Color picture forming device, color picture processor and method

[Detailed Description of the Invention]

[Industrial Application] The present invention relates to a color image forming device, a color image processing device, and a method provided with the color correction function. [Description of the Prior Art] Although various color image forming devices are known, the thing using the laser beam printer which performs image exposure to a photo conductor by a laser beam, develops it, and obtains a picture also in this is also used well. As for such a laser beam printer, printing quality is quantity (it has the strong points, like it is at high speed, for example, widely used as output units and the usual printers, such as a color copying machine.). Abnormal conditions which make the luminescence time of laser correspond to the size of an image signal, and what is called Pulse Density Modulation are performed, and the image is made to form in such a laser beam printer. Thus, a plurality of tone reproduction as depended on changing the synchronization of a reference pulse when performing Pulse Density Modulation, and shown in a of Drawing 3 and b can be chosen. A highlight part will be crushed by the reproducibility of a shown in a figure although the whole is sharply reproducible. With the reproducibility of b, although the story tonality of a highlight part is good, it is difficult to consider it as an image sharp as a whole. [Problem(s) to be Solved by the Invention] With the device which switches tone reproduction as mentioned above and processes a color picture, with the reproducibility of b, the story tonality of a highlight portion is good, and color reproduction nature is also good. On the other hand, a highlight part is crushed by the reproducibility of a, and it is hard to attach a color in this portion. Therefore, when the amount of lower color removal was decided on the basis of the reproducibility of a, with the reproducibility of b, ink volume increased and there was a problem which becomes a dark picture at the whole. When such a problem was a device from which not only a device but the tone reproduction or the color picture formation conditions of performing Pulse Density Modulation as mentioned above, and performing image formation change, it was a problem which occurs similarly. An object of the present invention is to be made in view of this problem and for * and color reproduction nature to provide a good color image forming device, a processing unit, and a method. [Means for Solving the Problem] It is a color image forming device of an invention of the 1st of this application in order to achieve the above-mentioned object, It is a preparation means to perform lower color processing of a supplied color picture signal, and a means to perform color picture formation according to a color picture signal processed by the means, and has a color picture formation means by which image formation conditions can be changed, and a means to control a processing state of a bottom color processing means of the above according to the formation conditions. A lower color processing means to perform lower color processing of a color picture signal in which a color image processing device of an invention of the 2nd of this application was supplied, It has a color-image-processing means to process a color picture according to a signal which has predetermined tone reproduction and in which lower color processing was carried out by the processing means, and a means to control a processing state of a bottom color processing means of the above according to the tone reproduction of the color-image-processing means. A color image processing method of an invention of the 2nd of this application controls a lower color processing state according to the tone reproduction of the color picture signal, when performing lower color processing of a supplied color picture signal. [Function] In the above-mentioned composition, the processing state of the bottom color processing means of the above is controlled by the invention of the 1st of this application according to the image formation conditions of the above-mentioned color picture formation means. According to the tone reproduction of the above-mentioned color-image-processing means, the processing state of the bottom color processing means of the above is controlled by the 2nd invention. According to the tone reproduction of a color picture signal, a lower color processing state is controlled by the 3rd invention. [Example] Hereinafter, a detailed description of the invention is carried out based on an example. Drawing 4 is a schematic structure figure of the device of a color picture reading means used for this example. In this figure, it is manuscript stand glass with which l places a manuscript and 2 places manuscript 1. 3 is a lighting installation and 4 is an image formation device array. 5 is an infrared cut filter, 6 is a stuck type COD color sensor (henceforth CCD), and 7 is an optical system unit. First, the reading process of a color copy is explained. When the copy key (not shown) is pressed, lighting installation 3 irradiates with manuscript l, and the catoptric light from a manuscript passes along image formation device array 4 and infrared cut filter 5. And a manuscript image is imaged on CCD6 and the manuscript is scanned in the direction of optical system unit 7 arrow (.). As shown in Drawing 5 CCD6, it is red for every pixel (R). The filter of green (G) and blue (B) is attached regularly. With the scan of a manuscript, the electric signal from CCD6 is processed by the signal-processing circuit shown in Drawing 1 [ one to ]. In Drawing 1 [ one to ], 6R, 6G, and 6B express the signal from R [ on CCD6 ], G, and B each element. Next, the signal of this R, G, and B is introduced into A/D conversion circuit 11 and LOG conversion circuit 12, and is changed into y of a digital signal form, M, c, and a signal. This Y, M, C, and a signal are introduced into image signal generation circuit 13 which performs lower color removal (it is described as following UCR), and the Sumi ON Process, and generate Y2.M2.C2 and Bk3 signal by operation processing shown in a following formula. It is YI = YIkm at the time of (YI, MI, and CI)-1-k4> O. (YI, MI, CI) -1nM! = MI ks (YI, MI, CI) mhCx = CI ks (YI, MI, Q), i-B kn = ks (YI, MI, CI), and th+kt music -- Between music ... the time of concave bend (i)(Yl, Ml, CI)-t-k 4<=0 -- Y2= Y. M2 = MI C, = C. B (YI, MI, CI) ks = k+-1 and +k two music concave bend Song listening (ii) -- here -- (YI+ MI+ CI) rn+n -- Y, M, and C. of -- it is the minimum inside signal and kI+k2+k3+k4 are a constant. It is UCR operation to compute man as mentioned above (Y++MI * CH), and to reduce the quantity of the color material of MMC, k3 is a To decide coefficient about UCRfi, and it is a coefficient which the point for which k4 begins UCR is, and determines it. It is the Sumi ON Operation to add black toners (or black ink etc.) instead of each color material according to the amount of UCR(s), and it is a coefficient which determines the point with which kl begins the amount of Sumi ON Re, and a To decide coefficient and k2 begin the Sumi ON Re. it is alike here, and although it is 3 or a value from which 4 differs mutually in 2. by being alike, respectively, it may be in agreement with When. (if) (i) -- how to decide the coefficient of 2, i.e., the Sumi ON Re, to be constant several kiloliter+ at the time of generating Y2.M2.C2 and Bk3 signal which were shown by the formula -- The -- state below. However, i shows each patch (for example, i= 0~63) on a standard color copy (it mentions below). y /. C' corresponds to M', Y in Drawing 1 [ one to ], M, and C, B k+ is alike, in being alike and deciding 2, the ink volume of each point on the color picture used is shown, and i is a number of each point. boiling a black valuation function as phi -- 2 -- To decide. - (Y'+, M"l, C;) sigmaBk+-i-] 20, therefore here -- an upper type -- [E] [F] = -- if expressed as [G] -- F = E- from '-G, it is alike and the coefficient of 2 can be found. E-1 is an inverse matrix of E. Thus, Y2.M2.C2 and Bk3 signal which were generated by the image signal generation circuit are introduced into color correction circuit 14, perform operation processing shown in a following formula, and turn into Y3.M3 *C3 and Bk3 signal. Since operation processing is not carried out at all about Bk signal in color correction circuit 14 in this example, it is set to Bk2=Bk3. It is a masking coefficient of a 11~a and Are color correction here. The above processing is controlled by CPU 20 (central processing unit), and an operation program and data are memorized to RAM21(random access memory).ROM 22 (random access memory). These Y3.M3.C3 and Bk3 signal is developed by color picture formation means (printer 17), such as a color thermal transfer printer, a color ink-jet printer, and a color laser beam printer. Drawing 2 shows an example of a circuit used when performing the above-mentioned Pulse Density Modulation and carrying out image formation. Digital color picture signal D Vln from interface 16 is latched with video clock VCLK by latch l, and a synchronization is taken. This image signal D Vln is changed into analog video signal AV by D/A converter 102. After the output of D/A converter 102 is changed into a voltage level by resistance 103, it is inputted into one input terminal of two comparators 104.113. Two triangular wave generating circuits which consider an integration circuit as basic composition are prepared in this example. It synchronizes with VCLK, respectively and integrates with an output of flip-flop 105,113 to J/which carries out the circumference of PHCLK from which a cycle differs mutually, and the TXCLK for 2 minutes. The frequency of TXCLK turns into frequency of a which becomes important [ resolution ] here. on the other hand, it sets up and comes out of the frequency of PHCLK so that it may become frequency (however, a>b). The clock of such Divide(ed) 50% duty serves as a triangular wave in the integration circuit which comprised variable resistors 107a and 107b and capacitors 108a and 108b through buffer 106,114. And capacitor 109a 109b, variable resistor 110a A part for bias is adjusted by 110b, and it is protection resistance 111a, It is inputted into another input terminal of the above-mentioned comparator 104*115 through 1llb and buffer amplifier 112a and 112b, is compared with analog video signal AV, and becomes two Pulse-Density-Modulation signals M and N. These two signals M and N are inputted into switch 118, and, in the case of the character manuscript, in the case of the photograph manuscript, it has switched to M by selector circuit 118 with control signal 123 from CPU20 at N. This change is performed by depending on operation of CPU20. Operation of this CPU20 is explained using Drawing 2 [ one to ]. The state of mode setting switch 26 is taken in first (#1), and it is distinguished whether photograph mode is set up or character mode is set up ($3). Photograph mode is the mode equivalent to the reproducibility of the intermediate color shown in Drawing 6 b mentioned below, and character mode is the mode equivalent to the reproducibility shown in Drawing 6 a mentioned below here. # When photograph mode is set up by 3, switch #5 and switch 118 which spread switch 25 on the b side to the Nantes gate 117 side (#7). # When character mode is set up by 3, switch #9 and switch 118 which spread switch 25 on the a side to the Nantes gate 116 side (#11). It depends on this and can perform color correction by changing Sumi ON Operation CR operation and a masking coefficient according to the tone reproduction of printer 17. The characteristic required of this color picture reading means here is that a picture output when the same color copy is read becomes the same. An example of the masking coefficient which is a compensation means for that below is explained. First, 14 color correction circuitY88 which is made to read the standard color copy in which the chromaticity coordinate has become clear by optical system unit 7 shown in Drawing 4, and is shown in Drawing 1. M, C, In this example, the procedure of the following least-squares methods determines a masking coefficient so that Bk3 signal may become the above-mentioned desired value. It is Y' here. M' C' corresponds to Y in Drawing 1, M, and C1, respectively, and Yl is a desired value, respectively, i is a number of each point on the color picture which is used in deciding a masking coefficient, and in this example, 64 places are chosen so that it may mention below. The valuation function of yellow, magenta, and cyanogen is set with phiY, phiM, and phiC, respectively. Then, about yellow, it is phi Y=sigma (+atsC: auYi+auM: Yt) 2-(sigmay; y; sword =0- (sigmay;Mi)) = 0. Similarly, if it carries out also about magenta and cyanogen, it will become like a lower type. Here, it is [C] about an upper type. [A] = Since it will be set to A=C-'-D if expressed as [D], the coefficient of "11+a33 can be found. C-1 is an inverse matrix of C. Thus, new coefficient all~a Ah which performed the operation which calculates all~a33 by CPU20 and then was able to be found. a44 is inputted into color correction circuit 14. In this way, Y when a standard color copy is read, M, C, and Bk output are controllable to always bring close to a desired value. By the way, it is as follows when the standard color copy used when calculating the above-mentioned masking coefficient all~a33 is described. A full color image forming means is usually yellow. Color reproduction is performed using magenta and the three-primary-colors toner of cyanogen. The image signal from a color picture reading means is told to a color picture formation means on the gradation level (for example, 256 gradation) defined beforehand. In a color picture formation means to use at this time, the three primary colors will be [ of 256 gradation ] reproducible, respectively, and the number of the colors obtained by monochrome and mixed colors of two or more colors will beX[ 256 ] 256X256 kinds. although a masking coefficient will be ideally defined in quest of the reproducibility about each of these colors -- this -- an operation -- very much -- Frequent -- it becomes coarse. Therefore, it is good to use the standard color copy by a standard character generator which it chose as it in these colors as the range of reappearance of a highlight part important when forming a color picture, each monochrome concentration reappearance, and color reproduction became the maximum as a color of a standard color copy. As an example of a standard color copy, it is at this example among [ 0.32.128.256 (0 being white here) ] the gradation levels of yellow. 256 prepares four levels of being a solid color which thought the reappearance by the side of a highlight as important like, The level of magenta and cyanogen as well as this prepares four levels, each color of four every levels and these are combined, and it is 64. The masking coefficient was decided by using as a standard color copy the pattern which has (=4X4X4) a color. As compared with Drawing 6, Pulse Density Modulation of each and the digital color picture signal of standard signal a1 standard Signal of a PWM means is carried out, and color reproduction nature when image formation is performed is shown. In Drawing 6, since color reproduction is expressed, it is used (L*!). It expresses with a* b* coordinates in a*l b* expression, and is the figure looked down on from L* axis. In this figure, it is in the tendency which image concentration and chroma saturation go up, so that it separates from the starting point. The chromaticity coordinate of the intermediate color which outputted the field (A) enclosed with in a straight line in the color reproduction range of the color picture formation means, and outputted O seal by standard signal a, and X seal are the chromaticity coordinates of the intermediate color outputted by standard Signal. Re from Drawing 6, or To -- when a picture is outputted using standard signal a, the chroma saturation of an intermediate color picture is [ like ] lower than the case where b is used. Chroma saturation (Aya and umbrella) is so low among a figure here that the distance from the starting point is short. That is, if b is used, rather than a, chroma saturation reappearance of intermediate color will be good, and Aya and kana color reproduction will be made. On the other hand, in a, it turns out that emphasis is put on the high concentration side for a color reproduction range by Drawing 3 and Drawing 6 rather than b. This is suitable for reappearance of a character etc., as stated previously. Therefore, it is good to think a highlight as important about b and to choose about a what has high concentration from b as an evaluation color used when determining the masking coefficient of a color correction means. The standard color copy (B) outputted by b is read, an image signal is built using the masking coefficient (b) calculated about the picture outputted using standard Signal, and the degree of color of the color reproduced by the color picture formation means by standard Signal is shown in Drawing 7 (1) by delta seal. The standard color copy (A) outputted by standard signal a is read using the above-mentioned masking coefficient (b), and the degree of color of the color reproduced with standard signal a is shown in Drawing 7 (2) by a mark. X seal in Drawing 7 (1) and O seal in Drawing 7 (2) are in agreement with X seal and O seal in Drawing 6, respectively. Drawing 7 (1) If standard Signal is used by an image forming means, almost equivalent reappearance is more possible to a total color than (2), but if standard signal a is used, the color reproduction of a highlight part is not good. What reproduced the standard color copy (A) for what reproduced the standard color copy (B) by standard Signal using the masking coefficient (a) to standard signal a similarly by standard signal a using Drawing 7 (3) and also the above-mentioned masking coefficient (a) is shown in Drawing 7 (4). Drawing 7 (3). By (4), if standard Signal is used to a masking coefficient (a), reappearance (there is nothing.) of a highlight part, This is a color of the highlight part which is hard to reproduce by a in Drawing 3. On the other hand, if standard signal a is used, good color reproduction can be obtained. As stated above, if the color picture signal and standard signal a which were changed with the above-mentioned masking coefficient (a) perform image formation and image formation is performed by the color picture signal and standard Signal which were changed with the above-mentioned masking coefficient (b), always good image quality will be obtained. Next, the effect of changing image signal generation circuit 13 according to tone reproduction using Drawing 8 like this example is explained. Drawing 8 is a* as [ it is a figure showing the difference in the color reproduction nature by standard signals a and b, and ] shown in Drawing 6. What expressed with the coordinates of chroma saturation and brightness (L*) the figure shown on b* surface is shown. O seal is standard signal a in Drawing 8, and they are yellow and magenta. Each monochrome of cyanogen or the coordinates of the intermediate color which carried out the mixed-colors output, and X seal are coordinates of the intermediate color outputted by standard Signal. When it outputs by standard Signal so that clearly from Drawing 8, there are many Ri and the reappearance colors of a bright color which the brightness of a highlight part subtracts from the case of a. That is, it can be said that there are many colors (it also includes no painting) which the direction which used standard Signal can reproduce using each monochrome of yellow, magenta, and cyanogen or mixed colors in 71 illite parts in the direction of brightness. Conversely, when standard signal a is used, a high concentration part has more colors obtained by monochrome or mixed colors than b. therefore, charge several [ which determines the quantity of UCR and the Sumi ON Re ] -- kl+ k2 + k31 k4 was mentioned above -- as it asks using the picture outputted by standard signal a (it is kn (a) about this) -- + (n"t+ 2+ a+ 4) it carries out -- kn If a picture is outputted by standard Signal using (a), it will become a picture dark to the whole. Even if this does not use Bk signal since the direction of standard Signal has many reappearance colors of the direction of a brightness axis in a highlight part as shown in Drawing 8, it is because UCR and the Sumi ON Re are performed also to the color in which color reproduction is possible. On the contrary, coefficient kn of UCR and the Sumi ON Re for which it asked about standard Signal If a picture is outputted by standard signal a using (b), there are few Bk signals and it cannot reproduce sufficient black. As stated above, it is coefficient kn of UCR and the Sumi ON Re. Using (a), if a picture is outputted by standard signal a, high brightness can also be reproduced, and it is kn. If a picture is outputted by standard Signal using (b), Aya and kana color reproduction of a highlight part will become possible. As mentioned above, in the case of a character manuscript, it is mainly coefficient kn of the above-mentioned masking coefficient (a), UCR, and the Sumi ON Re. It changes by (a), The color picture signal and standard signal a which were generated perform image formation, and, in the case of a photograph manuscript, it is mainly, The coefficient of the above-mentioned masking coefficient (b), UCR, and the Sumi ON Re, and kn If image formation is performed using the color picture signal and standard Signal which were changed and generated by (b), image quality always faithful to a manuscript will be obtained. kn of a more than (a) and kn In (b), selection of n is performed arbitrarily and any of UCR, the Sumi ON Re or OCR, and the Sumi ON Re may be sufficient as it. The selection of the combination of the masking coefficient and UCR coefficient which were described above, the Sumi ON Coefficient, or a standard signal should just switch character mode and photograph mode, for example by a final controlling element. Or a manuscript is automatically recognized by a color picture reading means, a standard signal is switched, and it can make it possible to switch a masking coefficient and the coefficient of UCR and the Sumi ON Re in connection with it. [Other Example(s)] Although this example explained the color image forming device which used Pulse Density Modulation, other examples are shown below. If the number of lines is switched also in the color image forming device of the method which changes the amount of luminescence of laser and carries out gradation reappearance by dot area abnormal conditions, it is clear that the problem same about gradation reappearance, color reproduction, etc. occurs. If the present invention is applied to such a device, corresponding to the number change of lines of an image forming means, it will become reproducible [ faithful image quality ] by preparing the masking coefficient and/or the UCR coefficient, and the Sumi ON Coefficient of an image read means, respectively, and switching them. Also in the color image forming device by the density modulating method for forming a specific pixel by the fixed laser spot or an ink-jet, and choosing lighting of each pixel, for example, the Daisa pattern method known well conventionally, Since gradation reappearance, color reproduction, etc. will change if a Daisa pattern is changed, it depends on applying the present invention and corresponds to each Daisa pattern, It becomes reproducible [ faithful image quality ] by preparing the masking coefficient, the OCR coefficient, or the Sumi ON Coefficient of an image read means, respectively, and switching it. It is considered as image signal generation circuit 13 shown in Drawing 1 as a processing means to perform lower color processing of the color picture signal supplied in this example described above, lower color removal operation -- that is, although it is alike, and 3(Y++ M+r C1)man is subtracted from the signal of each color and + (Yl+Mr+C1) was used as the Sumi ON Operation, i.e., a Bk signal, the present invention may not necessarily need operation of these both, but may depend on one of operations. These operations may be performed electrically and it may be made to carry out optically. It has predetermined tone reproduction, Pulse Density Modulation is performed as a color-image-processing means to process a color picture according to the signal in which lower color processing was carried out by the processing means. Although the color thermal transfer printer and color ink-jet printer into which the color laser beam printer which performs image formation according to the acquired signal, and tone reproduction are changeable were used, It may be a device which only processes an image signal electrically, without necessarily performing image formation, and outputs the signal to an external printer. It is although the color laser beam printer, the color thermal transfer printer, and the color ink-jet printer were used for a color picture formation means by which image formation conditions are changed, in this example, The present invention should just be a means by which for example, not only this but a Daisa matrix can be changed, or latent image formation conditions and development conditions can be changed, and image formation conditions can be changed in short. It was referred to as CPU20 which switches switch circuit 25 shown in Drawing 1 according to switching the state of switch circuit 118 which shows a means to control the processing state of a lower color processing means according to the tone reproduction of a color-image-processing means in Drawing 2. [Effect of the Invention] If it depends on the present invention as explained above, a good color picture can be processed.

[Brief Description of the Drawings]

The block diagram in which Drawing 1 [ one to ] shows the composition of the device of one example of the present invention, the flow chart Drawing 2 [ one to ] explains operation of CPU20 to be, Drawings 3 are a block diagram in which Drawing 2 shows the circuit inside printer 17, and a figure showing the difference of the gradation reappearance characteristic of printer 17, The figure and Drawing (1) 7 ~ (4) in which the sectional view of the image reader with which Drawing 4 contains CCD6, and Drawing 5 show the enlarged drawing of the surface of CCD6, and Drawing 6 shows a part of chromaticity coordinate of a standard color copy are the degrees of color of a standard color copy, The figure and Drawing 8 showing the chromaticity coordinate after reproducing the image are a figure showing the relation between the brightness at the time of reproducing the image of a standard color copy, and chroma saturation. R from 6R, 6G, and 6 B...CCD, G B signal [ ... Black extraction, a UCR circuit, 14 / ... A color correction circuit, l5 / ... A color conversion circuit 16 / ... An interface part, 17 / ... Color printer. ] 11 ... An A/D conversion circuit, 12 ... A LOG conversion circuit, 13 ' -- a reef -- /-27 Oshigi * Dried and dense ' A 30 The 77th (?)