JPS6261039A - Detecting method for original size in variable power copying machine - Google Patents

Abstract

PURPOSE:To detect a variety of originals in size and to sufficiently demonstrate APS and AMS functions by setting the variable power mirror of a scan optical system or an image forming lens at an magnified position even in a variable power mode and detecting the original size. CONSTITUTION:When an original size detecting mode is set, it is checked to be a variable power mode or not. If so, the 2nd and 3rd mirrors 13 and 14 and the image forming lens 15 are set at the unmagnified position. Thus the scan optical system 9 can fully scan, and detect the sizes of any originals 5. As a result, the APX and AMS functions can be demonstrated without being limited.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a document size detection method in a variable magnification copying machine.

BACKGROUND OF THE INVENTION Conventionally, some variable-magnification copying machines are designed to detect the fM document size. The effectiveness of size detection can be roughly divided into automatic paper selection (APS) and automatic magnification selection (APS).
There are two types: MS). APS is a function that automatically selects and feeds transfer paper of the same size as the original size determined by original size detection from a multi-stage cassette, and copies it at the same size. or.

The Seraglio AMS is a function that calculates the magnification based on the ratio of the preselected transfer paper size and the original size, and obtains a copy with the magnification corresponding to the transfer paper.

When detecting the original size by exposure scanning with the scanning optical system, if the magnification mode is set, the magnification mirror and imaging lens in the scanning optical system will adjust the optical path length according to the magnification ratio. It is moved to the magnification position so that At this time, especially when the magnification is set, the variable magnification mirror and lens become close to each other, and the scanning distance of the scanning optical system is restricted to be shorter than when it is at full magnification, which limits the size of the document that can be detected. Become. The range of this is limited by the magnification set by the APS function described above. For example, when the magnification is in the range of 0.5 to 1.04, A3°B4. A4R,B
Even if various sizes such as 5R, A4, 85, etc. can be detected, B4. A4R,
B5R, A4. BS size, magnification 1.16-1.27
In the range of A4R, B5R, A4. B5 size and magnification range of 1°28-1.44 are B5R, A4. In the B5 size and the magnification range of 1.45 to 1.55, the sizes that can be detected are limited to A4 and B5 sizes respectively.

Furthermore, with respect to the AMS function, it is inconvenient if the detection of the document size is restricted.

Purpose The present invention was made in view of the above points, and it is an object of the present invention to provide a document size detection method for a variable magnification copying machine that can detect the document size without being restricted by the variable magnification ratio. do.

Structure In order to achieve the above object, the present invention provides a scanning optical system including an exposure light source for exposing and scanning a document, a control means for controlling the reciprocating operation of the scanning optical system, a colored document pressure plate, a document and the document. A variable magnification device comprising: an original size detecting means for determining the original size from the difference in reflected light from the pressure plate; and a position movement control means for moving the positions of the mirror and the imaging lens of the scanning optical system according to the copying magnification. In the copying machine, in the original size detection mode, the scanning optical system and the original size detection means are operated after the magnification changing mirror and the imaging lens are set to the same magnification position by the position movement control means at the same time as the copy start command is issued. This feature is characterized in that the size of the document is detected by

Hereinafter, one embodiment of the present invention will be described based on the drawings. First, the configuration of a variable magnification copying machine will be explained with reference to FIG. A contact glass 2 is provided on the top of the copying machine body 1, and an automatic document feeder (ADF) is mounted on the contact glass 2.
3 is provided.

The ADF 3 is attached to the contact glass 2 in a manner that allows selection of a document pressure plate (not shown), and allows the document 5 stacked on the document table 4 to be fed one by one by the paper feeding unit 6 and transported. It is conveyed over the contact glass 2 by a belt 7 and stopped and set at a predetermined position. After copying, the conveyor belt 7 is driven again to discharge the original 5 onto the original tray 8.

On the other hand, a scanning optical system 9 is provided below the contact glass 2. This scanning optical system 9 is connected to a contact glass 2.
A halogen lamp 10 serves as an exposure light source for exposing and illuminating the upper original 5, first to third mirrors 12, 13, and 14 that receive reflected light from the original 5 and form an image on the photoreceptor 11, an imaging lens 15, and a third mirror. It consists of 4 mirrors 16. Here, the halogen lamp 10 and the first mirror 12 are used as a first scanner and are driven by a scanner motor 17. During copying, the home position Hp (g) is the original setting reference position on the contact glass 2 in the pressure plate mode. It is set to move forward from the maximum scanning position (corresponding to RP) to the maximum scanning position (return position) RP, and return again from this maximum scanning position RP to the home position HP. And the second
, 3 mirrors 13 and 14 are used as a second scanner and are set to move in the same direction at a speed of 172 as the first scanner. Also, during variable magnification copying, the second and third mirrors 13
, 14 are moved to predetermined positions according to the magnification by a mirror motor 18, and the imaging lens 15 is also set to be moved to a predetermined position by a lens motor 19.

Further, the first scanner is equipped with document size detection means 2o. The document size detecting means 20 has an optical fiber 21 mounted on the first scanner, and the other end of the optical fiber 21, so that the reflected light when the document 5 side is illuminated by the halogen lamp 10 is incident thereon. It is composed of a photodiode 22 provided in a fixed part within the main body of the apparatus. Here, the document size detection by the document size detection means 20 is carried out based on the difference in light intensity between the light reflected from the document 5 and the light reflected from the conveyor belt 7 functioning as a document pressure plate. Considering that the background of the original document 5 is white, the conveyor belt 7 is colored yellow to create a difference in the amount of reflected light (in this embodiment, an ADF 3 is used; The document pressure plate, which can be selected at will, is also colored yellow so that it has approximately the same spectral reflectance as the conveyor belt 7...Such a configuration is obvious even without turning it. be). The reason for coloring in yellowish color is to utilize the spectral sensitivity characteristics of the photoreceptor 11 shown in FIG. In other words, the sensitivity of the photoreceptor 11 to short-wavelength yellow light is low, so it is difficult to capture it as an image, and the photodiode 22 used in this example
This is because the sensitivity is on the shorter wavelength side, and the sensitivity is relatively high for white colors and low for yellow colors. By the way, the spectral sensitivity half width of each of the photoreceptor 11 and the photodiode 22 is approximately 490 to 620.
nm, 420 to 470 nm.

The surroundings of the photoreceptor 11 have a well-known configuration, and although not described in detail, processes such as charging, exposure, development, transfer, cleaning, and neutralization are repeated in synchronization with the scanning operation of the scanning optical system 9. A multi-stage transfer paper cassette 23 is provided as a single paper processing system, and settings are made such that transfer paper 24 of various sizes can be selected. The selectively fed transfer paper 24 is conveyed to the transfer section in synchronization with the image on the photoreceptor 11.

After that, it is fixed and discharged.

Next, a block diagram of the control system is shown in FIG.

Basically, input/output processing is executed by a CPU (microcomputer) 25 via a load port 26 and a port 27 for input.

The optical signal for detecting the document size from the optical fiber 21 is input to the photodiode 22, and the optical signal is input to the op amp 2.
8.29 and connected to the A/D input of the CPU 25, and further uses a built-in timer to detect the document size from the scanner operation and this A/D input value. In this embodiment, the first scanner of the scanning optical system 9 moves back to the left from the maximum scanning position [RP] with the original 5 set on the contact glass 2 based on the home position HP, as will be described later. The length of the document 5 is determined by calculation based on the timer value at the time when the right edge of the document 5 is detected. The scanner motor 17, the mirror motor 18, and the lens motor 9 are controlled by the CPU 25 via the DC motor controller 3o, and the speed of the scanner motor 17 is changed and the forward/reverse drive is performed. Reverse driving is performed. Further, for the halogen lamp 10, D/
The phase of the alternating voltage applied from the stabilized power supply 32 via the A converter 31 is controlled.

That is, this phase control is performed in accordance with the image density adjustment state of an operating section (not shown), and the lighting state of the halogen lamp 10 is controlled from 1 to 1. However, when detecting the document size, the amount of light incident on the photodiode 22 changes as shown in FIG. 6 depending on the amount of light from the halogen lamp 10, so the phase is controlled to be constant in order to always detect with a constant amount of light.

Control of the copying operation in this embodiment will be explained with reference to the timing chart of FIG. 3 and the flowchart 1- of FIG. 4. In addition, the operation section has size detection mode,
A switch is provided for selecting and inputting various modes such as variable magnification mode, ADF mode, APS mode, and AMS mode.

First, it is checked whether or not the size detection mode is set, and if the size detection mode is not set, the print signal is output.
It will be in a state of waiting for N. Then, when the print 1 button is pressed and the print signal is turned ON, it is checked again whether or not the document size detection mode is set. In this case, since it is not the document size detection mode, the normal copy routine is performed.

In this normal copy routine, the phase angle of the stabilized power source 32 is set in accordance with the notch of a'A degrees set by the operator, and the halogen lamp 10 is turned on. The drive motor that drives the photoreceptor 11, etc.
Do N. Here, the time it takes for the light intensity of the halogen lamp 10 to become stable after lighting it varies somewhat depending on its voltage and energizing voltage, but in this example it takes about 600m5.Therefore, after lighting the halogen lamp 10, 6
After 00 ms have elapsed, execution of the normal copy routine begins. That is, forward movement of the scanner motor 17 for exposure scanning of the original 5 is started. The driving speed of this scanner motor 17 is the third speed, and this speed changes depending on the magnification set by the operator. As a result, the scanning optical system 9
The first scanner moves forward from the home position HP toward the maximum scanning position [RP to expose and scan the document surface. and.

A copy processing routine is executed in parallel with this.

This copy processing routine includes control of devices surrounding the photoreceptor 11 such as charging, development, and transfer, feeding of the transfer paper 24, registration alignment, paper ejection, etc., but since they are well known, their explanation will be omitted. After that, when the first scanner performs exposure scanning for a length corresponding to the magnification and paper size, the preset scanner travel counters match, so at that point the scanner motor 17 is reversed to start backward movement. . The speed of the scanner motor 17 during this backward movement is a preset fourth speed, and is driven at high speed to increase the copying speed. As a result, the first scanner returns to the home position HP at high speed.

Here, it is checked whether the number of copies per copy matches the preset number of copies for repeat copying, and if they do not match, it is checked whether the first scanner has returned to the Ho 11 position HP by checking whether the HP sensor is turned on. do. Then, upon returning to the home position HP, the scanner motor 17 is turned off. Thereafter, the copy routine is executed repeatedly in the same manner. If the number of copies is equal to the number of copies set, it is checked whether the ADF mode is selected. If it is not the ADF mode, wait for the HP sensor to turn on, and when the first scanner returns to the home position HP, turn off the scanner motor 17 and turn off the halogen lamp 10. Then, post-copy processing such as cleaning the photoreceptor 11 and discharging the transfer paper 24 is executed. Finally, turn off the drive motor.
F and waits for the next print command. On the other hand, A
In DF mode, it is checked whether there is the next original 5, and if there is still original 5, after the previous original 5 is ejected, the copying operation is performed for the following original 5 in the same way, and the original 5 is
If it runs out, the copy post-processing etc. will be executed in the same way.

The case where the document size detection mode is set will now be described. When this mode is selected, it is first checked whether it is the variable magnification mode.

In the variable magnification mode, the second and third mirrors 13 and 14 and the imaging lens 15 are set at equal magnification positions. I will explain Kome-point in detail. Generally, in the case of variable magnification copying, the second and third mirrors 13, 14 and the imaging lens 15 are located at respective variable magnification positions as shown in FIG. is configured so that it can be obtained. In FIG. 1, the states 13a, 14a, and 15a are the same magnification m=1 position, the states 13b, 14b, and 15b are the reduction magnification m=0.5 position, and 13c,
The states indicated by 14c and 15c are the positions where the magnification magnification m=1.41. Therefore, at the time of enlarging copying, the second and third mirrors 1
3c, 14c, and the imaging lens 15c at a position of m=1.41. Therefore, when trying to move the first scanner of the scanning optical system 9 to the maximum scanning position RP, the third mirror 14c and the imaging lens 15c collide with each other due to the layout, and the first scanner cannot be moved to the starting position for document size detection. cannot be moved to the maximum scanning position RP. Therefore, even in variable size copy mode, these second and third
The mirrors 13, 14 and the imaging lens 15 are set to be moved to a position where the magnification m=1, and the first scanner can be moved to the maximum scanning position RP. Also, as mentioned above, the effectiveness of document size detection is APS and AMS, but when considering these functions, it is better to detect the document size with the document set in the same size state in advance when detecting the document size. This can be said to be advantageous in terms of control and operation.

For this reason, in this embodiment, in the document size detection mode, even in the variable magnification mode, the second,
The three mirrors 13 and 14 and the imaging lens 15 are set at equal magnification positions.

After this, when the print button is pressed and the print is turned on,
Since this is the document size detection mode, in this case, the halogen lamp 10 is controlled to be lit in four notches. This is to turn on the halogen lamp 10 at about 65 Vrms in order to always turn on the halogen lamp 10 with a constant light amount during size detection as described above. At the same time, the drive motor is also turned on to rotate the photoreceptor 11. This is halogen lamp 1
Since the light from 0 is also illuminated on the photoreceptor 11, the photoreceptor 1
This is to prevent partial optical fatigue of the photoreceptor 11 by rotating the photoreceptor 1. Next, if it is not the ADF mode, forward movement of the scanner motor 17 is started to move the first scanner from the home position HP to the maximum scanning position RP. At this time, the scanner motor 17 is driven at the first speed.

The reason why the first scanner is moved to the maximum scanning position 1i7RP in this way is that it takes about 600 m5 for the light intensity of the lit halogen lamp 10 to become stable, and within this time the first scanner is moved to the maximum scanning position 1i7RP. 1iWRP
A first speed is set to reach a speed of . Also, S.D.
In the F mode, the document conveyance motor is turned on to carry out document conveyance, and in order to stop the document 5 at a predetermined position on the contact glass 2, a document feed counter is also started.

At this time, the speed of the document transport motor is the same as that of the first scanner of the first scanner.
The document feed counter reaches a predetermined value and the document feed motor is turned off before the RP sensor, which detects that the first scanner has reached the maximum scanning position RP, is turned on. Here, - To give an example, the distance between the first scanner and document transport is approximately 480 range,
The first speed is approximately 800 nwm/s, and the original transport speed is approximately 10
00m/s, and the traveling time of the first scanner is 600m5. The conveyance time of the original 5 is 480 m5.

In this way, when the first scanner moves to the maximum scanning position RP, the amount of light from the halogen lamp 10 remains stable. Therefore, the document size detection operation is executed by starting the backward movement of the first scanner from this maximum scanning position [RP. Therefore, the size counter starts detecting the star 1-L and document size. At this time, the faster the backward movement speed of the first scanner is, the shorter the first copy time can be, but if it is too fast, the size detection error will increase as shown in Figure 7, which shows the relationship between the backward movement speed and the detection error. As the speed increases, the accuracy deteriorates, so in this embodiment, the second speed at this time is set to 480 nn/s to suppress the detection error to 3I or less (
However, in cases where poor detection accuracy is acceptable, this second
(The speed may be increased to about 1000 mm/s). Since the document 5 is set based on the home position HP during the backward movement of the first scanner, the reflected light from the conveyor belt 7 is initially guided to the photodiode 22 by the optical fiber 21. As the backward movement progresses, the amount of reflected light changes and the photodiode 22 receives reflected light from the edge of the original 5, resulting in a state where an original signal is present. As a result, the size counter stops, and the document size is determined by counting backwards from the count value of this size counter. In this embodiment, this size counter has a timer configuration, the distance from the RP sensor position to the HP sensor position is 480■, and the detection speed (second speed) is 480cm.
Since the speed is 80 nn/s, in order for the first scanner to move from the maximum scanning position RP to the home position HP, it takes 101 nn/s.
This will take 000 hours. Therefore, for example, the contents of the size counter (timer) are T=380m s (
31st! (see I), the size of document 5 at this time is 1.
000-380=620 (ms), 620 m
s×480m/5=297.6mm. This is determined to be document 5 of A4 lengthwise (297 mm) feed. Then, when the HP sensor detects ONL and the first scanner returns to the home position HP,
The scanner motor 17 is turned off.

Next, it is checked whether the size can be recognized in such document size detection. If the size is not recognized, the size unknown is displayed, the halogen lamp 10 and the drive motor are turned off, and the next command is waited for. If the size is recognized, it is determined whether the mode is APS mode or AMS mode. . In APS mode, it is checked whether a transfer paper 24 of the same size as the recognized original 5 is set, and if there is a transfer paper 24 of that size, this transfer paper 24 is automatically selected and fed. Paper and move on to the next step. If there is no transfer paper 24 of this size, the transfer paper check display is turned on, the halogen lamp 1o and the drive motor are turned off, and the next command is waited for. On the other hand, AMS
In the mode, the magnification is calculated from the ratio between the recognized original size and the preselected size of the transfer paper 24.

For example, if the original is A3 size and the transfer paper 24 is A4 size, the magnification will be 0.71. The second and third mirrors 13 and 14 and the imaging lens 15 are moved and set from the same magnification position to a predetermined position in accordance with the magnification calculated in this manner. Then, the exposure scanning speed (third speed) of the first scanner is calculated according to the magnification.

Proceed to the next step. Since such APS mode and AMS mode processing is well known, details thereof will be omitted.

In this manner, when the processing for the ASP mode or the AMS mode is completed, the notch of the halogen lamp 10 is deflected to the notch specified by the operator. Then, the scanner motor 17 is moved forward at a predetermined third speed, and the first scanner is started to perform exposure scanning from position P. After that, the copy routine is executed in the same way as the normal copy routine, and a series of Finish the copy process.

FIG. 3 shows an example of a timing chart corresponding to such processing, and in this case, the document size detection mode is selected and the number of sheets per repeat copy is one.

In this way, according to the document size detection method of this embodiment,
Even in the variable magnification mode, when detecting the document size, the second and third mirrors 13 and 14 for variable magnification and the imaging lens 15 are not moved to the variable magnification position, but are set to the same magnification position.
The scanning optical system 9 is capable of full scanning and can scan any original 5.
This means that the size of can be detected. As a result, the APS function and AMS function can be performed without restrictions.

In particular, since the AMS function is a function that automatically sets the magnification based on the 5M document size and the selected transfer paper size, it is reasonable to temporarily return to the same magnification as in this embodiment. Also, although it takes time for the light intensity of the halogen lamp 10 to become stable, the scanning optical system 9
Maximum scanning position 1 from the home position HP of the scanner
7RP, detect the original size when returning from this maximum scanning position RP, and when it returns to the home position HP, move it forward from this position HP to perform exposure scanning of the original original 5 to obtain a copy. Therefore, even if the document size is detected, the time required to obtain the first copy can be shortened without being affected by the stabilization time of the halogen lamp 10. Furthermore, if document size detection is not required, the operation at the time of document size detection is not performed, and normal exposure scanning from the home position HP is sufficient, so that the time required to obtain the first copy is shortened.

Effects As described above, the present invention sets the magnification mirror of the scanning optical system and the imaging lens at the same magnification position even when magnification is being changed when detecting the document size, so there is no restriction. It is possible to detect various JM document sizes and fully utilize the ASP function and AMS function.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a schematic side view, Fig. 2 is a block diagram, Fig. 3 is a timing chart, Fig. 4 is a flow chart, and Fig. 5 is a characteristic diagram of spectral sensitivity. , FIG. 6 is a characteristic diagram of detection speed versus detection error, and FIG. 7 is a characteristic diagram of lamp voltage versus detection voltage. 5... Original, 7... Conveyance belt (original pressure @), 9...
...Scanning optical system, 10...Halogen lamp (exposure light source), 13.14...Mirror, 15...Imaging lens,
2o...Document size detection means" Z style J3 Takumi 35 present 36 style

Claims (1)

[Claims] A scanning optical system including an exposure light source that exposes and scans the original, a control means that controls the reciprocation of this scanning optical system, a colored original pressure plate, and a document size determined from the difference in the amount of light reflected from the original and the original pressure plate. In a variable magnification copying machine equipped with a document size detecting means for detecting a document size, and a position movement control means for moving a mirror and an imaging lens of the scanning optical system in accordance with a copying magnification, a copying start command is issued in a document size detection mode. At the same time, the mirror and the imaging lens for variable magnification are set at the same magnification position by the position movement control means, and then the scanning optical system and the document size detection means are operated to detect the document size. A method for detecting document size in a double copying machine.