JPS6090349A - Copying machine - Google Patents

Abstract

PURPOSE:To prevent a detecting malfunction caused by adhesion of a toner, etc., to detect exactly running of a photosensitive body, and also to simplify a constitution by providing a detecting sensor for detecting the running of the photosensitive body, on the inside circumferential surface part of a belt-shaped photosensitive body. CONSTITUTION:A belt-shaped photosensitive body 20 is endlessly constituted, and is extended between rollers 21, 22, and a developing process is executed on its outside circumferential surface. In about the center of the inside circumferential surface of the photosensitive body, for instance, marks (a), (b) and (c), etc. by black painting are provided, and a photosensitive body position sensor 24 for detecting them is provided by using a reflection type opitcal sensor which has constituted, for instance, a light emitting device and a photodetecting device as one body in the inside. Accordingly, comparing with a detection of running of the photosensitive body by utilizing the surface of the photosensitive body, a detecting malfunction caused by contamination, etc. by a toner can be prevented, and also the constitution is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic copying machine, and particularly to a copying machine using a belt-shaped photoreceptor.

Structures of conventional examples and their problems In recent years, electrophotographic copying machines have become more and more compact, and various systems using belt-shaped photoreceptors have been considered.

Hereinafter, problems with a conventional copying machine using a belt-type photoreceptor will be explained with reference to the drawings.

FIGS. 1n and 1B show first and second conventional examples of methods for detecting the running of a photoreceptor in a copying machine using a conventional belt-shaped photoreceptor.

In FIG. 1 (8), 1 is a photoreceptor, 2 is a drive roller,
3 is a driven roller, 4 is a driving claw provided on the driving roller, 5 is a driven roller;
numeral 6 is a hole into which the driving claw fits, 6 is a detection roller that rotates together with the driving roller 2, and 7 is a sensor.

In FIG. 1(B), 8 is a detection mark provided on the photoreceptor 1, and 9 is a sensor.

Generally, when a belt-shaped photoreceptor is wound around a plurality of rollers and run, a slight slip occurs between the drive roller and the inner peripheral surface of the belt, resulting in a speed difference between the drive roller and the photoreceptor belt. For this reason, in the first conventional example, a drive roller tilting pawl 4 is provided, and the drive hole 6 provided in the photoreceptor is hooked to drive the drive roller, thereby eliminating the speed difference between the two and integrating the drive roller 2 with the drive roller 2. The sensor 7 reads the rotation of the rotating detection roller 6.

However, in such a configuration, since the photoreceptor 1 is forcibly driven by the driving claw 4, the drive hole provided in the photoreceptor must be sufficiently reinforced, which causes the problem of complicating the configuration. had.

Further, in the second conventional example, a mark 8 is provided on the photoreceptor 1,
This is read by the seventh sensor 9, but in this case, there is a problem in that developed toner adheres to the photoreceptor, which tends to cause reading errors.

OBJECTS OF THE INVENTION An object of the present invention is to make it possible to realize a copying machine with a simple structure that can reliably detect the running of the photoreceptor when constructing an electrophotographic copying machine using a belt-shaped photoreceptor. .

Structure of the Invention The copying machine of the present invention is configured such that a belt-like photoreceptor is stretched between a plurality of rollers, and at least a developing process is performed on the outer peripheral surface of the belt-like photoreceptor. The structure is such that a signal section for detecting the running of the photoreceptor is provided on the inner peripheral surface, thereby preventing detection errors due to contamination of developer material, etc., and ensuring reliable detection operation. This is what I did.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a side sectional view of an electrophotographic copying machine according to an embodiment of the present invention, and FIGS. 3 and 4.

FIGS. 5 and 6 are side sectional views for explaining the operation. FIG. 7 is a perspective view of the main part.

In FIG. 2, 2o is a belt-shaped photoreceptor, and 20' is a seam used to create an endless photoreceptor.

21 and 22 are first and second rollers that stretch and run the belt-like photoreceptor 20; 23 is a motor;

24 is a photoconductor position sensor that detects the rotational position of the photoconductor, and marks a and b are provided on the back surface of the photoconductor.

Detect C. 26 is a corotron, 26 is a fiber lens array, 27 is an exposure lamp, 28 is a reflector,
An image of the original 3o on the original table 29 is formed on the photoreceptor 20. 31 is a cleaning blade that scrapes off non-transferred toner on the photoreceptor. 32 is a static elimination lamp;
3 is a developing device which conveys toner 36 to the photoreceptor surface by a magnet roller 34 and develops it. 36 is a paper feed cassette, and 37 is a transfer material, which is placed on a paper feed plate 38 and pressed onto a paper feed bell 40 by a pressure bonding plate 39. 44 and 45 are timing rollers, and 46 is a fixing device. Reference numeral 47 is a document table position sensor, and marks d and e provided on the document table 29.

Detect f.

The twisted photoreceptor position sensor 24 and the marks a, b, and c provided on the back surface of the photoreceptor are provided approximately at the center of the inner circumferential surface of the photoreceptor, as shown in FIG.

In this embodiment, the photoreceptor position sensor 24 is a light projector.

A so-called reflective optical sensor having a light receiver integrated therein is used, and marks a, b, and C are painted black on the back surface of the photoreceptor.

The operation of the electrophotographic copying machine of this embodiment configured as described above will be explained below.

(1) Copy Start From the state shown in FIG. 2, the motor 23 is rotated as shown in FIG. 3, and the photoreceptor 20 is caused to travel in the direction of the arrow.

At the same time, the original platen 29 is moved back to the right as indicated by the arrow, and stopped when the original platen position sensor 47 detects the mark e.

Further, the paper feed belt 46 is rotated in the direction of the arrow to feed the transfer paper 37 into the paper feed path 43, and when the leading edge of the transfer paper 37' reaches the timing roller 44, 45 as shown in FIG. The belt 46 is stopped to complete the paper feeding operation.

(2) Start of charging As shown in FIG. 3, when the photoreceptor 2o rotates and the photoreceptor position sensor 24 detects the mark a provided on the back surface of the photoreceptor, the corotron 26 is activated and the photoreceptor 20 is charged. Start. At this time, as shown in FIG. 3, the surface of the photoreceptor 20 is cleaned by scraping off the residual toner 48 with a cleaning blade 31, and the surface of the photoreceptor 20 is cleaned by a cleaning blade 31.
Since the residual charge on the surface is eliminated by the static eliminating light 2, the surface remains clean even after passing through the developing device 33.

(3) Start of exposure From the charging start position shown in FIG.
When the photoconductor position sensor 24 detects the mark b, the exposure lamp 27 is turned on and the document table 29 starts moving leftward at the same speed as the photoconductor 20. Therefore, the image of the original 3o is transferred to the photoreceptor 2.
0 to create an electrostatic latent image corresponding to the original on the photoreceptor surface.

As shown in FIG. 4, when the photoconductor seam 20' almost reaches the cleaning blade 31, that is, when the photoconductor position sensor 24 detects the mark C, the cleaning blade 31 is rotated about the shaft 49. At the very least, it is evacuated from above the surface of the photoreceptor 200. At this time, the non-transfer toner 48' that has been scraped off by the cleaning blade 31 and dammed up on the photoreceptor moves while remaining on the photoreceptor and falls onto the developing device 33.

It is stored in the developing device, mixed with the tor inside the developing device, and used again.

Furthermore, by stopping the lighting of the static eliminating lamp 32 at the same time as the cleaning blade 31 is retracted, it is possible to prevent the cleaning blade and the static eliminating light from damaging the electrostatic latent image 5o on the photoreceptor.

With the above operations, the photoreceptor has made one rotation from the initial state shown in FIG.

(4) Development and Transfer As the photoreceptor 2o continues to rotate as shown in FIG. 5, the electrostatic latent image 50 on the photoreceptor passes through the developer 33,
Developed by the toner 35, a developed toner 61 is deposited on the photoreceptor.
is attached.

Further, when the photoreceptor seam 20' passes over the corotron 26 again, that is, when the photoreceptor position sensor 24 detects mark a, the timing rollers 44 and 46 are operated to feed the transfer paper 37' into the transfer path. Especially,
The transfer paper 37' is charged from the back side by the corotron 26, and the developed toner 51 on the photoreceptor is transferred onto the surface of the transfer paper 37'. Generally, the operating conditions during charging by the corotron 25 and during transfer are often different. Therefore, when the photoreceptor position sensor 24 detects mark a,
It is also possible to switch the corotron operating conditions from charging conditions to transfer conditions. In addition, in order to correctly align the leading edge of the developing toner 51 and the leading edge of the transfer paper 37', it is necessary to
This is possible by adjusting the position of the upper document leading edge position regulating plate 62.

(6) During transfer, the abrasion transfer portion is strongly charged by the corotron 26 from the back surface, and is therefore brought into close contact with the photoreceptor by electrostatic force. Therefore, in order to peel off the transfer portion from the photoreceptor, it is necessary to forcibly peel it off mechanically using a means such as a peeling claw.

Alternatively, it was necessary to eliminate static electricity using an alternating current (AC) corotron. In the case of the present invention, as shown in FIG.
2. The diameter of the 20th roller is sufficiently smaller than the diameter of the conventional photosensitive drum shown in FIG.

Therefore, the bending rigidity force of the transfer material 37' acts, and the transfer material is naturally peeled off from the photoreceptor surface against the electrostatic force on the photoreceptor, and is conveyed along the paper guide 62 toward the fixing device 46. .

From the state shown in FIG. 6, the photoreceptor continues to rotate, and when the joint 20' of the photoreceptor reaches below the fiber lens array 26 again, the exposure process of the original 30 is completed, and the original platen is moved to the original platen position sensor. 47 stops when it detects mark f.

It starts returning to its original position again, detects mark d, and stops.

(6) Start of cleaning As shown in FIG. 5, untransferred toner 48 remains on the photoreceptor after transfer. It is necessary to clean the photoreceptor surface before starting the next charging exposure step. After this, the photoconductor continues to rotate from the state shown in FIG. 6, and when the photoconductor position sensor 24 detects mark C as shown in FIG. 6, the cleaning blade 31 is pressed onto the photoconductor again.
, ; The operation of scraping off the toner 48 is started.

At this time, the static elimination lamp 32 is turned on and the photoreceptor 1n1 after cleaning is irradiated with light to eliminate the remaining l[101] on the photoreceptor and prepare for the next charging process. .

At this time, 11・\yt, the body 20 rotates 2 times from the initial state/Cumps 3, the photoreceptor 20 continues to rotate 4 times, and the seam 20' becomes 1[j
When passing over the + IJl-ron 25, the voltage stamp 11 to the corotron 25' is applied to the photoreceptor 20+.
3゜Sara (・ζ
,l,,ti When the light body 20 continues to rotate and the seam 20' reaches the vicinity of the cleaning blade 31, Ijll
When the photoconductor rotates 20 or 3 times, cleaning T'F'
+j is the thread γ, the motor 23 is stopped and the copy is started, γ
do. , +J1+chi photoconductor 20 &J: This is the result of 3 rotations from the initial state.

During this time, IN, r(-;
9 is also returned to (i>place-\return) of the box shown in FIG.

The above is the operation when copying one sheet.

When copying several sheets from one document, in the above operation description, after the transfer is completed, without stopping the voltage application to the corodor roller 25, switch to the next charging operation, and then turn the document table 29. By continuing to move to the exposure start position, continuous copying operations can be avoided. In this case, one copy can be obtained by two rotations of the photoreceptor 20, and the copy speed can be increased compared to a single copy operation.

In the above embodiment, a reflection type optical sensor is used as the photoconductor position detection sensor, and a mark is applied to the photoconductor side. However, the present invention is not limited to this, and the present invention is not limited to this. Anything is fine as long as the same effect can be obtained by applying the same effect.

Effects of the Invention As is clear from the above explanation, the present invention provides a detection sensor for detecting the running of the photoreceptor inside the belt-shaped photoreceptor, thereby providing an advantageous effect compared to the case where the surface of the photoreceptor is used. This can prevent detection errors due to toner stains and the like. Also.

Since the structure is such that a 1θ-contact mark is provided on the photoreceptor and read, there is no problem even if there is a speed difference between the photoreceptor and the drive roller due to a gap or the like.

This has advantages such as not requiring a complicated configuration for forcibly driving the photoreceptor, and makes it possible to realize a simple and compact copying machine.

[Brief explanation of drawings]

FIGS. 1A and 1B are perspective views showing a conventional method for detecting the running of a belt-shaped photoreceptor, and FIG. side sectional view, 3rd
4, 6, and 6 are partially cutaway perspective views showing an installation example of the device (till sectional view, and FIG. 7 is a sensor according to the present invention) for explaining its operation. 20... Belt-shaped photoconductor, 24... Photoconductor position sensor, 26... Corotron, 26...
...Fiber lens array, 29...Document stand, 31...Cleaning blade, 32...
... Static elimination lamp, 33 ... Developing device, 37...
...Transfer material, 46...Fuser, a, b, C.
····mark. Figure 1'I 1

Claims (1)

[Claims] A belt-shaped photoreceptor is stretched between a plurality of rollers. The belt-shaped photoreceptor is configured such that at least a developing step is performed on the outer circumferential surface thereof, and a signal section for detecting the running of the photoreceptor is provided on the inner circumferential surface of the belt-shaped photoreceptor. Copy machine