2.
The image is reliably separated from the photoreceptor belt l, which suddenly changes direction along the direction of the photoreceptor belt l, and heads upward via the suction conveyor belt 17A, and after the image is fused by the fixing roller 18, it passes through the paper ejection roller 19 and onto the top lid 20. It is ejected into a lft-shaped tray.

On the other hand, the photoreceptor belt 1 that has completed the transfer to the transfer material continues to be conveyed to the blade 13A and the toner conveying roller 13B.
The remaining toner was removed in the cleaning device 13 which was brought into pressure contact with the blade 13A, and the blade 13A was removed again after the cleaning was completed. A little later, the toner supply roller 13B smoothed out the toner accumulated on the tip of the blade 13A. Afterwards, the toner supply roller 13B is separated and a new image forming process begins.

The photosensitive drum 11, the charger 6, each developing device, and the cleaning device 13 are incorporated into an independent process cartridge 30 as process materials for image formation, and are integrally attached to and removed from the main body of the apparatus.

In other words, inside the device, there is a third
As shown in the figure, a pedestal 50 is provided that is slidably supported by engaging a pair of fixed guide rails 40 with legs 50A on the bottom surface, and supports the process cartridge 30.
is placed on the pedestal 50 and stored in the apparatus.

The pedestal 50 is the pinion PI of the motor Ml on the device main body side.
As shown in FIG. 2, the rack plate 51 is integrally meshed with the rack plate 51, and when the motor Ml rotates, the rack plate 51 is moved diagonally upward in parallel as shown in FIG.

On the other hand, the upper lid 20 is rotatably supported by the apparatus main body via a shaft 2OA, and is opened by rotating counterclockwise to open an opening in the upper part of the apparatus main body.

That is, the upper lid 20 has a flat gear 21 integrated in its rotating base that meshes with a pinion P2 of a motor M2 on the apparatus main body side, and is rotated counterclockwise as shown in FIG. 2 by the rotation of the motor M2 to a predetermined position. is held at an angle of

The movement of the pedestal 50 and the opening of the top cover 20, that is, the rotation of the motors M1 and M2, are started by operating an eject button provided on the operation panel outside the device. Photo sensor S2
On the other hand, the top cover 20 is turned OFF when the sector gear 21 presses the switch MS2 on the main body of the device.
They are automatically stopped at each angle when switching from F to ON.

As a result, the conveyance path for the transfer material is opened, making it easy to clear the jam, and at the same time, the process cartridge 30 can be removed, allowing inspection, replacement, etc. of the stored process materials.

Further, by operating the reset button, the motors Ml and M2 each start to reverse rotation, and the mount 50 is moved to a position where the light shielding plate 52 switches the photosensor S1 from ON to OFF, while the sector gear 21 moves the upper cover 20 to the position where the switch M
When SI is pressed to automatically stop at an angle that changes from OFF to ON and close the transfer material conveyance path, the process cartridge 30 is simultaneously returned to a position where image formation is possible.

Prior to the movement of the pedestal 50, the rotating shaft of the image carrier on the process cartridge 30 side, that is, the rotating roller 2
The rotary shaft 2A automatically retreats in the axial direction and separates from the drive shaft on the apparatus main body side, making it possible to remove the process cartridge 30. On the other hand, when the pedestal 50 on which the process cartridge 30 is placed returns, the above-mentioned The rotating shaft 2A automatically moves forward in the axial direction and is connected to the drive shaft on the apparatus main body side, so that the photoreceptor belt 1 can be conveyed.

FIG. 4(a) shows a side view of the process cartridge 30 alone, and FIGS. 4(b) and 4(c) show its cross section along arrow BB.

The rotating roller 2 has two rotating shafts each having a clutch CL2 formed at one end inserted therethrough, and is rotated as a unit by engagement between a pin P of the rotating shaft 2A and a groove S of the rotating roller 2.

Further, the rotary shaft 2A has a plate spring member 30 attached to the rear substrate 300 of the process cartridge 30 at its neck portion 2B.
0A is engaged.

The leaf spring member 300A is connected to a plunger PL of a solenoid SQL provided in the cartridge, and when the solenoid SQL is turned ON, the plunger PL is attracted, thereby retracting the rotating shaft 2A as shown in FIG. 4(b). ,
Clutch CL2 is connected to motor M3, which is the drive shaft on the device main body side.
Clutch CL2 is disengaged from the shut 1, or the rotary shaft 2A is moved forward as shown in FIG. It is now possible to connect it to the clutch CLI.

The operation of the solenoid SQL is turned on prior to the movement of the process cartridge 30 from the image forming position by operation of the eject button, that is, the start of the motor M1,
Waiting for disengagement with clutch CLI due to disengagement of clutch CL2, the motor Ml is turned ON, the process cartridge 30 finishes moving rightward in the figure, and at the time when the photo sensor S2 is switched OFF, the solenoid S is turned on.
QL is turned OFF and the suction of the leaf spring member 300A is released.

On the other hand, when the process cartridge 30 returns to the image forming position, the operation of the solenoid SQL is turned on simultaneously with the operation of the reset button, the motor Ml is turned on, and the process cartridge 30 is moved to the left in the figure. , after returning to the image forming position, the photosensor Sl becomes O.
At the time of switching to FF, solenoid SQL is turned off and clutch CL2 is placed in an engagement position with respect to clutch CLI.

Furthermore, instead of moving the rotary shaft 2A in the axial direction due to the operation of the solenoid SQL, the entire process cartridge 30 is moved parallel to the drive shaft on the apparatus main body side, thereby coupling the clutch CL2 to the clutch CLI. It is also possible to take a method of detachment.

FIG. 5(a) shows one embodiment of the present invention, and FIG. 5(b) shows a plan view of the main part thereof as indicated by arrow C.

The process cartridge 30 has a pair of rails 41 formed on its upper surface that are parallel to the insertion direction into the pedestal 50, and is engaged with and guided by a pair of eccentric cams C provided on the pedestal 50 side to be mounted in the pedestal 50. be placed.

Each of the eccentric cams C has a gear G having the same diameter, and is intermittently stopped at an angle of 1/2 rotation by rotation of a pinion P4 of a motor M4 via a rack plate R.

When the process cartridge 30 returns and the photosensor Sl is turned off, the motor M4 is started and the eccentric cam C rotates 1/2, moving the process cartridge 30 in parallel to the right in FIG. 5(, ). .

As a result, the clutch CL2 integrated with the rotating shaft 2A of the rotating roller 2 engages with the clutch CLI on the device main body side, thereby enabling power transmission.

In this embodiment, one of the clutches is equipped with a shock absorber using a compression spring or the like, and if the phases of clutch pawl engagement do not match, the clutch is temporarily retracted in the axial direction and engaged after rotation starts. The clutch is then engaged.

Although this embodiment describes a color image forming apparatus that uses a belt-shaped photoreceptor as an image carrier, the present invention can also be applied to an apparatus equipped with a drum-shaped photoreceptor or a monochrome-only apparatus. be.

〔Effect of the invention〕

The present invention employs a system in which the image carrier is directly driven by the power of the motor, and when the image carrier is attached or detached, the motor drive system can be automatically connected or disconnected, and as a result, it is possible to always A practically useful image forming apparatus has been provided which can obtain high-quality images through stable operation of the image carrier and is easy to handle during maintenance and the like.

[Brief explanation of drawings]

1 and 2 are cross-sectional configurations of a color image forming apparatus according to the present invention, FIG. 3 is a cross-sectional view of the main parts thereof, and FIGS. 4 and 5 are various parts showing the connection mechanism of the drive system in the apparatus. figure. 1... Photoreceptor belt 2... Rotating roller 2A...
Rotating shaft 6...Charger 8-11...Developer
13...Cleaning device 20...Top lid
30... Process cartridge 300... Rear board 300A... Leaf spring member CLI, CL2...
Clutch SQL... Solenoid PL... Plunger Ml-M4... Motor Pi~04... Pinion S l, S 2... Photo sensor

Claims (3)

[Claims] (1) In an image forming apparatus in which a process cartridge including an image carrier can be attached and detached in a direction perpendicular to the rotation axis of the image carrier, when the process cartridge is attached and detached, the process cartridge is attached to and detached from the drive shaft provided on the apparatus main body side. An image forming apparatus characterized in that a rotation shaft of the image carrier moves to connect and disconnect. (2) Claim (2) characterized in that the moving rotation axis is an axis movably provided with respect to the image carrier.
1) The image forming apparatus described above. (3) The image forming apparatus according to claim 1, wherein the moving rotation axis is an axis provided integrally with the image carrier.