JPH05323690A - Color image forming device - Google Patents

Abstract

PURPOSE:To easily perform jamming processing in a color image forming device using a photosensitive belt and to accurately attach/detach the photosensitive belt and a developing device which are formed to be a cartridge. CONSTITUTION:This device is a clamshell type color image forming device 50 which is opened/closed by turning an upper main body 30 centering around a common supporting shaft 41 with respect to a lower main body 40 so that the device may be divided into two, that is, the lower main body 40 and the upper main body 30. The photosensitive belt 1 and a developing device housing case C where the respective developing devices 8, 9, 10 and 11 are housed are formed to be the cartridge for the device 50. In the case of attaching the cartridge in the device 50, it is positioned with respect to a laser write system unit 7 and attached. In the case that a transfer material 44 is jammed, jamming processing is performed by opening the upper main body 30 which is opened/ closed in an up-and-down direction in a state where a carrying path 25 is set as a boundary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamshell type image forming apparatus which is divided into an upper body and a lower body, and more particularly to the structure of a color image forming apparatus using a belt-shaped image carrier.

[0002]

2. Description of the Related Art Generally, an electrophotographic image device having a structure in which a lower body and an upper body are divided into two, and the upper body is rotated around a common support shaft with respect to the lower body to open and close vertically It is called the clamshell type and is exclusively adapted to the field of small-sized popular machines.

In order to obtain a color image using the electrophotographic method, for example, a latent image is formed on the photosensitive drum in accordance with the number of separated colors of the original image and development with color toner is repeated to superpose the color image on the photosensitive drum. After that, there is a method of transferring to a transfer material to obtain a color image. The basic process for forming this multicolor image is described in Japanese Patent Application Laid-Open Nos. 60-75850, 60-76766 and 60-9 by the present applicant.
No. 5456, No. 60-95458, No. 60-158475 and the like. In a multi-color image forming apparatus which obtains a color image by such superposition, a plurality of developing devices accommodating color toners of different colors are arranged on the peripheral edge of a photosensitive drum, and in general, The body drum is rotated a plurality of times to develop the electrostatic latent image on the photosensitive drum to obtain a color image. For image formation, a belt-shaped image forming body has been proposed in which a photoconductor is coated or vapor-deposited on a flexible belt together with a photoconductor drum having a photoconductor coated or vapor-deposited on the peripheral surface of the drum. The shape of this belt-shaped image forming body (hereinafter referred to as a photoconductor belt) is determined by being stretched between rotating rollers including a driving roller, so it is very effective to use a space to compact the image forming apparatus. is there.

[0004]

In a color image forming apparatus using a photoconductor belt, facing the peripheral surface of the stretched photoconductor belt, a charging means, an image exposing means, and a plurality of developing device groups are provided. Image forming means such as a developing means, a transfer means to a transfer material, and a cleaning means are provided, and these image forming means are opposed to the rotating photosensitive belt at a constant interval. Then, the transfer material conveyed from the paper feed cassette loaded in the lower part of the image forming apparatus passes, for example, below the developing device group and a color image is transferred by the transfer means provided at one edge of the photosensitive belt. After that, the toner is fixed by the fixing means and discharged to the outside of the apparatus. However, since the transfer material transport section has an extremely narrow space because the laser writing system exposure unit and the developing device group are provided above it, the transfer material is removed if a jam occurs at this transport section or the transfer section. It is very difficult to remove. In addition, it is not preferable to remove the developing device group and the photoconductor belt from the image forming apparatus in order to maintain accuracy, and there is a drawback that it is very troublesome to repair them.

The present invention solves such a problem, for example, jam processing can be easily performed even if a jam occurs in the conveying section, and the photosensitive belt and the process unit of the developing device group are used as the exposure means of the laser writing system. An object of the present invention is to provide a color image forming apparatus that can be mounted with high precision.

[0006]

[Means for Solving the Problems]
It can be achieved by any means.

(A) A clamshell collar having a structure in which the upper body rotates about a common support shaft with respect to the lower body and is divided into two parts, the lower body and the upper body, to open and close. In the image forming apparatus, a belt-shaped image forming body stretched at least between rollers and a plurality of developing means are formed in a cartridge in the upper body, and a process cartridge is detachably mounted and a lower part of the process cartridge. Alternatively, the color image forming apparatus is characterized in that the upper main body is provided with an exposing means positioned above and the upper main body is opened upward with a transfer material conveying path provided in the lower main body as a boundary.

(B) In the color image forming apparatus of (a), the process cartridge is mounted while being positioned with respect to the exposing means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is a side sectional view showing the configuration of the clamshell type color image forming apparatus when opened and the side sectional view showing the configuration when the same color image forming apparatus of FIG. 2 is closed. Explain by and. However, the present invention is not limited to this embodiment.

As shown in FIG. 2, a clamshell type electrophotographic color image forming apparatus 50 (hereinafter simply referred to as an image forming apparatus) has a lower body 40 and a support shaft 41 common to the lower body 40.
It is divided into two parts, an upper main body 30 which is attached so as to be rotatable in the vertical direction via the and which is opened and closed.

In FIG. 2, reference numeral 1 denotes a flexible photosensitive belt which is a belt-shaped image forming body. The photosensitive belt 1 is provided between rotating rollers 2 and 3 and is driven by the rotating roller 2. Transported in the clockwise direction.

Reference numeral 4 denotes a support member, that is, a guide member, which is fixed to the main body of the apparatus so as to be inscribed in the photosensitive belt 1. The photosensitive belt 1 is tensioned by the upward mechanical action of the tension roller 5. The inner peripheral surface is rubbed against the guide member 4.

Therefore, the photoconductor on the outer peripheral surface of the photoconductor belt 1 is always kept in a constant relation position with respect to the surface of the guide member 4 even during conveyance, so that a stable image forming surface can be formed.

6 is a scorotron charger as a charging means, and 7
Is a laser writing system unit as an image exposing means, 8 to 11
Is a plurality of developing means, that is, developing devices, each containing a developer of a specific color, and these image forming means are arranged so as to face the outer peripheral surface of the photosensitive belt 1 with the guide member 4 on the back side. It

Each of the developing devices 8, 9, 10 and 11 is housed in a detachable developing device storage case C and its horizontal position is regulated, and a plurality of springs are further sandwiched on the bottom surface thereof. Due to the repulsive action of S, it is urged upward, that is, toward the photosensitive belt 1.

The photosensitive belt 1 is composed of rotating rollers 2, 3
And the tension roller 5 into a cartridge, and a developing device storage case C having a plurality of developing devices 8, 9, 10, 11
The right conveyance guide 15C, the right timing roller 17A, and the cleaning device 13 are integrated to form a process cartridge 1A indicated by a chain line, which is detachably mounted at a predetermined position of the color image forming apparatus 50. There is. The process cartridge 1A may be configured such that the cartridge for the photosensitive belt 1 and the developing device storage case C are separate units which are detachably attached to the apparatus 50.

The process cartridge 1A is positioned and attached to the laser writing system unit 7 by a known appropriate means, and is attached to the image forming apparatus with a predetermined accuracy.

For the laser writing system unit 7, an optical system in which a light emitting portion and a converging optical transmission body are integrated is used in addition to the optical system shown in the figure.

The developing units 8, 9, 10, and 11 contain, for example, yellow, magenta, cyan, and black developers, respectively, and the developing sleeves 8A, 9A, which keep a predetermined gap from the photosensitive belt 1. Equipped with 10A and 11A, it has a function of visualizing the latent image on the photosensitive belt 1 by a non-contact developing method. Unlike the contact development, this non-contact development has an advantage that it does not hinder the movement of the photosensitive belt.

Reference numeral 12 is a transfer device, 12A is a charge eliminating bar, 13 is a cleaning device, and the blade 13A of the cleaning device 13 and the toner carrying roller 13B are kept at a position separated from the surface of the photosensitive belt 1 during image formation. Only during cleaning after the transfer, the surface of the photosensitive belt 1 is pressed against the surface as shown in the drawing. The transfer path 25 for the transfer material 44 includes a U-turn guide plate 22, a U-turn transfer roller 23, a lower transfer guide 15B, a lower transfer roller 24B, a left timing roller 17, which is attached to the lower body 40.
Left transport guide 15 and upper transport guide 15 attached to the upper body 30
A, an upper conveyance roller 24A, a right timing roller 17A, and a right conveyance guide 15C. And the upper body 30
As described later, the transport guides 15A and 15C attached to the upper main body 30, the upper transport rollers 24A, and the right timing roller 17A are the transport guides 15 and 15B attached to the lower main body 40.
The lower conveyance roller 24B and the left timing roller 17 are separated from each other.

A color image forming process by the color image forming apparatus 50 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, the data obtained by the color image data input section in which the image sensor scans the original image is processed by the image data processing section to create image data, which is once stored in the image memory. Then, the image memory is taken out at the time of recording and is inputted to a color image forming apparatus 50 which is a recording unit, for example, shown in the embodiment of FIG.

That is, the color signals output from the image reading device separate from the printer are laser writing system unit 7.
Input to the laser writing system unit 7, a laser beam generated by a semiconductor laser (not shown) is rotationally scanned by a polygon mirror 7B rotated by a drive motor 7A, passes through an fθ lens 7C, and a mirror 7D. The optical path is bent by 7E, and a bright line is formed on the peripheral surface of the photoreceptor belt 1 to which electric charges have been previously applied by the charger 6 as a charging means.

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

That is, the photosensitive belt 1 is recharged by the charger 6, and then the second belt output from the signal processing section is output.
Is input to the writing system unit 7, writing is performed on the drum surface in the same manner as in the case of the first color signal described above, and a latent image is formed. The latent image is developed by the developing device 9 loaded with magenta (M) toner as the second color.

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

Reference numeral 10 denotes 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.

Further, 11 is a developing device having a black toner, and a black toner image is formed on the surface of the belt in a superposed manner by the same process. A DC or further AC bias is applied to each sleeve of each of these developing devices 8, 9, 10 and 11 to perform jumping development with a two-component developer which is a developing means, and a photoreceptor whose base is grounded. The belt 1 is designed to be developed in a non-contact manner. As the development, non-contact development using a one-component developer can be used.

The color toner image thus formed on the peripheral surface of the photosensitive belt 1 is transferred by the transfer device 12 to the transfer material 44 sent from the paper feeding cassette 14 through the paper feeding guide 15.

That is, the transfer material 44 stored in the paper feed cassette 14 is carried out by the rotation of the paper feed roller 16 so that the uppermost one sheet is carried out obliquely to the upper right, and then the U-turn guide plates 22 and U are placed.
The U-turn is carried to the left by the turn carrying roller 23 and carried to the laser writing system unit 7 and the developing device housing case C.
Below each of the conveyor guides 15A, 15B and each conveyor roller 24
After passing through the conveying path 25 formed by A and 24B, it stands by before the left and right timing rollers 17 and 17A. Then, the photosensitive belt 1 is formed by the timing rollers 17 and 17A.
The image is supplied to the transfer device 12 at the same timing as the above image formation. Further, as shown in the drawing, not only the paper feed cassette 14 but also the paper feed cassettes 14A, 14 that store transfer materials 44 of various sizes.
Transfer material 44 fed from a paper feeding stand 45 having B, 14C, etc.
In the same manner as described above, the U-turn guide plate 22 and the U-turn transport roller 23 are used to make a U-turn and the transport is performed to wait along the transport path 25 before the timing rollers 17 and 17A. The transfer material 44, which has been subjected to image transfer and charge removal, is reliably separated from the photoconductor belt 1 that suddenly changes its direction along the rotating roller 2 and moves upward, and after the image is fused by the fixing device 18, the paper discharge roller. It is discharged via tray 19 onto tray 20.

On the other hand, the photosensitive belt 1 which has finished the transfer to the transfer material 44 is further conveyed and the residual toner is removed by the cleaning device 13 in which the blade 13A and the toner supply roller 13B are in pressure contact with each other, and the end thereof is completed. Then, the blade 13A is separated again, and a little later, the toner supply roller 13B smoothes the toner accumulated on the tip of the blade 13A, and then the toner supply roller 13B is separated to start a new image forming process.

Then, the color image forming apparatus 50 shown in FIG.
As shown in FIG.
And a developing device storage case C in which the developing devices 8, 9, 10, 11 are stored, a right transport guide 15C, and a right timing roller 17
A, a process cartridge 1A including a cleaning device 13, a charger 6, a laser writing system unit 7, an upper conveyance guide 15A and an upper conveyance roller 24A attached to a main body frame (not shown) of the upper main body 30. The cleaning device 13 is configured to open and close upward and downward with the support shaft 41 as a center, and the cleaning device 13 is located below when the support shaft 41 is opened. The lower main body 40 has at least the paper feed cassette 14 and the transfer material 44.
The U-turn guide plate 22, the U-turn transport roller 23, the lower transport guide 15B and the lower transport roller 24B, the left timing roller 17, the transfer device 12, the fixing device 18, the discharge roller 19 and the like are provided. There is.

Therefore, in the clamshell type image forming apparatus 50 according to the present invention, the right timing roller 17A, the right conveying guide 15C, the upper conveying guide 15A attached to the upper main body 30 which is the conveying means including the conveying path 25 of the transfer material 44, The upper transport roller 24A is divided at the lower transport guide 15B attached to the lower body 40 and the lower transport roller 24B so that the transport path 25, the transport means, and the transfer device 12 are opened when the upper body 30 is opened. Is becoming

When the color image forming apparatus 50 is maintained or jammed, for example, the upper main body 30, which is opened by pivoting upward through the support shaft 41, is an expandable hydraulic type provided on both sides of the apparatus 50. An arm (not shown) opens and holds the lower body 40 at a predetermined interval.

If a transport jam occurs in the transport path 25 or the transfer device 12, as described above, the upper main body 30
After holding the opening of the
Take out. Therefore, since the transport path 25 and the transfer device 12 are opened and exposed, the jam processing can be performed extremely easily. Further, since replacement of the photosensitive belt 1 at the time of maintenance is made into a cartridge, it can be easily attached and detached in the left direction (or may be the direction perpendicular to the paper surface) shown by the arrow in FIG. 1 and the process cartridge 1A is a laser writing system unit. Since the process cartridge 1A is positioned with respect to 7, the process cartridge 1A can be mounted very easily and accurately.

[0036]

As described above, according to the present invention, the clamshell type color image forming apparatus using the photoconductor belt is divided into an upper main body and a lower main body with the transfer material conveying path as a boundary. Since the upper main body is opened and closed vertically with respect to the lower main body, conveyance jam of the transfer material can be handled very easily and at the same time as the laser writing system unit as a process cartridge in which the photosensitive belt and the developing device group are integrated. Since they are positioned and mounted, they can be easily mounted with high accuracy even if they are removed during maintenance, for example.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a configuration of a clamshell type color image forming apparatus according to an embodiment of the present invention when opened.

FIG. 2 is a side sectional view showing the configuration of the above color image forming apparatus when it is closed.

[Explanation of symbols]

 1 Photoconductor Belt 1A Process Cartridge 6 Charging Device 7 Laser Writing System Unit 12 Transfer Device 13 Cleaning Device 14 Paper Feed Cassette 15 Left Transport Guide 15A Upper Transport Guide 15B Lower Transport Guide 17 Left Timing Roller 17A Right Timing Roller 18 Fixer 24A Upper Transport roller 24B Lower transport roller 25 Transport path 30 Upper body 40 Lower body 41 Spindle 44 Transfer material 50 Color image forming device C Developing device storage case

Claims (2)

[Claims] 1. An upper body is rotated around a common support shaft with respect to a lower body, and the upper body and the lower body are connected to each other.
A clamshell type color image forming apparatus having a structure in which it is divided into two and opened and closed, wherein a belt-shaped image forming body stretched between at least rollers and a plurality of developing means are formed into a cartridge in the upper main body. A process cartridge detachably attached to the process cartridge, and an exposure unit located below or above the process cartridge, and the upper main body is opened upward with a transfer material conveyance path provided in the lower main body as a boundary. A color image forming apparatus characterized by the above. 2. A color image forming apparatus according to claim 1, wherein the process cartridge is mounted while being positioned with respect to the exposing means.