JPS6235339A - Image forming device - Google Patents

Abstract

PURPOSE:To detect the opening and closing of an original cover by installing a spot light source which moves a spot light beam irradiated on an original picture and designates an erasure range and a movable light receiving part together with said spot light source and detecting whether the original cover is opened or closed in the state where the light receiving part is moved outside a maximum transfer-enable original size. CONSTITUTION:The home positions HP of the spot light source 131 and the light receiving part 132 lie within an original platen 2 and outside the maximum transfer-enable original size. At the home position HP the original cover 11 is detected to be opened or closed. Thus the opening and closing of the original cover 11 can be detected even if the 1st carriage 411 is positioned at any place on the original platen 2.

Description

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

(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, when a copying operation is automatically performed, opening and closing of a document cover is detected. Conventionally, detection of opening/closing of the document cover has been performed using a switch or the like provided near the document cover. Therefore, special parts were required.

(Object of the invention) This invention was made based on the above circumstances,
The objective is to provide an image forming apparatus that can detect opening and closing of a document cover with a simple configuration.

(Summary of the Invention) This invention provides a spot light source that irradiates a spot light onto, for example, an original image and moves the spot light to specify an erasing range, and a spot light source that is movable together with the spot light source and that is irradiated by the spot light source. A light receiving part capable of receiving light is provided,
The spot light source and the light receiving section are moved inside the Ijili table and further outside the maximum size of the document that can be copied, so that opening and closing of the document cover is detected.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described 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 upper surface of the main body 1 for copying. 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 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 to maintain the light exposure φ. 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 conversion lens block 8, and further passes through the mirror 9. The light is reflected by the photoreceptor drum 10 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 1o 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 the 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 row 515 or 16, and the taken out paper is taken out from the paper guide path 17 or 18 and is guided to a resist roller pair 19, and guided to a transfer section by this resist roller pair 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 cassette size detection switches 60r and 602, respectively. This cassette size detection switch 60! , 602 are constituted by 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
20 causes the toner image on the photosensitive drum 10 to be transferred. 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 . After the photosensitive drum 10 has been transferred, the charge is removed by the charger 26, residual toner on the surface is removed by the cleaner 27, and the residual image is erased by the charge removal lamp 28, so that the drum 10 returns to its initial state. He is set to return. Note that 29 is a cooling fan for preventing the temperature inside the main body 1 from rising above the limit.

FIG. 5 shows an operation panel 3o provided on the main body 1. 301 is a copy key for instructing 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 cassettes 13 and 14, and 30s is a selected key. A cassette display section that displays the cassette; 306 is a magnification setting key that sets the magnification and reduction magnification of copies in a predetermined relationship; 307 is a zoom key that sets the magnification and reduction magnification steplessly; and 30th displays the set magnification. 30s is a density setting section for setting copy 1artJ, 30a, 30b, 30C130d are operation keys for moving a spot light source that indicates the erase position of the original, which will be described later, and 30e is a position for inputting the coordinate position indicated by the spot light source. The designation keys 30f and 30g are erase range designation keys that specify the erasure range at the designated positions, 30h is an open/close detection designation key that designates opening/closing detection of the document cover, and 30i is a size detection designation key that designates document size detection. The keys 30j and 30 are light emitting elements that indicate that the open/close detection designation key 30h and the size detection designation key 301 are being scanned, respectively.

FIG. 6 shows an example of the drive source configuration of each drive section 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. 32 is a mirror motor;
This is a motor for changing the distance (optical path length) between the mirror 5 and the mirror 6.7 for changing the magnification.

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 feed motor, and the feed roller 15, 16
This is a motor for driving. 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, respectively, 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 booby 944, 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, the second mirror supporting mirror 6.7
Two pulleys 47.47 are rotatably provided on the guide portion 46 of the carriage 422 at a distance in the axial direction of the rail 422, and a wire 4 is connected to these pulleys 47.47WR.
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 41! 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.

Furthermore, the copyable area corresponding to the specified paper is displayed on the rjrt manuscript table 2. tL6゜Is 61. 11 - Paper size specified by the key 304 (PxSP
y) and the copy magnification specified by the magnification setting key 306.30a is K, then the copyable range (X, y)
is [x-Px/KJ.

It becomes ry-Py/KJ. This copyable range (X1y)
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.

As shown in FIG. 8, the above-mentioned pointers 51.
The wire 57 is connected to the wire 55 via a spring 56. The pulley 55 is a motor 58
This motor 58
The distance between the hands 51 and 52 can be changed by rotating the hands according to the paper size and magnification.

Further, the first carriage 411 is moved to a predetermined position by driving the motor 33 according to the paper size and magnification.
f (home position according to the magnification). Then, when the copy key 301 is pressed,
First, the first carriage 411 is connected to the second carriage 412.
After that, the lamp 4 is turned on and the second carriage 412 is moved away from the second carriage 412 . When scanning of the original is completed, the lamp 4 is turned off and the first carriage 4 is turned off.
11 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, a blade solenoid 27a1 of the cleaner 27; a heater 23a of the fixing roller pair 23;
The exposure lamp 4 and each of the motors 31 to 40.5
8 etc. to perform the above-mentioned copying operation,
Controls the spot light +11131, light receiving unit 132, pulse motor 135, memory 140, erasing array 150, array drive unit 160, etc. to erase unnecessary parts of the document, detects opening/closing of the document cover, and detects the size of the document. This is what we do. Note that the spot light source 131, light receiving section 132, pulse motor 135, erasing array 150, array driving section 160, and memory 140 will be described later.

the above! - Of evening 31-40.58, motor 35.37
．． A toner motor 77 that supplies toner to 40 and the developing unit 12 is connected to the main processor group 71 via a motor driver 78, and the motors 31 to 34 and 135 are connected to the first sub-processor group via a pulse motor driver 79. 72, controlled by motor 36.39.38
．． 58 is controlled by the second sub-processor group 73 via the pulse motor driver 80. In addition, exposure lamp 4
The heater 23a is controlled by the main processor group 71 via the G, T lamp regulator 81, and the heater 23a is controlled by the heater control section 82.
It is controlled by the main processor group 71 via the main processor group 71. Then, commands to drive and stop each motor are sent from the main processor group 71 to the first and second sub-processor groups 72 and 73. A status signal indicating the drive/stop state of each motor is sent from the second sub-processor group 72, 73 to the main processor group 71. Further, the first sub-processor group 72 receives position information from a position sensor 83 that detects the initial positions of the motors 31 to 34.

FIG. 10 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. The input/output boat 93 includes a high voltage transformer 76 and a motor driver 7.
8, a lamp regulator 81 and other outputs are connected, a size switch for detecting the paper size and other human power are connected to the input/output boat 94, and a copying condition setting switch and other human power are connected to the input/output boat 95. Ru. 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 seven pulse motor drivers. 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 other.

FIG. 14 shows a method of controlling the speed of a pulse motor, in which (a) is the speed curve of the pulse motor, and (b) is 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 document image erasing means will be explained.

15 and 16, a guide shaft 130 is provided along the lamp 4 in a portion of the first carriage 411 where the light of the lamp 4 is blocked. This guide shaft 130 has a spot light source 1 as a means for instructing the erasing range of the document.
31, a light receiving section 132 is provided integrally and movably. As shown in FIGS. 16(a) and 16(b), the spot light source 131 and the light receiving section 132 are disposed such that the optical axis of the spot light [131] is orthogonal to the document table 2, and the optical axis of the light receiving section 132 is perpendicular to the document table 2. It is arranged so as to be inclined so as to intersect with the optical axis of the spot light vA131 at the surface portion of the light spot vA131. Of these, the spot light source 131 is composed of a light emitting element 131a such as a light emitting diode or a lamp, and a lens 131b that guides the light generated by the light emitting element 131a toward the document table 2. Lens 132 that guides reflected light from document table 2 to light receiving element 132a
It is composed of b. The lighting signal of the light emitting element 131a is supplied from the main processor group 71, and the output signal of the light receiving element 132a is supplied to the main processor group 71.

Incidentally, the spot light emitted from the spot light i1F, 131 has a brightness that allows it to pass through an original set on the original platen 2, for example, as thick as a postcard.

Further, the spot light m131 and the light receiving section 132 are connected to a timing belt (toothed belt) 134 disposed along the guide shaft 130.

This timing belt 134 is passed between a pulley 136 provided on the rotating shaft of a pulse motor 135 and a driven pulley 137. Therefore, by rotating the pulse motor 135, the spot light source 131 and the light receiving section 132 are moved in a direction perpendicular to the scanning direction of the first carriage 411. Further, the first carriage 411 located at the end of the guide shaft 130 on the pulse motor 135 side is provided with a position sensor 138 consisting of a microswitch that detects the initial positions of the spot light source 131 and the light receiving section 132. For example, when the spot light source 131 is moved, first, the spot light source 131 is moved to the position sensor 138.
The initial position is detected by contacting the

Next, using the factors of FIGS. 17 to 19, the spot light 1
l1131 was used. This section explains how to specify the erasing range of a document. This spot light is it! When the operation keys 30a to 30d are operated, the light emitting element 131a is moved with the light emitting element 131a lit. That is, the operation keys 30b, 3
When 0d is pressed, the motor 33 is driven, and the first carriage 411 and the spot light source 131 are moved in the scanning direction (the direction of the arrow y shown in FIG. 17). In addition, the operation key 30
When a or 30c is pressed, the motor 135 is driven and the spot light source 131 is moved in a direction perpendicular to the scanning direction (arrow x direction shown in FIG. 17). The operator operates the operation keys 308 to 30d while visually viewing the spot light transmitted through the document G. For example, after moving the spotlight to 81 points on the document G shown in FIG. 18(a), the operator presses the position designation key 30e. Press. 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 82 points on the document G and the position designation key 30e is pressed, the position of the 82 points is the main processor l! It will be stored as ¥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 that, when the erasure range designation key 30f is pressed, the S
s, a rectangular region with 82 points as diagonal points In! <indicated by diagonal lines) is designated as the erasing range. Also, Fig. 18 (
As shown in b), by specifying points 83 and 84 on the document G and pressing the erasure range designation key 30Q, the area other than the square with diagonal points 33 and 34 is designated as the erasure range. In this way, when you press the erase range specification keys 30f and 3 (l),
Calculations are performed in the main processor group 71 based on the designated two-point digit M and the copying magnification, and the memory 140 stores a high level signal "1" in the erase range area and a low level signal °'' in the other areas. 0'' is stored. That is, in this memory 140, for example, the capacity in each column direction is equal to that of the spot light source 1.
18 (a
), as shown in FIG. 19(a), and in the case of FIG. 18(b), as shown in FIG. 19(b), a high level signal is sent to the address corresponding to the shaded area. Low level signals are stored at other addresses.

In this case, the original is set with the copy side facing up, and after specifying the erasure area, the fixed scale 2 of the original table 2! It is turned over along the 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 FIGS. 21 and 22, this erasing array 150 has a plurality of light shielding cells 151 arranged in a direction perpendicular to the rotational direction of the photoreceptor drum 10, and each light shielding cell 151 has a plurality of light shielding cells 151 arranged therein in a direction perpendicular to the rotational direction of the photoreceptor drum 10. A light emitting element 152 made of, for example, a light emitting diode as shown in FIGS. 23(a) and 23(b) is provided.

Furthermore, a lens 153 is provided in the opening of each cell 151 facing the photoreceptor drum 10 to focus the light from the light emitting element 152 onto the surface of the photoreceptor drum 10 . 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. 24, this array driving section 160 includes a shift register 161. A store register 16 that holds the contents of this shift register 161
2. A switch circuit 16 consisting of a plurality of switch elements 163 that are controlled on and off by each output signal of the store register 162.
4, and these switch elements 163
The movable contact pieces 163a are grounded, and the fixed contacts 163b are connected to the light emitting elements 152 constituting the erasing array 150, respectively.
connected to each cathode. Each of these light emitting elements 15
The two anodes are connected to the power supply Vcc through current limiting resistors 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). This read data Dr 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 is transferred to the shift register 161, the charged portion of the photoreceptor drum 10 is transferred to the erase array 15.
When the value reaches 0, the main processor group 71 outputs a latch signal LTH, and the data stored in the shift register 161 is supplied to the store register 162 in response to this signal. That is, the erase array 150 includes the charger 11 and the exposure section ph.
For example, one row of data output from the memory 140 is arranged between the erase array 150 and
If the angle of the exposure part Ph is θ1 and the photosensitive drum 10 is rotating at each speed, the latch signal LTH is set so that it is supplied to the store register 162 before θ1/ω.
output timing is controlled.

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 one light emitting element 152 is turned on is charge-free, and even if the charge-free part is subsequently exposed to light, 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 column by column in the same manner, and the image is erased.

Next, the document size detection operation will be explained.

This document size detection is performed with the document cover 11 open. With the document G set on the fixed scale 21 of the document table 2, press the size detection designation key 30i.
When is operated, the spot light source 131 and the light receiving section 132 are moved to the center of the first carriage 411 under the control of the main processor group 71, and in this state, the first carriage 411 moves as shown in FIG. It is moved to the position farthest from the fixed scale 21. In this position, the light emitting element 131a of the spot light source 131 is turned on, and the first carriage 411 is connected to the fixed scale 21.
direction. During this movement, when the spot light source 131 and the light receiving section 132 reach the end of the original IG set, the light emitted from the light emitting element 131a is reflected by the original G, and the light receiving element 13 of the light receiving section 132
2a. Since the distance @ I 1 that the first carriage 411 moves from one end of the document table 2 to the other end is set in advance, the first carriage 4 at the time when the light receiving element 132a detects the light from the light emitting element 131a is determined from this distance.
By subtracting the moving path wi12 of 11, the length 13 of the set document G can be obtained, and from this, the document size can be determined. The moving distance of the first carriage 411 can be determined by counting the number of pulses of the pulse motor 33. ” Next, the gist of the invention will be explained.

In this invention, the home position of the spotlight 111131 and the light receiving section 132 is inside the document table 2 and outside the maximum document size that can be copied, as shown by HP in FIG. Therefore, in the operation of specifying the erase range of the original image using the spot light source 131 described above, from this home position HP, the spot light source 131
1. The light receiving section 132 is moved and the erasing range specification key 30f is pressed.
Alternatively, when 30o is operated and the erasure range designation operation is completed, the home position ()-IP is returned again.

In addition, in detecting the document size, first, from the home position HP, the spot light 51131 and the light receiving section 1 are
32 is moved to the center of the first carriage 411, and in this state, the document size detection operation described above is performed. When this detection operation is completed, the spotlight 1111
31 and the light receiving section 132 return to the home position H.
Returned to P.

On the other hand, when the opening/closing designation key 30h is operated, the open/closed state of the document cover 11 is detected by the spot light source 131 and the light receiving section 132 at the home position HP. For example, when a document is set on the document table 2 and the document erase range designation operation or document size detection operation using the spot light source 131 is completed as described above,
The spot light source 131 and the light receiving element 132 are located at the home position HP1. vI, and at this home position HP, the light emitting element 131a of the spot light source 131
is lit. In this state, when the document cover 11 is closed, the light emitted from the spot light 111131 is reflected by the document cover 11 and enters the light receiving section 132, as shown in FIG. In the light receiving section 132, this incident light is detected by a light receiving element 132a,
This detection output signal is supplied to the main processor group 71. Therefore, the main processor group 71 starts the above-described copying operation in response to this detection output signal.

According to the above embodiment, the spot light source 131, the light receiving element 1
The home position HP 32 is set inside the document table 2 and outside the maximum document size that can be copied, and the open/closed state of the document cover 11 is detected at this home position HP. Therefore, no matter where the first carriage 411 is located on the document table 2, the document cover 1
It is possible to detect the opening and closing of 1.

In addition, since the opening and closing of the document cover 11 is detected using the spot light source 131 and the light receiving section 132, the document cover 11
There is no need for a separate dedicated detection means to detect the opening/closing of the
It is possible to suppress an increase in the number of parts, and it is also possible to prevent an increase in the size of the device.

In the above embodiment, when detecting the opening/closing of the document cover 11,
Although the light emitting element 131a of the spotlight 1131 was turned on,
For example, as shown in FIG. 3, opening and closing of the document cover 11 is detected by reversing the positional relationship between the spot light source 131 and the light receiving section 132 and detecting external light reflected by the document cover 11 at the light receiving section 132. You can do it like this. Such a configuration has the advantage that there is no need to turn on the light emitting element 131a of the spotlight [131] when detecting the opening/closing of the document cover 11.

Furthermore, the arrangement position of the erasing array 150 is not limited to that shown in FIG. 20, but as shown in FIG. It is also possible to configure the data to be erased by

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 provide an image forming apparatus capable of detecting opening/closing of a document cover with a simple configuration.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of an image forming apparatus according to the present invention. FIG. 1(a) is a plan view of the main parts for explaining the home position, and FIG. FIG. 2 is a side sectional view showing another embodiment of the present invention, FIGS. 3 and 4 are side sectional views showing the configuration of an image forming apparatus, and FIG. 4 is a side sectional view, FIG. 5 is a plan view showing the configuration of the operation panel, FIG. 6 is a perspective view showing the configuration of the drive unit, and FIG.
The figure 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, Figure 9 is a configuration diagram showing the overall control circuit, and Figure 10 is the main A configuration diagram of the 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, FIG. 13 is a schematic configuration diagram showing the control circuit of the pulse motor, and FIG. 14 15 is a perspective view of the main parts showing the spot light source, FIG. 16 is a side cross-sectional view of the main parts showing the spot light source, and FIGS. 17 and 18 are diagrams for explaining the speed control method of the pulse motor. 19 is a plan view shown to explain the operation of specifying the erasing range of an original using a spot light source, FIG. 19 is a diagram shown to explain the contents of the memory, and FIG. 20 is a main part showing the arrangement of the erasing array. A side sectional view, FIG. 21, and FIG. 22 each show the relationship between the erasing array and the photosensitive drum, and FIG. 21 is a perspective view showing only the main part, and FIG. 22 is a front view showing only the main part. , FIG. 23 shows the configuration of the erasing array, FIG. 23 (a) is a side sectional view, FIG. 23 (b) is a front view with a portion cut away, and FIG. FIG. 25 is a plan view for explaining the document size detection operation, and FIG. 26 is a side sectional view of a main part showing another arrangement example of the erasing array. DESCRIPTION OF SYMBOLS 1...Main body, 2...Document stand, 10...Photosensitive drum, 30...Operation panel, 30a-30d...Operation keys, 30f, 30o...Erase range specification key, 30h
...Opening/closing detection designation key, 301...Size detection designation key, 71...Main processor group, 131...Spot light source, 132...Light receiving section, 140...
Memory, 150... Erasing array, 160... Array drive unit, P... Paper, Ph...
Exposure section. Applicant's representative Patent attorney Takehiko Suzue (a) Figure 1 (b) Figure 1 Figure 2 Figure 12 Figure 13 roll (b) Figure 16 Figure 17 (a) (b) (a) (b) @19 Figure 20v! J [26! l! i7 (a) (b) 吏0 15゜Fig. 24 Fig. 25

Claims (4)

[Claims] (1) In an image forming apparatus that has a cover that covers a document table and that optically scans a document placed on the document table by a scanning means and transfers an image corresponding to the image of the document to a transfer material, An indicating means provided in the scanning means for indicating a predetermined range of the document using transmitted light, an erasing means for erasing an image corresponding to the specified range, and a movable means together with the indicating means. a light receiving means located outside the maximum document size to be set inside the table and detecting light reflected from the cover; and a control means detecting opening/closing of the cover based on an output signal of the light receiving means. An image forming apparatus comprising: (2) The image forming apparatus according to claim 1, wherein the instruction means comprises a light emitting element that is movable in a direction perpendicular to the direction of movement of the scanning means and irradiates the document with a spot light. (3) The image forming apparatus according to claim 1, wherein the control means is capable of detecting the document size from the output signal of the light receiving means. (4) The image forming apparatus according to claim 1, wherein the control means starts the copying operation in response to an output of detection of opening/closing of the cover.