Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F31/00—Inking arrangements or devices
  • B41F31/02—Ducts, containers, supply or metering devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F31/00—Inking arrangements or devices
  • B41F31/02—Ducts, containers, supply or metering devices
  • B41F31/04—Ducts, containers, supply or metering devices with duct-blades or like metering devices
  • B41F31/045—Remote control of the duct keys
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F33/00—Indicating, counting, warning, control or safety devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F33/00—Indicating, counting, warning, control or safety devices
  • B41F33/0036—Devices for scanning or checking the printed matter for quality control
  • B41F33/0045—Devices for scanning or checking the printed matter for quality control for automatically regulating the ink supply

Definitions

• the present invention relates to a picture color tone control apparatus and a picture color tone control method for a printing press, which controls the color tone of a picture using information on printing characteristics of the printing press.
• Patent Document 1 proposes a technique for adjusting the color tone of a printed matter during a printing operation.
• a target mixed color halftone density is set for each ink supply unit width.
• the mixed color density is the reflection density of 1 (infrared light), R (red), G (green) and B (blue).
• the correspondence relationship between the halftone dot area ratio of each ink color of the black (k), black (c), red (m), yellow (y) ink colors set in advance and the mixed color density (a LUT (look Based on the uptable) or the well-known Neugebauer equation derived from the correspondence relationship, the actual dot area rate of each ink color corresponding to the actual color mixture density is determined.
• a newspaper mark Jjapan Color standard printed matter four basic ink colors [ink (k), ⁇ (c), red (yellow) m), a pattern having various combinations of yellow (y)) printed at a reference density Ds, and measured with an I RGB densitometer, various nets of four ink colors k, c, m, y
• the correspondence relation of the actual measurement values (mixed color density IRGB values) by the IRGB densitometer corresponding to the combination of the dot area ratio is determined, and the look-up table (LUT) can be obtained from this correspondence relation.
• target dot area ratios of the respective ink colors corresponding to the target mixed color mesh density are also determined.
• the target dot area rate does not have to be calculated each time as with the actual dot area rate, and should be calculated once as long as the target mixed color density does not change.
• the target halftone dot area rate may also be determined when the target mixed color halftone density is set.
• the actual monochrome dot density corresponding to the real dot area rate is determined.
• the above relationship is approximated using a map, table of actual monochrome density corresponding to the actual dot area rate, or a known Yule-Ilsen equation. You may use it to ask for it. Also, based on the correspondence relationship between the dot area ratio and the single color network density, a target single color network density corresponding to the target dot area ratio is also determined.
• the target single-color screen density does not have to be determined every time as in the case of actual single-color screen density, and may be determined once as long as the target halftone dot area ratio does not change. For example, when the target dot area rate is set, the target monochrome density may be obtained.
• the deviation between the target monochrome dot density and the actual monochrome dot density under the target dot area factor is determined. Find the corresponding beta concentration deviation.
• the ink supply amount is adjusted for each ink supply unit width based on the determined solid density deviation, and the ink supply amount of each color is controlled for each ink supply unit width.
• the adjustment amount of the ink supply amount based on the solid density deviation can be determined using the above-mentioned API function.
• kcmy halftone dot area rate data for example, image data for plate making etc.
• image data for example, image data for plate making etc.
• a pixel of interest corresponding to each ink color a pixel of interest may be a single pixel for each ink supply unit width
• the dot area rate of the target pixel is converted to the mixed dot density based on the correspondence relationship between the dot area rate and the mixed color dot density set in advance.
• the color mixture halftone density of the pixel of interest is set as the target color mixture halftone density.
• the actual mixed color halftone density of the set target pixel is measured.
• the pixel having the largest autocorrelation with respect to the dot area ratio of each pixel is calculated and extracted, and this is set as the target pixel, and the target single color halftone density and the actual single color are set for this target pixel.
• More stable color tone control can be performed by calculating the screen density and performing feedback control of the ink supply amount so that the actual single-color screen density approaches the target single-color screen density.
• Patent Document 1 Japanese Patent Application Laid-Open No. 2004-106523
• AM screening Amplitude Modulation Screen
• FM screening Frequency Modulation Screening
• AM screening and FM screening may be used in combination depending on the characteristics of the printed pattern.
• platemaking may be performed using different screening for each page.
• a plurality of pages are allocated to one printing plate, and therefore, when different screens are used for each page, a plurality of types of screening are used for one printing plate. . Even within the same page, different screenings may be used simultaneously.
• the color tone of the printed material may not be the desired color tone.
• the color tone of the printed matter varies depending on the type of screening. For example, when different screening is used for each page, the color tone of the printed matter is different for each page, which causes quality deterioration. [0011] When this cause was investigated, it was found that the AM screening and the FM screening are caused by the fact that the degree of dot gain is largely different.
• contrast is expressed by the size of the area of one relatively large area dot, while in the case of FM screening, a large number of small area dots are arranged to form a network.
• the light and shade are expressed by changing the distribution density of the points.
• the area of one dot is smaller in FM screening than in AM screening (the number of dots per unit area is larger in FM screening) !).
• the dot gain characteristics differ depending on the difference in the area of the halftone dots. This phenomenon also occurs when AM screening with different numbers of lines (the number of halftone dots per unit area) is used in combination.
• the present invention has been made in view of such problems, and a picture color tone control device for a printing machine capable of performing color tone control with high accuracy even when printing using different types of screening in parallel. And it aims at providing a picture color tone control method.
• the picture color tone control device of the printing machine of the present invention acquires the printing characteristic information of the printing machine corresponding to each type of screening used for making the printing picture Printing characteristic information acquiring means, screening information acquiring means for acquiring the type of screening used for each area of the printed pattern in correspondence with It is characterized in that it comprises: an ink supply amount control means for controlling the ink supply amount based on the printing characteristic information corresponding to the type.
• the ink supply method further includes a target pixel area setting unit configured to set a specific pixel area in the print pattern as a target pixel area for each ink supply zone of the printing press. It is preferable that the amount control means controls the ink supply amount on the basis of the printing characteristic information corresponding to the type of screening of the target pixel area set by the eye pixel area setting means. 2).
• the printing characteristic information is obtained by printing a predetermined pattern with a standard solid density for each type of screening, measuring the mixed color density of the printed matter with an IRGB densitometer, and obtaining halftone dots of each ink color obtained by this method. It is a look-up table for each kind of screening described above, which defines the correspondence between the area ratio k, c, m, y and the color mixture density I, R, G, B, and the ink supply amount control means It is preferable to control the ink supply rate using the look-up table corresponding to the type of screening of the area (Claim 3).
• the ink supply amount control means is an ink supply means for supplying ink to each of the divided regions in the printing width direction, and the above when the print pattern is divided by the ink supply unit width of the ink supply device.
• a target mixed color screen density setting means for setting a target mixed color screen density for each ink supply unit width and an IRGB density meter disposed on a running line of the main printing sheet obtained by printing
• the target halftone dot area rate of each ink color corresponding to the target mixed color halftone density is obtained based on the actual color mixture halftone density acquiring means for acquiring the color and the look-up table corresponding to the type of screening of the target pixel area.
• a target to be calculated A dot area rate calculating means, and each ink color corresponding to the actual mixed color halftone density based on the look-up table corresponding to the type of screening of the target pixel area
• the target monochrome dot density corresponding to the target dot area rate is calculated based on the actual dot area rate calculating means for calculating the actual dot area rate and the correspondence between the dot area rate and the monochrome dot density set in advance.
• Real monochrome density calculation means for computing the actual monochrome density corresponding to the real dot area ratio based on the correspondence between the dot area ratio and the monochrome density described above; And the deviation between the target monochrome density and the actual monochrome density under the target halftone area ratio, based on the correspondence relationship between the halftone dot area rate, the monochrome density and the solid density, which are set in advance. It is preferable to control the ink supply amount for each ink supply unit width by feedback control based on the solid density deviation, comprising solid density deviation calculation means for calculating the corresponding solid density deviation.
• the target mixed color halftone density setting unit is configured to calculate the kcmy halftone dot area rate of the print pattern.
• a dot area of the pixel area of interest obtained from the dot area ratio data using the dot area ratio data acquiring means for acquiring data and the look-up table corresponding to the type of the screen of the pixel area of interest
• Conversion means for converting the ratio into the mixed color density, and configured to set the mixed color density of the target pixel area as the target mixed color density
• the actual mixed color density acquisition means comprises: Preferably, it is configured to obtain a mixed color shade, U ⁇ (claim 5).
• the above-mentioned printing characteristic information can be obtained by printing a predetermined pattern made by the above screening, which is a standard, with a standard solid density, and measuring the mixed color density of the printed matter with an IRGB densitometer.
• Reference look-up table that defines the correspondence between dot area ratio k, c, m, y of each ink color and mixed color density I, R, G, B, Dot gain corresponding to the type of screening
• the ink supply amount control means corresponds to the lookup table of the reference, the dot gain characteristic information corresponding to the type of the screening of the target pixel area, and the type of the screening as the reference. It is preferable to control the ink supply amount based on the difference between the above dot gain characteristic information and the above-mentioned dot gain characteristic information (claim 6).
• the ink supply amount control means divides the printing pattern by the ink supply unit width of the ink supply device, and the ink supply means for supplying the ink to each area divided in the printing width direction.
• the target color mixing net density setting means for setting the target color mixing net density for each ink supply unit width of the above, and the color mixing of the above main printing sheet by the IRG B densitometer disposed on the running line of the main printing sheet obtained by printing.
• Target halftone area ratio computing means for computing a target halftone dot area rate of each ink color corresponding to the target mixed color halftone density based on the actual color mixture halftone density acquiring means for acquiring halftone density and the lookup table of the above standard
• real dot area ratio calculating means for calculating the actual dot area ratio of each ink color corresponding to the actual mixed color network density on the basis of the above standard lookup table, the previously set dot area ratio and monochrome network. concentration
• the target monochrome density calculation means for calculating the target monochrome density corresponding to the target dot area rate based on the correspondence relationship of the above, and the correspondence relationship between the halftone area density and the monochrome density above.
• the actual monochrome density calculation means for computing the actual monochrome density corresponding to the real dot area rate, and the correspondence relationship between the preset halftone area rate, the monochrome density and the solid density
• Solid density deviation computing means for computing a solid density deviation corresponding to a deviation between the target monochrome density under the target halftone dot area ratio and the real monochrome density
• the target mixed color halftone density setting means corresponds to a halftone dot area rate data acquiring means for acquiring kcmy halftone dot area rate data of the print pattern, and corresponds to the type of the screening of the target pixel area.
• the dot area ratio of the target pixel area obtained from the dot area ratio data based on the difference between the dot gain characteristic information and the dot gain characteristic information corresponding to the type of screening as the reference
• the image processing apparatus comprises: an after-correction dot area ratio calculation means for calculating an after-correction dot area ratio; and a conversion means for converting the after-correction dot area ratio into mixed color density using a lookup table of the reference.
• the color mixture halftone density of the pixel area of interest converted is set as the target color mixture halftone density, and the actual color mixture halftone density acquisition means acquires the actual color mixture halftone density of the pixel of interest.
• Made is in! /, Preferred is Rukoto, (claim 8).
• the screening information acquisition unit preferably acquires the job ticket data capability and the screening information.
• the screening information acquisition means preferably acquires the screening information from plate making data (claim 10).
• the print characteristic information acquisition unit acquires the print characteristic information as well as the job ticket data (Claim 11).
• the picture color tone control method of the printing press according to the present invention is a printing characteristic information acquiring step of acquiring printing characteristic information of a printing machine corresponding to each type of screening used for plate making of a printing picture. And a screening information acquisition step of acquiring the type of screening used for each area of the print pattern in correspondence with each area, and the printing characteristic information corresponding to the type of screening of the noted pixel area. Based on! /, Ink supply amount control step to control the supply amount of ink
• the ink supply amount is controlled based on the printing characteristic information corresponding to the type of screening of the target pixel area. Is preferred (Claim 13).
• the printing characteristic information is obtained by printing a predetermined pattern with a standard solid density for each type of screening, measuring the mixed color density of the printed matter with an IRGB densitometer, and obtaining each of them
• This is a look-up table for each type of screening that defines the correspondence between the dot area rates k, c, m and y of the ink color and the mixed color densities I, R, G and B.
• it is preferable to control the ink supply amount using the look-up table corresponding to the type of screening of the target pixel area (claim 14).
• the ink supply amount control step sets a target mixed color network density for setting the target mixed color network density for each ink supply unit width when the print pattern is divided by the ink supply unit width of the ink supply device.
• an actual mixed color halftone density acquiring step of acquiring the mixed color halftone density of the main printing sheet by an IRGB densitometer disposed on a running line of the main printing sheet obtained by printing, and the screening of the target pixel area.
• an actual monochrome network density calculation step of calculating an actual monochrome network density corresponding to the real dot area ratio, a preset halftone area ratio and a monochrome network density
• a solid density deviation calculating step of calculating a solid density deviation corresponding to a deviation between the target monochrome density under the target dot area ratio and the actual monochrome density based on the correspondence relationship with the solid density; It is preferable to control the ink supply amount for each ink supply unit width by feedback control based on the solid density deviation.
• the target mixed color halftone density setting step corresponds to a halftone dot area rate data acquiring step of acquiring kcmy halftone dot area rate data of the printed pattern, and the type of screening of the target pixel area. And converting the halftone dot area rate of the target pixel area obtained from the halftone dot area rate data into the mixed color density using the look-up table.
• the actual mixed color halftone density acquisition step is configured to acquire the actual mixed color halftone density of the pixel of interest (claim 16). .
• the above-mentioned printing characteristic information can be obtained by printing a predetermined pattern made by the above screening, which is a standard, with a standard solid density, and measuring the mixed color density of the printed matter with an IRGB densitometer.
• Reference look-up table that defines the correspondence between dot area ratio k, c, m, y of each ink color and mixed color density I, R, G, B, Dot gain corresponding to the type of screening
• the ink supply amount control step includes the look-up table of the reference, the dot gain characteristic information corresponding to the type of the screening of the target pixel area, and the type of the screening as the reference. It is preferable to control the ink supply amount based on the difference from the corresponding dot gain characteristic information (claim 17).
• the ink supply amount control step sets a target mixed color density for each ink supply unit width when the print pattern is divided by the ink supply unit width of the ink supply device.
• the actual mixed color density acquisition step of acquiring the mixed color density of the above main printing sheet by the IRGB densitometer arranged on the traveling line of the main printing sheet obtained by printing, and the above lookup table
• the target halftone dot area ratio computing step for computing the target halftone dot area ratio of each ink color corresponding to the target color mixture halftone density, and on the basis of the reference look-up table, Based on the correspondence relationship between the actual dot area ratio calculation step of calculating the actual dot area ratio of the ink color and the preset dot area ratio and the single color halftone density, the target dot area ratio is compared with the target dot area ratio.
• an actual monochrome density corresponding to the real halftone area ratio is calculated.
• the ink supply amount is preferably controlled for each ink supply unit width by feedback control based on the solid density deviation.
• the target mixed color halftone density setting step corresponds to a halftone dot area rate data acquiring step of acquiring kcmy halftone dot area rate data of the printed pattern, and corresponds to the type of screening of the target pixel area.
• the dot area ratio of the target pixel area obtained from the dot area data based on the dot area ratio data based on the difference between the dot gain characteristic information and the dot gain characteristic information corresponding to the type of the screen as the reference
• a corrected dot area ratio calculating step for calculating a corrected dot area ratio after correction, and a conversion step for converting the corrected dot area ratio into mixed color density using the reference lookup table described above.
• setting the converted mixed color density of the target pixel area as the target mixed color density, and the actual mixed color density acquisition step comprises: Is configured to acquire, Rukoto is preferred U, (claim 19).
• the screening information acquisition step it is preferable to acquire the job ticket data information.
• the screening information acquisition step it is preferable to acquire the screening information from plate making data (claim 21).
• the printing characteristic information acquisition step the printing characteristic information is preferably acquired from job ticket data.
• a specific pixel area (for example, an area where color tone control is performed with high accuracy) is set as a target pixel area for each ink supply zone of the printing press.
• each ink is specified using a look-up table that defines the correspondence between the dot area ratio k, c, m, y of each ink color for each screening type and the mixed color density I, R, G, B.
• a look-up table that defines the correspondence between the dot area ratio k, c, m, y of each ink color for each screening type and the mixed color density I, R, G, B.
• the ink supply amounts of the respective ink colors k, c, m and y are feedback-controlled based on the actual mixed color net density of the printing sheet detected by the IRGB densitometer and the target mixed color net density to ensure high. It is possible to control the image color tone of the printing machine with high accuracy (claims 4 and 15).
• the OK sheet is printed by setting the target mixed color screen density from the dot area ratio of the print pattern using the look-up table corresponding to the type of screening used for ink supply amount control.
• the ink supply amount of each ink color k, c, m, y is controlled based on the difference between the dot gain characteristic for each screening type and the dot gain characteristic in the standard screening.
• the image tone control of the printing press can be performed with high accuracy (claims 6, 17).
• the corrected dot area rate power corrected according to the difference between the dot gain characteristic information corresponding to the type of screening of the pixel area of interest and the dot gain characteristic information corresponding to the type of screening as a reference By setting the target mixed color screen density using the look-up table, the size of the dot gain due to the difference in the type of screening for the target pixel area immediately after the start of printing without waiting for the OK sheet to be printed. Color tone control can be accurately performed by correcting differences in printing, and the print starting force can be obtained until the OK sheet is obtained. It is possible to reduce the time for paper-breaking by reducing the time for paper-cutting (claims 8 and 19).
• a person in charge of the paper surface configuration such as a designer of the printing space, writes information on the screening type used for picture color tone control in the job ticket data.
• the information on the written screening type it is possible to perform high-accuracy pattern color control so that the printed material has the desired color tone.
• the print characteristic information is acquired in advance for each screening type at a base station or the like, and the print characteristic information is written in the job ticket data, and the print ticket information power is acquired in the print factory.
• the printing factory does not need to acquire printing characteristic information, and the workload of printing can be reduced (claims 1 and 22).
• FIG. 1 is a view showing a schematic configuration of a newspaper offset rotary press according to a first embodiment of the present invention.
• FIG. 2 is a functional block diagram focusing on the color tone control function of the arithmetic device of FIG.
• FIG. 3 is a flow chart showing a processing flow of color tone control (in particular, processing that focuses on calculation of a target mixed color halftone density) by the arithmetic device according to the first embodiment of the present invention.
• FIG. 4 is a flowchart showing a processing flow of color tone control by the arithmetic device according to the first embodiment of the present invention.
• FIG. 5 This is a map that relates monochrome mesh density to dot area ratio.
• FIG. 6 This is a map correlating solid density with dot area rate and monochrome density.
• FIG. 7 is a functional block diagram focusing on the color tone control function of the arithmetic device according to the second embodiment of the present invention.
• FIG. 8 is a diagram for explaining a dot gain curve, and is a graph correlating dot area ratio with dot area increase amount by dot gain.
• FIG. 9 Color tone control by the arithmetic unit according to the second embodiment of the present invention Is a flow chart showing a process flow of the process).
• FIG. 1 is a view showing a schematic configuration of a newspaper offset rotary press according to a first embodiment of the present invention.
• the offset rotary press for newspaper according to the present embodiment is a multi-color double-sided printing press, and ink colors [ink (k), amber (c), red ( m) and yellow (y)] printing units 2a, 2b, 2c and 2d are installed.
• the printing units 2a, 2b, 2c and 2d are ink key type ink jet printers comprising an ink key 7 and an ink source roller 6.
• An ink supply device (ink supply means) is provided.
• the amount of ink supplied can be adjusted by the amount of space between the ink key 7 and the ink source roller 6 (hereinafter this amount of space is referred to as the ink key opening).
• a digital pump device may be used as the ink supply device.
• a plurality of ink keys 7 are juxtaposed in the printing width direction, and the ink supply amount can be adjusted in the width unit of ink keys 7 (hereinafter, the ink supply unit width by ink key 7 is referred to as a key zone).
• the ink whose supply amount has been adjusted by the ink key 7 is appropriately kneaded in the ink roller group 5, formed into a thin film, and then supplied to the plate surface of the plate cylinder 4, and the ink adhered to the plate surface is supplied via the blanket cylinder 3 It is transferred to the printing sheet 8 as a pattern.
• the ink supply unit width by ink key 7 is referred to as a key zone.
• the conveyance path of the printing sheet 8 is interposed between the printing sheets 2a, 2b, 2c and 2d.
• a pair of blanket cylinders 3 and 3 are provided, and a plate cylinder 4 and an ink supply device are provided for each blanket cylinder 3.
• the newspaper offset rotary press according to the present embodiment is provided with a line sensor type IRGB densitometer 1 further downstream of the printing unit 2 d on the most downstream side.
• Line sensor type IRGB densitometer 1 prints the color of the pattern on the printing sheet 8 in the width direction of the printing I (infrared light), R (red), G (green), B (blue) reflection density (mixed color network It is a measuring instrument that measures as “density”, and it is possible to measure the reflection density of the entire printing sheet 8 or to measure the reflection density at any position.
• the line sensor type IRGB densitometer 1 is disposed on both sides of the print sheet 8 so as to sandwich the conveyance path of the printing sheet 8, and it becomes possible to measure reflection density on both sides. It is.
• the reflection density measured by the line sensor type IRGB densitometer 1 is transmitted to a computing device (computer) 10.
• the arithmetic unit 10 is a unit that calculates control data of the ink supply amount, and performs calculation based on the reflection density measured by the line sensor type IRGB densitometer 1 to match the color of the pattern on the print sheet 8 with the target color.
• FIG. 2 is a view showing a schematic configuration of a picture color tone control device of a newspaper offset rotary press as a printing press according to the first embodiment of the present invention.
• the color system of the arithmetic unit 10 It is a functional block diagram which paid its attention to the control function.
• the arithmetic unit 10 is composed of a DSP (digital 'signal' processor) 11 and a PC (personal computer) 12 installed apart from the printing machine. Functions as an arithmetic unit 15, an online control unit 16, a key opening limiter operation unit 17 and an information processing unit 18 are assigned.
• DSP digital 'signal' processor
• PC personal computer
• a line sensor type IRGB densitometer 1 is connected to the input side of the arithmetic device 10, and a control device 20 built in the printing press is connected to the output side.
• the control device 20 functions as an ink supply amount control means for adjusting the ink supply amount for each key zone of the ink key 7.
• the control device 20 controls an opening / closing device (not shown) for opening and closing the ink key 7. The key opening can be adjusted independently for each of the ink keys 7 of 2b, 2c, 2d.
• a display device for displaying a print pattern on a sheet is connected to the arithmetic device 10, and the printer rear monitor 40 also has a function as a touch panel.
• the touch panel 40 converts the printing surface of the printing sheet 8 into an image or displays the printing surface of the printing sheet 8 imaged by the line sensor type IRGB densitometer 1 by the touch panel 40, and any printing surface on the printing surface is displayed. The area can be selected with a finger.
• the PC 12 is provided in advance with data such as AM 100 line compatible print characteristic information DB (AMIOODB) 141 and FM compatible print characteristic information DB (FMDB) 142 as a storage area.
• AMIOODB AM 100 line compatible print characteristic information DB
• FMDB FM compatible print characteristic information DB
• a look-up table that defines the correspondence between mixed-color halftone density and dot area ratio is used as printing characteristic information.
• the AM 100 DB 141 and the FMDB 142 are input from a not-shown input device of a look-up table (LUT) power PC 12 as printing characteristic information obtained for the AM 100 line and FM screening in advance, stored and stored (printing characteristics). Information acquisition means).
• a printing plate obtained by screening a print pattern based on the above-mentioned newspaper imprint Ijj apanColor according to the FM method is printed with a reference density Ds, and an IRGB densitometer is used. By performing measurement, it is possible to obtain a lookup table compatible with FM screening.
• the LUT corresponding to each screening may be obtained when the printing characteristics change, such as when the printing material (paper, ink, blanket, etc.) changes, which need not be obtained each time printing is performed.
• the LUT may be obtained for the above and stored in the storage area of the PC 12.
• the number of lines is the number of dots (one line) per 1 inch when AM screening is performed, and represents the number of dots per unit area.
• the base station side mainly processes the paper surface preparation part for preparing the contents of the paper surface
• the printing part mainly processes the printing factory side.
• plate making data and job ticket data including dot area rate data of a print pattern supplied from the paper creation part to the receiving server 41 of the printing factory.
• dot area rate data of a print pattern supplied from the paper creation part to the receiving server 41 of the printing factory.
• dot area ratio data acquisition means are acquired (dot area ratio data acquisition means).
• the target pixel area setting section 18A of the information processing section 18 acquires the coordinates (the coordinate information of the above target pixel area) for the plate-making data on which color matching is important designated by the designer in the paper surface creation part and combines colors!
• the target pixel area is set (target pixel area setting means), and the dot area ratios ki, ci, mi and yi of the pixels in the target pixel area are output to the color conversion unit.
• the screening information acquisition unit 18 B acquires screening type information Sr at the coordinates of the plate-making data pixel (screening information acquisition means) and outputs it to the color conversion unit 14.
• the plate making data and the job ticket data may be directly input to the information processing unit 18 by the operator without acquiring the reception server 41 power. Here, the plate making data and the job ticket data will be described.
• a person in charge of paper composition such as a designer of the paper to be printed composes the paper to be printed and prepares plate making data based on this.
• the designer or the like also designates which area in the print pattern is to be printed using which screening type.
• information regarding the pixel area of interest including the type information of screening (hereinafter, screening information Sr) is written to the job ticket data related to this printing!
• the job ticket data corresponds to a process document describing each attribute and procedure of printing process control (Processes), prepress (Prepress), printing (Press) and post processing (Postpress), and is in charge of managing the entire printing.
• the information, etc., which is created by the parties etc., is added to the information on the pixel area of interest and the screening information Sr corresponding to the original area to a part of this job ticket data.
• CIP4 International Cooperation There is JDF (Job Definition Format) 7 "of the Integration for Principles in Prepress, Press, and Postpress standard and AMPAC data of JIS standard.
• the ink supply is controlled so that each ink used for the pixel area at the time of printing has a target density corresponding to the screen information Sr. Therefore, the color tone control is performed with high accuracy among the target print pattern, and the portion is set to the “target pixel area”.
• JDF of the CIP 4 standard uses XML language, so information for reflecting not only machine control instructions but also business management etc. More detailed information can be incorporated, and it is easy to write information about the pixel area of interest. Therefore, it is also preferable to adopt a general-purpose job ticket data format such as CIP4 JDF data.
• the LUT corresponding to each screening is obtained in advance on the base station side (paper creation part), and the LUT corresponding to the screening of the pixel area of interest is written in the job ticket data. Even if it does, it is good. In this way, it is not necessary for the printing factory (printing part) to obtain the LUT in advance. Also, if you do not receive screening information as job ticket data, you can also get it directly from CTP. CTP recognizes the type and coordinates of screening for plate-making.
• the information processing unit 18 may use bit map data (lbit-Tiff plate making data) or JDF data corresponding to 50.8 dpi, or from the base station of the plate making data.
• bit map data (lbit-Tiff plate making data) or JDF data corresponding to 50.8 dpi, or from the base station of the plate making data.
• ⁇ is the same resolution converted data (1200dpi or!, Is lq-tiff data of 2400dpi converted to 8bit-tiff of 50dpi)] Paper size information of newspaper coming to the printing factory] Is acquired (step D10), and the transmitted bit map data is converted into low resolution data equivalent to DF data according to the format of the printing press, and this low resolution data is used as pixel area ratio data. It is also possible to use bitmap data itself as pixel area ratio data in the post-power processing in order to share this resolution conversion processing with general JDF data. Further, the job ticket data described above is also acquired at the same time as the plate making data (step D20).
• step D30 the information processing section 18 automatically sets the pixel information area of interest corresponding to each ink color by automatically setting the pixel information area of interest of each pixel area written in the job ticket data.
• the area ratios ki, ci, mi and yi are output to the color conversion unit 14.
• step D40 the screening information Sr of the target pixel area for each ink supply zone is output from the job ticket data to the color conversion unit 14.
• screening corresponding to screening information Sr is referred to as use screening.
• step D50 the color conversion unit 14 selects the LUT corresponding to the used screening from among the LUTs stored in the AM 100 DB 141 and the FMDB 142, and selects each pixel network of the target pixel area of each ink color automatically set.
• the dot area rates ki, ci, mi and yi are converted to mixed color densities (conversion means), and they are averaged in the pixel area of interest and set as target mixed color densities Io, Ro, Go and Bo (target mixed color network Concentration setting means).
• the pixel-of-interest area is set for each ink supply zone, so that the LUT used for each ink supply zone corresponding to a page is different, for example, when the screening type is different for each page. Become. As described above, when the target color mixture halftone density Io, Ro, Go, Bo force is set, as shown in FIG. 4, the processing after step S10 is repeatedly executed.
• step S10 the line sensor type IRGB densitometer 1 measures the amount of reflected light i ′, r ′, g ′, b ′ for each pixel on the entire surface of the printing sheet 8.
• the reflected light amount i ′, r ′, g ′, b ′ of each pixel measured by the IRGB densitometer 1 is input to the DSP 11.
• step S20 the DSP 11 performs moving average on the basis of the number of printed sheets for each of the reflected light amounts i ′, r ′, g ′ and b ′ of each pixel, thereby reflecting the reflection of each pixel from which the noise component has been removed. Calculate the light quantity i, r, g, b.
• step S30 the actual mixed color halftone densities I, R, G, B of the target pixel of each color are acquired using the reflected light amounts i, r, g, b of each pixel calculated in step S20 Concentration acquisition means).
• the DSP 11 determines the actual mixed color halftone densities I, R, G, B from the reflected light amounts i, r, g, b of the attention point of the printing sheet (main printing sheet) 8 and the reflected light amounts of the white paper part.
• the pixel of interest is basically a set of a plurality of pixels, the reflected light amounts i, r, g, b are averaged with the plurality of pixels constituting the pixel of interest.
• the reflected light amount of the infrared light of the white paper portion is ip and the average reflected light amount of the infrared light in the key zone is ik
• the actual mixed color halftone densities I, R, G, B for each key zone calculated by the DSP 11 are input to the color conversion unit 14 of the PC 12.
• the color conversion unit 14 performs the processes of steps S40, S50 and S60.
• step S40 target mixed color halftone densities Io, Ro, Go, Bo set in step D50, and actual mixed color halftone densities I, R, G, B of the target pixel area of each color calculated in step S30.
• the dot area ratio of each ink color to be calculated is calculated respectively.
• a LUT corresponding to the used screening is used, and the dot area ratio of each ink color corresponding to the target mixed color network density Io, Ro, Go, Bo is set as the target dot area ratio ko, co, mo, yo Calculation (target dot area ratio calculating means), and calculating the dot area ratio of each ink color corresponding to the actual mixed color halftone density I, R, G, B as the actual dot area ratio k, c, m, y Yes (real dot area rate calculation means).
• the color conversion unit 14 sets the target halftone dot plane calculated in step S40 as step S50.
• a map as shown in Fig. 5 is used for these calculations.
• Fig. 5 is an example of a map in which the monochrome network density measured when the dot area ratio is changed is plotted as a characteristic curve, and is created from data measured in advance. In the example shown in FIG.
• the target monochrome dot density Dako and the actual monochrome dot density Dak are respectively extracted from the characteristic curves in the map by comparing the black target dot area ratio ko and the real dot area ratio k against the map. Is required.
• the color conversion unit 14 obtains the target single-color screen densities Dako, Daco, Damo, Dayo of each ink color and the actual single-color screen densities Dak, Dac, Dam, Day.
• step S60 the color conversion unit 14 corresponds to the deviation between the target pixel target monochrome density of each color Dako, Daco, Damo, Dayo and the real monochrome density Dak, Dac, Dam, Day.
• the solid density deviation of each ink color A Dskl, A Dscl, A Dsml, A Dsyl is calculated (Vet density deviation calculation means).
• the solid density also depends on the target dot area rate, and the solid density decreases as the target dot area rate increases with respect to the single-color screen density. Therefore, the color conversion unit 14 performs an operation using a map as shown in FIG. FIG. 6 is an example of a map in which the single-color screen density at each dot area rate measured when the single-color solid density is changed is plotted as a characteristic curve for each dot area rate, and it is generated from data measured in advance. It is done. The color conversion unit 14 selects the characteristic curve corresponding to the target dot area ratio ko, co, mo, yo for each ink color as shown in FIG.
• the target characteristic curve to obtain the target monochromatic density Dako, Daco, By matching Dam o, Dayo with real single-color net density Dak, Dac, Dam, Day, the solid density deviation A Dskl, A Dscl, A Dsml, A Dsyl, A Dsyl, A Dsk2, A Dsc2, A Dsm2, A Dsy2 Ask.
• the target dot area ratio ko for the black color is 75%
• the target single-color screen density Dako and the actual single-color screen density Dak are compared with the map to obtain 75% characteristic curve in the map.
• the solid density deviation ⁇ Dsk of the black color is determined.
• the solid density deviations of the ink colors A Dsk, A Dsc, A Dsm, and ⁇ Dsy calculated by the color conversion unit 14 are input to the ink supply amount calculation unit 15.
• the ink supply amount calculation unit 15 sets the key opening deviation corresponding to the solid density deviation A Dsk, A Dsc, A Dsm, ⁇ Dsy as Step S 70. Calculate the quantities AKk, AKc, ⁇ , AKy.
• Key opening deviations AKk, AKc, ⁇ , AKy are the current key openings KkO, KcO, KmO, KyO of each ink key 7 (The key opening output to the control device 20 of the printing press in the previous step S100 processing Kk, Kc, Km, and Ky), and the ink supply amount calculation unit 15 performs calculation using a known API function (auto-preset inking function).
• the API function shows the correspondence between the streaking factor A (Ak, Ac, Am, Ay) of each key zone and the key opening K (Kk, Kc, Km, Ky) in order to use the standard density. It is a function, and the drawing ratio A can also be obtained by averaging the dot area ratio of each key zone with the dot area ratio data strength of the printed pattern.
• determine the key opening K for making the reference density to the area rate A and calculate the solid density deviation ⁇ Ds to be zero as the product of these.
• Find the quantity ⁇ K (AK kd XK).
• step S80 the online control unit 16 calculates the key opening deviation amounts AKk, ⁇ , ⁇ , AKy calculated by the color conversion unit 14 from the respective printing units 2a, 2b, 2c, 2d.
• Sensor type IRGB densitometer Corrects in consideration of dead time up to 1, reaction time of ink key 7 per hour, and printing speed. This correction is detected by the IRGB densitometer 1 as a change in the amount of reflected light when the key opening signal is input and then the ink key 7 moves, the key opening is changed, and the amount of ink supplied to the printing sheet changes. It takes into consideration the time delay until As such an on-line feedback control system with a large dead time, for example, PI control with dead time compensation, fuzzy control, robust control, etc.
• the on-line control unit 16 calculates the current key opening KkO, KcO, KmO, and KyO by calculating the current key opening deviation KkO, KcO, KmO, and KyO for the corrected key opening deviation (the online control key opening deviation) AKk, ⁇ Kc, ⁇ , and AKy.
• the online control key openings Kkl, Kcl, Kml, and Kyi are input to the key opening limiter calculation unit 17.
• step S 90 the key opening limiter computing unit 17 performs correction for restricting the upper limit value to the online control key openings Kkl, Kcl, Kml, and Kyi computed by the online control unit 16. This is a process for restricting an abnormal increase in the key opening due to an estimation error of the color conversion algorithm (processing of steps S40, S50 and S60) particularly in the low image area. It is Then, in step S100, the key opening limiter computing unit 17 transmits the key openings Kk, Kc, Km, and Ky whose upper limit value is restricted, to the control device 20 of the printing press as a key opening signal.
• the control device 20 of the printing press determines the ink keys 7 of the printing units 2a, 2b, 2c, and 2d based on the key opening signals Kk, Kc, Km, and Ky transmitted from the computing device 10 in step S110. Adjust the opening degree. As a result, the amount of ink supplied to each ink color is controlled to be the target color tone for each key zone.
• the apparatus and method for controlling the color tone of a printing press according to the first embodiment of the present invention are configured as described above, even when a plurality of screenings are used in combination in the same printing plate,
• the client or designer performs color tone control based on the target mixed color network density calculated using the LUT corresponding to the screening type, for the target points specified by the client at printing or the important points that the designer considers important. It is possible to make the color tone of the point of interest that is important to be the desired color tone, and print high-quality printed matter.
• the present embodiment is characterized in that dot gain characteristics are used as printing characteristic information, and the other configuration is the same as that of the first embodiment, and therefore the description of the same portions as the first embodiment is omitted. Also, the same reference numerals are used for the same components as the first embodiment.
• FIG. 7 is a view showing a schematic configuration of a pattern color tone control device for a newspaper offset rotary press as a printing press according to a second embodiment of the present invention, and a function focused on the color tone control function of the arithmetic unit 10. It is a block diagram.
• the dot gain characteristic information DB (DGDB) 150 is provided as a storage area of the PC 12 instead of the FMDB 142, except for the first embodiment. It has the same configuration as the form.
• a LUT corresponding to the AM 100 line acquired in advance by the above-described method is input.
• LUT reference look-up table
• the screening corresponding to the LUT here AM100 line
• the standard screening is not limited to the AM100 line, but can be appropriately changed.
• D GDB 150 stores dot gain curve information (dot gain characteristic information) corresponding to a plurality of scripts (here, assumed to be AM 100 line, FM) including a reference script acquired in advance. (Printing characteristic information acquisition means).
• dot gain curve information corresponding to the reference screening and the plurality of screens is used as printing characteristic information! /.
• the dot gain curve will be described with reference to FIG. What is dot gain? Dots of printed matter are ink bleeding and spreading (this is called mechanical-cal dot gain) and light inside the dots is multi-reflected between ink and paper to make paper and ink power It refers to a phenomenon in which the reflection of light and the spread of optical dots (this is called optical dot gain) becomes larger than the dots written on the printing plate. Then, as shown in FIG. 8, the dot gain curve takes the dot area ratio on the printing plate (i.e., the dot area ratio of the plate making data) on the horizontal axis, and the image is actually transferred on the printing sheet on the vertical axis.
• the optical (apparent) dot area power calculated by the Murray Davis equation is also represented by a graph obtained by subtracting the dot area ratio on the printing plate (dot gain amount).
• the dot gain becomes larger as the average circumference of the halftone dots becomes longer as the number of halftone dots per unit area is larger. That is, in this case, the dot gain is larger in the FM screening than in the AM100 line.
• a densitometer for example, a printing sheet obtained by printing in advance a pattern of various dot area ratios (for example, every 5%) with a single color for each ink color. It can be determined by plotting the result of measurement by an IRGB densitometer) and the measurement by a known Murray Davis equation shown below.
• DG (1-10 "°) Z (1-10- Ds ) X 100-arbitrary dot area ratio on plate ' ⁇ ⁇ ⁇ (1) Is represented by However, D: density of arbitrary dot area rate, Ds: 100% dot density
• steps D10 to D40 of FIG. 3 are performed as in the first embodiment described above. Then, in the present embodiment, after the processing of steps D10 to D40 of FIG. 3, the processing of steps E10 to E40 shown in FIG. 9 is performed.
• step E10 the color conversion unit 14 acquires dot gain information corresponding to the used screening from the DGDB 150. More specifically, the color conversion unit 14 receives dot gain amount DGi (hereinafter referred to as reference dot gain amount DGi) corresponding to reference screening from DGDB 150 and dot gain amount DGr corresponding to used screening (hereinafter referred to used dot gain). Get the quantity DGr).
• dot gain amount DGi hereinafter referred to as reference dot gain amount DGi
• DGr dot gain amount DGr corresponding to used screening
• step E20 the color conversion unit 14 calculates the difference (DGr ⁇ DGi) between the reference dot gain amount DGi and the used dot gain amount DGr.
• step E30 the above difference (2) is applied to the dot area rates ki, ci, mi, yi
• step E40 the color conversion unit 14 converts each pixel dot area ratio kir, cir, mir, yir after correction of the control target pixel area into a mixed color density using the LUT stored in the AM 100 DB 141.
• Converting means The average value of each pixel density is set as the target mixed color network density Io, Ro, Go, Bo (target mixed color network density setting means).
• the apparatus and method for controlling the color tone of a printing press according to the second embodiment of the present invention is configured as described above, the case where a plurality of types of screening are used in combination in the same printing plate. Even in this case, accurate tone control can be performed by using the corrected dot area ratio corrected for the difference in the dot gain amount between the reference screening and the use screening. Further, acquisition of dot gain curve information is described above. So that each color of ink color dot plane As it is only necessary to actually measure the product ratio, as in the first embodiment, it is necessary to actually measure the density for the combination of each of the CMYK colors corresponding to the Japan color standard (928 colors). There is an advantage that the amount of work to acquire is small.
• the base station side writes information (target point and screening type) on the target pixel area in the job ticket data.
• LUT data corresponding to the screening type as printing characteristic information
• dot gain characteristic information may be written.
• color tone control may be performed as in the above-described first embodiment and second embodiment using LUT or dot gain curve data written in the job ticket. In this way, it is possible to omit the work of acquiring the LUT corresponding to the screen at the printing plant and inputting it to the PC 12 or the like.
• the screening information Sr is written in the job ticket data.
• a means for reading information on the type and arrangement of the screening is provided. Also good.
• the job ticket data is not essentially necessary for the printing operation, but it does not use the job ticket data, and even if it is from the plate making data, the information about the screening type and area to be used will be used. It can be acquired. In addition, even when the target pixel area is changed on the printing factory side, the type of screening corresponding to the changed target area can be acquired, and color tone control in a more versatile printer can be performed. Availability of
• the present invention is suitable for use in newspaper printing and the like where plate making may be performed using different screening for each page, but the present invention is not limited to newspaper printing and the like, and different types of screening may be used together for printing. It can be widely applied to various printing machines that do.

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• Inking, Control Or Cleaning Of Printing Machines (AREA)
• Facsimile Image Signal Circuits (AREA)

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• 2006
  • 2006-01-20 JP JP2006012447A patent/JP5311716B2/ja not_active Expired - Fee Related
• 2007
  • 2007-01-22 WO PCT/JP2007/050921 patent/WO2007083798A1/ja not_active Ceased
  • 2007-01-22 US US12/160,881 patent/US20090002767A1/en not_active Abandoned
  • 2007-01-22 EP EP07707184A patent/EP1977899A4/en not_active Withdrawn
  • 2007-01-22 KR KR1020087020207A patent/KR20080090511A/ko not_active Ceased

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