JPS6014256A - Copying device - Google Patents

Abstract

PURPOSE:To record only the original image on a copy and to prevent the unnecessary image except the original image from appearing on the copy irrespectively of the background color of the original by performing development after erasing selectively the electrostatic latent image obtd. by exposing except the original image. CONSTITUTION:The beginning end position Y1 and terminal end position Y2 of an original in the exposing position in the direction X coinciding with the turning position of a photosensitive drum 11 are read when the drum 11 turns to the position where the electrostatic latent image forming surface of the drum 11 faces an eraser 18. The eraser 18 is so controlled as to energize the light emitting diodes in the corresponding region between the beginning end Y0 and Y1 of the exposing position in the direction Y and between Y2 and the terminal end Y3 of the exposing position. Only the electrostatic latent image obtd. from the original remains after such control is performed repeatedly for all the exposing regions. The electrostatic latent image formed on the drum 11 by the exposing of the part except the original is erased by the eraser before developing and therefore the solid black image is not transferred on recording paper.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a copying device that forms an electrostatic latent image corresponding to an original image on a photoreceptor and develops it to record. Concerning erasure.

■Prior art In this type of copying apparatus, image reading scanning is performed by irradiating light onto a document on a document table and forming an image of the reflected light on a photoreceptor drum. A visible image is obtained by attaching toner to the electrostatic latent image, and this visible image is transferred to recording paper. In this case, the portion of the image reading surface with low light reflectance corresponds to the black part of the recorded image, that is, the part to which toner adheres, and the part with high light reflectance corresponds to the white part of the recorded image, that is, the part to which toner does not adhere.

Generally, with this type of copying device, you can specify the paper size,
An electrostatic latent image is formed only in the image reading area according to its size (
(delete unnecessary parts) and record. However, if you use a small document that is different from the normal size, or if the document is tilted when setting it, the background of the document will also enter the image reading area, so if the background is black, that part of the recording paper will be covered in solid black. The image is recorded. This type of solid black image is undesirable because it gives people a feeling of discomfort and consumes unnecessary toner.

Therefore, the back side of the pressure plate and the document conveyance belt, which serve as the background of the original, are generally painted white to prevent toner from adhering to the background of the copy. However, the pressure plate and document conveying belt are very easily stained and become stained immediately after being cleaned, so that copies are likely to be stained.

■Purpose The present invention can be used when a document smaller than a specified size is used, or when the document is tilted.・The purpose is to prevent unnecessary images other than the original image from appearing on the copy, regardless of the background color of the original, even if the image is copied.

■Construction Original Image Once the entire position of the original on the reading surface is known, the electrostatic latent image formed on the photoreceptor can be divided into the parts obtained by exposure of the original image and the parts obtained by exposure of parts other than the original image. It is possible to distinguish between the parts. If development is performed after selectively erasing the electrostatic latent image obtained by exposure other than the original image from the photoreceptor 2, only the original image will be recorded on the copy.

Accordingly, since it is acceptable to make the document background black, if the pressure plate, document conveyance belt, etc. are made black, the document sheet and the background can be distinguished from each other by an optical sensor from a position facing the document. Therefore, -3 = For example, if a large number of optical detection elements are arranged in a predetermined direction, an optical detection element array is placed facing the document image reading surface, rotated and scanned, and the obtained information is processed. You can grasp the position of the entire manuscript. The eraser for erasing electrostatic latent images is activated at minute intervals in the main scanning direction.

If the eraser is arranged so that deenergization can be controlled and the eraser is controlled according to the position of the original in the main scanning direction at the position of the original in the sub-scanning direction corresponding to the position of the photoreceptor, the Latent images can be erased.

If the position of the entire document can be determined, the size of the document can also be determined. Therefore, in one preferred embodiment of the present invention, the size of the document is automatically determined and the exposure range is set. This eliminates the need for troublesome size specifications.

If there is a sensor that directly detects the document position as described above,
It is possible to accurately detect the document position. Therefore,
In one preferred embodiment of the present invention, an automatic document feeder is provided, and its drive is controlled using the output of the sensor.

4- An embodiment of the present invention will be described below with reference to nine drawings. FIG. 1 shows one type of copier embodying the invention. 1st
This will be explained with reference to the figures. This copying machine 2 is of a type that fixes the original 7 and performs exposure by scanning the optical system. When a copy start instruction is given, the original 7 placed on the original platen 6 is transferred to the automatic document feeder 1. (ADF), the document is automatically positioned at the exposure position on the contact glass 9 (the leading edge of the document is at position 9a). 3 is a belt for conveying the document. The belt 3 is supported by rollers 4 and 5, and is driven by a document drive motor 58, which will be described later.

8 is a paper feed separation roller. When a predetermined copying process is completed, the original document 7 is ejected onto the paper ejection tray 10 by the belt 3.

Exposure lamp 13. An optical scanning system including a mirror 14 and the like scans the inside of the contact glass 9 in the left-right direction in the figure, and guides reflected light from the original 7 to a predetermined position on the photoreceptor drum 11 during forward scanning. A wide-angle lens 16 and an image sensor 15 are arranged at a position outside the operating range of this optical scanning system. The wide-angle lens 16 used here is an ultra-wide-angle lens with a short focal length and a wide angle of view (180 degrees or more).
The light from the center line in the scanning direction of the document 1- is focused on the image sensor 15.

Around the photosensitive drum 11, there is a charger I2, a beret lamp 18. Developer 19. Transfer/separation charger 20. Cleaning blade 31° Static elimination charger 32
Equipped with etc. Transfer paper is fed from one of the paper feed cassettes 21' and 22 through the paper feed mechanisms 23 and 24, and the transfer paper is placed on the surface of the photoreceptor drum 11 at a predetermined timing by the registration rollers 25. It is inserted along the line. This transfer paper has the visible image formed on the photoreceptor drum 11 transferred thereto, is separated from the photoreceptor drum 11, and is sent to a fixing roller 28 by a belt 27. The paper that has been fixed passes through the paper output roller 29 and is delivered to the paper output tray 30.
is discharged.

FIG. 2 shows the outside 11 of the display/operation section 80 of the copying machine shown in FIG. Referring to FIG. 2, this panel has a numeric keypad 81 for setting numerical values, a 7-segment numeric display 82 for displaying the set number of copies and the number of copies, and a dot display 83 for displaying the transfer paper size for cassette 1. .84.Paper feed selection key 8
5,86. Paper cassette display lamps 87, 88. Density setting change key 89.90. Concentration display 91. Print start key 92. Original display 93. A document jam indicator lamp 94 and the like are provided.

The document display device 93 is a liquid crystal display device capable of displaying graphics, and has display pixels arranged in a matrix of 100 vertical pixels.
×Equipped with 140 width. The document display 93 displays the movement state of the document 7 during transportation and the document arrangement state after positioning, as will be described later.

FIG. 3a shows the vicinity of the image sensor 15 in FIG. 1,
FIG. 3b and FIG. 3c show the image sensor 1, respectively.
FIG. 5 shows a plan view and a front view of No. 5.

The image sensor 15 used here is a one-dimensional COD image sensor with 2048 photosensor elements arranged in one axial direction and equipped with a CCD shift register 7- for signal storage, manufactured by Oki Electric. It is 0PA2048CA.

Referring to FIG. 3a, an image from one end of the long side of the contact glass 9 to the other is inverted by the wide-angle lens 16 and formed to correspond exactly to the end to end of the light receiving area 15a of the image sensor 15. Ru. In this example, the maximum document size is A3, so the image sensor 15 is Q,
Documents can be detected with a resolution of 2mm. The image of the exposure position 9a on the contact glass 9 is formed at 9 a I slightly to the left of the right end of the light receiving area 15a of the image sensor.

17 is a stepping motor, and a circular printed circuit board 26 is connected to the rotating shaft of the stepping motor. Image sensor 1
5 is mounted on the printed circuit board 26 so that its center coincides with the center of the rotation axis of the stepping motor 17.

FIG. 4 shows a schematic system configuration of the copying machine shown in FIG. 1. Referring to FIG. 4, the control device main body 4 of this copying machine
4 is a microprocessor 45 (CPU), a read-only memory 46 (ROM) that stores programs, and a read/write memory 47 (RAM).
, I10 boat 48, 49, 50, 51, 52.53.
Motor driver 55.57. It consists of a solid state relay 56 for controlling the exposure lamp.

The document detection device 40 includes a drive circuit 41. Image sensor 1
5. Signal amplification circuit 42. Figure 5a shows the structure of the image sensor 5 and its peripheral circuits, and Figure 5b shows the configuration of the image sensor 5 and its peripheral circuits. An example of the signal waveform of each terminal of 15 is shown. First, the general configuration of the image sensor 15 will be described. This device includes a 2048-bit photodiode, dummy sensors before and after it, a photogate, a phototransformer gate, an output gate, a preamplifier, a compensation preamplifier, and the like.

When the light-receiving region 15a is irradiated with light, charges corresponding to the light intensity and exposure time are accumulated in the region of the photodiode irradiated with light. The charge accumulated in the photodiode is simultaneously transferred to each adjacent bit of the CCD shift register in all pixels by applying a signal readout pulse to the transfer gate (terminal φt).

The charges transferred to the CCD shift register are transferred bit by bit to the output side by applying shift pulses to shift control terminals φla, φlb, φ2a, and φ2b, and after being shifted a predetermined number of times, the charges are transferred to the output side via the output gate and preamplifier. The signal is output to the signal output terminal C8. In other words, if a shift pulse is applied after a signal readout pulse is applied, each time a shift pulse is applied, the image sensor 15
Signals corresponding to the amount of light received at each position detected are sequentially read out. Terminal C8 outputs a dark signal, that is, a noise level.

This will be explained with reference to FIG. 5a. A clock pulse φ0, which is the basis of the operation of the image sensor 15, is generated by the oscillator 41a. This clock pulse φ0 is frequency-divided by a preset counter (163) and applied to the JK flip-flops 41b and 41c. I of the control device main body 44
When the read pulse SB is applied from the 10 port 48, the output terminals of the Noritsubu flops 41a and 41b are set, and from this timing the counter (163
) counts a predetermined number and resets the flip-flop 41a, the terminal φt of the image sensor 15 becomes H.

In other words, the high level H during this period is the signal read pulse. The monomulti (123) generates a reset pulse to be applied to the reset input terminal φr of the image sensor 15. The shift pulse applied to the CCD shift register is generated by delaying the reset pulse by one gate stage and triggering the flip-flop 41c.

In the signal amplification circuit 42, the signals from the image signal output terminal CS and the noise output terminal O8 of the image sensor 15 are respectively taken out, differentially amplified by an operational amplifier 42a, and further amplified by an operational amplifier 42b to obtain an output signal vout. ing.

This signal Vout is applied to the A/D (ana 1
1-log-digital) converter 43.

Referring to FIG. 5c, this circuit 43 includes eight analog comparators 43a, an AND gate 43b, and an OR gate 43.
c and a voltage dividing resistor 43d, which determines the level of the analog signal applied to the input terminal into one of eight levels, and outputs a digital signal coded into a 3-bit binary signal according to the result. Output. In this example, this 3-bit code corresponds to the level of the amount of light received by the image sensor 15 at a predetermined position.

FIG. 6 shows the motor driver 57 of FIG. 4.

Note that the motor 58 used for conveying the document is a DC servo motor. Referring to FIG. 6, the motor driver 57 includes four power transistors 64, 69, 65, 70 connected to both terminals of the motor 58, and a circuit for controlling them.

That is, when transistors 64 and 65 are turned on, current flows from terminal N to M of motor 58, causing the motor 58 to rotate forward, and when transistors 69 and 70 are turned on, current flows from terminal M to terminal N of motor 58. Motor 58 reverses as current flows.

The relay 60 switches and controls this forward rotation and reverse rotation.
This relay 60 is controlled by a transistor 59 connected to I10 port 49. The on-resistances of transistors 64 and 70 vary depending on the on-resistance of transistor 63, and the on-resistances of transistors 65 and 69 vary depending on the on-resistance of transistor 68.

In other words, the magnitude of the current flowing through motor 58 is set by the on-states of transistors 63 and 68. The input terminals of the transistors 63 and 68 are connected to four resistors 61 a, 6 l b, 6 having different resistance values, respectively.
1 c, 61 d and 66a, 66b, 66c, 6
6d to the I10 boat 49. At least one of resistors 61a, 61b, 61c and 61d
When one end of the resistor is set to a high level H by the I10 port 49, a predetermined potential determined by the voltage division ratio between the resistance value of that resistor and the resistance value of the grounding resistor 62 is applied to the base end of the 1-ranji star 3. The transistor 63 exhibits an on-resistance depending on the potential, and causes a current to flow in the motor 58 in accordance with the on-resistance.

In other words, the I10 port has resistors 61a and 61b.

The energizing level, ie, the driving speed, of the motor 58 is determined by the combination of H/L applied to 61c and 61d. In this example, there are 4 input ports, so 16
You can choose the speed of any of the stages. transistor 68
The same applies to the operation of .

FIG. 7 shows the configuration of the display operation section 80. Referring to FIG. 7, this circuit is equipped with decoders, drivers, gates, etc. for controlling the key switches and indicators on the operation panel shown in FIG. Control reading.

FIGS. 8a and 8b schematically show the control operation of the copying machine shown in FIG. 1 regarding a document. Figures 8a and 8b
This will be explained with reference to the figures. First, when the power is turned on, initial settings are performed, output port settings are initialized, and memory contents are cleared. In this initial state, the image sensor 15 is oriented in the direction in which the document is conveyed, as shown in FIG. 3a.

When the print start key 92 is turned on, it is first checked whether the ADF mode is in which the document is automatically transported. A
If the mode is DF mode, the process proceeds to the primary document conveyance process. First A
The DF motor 58 is set to be driven at a relatively fast predetermined speed, and the ADF clutch shown in FIG. 4 is turned on to start document conveyance.

Then, the next document position detection process is repeated until the document 7 reaches a predetermined position.

In the document position detection process, the image sensor 15 reads the image on the document reading surface (on the contact glass 9) and determines the position of the document. In this example, the document feed belt 3 located on the back side of the document 7 is made black so that its light reflectance is lower than that of the surface of the document.

Therefore, an unnecessary electrostatic latent image is formed on the back side of the document on the photoconductor drum 1, that is, in the area corresponding to the document feed belt, especially when the document is smaller than the recording paper or the document is tilted. If this is developed as is, an unnecessary solid black image will be transferred to the recording paper.

However, in this embodiment, the erase lamp 18 disposed in front of the developing device 19 is moved in the axial direction K of the photoreceptor drum 11.
By arranging 320 light emitting diodes at intervals of 1 mm, it is possible to erase any position on the entire surface of the photoreceptor drum 11, and as will be described later, it is possible to erase the electrostatic potential formed by parts other than the document 7. I try to erase the image before developing it.

FIG. 13 shows the configuration of the erase lamp 18 and the control circuit 79 that drives it. This will be explained with reference to FIG.

The control circuit 79 includes 64-bit serial-in/parallel-out type shift registers SRI, SR2, and SR.
3, SR4 and SR5, and drivers DVI, DV2.
DV3. The serial data input terminals of shift registers SR1, SR2, SR3, SR4 and SR5 are connected to ports PI, P2 . P3. P4 and R5 are connected, and the shift pulse input terminal is connected to port PO of I10 port 50.
It is connected to the.

Therefore, by setting predetermined data in ports P1 to P5 of I10 port 50 and applying a shift pulse to port PO, and repeating this 64 times, shift register SRI
A predetermined level is set at a total of 320 output terminals of ~SR5, and each light emitting diode L of the eraser 18 is set accordingly.
EDn (n=1-320) is energized.

In the document position detection process, first, the image reading signal SB is output from the I10 port 48, and the charge stored in the photodiode portion of the image sensor 15 is transferred to the COD ship register. Next, a shift pulse is output (this process is automatically performed by the drive circuit 41), and the I10 port 4
The 2048-bit image data applied to 8 is read. In this document position detection process, the output level of the signal amplification circuit 42 (3°5V in bright areas,
The document and the back surface are distinguished by directly reading the voltage (1 V or less in dark areas) without going through the A/D converter 43.

This binary data is read in synchronization with the clock pulse CK output from the drive circuit 41 and is sequentially stored in a predetermined address of the read/write memory 47. In this example, as shown in FIG. 9b, one pixel is assigned to one bit of the memory, and this data is stored in a predetermined area of 8 bits and 256 bytes.

The image signal of the image sensor 15 is approximately 2 per 2048 pixels.
m5ec, and the microprocessor CPU executes a processing loop including document position detection processing at a cycle of 5m5ec per time. Therefore, when the document transport speed is 600 mm/sec, the document position detection process is The resolution becomes 31111I+. However, as will be described later, since the vehicle decelerates before stopping, the detection resolution during deceleration is further improved.

The position of the document being transported is determined by referring to the document position data stored in the memory, and the document position is displayed on the liquid crystal display 93 on the operation panel each time. The document position is displayed by sequentially displaying dots indicating the leading edge of the document near the center of the liquid crystal display 93, as shown in FIG. 11a. In other words, if a dot is displayed at the left end of FIG. 11a, it means that the original 7 has been conveyed to the exposure position.

In determining the document position, the assigned deceleration bit and stop bit are checked as shown in FIGS. 9a and 9b. In other words, if the 2048 pixel data is checked and the element corresponding to the deceleration bit detects a change from the black level to the white level, it means that the original is passing through that position, so the process proceeds to deceleration processing and stops. If the element corresponding to the bit detects a change from the black level to the white level, the document is at the stop position and the conveyance is stopped.

Since the document transport speed before starting deceleration is relatively fast, the deceleration bit is divided into multiple bits in order to prevent the leading edge of the document from passing through the deceleration position between detection processes and causing a large detection position error. allocation, but the stop bit is 1
Bit only.

The document conveyance system is decelerated little by little each time a processing loop is executed. That is, since the ADF motor 5819- can be changed in 16 steps according to the settings of the 4-bit data applied to the drive circuit 57, by updating the 4-bit data little by little, the document conveyance speed is gradually slowed down.

After stopping the conveyance, the document position is detected again and document 7 is
Determine whether the is stopped at the stop bit position. In other words, if the leading edge of the document 7 is at the stop bit position of the image sensor 15, the content of the data at the memory address v255 is as shown in FIG.
Since ~7 is O, check whether the contents of the memory match this. If any of bits 1 to 7 of address v255 is 1, it is determined that an overrun has occurred.

When an overrun occurs, the ADF motor 58 is set to reverse drive (relatively low speed) and waits until the document is positioned at a predetermined position while repeating the document position detection process.
Conveyance is stopped when the contents of address 255 reach a predetermined state. In this case, even if the positioning accuracy is 20 - in the case of an overrun, the document transport speed before stopping is 11 - in high-speed driving.
By setting it to about 5, it can be made about 0.5 mm.

When the document is positioned at the exposure position, the image sensor 15 performs circular scanning to determine the condition and size of the document. That is, as shown in FIG. 10a, the motor 17 is rotated by minute angles.

Each time, an image is read from the image sensor 15, each image data is stored in a memory, and the results are used to determine the inclination of the document and the size of the document. When this circular scanning is performed, image data corresponding to each position of a radial point centered near the center of the contact glass is obtained as shown in FIG. 10b.

Note that since there is time to spare in this process, the image data is read from the output of the A/D converter 43, and 3
Obtaining bit gradation data. This data is the 12th
As shown in the figure, for convenience of processing, 1-bit clock data CLn (n=1 to 2048) is added and converted into a 4-bit code, and two pixels each are stored at one address in the memory. When the angle of the image sensor 15 changes, the data storage address is changed to +], 024, the data is moved to the next block, data is stored again from pixel 1, and image data is read and stored in the same manner until the angle reaches 180 degrees. .

When reading is completed, the motor 17 is driven in reverse to return the image sensor 15 to its original position.

The data obtained in this manner is processed to first determine the boundary position between the document 7 and the background. Since the data stored in memory is obtained at each angle of the circular scan,
Perform polar coordinate calculation to determine the main scanning direction position (Y) of the boundary position
and the sub-scanning direction (original transport direction) position (X). In other words, when calculating the relative coordinate X+'/ from the center of circular scanning, the angle θ corresponds to the rotation center (between pixels 1024 and 1025) and the end (pixel 2048) of the image sensor 15, respectively. If the distance between points on the detected image is the pixel where the R1 boundary was detected as n (1025≦n≦2048), then
x and y are as shown in the following equations.

x”RcosθX (n-1024,5)/(204
8-1024,5,)y=RsinθX (n-102
4, 5) / (204B-1024, 5) If this calculation is performed for all angles, coordinate data connecting the outline of the document 7 can be obtained, so display data is generated according to this result and shown in Figure 11b. The document status (angle and position) is displayed on the liquid crystal display 93 as shown in FIG. In FIG. 11b, the B5 size original is positioned at a predetermined position without being tilted, so the displayed original matches the dotted line frame, but if the original is tilted, the display will also be tilted accordingly. In this example, if the inclination of the document is too large, the subsequent copy process is not started until the print start switch is pressed again.

Also, here, a document position data table used for eraser control is generated. That is, the memory address associated with each position in the sub-scanning direction (X-direction in Fig. 3a) of the optical scanning system for reading a copy image is stored in the main-scanning direction (Y-direction in Fig. 3a) at each position. Data 23- of the document starting edge position Y1 and ending edge position Y2 are stored. When the copy process is started and the photoreceptor drum 11 rotates to a position where the electrostatic latent image forming surface of the photoreceptor drum 11 faces the eraser 18, the position of the photoreceptor drum 11 is determined by referring to the document position data table. Read the document start edge position Y1 and document end position Y2 at the X-direction exposure position that coincides with the rotation position, and
The eraser 18 is controlled so as to energize the light-emitting diodes in the corresponding areas between Y2 and the end of the exposure position [Y3. By repeating this process for all exposed areas, only the electrostatic latent image obtained from the document remains.

Therefore, according to this, even if the original is tilted,
The electrostatic latent image formed on the photoreceptor drum 11 by exposure of parts other than the document is erased by an eraser before being developed, so that a solid black image is not transferred to the recording paper.

By comparing the contour data with the coordinate data of the specified size, the closest size is determined and exposure size data is generated. By storing this exposure size data at a predetermined address in the memory 24 and starting a normal copying process operation, the operator's size designation operation becomes unnecessary.

When the set number of copies are completed, the original is ejected and the next original is sent in.

In the above embodiment, only the size of the original sheet itself is determined, but the exposure area and recording paper size are set by reading the distribution of images on the original so as not to copy unnecessary parts without images. It is also possible to do so. In that case, in order to match the exposure position and the effective position of the original, the target position may be changed after the original size is detected and the original positioning may be performed again.

Further, although the embodiment has been described with respect to a copying machine, the present invention can be similarly implemented in a device that recognizes characters on a document, an image processor that reads an image on a document, and performs predetermined processing.

■Effects According to the embodiment explained above, even if the background of the original is black or dirty, it will not be recorded as a copy, so high-quality copies can always be made without having to frequently clean the pressure plate 1M document transport belt, etc. is obtained. Furthermore, when an automatic document feeder is provided, highly accurate positioning can be performed.

[Brief explanation of drawings]

FIG. 1 is a front view of one type of copying machine embodying the present invention. FIG. 2 is a plan view showing the operation panel of the device shown in FIG. 1. FIG. 3a is a perspective view showing the vicinity of the image sensor 15 in FIG. 1, and FIGS. 3b and 3c are a plan view and a front view of the image sensor 15, respectively. FIG. 4 is a block diagram showing a schematic system configuration of the apparatus shown in FIG. 1. FIG. 5a is a block diagram showing the image sensor 15 and an electric circuit connected thereto, and FIG. 5b is a timing chart showing the circuit operation of FIG. 5a. FIG. 5c is a block diagram showing the configuration of the A/D converter 43. FIG. 6 is an electrical circuit diagram showing the circuit configuration of the motor driver 57. FIG. 7 is a block diagram showing the configuration of the display operation section 80 shown in FIG. 4. 8a and 8b are flowcharts showing the general operation of the microprocessor CPU shown in FIG. 4. FIG. FIG. 9a is a plan view showing the relationship between the arrangement of reading pixels of the image sensor 15 and pixel assignment. FIG. 9b is a memory map showing the relationship between pixels and memory addresses that store data output by the image sensor 15. 10a and 10b are plan views showing the relationship between the scanning position of the image sensor 15 and the reading pixel position. Figures 11a and 11b are plan views showing the display contents of the liquid crystal display 93 in different states. FIG. 12 is a memory map showing the allocation of memory addresses for storing data and pixels 27- when the image sensor 15 is circularly scanned. FIG. 13 is a block diagram showing the erase lamp 18 and the control circuit 79 that drives it. Engineering: Automatic document feeder 2: Copying machine body 3: Document feed belt 4.5: Roller 6: Document platen 7: Fi document 8: Paper feed separation roller 9: Contact glass 10; Paper ejection tray 1: Photosensitive drum 15 : Image sensor (optical detection element array) 16 = wide-angle lens I7: Stepping motor (drive source) 18: Erase lamp (eraser) 26: Printed circuit board 58: DC servo motor 44: Control device main body (electronic control means) 28- Rain 2■ 3rd a■ Tank 3b■ 5th bA SB 444- 〒5C 610th Kabuto 7■ Of course 1 convex 1- Fig. 9a Fig. 9b Car VCL Kyo Iob Fig. 11a Fig. ql Fig. 11b Fig. 3 Figure 12b Procedural Amendment (Method) 1. Display of the case 1982 Patent Application No. 122667 2
, Title of the invention Copying device 3, Relationship with the person making the amendment Patent applicant address 1-3-6 Nakamagome, Ota-ku, Tokyo Name (67
4) Ricoh Co., Ltd. Representative Hama 1) Hiro 4, Agent 103 Te 1.03-864-605
2 Address: 2-27-6-7, Higashi Nihonbashi, Chuo-ku, Tokyo Contents of amendment (1) Figures rlla and Ilb on page 28, line 16 of the specification" have been replaced with figures 11a and 111 ” is corrected. (2) Delete Figure 12b and add attached Figure 12. 8. Attached document drawing (Figure 12)...1 copy 2-

Claims (3)

[Claims] (1) A visible image obtained by guiding reflected light from a document placed on the document reading surface onto a photoreceptor, forming an electrostatic latent image on the photoreceptor, and making the electrostatic latent image visible. In a copying device that transfers an electrostatic latent image onto recording paper; an eraser arranged near a photoreceptor, which is formed by arranging a plurality of means for erasing an electrostatic latent image in a predetermined direction; an optical detection element arranged opposite to the original reading surface in a predetermined direction an optical detection element array arranged in a plurality of directions; a drive source that rotationally drives the optical detection element array; and a drive source that controls the drive source to rotate the optical detection element array to detect the optical detection elements at each rotational position. A copying apparatus comprising: electronic control means for reading output data from an array, processing the output data to grasp the position of a document, and controlling the eraser according to the position of the photoreceptor and the position of the document. (2) The electronic control means reads the output data of the optical detection element array, processes the output data to grasp the size of the document, and sets the exposure scanning range according to the size. A copying apparatus according to scope (1). (3) The electronic control means directs the optical detection element array in the original transport direction in an initial state, and controls the transport of the original while monitoring the output of the optical detection element array. or (2).