JPH04321058A - Image forming device - Google Patents

Abstract

PURPOSE:To automatically connect a bias power source with a developing device which is formed as a cartridge in accordance with the loading of a cartridge without using a connector and also arranging a lot of wiring. CONSTITUTION:Each fixed armatures 80, 90, 100 or 110 for connecting with each developing sleeve 8A, 9A, 10A or 11A for each developing devices 8, 9, 10 or 11 are installed on the outer surface of a process cartridge 30, meanwhile, each movable armatures 80A, 90A, 100A or 110A corresponding to the each fixed armatures are arranged on the inner surface of the panel of a device main body, and by pressing each fixed armatures in contact with the movable armatures by loading the process cartridge 30, a bias voltage is impressed on each developing device by the power source part of the device through the armature device.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus in which process materials for image forming, including an image carrier, are integrated into a cartridge and can be attached to and removed from the cartridge.

0002

2. Description of the Related Art As an apparatus for obtaining color images by electrophotography, a latent image is formed on a photoreceptor drum or a photoreceptor belt in accordance with the number of separated colors of an original image, and development with color toner is repeated. There is a method of superimposing color toner images on a drum or belt and then transferring them to obtain a color image. The basic process of forming multicolor images is disclosed in Japanese Patent Application Laid-open Nos. 60-75850, 60-76766, 60-95456, 60-95458, and 60-95458 by the present applicant.
This is disclosed in Japanese Patent No. 0-158475 and the like.

[0003] In a multicolor image forming apparatus that obtains a color image by superimposing the images, a plurality of developing devices containing different colored toners are arranged around the periphery of the photoreceptor. Generally, a photoreceptor is rotated multiple times to develop a latent image on the photoreceptor to obtain a color image.

[0004] 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 which have a useful life when they are exhausted. A structure has been proposed in which a member that integrates the essential parts of these image forming means is taken out of the apparatus 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. moreover,
In digital image forming apparatuses, a laser writing system is used as a means for forming a latent image on a photoreceptor, but the laser writing system is also unitized to facilitate cleaning and inspection. An image forming device with a clamshell structure has been proposed, which can be separated into two parts by opening the top and bottom, and can be housed in a separate detachable manner to facilitate the above-mentioned maintenance and disposal of jammed paper. has been done.

[0005]

[Problems to be Solved by the Invention] In such an apparatus in which the photoreceptor and the developing means are made into a cartridge, when the cartridge is attached or removed, the power system for the photoreceptor from the drive source or power source of the apparatus main body and the bias power supply circuit for the developing means must be connected. It is necessary to connect or separate them each time.

Regarding the power system for the photoreceptor, an extremely simple means is used in which the drive gear on the device main body side and the driven gear on the cartridge side are automatically engaged and disengaged in accordance with the insertion and removal of the cartridge. In this case, a connector must be installed between the device main body and the cartridge, which requires a large amount of wiring and wiring work on both the device main body side and the cartridge side. The present invention solves and improves this point, and as a result, does not use a connector, therefore does not require wiring or any work for that purpose, and by installing an extremely simple contact device, the bias power circuit for the developing means can be adjusted according to the attachment and detachment of the cartridge. The object of the present invention is to provide an image forming apparatus that can be automatically opened and closed.

[0007]

[Means for Solving the Problems] The above object is to provide a process cartridge which includes a belt-shaped photoreceptor and at least a developing means provided at its peripheral portion in a removable manner to an apparatus main body having an integral structure. An image forming apparatus, wherein a bias power supply to the developing means is connected by sliding and pressing a movable contact piece and a fixed contact piece provided between the apparatus main body and the process cartridge. achieved by.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention is shown in FIGS. 1 to 4.

In FIG. 1, reference numeral 1 denotes a flexible photoreceptor belt which is a belt-like image forming member. is transported clockwise.

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;
The photoreceptor belt 1 is brought into a tensioned state by the outward biasing action of the rotary roller 3, so that its inner circumferential surface slides against the guide member 4. Therefore, the photoreceptor belt 1
The photoreceptor on the outer circumferential surface of the photoreceptor is always maintained at a constant position relative to the surface of the guide member 4 during transportation, making it possible to form a stable image forming surface.

6 is a scorotron charger as a charging means; 7
8 to 1 are laser writing system units serving as image exposure means;
Reference numeral 1 denotes a plurality of developing means, that is, developing devices, each containing a developer of a specific color, and each of these image forming means is arranged opposite to the outer circumferential surface of the photoreceptor belt 1 with the guide member 4 as its back surface. will be established.

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, and 11 accommodates, for example, yellow, magenta, cyan, and black developers, respectively, and is provided with each developing sleeve that maintains a predetermined gap from the photoreceptor belt 1. It has a function of making the latent image on the photoreceptor belt 1 visible 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.

Reference numeral 12 denotes a transfer device, 12A denotes a charge eliminating bar, and 13 denotes a cleaning device, in which a blade 13A and a toner conveying roller 13B are kept at a position apart from the surface of the photoreceptor belt 1 during image formation. It is pressed against the surface of the photoreceptor belt 1 as shown in the figure only during post-transfer cleaning.

The color image forming process 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 temporarily 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, color signals outputted from an image reading device separate from the printer are transmitted to the laser writing system unit 7.
In the laser writing system unit 7, 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, passes through an fθ lens 7C, and then is transmitted to a mirror 7D and The photoreceptor belt 1 has its optical path bent by 7E and 7F and is charged in advance by a charger 6 serving as a charging means.
is projected onto the circumferential surface 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 1. 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 yellow (Y) in the developing means.
The toner (developing medium) is developed by the developing device 8 loaded with the toner (developing medium), and a toner image is formed on the belt surface. The obtained toner image, while being held on the belt surface, passes under a cleaning device 13, which is a cleaning means, which is separated from the peripheral 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 laser writing system unit 7, and the first color signal is Writing on the belt surface is performed in the same manner as in the case of signals, and a latent image is formed. 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 belt surface based on a control signal generated by a signal processing section.

Further, numeral 11 denotes a developing device containing black toner, which forms a black toner image superimposed on the belt surface by the same process. These developing devices 8, 9, 1
Direct current or even alternating current bias is applied to each sleeve 0 and 11, and jumping development is performed using a two-component developer, which is a developing means, and non-contact development is performed on the photoreceptor belt 1 whose base is grounded. It is about to be done. Note that as the development, non-contact development using a one-component developer can also be used.

The color toner image thus formed on the circumferential surface of the photoreceptor belt 1 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 uppermost layer of the transfer material housed in the paper feed cassette 14 is carried out by the rotation of the paper feed roller 16 and transferred to the photoreceptor belt 1 via the timing roller 17.
It is supplied to the transfer device 12 in synchronization with the above image formation.

The transfer material that has undergone image transfer and static electricity removal is reliably separated from the photoreceptor belt 1, which suddenly changes direction along the drive roller 2, and heads upward via the suction type conveyor belt 17A. After the image is fused by the fixing roller 18, the sheet is discharged via the discharge roller 19 onto a tray formed on the top lid 20.

On the other hand, the photoreceptor belt 1 that has completed the transfer onto the transfer material continues to be transported to the cleaning device 1 with the blade 13A and the toner transport roller 13B in pressure contact.
3, the remaining toner is removed, and after the removal is finished, the blade 13A is pulled away again. A little later, after the toner conveying roller 13B smoothes out the toner accumulated on the tip of the blade 13A, the toner conveying roller 13B is removed.
B is separated and a new image forming process begins.

The photosensitive drum 1, 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.

The process cartridge 30 is inserted into the apparatus by sliding obliquely from the upper right side through a guide device (not shown) constructed between the process cartridge 30 and the apparatus main body.

At the same time as the process cartridge 30 is installed, it is connected to the drive section and power supply section of the main body of the apparatus, and the aforementioned bias power supply for the conveyance and operation of the photoreceptor belt 1 and each developing device and for each developing sleeve is connected. be made into

FIG. 2 shows the front side of the process cartridge 30, and FIG. 3 shows the cross section taken along arrow AA. On the front side of the cartridge, there are fixed contact pieces 80, corresponding to the positions of the respective developing devices. 90, 100 and 110 are arranged.

Each of the fixed contact pieces has respective support members 81, 91, 101 and 1 into which the upper end is inserted and fixed.
As shown in the figure, they are arranged in parallel in two rows, one above the other, on the front side of the cartridge via 11.

Each of the fixed contact pieces has a cylindrical bent portion at its lower end, and as in the example of the developing device 8 shown in FIG. The developing sleeves 9A, 10A, 11A are pressed against the outer peripheral surface of the bearing 8B that supports the developing sleeves 9A, 10A, 11A.
, respectively, with similar bent portions.

On the other hand, FIG. 4 shows the main parts of the process cartridge 30 according to arrow B in FIG. Movable contact piece 80A, 90
A, 100A and 110A are provided.

Each of the movable contact pieces is formed in a chevron shape with a flat top, and each has a pair of guide pins 81A, 91.
A, 101A, and 111A, and is urged to protrude toward the process cartridge 30 by compression springs 81B, 91B, 101B, and 111B. Each fixed contact piece and each movable contact piece are made of phosphor bronze plate or stainless steel plate, and each fixed contact piece is connected to each support member and the cartridge body, while each movable contact piece is connected to each support member and each of the cartridge body. In addition to being electrically insulated by the substrate 82A, each movable contact piece is connected to a bias power supply circuit for each developing device from a power supply section of the main body of the apparatus.

When the process cartridge 30 is not installed, each of the movable contact pieces protrudes to the position indicated by the dashed line due to the bias of each compression spring, but when the process cartridge 30 is inserted, each of the movable contact pieces When the fixed contact pieces are brought into sliding contact, they are pressed against the bias of each compression spring to the position shown by the solid line, and are brought into a press-contact state.

[0036] Each of the movable contact pieces can always maintain the contact load, that is, the contact pressure, to each of the fixed contact pieces at an appropriate value of 150 to 200 g by the constant biasing force of each of the compression springs. As a result, a predetermined bias voltage, for example, a voltage obtained by superimposing 1.6 kv alternating current and 0.6 kv direct current, can be efficiently and reliably applied to each developing sleeve.

[0037]

Effects of the Invention The present invention makes it possible to automatically connect a bias power supply to a developing device in a removable process cartridge by installing an extremely simple contact device.As a result, the number of parts used is reduced. An image forming apparatus has been provided that has significantly reduced costs due to the reduction in work such as wiring, wiring, and bundled wires, and has improved operability.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram of an image forming apparatus of the present invention.

FIG. 2 is a front view of the process cartridge.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a diagram of main parts of the process cartridge.

[Explanation of symbols]

1...Photoreceptor belt 8
, 9, 10, 11...Developing device 8A, 9A, 10A, 11A...Developing sleeve 8B, 9B
, 10B, 11B...bearing 8C, 8D stirring member
30...Process cartridge

Claims (1)

[Claims] 1. An image forming apparatus in which a process cartridge including a belt-shaped photoreceptor and at least a developing means provided at a peripheral portion of the belt-shaped photoreceptor is removably attached to an apparatus main body configured as an integral structure, wherein the developing means An image forming apparatus characterized in that a bias power source is connected to the image forming apparatus by sliding and pressing a movable contact piece and a fixed contact piece provided between the apparatus main body and the process cartridge.