JPS62184483A - Variable power copying device - Google Patents

Abstract

PURPOSE:To obtain a small-sized and light-weight common photosensitive unit based on a four-mirror system by controlling timing from the positional detection of a platen or an optical system to the start of a regist roller member in accordance with copying magnification. CONSTITUTION:Encoder pulses from a pulse generator in a body driving system are counted based on a reference signal obtained at an original platen 23 scanning home position detected by an HP sensor 46 and a working plate, and after a prescribed time, a regist roller clutch for starting a regist roller 37 and an eraser 28 are controlled so as to be turned on/off. Thus, registration for matching transfer paper 30 with the leading edge of an image and erasing of the leading and final ends of the image are controlled. Since the ON/OFF timing of the clutch and eraser is controlled in accordance with magnification based on a scanning home position detecting signal for the original platen 23, the registration or erasing can be prevented from being shifted even if the position of an image forming point on the photosensitive body 25 is changed at the variation of magnification.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a variable magnification copying apparatus of a moving document table type or a moving optical system type using a planar photoreceptor such as a belt-shaped photoreceptor.

BACKGROUND OF THE INVENTION In recent years, many copying machines are equipped not only with the same size copying function but also with variable magnification functions such as enlargement and reduction, and there are various methods for doing so. Here, for example, under the premise that the photoreceptor is a flat photoreceptor such as a belt, the exposure part is set horizontally, and the scanning system is a system in which the document table moves, the image shown in FIG. 23 is used. A 6-mirror type is common.

That is, the first to third mirrors 3,
4.5, an imaging lens 6, and 4th to 6th mirrors 7.8.9.
This is accomplished by moving the mirror 4.5 or the 4.5-degree mirror 7.8 in the horizontal direction to correct the optical path length. However, in such a six-mirror system, the number of mirrors is large, and the number of mirror supporting members for these mirrors also increases, resulting in an increase in cost. Further, due to such a mirror arrangement configuration, the device becomes large in size.

On the other hand, as shown in FIG. 24, there is also one constructed as a four-mirror type. An optical system including the first to third mirrors 12° 13.14, an imaging lens 15, and a fourth mirror 16 is provided between the document table 10 and the belt-like photoreceptor 11, and It is designed to form an image.

During zooming, the imaging lens 15 and the second and third mirrors 1
3.14 becomes 2 which moves in position in the horizontal direction. According to this, the number of mirrors will be reduced, but for example, the number of Mira sheets will be reduced.
As shown in Fig. 5, a focusing optical transmitter array 17 such as a SELFOC lens array, which is advantageous as a small copying machine exclusively for cans, is used.
The image is formed on the photoreceptor 18 using
It is not possible to standardize photoconductor units. This is because in the case of FIG. 25, the exposure image is formed on the horizontal portion of the photoreceptor 18, whereas in the case of FIG. 24, the image is formed on the inclined portion of the photoreceptor 11. Therefore, it is inconvenient that the same photoreceptor unit cannot be used to manufacture a variable-magnification copying machine, a copying machine exclusively for cans, etc., depending on the application.
It is not possible to reduce the cost by a fraction of the cost. In particular, considering that in recent years, such a belt-shaped photoreceptor, including its surrounding members, has been unitized as an OPC belt photoreceptor magazine (OPC belt photoreceptor magazine), it is uneconomical that it cannot be used for both purposes.

Purpose The present invention was made in view of the above points, and it is possible to provide a variable magnification function with a single 4-mirror system that is small, lightweight, and low cost, and also to provide a converging optical transmission body exclusively for the same magnification. It is an object of the present invention to provide a variable-magnification copying device that can be used in common with a photoreceptor unit of a copying device using an array or the like, and can perform normal copying operations during variable-magnification operations.

Structure In order to achieve the above-mentioned object, the present invention includes a document table on which a document is placed, and a planar photoreceptor having a flat portion in an exposure section and on which an image of the document is formed. A first mirror, a second mirror, an imaging lens,
An optical system is provided in which a third mirror and a fourth mirror are arranged in this order, and the fourth mirror projects and forms the original image at right angles on the flat part of the photoreceptor, and the original table or this optical system is relatively A drive source for scanning and movement is provided, a position detection means is provided for detecting the position of the document table or the optical system, and the imaging lens and the third mirror are aligned along the lens optical axis direction when changing magnification for enlargement or reduction. A variable magnification driving means for moving the optical path length to correct the optical path length is provided, and a registration roller member is provided for feeding the transfer paper to the transfer position of the photoreceptor at a predetermined timing,
The present invention is characterized in that a control means is provided for controlling the timing from the detection of the position of the document table or the optical system by the position detection means until the start of the registration roller member according to the copying magnification.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 21. This embodiment is applied to a fixed optical system moving document table type copying machine, and the overall structure of the variable magnification copying machine will be explained with reference to FIG.

First, the original 21 is placed in the upper part of the copying machine body 20 manually or
A document table 23 on which a DF (automatic document feeder) 22 is set is provided. This document table 23 is reciprocated in the left and right directions in FIG. 2 by a dedicated servo motor (not shown). Here, when changing the magnification, the moving speed is varied in order to enlarge or reduce the scanning direction. On the other hand, a belt-shaped photoreceptor 25 is provided within the copying machine main body 20 and is supported by and rotationally driven by a plurality of rollers 24, for example, three rollers 24.

The space between the rollers 24a and 24b of the photoreceptor 25 is a flat portion 25a in a horizontal state. Further, this photoreceptor 25 has a seam 25b as shown in FIG. 2, and images are formed while avoiding this seam 25b. Here, this photoreceptor 25
For example, the Director General is compatible with A3 portrait size. Around the photoreceptor 25, there is a main charger 26 that performs uniform charging according to the electrophotographic process, an optical system 27 that forms an electrostatic latent image by forming an image of the original 21 on the flat portion 25a, and a leading and trailing end. , an eraser 28 having an LED array configuration for erasing unnecessary parts of the latent image such as site erase, a developing device 29 including a developing sleeve 29a for developing the electrostatic latent image into a visible image, and a transfer paper 30 for transferring the visible image. A transfer charger 31 for transferring the image, a cleaning device 32, and a discharge lamp 33 having an LED configuration are provided in this order.

Here, the transfer paper 3o is set in the lower part of the copying machine main body 20 by a transfer paper cassette 34, and the paper feed roller 3
5. It is set to be sent to the transfer position by the transfer charger 31 by an intermediate roller 36 and a registration roller 37 as a registration roller member. Here, an insertion roller 38 is also provided facing the intermediate roller 36, and is set so that paper can be manually fed from the outside. Further, a conveyance belt 39, a fixing device 4o, a paper discharge roller 41, and a paper discharge tray 42 are provided downstream of the transfer section. Here, a pre-intermediate sensor (manual feed sensor) 43 is provided before the intermediate roller 36, a pre-registration sensor 44 is provided before the registration roller 37, and a pre-discharge sensor 45 is provided before the paper discharge roller 41. .

Further, a home position HP sensor 46 is provided as a position detecting means for detecting the position of the document table 20, and a sensor operating plate 47 for activating the HP sensor 46 is attached to a predetermined position of the document table 20.

Next, the configuration of the optical system 27 will be explained.

First, a lamp 48 for exposing the original 21 on the original platen 20 to slit light, a reflector 49, and an auxiliary reflector 50 are provided. The reflected light from the original 21 is reflected by a first mirror 51,
A four-mirror system including a second mirror 52, an imaging lens 53, a third mirror 54, and a fourth mirror 55 are arranged in this order to form an image on the flat portion 25a of the photoreceptor 25.

More specifically, the optical path from the second mirror 52 to the imaging lens 53 to the third mirror 54 is set in a horizontal state parallel to the flat part 25a of the photoreceptor 25, and the fourth mirror 55 is set in a horizontal state parallel to the flat part 25a of the photoreceptor 25.
This is to form an image vertically above. Here, expand
1st degree 2.4 mirror 51, 52.55 when changing magnification for reduction
is fixed in position, but the imaging lens 53 and the third mirror 54 as an optical path length correction mirror are moved in the horizontal direction (that is, in the optical path direction connecting the imaging lens 53 and the fourth mirror 54) according to the variable magnification. Moving. First, at the same magnification, the imaging lens 53a and the third mirror 54a are at the positions indicated by the suffix a in FIG. 1, and an image is formed on the point A on the photoreceptor 25. Then, at the time of reduction copying, the imaging lens 53 moves rightward to the position shown by the imaging lens 53b, and the third mirror 54 also moves rightward to the position shown by the third mirror 54.
The image is formed at point B on the photoreceptor 25 at a position as shown by b. On the other hand, during enlarging copying, the imaging lens 53 moves to the left and takes the position shown by the imaging lens 53c, but the third mirror 54 also moves to the right when enlarging, and takes the position shown by the third mirror 54c. The position will be 0 on the photoreceptor 25.
The image is formed into a point. In other words, the imaging point on the photoreceptor 25 moves to the left during both reduction and enlargement compared to when the image is at the same magnification. Such an enlargement/reduction magnification variable system is possible by using a belt-shaped photoreceptor 25 and forming an image forming portion as its flat portion 25a.

Next, such an imaging lens 53 and third mirror 5
4 will be explained with reference to FIGS. 4 to 6. First, the imaging lens 53 is supported by a lens bracket 56 and is movable in the left-right direction along a guide rod 57. A stepping motor 58 is provided as a drive motor for moving the imaging lens 53. This stepping motor 58
A worm wheel 60 is provided which meshes with a worm gear 59 on the drive shaft. This worm wheel 6o
is a base 61 and a drive bracket 6 as shown in FIG.
2, and a drive pulley 64 is provided on the second shaft 63. A drive wire 67 is stretched between the drive pulley 64 and a tension pulley 66 urged outward by a spring 65. A portion of this drive wire 67 is secured to the lens bracket 56 by a wire clamp 68. As a result, the stepping motor 58
The rotation of the drive pulley 64 and drive wire 67
The lens bracket 56 (imaging lens 53) is moved in the left-right direction via the lens bracket 56 and the like. Here, the wire clamp 68 is configured so that the relative position of the imaging lens 53 with respect to the drive wire 67 can be adjusted by rotating an eccentric cam 69, thereby making it possible to finely adjust the magnification.

Further, a part of the flange of the drive pulley 64 is used as a sensor actuating plate 70, and is set to detect the same magnification position by actuating a sensor 71.

On the other hand, the third mirror 54 is supported by a mirror bracket 72 and is movable in the left-right direction along a guide rod 73. A bracket 75 supporting a cam follower 74 is attached to the tip of the mirror bracket 72. A rotating cam 76 serving as a driving source for moving the third mirror 54 via the cam follower 74 is integrally provided on the shaft 63 of the driving pulley 64. A cam follower operating spring 77 is provided to keep the cam follower 74 in constant contact with the rotating cam 76. Further, the bracket 75 is fixed to the mirror bracket 72 by an eccentric cam 78, and by adjusting the eccentric cam 78, the position of the third mirror 54 can be adjusted, and the focus is adjusted at the same magnification. .

In such a configuration, the operation during zooming will be described. First, during reduction, the drive pulley 64 rotates clockwise in FIG. 6, and during enlargement, the drive pulley 64 rotates counterclockwise. The third mirror 54 is moved between enlargement and reduction within one rotation of the rotary cam 76 that rotates integrally with the drive pulley 64. The operation in this case will be further explained with reference to FIGS. 7(a) to (C).

First, FIG. 7(a) shows the state at the same magnification. At the time of reduction, the rotary cam 76 rotates clockwise as shown in FIG.
move to the right. When enlarging, the rotating direction of the rotary cam 76 changes and rotates counterclockwise as shown in FIG. 3(c), but the third mirror 54 also moves to the right in this case. In any case, the curvature of this rotating cam 76 increases as the reduction rate and enlargement rate increase, and
It is understood that the pressure J angle (inclination) of No. 6 also increases as the reduction ratio and enlargement ratio increase, and the driving load increases.

In this embodiment, the cam follower 74 is connected to the rotating cam 76.
A cam follower actuating spring 77 for making follow-up contact with the cam follower 74 is located between a pin 79 provided on a bracket 75 integral with the cam follower 74 and a point on the rotating cam 76 on the side of the cam follower 74 from the center of rotation (shaft 63). and a pin 80 provided at a point away from the center. This results in
This reduces the driving load. To explain more specifically, the cam follower operating spring 77 is extended long when the magnification is the same as shown in FIG. 7(a), but in FIG. 7(b).

When reducing or enlarging as shown in FIG.
The position is closer to the 4 side, and the amount of extension of this cam follower operating spring 77 is reduced. This reduces the spring tension. In other words, the minimum tension required for the cam follower operating spring 77 can be set at the time of contraction or expansion, when the load increases the most. As a result, even if the spring tension at the same magnification increases, the driving load does not increase due to the relationship between the cam curvature of the rotary cam 76 and the cam pressure angle.

In this way, considering the sum of the cam pressure angle and the spring tension, the driving torque (driving load) can be reduced to a flat state as shown in FIG.

In this way, since the driving load is reduced, the imaging lens 53 and the third
There is no problem in driving the mirror 54, and no time is required for changing the magnification.

Further, since it uses one drive motor, the cost of the entire drive device can be reduced, and the mechanism can be simplified and lightened.

By the way, in this embodiment, as shown in FIG. 3, the photoreceptor 25 having a seam 25b is used.
The seam 25b is controlled so that no image is formed on the seam 25b.
A seam sensor 81 is provided at a predetermined position relative to the photoreceptor 25 to detect the position of the photoreceptor 25 . This seam sensor 8
Reference numeral 1 is configured as a photosensor or the like that optically detects a reflective mark member or the like attached to the joint 25b of the photoreceptor 25.

Next, the configuration of the operation panel 82 in this embodiment will be explained with reference to FIG. 9. Basically, it is divided into a key manual section 83 and a display section 84. First, the key manual section 83 includes a normal print key 85, clear key 86, count key 87, density adjustment key 88, and AE key 89 for automatic density adjustment, as well as an equal magnification key 90 and an up key for fixed magnification. 91, down key 92, up key 9 when zooming
3. A down key 94 is provided. In addition, the display section 84
is configured to display the magnification, number of copies, operation keys, etc. in response to these key operations.

Furthermore, the control system of this embodiment will be explained with reference to the block diagram of FIG. First, a one-chip CPU 97 is provided which includes a built-in RAM 95 and a ROM 96 and serves as a control means. This CPU97 has a main motor and 4 halogen lamps.
8. 08M solenoid for photoconductor drive, static elimination lamp 33
, bias, main charger 26, optical system motor, eraser 28, transfer charger 31, paper feed solenoid, multi-sheet feed solenoid, intermediate solenoid, registration solenoid, total counter, and other loads 98 are connected, as well as fixing heater, etc. Other loads 99 are also connected. Further, signals from a sensor group 100 such as the intermediate pre-sensor 43, the pre-registration sensor 44, the pre-discharge sensor 45, the HP sensor 46, and the seam sensor 81 are set to be input. Further, the key input section 83 and display section 84 of the operation panel 82 are also connected, and encoder signals, thermistor signals, and other signals are also taken in.

Next, the basic operation of the movable document table 23 will be explained with reference to FIG. 11, which schematically shows the operation. First, in the stationary state, the document table 23 is located at the standby home position as shown in FIG. This is the position where the copying machine main body 2o returns to approximately the center after the copying operation is completed, and the HP sensor 46
It is measured and controlled by encoder pulses from

FIG. 2B shows a state in which the document table 23 is located at the scanning home position where scanning actually starts.
This is the position detected by the HP sensor 46.

From the scanning home position, the document table 23 moves forward by the required length as shown in FIG. 11(c) to scan the document, and from this state shown in FIG.
Continuous copying is performed by moving backward to the scanning home position shown in ) and moving forward again. In the case of single-sheet copying or final copying of repeat copying, the document table 23 is moved back from the state shown in FIG. 3(c) to the standby home position shown in FIG. It is something.

Secondly, since the forward movement speed of the document table 23 as a scanning system is inversely proportional to the copying magnification m, the time required for the document table 23 to reach the image leading edge position of the document 21 from the scanning home position where scanning actually starts. differs depending on each magnification. However, the HP sensor 46 detects the start position (scanning home position R) of the document table 23, measures the length of the document 21 on the document table 23 to the leading edge of the image using the signal from the rotary encoder of the DC motor, and sends a signal. Output.

In other words, even if the moving speed changes during zooming, the signal is always output at a constant position.

However, the output time varies.

The photoreceptor 25 is always driven at a constant speed,
As shown in FIG. 1, the image formation positions (exposure points) on the flat portion 25a are A and B depending on the magnification ratio.

Move like C. As a result, if the registration timing of the transfer paper 3o by the registration roller 37 and the erasing timing of the leading and trailing edges of the image by the eraser 28 are controlled at the same magnification timing, a deviation occurs, and it is necessary to correct this.

In this regard, in this embodiment, the signal at the scanning home position of the document table 23 detected by the HP sensor 46 and the sensor actuating plate 47 is used as a reference signal, and the encoder pulses generated by the pulse generator of the main body drive system are counted. After a predetermined time (i.e., a predetermined pulse), the registration roller clutch that starts the registration roller 37 and the eraser 28 are controlled ON/OFF to perform registration to align the leading edge of the image with the transfer paper 30 and control of erasing the leading and trailing edges of the image. It is something. When changing the magnification, the scanning home position detection signal of the document table 23 is used as a reference, and the ON/OFF timing of the registration roller clutch and eraser is controlled according to the magnification change rate.
This is to prevent transfer paper registration and erase from shifting even if the position of the image forming point on the photoreceptor 25 changes during zooming. Such control is specifically performed by ROM9
This is done based on the registration data table and the leading edge erase data table built into the camera, but before that, the shift of the imaging point during magnification and the like will be further explained.

First, the relationship between the amount of movement of the imaging lens 53 and the amount of change in the conjugate length will be discussed with reference to FIG. In this figure, the object plane corresponds to the original 21, and the image plane corresponds to the photoreceptor 25. In the figure, Δa indicates the amount of movement of the imaging lens 53 from the same magnification position, and Llm.

is the distance between the front principal point of the imaging lens and the object plane at the same magnification, and is specifically 358.173 mm. Further, ΔL indicates the amount of change in the conjugate length, and ΔLOm=, indicates the conjugate length at the same magnification, which is specifically 722.18 mm. However,
The amount of change ΔL in the conjugate length when changing the magnification is determined by m for the magnification and f for the focal length.
In the general formula, ΔL = (m + -2) f However, in the case of this embodiment, the movable mirror is the third mirror 54 located in the image space, so first, the imaging lens The movement amount Δa of 53 is expressed as 8a=L1−L1m=. Then, the amount of change ΔL in the conjugate length during zooming is ΔL=LO−LOm! .

It is shown by.

Next, the amount of movement of the third mirror 54 and the amount of change in the exposure point are calculated with reference to FIG.

First, as explained in FIG. 1, in the variable magnification system of this embodiment, the document table 23, the flat portion 25a of the photoreceptor 25, and the lens optical axis are parallel, and the angle of incidence on the photoreceptor 25 is 90°. (vertical). When changing the magnification, the 1st, 2nd and 4th mirrors 5
1, 52, and 55 are fixed in position and move the imaging lens 53 and the third mirror 54.
4 moves parallel to the imaging lens 53 (that is, the angle θ is always constant), the exposure point position on the photoreceptor 25 also changes depending on the magnification. Therefore, here, the third mirror 54
The amount of movement ΔM of the image forming point and the amount of movement ΔE of the imaging point (the amount of movement at the center of the optical axis) are calculated using calculation formulas. Therefore,
Consider the dimensional relationship of each part as shown in FIG. In this figure, the imaging light beam at the same magnification is shown by a solid line, and the imaging light beam at the time of variable magnification is shown by a chain line. Then, the lens optical axis and the third
The angle θ (optical path refraction angle) formed with the mirror 54 is constant, specifically θ=22°. Also, the fourth mirror 55
The angle of inclination of is denoted by θ' with respect to the perpendicular. This 14th
According to the figure, the optical path length from the third mirror 54 to the top of the photoreceptor 25 at the same magnification is expressed as D100f. And the magnification m
When the optical path length is changed by Δ to change the magnification to the state shown by the dashed-dotted line, it is expressed as ΔM10a1111f. In other words, D100f0ΔL = ΔM+a+D0b+f As a result, ΔL is ΔL; ΔM+a+b− is length, c is b=e−cosθ′, C=e”co
Since sθ' and b=c, ΔL=ΔM+a. Here, since a=ΔM−CoSθ, substituting this into the above equation yields ΔL=ΔM+ΔM−CO8θ=(1+cosO)·ΔM. As a result, the relationship between the amount of movement ΔM of the third mirror 54 and the amount of change ΔL of the conjugate length can be expressed as in the following equation (1).

ΔL (1) ΔM=1+. .

5° Also, in Fig. 14, the length g is shown as g=Δm-5inθ, g=d, d=e-sinθ', ΔE=e-8i
Since nθ′ and ΔE=g, ΔE=ΔM−s
It is indicated by inθ. Substituting the above-described equation (1) into this equation gives the following equation, which represents the relationship between the amount of change ΔE of the exposure point and the amount of change ΔL of the conjugate length.

However, more specifically, the slit width of slit exposure also changes when changing the magnification, and the amount of change in the exposure start point that also takes into account this change in slit width is defined as ΔE' as shown in FIG. If the slit width at the time of doubling is S, then the amount of change ΔE' in the exposure start point is expressed as follows.

In this way, when changing the magnification based on the movement amount ΔM of the third mirror 54, the movement amount ΔE of the imaging point, and the movement amount ΔE' of the exposure start point as shown in equations (1), (2), and (3), The amount of movement of the exposure start point can be calculated, and the data calculated for each magnification can be used as a resist data table as shown in Table 1 and as a tip erase data table as shown in Table 2.
It is written in the table of ROM96 in PU97. Note that in these tables, DB means a data buffer, and each data is expressed as the number of encoder pulses.

In such a configuration, the main flowchart in FIG. 16, the interrupt flowcharts in FIGS. 17 to 19, and the magnification key reception subroutine flowchart in FIG. 20 regarding operations including basic copying operations and their control. and the timing chart of FIG. In addition, in the flowchart, the judgment and processing numbers shown in Table 1, Registration Data Table, Table 2, and Tip Erase Data Table are shown in parentheses as in (1). The numbers shown correspond to each other. Further, in the timing chart of FIG. 21, the numbers shown without parentheses are the number of encoder pulses regarding the timing of each process.

First, a copy operation is performed by pressing the print key 85, but if the print key 85 is not pressed, another copy control routine shown at (9-0) is executed based on the determination result of (1). And print key 85
If the button is pressed, the timer setting processing shown in (2) to (8) is performed.

The reason why the main motor ◯N timer is set in the process (2) is to delay turning on the main motor until the 08M solenoid starts up.

In step (3), an exposure lamp ON timer is set to turn on the lamp for reading the document density after a certain period of time. In (5), an optical motor return timer is set in order to move the document table 23 from the standby home position to the scanning position after a certain period of time. Then, in (8), a counter OFF timer is set. On the other hand, (4)
, (6), and (7), the 08M solenoid is turned on to prevent the photoreceptor 25 from rotating, the paper feed solenoid is turned on to rotate the paper feed roller, and the 08M solenoid is turned on to prevent the photoconductor 25 from rotating, and the paper feed solenoid is turned on to rotate the paper feed roller. Turn on the counter. After such processing, the intermediate front sensor 43 makes a judgment as shown in (10).
If 3 is not ON, another copy control routine indicated by (9-1) is executed. On the other hand, if the transfer paper 30 is fed and the front intermediate sensor 43 is ON, the paper feed solenoid OF is turned on to stop the rotation of the paper feed roller 35 after a certain period of time.
Set the F timer (process (11)).

Next, judgment is made to determine the position of the document table 23 (12).
Check the HP sensor 46 as shown in . If the document table 23 has not moved to the scanning home position, (
9-2) executes another copy control routine. However, if the document table 23 moves to the scanning home position and the HP sensor 46 is ON, (13) to (1)
Execute the process shown in .

First, in (13), reading of the original density is completed by moving to the scanning home position, so the exposure lamp 48
Turn off. In (14), the 08M solenoid is turned off in order to rotate the photoreceptor 25. In (15), the static elimination lamp 33 is turned on, and the developing bias is turned on. Then, in (16), the optical motor return operation is stopped in order to complete the movement of the document table 23 to the scanning home position.

After this, (17), (TMMSK (seam sensor mask timer) is set to O by IU processing, and FMSOPC (seam sensor mask flag, seam detection can be performed when this flag is O) is set to O. In this state, in order to detect the position of the seam 25b of the photoconductor 25, it is determined whether the seam sensor 81 shown in (19) is ON, and if it is not ON, the other seam sensor 81 shown in (9-3) is set. The copy control routine is executed.If the seam sensor 81 is turned on and the seam 25b is detected, TMMSK is set to 3.5 seconds as shown in (20), and then as shown in (152) Set FMSOPC to 1. As a result, (8
8) When TMMSK counts up in the processing of (89), (90), and (91), FMSOPC=O, and the detection signal of the seam sensor 81 must not be read for 3.5 seconds until the seam sensor mask is released. become. As a result, the hatched area in FIG. 16 is the seam sensor 81.
is a masked part and no detection operation is performed, and even if there is an erroneous signal such as noise shown by α or β during this time, it will not be captured, and the copy control will be performed based on the original seam 25.
This is normally performed based on the b detection timing.

This is because the seam sensor 81 detects the gold pattern pasted on the seam 25b of the photoconductor 25 using a reflective type. However, if the photoconductor 25 is damaged due to deterioration or curling, it may detect other patterns other than the gold pattern. In some areas, the seam sensor 81 malfunctions as seam detection due to α, β, etc., causing inconveniences such as inadvertently turning on the serviceman call and generating abnormal images, but this inconvenience can be prevented.

Continuing, (22) (23) (24) (25) (26)
(27) In each process (28>(29), timer setting process is performed after a certain period of time. That is, the exposure lamp ON timer and exposure lamp OFF timer are set, the main charger ON timer is set, and the optical motor Set the scan timer and optical motor return timer, set the leading edge erase OFF timer and trailing edge erase ON timer, and set the transfer charger ON timer and transfer charger OFF timer.In particular, set the leading edge erase OFF timer (26). In the process (169), which will be described later, the leading edge erase OFF data retrieved from Table 2 according to the magnification ratio is set.

After setting various timers as described above, it is determined whether the processing is for the first copy. The first one is the first one, so
The process waits for the pre-registration sensor 44 to turn ON based on the determination in (31), and then processes (32), (33), (34), and (7) are performed. That is, an intermediate solenoid ON timer is set to stop driving the intermediate roller 36 after a certain period of time, an intermediate solenoid OFF timer is set to make the intermediate roller 36 rotate again after a certain period of time, and after a certain period of time, the intermediate solenoid OFF timer is set to stop driving the intermediate roller 36. This is to set the registration solenoid ON timer to stop the drive.

Here, the registration data retrieved from Table 1 in accordance with the magnification ratio in the process (170) described later is set in the registration solenoid ON timer.

After this, it is determined in (35) whether this is the last paper in the copying operation, and if it is not the last paper, in order to continue the copying operation, steps (36), (37), and (38) are performed.
Set each timer according to the process.

That is, a counter ○N timer is set in order to count up the total counter after a certain period of time, and
Set the counter OFF timer and turn the paper feed solenoid OFF in order to drive the paper feed roller 35 again after a certain period of time.
This is to set the N timer. And (39)
It is determined whether the document table 23 has completed the return based on whether the HP sensor 46 is ON, and when the return is completed, the optical motor is stopped (process (40)), and the document table 23 is made to stand by at the scanning home position. . In this situation, FMSOPC (seam sensor mask flag)
It is determined by (41) whether or not is set to 1.

Here, this FMSOPC is as described above (152)
It is set to 1 by the processing of (88) (89) (90) (91) of the encoder interrupt routine described later.
) remains at 1 until it is reset by the processing decision in step (20), that is, it remains at 1 for 3.5 seconds set in step (20), and the seam sensor 81 is masked and does not perform a detection operation. Then, when the mask of the seam sensor 81 is released and the seam 25b is detected by the seam sensor 81, the process returns to step (20) and the above-described process is repeated.

Here, in the judgment of (30), since it is not the first copy, check the state of the transfer paper 30.

It is determined whether the intermediate front sensor 43 is ON or not (43), and if it is not ON, another copy control routine shown at (9-4) is executed. Intermediate front sensor 43
If it is ON, a paper feed solenoid OFF timer is set to stop the drive of the paper feed roller 35 after a certain period of time (process (44)). Next, as shown in (45), it is determined whether the pre-registration sensor 44 is in the OFF state, and the
If it is in the FF state, another copy control routine indicated by (9-6) is executed, and the processes after (31) are similarly executed.

On the other hand, in the judgment of (35), if it is determined that it is the last paper, (47) (48) (49) (50) (51) (52)
Processing (53) is performed. That is, the main motor OFF timer is set, and the OBM solenoid ON timer and OBM solenoid OFF timer are also set. This means that the main motor reaches ○FFL after a certain period of time has passed.
This is to stop the photoreceptor 25 during 199 pulses after the main motor is turned OFF in order to prevent the joint 25b of the photoreceptor 25 from shifting from the target position due to inertia even after . Then, a static elimination and bias OFF timer is set, a main charger OFF timer is set, an optical motor stop timer is set to stop the document table 23 at the standby home position after a certain period of time, and an erase OFF timer is set.

After this, the pre-registration sensor 44 indicated by (54) is turned ON.
If it is ON, a registration solenoid OFF timer is set to drive the registration roller 37 after a certain period of time (process (55)).

In addition, in the flowchart of FIG. 16, (9-0) ~
Other copy control routines shown in (9-n), such as (9-9), include fusing, temperature control, abnormality detection, manual key reception from the operation panel 82, toner end detection, paper end detection, etc. Others, Figures 17 to 19
The processing of the encoder interrupt routine shown in the figure is also included, and the processing of the magnification key acceptance subroutine shown in Fig. 20 is also included during the processing of (9-0).

The processing of the encoder interrupt routine shown in FIGS. 17 to 19 will now be described. First, in this encoder interrupt, an interrupt request flag is set every time there is an input from the encoder to the CPU 97, and this interrupt is accepted in the processing part shown by (9-n) in the main routine shown in FIG. It will be done. As a result, after processing the encoder interrupt flow, the program returns to the main routine at the position where the interrupt was accepted. The various processes in this encoder interrupt routine basically determine whether the corresponding timer is counting up, and if it is not counting up, the timer is counted down by -1, and when the timer has counted up, a predetermined value is set. This process performs the following processing.

Specifically, the processing collectively shown in (a) is shown in FIG.
2) is set to indicate the judgment and processing regarding the main motor ○N timer. Similarly, (b) is (3) below,
The judgment and processing of the exposure lamp ON timer set in (21) is shown. (c) shows the judgment and processing of the exposure lamp OFF timer set in (22). [d) is (5
), shows the judgment and processing of the optical motor return timer set in (25).

(e) is the counter set in (7) and (36).
The judgment and processing of the N timer is shown. (f) is (8).

The determination and processing of the counter OFF timer set in (37) is shown. (g) shows the judgment and processing of the paper feed solenoid OFF timer set in (11) and (44). (hl is the paper feed solenoid O set in (38)
The judgment and processing of the N timer is shown. (i) shows the determination and processing of TMMSK set in (20). (j) is (
23) shows the judgment and processing of the main charger ON timer set in step 23). (k) shows the judgment and processing of the main charger OFF timer set in (51). [
Ω] indicates the judgment and processing of the optical motor scan timer set in (24). Cm) is (46), (55
) shows the judgment and processing of the registration solenoid OFF timer set in (). [n] indicates the judgment and processing of the registration solenoid ON timer set in (34). [
O] shows the judgment and processing of the intermediate solenoid OFF timer set in (32). (p) shows the judgment and processing of the intermediate solenoid OFF timer set in (33). [q] indicates the determination and processing of the erase OFF timer set in (26) and (53). [r) is (2
7) shows the judgment and processing of the erase ○N timer set in step 7). (s) shows the judgment and processing of the transfer charger ON timer set in (28).

[1] is the transfer charger set in (29) OFF
Indicates the judgment and processing of the timer. [u) shows the judgment and processing of the optical motor stop timer set in (52). (V) shows the judgment and processing of the ○BM solenoid ON timer set in (48).

[w] is the ○BM solenoid OF set in (49)
The judgment and processing of the F timer is shown. (x) shows the judgment and processing of the static elimination and bias OFF timer set in (50). The above encoder interrupts are performed as necessary, and the process returns to the main flow shown in FIG. 16.

Next, the magnification key reception routine shown in FIG. 20 will be explained. This is the main routine (9) as mentioned above.
-0) is performed by operating keys 90 to 94 of operation panel 82 in wait mode.

First, as shown in (154), it is determined whether it is the up key 91 at fixed magnification, and if this is the up key 91, then (
The process moves to steps 155) to (167). If it is not the up key 91, it is determined whether it is the down key 92, zoom up key 93, or zoom down key 94 when the magnification is fixed, as shown in (168), (169), (170), etc., and which key 92 is selected. Up key 91 even if ~94
The processes shown in (155) to (167) are performed in the same way as in the case of (155) to (167) (the figures are omitted by broken lines). first,
At (155,), the magnification of 71% is stored in the magnification data buffer, and it is determined whether the set and displayed magnification is smaller than this magnification of 71%, and if it is, the process of (164) is performed and the set magnification data is displayed. Ru. Then, the imaging lens 53 is moved to a predetermined position according to this magnification data (process (165)).

Also, using this magnification data, the leading edge erase FF data is searched from the leading edge erase OFF data table shown in Table 2, and the data is stored in the leading edge erase OFF data buffer (processing (166)).

Furthermore, using this magnification data, the resist data is searched from the resist data table shown in Table 1, and the data is stored in the resist data buffer (process (167)).
). Also, if the set magnification is 71% or less, 82%
is stored in the magnification data buffer and compared with the set magnification, and if it is smaller, it is stored in (164) to (16) as described above.
The processing in 7) is performed according to the set magnification, and if it is larger, a comparison with the next magnification of 87% is performed in the same way, and the maximum magnification is 1.
This is done in the same way up to 41%.

As described above, according to this embodiment, the 4-mirror one-type optical system 27 has a variable power function, and the optical system 27
The configuration of the device can be simplified, and the device can be made smaller, lighter, and lower in cost. Further, although the optical system 27 is used in this embodiment, a photoconductor unit (OBM) including the photoconductor 25 may also be used in a system using a converging light transmitting body array such as a SELFOC lens array instead of the optical system 27.
) can be used in common, making it possible to provide versatility to the photoreceptor unit. In addition, in the case of the variable magnification method as in this embodiment, the position of the exposure point on the photoconductor 25 varies depending on the variable magnification ratio, but the resist data table and the tip erase data table shown in Tables 1 and 2 is prepared,
Since the CPU 97 controls the transfer paper registration and leading edge erase at different timings for each magnification based on the detection of the scanning home position of the document platen 23, no deviation occurs when changing the magnification.

By the way, in this embodiment, the optical system 27 is fixed and the document table 23 is
Although the explanation has been given as an example of application to a type in which the document table is moved, it can also be applied to a type in which the document table is fixed and the optical system is moved. FIG. 22 shows its schematic configuration. Photoreceptor 2
The fifth turn is the same as in Fig. 1, etc. First, a document table 102 whose position is fixed on which a document 101 is placed is provided, and an optical system 1.degree. 3 which scans and moves is provided between the document table 102 and the photoreceptor 25. As this optical system 103, the original 1
A lamp 104 for slit exposure of 01, a reflector 105, and an auxiliary reflector 106 are provided. And manuscript 1
A four-mirror system including a first mirror 107, a second mirror 108, an imaging lens 109, a third mirror 110, and a fourth mirror 111 is provided to form an image of the reflected light from 01 on the flat portion 25a of the photoreceptor 25. ing. More specifically, second mirror 108 → imaging lens 109 → third mirror 110
The optical axis of the lens is set slightly obliquely, and the fourth mirror 111
is to form an image at right angles on the flat portion 25a.

When copying, a lamp 104, a first mirror 1
07 etc. is the first scanner, and the second mirror 108 is the second scanner, and when the first scanner moves to scan the document surface in the right direction at a speed of V, the second scanner also moves in the same direction at a speed of V/2. (Such behavior is well known). Further, the second mirror 108 is provided vertically, and the incident angle θA from the first mirror 107 and the output angle θB toward the imaging lens 109 are the same angle.

Furthermore, when changing the magnification, the imaging lens 109 moves to positions 108b and 108c along the optical axis of the lens (
108a is the same size position). The third mirror 110 also moves to the right along the lens optical axis as shown by 109b and 109c during zooming (109a is the same magnification position). In other words, the first
This is the same as the case shown in the figure. As a result, when changing the magnification, the positions of the exposure points are A and B on the flat part 25a of the photoreceptor 25.
, C are also the same as in the case of the document table moving method, and registration deviations can be prevented by taking similar measures. Although not particularly shown in FIG. 22, an HP sensor for detecting the home position of the optical system 103 is provided in the main body of the copying machine, and a sensor for operating this HP sensor at the home position is provided in the first scanner. An actuating plate is provided (such HP detection schemes are also well known).

Effects Since the present invention is configured as described above, it is possible to perform variable magnification copying in which an image is orthogonally formed on the flat part of a planar photoreceptor using a 4-mirror system, and the configuration of the optical system can be simplified. As a result of (2), the entire device can be made smaller, lighter, and lower in cost, and the photoreceptor unit used can also be commonly applied to full-size dedicated machines that use a focusing light transmitter. The photoreceptor unit can be made more versatile, and the image forming point on the photoreceptor will shift when changing the magnification, but the registration timing of the transfer paper can be adjusted based on the position detection of the moving document table or optical system. Since it is controlled, no misregistration occurs.

[Brief explanation of drawings]

Figures 1 to 21 show one embodiment of the present invention, with Figure 1 being a schematic front view showing the optical system as the center, Figure 2 being a developed view of the photoreceptor, and Figure 3 showing the entire device. 4 is a schematic plan view of the variable power drive system, FIG. 5 is a longitudinal sectional front view of a portion thereof, FIG. 6 is a plan view showing a portion enlarged, and FIGS. 7(a) to 7(a). (C) is a plan view showing the same magnification, reduction, and enlargement states, Fig. 8 is a characteristic diagram, Fig. 9 is a plan view of the operation panel, Fig. 10 is a block diagram of the control system, and Fig. 11 ( a)～(
C) is a schematic front view showing the method of moving the document table, FIG. 12 is an explanatory diagram showing the dimensional relationship of the conjugate length of the optical system, and FIG. Fig. 14 is an explanatory diagram showing the dimensional relationship of the optical system, Fig. 15 is an explanatory diagram showing the dimensional relationship considering the slit width, Fig. 16 is a flowchart of the main routine, and Figs. 17 to 19 are explanatory diagrams of the encoder interrupt routine. Flowchart, Fig. 20 is a flowchart of the magnification key reception routine, Fig. 21 is a timing chart, Fig. 22 is a schematic front view showing an example of application to an optical system movement method, and Fig. 23 is a conventional 6-mirror one-type system. FIG. 24 is a schematic front view showing an example of a conventional four-mirror type, and FIG. 25 is a schematic front view of a SELFOC lens type. 21... Original document, 23... Document table, 25... Photoreceptor, 25a... Flat portion, 30... Transfer paper, 37...
Registration roller (registration roller member), 46...I
(P sensor (position detection sensor), 51... first mirror, 52... second mirror, 53... imaging lens,
54...Third mirror, 55...Fourth mirror, 58...
・Stepping motor (variable magnification drive means), 97...C
PLI (control means), 101...manuscript, 102...
・Original table, 103...Optical system, 107...First mirror, 108...Second mirror, 109...Imaging lens, 110...Third mirror, 111...Fourth mirror 3.11 figure, %Z figure, ¥) 6 figure y30 mother Jl q figure 3'' 薖J, /ZLE 平J3Figure 3JUwaJ Asshi

Claims (1)

[Claims] A document table on which a document is placed, and a planar photoreceptor having a flat portion at an exposure portion and on which an image of the document is formed,
A first mirror, a second mirror, an imaging lens, a third mirror, and a fourth mirror are arranged in this order between the document table and the photoreceptor, and the fourth mirror allows the photoreceptor to be perpendicular to the flat portion of the photoreceptor. An optical system for projecting and forming an original image is provided, a drive source is provided for relatively scanning and moving the document table or this optical system, and a position detection means is provided for detecting the position of the document table or the optical system. When changing magnification for reduction, the imaging lens and the third
A variable magnification drive means is provided for moving the mirror along the lens optical axis direction to correct the optical path length, and a registration roller member is provided for feeding the transfer paper to the transfer position of the photoreceptor at a predetermined timing, A variable magnification copying apparatus, comprising a control means for controlling the timing from the detection of the position of the document table or the optical system by the detection means until the start of the registration roller member according to a copying magnification.