JP4214262B2 - Printed halftone dot, its production method and printing method - Google Patents

Description

  The present invention is applicable to a wide variety of general prints that require anti-counterfeiting and falsification prevention functions, including banknotes, passports, securities, cards, and valuable prints, without using special paper, ink, and dedicated output machines. It is output from household pigment-based ink jet printers, color laser printers, and the like, and is used for printed materials that require originality and security.

  In recent years, with the increase in image quality of color copiers and computerization of color platemaking technology, counterfeiting means for banknotes and securities tend to be diversified. In particular, the resolution of image input / output devices used in the printing industry has significantly improved, and the extraction of fine lines and minute characters used in securities has become relatively easy. As a result, it has become possible to accurately extract what is composed of fine lines such as background patterns, chromatic patterns, relief patterns, etc., which are used in many current securities, by means of input / output devices such as scanners. In addition to counterfeiting by the general commercial printing method consisting of four-color halftone dot composition, more serious counterfeit tickets using many special color plates have increased.

  Therefore, in Japanese Patent No. 3544536 previously disclosed by the present applicant, basic four-color inks of C (cyan), M (magenta), Y (yellow), and K (black) used in general commercial printing ( Or toner) is a black pigment mainly composed of carbon black, and uses ink that exhibits absorption characteristics over the entire region from the ultraviolet region to the infrared region, and C, M, If the superposition of Y ink does not absorb infrared rays, only images printed with K-ink containing carbon black can be seen when using a special appraisal device such as an infrared camera. Focused on being able to.

  Therefore, in the above-described invention (Japanese Patent No. 3544536), as shown in FIG. 10, one first halftone dot region 10 and one second halftone dot region 20 adjacent to the first halftone dot region 10. And the first halftone dot region 10 is made larger by observing with the naked eye by taking a larger area than the second halftone dot region 20, and is formed of a CMY color coloring material. Further, the second region 20 is composed of a 2a halftone dot region 20a formed using a monochrome black color material (generally carbon black containing carbon) containing an infrared absorbing dye, and a background portion thereof. A second-b halftone dot region 20b composed of a black (so-called process black) ink obtained by superposing CMY color materials that does not contain an infrared-absorbing dye, and each second region 20, a printed matter in which a latent image is provided with gradation according to the ratio of the 2a halftone dot area 20 a and the 2b halftone dot area 20 b (hereinafter referred to as “latent image printed matter”). When the image is observed in an infrared environment, only the latent image formed with carbon black appears, and at the time of copying, a duplicate is formed in black without distinction between the two. In the above latent image The halftone dots are arranged so that the image cannot be viewed.

  By the way, when producing the above-mentioned latent image printed matter, there are two production methods. One method is a method of printing in large quantities and continuously using an offset printer. In this case, with the halftone dot arrangement shown in FIG. 10, plate making data is created by designating each color of K ink, which is a latent image, and C, M, Y ink, which is a gradation image, in advance. If the process is performed, it is easy to produce a latent image printed matter having a desired effect, so there is no particular difficulty.

  On the other hand, in addition to the method of printing with an offset printing machine, the above-described latent image printed matter can be produced with a printer. In particular, since the IT environment has been improved in recent years, since the computer or printer is prepared as an infrastructure, the above-described latent image printed matter can be easily output at any place. Therefore, in Japanese Patent Application Laid-Open No. 2004-240706 previously disclosed by the present applicant, regarding the issuing system for issuing various certificates such as a resident's card, a seal certificate, and a family register abstract or a certified copy, A certificate issuance system capable of preventing forgery is disclosed. Since the above-mentioned latent image is attached to various certificates, and the convenience is greatly improved by outputting it with a printer using a network, the method for producing the above-mentioned latent image printed matter with a printer attracts attention. Yes.

  However, when producing the above-mentioned latent image printed matter with a printer, various types of printers are sold by various manufacturers, and the control method, control program, printer driver, etc. of the printer are manufactured by each manufacturer. Since it is often developed independently by the manufacturer, there may be a difference in the print quality of the printed matter output by the printer. For example, when the same print image data is input to an image processing apparatus such as a computer and output by printers of different models or models, the print images printed by the respective printers may have different densities or hues. Such an event also becomes a problem in printing the latent image of the latent image print described above.

  Specifically, when the latent image data of the latent image printed matter described above is input to a computer and printed by a printer of a different model or model, the latent image may be output as an appropriate latent image printed matter, In some cases, it is output as an improper latent image print. That is, the print quality varies depending on the printer model.

  If this is caused by the toner density, color balance, and output method of each printer, an appropriate latent image can be obtained by changing the output setting already provided in the printer. However, Windows (registered trademark), MacOS, and the like support the sRGB color gamut as the standard color gamut at the OS level, and the image data created with YMCK data is converted into data in the sRGB color space, and is appropriate. A latent image may not be printed.

  The printing control method will be described with reference to FIG. For example, as shown in FIG. 10, a plurality of first halftone dot areas 10 and second halftone dot areas 20 colored with CMY colorants that can be observed with the naked eye are arranged, and the second halftone dot area 20 is arranged. Print control when a latent image 20a and a background image 20b are provided, and the latent image 20a is a single color K material and the background image 20b is a three-color latent image printed with a CMY color material. In the method, first, the latent image data and the background image data were created in the CMYK data format by the computer in the data creation of the halftone dot region 20 in FIG. As shown in FIG. 11B, the color component and halftone dot% of each CMYK data at this time are obtained as follows. The latent image 20a is composed of black color composed of one color of K color material (halftone dot area ratio 100%), The background image 20b for camouflaging this is black which is a combination of three colors of C (100%), M (100%), and Y (100%). When the above-described CMYK data is converted into the sRGB color space, as shown in FIG. 11C, for example, the background image 20b is converted into Red (24), Green (37), and Blue (39). Even if this value is converted into CMYK data necessary for printer output, it does not return to the same color component and halftone dot% as in FIG. 11B, and as shown in FIG. %), M (59%), Y (60%), and K (54%). This conversion method is almost similar to a process consisting of UCR (Under Color Removal) used in the printing industry. In addition to the process color printing method that uses offset printers for continuous printing in large quantities, black and gray can be expressed by mixing four colors of CMYK, but K (black). In general, the UCR method is used in the plate-making process and printer driver control system, which removes three equal amounts of CMY from the black part and increases the amount of K component accordingly. Is.

  For this reason, when the above-described latent image printed matter is output to the printer with the data once converted into RGB, the background image 20b also contains K color material components including carbon black having infrared absorption characteristics, and the latent image prints. Both the image image 20a and the background image 20b result in including the K color material. For this reason, even if the printed latent image printed matter is observed with infrared light, the density difference between the latent image 20a and the background image 20b cannot be obtained, and the latent image 20a cannot be visually recognized.

  On the other hand, in the case of a printer, particularly an ink jet printer, each ink ejected from the ink nozzle permeates and adheres to the paper. Therefore, if the ink is not evenly and efficiently discharged as much as possible, The increase deteriorates paper permeability and printing surface properties, and causes problems in drying time and the like. Therefore, in order to solve the problem that the ink cannot be fixed cleanly when the four colors are overlaid, a more complex algorithm than GCR (Gray-Component Replacement) is applied to control CMY from the gray part. The method of removing these three colors is also used.

  When GCR is applied, as shown in FIG. 11E, Red (24), Green (37), and Blue (39) of the background image 20b have C (42%), M (21%) depending on the function. ), Y (24%), and K (80%) are reproduced by combining the four colors of black. Therefore, even in GCR, K color material components including carbon black having infrared absorption characteristics are mixed. Both the latent image 20a and the background image 20b thereof include the result of including the K color material. Further, K (100%) of the latent image 20a in FIG. 11B is not shown, but when converted to sRGB and YMCK, K (75%) in the case of UCR and K (88) in the case of GCR. %). The term “appropriate” as used herein means that the latent image 20a formed with a K color material containing carbon black and the background image 20b formed with a C, M, Y color material have the same color under visible light, and the latent image. 20a can be concealed, while only the latent image 20a is visible with infrared light. On the contrary, the term “inappropriate” here means that the latent image 20a formed of a K color material containing carbon black and the background image 20b formed of a C, M, Y color material have the same color with visible light. The latent image 20a cannot be concealed, or the latent image 20a cannot be visually recognized with infrared light.

  Therefore, in order to solve the above problems, attention is paid to the data control method and conversion method of the image processing apparatus (computer) and the image forming apparatus (printer), and the YMCK data which is the print image data is converted into different colors such as sRGB. A method is disclosed in which the latent image is converted into a proper print image while avoiding conversion to space (see, for example, Patent Document 1).

JP 2006-53725 A

  In Patent Document 1, Y, M, C, and K data, which are print image data (including latent image data), are individually recorded on a disc without converting each color component data into data in another color space. A method is disclosed in which an identification image (latent image image in the present specification) is appropriately converted into a latent image by directly printing a print target document to which the identification image is added.

  However, in Patent Document 1, when an identification image is printed by a computer and a printer, a specific printer driver is installed in the computer or the printer, and an output machine specialized for these printing control methods is also essential. Therefore, identification images can be printed from a wide variety of general household pigment-based inkjet printers and color laser printers without using a printer driver or dedicated output device, and printed matter that requires its originality and security is output. It was hoped that it could be done.

  In particular, as described above, since the latent image printed material is expected to be used for a certificate or the like in an environment using a network, as a user, without adding a specific software function to a computer or printer, It is desirable to be able to print an appropriate latent image in a standard environment. On the other hand, in providing and expanding the technology, it is desirable to use a one-source multi-use method that can output a single document with an identification image to various printers.

  The present invention solves the above-described problems, and an appropriate latent image of the above-described latent image printed matter can be obtained without requiring a specific printer driver or an output machine specialized for these print control methods in a computer or printer. The present invention provides a printed matter, a production method thereof, and a printing method.

  In the halftone dot printed matter of the present invention, a visible image having a density gradation is formed by arranging a plurality of first halftone dot areas and second halftone dot areas on a substrate, and the first halftone dot area is infrared. A second halftone dot region having a region constituted by using a color material not including an absorption characteristic, the second halftone dot region being constituted by using a color material having an infrared absorption characteristic, and infrared absorption; A second-b halftone dot area formed by using a color material not including a characteristic, and a latent image is formed by the second-a halftone dot area, and the latent-image image includes the second-a halftone-dot area and the second-b halftone dot area; The gradation is expressed by the size of the 2a halftone dot area determined according to the ratio to the halftone dot area, and each color material constituting the 2a halftone dot area in the second halftone dot area Are divided into predetermined areas without overlapping, and the 2a halftone dot area and the 2b halftone dot area are visually recognized by the naked eye. It is characterized.

  Further, in the halftone dot printed matter of the present invention, a plurality of first halftone dot areas and second halftone dot areas are arranged with one second halftone dot area adjacent to one first halftone dot area. Each of the second halftone dot regions is surrounded by a plurality of first halftone dot regions.

  Further, in the halftone dot printed matter of the present invention, in the second area, the 2a halftone dot area and the 2b halftone dot area are composed of the respective color materials of four primary colors of cyan, magenta, yellow and black. It is characterized by.

  Further, the halftone dot printed matter of the present invention is characterized in that the first halftone dot area is divided and arranged in each predetermined area without the color materials of the three primary colors of cyan, magenta, and yellow overlapping.

  The halftone dot printed material of the present invention is characterized in that the first and second halftone dot areas are composed of the three primary colors of cyan, magenta, and yellow, and the arrangement of the predetermined areas is the same. Yes.

  In the halftone dot printed matter of the present invention, a halftone dot is arranged in each first halftone dot region using a color material that does not include infrared absorption characteristics, and the halftone dot is formed by the plurality of first halftone dot regions. Is characterized in that a gradation image expressing gradation is constructed.

  Further, the method for producing a halftone dot printed matter of the present invention forms a visible image having a density gradation by arranging a plurality of first halftone dot regions and second halftone dot regions on a substrate. The dot region has a region formed using a color material that does not include infrared absorption characteristics, and the second halftone dot region includes a second dot region that is configured using a color material including infrared absorption characteristics; It has a 2b halftone dot area configured using a color material that does not include infrared absorption characteristics, and a latent image is formed by the second a halftone dot area. The gradation is expressed by the size of the 2a halftone dot area determined according to the ratio to the 2b halftone dot area, and each color constituting the 2a halftone dot area in the second halftone dot area The material is divided into each predetermined region without overlapping, and the halftone dot region of the second a is predetermined so as to be visually recognized in the same color with the color material of the second b. It is characterized in placing the colorant.

  In the method for producing a halftone dot printed material according to the present invention, the first halftone dot region and the second halftone dot region include a plurality of one second halftone dot region adjacent to one first halftone dot region. It is characterized by being arranged in groups and surrounding each of the second halftone dot regions with a plurality of first halftone dot regions.

  Further, in the method for producing a halftone dot printed material according to the present invention, in the second area, the halftone dot area of the second area and the halftone dot area of the second area are composed of four primary colors of cyan, magenta, yellow, and black. It is characterized by that.

  Further, in the method for producing a halftone dot printed material according to the present invention, in the second area, the halftone dot area of the second area and the halftone dot area of the second area are composed of four primary colors of cyan, magenta, yellow, and black. It is characterized by that.

  Further, in the method for producing a halftone print according to the present invention, the first and second halftone dot areas are composed of the three primary colors of cyan, magenta, and yellow, and the arrangement of the predetermined areas is the same. It is characterized by that.

  Further, in the method for producing a halftone dot printed matter of the present invention, a plurality of first halftone dot regions are formed by arranging halftone dots in each first halftone dot region using a color material that does not include infrared absorption characteristics. Thus, a gradation image expressing gradation by halftone dots is constructed.

  Further, according to the printing method of the halftone printed matter of the present invention, the image data (YMCK) constituting the halftone printed matter is converted into the three primary colors (RGB) of colored light, processed as the sRGB color gamut without using the color management function, and sRGB The image data processed as a color gamut is converted into the three primary colors (YMC) and black (K) of the color material and output as a desired color material.

  The present invention temporarily converts CMYK data into another color space such as sRGB in an image processing apparatus (computer) or an image output apparatus (printer) in order to properly print the latent image of the latent image printed matter. In a general printing control system, there is no need to install a specific printer driver for a computer or printer, and there is no need to use special paper, ink, or a dedicated output machine. Appropriate latent images can be output from printers, color laser printers, etc., and used for printed matter that requires originality and security. For this reason, specialized document data is not created for each printer, so it can be used in a one-source, multi-use manner, and the document creation side does not require enormous costs or labor, and the user side In addition, there is no need for complicated environment setting for the computer or the printer.

  In addition, since the present invention does not have any special restrictions such as a computer or printer printing control method or an output machine for printing a latent image, even if it is printed on a general household printer using a network environment, Latent image printed matter can be produced.

  Embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the best mode for carrying out the invention described below, and various other modes can be implemented within the scope of the technical idea described in the scope of claims.

  First, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a halftone dot configuration diagram of a printed material according to the present invention. 2 and 3 are halftone dot arrangement diagrams of the CMYK area in the halftone area 20. FIG. FIG. 4 is a halftone dot configuration diagram of the printed material according to the present invention. FIG. 5 is a halftone dot arrangement diagram of the CMYK area in the halftone area 10. FIG. 6 is a process diagram of a printing control method when the present invention is printed by a printer. FIG. 7 is an example of color space conversion when the present invention is printed by a printer. 8 and 9 are schematic views of an embodiment of the present invention. FIG. 10 is a halftone dot configuration diagram of a conventional printed matter. FIG. 11 shows an example of color space conversion when printing is performed with a conventional printer.

(Use of printer)
The printed matter of the present invention uses halftone dots to represent a halftone, that is, continuous tone image, as shown in FIG. The present invention can also be printed by an offset printing machine, but is particularly characterized in producing a printed matter including a latent image using a printer. For this reason, four color materials of CMYK, which are standard equipment for pigment-based inkjet printers or color laser printers, are used.

(Halftone dot composition)
The present invention is based on Japanese Patent No. 3544536 previously disclosed by the present applicant. Specifically, as shown in FIG. 1, a plurality of sets of one first halftone dot region 10 and one second halftone dot region 20 adjacent to the first halftone dot region 10 are arranged. In addition, the periphery of each second halftone dot region 20 is surrounded by a plurality of first halftone dot regions 10. The first halftone dot region 10 is formed to have a larger area than the second halftone dot region 20, but may be equal or smaller. The second area 20 is arranged such that the printing areas of C, M, Y, and K, which are printer color materials, are completely divided into predetermined areas, and these are not superimposed and printed. .

  For example, in FIG. 1, the halftone dot region 20 is divided into five regions in a rectangular shape, and the K halftone dot region is provided in a substantially central region. Further, with reference to the K halftone dot area, the C halftone dot area is the left area close to the K halftone dot area, the Y halftone dot area is the right area close to the K halftone dot area, and the M halftone dot area. The dot areas were provided in the upper and lower areas adjacent to the K halftone dot area. However, although each area | region is adjoining, it does not overlap. The K halftone dot area, the C halftone dot area, the M halftone dot area, and the Y halftone dot area are respectively printed with halftone dots using the K, C, M, and Y color materials of the printer color material. The

  Further, the K halftone dot region is formed of a K color material having infrared absorption characteristics. On the other hand, the C halftone dot region, the M halftone dot region, and the Y halftone dot region in the halftone dot region 20 are formed of C, M, and Y color materials having no infrared absorption characteristics. Therefore, the latent image 20a composed of the K halftone dot area and the background image 20b composed of the C halftone dot area, the M halftone dot area, and the Y halftone dot area in the print state of the printed matter output by the printer, If each area and halftone dot percentage are configured in appropriate proportions and made fine so that they can be visually recognized as the same color in black (or black), color differences are recognized within the halftone dot area 20. However, it is only visible as uniform black (or black).

  At this time, even if the printed material is observed with visible light (or normal light), only a latent black image 20a composed of separate halftone dot regions 20 and a uniform black (or black system) composed of the background image 20b are visible. On the other hand, when observed by irradiating with infrared light, only the latent image 20a formed in the K halftone dot region is visible. According to this principle, each dot area of CMY does not have infrared absorption characteristics, so that infrared light is transmitted and can be visually recognized as white, whereas K dot area absorbs infrared light and becomes black. It depends on being visible. Therefore, it is possible to produce a printed matter that cannot recognize a latent image unless the infrared reflection / transmission characteristics are used and a special identification device such as an infrared camera is used.

  FIG. 2 shows an example in which a K dot area is provided in the center of the dot area 20, and each CMY dot area is divided into predetermined areas. FIG. 2A shows an example in which each dot area of CMY is divided in the horizontal direction. FIG. 2B shows an example in which each dot area of CMY is divided in an oblique direction. FIG. 2C shows an example in which each CMY halftone dot region is divided while being expanded along the outer periphery of the K halftone dot region. FIG. 2D shows an example in which each CMY halftone dot area is divided into a grid (or matrix), and there is no particular limitation as long as each CMY halftone dot area is divided. Each halftone dot region may be further subdivided.

  On the other hand, FIG. 3 shows an example in which each halftone dot area of CMY is divided into predetermined areas without providing a halftone dot area in the center of the halftone dot area 20. FIG. 3A shows an example in which each dot area of CMY is divided in the vertical direction and the dot area of K is arranged at the left end. FIG. 3B is an example in which each halftone dot area of CMYK is divided in an oblique direction, and the halftone dot area of K is arranged at the upper left. FIG. 3C shows an example in which each CMY halftone dot region is divided while being contracted along the outer periphery of the halftone dot region 20, and is an example in which the K halftone dot region is arranged at the outermost part. FIG. 3D shows an example in which each halftone dot area of CMY is divided into a grid (or matrix), and an example in which K halftone dot areas are arranged in a plurality of areas. 2 and 3 are examples schematically shown, and the present invention is not limited to this method.

(Halftone dot composition in halftone dot region 10)
In the configuration shown in FIG. 1, the second halftone dot region 20 is divided to provide each CMYK halftone region, and the halftone dot region 20 is adjusted and colored so as to be black or black. Uniform black (or black) consisting of the halftone dot region 20 is visible. On the other hand, in FIG. 4, in addition to the configuration of FIG. 1, halftone dots of the respective CMY color materials are arranged in the first halftone dot area 10 in each of the CMY halftone dot areas excluding the K halftone dot area. Thus, a gradation image can be produced from each halftone dot region 10. Further, if the halftone dot region 20 is finely configured, the halftone dot region 20 can be easily concealed by the gradation image composed of the halftone dot region 10. The enlarged view of FIG. 4 is an example in which the halftone dot area 10 is divided in the vertical direction, and the CMY halftone dot areas are the same division method except for the K halftone dot area in the halftone dot area 20. The halftone dot area 10 and the halftone dot area 20 may be divided in different ways. Note that a gradation image composed of halftone dots can be visually recognized as a black or gray gradation image with visible light when each CMY region is adjusted with the same area and the same density (for details, see Example 1). Described in). On the other hand, when the area and density of each CMY region are changed and adjusted, a color image with abundant colors can be visually recognized with visible light (details are described in Example 2).

  FIG. 5 is an example in which the CMY halftone dot areas are divided into areas for the halftone dot area 10. FIG. 5A shows an example in which each CMY halftone dot region is divided in the horizontal direction. FIG. 5B shows an example in which each CMY halftone dot region is divided in an oblique direction. FIG. 5C shows an example in which each CMY halftone dot region is divided while being contracted along the outer periphery of the halftone dot region 10. FIG. 5D shows an example in which each CMY halftone dot area is divided into a grid (or matrix), and the arrangement of each YMC halftone dot area is arbitrary. Each halftone dot region may be further subdivided.

(Printing method)
FIG. 6 shows a method of printing by color processing unique to the printer driver. This control method is a normal printing method that is most commonly used in home and office work, and does not use the color management function used in the plate making industry. The color management module (CMM) is turned off to work. In this case, the printing process is all controlled as an image in the sRGB color gamut and converted from RGB to CMYK data at the time of output.

  FIG. 7 shows an example of how the color change of the printed matter in the present invention occurs in the printing method. As shown in FIG. 7A, since CMYK is divided into areas with respect to the dot area 20, as shown in FIG. 7B, the K area, the C area, the M area, and the Y area are all 100. % Concentration. Even if the data is subjected to RGB conversion via a printer driver and the respective areas do not overlap, even when UCR or GCR processing is performed, each of CMYK has almost the same color as before RGB conversion. Converted by component. Therefore, the CMY region (or the 20b region serving as the background image) other than the K region (or other than the 20a region forming the latent image) with respect to the halftone dot region 20 has no CMY three-color mixed arrangement and includes a K component. Therefore, an appropriate latent image can be printed. Further, K (100%) of the latent image 20a in FIG. 7B is not shown, but when converted into sRGB and YMCK, K (75%) in the case of UCR and K (88) in the case of GCR. %).

  As described above, since the best mode for carrying out the present invention has been described on the assumption that printing is performed using a printer, the configuration is based on YMCK, but a desired ink such as an offset printing machine is used. When printing is performed, there is no particular limitation to YMC as long as the color is recognized as black when mixed.

Example 1
Example 1 is shown in FIG. 8, which is an example in which a certificate A is produced by a printer as shown in FIG. The certificate A is composed of characters necessary for a base material such as paper and a predetermined area 30. The predetermined area 30 is an area forming the embodiment of the present invention, and a mark, a character, a design, a face image, or the like can be applied. The base material of the certificate may be plastic or the like, and may be a card instead of a certificate.

  FIG. 8B is an enlarged view of the predetermined area 30. The predetermined area 30 includes a predetermined halftone dot area composed of a first halftone dot area 10 of m × m pixels and a second halftone dot area 20 of n × n pixels. It can be seen that each halftone dot area of CMY changes equally according to the gradation image of the mark. According to this configuration, a black or gray gradation image can be formed. Therefore, in order to obtain a black or gray gradation image, it is desirable that each CMY area has almost the same area and density in each halftone dot area 10. Further, the halftone dot region 20 is a 2a halftone dot region (not shown) configured using a color material including infrared absorption characteristics, and a first image (not illustrated) configured using a color material not including infrared absorption characteristics. 2b has a halftone dot area (or background area). In this embodiment, the 2a halftone dot region is a K region, and the 2b halftone dot region is a CMY region.

  Further, in FIG. 8B, the second halftone dot region 20 of n × n pixels is divided into six rectangular regions. The rectangular area is divided into a K halftone dot area, a C halftone dot area, an M halftone dot area, and a Y halftone dot area. Each halftone dot area includes a K color material, a C color material, and an M color. A halftone dot is formed of the material and the Y color material. In addition, printing is performed with halftone dots of one color of K color material including infrared absorption characteristics in the K halftone dot area, and each of the CMY halftone dot areas has infrared absorption characteristics around the K halftone dot area. A halftone dot of each color material of CMY that does not contain is arranged. The ratio of the CMYK area in each halftone dot area 20 is appropriately arranged depending on the latent image 30b, and the halftone dot% of each CMY halftone area is set to a ratio corresponding to the density of the K halftone dot area. , K can be camouflaged.

  In FIG. 8B, when the region 30 is observed with normal light, a star pattern is seen as a gradation image 30a by the color material printed in the CMYK region divided into regions. On the other hand, when the region 30 is observed with infrared light, only the K color material that is the K halftone dot region can be visually recognized, so that the number “1” appears as the latent image 30b.

  In addition, if the printing method of the printed matter is performed by the above-described printing method, a print image equivalent to the data or the setting can be obtained even if the print control device or the print output device converts it to a color space such as RGB. Therefore, an appropriate latent image can be produced.

(Example 2)
In the second embodiment, the configuration of the halftone dot region 10 in the first embodiment is changed. Therefore, the description of the same configuration as that in the first embodiment is omitted. The predetermined area 40 in the second embodiment corresponds to the predetermined area 30 in the first embodiment.

    FIG. 9B is an enlarged view of the predetermined area 40. The predetermined area 40 includes a predetermined halftone dot area composed of a first halftone dot area 10 of m × m pixels and a second halftone dot area 20 of n × n pixels. The second halftone dot region 20 is composed of halftone halftone dots.

  In FIG. 9B, the first halftone dot area 10 of m × m pixels is divided into three rectangular areas. The rectangular area is divided into a C halftone dot area, an M halftone dot area, and a Y halftone dot area, and each area is formed of a C color material, an M color material, and a Y color material. In addition, CMY color materials that do not include infrared absorption characteristics are arranged in the CMY halftone dot regions. The ratio of each CMY halftone dot area in each halftone dot area 10 is appropriately arranged depending on the color image 40a. Therefore, unlike the configuration of the first embodiment, the area of each CMY region is different in each halftone dot region 10.

  The second halftone dot region 20 has the same configuration as that of the first embodiment. However, if the area of the halftone dot region 10 is larger than the area of the halftone dot 20 and each halftone dot region 20 is regularly arranged in the same area, the halftone dot region 20 is easily camouflaged.

  In FIG. 9B, when the region 40 is observed with normal light, the mark design can be seen as a color image 40a by each color material printed in each of the CMY halftone dot regions divided in the region 40. On the other hand, in FIG. 9B, when the area 40 is observed with infrared light, only the K color material in the K halftone dot area in the halftone dot area 20 can be visually recognized, so the number “1” is the latent image. It looks as 40b.

  If this printed matter is implemented by the printing method shown in FIG. 6 described above, an appropriate latent image can be visually recognized even if it is converted into a color space such as RGB.

  Further, the halftone dot shape of each color region in the halftone dot regions 10 and 20 is not limited to a circular dot, but is proposed by random dots or Japanese Patent Application Laid-Open No. 11-268228 filed earlier by the present applicant. It is also possible to use a special halftone dot shape having a degree of freedom obtained by converting an input image into a continuous tone halftone dot composed of halftone dots (designing halftone screens) in consideration of design using the special halftone dot generation method. In the second halftone dot region 20 of the first and second embodiments, the K region is separated and arranged at a plurality of locations. With this configuration, the concealability of the latent image can be further improved. Moreover, although the halftone dot region 20 is shown as an example of uniform arrangement, it may be arranged randomly.

It is a halftone dot block diagram of printed matter in the present invention. 6 is a halftone dot arrangement diagram of a CMYK area in a halftone dot area. FIG. 6 is a halftone dot arrangement diagram of a CMYK area in a halftone dot area. FIG. It is a halftone dot block diagram of printed matter in the present invention. FIG. 4 is a halftone dot arrangement diagram of a CMYK area in a halftone dot area. It is process drawing of the printing control method at the time of printing this invention with a printer. 4 is an example of color space conversion when the present invention is printed by a printer. It is a schematic diagram of one example of the present invention. It is a schematic diagram of one example of the present invention. It is the halftone dot block diagram of the conventional printed matter. It is an example of color space conversion when printing with a conventional printer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Halftone dot area 20 Halftone dot area 20a Halftone dot area | region comprised using the color material containing an infrared absorption characteristic 20b Halftone dot area | region comprised using the color material which does not contain an infrared absorption characteristic 30 Predetermined area | region 30a Floor Tone image 30b Latent image 40 Predetermined area 40a Gradation image 40b Latent image K Black area C Yellow area M Magenta area Y Yellow area A Certificate

Claims (13)

A color material in which a plurality of first halftone dot regions and second halftone dot regions are arranged on a substrate to form a visible image having a density gradation, and the first halftone dot region does not include infrared absorption characteristics. And the second halftone dot area is a colorant that does not include infrared absorption characteristics, and the second halftone dot area that is constituted by using a colorant including infrared absorption characteristics. A latent image is formed by the 2a halftone dot area, and the latent image is composed of the 2a halftone dot area and the second b halftone dot area. The gradation is expressed by the size of the 2a halftone dot area determined according to the ratio to the area, and the second halftone dot area constitutes the 2a and 2b halftone dot areas. Each color material is divided and arranged in each predetermined area without overlapping, and the 2a halftone dot area and the 2b halftone dot area are the same with the naked eye. Dot printed matter characterized in that it is visually recognized. In the first halftone dot area and the second halftone dot area, a plurality of sets of one second halftone dot area adjacent to one first halftone dot area are arranged, and each of the second halftone dot areas is arranged. The halftone dot printed matter according to claim 1, wherein the perimeter of the halftone dot region is surrounded by the plurality of first halftone dot regions. 2. In the second area, the 2a halftone dot area and the 2b halftone dot area are composed of four primary colors of cyan, magenta, yellow, and black. Or the halftone dot printed matter of 2. 4. The halftone dot area according to claim 1, wherein the first halftone dot area is divided into predetermined areas without overlapping each of the three primary colors of cyan, magenta, and yellow. Dot print. 5. A halftone dot area according to claim 4, wherein the halftone dot area of said first and said second b is composed of color materials of three primary colors of cyan, magenta and yellow, and the arrangement of each predetermined area is the same. Printed matter. In each of the first halftone dot areas, a halftone dot is arranged using a color material that does not include infrared absorption characteristics, and a gradation is expressed by a halftone dot by the plurality of first halftone dot areas. 6. A halftone print according to claim 4 or 5, wherein a tone image is constructed. A color material in which a plurality of first halftone dot areas and a plurality of second halftone dot areas are arranged on a substrate to form a visible image having a density gradation, and the first halftone dot area does not include infrared absorption characteristics. The second halftone dot region is composed of a second halftone dot region composed of a color material including infrared absorption characteristics, and a color material not including infrared absorption characteristics is used. A latent image is formed by the 2a halftone dot area, and the latent image is composed of the second a halftone dot area and the second b halftone dot area. The gradation is expressed by the size of the 2a halftone dot area determined according to the ratio, and in the second halftone dot area, the color materials constituting the 2a halftone dot area overlap each other. Without being divided into each predetermined region, and the second 2a halftone dot so that the second color material and the naked eye can be visually recognized in the same color. The method for manufacturing a halftone dot printed product characterized by placing a predetermined colorant to pass. In the first halftone dot area and the second halftone dot area, a plurality of sets of one second halftone dot area adjacent to the first halftone dot area are arranged, and each of the second halftone dot areas is arranged. 8. The method for producing a halftone dot printed product according to claim 7, wherein the halftone dot region is surrounded by the plurality of first halftone dot regions. 9. The second area, wherein the 2a halftone dot area and the 2b halftone dot area are composed of four primary colors of cyan, magenta, yellow, and black. A method for producing the halftone printed matter according to the description. 10. The halftone dot printed material according to claim 7, wherein the first halftone dot region is formed by dividing each of the three primary colors of cyan, magenta, and yellow into predetermined regions without overlapping each other. Manufacturing method. 11. The halftone dot area according to claim 10, wherein the first and second halftone dot areas are composed of color materials of three primary colors of cyan, magenta, and yellow, and the arrangement of the predetermined areas is the same. A method for producing dot prints. In each of the first halftone dot areas, a halftone dot is arranged using a color material that does not include infrared absorption characteristics, and a gray scale is expressed by a halftone dot by the plurality of first halftone dot areas. 12. The method for producing a halftone print according to claim 10 or 11, wherein an image is formed. 7. A method for printing a halftone print according to claim 1, wherein the image data (YMCK) constituting the halftone print is converted into three primary colors (RGB) of colored light, and an sRGB color gamut without using a color management function. The halftone print product is processed as above, and the image data processed as the sRGB color gamut is converted into the three primary colors (YMC) and black (K) of the color material and output as the desired color material.

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