JPH04291362A - Image forming device - Google Patents

Abstract

PURPOSE:To automatically open and close the paper feeding and carrying path of a transferring material while interlocking with the loading and unloading action of a process cartridge with respect to a device main body, and also to accurately set the paper feeding and carrying path toward an image transferred area when the process cartidge is loaded. CONSTITUTION:A pair of guiding members constituting the paper feeding and carrying path of the transferring material is set as movable guiding boards 151 and 152 which are tunable together. And when the process catridge 30 is loaded, the carrying path is formed by successively superimposing and press- contacting the movable guiding board 152 through a torsion spring 154, and the movable guiding board 151 through a compression spring 156 on a front surface, and when the process cartridge 30 is unloaded, the carrying path is constituted to be automatically opened by opening the movable guiding board 152 large and the movable guiding board 151 small by being pressed by the spring 154 and the spring 156.

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. This 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 system has been proposed in which a member that integrates the essential parts of the image forming means is taken out of the apparatus and replaced in a maintenance area. 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.

[0005]

[Problems to be Solved by the Invention] However, it is not only a troublesome task to insert one's hand into the device to open the conveyance path of the transfer material after taking out the cartridge, but it is also difficult to open the conveyance path with the conveyance path open. If you insert a cartridge into the unit, it may lead to an accident that may damage the equipment.

[0006] As a result of solving this problem and improving the present invention,
The object of the present invention is to provide an image forming apparatus that can automatically open and close a paper feed conveyance path for a transfer material and can always accurately set the paper feed direction with respect to an image transfer surface.

[0007]

[Means for Solving the Problems] The above object is to provide an image forming apparatus in which a process cartridge including at least a photoreceptor can be inserted into and removed from a body frame having an integral structure. This is achieved by an image forming apparatus characterized in that the position of the paper feed conveyance path for the transfer material provided on the upstream side of the transfer area is set.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention is shown in FIGS. 1 to 3.

In FIG. 1, reference numeral 1 denotes a flexible photoreceptor belt, which is a belt-shaped photoreceptor. 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 devices 8, 9, 10, and 11 accommodates, for example, yellow, magenta, cyan, and black developers, respectively, and includes developing sleeves that maintain 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, when a color signal output from an image reading device separate from the printer is input to the laser writing system unit 7, the color signal is generated by a semiconductor laser (not shown) in the laser writing system unit 7. The laser beam is transmitted to a polygon mirror 7 rotated by a drive motor 7A.
B, it is rotated and scanned by the mirror 7 via the fθ lens 7C.
The optical path is bent by D, 7E, and 7F, 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 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 photosensitive belt 1 is charged again by the charger 6, and then the second color signal outputted from the signal processing section is inputted to the writing system unit 7, and the above-mentioned first color signal Writing is performed on the belt surface in the same manner as in the case of , 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 drum 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 conveyance path 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 17, and is transferred through the paper feed roller 17 in synchronization with the image formation on the photoreceptor belt 1. and is supplied to the transfer device 12.

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 rotating roller 3, and is transported 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 upper 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, and a little later, after the toner supply roller 13B smoothes out the toner accumulated on the tip of the blade 13A, the toner supply roller 13 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 paper feed conveyance path 15 is composed of a movable guide plate 151 and a movable guide plate 152 which are rotatable about a shaft 151A and a shaft 152A shown in FIGS. 2 and 3 as fulcrums, respectively.

On the movable guide plate 151 side are a pair of drive rollers 171 constituting the aforementioned paper feed roller 17, while on the movable guide plate 152 side are the drive rollers 171.
A pair of driven rollers 172 are installed which are pressed into contact with.

Each of the driven rollers 172 has its support shaft guided by a guide groove 173 so that it can move in the direction perpendicular to the conveying surface, and is further moved in the direction of the conveying surface by the reaction force of a torsion spring 174 that is locked at both ends. It is strongly urged and brought into pressure contact with the drive roller 171.

Furthermore, the movable guide plate 152 is biased clockwise by a torsion spring 154 while keeping the driven roller 172 in pressure contact, and its upper end abuts against the regulating member 30B on the front surface of the process cartridge 30. It has been stopped.

On the other hand, the movable guide plate 151 is pressed against the movable guide plate 152 by the action of a compression spring 156 attached to the main body of the apparatus, so that the transfer material is transferred by the paper feed conveyance path 15 and the paper feed roller 17 described above. Each function of guidance and transportation is demonstrated.

That is, the transfer material carried out from the paper feed cassette 14 is carried into the paper feed conveyance path 15 by the paper feed roller 17, and is temporarily stopped in a slipping state by contacting the stop member 180.

When the solenoid SL is turned on by a signal timed to the image device on the photoreceptor belt 1, the stop member 180 moves counterclockwise about the shaft 181 against the tension spring 182 due to the movement of the plunger PL. direction and retreat from the conveyance surface. Therefore, the transfer material starts to be conveyed again by the paper feed roller 17 from the slip state, is fed to the image transfer area, and receives the image transfer to a predetermined position.

On the other hand, the process cartridge 30 is slid and inserted while being supported by a pair of guide rails 30A installed on the apparatus main body, and a pair of reference holes H opened on the front side of the process cartridge 30 are inserted into a pair of guide rails 30A fixed to the apparatus main body. It is placed in a predetermined mounting position by engaging and abutting the reference pin P, and is fixed at that position by its own weight and the action of a click device (not shown).

Therefore, as shown in FIG. 3, the process cartridge 30 can be removed from the main body of the apparatus by pulling it diagonally upward and to the right along the guide rail 30A.
As a result, the movable guide plate 152
is retracted, so it rotates clockwise due to the bias of the torsion spring 154 and comes into contact with the stopper 155 and is stopped.

As the movable guide plate 152 rotates clockwise, the movable guide plate 151 then releases the compression spring 15.
Due to the action of 6, the stopper 15 also rotates clockwise.
7 and comes to a halt.

By setting the rotation angle of the movable guide plate 151 to the minimum necessary value and making the rotation angle of the movable guide plate 152 as large as possible, the surface for transporting the transfer material can be largely opened.

This makes it easier to carry out maintenance such as removing jammed paper and cleaning and inspecting the conveyance surface, and furthermore, when the process cartridge 30 is installed, the transfer material can be fed from the correct direction to the image transfer area. It becomes possible.

[0040]

[Effects of the Invention] According to the present invention, the paper feed and conveyance path for transfer material is automatically opened and closed by attaching and detaching the process cartridge to the main body of the apparatus, and as a result, removal of jammed paper and maintenance work are greatly facilitated. An image forming apparatus that is easy to use and at the same time can accurately feed a transfer material to an image transfer area to obtain a high quality image has been provided.

[Brief explanation of the drawing]

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

FIG. 2 is a detailed view of a paper feed conveyance path with a process cartridge attached.

FIG. 3 is a detailed view of the paper feed conveyance path when the process cartridge is removed.

[Explanation of symbols]

1... Photoreceptor belt 6... Charger
8, 9, 10, 11...Developing device 12...Transfer device 13...Cleaning device
14...Paper feed cassette 15...Paper feed transport path 17...Paper feed roller
30...Process cartridge 30A...Guide rail 30B...Regulation member
151, 152...Movable guide plate 154, 174...Torsion spring 156...Compression spring 171...Drive roller 172...Followed roller 173...Guide groove
180...Stopping member P...Reference pin H...Reference hole

Claims (1)

[Claims] 1. An image forming apparatus in which a process cartridge including at least a photoreceptor can be inserted into and removed from a main body frame having an integral structure, wherein a transfer area is provided upstream of an image transfer area by insertion of the process cartridge. An image forming apparatus characterized in that the position of a paper feed conveyance path for a material is set.