JPH07120099B2 - Copying device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine using a belt-shaped photoconductive photoconductor having a start end and an end and connected by a seam.

2. Description of the Related Art Conventionally, in this type of copying apparatus, a belt-shaped photosensitive member having a length of several sheets of transfer paper is used, and a sensor detects a starting end mark attached to the starting end of the photosensitive member, and the starting end mark position is used as a reference. A plurality of, for example, 3 to 4 image forming positions with respect to the photoconductor are set for each transfer paper size used as. In the copy operation, image forming processes such as charging and exposure are sequentially performed on these image forming positions. However, in the case of such a system, even if a part of the photoconductor is scratched for some reason, the copy operation is always performed at the image forming position. Therefore, if the operator notices a scratch on the photoconductor due to the copy finish condition, the photoconductor will be replaced by a new one even if the copy at another image forming position is good, and the photoconductor will be uneconomical. It is something that will be spoiled.

The present invention has been made in view of the above point, and even if the photoconductor is scratched or the like, the photoconductor is effective for its entire life by performing a copying operation at an effective image forming position. The purpose is to obtain an economical copying apparatus that can be used for.

In order to achieve the above-mentioned object, the present invention uses a belt-shaped photosensitive member having a seam, detects the starting end mark attached to the starting end of the photosensitive member by the detection means, and is used with this starting end mark position as a reference. In a copying machine in which a plurality of image forming positions for the photoconductor are set for each transfer paper size, an operation of key-inputting for prohibiting and releasing the prohibition of image forming at any one of these image forming positions Part,
According to this key input, a control unit is provided for controlling the inhibition of image formation at the image formation position designated and its cancellation.

An embodiment of the present invention will be described below with reference to the drawings. First, the outline of a copying apparatus to which the present invention is applied will be described with reference to FIG. A belt-shaped photoconductive photoconductor 3 supported by a plurality of rollers 2 and rotating is provided in the main body 1 of the copying machine. An charging system 4 for uniformly charging the surface of the photoconductor 3 is arranged oppositely, and an optical system for exposing and scanning a set original on the contact glass 5 to form an image of the optical image on the photoconductor 3 is exposed. 6 is provided. Further, an eraser 7 for erasing an unnecessary electrostatic latent image, a developing device 8 for developing the electrostatic latent image to make it visible, and a transfer charger 10 for transferring this visible image to a transfer paper 9 are provided downstream of the rotation direction. They are provided in sequence. The transfer paper 9 on which the image has been transferred by the action of the transfer charger 10 is sent from the conveying path 11 to the fixing roller 12 and fixed, and then discharged onto the paper discharge tray 13. Here, a transfer paper cassette 14 accommodating transfer paper 9 of different size is detachably set in the copying machine main body 1, and is selectively fed by each paper feed roller 15 for common conveyance. The sheet is fed to the transfer section by the transfer charger 10 at a predetermined timing by the path 16 and the registration roller 17. A paper discharge sensor 18 is provided near the paper discharge tray 13, and a registration sensor 19 is provided in the transport path 16. Further, on the upper part of the copying machine main body 1, there is provided an operation section 20 having various key switches for controlling the operation of the copying machine and a display section for displaying a status.

Here, the photoconductor 3 has a starting end and a terminating end and is connected in a loop at a seam, and when developed, it becomes as shown in FIG. A start end mark 21 is attached to a predetermined position on the start end side of the photoconductor 3. Such a start mark
A belt sensor 22 as a detecting means for detecting 21 is provided facing the photoconductor 3. As a result, the operation unit 20
When a copying operation start command is given by the operation of, the photoconductor 3 is rotationally driven by the rotation of the main motor, the starting end mark 21 is detected by the belt sensor 22, and the copying operation is controlled based on the starting end mark 21. Will be done. This is because there is a seam between the start end and the end, and it is not preferable to form an image on this portion. Now, assuming that the total length (peripheral length) of the photoconductor 3 is 1000 mm and the size of the transfer paper 9 used is A3 size, as shown in FIG. _{1 to} P ₃ is the start mark 21
Is set based on. Where dimensions l ₁ = 18mm, l ₂ = 297m
m, l ₃ = 36 mm, l ₄ = 19 mm. Also, used transfer paper 9
If the size is A4 size, as shown in FIG. 2B, the image forming positions P _{1 to} P ₄ for four sheets are set with the starting end mark 21 as a reference. Where dimensions l ₅ = 20mm, P ₆ = 210mm, P ₇ = 40mm
Is.

Thus, for example, when the A3-size transfer paper 9 is used, the image forming position with respect to the photosensitive member 3 as shown in FIG. 2 is a copy operation (a) P ₁ → the imaging position P ₂ → Imaging position P ₃ →
The image forming positions P ₁ ... are sequentially performed in this order. The same applies when the A4 size transfer paper 9 is used, and the image forming positions P _{1 to} P ₄ shown in FIG.

Now, let us consider a case where, for example, the photoconductor 3 has a scratch 23 due to some cause in such a configuration as shown in FIG. When such a scratch 23 occurs, the operator can know that the scratch 23 exists in the _second image forming position P ₂ by sequentially looking at the copy finishing state. Therefore, in this embodiment, in such a case, by inputting the image formation prohibition to the _second image formation position P ₂ by the operation unit 20, the control unit such as the CPU changes the image formation position P ₂ to this image formation position P ₂ . On the other hand, the operation is controlled so that the image forming process is not executed. That is, in this case, the image forming position P ₁ → the image forming position P ₃ →
The image forming operation is executed by skipping the image forming position P ₂ in the order of the image forming position P ₁ → the image forming position P ₃ . This is the same when the A4 size transfer paper 9 is used. For example, when the photoconductor 3 is scratched 23 as shown in FIG. by providing the control unit an input of the imaging prohibition against P _3, skip the imaging position P ₁ → the imaging position P ₂ → the imaging position P ₄ → the imaging position P ₁ ... the imaging position P ₃ in the order of The image forming operation will be executed.

In this way, a good copy can be obtained without making a copy at the image forming position where the scratch 23 has occurred. Therefore, even if the scratch 23 occurs on a part of the photoconductor 3, it is not necessary to immediately replace the photoconductor 3, and the photoconductor 3 can be economically used. Even if the scratches 23 require replacement of the photoconductor 3, the copying operation can be executed before the replacement by the service person. It can be stopped to the limit of functional decline.

By the way, when the photoconductor 3 is replaced after such processing, if the image formation prohibition input by the operation unit 20 described above is effective, even if a new photoconductor 3 is formed at the image formation position. This leads to the statue not being performed. Therefore, the operation unit
By the operation of 20, the input for canceling the image formation prohibition is performed next time, and the normal image formation operation is restored. this is,
The image formation prohibition input described above may be automatically canceled when the power of the copying machine is turned off. However, in some cases, the power supply may be turned off without replacing the photoconductor 3. This is because it is better to store it in the non-volatile memory. Then, the prohibition input information is also stored in this nonvolatile memory.

Advantageous Effects of the Invention According to the present invention, it is possible to specify, by the operation unit, the inhibition or cancellation of image formation at an arbitrary image formation position among a plurality of image formation positions set on the photoconductor as described above. Since the control unit controls the image formation inhibition or cancellation to execute the image formation process, when a part of the photoconductor is scratched, the image formation at the image formation position including the scratch is performed. By prohibiting it, a good copy can be obtained in all cases, and it is not necessary to immediately replace the photoconductor, and the photoconductor can be economically used.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a schematic side view, and FIGS. 2 (a) and 2 (b) are plan views showing the photosensitive member in a developed state. 3 ... Photoconductor, 20 ... Operating part, 21 ... Starting mark, 22 ...
… Belt sensor (detection means), 23 …… Scratches, P _{1 to} P ₄ ……
Image position

Claims (1)

[Claims] 1. A belt-shaped photosensitive member having a seam is used, a starting end mark attached to a starting end of the photosensitive member is detected by a detecting means, and the photosensitive member is used for each transfer paper size used with the starting end mark position as a reference. In a copying machine in which a plurality of image forming positions with respect to the body are set, an operation unit is provided for inputting a key for prohibiting or canceling the prohibition of image forming for any one of these image forming positions. A copying apparatus comprising a control unit for controlling the inhibition of image formation at the image formation position designated in accordance with the above and the cancellation thereof.