JPH04106557A - Color image forming device - Google Patents

Abstract

PURPOSE:To attach and detach a process cartridge without dividing a device into two parts and opening a clover by taking out a process cartridge to the side opposite to a transfer part, and engaging with gears provided on plural developing units with respective driving gears disposed on the straight line of a main body side at the time of attachment to a main body. CONSTITUTION:A photosensitive belt 1, an electrifying unit 6, respective developing units 8, 9, 10, and 11, and a cleaning device 13 are integrally incorporated in an independent process cartridge 30, and further, slidably inserted into the device from a specific direction and attached. Simultaneously with the attachment, respective gear groups connected with, first, the photosensitive belt 1 and respective developing units are engaged with respective gears of the driving system of a device main body, to obtain an operable state. In other words, a gear 2G integrated to a turning roller 2 turning a gear 8GA or 11GA and the photosensitive belt 1, is engaged, to obtain a state where electric power can be transmitted. When the cartridge 30 is taken out, a knob 30A is held and pulled out to the side opposite to the transfer part of an image in the state where a cover 35 is released, and a releasing lever is pushed down, so that the cartridge 30 is easily taken out from the device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic color image forming apparatus for forming an image on a transfer material such as a copying machine or a printer.

[Background of the invention]

In image forming devices such as monochrome analog copying machines using electrophotography and copying machines and printers using semiconductor laser and LED scanning systems, various photoreceptors, developer carriers, cleaning members, and developer toners that have a long service life are used. A part of the image forming means is made into a cartridge for replenishment and replacement when worn out, etc., and a member integrating the main parts of the image forming means is taken out of the apparatus for maintenance or replacement. something is proposed. 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.

A typical configuration of these is as disclosed in Japanese Patent Publication No. 58-54392, in which the photoreceptor drum, developer, cleaner, etc. are integrally attached to a support member, and can be pulled out from the main body of the apparatus, and each unit is Proposals have been made to make replacement and repair easier, and the next step was to integrate the main parts of these image forming means and make them disposable in Japanese Patent Laid-Open No. 57-15.
4255, and Japanese Patent Laid-Open No. 147366/1989 discloses a printer configuration that uses a similar disposable cartridge and forms a latent image on a photosensitive drum by dot exposure scanning writing using a semiconductor laser. There is.

Further, these publications disclose a configuration in which the upper housing of the divided structure is opened to open the transfer material conveyance path and take out the transfer material in the event of a jam, and the above-mentioned Japanese Patent Application Laid-Open No. 57-154255 , a configuration is adopted in which a disposable process cartridge is replaceably disposed in an upper housing having a two-part structure, and attempts are made to improve the workability of cartridge replacement and ease of jam removal. In addition, with emphasis on ease of replacement of process cartridges, mainly replenishment toner cartridges and recovery toner relining cartridges, the structure is divided into two parts. A method with improved properties is disclosed in JP-A-58-1161.

In addition, the above structure is made vertical, and JP-A-63-2
No. 44058, No. 63-244059, No. 63-24
No. 4064, JP-A-17916. This has been proposed in Publication No. f, etc., and is aimed at improving the same direction operation and jam handling.

[Problem that the invention seeks to solve]

However, when attaching and detaching the process cartridge from the main body of the apparatus, as mentioned above, the apparatus is divided into two parts, so that the cartridge insertion/ejection opening can be opened and closed, and at the same time, the drive that connects to the photoconductor and developer that make up the cartridge is required. It is necessary to be able to easily and reliably engage and disengage the gears of the system as the cartridge is inserted and removed, which makes the main body structure complicated and the handling operations difficult.

The present invention solves this problem and improves it, and aims to provide an image forming apparatus in which a process cartridge can be easily and reliably attached and detached without having to open the lid of the apparatus in a two-part structure. be.

[Means for solving problems]

The above object is to provide a color image forming apparatus in which a process cartridge including at least an image bearing member and a plurality of developing devices is removably installed, in which the process cartridge can be taken out on the side opposite to the transfer section, and the process cartridge can be removed from the transfer section. This is achieved by a color image forming apparatus characterized in that, when installed in the apparatus main body, the gears provided on each of the plurality of developing units mesh with respective driving gears disposed on a straight line on the main body side.

[Tora example]

An embodiment of the color image forming apparatus of the present invention is shown in FIGS. 1 to 4.

In FIG. 1, reference numeral 1 denotes a flexible photoreceptor belt serving as a belt-shaped image carrier. The photoreceptor belt 1 is installed between rotating rollers 2 and 3, and is rotated clockwise by the rotational roller 2. transported to.

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 1, and the photoreceptor belt 1 is brought into a tensioned state by the outward biasing action of the rotary roller 3. The inner peripheral surface of the guide member 4
Let it rub.

Therefore, the photoreceptors on the outer circumferential surface of the photoreceptor belt 1 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.

The laser writing system unit 7 is housed in a holding casing 7o having a slit-shaped exposure opening 70A on its upper surface, and is incorporated into the main body of the apparatus.

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 includes developing sleeves that maintain a predetermined gap from the photosensitive belt 1 (photosensitive belt). It has the function of making the latent image on the image visible using 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 elimination bar; 13 is a cleaning device; the blade 13A and toner conveying roller 13B of the cleaning device 13 are kept at a position apart from the surface of the photoreceptor belt l during image formation; and cleaning after image transfer is performed. Only when the photoreceptor belt 1 is pressed against the surface of the photoreceptor belt 1 as shown in the figure.

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 input to 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, the laser writing system unit 7 outputs a laser beam generated by a semiconductor laser (not shown). is rotated and scanned by a polygon mirror 7B rotated by a drive motor 7A, and passes through an fθ lens 7C to mirrors 7D and 7E.
, 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 over 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 l by the main scanning by the laser beam and the sub-scanning by the conveyance of the photoreceptor belt l-1. This latent image is created using yellow (Y) toner (
The toner image is developed by the developing device 8 loaded with a developing medium (developing medium), 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 l is charged again by the charger 6, and then the second color signal outputted 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.

A developing device 10 has cyan (C) toner, and 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 devices 8, 9゜lO 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 l 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 l. supplied to.

The transfer material that has undergone image transfer and static electricity removal is transferred to the rotating roller 2.
It is reliably separated from the photoreceptor belt 1, which suddenly changes direction along the direction of the photoreceptor belt 1, and heads upwards via the photoreceptor belt 17A, where the image is fused by the fixing roller 18, and then passed through the paper ejection roller 19 to the upper lid 20. The paper is discharged onto a tray formed on the tray.

On the other hand, the photoreceptor belt l, which has completed the transfer to the transfer material, continues to be roughly 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 after the cleaning was finished, the blade 13A was separated again, and a little later, the toner conveying roller 13B leveled the toner accumulated on the tip of the blade 13A. Afterwards, the toner conveying roller 13B is separated and a new image forming process begins.

The photoreceptor belt 1, the charger 6, each developing device 8°9,
10.11 and the cleaning device 13 are assembled and integrated into an independent process cartridge 30, and are inserted and mounted inside the device by sliding from the direction indicated by the dashed line.

That is, the process cartridge 30 has a rail member 3 having a convex cross-sectional shape on both sides thereof, as shown in FIG.
1, and is attached to the device by being inserted into and engaged with a guide member 32 having a concave cross-sectional shape built inside the device.

The process cartridge 30 is attached to the rail member 31 @m
The mounting position is determined by the contact of the rail member 31A with the guide member 32, and at the same time, the notch 31B of the rail member 3I is provided on the main body side and is fixed by engaging with the top 33A of the locking plate 33. Each built-in process material is set at a position that enables image formation.

Furthermore, at the same time that the process cartridge 30 is installed inside the apparatus, each group of gears connected to each developing device, including the photoreceptor belt 1, meshes with each gear of the drive system of the main body of the apparatus and becomes ready for operation. Ru.

FIG. 3 shows the arrangement of each gear group as seen from the back of the device, and FIG. 4 shows the main parts thereof as viewed from arrow A.

In the figure 8GA, 9GA, 10GA and 11G
A is a developing sleeve 8A, 9A built in each developing device,
10A8 and IIA coaxial gears of equal diameter, and 8
GB and 8GG, 9GB and 9GC, l0CB and l OGG
And IIGB and 1IGC are a pair of stirring screws 8B and 8C, 9B and 9C, IOB and IOc built in each developing device.
and llB and 11c are coaxially provided gears, both of which have the same diameter.

The gears 8GA to IIGA and the gears 8GO to IIGc are at different positions in the axial direction and do not mesh with each other, but only with the gears 8GB to IIGB.

Meanwhile, CIA, G2A, G3A and G4A as well as G5
are gears for output of the drive system provided on the main body side of the apparatus, and when the process cartridge 30 is attached to the main body, the gears 8GA to IIGA and the rotation roller 2 for rotating the photoreceptor belt 1 are integrated. The gears 2G are brought into mesh and the power can be transmitted.

As shown in FIG. 84, the teeth IE GIA to G4A are coaxially integrated with gears GIB, G2B, G3B and G4B of equal diameter through electromagnetic clutches C, respectively.

Each of the gears GIB to G4B is an intermediate gear 11 with the same diameter.
, ]2 and I, and is connected to a drive gear DC coaxially with the intermediate gear I2.
are rotated all at once in the same direction by the rotation of the pinions P.

Therefore, by switching the electromagnetic clutch C from the OFF state to the ON state, the gears GIA, G2A,
Either G3A or G4A rotates, and the specified developing devices in mesh with the G3A or G4A are sequentially operated to perform the above-mentioned color image development.

Here, each of the above-mentioned developing units is arranged along the circumferential surface of the photoreceptor belt, and therefore, each of the above-mentioned gears 8GB to IIGB is arranged in an arc shape, so that the sliding surface for inserting the process cartridge 30 is When used as a standard,
It is possible to arrange the gear 8GB at the lowest position and sequentially provide appropriate steps S so that the gear 11GB occupies the highest position.

As a result, even if the gears 8GB to IIGB are arranged in a straight line and housed in the same vertical plane as shown in FIG. Gear 8GB and tooth 1GI without interference and in the installed position
A, gear 09B,! : Gear G2A, gear 10GB and gear G3A, and gear 11GB and gear G4A can be meshed or disengaged smoothly and accurately.

On the other hand, when removing the process cartridge 3o,
The locking plate 33 has a part thereof as a release lever 33B that protrudes to the side of the cartridge, and the release lever 33B
By pushing down the locking plate 33, the tension spring 34
can be evacuated downward against the urging force.

Therefore, when the process cartridge 30 is opened, the cover 35 is opened and the release lever 33B is pressed down.
It can be easily taken out from the apparatus by pulling it out to the side opposite to the image transfer section using the handle.

Note that once the process cartridge 30 is removed, the transfer material conveyance path and the upper part of the apparatus are both opened by simply opening the relatively small upper cover 20, making it easy to perform jam removal and other tasks. .

Furthermore, replenishing toner in the toner replenishing section 21 can be done by simply opening the small top cover 22, making the task extremely simple.

〔Effect of the invention〕

The present invention makes it possible to easily attach and detach the process cartridge while extremely simplifying the structure of the device.As a result, maintenance of process materials and removal of jams in transfer materials can be performed easily and quickly. As a result, a color image forming apparatus that is easy to handle and can always produce high-quality images has been provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus of the present invention, FIG. 2 is a perspective view of the main parts thereof, and FIGS. 3 and 4 are arrangement diagrams of drive system gears and side views of the main parts thereof. l... Photoreceptor belt 6... Charger 8-11...
・Developer 8A-11A...Developer sleeve 8B-
11B, 8C-11C... Stirring screw 13...
Cleaning device 30... Process cartridge 31... Rail member 32... Guide member 33
...Latching plate 35...Cover 8GA-II
GA, 8GB-11Gc, 8GC-11Gc...(
Process cartridge side) Gear

Claims (1)

[Scope of Claims] A color image forming apparatus in which a process cartridge including at least an image carrier and a plurality of developing devices is removably provided, wherein the process cartridge is removable on the side opposite to the transfer section, and the process cartridge A color image forming apparatus characterized in that, when the apparatus is mounted on the apparatus main body, the gears provided on each of the plurality of developing devices mesh with respective driving gears disposed in a straight line on the main body side.