JPS62103671A - Image forming device - Google Patents

Abstract

PURPOSE:To improve erase precision by shifting successively the light emission timing of the first and second light emitting diodes, which constitute an erasing array, in synchronizing with the rotative speed of a photosensitive drum. CONSTITUTION:The second light emitting diodes 152b are arranged at a half pitch of the first light emitting diodes to arrange the first and second light emitting diodes 152a and 152b zigzag. The light emission timing of the first and second light emitting diodes 152a and 152b is controlled in synchronizing with the rotative speed of a photosensitive drum 10. Thus, the light emission position is not deviated between the first and second light emitting diodes 152a and 152b on the surface of the photosensitive drum 10 and a designated erase range is erased surely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming method applied to, for example, an electronic copying machine.
Regarding AM.

(Technical Background of the Invention and Problems Therewith) Generally, electronic copying machines have the function of copying an original image onto paper as is, or enlarging or reducing the original image and making a copy.

Incidentally, recently, a copying machine has been developed that erases unnecessary portions of an original image and copies the image. This copying machine is equipped with an erasing array consisting of a plurality of commercially available lens-equipped light-emitting diodes in front of the photoreceptor drum, and the light-emitting diodes of this erasing array are designated! The image is erased by selectively turning on the light in accordance with the erasing range of the original, thereby erasing the charge on the photoreceptor drum or the electrostatic latent image.

However, since the erase array has a plurality of light emitting diodes arranged in a row, the arrangement pitch (mutual spacing) of the light emitting diodes is naturally limited due to the size of the light emitting diodes and the thickness of the partition walls provided between the light emitting diodes. There was [1. Therefore, it is difficult to narrow the arrangement pitch of the light emitting diodes, making it difficult to improve the accuracy of erasing images.

Therefore, using a light emitting diode chip as a light emitting element,
A method of directly bonding this light emitting diode chip to a substrate is being considered. With such a configuration, since the light emitting diode chips themselves are small, the arrangement pitch can be narrower than in the case where the light emitting diodes are arranged. However, for this configuration,
This has had problems with wiring, board arrangement, etc., and increased manufacturing costs.

[Purpose of the invention]

This invention was made based on the above circumstances,
The objective is to provide an image forming apparatus that can reduce the arrangement pitch of light emitting elements with a simple configuration and improve erasing accuracy through reliable light emission control. .

(Summary of the Invention) The present invention provides a method for arranging a plurality of first light emitting diodes constituting an erasing array along the longitudinal direction of a photoreceptor drum, shifting the arrangement pitch of the first light emitting diodes by half a pitch, A plurality of second light emitting diodes having the same shape as the first light emitting diode are arranged, and the light emission timings of these first and second light emitting diodes are sequentially shifted in synchronization with the rotational speed of the photoreceptor drum. be.

[Embodiments of the invention]

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

FIGS. 3 and 4 schematically show an image forming apparatus of the present invention, such as a copying machine. A document table (transparent glass) 2 for supporting a document is fixed to the top surface of the copying machine main body 1. The document table 2 is provided with a fixed scale 21 that serves as a reference for setting the document, and furthermore, a document cover 11 and a work table 12, which can be opened and closed, are provided near the document table 2. The original placed on the original platen 2 is processed by an optical system consisting of an exposure lamp 4 and mirrors 5, 6, and 7.
Exposure scanning is performed by reciprocating in the direction of arrow a along the lower surface of document table 2. in this case,
Mirror 6.7 is 1/1/2 of mirror 5 to maintain the light exposure length.
It is moved at a speed of 2.

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 the 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 electrostatic m1Il on the surface. This electrostatic latent image is made visible by applying toner by the developing device 12.

On the other hand, the paper (one 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 601 and 602 are composed of a plurality of microswitches that are turned on and off according to 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 photoreceptor drum 10 by the action of a peeling charger 21, and is sent to a fixing roller 23 as a fixing device provided at the end of the conveyor belt 22. It will be done. By passing through this, the transferred image is fixed, and the regular roll of paper P is discharged to a tray 25 outside the main body 1 by a pair of paper discharge rollers 24. Further, after the transfer pattern photosensitive drum 10 is neutralized by an electrostatic charger 26, residual toner on the surface is removed by a cleaner 27, and residual toner is removed by a static elimination lamp 28.
By erasing , the initial state is restored. Note that 29 is a cooling fan for preventing the temperature inside the main body 1 from rising by 1 degree.

FIG. 5 shows an operation panel 30 provided on the main body 1. 30i is a copy key for commanding the start of copying, 302
is a numeric keypad for setting the number of copies, etc., 303 is a display unit that displays the operating status of each part and paper jams, etc., 304 is a cassette selection key for selecting the upper and lower paper feed force cellar h13.14, and 305 is a selected key. 306 is a magnification setting key for setting the enlargement/reduction magnification of the copy in a predetermined relationship, 307 is a zoom key for steplessly setting the enlargement/reduction magnification, and 30a is the set magnification 30s is an S degree setting section for setting the copying degree; 30a, 30b, and 30C130d are operation keys for moving a spot light source that indicates the erase position of the original, which will be described later; 30e is a coordinate position indicated by the spot light source. The position designation keys 30f and 30c+ for inputting are erase range designation keys for designating the erasure range at the designated position, respectively.

FIG. 6 shows an example of the drive source configuration of each drive section of the copying rock constructed 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. 32 is a mirror motor;
Distance between mirror 5 and mirror 6.7 for performing magnification change! 11 (optical path length).

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. Reference numeral 34 denotes a shutter motor, which is a motor for moving a scissor (not shown) for adjusting the charging width of the photosensitive drum 10 by the charger 11 during zooming. 35 is a phenomenon motor, f
This is a motor for driving the developing roller and the like of the t1 period developing device 12. 36 is a drum motor, which is a motor for driving the photosensitive drum 10. 37 is a fixing motor, which connects the paper conveyance path 22 and the fixing roller pair 2.
3 and a pair of paper discharge rollers 24. 38 is a paper feed motor, and the feed roller 15,
This is a motor for driving 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. 7 shows a drive mechanism for reciprocating the optical system. That is, the mirror 5 and the exposure lamp 4 are supported by a first carriage 411, and the mirror 6.7 is supported by a second carriage 422, and these carriages 411.412 are guided by guide rails 421.422 in the direction of arrow a. It is said to be able to move in parallel. Further, the four-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 the first hinge 41+ that supports the mirror 5 is fixed to a midway portion of the belt 45. On the other hand, the second mirror supporting mirror 6.7
Two pulleys 47.47 are rotatably provided on the guide portion 46 of the V-ridge 422, spaced apart in the axial direction of the rail 422, and a wire 48 is connected between these pulleys 47.47.
is being handed over. One end of this wire 48 is connected to the four fixed parts, and the other end is connected to the four fixed parts 4 through the spring 50.
9, respectively. Further, one end of the first carriage 41+ is fixed to a midway portion of the wire 48. 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. The moving directions of the first and second carriages 411° and 412 are as follows:
It is 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/Kl.

It becomes ry-Py/KJ. This copyable range (X, V)
In the X direction, a pointer 51 provided on the back side of the document table 2
．． 52, and the y direction is indicated by a scale 53 provided on the upper surface of the first carriage 411.
and the distance between the fixed scales 21.

As shown in FIG. 8, the above-mentioned pointers 51.
55 via a spring 56. The pulley 55 is rotated by a motor 58, and the distance between the pointers 51 and 52 is changed by driving the motor 58 in accordance with the determined copyable range in the X direction. It looks like this.

Further, the first carriage 411 is moved to a predetermined position (home position according to the magnification) 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 41
1 is returned to the home position.

FIG. 9 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, for example, the cassette size detection switches 601 and 602, and includes a high-voltage transformer 76 that drives the various chargers, and the static elimination lamp. 28, the blade solenoid 27a of the cleaner 27, the heater 23a of the fixing roller pair 23, the exposure lamp 4, and each of the motors 31 to 40.58
In addition to controlling the above-mentioned copying operation, the spot light 1131, pulse motor 135, memory 14
0, the erase array 150, the array drive unit 160, etc. are controlled to erase unnecessary portions of the document. In addition, a spot light source 131, a pulse motor 135, an erasing array 150, an array drive 1!1s160, a memory 1
40 is illustrated.

Among the above motors 31 to 40.58, motor 35.37
．． A toner motor 77 that supplies toner to the image carrier 40 and the image carrier 12 is controlled by the main processor group 71 via a motor driver 78.
is controlled by the first sub-processor 72 via the pulse motor driver 79, and the motors 36, 39, 38, 58
is controlled by the second sub-processor group 73 via the pulse motor driver 80. 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, from the main processor group 71 to the first and second sub-processor groups 72.7
Drive and stop commands for each motor are sent to the first motor. Second
From sub-processor group 72 and 73 to main processor group 7
1, a status signal indicating the driving or stopping state of each motor is sent. The first sub-processor group 72 also includes a position sensor 83 that detects each initial position of the motors 31 to 34.
Location information has been entered from.

FIG. 10 shows an example of the configuration of the main processor group 71. A one-chip microcomputer 91 (hereinafter abbreviated as microcomputer) performs key human power detection on an operation panel (not shown) and various display controls via an input/output board 92.

Further, 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.
A size switch for detecting paper size and other inputs are connected to 4, and a copying condition setting switch and other inputs are connected to input/output port 95. Note that the input/output port 96 is an option.

FIG. 11 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 34.135 via the pulse motor driver 79. still,
The input/output board 103 is used, for example, when outputting status signals of each pulse motor to the main processor group 71.

FIG. 12 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 when a set value is set from the microcomputer 111, it starts counting reference clock pulses based on it, and when the count is out, it starts counting the end pulse. It is designed to be output. 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. Further, an input/output boat 114 is connected to the microcomputer 111, and this input/output boat 114 is connected to the pulse motor driver 8.
Motors 36.38.39.58 are connected via 0.

Figure 13 shows the control circuit of the pulse motor.
The input/output boat 121 (corresponding to the input/output boats 104 and 114 in Figs. 11 and 12) has a pulse motor driver 1.
22 (corresponding to the pulse motor drivers 79 and 80 in FIG.
．． 38.39) are connected to each winding A%B, A, and B.

FIG. 14 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 slew-up and slew-down of the pulse motor, starting from the self-starting region, being used in the high speed region, and finally falling. Note that tl, t2, . . . tx indicate the time of the phase switching interval.

Next, the document image erasing means will be explained.

In FIGS. 15 and 16, a guide shaft 130 is provided in the first carriage 411 along the lamp 4 in the part where the light of the lamp 4 is blocked, and this guide shaft 130 has a guide shaft 130 with which the erasing range of the document is set. Spot light 11 as a means of giving instructions
1131 is movably provided. This spot light source 131 is, as shown in FIG.
The light generated by the lens 32 is irradiated onto the document table 2 by a lens 133 as a spot light having a diameter d. For example, this spot light is set on the document table 2! It has a brightness that can pass through 16G of original thickness. Further, the spot light 111131 is connected to a timing belt (toothed belt) 134 disposed on the guide shaft 130 . This timing bell I-134 is passed between a pulley 136 and a driven pulley 137, which are constructed on the rotating shaft of a pulse motor 135. Therefore, by rotating the pulse motor 135, the spot light source 131 is moved to the first carriage 411.
is moved in a direction perpendicular to the scanning direction. Further, a position sensor 138 consisting of a microswitch for detecting the initial position of the spot light source 131 is provided in the first carriage 411 located at the end of the guide shaft 130 on the pulse motor 135 side. For example, when the spot light source 131 is moved, the spot light source 131 first comes into contact with the position sensor 138. The JJ phase position is now detected.

Next, a method for specifying the erasing range of a document using the spot light source 131 will be described with reference to FIGS. 17 to 19. This spot light if! 131 is operation key 3
When 0a to 30d are operated, the light emitting element 132 is moved in a lit state. That is, when the operation keys 30b and 30d are pressed, the motor 33 is driven and the first carriage 41+
#Yo Spotlight II! 131 is moved in the scanning direction (arrow y direction shown in FIG. 17). In addition, the operation key 30a
, 30G, the motor 135 is driven and the spot light source 131 is moved in a direction perpendicular to the scanning direction (in the direction of arrow X shown in FIG. 17). The operator operates the operation keys 30a to 30d while visually viewing the spot light transmitted through the document G, and presses the position designation key 30e after moving the spot light to point S1 on the original IG shown in FIG. 18(a), for example. Press. Then, the coordinate position specified in 81 is stored in the main processor group 71 shown in FIG. Similarly, when the position designation key 30e is pressed with the spotlight moved to 82 points on the document G, the positions of the 82 points are stored in the main processor group 71. The position of this spot light can be detected, for example, by counting the number of drive pulses of the pulse motor 33.135. After this, when the erasure range designation key 30f is pressed, 81.8
A rectangular area (indicated by diagonal lines) with two diagonal points is designated as the erasing range. Also, as shown in FIG. 18(b), if you specify points 83 and 84 on the original G and press the erase range designation key 30Q, the area other than the square with 83 and 84 points as diagonal points will be set as the erase range. It is specified. In this way, when the erasure range specification keys 30f and 30q are pressed, the specified 2
Calculations are performed in the main processor group 71 based on the position of the point and the forward magnification, and the memory 140 stores a high level signal ``°1'''' in the erase range area and a low level signal ``o'' in the other areas. be done. That is, this memory 140 is constituted by, for example, a RAM whose capacity in each column direction is approximately equal to the movement distance of the spotlight a 131 in the X direction divided by the position resolution in the y direction. , in the case of FIG. 18(a), as shown in FIG. 19(a), and in the case of FIG. 18(b), as shown in FIG. 19(b), corresponding to the shaded area. High level signals are stored at addresses and low level signals are stored at other addresses.

In this case, the original is set with the copy side facing up, and after the erasure range is specified, it is turned over along the fixed scale 21 of the original table 2. Therefore, as shown in FIG. 19, the information stored in the memory 140 is also actually inverted in the column direction.

On the other hand, as shown in FIG. 20, 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 FIG. 21, this erasing array 150 is fixed via a connecting member 1501 to a charging charger 11 provided on the copying 1 main body 1 via a slide rail 11a, for example. It can also be taken out from the copying machine main body 1. As shown in FIG. 22, this erasing array 150 is arranged along the longitudinal direction of the photosensitive drum 10, and inside this erasing array 150, as shown in FIG. 1, a plurality of light emitting elements are arranged. It is set up.

That is, - In FIG. 1 (a>(b) and (c), a plurality of first accommodating parts 151a are arranged at a predetermined pitch on the holder 151 of the erasing array 150, and these first accommodating parts 151
A plurality of second accommodating parts 151b are arranged along the direction a and shifted by half a pitch with respect to the first accommodating part 151a. A first light emitting diode 152a is housed in the first housing part 151a, and a second light emitting diode 152b having the same shape as the first light emitting diode is housed in the second housing part. Furthermore, openings 151C1151d are provided in the first and second housing portions 151a and 151b, respectively, facing the photosensitive drum 10. These openings 151G and 151d are shown in the same figure (b).
As shown in the figure, they are arranged in a staggered manner, and these openings 1
Light generated from the first and second light emitting diodes 152a and 152b is irradiated onto the photoreceptor drum 10 via the 51C1151d. Further, the holding body 151 is provided with a circuit board 153, and the first,
The lead wires of the second light emitting diodes 152a and 152b are wired. This substrate 153 is provided with, for example, an array driving section, which will be described later.
53, as shown in FIG. 22, is detachably connected to a connector 154 provided on the copying body.

Note that the number of light emitting diodes arranged in this erase array 150 matches, for example, each layer of the memory 140 in the column direction.

The erase array 150 is driven by the array driver 160 described above. This array drive section 160 is shown in FIG.
As shown in a), a shift register 161 having the same number of bits as the number of bits in the column direction of the memory 140, a store register 162 in which the contents of this shift register 161 are held, and each output signal of this store register 162 turns on and off. A switch circuit 164 consisting of a plurality of switch elements 163 that are turned off. Even-numbered output terminals of the store register 162 and even-numbered switch elements 163
The movable contact piece 16 of the switch element 163 is configured by a delay element (DL) 165 that is provided between the switch element 163 and delays the output signal of the store register 162 for a predetermined time.
3a is grounded, and fixed contacts 163b are connected to the first and second light emitting diodes 1 constituting the erasing array 150, respectively.
It is connected to each cathode of 52a and 152b. That is, the odd numbered switch elements 163 among the switch elements 163 are connected to the cathode of the first light emitting diode 152a, and the even numbered switch elements 163 are connected to the cathode of the second light emitting diode 152b. The anodes of each of these light emitting diodes 152a and 152b are connected to the power supply Vcc via a current limiting resistor R, respectively.

After specifying the erase range of the original as described above, when the original cover 11 is closed and the copy key 301 is pressed, the first carriage 411 and the photosensitive drum 10 are operated, and the memory 140 is read in the row direction. One column of data is sequentially read out (as shown in FIG. 19). The read data D is transferred to the shift register 161 of the array driving section 160 in response to the clock signal CLK.

After one column of data has been transferred to the shift register 161, when the charged portion of the -1 photosensitive drum 10 reaches the position of the first light emitting diode 152a of the erasing array 150, the main processor details 71 outputs a latch signal. LTH is output, and the data stored in shift register 161 is supplied to store register 162 in response to this signal. That is,
Since the erase array 150 is disposed between the charger 11 and the exposure section Ph, one column of data output from the memory 140 is stored in the first column of the erase array 150, for example, as shown in FIG. Light emitting diode 152a and exposure section p
Assuming that the angle of h is θ1 and the photosensitive drum 10 is rotating at an angular velocity ω, the output timing of the latch signal LTH is controlled so that it is supplied to the store register 162 before θl/ω.

Among the switch elements 163 of the switch circuit 164, the odd-numbered switch elements 163 are supplied with erase data to the store register 162 and are controlled by the erase data. 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 first light emitting diode 152 connected to the odd numbered switch element 163
A is turned on when the switch element 163 is on, and is turned off when the switch element 163 is off. Further, the erase data outputted from the even-numbered output terminals of the store register 162 is delayed by a predetermined delay time td by a delay element 165 and then supplied to the switch element 163. The delay time td is the distance 1! between the first and second light emitting diodes 152a and 152b! (shown in FIG. 1(b)) and corresponds to the time specified according to the rotational speed of the photoreceptor drum 10, and the erase data output from the store register 162 is transmitted by the delay element 163 to the first light emission. The portion erased by the diode 152a is delayed and supplied to the switch element 163 until it reaches the position of the second light emitting diode 152b. FIG. 2(b) shows the first and second light emitting diodes 15.
2a and 152b are shown. By turning on the switch element 163 in this way, the portion of the charged portion of the photoreceptor drum 10 where the light emitting diodes 152a and 152b are turned on is neutralized, and even if the portion from which the static electricity has been removed is subsequently exposed to light, This means that no electrostatic latent image is formed and the original image has been erased. Thereafter, the data in the memory 140 is read out one column at a time in the same manner, and the image is erased.

According to the above embodiment, the second light emitting diodes 152b are arranged at half the pitch of the first light emitting diodes 152a, and the first and second light emitting diodes 152a, 152b are arranged in a staggered pattern. Therefore, the overall arrangement pitch can be reduced to 1/2 with the same arrangement pitch as the conventional arrangement pitch, and it is possible to improve erasing accuracy. Moreover, the first and second
The light emitting timing of the light emitting diodes 152a and 152bt is controlled in synchronization with the rotational speed of the photosensitive drum 10. Therefore, on the surface of the photoreceptor drum 10,
There is no deviation in the light emitting positions of the first and second light emitting diodes 152a and 152b, and it is possible to reliably erase the specified erasing range.

Furthermore, since it is possible to arrange the light emitting diodes at the same pitch as in the past, it is possible to use commercially available light emitting diodes, and it is possible to suppress high manufacturing costs.

Furthermore, first and second light emitting diodes 152a, 152
b are provided on one side of the circuit 1tN153, so wiring and soldering are easy.

In the above embodiment, the light emitting diodes constituting the erasure 7 ray 150 are arranged in two rows, but the invention is not limited to this, and the light emission timing of each row can be controlled in synchronization with the rotation of the photoreceptor drum 10. By doing so, it is possible to further improve the erasure accuracy.

Further, the configuration of the array driving section 160 is not limited to the above embodiment, and for example, the erase data supplied to the first and second light emitting diodes 152a and 152b can be main-pushed. If the erasing data that is generated separately by the group 71 and supplied to the second light emitting diode 152b is delayed by a predetermined delay time from the erasing data that is supplied to the first light emitting diode 152a, then the erasing data is output. It is possible to eliminate delay element 165.

Furthermore, the arrangement position of the erasing array 150 is not limited to that shown in FIG. 20, but as shown in FIG.
An opening through which light from the scanning means passes is provided in a connecting portion 41 (not shown) disposed between the erase array and the charger 11 for charging, and the light exposed through this opening is provided. It is also possible to configure the static N latent image formed in accordance with the above to be erased in accordance with a designation.

Others Of course, various modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As detailed above, according to the present invention, the arrangement pitch of the light emitting elements can be narrowed with a simple configuration, and furthermore,
It is possible to provide an image forming apparatus that can improve erasing accuracy through reliable light emission mil control.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of an image forming apparatus according to the present invention. FIG. ) bottom view,
2(C) is a side sectional view of FIG. 2(a), FIG. 2(a) is a circuit configuration diagram showing the array drive section, and FIG. 2(b) is a diagram shown to explain the light emission timing of the erasing array. , 3 and 4 show the configuration of the image forming apparatus, FIG. 3 is an external perspective view, FIG. 4 is a side sectional view, and FIG. 5 is a plan view showing the configuration of the operation panel. Figure 6 is a perspective view showing the configuration of the drive section, Figure 7 is a perspective view schematically showing the drive mechanism of the optical system, Figure 8 is a perspective view schematically showing the drive mechanism of the pointer, and Figure 9 is the overall view. FIG. 10 is a configuration diagram of the main processor group, FIG. 11 is a configuration diagram of the first sub-processor group, FIG. 12 is a configuration diagram of the second sub-processor group, and FIG. 13 is a configuration diagram of the second sub-processor group. A schematic configuration diagram showing a control circuit of a pulse motor, FIG. 14 is a diagram for explaining the speed control method of a pulse motor, FIG. 15 is a perspective view of the main part showing a spot light source, and FIG.
Figure 6 is a side sectional view of the main part showing the spot light source, Figures 17 and 18 are plan views shown to explain the operation of specifying the erasing range of an original using the spot light source, and Figure 19 is the contents of the memory. FIG. 20 is a side sectional view of the main part showing the arrangement of the erase array, and FIG.
22 is a perspective view showing the relationship between the erasing array and the photosensitive drum, and FIG. 23 is a side sectional view of the main parts showing another example of the arrangement of the erasing array. be. DESCRIPTION OF SYMBOLS 1...Main body, 2...Document stand, 10...Photosensitive drum, 30...Operation panel, 30a-30d...Operation keys, 30e...Position specification key, 30f, 300...
・Erase range specification key, 71...main processor group,
131... Spot light source, 132... Light emitting element, 133... Lens, 135... Pulse motor,
140...Memory, 150...Erasing array, 151
...Holder, 152a, 152b...First and second light emitting diodes, 153...Circuit board, 160...
Array drive unit, P...paper, Ph...exposure unit. Applicant's agent Patent attorney Takehiko Suzue (C) Figure 1, 160 15゛O Figure 2 (a) Figure 13 @ Figure 16 Figure 17 Figure 18 (a) Figure 18 (b) (a) (b) Figure 19 Figure 20 IP! l Figure 23 Figure 21 Inguchi Figure 22

Claims (2)

[Claims] (1) A scanning device that optically scans a document placed on a document table; an optical system that forms an optical image obtained by the scanning device onto a charged image carrier; and the image carrier. a developing means for developing an image formed on the body; a transfer means for transferring the developed image onto a transfer material; a designation means for designating an erasing range of the document; and a designation means provided near the image carrier. In an image forming apparatus comprising an erasing means for erasing from an image carrier a portion designated by the designating means, the erasing means has a light emitting element group consisting of a plurality of light emitting elements disposed in the longitudinal direction of the image carrier. The n-stage light-emitting element groups are arranged in stages, and the n-stage light-emitting element groups are staggered by 1/n pitch, and the light emission timings of these n-stage light-emitting element groups are sequentially shifted in synchronization with the rotational speed of the image carrier. An image forming apparatus characterized in that: (2) The specifying means is provided in the scanning means and is made of a light emitting element that is movable in a direction perpendicular to the moving direction of the scanning means and irradiates the original with a spot light. image forming device.