JPS62150267A - Device for controlling stop position of belt-like photosensitive body - Google Patents

Abstract

PURPOSE:To fix the pre-running time at the next image forming time, by comparing the number of pulses produced after a synchronizing mark is detected by a sensor with the number of pulses corresponding to a previously determined stop position. CONSTITUTION:A belt-like photosensitive body 105 is wound around a driving pulley 3 which is rotated by a driving motor 4 and driven by the motor 4 and a pulse generator 5 is fitted to the shaft of the motor 4 integrally and the pulses of a number proportional to the moving distance of the photosensitive body 10 are produced. Upon detecting a synchronizing mark 2, a sensor 6 outputs a signal to a pulse counter 7 and resets the pulse counter 7. The pulse number corresponding to the position, at which the belt-like photosensitive body 105 is to be stopped after the completion of copying operations, is set in a pulse setter 9 and the count number of the pulse counter 7 is compared with the pulse number corresponding to the stop position set in the pulse setter 9 at a pulse comparator 8. When the two values coincide with each other, a signal is outputted to a motor driving device 10 and the belt-like photosensitive body 105 is stopped by stopping the driving motor 4.

Description

TECHNICAL FIELD The present invention relates to a stop position control device for an endless belt photoreceptor used in an electrostatic recording device.

BACKGROUND OF THE INVENTION Endless belt photoreceptors are widely used as one of the photoreceptors in electrostatic recording devices such as electrophotographic copying machines, electrostatic printers, and facsimile machines. An endless belt photoreceptor is made into an endless shape by rolling up a sheet and welding both ends, so the joint portion cannot be used as an image forming area. Therefore, the image forming areas on the belt are determined to be equally spaced for each size, avoiding the joints of the belt photoreceptors. FIG. 2 is a diagram showing an example of the arrangement of image forming areas (segments) of a belt photoreceptor cut at a seam and developed.

In the example shown in the figure, five A4 segments indicated by one-dot chain lines, four B4 segments indicated by broken lines, and three A3 segments indicated by two-dot chain lines are determined to be equally spaced. In order to time all the image forming processes to avoid the seam and form images, a synchronization mark 2 is provided on the edge of the photoreceptor at a certain distance from the seam 1.
It is now detected by a sensor. At the start of the image forming operation, the belt photoconductor begins to rotate due to the rotation of the drive motor, and when synchronization mark 2 is detected by the sensor, the signal is input to the control circuit, and a signal is generated in proportion to the movement of the belt photoconductor. All image forming processes start operating at preset timings for each image size.

Conventionally, in a copying machine using such a belt photoreceptor, the belt photoreceptor was stopped at the same time as the copying operation was completed, so the next copying time depends on which image forming area was used last. At the start, the pre-travel time to the image forming area differs, resulting in a problem that the first copying time varies.

Purpose The present invention provides a stop position control device for a belt photoreceptor, which eliminates the above-mentioned problems of the belt photoreceptor of a conventional electrostatic recording device, and which has a simple configuration and keeps the pre-travel time constant during image formation. The purpose is to

Structure In order to achieve the above object, the present invention makes it possible to keep the stop position of the belt photoreceptor constant by comparing the number of pulses generated after a synchronization mark is detected by a sensor with the number of pulses corresponding to a predetermined stop position. position,
This allows the pre-travel time during image formation to be constant.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an example of a copying machine having a belt photoreceptor to which the present invention is applied.

An automatic circulation document feeder (RDF) 200 is provided on the contact glass 101 on the top plate of the copying machine 100, and the document is automatically circulated and fed onto the contact glass 101 a desired number of times. The entire surface of the document stopped on the contact glass is irradiated with light at the same time, and the first mirror 102 and lens 1
05, the belt photoreceptor 105 is exposed through the second mirror 104.

Around the belt photoreceptor 105 are a charger 106, the exposure section, an eraser 107, a developer 108, and a transfer charger 1.
09 are disposed, and the toner image formed on the photoconductor 105 by these transfer paper is fed to the transfer section from one of the paper feed trays 110, 111, and 112 through the conveyance path x 113 and the registration rollers 114. After the transfer, the transfer paper is sent to a fixing device 116 by a conveyance belt 115, where it is fixed, and then discharged to a paper discharge tray 117.

As shown in FIG. 6, the belt photoreceptor 105 is wound around a drive pulley 3 rotated by a drive motor 4, and is driven by the drive motor 4. A pulse generator 5 is integrally attached to the shaft of the drive motor 4.
A number of pulses are generated that is proportional to the distance that the belt photoreceptor 105 moves. The pulse signal from the pulse generator 5 is input to a pulse counter 7 and counted. Reference numeral 6 denotes a sensor that detects the synchronization mark 2 (see FIG. 2) provided on the edge of the belt photoreceptor 105. When mark 2 is detected, it outputs a signal to the pulse counter 7. Reset. The number of pulses corresponding to the position at which the belt photoreceptor 105 should be stopped after the copying operation is completed is set in the pulse setter 9, and the number of pulses corresponding to the count number of the pulse counter 7 and the stop position set in the pulse setter 9 is set. is compared by the pulse comparator 8. If the above two values match, a signal is output to the motor drive device 10 to stop the drive motor 4, thereby stopping the belt photoreceptor. The above flow is shown as a flowchart in FIG.

Effect: With the stop position control device described above, no matter which image forming area on the belt photoreceptor the copying operation ends at, the belt photoreceptor moves a certain distance after detecting the synchronization mark and then stops. The pre-travel time for the next image formation can be made constant.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a schematic configuration of an example of a copying machine having a belt photoreceptor to which the present invention is applied; FIG. 2 is an explanatory view showing the arrangement of image forming areas of various sizes on the belt photoreceptor; FIG. 3 is a block diagram showing an embodiment of the belt photoreceptor stop position control device according to the present invention, and FIG. 4 is a flowchart thereof. 1...Belt photoreceptor joint 2...Synchronization mark 6...
・Belt photoconductor drive pulley 4...Belt photoconductor drive motor 5...Pulse generation means 6...Mark detection means 7
...Pulse counting means 8...Pulse comparator 9...
・Pulse setter 100...electrostatic recording device 105
...Belt photoreceptor-1;-〆Fig. 2

Claims (1)

[Claims] an endless belt photoreceptor having a plurality of image areas in one rotation and a synchronization mark provided at a certain distance from a belt seam;
An electrostatic recording device comprising a pulse generating means for generating a number of pulse signals proportional to the moving distance of the photoreceptor, a counting means for counting the pulses emitted by the pulse generating means, and a detecting means for detecting the mark. In this belt photoreceptor stop position control device, the stop position is determined by comparing the number of pulses generated after the detection means detects the synchronization mark with the number of pulses corresponding to a preset belt photoreceptor stop position. Stop position control device for belt photoreceptor.