JPS6058483B2 - Fine timing adjustment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for fine-tuning timing in copying machines, other control devices, etc. that employ a pulse count control method.

In general, in a copying machine that uses a photoreceptor belt, exposes it to light using a flashlight to form an image, and then transfers the image to transfer paper to make a copy, the photoreceptor or the photoreceptor belt is used.

The so-called pulse counting method detects a pulse train proportional to the speed of the photoconductor using multiple timing marks formed on a member that moves in synchronization with the photoconductor, and counts the pulse train to create the timing for performing the copying process. A control method is used, but in this case, for example, the time between exposure timing and paper feeding timing must be determined so as not to cause misalignment between the image and the transfer paper, and fine adjustment is often required. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for extremely easily fine-tuning the timing of a copying machine or the like that uses a pulse count control method.

Hereinafter, the content of the present invention will be explained in detail with reference to the drawings.
FIG. 1 is a diagram showing the basic configuration of the present invention, and FIG.
This is an example of obtaining a pulse train by detecting the photoreceptor 2.
This is an example in which a timing mark 21 is provided directly on 0 and is detected by a sensor 22.

In either case, the timing marks 11 and 21 are formed so that their widths gradually change in the direction perpendicular to the movement direction, as shown in the figure.
2 and 22 are also attached to appropriate members so as to be able to take variable positions in the direction perpendicular to the movement of the timing marks 11 and 21. As a result, the duty of the pulse train changes depending on the positions of the sensors 1-2, 22, making it possible to finely adjust the timing. For example, FIG. 2a shows a case where the duty of the pulse train is 112, the synchronization is T, and the two timings Tl and T.

If one of the two timings is taken as the positive edge of the counter output and the other as the negative edge, the time difference between the two timings becomes (1).

On the other hand, if the positions of the sensors 12 and 22 are changed and the duty of the pulse train is increased to more than 112 as shown in the figure, the time difference between the two timings Tl and T2 becomes, whereas T2 becomes ± 112T can be finely adjusted.

FIG. 3 is a block diagram showing a schematic configuration of a pulse count control method to which the present invention is applied.

In the figure, a photoreceptor belt 20 is normally folded and stored in a stocker, and is sent out by a drive roller 30 during the copying process and used for image formation. A mark 23 is attached to each fold of the photoreceptor belt 20, and the mark 23 is detected by a mark sensor 25 receiving light reflected from the photoreceptor surface by a light source 24, for example. Timing disk 10 explained in FIG. 1a
is connected to the shaft of the drive roller 30, and the light emitting element 13
A pulse train corresponding to the running speed of the photoreceptor belt 20 is detected by applying light from the photoreceptor to the timing mark 11 and receiving the passing light by the timing mark sensor 12. As shown in FIG. 4, the timing mark ● sensor 12 and the light emitting element 13 are mounted on a support member 14 so as to face each other with the timing disk 10 sandwiched therebetween.

The support member 14 is fixed to a rack 15, a pinion 16 meshes with the rack 15, and a knob 17 is attached to the shaft of the pinion 16. Therefore, by operating the knob 17, the sensor 12 and the light emitting element 13 are moved in the radial direction of the timing disk 10, and the duty of the output pulse train of the sensor 12 is changed depending on the position thereof. This is the case when the timing disk 10 is used, but of course timing marks are provided directly on the photoreceptor belt 20 as shown in FIG. You can do it like this. The output of the mark sensor 25 is taken into the shift register 50 directly or through an AND gate 40 that opens in the presence of the print-on signal and the number of copies selection signal, while the output pulse train of the timing mark sensor 12 is taken into the counter 60 and counted. be done.

Further, the counter 60 is reset by the output of the mark sensor 25, and is initialized each time a mark of each image forming portion is detected. These shift register 50 and counter 6
The contents of the 0 are fed to a combinational logic circuit 70, and the combination of the two sequentially generates the desired control signal to control the timing of the copying process. Up to now, the timing fine adjustment of the present invention has been explained using a pulse count control type copying machine as an example, but the present invention generally relates to a timing mark formed on a moving object or a member that moves in synchronization with the moving object. Needless to say, the present invention is widely applied to control devices that detect a pulse train corresponding to the moving speed of a moving object, count the pulse trains, and issue a desired control signal as the output.

As described above, according to the present invention, fine adjustment of timing in pulse count control type copying machines and other control devices can be achieved very easily, and the effects thereof are very large.

[Brief explanation of the drawing]

1 and 2 are diagrams explaining the principle of the timing fine adjustment method according to the present invention, FIG. 3 is a schematic diagram of the pulse count control method of a copying machine to which the present invention is applied, and FIG. This is a specific example of a timing fine adjustment mechanism used. 10... Timing disk, 11...
・Timing mark, 12...Timing mark ●Sensor, 20...Photoconductor belt, 21...
...Timing mark, 22...Timing mark sensor, 60...Counter.

Claims (1)

[Claims] 1. A control device that detects a plurality of timing marks formed on a moving member or a member that moves in synchronization with the moving member using a mark detection means to obtain a pulse train, counts the pulse trains, and creates desired timing using the output thereof. In the timing mark, the width in the direction perpendicular to the movement direction of the timing mark gradually changes, and the mark detection means takes a variable position in the direction perpendicular to the movement of the timing mark, and the position of the mark detection means is changed. A timing fine adjustment method characterized in that the timing is adjusted by changing the duty of the pulse train.