JPS60258567A - Scanning controller of optical system in electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To prevent troubles due to heating of an exposure lamp at a continuous copying time by inputting information form a scan position detecting means of an optical system and information from a paper feed position detecting means, which detects the position of a supplied form, to determine the scan return speed of the optical system properly. CONSTITUTION:A scan end sensor 3 is provided in the scan limit position in the right end of a platen glass 1, and a return end sensor 4 is provided in the return limit position in the left end. A registration sensor 5 used for coincidence between the front end of the supplied form and that of an original is arranged in a prescribed position near the sensor 4. Signals from sensors 3-5 and a paper feed sensor 6 are inputted to a CPU 10, and driving control signals for a scanning motor 15, a feed roll driving motor 16, and an exposure lamp 2 of the optical system are outputted from the CPU 10. Thus, the return speed of scanning of the optical system is controlled to an optimum value to prevent troubles due to heating of the lamp without holding the optical system in case of continuous copying.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to scanning drive of an optical system in a dry type electrophotographic copying machine.

Scanning with conventional optical systems involves a scan run in which light from an exposure lamp scans the surface of the original on the platen glass on the document table T, and a return run, and the return run is usually faster than the scan run. After the scan is completed, it returns at high speed and prepares for the next scan start timing.

The scan start timing is set at a time when the leading edge of the original document and the leading edge of the copy sheet must be aligned, and the sheet is in a constant feeding state regardless of the size of the sheet.

Therefore, if the paper size is large compared to the scanning distance of the optical system, the paper # will still remain in place at the end of the return.Secondly, the return will remain in the state until the next paper is fed and scanning begins. You will have to wait. At this time, when there is a continuous copying state f, the exposure lamp continues to be lit, so heat generation at the standby position becomes a problem.

Scanning by a conventional optical system will now be explained with reference to FIGS. 2 to 5.

FIG. 2 is a schematic explanatory view of the main parts of the copying machine. In the figure, 01 is a platen glass on which an original is placed, and an original 02 is placed under the surface thereof. Below the platen glass 01 there is an exposure lamp 03 such as a halogen lamp which is the light source of the scanning optical system, and the direction of the light emitted from the exposure lamp 03! A drum-shaped photoreceptor 05 is installed on which light is imaged through a plurality of mirrors 04 that are changed.

A charge corotron 06 is placed around the drum-shaped photoreceptor 05.
, developer 07. A transfer corotron 08 etc. is arranged, and an electrostatic latent image is formed by light reaching the photoreceptor surface uniformly charged by the charge corotron o6 through the optical system, and then toner is attached by a developing device 07. Then, the toner image is transferred to paper by a transfer corotron 08.

An image is transferred to the transfer paper by a fixing device (not shown), and a series of copying processes is completed.

Reference numeral 09 denotes a paper tray for storing paper, and the paper is fed one by one starting from the top layer by driving a feed roll 010.

Along the paper transport path from the paper tray 09 to the position of the transfer corotron 08, a photo sensor (111) is installed together with a transport device (not shown) to detect the passing position of the paper before transfer.

Timing charts showing the scanning of the optical system, the driving states of the exposure range and the photosensor are shown in FIGS. 3 to 5 below.

In the same timing chart, the upper diagram shows the position of the optical system, and the middle signal (■) shows the lighting status Mv of the exposure lamp.When it is at a high level, it is on and when it is at a low level, it is off. . The lower signal indicates the state of paper detection by the photo sensor 011; when it is at a high level, it is in a state where paper is being detected, and when it is at a low level, it is in a state where no paper is being detected. The timing charts shown in FIGS. 3 to 5 show the case where three copies are made consecutively.

FIG. 3 is a timing chart when the copying paper is short compared to the scanning distance of the optical system, and such drive 2 is normally performed.

That is, when copying starts, first the exposure lamp is turned on (at the rising edge of the signal ()), then the feed roll 01 is turned on.
0 becomes 4, the paper is fed, and the same paper 7 photosensor 01
1 is detected (at the rising edge of the signal ■), at the same time the optical system starts scanning.

When the paper passes through the photo sensor 011'Y (
At the falling edge of the signal (2), the scan run is switched to the turn run.

The second sheet of paper is fed and detected by the photo sensor 011, and scanning starts again at 5 o'clock.As shown in Figure 3, the scanning of the optical system starts the next scanning run without waiting at the return end position. can move.

This also applies when the paper size becomes smaller.

However, if the paper size is long compared to the scanning distance of the optical system, the optical system uses the photo sensor 011 as shown in Figure 4.
Instead of waiting 2 seconds for the paper to pass through, the paper changes to the return run at the scan end position at the limit of the scanning distance, and even after completing one stroke, the paper still has not passed through the photo sensor 0117a', so it waits at the return end position. become.

After the optical system reaches the return end position, the photo sensor Q
11 is a waiting time (between X and Y in FIG. 4) until the next sheet is detected.

During continuous copying, the exposure lamp remains lit during this standby time.
As a result, heat generated by a halogen lamp or the like will be concentrated on a part of the platen glass, causing the shape of the platen to change due to high heat and causing problems.

Therefore, if the paper is long compared to the scanning distance, it may be possible to slow down the return speed to shorten the waiting time, but if the return speed is kept constant at a slow speed, the 5th As shown in the figure (just delaying the scan start point will lengthen the entire copying time).

Problems to be Solved by the Invention The present invention is concerned with improving the above-mentioned drawbacks. The purpose is to avoid waiting for a long time and to avoid delaying the copying time.

Methods and actions for solving problems The methods for solving such problems will be explained based on a diagram.

In a dry type electrophotographic copying machine having a scanning optical system, A is a scanning position detection means for detecting the scanning position of the optical system,
Reference numeral B denotes a paper feeding position detection means for detecting the position of the supplied paper before transfer.

O is a scanning control means for controlling the scanning drive of the optical system.
D is a scanning drive means for driving the optical system under the control of the same scanning control means.

E inputs the information from the scanning position detection means A and the information from the paper feeding position detection means B, appropriately determines the scanning return speed of the optical system based on the image information, and transmits the speed signal to the scanning control means. It is an information processing means that outputs to C.

In the above configuration, the information processing means E performs the scanning of the optical system based on the information of the scanning position detection signal of the optical system by the scanning position detection means A and the paper conveyance position detection signal by the paper feeding position detection means B. The scanning drive of the optical system proceeds smoothly based on the distance and paper size, and even when the paper is long compared to the scanning distance during continuous copying, the scanning return speed is controlled to eliminate waiting time and improve overall copying efficiency. You can make sure that the time it takes is not too late.

Embodiment An embodiment of the present invention shown in FIGS. 6 to 10 will be explained below. FIG.

In the figure, 1 is a platen glass, 2 is an exposure lamp, and the exposure lamp 2 scans to the right and returns to the left.

A scan end sensor 3 is installed at the scan limit position at the right end of the platen glass 1, and a return end sensor 4 is installed at the return travel limit position at the left MaK.

A V-distortion sensor 5 for positioning the leading edge of the low-feed paper and the leading edge of the document is arranged at a predetermined position near the return end sensor 4.

The above three sensors are reflective photosensors, and an actuator integrally attached to the scanning optical system detects when the optical system reaches a predetermined position.

The other devices are the same as those shown and explained in FIG. 2 in the prior art section.

FIG. 7 is a block diagram of the control system of this embodiment, and numeral 10 is a CPU which is the central part of information processing, and is driven according to a predetermined program written in ROM 11 while appropriately using RAM 12.

Input signals include signals from the scan end sensor 3, return end sensor 4, and registration L/- John sensor 5, as well as a detection signal from the paper feed sensor 6, which corresponds to the constant photo sensor 011 described in the prior art section. The information is input to the OPU iO through the personal interface 13.

Drive control signals are output from the CPU 10 to the scanning motor 15, feed roll drive motor 16, and exposure lamp 2 of the optical system via the output interface 14.

In the above control system, the scanning of the optical system is compared to the scanning distance.
When the paper is short, conventional scanning control is performed, and when the paper is long compared to the scanning distance, the following control is performed. 2 is a timing chart when performing continuous copying.

In the same figure, the signal ■ indicates the lighting state of the exposure lamp, and the signal Mw indicates the detection state of the paper by the paper feed sensor 6.
It shows.

Further, signal (2) is a drive signal for the feed roll drive motor 16 and is driven when the feed roll drive motor 16 is at a high V level.

When copying is started - the feed roll drive signal is set to high V bell, the feed roll is driven, and paper is fed twice - then the exposure lamp is turned on and the paper is detected by the paper feed sensor 6 ( Scanning of the optical system is started at the rising edge of the signal (2).

If the paper feed sensor 6 is still in a state where it has detected a paper shortage (the signal is in a high V bell state) even when the scanning of the optical system has reached the scan travel limit position, that is, if the paper is longer than the scanning distance, the return run is started at this point. When the paper passes through the paper feed sensor 6 (signal ■
If the optical system has not returned to the predetermined position at the falling point P), the return speed is increased at that point.

Here, the predetermined position is the V distortion sensor 5.
This is the position corresponding to the horizontal axis in the top diagram showing the scanning position 2 of the optical system in the timing chart.

After the return speed is changed from low speed to high speed, the optical system passes the V storage 9th position, and at this point the feed roll is driven at Q. The next paper is fed, and the optical system switches to scan travel at the return travel limit position.

Further, if the optical system has returned to the predetermined position at the time point P when the signal falls during low-speed return travel, the return speed is not changed. However, in this case, the paper is extremely long compared to the scanning distance, and the optical system detects the resin V at almost the same time as the binding 5 signal, which is approximately the longest among the paper used, falls. - Set in advance to return to the sensor position.

By designing in this way, it is possible to move on to the next scanning run even for the longest paper without having the optical system wait at the return end position.

Therefore, in the case of paper other than the maximum length, the return run is 2
By changing the speed change point 7 from low speed to high speed according to the length of the paper, the timing at which the optical system returns to the return end position can be adjusted appropriately to the length of the paper as shown in FIG. This eliminates the need for the optical system to be on standby, and there is no delay in copying time.

The operation of the scanning drive control of the above optical system is shown in Fig. 9 and 1.
The process is shown and explained as a flowchart in Figure 0.0 First, the reduction ratio, number of copies Z, etc. are set (step ■), and then when the start button is pressed (step ■)
, the feed roll is driven (step ■), the paper is fed, and then the exposure lamp is turned on (step ■).

When the paper feed sensor 6 detects paper due to paper feeding,
(Step ■), the drive of the feed roll is stopped (Step ■), and at the same time scanning travel is started (Step ■).

Next, the paper passes through the paper feed sensor 7 and the paper feed sensor turns OFF.
F'? The optical system reaches the scanning distance limit and the scan end sensor 3 turns ON.
If it turns OFF, the mode symbol is set to O, step O), and scanning stops (step 0).

This operation is the same as that of the conventional example when the paper is short compared to the scanning distance.

If the scan end sensor 3 is turned on first, the mode symbol is set to the value 'Yl (step 0), and scanning is stopped (step 0).

This is the case when the paper is long compared to the scanning distance.

Then, the number of copies Z is decreased by 1 (step 0), and it is determined whether Z is 0 or not (step start).

If Z = Q, the exposure lamp turns off (step ■)
.

Here, it is determined whether the mode symbol K is 1 or not (Step I[D). If K is not 1 but 0, the return run is started at high speed as in the conventional example (Step 0).
, proceed to step ■.

If = 1, the return travel starts at low speed (step O) 8. When the return travels at low speed, the paper is detected at the paper feed sensor 6.
2. Wait for the paper feed sensor to turn off after it passes (
The scanning position of the optical system is determined based on the value of the symbol R at the same time (step ■).

The value of H is determined by the register l/-john sensor interrupt routine shown in FIG. Then, the value of R before the interrupt is determined (Step 2) If R=Q, the value of R is set to Yl, and if R=Q, the value of P is set to 70 (Step 2).

At that time, in FIG. 6, the V distortion sensor 5
It is set in advance so that when the optical system is on the left side of the return end sensor 4, the value of B is O, and when it is on the right side, the value of B is 1.

Therefore, in step ① of Fig. 9, the value of R is determined to be 7, and if it is not 0 but 1, the optical system has not returned to the position of the registration sensor 5 yet, and in this case, the return speed is switched from low to high speed. (Step 0).

Next, to determine the value of Z, step 0) - 2 = 0 and if the next paper feeding is not necessary, jump to step ○, and if it is not 220, the optical system passes the position of the registration sensor 5. R17) Wait for the value to become O (step ■), drive the feed roll (step θ),
Proceed to step O.

In addition, when the value of R is already O in step ■, move to step ■, determine the value 7 of 2, and if 2 = 0, the feed roll is immediately driven (step θ).
, proceed to step 0, and if Z=Q, continue to step O
8 When moving from step ① to step ②, the paper is at its maximum length, and as mentioned above, the paper passes through the V-syst V-Jon sensor 5 and the paper reaches R=Q. The paper passes through the paper feed sensor 6, and during the first scan run, the paper can be aligned without any hindrance in starting paper supply.

In this case, the return speed is not switched.

At step 0, the optical system reaches the position of the return end sensor 4, wait for the sensor 4 to turn on, and then stop the return run (step ■).

In the next step ■, the value of Z is determined, and if 2 = 0, the program stops progressing, and if the value of Z is not O, it returns to step ■, and the same operation as above is performed to set the set number of copies Z.
Repeat until Y is digested and end.

In this way, when the length of the paper is long compared to the scanning distance, the return speed is changed in two steps except for the maximum length, and the speed change point is set to match the length of the paper (step 0, 0), the optical system does not have to wait at the return end position to align with the next sheet, and by slowing down the return speed, it is possible to prevent the copying time from increasing.

Effects of the Invention The present invention makes it possible to keep the optical system in a standby state during continuous copying by controlling the return travel and optimum speed in scanning of the optical system, regardless of the scanning distance of the optical system and the length of paper. Since there is no heat generated by the exposure lamp, it is possible to prevent problems caused by the heat generated by the exposure lamp, and the copying time is not increased, making copying work more efficient.

[Brief explanation of the drawing]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a schematic explanatory diagram of main parts of a dry type electrophotographic copying machine, Figs. 3, 4, and 5.
The figure shows a conventional scanning drive of an optical system and a timing chart of a predetermined signal, FIG. 6 shows an arrangement of sensors provided on a scanning path in an embodiment according to the present invention, and FIG. 7 shows an embodiment of the present invention. FIG. 8 is a block diagram of the control system of this embodiment, FIG. 8 is a diagram showing the scanning drive of the optical system and timing chart of predetermined signals in this embodiment, and FIGS. 9 and 10 are flowcharts of the control program of this embodiment) It is a diagram. 01...Platen glass, 02...Original, 03...
・Exposure lamp, 04...Mirror, 05...Drum-shaped sensitive element, o6...Charge corotron, o7...Developer, o8・°°transfer corotron, 09...Paper tray, 01o ...Feed roll, 011...Photo sensor - ■...Platen glass, 2...Exposure lamp -3...Scan ent sensor, 4...Return end sensor, 5...V register John sensor, 10-01P, U, 11...ROM, 12.
RAM, 13--input interface, 14-.
・Output interface, 15...scanning motor 16
..."Feed roll drive-t-ta. Agent: Patent attorney Ehara, 2 people, Figure 2, Figure 10.

Claims (1)

[Claims] An electrophotographic copying machine having a scanning optical system includes a scanning position detection means for detecting the scanning position of the optical system, a paper feeding position detection means for detecting the position of the supplied regular paper before transfer, and a scanning drive of the optical system. a scanning control means for controlling the scanning control means; a scanning driving means for driving the original computer under the control of the scanning control means; inputting information from the scanning position detection means and information from the paper feeding position detection means; 1. An optical system scanning control device, comprising information processing means for appropriately determining the scanning return speed of the optical system based on image information and outputting the speed signal to the scanning control means.