JPH03156471A - Color image forming device - Google Patents

Abstract

PURPOSE:To improve workability in processing for jamming and maintenance, etc., by opening the side cover of the device and opening a paper feeding conveyance path for recording paper. CONSTITUTION:A photosensitive belt 1 is laid between turning rollers 2 and 3 and plural developing devices 8-11 are provided below the belt 1. A color toner image formed on the circumferential surface of the belt 1 is transferred to a transfer material fed from a paper feeding cassette 14 through a paper feeding guide 15 in a transfer part. In such a case, the paper feeding part and a fixing part for the transfer material have such structure that they can be opened at any time. Namely, either member of the paper feeding guides 15, a timing roller pair 17, a fixing roller pair 18 and a paper ejecting roller pair 19 and a transfer device 12 are attached and supported to the side cover 50 which can be opened by taking the rotary shaft 50A of a device main body as a fulcrum. Thus, the processing for jamming of the transfer material and the maintenance operation are easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a color image forming apparatus that forms a toner image on a body and transfers it onto a transfer material to obtain an image.

[Background of the invention]

There are many ways to obtain color images using electrophotography.
A device has been proposed. For example, Japanese Patent Publication No. 61100770
As disclosed in the publication, a latent image is formed and developed on a photosensitive drum, which is an image carrier, according to the number of separated colors of the original image, and is transferred onto a transfer drum each time it is developed. There is a method of forming a multicolor image and then transferring it onto recording paper to obtain a color copy. A device using this method requires a transfer drum large enough to transfer one sheet of image onto its circumferential surface in addition to the photoreceptor drum, and the device does not have a large and complicated structure. Inevitable.

For example, as disclosed in Japanese Patent Laid-Open No. 61-149972, a latent image is formed and developed on a photoreceptor drum according to the number of separated colors of the original image, and is transferred onto a transfer material each time it is developed. This is a method of obtaining multicolor copies. With this method, it is difficult to overlap multicolor images with high precision, and it is impossible to obtain high-quality color copies.

Another method is to repeatedly form a latent image on a photoreceptor drum according to the number of separated colors of an original image and develop it with color toner, and then overlap the color toner images on the photoreceptor drum and then transfer the images to obtain a color image. The basic process of forming a multicolor image is disclosed in Japanese Patent Application Laid-open No. 60-75850 and No. 60-7 by the present applicant.
No. 6766, No. 60-95456, No. 60-9545
No. 8, No. 60-158475, etc.

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

As for image forming bodies, as explained above, there are photosensitive drums with a photoconductor coated or vapor-deposited on the circumferential surface of the drum, and belt-shaped image forming bodies with a photoconductor coated or mounted on a flexible belt. has also been proposed. The shape of the belt-shaped image forming body (hereinafter also referred to as a photoconductor belt) is determined by stretching it between rotating rollers including a drive roller, so it is possible to effectively utilize space and create a compact color image forming apparatus. It is effective when configured. Also, since the photoreceptor belt can run along a small curvature,
By using a rotating roller with a small diameter and separating the transfer material using this curvature, it is also possible to prevent poor separation of the transfer material.

Also, JP-A-63-244059, JP-A No. 63-2440
In an image forming apparatus using a process cartridge cartridge disclosed in Publication No. 64, etc., a structure in which the conveyance path is divided when handling a jam has been proposed, but it is difficult to separate the wiring of the fixing section or the main unit of the fixing section. Due to the split structure, there were many difficulties in manufacturing the device and in terms of user operation.

[Purpose of the invention]

In order to limit the height of the apparatus, such a photoreceptor belt is stretched horizontally flat, and image forming means such as developing devices are arranged in parallel on the underside of the photoreceptor belt. .

The aforementioned photoreceptor belt and developer group are each housed as a unit in the main body of the apparatus, and the paper feed cassette for storing the recording paper can also be stored in a stacked state using the space below them. In image forming apparatuses that use such photoreceptor belts, the paper feed and conveyance path for recording paper is often formed vertically from bottom to top on the side of the main body of the apparatus. The structure is such that it is not possible to open the paper feed conveyance path just by taking it out, which poses problems in the workability of jam removal and maintenance.

The present invention solves this problem and improves it by opening the side cover of the apparatus to open the paper feeding and conveying path of the recording paper. The object of the present invention is to provide a color image forming apparatus in which a unit is configured to be horizontally attachable to and detachable from an apparatus main body.

[Structure of the invention]

The above purpose is to supply transfer material to a color image forming apparatus that includes a belt-shaped image forming body stretched between rollers located in the horizontal direction, and a plurality of developing devices located below the belt-shaped image forming body. This is achieved by a color image forming apparatus characterized in that the feeding and fixing section is also preferably openable, and the process unit having the belt-shaped image forming body is detachable in the opening direction.

〔Example〕

Embodiments of the color image forming apparatus of the present invention are shown in FIGS. 1 to 7.

In FIG. 1, ■ is a flexible photoreceptor belt with a belt-like image forming body, and the photoreceptor belt 1 is installed between rotating rollers 2 and 3, and is clocked by driving of the rotating roller 2. conveyed in the direction.

Reference numeral 4 denotes a 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 action of the tension roller 5, so that its inner circumferential surface is kept in the predetermined range. The guide member 4 having a curvature is made to rub. Note that the guide member 4 is provided with a recessed portion in an area unnecessary for image formation to reduce resistance due to rubbing. Of course, this recess does not need to be provided if the sliding resistance is low. In addition, in order to reduce the sliding resistance between the photoreceptor belt l or the guide member 4, a low-friction member such as Teflon coating is provided on the surface of either the photoreceptor belt l or the guide member 4, or the low-friction member is made of the above-mentioned low-friction member. It is preferable to do so.

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.

Further, by providing the developing device and the cleaning device below the photoreceptor belt, it is possible to prevent the developer from scattering or spilling.

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 each containing a developer of a specific color. The means is disposed on the photoreceptor belt l at a position facing the guide member 4. In order to maintain a gap without interfering with the movement of the photoreceptor belt (l), the guide member 4 is brought into contact with the guide member 4 on the outside of the photoreceptor belt (l) with a gap retaining means.

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 devices 8.9.10.11 accommodates, for example, yellow magenta, cyan, and black developers, respectively, and each developing sleeve 8A, 9A, 1OA, IIA maintains a predetermined gap with the photoreceptor belt 1. It has a function of visualizing the latent image on the photoreceptor belt l 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 elimination bar, 13 is a cleaning device, and a blade 13A and a toner conveying roller 13B of the cleaning device 13 are connected to the photoreceptor belt l 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 image forming system shown in FIG. In other words, the color image data input section (Figure 2 (a)) where the image sensor scans the original image.
) is processed by the image data processing unit (Figure 2 (b)) to create image data, which is then stored in the image memory (Figure 2 (c)). . Then, the image memory is taken out at the time of recording and sent to the recording section (FIG. 2 (d)).
For example, the image data is input to 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.
The optical path is bent by this, and the light is projected onto the circumferential surface of the photoreceptor belt 1, which has been charged in advance by a 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 is transmitted to the photoreceptor bell l-1.
scan the circumferential surface of the 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. This latent image is created using yellow (Y) toner (
A toner image is formed on the belt surface by reversal development in a non-contact state by the developing device 8 loaded with a developing medium (developing medium).

The obtained toner image, while being held on the belt surface, passes under a cleaning device ft13, which is a cleaning means, which is separated from the circumferential surface of the photoreceptor belt l, and enters the next copy cycle.

That is, the photoreceptor bell I-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 above-mentioned first color signal is Writing is performed on the drum surface in the same manner as in the case of the drum surface, and a latent image is formed. The latent image is reversely developed in a non-contact manner by a developing device 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.

Further, It is a developing device having black toner,
A similar process is used to form a black toner image superimposed on the drum surface. These developing units 8°9, to and 1
DC or AC bias is applied to each sleeve of 1, and jumping development is performed using an l-component or two-component developer as a developing means, and a non-current is applied to the photoreceptor belt l whose base body is grounded. Developing is now done by contact.

The color toner image thus formed on the circumferential surface of the photoreceptor bell l-1 is transferred to the transfer material fed through the paper feed guide 15 from the paper feed force sensor 1-14 in 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 charge removal is reliably separated from the photoreceptor belt l, which suddenly changes direction along the rotating roller 2, without being affected by image quality such as toner scattering due to the charge removal effect. After the image is fused by the fixing roller 18, the sheet is discharged onto the tray 20 via the discharge roller 19.

On the other hand, the photoreceptor belt l, which has completed the transfer to the transfer material, continues to be transported, and the cleaning device 13, in which the blade 13A facing the rotating roller 3 and the rotating toner transport roller 13B are brought into pressure contact, removes the remaining toner. After the removal is completed, the blade 13A is separated again, and a little later, the toner conveying roller 13B is separated and a new image forming process begins.

The transfer material feeding section and the fixing section in the main body of the apparatus are structured so that they can be opened at any time, thereby making it easy to clear jams of the transfer material and perform maintenance work.

That is, the paper feed guide 15 and the timing roller 17
, one member of the multiple pairs of the fixing roller 18 and the paper ejection roller 19 and the transfer 512 are connected to the rotating shaft 50A of the apparatus main body.
The installation is supported by a horizontal cover 50 that can be opened counterclockwise at right angles with A structure is adopted in which the member is moved and retracted from the position shown by the dashed line to the position shown by the solid line, thereby completely opening the transfer material feeding and conveying section.

On the other hand, the image forming means of the photoreceptor belt 1, guide member 4, and cleaning device 13 are incorporated into a process unit 30 consisting of front and rear substrates 3OA and 30B, as shown in FIG. It is attached and detached.

As described above, since the process unit is flat, it is easy to attach and detach the process unit from the supply/removal section.

The cartridge 30 integrates the front and rear substrates 3OA and 30B via the guide member 4 and two stays 31, and holds the image forming means therebetween, and is attached to and detached from the main body of the apparatus.

The process unit 30 further includes front and rear substrates 30A.
A rail member 32 having a convex rail 32A is provided on the outer surface of the lateral cover 30B. It is attached by sliding it on.

FIG. 4 shows the arrow A A 'I of the process unit 30.
This figure shows the fr side, and a groove portion 34 (indicated by a dashed dashed line) forming a concave guide groove that engages with the rail 32A of the rail' member 32 is installed in the main body of the device. By engaging the rail member 32 with the member 34, the process unit 30 is installed in the apparatus main body and fixed in a predetermined position by the action of a locking member (not shown). Note that this process unit is covered with a protective cover 38 except for the charging, exposure, image, and transfer parts necessary for image formation. Furthermore, in the transfer section, it is preferable to provide a protective cover 38A integrally with the process unit, which closes and opens in conjunction with the opening and closing operations of the paper feed section.

Note that the guide piece 15A forming the upper part of the paper feed guide 15
is mounted and supported on the process unit 30 side, and is attached to and detached from the main body of the apparatus integrally with the process unit 30.

Further, each of the developing devices is integrated into a developing container 41, which is formed of a flexible member at the joint portion thereof, as shown in FIG. The developing device unit 40 is mounted on and removed from the main body of the apparatus. Each developer unit can also be configured independently.

The developing container 41 has a plurality of compression springs 43 disposed in the front and back direction sandwiched between the bottom surface corresponding to the developing devices 8 and 11 and the supporting base 42, so that the circumferential surfaces of the developing sleeves are in contact with each other. The curvature of the curved surface formed by the guide member 4
The photoreceptor belt 1 is stored in the main body of the apparatus in a state in which it is locked by the claw portion 42A so that the curvature is smaller than the curvature of the image forming surface of the photoreceptor belt 1 formed by the above.

The developing unit 40 further includes a pair of engagement pins P on the right side of the support base 42 and a pair of cam surfaces C on the left end of the bottom surface at appropriate intervals in the depth direction.

The developing unit 40 is housed in the main body of the apparatus before the process unit 3o is installed, and the retaining pin P is engaged with the hole of the guide plate 44 in the main body, and the cam surface C is connected to the corresponding pressure contact plate 45. It is supported by being placed on the upper rollers 46.

Next, the process unit 3o is attached, and the horizontal cover 5
0 clockwise to close the lid, the correction pressure contact plate 45 moves to the right under pressure from the inner wall of the horizontal cover 50, and the rollers 46 push up the cam surface C, causing the developer unit 40 to close. is moved to the process unit 3° side.

In the image forming unit 40, each developing unit pushes the respective developing sleeve onto the photoreceptor belt by the abutting action of well-known abutting rollers under the action of the compression spring 43.
It is possible to form a predetermined development interval by applying force to the surface.

Furthermore, when the process unit 30 is removed from the apparatus main body, when the horizontal cover 50 is opened, the pressing action on the pressure contact plate 45 is released, so that the pressure contact plate 45 is pressed against the tension spring 4.
7 returns to the left, and the developing unit 40 is retracted downward by its own weight.

Therefore, the contact relationship of each developer with respect to the photoreceptor bell I-1 is released, and the process unit 30 is moved to the developer unit 40.
It can be removed from the device body without interfering with the device.

FIG. 7 shows a color image forming apparatus in which a process unit and a developing unit are integrated and configured to be attached to and removed from the apparatus body at the same time, and the present invention can of course be applied to such an apparatus. It is.

By opening the horizontal cover 150, the transfer material feeding and conveying section is opened, and even a large process unit 130 containing a developing device can be attached to and detached from the main body of the apparatus using the opening.

In this case, the process unit 130 can incorporate the charger 106, and the guide piece 115A on the upper part of the paper feed guide +15, including the timing roller 117A, is mounted and supported on the process unit 130 side.

〔Effect of the invention〕

The present invention has a structure in which one side of the main body of the device can be opened and closed, thereby making it extremely easy to handle troubles that occur in the paper feed conveyance section, such as taking out and removing jammed transfer material. A collar @ image forming device with an extremely simple structure that makes it possible to easily and safely attach and detach each image forming means such as a belt-shaped image forming body and a plurality of developing unit groups to and from the main body of the device by using the opening. It was decided to provide the following.

[Brief explanation of the drawing]

1 and 7 are cross-sectional configuration diagrams of a color image forming apparatus of the present invention, and FIG. 2 is a block diagram showing an image forming system.
3 and 4 are front and cross-sectional views of the process unit housed in the apparatus, FIG. 5 is a front view of the developing unit, and FIG. 6 is an explanation showing how each unit is installed. figure. 1.101... Photoreceptor belt 4, 104... Guide member 6.106... Charger 7.107... Laser writing system unit 8.9.10
．． 1! , 108.109.11O, 111...Developer 12.112...Transfer device 13.113...Cleaning device 14.114...Paper feed cassette 15.115...
Paper feed guide 16,116...Paper feed roller 17,117...Timing roller 18,118...Fixing roller 19,119...
Paper discharge roller 30.130...Process unit 32...Rail member 32A...Rail 34...Groove member 40...Developer unit 42...
Support stand 43... Compression spring 44... Guide plate 45... Pressure plate 46... Roller
47...Tension spring 50.150...Horizontal cover 5OA, 150A...Rotating shaft P...Engagement pin C...Cam surface (A) (B) (C) (D)

Claims (3)

[Claims] (1) Transfer material feeding section of a color image forming apparatus having a belt-shaped image forming body stretched between rollers positioned in the lateral direction, and a plurality of developing devices positioned below the belt-shaped image forming body. 1. A color image forming apparatus characterized in that the belt-like image forming body can be opened, and the process unit having the belt-like image forming body can be attached and detached in the opening direction. (2) The color image forming apparatus according to claim 1, wherein the fixing section is openable together with the transfer material feeding section. (3) The color image forming apparatus according to claim 1, wherein the process unit can be taken out after releasing the contact relationship between the belt-shaped image forming body and the plurality of developing devices.