JP5116289B2 - Method and apparatus for printing on uneven printing surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for printing having advantage in coloring variation or clearness of an image more than heretofore in the event of printing on a printing face having irregularities, and a printer. <P>SOLUTION: There is disclosed a method for printing on a printing face PH having irregularities ED by using a print head. The print head is installed to be ready for a straight movement relative to the printing face PH so as to allow the whole of the printing face PH to be scanned with the print head in a condition that it is not in contact with the printing face PH. A distance between the print head and the printing face PH is divided into a plurality of height levels TL1-TL3, and the scanning is carried out by each of the height levels TL1-TL3. The printing of images by means of the print head is carried out on each of regions ER1-ER3 of the printing face PH included in the stage level of the scanning by each scanning. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a method and a printing apparatus for printing on a printing surface having irregularities by a printer head such as an inkjet method.

  Conventionally, there are some reproductions of three-dimensional reliefs of paintings and sculptures that are works of art. Further, there is also known one in which a three-dimensional relief is restored based on a two-dimensional image of a person, a landscape, or a natural terrain such as a mountain or a valley.

  A processing system for automatically manufacturing such a three-dimensional relief has been proposed (Patent Document 1). That is, according to Patent Document 1, when an image serving as a relief motif is input by a digital camera or the like, Z coordinate data representing the height of the relief is set based on the gradation data calculated based on the tone data of each pixel. XY coordinate data representing the planar position of the relief is set based on the two-dimensional position data D (x, y) of each pixel. Then, a cutter path of the tool is calculated based on the three-dimensional shape data using these as XYZ coordinates, and the surface of the workpiece is ground by the NC processing machine based on the calculated cutter path.

  After the workpiece whose surface has been ground by the NC machine is moved to the printer, the color or brightness represented by the tone data at the position corresponding to the two-dimensional position data of the pixel information for the workpiece. The ink is sprayed for coloring.

  However, in the case of the processing system of Patent Document 1 described above, when coloring the workpiece whose surface is ground by the NC processing machine, the original shape is not considered without considering the uneven shape of the surface of the workpiece. Since only the ink of the color represented by the color tone data of the image is sprayed on the workpiece, uneven coloring occurs due to the uneven shape, and the image becomes inaccurate or unclear.

  That is, for example, when printing (coloring) on a two-dimensional planar sheet as in the past, for example, ink may be ejected according to the density of the image while scanning the printer head of an inkjet printer at a constant speed. However, if the surface is uneven, the actual surface area increases due to the unevenness. Lower. In addition, since the distance from the printer head is long at the low portion due to the unevenness, it is difficult to print a clear image as it is. As a result, the image has uneven density, which is not faithful to the original image and becomes unclear.

In addition, as a method for reducing printing unevenness due to different distances from the printer head in this way, the distance from the print head to the three-dimensional print surface is measured for each discharge point during the scan of the print head. It has been proposed that the amount of displacement of the measurement distance with respect to the interval between the discharge points is obtained and the ink discharge amount is changed based on this (Patent Document 2).
JP-A-9-311707 JP-A-9-193368

  However, in Patent Document 2 described above, the ink discharge amount is changed according to the distance from the print head to the print surface of the three-dimensional object, but for changing the ink discharge amount while running the print head. Control is not easy. Moreover, even if such control is performed, the control is not always performed accurately due to the limit of the performance of the print head. For this reason, there are actually problems in the uneven coloring and the sharpness of the image.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a printing method and a printing apparatus that are more advantageous than conventional methods in terms of coloring unevenness and image sharpness when printing on a printed surface having irregularities. And

The method according to the present invention is a method of printing on a printing surface having irregularities by an ink jet printer head, wherein the printer head is relatively linear with respect to the printing surface without contacting the printing surface. The entire print surface can be scanned, and the distance from the printer head to the print surface is divided into a plurality of step levels, the scan is performed for each step level, For each of the scans, printing of an image by the printer head is performed on the area of the printing surface included in the step level in the scan, and for each scan, the printing conditions by the printer head are set for the scan. Printing is performed so as to be optimal for the step level, and the printing conditions Te, the mass of the particle units of ink ejection from the printer head as the distance increases to the printing surface from the printer head is controlled to be increased.

Preferably , in the vicinity of the boundary of the area of the printing surface included in each of the step levels, an image is printed in each scan and synthesized in a predetermined range on both sides of the boundary.

  Further, at the time of synthesizing the image, in each scan, the density of the image is changed so as to decrease toward the outside of the region.

  In addition, when there is no area of the printing surface included in the step level, control is performed so that scanning corresponding to the step level is not performed.

An apparatus according to the present invention is a printing apparatus that performs printing on a printing surface having irregularities by a printer head, and the printer head moves linearly relative to the printing surface without contacting the printing surface. A scanning mechanism that scans the entire printing surface, and scan control that controls the scanning to be performed at each step level divided into a plurality of step levels according to the distance from the printer head to the printing surface A region image control unit that prints an image by the printer head on the region of the printing surface included in the step level in the scan for each scan, and the printer head for each scan Print conditions that are set to optimize the print conditions according to the level of the scan. Includes a control unit, wherein the printing condition control unit, as the printing conditions, the control as particle mass units of ink ejection from the printer head as the distance to the printing surface from the printer head is increased becomes larger To do.

  According to the present invention, when printing is performed on a printing surface having irregularities, it is more advantageous than conventional methods in terms of coloring unevenness and image sharpness.

[First Embodiment]
1 is a plan view of a three-dimensional relief creating apparatus 1 including a printer 3 according to the first embodiment of the present invention, FIG. 2 is a front view of the three-dimensional relief creating apparatus 1, and FIG. 3 is a three-dimensional relief creating apparatus 1 FIG. 4 is a block diagram showing functions of the control device 18.

  1 to 3, the three-dimensional relief creating apparatus 1 includes a base 11, a material mounting table 12, a travel guide 13, an engraving travel frame 14, a printer travel frame 15, an engraving head 16, a printer head 17, and a control device 18. It consists of such.

  The base 11 is composed of four legs, a reinforcing beam, and the like, and is used to stably install the three-dimensional relief creating device 1 on the floor and to support other members with sufficient rigidity. . Further, by having an appropriate height, the operator can easily attach and detach the relief material RZ.

  The material mounting table 12 is for fixing the relief material RZ by mounting the relief material RZ on the mounting surface on the upper surface and adsorbing the relief material RZ with a negative pressure. The mounting surface of the relief material RZ is rectangular in plan view and is provided horizontally. A large number of holes are provided on the mounting surface, and when a relief material RZ is mounted by suctioning air from these holes by a vacuum pump (not shown), a negative pressure acts on the back surface of the relief material. The RZ is attracted and fixed to the material mounting table 12.

  The relief material RZ is a plate-like material made of a synthetic resin material, gypsum, marble or the like, and the surface opposite to the surface adsorbed by the material mounting table 12 is engraved by the engraving head 16. Concavities and convexities are formed on the surface by engraving, but printing is performed by the printer head 17 on the surface after the concavities and convexities are formed, whereby an image corresponding to the engraving is formed.

  The travel guide 13 is a guide that is provided outside both sides of the material placing table 12 and that allows the engraving travel frame 14 and the printer travel frame 15 to travel linearly in the X direction.

  The engraving traveling frame 14 itself travels in the X direction along the traveling guide 13, while the engraving head 16 travels in the Y direction along the engraving traveling frame 14. As a result, the engraving head 16 can travel in the X direction and the Y direction, and can scan the surface of the relief material RZ placed on the material placing table 12.

  The printer travel frame 15 travels in the X direction along the travel guide 13, while the printer head 17 travels in the Y direction along the printer travel frame 15. Thus, the printer head 17 can travel in the X direction and the Y direction, and can scan the surface of the relief material RZ placed on the material placing table 12.

  In this way, the engraving head 16 and the printer head 17 can scan the surface of the relief material RZ independently of each other. While one of them is scanning the surface of the relief material RZ, the other is controlled to stand by in the standby spaces TP1 and TP2 together with the traveling frame.

  For driving the engraving running frame 14, the printer running frame 15, the engraving head 16, and the printer head 17, a known driving device including a step motor or a servo motor (not shown) is used. The stop position is controlled by the control device 18.

  The engraving head 16 includes a cutting tool such as a rotary drill, and the cutting tool can move in the Z direction, that is, in a direction perpendicular to the surface of the relief material RZ. The position of the cutter in the Z direction is controlled by the control device 18 based on distance data corresponding to the contents of the engraving.

  The printer head 17 includes a plurality of nozzles corresponding to each color of YMCK, and ejects ink of each color from the nozzles to form an image on the surface (printing surface) of the relief material RZ. The printer head 17 itself does not move in the Z direction. Accordingly, the distance between the printer head 17 and the surface of the material mounting table 12 is constant, and even when the relief material RZ is placed, the printer head 17 and the relief material RZ do not come into contact with each other. When the RZ is engraved, the distance between the printer head 17 and the printing surface changes depending on the shape of the engraving. That is, the distance until the ink ejected from the nozzles of the printer head 17 reaches the surface of the relief material RZ changes according to the engraving shape of the printing surface.

Therefore, the printer head 17 can perform various controls according to the distance to the printing surface. For example,
(1) Control is performed such that the moving speed of the scan becomes slower as the distance from the printer head 17 to the printing surface increases.

That is, since the printer head 17 is traveling for scanning, the ink ejected from the nozzles is displaced or diffused along the traveling direction when it reaches the printing surface. The greater the distance, the greater the deviation. Therefore, when the distance to the printing surface is long, the scan speed of the printer head 17 is slowed down to reduce ink misalignment. This minimizes blurring of the image as much as possible.
(2) Control is performed so that the speed of the ejected ink increases as the distance from the printer head 17 to the printing surface increases.

This reduces ink misalignment and suppresses blurring of the image as much as possible.
(3) In order to increase the speed of the ejected ink, the voltage applied to the printer head 17 is controlled to be high. That is, by applying a high voltage to the piezoelectric element of the printer head 17, the ink ejection speed is increased.
(4) Control is performed so that the mass of the ejected ink in units of particles increases as the distance from the printer head 17 to the printing surface increases. For example, when ink is continuously ejected from the nozzle, water droplet particles of the ejected ink are connected and enlarged, and the mass of the particles is increased.

  As described above, the three-dimensional relief creating apparatus 1 includes the engraving apparatus TS including the engraving running frame 14 and the engraving head 16 on the surface of the relief material RZ placed on one material placing table 12, and the printer running frame. 15 and the printing device (printer) PS comprising the printer head 17 can independently scan, engrave or print. Therefore, by setting the plate-shaped relief material RZ on the material mounting table 12, the surface can be engraved and further printed on the surface to form an image, and the relief material RZ is moved. 3D relief can be created.

  Therefore, since the positioning of the relief material RZ only needs to be performed once, it is easy to align and work, and there is no positional deviation between engraving and printing, and high-precision three-dimensional Relief can be created. Further, the distance data (engraving data) used for controlling the blade of the engraving apparatus TS can be used as it is for the control according to the distance between the printer head 17 and the printing surface in the printing apparatus PS, and control data can be easily generated. And high precision.

  As shown in FIG. 4, the control device 18 includes a scan mechanism SK, a scan control unit 21, a region image control unit 22, a print condition control unit 23, and the like.

  The scanning mechanism SK scans the entire printing surface PH by moving the printer head 17 linearly relative to the printing surface PH without contacting the printing surface PH. The scanning mechanism SK includes the engraving traveling frame 14, the printer traveling frame 15, and a portion that drives the engraving head 16 and the printer head 17 to move.

  The scan control unit 21 performs control so that scanning is performed for each height level TL divided into a plurality of height levels TL according to the distance from the printer head 17 to the printing surface PH.

  For each scan, the area image control unit 22 prints an image with the printer head 17 on the area of the print surface PH included in the height level TL in the scan.

  The print condition control unit 23 sets the print condition by the printer head 17 so as to be optimal with respect to the height level TL of the scan for each scan.

  In the three-dimensional relief creating apparatus 1, as described above, when printing is performed by the printing apparatus PS, the printer head 17 is not contacted with the printing surface of the relief material RZ with respect to the printing surface. It is possible to scan the entire printing surface by moving relatively linearly.

  In the present embodiment, the three-dimensional relief creating apparatus 1 divides the distance from the printer head 17 to the printing surface into a plurality of step levels, performs a scan for each step level, and performs each scan. In addition, an image is printed by the printer head 17 on the area of the printing surface included in the step level in the scan. That is, the entire image is divided according to the height level TL, and each image is printed by one scan.

  Next, a printing method using the printing apparatus PS in the three-dimensional relief creating apparatus 1 will be described.

  5 is a top view of the relief material RZ after engraving, FIG. 6 is a front view of the relief material RZ in FIG. 5, FIG. 7 is an enlarged view of FIG. 6, and FIG. 8 is a print in each scan. FIG. 9 is a diagram illustrating an example of a change in print density of an image at a boundary portion of the region ER.

  5 to 8, the relief material RZ has a truncated cone ED formed by engraving at the center of its surface. Printing is performed by the printing apparatus PS on the entire surface of the relief material RZ on which the truncated cone ED is formed.

  As shown in FIGS. 6 and 7, there are three height levels (step levels) between the tip of the nozzle of the printer head 17 and the farthest surface of the printing surface PH of the relief material RZ depending on the distance. It is divided into TL1-3.

  That is, the height level TL1 is from the position KL1 closest to the nozzles of the printer head 17 to the position KL2 that is a predetermined distance away. The height level TL2 is from the position KL2 to a position KL3 that is a predetermined distance away, and the height level TL3 is from the position KL3 to the position KL4 that is the farthest surface.

  By dividing into three height levels TL1 to TL1, the printing surface PH is divided into three types of regions ER1 to ER3 included in the respective height levels TL1 to TL3. The respective regions ER1 to ER3 are indicated by hatching in FIGS.

  That is, the region ER1 shown in FIG. 8A is a region in the range of the height level TL1, the region ER2 shown in FIG. 8B is a region in the range of the height level TL2, and FIG. The region ER3 shown in (2) is a region in the range of the height level TL3.

  Note that the ranges (gap widths) of these TL1 to TL3 may be the same as each other or different from each other. The position KL1 closest to the nozzles of the printer head 17 and the position KL4 which is the farthest surface can be variously set according to the structure of the three-dimensional relief creating apparatus 1 and the specifications of the printing apparatus PS. In this embodiment, the height level is divided into three levels TL1 to TL1, but may be two levels or four or more levels, for example, eight levels, ten levels, sixteen levels, and so on.

  Now, since it is divided into three height levels TL1 to TL3, the printer head 17 is scanned three times during printing.

  In the first scan, an image is printed only on the region ER1 corresponding to the height level TL1. As a result, printing is performed for the region ER1 hatched in FIG. In the second scan, an image is printed only on the region ER2 corresponding to the height level TL2. As a result, printing is performed for the region ER2 hatched in FIG. In the third scan, the image is printed only on the region ER3 corresponding to the height level TL3. As a result, printing is performed for the region ER3 hatched in FIG. Three times of scanning completes the printing of the image on the entire printing surface PH.

  The image printed in each scan is an image corresponding to each of the areas ER1 to ER3, and even if printing is performed in three times, the contents of the entire image are not changed. Note that when printing an image in each scan, the image in the region ER that is not printed in that scan may be masked. As a masking method, there are a method of masking image data, a method of covering a sheet for masking on the printing surface PH, and the like.

  As the image, for example, when the truncated cone ED is a mountain in a topographic map, for example, an image of the mountain or an image obtained by modifying the image.

  Then, for each scan, printing is performed by setting the printing conditions by the printer head 17 to be optimal with respect to the height level TL of the scan. For example, for each scan, the printing apparatus PS is controlled as described in (1) to (4) above according to the height levels TL1 to TL3.

  For example, printing is performed with the normal setting at the height level TL1, and the control of (1) above or the combination of (1), (2), and (3) is performed at the height level TL2, and the height is set. In the level TL3, the control (1) above, the control combining (1), (2), and (3), or the control combining (1) to (4) is performed.

  Note that the scanning order may be performed in order from the area ER1 with a short distance, in order from the area ER3 with a long distance, or randomly.

  In addition, when printing is performed for each region ER in each scan, the image is printed in each scan in a predetermined range on both sides of the boundary in the vicinity of the boundary of each region ER to synthesize an image. It may be. At the time of the synthesis, it is only necessary to change the density of the image so as to decrease as it goes outside the region in each scan.

  For example, as shown in FIG. 9, in the vicinity of the boundary between the region ER1 and the region ER2, the density of each image of YMCK is gradually decreased from 100%, and enters the other regions ER2,1. Control is performed so that the image density becomes 0% in the vicinity of the rear. In this way, the image in the vicinity of the boundary is smoothly synthesized and the print joint is not conspicuous.

  In the above description, the gradation is gradually reduced near the boundary of the region ER to add gradation (blurring). Alternatively, the color may be gradually reduced to a lighter one.

Further, depending on the contents of the image or engraving, there may be no region ER corresponding to the height level TL on the printing surface PH. In such a case, the time required for printing can be shortened by controlling not to perform scanning corresponding to the height level TL.
[Second Embodiment]
Next, a three-dimensional relief creating apparatus 1B according to the second embodiment of the present invention will be described.

  The three-dimensional relief creating apparatus 1B according to the second embodiment basically has the same configuration and function as the three-dimensional relief creating apparatus 1 according to the first embodiment described above. In the second embodiment, an example of a method of creating a three-dimensional relief by engraving based on the original image GF by the three-dimensional relief creating apparatus 1B will be described.

  FIG. 10 is a diagram showing the overall configuration of the three-dimensional relief creating apparatus 1B according to the second embodiment of the present invention, FIG. 11 is a diagram showing the configuration of the original image GF, and FIG. 12 is the configuration of the height image TF. FIG. 13 is a diagram showing the configuration of the height change data HF, FIG. 14 is a diagram showing an example in which the height level TL is set in the area AR dividing the original image GF, and FIG. 15 is a diagram showing an example of the pattern PT. 16 is a diagram showing an example of a grayscale image NF for the pattern PT, FIG. 17 is a diagram showing an example of the relationship between the three-dimensional relief original RG and the printer head 17, and FIG. 18 is a diagram showing the three-dimensional relief original RG and the printer head 17. FIG. 19 is a diagram for explaining the height change data HF.

  In FIG. 10, a three-dimensional relief creating apparatus 1B includes a computer 110 for image processing, a control data generation unit 121, a numerically controlled engraving apparatus TS, and an inkjet printing apparatus PS.

  The computer 110 includes a processing device such as a CPU and a DSP, a storage device such as a semiconductor memory and a magnetic disk, an input device such as a keyboard and a mouse, a display device, and various interface circuits. As a result, the original image storage unit 111, the height image generation unit 112, the height image storage unit 113, the height change data generation unit 114, and the height change data are stored in the computer 110 in terms of software or hardware. The storage unit 115 and the data output unit 116 are functionally formed.

  The original image storage unit 111 stores the original image GF. Note that the original image GF is image data, but may refer to an image from which the image data is based. In particular, when distinguishing between a visible image and image data, “original image data GF”, “original image GF data”, “image data”, and the like may be described. The same applies to other images.

  As the original image GF, various images such as a person, an animal, a building, a landscape, a bird's-eye view of a natural landform such as a mountain or a valley, and an aerial photograph are used.

  As shown in FIG. 11, the original image GF is a two-dimensional image including a large number of pixels GS arranged in a matrix in the X direction and the Y direction orthogonal to the X direction. Each pixel GS has color information CD. The color information CD includes density information. For example, when each pixel GS is expressed in RGB, CMYK, or the like, the color of each pixel GS, that is, hue, saturation, and lightness is determined by the density information of each primary color. The pixel GS may be expressed by other color system data.

  In order to obtain such an original image GF, those actual objects may be taken by a digital camera, a video camera, or the like. Further, a photograph or printed matter already taken may be read by a scanner or the like and digitized. It is also possible to obtain the original image GF that has already been digitized into image data by downloading it from a storage medium such as a CD-ROM or a memory chip, or from a network. Further, the original image GF may be generated in the computer 110 using various applications.

  The original image GF may be stored as bitmap data as shown in FIG. 11, but may be stored as compressed data compressed by an appropriate compression method. The original image GF is usually a full color image, but may be a monochrome image.

  The height image generation unit 112 generates a height image TF indicating the height of each part in the original image GF based on the original image GF. The generated height image TF is stored in the height image storage unit 113.

  As shown in FIG. 12, the height image TF includes height data TD that is data in the Z direction orthogonal to the X direction and the Y direction for each of the large number of pixels GS arranged in a matrix in the X direction and the Y direction. Is recorded. The pitch or number of pixels GS in the height image TF may be the same as the pitch or number of pixels GS in the original image GF, or may be obtained by thinning out the pixels GS in the original image GF.

  As the height data TD, for example, data of 256 gradations (8 bits), 64 gradations (6 bits), etc. are used. The height data TD indicates, for example, a position between the lowest position (for example, the background position) and the highest position. Further, the height data TD may directly indicate the distance from the lowest position. In FIG. 18, the height data TD is indicated by TD2, TD3, TD4, and the like. In FIG. 18, the height data TD may be indicated by distances PD2, PD3, and PD4 from the printer head 17. Although the height data TD indicates the height in the original image GF, it can also be said that it indicates the depth or depth when viewed from the printer head 17 or the cutting tool, so it is referred to as depth data or depth data. You can also.

  In order to obtain such a height image TF, for example, as shown in FIG. 14, the original image GF is divided into a plurality of areas AR, and a height level TL is given to each of the divided areas AR. The application of the height level TL may be performed manually by the user, or may be performed automatically by causing the computer 110 to recognize the state of the area AR in the image.

  In the example illustrated in FIG. 14, the height level TL is set to, for example, 10 levels of 1 to 10. In the regions AR1 to AR5, “3”, “1”, “2”, “ “4” and “6” are set. In this case, the height level TL defines the maximum height in the area AR, and “1” is the highest and “10” is the lowest. Therefore, for example, the background area (background portion, background position) has a height level TL of “10”.

  In addition, various things can be employ | adopted for the number of the steps of the height level TL, the code | symbol or symbol provided as the height level TL, the meaning given to these code | symbols or a symbol, etc.

  In addition, as to how to divide the area AR, an outline is set as the boundary line of the area AR, and a portion where the density and color are greatly changed is set as the boundary line of the area AR. Moreover, you may partition by a user manually.

  The height of each part (each pixel GS) in each area AR is determined in accordance with the height level TL assigned in each area AR.

  In this case, for example, as shown in FIG. 15, a plurality of patterns PT1 to PT6 are registered in advance with respect to the generation pattern of the height data TD in the area AR to which the height level TL is assigned. Then, for each area AR, one pattern PT is manually or automatically selected from the plurality of registered patterns PT1 to PT6 by the user. Based on the selected pattern PT, the height of each part (each pixel GS) is determined.

  For example, when the pattern PT1 in FIG. 15 is selected, the central position in the area AR is set to the maximum height specified by the height level TL, and the arc shape as indicated by the pattern PT1 toward the periphery. The height gradually decreases. When the pattern PT2 of FIG. 15 is selected, the height decreases linearly as shown by the pattern PT2 from the center position of the area AR toward the periphery. When the pattern PT6 in FIG. 15 is selected, the center position of the area AR is flat, and the height decreases linearly around the periphery.

  By the way, in the present embodiment, the height image TF is a grayscale image showing the height of each part using a gray scale. For example, with respect to the pattern PT6 of FIG. 15 described above, an example of a grayscale image is shown in FIG.

  That is, in FIG. 16, a grayscale image NF (FIG. 16B) and a gray scale GS (FIG. 16A) corresponding to the pattern PT6 (FIG. 16C) are shown. The highest position is white, the lowest position is black, and the middle height is gray according to the height. That is, the density of the grayscale image NF decreases as the height from the background portion increases. In the pattern PT6 in FIG. 16, there are 10 stages, but actually, for example, 64 stages, 256 stages, etc. may be used.

  In FIG. 16, the highest position corresponds to the height level TL “1”, and the lowest position corresponds to the height level TL “10”. However, the height of the pattern PT is a relative one, and is adjusted so that the highest position and the lowest position of the pattern PT become the designated arbitrary height positions. That is, when the pattern PT6 is applied to the area AR having the height level TL “3”, for example, the white portion at the highest position of the pattern PT6 has the height level “3” and the lowest position of the pattern PT6. The black part is the height level of the peripheral part of the area AR.

  In addition, in FIG. 16, although the height is shown by the gray scale GS, you may show the height of each part by a mutually different hue. For example, the highest position is brown, the lowest position is blue, and the middle height is green, so that the shade of each color changes according to the height.

  As can be seen from the grayscale image NF shown in FIG. 16, the cross section along the Z-axis of the grayscale image NF is not the same at any position. That is, there are various size ratios in the X-axis direction and the Y-axis direction for various patterns PT shown in FIG.

  Here, an example of what height data TD is assigned to each pixel GS after the height level TL and the pattern PT are set in each area AR will be described.

  That is, for example, when the height level TL is set to “3” and the pattern PT6 is selected, the highest position of the pattern PT6 is the height level “3”, and the lowest position is the periphery of the area AR. It becomes the height level of the part. Similar deformation is performed so that the periphery of the pattern PT6 coincides with the peripheral edge of the area AR. As a result, when the height level TL is, for example, 10 levels, the highest position of the pattern PT6 becomes three-tenths of the maximum height, and is proportional to the change of the pattern PT6 from there to the lowest position. As described above, the height data TD is assigned to each pixel GS. Then, for the area AR, the assigned height data TD is displayed as a grayscale image, for example, on a screen of a display device or printed paper. The user looks at the grayscale image and corrects the grayscale image as necessary. For example, the perspective relationship between a certain part and another part, the uneven state of a certain part, the three-dimensional shape of a certain part, etc. are corrected so as to match the contents of the original image GF.

  Next, the height change data generation unit 14 generates height change data HF indicating the change in height LZ per unit length LX of the original image GF for each part based on the height image TF. (See FIG. 19). The generated height change data HF is stored in the height change data storage unit 115.

  As shown in FIG. 13, the height change data HF is a change amount of data in the Z direction orthogonal to the X direction and the Y direction with respect to a large number of pixels GS arranged in a matrix in the X direction and the Y direction. Inclination data KD is recorded. The pitch or number of the pixels GS of the height change data HF may be the same as the pitch or number of the pixels GS of the height image TF, or the pixels GS of the height image TF may be thinned out. .

  As the gradient data KD, for example, data of 256 gradations (8 bits), 64 gradations (6 bits), etc. are used. For example, the inclination data KD indicates the absolute value of the inclination angle θ from the horizontal surface of the surface obtained at the position of each pixel GS based on the height image TF with the inclination angle of the horizontal surface being 0 degree. May be. In this case, the inclination data KD indicates 0 to 90 degrees. In FIG. 18, the tilt data KD is indicated by θ1, θ2, θ3, θ4, and the like. Further, as the tilt data KD, data indicating in which direction the tilt is made may be added.

  In order to obtain such height change data HF, for example, the following may be performed.

  That is, a certain pixel GS is set as the target pixel GST, and for the target pixel GST, the difference between the height data TD and the height data TD of the eight surrounding pixels GS is obtained, and the maximum value of the difference is determined as the target pixel. The gradient data KD of GST is used. Or standardize it as needed.

  Further, for the target pixel GST, the maximum value of the difference between the height data TD of the eight surrounding pixels GS is obtained, and this is used as the inclination data KD of the target pixel GST. Standardize as necessary. In this way, the inclination data KD for all the pixels GS is obtained.

  In addition, for example, the inclination of a surface composed of 3 × 3 adjacent pixels, that is, nine pixels GS, is obtained and used as inclination data KD for the nine pixels GS. This may be 2 × 2, 4 × 4, or the like.

  The data output unit 16 outputs the height image TF for control of the numerical control processing device 22 in order to form unevenness corresponding to the height indicated by the height image TF in the three-dimensional relief original. The data output unit 16 may be an appropriate interface for data input / output. Further, it may be a medium drive device for writing data to an appropriate recording medium.

  The control data generation unit 121 generates control data for controlling the engraving apparatus TS based on the height image TF output from the data output unit 116. Note that when generating such control data, the data of the original image GF may also be used. Alternatively, the control data may be generated inside the computer 110, and the control data may be output to the engraving apparatus TS via an appropriate interface.

  The engraving device (router) TS processes the relief material RZ based on the control data to create a three-dimensional relief original RG for the original image GF. As the engraving apparatus TS, it is possible to use the same mechanisms as various NC lathes, machining centers, laser processing machines, sandblasting, routers and the like. Note that various materials such as timber, gypsum, synthetic resin, or metal are used for the relief material RZ, and various shapes such as a rectangular parallelepiped shape, a plate shape, a cylindrical shape, each columnar shape, and a spherical shape are used. Is used. Since the three-dimensional relief original shape RG is obtained by processing the relief material RZ, the processed surface is usually the same color as the relief material RZ.

  The printing apparatus PS colors the three-dimensional relief original RG by performing image printing based on the original image GF on the surface of the three-dimensional relief original RG. The printing apparatus PS holds, for example, each color ink of Y, M, C, and K, and ejects a small amount of each ink in a pulsed manner at high speed according to the color data of the original image GF, thereby producing a three-dimensional relief original shape. A full-color image is generated on the uneven surface of the RG. As basic functions of the printing apparatus PS, functions of various known ink jet printers that have conventionally existed can be provided, including the apparatus of Patent Document 2 described above.

  Now, the control device 18B is provided in the printing apparatus PS of the second embodiment.

  When assuming that the density of the original image GF is uniform with respect to the printing apparatus PS based on the height change data HF, the control device 18B makes the density on the surface of the three-dimensional relief original RG uniform. Control the amount of ink discharged.

  That is, due to the unevenness on the surface of the three-dimensional relief original RG, the surface distance of the three-dimensional relief original RG along the linear movement distance of the printer head 17 in the main scanning direction (X direction) is longer. Become. As described in the background section, it is necessary to correct this difference in distance in order to obtain a clear image by reducing uneven coloring or printing unevenness due to ink. In the control device 18B, density control is performed so that coloring unevenness is eliminated. Moreover, the height image TF used for controlling the engraving apparatus TS is also used here for density control.

  The linear movement distance of the printer head 17 in the main scanning direction is determined by the design value of the printing apparatus PS. For example, the distance L1 shown in FIG. 17 is a linear movement distance. On the other hand, the surface distance of the three-dimensional relief original RG is a length L2 along the surface unevenness HT (printing surface PH) of the three-dimensional relief original RG shown in FIG. The surface distance of the three-dimensional relief original RG is, for example, the movement distance of the tool tip of the engraving apparatus TS, and can be read from the height image TF or from control data generated based on the height image TF. Further, height change data HF may be used for density control. For example, the density of the printer head 17 may be controlled so as to increase according to the size of the height change data HF.

  Now, in the density control, control is performed so that more ink is ejected in a portion where the height change data HF is large or in the pixel GS.

For example, the following method is available.
(1) The traveling speed of the printer head 17 is constant, and the ejection amount per ink ejection is controlled according to the magnitude of the height change data HF. In that case, for example, the voltage applied to the printer head 17 is controlled. That is, when the height change data HF is large, the voltage applied to the printer head 17 is increased to increase the ejection amount. Increasing the discharge amount per time increases the ink discharge speed, so that the ink quickly reaches the surface of the three-dimensional relief original RG, thereby reducing the error of the printing position and suppressing the decrease in the sharpness of the image. It is done.
(2) The traveling speed of the printer head 17 is constant, and the number of ink ejections per unit time is controlled according to the magnitude of the height change data HF. When the number of ink ejections per unit time is increased, for example, a plurality of ink ejected ink droplets continue, and the next ink is ejected at a slight interval. The ink droplets ejected later catch up and coalesce. This also increases the ink ejection speed or increases the mass of the ink droplet, increases the accuracy of the spot due to the ink droplet , reduces the error in the printing position, and suppresses the decrease in the sharpness of the image.
(3) The ejection amount per ejection of ink by the printer head 17 and the number of ink ejections per unit time are made constant, and the moving speed of the printer head 17 is controlled according to the magnitude of the height change data HF. In this case, the moving speed of the printer head 17 along the surface of the three-dimensional relief original RG is controlled to be uniform.

  By performing the density control in this way, more ink adheres to the portion with the large inclination angle θ shown in FIG. 18, and as a result, the image density of the entire surface unevenness HT of the three-dimensional relief original RG is reduced. The amount of ink adhering per unit area when the same is assumed is uniform.

  In FIG. 18, regarding the background portion of the three-dimensional relief original RG, the distance from the printer head PH increases, and the ink from the printer head PH tends to spread to the periphery. It can be compensated to some extent by increasing the mass.

  In the printing apparatus PS, mechanisms and circuits necessary for control by the control device 18B are provided. Further, the processing for control in the control device 18B may be performed by the computer 110, and only executed by the printing device PS.

  Next, the overall operation of the three-dimensional relief creating apparatus 1B will be described with reference to a flowchart.

  FIG. 20 is a flowchart showing the overall operation flow of the three-dimensional relief creating apparatus 1B, FIG. 21 is a flowchart showing the procedure of height image creation processing, FIG. 22 is a flowchart showing the procedure of processing processing, and FIG. It is a flowchart which shows a procedure.

  In FIG. 20, an original image GF is acquired (# 1), and a height image TF is generated based on the original image GF (# 2). The engraving apparatus TS is controlled using control data based on the height image TF, and the relief material RZ is processed to create a three-dimensional relief original RG (# 3). The printing apparatus PS is controlled using the height change data HF or the height data TD, which is data based on the height image TF, and the three-dimensional relief original RG is printed and colored (# 4).

  In FIG. 21, in the height image creation process, the original image GF is partitioned into regions AR, and a height level TL is assigned to each partitioned region AR (# 11). At this time, a pattern PT to be applied to each area AR is designated. A gray image is generated for each area AR and displayed (# 12). The user corrects the grayscale image as necessary (# 13). The gray image thus obtained shows a height image TF. Alternatively, the obtained grayscale image is converted into gradation data to obtain a height image TF (# 14).

  In FIG. 22, the height image TF is output as control data (# 21). Control data is generated based on the height image TF (# 22). The engraving apparatus TS is operated using the control data, and the relief material RZ is processed to create a three-dimensional relief original RG (# 23).

  In FIG. 23, the distance from the printer head 17 to the printing surface PH is divided into a plurality of height levels TL (# 31). A scan is executed for one height level TL, and a corresponding image is printed for the corresponding region ER (# 32). At this time, as described above, printing is performed by setting the printing conditions by the printer head 17 so as to be optimal with respect to the height level TL of the scan. Scanning is performed until printing is performed on all the areas ER of the printing surface PH. When printing is performed on all the areas ER of the printing surface PH, the process ends (# 33). Thereby, the three-dimensional relief RR is completed.

  According to the three-dimensional relief creating apparatus 1B of the second embodiment, numerical control based on the height image TF is performed to process the relief material RZ to create a three-dimensional relief original RG, and a three-dimensional relief original Coloring is performed by performing image printing based on the original image GF while performing density control on the RG while performing density control based on the height image TF, so that density control is performed accurately and coloring unevenness and image sharpness are conventionally achieved. Better than. There is no need to separately create control data for density control. As a result, the printing speed can be increased and a three-dimensional relief faithful to the original image GF can be created quickly.

  In the three-dimensional relief creating apparatus 1B of the embodiment described above, the number of patterns PT1 to PT6 may be larger or smaller. The pattern PT may be variously modified. The height of each pixel GS may be determined without using the pattern PT.

  In the three-dimensional relief creating apparatus 1B of the second embodiment, the height level TL is assigned to each area AR that divides the original image GF, but the height level TL assigned here is applied to the printing apparatus PS. Control may be performed using the height level TL for each scan.

  In the second embodiment, an apparatus in which the engraving apparatus TS and the printing apparatus PS are integrated may be used.

  In the first embodiment, the three-dimensional relief creating apparatus 1 in which the engraving apparatus TS and the printing apparatus PS are integrated is used. However, apparatuses configured separately from each other may be used.

  In the above embodiment, various well-known devices other than those described above may be adopted as devices or mechanisms for running the engraving running frame 14, the printer running frame 15, the engraving head 16, and the printer head 17. Is possible.

  In addition, the configuration, shape, dimensions, number, material, image content, control device 18 of the whole or each part of the printing device PS, engraving device TS, control devices 18, 18B, computer 110, or three-dimensional relief creation devices 1, 1B , 18B and the processing contents in the computer 110, the processing order, and the like can be appropriately changed in accordance with the spirit of the present invention.

It is a top view of the three-dimensional relief production apparatus of 1st Embodiment. It is a front view of a three-dimensional relief production apparatus. It is a side view of a three-dimensional relief production apparatus. It is a block diagram which shows the function of a control apparatus. It is a top view of the relief material after engraving. It is a front view of the relief material of FIG. It is a figure which expands and shows FIG. It is a figure which shows the area | region which prints in each scan. It is a figure which shows the change of the image density in the boundary part of an area | region. It is a figure which shows the whole structure of the three-dimensional relief production apparatus of 2nd Embodiment. It is a figure which shows the structure of an original image. It is a figure which shows the structure of a height image. It is a figure which shows the structure of height change data. It is a figure which shows the example which set the height level to the area | region which divided the original image. It is a figure which shows the example of a pattern. It is a figure which shows the example of the grayscale image about a pattern. It is a figure which shows the example of the relationship between a three-dimensional relief original form and a printer head. It is a figure which shows the example of the relationship between a three-dimensional relief original form and a printer head. It is a figure explaining height change data. It is a flowchart which shows the flow of the whole operation | movement of a three-dimensional relief production apparatus. It is a flowchart which shows the procedure of a height image creation process. It is a flowchart which shows the procedure of a process. It is a flowchart which shows the procedure of a printing process.

Explanation of symbols

1,1B Three-dimensional relief creation device PS Printing device TS Engraving device SK Scan mechanism 17 Printer head 18, 18B Control device 21 Scan control unit 22 Area image control unit 23 Print condition control unit TF Height image TL Height level PH Printing surface

Claims (5)

A method of printing on a printing surface having irregularities by an inkjet printer head,
Enabling the printer head to scan the entire print surface by moving linearly relative to the print surface without contacting the print surface;
Dividing the distance from the printer head to the printing surface into a plurality of step levels;
The scanning is performed for each stage level, and for each of the scans, an image is printed by the printer head on the area of the print surface included in the stage level in the scan ,
For each scan, printing is performed by setting the printing conditions by the printer head to be optimal for the stage level of the scan,
As the printing condition, control is performed so that the mass of the ink particle unit ejected from the printer head increases as the distance from the printer head to the printing surface increases.
The printing method to the printing surface which has the unevenness | corrugation characterized by the above-mentioned. In the vicinity of the boundary of the region of the printing surface included in each of the step levels, in a predetermined range on both sides of the boundary, the image is printed in each scan to synthesize the image.
The printing method to the printing surface which has an unevenness | corrugation of Claim 1 . When synthesizing the image, in each scan, the density of the image is changed so as to decrease toward the outside of the region.
The printing method to the printing surface which has an unevenness | corrugation of Claim 2 . When there is no area of the printing surface included in the step level, control is performed so that scanning corresponding to the step level is not performed.
The printing method to the printing surface which has an unevenness | corrugation in any one of Claim 1 thru | or 3 . A printing apparatus that performs printing on a printing surface having unevenness by a printer head,
A scanning mechanism for scanning the entire printing surface by moving the printer head linearly relative to the printing surface without contacting the printing surface;
A scan control unit that controls to execute the scan for each step level divided into a plurality of step levels according to the distance from the printer head to the printing surface;
For each of the scans, an area image control unit that prints an image by the printer head on the area of the print surface included in the step level in the scan;
A printing condition control unit that sets printing conditions by the printer head so as to be optimal for the stage level of the scanning for each scan;
The printing condition control unit controls the printing condition such that the mass of the ink particle unit ejected from the printer head increases as the distance from the printer head to the printing surface increases.
A printing apparatus characterized by that.

Images