JPS616637A - Image processor - Google Patents

Abstract

PURPOSE:To copy making the contour and fold of a book blank without reference to its size by photodetecting reflected light from an original indication table and detecting the fold of the book, and preventing toner from sticking on the detected fold part. CONSTITUTION:For example, a switch 29 provided near an original platen is turned on and a signal generated by detected an original pressure plate 21 not contacting original platen glass 19 is inputted to an input port i12 of an MP55, which then judges that an original 20 is a book. When there are halftones having a reflection factor lower than a predetermined reflection factor in reflection density detected by a reflection density detector 35, the MP55 judges that a set of the halftones is present in the edge direction of the original 20 and outputs control signals to respective output ports O1-O9 so that LEDs corresponding to the positions of the halftones turn on. A driver 62 which receives the output turns on the LEDs corresponding to the positions of the halftones. Consequently, toner is prevented from sticking on the halftone positions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image processing apparatus that performs image formation without adhering toner to the folds of a book placed on a document indicator.

[Prior art and its problems]

Conventionally, when copying a thick original such as a book using this type of device, the book is placed on the document support plate, and the document pressure plate or operator applies weight to the book to create a space between the document support and the book. The copy operation was performed with no gaps created. However, even if the operator applies weight to the book, it is not only impossible to eliminate the folds in the book, but also an unreasonable weight is applied to the document support table, which may cause deformation of the document support table. . Furthermore, if the operator performs copying without using a document pressure plate, toner adheres to the contours and folds of the book, making the finished product very difficult to see.

In order to solve this problem, some models have been proposed that control the adhesion of toner to a part of the book by a predetermined width, but most of the books are of a size that is outside the standard size.
It was not possible to control the toner so that it did not always adhere to the folds of the book, and there were drawbacks such as the inability to obtain clear copies.

[Purpose of the invention]

This invention was made in order to eliminate the above-mentioned drawbacks, and detects the fold of the book by receiving the reflected light from the book placed on the document indicator table. An object of the present invention is to provide an image processing device that can copy the outline and folds of a book onto the white area regardless of the size of the book by controlling so that toner does not adhere to the book.

〔Example〕

FIG. 1 is a schematic sectional view showing an embodiment of an image processing apparatus according to the present invention, FIG. 2 is a control circuit diagram, and FIG. 3 is a front view of a reflection density sensing element.

In FIG. 1, 1 is a drum, 2 is a pre-elimination charger, 3 is a primary charger, and 4 is a charger, which performs corona charge removal on the drum 1. 5 is a copying charger, 6 is a cleaning device,
Consists of a cleaning roller and an elastic blade. 7 is a developing device, and 8 is a pre-exposure lamp, which eliminates static electricity from the drum 1. 9
is a full-surface exposure lamp which forms an electrostatic latent image on the drum 1.

10. Reference numeral 11 is a paper feed roller, and 12 is an upper cassette in which copy paper is stored. 13 is also the lower cassette, 14
15 is a registration roller, 15 is a transport belt, 16 is a fixing roller, 17 is an ejection roller, 18 is a tray, 19 is an original table glass, 20 is an original, 21 is an original pressure plate, and the surface in contact with the original 20 is a mirror surface or has a low reflectance. The parts are coated. 2
2.23 is a standard white plate, 24 is a moving optical system unit, which is composed of an irradiation lamp 25 and a first scanning mirror 26. 27 is a second scanning mirror, and 28 is a position detection piece, which is provided outside the moving optical system unit 24. Reference numeral 29 denotes a switch for detecting the contact state between the original pressure plate 21 and the original platen glass 19, which constitutes the book copy detection means of the present invention. 30°31.32 is a position sensor, position detection piece 2
8 is detected. 33 is a slit, j4 is the first scanning mirror 26. A document detection lens 35 forms an image of the reflected light guided by the second scanning mirror 27, and 35 is a reflection density lens in which a group of light-receiving elements such as COD are arranged in a row in the main scanning direction B (perpendicular to the sub-scanning direction A). The manuscript information detecting means 9 of the present invention is a detector.
Image area detection means.

It constitutes a reflection density detection means, and the document platen glass 19
The document size of the document 20 placed above, the image area within the document, the reflection density of the document, and the document position within the copyable area are detected. 36 is a projection lens that forms an image of the reflected light guided to the second scanning mirror 27, 37 is a third scanning mirror, 38 is a fourth scanning mirror, 39 is an optical system drive motor,
The moving optical system unit 24 is driven. A main motor 40 drives the drum 1. Reference numeral 41 denotes an eraser constituting the eraser means of the present invention, which prevents toner from adhering to the non-image area portion of the drum 1. This eraser 41 is composed of a group of LEDs that emit light corresponding to one pixel of the light receiving element group of the reflection density detector 35. Therefore, the erasers 41 are also arranged in a line in the main scanning direction B.

In the control circuit shown in FIG. 2, 51 is an oscillator that oscillates a clock signal. 52 is a frequency divider, 53 is an amplifier for amplifying the detection signal of the reflection density detector 35, and 54 is an A/D converter, which converts the output of the amplifier 53 into A/D and sends the digital value to each input port 11 to i4. Output to. A microprocessor (MP) 55 receives each sensor output 1, the output of the reflection density detector 35, and each timing signal at each input port, and outputs each control signal from each output port. This MP5
Reference numeral 5 includes an internal timer, and also serves as copy density setting means, automatic copy magnification adjustment means, eraser control means, and copy magnification setting means of the present invention. 56 is the M
RAM randomly accessed by P55, 57,
573 is a cassette size input key which constitutes the copy paper size detection means of this invention, and the cassette size is MP55.
input to each input port 19 to 11□. 58 is an input key such as copy start key, numeric keypad, clear key, etc.
Copy start signal, number of copies signal.

Clear signals etc. are sent to each input port 113 to i+6 of MP55.
Enter. Reference numeral 59 denotes a D/A converter, which converts the lamp signals to the irradiation lamp 25, which the MP 55 outputs to each of the output ports 0+3 to 016, from D/A.

60 is an amplifier that amplifies the lamp signal, and 61 is a lamp regulator (CVR) that controls the voltage of the irradiation lamp 25. Reference numeral 62 denotes a drive driver which receives eraser drive control signals outputted to each output port 01 to 09 by the MP 55 and drives the eraser 41. 63 is a drive driver, MP
55 receives the motor drive control signals outputted to each output port 021+022 and drives the optical system drive motor 39.

641 is an AND circuit which ANDs the output signal of the frequency divider 52 and the control signal outputted from the MP55 to the output port O12, and outputs the shift pulse signal (SH) to the reflection density detector 3.
Enter 5. 642 is an AND circuit which similarly ANDs the output signal of the frequency divider 52 and the control signal outputted by the MP55 to the output port 01□, and inputs the clock signal φl to the reflection density detector 35. 65□ is an inverter that inverts the signal from the oscillator 51, and 652 is an AND circuit that connects the frequency divider 52 and the inverter 65. Take the AND with and A/D
The in signal is input to the input port i5 of MP55. 66
is an in/hater that inverts the clock signal φ1 of the AND circuit 642, and outputs the clock signal φ1 to the reflection density detector 35.
Enter 2.

67 is a clock signal input to the input port i6 of the MP55. Note that the output of the switch 29 is input to the input port iI2 of the MP55.

In the reflection density detector 35 shown in FIG. 3, 71 is a light receiving element group consisting of light receiving elements (1-N), which are arranged in one row and divide the reflected light from the entire area in the main scanning direction of the original into parts 1 to N. It receives light and outputs an output voltage (V) corresponding to the reflection density (CD) as shown in FIG.

Next, document exposure and copying operations of the image processing apparatus will be explained with reference to FIGS. 1 and 2.

The surface of the drum 1 is a photoreceptor, and the main motor 4 is activated when the copy start key of the input key 58 is turned on.
0 starts rotation in the direction of the arrow. Due to this rotation, the document 20 placed on the document glass 19 (hereinafter, the light-receiving surface of the document glass 19 will be referred to as an image area) is exposed to the slit'R light by the irradiation lamp 25 integrated in the optical system moving unit 24. The reflected light is scanned by a first scanning mirror 26 and a second scanning mirror 27. By moving the first scanning mirror 26 and the second scanning mirror 27 at a speed of 1:1/2, the original 20 is scanned while the optical path length in front of the projection lens 36 is always kept constant, and the moving optical system The unit 24 is driven by an optical system drive motor 39. At this time, the slit 33. Projection lens 36. Third scanning mirror 37. The reflected image passing through the fourth scanning mirror 38 has already been simultaneously neutralized by the pre-exposure lamp 8 and the pre-static charger 2, and is further transferred to the drum 1, which has been corona-charged by the charger 3, to a high level. Forms a contrast electrostatic latent image. The electrostatic latent image formed on the drum 1 is developed by the developing roller of the next developing device 7 and visualized as a toner image, and this toner image is copied onto copy paper. After copying, the drum 1 continues to rotate and is cleaned by the cleaning roller and elastic blade of the cleaning device 6 in preparation for the next image formation.

The copy paper stored in the upper cassette 12 or the lower cassette 13 is fed by a paper feed roller 10. '11, the copy paper is conveyed into the machine, the registration roller 14 temporarily stops the copy paper being sent in the direction of drum 1, and when the leading edge of the copy paper and the leading edge of the latent image coincide, the copy paper is sent out again in the direction of drum 1. . Next, while the copy paper passes between the copy charger 5 and the drum 1, the toner image on the drum 1 is copied onto the copy paper. After copying is completed, the copy paper is separated from the drum 1 and guided by a conveyor belt 15 to a fixing roller 6, where it is pressurized and heated to fix the copy image. Next, the discharge roller 17
The copy paper is discharged onto the tray 18.

Next, the operation of detecting the document position, document size, and document density will be explained with reference to the drawings.

After the main switch is turned on, the optical system drive motor 39 is driven to correct variations in characteristics of the light receiving element group 71 constituting the reflection density detector 35 and ripples of the light source, and the position sensor 30 indicating the position of the standard white plate 22 is moved. The moving optical system unit 24 is moved until the position detection piece 28 attached to the outside of the optical system unit 24 is detected. Next, when the irradiation lamp 25 irradiates the standard white plate 22 that provides a uniform reflection density, the reflected light is transmitted to the first scanning mirror 26.
．． Second scanning mirror 27. The document is fed into a reflection density detector 35 via a document detection lens 34. This reflection density is stored in the RAM 56 as a density correction value. Thereafter, the optical system drive motor 39 is driven to move the moving optical system unit 24 until the position sensor 31 indicating the image area tip position detects the position detection piece 28. move it. Next, the document platen glass 19 on which the document 20 is placed with the document pressure plate 21 closed.
The upper image area is irradiated with the irradiation lamp 25 and measurement of the reflection density of the image area is started.

FIG. 5 is a diagram showing the correlation between the original 20 and the eraser 41, and (I) shows that the original 2o is connected to the original platen glass 19 and the original pressure plate 21.
(II) shows the state in which the original 2o is placed on the original table glass 19,
II) shows the relationship between the eraser 41 and the drum 1. In (U) of FIG. 5, A indicates the sub-scanning direction, B indicates the main scanning direction, and the shaded area indicates the image area. Note that 1-n', .about.N, 1-m', and .about.M indicate areas divided corresponding to the light receiving element groups 71 of the reflection density detector 35.

Now, the reflection density detector 35 having a light receiving element group 71 finely divided in the main scanning direction B shown in (IF) in FIG. 5 detects the reflection density of the entire image area as the moving optical system unit 24 moves. Then, that value is corrected using the density correction value and stored in the RAM 56 as an image density. That is,
The moving optical system unit 24 is moved at a predetermined speed in the sub-scanning direction A shown in FIG. 5 (for example, 260 mrn/sea; at the same magnification).
While moving it, irradiate it with the irradiation lamp 25 again,
The reflection density of the entire image area of the original table glass 19 is detected, and the value is corrected using the density correction value and stored in the RAM 56 as the image density. Therefore, by performing this operation, the reflection density obtained by dividing the entire image area into fine meshes is detected as shown in FIG. Information on the document size, image area within the document, and maximum and minimum reflection density of the document can be obtained from the image density obtained by correcting this reflection density using a density correction value. The MP 55 sends out each control signal based on this information.

Note that if the standard white board 23 is installed near the rear end of the image area as shown in FIG. After obtaining the density correction value, the position sensor 3
The movable optical system unit 24 is scanned in the sub-scanning direction A to the position 1, and the entire area of the document copyable area is divided into meshes as described above, and the reflection density is measured.

Next, the operation of the control circuit of the present invention will be explained with reference to the control circuit diagram in FIG. 2 and the control signal timing chart in FIG. 6.

First, after turning on the main switch, in order to measure the reflection density of the standard white plate 22, the MP55 outputs a motor control signal to drive the optical system drive motor 39 to the output ports oz+, oz.
After moving the moving optical system unit 24 until the position sensor 3o detects the position detection piece 28 as described above, the standard white board 22 is irradiated with the irradiation lamp 25.

Then, a shift pulse signal SH shown in FIG. 6 is applied to the reflection density detector 35, and a clock signal φ1 obtained by frequency-dividing the clock signal CLOCK oscillated by the oscillator 51 by the frequency divider 52 and a clock signal which is its inverted signal Give φ2 and operate. The reflected light from the standard white plate 22 is transmitted to the light receiving element group 7.
Each element 1 to N of 1 detects the output voltage and sends the output voltage to the amplifier 5.
This output signal O5 is amplified by A/D converter 5.
4 is converted into a digital value, but the predetermined count number is processed as a dummy signal (A) as shown in Figure 6 (hereinafter referred to as dummy processing). This refers to the process of removing unnecessary signals (dummy signals) from among the signals of the l scanning lines outputted from the 35.

After that, the reflection density is read at the timing specified by the A/D in signal shown in Fig. 6, and when it is read 1 to N times as a detection signal (b), it is read in as much as the predetermined dummy signal (a). Count and perform dummy processing again. Note that the read reflection density data is RA
It is stored as a density correction value in the designated area M56. Next, after the MP55 completes the dummy processing, the irradiation lamp 25 is turned off to zero.
FFL waits for the input of the copy start key among the input keys 58. Next, when the input of the copy start key is applied to the MP55, the MP55 turns on the optical system drive motor 39 and starts irradiating the irradiation lamp 25. After moving the moving optical system unit 24 until the position sensor 31 detects the position detection piece 28, reading of the original image is started. While the moving optical system unit 24 moves in the sub-scanning direction A shown in FIG. 5, the MP55 starts an internal timer to output a shift pulse signal SH to the reflection density detector 35 at predetermined intervals (for example, 10 m5ec). , outputs a shift pulse signal SH every time the internal timer finishes counting. Then, the MP55 starts counting the A/Din signals in order to perform dummy processing together with the output of the shift pulse signal SH, and when a predetermined number of A/Din signals have been counted, it is considered that the dummy processing is completed, and after that, the A/Din signal is Reflection density data numbers 1 to N are sequentially input to each input port 11 to i of the MP55 at the reading timing specified by the signal.
4, correction is performed using the density correction value stored in the RAM 56, and the image density data is stored in a designated area of the RAM 56. When the input of reflection densities from 1 to N is completed, MP55 inputs a predetermined number of A/Din.
Dummy processing similar to that described above is performed again until the signal count ends, and when the dummy processing ends, the process waits until the internal timer ends counting. When the internal timer finishes counting, the shift pulse signal SH is again applied to the reflection density detector 35, the internal timer is restarted, and the same process as described above is repeated.

This operation is repeated up to number M in the sub-scanning direction A, and the image density in the image area is obtained from the reflection density detected by the reflection density detector 35 as shown in FIG. , the original density is determined.

The driving driver 62 is driven in accordance with the document position, and a signal for controlling the eraser 41 is outputted to each output port 01 to 0° to prevent toner from adhering to the non-image area. Also,
For example, the bias value of the developing device 7 is controlled so that the maximum density and minimum density are obtained by comparing the density of the original stored in the RAM 56 with predetermined reference black level values and reference white level values, and obtaining the optimum contrast. do.

Next, control of the eraser 41 based on the reflection density detected by the reflection density detector 35 will be explained with reference to FIGS. 1 and 2.

The eraser 41 is configured to emit light corresponding to each pixel of the light receiving element group 71 of the reflection density detector 35, and is
From the image density stored in M56, a set of pixels, that is, a non-image area, whose reflectance is lower than a predetermined reflectance is obtained. L of the eraser 41 corresponding to this non-image area
The ED emits light according to the copy magnification to prevent toner from adhering to this non-image area.

In addition, the reflectance of pixels on the boundary between the non-image area and the image area is lower than that of a blank original when the original pressure plate 21 is made of a mirror surface, etc., and when developing and copying is performed in this state, the copy paper Toner adheres to the outline of the image. To prevent this, the LED of the eraser 41 corresponding to the pixel on the boundary between the non-image area and the image area is caused to emit light to prevent toner from adhering (edge processing).

Furthermore, a switch 29 provided near the original support table is turned on.
When a signal indicating a non-contact state between the NL original pressure plate 21 and the original platen glass 19 is input to the input port 11□ of the MP 55, the MP 55 determines that the original 20 is a book. Therefore, after the reflection density detector 35 detects a document edge, until it detects a white standard higher than a predetermined reflectance, it is determined that the edge is a collection of book edges, and the eraser 41 detects this edge. A control signal is output to each output port OX~09 so that the LED corresponding to the set of edges emits light, and the drive driver 62 receives this output and drives, and the LED corresponding to the above-mentioned set of edges emits light. This prevents toner from adhering to the edges where the edges gather.

Further, when the original 2o is a book, there is a halftone in the center of the original with a reflectance lower than a predetermined reflectance in the reflection density detected by the reflection density detector 35, and the main scanning As a result, the set of halftones is manuscript 2.
If the halftone exists in the edge direction of 0, the MP55 determines that this halftone is due to the fold of the book, and sets each output boat 01 to 09 so that the LED corresponding to the position of this halftone in the eraser 41 emits light. A control signal is output to the drive driver 62 that receives this output, and the LED corresponding to the above-mentioned halftone position emits light.

This prevents toner from adhering to the halftone position.

Next, edge control in the image area will be explained.

Note that, hereinafter, the original pressure plate 21 is assumed to have a mirror surface.

As mentioned above, the reflection density of the image area is detected by the reflection density detector 3.
When each pixel is detected by the light receiving element group 71 of 5,
After the set of pixels showing low reflectance, a set of pixels showing high reflectance (original portion) is obtained. The document position and document size can be obtained from the boundary between the set of pixels exhibiting low reflectance and the set of pixels exhibiting high reflectance. In particular, when the document 2o on this boundary needs to be copied, it is stored in the RAM 56. When copying is performed at the specified original size and original position, the eraser 41 prevents toner from adhering to the original 2o on the boundary, including the edge of the original. Judgment is made from the reflectance of the pixel next to the pixel on the boundary.In other words, if characters, etc. are printed on the document on the pixel next to the pixel on the boundary, the reflectance will be low.Using this as a criterion, the reflectance is determined in advance. If the reflectance is lower than the set reflectance, the MP55 determines that it is necessary to attach toner to the pixels on the edge of the document, and controls the image to be reduced and copied at a predetermined magnification (for example, 98%). Furthermore, if the reflectance of the pixel next to the pixel on the boundary is higher than a predetermined reflectance, control is performed to copy at the same size.

Therefore, if there are characters or the like near the boundary, they are reduced, so the characters near the boundary are not affected by image erasure (edge processing) by the LED, that is, the eraser 41.

Next, the control operation for automatic magnification change will be explained.

As mentioned above, the reflection density of the image area is detected by the reflection density detector 3.
When each pixel is detected by the light receiving element group 71 of 5,
After a set of pixels exhibiting high reflectance, a set of pixels exhibiting low reflectance is obtained. An image area is obtained from the boundary between the set of pixels exhibiting high reflectance and the set of pixels exhibiting low reflectance. This image area and cassette size oysters-571~
573, and compare the size of the copy paper stored in the upper cassette 12 or lower cassette 13 with the copy paper size of the copy paper obtained by 573, and if the same size copy paper is stored in the upper cassette 12 or lower cassette 13, copy at the same size. conduct. on the other hand,
If the above image area and the above copy paper size are different,
The most appropriate reduction or enlargement is selected and the copy is made at a predetermined magnification so that the entire image area is copied onto the copy paper. Next, the operation of automatic immersion level control will be explained with reference to FIGS. 1, 2, and 7.

Figure 2 is a characteristic waveform diagram showing the density characteristics, and the first quadrant shows the relationship between the exposure amount (E) and the potential (V) of the drum 1.
The second quadrant is the potential of the drum 1 (V) and the density of the copied image (DC
), and the third quadrant is the density of the copied image (DC).
and the document density (DO) obtained from the reflection density detected by the reflection density detector 35, and the fourth quadrant shows the relationship between the document density (D
It shows the relationship between the exposure amount (E) and the exposure amount (E).

As mentioned above, the reflection density of the image area is detected by the reflection density detector 3.
When each pixel is detected by the light receiving element group 71 of 5,
After a collection of pixels exhibiting high reflectance, pixels exhibiting low reflectance are obtained. Among these images, the one with the highest reflectance (ground color, reference white level) among the images showing low reflectance has a density of 0.
．． 07, and when the minimum reflectance is at a density of 0.5, an input voltage of 65V is applied to the irradiation lamp 25, and the potential of the drum 1 is determined by the E-V characteristic shown in the first quadrant. Development characteristics determined and shown in the second quadrant (7) lo
oOHz, a copy image with a density determined by a 1000Vp-p curve is obtained.In the above example, an original density of 0.07 is developed to a copy density of 0.07, and an original density of 0.5 is developed to a copy density. Developed to a density of 0.5. In other words, the original density and the copy density are the same. On the other hand, if the difference between the maximum and minimum document densities is smaller than a predetermined value, the copy density is changed as described below.

For example, if the minimum value of the original density before the change was 0.2 and the maximum value was 0.5, it is assumed that the EV characteristic in the first quadrant does not change, and the original density of 0.2 is copied to 0. When changing to .07, the original density is reduced to 0.5 by controlling the input voltage of the irradiation lamp 25 shown in the fourth quadrant to be set to 80V. Further, the development characteristics in the second quadrant are controlled at 1600 Hz and 800 Vp-p at a constant speed of 1,600 Vp-p. With this control, if the difference between the maximum and minimum document density is smaller than a predetermined value, that is, if the contrast is not clear, contrast is artificially added to the document 20, and the appropriate density is adjusted. settings to obtain a clear copy image.

Next, the registration roller 14 and eraser 4
1 will be explained with reference to FIGS. 1 and 2.

There is a predetermined document reference position on the document platen glass 19, and when it is determined from the reflection density detected by the reflection density detector 35 that the leading edge of the document deviates from this document reference position, as described above. is the LED of the eraser 41 corresponding to the pixel of the light receiving element group 71 that detected high reflectance.
In addition to emitting light to prevent toner adhesion, the drive timing of the registration rollers 14 is delayed and the registration (
By aligning the leading edge of the copy paper and the leading edge of the image, deviation of the leading edge of the original from the original reference position can be corrected and a proper image can be obtained. In addition, if it is determined from the reflection density detected by the reflection density detector 35 as described above that the leading edge of the original is set at an angle of more than a predetermined parallelism with respect to the original reference position, Stop copying and copy original 20
Displays a request for resetting.

Next, control by the MP55 will be explained with reference to flowcharts shown in FIGS. 8(a), 8(b), and 8(c). Note that (1) to (47) represent each step.

When the power of the image processing device is turned on, it starts warming up and determines whether it is the measurement position of the standard white board 221)
, the optical system drive motor 39 is rotated in the reverse direction until the position sensor 30 detects the position detection piece 28 (2). Step (1
), if the standard white plate 22 is at the measurement position, the optical system drive motor 39 is set to 0FFL (3) and the irradiation lamp 25 is set to O.
Do N (4). Next, it waits for the input of the shift pulse signal SH, and when the shift pulse signal SH is input, the A/D
The in signal is counted and dummy processing is performed (5), and then the reflection density of the standard white board 22 is detected and the input of the shift pulse signal SH is waited again (6).

After inputting the shift pulse signal SH, turn the irradiation lamp 25 to 0F.
FL (?), wait for input of copy start key (8
). From this point on, the process moves to the flow shown in FIG. 8(b), and when there is a copy start input, it is determined whether the stopping position of the movable optical system unit 24 is at the position of the standard white board 22 (8), No.
If so, the optical system drive motor 39 is rotated in the reverse direction (10). If YES in step (9), the optical system drive motor 39 is rotated forward (11), the moving optical system unit 24 is moved in the sub-scanning direction, and the irradiation lamp 25 is turned on (12). Next, the position sensor 31 determines whether the moving optical system unit 24 has reached the leading edge of the image area (13), and if NO, the system waits until it reaches the leading edge of the image area. Step (
If YES in 13), set the initial values for the image area and document area. 14)1. Further, a reference black level and a reference white level of reflection density are set (15). After setting, wait for input of shift pulse signal SH and input A/Di.
The n signal is counted 18), and after the count is completed, the reflection density of the image area in the sub-scanning direction is detected and stored for each light receiving element of the light receiving element group 71 (17). Next, it is determined whether the measurement of the reflection density of the image area is completed (18);
If the judgment in step (18) is NO, step (16)
Return to the previous step and continue detecting the reflection density of one image area. If YES, the same dummy process as in step (16) is performed, the irradiation lamp 25 is turned off (19), and then step (17) is performed using the density correction value stored in step (6).
) and corrects the stored reflection density (20). Next, the reflection density corrected in step (20) is compared with the reference black level reflection density set in step (15) for each light receiving element (21), and the maximum reflection density is determined and stored in the RAM 56 (22). ), then, similarly, the reflection density stored in step (17) is compared with the reflection density of the reference white level set in step (15) for each light receiving element (23).
, find the minimum reflection density and store it in the RAM 56 (24);
After this, the process moves to the flow shown in FIG. 8(C), and then the reflectance of each pixel of the reflection density data stored in step (18) is examined (25), and a set of pixels with a reflectance smaller than 1 is determined. 26) to detect the document size and the image area within the document size, and erase the eraser 4 corresponding to the non-image area.
Set the light emission of LED 1 (2?), and then set the reflectance of the pixel next to the pixel on the outline of the document size detected in step (28) to be lower than the predetermined reflectance. 28), if NO, set the copy magnification to reduction 2111), set the LED light emission of the eraser 41 according to this magnification (30), then step (22), step (24) The density difference between the maximum density and the minimum density in the reflection density data stored in step 31) is calculated, and it is determined whether the density difference is smaller than a predetermined density difference (32). If YES in this judgment, then calculate the distance from the document size outline to the leading edge of the image in the document size and judge whether the distance is smaller than a predetermined distance difference33).
If YES, check whether the cassette size is equal to the document size 34); if YES, set the bias value of the developing device 7 or the light intensity of the irradiation lamp 25 according to the reflection density stored in step (18) 38) , start copying (39), while step (33), (3
If no in step 4), change the copy magnification (35), set the LED light emission of the eraser 41 according to this copy magnification (3B), proceed to step (38), and if no in step (32) If so, please set the copy density37)
, the light amount of the irradiation lamp 25 or the bias value of the developing device 7 is set in accordance with this copy density (3B).

On the other hand, if YES in step (28), the copy magnification is set to the same size (40), and then the switch 29 is turned ON.
Please check the status 41), it is OFF instead of ON.
Then, L of the eraser 41 corresponding to the contour point of the document size
Set the ED light emission (44), and jump to step (31). If YES, determine whether there is a set of pixels exhibiting high reflectance from the document size contour point to the edge of the image area in the document size (42). ), if YES, it is further determined whether there is a set of pixels exhibiting high reflectance in the main scanning direction within the original size (43); if YES in this judgment, the main scanning direction within the original size is determined. Set the light emission of the eraser 41 corresponding to the high reflectance area (47), jump to step (31), and press N at step (42).

In this case, a document setting failure is displayed (45), and
If NO in step (43), set the emission of the eraser 41 corresponding to the pixels from the document size outline to the tip of the pixel area in the document size 46) 1, step (31)
fly to

〔Effect of the invention〕

As explained above, the present invention includes a book copy detection means for detecting that a document placed on a document indicator is a book, and a reflection density detecting means for detecting folds of the book by receiving reflected light from the book. Since a detection means and an eraser means for irradiating light onto the photoreceptor corresponding to the fold of the book detected by the reflection density detection means are provided, the outline and fold of the book can be copied inside regardless of the size of the book. , it has the advantage of always providing clear and easy-to-see images.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an image processing device showing an embodiment of the present invention, FIG. 2 is a control circuit diagram, FIG. 3 is a front view of a reflection density sensing element showing an embodiment of the invention, and FIG. The figure is a density characteristic waveform diagram showing the relationship between reflected density and output voltage, Figure 5 is a scan schematic diagram showing division in the scanning direction, Figure 6 is a timing chart of each control signal, and Figure 7 is a density characteristic diagram. Characteristic waveform diagrams, FIGS. 8(a), (b), and (c) are flowcharts showing an example of control. In the figure, 1 is a drum, 2 is a pre-static charger, 3 is a primary charger, 4 is a charger, 5 is a copying charger, 6 is a cleaning device, 7 is a developer, 8 is a pre-exposure lamp, and 9 is a front surface Exposure lamp, 10.11 is paper feed cassette, 12 is upper cassette, 1
3 is a lower cassette, 14 is a registration roller, 15 is a transport belt, 16 is a fixing roller, 17 is an ejection roller, 18 is a tray, 19 is an original table glass, 2o is an original, 21 is an original pressure plate, 22.23 is a standard white board , 24 is a moving optical system unit, 25 is an irradiation lamp, 26 is a first scanning mirror, 27 is a second scanning mirror, 28 is a position detection piece, 29 is a switch,
30, 31. 32 is a position sensor, 33 is a slit, 34
36 is a projection lens, 35 is a reflection density detector, 37 is a third scanning mirror, 38 is a fourth scanning mirror, 39 is an optical system drive motor, 40 is a main motor, 4
1 is an eraser, 51 is an oscillator, 52 is a frequency divider, 53.6
0 is an amplifier, 54 is an A/D converter, 55 is a microprocessor, 56 is a RAM, 57i to 573 are cassette size input keys, 158 is input keys, 159 is a D/A converter, 6
1 is a lamp regulator, 62.63 is a drive driver,
641. 642 is an AND circuit, 65+, 652.66 are inverters, 67 is a clock signal, and 71 is a group of light receiving elements. Figure 3 Figure 5-1111111 Figure 8 (a) Figure 8 (b)

Claims (1)

[Claims] In an image processing device that irradiates a document placed on a document indicator with an irradiation lamp and forms an image of the reflected light on the surface of a photoreceptor, it is detected that the document placed on the document indicator is a book. a book copy detection means; a reflection density detection means for detecting a fold of the book by receiving reflected light from the book; and a reflection density detection means for detecting a fold of the book by detecting light reflected from the book; An image processing device characterized by comprising: an eraser means for irradiating.