JPH0759034B2 - Image processing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an image processing apparatus capable of reading a line image of a color original having a complicated density changing portion without human labor.

[Conventional technology]

As a digital copier for signal processing an original image to obtain a line image, various image processing such as dither processing, γ correction, and undercolor removal have been considered. It is for duplicating various playback images,
This function is not intended to create a playback image by converting a complicated original image into a simple form, so it is more complicated when the user makes annotations or marks on the playback image. Then, there was a problem that it became difficult to see.

[Problems to be Solved by the Invention]

The present invention has been made by paying attention to the problems of the above-described conventional example, and when reading a color original and outputting it as a plurality of reproduction color component signals, the density changing portion of the color original is read with a simple configuration. Thus, for example, an object of the present invention is to provide an image processing apparatus that can obtain a color line image that is easy for a user to add or correct, without the need for manpower.

[Means for Solving the Problems]

For this reason, in the present invention, a reading unit that generates a plurality of color component signals representing the color original by scanning the color original, and a plurality of color component signals generated by the first scanning by the reading unit are provided. Processing, outputting a first reproduction color component signal, and after outputting the first reproduction color component signal,
Signal processing means for processing a plurality of color component signals generated by the second scanning by the reading means and outputting a second reproduced color component signal, wherein the signal processing means comprises the first means for the reading means. The density change portion of the color original represented by the first reproduction color component signal is detected based on the plurality of color component signals generated by the scanning, and the plurality of colors generated by the second scanning by the reading unit are detected. It is configured to include a detection unit common to the first and second reproduction color component signals, which detects a density change portion of the color original represented by the second reproduction color component signal based on the component signal. Therefore, the above-mentioned object is to be achieved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 13. In addition, in the drawings, the same or corresponding portions are denoted by the same reference numerals, and duplicate description will be omitted.

(Structure) FIG. 1 is a sectional view of an embodiment of an image processing apparatus to which the present invention can be applied. 1 is a document, 2 is a transparent plate on which the document 1 is placed, and 3 is a transparent plate 2. An original mat for pressing the original 1 from above, 4 and 5 are illumination lamps, 6 and 7 are reflectors, 8 is a main body control section for controlling each section, and 9 and 10 are
Different speeds (V, 1 / 2V) under the control of the body control unit 8
Each of the moving reflection mirrors, 11 is a lens for collecting the light reflected by these moving reflection mirrors 9 and 10, and 12 is the light of the blue wavelength and the green wavelength of the light passing through the lens 11. , And a dichroic mirror for spectrally splitting into red light, 13 is a blue filter that passes the decomposed light of the blue wavelength among these decomposed lights,
14 is a solid-state image sensor such as a CCD for receiving the light that has passed through the blue filter 13, 15 is a green filter that similarly passes a green wavelength, and 16 is a green filter 15
The solid-state image pickup device 17 for receiving the light of the red light is a red filter that passes the light of the red wavelength.

18 is a solid-state image sensor for receiving the light from the red filter 17, 19 is a white calibration plate, 20, 21 are cooling fans arranged in the optical system for heat dissipation of the illumination system, 22 is ,
An image processing unit as an image processing unit described later, 23 is a semiconductor laser, 24 is a laser beam La from the semiconductor laser 23.
Is a polygon mirror, 25 is a polygon mirror 24
A scanning motor for rotating the photosensitive drum, a photosensitive drum for scanning the photosensitive drum with the laser beam La perpendicular to the rotating direction, and a photosensitive drum for detecting the light scanning the photosensitive drum. Sensor 28 for generating a beam detector (B / D) signal, 28 is a high-voltage power source for generating a negative high voltage, 28a is a negative charger, and 29 is an exposure unit.

30 to 33 are developing units for four colors of B, G, R, and BK, 34 is a ghost lamp for erasing an electrostatic latent image, and 35 is a voltage higher than the negative high voltage power source 28. Negative post electrodes, 36 and 37, are supplied for each cassette selected by the operation unit, 3
Reference numerals 8 and 39 denote paper feed rollers, 40 denotes copy paper conveyed by the paper feed rollers 38 and 39, 41 and 42 denote upper and lower first registration rollers, 43 is a conveyance roller, and 44 is a second registration roller.
Reference numeral 45 is a transfer drum for transferring the toner on the photoconductor of the drum 26 onto the copy paper 40, 46 is a transfer electrode for copying the toner on the photoconductor onto the copy paper 40, and 47 is a transfer drum.
A transfer drum cleaner for cleaning 45, a static elimination electrode for removing static electricity of the transfer paper 40 by being supplied with a high voltage from the high-voltage power source 28, a gripper 48, a conveying fan 50, a 51
Is a conveyor belt for attracting and conveying the copy paper 40, 52
Is a fixing unit, 53 is a pre-cleaner charge eliminator for removing the electric potential remaining on the photosensitive drum 26, 54 is a cleaner unit for removing toner on the photosensitive drum 26, and 55 is also for the photosensitive drum 26. It is a pre-AC static eliminator to remove the electric potential.

(Image Processing Unit) Next, FIG. 2 shows a circuit block diagram of the image processing unit 22.

In the figure, 56, 57 and 58 are the solid-state image pickup devices (CCD) 1
Each CCD light receiving unit as density detecting means for A / D converting the light received by 4, 16, 18 and detecting the density change of the original 1, 59 is each CCD light receiving unit 56, 57, 58 Is a shading unit for calibrating so that the output level of the CCD is constant, 60 is a γ (gamma) correction unit for switching the input sensitivity of the CCD in response to a signal from the main body control unit 8, and 61 is the γ correction unit. The signal from the correction unit 60 is B,
A masking processing unit for performing G, R color correction, 62
Is a UCR processing unit for obtaining a black level signal from the B, G and R signals by a signal from the main body control unit 8, 63, 64, 6
Reference numeral 5 is each buffer circuit disposed on the CCD substrate P constituting each CCD light receiving unit 56, 57, 58, and 66, 67, 68.
Is each CLK driver, 69, 70, 71 are each solid-state image sensor (C
CD) Amplifiers for amplifying the signals obtained from 14, 16, 18 respectively, 72, 73, 74 are A / A for converting the analog signals from these amplifiers 69, 70, 71 into digital signals. D
It is a converter.

75,76,77 are ROMs for shading correction corresponding to B, G, R respectively, 78,79,80 are RAMs as memories connected to the ROMs 75,76,77, 81,82 , 83 are ROMs for γ correction corresponding to B, G, and R colors, 84, 85, 86 are latches for holding the γ-corrected signal, and 87 to 95 are for counting multiplication. Each ROM, 96,97,98 is each ROM for addition and subtraction, 99,100,101
Is a latch for holding the signal from the masking processing unit 61 corresponding to each color of B, G and R, 10
2 constitutes the UCR processing unit 62 and includes latches 100 and 101.
Comparing the B color data with the G color data, 103 is a comparator for comparing the G color data and the R color data of the latches 99 and 101, 104
Is a comparator for comparing the B color data and the R color data from the latches 99, 100 in the same manner, and 105, 106, 107 are each N arranged on the output side of each of the comparators 102, 103, 104.
OT circuit, 108, 109, 110 are the comparators 102, 103, 1
Each AN for ANDing 04 and each NOT circuit 105, 106, 107
D circuits 111, 112, 113 are latches 114, 115, 116 for holding the minimum values of the signals of three colors of blue, green and red, respectively, using the outputs of the AND circuits 108, 109, 110 as enable signals.
Corresponds to each color of B, G, R, each of the latches 99, 100,
Each latch, 117, 118, 119, 120 connected to the output side of 101,
Each ROM for UCR correction 121, which is separately driven by the enable signal (E), 121 is a latch connected to the output side of the ROM 120 for UCR correction, and 122 is a gate circuit.

(Line Drawing Processing Circuit) Further, FIG. 3 shows a line drawing processing circuit 123 as a line drawing processing means.
The detailed drawing of is shown. In the figure, 124 is a latch for holding a signal from the image processing unit 22, 125, 126,
127 is each shift register, 128 is a select signal (CS)
Each data selector for selecting each of the input ports P _{1 to} P ₃ by, P ₄ is an output port, 129 is a subtraction circuit, and 130 is
A two-input EX-OR circuit that constitutes the subtraction circuit 129, 131
Is a latch for holding the output of the subtraction circuit 129. 132 is a dither processing unit, 133, 134, 135 are ROMs for dither processing. 136, 137, 138 are comparators for comparing the data of the latch 131 of the line drawing processing circuit 123 with the data of the ROMs 133, 134, 135, and 139.140.141 are these comparators. Latches for holding the outputs of the comparators 136, 137, 138, 142, 143, 144 are R / W line memories for storing the data held in the latches 139, 140, 141, 145
Is a multi-value processing unit, 146 is a latch that constitutes this multi-value processing unit 145, 147, 148 and 149 are each AND circuits that are configured on the output side of the latch 146, and 150 is a synchronization that gates these AND circuits 147, 148 and 149. A counter, 151 is a B / D signal generator connected to a synchronous counter 148 for transmitting a B / D signal as a synchronization signal, and 152 is an OR circuit arranged on the output side of each of the AND circuits 147, 148, 149. , 153 is
A blanking circuit provided after the OR circuit 152, 154
Is a pattern generator for generating a sending pattern signal to the blanking circuit 153, and 155 receives the signal from the blanking circuit 153 and the semiconductor laser 23 described above.
156 is a laser driver for driving the laser beam, and 156 is a scanner unit for scanning the laser beam La from the semiconductor laser 23.

Copying Process Next, the copying process will be outlined. The original 1 is placed on the transparent plate 1 and pressed by the original mat 3 from above. Then, when the apparatus is started, light is emitted from the illumination lamps 4 and 5 and is combined with the light from the reflecting mirrors 6 and 7, so that the original 1
The reflected light from the original 1 is reflected by the movable reflecting mirrors 9 and 10 and passes through the lens 11 and the dichroic mirror 12. Then, the light passing through the dichroic mirror 12 is split into blue light, green light, and red light, and the decomposed light having a blue wavelength of each decomposed light is passed through the blue filter 13 to Light received by the solid-state imaging device 14, light having a green wavelength in the same manner is received by the solid-state imaging device 16 through the green filter 15, and light having a red wavelength passes through the red filter 17. It is received by 18. Then, the original 1 moves together with the illumination lamps 4 and 5, and the moving reflection mirror 9 moves.
And another moving reflecting mirror 10 keeps the optical path length constant, and images are formed on the solid-state imaging devices 14, 16, 18 of each color via the lens 11 and the tyroic mirror 12.

Further, a white end plate 19 for correcting the above-mentioned light amount when the illumination lamp 4 moves along the original 1 is arranged in front of the original 1. At this time, the optical system is equipped with cooling fans.
The heat of the illumination system is released by 20, 21 and the specified temperature is maintained.

Further, the outputs of the respective solid-state image pickup devices 14, 16 and 18 are ON-OFF controlled by a semiconductor laser 23 via an image processing unit 22 as an image processing means, and the laser light is applied to a polygon mirror 24. The polygon mirror 24 is a scanning motor 25
Since it is rotated by, the laser beam La is scanned perpendicularly to the rotation direction of the photosensitive drum 26.

Since the B / D sensor 27 is arranged at a position about 1 mm before the laser beam La starts optical scanning on the photosensitive drum 26, a B / D signal is emitted when the laser beam La is received. Each part is synchronized. At this time, the photosensitive drum 26 is supplied with a negative high voltage from the high-voltage power supply 28 and the negative charger 28a.
Is charged negatively by. On the other hand, the original 1 on the transparent plate 2
Is illuminated by the illumination lamps 4 and 5, so the image of the original 1 passes through the movable reflection mirrors 9 and 10, the lens 11, the dichroic mirror 12, the blue filter 13, the green filter 15, and the red filter 17 and the respective solid images. Image sensor 14,16,18
Imaged above.

The image output obtained there is the image processing unit shown in FIG.
22 for each color, that is, shading correction is performed by the shading unit 59, and γ
The γ correction is performed by the correction unit 60, the color correction is performed by the masking processing unit 61, and the under color adjustment is performed by the UCR processing unit 62 at the next stage.
A signal corresponding to the light and shade of the original 1 is obtained by the 2 and multi-value processing unit 145. This signal is sent to the laser driver 155, the semiconductor laser 23 is driven, laser light La is emitted, and the photosensitive drum 26 is irradiated via the polygon mirror 24. Then, an electrostatic latent image is formed, and as the photosensitive drum 26 rotates, the electrostatic latent image enters the developing devices 30 to 33 of four colors.

Here, if one color is selected from the three-color separated light through the line drawing processing unit 123 based on the signal of the main body control unit 8 by one exposure scanning, the corresponding one developing device (for example, 31)
Is selected. Then, powder development by the magnetic blade method is performed by the selected developing device 31 to visualize the electrostatic latent image. Then, the ghost miniature lamp 34 for erasing the electrostatic latent image and the post electrode 35 to which a negative high voltage is applied from the high voltage power source 28 are charged to remove the electrostatic latent image on the drum 26.

Next, the upper and lower cassettes 36 and 37 are selected by the operating section and one of the paper feed rollers 38 and 39 is rotated to convey the copy paper 40. The toner of the image formed on the photosensitive drum 26 by being caught in the gripper 49 through any one of 42 and being wound around the transfer drum 45 is transferred to the copy paper 40 by the transfer electrode 46.

This transfer is performed the number of times of the selected color, and each time the charge is removed from the copy paper 40 by the charge removing electrode 48 to which a high voltage is supplied from the high voltage power supply 28. Then, when the transfer is completed the selected number of times, the copy paper 40 is peeled off from the gripper 49, adsorbed on the conveyor belt 51 by the conveyor fan 50, and guided to the fixing section 52.

On the other hand, the potential remaining on the photosensitive drum 26 is further neutralized by the pre-cleaner static eliminator 53, and the toner on the photosensitive drum 26 is removed by the cleaner unit 54. The potential on the photosensitive drum 26 is removed by the AC pre-eliminating device 55.

(Image Signal Processing) Image signal processing in the transfer process will be described in detail below with reference to the circuit diagram of FIG.

The light of the original 1 separated into three colors by the dichroic mirror 12 in the preceding stage of the image processing unit 22 is received by each solid-state image pickup device 14, 16, 18 and the information signal thereof is received by each amplifier 6.
The signals are amplified by 9,70,71 and A / D converted by the A / D converters 72,73,74, respectively, and sent to the next shading unit 59 via the buffer 65.

Then, the optical system of the white calibration plate 19, that is, each illumination lamp 5,
When 6 etc. pass, a signal is sent from the body control unit 8 and each C
The shading unit 59 corrects the output level of each bit of the CD light receiving units 56, 57 and 58 so that the output level becomes constant. In the γ correction unit 60 in the next stage, an appropriate γ characteristic curve is selected by the signal of the main body control unit 8, γ correction is performed according to the curve, and then the masking processing unit 61 in the subsequent stage
Then, the color signals of B, G, and R are simultaneously processed to perform color correction by changing the mixing ratio of each color component. The mixing ratio of each color of B, G and R is switched by a control signal from the main body control section 8.

Further, as for the information signal, the UCR processing unit 62 determines the minimum signal of B, G, and R. The body control unit 8 receives the minimum signal.
The value obtained by multiplying the arbitrary coefficient written in the ROM 120 selected by the signal from is the black level. Whether or not the value multiplied by the coefficient is subtracted from each color is determined by the contents of the ROMs 117, 118 and 119 selected by the signal from the main body control unit 8.

Therefore, among the signals of B, G, R, and BK of each color, a signal of one color of B, G, and BK is sent to the line drawing processing circuit 123 by the select signal (CS) of the main body control unit. Then, the line drawing processing circuit 123 temporarily holds each 6-bit color signal by the latch 124, and then branches to two circuits. Then, for example, when the input port P ₃ of the data selector 128 is selected by the select signal (CS), one branched signal passes through the shift register 127 and the input port of the data selector 128.
It is sent to the subtraction circuit 129 via P ₃ and the output port P ₄ with a delay of several clocks or 1,000 clocks. The delay time can be switched by selecting any _one of the input ports P ₁ , P ₂ , P ₃ by the select signal (CS) of the data selector 128.

Since the subtraction circuit 129 is composed of the 2-input EX-OR gate 130 as described above, the signal directly input from the latch 124 and the 6-bit input via the shift registers 125 to 127 are input.
When the values of the bit signals are compared with each other, and the values of the two signals are equal, the output becomes zero, and when the values of the input 6-bit signals are different, the absolute value of the difference is output.

That is, when an original document as shown in FIG. 5 is read by the CCD light receiving unit 56 as shown by the alternate long and short dash line, the output signal of the latch 124 becomes as shown in FIG. 6 (1) while passing through the shift register 125. The signal is as shown in Fig. 6 (2). At this time, if the input port P _{1 of the} data selector 128
If is selected, the absolute value of the difference between (1) and (2) in FIG. 6 is as shown in (3) in FIG.

If an image is reproduced based on the signals shown in FIGS. 6 (1), (2), and (3), then FIG. 7 and FIG.
The images as shown in FIG. 9 and FIG. 9 are reproduced respectively. As can be seen from the reproduced image in FIG. 9, the vertical lines are reproduced, but the horizontal lines have disappeared. Therefore, for example, the original image shown in FIG. 5 is read by the CCD light receiving unit 56 described above so that the delay time in the line drawing processing circuit 123 is set to be large not only in the horizontal direction but also in the vertical direction. When reproduced, a reproduced image as shown in FIG. 11 is obtained.

If the image is reproduced by the signal that has passed through the shift registers 125, 126 and 127, the image is reproduced as shown in FIG. The output of the subtraction circuit 129 thus obtained is latched 1
It is held at 31 and sent to the dither processing unit 132.

The dither processing unit 132 compares each signal having a deep signal, for example, a 6-bit signal, using a ROM for table reference, converts it into a digital signal of 1 or 0, and modulates the semiconductor laser 23. I do. The dither processing blocks existing in parallel inside the dither processing unit 132 perform the dither processing, the data obtained by the processing are sent to the multi-value quantization processing unit 145, and the main body control unit 8 controls the selection. Signal processing is performed. When the semiconductor laser 23 is driven through the laser driver 155 based on the obtained processed data and the image is reproduced, a line image as shown in FIG. 13 is obtained.

In the above description, one of the colors has been described, but the above-described operation is repeated four times so that the B, G, R, and BK colors are superimposed, and a full-color reproduced image can be obtained. That is, (1) B, G, R, obtained by signal processing the image information of the original 1
By reproducing an image with only one or two signals of each of BK, it is possible to create a line drawing of only a specific color of the original image.

(2) Then, by reproducing the image of R color by the signal of B color, for example, a line image subjected to color conversion can be created. That is, after processing the B-color signal, laser modulation is performed, and at this time, the developing device having the R-color toner is selected and development is performed.

(3) Also, the select signal (C
S) to switch the delay time of the line drawing processing unit by appropriately selecting each input port P ₁ , P ₂ , P ₃ of the data selector 128. For example, if the delay time is increased, a thicker line can be obtained. It is possible to obtain a line image having a thickness of.

(Other Embodiments) FIG. 4 is a line drawing processing circuit diagram showing another embodiment of the present invention in which the latch 131 and thereafter shown in FIG. 3 are modified.

In the figure, 157 is connected to the output side of the latch 131.
An OR gate, 158 is an R / W line memory, 159 is a latch, 160 is a blanking circuit, and 161 is a pattern generator connected to the blanking circuit 160 to generate a pattern.

The OR gate 157 connected to the latch 131 is the latch 13
If the output of 1 is a 1-bit high signal, its OR gate 1
57 output goes high. That is, if there is a difference between the output of the latch 131 and the signal passed through the shift register 125, the laser light La is turned on, and if not, it is turned off. In FIG. 3, the density of the reproduced line image changes depending on the magnitude of the signal difference, but in FIG. 4, the density of the line image always becomes constant as described above.

Also, by ignoring the lower several bits of the 6-bit output of the latch 124 in FIG. 3, it is possible to reproduce as a line drawing only the portion where the density change has a difference equal to or larger than a certain value.

〔The invention's effect〕

As described above, according to the present invention, in this type of image processing apparatus, when a color original is read and output as a plurality of reproduction color component signals, the density changing portion of the color original is read with a simple configuration. This makes it possible to obtain a color line image that is easy for the user to add or correct, for example, without annoying human labor.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of an image processing apparatus according to the present invention, FIG. 2 is a circuit block diagram of an image processing unit showing an essential part of the present invention, and FIG. Part detail drawing,
FIG. 4 is a line drawing processing circuit diagram showing another embodiment of the present invention, FIGS. 5 and 10 are original image diagrams, and FIG. 6 is an original image according to the present invention. Signal waveform diagrams, FIGS. 7 and 11 are explanatory diagrams of line images obtained when an original image according to the present invention is reproduced, FIGS. 8 and 12
Similarly, FIG. 9 is an explanatory view of a line image when an original image according to the present invention is reproduced with a signal delayed, and FIGS. 9 and 13 are line images shown in FIG. 7 and FIG. 11 and
FIG. 12 is an explanatory diagram of each image when the line images shown in FIGS. 56,57,58 …… CCD light receiving unit (density detection means) 22 …… Image processing unit (image processing means) 123 …… Line drawing processing circuit (line drawing processing means)

Claims (1)

[Claims] 1. A reading unit for scanning a color original document to generate a plurality of color component signals representing the color original document,
A plurality of color component signals generated by the first scanning by the reading unit are processed, a first reproduction color component signal is output, and after the first reproduction color component signal is output, a second reproduction color component signal is output by the reading unit. Signal processing means for processing a plurality of color component signals generated by scanning and outputting a second reproduced color component signal, wherein the signal processing means includes a plurality of signal processing means generated by the first scanning by the reading means. The density changing portion of the color original represented by the first reproduction color component signal is detected based on the color component signal, and the density changing portion of the color original is detected based on the plurality of color component signals generated by the second scanning by the reading unit. An image processing apparatus comprising: a detection unit common to the first and second reproduction color component signals for detecting a density change portion of the color original represented by two reproduction color component signals.