JPS6310145A - Copying device for making optical system driving timing variable - Google Patents

Abstract

PURPOSE:To execute an appropriate optical system driving control with regard to each device, by storing a data related to the driving timing of a reciprocating operation of an optical system, in a nonvolatile RAM, and setting the at every device. CONSTITUTION:When there is a variance in an optical system load, if a brake control time T is fixed, deceleration cannot be executed enough within this time T. Therefore, in addition to a ROM 30 storing control programs for the reciprocating movement of an optical system and others, a nonvolatile RAM 31 is also connected to a control circuit 32, so that the data of the brake control time T can be written in its nonvolatile RAM 31. For instance, when the optical system load is heavy, it may suffice that its brake control time is set long. In such way, at every copying device, the brake control time length corresponding to weight, etc., of the optical system load of its device is written in advance in the nonvolatile RAM 31, by which various inconveniences based on the variance of the device can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a copying apparatus that stores information regarding the drive timing of an optical system in a nonvolatile RAM and makes the timing variable.

(Prior art) In a copying machine, the program for the reciprocating movement of the optical system is
Usually, it is stored in a ROM (read-only memory), and the reciprocating motion of the optical system is driven at a fixed timing according to the program.

However, this optical system has variations in its mechanical load depending on the individual copying machines, and therefore, if it is controlled at the fixed timing as described above, it will not be able to deal with the variations, resulting in various inconveniences. .

[Purpose of the invention]

An object of the present invention is to enable appropriate optical system drive control for each device even if there are variations in the devices.

[Structure of the invention]

For this purpose, in the present invention, data regarding the drive timing of the reciprocating motion of the optical system is stored in a random RAM, and the data is set for each device.

〔Example〕

Examples of the present invention will be described below. FIG. 1 is a diagram schematically showing the entire copying apparatus. After setting the original 2 on the platen glass 1, closing the platen cover (not shown) and operating the copy start key (not shown),
The exposure light source 3 exposes and scans the original 2 in the direction of arrow a, and the optical image of the original 2 passes through mirrors 4 to 6, a condensing lens 7, and a mirror 8 to a photoreceptor drum serving as an image forming photoreceptor. 9
is guided to the photosensitive surface. The photosensitive drum 9 is a grounded metal cylinder with a photoconductive layer made of selenium or the like provided on the outer peripheral surface thereof, and rotates in the direction indicated by the arrow in conjunction with the exposure scanning.

In the photosensitive drum 9, the photoconductive layer is uniformly charged with, for example, a positive charge by a charging 810 to which a DC high voltage is applied, and the photoconductive layer in this state is photosensitive. When an image is received, the conductivity of the part that receives the light increases, and the electrical charge in that part escapes to the metal cylinder, leaving a positive charge in the dark part depending on the degree of brightness. An electrostatic latent image corresponding to the image of the original is formed on the surface of the photoconductive layer.

When the portion on which this electrostatic latent image is formed reaches the developing sleeve ILa of the developing device 11, the negatively charged toner is transferred to the remaining positively charged portion of the photoreceptor drum 9. The developing sleeve lla is attracted by electrostatic force due to the developing bias voltage applied between the developing sleeve lla and the developing sleeve lla. As a result, a toner image corresponding to the electrostatic latent image is formed on the surface of the photoreceptor drum 9.

The transfer paper 13 in the paper feed cassette 12 is sent out in the direction of the registration roller 15 by the paper feed roller 14, hits the roller 15 and stops once, and the leading edge of the transfer paper 13 and the photosensitive drum 9 The toner on the surface of the photoreceptor drum 9 is sent out again from the registration roller 15 at the timing when the leading edge of the upper toner image matches, and the transfer pole 16 to which DC high pressure is applied to the sent out transfer paper removes the toner on the surface of the photoreceptor drum 9. The image is transferred.

Thereafter, the transfer paper is separated from the photoreceptor drum 9 by the separation electrode 17 to which AC high voltage is applied, and is sent to the thermal fixing device 19 by the conveyor belt 18, where the developer image is fixed.
The receiver is discharged into a tray 20.

The photosensitive drum 9 having the toner image transferred onto the transfer paper is then cleaned by a cleaning device 21 and subjected to the next process.

In the above, when the original 2 is scanned by the exposure light source 3, the mirror 5.6 moves in the same direction as the scanning direction at the scanning speed A, and the optical path length is maintained at a constant length.
When the original exposure scan is completed, the light source 3 and the mirror 4 enter the return operation at the highest speed (approximately three times the speed of the exposure scan).

Therefore, in order to stop the vehicle at the regular home position, it is necessary to apply the brakes in advance to decelerate the vehicle. After the optical loads such as the light source 3 and mirrors 4 to 6 described above are sufficiently decelerated by this brake control, they are shifted to low-speed control by the PLL and stopped at a predetermined home position by receiving a signal from the home position sensor. do.

FIG. 2 is a diagram showing this characteristic. When the optical system load returning at speed Vl is detected by brake sensor BS at time t, brake control is performed for time T until the speed reaches v2. decelerates, and then increases speed by PLL control.
2, and then when the optical system is detected by the home position sensor HPS at time t2, its PLL control is also canceled, and it moves back by inertia and stops at the home position (IP) at time t3.

However, when there are variations in the optical system load, if the brake control time T is fixed, as shown by the broken line in Figure 2, sufficient deceleration cannot be achieved with this time T, and therefore the speed (2) PLL lock cannot be applied to 2, and the vehicle may reach the home position sensor without decelerating sufficiently, go beyond the home position, and collide with the inner wall of the device.

Therefore, in this embodiment, as shown in Fig. 3, in addition to the ROM 30 that stores control programs for the reciprocating movement of the optical system and other control programs, a non-volatile RAM (memory that is free to write and read and can retain data even when the power is turned off) is used. 31 is also connected to the control circuit 32 so that data of the brake control time T can be written into the nonvolatile RAM 31.

For example, if the load on the optical system is heavy as shown by the broken line in FIG. 2, the brake control time may be set longer.

In this way, for each copying machine, the brake control time length is stored in the non-volatile RAM 3 according to the weight of the optical system load of that machine.
1, thereby eliminating various inconveniences due to device variations.

〔Effect of the invention〕

As described above, the present invention is characterized in that it is possible to eliminate control variations due to device variations and to perform appropriate optical system drive control for each device.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a copying apparatus to which the present invention is applied;
The figure is a speed characteristic diagram of the return operation of the optical system, and FIG. 3 is a control block diagram. 31...Nonvolatile RAM

Claims (2)

[Claims] (1) A copying apparatus characterized in that data regarding the drive timing of the reciprocating movement of the optical system is stored in a non-volatile RAM so that the data can be set for each apparatus. (2) The copying apparatus according to claim 1, wherein the data is data regarding a brake control time at the end of the return operation of the optical system.