JPH04102866A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the accuracy of the mutual positioning from secularly lowering by integrally removing the photosensitive drum and the transferring belt, etc., of a color copying machine or enabling them to be drawn to a maintenance and inspecting position. CONSTITUTION:The photosensitive drum 2, a transferring belt unit 11, and a cleaner 12, etc., are supported by the same frame 10, and disposed on a guiding member 15 provided on a copying machine main body 1 in such a way that they can move to be positioned to a copying position A and to the maintenance and inspecting position B. The frame 10 is fitted to the guiding rails 15a and 15b of the guiding member 15 in which sliding guides 10g and 10h on upper and lower parts on the opposite side to a side where the photosensitive drum 2, etc., are fixed are provided on the copying machine main body 1, and is made to be movable in a parallel direction with the axial direction of the photosensitive drum 2. And positioning pins 16a and 16b, and positioning collar 16c are respectively provided on the frames 16f and 16g, so that the positioning of the photosensitive drum 2 and the transferring belt unit 11 with respect to the copying machine main body 1 is made possible.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is characterized in that after an electrostatic latent image formed on a photoreceptor drum is visualized with toner, this is transferred to copy paper via a transfer heald. The present invention relates to an image forming apparatus used as a color copying machine, a laser printer, etc.

[Conventional technology]

For example, the image forming device in a color copying machine includes a photoreceptor drum, a developing device arranged around the drum containing toner of a different color, and a transfer belt that sequentially transfers and holds toner images of each color formed on the surface of the photoreceptor drum. , or a transfer drum, etc., and scans the same document multiple times (usually 4 times), and each scan prints B (blue) and G (green).
1R (red).

The original is color-separated using each ND filter, and the developer is switched according to each separated color to form and develop an electrostatic latent image on the photoreceptor drum, and the toner image is sequentially transferred to the transfer belt. After forming a toner image of each color superimposed on the transfer heald, the superimposed toner images are secondarily transferred all at once onto copy paper to obtain a color image.

[Problem to be solved by the invention]

By the way, in the conventional image forming apparatus as described above, it is necessary to position the photoreceptor drum, a plurality of developing devices, the transfer belt 1 unit, etc. with respect to each other with high precision. , the developing unit, the transfer hold unit, etc. require two maintenance inspections such as replenishment of consumables and replacement of parts, so each component is constructed so that it can be independently removed or pulled out to the maintenance one inspection position. There is a need.

Therefore, as mentioned above, if each member is made to be able to be removed independently while maintaining high positioning accuracy with respect to each other, the structure becomes complicated, and there is a problem that the positioning accuracy inevitably deteriorates over time. there were.

The present invention has been made in view of the above circumstances, and its purpose is to enable the photosensitive drum, transfer belt, etc. to be removed integrally or pulled out to the maintenance/inspection position, and to enable mutual maintenance over time. An object of the present invention is to provide an image forming apparatus that can prevent a decrease in positioning accuracy.

[Means to solve the problem]

An image forming apparatus according to the present invention is an apparatus that forms an image by transferring a toner image on the surface of a photoreceptor drum to copy paper via a transfer belt, wherein the photoreceptor drum;
The present invention is characterized in that the transfer heald and the roller that tensions it are attached to a common support frame so that they can be integrally attached to and detached from the machine frame.

[Effect]

According to the present invention, the photosensitive drum and the transfer heald can be handled as one unit, and a decrease in mutual positioning accuracy can be prevented.

[Example] Hereinafter, a case in which the present invention is applied to a copying machine will be specifically explained based on the drawings.

FIG. 1 is a cross-sectional front view showing the general configuration of a copying machine.
In the figure, 1 indicates the main body of the copying machine.

A photoreceptor drum 2 is arranged approximately in the center of the copying machine body 1 so as to be rotatable in clockwise directions, and around the photoreceptor F ram 2 are a charger 3, an editing eraser 4, developing units 5 to 8, and an intermediate transfer medium. Transfer held unit 11. Cleaner 12. A main eraser 13 and the like are provided.

2 is an enlarged side view of the photosensitive drum 2 and the transfer belt unit 11, FIG. 3 is a perspective view of the photosensitive drum 2 and the transfer belt unit viewed from the side where the developing devices 5 to 8 are arranged, and FIG. 4 is a side view of the photosensitive drum 2 and the transfer belt unit 11. FIG. 2 is an enlarged sectional view taken along the line IV-IV in FIG. 2;

Photosensitive drum 2. Transfer heart unit 1. Cleaner 12
etc. are supported by the same support frame 10 and the copying machine main body 1
As shown in FIG. 3, the guide member 15 is arranged so as to be movable and positionable between a copying position and a maintenance 1 inspection position B.

As shown in FIG. 4, the photoreceptor drum 2 has a shaft 2a fixedly inserted through its center and supported by brackets 10a and 10b formed on the support frame IO.
, 10b, one end of the shaft 2a protruding outward is prevented from being removed by a set screw 2b, and a drum gear 2c is fixed to the other end.

The photosensitive drum 2 is configured by providing a photosensitive layer on the surface of a cylindrical body, and as the photosensitive drum 2 rotates, the surface is uniformly charged in the process of passing through the main eraser 13 and the charging charger 3, as will be described later. It receives exposure from an optical system 20 for forming an electrostatic latent image.

On the other hand, the transfer belt unit 11 is driven by a pair of sleeve plates 11a and Ilb provided at a predetermined interval in the axial direction of the photoreceptor drum 2 on the same side of the support frame 10 on which the photoreceptor drum 2 is pivotally supported. It is constructed by rotating a plurality of guide rollers lid to l1g including roller llc in parallel with a shaft support L7, and a transfer bell l-11h hooked to the outside □ of these driving rollers llc and guy, and trollers lid to 11g.

A transfer charger Ili for primary transfer of the toner image from the photoreceptor drum 2 onto a transfer bell (Ilb) is arranged inside the transfer heald 1h, and a transfer charger Ili for secondary transfer is arranged outside the transfer heald 11h. Transfer charger 11j, separation charger 11k that separates paper P from transfer charger l-11h
, and a belt cleaner IIN for cleaning the outer surfaces of the transfer heals I and llh.

The transfer bell) llh moves in a counterclockwise direction (arrow) while contacting the surface of the photoreceptor drum 2 in order to transfer the toner images of each color sequentially formed on the surface of the photoreceptor drum 2 and superimpose them. direction), and also rotates in synchronization with the copy paper P in order to transfer the superimposed toner images onto the copy paper P all at once.

1], m is a helmet mark sensor for detecting the rotational angular position of the transfer mark 1h.

As shown in FIGS. 2 and 4, the cleaner 12 is connected to the photosensitive drum 2.
A blade 12a that slides around the periphery of the photosensitive drum 2 and a screw roll +2b that rolls into contact with the circumferential surface of the photosensitive drum 2 are pivotally supported on the brackets 1loa and fob of the support frame 10 via a shaft 12C that is inserted through and fixed to the center thereof. Oa
, a gear 12 is attached to one end of the shaft 12c protruding from the outside of the job.
d and 12e are fixed. The gear 12d meshes with the gear 2c fixed to the shaft 2a of the photosensitive drum 2, and the gear 12e meshes with the drive roller llc of the transfer belt unit 11.
The supporting frame 10 with the gear 12i fixed to the shaft of
The gear M of the output shaft of the motor M fixed to the bracket eye Ob of
The photoreceptor drum 2.a is engaged with the photoreceptor drum 2. The transfer belt llh and the screw roll 12b are simultaneously driven to rotate.

The support frame 10 has slide guides 10g at the top and bottom on the side opposite to the side on which the photoreceptor drum 2 etc. are fixed.

10h, both slide guides Log,
10h are slidably fitted into guide rails 15a and 15b of a guide member 15 provided in the copying machine main body 1, and are movable in a direction parallel to the axial direction of the photosensitive drum 2.

1.6f and 16g are the front and rear frames of the copying machine main body 1, and the front frame 16f has a positioning pin 1.
6a is provided so that when the support frame 10 is moved to the copying position IA, a hole tOC formed in the bracket ]Oa is engaged with the positioning pin 16a. Further, the rear frame 16g is provided with a positioning pin 16b and a positioning collar 16c, and similarly, when the support frame 10 is moved to the copying position wA, the hole 10d provided in the bracket 10b of the support frame 10 is positioned. One end of the shaft 2a of the photoreceptor drum 2 is engaged with the pin 16b and one end of the shaft 2a of the photoreceptor drum 2 is engaged with the positioning collar 16c, respectively, so that the photoreceptor drum 2 and the transfer belt unit i/11 are positioned with respect to the copying machine main body 1. It has become.

Yellow (Y) is applied to each developing device 5, 6, 7.8.

Developers containing toners of magenta (M), cyan (C), and black (BK) mixed with carrier are stored, and the i-toner is transferred from the selected developer 5, 6, 7.8 to the photoreceptor drum 2. The toner is supplied to the surface of the toner to perform toner visualization.

A document table glass 28 is installed on the top surface of the copying machine main body 1.
An optical system 20 is arranged below it.

The optical system 20 includes a scanner 21 that is movable in a reciprocating manner below the document platen glass 28, a main lens 22 whose position is adjusted according to the copying magnification, a filter selection W 23 that performs color separation exposure, and a mirror of the filter selection device 23. It is composed of a fixed mirror 24 that guides the scanning light [, reflected by the photoreceptor drum 2, and a color image sensor 25 that receives the scanning light I that has passed through the mirror of the filter selection device 23.
When the scanner 21 moves forward, it scans the document on the document table glass 28 to expose the photosensitive drum 2.

The filter selection 223 is a half mirror centered on the axis.
23a (the ratio of transmission and reflection is 6:4), and three filter mirrors 23b, 23c, and 23d are provided radially at an angle of 90 degrees to each other, and one of these mirrors can be selected by rotating. It is possible to switch between them. The filter mirrors 23h to 23d are
The mirror and filter are integrated by vapor-depositing blue (B), green (G), and red (R) color separation filters on the mirror surface, respectively.
, C are used corresponding to the toners of each color.

The color image sensor 25 has three element rows each consisting of a large number of light receiving elements arranged in the main scanning direction, and each of the first to third element rows has an R filter, a G filter, and a B filter. One light receiving element corresponds to one pixel of the original image, and each light receiving element sends a photoelectric conversion signal corresponding to the intensity of reflected light for one color of the pixel to the image processing section 26 as original information. There is.

On the other hand, in the lower part of the copying machine main body 1, paper pressurizers 1-31 and 32 containing paper P are installed at the top and bottom, and the copying machine main body 1
A manual paper feed port 33 for manually feeding paper P is provided on the left side of the paper cassette 31.
, paper cassette 32, and manual paper feed port 33 are used selectively when feeding paper.

The paper P fed out from the paper cassette 31 or 32 is
Timing roller 35 by paper feed roller 34 or 36
They will be transported to the hospital and wait there. Also, manual paper feed slot 3
The paper P inserted into the timing roller 35 is similarly conveyed to the timing roller 35 by a manual feed roller.

The waiting paper P is conveyed by the rotation of the timing roller 35 in synchronization with the transfer heald llh,
After the toner image is secondarily transferred to the paper P from the transfer heald 1-11h at the transfer position, the paper P is sent to the fixing unit 38 by the conveyance heald 37, where the toner image is melted and fixed.

The paper P on which the desired copy image has been formed by fixing the toner image is sent to the sorter 40 by the discharge roller 39, and is sent to the storage tray 41 of the sorter 40 or the sorting hem (
(shelf) 42.

FIG. 5 is an enlarged side view of the photosensitive drum 2 and the transfer heat unit 11 showing another embodiment of the present invention.
, the screw roll 121 of the cleaner I2], the supporting frame 1 together with the housing 9 that supports the developing units 5 to 8.
0, and is integrally fixed to the copying machine body 1.
It is designed so that it can be attached to and detached from the body.

The other structures and operations are substantially the same as those of the embodiment shown in FIGS. 1 to 4, and corresponding parts are designated by the same numbers.
The explanation will be omitted.

A support frame 10a that shares the photoreceptor drum 2, the transfer hell l-11h, and the rollers lie and l1g for stretching it.
.

10b, 1], a, Ilb, etc. in the image forming apparatus, which is integrally attachable and removable to the machine frame. A counter or the like may be added to display the information, and screws may be provided to attach a cover or the like to prevent scratches caused by outside light or service when these are pulled out. Alternatively, a flexible sheet such as black Mylar may be rolled into a roll and placed on a part of the unit as a cover, and when the unit is taken out, the sheets 1 to 1 can be pulled out to cover the unit.

〔effect〕

As described above, in the apparatus of the present invention, the photoreceptor drum and the transfer belt unit are integrally attached to the support frame, and can be attached to and detached from the machine frame as a whole, so that it can be easily removed during maintenance, etc. The present invention has excellent effects such as ease of handling and prevention of deterioration in mutual positioning accuracy.

[Brief explanation of drawings]

FIG. 1 is a front cross-sectional view schematically showing a copying machine to which the present invention is applied, FIG. 2 is an enlarged side view of a photoreceptor drum and transfer belt unit, and FIG. 3 is an enlarged side view of a photoreceptor drum and transfer belt unit. FIG. 4 is an enlarged sectional view taken along the line IV--IV in FIG. 2, and FIG. 5 is an enlarged side view showing another embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. An apparatus for forming an image by transferring a toner image on the surface of a photoreceptor drum to copy paper via a transfer belt, comprising: the photoreceptor drum, the transfer belt, and a roller that tensions the transfer belt. An image forming apparatus characterized in that an image forming apparatus is attached to a common support frame, and is integrally attachable to and detachable from a machine frame.