JPS64702B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feeding device for a strip-shaped photoreceptor in a transfer type electrophotographic apparatus using a multi-aperture optical system.

A slit exposure method is generally adopted as an exposure method for electrophotographic devices such as copying machines.
This method is suitable for devices that consistently perform a series of image-forming processes such as charging, exposure, development, and transfer.The optical image in the slit is It is moved in synchronization with the photoreceptor to obtain a two-dimensional image.

By the way, multi-aperture optical systems using focusing light transmitters or self-focusing photoconductive optical fibers, which have been put into practical use in recent years, have problems when applied to electrophotographic devices.
While this technology is excellent in that it allows highly accurate recorded images to be obtained and allows the device to be made more compact, it also requires the document and photoreceptor to be relatively stationary in order to expose a two-dimensional optical image. It has difficulty. In other words, a device that uses the document table moving method as shown in Figure 1 not only has poor operability, but also has the drawback that the copying speed is low because there is a limit to the backward movement speed of the document table, as shown in Figure 2. A type that stops the photoconductor not only requires an intermittent drive mechanism, which complicates the device, but also makes it impossible to perform development, transfer, and cleaning operations during exposure; This has the drawback that consistent copying operations cannot be performed. In these figures, the code 1 is the photoreceptor, and 2 is the photoreceptor.
3 is a contact glass, 3 is a multi-aperture optical system, 4 is a developing device, 5 is a cleaning device, and 6 is a fixing device.

The apparatus disclosed in Japanese Patent Application Laid-Open No. 53-123142 is intended to solve the above-mentioned drawbacks of the conventional apparatus. However, a large space is required to move the two rollers outside the exposure area, so a convergent light transmitter is used, which has the advantage of making the device more compact. This has the disadvantage that the significance of the project is lost.

The present invention is intended to solve the above-mentioned drawbacks of the conventional apparatus, and proposes a small and simple electrophotographic apparatus using a multi-aperture optical system capable of high-speed copying.

Hereinafter, details of the present invention will be explained with reference to the drawings.

FIG. 3 is a schematic diagram of an apparatus constituting an embodiment of the present invention, in which numeral 10 indicates a strip-shaped photoreceptor and numeral 11 indicates a platen for placing an original. The later-described scanner indicated by the reference numeral 12 includes an illumination device 13, a convergent light transmission body 14,
Charger 15 and two pairs of photoreceptor conveying rollers 1
6 and 17, and the platen 11 mentioned above.
Scan the document surface along the Reference numeral 20 denotes a back-up roller, around which are a developing device 21, a transfer charger 22, a separation charger 23, and a cleaning device 2.
4 are arranged in order of the image forming process. Furthermore, on the circumference of this backup roller 20,
The first and second pinch rollers 25 and 26 are rotatably mounted and function to bring the strip-shaped photoreceptor 10 into close contact with the back-up roller 20, as will be described later. In the figure, reference numeral 27 indicates a back-up roller cleaning device, 28 a fixing device, 29 a registration roller, 30 a paper feed roller, and 31 a cassette.

Next, a strip-shaped photoreceptor 10, which is a characteristic part of the present invention, will be described.
The transport mechanism will be explained. FIG. 7 shows the above-mentioned scanner 12, and in order to avoid complicating the diagram, the well-known illumination device 13, charging device 15, and focusing light transmitting body 14 installed above the diagram are explained below. The illustration of is omitted.

A pair of guide rods 18 are fixed to the main body of the apparatus, extend below the platen 11 in parallel to the scanning direction, and slidably support the scanner block 12a. 19a is the scanner block 12a
A scanner driving wire fastened to the scanner 12 is stretched around a driving pulley (not shown) provided outside the scanning area, and drives the scanner 12 back and forth. 19b
is a conveyance roller driving wire wound around a pulley 16a of the conveyance roller 16, which will be described later, and both ends thereof are fixed to the main body of the apparatus. Of the two pairs of rollers collectively referred to as photoreceptor conveyance rollers, the roller located at the rear in the scanning direction is a driving roller, and the roller located at the front is a braking roller.
It is pivoted in parallel between 2b. 16a is a pulley loosely fitted to the shaft end of the driving roller 16;
b is a first one-way cut-off ring that engages with this pulley 16a, and transmits only rotation in the direction of arrow B to the shaft. 16c is a second one-way coupling that frees the shaft only when it rotates in the direction of arrow B, and 16' is a pinch roller that cooperates with this drive roller 16. 17a is a friction coupling, and the braking roller 17 is attached to the scanner block via this friction coupling 17a to perform a braking function.
Reference numeral 17' indicates a pinch roller that cooperates with the braking roller 17, reference numeral 12c indicates a back plate that supports the back surface of the strip-shaped photoreceptor 10, and reference numeral 12d indicates a roller that rolls on the guide rod 18.

FIG. 5 shows a mechanism for guiding the band-shaped photoreceptor 10 to an image forming process other than the latent image forming process.
Reference numeral 5 indicates a pinch roller for driving the band-shaped photoreceptor 10 driven by the gear 20a of the back-up roller 20, and 25a indicates a pinion thereof. Reference numeral 26 denotes a braking pinch roller attached to the main body of the apparatus via a friction coupling 26a, which cooperates with the driving pinch roller 25 to move the strip-shaped photoreceptor 10.
It has the effect of bringing the roller 20 into close contact with the back up roller 20 by tension. Note that the reference numeral 32 in FIG.
is a guide member of the photoreceptor strip 10, which supports the non-image forming surface of the photoreceptor strip 10 to prevent its latent image forming surface from coming into contact with other devices when the photoreceptor strip 10 is abnormally bent. It is attached to the inner surface of both side walls of the main body.

Next, the operation of this embodiment will be explained.

When a drive pulley (not shown) starts winding up the scanner drive wire in response to an exposure operation output signal, the scanner 12 starts moving rightward (in the direction of arrow A in FIG. 7) from the exposure scan start position shown in FIG. 3. Along with this movement, the pulley 16a wound around the transport roller driving wire 19b
rotates in the direction of arrow B in FIG.
b, 16c to the driving roller 16 having the same diameter. Thereby, the driving roller 16 feeds out the band-shaped photoreceptor 10 at the same speed in the direction opposite to the advancing direction of the scanner 12 (arrow C) while resisting the braking force of the braking roller 17 . Therefore, since the strip-shaped photoreceptor 10 stands still with respect to the document while maintaining tension at the exposure position, the focusing light transmitting member 1
The two-dimensional image exposure operation according to No. 4 is carried out without any problem.

On the other hand, the back-up roller 20, which is constantly rotating, winds the strip-shaped photoreceptor 10 sent out by the conveying roller 16 onto its own circumference. In addition to this, the driving pinch roller 25 that is rotating with driving force is connected to the braking pinch roller 26.
Since tension is applied to the strip-shaped photoreceptor 10 in the discharge direction (direction of arrow D in FIG. 5) through the circumferential surface of the back-up roller 20 while resisting the braking force of the back-up roller 20, this strip-shaped photoreceptor 10 During this period, necessary development, transfer, and cleaning processes are performed.

The photoreceptor 10 sent out from the back-up roller 20 returns to the scanner 12 again, and the repeated operation is repeated thereafter.

Eventually, when the scanner 12 reaches the end point of the exposure operation, the other drive pulley (not shown) begins to rotate, winds up the scanner drive wire 19a, and causes the scanner block 12a to move in the opposite direction, that is, on the backward stroke. enter. Along with this movement, the pulley 16a wound around the transport roller drive wire 19b rotates in the opposite direction to the arrow B, but as described above, the one-way coupling 16b responds to this rotation in the opposite direction. On the other hand, since the second one-way coupling ring 16c prevents rotation, the band-shaped photoreceptor 10 is transported integrally with the scanner 12 without being drawn out. On the other hand, Backup Prowler 20
takes in the band-shaped photoreceptor 10 that is sent together with the scanner 12 that takes a backward stroke, continues its rotation, and moves the scanner block 12
A returns to the exposure scanning start point and one cycle ends.

Next, the relative movements of the various parts necessary to bring about the above-mentioned effects will be explained with reference to FIG. 4. If the speed of the scanner 12 during exposure scanning is v _s , then the strip-shaped photoreceptor 10 at the exposure position
must remain stationary relative to the document, the circumferential speed of the drive roller 16 is also v _s , the speed of the scanner 12 during backward movement is v _sr , and the circumferential speed of the transport roller 16 at this time is v sr . v _pr is the peripheral speed of the backup roller 20 during the copying cycle, v _p is the stop time of the scanner 12 at the exposure scan start position, t ₁ is the exposure scan time, t ₂ is the stop time at the exposure scan end position is t ₃ , if the backward movement time is t ₄ , the time t required from the start of an exposure scan to the start of the next exposure scan is t = t ₁ + t ₂ + t ₃ + t ₄ Also, from the back-up roller 20 to the path of the strip-shaped photoreceptor 10, If the distance from the exposure scan start position to the exposure end position is L ₁ and the distance to the exposure scan end position is L ₂ , L = L ₁ - L ₂ , then during exposure scan v _p (t ₂ + t ₃ ) = L - During double movement (v _sr + v _pr ) t ₄ - v _p (t ₄ + t ₁ ) = L - In order to simplify the drive device, it is possible to stop the conveyance roller 16 during double movement. structure, i.e.
In order to set v _pr =O, it is sufficient to determine the speed of each part so that v _sr t ₄ −v _p (t ₄ +t ₁ )=L −′ from the equation.

FIG. 8 shows another embodiment of the present invention,
Components common to those in the first embodiment are given the same reference numerals. This embodiment uses a backup roller 20
In addition to this, a drive roller 20' is added, and the back up roller 2 of the strip photoreceptor 10 is
0 and maintain the tension between the drive roller 20' and the back-up roller 20 by attaching the brake pinch roller 26 to the scanner block 12a via a friction coupling 26a, as in the first embodiment. It is obtained by According to this embodiment, by adding the drive roller 20', the diameter of the back-up roller can be reduced, so the stiffness of the paper is utilized to improve the separation performance between the transfer paper and the strip-shaped photoreceptor 10. can be done.

In each of the above-mentioned embodiments, the band-shaped photoreceptor 10
Because the back-up roller 20 and the scanner 12 are used to transport the strip separately, there is a possibility that the left and right slack may deviate from the optimum value, and if this exceeds a certain limit, excessive force will be applied to the strip-shaped photoreceptor. It may also cause trouble. For this,
Marks are attached to appropriate positions on the side edge of the band-shaped photoreceptor 10, and optical detection devices, for example, are provided near the back-up roller 20 and at required positions on the scanner 12 to detect when the marks pass through these points. It is also possible to provide a mechanism that detects slack from the time difference and changes the stop time of the scanner 12 at the exposure scan start position or the exposure scan end position to correct the amount of left and right slack of the band-shaped photoreceptor 10 to an appropriate value. .

Note that the conveyance rollers 16, 17 and pinch rollers 16', 1 used in each of the above-mentioned embodiments
It goes without saying that 7', 25, and 26 are all brought into contact with the non-electrified portion of the strip-shaped photoreceptor 10. In addition, the photosensitive layers on both sides of the band-shaped photoreceptor 10 are removed to expose the electrodes, and the pinch rollers 16', 17', 25, and 26 that contact these areas are made of a low-resistance material to ensure grounding. It is also added as a preferred embodiment of the present invention.

As described above, according to the present invention, the endless photoreceptor is transported in the opposite direction to the scanning direction at the same speed as the scanning speed by the transport means provided on the document scanning member. The body can be kept stationary with respect to the original, and it has become possible to employ an exposure means that enters a two-dimensional optical image into the exposure section of an electrophotographic device. Moreover, even though the photoreceptor is held by the scanning member, the photoreceptor can be continuously fed to the image forming process means other than the exposure means by the conveyance means, so that the photoreceptor can be continuously transported to an image forming process means other than the exposure means, similar to a normal electrophotographic apparatus. A series of image creation processes can be automated and copying efficiency can be improved. Furthermore, by incorporating the photoreceptor conveying means onto the scanning member, it is possible to reduce the size of the electrophotographic apparatus to the minimum size determined by the document size, so that it is possible to reduce the size of the electrophotographic apparatus to the minimum size determined by the document size. It has excellent effects as an electrophotographic device, such as being able to fully bring out the characteristics of the exposure means.

[Brief explanation of drawings]

1 and 2 are schematic diagrams of a conventional electrophotographic device using a multi-aperture optical system, FIG. 3 is a schematic diagram of a device showing an embodiment of the present invention, and FIG. 4 is an endless diagram of the same device as described above. FIGS. 5 to 7 are perspective views of various parts of the above-mentioned apparatus, and FIG. 8 is an explanatory view of main parts showing a second embodiment of the present invention. 10... Band-shaped photoreceptor, 11... Platen, 12
... Scanner, 13 ... Illumination device, 14 ... Focusing light transmission body, 15 ... Charger, 16, 17 ...
Conveyance roller, 18...Guide rod, 19a...
... wire for scanner conveyance, 19b ... wire for driving conveyance roller, 20 ... back up roller, 21 ... developing device, 22 ... transfer charger, 25 ... cleaning device.

Claims (1)

[Claims] 1. A document scanning member equipped with an exposure means consisting of a movable multi-aperture optical system into which a two-dimensional optical image is incident; A conveying means for conveying a part of the endless photoconductor, and a photoconductor carrying means comprising a pinch roller and a back-up roller that receives the conveyed photoconductor in a non-tensioned state and returns it to the scanning member in a non-tensioned state. and an image forming process means other than an exposure means arranged around the photoreceptor supporting means.