JPS6262351A - Image forming device - Google Patents

Abstract

PURPOSE:To make it possible to recognize the extent of image forming with an original feeding device closed by driving and controlling an indicator provided in an automatic original feeding device and indicating the extent of image forming. CONSTITUTION:A carriage 134 is provided in an automatic original feeding device that can be opened and closed freely provided in the upper part of an original platen. The carriage 134 and a freely movable pointer 146 are moved in the direction of original scanning and in the direction at right angles to the direction of scanning by stepping motors 143, 137 that rotate according to the size of copying paper and the set variable magnification etc. The extent that can be copied can be recognized through the pointer 146 with the automatic original feeding device in closed state, and occurrence of mistake in copying can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an image forming apparatus such as a copying machine having a document feed Ill.

[Technical Background of the Invention and Problems Therewith] As is well known, the copyable range of a document on a document table is determined by, for example, a guideline, depending on a set copy magnification, a selected paper size, and a paper setting direction. A copying machine that displays images has been developed. The copyable range is visible when the document cover is opened.

By the way, when an automatic document feeder is installed in the above-mentioned copying machine instead of the document cover and a copying operation is performed using this document feeder, the automatic document feeder is opened and the copyable range on the document table is adjusted to Ts. It is rare to admit it. For this reason, a copying error may occur, for example, when the original is inserted horizontally even though the feeding direction of the selected paper is vertical, and only a portion of the original image is copied onto the paper. was there.

[Object of the Invention] This invention has been made based on the above-mentioned circumstances, and its object is to make it possible to identify the image forming area of a document when the automatic document feeder is closed. The present invention aims to provide an image forming apparatus that can prevent image forming errors.

[Summary of the Invention] The present invention provides an image forming apparatus having a document feeder that automatically feeds a document onto a document table, in which the document feeder is provided with an instruction means for displaying a copyable range of the document. It is.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 14 and 15 schematically show an image forming apparatus of the present invention, for example, a copying machine with a document feeding device. A document table (transparent glass) 2 for supporting a document is fixed to the top surface of the copying machine main body 1. This document table 2 is provided with a fixed scale 21 that serves as a reference for setting the document, and furthermore, the document table 2 is provided with an automatic document feeder f61 that also serves as a document cover and automatically feeds the document to the document table 2. It can be opened and closed freely. The original placed on the original platen 2 is exposed by an optical system consisting of an exposure lamp 4 and mirrors 5, 6, 7 being reciprocated in the direction of arrow a along the lower surface of the original platen 2. It is meant to be scanned. In this case, mirror 6.7 is moved at 1/2 the speed of mirror 5 so as to maintain the light exposure length. The light reflected from the original by the scanning of the optical system, that is, the light reflected from the original by the light irradiation of the exposure lamp 4, is reflected by the mirror 5, 6, 7, passes through the variable magnification lens block 8, and is further reflected by the mirror. 9 and guided to the photoreceptor drum 10, so that an image of the document is formed on the surface of the photoreceptor drum 10.

The photosensitive drum 10 is rotated in the direction of arrow C in the figure, and first, the surface thereof is charged by the charging device 11. Thereafter, the image is exposed to slit light to form an electrostatic latent image on the surface. This electrostatic latent image is made visible by applying toner by a developing device 12.

On the other hand, the paper (transfer material) P is taken out one by one from the selected upper paper feed cassette 13 or lower paper feed cassette 14 by the delivery roller 15 or 16, and the taken out paper is taken out from the paper guide path 17 or 18 and is guided to a pair of registration rollers 19, and guided to a transfer section by this pair of registration rollers 19. Here, the paper feed cassettes 13 and 14 are removably provided at the lower right end of the main body 1, and one of them can be selected from an operation panel to be described later.

The cassette size of each of the paper feed cassettes 13 and 14 is detected by a cassette size detection switch 601 and 602, respectively. The cassette size detection switches 60r and 602 are composed of a plurality of microswitches that are turned on and off in accordance with the insertion of cassettes of different sizes.

The paper P sent to the transfer section is brought into close contact with the surface of the photoreceptor drum 10 at the transfer charger 20, and
The toner image on the photoreceptor drum 10 is transferred by the action of 0. The transferred paper P is electrostatically peeled off from the photosensitive drum 10 by the action of a peeling charger 21, and is sent by a conveyor belt 22 to a fixing roller 23 as a fixing device provided at the end thereof. The transferred image is fixed by passing through this, and the fixed paper P is discharged to a tray 25 outside the main body 1 by a pair of paper discharge rollers 24 . Further, the photoreceptor drum 10 after the transfer is transferred to a charger 2 for removing static electricity.
6, residual toner on the surface is removed by a cleaner 27, and afterimages are roughly erased by a static elimination lamp 28, so that the initial state is restored. Note that 29 is a cooling fan for preventing the temperature inside the main body 1 from rising.

FIG. 16 shows the operation panel 30 provided on the main body 1. 301 is a copy key for commanding the start of copying; 30
2 is a numeric keypad for setting the number of copies, etc.; 303 is a display unit for displaying the operating status of each part and paper jams; and 304
305 is a cassette display section for displaying the selected cassette; 306 is a magnification setting key for setting copy enlargement and reduction magnification in a predetermined relationship; 307 30g is a display section that displays the set magnification; 30s is a density setting section that sets copy density; 30a, 30b.

30c and 30d are operation keys for moving a spot light source indicating the erasing position of the document, which will be described later, 30e is a position specification key for inputting the coordinate position indicated by the spot light source, and 30f
, 3C1 are erase range designation keys for specifying erase ranges at designated positions, respectively.

FIG. 17 shows an example of the drive source configuration of each drive unit of the copying machine configured as described above, and is composed of the following motors. That is, 31 is a lens motor, which is a motor for moving the position of the lens block 8 for performing magnification change. Reference numeral 32 denotes a mirror motor, which connects the mirror 5 and mirrors 6 and 7 for variable magnification.
This is a motor for changing the distance (optical path length) between the A scanning motor 33 is a motor for moving the exposure lamp 4, the mirror 5, and the mirror 6.7 for scanning the original. A shutter motor 34 is a motor for moving a shutter (not shown) for adjusting the charging width of the photosensitive drum 10 by the charger 11 during zooming. A developing motor 35 is a motor for driving the developing roller of the developing device 12 and the like. 36 is a drum motor, which is a motor for driving the photosensitive drum 10.

Reference numeral 37 denotes a fixing motor, which is a motor for driving the paper conveyance path 22, the pair of fixing rollers 23, and the pair of paper discharge rollers 24. 38 is a paper feeding motor, which is a motor for driving the delivery rollers 15 and 16. A paper feeding motor 39 is a motor for driving the registration roller pair 19. A fan motor 40 is a motor for driving the cooling fan 29.

FIG. 18 shows a drive mechanism for reciprocating the optical system. That is, the mirror 5 and the exposure lamp 4
is supported by a first carriage 411, and mirror 6.7 is supported by a second carriage 422, respectively, and these carriages 411, 412 are guided by guide rails 421, 422 and are movable in parallel in the direction of arrow a. Also, 4
The phase pulse motor 33 drives a pulley 43. An endless belt 45 is stretched between the pulley 43 and the idle pulley 44, and one end of a first carriage 411 that supports the mirror 5 is fixed to a midway portion of the belt 45. On the other hand, two pulleys 47.47 are rotatably provided on the guide portion 46 of the second carriage 422 that supports the mirror 6.7, spaced apart in the axial direction of the guide wheel 422. Wire 4 between 47
8 is hanging. One end of this wire 48 is attached to the fixed part 4
9, the other end is fixed to the fixing part 49 via a coil spring 50, respectively. In addition, the wire 48
One end of the first carriage 411 is fixed in the middle. Therefore, by rotating the pulse motor 33, the belt 45 rotates and the first carriage 411 is moved, and the second carriage 422 is also moved accordingly. At this time, since the pulleys 47, 47 serve as movable pulleys, the second carriage 422 is moved in the same direction as the first carriage 411 at 1/2 the speed.

Note that the moving directions of the first and second carriages 411 and 412 are controlled by switching the rotation direction of the pulse motor 33.

Further, on the document table 2, a copyable range corresponding to the specified paper is displayed. That is, the cassette selection key 304
Let the paper size specified by (Px, Py) be,
If the copy magnification specified by the magnification setting keys 306 and 307 is K, the copyable range (x, y) is "x-P
x/KJ.

It becomes ry-Py/KJ. This copyable range (X.

As shown in FIG. Scale 5 provided on the upper surface of the first carriage 411
3 and the distance between the fixed scales 21.

The pointer 51 is connected to pulleys 54 and 55 as shown in FIG.
A wire 57 is suspended between the wire 57 and the spring 56.
It is set in. The pulley 55 is rotated by a motor 58, and when the motor 58 is driven according to the water-filled copyable range in the X direction, the pointer 51 and one end of the fixed scale 21 are connected to each other. The distance between them can be changed. Furthermore, Guideline 51
As shown in FIG. 19, it can be visually observed through a transparent section 2a provided on the fixed scale 21.

Further, the first carriage 411 is moved to the copyable range display position (home position according to the magnification) shown in FIG. 19 by driving the motor 33 according to the paper size and magnification. . When the copy key 301 is pressed, the first carriage 411 is first moved toward the second carriage 412, and then the lamp 4 is turned on and moved away from the second carriage 412. When scanning of the original is completed, the lamp 4 is turned off and the first carriage 411 is returned to the home position.

FIG. 21 shows the overall control circuit.

The main processor group 71 detects inputs from the operation panel 30 and input devices 75 such as various switches and sensors, such as the cassette size detection switches 60s and 602, and drives the various chargers.
the static elimination lamp 28, the blade solenoid 27a1 of the cleaner 27, the heater 23a of the fixing roller pair 23,
The exposure lamp 4 and each of the motors 31 to 40.5
Ill like 8! II, the above-described copying operation is performed, and the spot light source 131 and pulse motor 137.1 are
43, the memory 140, the erasing array 150, the array driving section 160, etc. are controlled to erase unnecessary portions of the document. Note that the spot light a 131, pulse motors 137 and 143, erasure array 150, array drive unit 1601 and memory 140 will be described later.

Among the motors 31 to 40.58.137.143,
A toner motor 77 that supplies toner to the motors 35, 37, and 40 and the developing device 12 is controlled by the main processor group 71 via a motor driver 78, and
34 and 137.143 are pulse motor driver 7
The motor 36.39.38.58 is controlled by the first sub-processor group 72 via the pulse motor driver 8.
0 and is controlled by the second sub-processor group 73.

Further, the exposure lamp 4 is controlled by the main processor group 71 via the lamp regulator 81, and the heater 23a is controlled by the main processor group 71 via the heater control section 82. Then, main processor group 71 or q-th . Commands to drive and stop each motor are sent to the second sub-processor group 72, 73, and the first. Second sub-processor group 72.7
3 sends a status signal to the main processor group 71 indicating the drive or stop state of each motor. The first sub-processor group 72 also includes motors 31 to 34, 137.
Position information from a position sensor 83 that detects each initial position of 143 is input.

FIG. 22 shows an example of the configuration of the main processor group 71. One-chip microcomputer 91 (hereinafter referred to as
The microcomputer (simply referred to as a microcomputer) detects human power on keys on an operation panel (not shown) and performs various display controls via an input/output board 92.

Furthermore, the microcomputer 91 is expanded by input/output ports 93-96. A high voltage transformer 76, a motor driver 78, a lamp regulator 81, and other outputs are connected to the input/output boat 93.
4 is connected to a size switch for detecting paper size and other human power, and to the input/output port 95 is connected a copying condition setting switch and other human power. Note that the input/output port 96 is an option.

FIG. 23 shows an example of the configuration of the first sub-processor group 72. The microcomputer 101 is the main processor group 7
1 is connected. Programmable interval
The timer 102 controls the phase switching interval time of the pulse motor. When a set value is set from the microcomputer 101, the timer 102 starts counting reference clock pulses based on the setting value. When the timer 102 has counted out, the end pulse is sent to the microcomputer 101. It is configured to output to the interrupt line. The microcomputer 101 also includes the position sensor 8.
Position information from 3 is input, and input/output boats 103 and 104 are connected. The input/output boat 104 is connected to the motors 31 to 34, 137, and 143 via the pulse motor driver 79. The input/output board 103 is used, for example, to output status signals of each pulse motor to the main processor group 71.

FIG. 24 shows the configuration of the second sub-processor group 73. The microcomputer 111 is connected to the main processor group 71
is connected to. The programmable interval timer 112 controls the phase switching interval time of the pulse motor, and outputs a termination pulse when the set value is set from the microcomputer 111. This termination pulse is latched by the latch circuit 113, and its output is supplied to the interrupt line and input/output board input line of the microcomputer 111. In addition, the microcomputer 111 also has an input/output board 11.
4 are connected to this input/output boat 114 via the pulse motor driver 80.
39.58 is connected.

Figure 25 shows the control circuit of the pulse motor.
The input/output boat 121 (corresponding to the input/output boats 104 and 114 in FIGS. 23 and 24) has a pulse motor driver 1.
22 (corresponding to the pulse motor driver 79.80 in FIG. 21) is connected to the pulse motor driver 122.
6.38.39.137.143) each winding A1
B and A1B are connected.

FIG. 26 shows a method for controlling the speed of a pulse motor. FIG. 3(a) shows the speed curve of the pulse motor, and FIG. 1(b) shows the phase switching interval.

As is clear from this figure, the phase switching interval is long at the beginning;
They gradually shorten, then become evenly spaced, then gradually lengthen again, and then stop. In other words, this indicates the through-up and through-down of the pulse motor, starting from the self-starting region, being used in the high-speed region, and finally falling down. Note that tl, t2, . . . tx indicate the time of the phase switching interval.

Next, the automatic document feeder [61] will be explained. In FIG. 2, the automatic document feeder @61 is composed of a paper feed section 62 that feeds the document, and a conveyance section 63 that conveys the document. The paper feed section 62 is a document feed table 62 on which a document is placed.
a1 A paper feed roller 62b, a conveyance roller 62c, and a separation roller 62 that feed the document placed on the document feed tray 62a.
d. It is composed of a pair of aligning rollers 62e. Further, a detector 62f is provided near the transport roller 62c to detect the presence or absence of a document on the document feed table 62a. A detector 62Q is provided to detect the aligning roller pair 62e and the conveyance section 6.
A detector 62h that detects the size of the fed document is provided between the document sheets 3 and 3. These detectors 62f, 62a
, 62h are each composed of, for example, a detection lever and a microswitch. Further, document guides 62i, 62i are provided on the document feed tray 62a, and the width thereof is set to correspond to the width of the document to be inserted.

Further, a document receiving portion 63a made of transparent glass is provided on the surface portion of the conveyance portion 63. The document receiver section 63a is approximately the same size as the document table 2, and a document whose erasing range is specified, for example, is placed on the document receiver section 63a. The document receiving section 63a is provided with a document insertion port 63j on the paper feed section 62 side, and the document fed through the document insertion port 63j is taken into the transport section 63 by a pair of take-in rollers 63b. . Inside the conveying section 63, there is a guide 63C for guiding the document taken in by the pair of take-in rollers 63b toward the document table 2. an endless belt 63d as a document conveying means for conveying the document; rollers 63e and 63f on which the endless belt 63d is mounted;
3Q, a guide 63h1 that guides the document conveyed from the end of the belt 63d to the document receiver section 63a; the document guided by this guide 63h is guided to the document receiver section 63a;
A pair of discharge rollers 631. The intake roller pair 6
A detector 63 is provided near the document receiving part 63b and detects that a document has been fed into the document insertion slot 63j from the document receiving section 63a.
k. A detector 631 is provided near the pair of ejecting rollers 63i to detect an abnormality in the conveyance of the ejected document. These detectors 63k and 631 are composed of, for example, a detection lever and a microswitch. Further, an automatic document feeder 61 is located near the belt 63d.
A detector 61a is provided to optically detect the opening and closing of the opening and closing. Further, the document receiver is provided in the document insertion slot 63j of the portion 63a.
Near the document ejection port 630, there is a document tray 6.
Fixed scales 63m and 63n on which document setting standards are displayed are provided along the width direction of 3a, respectively.

On the other hand, a spot light WA131 for specifying the erasing range of the original and a means for displaying the copyable range are provided on the back side of the document receiver 63a.

In FIG. 3, a spot light source 131 includes a light emitting element 132 made of, for example, a light emitting diode or a lamp, and the output light of this light emitting element 132 is transmitted to the document receiving section 63a.
It is composed of a lens 133 that illuminates the area. The output light of this spot light source 131 is irradiated onto the document receiving section 63a as a spot light having a diameter d, and this spot light is applied to the original document set on the document receiving section 63a with a thickness similar to that of the back of a leaf. It has a brightness that allows it to pass through.

Spot light above! 131 is adapted to be moved in the X and Y directions in the drawing by a drive mechanism as shown in FIG. That is, the spot light source 131 is slidably held on a guide shaft 135 provided on the carriage 134. This spot light source 131 is connected to a timing belt (toothed belt) 136 disposed along a guide shaft 135. This timing belt 136 is passed between a pulley 138 provided on the rotating shaft of a pulse motor 137 and a driven pulley 139. Therefore, when the pulse motor 137 is rotated, the spot light source 131 is moved in the X direction in the drawing.

Further, the carriage 134 is guided by a guide rail 149 and a guide guide 141 and is movable in the direction of arrow y. A timing belt (toothed belt) 142 is connected to this carriage 134 . This timing belt 142 is wrapped around a pulley 144 provided on the rotating shaft of a pulse motor 143 and a driven pulley (not shown).

Therefore, when the pulse motor 143 is rotated, the spot light source 131 is moved in the y direction (the first carriage 41
1). Further, on the carriage 134 located at the end of the guide shaft 135 on the pulse motor 137 side, a position sensor 1 consisting of a microswitch for detecting the initial position of the spotlight 11!131 is mounted.
45 are provided. When the spot light source 131 is moved, the spot light source 131 is first brought into contact with the position sensor 145 to detect its initial position.

Further, the spotlight m131 is provided with a pointer 146 that displays the above-mentioned copyable range in the X direction, and the carriage 134 is provided with a scale 147 that displays the above-mentioned copyable range in the y direction.

Next, first, a method of specifying the erasing range of the document using the spot light source 131 will be explained using FIGS. 5 to 7. When specifying the erasing range of a document, the document G is set with the copy side facing up along the fixed scale 63m of the document receiver 63a, as shown in FIG. Further, when the operation keys 30a to 30d on the operation panel 30 are operated, the spot light source 131 is activated by the light emitting element 132.
will be moved while the is lit. That is, operation key 30t)
, 30 (When I is pressed, the pulse motor 143 is driven, and the carriage 134 and the spot light [131 are
It is moved in the direction of the arrow y shown in the figure.

Further, when the operation keys 30a and 30C are pressed, the pulse motor 137 is driven, and the spot light source 131 is moved in the direction of the arrow X shown in FIG. The operator operates the operation keys 30a to 30d while visually observing the spotlight transmitted through the document G, and presses the position designation key after moving the spotlight to point S1 on the document G shown in FIG. 6(a), for example. Press 30e. Then, the coordinate position specified by this Sl is stored in the main processor group 71 shown in FIG. Similarly, when the spot light is moved to the 82nd point on the document G and the position specification key 30e is pressed, the position of the 82nd point is moved to the main processor group 7.
1 is stored. The position of this spot light can be detected, for example, by counting the number of driving pulses of the pulse motors 137 and 143. When this invasion/erasure range designation key 30f is pressed, 81.82
A rectangular area (indicated by diagonal lines) with the points as diagonal points is designated as the erasing range. Also, as shown in FIG. 6(b), specify points 83 and 84 on the original G, and press the erase range specifying key 30.
When o is pressed, the area other than the square with the diagonal points Sl and 84 points is designated as the erasing range. In this way, when the erasure range specification keys 30f and 30g are pressed, the main processor group 7
1, and the memory 140 stores a high level signal "1" in the erase range part and a low level signal "O" in the other part. That is, this memory 140 is constituted by, for example, a RAM whose capacity in each column direction is approximately equal to the moving distance of the spot light source 131 in the X direction divided by the position resolution in the y force direction. , corresponds to the shaded area as shown in FIG. 7(a) in the case of FIG. 6(a), and as shown in FIG. 7(b) in the case of FIG. 6(b). High level signals are stored at addresses and low level signals are stored at other addresses. Note that if the magnification setting key 306 or zoom key 307 of the operation panel 30 is operated at this time, the erased data stored in the memory 140 is changed according to the set copy magnification. It has become.

After specifying the erasing range of the original IG as described above, place the original G with its copy side facing up into the original insertion slot 6.
3", the detector 63k detects that the document has been inserted, and the pair of take-in rollers 63b and the belt 6
3d is driven.

Therefore, the document G is transferred to the conveying section 6 by the pair of take-in rollers 63.
3, is conveyed on the surface of the document table 2 by the belt 63d, and is set along the fixed scale 21 of the document table 2. In this set state, the copy side of the original G is facing down. Therefore, the original image and the erased data stored in the memory 140 are associated with each other.

On the other hand, as shown in FIG. 8, an erasing array 150 serving as erasing means is provided close to the photosensitive drum 10, for example, between the charger 11 and the exposure section Ph. As shown in FIGS. 9 and 10, this erasing array 150 is arranged on the photosensitive drum 1.
A plurality of light shielding cells 15 in a direction perpendicular to the rotation direction of
1, and inside each of these light-shielding cells 151, a light-emitting element 152 made of, for example, a light-emitting diode is provided, as shown in FIGS. 11(a) and 11(b). Further, a light emitting element 152 is provided in the opening of each cell 151 facing the photoreceptor drum 10.
A lens 153 that focuses the light on the surface of the photoreceptor drum 10
is provided. The number of light emitting elements arranged in this erasing array 150 matches, for example, the capacity of the memory 140 in the column direction. Here, if the distance between the light emitting elements 152 is P and the number is N, the total length of the erasing array 150 is Q=NxP.

The erase array 150 is driven by the array driver 160 described above. As shown in FIG. 12, this array driving section 160 includes a shift register 161 having the same number of bits as the number of pits in the column direction of the memory 140, and a store register 16 in which the contents of this shift register 161 are held.
2. It is constituted by a switch circuit 164 consisting of a plurality of switch elements 163 that are controlled on and off by each output signal of the store register 162. The movable contacts 163a of these switch elements 163 are grounded, and the fixed contacts 163b are grounded. Each of the light emitting elements 152 constituting the erasing array 150 is connected to each cathode. The anode of each of these light emitting elements 152 is connected to the 1R source VCC through a current limiting resistor R, respectively.

Therefore, after specifying the erase range of the original as described above, when the original is inserted into the original insertion slot 63j and automatically set on the original table 2, the first carriage 411 and the photosensitive drum 10 are moved. When operated, the memory 1
40, data for one column is sequentially read out in the row direction (shown in FIG. 7).

This read data D1 is transferred to the shift register 161 of the array driving section 160 by the clock signal @CLK. After one column of data has been transferred to the shift register 161, when the charged portion of the photosensitive drum 10 reaches the erase array 150, the main processor group 71 outputs a latch signal LTH, and the shift register 161 outputs a latch signal LTH. The data stored in register 161 is stored in store register 162.
supplied to That is, since the erase array 150 is disposed between the charger 11 and the exposure section ph, the memory 1
For example, if the angle between the erasing array 150 and the exposure section ph is θ1, and the photosensitive drum 10 is rotating at each speed, one column of data outputted by 40 is θ! The output timing of TH is controlled by a latch signal so that it is supplied to the store register 162 before /ω.

Each switch element 163 of the switch circuit 164 is controlled by the output signal of the store register 162. That is, when the output level of the store register 162 is high level, it is turned on, and when it is low level, it is turned off. As a result, the light emitting elements 152 connected to each switch element 163 are turned on when the switch element 163 is on, and are turned off when the switch element 163 is off. Therefore, among the charged parts of the photoreceptor drum 10, the part where the light emitting element 152 is turned on is charge-free, and even if the charge-free part is exposed afterwards, no electrostatic latent image is formed, and the original image is not erased. It means that it was done. Thereafter, the data in the memory 140 is read out one column at a time in the same manner, and the image is erased.

Next, the gist of the invention will be explained. In this embodiment, normally, the copyable range is displayed on the document receiving section 63a of the automatic document feeder 61 using the above-mentioned pointer 146 and scale 147 in the same way as on the document table 2. That is, the spot light source 131 and the carriage 134 are moved to a predetermined copyable range by driving the pulse motors 137 and 143 according to the filled copyable ranges in the X and Y directions. Therefore, as shown in FIG. 1 (a>(b)), the copyable range is displayed by the pointer 146, the scale 147, and the fixed scale 63n. Therefore, when performing a copying operation using the automatic document feeder 61, , open the automatic document feeder 61 and place the document on the document table 2.
It is possible to recognize the copyable range of a document without visually checking the copyable range displayed on the screen.

According to the above embodiment, a fixed scale 63n, a pointer 146, and a scale 147 are provided on the surface of the automatic document feeder 61, and these points 146 and scale 147 are used to determine the copy magnification, the selected paper size, and the paper feeding direction. The automatic document feeder 61 is driven to display the copyable range on the surface of the automatic document feeder 61. Therefore, when performing a copying operation using the automatic document feeder 161, it is possible to recognize the copyable range of the original without opening the automatic document feeder 61 and visually checking the copyable range displayed on the document table 2. This makes it possible to prevent the insertion of a document with a paper size and feeding direction different from the selected paper size and paper feed direction, thereby preventing copying errors.

In addition, since the copyable range displayed on the automatic document feeder 61 is displayed in almost the same position and in the same state as the copyable range displayed on the document table 2, the automatic document feeder 1161
It has the advantage that the copyable range can be recognized with the same image whether it is used or not, and it is easy to use.

Further, the pointer 146 and the scale 147 are connected to the spot light source 1.
31 and the carriage 134, no separate installation space is required and it is possible to suppress the increase in size of the apparatus.

In the above embodiment, the spot light source 131 is provided only on the automatic document feeder 161 side, but the present invention is not limited to this. A similar spot light source 131 may also be provided on the first carriage 411 located on the back surface of the document table 2 When the automatic document feeder 61 is used, a spot light source provided therein may be used, and when the automatic document feeder 61 is not used, a spot light source on the document table 2 side may be used.

Further, in the above embodiment, the original is set on one side of the fixed scale 21 for copying, but the original is not limited to this, and it is also possible to set the original with the center of the fixed scale 21 as a reference. In this case, the pointer is connected to a wire 57 shown in FIG.
The distance between these points may be changed based on the copyable range. Also,
Similarly, for the automatic document feeder [61 side], a pointer may be provided in addition to the pointer 146 on the timing belt 136 shown in FIG. .

Furthermore, the arrangement position of the erasing array 150 is not limited to that shown in FIG. 8, but as shown in FIG. It is also possible to configure the data to be erased.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to recognize the image forming range of a document when the automatic document feeder is closed, and to prevent image formation errors. A forming device can be provided.

[Brief explanation of the drawing]

The drawings show an embodiment of an image forming apparatus according to the present invention, and FIG. 1 is a plan view of the main parts for explaining the copyable range, and FIG. 2 shows the configuration of an automatic document feeder. A side sectional view of the main part, FIGS. 3 and 4 respectively show the configuration of a spot light source and an indicating means, FIG. 3 is a side sectional view of the main part, and FIG. 4 is a perspective view of the main part. Figures 5 and 6
The figures are a plan view of the main parts shown to explain the operation of specifying the erasing range of an original using a spot light source, FIG. 7 is a diagram shown to explain the contents of the memory, and FIG. 8 is a diagram showing the arrangement of the erasing array. 9 and 10 show the relationship between the erasing array and the photosensitive drum, FIG. 9 is a perspective view showing only the main part, and FIG. 10 is a side sectional view showing only the main part. 11(a) and 11(b) show the structure of the erasing array, and FIG. 11(a) is a side sectional view, FIG. FIG. 12 is a circuit diagram showing the configuration of the array driving section, FIG. 13 is a side sectional view of the main parts showing another example of the arrangement of the erasing array, and FIGS. 14 and 15 each show the configuration of the image forming apparatus. Fig. 14 is an external perspective view, Fig. 15 is a side sectional view, Fig. 16 is a plan view showing the structure of the operation panel, Fig. 17 is a perspective view showing the structure of the drive section, and Fig. 18 is a FIG. 19 is a perspective view schematically showing the drive mechanism of the optical system; FIG. Figure 21 is a configuration diagram showing the overall control circuit.
Fig. 22 is a block diagram of the main processor group, Fig. 23 is a block diagram of the first sub-processor group, Fig. 24 is a block diagram of the second sub-processor group, and Fig. 25 is a schematic diagram showing the control circuit of the pulse motor. 26 are diagrams for explaining the speed control method of the pulse motor. DESCRIPTION OF SYMBOLS 1... Copying machine main body, 2... Original table, 10... Photosensitive drum, 61... Automatic document feeder, 62... Paper feeding section, 63... Conveying section, 131...・Spot light source,
132... Light emitting element, 133... Lens, 137.
143...Pulse motor, 146...Pointer, 147
... Scale, 71 ... Main processor group, 14
0...Memory, 150...Erase array, 152...
- Light emitting element, 160...Array drive unit, G...Original, P...Paper, ph...Exposure unit. Applicant's agent Patent attorney Takehiko Suzue 313 Figure 39 No. II (h) (a) (b) Fig. 7 LLJ/ Fig. 8 Fig. 13 (a) (b) 16° 1 bow O Fig. 72 Fig. 17

Claims (3)

[Claims] (1) a document feeding device that feeds a document onto the document table; an optical system that optically scans the document image set on the document table and forms an image corresponding to the document image on an image carrier; In an image forming apparatus having a transfer means for transferring an image formed on an image carrier to a transfer material, an instruction means provided in the document feeder for displaying an image forming area of a document; An image forming apparatus comprising: a control means for driving the instruction means accordingly. (2) A patent claim characterized in that the indicating means comprises a carriage movable in the same direction as the scanning means and on which a scale is formed, and a pointer provided on the carriage and movable in a direction perpendicular to the carriage. The image forming apparatus according to item 1. (3) The image forming apparatus according to claim 1, wherein the image forming range is set based on the size of the transfer material and the image forming magnification.