JP5463649B2 - Gradation resin plate and printed matter using gradation resin plate - Google Patents

Description

  The present invention relates to a resin plate surface for obtaining a printed matter to which a gradation pattern having continuous gradation expression is applied.

  Conventionally, gradation printing is known as a printing method that uses a resin plate surface to give a gradation pattern having continuous gradation expression to a printing material such as metal, cloth, and paper. The gradation printing method is a printing method for obtaining a gradation pattern having a continuous gradation expression by changing the gradation of an image stepwise from a highlight to a halftone to a shadow. For example, the gradation printing method includes an overlap printing method.

  For example, Patent Document 1 discloses a gradation printed matter using an overlap printing method and a printing method thereof. In the overlap printing method, first, a photosensitive resin plate material is exposed and developed by a known method, thereby producing a plurality of partial plates in which the dot area ratio or the line width of the line changes. The produced partial plates are each mounted so as to be transferred onto the same blanket in the printing press. Next, after a plurality of inks having different printing color densities are respectively deposited on the partial plate, they are given a certain amount of overlap (overlapping) and transferred onto a collective blanket. The transferred ink has a high printing color density at a location where a large amount of ink is overlapped on the aggregate blanket, and conversely, a printing color density is low at a location where there is little overlap. Finally, after the ink on the assembly blanket is deposited on the resin plate surface, it is transferred to the printing material, whereby a printed material with a gradation pattern can be obtained.

  In addition, the applicant has already filed an application for a resin plate surface produced using an original film having continuous gradation (see Patent Document 2). FIG. 17A is a cross-sectional view of a resin plate surface using a conventional photosensitive resin plate material, and FIG. 17B is a diagram of a flexographic print obtained using the resin plate surface shown in FIG. It is a top view. Moreover, FIG.17 (c) is a cross-sectional view of the resin plate surface currently disclosed by patent document 2, and FIG.17 (d) was obtained using the resin plate surface shown in FIG.17 (c). It is a top view of a flexo print.

  As a method for producing the resin plate surface shown in FIG. 17C, first, an original film having a continuously changing dot area ratio is produced. Next, the photosensitive resin plate material is irradiated with an actinic ray such as ultraviolet rays through the produced original image film, and is exposed and cured to form a gradation pattern. By exposing through the original film in which the halftone dot area ratio has been continuously changed, the amount of transmitted actinic rays changes for each halftone dot area ratio, and the exposure state of the photosensitive resin plate material changes. Finally, the resin plate surface shown in FIG. 17C is obtained by washing away the photosensitive resin plate material after exposure with a solvent. The flexographic printed matter obtained by printing with the flexographic printing machine using the produced resin plate surface is a printed matter having a gradation pattern as shown in FIG.

Japanese Patent Publication No. 5-64600 Japanese Patent Application No. 2007-133048

  However, in the overlap printing method disclosed in Patent Document 1, a gradation pattern having continuous gradation expression is obtained by overlapping a plurality of inks having different printing color densities. Therefore, it is necessary to prepare a plurality of inks having different printing color densities in advance. Moreover, when the obtained gradation pattern is enlarged and visually recognized with a magnifying glass or the like, an overlap portion is visually recognized in the gradation pattern. Therefore, in order to camouflage the overlap portion, it is necessary to limit the ink used for the gradation pattern printing portion to a light color ink, or to print the camouflage pattern on the overlap portion in the gradation pattern.

  Further, in the resin plate surface disclosed in Patent Document 2, since the resin plate surface is produced by exposing through the original image film having continuous gradation, the floor is continuously formed using the resin plate material. It became possible to express. The photosensitive resin plate material is formed by alternately laminating cured portions and dissolved portions at a fixed amount of actinic ray irradiation. Therefore, as shown in FIG. 17 (c), the produced resin plate surface has a stepped inclined surface on the ink-implanted surface, and the obtained flexographic print is also stepwise as shown in FIG. 17 (d). The printed matter has a gradation pattern with changed gradation. That is, there still remains a problem in obtaining a gradation pattern in which gradation changes continuously and gently using the resin plate surface of FIG. Further, since an original film is required, the plate-making process is divided into a plurality of processes, so that much labor and time are consumed.

The present invention aims to solve the above-described problems. Specifically, when forming a resin plate surface by forming a gradation pattern on a resin plate material, the gradation has a gradual level difference. The purpose is to make a pattern. Further, a gradation pattern having a continuous tone representation in the substrate, to provide a once resin printing plate capable and granted child in printing.

In order to achieve the above-described object, the present invention provides a laser processing region in a resin plate material by using a gradation resin plate surface preparation apparatus including an original image acquisition unit having at least an acquisition unit, a data preparation unit, and a laser processing unit. , A resin plate surface provided by a gradation resin plate surface preparation method that continuously provides a gradation pattern with a gradual elevation difference by irradiation of a laser beam, the gradation pattern applied to the resin plate material in the original image acquisition unit In order to provide an original image acquisition step of acquiring an original image, converting the digital image into an original image that has been converted into digital data, or acquiring an original image that has been converted into digital data in advance, A tone reproduction model showing the contrast between the image density in the original image and the image density in the printed material prepared based on the original image. Based on the processing data preparation process for correcting the gradation range of the digital data and generating processing data in a data format that can be output by the laser processing unit, and the intensity of the laser beam based on the processing data, Set the processing conditions of the rotation speed, pitch and control signal, send the processing conditions to the laser processing section, and the laser processing section in the laser processing area of the resin plate material according to the processing data and the laser processing conditions It is possible to provide a gradation resin plate surface preparation method characterized by having at least a laser processing step of forming a gradation pattern by irradiating a laser beam.

In the gradation resin plate surface preparation method by laser processing described in the previous paragraph , the present invention provides a processing data preparation step for determining an image input resolution of a gradation pattern to be applied to a resin plate material in a laser processing unit. The image input resolution setting means for setting the image input resolution of the digital data, and the highest first image density and the lowest second in the original image in order to determine the gradation range in the digital data for which the image input resolution is set The image density setting means for setting the image density of the digital data to the same value as the measured image density, and the gradation that the original image has the gradation in the printed material produced based on the original image The image density in the original image and the image density in the printed material prepared based on the original image are pre-made to Tone correction based on a proportional relationship between the image density in the digital data in which the image density is set and the image density in the printed material created based on the original image by correcting the tone range based on the tone reproduction curve indicating the ratio In order to make the gradation range correction means for producing data and the gradation correction data data that can be output by the laser processing unit, the gradation from 0 gradation to 255 gradation is represented by an achromatic color having a constant density interval. It is possible to provide a gradation resin plate surface preparation method characterized by having at least gray scale data conversion means for converting into gray scale data.

Further, the present invention provides the gradation resin plate surface preparation method by laser processing described in the preceding two paragraphs, wherein the processing data preparation step continuously represents a gradation expression in the digital data after the image input resolution setting means with a gradual elevation difference. In order to obtain a resin plate surface having digital data, when the gradation representation of the digital data is data expressed by the size of halftone dots and / or overlapping of halftone dots, the size of one square is the size of one pixel. The image density of each pixel arranged in the matrix is measured, and the average value of the image density is calculated for the desired pixel to be converted from the halftone dot representation to the pixel representation and the pixels surrounding the desired pixel. Then, the average value is uniformly distributed to the desired pixels and the image density is expressed in a solid pattern, so that the pixels arranged in a matrix are displayed. In order to give continuous gradation expression to the digital data after the gradation conversion means for converting to gradation-represented digital data by the image density change for each image and the image density setting means, continuous gradation is given. When digital data is acquired based on a non-original image, gradation effect applying means for adding at least one gradation effect including shadows, halftones, and highlights to the digital data; To make the tone correction data independent of the type of image processing software, when the tone correction data is data that depends on the type of image processing software, the tone correction data is converted into postscript data. In order to convert the gradation correction data after the postscript data conversion means and gradation range correction means to digital data that can be printed in multiple colors, There when was color document consisting of a plurality of colors, it is possible to provide a gradation resin printing plate manufacturing method characterized by having a color separation means for performing color separation of at least one further.

Further, according to the present invention, in the gradation resin plate production method by laser processing described in any of the preceding three paragraphs , the conversion to grayscale data is performed by converting the gradation in the digital data from 0 gradation to 255 gradation. / DIS12218: It is represented by an achromatic color having a constant density interval of 0.15 defined in 1996.

The present invention is characterized in that it is a gradation resin printing plate having a continuously gentle difference in height that can be printed in a convex printing plate format .

Further, the invention described in claim 2 is a printed matter obtained from the gradation resin plate surface described in claim 1 .

  In the resin plate surface preparation method, processing data is prepared based on the original image, and laser processing is performed on the resin plate material using the processing data, thereby forming a simple resin plate surface or stepped uneven shape. Instead of the resin plate surface, it is possible to produce a resin plate surface having a gradual level difference. In addition, by printing the resin plate surface using a known printing machine such as a relief printing system as shown in FIG. 15, a gradation pattern having continuous gradation expression is once printed by printing. Is possible.

Furthermore, the gradation pattern in the present invention has a continuous gradation change without having a halftone dot shape. Therefore, unlike gradation patterns imitated using inkjet printers, copiers, etc., they can be easily identified by magnifying and observing them using a magnifying glass. Can be granted.

  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 claims.

  FIG. 1 is an example of a schematic diagram showing the entire configuration of a gradation resin plate surface production apparatus according to the present invention. FIG. 2 is a block diagram showing the configuration of the gradation resin plate manufacturing apparatus according to the present invention. FIG. 3 is an example of a schematic diagram showing a procedure for converting the gradation in the digital data according to the present invention from a halftone dot representation to a pixel representation. FIG. 4 is a diagram showing image density and laser output according to the present invention. FIG. 5 is an example of a schematic diagram showing a gradation range correction procedure in digital data according to the present invention. FIG. 6 is a flowchart showing the flow of the gradation resin plate production process according to the present invention. FIG. 7 is a flowchart showing the flow of step 2 in the production process of the gradation resin plate surface according to the present invention. FIG. 8 shows an example in which a gradation effect is given to digital data after image density setting according to the present invention. FIG. 9 is a tone curve used for tone correction of image density in digital data according to the present invention. FIG. 10 is a cross-sectional view of a gradation resin plate surface according to the present invention and a plan view of a printed matter obtained from a resin plate surface having a gradual height difference. FIG. 11 is a plan view showing an original image according to the present invention. FIG. 12 shows digital data expressed by image density change for each pixel according to the present invention. FIG. 13 shows grayscale data according to the present invention. FIG. 14 is a gradation resin plate according to the present invention. FIG. 15 is a schematic view of a printing unit in a relief printing press according to the present invention. FIG. 16 is a plan view showing printed matter and imitation printed matter obtained using the gradation resin plate according to the present invention. FIG. 17 is a diagram for explaining a difference between a resin plate surface by a conventional photosensitive resin plate material and a resin plate surface by a photosensitive resin plate material of Patent Document 2. In FIG.

  FIG. 1 is an example of a schematic diagram illustrating the entire configuration of a gradation resin plate producing apparatus for producing a gradation resin plate in the present invention. The gradation resin plate surface production apparatus (1) comprises an original image acquisition unit (2), a data production unit (3), and a laser processing unit (4), each directly and / or indirectly via a connection means (5). Connected. The original image acquisition unit (2) acquires an original image of a gradation pattern formed on the resin plate material (S), and the data preparation unit (3) acquires the original image acquired by the original image acquisition unit (2). The processing data is created based on the image. The laser processing section (4) is a place where the resin plate material (S) is irradiated with a laser beam based on the processing data prepared by the data preparation section (3). The connection means (5) in the present invention includes a cable, a wireless LAN, an information communication network, and the like.

  FIG. 2 is a block diagram showing a configuration of the gradation resin plate surface production apparatus (1) described above. The original image acquisition unit (2) in the gradation resin plate manufacturing apparatus (1) has at least acquisition means (6) for acquiring or inputting an original image of a gradation pattern to be formed on the resin plate material (S). If the original image acquired or inputted by the acquisition means (6) is not converted into digital data, it is necessary to convert the original image into digital data. Therefore, the data conversion means (7) for converting the original image into digital data is further provided. It is necessary to have. The digital data of the original image acquired in the original image acquisition unit (2) is transmitted to the data preparation unit (3) via the connection means (5).

  The original image acquisition unit (2) includes an acquisition unit (6) that acquires an original image that is a source of a gradation pattern to be applied to the resin plate material (S), and a data conversion unit that converts the acquired original image into digital data. (7) may be a reading device such as a scanner provided in one device or an imaging device such as a digital camera, a video camera, or a portable terminal. The acquisition means (6) includes an MO drive, a CD that acquires digital data from an information recording medium such as a CD-ROM, FD, or USB memory in which an original image produced and / or acquired in advance is recorded as digital data. -It is good also as input / output devices, such as a ROM drive, FD drive, and an image card reader. In this case, as described above, since the original image has already been converted into digital data, the data conversion means (7) is not required. Furthermore, even when the original image converted into digital data is acquired by the acquisition means (6) from a remote place via the connection means (5), since it has already been converted into digital data, the data conversion means (7) Do not need.

  Next, the data preparation unit (3) will be described. The data production unit (3) in the gradation resin plate production apparatus (1) is a personal computer (hereinafter referred to as “PC”), and includes a CPU (10), RIP (11), lookup table production means (12), and storage means. (13) comprises a display means (14), a keyboard (8) and a pointing device (9). The CPU (10) includes an image input resolution setting means (15), a gradation conversion means (16), an image density setting means (17), a gradation effect applying means (18), a gradation correction means (19), and a postscript. It consists of data conversion means (20). Further, the RIP (11) includes a color separation unit (21), a gray scale data conversion unit (22), and a TIFF data conversion unit (23).

  The image input resolution setting means (15) is a means for setting the image input resolution of the digital data input to the CPU (10) and then transmitting it to the image density setting means (17). The image input resolution is an image output resolution of a gradation pattern in which digital data input to the PC (3) is applied to the resin plate material by irradiating a laser beam in the laser processing unit (4). Expressed by the number of lines. The number of screen lines is the number of rows of halftone dots between 1 inch or 1 cm. When the number of screen lines increases, the halftone dots on the digital data become inconspicuous, and when the number of screen lines decreases, the halftone dots become conspicuous on the digital data. The image input resolution can be set as appropriate, but is preferably in the range of 200 to 300 lpi.

  The gradation converting means (16) is arranged in a matrix form when the gradation expression of the digital data input to the CPU (10) is data expressed by the size of halftone dots and / or overlapping of halftone dots. It is a means for converting into digital data expressing gradation by changing the image density for each pixel. When the gradation of the image in the digital data is expressed by halftone dots, the obtained printing plate is a resin printing plate having no height difference, as shown in FIG. However, when the gradation of the image in the digital data is expressed by a change in image density for each pixel, the obtained printing plate is a resin printing plate having a continuous moderate level difference. Note that when digital data is acquired as an original image expressed in gradation by changing the image density for each pixel arranged in a matrix, the gradation conversion means (16) is not required.

  FIG. 3 is an example of a schematic diagram illustrating a procedure for converting gradation in digital data from halftone dot representation to pixel representation. As shown in FIG. 3 (1), as a method of converting digital data expressed in gradation by the size of halftone dots and / or overlapping of halftone dots into digital data expressed in gradation by a change in image density for each pixel. First, as shown in FIG. 3B, the digital data is divided into a matrix in which one square has a size of one pixel. Next, as shown in FIG. 3 (3), an arbitrary symbol or the like is assigned to each pixel. As an example, let (a) to (i). In order to convert (e) from a halftone dot representation to a pixel representation, first, (a) to (i) the image density for every nine pixels is measured. Next, as shown in FIG. 3 (4), a desired pixel (e) to be converted from a halftone dot representation to a pixel representation and pixels (a), (b), (c) surrounding the desired pixel. From the image densities of (d), (f), (g), (h), and (i), an average value of nine pixels is calculated. Further, as shown in FIG. 3 (5), by expressing the calculated image density uniformly in a solid shape at the location (e), the area (e) in the digital data can be converted into a pixel representation. End. Next, as shown in FIG. 3 (6), the same procedure is repeated for (f) that is partially adjacent to (e), and as shown in FIG. The region has been converted to pixel representation. Further, by repeating the same procedure for all the pixels divided into a matrix, as shown in FIG. 3 (8), the digital data gradation is represented by a change in image density for each pixel from a halftone dot representation. Convert to data.

  The image density setting means (17) is a means for setting the image density of the digital data. The image density is the image density at the highest image density in the original image (hereinafter referred to as “first image density”) and the image density at the lowest image density (hereinafter referred to as “second image density”). ) Is measured using a known density measuring device such as a reflection density measuring device, and then the image density of the digital data is set to the same value as the measured image density. Thereby, it is possible to set the gradation range in the digital data.

  The gradation effect applying means (18) is means for applying continuous gradation expression to digital data and then transmitting it to the gradation correcting means (19). Key and highlight. A shadow is a dark part in a gradation pattern, a halftone is a halftone part between the shadow and highlight in a gradation pattern, and a highlight is a bright part in a gradation pattern. When digital data is acquired based on an original image to which continuous tone is added, since the digital data has already been provided with continuous tone, the tone effect applying means (18) is not required.

  The gradation correction means (19) is a means for correcting the gradation range of the digital data after the gradation effect is imparted. As described above, the digital data represents the 0th gradation to the 255th gradation with a color image. First, the reason why the gradation range of the digital data for the original image must be corrected will be described.

  FIG. 4 is a diagram showing image density and laser output. In order to faithfully reproduce the gradation range of the original image, a gradation resin plate surface was prepared based on the image density and the original image of the original image, and printed using the resin plate surface. It is necessary to make the relationship of the image density in the printed matter proportional. In FIG. 4A, the horizontal axis represents the image density in the digital data obtained from the original image, and the vertical axis represents the laser output according to the image density. The first image density (A) having the highest image density in the digital data is a portion having the highest printing pressure. As shown in FIG. 10, which will be described later, the resin printing plate obtained by laser processing has a higher printing pressure as the thickness increases. Further, since the resin plate surface becomes thinner as the laser output is larger, the portion having the largest printing pressure is the portion having the smallest laser output value (hereinafter referred to as “minimum output value”).

  The second image density (B) having the lowest image density in the digital data is a portion having the smallest printing pressure. As described above, the resin printing plate surface obtained by laser processing has a higher printing pressure as the thickness increases. On the contrary, the part with the smallest printing pressure is the part with the largest laser output value (hereinafter referred to as “maximum output”). Value ”). Based on the first image density (A) and the second image density (B), the maximum output value and the minimum output value are set, and then the laser output value is set for each image density by connecting the respective values. (Hereinafter, the line (Y1) connecting the maximum output value and the minimum output value is referred to as “output curve”). Note that the maximum output value and the minimum output value vary depending on the resin plate surface used, the printing pressure, and the like, and therefore need to be set as appropriate.

  FIG. 4B is a first floor showing a comparison between the image density in the original image and the image density in the printed material that is printed using the gradation resin plate surface produced by laser output shown in FIG. It is an example of a tone reproduction curve (X1). The tone reproduction curve indicates how the tone (image density) of the original image is reproduced in the printed material. As shown in FIG. 4B, in practice, the laser output set by simply connecting the minimum output value and the maximum output value cannot faithfully reproduce the image density of the original image on the printed matter.

  Therefore, as shown in FIG. 4C, the image density in the original image shown on the horizontal axis and the image density in the printed material produced based on the resin plate surface obtained by laser processing shown on the vertical axis are proportional to each other. The first gradation reproduction curve (X1) is corrected so that the ideal second gradation reproduction curve (X2) is obtained. Since the image density in the original image and the image density in the printed material produced based on the resin plate surface obtained by laser processing have a proportional relationship, the tone (image density) of the original image is faithfully reproduced in the printed material. Will be.

  FIG. 4D is a diagram in which the first gradation reproduction curve (X1) shown in FIG. 4B and the second gradation reproduction curve (X2) shown in FIG. is there. As shown in FIG. 4D, there is a difference (α) between the first gradation reproduction curve (X1) and the second gradation reproduction curve (X2). Based on this difference (α), it is necessary to correct the output curve (Y1) in FIG. Therefore, as shown in FIG. 4E, an output curve (Y2) obtained by deforming the output curve (Y1) shown in FIG. 4A by a difference (α) is obtained.

  The contrast between the image density in the printed matter printed using the gradation resin plate produced based on the output curve (Y2) obtained in FIG. 4 (e) and the image density in the original image is as shown in FIG. 4 (f). The third tone reproduction curve (X3) is obtained. By correcting the output curve (Y1) to the output curve (Y2), the image density in the original image and the image density in the printed material produced based on the resin plate surface obtained by laser processing have a proportional relationship. . That is, the tone (image density) of the original image is faithfully reproduced on the printed matter.

  The gradation reproduction curve used for the correction of the gradation range of the digital data described above includes the laser processing conditions in the laser processing section (4), the type of the resin plate material (S), the printing method, and various working conditions such as ink used for printing. A plurality of modified versions are prepared in advance and stored as preparation data (25) in the storage means (13) described later. Among the plurality of gradation reproduction curves, the one that meets the working conditions is read from the storage means (13), and the gradation range of the digital data is corrected based on the gradation reproduction curves.

FIG. 5 is an example of a schematic diagram illustrating a gradation range correction procedure in digital data. If none of the gradation reproduction curves prepared in advance meet the work conditions, it is necessary to newly correct the gradation range as shown in FIG. As a method of correcting the gradation range, first, gray scale data represented by an achromatic color having a constant image density interval from 0 gradation to 255 gradation is produced as the original image shown in FIG. After that, it is converted into digital data. Next, processing data is prepared based on the digital data, and the resin plate material (S) is manufactured by a conventional manufacturing method, and the gray scale plate surface shown in FIG. 5B (hereinafter, manufactured by a conventional manufacturing method). The prepared resin plate surface is referred to as “gray scale plate surface”). At this time, the resin plate material (S) used is the same as the resin plate material (S) used when producing the gradation resin plate surface of the present invention. Next, letterpress printing, and printing by a known method to produce a printed material shown in FIG. 5 (c) using the grayscale printing plate. The image density in the printed material produced last is measured using a known density measuring device such as a reflection density measuring device, and printing is performed using the image density and gray scale plate surface in the original image as shown in FIG. Then, a gradation reproduction curve indicating the contrast of image density in the produced printed material is produced.

  Next, printing is performed using the image density in the digital data and the gray scale plate, and the gradation of the digital data is corrected by the gradation correction means (19) so that the relationship between the image density in the produced printed matter is proportional. . Details of the correction method will be described later. FIG. 5 (e) is a gradation reproduction curve showing the contrast between the image density in the original printed image and the gray scale plate produced using the digital data after gradation range correction, and the printed image produced. It is an example. As shown in FIG. 5E, by correcting the gradation range, it is possible to obtain processing data having a simple proportional relationship. In order to obtain processing data having a simple proportional relationship, it is necessary to repeat the steps from FIG. 5A to FIG. 5D described above.

  The gradation range once determined can be newly stored as preparation data (25) in the storage means (13) described later, and can be recalled as necessary.

  The postscript data conversion means (20) is means for converting gradation correction data into postscript data. Postscript data is one of file formats for exchanging data such as characters and graphics, and is a file in which arrangement, display contents, and images are added to data described in the PostScript language. Postscript data includes both vector format and bitmap format for images to be added to the file, so it can be converted to Postscript data without depending on the type of publicly known image processing software. Data can be transmitted to the RIP (11). Depending on the type of image processing software to be used, it may be possible to transmit the gradation correction data to the RIP (11) as it is without converting it to Postscript data. In that case, it is not necessary to convert the gradation correction data into Postscript data by the PostScript data converting means (20).

  The RIP (11) includes color separation means (21), gray scale data conversion means (22), and TIFF data conversion means (23). RIP is a general abbreviation for Raster Image Processor. Based on the input page description language, RIP generates image data as a set of pixels according to resolution in units of rasters (lines), and generates continuous tone data. It is a means to produce.

  The color separation means (21) is means for performing color separation in order to convert gradation correction data into digital data that can be printed in multiple colors. When the original image is a color original composed of a plurality of colors, it is necessary to perform color separation. Color separation includes analog separation methods and digital separation methods. In the analog separation method, first, a color original is photographed through three color filters of red, green and blue-violet. Since the filter absorbs a color complementary to its own color, three types of data of CMY (cyan, magenta, yellow) excluding the filter color (absorption color) in the color original are obtained. In the digital decomposition method, the gradation correction data is converted into data expressed by three types of data of CMY or four types of data of CMYK (cyan, magenta, yellow and black), and the gradation for each color component. It is to obtain correction data. Note that when digital data expressed in a single color is used for an original image, the gradation correction data may be expressed by any one type of CMYK data. In this case, it is not necessary to perform color separation conversion on the gradation correction data by the color separation means (21).

  The gray scale data conversion means (22) is means for converting the gradation correction data into gray scale data in order to acquire gray scale data. The gray scale data is represented by an achromatic color that is a color having only luminance components such as white, gray, and black. In grayscale data, the 0th gradation is black, the 255th gradation is white, and the 0th gradation to the 255th gradation is represented by a constant image density interval. Note that the fixed image density interval is defined as 0.15 in ISO / DIS12218: 1996. By transmitting the gray scale data to the laser processing unit (4), it becomes processing data.

  The TIFF data conversion means (23) is means for converting gray scale data into TIFF data. Since the gray scale data depends on the type of OS (Operating System) such as Windows (registered trademark) or Macintosh (registered trademark), it may not be directly output by the laser processing unit (4) depending on the data format. At that time, the TIFF data conversion means (23) converts the grayscale data into TIFF data, which becomes processing data that can be output by the laser processing section (4). TIFF is a general abbreviation for Tagged Image File Format, and is one of image data storage formats. By converting to TIFF data, the grayscale data after gradation conversion becomes processing data in a data format that can be handled by all OSs, regardless of the type of OS. Depending on the type of OS, the gray scale data may be output by the laser processing unit (4) without being converted into TIFF data. In that case, the TIFF data conversion means (23) is not required, and the grayscale data becomes the processing data as it is.

  The lookup table creation means (12) is a means for creating a lookup table (hereinafter referred to as “LUT”) based on the processing data and the tone curve. In the LUT, data calculated in advance is stored in an array or conversion table. Next, the target data is extracted from the array or the correspondence table by the PC. Thereby, the data conversion time is only the access time to the target data, and data conversion can be performed at high speed. In the present invention, the LUT is a conversion table that stores the laser output value corresponding to the image density of each pixel in the processing data and the depth of the resin plate surface corresponding to the laser output value. By creating the LUT, it is possible to easily search for the engraving depth corresponding to the image density of each pixel when an arbitrary tone curve is used. As for the depth of the resin plate surface, the depth of the gray scale plate surface used when the gradation reproduction curve as shown in FIG. 5E is obtained is measured in advance, and the value is used. The LUT differs depending on the processing data and tone curve used at the time of LUT production. Therefore, when using different processing data and tone curves, it is necessary to prepare the LUT again. However, the LUT once produced can be stored as preparation data (25) in the storage means (13) to be described later, and can be called up as necessary.

  The storage means (13) is means for storing CPU data (24) and preparation data (25). The CPU data (24) is program data for operating the CPU (10). The preparation data (25) is data in which an original image prepared and / or acquired in advance is stored as digital data, gradation reproduction curve data used for digital data gradation range correction, and resin in the laser processing section (4). This is data in which laser processing conditions for laser processing on the plate material (S) are stored in advance.

  The display means (14) is means for displaying digital data input to the CPU (10), and is, for example, a display. The keyboard (8) and the pointing device (9) input the original image as digital data on the display (14), or the CPU data (24) and the preparation data (25) stored in the storage means (13) by the input operation. And means for reading the LUT.

  Next, a laser processing part (4) is demonstrated. The laser processing section (4) in the gradation resin plate surface production apparatus (1) includes a laser irradiation means (26) and a cylinder (27). The laser irradiation means (26) includes a data control means (28), an oscillator (29), a condenser lens (30), and a scanner motor (not shown). The data control means (28) is means for determining the electrical energy that becomes the laser output for each pixel unit based on the LUT corresponding to the received processing data after receiving the processing data produced by the PC (3). is there. The oscillator (29) is a means for outputting after exciting the laser light, and outputs the laser light excited according to the electric energy determined by the data control means (28). The condensing lens (30) is a lens that condenses the laser light, and is a means for condensing the laser light output from the oscillator (29) onto the laser processing region (S1) in the resin plate material (S). . The scanner motor is means for scanning the laser beam condensed by the condenser lens (30) in the axial direction of a cylinder (27) described later. The laser beam condensed on the laser processing region (S1) is scanned from the unevenness on the laser processing region (S1) in the resin plate material (S) by scanning the condensing lens (30) with a scanner motor. A gradation pattern is given. The resin plate material (S) after the gradation pattern is applied becomes a gradation resin plate surface.

  The cylinder (27) is a cylinder on which the resin plate material (S) is placed. The cylinder (27) is hollow, and the resin plate material (S) is placed on the inner peripheral surface thereof. The cylinder (27) is made of an aluminum material, and the inner peripheral surface thereof is polished with high precision so that the surface irregularities are in the range of ± 5 μm. This is because the distance between the laser irradiation means (26) and the inner peripheral surface of the cylinder (27) is always kept constant. The cylinder (27) includes a cylinder rotation mechanism (not shown). The cylinder rotation mechanism is provided so as to hold the cylinder (27) at both ends of the cylinder (27). The laser beam condensed by the condenser lens (30) is scanned into the processing data by sequentially scanning the surface of the resin plate material (S) placed on the cylinder (27) in the circumferential direction of the cylinder (27). Based on this, the unevenness that becomes a part of the gradation pattern is given. Next, the condensing lens (30) is moved by one pixel in the axial direction of the cylinder (27) by the scanner motor, and then irregularities that are part of the gradation pattern are given again based on the processing data. As described above, when the laser beam is irradiated, the cylinder (27) and the cylinder rotation mechanism rotate, and the condenser lens (30) is moved in the axial direction of the cylinder (27) by the scanner motor. It is possible to sequentially scan the surface of the resin plate material (S) and create a gradation resin plate surface based on the processing data.

  Note that suction means is preferably provided on the cylinder (27). The suction means is means for removing products such as combustion residue generated when the resin plate material (S) is irradiated with laser light. By operating the suction means at the time of laser processing, it is possible to suppress processing unevenness and the like that occur when the combustion residue adheres to the laser processing region (S1).

  Hereinafter, a method for producing a gradation resin plate surface by applying a gradation pattern to the resin plate material (S) of the original image using the gradation resin plate surface production apparatus (1) of FIG. 1 will be described with reference to FIGS. .

  FIG. 6 is a flowchart showing the flow of the production process of the gradation resin plate surface. First, an original image of a gradation pattern to be applied on the resin plate material (S) is acquired (step 1). First, the user prepares an original image of a gradation pattern to be applied on the resin plate material (S). As a method for acquiring an original image, a method of directly acquiring from a medium on which the original image is applied, a method of acquiring and / or inputting an original image with a PC (3), an original image is captured with an imaging device. There are a method of acquiring, a method of acquiring an original image by an input / output device, and a method of acquiring an original image stored in the PC (3) in advance. In the method of directly acquiring from a medium on which an original image is applied, first, a medium to which an original image such as a photograph, a logo mark, a character, or a picture is attached is prepared. The medium provided with the original image is a printed matter on which the original image is printed or a photographic paper on which the original image is printed. Next, the acquisition unit (6) in the original image acquisition unit (2) is operated to read the original image from the prepared medium and then transmit it to the data conversion unit (7). The data conversion means (7) converts the received original image into digital data and then transmits it to the CPU (10) in the PC (3) via the connection means (5).

  The method of creating and / or inputting an original image with the PC (3) is to create and / or input an original image with the keyboard (8) and / or the pointing device (9) provided in the PC (3). Is the method. Using an image processing software (for example, Adobe Photoshop), the keyboard (8) and / or pointing device (9) is operated to generate and / or input an original image on the display (14). The original image created and / or input can be directly transmitted to the CPU (10) as digital data. The original image once created and / or inputted can be used as the original image again by storing it as preparation data (25) in the storage means (13).

  The method of capturing and acquiring an original image with an imaging device is to acquire an original image by operating an imaging device and capturing an object such as a landscape, a person, and a photograph. The acquired original image is converted into digital data and transmitted to the CPU (10) in the PC (3) via the connection means (5).

  The method of acquiring an original image by an input / output device is an input / output that is connected to a PC (3) via a connection means (5) from an information recording medium in which the original image produced and / or acquired is recorded as digital data. This is a method of acquiring an original image using a device. The acquired original image is directly transmitted to the CPU (10) as digital data.

  The method of reading and acquiring the original image stored in the storage means (13) in the PC (3) in advance is prepared and / or input by the PC (3) and prepared in the storage means (13) in the PC (3). In this method, the original image stored as data (25) is acquired by operating the keyboard (8) and / or the pointing device (9) and reading it. The acquired original image is directly transmitted to the CPU (10) as digital data. Further, the original image may be directly input to the CPU (10) as digital data from a remote place via the connection means (5). Next, the digital data is transmitted to the PC (3) through the connection means (5).

  In a color image in which the original image is expressed in full colors such as red, green, blue, yellow, and purple, the gradation of the digital data received by the PC (3) is also expressed in full color from 0 gradation to 255 gradations. However, in the gradation pattern applied to the resin plate material (S) by laser processing, gradations from 0 gradation to 255 gradations are represented by achromatic colors. Therefore, in order to obtain achromatic digital data that can be input / output in the laser processing section (4) from the digital data stored in the PC (3), processing data is created (step 2).

  FIG. 7 is a flowchart showing the flow of step 2 in the production process of the gradation resin plate surface according to the present invention. First, the digital data transmitted from the data conversion means (7) in the original image acquisition unit (2) is received by the CPU (10) in the PC (3). For the received digital data, the image input resolution of the digital data is set by the image input resolution setting means (15) (step 2-1). For the image input resolution setting means (15), image processing software (for example, Photoshop or the like manufactured by Adobe) is used. By setting the resolution using the image processing software, the laser processing unit (4) determines the image input resolution of the gradation pattern to be applied to the resin plate material by irradiation with the laser beam.

  When the gradation expression in the digital data is data expressed by the size of halftone dots and / or overlapping of halftone dots, the gradation conversion means (16) changes the image density for each pixel arranged in a matrix. Is converted into digital data expressed in gradation (step 2-2-1). As the gradation conversion means (16), a blurring process of image processing software (for example, Photoshop, etc. manufactured by Adobe) was used. The blurring process is a means for performing conversion into digital data expressed in gradation by a change in image density for each pixel, as shown in FIGS. 3 (1) to 3 (8). By using the blurring process, the gradation in the digital data is changed from halftone dot representation to pixel representation.

  Next, the image density setting means (17) sets the image density in the digital data (step 2-2). The gradation in the original image is represented by a change in image density from 0 gradation to 255 gradation. First, in the original image, the respective image densities at the first location with the highest image density and the second location with the lowest image density are measured using a known density measuring instrument such as a reflection density measuring instrument. . Next, the image density of the first part and the second part on the digital data is set to the same image density as the measured original image. Thereby, the digital data after the image density setting is data in which the same gradation range as that of the original image is set.

  When digital data is acquired based on an original image to which no continuous tone is given, a tone effect is given by the tone effect applying means (18) (step 2-2-1). An example of applying a gradation effect to digital data after setting the image density will be described with reference to FIG. First, as shown by a broken line in FIG. 8A1, an area to which a gradation effect is applied in digital data is selected. In FIG. 8 (a1), the continuous gradation shown in FIG. 8 (b1) is applied. Next, as shown in FIG. 8C1, the region selected in FIG. 8A1 is appropriately divided into shadow, halftone, and highlight. In the present embodiment, as shown in FIG. 8 (c1), (i), (ii) and (iii) are divided into three parts. Next, the gradation effect to be applied to the regions shown in (i), (ii), and (iii) in FIG. 8C1 is selected. The gradation effect to be applied is shadow, halftone and highlight. In the present invention, in FIG. 8C1, shadow is applied to (i), halftone is applied to (ii), and highlight is applied to (iii). As a result, the obtained digital data is data whose gradation is continuously changed as shown in FIG.

  Further, when the digital data is acquired based on the original image with halftone and highlight shown in FIG. 8 (a2), the gradation effect applying means (18) provides the gradation effect. . First, as shown by a broken line in FIG. 8A2, a region to which a gradation effect is applied in digital data is selected. In FIG. 8 (a2), the continuous gradation shown in FIG. 8 (b2) is applied. Next, as shown in FIG. 8C2, the region to which the gradation effect is applied is appropriately divided within the region selected in FIG. 8A2. In the present embodiment, halftones and highlights have already been added in the original image as shown in FIG. 8 (a2), so that gradation is given as shown in FIG. 8 (c2). The area shown in (i) is not selected. Next, the gradation effect to be applied to the region shown in (i) in FIG. 8 (c2) is selected. The gradation effect to be applied is shadow. As a result, the obtained digital data is data whose gradation is continuously changed as shown in FIG. 8 (d2).

  Furthermore, shadows, halftones and highlights can be added to a plurality of locations. First, as shown by a broken line in FIG. 8A3, a region to which a gradation effect is applied in digital data is selected. In FIG. 8A3, the continuous gradation shown in FIG. 8B3 is applied. Next, as shown in FIG. 8C3, the area selected in FIG. 8A3 is appropriately divided into shadows, halftones, and highlights. In this embodiment, as shown in FIG. 8 (c3), (i), (ii), (iii), (iv) and (v) are divided into five. Next, the gradation effect to be applied to the regions shown in (i), (ii), (iii), (iv) and (v) in FIG. 8 (c3) is selected. The gradation effect to be applied is shadow, halftone and highlight. In the present invention, in FIG. 8 (c3), shadows are assigned to (i) and (v), halftones are assigned to (ii) and (iv), and highlights are added to (iii). Give. As a result, the obtained digital data is data whose gradation is continuously changed as shown in FIG. 8 (d3).

  The gradation effect imparting means (18) in the present invention can use existing image processing software such as a pen tablet, Photoshop (manufactured by Adobe) or Illustrator (manufactured by Adobe). The pen tablet is composed of an input unit and a tablet as a pointing device (9). The input unit is a pen-shaped position indicator, and includes a pressure sensor that detects the pen pressure applied to the pen tip, a position sensor that detects coordinates indicated by the pen tip, and an axis centered on the pen tip. A rotation angle sensor for detecting the rotation angle is provided. The tablet is a plate-like detector that detects coordinates, writing pressure, and shaft rotation angle indicated by the input unit.

  As an operation method, first, a drawing size, resolution, color mode, drawing color, drawing mode, and line type to be drawn are set. The drawing size is the campus size on the display means (14) that performs the work of imparting the gradation effect, and the width and height directions of the image can be set by the number of pixels. The resolution is the number of pixels per inch in the display image. As the number of pixels per inch increases, the resolution increases. Generally, the higher the image resolution, the higher the quality of the output image. However, when an image is output using halftone dots, the appropriate resolution varies depending on the number of halftone lines that the output device such as a printer has. In general, the output image quality is low at the same resolution as the screen line number, and the output image quality is standard at a resolution 1.5 times the screen line number. In addition, the quality of the output image is high at a resolution twice the number of screen lines. The color mode is a display format of color information used when the image is displayed on the display means (14) or printed by the output device based on the color information of the original image, and is RGB (red, green, blue), CMYK. , Lab color (CIE L * a * b *) and gray scale. In the present invention, since the purpose is to produce a plate surface to be printed with ink, a color mode is set for RGB used in normal plate making.

  The drawing color is a color used for drawing and painting, and RGB values can be set in the range of 0 to 255, respectively. Drawing mode is a means to specify drawing and image editing methods and opacity, usually dither composition, comparison (dark), multiplication, comparison (bright), dodging (linear)-addition, absolute value of difference , Hue, saturation, color, brightness, color comparison (light) and color comparison (dark). In addition, the opacity of the color used for drawing can be set so that when drawing an arbitrary area, until the pointing device (9) is released, even if the pointing device (9) is moved a plurality of times within that area, The opacity never exceeds the set value. When the opacity is 100%, the transparency is lost. Conversely, the transparency increases as the opacity approaches 1%.

  In the gradation effect applying method using a pen tablet, first, as shown by a broken line in FIG. 8A1, an area to which a gradation effect is applied in digital data is selected. In FIG. 8 (a1), the continuous gradation shown in FIG. 8 (b1) is applied. Next, as shown in FIG. 8C1, the region selected in FIG. 8A1 is appropriately divided. In FIG. 8 (c1), (i), (ii) and (iii) are divided into three parts. Next, the gradation effect to be applied to the regions shown in (i), (ii), and (iii) in FIG. 8C1 is selected. The gradation effect to be applied is shadow, halftone and highlight. When applying shadows, the opacity of the pen tablet described above is set to 100%. When applying highlights, the opacity is set to 1%. It becomes possible to grant by moving 9). In the present invention, in FIG. 8C1, shadow is applied to (i), halftone is applied to (ii), and highlight is applied to (iii). In addition, the boundary adjacent to each other region in (i), (ii) and (iii) is digital data whose gradation is continuously changed by moving the pointing device (9) a plurality of times on the boundary line. Become.

  Next, the gradation range of the digital data having the gradation effect is corrected by the gradation correction means (19) (step 2-3). The gradation range is corrected based on the gradation reproduction curve prepared in advance as shown in FIG. For the gradation correction means (19), for example, known image processing software such as Photoshop (manufactured by Adobe) is used. FIG. 9 is a tone curve used when the image density in the digital data is subjected to gradation correction. The tone range of the digital data is corrected by modifying the tone curve in the image processing software shown in FIG.

  The tone curve is a means for correcting the gradation of the image density, and includes a horizontal axis, a vertical axis, and a channel. The horizontal axis represents the image density (hereinafter referred to as “input value”) in digital data to which a gradation effect is applied. If the digital data is RGB, the value is 255 to 0. If the digital data is CMYK, the value is 0-100. The vertical axis represents the image density (hereinafter referred to as “output value”) in the digital data to which the gradation effect after gradation correction is applied. If the digital data is RGB, the value is 255 to 0. If the digital data is CMYK, the value is 0-100. The channel is a means for setting whether the input value is RGB or CMYK. If it is RGB, the channel is switched to the RGB mode as shown in FIG. 9, and if it is CMYK, the horizontal axis and the vertical axis. The image density increases as the value increases. In other words, the value changes from light to dark as the value increases. Before the gradation correction, the input value and the output value are the same, and the graph is a proportional linear graph inclined at 45 degrees. By deforming this straight line into a curve, the engraving data for the three colors cyan, magenta, and yellow is adjusted, and in the digital data, a contrast value that is an image density difference between the first image density and the second image density is set. adjust. In the present invention, increasing the image density difference is referred to as “increasing the contrast value”, and decreasing the image density difference is referred to as “decreasing the contrast value”.

  When increasing the contrast value in the digital data, first, the input value and the output value are each divided equally, so that the inside of the graph is divided into four from (A) to (D) as shown in FIG. To. Next, the center of the four divided areas (c) is lowered. By lowering the output value, the output value is lower than the input value, so that the image density after gradation correction is lowered. Further, the center of the four divided areas (b) is raised upward. By raising the output value, the output value becomes higher than the input value, so that the image density after gradation correction becomes higher. In this way, the contrast value of the digital data is strengthened by transforming the tone curve into an S-shaped curve.

  When the contrast value in the digital data is weakened, as shown in FIG. 9B, first, the graph is divided into (4) from (A) to (D) as in FIG. 9A. Next, the center of the four divided areas (c) is raised upward. Furthermore, the tone curve is transformed into an inverted S-shaped curve by lowering the approximate center of the four divided areas (b) downward. By transforming into an inverted S-shaped curve, the contrast value of the digital data becomes weak.

  When lowering the brightness in digital data, as shown in FIG. 9C, first, the graph is divided into (4) from (A) to (D) as in FIGS. 9A and 9B. To do. Next, the center of (4) divided areas (a) to (d) is lowered downward. As a result, the tone curve is deformed into a shape with a depressed center. The lightness of the digital data is reduced by deforming the center into a concave shape.

  When increasing the brightness of digital data, as shown in FIG. 9 (d), first, as in FIG. 9 (a), FIG. 9 (b) and FIG. ) And 4 divisions. Next, the center of the four divided areas (A) to (D) is raised upward. As a result, the tone curve is deformed into a shape in which the center is swollen. The brightness of the digital data is increased by deforming the center into a bulging shape.

  A plurality of gradation reproduction curves according to the present invention are prepared by changing the tone curve, and the gradation reproduction curve in which the relationship between the image density in the digital data and the image density in the printed matter obtained using the gradation resin printing plate is proportional. Make until there exists. Next, the relationship between the image density in the digital data and the image density in the printed matter obtained using the gradation resin plate surface is obtained by correcting the image density of the digital data using a gradation reproduction curve that is proportional. The printed matter is a printed matter having a continuous tone that reproduces the continuous tone given to the digital data. The digital data after the gradation range correction is gradation correction data. The gradation correction data is then transmitted to RIP (11).

  Depending on the type of image processing software to be used, it is necessary to convert to postscript data (step 2-3-1). In that case, the gradation correction data is converted into Postscript data by the Postscript data conversion means (20), and then transmitted to the RIP (11).

  Next, the grayscale data is converted to grayscale data by the grayscale data conversion means (22) in the RIP (11) (step 2-4). For the gray scale data conversion means (22), image processing software (for example, Photoshop manufactured by Adobe) is used. By using the image processing software, expressing gradation correction data representing 0 gradation to 255 gradation in RGB full color, and expressing 0 gradation to 255 gradation by an achromatic color image density change, Grayscale data. When the original image is a black and white image represented by white, gray, and black achromatic colors, the digital data received by the PC (3) is directly grayscale data.

  When a color image expressed in full color is used as an original image, color separation is performed by color separation means (21) before grayscale data conversion (step 2-3-2). By color separation, the data is converted into three types of CMY data or four types of CMYK data.

  Next, the grayscale data is converted into TIFF data by the TIFF data conversion means (23) (step 2-4-1). By converting to TIFF data, continuous tone data is obtained.

  Next, the lookup table creation means (12) creates an LUT based on the continuous tone data and the tone reproduction curve described above (step 2-4-1). Since the LUT is a conversion table that stores the laser output value corresponding to the image density of each pixel in the processing data and the depth of the resin plate corresponding to the LUT, first, a conversion table having the same size as the continuous tone data is obtained. For example, it is produced using existing image processing software such as Photoshop (manufactured by Adobe), Illustrator (manufactured by Adobe), RTI RIP-Kit (manufactured by Global Graphics). Next, the depth corresponding to the density of each pixel in the continuous tone data and the laser output value corresponding to the depth are distributed to the created conversion table. Finally, the sorted conversion table is saved as look-up table data, and becomes processing data.

  Next, the laser processing conditions for applying a gradation pattern to the resin plate material (S) are set (step 3). Laser processing conditions include laser light intensity, rotation speed, pitch, control signal, and the like. The laser light intensity, the rotation speed, and the pitch are set to be the same for all the pixel units in the processing data, and the control signal changes according to the image density for each pixel unit of the processing data. However, when newly producing a gradation resin plate using different original images, it is necessary to reset the laser processing conditions.

  After setting the laser processing conditions, the resin plate material (S) is irradiated with laser light using the laser irradiation means (26) to perform laser processing (step 4). The laser irradiation means (26) is conventionally known, and for example, a carbon dioxide laser, a YAG laser, an excimer laser or the like is used. First, pre-exposure is performed with ultraviolet rays to cure the resin, and then the resin plate material (S) is fixed on the cylinder (27) with an adhesive tape or the like. The photosensitive resin layer is cured by pre-exposure. Next, the processing data produced by the PC (3) is transmitted to the data control means (28) in the laser irradiation means (26). The data control means (28) outputs a laser beam corresponding to the image density for each pixel in the received processing data from the oscillator (29). When the image density is high, the laser beam output from the oscillator (29) increases with the image density. On the other hand, when the image density is low, the laser beam output from the oscillator (29) decreases as the image density decreases. The output laser light is condensed on the surface of the resin plate material (S) through the condenser lens (30), and then irradiated to the resin plate material (S) by scanning the scanner motor. By irradiating the laser beam, a gradation pattern having a continuous gradation based on the original image is processed on the resin plate material (S). After the laser processing is completed, the laser irradiation means (26) is stopped, the resin plate material (S) is removed from the cylinder (27), and lightly washed with water. Finally, a gradation resin plate surface is obtained by drying. Depending on the amount of curing in the pre-exposure, after drying, the resin may be cured by exposure again with ultraviolet rays.

  FIG. 10 is a cross-sectional view of a gradation resin plate surface and a plan view of a printed matter obtained from a resin plate surface having a gradual moderate height difference. As shown in FIG. 10 (a), the gradation resin plate surface produced according to the present invention has a surface where the ink-implanted surface continuously has a gradual difference in height, and the printed matter obtained is also shown in FIG. 10 (b). In this way, the printed matter has a gradation pattern in which gradation gradually changes continuously. Further, in the gradation resin plate surface, the printing pressure increases as the plate surface thickness increases. As a result, the printing pressure continuously changes due to the continuously gradual elevation difference, so that it is possible to apply a gradation pattern having a gradual gradation expression to the printing material once by printing. .

  The resin plate material (S) for producing a gradation pattern by laser processing is formed by vulcanization crosslinking of a rubber-based material, as long as the material can be laser engraved and has good dimensional stability. It is possible to use one formed by thermally cross-linking a thermosetting resin, one formed by photo-crosslinking a photosensitive resin, or the like. Examples of rubber materials include urethane rubber, butyl rubber, silicon rubber, nitrile rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, acrylonitrile rubber, and ethylene propylene rubber. Examples of the thermosetting resin include a phenol resin, a melamine resin, a polyester resin, and a phenol resin. There exist a liquid type and a solid type as photosensitive resin. Some liquid types include unsaturated polyesters, acrylic monomers, urethane oligomers, polythiols and the like as basic components. Solid types include PVA, acrylamide oligomer, nylon, acrylic monomer, unsaturated urethane oligomer, water-soluble nylon, cellulose acetate and the like as basic components. Further, films made of these polymers, those obtained by laminating a plurality of different materials, and those made of a soft or hard porous resin are more preferred. In addition, from the viewpoint of printing suitability and printing quality, it is more preferable that a solid or liquid photosensitive resin is photocured and used as a resin plate material. The thickness of the resin plate material can be appropriately set according to the printing machine to be used, but is preferably 0.1 to 0.7 mm.

  Hereinafter, examples of the present invention will be described more specifically with reference to the drawings, but the present invention is not limited thereto.

  As an embodiment, an example will be described in which a gradation resin plate surface by laser processing shown in FIGS. 14A, 14B, and 14C is produced from a color original that is an original image shown in FIG. This figure is a color original having an arbitrary pattern employed in the present invention, but this is only an example, and the present invention is not limited to this example.

  First, an original image shown in FIG. 11A was prepared. The original image is a printed material in which a picture is applied to a paper substrate by an ink jet printer (PX-6000, manufactured by Epson Corporation). FIG. 11B is a diagram obtained by enlarging the illustrated region (Z) by 800% on the printed matter illustrated in FIG. The original image is a printed material in which gradation is expressed by halftone dots as shown in FIG.

  Next, an image of the prepared printed matter was read by operating the acquisition unit (6) in the original image acquisition unit (2). In this embodiment, the original image acquisition unit (2) is a scanner (GT-X700, manufactured by Epson Corporation). The read image was transmitted to the data conversion means (7) in the scanner (2) and then converted into digital data. Next, the digital data was transmitted to the PC (3) via the cable (5). Next, processing data was created based on the digital data received by the PC (3). First, digital data transmitted from the scanner (2) was received by the CPU (10) in the PC (3). The received digital data was converted in resolution by the image input resolution setting means (15). Image processing software (Photoshop, manufactured by Adobe) was used as the image input resolution setting means (15). The resolution was 350 dpi.

  Next, the gradation conversion means (16) converts the gradation in the digital data from halftone dot expression to data expressed by image density change for each pixel. Image processing software (Photoshop, manufactured by Adobe) was used for the gradation conversion means (16). The digital data after the image density change was converted into digital data expressed by the image density change for each pixel as shown in FIG. FIG. 12B is a diagram obtained by enlarging the illustrated region (Z) by 800% in the digital data shown in FIG. The digital data became data with continuous gradation expression as shown in FIG.

  Next, in the image density setting means (17), the image density in the digital data was set. First, in the original image, the first image density (A) having the highest image density and the second image density (B) having the lowest image density are respectively measured by a reflection density measuring device (D-196C, manufactured by Gretac). It measured using. The first image density (A) was 2.8 and the second image density (B) was 0.3. Next, using image processing software (Photoshop, manufactured by Adobe), the image density at the first and second locations on the digital data was set to the same image density as the measured original image. In the original image used in the example, as shown in FIG. 11, since the continuous tone is given, the tone effect imparting means (18) is not necessary.

  Next, in the gradation correction means (19), the gradation range in the digital data was corrected based on the gradation reproduction curve shown in FIG. For the tone correction means (19), a tone curve in image processing software (Photoshop from Adobe) was used. In this embodiment, in order to obtain the gradation reproduction curve shown in FIG. 5E, the gradation is corrected by modifying the tone curve in the digital data as shown in FIG. 9D. The tone correction data was obtained.

  In order to enable transmission to the RIP (11) without depending on the type of image processing software, the gradation correction data is then converted into postscript data by the postscript data conversion means (20). did. Image processing software (Photoshop from Adobe) was used for the postscript data conversion means (20). Next, the postscript data was separated into three colors of CMY by the color separation means (21) in the RIP (11). As the color separation means (21), image processing software (for example, Photoshop manufactured by Adobe) was used.

  The postscript data for each color component of CMY after color separation was then converted into grayscale data by the grayscale data conversion means (22). The gray scale data conversion means (22) sets the color mode in the image processing software (Photoshop from Adobe) to gray scale, so that the postscript data is from 0 gradation to 255 gradation shown in FIG. Became gray scale data expressed by a change in image density of achromatic color. 13A shows cyan gray scale data, FIG. 13B shows magenta gray scale data, and FIG. 13C shows yellow gray scale data. Next, each gray scale data was converted into TIFF data by TIFF data conversion means (23) to obtain continuous tone data. Image processing software (Photoshop, manufactured by Adobe) was used for the TIFF data conversion means (23).

  Next, in the lookup table preparation means (12), an LUT was prepared based on the continuous gradation data and the gradation reproduction curve described above. First, a conversion table having the same size as the continuous tone data was prepared using a calibration (dot gain) manager in image processing software (RTI RIP-Kit manufactured by Global Graphics). Next, the depth according to the density for each pixel in the continuous tone data and the laser output value corresponding to the depth were assigned to the created conversion table. Finally, the sorted conversion table is stored as lookup table data. This lookup data was used as processing data.

  Using the processing data, the resin plate material (S) was irradiated with laser light to complete a partial plate constituting the gradation resin plate surface. As the laser irradiation means (26), a flexo direct engraving machine (Adflex, manufactured by Comtex Co., Ltd.) using a carbon dioxide laser was used. First, the flexo direct engraving machine (26) was started, the mode was switched to online, and the output mode was switched to 3D emboss mode. The 3D emboss mode is a function capable of smoothly laser processing an 8-bit 256 gradation grayscale image (monochrome grayscale image) in the depth direction of the laser workpiece. Therefore, the laser processed product produced by the previous function is continuously formed with a convex portion having a gentle elevation difference. When this laser-processed product is used as a printing plate, it becomes a relief plate having no halftone dots, and the printed matter obtained using the produced relief plate is a printed matter having continuous gradation expression that does not have halftone dots. It becomes.

  The processing data that has already been created is previewed on the display (14) screen connected to the PC (3) using Windows (registered trademark), and then an arbitrary position within the allowable size in the resin plate material (S). After specifying, plotting the angle of view size and enlarging / reducing values, plotting, the data was transmitted to the data control means (28) in the flexo direct engraving machine (26). Next, laser processing conditions for applying a gradation pattern to the resin plate material (S) were set based on the processing data received by the data control means (28). In this example, the laser beam intensity was set to 300 W, the rotation speed was 180 cm / s, and the pitch was 20.0 μm.

  After setting the laser processing conditions, a sheet-shaped resin plate material (FSH Film Co., Ltd., WSH83HT IV) was fixed on the cylinder (27) in the flexo direct engraving machine (26) with an adhesive tape. The resin plate material (S) used was irradiated with ultraviolet rays for 40 minutes as the pre-exposure described above. First, at the time of laser light irradiation, the cylinder (27) and the cylinder rotating mechanism were rotated, and then a control signal corresponding to the image density in the processing data was oscillated from the oscillator (29). By scanning the surface of the resin plate material (S) while the laser intensity varies variably according to the image density by the oscillation of the control signal, the resin plate material (S) has a gradual difference in height continuously. Protrusions were formed.

  After the laser processing was completed, the flexo direct engraving machine (26) was stopped, and then the resin plate material (S) fixed with the adhesive tape was removed. Thereafter, the product adhering to the resin plate material (S) was removed by washing with water, followed by air drying. Finally, the naturally dried resin plate material (S) was subjected to post-exposure with ultraviolet rays for 5 minutes and cured to complete the gradation resin plate surface shown in FIG. 14A is a cyan printing plate, FIG. 14B is a magenta printing plate, and FIG. 14C is a yellow printing plate.

Next, an example using a relief printing machine will be described as a method for obtaining a printed matter using the produced gradation resin plate surface. FIG. 15 is a schematic view of a printing unit in a letterpress printing machine. A plate cylinder (31, 32, 33), an impression cylinder (34, 35, 36), an ink form roller (37, 38, 39), three not shown. Consists of two inkwells. On the outer peripheral surface of the plate cylinder (31, 32, 33), the cyan printing plate (40) shown in FIG. 15 (a), the magenta printing plate (41) shown in FIG. 15 (b), and FIG. Each indicated yellow printing plate (42) was installed. Cyan, magenta, and yellow inks were added to the ink fountain. The ink supplied from the ink fountain was applied to the cyan printing plate (40), the magenta printing plate (41), and the yellow printing plate (42) through ink form rollers (37, 38, 39), respectively. After that, the printed material such as paper (kishu fine paper) is transported between the cyan printing plate (40), magenta printing plate (41), yellow printing plate (42), and impression cylinder (34, 35, 36) in the direction of the arrow. As a result, the ink that was deposited on each printing plate was transferred onto the printing material, and a printed material having a gradation pattern was obtained.

  FIG. 16A is a plan view of a printed matter obtained using the gradation resin plate surface produced according to the present invention. As shown in FIG. 16 (a), a printed matter obtained using a gradation resin plate surface on which convex portions having a gradual height difference are continuously formed has a gradation pattern with continuous gradation expression. It becomes a printed matter having. FIG. 16B is a diagram obtained by enlarging the illustrated region (Z) by 800% on the printed matter illustrated in FIG.

  FIG. 16C shows a relief printing press shown in FIG. 16 after producing a resin plate surface by the conventional production method shown in FIG. 16A on the basis of the same original image as the embodiment of the present invention. In the imitation printed matter produced using this, it is the figure which expanded the (Z) area | region in the original image to the same magnification similarly. Since the printed matter obtained using the gradation resin plate surface produced in accordance with the present invention does not have halftone dots, as shown in FIG. The printed matter changed. On the other hand, as shown in FIG. 16C, the imitation print has a halftone dot, and thus cannot be said to be a print having a continuous change in gray scale when observed in an enlarged manner.

  The present invention can continuously change a gradual elevation difference only by laser light irradiation, and it is not necessary to repeat development multiple times or to prepare a film used for development efficiently. And the gradation resin plate surface which has a gradation can be produced simply.

  Moreover, since the produced gradation resin plate surface does not have a halftone dot, the printed matter obtained also does not have a halftone dot. Therefore, when the printed material is imitated using an offset printing method, an ink jet printer, etc., and imitated printed material is produced, the authenticity can be easily determined based on the presence or absence of halftone dots when enlarged and observed using a magnifying glass or the like. Is possible.

  In this embodiment, the design data is produced in full color, but the present invention is not limited to this, and the design data may be produced in monochrome gradation. In addition, when design data is produced in monochrome gradation, it is not necessary to produce each color portion of the gradation resin plate surface, and the printed matter obtained in this case is a printed matter in which the continuous gradation gradation is changed by a single color.

  Moreover, although the sheet-shaped resin plate material was used, you may use a hollow cylindrical resin plate material. When a hollow cylindrical resin plate material is used, it becomes a continuous hollow cylindrical gradation resin plate surface that is seamless, and can be installed in a printing machine.

Although the printing apparatus used for carrying out the present invention is a relief printing press, the printing machine that can use the gradation printing plate of the present invention is a convex printing plate type such as a relief printing press or a flexographic printing press. It is possible to use a known printing machine capable of printing. Further, the printing material is not limited to paper, and can be appropriately selected from metal, cloth, and the like.

An example of the schematic diagram showing the gradation resin plate surface preparation apparatus whole structure concerning this invention. The block diagram which shows the structure of the gradation resin plate surface preparation apparatus concerning this invention. An example of the schematic diagram which shows the procedure which converts the gradation in the digital data concerning this invention from a halftone dot representation to a pixel representation. The figure which shows the image density and laser output concerning this invention. An example of the schematic diagram which shows the gradation range correction | amendment procedure in the digital data concerning this invention. The flowchart which shows the flow of the production process of the gradation resin plate surface concerning this invention. The flowchart which shows the flow of step 2 in the preparation process of the gradation resin plate surface concerning this invention. An example in which a gradation effect is given to digital data after image density setting according to the present invention. 6 is a tone curve used when tone correction is performed on image density in digital data according to the present invention. The cross-sectional view of the gradation resin plate surface concerning this invention, and the top view of the printed matter obtained from the resin plate surface which has a moderate moderate height difference. The top view which shows the original image concerning this invention. Digital data expressed by image density change for each pixel according to the present invention. Grayscale data according to the present invention. A gradation resin plate according to the present invention. 1 is a schematic view of a printing unit in a letterpress printing machine according to the present invention. The top view which shows the printed matter and imitation printed matter which were obtained using the gradation resin plate concerning this invention. The figure explaining the difference with the resin plate surface by the conventional photosensitive resin plate material, and the resin plate surface by the photosensitive resin plate material of patent document 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gradient resin plate surface preparation apparatus 2 Original image acquisition part 3 Data preparation part 4 Laser processing part 5 Connection means 6 Acquisition means 7 Data conversion means 8 Keyboard 9 Pointing device 10 CPU
11 RIP
12 Lookup table preparation means 13 Storage means 14 Display means 15 Image input resolution setting means 16 Gradation conversion means 17 Image density setting means 18 Gradation effect applying means 19 Gradation correction means 20 Postscript data conversion means 21 Color separation means 22 Gray scale data conversion means 23 TIFF data conversion means 24 CPU data 25 Preparation data 26 Laser irradiation means 27 Cylinder 28 Data control means 29 Oscillator 30 Condensing lenses 31, 32, 33 Plate cylinders 34, 35, 36 Impression cylinders 37, 38, 39 Inking roller 40 Cyan printing plate 41 Magenta printing plate 42 Yellow printing plate S Resin plate material S1 Laser processing area

Claims (2)

A gradation resin plate surface on which the ink-implanted surface does not have a halftone dot shape and is continuously formed with convex portions having a gradual height difference.   A printed matter obtained from the gradation resin plate surface according to claim 1, which does not have a halftone dot shape, and the gradation gradation changes continuously due to an increase in printing pressure accompanying an increase in plate surface thickness. Printed matter.

Images