JPS60247635A - Control method of scanning system - Google Patents

Abstract

PURPOSE:To control a scanning length to a min. required length so as to maximize the copying speed per unit time according to a magnification and paper size by controlling the scanning length by time without providing a scanning end sensor. CONSTITUTION:An original imposed on an original plate 1 is scanned by a scanning lamp 2 and a mirror 3 and the scanning end sensor is not provided on the right end side of the plate 1. The scanning system is so controlled as to determine the scanning length on the basis of the time obtd. by dividing the length of the paper by the moving speed of the surface of a photosensitive drum 9 in the case of unmagnified or larger copying and the shorter time of the time obtd. by dividing the length of the plate 1 by the scanning speed or the time obtd. by dividing the length of the paper by the moving speed of the surface of the drum 9 in the case of reduced copying. Such control is executed by a microcomputer constituting the control system.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to scanning control of a scanning system when making copies;
More specifically, the present invention relates to a method of controlling scan length over time.

[Prior art]

A copying machine with a movable optical system and a variable copy magnification in multiple stages can obtain the desired vertical magnification by changing the scanning speed of the optical system. The scanning speed is increased, and if the scanner has an enlargement function, the scanning speed is slowed down during enlargement.

By the way, regarding the control when returning such a scanning system to its original state, conventionally, a scanning end sensor is provided at the maximum length position of the document table, and scanning is terminated when the scanning system reaches this sensor. However, this method has problems due to the use of the scanning end sensor, such as its cost and the inability to eliminate troubles due to sensor failure. In addition, in the case of a copying machine with a reduction function, even if the reduction ratio is 90 inches, it is unnecessary if the number of copies that can be made per unit time is between 90% and 100 inches because it scans the same length as 70 inches. There is a disadvantage that the amount decreases.

Another control method for the scanning system is to determine the scanning length according to the passage of the paper over a sensor installed in the paper path, but even this method does not work well when making reduced copies on large paper. If so, it is necessary to perform control to terminate the scan using a scan end sensor, and it is not possible to perform scan control without removing the scan end length and not using it at all.

[Purpose of the invention]

The present invention aims to eliminate the need for the scanning end sensor as described above, and to minimize the scanning length so as to maximize the copying speed per unit time according to the magnification and paper size used during scanning. It is something.

[Structure of the invention]

In order to achieve the above object, the present invention determines the scanning length based on the time obtained by dividing the length of the paper by the moving speed of the photosensitive material in the case of the same magnification, so that the length of the scan is exactly the same as the length of the paper being used. Scanning is stopped when the image is placed on the screen, and in the case of reduction, the scan is performed based on the shorter of the length of the paper divided by the moving speed of the photosensitive material or the length of the platen divided by the scanning speed. The length of the scan is determined, and the scan is terminated when the image exactly covers the entire length of the paper or when the scanning system reaches the end of the document table, whichever is shorter.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a schematic diagram of the interior of a copying machine equipped with reduction and enlargement functions in which the present invention is applied to the scanning control of its optical system.
(2) is a scanning lamp for exposure, (3) to (6) are mirrors, (7) is a lens, and (7) is a scanning lamp ( 2) and the document table (1) by the mirror (3)
Scans the original placed on top. Scanning is performed in the right direction in the figure as indicated by arrow a, but no scan end sensor is provided on the right end side of the document table (1). The lamp home sensor (8) is composed of a light sensor, and an actuator (not shown) is attached to the scanning lamp (2), and the actuator turns the lamp home sensor (8) on and off. Ru. That is, when the scanning lamp (2) starts moving, the actuator is located on the left side of the lamp home sensor (8) and is not blocking the lamp home sensor (8), and the scanning lamp (2) is moved for scanning. When the actuator starts moving in the scanning direction a, it interrupts the lamp home sensor (8), which turns on the lamp home sensor (8), and then when the actuator leaves the lamp home sensor (8), it turns on the lamp home sensor (8). is turned off again. Then, when the actuator comes off the lamp home sensor (8) in this manner, the leading edge of the document on the document table (1) is imaged on the surface of the photosensitive material, in the illustrated example, the surface of the photosensitive drum (9). The start of the scanning time is at this point, ie when the actuator disengages from the lamp home sensor (8).

The photosensitive drum (9) is supported to rotate at a predetermined surface speed in the direction indicated by the arrow, and around it are provided a charge corotron αω, a developing device 01), a transfer corotron α, and a cleaner blade α3. The optical image created by scanning the original with the scanning lamp (2) and mirror (3) is transmitted through the mirrors (4) to (6) and the lens (
7), the image is formed on a rotating photoreceptor drum (9). In the case of reduction and enlargement, the magnification can be changed by changing the vertical magnification by changing the scanning speed of the scanning lamp (2) and mirror (3) as described below (as described below), and by changing the horizontal magnification by changing the scanning speed of the above-mentioned lens. (7) and mirror f41, +
This is done by moving the position of 51 with a stepping motor to make it variable as will be described later.

The image formed on the photoreceptor drum (9) through the above-described exposure process is developed by a developing device (111) and visualized as a toner image, which is then transferred and fixed onto paper. That is, , the paper is in the paper cassette (1
The paper is fed from feeder α9 from 41, passes through the misfeed sensor (161), and is sent to the registration gate (161).
In addition, the size of this paper is detected by a paper size detection means (not shown). The registration gate aη is configured to be lowered by turning on a solenoid after a predetermined period of time from the start of scanning of the scanning lamp (2), and when the registration gate (171) is lowered, the paper is The toner image on the photosensitive drum (9) that is aligned with the paper is transferred to the transfer corotron α.
It is transferred onto the paper by the
The toner image on the paper is fixed and ejected from the copying machine. Note that (4) in the figure is a lens; and (4) is a paper ejection sensor.

Figure 2 shows that in such a copying machine, in the case of a copy of the same size or larger, the time calculated by dividing the length of the paper by the speed of movement of the surface of the photoreceptor drum 9) is used as the standard, and in the case of a reduced copy, the time is calculated as the standard. The scanning length is determined based on the shorter of the length of the document table (1) divided by the scanning speed or the length of the paper divided by the moving speed of the surface of the photoreceptor drum (9). FIG. 2 is a configuration diagram of a microcomputer for such control. In the same figure, (2) is a programmable counter, (2) is a programmable counter, (2) is a lens motor, (C) is a lamp scanning motor, and each of these motors (C) and (C) is a stepping motor, DC It consists of a servo motor, and a programmable counter (in which a scanning speed is set in accordance with the copy magnification). (c)
is the input/output controller, (c) is the RAM, (c) is the ROM,
This ROM (c) stores in advance a program for determining the scanning time as shown in the flowchart of FIG.

At the start of scanning, the CPUq
) stops and the lamp home sensor (8) stops as described above.
) This routine is executed when the scanning lamp (2) is to be moved for the first time from a state where the actuator is located on the left side of the position. In FIG. 2, (c) is an address data bus, and (g) is a crystal oscillator.

Next, referring to FIGS. 3 and 4, scanning control in the case of one-time original size and enlargement copying, and one-time reduction copying will be explained. In the following explanation, the maximum original size that can be set on the original platen (1) is AJ, and the surface speed of the photosensitive drum (9) is 130 (wl/sec).
'Furthermore, the width of the slit attached to the scanning lamp (2) is 5.
It is considered as [throat].

First, assuming that the maximum original size of the original that can be set on the placing surface of the original platen (1) is 88, its length is 420 [mm], and the maximum scanning length is 55 cm (420 C+nm) plus the slit width. Including [pus], it is 425 (ran:].

The surface speed of the photoreceptor drum (9) is 130 (mm/sec)
Therefore, the maximum scanning time at the same magnification (1001 magnification) is 4257130 = 8.27 C seconds. This time is set by a microcomputer and is used as the scan return timing.

The scanning time for A8 paper at the same size is set in this manner, but the scanning time for cases other than the same size for A8 paper is set as shown in FIG.

In other words, in the case of one-time original size and enlarged copying, (paper size of traveling paper + 5) (+mn) is set to 180 [I++
++I/sec]. For example, in the case of B-hand paper, (364+5) 7130 = 2.
84C seconds]. For a magnification of 140 inches, the scanning speed is 1ao/1. +=92. s6 (throat/second),
The scanning distance of the scanning lamp (2) is 92.86 x 2.8
4=267.7 (kaku).

In this way, in the case of normal magnification and enlargement, the scanning time is determined by the size of the paper being traveled. In other words, as shown in Figure 4, 88 is 827 seconds, B4 is 2.84 seconds, A4 is 232 seconds, and A5 is 165 seconds.
seconds]. Therefore, at the start of scanning, if the determination result of YES is obtained by determining whether the image is enlarged or the same size in step 2 of FIG. seconds], and in step ◎ set the scanning speed corresponding to the magnification on the programmable counter and start scanning. In this way, when the image size is equal to or greater than the same size, scanning is stopped when the image exactly covers the length of the paper.

Next, for reduced copying, the maximum scanning time is the maximum scanning length 4
25 (from the relationship with wn:l and scanning speed, 8z7゛X
It is regarded as Here, X is the magnification ratio, for example 7
For 0% reduction, -X=07 and 8.27x=3
．． 27 x 0.7 = 2.29 (seconds).The change in the value of 827X corresponding to the magnification ratio
3010.7 = 185.7 (wa/sec),
In the end, the maximum scanning time is 425/185.7=2.29 (seconds).

For reduced copying, for example, when making an 85% reduced copy on A4 paper, the scanning time from straight line 0◇ is 3.27
X O,85=2.78 C seconds], which is longer than necessary. If we apply the above-mentioned method of determining the scanning time for one-time copying at the same size and enlargement, in the case of Person 4, it would be 232 [seconds], and an image sufficient to cover the entire surface of an A4 sheet of paper would be formed within this scanning time. That will happen.

Therefore, in the case of reduced copying, taking these points into account, when the determination result in step ① above is No, in step [F] the value of (paper size + 5) / lao is set to the value of 3.27x magnification. According to the result of the determination, if YES, set the scanning time to 827 x magnification [seconds] and proceed to step ◎; Step [F] if
The scanning time is (paper size + 5)/130 (seconds).
Set it and proceed to step ◎. That is,
In the case of reduction, scanning is controlled to be terminated when the image exactly covers the entire length of the paper or when the scanning system reaches the end of the document table (1), whichever is shorter.

In this way, the scan length can be controlled by time without providing a scan end sensor. Therefore, a scan end sensor is not required, and costs can be reduced and troubles caused by failure of the sensor can be eliminated. Moreover, the problem that the number of copies that can be made per unit time is reduced unnecessarily depending on the reduction rate can be solved, and the copy speed per unit time can be maximized depending on the reduction, enlargement, and paper size. The scan length can be controlled to the minimum required.

Furthermore, copying machines that have a zoom function, for example, a function that allows setting of magnification in 1% increments, require an effective method of controlling the scan length, and it is not possible to meet such demands. This can be done even in the case of zoom magnification.

〔Effect of the invention〕

As described above, the present invention enables scanning control to be performed without using a scanning end sensor, and also requires a scanning length that maximizes the copying speed per unit time according to the magnification and paper size. It has the advantage of being able to minimize the

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the interior of a copying machine to which an embodiment of the present invention is applied, Fig. 2 is a configuration diagram of a microcomputer, Fig. 3 is a flowchart for determining the scanning time, and Fig. 4 is a diagram showing the magnification ratio. FIG. 3 is a diagram showing the relationship between scanning times. Explanation of symbols (1)...Original table (2)...Scanning lamp (9)...Photoconductor drum)...
・CPU Patent Applicant: Fuji Xerox Co., Ltd. Agent: Tomohiro Nakamura, Patent Attorney, Katsuo Naruse, Figure 1, Figure 2, Figure 3, Figure 4

Claims (1)

[Claims] A method of controlling the scanning length of a scanning system according to time, the method comprising:
For full-size copies, the time calculated by dividing the length of the paper by the moving speed of the photosensitive material is used as the standard, and for reduced copies, the time calculated by dividing the length of the platen by the scanning speed or the length of the paper is used as the standard. A scanning system control method characterized in that the scanning length is determined based on the shorter of the time divided by the moving speed of the material.