JP5535525B2 - Colorimetric value conversion method and device for traveling printed matter, print control method and device, and print state determination method and device - Google Patents

Description

  The present invention is suitable for use in ink supply control, dampening water supply, quality inspection, and the like of a printing press, and a colorimetric value conversion method and apparatus for a printed material that travels, and various types of printing presses using such a method. The present invention relates to a control method and apparatus, and a printing state determination method and apparatus.

Conventionally, in a printing machine that performs printing by transferring ink, an operator visually checks the printing result and confirms printing, and manually performs quality inspection, ink supply control based on this, and dampening water supply control. It was done in.
In recent years, a sensor has been installed on a printing press, and the color of the printing result is measured by this sensor. Based on the color measurement result, quality inspection, control of the ink supply based on this, and dampening water Technology for automatically controlling supply control has been developed and put into practical use.

For example, in Patent Document 1, a printed material is extracted, the color of the printed material is read off-line photoelectrically, spectrally dispersed by a spectrometer, converted from a spectral spectral value to a colorimetric value of a color coordinate system, and the converted measurement is performed. A technique is described in which a color difference vector ΔEn is calculated from color values and the ink supply amount is controlled based on the color difference.
Further, in Patent Documents 2 and 3, the spectral reflectance of a desired pattern area of the printed material being run is measured, and the Lab chromaticity and the spectral density D (λ) are calculated from the measured spectral reflectance. When each value is compared with the standard Lab chromaticity and spectral density D (λ), a difference is obtained, and whether or not the printing color tone is good is determined based on whether or not the difference is within an allowable range. Describes a technique for adjusting the ink supply amount.

Furthermore, Patent Document 4 obtains the actual halftone dot area ratio of each ink color from the colorimetric values measured by the densitometer, determines whether or not the actual halftone dot area ratio exceeds a threshold, and determines the actual halftone dot area. A technique is described in which if there is an ink color whose rate exceeds a threshold, it is determined that the ink color is smeared.
Patent Document 5 discloses a standard defined in advance as a technique related to a technique for estimating the spectral reflectance of a commercial print according to multispectral information obtained by multispectral measurement of the commercial print and measuring its color tone. After separating the black color from the printed color of the printed material and specifying the area occupied by each color except for the black color, the black transfer function defining the relationship between the multispectral information about the black color and the spectral reflectance is obtained. Multi-spectrum obtained by multi-spectral measurement of commercial prints based on the black transfer function and each color transfer function by obtaining each color transfer function that defines the relationship between multi-spectral information and spectral reflectance for each color according to the area occupied Techniques for estimating spectral reflectance from spectral information are described, and the number of channels for multispectral measurement is reduced, resulting in commercial accuracy. Estimating the spectral reflectance of Surimono the effect that can measure the color tone.

  Furthermore, Patent Document 6 describes a technique for measuring a white substrate (white plate) and correcting (calibrating) a color measurement detection value obtained by a sensor based on a white value obtained thereby. Yes.

Japanese Patent Laid-Open No. Sho 62-146633 JP 2001-18364 A JP 2001-47605 A Japanese Patent No. 4022233 JP 2004-198146 A JP 2007-536128 A

  By the way, a sensor (online sensor) is provided directly on the printing line of the printing press, and during printing, based on the color information (colorimetric value) detected by this online sensor, print quality inspection and ink based on this When the supply amount control or the dampening water supply control is automatically performed, the on-line sensor has a high-speed printing speed for any part of the printed pattern [for example, about 15 (m / s for high-speed offset printing). ) Or more] is required to be detected at high speed.

On the other hand, in order to appropriately determine the color, color information based on an appropriate color reference, that is, absolute color information expressed by, for example, color coordinates is required. For example, to obtain absolute color information directly as spectral reflectance, it is necessary to install an absolute white plate for reference light.
For example, in Patent Documents 2 and 3 described above, the color coordinates L ^* a ^* b ^* and the spectral density D (λ) are calculated from the spectral reflectance. When using the spectral reflectance, an absolute white plate is installed. There is a need.

In this regard, as in Patent Document 6, if a technique for measuring the color of a white substrate (absolute white plate) to obtain an absolute white value and calibrating the detection value of the color measurement obtained by the sensor is used, Color information can be obtained directly.
However, in this case, it is difficult to secure a space for installing the absolute white plate on the printing press, and even if the installation space can be secured, the installed absolute white plate is soiled by ink mist. Since the possibility is high, the absolute white color cannot be maintained, and practical application is difficult.

In addition, when obtaining multi-channel spectral reflectance, the light quantity input to the sensor is reduced, resulting in insufficient exposure during high-speed printing. There is a problem of inviting.
In Patent Document 4, the actual halftone dot area ratio of each ink color is obtained from the colorimetric values measured by the densitometer. However, since it is not color information based on an appropriate color standard, The color information is not sufficient to determine the color according to the characteristics.

  In addition, color information needs to be color information based on an appropriate color standard, and more detailed color corresponding to the printing conditions can be obtained by detecting a color of a multi-channel wavelength with a larger amount of color information. It is advantageous because information can be taken. However, for example, if a spectrometer or the like that measures multi-channel wavelengths with a larger amount of color information is used as an on-line sensor, there will be a problem of underexposure during high-speed printing and a significant cost increase. Therefore, in order to cope with high-speed printing and suppress cost increase, it is necessary to use a spectrometer that measures the wavelength of a small number of channels, a color difference meter (for example, a sensor that directly measures the color coordinates XYZ), and the like. Become.

In this regard, in the case of the multispectral method of Patent Document 5, it is possible to estimate a true value spectrum with a small number of wavelengths and calculate the color coordinates L ^* a ^* b ^* from this estimated spectrum. Is necessary, and there is a problem of white plate installation.
In the case of an on-line sensor, since the color immediately after printing is measured, the effect of dry-down occurs. In other words, for the color immediately after printing, until the printed material reaches the consumer, color development called so-called dry-down occurs, so it is actually evaluated as a colorimetric value measured by an online sensor. There is a difference between the colorimetric values. As a means for avoiding this, there is a technique using a densitometer with a polarizing filter. In this case, the amount of light input to the sensor is reduced, so that at the time of high-speed printing, there is still a problem of underexposure, and accurate measurement is possible. It becomes difficult.

On the other hand, in the case of a sensor outside the printing press (off-line sensor), there is no restriction required for an online sensor, for example, an absolute color according to a standard such as ISO or CIE (International Lighting Commission). Information [for example, density filtered by a filter such as Status-T, E, I for a densitometer, CIE (International Lighting Commission) recommended L ^* a ^* b ^* , L ^* u ^* v ^* , for color coordinates, If it is spectral reflectance, it is possible to reliably obtain the spectral reflectance referring to the absolute white plate], and according to such color information, color determination can be easily performed. In addition, since the density value can be measured by inserting a polarization filter, the influence of dry-down can be avoided.

However, since it is not possible to measure colors in real time during printing, it is impossible to quickly feed back the results to ongoing printing while measuring colors in real time during printing.
For example, although the technique disclosed in Patent Document 1 can easily convert a spectral spectral value to a colorimetric value of a color coordinate system, it can be applied to an offline system but cannot be applied to an online system.

  As described above, a sensor suitable for an online sensor cannot obtain color information based on an appropriate color reference, and an offline sensor can obtain color information based on an appropriate color reference. As a method paying attention to each advantage, it can be considered that the color information of the online sensor is converted into the color information of the offline sensor based on an appropriate color standard. For example, there is a method of recording a conversion table corresponding to both color information in a database and using the conversion table, and a method of creating an arithmetic expression corresponding to the conversion characteristic and using the arithmetic expression. is there.

Regardless of which method is used to convert sensor color information to color information for color determination, etc., printing materials such as ink and printing paper, and printing conditions such as temperature and humidity during printing are generally used. If it changes, the conversion characteristics also change. Therefore, even if the printing material conditions and the printing conditions change, if a color is determined using the same conversion table or arithmetic expression, a determination error occurs.
Therefore, if the printing material condition or the printing condition changes, it is necessary to use a conversion table or an arithmetic expression that matches the changed printing material condition or the printing condition.

Therefore, it is necessary to prepare a unique conversion table and arithmetic expression corresponding to each printing material condition and each printing condition combination.
However, when preparing a set of printing material conditions and conversion tables and arithmetic expressions for printing conditions, a huge amount of data processing is required. Therefore, conversion tables and arithmetic expressions specific to each combination of printing material conditions and printing conditions are required. Preparing each of them requires a lot of labor and time and cannot be easily implemented.

  The present invention has been devised in view of such a problem, and is not color information based on an appropriate color reference like a sensor suitable for the above-described online sensor. The correspondence between the color information by the color sensor that satisfies the sensor requirement and the color information by the color sensor that does not satisfy the specific sensor requirement but can obtain color information based on an appropriate color standard Colorimetric value conversion method for printed materials that can be easily corrected in response to changes in conditions so that printed colors can be determined with high accuracy even when conditions change And an apparatus, a printing control method and apparatus, and a printing state determination method and apparatus.

In order to achieve the above-mentioned target, the colorimetric value conversion method for a printed product that travels according to the present invention is a first measurement that is an on-line sensor that is installed in a printing machine and measures each print color during printing under any printing condition. the color meter, with obtaining a first colorimetric value Shi measuring a print meter is colorimetric values of first color information traveling on the printing press, is off-line sensor for measuring the printed color in the off-press by the second colorimeter, a measuring step of obtaining a second colorimetric value types and a total measuring Shi said first color information specific locations are colorimetric values of the second color different from the information of the printed matter The first color information and the second color information when the same color is measured using the first colorimeter and the second colorimeter under the preset standard printing conditions. Correspondence relationship and the specific location of the printed matter by the measurement step Has been using a first colorimetric value and the second colorimetric value, the first colorimetric values obtained by measuring by the first colorimeter the printed material travels, the A conversion step for converting to the second colorimetric value when measured by the second colorimeter.

In the conversion step, it is preferable to obtain a correction amount when the first colorimetric value is converted to the second colorimetric value, and perform the conversion using the correspondence and the correction amount.
In the conversion step, the correction amount is obtained from the first color measurement value and the second color measurement value measured for the specific portion of the printed matter by the measurement step using the correspondence relationship. preferable.

Note that the colorimetric value refers to all values that define the color. Further, the first colorimetric value and the second colorimetric value define the kind of colorimetric value, and do not indicate specific values. That is, the first color measurement value and the second color measurement value are different types of color measurement values.
When the correction amount exceeds a predetermined range, the method further includes a step of correcting the correspondence relationship by the correction amount. When the correspondence relationship is corrected by the correspondence relationship correction step, the correction step corrects the correspondence relationship. It is preferable to use the correspondence relationship.

The correspondence relationship is a correspondence table in which the first color information measured by the first colorimeter and the second color information measured by the second colorimeter are associated with each other. ,
In the conversion step, the first color information corresponding to the first color information in the correspondence table for a region near one of the first colorimetric value and the second colorimetric value in the correspondence table. obtains the second of the second variation correspondence table and change in colorimetric value is made to correspond for the color information variation with in the correspondence table of the colorimetric values, of any of said change amount corresponding table It is preferable that the amount of change is the correction amount.

The neighborhood area is preferably an area within a certain color space distance range preset for the one value.
Alternatively, the neighborhood area is preferably an area within a predetermined number of values in order from the value closest to the color space distance with respect to the one value in the correspondence table.
The second colorimetric value is preferably a color coordinate value, for example, a color coordinate value (for example, L ^* a ^* b ^* or L ^* u ^* v ^* ) of the uniform perceptual color coordinate system.

The correspondence relationship is obtained by printing a plurality of colors covering the color reproduction range by the printing machine, and measuring each of the plurality of printing colors by the first colorimetric value. The first colorimetric value is measured by a second colorimeter that can measure the second colorimetric value and is obtained from the correspondence of the plurality of measurement values, and is used in the measurement step. And the first colorimeter used for obtaining the correspondence relationship are the same colorimeter and different colorimeters, but the same detection characteristic colorimeter and different colorimetry A colorimeter that is another detection characteristic but has a known correspondence between the two detection characteristics, and the correspondence between the second colorimeter used in the measurement step and the correspondence relationship. The second colorimeter used for acquisition is the same colorimeter or another colorimeter, but the same detection characteristics Colorimeter, it is preferred that a separate detection characteristic be another colorimeter is correspondence relationship is known colorimeter, either of the detection characteristics of both.

Before SL first colorimetric values are red (R), green (G), and blue three colors of RGB density values of (B), or red (R), green (G), and blue (B), red RGB density meter which is given by RGBI density values of four colors of outside (I), and the first colorimeter detects density values of three colors of red (R), green (G) and blue (B). Or an RGBI densitometer that detects density values of four colors of red (R), green (G), blue (B), and infrared (I).

The first colorimeter for detecting the first colorimetric value applied to the online sensor is not limited to the RGB densitometer and the RGBI densitometer, and other colorimeters such as a reflectometer and a reflected light meter can be applied. Is also possible.
As the second colorimeter for detecting the second colorimetric value applied to the off-line sensor, for example, a density value based on a white plate filtered by a filter such as Status-T, E, or I standardized by ISO As a second colorimetric value, and CIE (International Commission on Illumination) recommended color coordinate systems L ^* a ^* b ^* , L ^* u ^* v ^* , XYZ, etc. as second colorimetric values It is also possible to apply a sensor for detection, a spectrometer for detecting the spectral reflectance referring to the absolute white plate as the second colorimetric value, or the like.

Furthermore, the first color measurement value and the second color measurement value can be defined in a color space. For example, RGB density values of three colors of red (R), green (G), and blue (B). The color coordinates L ^* a ^* b ^* or L ^* u ^* v ^* of the uniform perceptual color coordinate system can be defined on a three-dimensional color space, and the smaller the dimension, the simpler the handling. On the other hand, for example, the density values of four colors of red (R), green (G), blue (B), and infrared (I) can be defined on a four-dimensional color space, and the spectral reflectance value R There is a colorimetric value (color information) that can be defined in a color space with more dimensions (n dimensions), such as (λ), and any dimension of the colorimetric value (color information) can be applied to the present invention.

The conversion step is performed at the time of normal printing for printing a normal printing pattern as a printed product, and the measurement step is to print the normal printing pattern similar to the conversion step to obtain the measurement value. preferable.
The measurement step is preferably performed when the printing conditions are changed.
The printing conditions are preferably printing material conditions including paper or ink used for printing, or printing patterns.

The printing control method of the present invention uses the colorimetric value conversion method described above to perform the conversion step while performing printing by the printing press, and converts the first colorimetric value to the second colorimetric value. A method of converting and controlling printing by the printing press, the comparing step of comparing the converted second colorimetric value with a preset target value of the second colorimetric value; If it is determined in the comparison step that the color difference between the converted second colorimetric value and the target value exceeds a preset allowable value, an adjustment signal for adjusting the ink supply amount in a direction in which the color difference decreases. And an adjustment step for outputting.

Another printing control method of the present invention uses the colorimetric value conversion method described above, and performs the conversion step while performing printing by the printing machine with the non-image portion related to printing as the specific portion, A method of controlling printing by the printing press by converting a first colorimetric value into the second colorimetric value, wherein the converted second colorimetric value is previously applied to the non-image portion. A comparison step for comparing with the set target value of the second colorimetric value, and an allowable value in which a color difference between the converted second colorimetric value and the target value is set in advance by the comparison step. If it is determined that the ink stain has been exceeded, it is determined that the ink stain has occurred, and an adjustment step for adjusting the amount of dampening water so as to reduce the ink stain is provided.

The printing state determination method of the present invention uses the colorimetric value conversion method described above to perform the conversion step while performing printing by the printing machine with the non-image line portion relating to printing as the specific location, of the colorimetric values in terms of the second colorimetric value, there is provided a method for determining the printing state by the printing press, set for in advance the non-image portion of said second colorimetric values the conversion A comparison step for comparing with the target value of the second colorimetric value, and a color difference between the converted second colorimetric value and the target value exceeds a preset allowable value by the comparison step. If it is determined that there is a print defect, a determination step for determining a print defect is provided.

The printing control apparatus of the present invention performs the conversion step while performing printing by the printing machine using the colorimetric value conversion method described above, and converts the first colorimetric value to the second colorimetric value. A conversion means for controlling printing by the printing press, the comparing means for comparing the converted second colorimetric value with a preset target value of the second colorimetric value; If the comparing means determines that the color difference between the converted second colorimetric value and the target value exceeds a preset allowable value, the ink supply amount is adjusted in a direction in which the difference between the colorimetric values decreases. And adjusting means for adjusting.

Another printing control apparatus of the present invention uses the colorimetric value conversion method described above, and performs the conversion step while performing printing by the printing machine with the non-image portion related to printing as the specific portion, A device for converting a first colorimetric value into the second colorimetric value and controlling printing by the printing press, wherein the converted second colorimetric value is previously applied to the non-image portion. Comparison means for comparing with the set target value of the second colorimetric value, and an allowable value in which the color difference between the converted second colorimetric value and the target value is set in advance by the comparison means. If it is determined that the ink stain has been exceeded, it is determined that the ink stain has occurred, and adjusting means for adjusting the amount of dampening water so as to reduce the ink stain is provided.

The printing state determination apparatus of the present invention uses the colorimetric value conversion method described above to perform the conversion step while performing printing by the printing machine with the non-image line portion relating to printing as the specific location, of the colorimetric values in terms of the second colorimetric value, an apparatus for determining a printing condition according to the predetermined printing press, the previously said non-image portion of the previously described conversion second colorimetric value Comparison means for comparing with the set target value of the second colorimetric value, and an allowable value in which the color difference between the converted second colorimetric value and the target value is set in advance by the comparison means. And determining means for determining a printing failure when it is determined that the number has exceeded.

The colorimetric value conversion device for a printed matter that travels according to the present invention is an on-line sensor that is installed in a printing press and measures each print color during printing, and measures the printed matter that runs on the printing press to measure first color information. A first colorimeter that obtains a first colorimetric value, and an off-line sensor that measures a print color outside the printing press, and measures a specific part of the printed matter to measure the first colorimetric value. A second colorimeter that obtains a second colorimetric value that is a colorimetric value of second color information that is different from the color information, and the first colorimeter and the second colorimeter under standard printing conditions. storage means for storing a correspondence between said when the same color was measured using a colorimeter first color information and said second color information, and the correspondence relationship stored in the storage means, any wherein the for the particular location of the printed matter was measured by the first colorimeter in the printing conditions Using said second colorimetric value measured by a colorimetric values and the second colorimeter, wherein the said printed matter for the traveling obtained by measurement by the first colorimeter Conversion means for converting one colorimetric value into the second colorimetric value when measured by the second colorimeter.

It is preferable that the conversion means obtains a correction amount when the first colorimetric value is converted to the second colorimetric value, and performs the conversion using the correspondence relationship and the correction amount.
In this case, the conversion means uses the correspondence relationship, the first colorimetric value measured for the specific portion of the printed matter by the first colorimeter and the second colorimeter, and the It is preferable to obtain the correction amount from the second colorimetric value.

The correspondence stored in the storage means corresponds to the first color information measured by the first colorimeter and the second color information measured by the second colorimeter. In the correspondence table, the conversion unit is configured to perform the first region in the correspondence table in the vicinity of either one of the first colorimetric value and the second colorimetric value in the correspondence table. seeking the first second of the second variation correspondence table and change in colorimetric value is made to correspond for the color information variation with in the correspondence table of colorimetric values for one of the color information, the It is preferable that any change in the change correspondence table be the correction amount.

The neighborhood area is preferably an area within a certain color space distance range preset for the one value.
Alternatively, the neighborhood area is preferably an area within a predetermined number of values in order from the value closest to the color space distance with respect to the one value in the correspondence table.
The second colorimetric value is preferably a color coordinate value, for example, a color coordinate value (L ^* a ^* b ^* or L ^* u ^* v ^* ) of a uniform perceptual color coordinate system.

  The correspondence relationship stored in the storage unit can print a plurality of colors covering a color reproduction range by the printing machine, and measure the first colorimetric values for each of the plurality of printing colors. The correspondence relationship is obtained from the correspondence between the plurality of measurement values by measuring with the first colorimeter and the second colorimeter capable of measuring the second colorimetric value. Thus, the first colorimeter used for calculating the correction amount by the conversion means and the first colorimeter used for obtaining the correspondence relationship are the same colorimeter and different colorimeters. However, it is either a colorimeter with the same detection characteristics, a colorimeter with different detection characteristics and different detection characteristics, but the correspondence between the detection characteristics of both is known, and the conversion The second colorimeter used for calculating the correction amount by means and the correspondence used for acquiring the correspondence relationship The two colorimeters are the same sensor, another sensor but the same detection characteristic sensor, another sensor and another detection characteristic, but the correspondence between the two detection characteristics is known, It is preferable that it is either.

The second colorimetric value is preferably a color coordinate value . The first colorimetric values are RGB density values of three colors of red (R), green (G), and blue (B), or red (R), green (G), blue (B), and infrared. An RGB densitometer that detects the density values of three colors of red (R), green (G), and blue (B). Alternatively, an RGBI densitometer that detects density values of four colors of red (R), green (G), blue (B), and infrared (I) is preferable.

According to the colorimetric value conversion method or apparatus for a printed matter that travels according to the present invention, the printed matter is measured by the first colorimeter using the existing correspondence between the first color information and the second color information. the second colorimetric a specific part of the first first colorimetric value and prints a colorimetric value of the color information is color measurement values of the second color information that was measured by the second colorimeter and a value, then, since the converted first colorimetric values obtained by measuring the printed matter to travel by the first calorimeter to a second colorimetric value, for example, a paper or ink used for printing In response to changes in various printing conditions, such as when the printing material conditions to be included are changed, the first colorimetric value obtained by the first colorimeter is changed to the second colorimetric under the changed printing conditions. It can be converted into a value appropriately and easily.

If the correction amount exceeds the predetermined range, the correspondence relationship is corrected by the correction amount, and then the conversion step is performed using the corrected correspondence relationship, the correction amount itself becomes small, and the colorimetry is performed. The conversion accuracy of the value can be improved.
Further, by obtaining a correction amount when converting the first colorimetric value to the second colorimetric value and performing conversion using the correspondence and the correction amount, the conversion can be performed appropriately and easily. it can.

Further, the correspondence relationship is a correspondence table in which the first color information measured by the first colorimeter and the second color information measured by the second colorimeter are associated with each other, and correction is made at the time of conversion. If to determine the amount, the region near the first colorimetric values and one of the values of the second color measurement values in the correspondence table, the first colorimetric values for the first color information in the corresponding table variation and determine the second variation correspondence table and change of the second colorimetric value to correspond with respect to the color information in the corresponding table, and one of the change in the variation correspondence table between the correction amount that Thus, the correction amount can be easily obtained.

The correspondence is printed by printing a plurality of colors covering the color reproduction range by a printing machine, and each of the plurality of printing colors is measured by a first colorimeter capable of measuring a first colorimetric value. When the second colorimeter that can measure the second colorimetric value is measured and obtained from the correspondence of the plurality of measurement values, the correspondence relationship with the first colorimeter used in the measurement step is obtained. Another colorimeter for the first colorimeter used in the measurement and / or the second colorimeter used in the measurement step and the second colorimeter used for obtaining the correspondence relationship However, if the colorimeters have the same detection characteristics, or are different colorimeters and have different detection characteristics, the correspondence between the two detection characteristics is known. Therefore, appropriate measurement can be performed without using the same colorimeter.

In particular, the first colorimeter an online sensor, a second colorimeter Ri offline sensor der, on-line sensors, colorimetric values based on appropriate color reference (color information) is obtained Although it is not, but the detection speed is fast and the equipment cost is low, the first colorimetric value is obtained by applying a colorimeter, and the offline sensor does not have a high detection speed but it is based on an appropriate color standard. By using a colorimeter that can obtain the value as the second colorimetric value, the first colorimetric value is obtained in real time and with high accuracy by an online sensor during printing, and this is obtained based on an appropriate color standard. In addition, color determination based on an appropriate color standard can be performed by converting the second colorimetric value into a color determination, and using the determination result for print control, print quality can be improved and printing cost can be reduced. Can be achieved.

For example, the second colorimetric value detected by a second colorimeter equipped as an off-line sensor is used as a color coordinate such as color coordinate L ^* a ^* b ^* or L ^* u ^* v ^* of the uniform perceptual color coordinate system. If given as a value, it is possible to perform color determination according to human vision, and it is possible to perform control of printing color tone and the like with higher accuracy.
This makes it possible to perform printing control for adjusting the ink supply amount, printing control for adjusting the amount of dampening water, and determination of defective printing in real time and with high accuracy during printing while properly determining the color. Can be done.

The RGB densitometer and the RGBI densitometer are suitable for the first color sensor as an on-line sensor because the detection speed is high and the equipment cost burden is low.
The first colorimetry is performed by measuring the printed matter by the first and second colorimeters when the printing conditions such as the printing material conditions including the paper or ink used for printing or the printing pattern are changed. The measurement value of the first colorimetric value obtained by the meter can always be appropriately converted into the second colorimetric value.

It is a flowchart explaining the colorimetric value conversion method concerning one Embodiment of this invention. A correspondence relationship (correspondence table, lookup table) between the first colorimetric value and the second colorimetric value in the colorimetric value conversion method and apparatus according to the embodiment of the present invention will be described using a color space. FIG. 6A shows a first color space related to a first colorimetric value, and FIG. 5B shows a second color space related to a second colorimetric value. It is a figure explaining the correspondence of the 1st colorimetric value and the 2nd colorimetric value after printing condition change in a colorimetric value conversion method and device concerning one embodiment of the present invention using a color space. (A) shows the first color space related to the first colorimetric value, and (B) shows the second color space related to the second colorimetric value. It is a figure explaining the measurement by the online sensor in the colorimetric value conversion method and apparatus concerning one Embodiment of this invention. It is a figure explaining the measurement by the offline sensor in the colorimetric value conversion method and apparatus concerning one Embodiment of this invention. It is a flowchart explaining the 1st example (ink supply) of the printing control using the colorimetric value conversion method concerning one Embodiment of this invention. It is a flowchart explaining the 2nd example (ink supply) of the printing control using the colorimetric value conversion method concerning one Embodiment of this invention. It is a flowchart explaining the 3rd example (fountain solution supply) of the printing control using the colorimetric value conversion method concerning one Embodiment of this invention. It is a flowchart explaining an example of printing determination (paper surface fault determination) using the colorimetric value conversion method according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Colorimetric value correspondence setting method)
1 to 5 illustrate a colorimetric value conversion method for a printed material that travels according to an embodiment of the present invention.
In this method, first, a large number of patches covering the color reproduction range are combined using a predetermined printing machine (printing machine used for actual printing) under a certain printing condition (first printing condition). A color measurement pattern is printed, and each printed color (each color of a large number of patches) is displayed as a first colorimetric value (not a specific value relating to color, but a type of color information, Measured by a first colorimeter (first color sensor) that detects "first color information" or "first type colorimetric value") and printed colors (multiple patches) Each color) is a second colorimetric value (not a specific value related to color, but a type of color information, and is referred to as “second color information” or “second type colorimetric value”). Measured by a color sensor (second color sensor) that detects the first colorimetric value and the second colorimetric value of each print color. Correspondence relationship between the value (standard correspondence), created as a correspondence table (also referred to as a look-up table from the reference at the time of control).

  Here, the first color sensor is an on-line sensor that is installed in a predetermined printing machine and measures each print color during printing, and a colorimetric value (color information) based on an appropriate color reference is obtained. Although there is no color sensor, it is a color sensor that satisfies requirements such as detection speed and equipment cost required as an online sensor. Here, as an example, the colorimetric values (first colorimetric values) detected by the first color sensor are represented by values (x, y, z) in the xyz color space. As the color sensor, for example, an RGB densitometer that detects density values of three colors of red (R), green (G), and blue (B) as the first colorimetric values can be applied. Of course, the colorimetric values applied to the first color sensor are not limited to three-dimensional information, and are based on a blank paper-based multi-channel spectral reflectance that does not use a white plate (for example, four RGBI channels, R2, G2, B2). For example, paper color reference color values X, Y, Z (values used as color values different from the simple coordinates XYZ) can be used.

In addition to using the same color sensor as the first color sensor, different color sensors having the same detection characteristics of the first colorimetric values, or the detection characteristics of the first colorimetric values are different from each other. However, it is possible to use a sensor having a known correspondence relationship between the detection characteristics of the color sensors.
That is, if the color sensors have the same detection characteristics, the measured values can be handled equally, and the measured values can be obtained without using the same color sensor.

In addition, even if the detection characteristics of each color sensor are different, if the correspondence between these detection characteristics is a known sensor, the measured value of one color sensor is converted to that of the other color sensor using the correspondence. Thus, a necessary measurement value can be obtained without using the same color sensor.
On the other hand, the second color sensor is an off-line sensor that measures a print color outside a predetermined printing machine, and does not have to satisfy requirements such as detection speed and equipment cost required as an on-line sensor. It is a sensor capable of measuring color information [standard values established by ISO (International Organization for Standardization), CIE (International Lighting Commission), etc.] based on (appropriate) color standards. Here, as an example, the colorimetric values (second colorimetric values) detected by the second color sensor are represented by values (X, Y, Z) in the XYZ color space. The colorimetric values applied to the second color sensor are not limited to three-dimensional information. Further, the first colorimetric value applied to the first color sensor and the second colorimetric value applied to the second color sensor are not limited to the same dimension. For example, the first color sensor may be RGBI four-dimensional, and the second color sensor may be RGB, Lab three-dimensional, or RGBI four-dimensional. Further, as the second color sensor, for example, a densitometer that detects, as the second colorimetric value, a white plate reference density value filtered by a filter such as Status-T, E, or I standardized by ISO. , CIE (International Commission on Illumination) recommended color coordinate system L ^* a ^* b ^* , L ^* u ^* v ^* , XYZ, etc. as a second colorimetric value sensor, spectral reflection referring to an absolute white plate It is also possible to apply a spectrometer or the like that is detected as the second colorimetric value, and the density value (white plate) filtered by a filter such as Status-T, E, or I that has a polarizing filter and the effect of dry-down is canceled. A so-called commercially available color sensor can also be applied.

As the second color sensor, in addition to using the same color sensor, another color sensor having the same detection characteristic of the second colorimetric value, or the detection characteristic of the second colorimetric value are different from each other. However, it is possible to use a sensor having a known correspondence relationship between the detection characteristics of the color sensors.
That is, if the color sensors have the same detection characteristics, the measured values can be handled equally, and the measured values can be obtained without using the same color sensor.

In addition, even if the detection characteristics of each color sensor are different, if the correspondence between these detection characteristics is a known sensor, the measured value of one color sensor is converted to that of the other color sensor using the correspondence. Thus, a necessary measurement value can be obtained without using the same color sensor.
As shown in FIG. 1, first, as step S1, as shown in FIG. 4 and FIG. 5, a color scale (standard printing material (standard ink on standard printing paper), for example, as shown in FIG. 4 and FIG. A colorimetric pattern 2 formed by combining a large number of patches covering the color reproduction range is printed, and as shown in FIG. 4, the first color information values (x, y , Z), the sensor output (x, y, z) of the first color sensor (online sensor) 1 and the second output offline (a part different from the predetermined printing press) as shown in FIG. The sensor output (X, Y, Z) of the second color sensor (offline sensor) 3 for measuring the value (X, Y, Z) of color information is obtained corresponding to each of a large number of patches. Find the relationship (correspondence). This correspondence relationship is obtained by mapping the first color information value (x, y, z) [FIG. 2 (a)] to the second color information value (X, Y, Z) [FIG. 2 (b)]. Therefore, it is stored in a database (not shown) as a correspondence table (also referred to as a lookup table because it is referred to during control).

  Next, as step S2, printing is performed with an arbitrary printing material and printing environment (second printing conditions). When printing is performed in an arbitrary printing material and printing environment as described above, usually, at least one of the materials or the printing environment is different from the case where the correspondence table is created (first printing condition). Then, an arbitrary pattern point (specific part) of the printed printed pattern is designated. Here, a case where normal commercial printing is performed will be described as an example. However, printing of a print pattern (for example, the above color scale) for setting a correspondence relationship between colorimetric values is performed, and an arbitrary point of the color scale is set. May be specified. In addition, when a monitor that displays a printed pattern and a touch panel attached to the monitor are provided, if the printed pattern is displayed on the monitor and specified by the touch panel, the design point can be easily specified.

Next, as step S3, sensor output values (x ₀ , y ₀ , z ₀ ) that are measured values are stored by the first color sensor (online sensor) 1 at the designated point during printing. At the same time, in step S4, the printed matter at that time is extracted, the same point is measured by the second color sensor (offline sensor) 3, and the sensor output values (X ₀ , Y ₀ , Z) are measured in step S5. ₀ ) is stored. Steps S3 to S5 correspond to measurement steps.

Then, from the second color information column in the correspondence table corresponding to the correspondence relationship, that is, the mapping relationship of FIG. 2, the measured value of the second color information at the specified point (offline sensor measured value, X ₀ , Y _0). , Z ₀ ), a large number of values (X _n , Y _n , Z _n ) in the region (neighboring region) are searched as corresponding values, and each value [(X _k , Y _k , Z _k ), _{(X l, Y l, Z} l) ( change of the off-line sensor value) difference ···] (ΔX, ΔY, ΔZ ) [ _{where, ΔX = X k -X l,} ΔY = Y k -Y l, ΔZ ₌ Z k _-Z l ···] the calculated respectively. Then, the first value on the correspondence table corresponding to each value [(X _k , Y _k , Z _k ), (X _l , Y _l , Z _l )...] Of the second color information on the correspondence table. Similarly, for each value [(x _k , y _k , z _k ), (x _l , y _l , z _l )...] Of color information, each value [(x _k , y _k , z _k ), (X _l , y _l , z _l )...] (Online sensor value change) (Δx, Δy, Δz) [where Δx = x _k −x _l , Δy = y _k −y _l , Δz ₌ z k _-z l ···] the calculated respectively.

As a result, Δx, Δy, Δz and ΔX, ΔY, ΔZ are associated with each other in the region (near region) close to the measurement value (X ₀ , Y ₀ , Z ₀ ) of the second color information at the specified point. The change correspondence table (change change correspondence, auxiliary lookup table) is obtained (step S6).
Here, the change correspondence table (change correspondence relationship) is obtained for the vicinity region of the second color information measurement value (X ₀ , Y ₀ , Z ₀ ) of the specified point. A change correspondence table (change correspondence relationship, auxiliary lookup table) may be obtained for the vicinity region of the first color information measurement value (x ₀ , y ₀ , z ₀ ).

Here, the neighborhood region is centered on the second color information measurement value (X ₀ , Y ₀ , Z ₀ ) or the first color information measurement value (x ₀ , y ₀ , z ₀ ) at the specified point. An area within a certain color space distance range set in advance as the approximate center [refer to each small circle in the color space of FIGS. 3A and 3B], or a neighboring area is For the second color information measurement value (X ₀ , Y ₀ , Z ₀ ) or the first color information measurement value (x ₀ , y ₀ , z ₀ ) at the point specified in the correspondence table, An area within a range of a predetermined number of values can also be set in order from the closest value.

  If this is an area in the vicinity of the designated point, the distortion characteristic of the correspondence relationship (that is, mapping relationship) between the change amount of the first color information and the change amount of the second color information due to the change of the printing condition is obtained. This is because there seems to be no major change. Therefore, in order to define this neighboring region, it is preferable to refer to the distortion characteristic of the correspondence relationship (mapping relationship) and set a region as large as possible within a range in which the distortion characteristic does not change greatly. The distortion characteristics can be learned while implementing the present technology.

Thus, when the change correspondence table (change change correspondence) is obtained, the first color sensor (online sensor) of the designated point that is sequentially measured in the subsequent normal printing (that is, printing of the printed product). Changes (differences) Δx, Δy, Δz from the first color information measurement values (x ₀ , y ₀ , z ₀ ) of the follow-up values (x, y, z) that are measurement values of 1 are calculated ( Step S7).

The second color sensor (offline sensor) corresponding to the changes Δx, Δy, Δz of the sensor output value of the first color sensor (online sensor) 1 using the change correspondence table (change correspondence). ΔX, ΔY, ΔZ (in this case, corresponding to the correction amount) of the value of 3 are calculated. Further, the second color information measurement values (X ₀ , Y ₀ , Z ₀ ) are added / subtracted and corrected by the calculated changes (correction amounts) ΔX, ΔY, ΔZ to obtain the first color sensor (online sensor). ) The value (X ′, Y ′, Z ′) of the second color sensor (offline sensor) 3 corresponding to the measured value (following report value) (x, y, z) of 1 is obtained (step S8).

Steps S6, S7 and S8 correspond to conversion steps.
Although only one designated point is described here, a designated point may be set for each of a plurality of ink supply zones, or a plurality of points may be set for the entire pattern.
In this embodiment, the case where the correspondence table does not have the same value of the first color information as the sensor measurement value (x ₀ , y ₀ , z ₀ ) at the specified point has been described. If there is a value of the first color information, this is used. You may obtain | require by the least square approximation based on the data of a vicinity.

The change correspondence table can be enhanced by creating a database while updating and recording a plurality of designated points.
If the change (correction amount) in the change correspondence table (change correspondence) is larger than a preset value, the change correspondence table (change correspondence) is used as a basis. The correspondence table (standard correspondence lookup table) itself may be modified. That is, for the range in which the change correspondence table is obtained, the basic correspondence table is corrected with the change correspondence table change (correction amount). Thus, thereafter, if the conversion steps of Steps S6, S7 and Step S8 are performed based on the corrected correspondence table, the correction amount itself becomes small, and the conversion accuracy of the colorimetric values is reduced. Improvements can be made.

  Further, if the processing of each step of this method is configured to function on a computer, the colorimetric value correspondence acquisition apparatus according to the present invention can be achieved. In this case, as a functional configuration of the computer, a database (storage means) in which a correspondence table (lookup table) as a correspondence relation (standard correspondence relation) is stored, an input means for inputting color information, and the first color A change correspondence corresponding to the change of the information and the change of the second color information is obtained, and an online sensor value (first color information follow-up value) is obtained using the change correspondence (correction amount). Is converted to an off-line sensor value (value of second color information) corresponding to the function.

Then, the detected value (x ₀ , y ₀ , z ₀ ) of the first color information measured from the print color printed by changing the print condition to the second print condition and the second color are input to the input means. The detected values (X ₀ , Y ₀ , Z ₀ ) of information are input, and the change correspondence acquisition unit (correction amount acquisition unit) of the conversion unit is input by the input unit using the correspondence table. The change in the first color information (first change) and the second color information in the vicinity of either one of the detected value of the first color information and the detected value of the second color information The change correspondence corresponding to the change (second change) is obtained. Further, in the conversion means, the first color information follow-up information with respect to the online sensor value (first color information follow-up value) obtained by the online sensor (first color sensor) during printing under the second print condition. A change (first change) (Δx, Δy, Δz) with respect to the first color information detection value (x ₀ , y ₀ , z ₀ ) of the value (x, y, z) is obtained, and the obtained first A second change (ΔX, ΔY, ΔZ) corresponding to one change (Δx, Δy, Δz) is obtained from the change correspondence, and the obtained second change (ΔX, ΔY, ΔZ) is obtained. As a correction amount, the offline sensor detection value (second color information detection value) (X ₀ , Y ₀ , Z ₀ ) is corrected thereby, and the online sensor value (first color information follow-up value) is offline corresponding to this. The sensor value (second color information value) (X ′, Y ′, Z ′) is converted into the sensor value.

Since the colorimetric value conversion method and apparatus for a printed matter that travels according to an embodiment of the present invention is configured as described above, the first color information value (x, y, z) when the printing condition is changed. And the second color information value (X, Y, Z) are designated (selected) by a few points of the print pattern, and the selected print color is designated as the first color sensor (online sensor) 1. Alternatively, the first color information detection value (x ₀ , y ₀ , z ₀ ) is obtained by measuring with another first color sensor equivalent to this, and the selected print color is set to the second color sensor (offline sensor). ) 3 or another equivalent second color sensor to obtain a second color information detection value (X ₀ , Y ₀ , Z ₀ ) and obtain the obtained second color information value ( since _{X 0, Y 0, Z 0} ) or the first color information detected values _{(x 0, y 0, z} 0) and the corresponding relation between (correspondence table), Second color information values _{(X 0, Y 0, Z} 0) or determine the change in the correspondence between the respective color information of the region near the first color information detected values _{(x 0, y 0, z} 0), followed by For the first color sensor (online sensor) 1, a follow-up value (x, y, z), which is a measurement value of the first color sensor (online sensor) 1, using the corresponding relationship of the change. And the first color information detection value (x ₀ , y ₀ , z ₀ ) change (difference) Δx, Δy, Δz corresponding to the change in the value of the second color sensor (offline sensor) 3 ( Correction amounts) ΔX, ΔY, ΔZ are calculated, and the second color information detection values (X ₀ , Y ₀ , Z ₀ ) are added / subtracted corrected by the calculated changes (correction amounts) ΔX, ΔY, ΔZ. The second color corresponding to the sensor output value (following report value) (x, y, z) of the first color sensor (online sensor) 1 Since the values (X ′, Y ′, Z ′) of the sensor (offline sensor) 3 are obtained, the correspondence at the time of changing the conditions can be obtained very easily. Easily convert the colorimetric values of the printed printed material under the printing conditions from the first colorimetric value (color information) suitable for the online sensor to the second colorimetric value (color information) suitable for the offline sensor. can do.

  That is, the first colorimetric value is not color information based on a predetermined (appropriate) color standard, but is color information that is suitable for an online sensor and can be easily and quickly performed. If the first color sensor 1 to be measured is installed in a predetermined printing press used for printing, the first color information of the print color is measured by the first color sensor 1 during actual printing, and this measurement result (first This is convenient for feedback control regarding printing based on the color measurement value of 1).

Further, if the second colorimetric value is color information based on a predetermined (appropriate) color standard, the information is not suitable for an online sensor but is convenient for color determination. ) To convert the first colorimetric value to the second colorimetric value and use it for color determination, it is possible to perform appropriate color determination online.
This correspondence (or change correspondence) is stored and used as a correspondence table in which a large number of density values (or density value changes) and color coordinate values (or color coordinate changes) are associated with each other. Measuring all the correspondences between a large number of density values and color coordinate values leads to enormous time and a large work load. In this respect, according to this colorimetric value conversion method or apparatus, it is possible to easily obtain the correspondence according to each printing condition, so a correspondence corresponding to the printing condition to be printed in advance is prepared. The color information color (second color) based on a predetermined (appropriate) color standard can be used for each print control, and the print color measurement value (first color information) measured by the online sensor can be used. Information) and feedback control for printing based on the color information can be performed with high accuracy.

Even when the printing conditions are changed, if the color measurement pattern consisting of a number of patches covering the color reproduction range is combined and one of the patches is selected as the selected printing color, It becomes easy to set the correspondence.
In addition, by updating the correspondence at the time of changing the condition within a preset color range with the selected print point as the center, the correction region of the correspondence is limited, but the correspondence can be corrected with high accuracy. .

Here, an example in which the colorimetric value conversion method according to the present invention is applied to a print control method and apparatus, and an example in which it is applied to a print state determination method and apparatus will be described.
・ First example (ink supply)
Ink supply control will be described as a first example of print control using a colorimetric value conversion method.
In this case, the method can be applied to all methods for controlling a picture with color coordinates. However, the first measuring instrument cannot measure the color coordinates.

  As shown in FIG. 6, a known design (see Japanese Patent Application Laid-Open No. 2001-18364, Japanese Patent Application Laid-Open No. 2001-47605) is started (step A1). A point on which color tone control is desired is designated on the monitor (step A2). Then, the value of the first color sensor (online sensor) at this designated point is stored (step A3), and the correspondence relationship between the value of the first color sensor and the value of the second color sensor prepared in advance ( The value of the color information (second color information) of the second color sensor (offline sensor) is calculated from the look-up table (step A4).

Then, the same point of the actual printed matter is measured by the second color sensor (offline sensor) (step A5). In this case, the measurement may be performed by a fourth color sensor that has the same detection characteristics as the second color sensor or can obtain the same detection characteristic value. Then, it is determined whether the color difference between the calculated value in step A4 and the measured value in step A5 (the color difference in the second color information) is less than a preset reference value A (step A6). If the color difference of the second color information is expressed as ΔX, ΔY, ΔZ, for example, the color difference can be represented by √ (ΔX ² + ΔY ² + ΔZ ² ).

If the second color information is the uniform perceptual color coordinate system L ^* a ^* b ^* or L ^* u ^* v ^* advocated by the CIE, the color difference can be evaluated with the same feeling as human visual characteristics, and the determination is easy. Become.
Here, if the color difference is not less than the reference value A, the change correspondence relationship is obtained by the above-described method (step A7), and the change amounts Δx, Δy, Δz of the detection values of the first color sensor (online sensor) are obtained ( Step A8), a second change (ΔX, ΔY, ΔZ) corresponding to the obtained first change (Δx, Δy, Δz) is obtained from the change correspondence, and the obtained second change. An offline sensor detection value (second color information detection value) (X ₀ , Y ₀ , Z ₀ ) corrected by (ΔX, ΔY, ΔZ) is used as an online sensor value (first color information follow-up value). The corresponding offline sensor value (second color information value) (X ′, Y ′, Z ′) is set (step A9).

Then, the calculated value (the value of the second color information at the point to be controlled) is displayed on the monitor (step A10), and the pattern color tone control is started (step A11).
On the other hand, if the color difference is less than the reference value A in step A6, the corresponding value (lookup table) between the first and second color sensors is not updated and the calculated value (second color at the point to be controlled) is displayed on the monitor. Information value) is displayed (step A12), and the pattern color tone control is started (step A13).
Thereby, ink supply amount control can be performed appropriately and a printed pattern can be brought close to a desired one.
Steps A11 and A13 can be omitted.

・ Second example (ink supply)
Ink supply control will be described as a second example of printing control using the colorimetric value conversion method.

In this case, the method can be applied to all methods for controlling a picture with color coordinates. However, the first measuring instrument cannot measure the color coordinates.
As shown in FIG. 7, by ink supply amount control using a known color scale (refer to Japanese Laid-Open Patent Publication No. 62-146633) color scale (colorimetric pattern formed by combining a large number of patches covering the color reproduction range). The design color tone control (patch color tone control) is started (step B1), and the measured value of the first color sensor of the designated patch is stored (step B2). Then, a second color sensor color information value (second color information value, corresponding to the measurement value of the first color sensor from a correspondence relationship (lookup table) between the first and second color sensors prepared in advance. (Standard value) is calculated (step B3).

Then, the specified patch of the actual printed matter is measured by the second color sensor (offline sensor) (step B4). In this case, the detection characteristic is the same as that of the second color sensor or a value of the same detection characteristic is obtained. You may measure by the 4th color sensor which can do. Then, it is determined whether or not the color difference (color difference of the second color information) √ (ΔX ² + ΔY ² + ΔZ ² ) between the calculated value in step B3 and the measured value in step B4 is less than a preset reference value A (step B5). If the color difference is not less than the reference value A, the change correspondence relationship is obtained by the above-described method (step B6), and the change amounts Δx, Δy, Δz of the detection values of the first color sensor (online sensor) are obtained ( Step B7), the second change (ΔX, ΔY, ΔZ) corresponding to the obtained first change (Δx, Δy, Δz) is obtained from the change correspondence, and the obtained second change. An offline sensor detection value (second color information detection value) (X ₀ , Y ₀ , Z ₀ ) corrected by (ΔX, ΔY, ΔZ) is used as an online sensor value (first color information follow-up value). The corresponding offline sensor value (second color information value) (X ′, Y ′, Z ′) is set (step B8).

Then, the calculated value (the value of the second color information at the point to be controlled) is displayed on the monitor (step B9), and the design color tone control is started (step B10).
On the other hand, if the color difference is less than the reference value A in step B5, the calculated value (the second color at the point to be controlled) is not updated on the monitor without updating the correspondence relationship (lookup table) between the first and second color sensors. Information value) is displayed (step B11), and the pattern color tone control is started (step B12).
Thereby, ink supply amount control can be performed appropriately and a printed pattern can be brought close to a desired one.
Steps B9 and B11 can be omitted.

・ Third example (Dampening water supply)
A dampening water supply control will be described as a third example of the printing control using the colorimetric value conversion method.

In this case, any method for controlling dampening water using color coordinates can be applied. However, the first measuring instrument cannot measure the color coordinates.
As shown in FIG. 8, the dampening water control known in the art (see Japanese Patent No. 4022223) is started (Step C1), and a non-image area is designated on the monitor (see Step C2, Japanese Patent No. 3825427). Then, the color information value of the second color sensor in the non-image area specified from the correspondence (lookup table) between the first and second color sensors prepared in advance is calculated (step C3).

Then, the designated non-image portion of the actual printed matter is measured by the second color sensor (step C4). Also in this case, measurement may be performed by a fourth color sensor that has the same detection characteristic as the second color sensor or can obtain the same detection characteristic value. Then, it is determined whether the color difference between the calculated value in step C3 and the measured value in step C4 is less than a preset reference value A (step C5). Here, if the color difference is not less than the reference value A, the change correspondence relationship is obtained by the above method (step C6), and the change amounts Δx, Δy, Δz of the detection values of the first color sensor (online sensor) are obtained ( Step C7), the second change (ΔX, ΔY, ΔZ) corresponding to the obtained first change (Δx, Δy, Δz) is obtained from the change correspondence, and the obtained second change. An offline sensor detection value (second color information detection value) (X ₀ , Y ₀ , Z ₀ ) corrected by (ΔX, ΔY, ΔZ) is used as an online sensor value (first color information follow-up value). The corresponding offline sensor value (second color information value) (X ′, Y ′, Z ′) is set (step C8).

Then, the calculated value (second color information value of the non-image portion) is displayed on the monitor (step C9), and it is determined whether the color difference (dirt color difference) of the stain target portion is greater than or equal to the reference value B (step S9). C10) If the stain color difference is not less than the reference value B, the dampening water is fired to suppress the stain (step C11).
If the color difference is less than the reference value A in step C5, the calculated value (second color information of the non-image portion) is not updated on the monitor without updating the correspondence relationship (lookup table) between the first and second color sensors. Value) is displayed (step C12), and control for suppressing dirt is appropriately performed (steps C10 and C11).
Thereby, printing stains can be suppressed.

-Fourth example (applied to quality inspection equipment)
Quality inspection will be described as a fourth example using the colorimetric value conversion method.
In this case, as shown in FIG. 9, a reference image (first color information value) is generated (step D1), and the first correspondence between the first and second color sensors (lookup table) prepared in advance is used. The color information value of the second color sensor is calculated (step D2). Then, a reference image (second color information value) is generated (step D3).

Further, the actual printed matter is measured by the second color sensor (step D4).
Here, it is determined whether the color difference between the color information value (calculated value) of the reference image in step D3 and the color information value (measured value) of the actual printed material in step D4 is less than a preset reference value A. (Step D5). Here, if the color difference is not less than the reference value A, the change correspondence relationship is obtained by the above-described method (step D6), and the change values Δx, Δy, Δz of the detection values of the first color sensor (online sensor) are obtained ( Step D7), a second change (ΔX, ΔY, ΔZ) corresponding to the obtained first change (Δx, Δy, Δz) is obtained from the change correspondence, and the obtained second change. An offline sensor detection value (second color information detection value) (X ₀ , Y ₀ , Z ₀ ) corrected by (ΔX, ΔY, ΔZ) is used as an online sensor value (first color information follow-up value). The corresponding offline sensor value (second color information value) (X ′, Y ′, Z ′) is set (step D8).

  Then, the actual printed matter is measured by the second color sensor (step D9), and a measurement image (measurement value of the second color information) is generated (step D10). Further, the actual color value (measured value of the second color information) measured in step D9 is subtracted from the color value of the reference image in step D3 (reference value of the second color information). Is determined to have exceeded the permissible value C (step D11), and if the subtracted value exceeds the permissible value C, it is determined that there is a paper surface failure (printing failure) (step D12).

If the color difference is less than the reference value A in step D5, a measurement image (measurement value of the second color information) is generated without updating the correspondence (lookup table) between the first and second color sensors ( Step D13), a paper surface failure (printing failure) is determined (steps D11 and D12).
As a result, it is possible to appropriately determine a paper surface failure (printing failure).
Although the embodiments of the present invention have been described above, the present invention can be implemented by appropriately changing the above embodiments without departing from the spirit of the present invention.

  For example, in the above embodiment, a change correspondence table in which Δx, Δy, Δz and ΔX, ΔY, ΔZ are associated with each other is obtained, and the first color sensor (online sensor) 1 sensor obtained during printing is obtained. When the output value (x, y, z) is obtained, the change (Δx, Δy, Δz) of the output value (x, y, z) is obtained, and the output value (converted from the basic correspondence table) The second color sensor corresponding to the change (Δx, Δy, Δz) with respect to the output value (X, Y, Z) of the second color sensor (offline sensor) 3 corresponding to x, y, z) 3 is added / subtracted and corrected by the amount of change (correction amount) ΔX, ΔY, ΔZ, and finally converted to the value (X ′, Y ′, Z ′) of the second color sensor 3.

However, the correction amount used at this time is not limited to the changes ΔX, ΔY, ΔZ obtained from the change correspondence table. In other words, for the same color, as long obtain first and colorimetric values a ₁ color sensor 1 and the colorimetric value b ₁ of the second color sensor 3, the first colorimetric values of color sensor 1 For a ₁ , the colorimetric value b ′ ₁ when the color measurement is performed by the second color sensor 3 from the basic correspondence table can be converted, and converted to that of the second color sensor 3. and colorimetric value _b'1, deviation Δb (= b ₁ -b' ₁₎ the colorimetric value b ₁ of the second color sensor actually measured can be obtained. Therefore, when the deviation Δb is used as a correction amount, the colorimetric value a of the first color sensor 1 measured thereafter is converted into the colorimetric value b when the color measurement is performed by the second color sensor 3. A value b ′ (= b + Δb) obtained by correcting only the deviation Δb (that is, correcting b by adding Δb) may be used as the converted value.

Thus, the correction amount is not limited to that in the above embodiment.
Further, the colorimetric value b ′ when the color measurement is performed by the second color sensor 3 can be converted from the colorimetric value a of the first color sensor 1 without obtaining the correction amount. For example, the correspondence between the colorimetric value a of the first color sensor 1 and the colorimetric value b of the second color sensor 3 is changed from the set A of the colorimetric values of the first color sensor 1 to the second color sensor. 3 to the set B of colorimetric values, or the colorimetric value a of the first color sensor 1 and the colorimetric value b of the second color sensor 3 are functions f [that is, b = f ( a)] can be considered. Each colorimetric value a, b is assumed to have an element of a required order (for example, tertiary or quaternary).

For example, when focusing on the subsets Ap and Bp of the colorimetric value set A or the colorimetric value set B, the function f [b = f (a)] is more simply expressed as b = α (a) + β F), one of α and β is fixed and the other is changed according to the printing conditions. In this case, if the actual colorimetric values a ₀ and b ₀ are measured, the measured values a ₀ and b ₀ are substituted into the formula F and changed according to the printing conditions of α and β. Then, using the formula F, the colorimetric value b ′ when the colorimetric value a is measured by the second color sensor 3 from the colorimetric value a of the first color sensor 1 obtained while printing is converted. can do. That is, the colorimetric value can be converted without obtaining the correction amount.

  The present invention can be widely applied to the printing industry using printing machines that perform printing by transferring ink.

1 First color sensor (online sensor)
2 Color scale (colorimetric pattern made up of a number of patches covering the color reproduction range)
3 Second color sensor (offline sensor)

Claims (28)

In any printing condition, the first calorimeter is online sensors for measuring each print color in the print is placed on a printing press, Shi measuring a printed material meter running the printing press of the first color information together to obtain a first colorimetric value is colorimetric values, the second calorimeter is offline sensor for measuring a print color in the off-press, said Shi measuring a specific position of the printed material meter the first a measuring step of obtaining a second colorimetric value type is colorimetric values of the second color different information from the color information,
Correspondence between the first color information and the second color information when the same color is measured using the first colorimeter and the second colorimeter under preset standard printing conditions By using the first colorimetric value and the second colorimetric value measured for the specific location of the printed matter by the relationship and the measurement step, the printed color matter that travels is measured by the first colorimeter. the first colorimetric values obtained by measuring, characterized in that it comprises a conversion step of converting the to the second colorimetric values when measured by the second colorimeter travels Colorimetric value conversion method for printed materials. In the conversion step, a correction amount for converting the first colorimetric value to the second colorimetric value is obtained, and the conversion is performed using the correspondence and the correction amount. The colorimetric value conversion method for a printed printed matter according to claim 1. In the conversion step, the correction amount is obtained from the first color measurement value and the second color measurement value measured for the specific portion of the printed matter by the measurement step using the correspondence relationship. The colorimetric value conversion method for a printed matter that travels according to claim 2. If the correction amount exceeds a predetermined range, the method further comprises the step of correcting the correspondence relationship with the correction amount;
4. The color value conversion method for a printed printed matter according to claim 2, wherein when the correspondence relationship is corrected by the correspondence relationship correction step, the corrected correspondence relationship is used in the conversion step. 5. The correspondence relationship is a correspondence table in which the first color information measured by the first colorimeter and the second color information measured by the second colorimeter are associated with each other. ,
In the conversion step, the first color information corresponding to the first color information in the correspondence table for a region near one of the first colorimetric value and the second colorimetric value in the correspondence table. obtains the second of the second variation correspondence table and change in colorimetric value is made to correspond for the color information variation with in the correspondence table of the colorimetric values, of any of said change amount corresponding table 5. The colorimetric value conversion method for a printed matter that travels according to claim 1, wherein a change amount is used as the correction amount. 6. The colorimetric value conversion method for a printed printed article according to claim 5, wherein the neighboring area is an area within a predetermined color space distance range set in advance for the one value. 6. The traveling according to claim 5, wherein the neighboring area is an area within a predetermined number of values in order from a value closest to a color space distance to the one value in the correspondence table. Colorimetric value conversion method for printed materials. The colorimetric value conversion method for a printed printed matter according to any one of claims 1 to 7, wherein the second colorimetric value is a color coordinate value. The correspondence relationship is obtained by printing a plurality of colors covering the color reproduction range by the printing machine, and measuring each of the plurality of printing colors by the first colorimetric value. Measured by the second colorimeter capable of measuring the second colorimetric value and obtained from the correspondence of the plurality of measured values,
The first colorimeter used in the measurement step and the first colorimeter used when acquiring the correspondence are the same colorimeter and different colorimeters, but the same detection characteristics And a colorimeter that is another colorimeter and another detection characteristic, but whose correspondence between the two detection characteristics is known,
The second colorimeter used in the measurement step and the second colorimeter used in acquiring the correspondence relationship are the same colorimeter and different colorimeters, but the same detection characteristics 9. The colorimeter of claim 1, wherein the colorimeter is another colorimeter and different detection characteristics, but the correspondence relationship between the two detection characteristics is known. The colorimetric value conversion method for a printed matter that travels according to any one of the above . The first colorimetric values are RGB density values of three colors of red (R), green (G), and blue (B), or red (R), green (G), blue (B), and infrared. Given by the RGBI density values of the four colors of (I),
The first colorimeter is an RGB densitometer that detects density values of three colors of red (R), green (G), and blue (B), or red (R), green (G), and blue ( B), characterized in that it is a RGBI densitometer for detecting the density value of four colors of infrared (I), traveling printed matter method colorimetric values converted to according to any one of claims 1-9 . The conversion step is performed at the time of normal printing for printing a pattern for normal printing as a printed product,
Wherein the measurement step, and acquires the measurement value by printing the normal printing picture similar to the conversion step, measuring of printed matter running according to any one of claims 1-10 Color value conversion method. 12. The colorimetric value conversion method for a printed matter that travels according to claim 11 , wherein the measuring step is performed when a printing condition is changed. The color measurement value of the printed printed matter according to any one of claims 1 to 12 , wherein the printing condition is a printing material condition including paper or ink used for printing, or a printed pattern. Conversion method. The method according to any one of claims 1 to 13 , wherein the conversion step is performed while printing is performed by the printing press, and the first colorimetric value is converted into the second colorimetric value. A method for controlling printing by the printing press,
A comparison step of comparing the converted second colorimetric value with a preset target value of the second colorimetric value;
If it is determined in the comparison step that the color difference between the converted second colorimetric value and the target value exceeds a preset allowable value, an adjustment signal for adjusting the ink supply amount in a direction in which the color difference decreases. A printing control method comprising: an adjustment step for outputting the output. Using the method according to any one of claims 1 to 13, the conversion step is performed while printing is performed by the printer with a non-image portion related to printing as the specific portion, and the first measurement is performed. by converting the color value to the second colorimetric value, a method for controlling the printing by the printing press,
A comparison step of comparing the converted second colorimetric value with a target value of the second colorimetric value set in advance for the non-image portion;
If it is determined in the comparison step that the color difference between the converted second colorimetric value and the target value exceeds a preset allowable value, it is determined that ink stain has occurred, and ink stain is reduced. And a control step for adjusting the amount of dampening water as described above. Using the method according to any one of claims 1 to 13, the conversion step is performed while printing is performed by the printer with a non-image portion related to printing as the specific portion, and the first measurement is performed. by converting the color value to the second colorimetric value, there is provided a method for determining the printing state by the printing press,
A comparison step of comparing the converted second colorimetric value with a target value of the second colorimetric value set in advance for the non-image portion;
A determination step for determining a printing defect if the comparison step determines that the color difference between the converted second colorimetric value and the target value exceeds a preset allowable value. A printing state determination method as a feature. The method according to any one of claims 1 to 13 , wherein the conversion step is performed while printing is performed by the printing press, and the first colorimetric value is converted into the second colorimetric value. An apparatus for controlling printing by the printing press,
Comparing means for comparing the converted second colorimetric value with a preset target value of the second colorimetric value;
If the comparing means determines that the color difference between the converted second colorimetric value and the target value exceeds a preset allowable value, the ink supply amount is adjusted in a direction in which the difference between the colorimetric values decreases. A printing control apparatus comprising an adjusting means for adjusting. Using the method according to any one of claims 1 to 13, the conversion step is performed while printing is performed by the printer with a non-image portion related to printing as the specific portion, and the first measurement is performed. by converting the color value to the second colorimetric value, an apparatus for controlling the printing by the printing press,
Comparing means for comparing the converted second colorimetric value with a target value of the second colorimetric value set in advance for the non-image portion;
If the comparison means determines that the color difference between the converted second colorimetric value and the target value exceeds a preset allowable value, it is determined that ink stain has occurred and ink stain is reduced. And a control means for adjusting the amount of dampening water as described above. Using the method according to any one of claims 1 to 13, the conversion step is performed while printing is performed by the printer with a non-image portion related to printing as the specific portion, and the first measurement is performed. by converting the color value to the second colorimetric value, an apparatus for determining a printing condition according to the predetermined printing press,
Comparing means for comparing the converted second colorimetric value with a target value of the second colorimetric value set in advance for the non-image portion;
And determining means for determining a printing defect when the comparing means determines that the color difference between the converted second colorimetric value and the target value exceeds a preset allowable value. A printing state determination device as a feature. An on-line sensor that is installed in a printing press and measures each printing color during printing, and measures a printed matter that travels through the printing press to obtain a first colorimetric value that is a colorimetric value of first color information. A first colorimeter;
An off-line sensor for measuring a print color outside the printing press, wherein the second measurement is a colorimetric value of second color information that is different from the first color information by measuring a specific portion of the printed matter. A second colorimeter for obtaining color values;
A memory storing a correspondence relationship between the first color information and the second color information when the same color is measured using the first colorimeter and the second colorimeter under standard printing conditions. Means,
The correspondence relationship stored in the storage means and the first colorimetric value and the second colorimeter measured by the first colorimeter for the specific location of the printed matter under an arbitrary printing condition The first colorimetric value obtained by measuring the printed matter traveling with the first colorimeter using the second colorimetric value measured by the second colorimetric value. A colorimetric value conversion device for a printed matter that travels, comprising: a conversion unit that converts the second colorimetric value when measured by a meter. The conversion means obtains a correction amount when the first colorimetric value is converted to the second colorimetric value, and performs the conversion using the correspondence and the correction amount. 21. A colorimetric value conversion device for a printed matter traveling according to claim 20 . The conversion means uses the correspondence relationship and the first colorimetric value and the second colorimetric value measured for the specific portion of the printed matter by the first colorimeter and the second colorimeter. 22. The colorimetric value conversion device for a printed matter that travels according to claim 21 , wherein the correction amount is obtained from a colorimetric value. The correspondence stored in the storage means corresponds to the first color information measured by the first colorimeter and the second color information measured by the second colorimeter. A correspondence table,
The conversion means includes the first color information for the first color information in the correspondence table for a region near one of the first colorimetric value and the second colorimetric value in the correspondence table. A change correspondence table is obtained by associating the change in colorimetric value with the change in the second colorimetric value with respect to the second color information in the correspondence table, and any one of the change correspondence tables 23. The colorimetric value conversion device for a printed printed matter according to claim 22 , wherein the amount of change is the correction amount. 24. The colorimetric value conversion device for a printed printed matter according to claim 23 , wherein the neighboring region is a region within a predetermined color space distance range set in advance for the one value. 24. The running according to claim 23 , wherein the neighboring area is an area within a predetermined number of values in order from a value closest to a color space distance to the one value in the correspondence table. Colorimetric value conversion device for printed materials. The correspondence relationship stored in the storage unit can print a plurality of colors covering a color reproduction range by the printing machine, and measure the first colorimetric values for each of the plurality of printing colors. The correspondence relationship is obtained from the correspondence between the plurality of measurement values by measuring with the first colorimeter and the second colorimeter capable of measuring the second colorimetric value. And
The first colorimeter used for calculating the correction amount by the conversion means and the first colorimeter used for obtaining the correspondence relationship are the same colorimeter and different colorimeters. Is a colorimeter having the same detection characteristics, a different colorimeter and a different detection characteristic, but a correspondence between the detection characteristics of both is known, and
The second colorimeter used for calculating the correction amount by the conversion means and the second colorimeter used for obtaining the correspondence relationship are the same sensor, different sensors but the same detection. 26. The sensor according to any one of claims 22 to 25 , wherein the sensor is one of a characteristic sensor and another sensor which is another detection characteristic but a correspondence relationship between the detection characteristics of both is known. The colorimetric value conversion device for printed printed matter described in 1. 27. The colorimetric value conversion device for a printed matter that travels according to any one of claims 20 to 26 , wherein the second colorimetric value is a color coordinate value . The first colorimetric values are RGB density values of three colors of red (R), green (G), and blue (B), or red (R), green (G), blue (B), and infrared. Given by the RGBI density values of the four colors of (I),
The first colorimeter is an RGB densitometer that detects density values of three colors of red (R), green (G), and blue (B), or red (R), green (G), and blue ( 28. A colorimetric value conversion device for a printed printed matter according to any one of claims 20 to 27 , which is an RGBI densitometer that detects density values of four colors of B) and infrared (I). .