JPS6258777A - Color picture processor - Google Patents

Abstract

PURPOSE:To facilitate the gradation correction and the adjustment of color correction processing by reading a specified gradation correction function, correcting the gradation of a recorded color at each input color picture information, reading the specified color correction function so as to correct the reproducibility of the recorded color for each combination of plural kinds of input color picture information. CONSTITUTION:A color conversion processing circuit 110 consists mainly of a gamma correction circuit 112, a color correction circuit 113 and an arithmetic circuit 114. The gamma correction circuit 112 consists of 3 gamma correction ROMs 112b-112r processing and correcting the gradation of each reading color gradation data. Then an 8-bit read color gradation data is subject to correction processing into a 6-bit recording color gradation data. The color correction circuit 113 consists of 3 ROMs 113y, 113m, 113c, inputs the high-order 5-bit of each read color gradation data in 8-bit is inputted and corrected into a 6-bit color correction data. That is, since the gradation correction processing and the color correction processing are both executed independently of the input color picture information, the gradation and color correction processing are facilitated.

Description

[Detailed description of the invention] ■Technical field The present invention provides blue (B) reading by reading color originals, etc.
, green (G), red (R) data to recording system yellow (Y), magenta (M), cyan (C) data, especially correcting the gradation of recorded colors. The present invention relates to gradation correction processing and color correction processing for correcting color reproducibility of recorded colors.

(2) Prior Art For example, when a color original is read by a color scanner, blue (B), green (G), and red (R) data of signal levels corresponding to the color components of the image are obtained as color image information. Theoretically, a color original can be reproduced by subtractively mixing yellow (Y), magenta (M), and cyan (C) inks using these data.

However, factors such as the spectral transmission characteristics of the filter used in the three-color separation of the color scanner and the color development characteristics of the ink act in a complex manner, and generally this subtractive color mixture is not followed.

Therefore, color conversion processing is performed to obtain Y, M, and C data, which is recorded color image information, from B, G, and R data, which is input color image information. Generally, this color conversion process is
It consists of two systems of processing.

The first is a gradation correction process that corrects the gradation of input color image information to match the gradation of the recording system, which is the so-called γ correction process.

The second is a color correction process that corrects the color reproducibility of the input color image information to match the color reproducibility of the recorded color image information, which is a so-called masking process.

In a conventional color image processing apparatus of this kind, processing is performed in series, for example, γ correction processing is performed in the first stage and masking processing is performed in the latter stage.

Incidentally, there are various types of color originals prepared by operators, and their color reproduction ranges are also undefined.

In other words, since the color reproducibility of the input color image information is uncertain, it is desirable that the operator can adjust the color portion processing (masking processing) in accordance with the characteristics (color reproduction range) of the color original or the like.

Further, in order to enhance the contrast of the reproduced image or adjust the resolution of the reproduced image by changing the size of the dither matrix, it is desirable that the operator side be able to adjust tone complementation processing (γ correction processing).

In response to these demands, various color image processing devices have been proposed in which γ correction processing and masking processing can be adjusted on the operator side, but all of these devices perform the above γ correction processing and masking processing in series. This method was developed in a color image processing apparatus (for example, Japanese Patent Laid-Open No. 161980/1983).

However, color image processing apparatuses that perform γ correction processing in the first stage and masking processing in the second stage have the following problems.

Here, the same applies to other magenta M and cyan C, but to explain the case of yellow as an example, if the γ correction processing function is γ() and the masking processing numerical value of yellow is y(), then the yellow record There is a relationship between color image information Y and input color image information B, G, and R: Y=y (γ(B), γ(G), γ(R)). That is, yellow Y is Since it is a function of the input color image information after the γ correction, the yellow masking process changes by adjusting the γ correction.

Therefore, in this type of conventional color image processing device, γ
The adjustment of the correction process and the adjustment of the masking process must be made in consideration of their relationship with each other, and a specialized operator who is familiar with this adjustment is required, which is not common.

(1) Purpose of the Invention An object of the present invention is to provide a color image processing device that can easily adjust color conversion processing.

■Structure of the Invention In order to achieve the above object, the present invention generates multiple types of recorded color image information based on multiple types of input color image information, and records color images according to each recorded color image information. In a color image processing apparatus that performs color image recording by energizing means: A plurality of types of gradation correction functions for correcting gradation of recorded colors are stored in association with each of the input color image information. The first storage means that is storing data = the first specification means that specifies one of the gradation correction functions stored in the first storage means for each input color image information; from the first storage means; , reads out the gradation correction function specified by the first specifying means.

A gradation correction processing means that generates first information in which the gradation of the recorded color is corrected for each input color image information; reproduction of the recorded color in correspondence with each of the combinations of the plurality of types of input color image information; a second storage means storing a plurality of types of color correction functions for correcting the color difference; a color correction function stored in the second storage means for each combination of the plurality of types of input color image information; a second specifying means for specifying one of the functions; reading out the color correction function specified by the second specifying means from the second storage means, and specifying the recording color for each combination of the plurality of types of input color image information; Color correction processing means for generating second information whose reproducibility has been corrected; and generating the plurality of types of recorded color image information corresponding to the first information by the gradation correction processing means and the second information by the color correction processing means. The recording color image information generating means is configured to include: recording color image information generating means;

According to this, both gradation correction processing and color correction processing are performed on input color image information, and each process is independent, so gradation correction processing can be performed without the need for special knowledge or experience. and color correction processing can be easily adjusted.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

FIG. 2 shows an outline of the structure of the mechanical section of a digital color copying apparatus according to an embodiment of the present invention, and FIG. 5 shows an outline of the structure of its electrical section.

First, referring to FIG. 2, an original 1 is placed on a platen (contact glass) 2, and fluorescent lamps 3i+3 for illuminating the original are placed on a platen (contact glass) 2.
2, the reflected light is illuminated by a movable first mirror 41. It is reflected by the second mirror 42 and the third mirror 43 and passes through the imaging lens 5.

Enters the dichroic prism 6, where the three wavelengths of light, red (R), green (G) and blue CB)
It is spectrally separated into The separated light is C0, which is a solid-state image sensor.
D7rt 7g and 7b, respectively. In other words, red light goes to CCD7r, green light goes to COD7g.
Furthermore, the blue light enters the CCD 7b.

The fluorescent lamps 31, 3□ and the first mirror 41 are connected to the first carriage 8.
A second mirror 42 and a third mirror 43 are mounted on the second carriage 9.

The first carriage 8 is coupled to a carriage drive wire 12 wound around a carriage drive pulley 11 fixed to the shaft of a carriage drive motor 10, the wire 12 being
It is wound around a movable pulley (not shown) on the second carriage 9. As a result, the first carriage 8 and the second carriage move forward (from right to left: original reading scanning) and backward (from left to right: return) by the forward and reverse rotation of the motor 10, and the second carriage 9 moves forward and backward (from left to right: return). Carriage 8 moves at a speed of 172. That is, by moving the second carriage 9 at half the speed of the first carriage 8, the original image is read and scanned while keeping the optical path length from the original 1 to the COD constant.

When the first carriage 8 is at the home position shown in FIG. 2, the first carriage 8 is detected by the home position sensor 39, which is a reflective boot sensor. This checking mode is shown in FIG. When the first carriage 8 is driven to the right during exposure scanning and moves away from the home position, the sensor 39 does not receive light (carriage non-detection). When the first carriage 8 returns to the home position, the sensor 39 receives light ( (carriage detection), and the carriage 8 is stopped when the state changes from non-light reception to light reception.

Referring now to FIG. 5, C0D7r, 7g.

The output of 7b is subjected to analog/digital conversion and shading correction, and is subjected to necessary processing in the image processing unit 100, and is then converted into binary signals for recording activation, that is, color image information, yellow (Y), and magenta. (M),
Converted to cyan (C) and black (BK). 2
Each of the value signals is transmitted to the laser drivers LDy and LDm.
, LDc and LDbk, and each laser driver outputs semiconductor lasers 43y, 43m, 43c and 4.
By energizing 3bk, laser light modulated with each recording color image information (binarized) is emitted.

Referring again to FIG. The emitted laser beams are transmitted through rotating polygon mirrors 13bk, 13y, 13m and 1, respectively.
3c and is reflected by f-theta lens 14bk.

14y, 14m and 14c, the fourth mirror 15b
k, 15y, 15m and 15c and the fifth mirror 16
bk, 16y, 16m and 16c, polygonal mirror surface tilt correction cylindrical lenses 17bk, 17y, 1
7m and 17c, photoreceptor drum 18bk,
18y, 18m and 18c are imaged and irradiated.

Rotating polygon mirrors 13bk, 13y, 13m and 13c
are fixed to the rotating shafts of polygon mirror drive motors 41bk, 41y, 41m, and 41c, and each motor rotates at a constant speed to rotate the polygon mirror at a constant speed. As the polygon mirror rotates, the laser beam is scanned in a direction perpendicular to the rotation direction (clockwise) of the photoreceptor drum, that is, in a direction along the drum axis.

FIG. 4 shows the laser scanning system of the cyan color recording device in detail. 43c is a semiconductor laser. A sensor 44c made of a photoelectric conversion element is arranged to receive the laser beam at one end of the laser scan (double-dot chain line) in the direction along the axis of the photoreceptor drum 18c, and this sensor 44c detects the laser beam. The starting point of one line scan is detected at the time when the detection changes from detection to non-detection. That is, the laser light detection signal (pulse) from the sensor 44c is processed as a line synchronization pulse for laser scanning.

The configurations of the magenta recording device, yellow recording device, and black recording device are also exactly the same as the configuration of the cyan recording device shown in FIG.

Returning to FIG. 2, the surface of the photoreceptor drum is uniformly charged by charge scorotrons 19bk, 19y, 19m and 19c connected to a negative high voltage generator (not shown). A○ modulation (Acou+
When the uniformly charged surface of the photoreceptor is irradiated with a laser beam that has been applied (t, ○ptic module), the electric charge on the photoreceptor surface flows to the equipment ground of the drum body and disappears due to the photoconductive phenomenon. . Here, the laser is not turned on for portions of the document that have image components, and the laser is turned on for portions of the document that do not have image components. As a result, photoreceptor drums 18bkt l 8y+ 18m and 18c
The part of the surface corresponding to the part with the image component is about -8
At a potential of 00V, a portion corresponding to a portion without an image component becomes a potential of about -1oOV, and an electrostatic latent image is formed corresponding to the original image. This electrostatic latent image is transferred to a black developing unit 20bk, a yellow developing unit h20y, a magenta developing unit 20m, and a cyan developing unit 2, respectively.
Developed with 0c, photoreceptor drum 18bk, 18V
A black toner image, a yellow toner image, a magenta toner image, and a cyan toner image are formed on the surfaces of r 18m and 18c, respectively.

The toner in the developing unit is positively charged by stirring, and the developing unit is biased to about -200V by a developing bias generator (not shown), and the toner adheres to the area where the surface potential of the photoreceptor is higher than the developing bias, and the original image is formed. A toner image corresponding to the image is formed.

On the other hand, the recording paper stored in the transfer paper cassette 22 is fed by the feed operation of the feed roller 23, and is sent to the transfer belt 25 by a pair of registration rollers 24 at a predetermined timing. As the transfer belt 25 moves, the recording paper placed on the transfer belt 25 is transferred to the photoreceptor drum 1.8bk,
18Y, 18m and 18c sequentially, and each photoreceptor drum 18bk, 18y, 18m and 1
While passing under the recording paper 8c, black, yellow, magenta and cyan toner images are sequentially transferred onto the recording paper by the action of the transfer corotrons 29bk, 29y, 29m and 29c at the lower part of the transfer belt. The transferred recording paper is then sent to a thermal fixing unit 36, where the toner is fixed to the recording paper, and the recording paper is discharged to a tray 37.

Further, residual toner on the photoreceptor surface after transfer is removed by cleaner units 21bk, 21y, 21m, and 21c.

A cleaner unit 21bk and a black developing unit 20bk that collect black toner are connected to a toner collection pipe 42.
The black toner collected by the cleaner unit 21bk is collected by the developing unit 20bk. Note that in the case of the photosensitive drums I F3 y y 18 m and 18e, especially the toner in the previous stage thereof, that is, the black toner, yellow 1-toner, or magenta toner may be reversely transferred from the recording paper during transfer.
Cleaner units 21y + 21m and 21c
The yellow, magenta and cyan toners collected will not be collected for reuse.

The transfer belt 25 that conveys the recording paper in the direction from the photoreceptor drums 18bk to 18c includes an idle roller 26° and a drive roller 2.
7. It is stretched between an idle roller 28 and an idle roller 30, and is rotated counterclockwise by a drive roller 27. The drive roller 27 is pivotally connected to the left end of a lever 31 that is pivotally connected to a shaft 32 . A plunger 35 of a black mode setting solenoid (not shown) is pivotally attached to the right end of the lever 31. A compression coil spring 34 is disposed between the plunger 35 and the shaft 32, and this spring 3
4 applies clockwise rotational force to the lever 31.

When the black mode setting solenoid is de-energized (color mode), the transfer belt 25 on which the recording paper is placed is the photosensitive drum 18bk, as shown by the solid line in FIG.

'8Yy18m and 18c are in contact. In this state, when recording paper is placed on the transfer belt 25 and toner images are formed on all the drums, each toner image is transferred onto the recording paper as the recording paper moves (color mode).

When the black mode setting solenoid is energized (black mode),
The lever 31 resists the repulsive force of the compression coil spring 34.
rotates counterclockwise, the drive roller 27 descends 5 m+e, and the transfer belt 25 separates from the photoreceptor drums 187, 18m and 18c, and remains in contact with the photoreceptor drum 18bk. In this state, the recording paper on the transfer belt 25 only contacts the photosensitive drum 18bk.
Only the black toner image is transferred to the recording paper (black mode).

At this time, the recording paper does not contact the photoreceptor drums 18y, 18m, and 18c, so the toner image on the recording paper is reversely transferred to the photoreceptor drums 18y+18m and 18c, which prevents copying and prevents copying. You can get copies similar to those from a copier. Note that in the black mode, the yellow, magenta, and cyan recording systems are not energized.

The console board 300 includes a copy start switch 301. Color mode/black mode designation switch 302 (
It is a lighting display type alternate switch with an indicator lamp on the back, and it lights up and sets color mode for each input; repeats turning off and setting black mode; however, immediately after power is turned on, it lights up and sets color mode) 2-color conversion processing (γ correction) rotary dip switch 304 for manual adjustment of color conversion processing (gamma correction processing and color correction processing); rotary dip switch 305 for automatic adjustment of color conversion processing (gamma correction processing and color correction processing); and a changeover switch 306 for inputting switching instructions for these inputs (it is a lighting display type alternate switch with an indicator lamp on the back side; lights up for each input and selects auto adjustment input; turns off and repeats manual adjustment input selection; however, power supply Immediately after power on, it lights up and auto adjustment input selection).

and other key switches 303. Numeric keypad.

Equipped with character display and indicator lights.

Next, the general operation timing of the main parts of the copying mechanism will be explained with reference to the time chart shown in FIG.

FIG. 6 shows the case when two identical full-color copies are made. At approximately the same timing as the start of exposure scanning of the first carriage 8, modulation energization of the laser 43bk based on recorded color image information (binarization) is started, and the laser 43bk
yy 43m and 43c are photosensitive drums 18bk to 18y, respectively.

Modulation energization is started after a delay of movement times Ty, Tm, and Tc of the transfer belt 25 corresponding to the distances 18 m and 18e. Corotron 29bk for transcription.

29y, 29m and 29c are the lasers 43b, respectively.
They are energized after a delay of a predetermined time (the time required for the laser irradiation position on the photosensitive drum to reach the transfer corotron) from the start of modulation energization of 43k, 43y, 43m, and 43c.

Binarized recorded color image information for modulating and energizing these lasers 43bk, 43y, 43m, and 43C, that is, each recording of black (BK), yellow (Y), magenta (M), and cyan (C). The signals are sent to buffer memories 140bk, 140y, and
140+m and 140c (see FIG. 5).

Buffer memories 140bk, 140y, 140m and 140c are first-in first-out (FI
Regarding the F○) memory, referring to Fig. 6, 140bk is a through buffer because the BK recording signal has no delay time, and the Y, M, and C recording signals have delay times Ty, Tm, and Tc. 140y, 14
0m and 140c are Ty, Tm and Tc, respectively
It is a time delay buffer. The outputs of these buffer memories 140bk, 140y, 140m and 140c are respectively output to laser drivers L Dbk and L D
Y.

given to LDn+ and LDc.

Please refer to FIG.

The output signals of C0D7b, 7g, and 7r are digitally converted into 8-bit data by A/D converters 70b, 70g, and 70r, and the shading correction circuit 71b,
71g and 71r, optical illumination unevenness, CC
After correction is made for variations in sensitivity of the internal unit elements of D7b, 7g, and 7r, the data is provided to the image processing unit 100 as read color gradation data (input color image information) B, G, and R.

In the image processing unit 100, first, the color conversion processing circuit 1
10, 8-bit read color gradation data B
, G, and R are converted into 6-bit recorded color gradation data (recorded color image information) Y, M, and C. Color conversion processing circuit 1
10 is shown in detail in FIG. 1a. This will be explained with reference to FIG. 1a.

The color conversion processing circuit 110 mainly includes a γ correction circuit 112, a color correction circuit 113, and an arithmetic circuit 114.

The γ correction circuit 112 includes three γ correction ROMIs 12 that correct the gradation of each read color gradation data into gradation data that is suitable for the next stage dither processing and the characteristics of the recording system.
b, 112g and 112r. In this example,
64 with dither processing circuit (120y, 120m, 120)
Binarization processing is performed using a gradation dither matrix, so 8
The bit read color gradation data is corrected to 6-bit recorded color gradation data. In other words, γ correction R
The OM112b has 8 types of gradations for correcting the gradation of the 8-bit read color gradation data B into 6-bit gradation correction data (first information: the same applies hereinafter) by changing the characteristics of each. A correction table is stored; the γ correction ROM 112g contains eight types of correction processing for correcting the gradation of the 8-bit read color gradation data G into 6-bit gradation correction data by changing the characteristics of each. A gradation correction table is stored in the γ correction ROM 112r.
Eight types of gradation correction tables are stored for correcting the gradation characteristics of the 8-bit read color gradation data R into 6-bit gradation correction data by changing the characteristics. These, γ correction R○M112b, 112g and 1
The gradation correction table stored in 12r is designated by a 3-bit first table switching signal for each γ correction ROM. When the manual adjustment input is selected, the first table switching signal is given in response to the operation of the rotary dip switch 304 for manual adjustment of color conversion processing, and when the automatic adjustment input is selected, the first table switching signal is given by the rotary dip switch 304 for automatic adjustment of color conversion processing. It is given in response to the operation of 305. That is, if manual adjustment input is selected, 83 types of gradation correction processing can be selected by operating the rotary dip switch 304 for manual adjustment of color conversion processing, but if automatic adjustment input is selected, automatic adjustment of one color conversion processing can be selected. By operating the rotary dip switch 305, each standard gradation correction process can be selected from the processes classified in advance into 16 categories (details will be described next).

The color correction circuit 113 includes three color correction ROMIs that correct the color reproducibility of each read color gradation data according to the color reproducibility of the recording system (coloring characteristics of toner, etc.). y,
Consists of 113m and 113c.

In this embodiment, the upper 5 bits of each 8-bit read color gradation data branched before the γ correction circuit 112 are input and corrected to 6-bit color correction data.

That is, 8-bit read color gradation data B is stored in the one-color correction ROM 113y.

Eight types of color correction for generating 6-bit color correction data (second information 2 and below is the same) corresponding to recorded color gradation data Y by changing the characteristics of each of the upper 5 bits of G and R as input. The table is stored; color correction R
The OM 113m inputs the upper 5 bits of each of the 8-bit read color gradation data B, G, and R, and changes the characteristics of each to 6 bits corresponding to the recorded color gradation data M.
Eight types of color correction tables for generating bit color correction data are stored; color correction ROMll3c contains 8-bit read color gradation data B, G, and R.
Eight types of color correction tables are stored for generating 6-bit color correction data corresponding to the recorded color gradation data C by changing the characteristics of each of the upper 5 bits of the input data.

These, color correction ROMI 13y, 113m and 11
The color correction table stored in 3c is for each color correction RO.
Each M is specified by a 3-bit second table switching signal, but in this way, the upper 5 bits of each of 8-bit read color gradation data B, G, and R are input and
Since bit color correction data is generated, each color correction R
The capacity of OM is 2'X2'X2'X23X6'', 1573 [k
bit], making it possible to downsize.

When the manual adjustment input is selected, the second table switching signal is given in response to the operation of the rotary dip switch 304 for manual adjustment of color conversion processing, and when the automatic adjustment input is selected, the second table switching signal is given according to the operation of the rotary dip switch 304 for automatic adjustment of color conversion processing. It is given in response to the operation of 305.

To explain the auto adjustment input in a little more detail, for example, color conversion processing is classified into 16 categories such as "Erase blue lines", "Improve skin tone reproduction", etc.
Tone correction tables stored in each γ correction ROM 112b, 112g and 112r for performing standard tone correction processing in each classified process, and standard tone correction tables in each classified process. Color correction ROMI 13yp 113 for color correction processing
The color correction table stored in m and 113C is
Each one is designated as one set.

In other words, if you select manual adjustment input, the rotary dip switch 3 for manual adjustment of color conversion processing
04, 83 color correction processes can be selected, but when auto adjustment input is selected, each of the processes classified into 16 categories can be selected by operating the rotary dip switch 305 for automatic adjustment of one color conversion process. Standard color correction processing can be selected.

The arithmetic circuit 114 uses the 6-bit gradation correction data (first information) output from the γ correction circuit 112 and the color correction circuit 113.
Each 6 bits of color correction data (second information) is output.
Bit recorded color gradation data (recorded color image information) Y
, M and C three operations ROMI 14y,
Consisting of 114m and 114c.

That is, the calculation ROM 114y contains tone correction data (output from the γ correction ROM 112b) of the read color tone data B which has a complementary color relationship with the recorded color tone data Y, and color correction data (output from the γ correction ROM 112b) corresponding to the recorded color tone data Y. A table for specifying 6-bit recorded color gradation data Y is stored by the color correction ROM 113y (output); Tone correction data (output from γ correction ROM 112g) and color correction data (output from color correction ROM 113) corresponding to recorded color gradation data M
m output) stores a table for specifying 6-bit recorded color gradation data M; calculation ROM 11
4c contains the gradation correction data (output from the γ correction ROM 112r) of the read color gradation data R, which has a complementary color relationship with the recorded color gradation data Y, and the recorded color gradation data C.
Color correction data corresponding to (color correction ROM113C output)
A table for specifying 6-bit recorded color gradation data C is stored. In this embodiment, each operation RO
M114y, 114m, and 114c store a table in which the upper 6 bits of the sum of these data (up to 7 bits) are specified by 6-bit gradation correction data and 6-bit color correction data. 111b, 111g, 1llr, 115y.

115m and 115c are latches, and input and output are synchronized by a synchronization control signal.

Returning to Figure 5 again.

Each recorded color gradation data Y, M, and C generated by the color conversion processing circuit 110 is processed by a dither processing circuit 120.
It is binarized at y, 120m and 120c. Each dither processing circuit +20yy120m and 120c is
It is composed of a dither ROM that stores dither matrices of 64 gradations with different screen angles, a digital comparator, etc., and each has an address in the sub-scanning direction (exposure scanning direction of the first carriage 8) and an address in the main scanning direction. (Direction perpendicular to the exposure scanning direction of the first carriage 8:
(Scanning direction of CCD electronic circuit) Dither matrix threshold specified by address and each recorded color gradation data Y
, M, or C, and binarized with the presence of an image component as 12 and the absence of an image component as 0.

Although illustrations and detailed explanations are omitted, - The dither matrix of each dither processing circuit 120y, 120m, and 120c can be updated as appropriate by operating the operation switch 303 of the console board 300.

A black component BK is extracted from the binarized recorded color image information in a black component extraction circuit 130.

FIG. 7 shows a black component extraction circuit. Referring to Figure 7,
This circuit consists of four AND gates A N DY +AN
It is composed of Dm, ANDc and ANDbk.

In other words, the recorded color image information Y is binarized.

If M and C all have an image component (1), the AND gate ANDbk outputs 1, indicating that the image component of the binarized recorded color image information BK is present (1). This output is passed through the inverter INV to each AND gate ANDy, A
Since it is added to NDm and A N D c, other recorded color image information Y, M and C are replaced with BK.

Next-stage buffer memories 140y and 140m.

As described above, 140c and 140bk are simply FIFO memories (first-in-first-out memories) that generate a time delay corresponding to the distance between the photoreceptor drums.

The write timing of each memory is simultaneous, but the read timing is as shown in FIG.
k is a through buffer without time delay), 140
Since y corresponds to the modulation activation timing of the laser 43y, the memory 140m corresponds to the modulation activation timing of the laser 43m, and the memory 140c corresponds to the modulation activation timing of the laser 43c, Ty, Tm, and Tc, respectively.
There is a time delay. The capacity of each memory is based on the distance between each photoreceptor drum, and when A3 is the maximum size, memory 14
0y, minimum 24% of maximum required amount of A3 original, memory 1
It is sufficient if it is 48% at 40m and about 72% at memory 1400.

Each buffer memory 140y of the image processing unit 100,
Recorded color image information Y, M, C, and B binarized at predetermined timing from 140m, 140c, and 140bk
K is read out, and the laser driver L Dy, L
Once transferred to D m , L D c and LDbk, the laser driver LDy receives this.

For LDm, LDc and LDbk, there is an image component (1
), each laser 43 y r 43 rn
+43c and 43bk are not energized, and as a result, photoreceptor drums 18y+ 18m, 18c and 18
Since the charge at that part of bk remains, it becomes a record due to toner adhesion.Also, if there is no image component (0), the opposite is true, because each corresponding laser is energized and the charge at that part is removed by exposure. It will not be recorded.

In addition, in the black mode for creating a monochromatic black copy, the Y, M, and C recording systems are deenergized, only the BK recording system is energized, and the laser 43bk is modulated and energized by the binarized recorded color image information BK. to create a monochrome black copy.

The image processing control circuit 150 determines the energization timing of each of the above elements and matches the timing between each element. 200
is a microprocessor system that controls all the elements shown in FIG. 2 described above, that is, controls the copying machine. This processor system 200 performs copy control in various modes set on the console board 300, and includes not only the image reading and recording system shown in FIG. 2, but also the photoreceptor power system, exposure system, charger system, and development system.

Performs sequence control of the fixing system, etc.

FIG. 1b shows another fourth embodiment of the color correction circuit 113 shown in FIG. 1a, and shows a circuit corresponding to the one-color correction ROM 113y. In addition, other color correction ROMs 113m, 1
The circuit corresponding to 13c also has the same configuration as in FIG. 1b.

In this embodiment, the color correction ROM 113 of FIG.
The circuit corresponding to y inputs the 8-bit read color gradation data B and corrects it to 5-bit color correction data, and the circuit that inputs the 8-bit read color gradation data G and corrects it to 5-bit color correction data. G correction ROM that corrects the data into 5-bit color correction data, R correction ROM that inputs 8-bit read color gradation data R and corrects it into 5-bit color correction data, and each read color gradation. It is constituted by a Y processing ROM that generates color correction data corresponding to recorded color gradation data Y using color correction data (each ROM output) of data B, G, and R. Each B correction RO
The M, G correction ROM, and R correction ROM each store eight types of tables for correction processing, and are designated by the 3-bit second table switching signal as described above.

The Y processing ROM stores a single table in order to execute processing using data corrected by each selected table.

According to this, 8-bit read color gradation data B
, G, and R are all effectively used to perform the color correction process, so that the processing accuracy of the color correction process can be made higher.

Furthermore, the total capacity of the memory that stores the table required to generate the color correction data corresponding to the recorded color gradation data Y from the read color gradation data B, G, and R is (the memory capacity of the color correction ROM 113y described above). ), 2” x 2’ x 5 x 3+2”’
X 6'=, 227 [kbit,],
Further miniaturization becomes possible.

In the above embodiment, an electrophotographic digital color copying apparatus is shown, but the present invention is not limited thereto, and may be applied to an electrostatic recording type using an electrostatic recording needle.

Alternatively, color copying machines and color printers using a thermal transfer method or an inkjet method are similarly effective.

■Effects of the Invention As described above, according to the present invention, both gradation correction processing and color correction processing are performed on input color image information, and each processing is independent, so special knowledge and experience are not required. Adjustment of gradation correction processing and adjustment of color correction processing can be easily performed without the need.

[Brief explanation of drawings]

FIG. 1a is a block diagram showing a color conversion processing circuit showing an example of the features of the present invention, and FIG. 1b is a block diagram showing a modification thereof. FIG. 2 is a sectional view showing the structure of the main mechanical parts of a digital color copying apparatus according to an embodiment of the present invention. 3 is an enlarged perspective view of a portion of the first carriage 8 of the apparatus shown in FIG. 2, and FIG. 4 is an exploded perspective view of the cyan recording device section of the apparatus shown in FIG. 2. FIG. 5 is a block diagram showing the configuration of the main parts of the electrical system of the device shown in FIG. 2. FIG. 6 is a time chart showing the relationship between original reading scanning timing, recording biasing timing, and transfer biasing timing of the apparatus shown in FIG. 2. FIG. 7 is a block diagram showing the configuration of the black component extraction circuit 130 shown in FIG. 5. 1: Original 2 Nibraten 31132: Fluorescent lamp 41-43: Mirror 5: Variable magnification lens unit 6: Dichroic prism 7r, 7g, 7b: CCD 8: First
Carriage 9: Second carriage 10: Carriage drive motor 11: Pulley 12: Wire 13bk, 1
3y, 13m, 13c: polygon mirror 14bk, 14y
T 14m p 14c: f-theta lens 15bk,
15y, 15m, 15c, 16bk, 16y, 16m,
16c: Mirror 17bk, 17y, 17m, 17c
Nijilintorical lens 18bk, 18y, 18m
, 18c: Photosensitive drums 19bk, 19y, 19m
, 19c: Charge Scorotron 20bk, 20y,
20m, 20c: developing device 21bk, 21y, 21m,
21c: Cleaner 22: Paper feed cassette 23: Paper feed roller 24 Ni registration roller 25: Transfer belt 26
．． 28, 30: Idle roller 27: Drive roller 29bk, 29y, 29+m, 29c: Transfer corotron 31 ni lever 32: Shaft 33: Pin 34: Compression coil spring 35
Nib run gear 36: Fixing device 37: Tray 39: Home position sensor 40; Carriage guide bar 41bk, 41y, 41m, 41e: Polygon mirror drive motor 42: Toner collection pipe 43t>k, 43y, 43+*, 43c: Laser 44
bk, 44y, 44m, 44c: Beam sensor 70b
, 70g, 70r: A/D converters 71b, 71
g, 71r: shading correction circuit 100: image processing unit 110; color conversion processing circuits 111b, 111g, 111r, 115y, 115m,
115c: Latch 112: γ correction circuit (first storage means two-tone correction processing means) 113: Color correction circuit (second storage means two-color correction processing means) 114: Arithmetic circuit (recorded color image information generation means) 120
y, 120m, 120c: dither processing circuit 130
:Black component extraction circuit 140y, 140m, 140c, 140bk:
Buffer memory 150; Image processing control circuit 200: Microprocessor system 300: Console board 301: Copy start switch 302: Mode designation switch 303: Other key switches 304: Rotary dip switch for manual adjustment (first designation means, second (specifying means) 305: Rotary dip switch for automatic adjustment ANDy, AND+w
, ANDc, ANDbk: AND gate INV: Inverter patent applicant Ricoh Co., Ltd., 17 letters! , j7. ;
J'1

Claims (5)

[Claims] (1) Color image processing that generates multiple types of recorded color image information based on multiple types of input color image information, energizes a color image recording means according to each recorded color image information, and performs color image recording. In the apparatus: a first storage means storing a plurality of types of gradation correction functions for correcting tonality of recorded colors in association with each of the input color image information; A first specifying means for specifying one of the tone correction functions stored in the first storage means for each piece of information; a tone correction function specified by the first specifying means from the first storage means; gradation correction processing means for reading the information and generating first information in which the gradation of the recorded color is corrected for each input color image information; a second storage means storing a plurality of types of color correction functions for correcting color reproducibility; the second storage means stores a plurality of types of color correction functions for each combination of the plurality of types of input color image information; second specifying means for specifying one of the color correction functions;
color correction processing means for reading out the color correction function specified by the specifying means and generating second information in which recorded color reproducibility is corrected for each combination of the plurality of types of input color image information;
and a recorded color image information generating means for generating the plurality of types of recorded color image information corresponding to the first information by the gradation correction processing means and the second information by the color correction processing means; Processing equipment. (2) The color image according to claim (1), wherein the input color image information is of three types: blue, green, and red; and the recorded color image information is of three types: yellow, magenta, and cyan. Processing equipment. (3) The color image processing apparatus according to claim (1), wherein the input color image information and the recorded color image information are of three types: yellow, magenta, and cyan. (4) The gradation correction processing means is a γ correction circuit that performs γ correction processing on the input color image; and the color correction processing means is a masking correction circuit that performs masking correction processing on the input color image. 1) The color image processing device described in item 1). (5) The recording color image information generating means is a calculation means for adding the first information and the second information.
The color image processing device described in item 1), item (2), item (3), or item (4).