JP3356318B2 - Color matching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color matching apparatus for adjusting the amounts of ink of black, indigo, indigo, red, and yellow in an offset printing press in order to match a color with a sample proof print. About.

[0002]

2. Description of the Related Art Conventionally, the following method has been used as a means for matching a color with a proof print. In other words, the operator in charge of the printing press visually compares the proof print and the extracted print on a color stand that is integrated with the ink fountain key opening control device, and based on his experience and intuition,
In this method, the amount of ink adjustment for each color of red and yellow is determined and the opening of the ink fountain key is controlled. If the operator has high skill, this method is used to judge which color of black, indigo, indigo, red, and yellow should be adjusted and how much the proof print and print start color can be matched, and This is an effective means because it can be determined in a very short time how much the ink fountain key should be opened in order to match the ink amount. For a highly skilled operator, the speed and accuracy of that decision is something that a machine cannot substitute.
However, in reality, there are few operators with such a high level of skill, and at present the color matching work consumes considerable time and paper.

[0003] In order to solve such a problem, an apparatus has been developed which aims at making the color matching work skillless and short. A typical example is to put a control strip at the edge of the printed matter, measure the optical density or chromaticity of the part, and calculate the ink adjustment amount for each of black, indigo, red, red and yellow from the result. is there. This method is a very effective means of managing proof prints,
This is a widely used technology. However, in the case of printing with this machine, the printing paper of the size corresponding to the pattern to be printed is used first, so there is no margin for inserting the control strip, and the print results of the control strip and the pattern part do not match. Therefore, this method is not effective.

In printing, the optical density is usually used as a control index for the amount of ink. However, when a control strip is inserted into the edge of the printed matter to control the ink, black, indigo, red, and yellow are used. This is an effective method because the solid density of each color can be accurately grasped. However, in this case, it is nothing more than managing colors in the picture, but only managing printing stability.

[0005] In managing colors in a picture, there may be a problem with the optical density. Densitometers used in printing sites are for measuring solid densities of black, indigo, red, and yellow as described above, and often use narrow-band filters. When this densitometer is used, solid densities of black, indigo, red, and yellow can be measured accurately, but densitometers cannot identify combinations of colors that have different spectral reflectances between the bands of each filter. . In other words, colors that look completely different can be mistaken for the same color.

[0006] Expressing a color by the density of each of black, indigo, red, and yellow is easy to understand when adjusting the amount of ink, but it is difficult to express how different the density is and how different the color is. Since the correlation between the difference and the color difference is not known, it is inappropriate to express the color using the density of each of black, indigo, red, and yellow in terms of color management.

For the purpose of managing colors, chromaticity has recently been in the spotlight, and among them, the CIELAB color system is often used. This expresses a color by a combination of three values of L, a, and b. The combination of each value of L, a, and b indicates a color, and a color difference ΔE = [△ L
By using ^{2 + △ a 2 + △ b} 2 ] ^1/2, whether the color is away much is one that can be quantitatively grasped.

However, the L, a, and b values and the black, indigo,
The relationship between the red and yellow colors and the amount of ink is not known.
It was not known how to adjust the indigo, red, and yellow inks.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of such a technical background. By using chromaticity, the color of a pattern and the color of a proof print as a sample can be obtained. The difference can be grasped quantitatively.
Since the relationship between the ink amounts of indigo, red, and yellow colors is known, the necessary ink adjustment amount can be calculated, and the color matching work of proof printing and printing start, which is a sample when printing this machine, is not a skill. An object of the present invention is to provide a new color matching device provided with means for instructing ink adjustment amounts of black, indigo, red, and yellow so that an operator who is not expensive can easily and in a short time.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an offset printing press, in which colors of black, indigo, indigo, red, and yellow are adjusted to match a color with a sample proof print. a color matching apparatus comprising means for instructing an ink amount of adjustment, means for instructing the ink adjusting weight is color matching apparatus characterized by comprising means of the following (a) to (f) . (A) a means for measuring the spectral reflectance of an arbitrary pattern at which a sample and a printed color are desired to be matched (b) a means for calculating chromaticity from the obtained spectral reflectance (c) a measured position is: Means that can be accurately read using the relative position based on the two register marks provided at the four corners. (D) The position measured from the difference in chromaticity between the sample and the print.
Display the previous SL register mark in the corresponding black, cyan, red and yellow colors means for determining an ink amount of adjustment required (e) the same monitor screen, the display the measured position of the sample, current spectrophotometric means for displaying the position of the total in the crosshairs (f) means for displaying the ink adjustment amount required

[0011]

According to the color matching apparatus of the present invention, in the color matching work between the proof printing and the printing start at the time of printing on the machine, the means for designating the ink adjustment amount for each color has the following configuration: (a) ) A means for measuring the spectral reflectance of a portion of an arbitrary pattern for which the sample and the printed color are desired to be matched is provided. (B) A means for calculating chromaticity from the obtained spectral reflectance is provided. (C) The measured position is a means that can be accurately read using the relative position based on the two register marks provided at the four corners. (D) The position measured from the difference in chromaticity between the sample and the printing start
Table Table shows the measured position of the swatch before Symbol register mark to the corresponding to black, cyan, red and yellow colors means for determining an ink amount of adjustment required is provided (e) the same monitor screen on the shown, because that is the fact that means for displaying the (f) the ink amount of adjustment necessary means for displaying the current position of the spectrometer in the crosshairs are provided is provided, the chromaticity By using it, it is possible to quantitatively grasp the color difference between the color in the pattern and the proof print as a sample, and grasp the relationship between the combination of chromaticity and the ink amount of each color of black, indigo, red, yellow. Since the required amount of ink adjustment can be calculated, in the color matching work between the proof print and the print starter, which is a sample when printing this machine, Since you can specify the ink adjustment amount for each color of red and yellow, Easy in a short time it is possible to perform the color matching in the not too high operator performance, decrease of improvement and printing paper loss of skill-less-efficiency can be expected.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a color matching apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram corresponding to the claims of the present invention. A means 100 for measuring the spectral reflectance of an arbitrary portion of a printed book, a measuring position reading means 200, and a measuring point / required ink adjustment amount are displayed via a computer having a CPU 600 and a memory 500 and an input / output interface 400. Means 300 are provided. CPU 60
In 0, there is provided a means for obtaining the necessary ink adjustment amounts for each of the black, indigo, red, and yellow colors from the chromaticity difference between the sample and the printing start.

FIG. 2 shows a color matching device according to this embodiment.
FIG. 3 is a perspective view showing a state in which the printer is used in addition to a light booth provided with an ink fountain key opening control button attached to the printing press. In the figure, reference numeral 1 denotes a high-speed spectrophotometer for measuring the spectral reflectance of a printed matter. The measurement is performed by aligning the center of the window 25 with the measurement point, leaning the upper part and pressing the measurement button 23. A coil is provided inside the window 25 so that the coordinates of the measurement point can be determined in combination with the digitizer board 19. The spectral reflectance measured by the high-speed spectrophotometer 1 is internally converted into chromaticity and sent to the main body 7 by the cable 3.

In the drawing, reference numeral 17 denotes a control box integrated with the digitizer board 19. The control box 17 is provided with buttons and the like for selecting a work mode. The coordinates of the measurement points measured by the digitizer board 19 and the work mode specified by the control box are sent to the main body 7 via the cable 21.

In the figure, reference numeral 5 denotes a monitor for displaying a measurement position and an index of an ink adjustment amount.

In addition, reference numeral 9 in the drawing denotes a color stand with an ink fountain key opening control button attached to the printing press.
Reference numeral 1 denotes an ink fountain key opening control button, and reference numeral 13 denotes an ate for placing a printing book 15.

This apparatus comprises a high-speed spectrophotometer 1, a digitizer board 19 with a control box 17, a main body 7, a monitor 5, a cable 3 connecting the high-speed spectrophotometer 1 to the main body 7, a control box 17 and the main body 7, And a cable 21 that connects
Light stand 9 with a standard light source of 5000 K attached to the printing press
It is desirable to install as shown in this figure.

FIG. 3 shows a high-speed spectrophotometer for measuring the spectral reflectance of a printed matter of the color matching apparatus according to the embodiment of the present invention, as viewed from directly above and from below. I have. In the figure, 23 is a measurement button, and 25 is a measurement window. The window 25 has a coiled part 33 and a gauge 31
It is composed of The gauge 31 is transparent and has cross lines so that it can be accurately aligned with the measurement points. By using this line, the coordinates of the register of the printed matter can be measured very accurately.

FIG. 4 is a perspective view of a high-speed spectrophotometer for measuring the spectral reflectance of a printed matter of the color matching apparatus according to the embodiment of the present invention. The window 25 is aligned with the measurement point, the upper part 37 is pressed, and the measurement part 35 is brought into close contact with the printed matter,
By pressing the measurement button 23, the spectral reflectance is measured. The measured spectral reflectance is converted to chromaticity by a program inside the upper part 37. Also, the measurement button 23
When is pressed, the coordinates of the measurement points are measured by the digitizer board 19 described above.

FIG. 5 is a schematic view of a printed matter to be used when using the color matching apparatus according to the embodiment of the present invention. Reference numeral 41 in the figure denotes a register mark (register mark). Most printed materials have register marks at four corners as shown in FIG. Some prints have register marks at other positions, but when using the color matching device of the present invention, register marks at the four corners shown in FIG. Good to use).

FIG. 6 is a view of a control box integrated with a digitizer board as viewed from directly above, which constitutes a color matching apparatus according to an embodiment of the present invention. 1 in the figure
9 is a part of the digitizer board, and 17 is a control box. As shown in the figure, the control box 17 includes buttons 51, 5 for selecting a work mode.
3, 55 and buttons for selecting a work mode, a mode release button 57 for releasing each mode, and a power button 59 are provided.

FIG. 7 is a schematic diagram showing an operation state of the color matching apparatus according to the embodiment of the present invention. In the figure, reference numeral 7 denotes a main body of the color matching apparatus of the present invention, and reference numeral 5 denotes a monitor for displaying measurement points, ink amount adjustment indexes, and the like. In this figure, of the register marks at the four corners of the printed matter, the leftmost two
FIG.

When the measurement button 23 of the high-speed spectrophotometer 1 is pressed, the coordinates of the measurement point are measured, and
A register mark (register mark) 61 and a measurement point 65 are displayed. In the drawing, reference numeral 63 denotes a crosshair indicating the current position of the high-speed spectrophotometer 1, and the intersection of the cross indicates the coordinates of the high-speed spectrophotometer 1. When measuring the printing start, by moving the high-speed spectrophotometer 1 so that the intersection of the crosshairs 63 is located at the center of the measurement point 65, the spectral reflectance at the point to be compared can be accurately measured.

In the figure, reference numeral 67 denotes an ink amount adjustment index, which indicates the required ink adjustment amounts of black, indigo, red, and yellow for each measurement point 65 in a bar graph. This bar graph is one each for black, indigo, red and yellow, and there are a total of four for each measurement point 65. On the monitor, black is white, indigo is blue, red is pink, Yellow is color-coded with yellow. Also, in this bar graph, the one that extends upward indicates that ink is added, and the one that extends downward indicates that ink is to be reduced.
The operator may operate the ink fountain key opening control button in the direction of the graph.

Next, a color matching apparatus according to an embodiment of the present invention will be described according to an actual operation procedure.

In FIG. 2, the operator first takes in information of a sample printed matter. In most cases, the sample printed matter is often a proof print. The operator sends a sample proof to the digitizer board 19
Put on. At this time, make sure that the proof print does not move.
It is better to put on. In order to capture this proof,
The sample capture button 51 of the control box 17 is pressed. Then, the color matching apparatus enters a sample capturing mode. First, any two of the register marks at the four corners of the proof print are selected as a reference for the coordinates of the measurement points, and measured with the high-speed spectrophotometer 1. In the present color matching device, the first two measurements are set to register target registration.
, Only the absolute coordinates of the measured point are registered, and the chromaticity value is not stored.

Next, the spectral reflectance at the point to be measured is measured. The number of measurement points is arbitrary.
Measurement results up to about 200 points can be stored. At the time of measurement, the point to be measured is aligned with the center of the window 25 of the high-speed spectrophotometer 1 for measurement. Then, the calculated chromaticity value and the relative coordinates based on the two previously registered register marks are stored in the main body 7. When the measurement of all the points to be measured is completed, the mode release button 57 of the control box 17 is pressed. This completes the sample capturing operation.

Next, a comparison with a printed book will be made. The operator extracts the print from the printing press and places it on the digitizer board 19 as shown in FIG. At this time, it is preferable to place the print book against the ate 13 so that the print book is stable. At this time, note that the top and bottom directions of the printed book are the same as the directions when the proof print was measured.

First, the comparison button 53 of the control box 17 is pressed to enter the comparison mode. Then, as in the case of proof printing, the absolute coordinates of the reference register
It is measured by the high-speed spectrophotometer 1 and the digitizer board 19. At this time, the register mark to be selected must be the same as that at the time of proof printing measurement.

When the measurement of the register mark (register mark) is completed, the screen is displayed as shown in FIG. Here, an example is shown based on the two leftmost register marks (register marks) of the printed matter. On the screen of the monitor 5, two register marks (register marks) 61 are white lines, and measurement points 65 at the time of proof printing measurement are white circles.
A crosshair 63 indicating the current position of the high-speed spectrophotometer 1 is displayed as a white wavy line. The operator may measure each point so that the crosshair 63 indicating the position of the high-speed spectrophotometer 1 is located at the center of the measurement point 65 while viewing this screen.

In the color matching apparatus main body 7, the measurement result of the proof print is already stored in the combination of the measurement position and the chromaticity by the above-mentioned operation. Here, when a certain measurement point in the print is measured, the chromaticity data at the corresponding position of the proof print is called from the coordinates of the point. By comparing the data with the printing data, the adjustment amounts of the black, indigo, red, and yellow inks are calculated. At the same time, an instruction is given to change the color of the white circle at the measurement point 65 to green when the chromaticity difference between the sample proof print and the print start is within the allowable range, to red when the chromaticity difference is outside the allowable range. Get out. The measurement point is a white circle before the measurement, but the color changes to green or red when the measurement is performed, so that the measured point and the unmeasured point can be easily distinguished.

The allowable chromaticity difference is specified in advance using the control box 17. First, the reference color difference button 55 of the control box 17 is pressed. Then, a reference color difference setting mode is set. The ten-key 71 is used to enter an allowable chromaticity difference. Thereby, the allowable chromaticity difference is stored in the main body 7. When the input is completed, the mode release button 57 is pressed.

When the measurement points are measured, the measurement points 65 on the screen of the monitor 5 change to green or red circles as described above. At the same time, a graph serving as an index of ink amount adjustment is displayed at the bottom of the screen. This graph is also displayed when the chromaticity difference between the proof print and the print start is within an allowable range. This graph has one each of black, indigo, red, and yellow as described above, and is displayed as a set of four for one measurement point 65. On the monitor, black is white,
Indigo is blue, red is pink, and yellow is yellow. Also, the bar graph that extends above is
The operator can operate the ink fountain key opening control button in the direction shown in the graph because the ink is to be added and the one extending downward is to reduce the ink.

When it is desired to measure at points other than the measurement point designated at the time of the first sample taking, the same operation is repeated from the sample taking. In order to avoid such troubles, it is important to determine the color matching point when importing samples.

Thus, for all measurement points,
By performing the same operation, even a low-skilled operator can perform the color matching operation in a short time without losing the required ink and the amount of adjustment.

In the color matching device according to the embodiment of the present invention,
A method of calculating the ink adjustment amounts of the black, indigo, red, and yellow colors from the chromaticity difference between the sample and the printing start will be described. In the main body 7, when the solid density of each of black, indigo, red and yellow is printed at the factory standard density, the combination of the net% of each of black, indigo, red and yellow and the black, indigo, red and yellow A table showing the relationship between the combination of each density and the chromaticity, the relational expression between the shade% and the density for each color of black, indigo, red and yellow, and the ink amount and solid density for each color of black, indigo, red and yellow The relational expression with is incorporated.

In preparing a table showing the relationship between the combination of the dot percentages of the ink, indigo, red and yellow colors and the combination of the density of the black, indigo, red and yellow colors and the chromaticity, first, the ink, indigo, red and yellow colors Twenty-one levels of flat screen from 0% to 100% were created in 5% increments for each color, and these were multiplied to create a chart in which all combinations of 194481 colors were printed by the printing press. At this time, the solid density is adjusted to the reference density at the time of normal printing in the factory. Spectral reflectance measurement was performed for all of the 194481 colors, and the combination of halftone percentages of black, indigo, red, and yellow,
Create a table showing the relationship between the combination of indigo / red / yellow density and chromaticity. In this embodiment, the chromaticity is CI
Although the ELAB color system is used, this is an example and does not limit the scope of the present invention. This is shown in FIG.

Next, net% for each of the ink, indigo, indigo, red and yellow colors
In preparing the relational expression between the density and the density, based on the Murray-Davis equation, the density measurement results of all the colors of the above-mentioned 194481 color chart were applied, and the dot% and density of the type in which the Murray-Davis was corrected were applied. Was obtained. This example is shown in FIG.
Shown in

Regarding the relational expression between the ink amount and the solid density for each of black, indigo, red, and yellow, the relationship between the adjustment amount of the ink fountain key opening control button and the solid density to be printed is determined by printing. In the present embodiment, a relational expression unique to the printing press actually used was obtained by an experiment, since the relationship differs depending on the manufacturer and type of the printing press. This method is an example and does not limit the scope of the invention. If the relationship between the adjustment amount of the ink fountain key opening control button and the solid density to be printed can be obtained for each printing machine manufacturer and type of printing machine, it can be applied to any printing machine. deep red·
A relational expression between the amount of ink and the solid density for each yellow color could be created.

FIG. 10 is a flowchart for explaining a method of calculating the ink adjustment amounts of black, indigo, indigo, red, and yellow from the chromaticity difference between the sample and the start of printing by the color matching apparatus according to the embodiment of the present invention. . In this embodiment, the chromaticity is CIELA.
Although the B color system is used, this is an example and does not limit the scope of the present invention.

A description will be given with reference to FIG. First, a spectral reflectance measurement at a measurement point of a proof print serving as a sample is performed.
The spectral reflectance is converted into L, a, b values in the high-speed spectrophotometer 1. The obtained combinations of L, a, and b values are the combination of the dot percentages of the black, indigo, red, and yellow colors and the combination of the black, indigo, red, and yellow densities and the chromaticity built in the color matching device main body 7. (L, a, b values) are converted into a combination of halftone% of each of black, indigo, indigo, red, and yellow using a table representing the relationship with (L, a, b values). The combination of the dot% and the combination of the densities are converted into the dot% for each of the ink, indigo, indigo, red, and yellow colors in the color matching device body 7.
By substituting into the relational expression between
The solid density of each yellow color is calculated.

Next, the spectral reflectance of the printing start to be compared is measured. The spectral reflectance is L, a, b in the high-speed spectrophotometer 1.
Converted to a value. The obtained combinations of L, a, and b values are obtained by combining the combinations of the dot percentages of the black, indigo, red, and yellow colors and the combinations of the black, indigo, red, and yellow densities and the chromaticity, which are built in the color matching device body 7 (L, a, b values) are converted into a combination of densities of black, indigo, indigo, red, and yellow using a table representing the relationship with (L, a, b values). The combination of this density and the proof print
By substituting the combination of the dot percentages of indigo, red, and yellow into the relational expression between the dot percentages and the densities for the black, indigo, red, and yellow colors in the color matching device body 7 described above,・ The solid density of each color of indigo, red and yellow is calculated.

The solid density of each color of ink, indigo, indigo, red, and yellow is compared with that of the proof printing, and the difference between the solid density of each color of black, indigo, red, and yellow is calculated. The difference between the calculated solid density and the solid density of the proof print are substituted into a relational expression between the ink amount and the solid density for each of black, indigo, red, and yellow in the color matching device main body 7. In this way, a difference in ink amount for each of black, indigo, indigo, red, and yellow, that is, a necessary adjustment ink amount can be obtained.

[0045]

According to the color matching apparatus of the present invention, in the color matching work between the proof print and the printing start serving as a sample at the time of printing on this machine, the black and white portions of the arbitrary place on the printing paper surface where color matching is desired. The required amount of ink adjustment for each color of indigo, red and yellow can be specified, so even an inexperienced operator can easily perform color matching in a short time, making skills less, improving efficiency, and printing loss. We can expect reduction of paper.

Further, according to the color matching apparatus of the present invention, the means for designating the adjustment amount for each ink can be a means for measuring the spectral reflectance of an arbitrary portion where the color of the sample and the print are desired to be matched. Means for calculating the chromaticity from the measured spectral reflectance, means for accurately reading the measured position, means for calculating the necessary ink adjustment amounts for each of black, indigo, red, and yellow from the chromaticity difference between the sample and the print, And because there is a means to display the measurement points and the required ink adjustment amount, by using the chromaticity, it is possible to quantitatively grasp the color difference between the color in the picture and the sample proof print, In addition, since we know the relationship between the combination of chromaticity and the ink amount of each of black, indigo, red, yellow,
The required amount of ink adjustment can be calculated, and in the color matching work between the proof print and the print starter, which is a sample when printing this machine, the ink, indigo, red, red,
Since the yellow ink adjustment amount can be instructed, even a skillless operator can easily perform color matching in a short period of time, making skills less and improving efficiency.
We can expect reduction of printing waste paper.

[0047]

[Brief description of the drawings]

FIG. 1 is a configuration diagram corresponding to the claims of the present invention.

FIG. 2 is a perspective view showing that the color matching device according to one embodiment of the present invention is used by being added to a light booth provided with an ink fountain key opening control button attached to the printing press. .

3A and 3B are a top view and a bottom view of a high-speed spectrophotometer for measuring a spectral reflectance of a printed matter of the color matching apparatus according to the embodiment of the present invention.

FIG. 4 is a perspective view of a high-speed spectrophotometer for measuring a spectral reflectance of a printed matter in the color matching apparatus according to the embodiment of the present invention.

FIG. 5 is a schematic view of a printed material to be used when the color matching device according to the embodiment of the present invention is used.

FIG. 6 is a view of the control box integrated with the digitizer board, which is included in the color matching device according to the embodiment of the present invention, as viewed from directly above.

FIG. 7 is a schematic diagram showing an operation state of the color matching device according to the embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating a color matching device according to an embodiment of the present invention.
It is a table showing the relationship between the combination of the shade% of each color of indigo, red, and yellow, and the combination of each density of black, indigo, red, and yellow and the chromaticity.

FIG. 9 is a graph showing a part of a relational expression between halftone% and density of a type in which the Murray-Davis equation is corrected in the color matching apparatus according to the embodiment of the present invention.

FIG. 10 is a flowchart illustrating a method of calculating necessary ink adjustment amounts for each of black, indigo, red, and yellow from a chromaticity difference between a sample and a printing start in the color matching apparatus according to the embodiment of the present invention.

[Explanation of symbols]

1. High-speed spectrophotometer 3. Cable 5. Monitor 7.
... Main body 9 ... Light booth 11 ... Ink fountain key opening control button 13 ... Ate 15 ... Printing book 17 ... Control box 19 ... Digitizer board 21 ... Cable 23 ... Measurement button 25 ... Window 31 ... Gauge
33 ... the part containing the coil 35 ... measuring part 37 ...
Upper part 41: Register mark (register mark) 51 ... Mode selection button (sample capture button) 53 ... Mode selection button (comparison button) 55 ... Mode selection button (reference color difference button) 57 ... Mode release button 59 ... Power button 61 ... Register Marker (register mark) 63 ... crosshair 65 ... measurement point 67 ... ink amount adjustment index 7
DESCRIPTION OF SYMBOLS 1 ... Numeric keypad 100 ... Means for measuring the spectral reflectance of an arbitrary part of a printed material 200 ... Measurement position reading means 300 ...
Means for displaying measurement points and required ink adjustment amounts 40
0: input / output interface 500: memory 600
... CPU

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-146633 (JP, A) JP-A-63-191041 (JP, A) JP-A-4-303660 (JP, A) JP-A-3-3 218836 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41F 31/02 B41F 33/14 G01J 3/46 G01N 21/27

Claims (1)

(57) [Claims] 1. A color matching apparatus comprising means for designating ink adjustment amounts of black, indigo, indigo, red and yellow in order to match a color with a proof print as a sample in an offset printing press. Means for instructing the ink adjustment amount is as follows:
A color matching device comprising: means ( f ) to ( f ). (A) a means for measuring the spectral reflectance of an arbitrary pattern at which a sample and a printed color are desired to be matched (b) a means for calculating chromaticity from the obtained spectral reflectance (c) a measured position is: Means that can be accurately read using the relative position based on the two register marks provided at the four corners. (D) The position measured from the difference in chromaticity between the sample and the print.
Display the previous SL register mark in the corresponding black, cyan, red and yellow colors means for determining an ink amount of adjustment required (e) the same monitor screen, the display the measured position of the sample, current spectrophotometric means for displaying the position of the total in the crosshairs (f) means for displaying the ink adjustment amount required