JPS59146044A - Scanning control method of scanning type copying machine - Google Patents

Abstract

PURPOSE:To complete scanning without using any parts such as a limit switch by monitoring the scanning time of a carriage and completing the scanning of the carriage preferentially when the scanning time exceeds a maximum permissible scanning time. CONSTITUTION:A main control part 22 is provided with a timer 23 to monitor, i.e. measure the scanning time from the beginning of the scanning of the carriage. A controller waits for a detection signal for the rear end of a copy form from a form sensor after the scanning is started, but when there is not this signal, the main control part 22 decides invariably on whether the timer 23 for the longest scanning time finishes measuring the time; when the length of the copying form is larger than the length corresponding to the maximum permissible scanning distance of the carriage, the main control part 22 completes the scanning before the signal for the rear end of the form is inputted to generate a scanning completion signal. Consequently, a light source activating signal is turned off and the timer 23 is also turned off.

Description

[Detailed description of the invention] In particular, it relates to a method of controlling the end of sloughing.

In a conventional scanning copying machine, an electrostatic latent image is formed on the surface of a drum or belt-like moving photoreceptor by scanning a document on a platen at a predetermined speed with a carrier supporting a light source and an optical system. Scan control methods for returning the gear ridge to stop 1- or to its original or home position at the end are well known.

In this scanning control force method, the scanning of the gear ridge is performed by using a paper sensor provided in the copy paper feeding path, and when the trailing edge of the copy paper passes the sensor, the scanning of the gear ridge is performed at the time when the trailing edge of the copy paper passes the sensor, or after a predetermined period of time from that time. It was normal for it to end after that. However, in this method, if the maximum allowable travel distance of the carriage is shorter than the length of the copy paper, there is a risk that the carriage will collide with the end of the travel, resulting in mechanical damage.

In order to prevent this, it is known that a sensor is provided before the end of the travel, and when the carriage reaches the sensor, the scan 1, that is, the travel ends, is completed. This scanning termination method requires a sensor, such as a limit switch, at the end of the travel, which not only increases the number of parts but also increases the number of installation steps.Furthermore, there is a risk of detection errors due to component failure or deterioration. There are also.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a scanning control method for a scanning copying machine that can reliably and safely complete scanning without requiring parts such as limit switches.

In order to achieve such an object, according to the present invention, the scanning time from the start of scanning of the carriage is monitored, and the scanning time is
When the carriage's maximum allowable scanning time is within the carriage's maximum allowable scanning time, the scanning of the carriage ends when the trailing edge of the copy paper exceeds the sensor on the feeding path, but when the scanning time exceeds the carriage's allowable maximum scanning time, priority is given. A scanning control method for a scanning copying machine is provided, which is characterized in that the scanning of the carriage is terminated at There is no increase in assembly man-hours, and there are no detection errors due to failure or deterioration of sensor parts.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 7 shows an outline of a scanning copying machine, and before explaining the scanning control method of the present invention, an outline of the structure and operation will be explained.

In FIG. 1, a document 2 is placed on the grating 1 with its edge aligned with point A, and the grating 1
A sensor switch 3 is provided on the lower surface corresponding to point A. Further, below the platen 1, there is provided a carriage 4 that moves at a predetermined speed in the direction of the arrow.
and a mirror 6 that receives a reflected light image from the original. When the carriage 4 moves in the direction of the arrow and turns on the sensor switch 3, the light source 5 is energized. It moves, or scans, while irradiating it. The start of this scanning is performed at point A, and point A becomes the exposure start point.

The reflected light image from the original document 2 is projected via other mirrors 7 to 9 (lenses if necessary) onto an imaging position B of the photoreceptor 10 rotating in the direction of the arrow. The photoreceptor 10 has an imaging position B
A corona charger 11 is provided upstream of the photoreceptor to uniformly charge the surface of the photoreceptor to impart photosensitivity. Therefore, when an optical image is projected onto the imaging position B, an electrostatic latent image is formed on the surface of the photoreceptor. This latent image is developed by a developing device 12, and the developed toner image moves to a transfer position C. Note that photoreceptor 1
The 00 surface speed is synchronized with the scanning speed of the carriage 4, and is the same speed in the case of identical copying.

Next, the copy paper 13 is fed along a copy paper feed path 14 at a speed synchronized with the surface speed of the photoreceptor 100, and a paper sensor 15 is placed on the feed path to align the copy paper with the toner image on the photoreceptor 10. is provided. At transfer position C, the toner image on the photoreceptor surface is transferred to copy paper 13 with the aid of transfer corona discharger 16 . After the transfer, the copy paper 13 passes through a fuser (not shown), where the toner image is fused to the copy paper and output as a copy. On the other hand,
A cleaning device 17 is provided on the photoreceptor lO downstream of the transfer position C, and the toner and latent image deposited on the surface of the photoreceptor are neutralized and cleaned in preparation for the next image formation. The above is a general description of scanning copying machines.

The scanning movement of the carriage 4 is controlled by a control device 18. When a document 2 is placed on the platen 1 and a button (not shown) is pressed to operate the copying machine or start the motherboard, the photoreceptor 10 and the copy paper 13 are driven at a predetermined time interval, and the carriage 46 is driven. The controller 18 starts moving in the direction of the arrow in a predetermined time relationship and at a predetermined speed. When the carry tool 4 reaches the exposure start point A, the light source 5 is activated and exposure scanning is started, and this scanning is continued until a predetermined period of time has elapsed after the trailing edge of the copy paper 13 turns off the paper sensor 15. After the scanning is completed, the carriage 4 is stopped at that position, but is quickly returned to its original position, that is, the home position, in preparation for the next image formation.

In the following description, for convenience, the carriage 4 will be described as one that returns quickly.

In the above scanning, the scanning is completed in synchronization with the end of the trailing edge of the copy paper 13 passing the paper sensor 15. In the case of correspondence copying, there is no problem if the copy paper 13 has a specified length and is shorter than the maximum allowable scanning length of the carriage, but if the copy paper 13 is longer than the length , even if the carriage 4 exceeds the length, it continues its scanning and collides with the stopper 19 provided at the end of its travel, causing mechanical damage to the carriage 4, light source 5, mirror 6, etc. There is. In order to prevent this, conventionally, as shown by the broken line 1 in Fig. 1, a
A sensor with 20 limit switches was provided, and when the carriage reached this sensor, the scanning operation of the carriage 4 was terminated. However, this sensor increases the number of parts, which is undesirable. In the present invention, such a sensor is not provided at all.

The scanning control method according to the present invention will be explained with reference to the rabbit diagram and FIG. The control method of the present invention is realized by configuring the control device 18 as shown in FIG. That is, the input circuit 21 of the control device 18 receives a signal from the sensor switch 3 for the exposure start point and a signal from the paper sensor 1.
5 signals, a clock signal from the copying machine, and a control signal from the copying machine main control section are input. These signals are sent to the main control section 22, where various signals are generated for driving the carriage 4. Further, this main control section is provided with a timer 23, which monitors or measures the scanning time from the start of scanning of the carriage. Preferably, this timer 23 can set the maximum permissible scanning time when the carriage 4 moves at a predetermined scanning speed over the maximum permissible travel length.
Also referred to as the longest scan time timer. Note that when the maximum allowable scanning time changes with a predetermined copying magnification, it is preferable that the maximum allowable scanning time is set to a predetermined value as the magnification changes.

Various signals generated by the main control unit 24 are sent to the output circuit 24, which outputs a light source energizing signal, a carriage horn running signal, and a carriage return signal, and energizes the light source in the cylinder chamber. The carriage is scanned at a predetermined speed and returned.

The scanning control method according to the present invention will be explained using flowchart 1 in FIG. When the start switch ζ of the copying machine is pressed, the input circuit 211 of the control device 18 is input, and a carriage running signal is output from the output circuit 24 at a predetermined time interval, and the carriage 4 starts running. start. When the carriage 4 passes to the exposure start point, the signal from the switch 3 is input to the input circuit 21, and the main control section 22 generates a light source activation signal and also generates the longest shortest time timer 23 to activate the copying machine. The scanning time from the start of scanning of the carriage 4 starts to be measured and compared using the clock signal or another clock signal. The light source energizing signal is passed through the main output circuit 24 to energize the light source 5.

After the start of scanning, the controller 18 waits for a copy paper trailing edge detection signal from the paper center 15, and upon receiving this signal, the main controller 22 turns off the maximum scanning time timer and the light source activation signal. A scanning end signal is formed and a carriage return signal is applied to the carriage 4 from the output circuit 24. As a result, the light source 5 is de-energized, and the carriage 4 quickly returns to its home position.

As mentioned above, the control device 18 waits for the copy paper trailing edge detection signal, but if the signal is not received, the main control section 2
2, the longest scan time timer 23 constantly determines whether to end its timing (ie, time up). Therefore, the copy paper 13 is y+i! of the carriage 4! If the length is longer than the length corresponding to the long scanning distance section, the maximum scanning time timer 23 times out before the paper trailing edge detection signal is input. In this case, the main control unit 22 puts the scanning end state in priority over the paper trailing edge detection signal, creates a scanning end state bow, turns off the light source activation signal, and turns off the timer 23. Ru. Therefore, the light source 5 is deenergized and the carriage 4 is quickly returned.

As mentioned above, in the scan control method according to the present invention,
When the carriage scanning time (and therefore the travel length) exceeds the carriage's permissible μ゛ length scanning time (and therefore the maximum permissible travel length), the carriage is terminated using external light, so a limit is set at the end of the carriage travel. - There is no need for any parts such as switches, there is no increase in the number of parts and assembly man-hours associated with such parts, and there are no defects associated with component failures.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a scanning copying machine, FIG. 2 is a circuit diagram of the control device of FIG. 1 and is suitable for carrying out the scanning control method according to the present invention, and FIG. , which is a flowchart of a scanning control method according to the present invention. 1... Platen, 3... Exposure start point sensor, 4... Carriage, 5...
...Light source, 10...Photoreceptor, 13...
... Copy paper, 14 ... Feeding path, 1
5...Paper separator/za, 18...Control device, A...Exposure start point, B...Image formation position, C......・Transfer position. Figure 1 Figure 2 316-

Claims (1)

[Claims] A gear ridge supporting a light source and an optical system is moved at a predetermined speed to scan an original on a platen, and a reflected light image from the scanned original is projected onto a moving photoreceptor to form a latent image on the surface of the photoreceptor. In a scanning control method for a scanning copying machine in which a carriage is stopped or returned to a scanning start position at the end of scanning, the scanning time from the start of scanning of the carriage is monitored t2;
If this scanning time is within the maximum allowable scanning time of the carriage, the trailing edge of the copy paper exceeds a predetermined position on the copy paper feeding path, and the scanning of the carriage is terminated;
1. A scanning control method characterized in that when the scanning time exceeds the maximum allowable time, the scanning of the carry-zoom is terminated preferentially.