JP2012240375A - Color tone measuring device and method, color tone management device, and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a device and reduce cost of a color tone measuring device and method, a color tone management device, and a printer.SOLUTION: The color tone measuring device includes: a translucent light diffusion sheet D which covers a surface of a print sheet S; light emitting elements 22, 23 which irradiate light to the translucent light diffusion sheet D; a light receiving element 24 which receives scattered light reflected from the print sheet S through the translucent light diffusion sheet D; and a measurement part 25 which measures a color tone of the surface of the print sheet S based on the scattered light received by the light receiving element 24.

Description

  The present invention relates to a color tone measuring device and method for measuring the color of a printed matter printed on a predetermined sheet, and a color tone managing device and a printing machine to which the color tone measuring device is applied.

  A typical offset printing machine has a plurality of printing units, for example, four ink colors, black, cyan, magenta, and yellow, along the print sheet conveyance path. The ink supply amount of each printing unit can be controlled by a color management device. This color tone management apparatus measures a color scale or a pattern printed on the margin of a print sheet with a colorimeter, and adjusts an appropriate ink supply amount for printing with a target color. In this case, the colorimeter measures the amount of light reflected from the color scale or pattern, and the color tone management device calculates the density for each color, separates the color adjustment according to the operator's intention into process colors, and determines the amount of change. The color adjustment is performed by converting the ink key opening to the ink key opening in consideration of various factors such as the pattern area ratio, the rotation speed of the ink base roller, and the printing response.

  By the way, as a printing sheet on which printing is performed, a special raw material material may be used in addition to white paper, and in recent years, printing on aluminum vapor-deposited paper is also performed. However, since this aluminum vapor-deposited paper has a mirror surface, the colorimeter cannot receive an appropriate amount of reflected light from the surface of the aluminum vapor-deposited paper and can perform color adjustment during printing. It becomes difficult. The special raw material is not only printed on the aluminum vapor-deposited paper, but also when passing the printing sheet through the printing machine, the adhesive is applied to the white paper that is not aluminum vapor-deposited, and the foil is applied to the mirror surface. There is also a printing method (inline foiler) that creates a printing sheet and prints ink on it.

  As what solves such a problem, there exists a thing described in the following patent document 1, for example. In this method of controlling the color of a duplicating product of a printing machine described in Patent Document 1, a substrate that appears dark by color measurement according to a standard is printed with a white ink that is brighter than the substrate, and the color of the white ink is printed. When performing color control of a printed duplicate product whose value is calculated from the measured amount, the color value of the white ink is controlled using a predetermined reference value of the color position in the color space brighter than the printing ink.

JP 2007-223322 A

  In the conventional method described above, white ink is printed on the surface of the aluminum vapor-deposited paper, and color tone control is performed using the color value of the white ink as a reference value. According to this method, even if it is aluminum vapor deposition paper, since the white ink printed on the surface is used as the reference value of the color value, the color tone control can be performed as in the conventional case.

  However, such a method requires a printing unit for white in addition to one printing unit for black, indigo, red, and yellow, leading to an increase in the size and cost of the apparatus and a complicated printing control. There is a problem of inviting.

  SUMMARY An advantage of some aspects of the invention is that it provides a color tone measuring device and method, a color tone management device, and a printing press that can simplify and reduce the cost of the device.

  To achieve the above object, the color tone measuring apparatus of the present invention includes a transparent light diffusing medium that covers the surface of a printing sheet, an irradiation unit that irradiates light toward the transparent light diffusing medium, and the printing sheet from the above A light receiving unit that receives scattered light reflected through the transparent light diffusion medium, and a measurement unit that measures a color tone on the surface of the print sheet based on the scattered light received by the light receiving unit. is there.

  Accordingly, a transparent light diffusing medium covering the surface of the printing sheet is used, light is irradiated toward the transparent light diffusing medium, scattered light reflected from the printing sheet through the transparent light diffusing medium is received, and based on the scattered light. The color tone on the surface of the print sheet is measured, and the color tone on the surface of the print sheet can be measured without providing a white printing unit, which can simplify the apparatus and reduce the cost. it can.

  In the color tone measuring apparatus of the present invention, the transparent light diffusion medium is a translucent light diffusion sheet having a predetermined light transmittance and a light diffusion function.

  Therefore, by having a predetermined light transmittance, it is possible to transmit light up to the print sheet and to receive reflected light from the print sheet. By using the transparent light diffusion medium as a sheet, It can be made compact.

  In the color tone measuring apparatus of the present invention, the printing sheet is sucked and held on a suction plate, and the translucent light diffusing sheet covers the surface of the printing sheet and the outer peripheral portion is sucked and held on the suction plate. It is said.

  Therefore, by adsorbing and holding the translucent light diffusion sheet together with the print sheet on the adsorption plate, the print sheet and the translucent light diffusion sheet can be brought into close contact with each other without gaps, and the color tone measurement accuracy can be improved.

  In the color tone measuring apparatus of the present invention, the irradiation unit and the light receiving unit are provided in an apparatus main body supported movably along the surface of the print sheet, and the translucent light diffusion sheet is supported by the apparatus main body. It is possible to adhere to the surface of the printing sheet.

  Therefore, by supporting the translucent light diffusing sheet on the apparatus main body side and allowing the translucent light diffusing sheet to adhere to the surface of the printing sheet, it is possible to facilitate the handling of the translucent light diffusing sheet and simplify the color tone measurement operation. .

  In the color tone measuring apparatus of the present invention, the printing sheet is characterized in that a printing surface is opaque and a mirror surface.

  Therefore, even if the printing surface of the printing sheet is opaque and mirror-like, the color tone on the surface of the printing sheet can be appropriately measured by using the transparent light diffusing medium.

  Further, the color tone measuring method of the present invention is a scattered light that covers the surface of a printing sheet with a transparent light diffusing medium, irradiates light toward the transparent light diffusing medium, and reflects from the printing sheet through the transparent light diffusing medium. The color tone on the surface of the printing sheet is measured based on the scattered light.

  Therefore, the color tone on the surface of the printing sheet can be measured without providing a white printing unit, and the apparatus can be simplified and reduced in cost.

  Further, the color tone management device of the present invention is based on a color tone measurement device that measures the color tone on the surface of the print sheet based on scattered light reflected from the surface of the print sheet through the transparent light diffusing medium, and image information of the printed pattern. A color adjustment amount setting device that sets a color adjustment amount by comparing a color tone and a color tone based on the measurement result of the color tone measurement device, and an ink supply amount based on the color adjustment amount set by the color adjustment amount setting device And an ink supply amount changing device for changing the ink supply amount.

  Therefore, the color tone measuring device measures the color tone on the surface of the print sheet based on the scattered light reflected from the surface of the print sheet through the transparent light diffusing medium, and the color adjustment amount setting device measures the color tone and measurement based on the image information of the printed pattern. The color adjustment amount is set by comparing with the color tone, and the ink supply amount change device changes the ink supply amount based on the set color adjustment amount, without providing a printing unit for white. By measuring the color tone on the surface, it is possible to set an appropriate ink supply amount, thereby enabling simplification and cost reduction of the apparatus and improving the color tone management accuracy.

  In the color management device of the present invention, the color measurement device measures a color tone on the surface of the print sheet based on scattered light reflected through the transparent light diffusing medium from a printed pattern printed on the surface of the print sheet. It is characterized by.

  Therefore, the color tone on the surface of the print sheet is measured based on the scattered light reflected from the print pattern of the print sheet through the transparent light diffusing medium, and the color tone control corresponding to the entire print pattern of the print sheet can be performed. .

  In the color management device of the present invention, the color measurement device measures a color tone on the surface of the print sheet based on scattered light reflected through the transparent light diffusion medium from a color scale printed on the surface of the print sheet. It is characterized by.

  Therefore, the color tone on the surface of the print sheet is measured based on the scattered light reflected from the color scale of the print sheet through the transparent light diffusing medium, and the tone control can be easily performed with a simple configuration.

  In the color tone management device of the present invention, the color adjustment amount setting device creates a color conversion table by comparing the color tone based on the image information of the printed pattern and the color tone based on the measurement result of the color tone measuring device, It is characterized in that a color adjustment amount is set using a color conversion table.

  Therefore, the color tone control can be easily performed by setting the color adjustment amount using the color conversion table created based on the measured color tone.

  Further, the printing machine of the present invention is a paper feeding device that supplies a printing sheet, a printing device that transfers ink onto the surface of the fed printing sheet, and a reflection from the surface of the printing sheet through a transparent light diffusing medium. A color tone measuring device that measures the color tone on the surface of the printing sheet based on scattered light, a print control device that adjusts and controls the ink supply amount in the printing device based on the measurement result of the color tone measuring device, and printed printing And a paper discharge device that discharges the sheet.

  Therefore, when the paper feeding device supplies the printing sheet, the printing device transfers the ink to the surface of the printing sheet, and the paper discharge device discharges the printed printing sheet. At this time, the color tone measuring device measures the color tone on the printing surface based on the scattered light reflected from the surface of the print sheet through the transparent light diffusion medium, and adjusts the ink supply amount in the printing device based on the color tone measured by the print control device. It is possible to control the color tone on the surface of the printing sheet without providing a white printing unit, which can simplify the apparatus and reduce the cost, and improve the printing quality. Can be possible.

  According to the color tone measuring device and method, the color tone management device, and the printing machine of the present invention, the transparent light diffusing medium that covers the surface of the printing sheet is used, light is irradiated toward the transparent light diffusing medium, and the transparent sheet is transparent. The scattered light reflected through the light diffusing medium is received, the color tone on the surface of the print sheet is measured based on the scattered light, and the color tone is managed and printed based on the measured color tone. Cost reduction can be achieved.

FIG. 1 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 1 of the present invention. FIG. 2 is a schematic diagram illustrating a color tone measuring method performed by the color tone measuring apparatus according to the first embodiment. FIG. 3 is a perspective view of the color tone measuring apparatus according to the first embodiment. FIG. 4 is a schematic configuration diagram illustrating a color tone management apparatus according to the first embodiment. FIG. 5 is a conceptual diagram illustrating a color tone control method performed by the color tone management apparatus according to the first embodiment. FIG. 6 is a conceptual diagram illustrating another color tone control method performed by the color tone management apparatus according to the first embodiment. FIG. 7 is an explanatory diagram illustrating a color tone control method performed by the color tone management apparatus according to the first embodiment. FIG. 8 is a schematic diagram illustrating an offset sheet-fed printing press to which the color management device according to the first embodiment is applied. FIG. 9 is a schematic diagram illustrating another offset sheet-fed printing press to which the color management device according to the first embodiment is applied. FIG. 10 is a schematic diagram illustrating a color tone measuring apparatus and method according to the second embodiment of the present invention. FIG. 11 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 3 of the present invention. FIG. 12 is a schematic diagram illustrating an offset sheet-fed printing press to which the color management device according to the fourth embodiment is applied. FIG. 13 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 5 of the present invention. FIG. 14 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 6 of the present invention. FIG. 15 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 7 of the present invention.

  Exemplary embodiments of a color tone measuring device and method, a color tone management device, and a printing press according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

  1 is a schematic diagram illustrating a color tone measuring apparatus and method according to a first embodiment of the present invention, FIG. 2 is a schematic diagram illustrating a color tone measuring method by the color tone measuring apparatus according to the first embodiment, and FIG. FIG. 4 is a schematic configuration diagram illustrating a color management device according to the first embodiment, FIG. 5 is a conceptual diagram illustrating a color control method performed by the color management device according to the first embodiment, and FIG. 7 is a conceptual diagram showing another color tone control method by one color tone management apparatus, FIG. 7 is an explanatory diagram showing a color tone control method by the color tone management apparatus according to the first embodiment, and FIG. 8 is applied with the color tone management apparatus according to the first embodiment. FIG. 9 is a schematic diagram illustrating another offset sheet-fed printing machine to which the color tone management apparatus according to the first embodiment is applied.

  In the first embodiment, as illustrated in FIG. 8, the offset sheet-fed printing press 60 includes a paper feeding device 61, a printing device 62, and a paper discharge device 63 arranged in series in the conveyance direction of the printing sheet S. 62 is constituted by four printing units 62a, 62b, 62c and 62d. Although the paper discharge device 63 is constituted by a plurality of paper discharge cylinders and a conveyance chain, it may be constituted by only the conveyance chain. Accordingly, when the printing sheet S is supplied from the paper feeding device 61 to the printing device 62, four colors of ink (for example, cyan, magenta, yellow, and black) are supplied to the printing units 62a, 62b, Each of 62c and 62d is transferred to the surface of the printing sheet S serving as a printing surface via the plate cylinder and the blanket cylinder. Then, the print sheet S on which the surface is printed is discharged by the paper discharge device 63.

  Further, the offset sheet-fed printing press 60 is provided with a color tone management device 31 that controls at least the color tone in the printing device 62, and this color tone management device 31 measures the color tone on the printing surface of the printed sheet S after printing. The color tone measuring device 11 and an ink amount control device 36 that adjusts the ink supply amount (ink key opening) based on the color tone measured by the color tone measuring device 11 are provided. In this case, the ink amount control device 36 is connected to the offset sheet-fed printing press 60, and the color tone measuring device 11 is connected to the ink amount control device 36.

  As shown in FIG. 3, the color tone measuring device 11 includes a color viewing stand 12, a suction plate 13 provided on the color viewing stand 12 in a predetermined inclination state, and a printing sheet sucked and held on the suction plate 13. A color sensor (colorimeter) 14 that measures the color tone of the surface (printed pattern or color scale) of S, a moving device 15 that can move the color sensor 14, a touch operation device 16, and data And a processing device 17.

  The suction plate 13 is provided with a number of suction grooves (not shown) on the surface, and can hold the printed sheet S placed thereon. As will be described in detail later, the color sensor 14 can measure the color tone of a printed image or color scale by scanning the print sheet S held on the suction plate 13 by the moving device 15. The operation device 16 can be operated by an operator, and the data processing device 17 can perform print control so that the color tone measured by the color tone sensor 14 becomes the target color tone.

  Here, the color tone sensor 14 will be described in detail. As shown in FIGS. 1 to 3, in the color sensor 14, the sensor body 21 has a box shape that is long in the vertical direction of the suction plate 13, and is front and rear in the scanning direction (left and right directions in FIGS. 1 and 2). Further, inclined surfaces 21 a and 21 b are formed to face the surface of the suction plate 13. The inclined surfaces 21 a and 21 b are formed symmetrically with a certain angle (for example, 45 degrees) with respect to the direction orthogonal to the surface of the suction plate 13.

  The light emitting elements (irradiation units) 22 and 23 are attached to the inclined surfaces 21a and 21b, and can irradiate the print sheet S held on the surface of the suction plate 13 with light. The light receiving element (light receiving unit) 24 is mounted between the inclined surfaces 21 a and 21 b, that is, between the light emitting elements 22 and 23, facing the surface of the suction plate 13. The measuring unit 25 is connected to the light emitting elements 22 and 23 and the light receiving element 24, and can measure the color tone on the surface of the print sheet S based on the reflected light (scattered light) received by the light receiving unit 24.

  This color tone sensor 14 can measure the color tone of the print sheet S as well as a blank sheet, as well as a print sheet having a mirror print surface. In this embodiment, aluminum vapor-deposited paper is applied as a printing sheet having a printing surface that is a mirror surface. The aluminum vapor-deposited paper is obtained by depositing an aluminum vapor-deposited film on the surface of white paper, and can be formed by a dry method such as a vacuum thin film forming method. In addition, as a printing sheet whose printing surface is a mirror surface, not only this aluminum vapor-deposited paper but also a metal vapor-deposited sheet in which a vapor-deposited film of metal such as gold or silver is deposited on the surface of a white paper or a resin film. It may be a printing sheet having a printing surface as a mirror without depositing metal on the surface. However, the printed sheet S needs to have a low light transmittance. In addition, as a printing sheet with a mirrored printing surface, when passing the printing sheet through a printing press, an adhesive is applied to white paper that is not aluminum-deposited, and a foil is pasted to create a mirror surface. There is an inline boiler as a printing method for printing on the surface of such a printing sheet.

  The color tone sensor 14 can measure the color tone of the aluminum vapor-deposited paper itself, an image printed on the surface (printed pattern), and the color scale (color patch). In this case, it is necessary to coat the surface of the aluminum vapor-deposited paper S with a transparent light diffusion medium. This transparent light diffusing medium is a transparent diffusing sheet, and a translucent light diffusing sheet D is used in this embodiment. Specifically, the translucent light diffusing sheet D is, for example, tracing paper, a tracing film, or a non-reflective sheet, and has a predetermined light transmittance and a function of diffusing (scattering) light. The tracing paper is translucent paper, and sulfate paper, paraffin paper, glassine paper, and the like can be applied as the translucent light diffusion sheet. In addition, the non-reflective sheet is a sheet having a structure in which a regular (or irregular) protrusion arrangement is made on a nanoscale unit on the surface of the sheet.

  That is, since the surface of the aluminum vapor-deposited paper S is a mirror surface, when the light irradiated from the light emitting elements 22 and 23 reaches the surface of the aluminum vapor-deposited paper S, it is specularly reflected (regular reflection). That is, the aluminum vapor-deposited paper S totally reflects light from one direction in another direction, the light quantity in the totally reflected direction is 100, and the light quantity in the other direction is almost zero. If the color sensor 14 receives all the light in the direction in which the light receiving element 24 is totally reflected, or the light amount becomes almost zero, it becomes difficult to measure the color with high accuracy. Therefore, by covering the surface of the aluminum vapor-deposited paper S with the translucent light diffusing sheet D, the specular reflection is changed to diffuse reflection (irregular reflection), so that an appropriate amount of reflected light enters the light receiving element 24.

  The transparent light diffusing medium is not limited to the translucent light diffusing sheet D, and may be a transparent diffusing gas. Examples of the transparent diffusing gas include an inert gas such as nitrogen gas and a micro unit (or , Nano-unit) fine particles may be applied. Specifically, a transparent diffusion gas may be sprayed along the surface of the aluminum vapor-deposited paper S from one side, and the transparent diffusion gas may be sucked on the other side.

  Specifically, when aluminum vapor-deposited paper is used as the printing sheet S, a translucent light diffusion sheet D that is slightly larger than the aluminum vapor-deposited paper is prepared. Then, the aluminum vapor-deposited paper S is placed on the suction plate 13 and sucked and held, the translucent light diffusion sheet D is placed on the aluminum vapor-deposited paper S, and the outer peripheral portion is sucked and held by the suction plate 13. Therefore, the surface of the aluminum vapor-deposited paper on the suction plate 13 is covered with the semi-transparent light diffusion sheet D in a close contact state with no gap.

  And when each light emitting element 22 and 23 irradiates light toward the semi-transparent light diffusion sheet D, a part of the irradiation light passes through the semi-transparent light diffusion sheet D and is irradiated to the aluminum vapor-deposited paper S and reflected. . The light receiving element 24 receives scattered light reflected from the aluminum vapor-deposited paper S through the translucent light diffusion sheet D. And the measurement part 25 measures the color tone in the surface of the aluminum vapor deposition paper S based on the reflected light (scattered light) which the light receiving element 24 received.

  The measuring unit 25 performs optical / electrical conversion on the reflected light received by the light receiving element 24 and then analog / digital conversion, thereby obtaining a color value L value, a value, b value in the CIELAB color space as a colorimetric value. Density values Dc, Dm, Dy, Dk, and spectral reflectance R (λ) can be measured. By measuring the wavelength, black (K) is converted from indigo (C), red (M), and yellow (Y). It is possible to separate and control the mixed color halftone dot portion including this black (K).

  In this case, as described above, the translucent light diffusing sheet D transmits a predetermined amount of the light emitted from the light emitting elements 22 and 23 and transmits the light that is transmitted and reflected by the aluminum vapor-deposited paper S. It is necessary to have a diffusion function of diffusing and guiding the light to the light receiving element 24. However, in order to secure the amount of reflected light necessary for the color tone sensor 14 to measure the color tone, not only the transmittance of the translucent light diffusion sheet D but also the amount of light emitted from the light emitting elements 22 and 23 is important. 24 needs to be set to have a signal-noise ratio (S / N ratio) of a predetermined value or more.

  That is, in order to measure the color tone with a predetermined accuracy by the color tone sensor 14, it is necessary to compensate for the light amount decrease due to the transmittance of the translucent light diffusion sheet D. As a method for compensating for the light amount decrease, for example, there is a method of increasing the amount of light emitted from the light emitting elements 22 and 23 by the amount corresponding to the light amount decrease. In addition, in order to perform color tone measurement with a predetermined accuracy by the color sensor 14, a reduction in the amount of light due to the transmittance of the translucent light diffusing sheet D is compensated, and the signal noise ratio (S / N ratio) of the light receiving element 24 is set to a predetermined level. Must be within accuracy. As a method for compensating for the light amount decrease, for example, there is a method of increasing the amount of light emitted from the light emitting elements 22 and 23 by the amount corresponding to the light amount decrease.

  Next, a color tone management device using the color tone measuring device 11 will be described. As shown in FIG. 4, in this color management device 31, a RIP (Raster Image Processor) 32 is a bitmap image (raster data) corresponding to the resolution of the offset sheet-fed printing press 60 based on design data (digital data). ) Is generated. A DDCP (Direct Digital Color Proofing) 33 prints digital proof paper based on the raster data. The DDCP 33 is a color printer having a function that can be used for color calibration, for example. A CTP (Computer to Plate / plate making machine) 34 produces four printing plates corresponding to each color based on raster data.

  Further, the image data server 35 receives the pattern image data based on the raster data from the RIP 32 and generates the line rate data. The ink amount control device 36 controls the offset sheet-fed printing press 60 based on the pattern area ratio data sent from the image data server 35, that is, adjusts the ink supply amount (ink key opening). Various data necessary for operation and driving conditions can be grasped on the display.

  The offset sheet-fed printing press 60 performs printing using each printing plate manufactured by CTP. The color tone measuring device 11 receives the pattern image data from the image data server 35, receives job data such as the ink supply amount (ink key opening) from the ink amount control device 36, and is printed by the offset sheet-fed printing press 60. Receive a print sample and measure the color tone. The color tone measuring device 11 calculates a correction value such as an ink supply amount (ink key opening) based on the pattern image data, job data, and color tone measurement value, and outputs the correction value to the ink amount control device 36 as control data. The ink amount control device 36 controls the offset sheet-fed printing press 60 based on the corrected job data.

  In the present embodiment, a color adjustment amount setting device that sets a color adjustment amount by comparing a color tone based on image information of a printed pattern and a color tone based on a measurement result of the color tone measuring device 11, and a color adjustment amount The ink amount control device 36 functions as an ink supply amount changing device that changes the ink supply amount based on the color adjustment amount set by the setting device.

  Here, the color tone management by the color tone management device 31 when printing on the aluminum vapor-deposited paper S by the offset sheet-fed printing press 60 will be described.

  In the first embodiment, as shown in FIG. 5, at the start of normal printing, the operator performs initial adjustment of printing with inexpensive white paper for trial printing without using an expensive special raw material. That is, color matching (color tone control) with respect to the target density T is automatically performed over a predetermined time A by operating the color tone management device 31 using a blank paper LUT (Look up Table / white color conversion table). When the color matching (color tone control) using this white paper LUT is completed, the operator switches from the white paper LUT to the diffusion LUT (diffuse paper color conversion table) for aluminum vapor deposition paper, and uses this diffusion LUT to manage the color tone. By operating the device 31, color matching (tone control) with respect to the target density T is automatically performed over a predetermined time B.

  If the performance of the color tone management device 31 is good and sufficient accuracy can be ensured only by color matching (color tone control) using the diffusion LUT by the color tone management device 31, use a blank paper LUT as shown in FIG. Instead, only the diffusion LUT may be used, and the color tone control may be automatically performed over a predetermined time C.

  Further, the white paper LUT and the diffusion LUT are tables in which the color development data characteristics of the offset sheet-fed printing press 60 are preliminarily created, and the offset sheet-fed printing is performed on the digital calibration paper calibrated by the design data (digital data). The color tone measurement device 11 reads the color development characteristics of the machine 60 and prints it as a table. In this case, the aluminum vapor-deposited paper is printed on the aluminum vapor-deposited paper with the color tone control setting, and the color tone measuring device 11 reads this is the diffusion LUT, and the color tone setting printed on the aluminum vapor-deposited paper is printed on the white paper. A blank sheet LUT is read by the color tone measuring device 11.

  Here, the color tone control by the color tone management device 31 will be specifically described.

  4 and 7, a sample printing plate having an evaluation pattern 102a, an LUT chart 102b, and a color patch (color scale) 102c corresponding to the actual printed pattern 101 printed by the offset sheet-fed printing press 60. 102 is produced. That is, the RIP 32 generates a bitmap image (raster data) corresponding to the resolution of the offset sheet-fed printing press 60 based on the design data (digital data), and the DDCP 33 prints digital proof paper based on the raster data. Then, the CTP 34 produces four plates corresponding to each color based on the raster data. Here, the evaluation pattern 102a is a pattern that can appropriately evaluate the printed pattern when printing is performed on the aluminum vapor-deposited paper. The LUT chart 102b is a patch composed of a combination of a plurality of colors for evaluating the color development characteristics of the offset sheet-fed printing press 60. The color patch 102 c is a patch composed of four colors (CMYK) for evaluating the color development characteristics of the offset sheet-fed printing press 60.

  Then, the DDCP 33 prints the digital calibration paper 103 using, for example, an aluminum vapor-deposited paper with a color printer based on the raster data. On the other hand, the image data server 35 generates the pattern area ratio data based on the raster data, and the ink amount control device 36 controls the offset sheet-fed printing press 60 based on the pattern area ratio data to perform the offset sheet-fed printing. The machine 60 mounts each printing plate 102 and starts printing using aluminum vapor-deposited paper. Thereafter, the operator operates the ink amount control device 36, finely adjusts the offset sheet-fed printing press 60 so that the hue matches with the digital calibration paper 103 as a reference, and prints the aluminum vapor-deposited paper print sample 104.

  Then, the color tone of the aluminum vapor-deposited paper print sample 104 is measured by the color tone measuring device 11. That is, the translucent light diffusion sheet D is mounted on the printing surface of the aluminum vapor-deposited paper print sample 104, and the color of the aluminum vapor-deposited paper print sample 104 is measured through the translucent light diffusion sheet D to generate the diffusion LUT 105. Also, printing is performed using a white paper for trial printing with the print setting of the offset sheet-fed printing press 60 on which the aluminum vapor-deposited paper print sample 104 is printed, and a white paper print sample 106 is obtained. The color tone measuring device 11 measures the color tone of the blank paper print sample 106. In other words, the translucent light diffusion sheet D is mounted on the printing surface of the blank paper print sample 106, and the color tone of the blank paper print sample 106 is directly measured through the translucent light diffusion sheet D, thereby generating the blank paper LUT 107.

  Thereafter, as shown in FIG. 7, the blank sheet LUT is applied, and the blank sheet target pattern in the actual printed pattern 101 is compared with the blank sheet printed pattern printed by the offset sheet-fed printing machine 60, and the offset sheet-fed printing press 60. The color tone control in the offset sheet-fed printing press 60 is then performed by comparing the aluminum vapor-deposited paper target pattern in the actual printed pattern 101 with the aluminum vapor-deposited paper printing pattern printed by the offset sheet-fed printing press 60. I do. Then, when the color tone control in the aluminum vapor-deposited paper printing pattern is completed and the trial printing is completed, the main printing is started.

  Further, even during printing by the offset sheet-fed printing press 60, the color tone measuring device 11 periodically performs color tone measurement using the translucent light diffusing sheet D on the printed matter, and the color tone managing device 31 is constantly updated. Perform color correction.

  Depending on the format of the color tone measuring device 11, only the evaluation pattern 102a and the LUT chart 102b may be measured to generate an LUT (diffusion LUT, white paper LUT), or only the color patch 102c may be measured to measure the LUT (diffusion LUT). , White paper LUT) may be generated.

  As described above, in the color tone measuring apparatus according to the first embodiment, the translucent light diffusion sheet D that covers the surface of the print sheet S and the shipping elements 22 and 23 that irradiate light toward the translucent light diffusion sheet D. A light receiving element 24 that receives scattered light reflected from the print sheet S through the translucent light diffusion sheet D, and a measurement unit 25 that measures the color tone on the surface of the print sheet S based on the scattered light received by the light receiving element 24. Is provided.

  Accordingly, the translucent light diffusing sheet D that covers the surface of the printing sheet S is used, light is irradiated toward the translucent light diffusing sheet D, and scattered light reflected from the printing sheet S through the translucent light diffusing sheet D is reflected. The color tone on the surface of the print sheet S is measured based on the scattered light, and the color tone on the surface of the print sheet S can be measured without providing a printing unit for white. And cost reduction and initial investment of the device itself can be suppressed.

  Moreover, in the color tone measuring apparatus of Example 1, the translucent light-diffusion sheet D which has a predetermined light transmittance and has a light-diffusion function is used. Therefore, by having a predetermined light transmittance, light is transmitted to the print sheet S, reflected light from the print sheet S is received, and the color tone on the surface of the print sheet S can be appropriately measured. By using a sheet shape, the apparatus can be made compact.

  Further, in the color tone measuring apparatus according to the first embodiment, the print sheet S can be sucked and held on the suction plate 13, the surface of the print sheet S can be covered with the translucent light diffusion sheet D, and the outer peripheral portion can be sucked and held on the suction plate 13. It is said. Accordingly, by adsorbing and holding the translucent light diffusing sheet D together with the printing sheet S, the printing sheet S and the translucent light diffusing sheet D can be brought into close contact with each other without any gap, and the color tone measurement accuracy is improved. can do.

  In the color tone measuring device 11, the suction plate 13 is provided on the color stand 12 so that the print sheet S and the translucent light diffusion sheet D can be air-adsorbed. There may be. Further, when the print sheet S or the translucent light diffusion sheet D has sufficient hardness or weight, the print sheet S or the translucent light diffusion sheet D may be held by its own weight.

  In the color tone measuring apparatus according to the first embodiment, the printing sheet S is an aluminum vapor-deposited paper whose printing surface is opaque and has a mirror surface. Even if it is aluminum vapor deposition paper, the color tone in the printing surface can be measured appropriately by using the translucent light diffusion sheet D.

  In the color tone measurement method of Example 1, the surface of the printing sheet S is covered with the translucent light diffusion sheet D, light is irradiated toward the translucent light diffusion sheet D, and the translucent light diffusion sheet is irradiated from the printing sheet S. The scattered light reflected through D is received, and the color tone on the surface of the print sheet S is measured based on the scattered light. Therefore, the color tone on the surface of the printing sheet S can be measured without providing a white printing unit, and the apparatus can be simplified and reduced in cost.

  In the color management device according to the first embodiment, the color measurement device 11 that measures the color tone on the surface of the print sheet S based on the scattered light reflected from the surface of the print sheet S through the translucent light diffusion sheet D; An ink supply amount changing device that sets a color adjustment amount by comparing a color tone based on image information with a color tone based on a measurement result of the color tone measuring device 11 and changes the ink supply amount based on the set color adjustment amount. As shown, an ink amount control device 36 is provided.

  Therefore, the color tone measuring device 11 measures the color tone on the surface of the print sheet S based on the scattered light reflected from the surface of the print sheet S through the ink amount control device 36, and the color tone managing device 31 is based on the image information of the printed pattern. The color adjustment amount is set by comparing the measured color tone with the measured color tone, and the ink supply amount is changed based on the set color adjustment amount, so that the printing sheet S can be provided without providing a white printing unit. By measuring the color tone on the surface, it is possible to set an appropriate ink supply amount, thereby enabling simplification and cost reduction of the apparatus and improving the color tone management accuracy.

  In the color management device according to the first exemplary embodiment, the color measurement device 11 is arranged on the surface of the print sheet S based on the scattered light reflected through the translucent light diffusion sheet D from the printed pattern printed on the surface of the print sheet S. The color tone is measured. Accordingly, the color tone on the surface of the print sheet S is measured based on the scattered light reflected from the print pattern of the print sheet S through the translucent light diffusing sheet D, and color tone control corresponding to the entire print pattern of the print sheet S is possible. Thus, it is possible to improve the accuracy of color tone control.

  In the color management device of Example 1, the color tone on the surface of the printing sheet S is measured based on the scattered light reflected from the color scale printed on the surface of the printing sheet S through the translucent light diffusion sheet D. . Therefore, the color tone on the surface of the print sheet S is measured based on the scattered light reflected from the color scale of the print sheet S through the translucent light diffusion sheet D, and the tone control can be easily performed with a simple configuration.

  In the color management device according to the first embodiment, the color management device 31 compares the color tone based on the image information of the printed pattern with the color tone based on the measurement result of the color measurement device 11, and uses the LUT (color conversion table). The color adjustment amount is set using this LUT. Therefore, the color tone control can be easily performed by setting the color adjustment amount using the LUT created based on the measured color tone and the image information of the printed pattern.

  In the first embodiment, the offset sheet-fed printing press 60 is provided with a color tone management device 31, and the color tone management device 31 is provided with the color tone measurement device 11 and the ink amount control device 36 that are individually arranged. It is not limited to this configuration. For example, as shown in FIG. 9, a color tone management device 31A in which a color tone measurement device and an ink amount control device are integrated may be provided.

  FIG. 10 is a schematic diagram illustrating a color tone measuring apparatus and method according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  In Example 2, as shown in FIG. 10, in the color tone sensor 41, the sensor body 21 is formed with inclined surfaces 21 a and 21 b so as to face the surface of the suction plate 13. Elements 22 and 23 are mounted, and a light receiving element 24 is mounted between the light emitting elements 22 and 23. The measuring unit 25 is connected to the light emitting elements 22 and 23 and the light receiving element 24, and can measure the color tone on the surface of the print sheet S based on the reflected light (scattered light) received by the light receiving unit 24. .

  The sensor body 21 is provided with support members 43a and 43b via a pair of support rods 42a and 42b before and after the moving direction, and the translucent light diffusion sheet D is supported by the support members 43a and 43b. In this case, the translucent light diffusing sheet D supported by the sensor body 21 can cover the aluminum vapor-deposited paper S on the suction plate 13 in a close contact state without any gap.

  And when each light emitting element 22 and 23 irradiates light toward the semi-transparent light diffusion sheet D, a part of the irradiation light passes through the semi-transparent light diffusion sheet D and is irradiated to the aluminum vapor-deposited paper S and reflected. . The light receiving element 24 receives scattered light reflected from the aluminum vapor-deposited paper S through the translucent light diffusion sheet D. And the measurement part 25 can measure the color tone in the surface of the aluminum vapor deposition paper S based on the reflected light (scattered light) which the light receiving element 24 received.

  Thus, in the color tone measuring apparatus of Example 2, the sensor body 21 is provided with the light emitting elements 22, 23, the light receiving element 24, and the measuring unit 25, and the translucent light diffusing sheet D is provided via the support rods 42a, 42b. Support.

  Therefore, by supporting the translucent light diffusing sheet D on the sensor body 21 and allowing the translucent light diffusing sheet D to be in close contact with the surface of the printing sheet S, it is possible to easily handle the translucent light diffusing sheet D and to simplify the color tone measurement operation. be able to.

  The translucent light diffusion sheet D does not need to be completely adhered to the surface of the printing sheet S, and even in this case, measurement can be performed with appropriate accuracy. Moreover, an error can be equalized by measuring several times and calculating | requiring the average value.

  FIG. 11 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  In Example 3, as shown in FIG. 11, in the color tone sensor 51, the sensor body 21 is formed with inclined surfaces 21 a and 21 b so as to face the surface of the suction plate 13, and each of the inclined surfaces 21 a and 21 b and the light emitting elements are formed. 22 and 23 are mounted, and a light receiving element is mounted between the light emitting elements 22 and 23. The measuring unit 25 is connected to the light emitting elements 22 and 23 and the light receiving element 24, and can measure the color tone on the surface of the print sheet S based on the reflected light (scattered light) received by the light receiving unit 24. .

  The sensor body 21 is provided with winding rollers 53a and 53b by a pair of support brackets 52a and 52b before and after the moving direction, and support rollers 55a and 55b through a pair of support rods 54a and 54b. The translucent light diffusion sheet D is supported by the winding rollers 53a and 53b and the support rollers 55a and 55b. In this case, as the color tone sensor 51 moves, the translucent light diffusion sheet D does not slide on the printing paper surface, and one of the winding rollers 53a and 53b is translucent at the same speed as the color tone sensor 51 moving speed. The semi-transparent light diffusion sheet D moves while being supported by the support rollers 55a and 55b, and is closely attached to the aluminum vapor-deposited paper S on the suction plate 13 by unwinding the light diffusion sheet D and winding the other, and It is possible to coat without relative movement.

  And when each light emitting element 22 and 23 irradiates light toward the semi-transparent light diffusion sheet D, a part of the irradiation light passes through the semi-transparent light diffusion sheet D and is irradiated to the aluminum vapor-deposited paper S and reflected. . The light receiving element 24 receives scattered light reflected from the aluminum vapor-deposited paper S through the translucent light diffusion sheet D. And the measurement part 25 can measure the color tone in the surface of the aluminum vapor deposition paper S based on the reflected light (scattered light) which the light receiving element 24 received.

  As described above, in the color tone measuring apparatus according to the third embodiment, the sensor main body 21 is provided with the light emitting elements 22 and 23, the light receiving element 24, and the measuring unit 25, and halfway by the winding rollers 53a and 53b and the support rollers 55a and 55b. The transparent light diffusion sheet D is movably supported.

  Therefore, by supporting the translucent light diffusing sheet D on the sensor body 21 and allowing the translucent light diffusing sheet D to be in close contact with the surface of the printing sheet S, it is possible to easily handle the translucent light diffusing sheet D and to simplify the color tone measurement operation. be able to. Further, by moving the translucent light diffusing sheet D as the color tone sensor 51 moves, the translucent light diffusing sheet D and the printed sheet can be in close contact with each other without any gap, and can be covered without relative movement. Further, it is possible to prevent damage to the printing surface of the printing sheet S and the translucent light diffusion sheet D. Moreover, adhesiveness can be improved by pressing the translucent light-diffusion sheet D with the support rollers 55a and 55b.

  FIG. 12 illustrates an offset sheet-fed printing machine to which the color tone management apparatus according to the fourth embodiment is applied. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  In the fourth embodiment, as illustrated in FIG. 12, the offset sheet-fed printing press 60 includes a paper feeding device 61, a printing device 62, and a paper discharge device 63 arranged in series in the conveyance direction of the print sheet S. Yes. Accordingly, when the printing sheet S is supplied from the paper feeding device 61 to the printing device 62, four colors of ink (for example, cyan, magenta, yellow, and black) are supplied to the printing units 62a, 62b, Each of 62c and 62d is transferred to the surface of the printing sheet S serving as a printing surface via the plate cylinder and the blanket cylinder. Then, the print sheet S on which the surface is printed is discharged by the paper discharge device 63.

  Further, the offset sheet-fed printing press 60 is provided with a color tone management device 31B that controls at least the color tone in the printing device 62, and this color tone management device 31B measures the color tone on the printing surface of the printed sheet S after printing. A color tone measuring device 11B and an ink amount control device 36B that adjusts the ink supply amount (ink key opening) based on the color tone measured by the color tone measuring device 11B are provided. In this case, the color tone management device 31B, the color tone measurement device 11B, and the ink amount control device 36B have the same configuration as the color tone management device 31, the color tone measurement device 11, and the ink amount control device 36 described in the first embodiment. The description is omitted.

  Accordingly, the color tone measuring device 11B measures the color tone on the printing surface of the print sheet S before and during the printing operation by the offset sheet-fed printing press 60, and the color tone managing device 31B The printing apparatus 62 can be controlled based on the measurement result.

  As described above, in the printing machine according to the fourth embodiment, the paper feeding device 61, the printing device 62, and the paper discharge device 63 are provided, and based on the scattered light reflected from the surface of the printing sheet S through the translucent light diffusion sheet D. A color tone measuring device 11B that measures the color tone on the surface of the print sheet S, and a color tone management device (printing control device) 31B that adjusts and controls the ink supply amount in the printing device 62 based on the measurement result of the color tone measuring device 11B. ing.

  Accordingly, the color tone measuring device 11B measures the color tone on the printing surface based on the scattered light reflected from the surface of the printing sheet S through the translucent light diffusing sheet D, and the color tone managing device 31B determines the ink in the printing device 62 based on this color tone. The supply amount is adjusted and controlled, the color tone on the surface of the print sheet S can be measured without providing a white printing unit, and the apparatus can be simplified and reduced in cost. The print quality can be improved.

  FIG. 13 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 5 of the present invention.

  In the fifth embodiment, as shown in FIG. 13, the color tone measuring device 71 is disposed so as to face a position separated from the outer peripheral surface of the impression cylinder 72 in the printing device by a predetermined distance. That is, the impression cylinder 72 has a claw 72a capable of gripping the front end portion with the printing sheet S on the outer peripheral portion, and the claw 72a can grip and convey the printing sheet S. A transparent and hollow casing 73 facing the outer peripheral surface of the impression cylinder 72 is supported by, for example, a printing machine frame (not shown).

  The casing 73 has a curved shape along the outer peripheral surface of the impression cylinder 72, and the leading end of the supply pipe 74 is connected to the upstream end in the rotation direction of the impression cylinder 72. The other end of the supply pipe 74 is connected to an air supply pipe 76 via a switching valve 75 and a gas supply pipe 77 is connected. The air supply pipe 76 is open to the atmosphere, and the gas supply pipe 77 is connected to a tank 78 of a transparent diffusion gas (transparent light diffusion medium). Further, the casing 73 has a proximal end portion of the discharge pipe 79 connected to an end portion on the downstream side in the rotation direction of the impression cylinder 72. The discharge pipe 79 is fitted with a pump 80, and the tip is open to the atmosphere.

  Further, the casing 73 is located on the side opposite to the impression cylinder 72 and is mounted with the color tone sensor 14. The color tone sensor 14 is the same as that described in the first embodiment. The color sensor 14 irradiates light toward the printed print sheet S conveyed to the impression cylinder 72, and prints based on the received reflected light (scattered light). The color tone on the surface of S can be measured.

  Therefore, when the printing sheet S is white paper, the supply pipe 74 and the air supply pipe 76 are connected by the switching valve 75 and the pump 80 is operated to fill the casing 73 with air and stop. In this state, when the color tone sensor 14 irradiates the casing 73 with light, most of the irradiating light is transmitted through the casing 73 and applied to the print sheet (white paper) S to be reflected. The reflected light is received by the color sensor 14 from the print sheet S through the casing 73. Then, the color tone sensor 14 can measure the color tone of the print sheet (white paper) S based on the received reflected light (scattered light).

  On the other hand, when the printing sheet S is aluminum vapor-deposited paper, the supply pipe 74 and the gas supply pipe 77 are connected by the switching valve 75 and the pump 80 is operated to discharge the air in the casing 73 from the discharge pipe. Fill the inside with transparent diffusion gas and stop. In this state, when the color tone sensor 14 irradiates the casing 73 with light, a part of the irradiating light passes through the casing 73 and is applied to the printing sheet (aluminum vapor-deposited paper) S to be reflected. The reflected light is received by the color sensor 14 from the print sheet S through the casing 73. Then, the color tone sensor 14 can measure the color tone of the printed sheet (aluminum vapor-deposited paper) S based on the received reflected light (scattered light).

  As described above, in the color tone measuring apparatus according to the fifth embodiment, the transparent and hollow casing 73 is disposed at a position separated by a predetermined distance on the outer peripheral surface of the impression cylinder 72 in the printing apparatus, and the air is contained in the casing 73. The transparent diffusion gas can be switched and filled, and the color tone sensor 14 is mounted on the casing 73.

  Therefore, the color tone on the surface of the printing sheet S can be measured during printing, and even if the printing sheet S is white paper or aluminum vapor-deposited paper by filling the casing 73 with air or a transparent diffusion gas, it is appropriate. In addition, the color tone on the surface of the printing sheet S can be measured.

  FIG. 14 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 6 of the present invention.

  In the sixth embodiment, as shown in FIG. 14, the color tone measuring device 81 is disposed so as to face a position separated from the outer peripheral surface of the impression cylinder 82 in the printing device by a predetermined distance. In other words, the impression cylinder 82 has a claw 82a that can grip the front end of the printing sheet S on the outer periphery, and the claw 82a can grip and convey the printing sheet S. A support plate 83 is supported by, for example, a printing machine frame (not shown) so as to face the outer peripheral surface of the impression cylinder 82.

  The support plate 83 has a curved shape along the outer peripheral surface of the impression cylinder 82, and a paper guide portion 83 a that bends in a direction in which the upstream end in the rotation direction of the impression cylinder 82 is separated from the impression cylinder 82. Is formed. The support plate 83 has a translucent light diffusion plate (transparent light diffusion medium) 84 fixed at the center. Further, an air nozzle 85 that guides the conveyance of the printing sheet S is disposed by injecting air between the support plate 83 and the impression cylinder 83 on the upstream side in the rotation direction of the impression cylinder 82 from the support plate 83.

  The support plate 83 is located on the side opposite to the impression cylinder 82 and is mounted with the color tone sensor 14 corresponding to the translucent light diffusion plate 84.

  Therefore, when the printing sheet S is aluminum vapor-deposited paper, when the color tone sensor 14 irradiates light to the translucent light diffusion plate 84, a part of the irradiation light passes through the translucent light diffusion plate 84 and the printing sheet ( The aluminum vapor-deposited paper) S is irradiated and reflected. The reflected light is received by the color tone sensor 14 from the print sheet S through the translucent light diffusion plate 84. Then, the color tone sensor 14 can measure the color tone of the printed sheet (aluminum vapor-deposited paper) S based on the received reflected light (scattered light).

  On the other hand, when the printing sheet S is white paper, the above-described operation may be performed with the support plate 83 having the translucent light diffusion plate 84 removed. Note that the support plate 83 may be movable or rotatable without being detachable, and may be switched between aluminum vapor-deposited paper and white paper.

  As described above, in the color tone measuring apparatus according to the sixth embodiment, the support plate 83 having the translucent light diffusing plate 84 is detachably disposed at a position separated by a predetermined distance on the outer peripheral surface of the impression cylinder 82 in the printing apparatus. The color tone sensor 14 is attached to the support plate 83.

  Accordingly, it is possible to appropriately measure the color tone on the surface of the print sheet S during printing.

  FIG. 15 is a schematic diagram illustrating a color tone measuring apparatus and method according to Embodiment 7 of the present invention.

  In the seventh embodiment, as shown in FIG. 15, the color tone measuring device 91 is disposed so as to face a position separated from the outer peripheral surface of the impression cylinder 92 in the printing device by a predetermined distance. In other words, the impression cylinder 92 has a claw 92 a that can grip the front end of the printing sheet S on the outer periphery, and the claw 92 a can grip and convey the printing sheet S. A translucent light diffusing roller (transparent light diffusing medium) 93 is disposed in contact with the outer peripheral surface of the pressure drum 92. The translucent light diffusing roller 93 can rotate in synchronization with the impression cylinder 92, and can convey the printing sheet S between the impression cylinder 92.

  The color sensor 14 is mounted inside the translucent light diffusing roller 93 via a support bracket 94 supported by a printing frame (not shown).

  Therefore, when the printing sheet S is aluminum vapor-deposited paper, when the color tone sensor 14 irradiates light to the impression cylinder 92 side through the semi-transparent light diffusion roller 93, a part of the irradiation light is transmitted through the semi-transparent light diffusion roller 93. Then, the printed sheet (aluminum vapor-deposited paper) S is irradiated and reflected. The reflected light is received by the color tone sensor 14 from the print sheet S through the translucent light diffusion roller 93. Then, the color tone sensor 14 can measure the color tone of the printed sheet (aluminum vapor-deposited paper) S based on the received reflected light (scattered light).

  On the other hand, when the print sheet S is a blank sheet, the above-described operation may be performed with the translucent light diffusion roller 93 removed.

  As described above, in the color tone measuring apparatus according to the seventh embodiment, the translucent light diffusion roller 93 is disposed in contact with the outer peripheral surface of the impression cylinder 92 in the printing apparatus, and the color sensor is disposed inside the translucent light diffusion roller 93. 14 is installed.

  Accordingly, it is possible to appropriately measure the color tone on the surface of the print sheet S during printing.

11, 11B, 71, 81, 91 Color tone measuring device 13 Suction plate 14, 41, 51 Color tone sensor 21 Sensor body 22, 23 Light emitting element (irradiation part)
24 Light receiving element (light receiving part)
25 Measuring unit 31, 31A, 31B Color management device 32 RIP
33 DDCP
34 CTP
35 Image data server 36, 36B Ink quantity control device 60 Offset sheet-fed printing machine (printing machine)
61 Paper feeder 62 Printing device 63 Paper delivery device 72, 82, 82 Impression cylinder 73 Casing 83 Support plate 84 Translucent light diffusion plate (transparent light diffusion medium)
93 Translucent light diffusion roller (transparent light diffusion medium)
S Printing sheet (white paper, aluminum evaporated paper)
D Translucent light diffusion sheet (transparent light diffusion medium)

Claims (11)

A transparent light diffusing medium covering the surface of the printing sheet;
An irradiation unit for irradiating light toward the transparent light diffusion medium;
A light receiving unit that receives scattered light reflected from the printing sheet through the transparent light diffusion medium;
A measuring unit for measuring a color tone on the surface of the print sheet based on scattered light received by the light receiving unit;
A color tone measuring device comprising:   2. The color tone measuring device according to claim 1, wherein the transparent light diffusing medium is a translucent light diffusing sheet having a predetermined light transmittance and a light diffusing function.   3. The printing sheet according to claim 2, wherein the printing sheet is sucked and held by a suction plate, and the translucent light diffusion sheet covers the surface of the printing sheet and an outer peripheral portion is sucked and held by the suction plate. Color tone measuring device.   The irradiation unit and the light receiving unit are provided in an apparatus main body that is movably supported along the surface of the printing sheet, and the translucent light diffusion sheet is supported by the apparatus main body and is in close contact with the surface of the printing sheet. The color measuring device according to claim 2, wherein the color measuring device is possible.   5. The color tone measuring apparatus according to claim 1, wherein the print sheet has a non-transparent print surface and a mirror surface.   The surface of the printing sheet is covered with a transparent light diffusing medium, light is irradiated toward the transparent light diffusing medium, scattered light reflected from the printing sheet through the transparent light diffusing medium is received, and based on the scattered light A color tone measuring method comprising measuring a color tone on the surface of the print sheet. A color tone measuring device for measuring the color tone on the surface of the print sheet based on scattered light reflected from the surface of the print sheet through the transparent light diffusion medium;
A color adjustment amount setting device that sets a color adjustment amount by comparing a color tone based on image information of a printed pattern and a color tone based on a measurement result of the color tone measuring device;
An ink supply amount changing device for changing the ink supply amount based on the color adjustment amount set by the color adjustment amount setting device;
A color tone management apparatus comprising:   The color tone measuring apparatus measures a color tone on the surface of the print sheet based on scattered light reflected through the transparent light diffusion medium from a printed pattern printed on the surface of the print sheet. The color management device described.   The color tone measuring device measures a color tone on the surface of the print sheet based on scattered light reflected through the transparent light diffusion medium from a color scale printed on the surface of the print sheet. The color management device described.   The color adjustment amount setting device creates a color conversion table by comparing a color tone based on image information of a printed pattern and a color tone based on a measurement result of the color tone measuring device, and performs color adjustment using the color conversion table The color management device according to any one of claims 7 to 9, wherein an amount is set. A paper feeding device for supplying printing sheets;
A printing apparatus for transferring ink to the surface of the fed printing sheet;
A color tone measuring device for measuring a color tone on the surface of the print sheet based on scattered light reflected from the surface of the print sheet through a transparent light diffusion medium;
A printing control device for adjusting and controlling the ink supply amount in the printing device based on the measurement result of the color tone measuring device;
A paper discharge device for discharging the printed sheet,
A printing machine comprising:

Images