JP2006047127A - Calibration method of colorimetric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a calibration method of a colorimetric device capable of uniformizing measurement accuracy of a plurality of colorimetric devices, and manufacturing a plurality of prints having qualities with no dispersion by using a plurality of printing devices. <P>SOLUTION: A photograph processing system 200 includes the plurality of printing devices 10. In the photograph processing system 200, a colorimetric unit 24 of an optional printing device 10 is used as a reference machine, and a colorimetric unit 24 of another printing device 10 is used as a calibration machine, and a measured value of the coloring density of a test print 100 by the reference machine is compared with a measured value of the coloring density of the test print 100 by the calibration machine, to thereby acquire a calibration coefficient. When setting up the printing device 10 including the calibration machine, the measured value of the coloring density of the test print 100 by the calibration machine is calibrated by using the calibration coefficient. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a calibration method for a color measurement device, and more particularly to a calibration method for a color measurement device that measures the color of an image formed on a print material.

  2. Description of the Related Art Conventionally, a photographic processing system that forms an image recorded on a photographic film or the like on photographic paper, which is an example of a printing material, is used in a developing laboratory (laboratory). In a photographic processing system, an image is formed on photographic paper by performing exposure processing and development processing. When adjusting the exposure conditions of a printing apparatus that performs exposure processing in a photographic processing system, a predetermined image (calibration image) with different colors (color density) is exposed to photographic paper to produce a test print. . Then, the color density of each portion of the calibration image formed on the test print is measured by a color measuring device provided corresponding to the printing device. When each measured value by the colorimetric device is not a prescribed value, the exposure amount, the exposure time, etc. of the printing device are adjusted so that the color density of each part of the calibration image formed on the test print becomes the prescribed value.

  For example, as disclosed in Patent Document 1, the colorimetric device is calibrated using a calibration plate. Generally, the calibration plate is provided with a black colorimetric point having the highest density that can be assumed on the print and a white colorimetric point having the lowest density that can be assumed on the print. In the calibration of the color measuring device, the color density of the black color measurement point and the white color measurement point on the calibration plate is measured, and it is confirmed whether or not each measurement value is a specified value. Then, when the measured value of the black measured color point and / or the white measured color point is not the specified value, the color measuring device is set so that the measured value of the color density of the measured color point becomes the specified value. The amount of light from the light source is adjusted.

In a large-scale developing laboratory, by using a photographic processing system including a plurality of printing devices and a plurality of colorimetric devices provided corresponding to the respective printing devices, each printing device exposes the same image on each photographic paper, A large number of prints on which the same image is formed are produced. Usually, in a photographic processing system including a plurality of color measuring devices, a dedicated calibration plate is prepared for each color measuring device.
JP 2001-174937 A

  However, in each calibration plate prepared for each color measuring device, even if there is an error in the color density of the measured color point due to differences between the calibration plates, fading, dirt, etc. Since each color measuring device is calibrated so that the measured value of the point becomes a specified value uniformly, a deviation occurs in the measurement accuracy of each color measuring device. As a result, the color density of each test print produced by exposure processing with the corresponding printing device is measured with each color measuring device, and even if the measured value by each color measuring device is a specified value, actually There was a problem that the color density of each test print was different.

  As a result, the exposure conditions of each printing apparatus cannot be adjusted so that the color density of the image to be exposed is equal, and when a plurality of prints of the same image are produced using a plurality of printing apparatuses, the color density of each print varies. There was a problem.

  Therefore, a main object of the present invention is to provide a calibration method for a colorimetric device that can make the measurement accuracy of a plurality of colorimetric devices uniform, and thus can produce a plurality of prints having no variation in quality using a plurality of printing devices. It is to be.

  In order to achieve the above object, a calibration method for a colorimetric device according to claim 1 is a calibration method for a colorimetric device for measuring the color of an image formed on a print material, wherein an image is formed. A step of preparing a colorimetric member, a step of measuring the color of an image formed on the colorimetric member with a first colorimetric device as a reference and a second colorimetric device to be calibrated, A step of comparing the measurement value with the measurement value of the second color measurement device, calculating a calibration coefficient for calibrating the measurement value of the second color measurement device to the same value as the measurement value of the first color measurement device, and calibration A step of storing the coefficient in the storage means.

  The color measuring device calibration method according to claim 2 is the color measuring device calibration method according to claim 1, wherein the image formed on the member to be measured has a minimum density portion and an intermediate density each having a different color density. Part and the highest density part.

  In the calibration method of the colorimetric device according to claim 1, the color of the image of one colorimetric member is measured by the first colorimetric device serving as a reference and the second colorimetric device to be calibrated. The measurement value of the color device is compared with the measurement value of the second color measurement device, and a calibration coefficient for calibrating the measurement value of the second color measurement device to the same value as the measurement value of the first color measurement device is calculated. . Therefore, when the color of the image formed on the print material is measured by the second color measurement device, the measurement value of the second color measurement device is calibrated using the calibration coefficient, and the measurement accuracy of the plurality of color measurement devices is substantially increased. Therefore, it is possible to make the measurement accuracy of the first colorimetric device, which is a standard, uniform. As a result, even when the same image is formed on the print material using a plurality of printing apparatuses, a plurality of prints having no variation in quality can be produced.

  Generally, the calibration plate is provided with only two measured color points, ie, a black measured color point that is the highest density portion and a white measured color point that is the lowest density portion. For this reason, the deviation of the measurement accuracy in each color measuring device is particularly large with respect to the intermediate density color. According to a calibration method for a color measurement device according to a second aspect, a calibration coefficient is calculated using a colorimetric member on which an image including a lowest density portion, an intermediate density portion, and a highest density portion is formed. As a result, the measurement accuracy of each color measurement device can be made uniform even for intermediate density colors, and the measurement accuracy of each color measurement device can be made more accurate.

  According to this invention, the measurement accuracy of a plurality of colorimetric devices can be made uniform. As a result, a plurality of prints having no variation in quality can be produced using a plurality of printing apparatuses.

Embodiments of the present invention will be described below with reference to the drawings.
A printing apparatus 10 to which the present invention is applied will be described with reference to FIGS.
The printing apparatus 10 is an apparatus that is suitably used in a large-scale developing station or the like that produces a large number of prints of images recorded on photographic film or the like. The exposure process and the development process for the photographic paper P are separately performed. It is suitably used for a separation type photographic processing system performed by the apparatus.

  The printing apparatus 10 includes a supply magazine 12 that winds and stores silver salt photographic paper (hereinafter simply referred to as photographic paper) P, which is an example of a print material, and an exposure processing unit 14 that exposes and forms an image on the photographic paper P. A take-up magazine 16 for taking up and storing the exposed photographic paper P in a roll again, a control unit 18 for controlling the operation of the printing apparatus 10, a keyboard and a mouse for an operator to input data and give instructions, etc. An input unit 20, a GUI (Graphical User Interface) that facilitates operation of the printing apparatus 10, a display unit 22 for displaying a message to the operator, an image to be formed on the photographic paper P, and the print color (color density) A colorimetric unit 24 for measuring In this embodiment, the color measurement unit 24 of the printing apparatus 10 corresponds to a color measurement apparatus.

  As shown in FIG. 3, the exposure processing unit 14 includes a supply unit 26 for pulling out the roll-shaped photographic paper P stored in the supply magazine 12. A paper cutter 28 used when ordering or forcibly cutting the photographic paper P is disposed on the transport path of the long photographic paper P drawn by the supply unit 26 and on the downstream side of the supply unit 26. The order cut refers to a process of separating the photographic paper P from the roll in a predetermined order unit, and the forced cut refers to a process of forcibly separating the photographic paper P when dealing with a trouble such as a paper jam.

  On the conveyance path of the photographic paper P in the exposure processing unit 14 and on the downstream side of the paper cutter 28, guide rollers 30 and 32 for changing the direction of the photographic paper P and conveyance roller pairs 34, 36, and 38 for conveying the photographic paper P , 40, 42 are arranged in order. The conveyance roller pairs 34, 36, 38, 40, and 42 rotate with the driving of the stepping motor, and convey the photographic paper P.

  Between the guide rollers 30 and 32, there is provided a loop forming portion 46 that forms a loop when the roller 44 moves up and down. The tension or the like applied to the photographic paper P is absorbed by the loop forming unit 46. Further, a loop forming unit 48 is provided between the conveying roller pair 34 and 36, and a loop forming unit 50 is provided between the conveying roller pair 40 and 42. Similar to the loop forming unit 46, the tension and the like applied to the photographic printing paper P are absorbed by the loop forming units 48 and 50.

  A punch 52 that forms punch holes as marks on the photographic paper P is further arranged on the conveyance path of the photographic paper P. For example, a cut mark H1 and an order mark H2 as shown in FIG.

  In such an exposure processing unit 14, the long photographic printing paper P is exposed by the exposure unit 54 between the conveyance roller pairs 38 and 40, and a plurality of images are continuously formed as latent images. The exposure unit 54 is configured, for example, in a laser exposure system in which an image is exposed and formed on the photographic paper P by scanning a laser beam in a direction (main scanning direction) perpendicular to the conveyance direction of the photographic paper P.

  The exposure unit 54 is not limited to the laser exposure type, and for example, any exposure unit 54 adopting a PLZT shutter method, a fluorescent beam method, a DMD method, or the like can be used.

  The photographic paper P subjected to the exposure processing in the exposure processing unit 14 is wound up in the winding magazine 16 without being developed and stored in a roll shape. Thereafter, the exposed photographic paper P is loaded into another developing device 300 (see FIG. 6) by the operator and developed, and further, cutting and sorting are performed in units of one frame (frame image), and the finished print is printed. Produced.

Returning to FIG. 1, the supply magazine 12, the exposure processing unit 14, the take-up magazine 16, the input unit 20, the display unit 22, and the color measurement unit 24 are controlled by the control unit 18.
The control unit 18 includes a CPU 58, a ROM 60, a RAM 62, a hard disk drive (HDD: including a hard disk) 64, a CD-RW drive 66, a flexible disk (FD) drive 68, and a network interface (I / F) connected to each other via a bus 56. 70.

  The CPU 58 executes various programs stored in the ROM 60, the HDD 64, and the like, gives instructions to each component in the printing apparatus 10, and controls their operations.

  The ROM 60 stores a startup program and the like. The activation program is executed by the CPU 58 when the printing apparatus 10 is powered on. As a result, a program such as an operating system (OS) recorded in the HDD 64 is loaded into the RAM 62, and various processes and controls can be executed.

  In the RAM 62, a program for controlling the printing apparatus 10 is developed. The processing result by this program, temporary data for processing, and display data for displaying information on the screen of the display unit 22 (text data, image data) Etc.) and is used as a work area of the CPU 58. The display data developed on the RAM 62 is transmitted to the display unit 22, and the display unit 22 displays the display content (text, image, etc.) corresponding to the display data on the screen.

  The HDD 64 is a device for writing and reading programs, control data, text data, image data, and the like to and from the hard disk in accordance with instructions from the CPU 58. The hard disk in the HDD 64 stores a program for operating the printing apparatus 10, image data of the calibration image 102 (see FIG. 4A) to be formed on the photographic paper P, and the like. In this embodiment, the HDD 64 corresponds to a storage unit.

  The CD-RW drive 66 writes the program or data recorded in the HDD 64 or the like or the data held in the RAM 62 to the CD-R (RW) 66a in accordance with an instruction from the CPU 58, and the program or data from the CD-R 66a. read out. Needless to say, the CD-RW drive 66 can read programs and data from the CD-ROM.

  Similarly, the FD drive 68 writes a program or data recorded in the HDD 64 or the like or data held in the RAM 62 to the flexible disk (FD) 68a in accordance with an instruction from the CPU 58, and a program or data recorded in the FD 68a. Read data.

  The network I / F 70 is connected to a network NT such as a LAN (Local Area Network) or the like, and performs data transmission / reception to / from other devices or downloading of programs and data via the network NT in accordance with instructions from the CPU 58. Used for. As a communication protocol of the network NT, for example, a TCP / IP communication protocol is used.

  Further, the color measuring unit 24 for measuring the color density of the calibration image 102 formed on the test print 100 is connected to the control unit 18 in accordance with an instruction from the CPU 58.

  Here, the test print 100 and the color measurement unit 24 will be described with reference to FIG. 4A, FIG. 4B, and FIG. First, the test print 100 will be described with reference to FIGS. 4 (a) and 4 (b).

  As shown in FIG. 4A, a leading end loss portion 104 is provided at the leading end of the photographic paper P developed by the developing device 300 after the calibration image 102 is exposed and formed by the exposure unit 54, and the trailing end. A rear end loss part 106 is provided in the part.

  The calibration image 102 is, for example, rectangular, and includes a gray scale image 108 for measuring the color density and a cut line 110 formed by making the tip of the gray scale image 108 a broken line. The cut line 110 indicates the cut position on the leading end side of the photographic paper P, and below that, character information 110a <cut line> and triangular graphic information 110b indicating the insertion direction into the colorimetric unit 24 are combined. . The gray scale image 108 is an image of color data (8-bit gray value: 0 to 255) represented by 18 scales Sc1 to Sc18 in order to measure the color density. Here, the gray scale image 108 is configured such that the dimensions of the scales Sc1 to Sc18 in the direction of arrow A are equal, and the color density increases stepwise as the scale Sc1 to Sc18 moves. In the gray scale image 108, the scale Sc1 is set to be the lowest density image that can be formed on the photographic paper P, and the scale Sc18 is set to be the highest density image that can be formed on the photographic paper P. Is set.

  By cutting the leading end side of such a photographic paper P with a cutting line 110 and cutting the trailing end side at a predetermined position by a cutting device (not shown), the test print 100 as shown in FIG. Is obtained. Such a test print 100 is inserted into the color measurement unit 24 so that the gray scale image 108 is on the upper side in the direction of arrow A, and the color density of the scales Sc1 to Sc18 constituting the gray scale image 108 is adjusted by the color measurement unit 24. Each is measured.

Next, the color measurement unit 24 will be described with reference to FIG.
The color measurement unit 24 includes a housing 72, and the housing 72 is provided with an insertion port 72 a into which the test print 100 is inserted. In the casing 72, conveyance roller pairs 74 and 76 for conveying the test print 100 inserted from the insertion opening 72a are provided in order, and a measuring unit 78 is disposed between the conveyance roller pairs 74 and 76.

  The conveyance roller pairs 74 and 76 are configured by conveyance rollers 74a and 76a that rotate in accordance with driving of the stepping motor, and pressure-bonding rollers 74b and 76b that press the test print 100 against the conveyance rollers 74a and 76a, respectively.

  The transport roller pairs 74 and 76 stop transporting the test print 100 when measuring the color density of the scales Sc1 to Sc18, and when the measurement of the color density of one scale is completed, the dimension of the one scale in the direction of arrow A is completed. Only the test print 100 is conveyed.

  The measurement unit 78 includes a housing 80, an opening 80 a is provided on the surface of the housing 80 facing the test print 100, and a light source 82, a lens 84, and a light receiving unit 86 are provided in the housing 80.

  The light source 82 includes a plurality of LEDs that respectively emit light in the wavelength regions of R (red), G (green), and B (blue). The light emitted by the light source 82 is collected by the lens 84, passes through the opening 80 a, and is given to the test print 100. The light given to the test print 100 is reflected by the main surface of the test print 100 (the surface on which the gray scale image 108 is formed), returns from the opening 80 a into the housing 80, and is reflected by the inner wall of the housing 80. And provided to the light receiving unit 86.

  The light receiving unit 86 includes a plurality of light receiving elements that respectively detect the light intensities in the R, G, and B wavelength regions, and the color densities of the scales Sc1 to Sc18 from the light reflected from the gray scale image 108 of the test print 100, respectively. taking measurement.

  In addition, a pressing mechanism 88 for pressing the test print 100 against the opening 80 a is provided in the housing 72 and below the measurement unit 78. The pressing mechanism 88 includes a pressing plate 88a that presses the test print 100 against the opening 80a from below, an arrangement member 88b that arranges the pressing plate 88a, and a support shaft 88c that is connected to the arrangement member 88b.

  The pressing mechanism 88 presses or releases the test print 100 against the opening 80a by the arrangement member 88b and the pressing plate 88a swinging in the arrow B direction as the support shaft 88c swings. The pressing mechanism 88 presses the test print 100 against the opening 80a when measuring the color density of the scales Sc1 to Sc18, and releases the pressing when the test print 100 is conveyed.

  Using such a test print 100 and the colorimetric unit 24, for example, before starting daily work or when changing the photographic paper P to be used, the exposure conditions of the printing apparatus 10 are adjusted (the printing apparatus 10 is set up). . Specifically, in the setup of the printing apparatus 10, the color measuring unit 24 determines the color density of the scales Sc <b> 1 to Sc <b> 18 of the test print 100 produced by exposing the calibration image 102 to the photographic paper P by the exposure processing unit 14. Measure each. If each measured value is not an appropriate value (specified value), the exposure amount and exposure time setting of the exposure unit 54 are adjusted so that the scales Sc1 to Sc18 having appropriate color density can be formed by exposure.

  Returning to FIG. 1, the controller 18 is further connected to a scanner 90 that operates in accordance with an instruction from the CPU 58 and acquires a frame image formed on a photographic film as image data. The image data acquired by the scanner 90 is recorded in, for example, the HDD 64, and an image based on the image data is exposed and formed on the photographic paper P by the exposure unit 54.

A photo processing system is configured in a developing station that uses a plurality of such printing apparatuses 10 to produce a large number of prints. FIG. 6 shows an example of a photographic processing system using a plurality of printing apparatuses 10.
A photographic processing system 200 shown in FIG. 6 includes a plurality of printing apparatuses 10 (here, the printing apparatuses 10a, 10c, and 10b) and a developing apparatus 300 connected to the network NT via a network I / F 70, respectively.

  In the photographic processing system 200, the developing device 300 may be provided for each of the printing devices 10a, 10b, and 10c.

  In the photographic processing system 200, for example, image data is transmitted and received between the printing apparatuses 10a, 10b, and 10c, and an image based on the same image data is exposed and formed on the photographic paper P by the exposure processing unit 14 of each printing apparatus 10. Then, the developing device 300 performs development processing on the photographic paper P that has been subjected to exposure processing by each printing apparatus 10, and performs cutting and sorting operations to produce a plurality of prints on which the same image is formed.

  In such a photographic processing system 200, the calibration image 102 is exposed and formed on the photographic paper P for each of the printing apparatuses 10a, 10b, and 10c to produce the test print 100, and setup is performed for each of the printing apparatuses 10a, 10b, and 10c. Is called. In the setup of each printing apparatus 10, if the measurement accuracy of each color measurement unit 24 is shifted, even if the measurement values of the scales Sc <b> 1 to Sc <b> 18 of each test print 100 by each color measurement unit 24 are the specified values, This means that the color densities of the scales Sc1 to Sc18 of each test print 100 are different. That is, the exposure conditions of the printing apparatuses 10a, 10b, and 10c cannot be adjusted so that the color densities of the images to be exposed and formed are equal.

  In order to prevent this, in the photo processing system 200, the color measurement unit 24 of an arbitrary printing apparatus 10 is used as a reference machine (corresponding to the first color measurement apparatus), and the color measurement units 24 of the other printing apparatuses 10 are calibrated (second machine). As a color measuring device), the calibration coefficient is obtained by comparing the measured value of the color density of the test print 100 by the reference machine and the measured value of the color density of the test print 100 by the calibrator. Then, when setting up the printing apparatus 10 including the proofing machine, the measured value of the color density of the test print 100 by the proofing machine is calibrated using the calibration coefficient.

Next, the calibration coefficient acquisition operation in the photo processing system 200 and the setup operation of the printing apparatus 10 including the proofing machine will be described.
First, calibration coefficient acquisition work in the photo processing system 200 will be described. Here, the color measurement unit 24 of the printing apparatus 10a is used as a reference machine, and the color measurement unit 24 of the printing apparatuses 10b and 10c is used as a calibration machine. Since the operations of the printing apparatuses 10b and 10c are the same in the calibration coefficient acquisition operation of the photo processing system 200, only the operation of the printing apparatus 10b will be described here.

  Referring to FIG. 7, first, the exposure processing unit 14 of the printing apparatus 10a exposes and forms the calibration image 102 on the photographic paper P, and the test print 100 is produced (step S1). In this embodiment, the test print 100 produced in step S1 corresponds to the color member to be measured. The scale Sc1 corresponds to the lowest density part, the scales Sc2 to Sc17 correspond to the intermediate density part, and the scale Sc18 corresponds to the highest density part.

  Subsequently, the test print 100 produced in step S1 is inserted into the color measurement unit 24 of the printing apparatus 10a, the color density of the scales Sc1 to Sc18 is measured by the color measurement unit 24, and the data of each measurement value is stored in the RAM 62. It is held (step S3).

  Subsequently, in the printing apparatus 10a, the data of the measured values of the scales Sc1 to Sc18 held in the RAM 62 are written into the FD 68a as the data of the reference measured values of the scales Sc1 to Sc18 by the FD drive 68 (step S5).

  Subsequently, the FD 68a in which the data of the reference measurement values of the scales Sc1 to Sc18 is written in step S5 is set in the FD drive 68 of the printing apparatus 10b, and the data of the scale Sc1 to Sc18 reference measurement values is held in the RAM 62 of the printing apparatus 10b. (Step S7).

  Subsequently, the test print 100 produced in step S1 is inserted into the color measurement unit 24 of the printing apparatus 10b, and the color density of the scales Sc1 to Sc18 is measured by the color measurement unit 24, and the data of each measurement value is stored in the RAM 62. It is held (step S9).

  Then, in the printing apparatus 10b, the reference measurement value data of the scales Sc1 to Sc18 and the measurement value data of the scales Sc1 to Sc18 are respectively compared, and each measurement value is calibrated to the same value as each reference measurement value. Calibration coefficients α1 to α18 are calculated (step S11). In step S11, the CPU 58 of the printing apparatus 10b calculates (reference measurement value) / (measurement value) so as to correspond to the scales Sc1 to Sc18, and calculates calibration coefficients α1 to α18.

  Thereafter, the data of the calibration coefficients α1 to α18 are stored in the HDD 64 of the printing apparatus 10b (step S13), and the calibration coefficient acquisition operation in the photo processing system 200 is completed.

  Note that the exposure formation of the calibration image 102 in the process of step S <b> 1 may be performed by any printing apparatus 10.

  Further, since the color density characteristics of the scales Sc1 to Sc18 differ depending on the type of the photographic paper P, the above-described calibration coefficient acquisition operation is performed for each type of the photographic paper P to be used. Calibration coefficients α corresponding to the types of paper P are calculated and recorded in the HDD 64.

Next, a setup operation of the printing apparatus 10 (here, the printing apparatuses 10b and 10c) including the calibration machine will be described.
Since the setup operations in the printing apparatuses 10b and 10c are the same, the operation of the printing apparatus 10b will be described here.

  Referring to FIG. 8, first, the exposure processing unit 14 of the printing apparatus 10b exposes and forms the calibration image 102 on the photographic paper P, and the test print 100 is produced (step S101). Subsequently, the test print 100 produced in step S101 is inserted into the color measurement unit 24 of the printing apparatus 10b, and the color measurement density of the scales Sc1 to Sc18 is measured by the color measurement unit 24, and the data of each measurement value is stored in the RAM 62. It is held (step S103).

  Then, the data of the calibration coefficients α1 to α18 stored in the HDD 64 of the printing apparatus 10b is read to the RAM 62 (step S105), and the data of the measured values of the scales Sc1 to Sc18 held in the RAM 62 are the calibration coefficients α1 to α18. Each data is calibrated using the data (step S107). In step S107, the CPU 58 of the printing apparatus 10b calculates (measured value) × (calibration coefficient α) so as to correspond to the measured values of the scales Sc1 to Sc18, and the data of each measured value after calibration is stored in the RAM 62. Retained.

  Thereafter, each measured value after calibration is displayed on the display unit 22 of the printing apparatus 10b (step S109), and it is determined by the operator whether or not the measured values after calibration of the scales Sc1 to Sc18 are specified values (step S109). Step S111). That is, it is determined whether or not the color densities of the scales Sc1 to Sc18 are appropriate.

  If the color density of the scales Sc1 to Sc18 is not appropriate (NO in step S111), the exposure amount and the exposure time of the exposure unit 54 of the printing apparatus 10b are set so that the color densities of the scales Sc1 to Sc18 are appropriate. The adjustment is made (step S113), and the process returns to step S101.

  On the other hand, when the color densities of the scales Sc1 to Sc18 are appropriate (YES in step S111), the setup of the printing apparatus 10b ends.

  In step S105, the calibration coefficient α corresponding to the type of photographic paper P of the test print 100 produced in step S101 is read from the HDD 64.

  Further, at the time of setting up the printing apparatus 10 including the reference machine (printing apparatus 10a), the process at steps S105 and S107 is not performed, and the measurement value measured at step S103 is displayed on the display unit 22 at step S109.

  In such a photographic processing system 200, the measurement values of the scales Sc1 to Sc18 of the proofing machine are calibrated using the calibration coefficients α1 to α18, respectively, and the measurement accuracy of the color measuring unit 24 of each printing apparatus 10 is substantially set as the reference machine. The measurement accuracy can be made uniform. As a result, even when the same image is exposed and formed on the photographic paper P by the plurality of printing apparatuses 10, a plurality of prints having no variation in quality can be produced.

  Further, the calibration coefficients α1 to α18 are obtained using the test print 100 on which the gray scale image 108 including the scale Sc1 as the lowest density portion, the scales Sc2 to Sc17 as the intermediate density portion, and the scale Sc18 as the highest density portion is formed. Since the calculation is performed, the measurement accuracy of the color measurement unit 24 of each printing apparatus 10 can be made uniform with respect to the intermediate density color, and the measurement accuracy of each color measurement unit 24 can be made more accurate.

  In the above-described embodiment, the case where the gray scale image 108 of the test print 100 includes the scales Sc1 to Sc18 has been described. However, the number of scales of the gray scale image includes the lowest density portion, the intermediate density portion, and the highest density portion. Can be arbitrarily set. For example, a gray scale image having 15 scales may be formed on the test print 100.

  In the above-described embodiment, the case where the photo processing system 200 is configured using the printing apparatuses 10a, 10b, and 10c has been described. However, the number of the printing apparatuses 10 can be arbitrarily set.

  In the above-described embodiment, the case where the color measurement unit 24 of the printing apparatus 10a is the reference machine and the color measurement unit 24 of the printing apparatuses 10b and 10c is the calibration machine has been described. It can be set arbitrarily.

  In the above-described embodiment, the case where the reference measurement value data is written to the FD 68a has been described. However, the reference measurement value data is transmitted from the printing apparatus 10 including the reference apparatus to the printing apparatus 10 including the calibration machine via the network NT. You may make it do.

  Furthermore, although the case where the color measurement unit 24 is provided in the printing apparatus 10 has been described in the above-described embodiment, the present invention can also be applied to a color measurement apparatus provided independently of the printing apparatus. In this case, the color measuring device may not be paired with the printing device. For example, two color measuring devices may be prepared for four printing devices.

1 is a block diagram illustrating an example of a printing apparatus to which the present invention is applied. 1 is an external view illustrating an example of a printing apparatus to which the present invention is applied. It is an illustration figure which shows schematic structure of an image process part. (A) is an illustrative view showing an example of photographic paper on which a setup image or the like is formed, and (b) is an illustrative view showing an example of a test print. It is an illustration figure which shows an example of the setup information displayed on a display part. It is a block diagram which shows an example of a photograph processing system. It is a flowchart which shows an example of the operation | work for acquiring a calibration coefficient. It is a flowchart which shows an example of the calibration operation | movement of a calibration machine.

Explanation of symbols

10, 10a, 10b, 10c Printing device 14 Exposure processing unit 24 Color measurement unit 54 Exposure unit 68 FD drive 68a FD
58 CPU
DESCRIPTION OF SYMBOLS 100 Test print 102 Calibration image 108 Gray scale image 200 Photo processing system 300 Developer NT network P Printing paper Sc scale α Calibration coefficient

Claims (2)

A calibration method for a color measuring device for measuring the color of an image formed on a print material,
Preparing a colorimetric member having an image formed thereon;
Measuring the color of the image formed on the colorimetric member with a first colorimetric device as a reference and a second colorimetric device to be calibrated;
To compare the measurement value of the first color measurement device with the measurement value of the second color measurement device and calibrate the measurement value of the second color measurement device to the same value as the measurement value of the first color measurement device. A method for calibrating a colorimetric device, comprising: calculating a calibration coefficient for the colorimetric method; and storing the calibration coefficient in a storage unit.   The color measuring device calibration method according to claim 1, wherein the image formed on the color measurement member includes a minimum density portion, an intermediate density portion, and a maximum density portion having different color densities.

Images