JPS6084569A - Fitting device for photosensitive body - Google Patents

Abstract

PURPOSE:To replace a photosensitive body easily in a roller axis direction and tensing the photosensitive belt properly by allowing one roller to move and holding the endless phtososensitive body. CONSTITUTION:A driving roller 13 is held at a specific position. A roller 14 is supported pivotally on a bearing where the other terminal (not shown in figure) of a turning shaft 16 is held in a freely oscillatory state. Its tip is fitted rotatably to a tension plate 17. The plate 17 has an L-shaped hole 18 and one terminal of a shaft 19 fixed at its terminal (not shown in figure) to the same frame with the driving roller 13 pieces the hole 18. A guide pin 21 piercing the L- shaped hole 18 of the plate 17 and a lever 22 for turning a coupling plate 20 around the shaft 19 are fixed to the coupling plate 20 atop the shaft 19. A spring 25 energizes the plate 17 through the pin 23 as shown by an arrow A to tense the photosensitive body by the roller 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a device for mounting a photoreceptor in a predetermined position in order to drive the photoreceptor, which is an image forming member of an electrophotographic copying machine.

<Prior art> An electrophotographic copying machine uniformly charges a driven photoreceptor and projects an image of the original (C exposure) to form an electrostatic latent image on the upper surface of the photoreceptor according to the original. Next, toner is attached to the electrostatic latent image and developed, and this toner image is transferred onto a transfer paper, and then the transfer paper is passed through a fixing section to fix the toner image and obtain a copy image.

In order to drive the photoreceptor, conventionally the photoreceptor is supported on a drum made of A-shaped or the like, and the photoreceptor is moved by rotating the drum. An image is projected onto this moving photoreceptor by an optical scanning means that optically scans the document. When the photoreceptor is supported on a drum, if it is an endless photoreceptor, a photosensitive layer is formed on the drum itself.

Therefore, when replacing the photoreceptor, the drum itself is replaced, making the photoreceptor as a whole very expensive.

In addition, as a method for supporting a photoreceptor on a drum, there is a method in which a sheet-like photoreceptor is wound around the circumferential surface of the drum. this is,
One end of the sheet-like photoreceptor is fixed on the drum, and the other end is also fixed on the C drum using other supporting means. In this case, it goes without saying that unless the back surface of the photoreceptor is supported in close contact with the circumferential surface of the drum, image formation will be greatly affected.

Therefore, not only is the operation of mounting a sheet-shaped photoreceptor extremely troublesome, but the means for supporting it on the drum also has a very complicated structure and is expensive. was. Furthermore, when replacing the photoreceptor, fingers or the like often touch the surface of the photoreceptor, disrupting image formation.

<Objective of the Invention> An object of the present invention is to simplify the replacement and operability of a photoreceptor, which is an image forming member, in an electrophotographic copying machine or the like.

<Embodiment> FIG. 1 is a sectional view showing an electrophotographic copying machine according to the present invention. In the figure, reference numeral 1 denotes a document table that is movably mounted on the main body of the copying machine and holds a document, 2 is a lighting device that illuminates the document on the document table, and 3 is a photoreceptor 4 that is rotated and driven to use reflected light from the document. This is an optical means for projecting images onto the image. Before the image projection (exposure) process by the optical means 3, the photoreceptor 4 is uniformly charged to a specific polarity by a corona discharger 5 provided opposite to the photoreceptor 4, and the image is projected. As a result, an electrostatic latent image corresponding to the copy document is formed. This latent image is then developed in a developing/cleaning device 6, and toner is applied thereto.

In addition, a cassette 7 etc. containing a large number of papers is mounted on the photoreceptor.
It is detachably provided, and a paper feed roller 8 is provided facing the paper in the attached cassette. The paper feed roller 8 is driven in response to a paper feed signal from a control means for controlling copying of the copying machine, and feeds the sheets in the cassette 7 one by one. The fed paper is first sent to a conveyance roller 9, and the conveyance roller 9 synchronizes the rotational position of the photoconductor 4 to the transfer process so that the leading edge of the image on the photoconductor 4 and the leading edge of the paper coincide in the transfer process. transported. A corona discharger 10 that performs corona discharge from the back side of the paper is disposed at a position where the paper is conveyed to coincide with the image forming tip of the photoconductor 4, facing the photoconductor. Through this transfer process, the toner image formed on the photoconductor 4 is transferred onto the paper, and the paper supporting the toner image is peeled off from the photoconductor 4, and the fixing roller 11 is placed in a direction away from the photoconductor 4. The paper is discharged outside the machine as shown by arrow 12.

On the other hand, in the second rotation after the photoreceptor 4\i transfer step,
By facing the developing/cleaning device 6, the toner remaining on the surface is cleaned and prepared for the next image formation. This photoreceptor 4 is different from the one supported by a cylindrical drum, and has a large diameter drive roller 13 and a small diameter roller 1.
4 and is maintained under tension. The drive roller 13 is fixed to the main body of the copying machine at a fixed position so as to be rotated by the rotational force of the drive means.
It will not move beyond the position shown. This drive roller 13
A roller 14 is provided facing the .

Although it is normally rotatably held at the position shown in the figure, it is configured to be moved in the direction of the arrow when the photoreceptor 4 is replaced. Therefore, by moving the rollers 14 in the direction of the arrow, the tension state of the photoreceptor 4 held between the rollers is released.
The photoreceptor 4 can be replaced easily. Especially the photoreceptor 41
d As shown in FIG. 2, the front and rear ends of the sheet-like photoreceptor are fixed with fixtures 15 to form an endless shape. It is well known that such photoreceptors can be deformed to some extent. Therefore, since the photoreceptor 4 has an endless shape, it is very easy to take out the photoreceptor 4 or insert it between the rollers. Appropriate tension is applied, and the back surface of the photoreceptor 4 is fixed without being lifted up from the drive roller 13, for example. It goes without saying that the photoreceptor 4 may have an endless structure without fixing its front and rear ends as shown in FIG.

Next, the tension state holding position of the photoreceptor 4.

Roller 1 moved to position for releasing tension
The configuration of No. 4 will be explained in more detail with reference to the drawings.

FIG. 3 is a perspective view showing an example thereof. As shown, the drive roller 13 is held in place. On the other hand, the other end (not shown) of the rotating shaft 16 of the roller 14Ii is rotatably supported by a bearing that is swingably held, and the tip shown is rotatably attached to the tension plate 17. The tension plate 17 is formed with an L-shaped hole 18 like a boss in the figure, and one end of a shaft 19 whose other end (not shown) is fixed to the same frame or the like as the drive roller 13 passes through the hole 18. are doing. A connecting plate 20 is attached to the tip of the shaft 19. A guide pin 21 passing through the L-shaped hole 18 of the tension plate 17 and a lever 22 for rotating the connecting plate 20 about the shaft 19 are fixed to the connecting plate 20 . Furthermore, a pin 23 is fixed to the other end of the tension plate 17, and between this pin 23 and a fixed plate 24 fixed to a frame (not shown) that is attached to the shaft 19, a roller 14 is fixed. A spring 25 is attached to apply tension. This spring 25 urges the tension plate 17 in the direction of arrow A in the state shown in FIG. 3, and causes the reeler 14 to apply tension.

In the structure described above, when removing the endless photoreceptor 4 from between the rollers, turn the lever 22 in the right direction of the arrow in the state shown in FIG. Rotate around.

At this time, the tension plate 17 is moved rightward in the drawing while the L-shaped hole 18 is guided by the shaft 19 as the guide pin 21 moves, and is held in the state shown in FIG. In other words, the amount of movement of the roller 14 is the distance X between the shaft 19 and the guide pin 21.

If this X is set appropriately, it can greatly contribute to the tension or attachment of the photoreceptor 4.

In the state shown in FIG. 5, the photoreceptor 4 between the rollers can be easily taken out, and a new endless photoreceptor 4 can be inserted between the rollers. After this insertion is completed, if the lever 22 is turned upward in the opposite direction as described above, as the connecting plate 20 rotates, the tension plate 17 is moved to the left while being guided by the shaft 19, and is in the state shown in FIG. be positioned.

Therefore, the photoreceptor 4 inserted between the rollers is brought into close contact with each roller under an appropriate tension.

Although the explanation has been given as a structure in which the shaft is supported by a bearing that can be held, this shaft support may be similarly configured to move in conjunction with the rotation of the lever 22. That is, the other end of the shaft 16 also has an L-shaped hole 18 as shown in FIG. 3, and a tension plate 17. A connecting plate 2o, a spring 25, etc. are provided, and the connecting plate 2
It is sufficient to connect the guide pin 21 between 0 and 0. Furthermore, the present invention is not limited to this, and the rollers 14 may be biased via a biasing means so that the distance between the rollers is opened while the photoconductor 4 is being held, and the biasing means may be released when the photoconductor 4 is removed. The configuration may be such that the roller 14 is moved in the direction of the roller 13. The point is that the roller 14 should be configured to be movable.

When replacing the photoconductor 4, there is no problem in touching the surface of the unnecessary photoconductor with your hand, but when inserting a new photoconductor 4, be careful not to touch the surface of the photoconductor with your hand. Just insert it while holding it. In order to facilitate this insertion, the surface of the photoreceptor 4 is covered with an endless cover sheet 26, as shown in FIG. Then, the cover sheet 26 is formed to be somewhat smaller than the outer circumference of the photoreceptor 4. This photoreceptor 4 is inserted between the rollers, and the roller 14
When the cover sheet 26 is moved to the left and tension is applied, the cover sheet 26 is torn, and the cover sheet 26 can be taken out. Since the cover sheet 26 is easily torn when tension is applied, perforations 27 may be formed as shown in the figure, or a sheet that is easily torn may be used. Further, the tip of the cover sheet 26 may be lightly adhered with tape or the like. In this case, the sheet 26 may have the same length as the photoreceptor 4.

<Effects of the Invention> According to the photoreceptor mounting device of the present invention, one of the rollers is movably provided to hold the endless photoreceptor between at least two rollers. The photoreceptor can be replaced along the axial direction of the roller, making the replacement operation very simple. In addition, since the movement of one of the rollers is 5 tsubo, a moderate amount of electric tension can be applied to the photoreceptor held between the rollers, and there is no need to worry about the nurse's hesitancy or the like.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an outline of an electrophotographic copying machine using an apparatus for mounting a photoreceptor according to the present invention, FIG. 2 is a cross-sectional view showing a specific example of an endless photoreceptor according to the present invention, and FIG.
The figure is a perspective view showing one specific example of the photoconductor mounting device of the present invention, FIGS. 4 and 5 are side views for explaining the operation of the present invention, and FIG. 6 is another specific example of the photoconductor of the present invention. It is a perspective view showing an example. 4: Photoreceptor, 13: Drive roller, 14: Roller, 16:
Rotating shaft, 17: Tension plate. 18: L-shaped hole, 19: Shaft, 20: Connecting plate, 21 Ni guide pin, 22 Ni lever, 25 Ni spring. 26 two cover sheets, 27: perforation. Agent Patent attorney Aihiko Fukushi (and 2 others) 0η Kago 1 Figure R Figure 6

Claims (1)

[Claims] 1. A deformable photoreceptor formed in an endless shape, a 10th roller that supports and drives the photoreceptor, and a rotatably provided opposite the 10th roller that connects the photoreceptor with the first roller. A 20th-ra supported with tension applied between;
and means for releasing the tension state of the photoreceptor by moving the 20th roller in the direction of the first roller to loosen the supported photoreceptor.