JP2016060166A - Stereoscopic image forming device, stereoscopic image forming method, pattern data generation method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stereoscopic image forming device, a stereoscopic image forming method, a pattern data generation method, and a program capable for forming a high-quality stereoscopic image while suppressing the material consumption amount of a density difference suppression part.SOLUTION: The stereoscopic image forming device includes heat absorption part forming means for forming, on the surface of a medium foam-expanded according to the amount of absorbed heat, a heat absorption part capable of absorbing heat energy more easily than the medium, heat energy radiation means for radiating the heat energy to the medium, a control unit for generating pattern data so that the density difference suppression part for suppressing the density difference of the heat absorption part can be superposed on at least the heat absorption part and the density difference suppression part can be formed nonuniformly on the surface of the medium, and density difference suppression part forming means for forming the density difference suppression part corresponding to the pattern data.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image forming apparatus and an image forming method for forming a density difference suppression unit that suppresses a density difference of a heat absorption unit formed on the surface of a medium that expands and expands according to the amount of absorbed heat, and a density difference suppression unit. The present invention relates to a pattern data generation method for generating the pattern data by a computer, and a program for causing a computer to execute a process for generating pattern data of a shading difference suppressing unit.

  Conventionally, a region selected from a color image on a surface of a medium that expands and expands according to the amount of heat absorbed (for example, a thermally expandable sheet) is a region where a heat absorbing portion (for example, black toner) is to be formed. There is known a three-dimensional printing apparatus that prints a heat absorbing portion in the area and bulges and expands a print site of the heat absorbing portion by radiant heat radiation. In this three-dimensional printing apparatus, after the foaming and expansion of the printing portion of the heat absorption unit is performed, a solid white image is printed on the entire surface of the medium, and then the original color image is printed.

  In such a three-dimensional printing apparatus, the higher the density of the heat absorption part, the higher the foaming height of the medium. Therefore, based on the target height of the three-dimensional shape formed when the medium is expanded and expanded, The concentration is determined. However, the concentration of the heat absorption part in the medium is constant due to the fact that the light heat irradiation temperature at the longitudinal end of the light heat irradiation part such as a halogen lamp for foaming and expanding the medium is lower than the light heat irradiation temperature at the center in the longitudinal direction. Even so, the foam height at the end of the medium in the direction parallel to the longitudinal direction of the photothermal irradiation section may be lower than the foam height at the center.

  Therefore, even if the target foaming height is the same, the concentration of the heat absorption part at both ends of the medium in the direction parallel to the longitudinal direction of the photothermal irradiation part is higher than the concentration of the heat absorption part at the center of the medium. There is a known technique (see, for example, Patent Document 1).

JP 2014-81582 A

  However, since the density of the heat absorption part in the medium is changed according to the position of the medium according to the temperature distribution of the light beam irradiation part and the target foaming height of the medium, the density difference suppressing part after the foam expansion of the medium. Even if a solid white image (for example, a solid white image) is printed on the entire surface of the medium, a portion of the heat absorbing portion that is darker than the other portions may be dimly exposed. As described above, when the portion having a high density of the heat absorbing portion is exposed to be dim, when the color image is printed after the density difference suppressing portion is printed, the color image of the color image in the portion having the high density of the heat absorbing portion becomes dark. Further, when the solid white image is used as it is as a part of the color image for the white portion of the color image, the white color also varies depending on the position of the medium. Therefore, it becomes difficult to form a high-quality stereoscopic image.

  Further, by increasing the white density of the density difference suppressing portion printed on the entire surface of the medium, it is possible to prevent the dark portion of the heat absorbing portion from being exposed dimly, but it is used for the density difference suppressing portion. The consumption of materials such as white ink increases. In addition, if the density difference suppressing portion is always printed on the entire surface of the medium regardless of the area where the heat absorbing portion is formed, the consumption of the material used for the density difference suppressing portion is wasted.

  An object of the present invention is to provide a three-dimensional image forming apparatus, a three-dimensional image forming method, a pattern data generating method, and a program capable of forming a high-quality three-dimensional image while suppressing the consumption of material of the density difference suppressing unit. That is.

  In one aspect, the image forming apparatus includes: a heat absorption unit forming unit that forms a heat absorption unit that absorbs heat energy more easily than the medium on the surface of the medium that expands and expands according to the amount of heat absorbed; Based on the formation information of the heat absorption part and the heat absorption part, the density difference suppression part that suppresses the density difference of the heat absorption part overlaps at least the heat absorption part, and A control unit that generates pattern data generated such that a density difference suppression unit is formed unevenly on the surface of the medium, and a density difference suppression unit that forms the density difference suppression unit corresponding to the pattern data Means.

  In another aspect, the image forming method forms a heat absorbing portion that absorbs heat energy more easily than the medium on the surface of the medium that expands and expands according to the amount of heat absorbed, and the heat energy is applied to the medium. Radiating, and based on the formation information of the heat absorption part, the density difference suppression part that suppresses the density difference of the heat absorption part overlaps at least the heat absorption part, and the density difference suppression part is the medium of the medium The shading difference suppressing portion corresponding to the pattern data generated so as to be formed unevenly on the surface is formed.

  In another aspect, the pattern data generation method suppresses a difference in light and shade of a heat absorption part that absorbs heat energy more easily than the medium formed on the surface of the medium that expands and expands according to the amount of heat absorbed. When the pattern data of the difference suppression unit is generated by a computer, based on the formation information of the heat absorption unit, the density difference suppression unit overlaps at least the heat absorption unit, and the density difference suppression unit The pattern data is generated so as to be unevenly formed on the surface.

  In another aspect, the program is a density difference suppression unit that suppresses the density difference of the heat absorption unit that absorbs heat energy more easily than the medium formed on the surface of the medium that expands and expands according to the amount of heat absorbed. When generating the pattern data of the computer, based on the formation information of the heat absorption part, the lightness difference suppression part overlaps at least the heat absorption part, and the lightness difference suppression part is the medium of the medium The computer is caused to execute a process of generating the pattern data so that the surface is formed unevenly.

  According to the present invention, it is possible to form a high-quality stereoscopic image while suppressing the consumption amount of the material of the density difference suppressing portion.

It is sectional drawing which shows typically the internal structure of the three-dimensional image forming apparatus which concerns on embodiment of this invention. It is a perspective view which shows the structure of the inkjet printer part in embodiment of this invention. It is a circuit block diagram including the control part of the three-dimensional image forming apparatus which concerns on embodiment of this invention. It is a flowchart for demonstrating the three-dimensional image formation method which concerns on embodiment of this invention. (A)-(e) is explanatory drawing for demonstrating the heat absorption part formation process and thermal energy irradiation process in embodiment of this invention. It is a hardware configuration example of a computer capable of operating as a control unit in the embodiment of the present invention. (A)-(d) is explanatory drawing for demonstrating the density | concentration difference suppression part formation process in embodiment of this invention. It is a flowchart for demonstrating the three-dimensional image formation method which concerns on the modification of embodiment of this invention. (A) And (b) is explanatory drawing for demonstrating the density | concentration difference suppression part formation process in the modification of embodiment of this invention.

<Stereoscopic image forming apparatus>
FIG. 1 is a cross-sectional view schematically showing the internal structure of a stereoscopic image forming apparatus 1 according to an embodiment of the present invention.

  As shown in FIG. 1, the stereoscopic image forming apparatus 1 includes a lowermost black toner printing unit 2, a thermal expansion processing unit 3 thereon, and an uppermost inkjet printer unit 4. The black toner printing unit 2 is an example of a heat absorption unit forming unit, the thermal expansion processing unit 3 is an example of a thermal energy applying unit, and the ink jet printer unit 4 is an example of a density difference suppressing unit forming unit.

  The black toner printing unit 2 includes an endless transfer belt 6 that extends in the horizontal direction at the center inside the apparatus housing 5. The transfer belt 6 is stretched between a driving roller 7 and a driven roller 8 while being stretched by a tension mechanism (not shown), and is driven by the driving roller 7 to be counterclockwise as indicated by an arrow a in FIG. Circulate to

  A photosensitive drum 11 of the image forming unit 9 is disposed in contact with the upper circulation moving surface of the transfer belt 6. The photosensitive drum 11 is provided with a developing roller 12 and the like following the cleaner, the initialization charger, the optical writing head (not shown) and so on so as to surround the peripheral surface.

  The developing roller 12 is disposed in the side opening of the toner container 13. A black toner K is stored in the toner container 13. The black toner K is made of a nonmagnetic one-component toner.

  The developing roller 12 carries a thin layer of black toner K contained in a toner container 13 on its surface, and an electrostatic latent image formed on the peripheral surface of the photosensitive drum 11 by an optical writing head. Then, an image of black toner K is developed.

  A primary transfer roller 14 is pressed against the lower portion of the photosensitive drum 11 via a transfer belt 6 to form a primary transfer portion. A bias voltage is supplied to the primary transfer roller 14 from a bias power source (not shown).

  The primary transfer roller 14 applies a bias voltage supplied from a bias power source to the transfer belt 6 in the primary transfer portion, and transfers an image of the black toner K developed on the peripheral surface of the photosensitive drum 11 to the transfer belt 6. Transcript to.

  A secondary transfer roller 15 is pressed against the driven roller 8 over which the right end portion of the transfer belt 6 shown in FIG. 1 is stretched via the transfer belt 6 to form a secondary transfer portion. A bias voltage is supplied to the secondary transfer roller 15 from a bias power source (not shown).

  The secondary transfer roller 15 applies a bias voltage supplied from a bias power source to the transfer belt 6 at the secondary transfer unit, and the image of the black toner K that is primarily transferred to the transfer belt 6 is transferred to the image forming conveyance path. As indicated by arrows along the line 16, the image is transferred to the thermally expandable sheet S conveyed from below in FIG.

Here, the thermally expandable sheet S is an example of a medium that expands and expands according to the amount of heat absorbed.
Further, the image of the black toner K transferred to the thermally expandable sheet S is an example of a heat absorbing portion that is formed on the surface of the thermally expandable sheet S and absorbs heat energy more easily than the thermally expandable sheet S. .

  The thermally expandable sheet S is stacked and stored in a sheet storage unit 18 including a paper feed cassette, and the uppermost sheet is taken out by a paper supply roller (not shown) and sent to the image forming conveyance path 16. . Further, the thermally expandable sheet S is transported through the image forming transport path 19, and the image of the black toner K is transferred while passing through the secondary transfer portion.

  The thermally expandable sheet S that has passed the secondary transfer portion while transferring the image of the black toner K is conveyed along the fixing conveyance path 19 to the fixing unit 21. The heating roller 22 and the pressing roller 23 of the fixing unit 21 sandwich the thermally expandable sheet S and convey it while applying heat and pressure.

  As a result, the image of the black toner K that has been secondarily transferred is fixed on the paper surface of the thermally expandable sheet S, and is further conveyed by the heating roller 22 and the pressing roller 23, and the conveyance is taken over by the fixing unit discharge roller pair 24. Then, it is discharged to the upper thermal expansion processing section 3. Here, since the conveying speed of the thermally expandable sheet S in the fixing unit 21 is relatively fast, the black toner print portion of the thermally expandable sheet S does not expand due to the heating of the heating roller 22.

  The thermal expansion processing unit 3 has a medium transport path 25 formed in the upper part, and four transport roller pairs 26 (26a, 26b, 26c, 26d) are arranged along the medium transport path 25. A light source unit 27 is disposed substantially below the center of the medium transport path 25.

  The light source unit 27 has an elongated halogen lamp 27a and a reflecting mirror 27b having a substantially semicircular cross section surrounding the lower half of the halogen lamp 27a, and the thermally expandable sheet S is arranged in the depth direction of FIG. The whole is heated.

  In the present embodiment, 900 W lamp is used as the halogen lamp 27a, and is disposed at a position 4 cm away from the surface of the thermally expandable sheet S conveyed through the medium conveyance path 25. The conveyance speed of the conveyance roller pair 26 that conveys the thermally expandable sheet S is 20 mm / second. Under this condition, the thermally expandable sheet S is heated to 100 ° C. to 110 ° C., and the portion of the thermally expandable sheet S on which the black toner image is printed is thermally expanded.

  In addition, although the conveyance speed of the thermal expansion sheet S of the black toner printing unit 2 is fast and the conveyance speed of the thermal expansion sheet S of the thermal expansion processing unit 3 is low, the thermal expansion sheet S is one sheet from the sheet storage unit 18. The continuous conveyance is not performed until the conveyance of the thermal expansion processing unit 3 is completed.

  Therefore, the thermally expandable sheet S conveyed to the thermal expansion processing unit 3 is transported between the fixing unit discharge roller pair 24 of the black toner printing unit 2 and the first conveyance roller pair 26a of the thermal expansion processing unit 03. In a state of being bent by the above, there is no inconvenience in conveyance as a whole only by staying for a short time.

The thermally expandable sheet S, which has been raised by the thermal expansion of the black solid print portion in the thermal expansion processing unit 3, is carried into the inkjet printer unit 4 along the conveyance path c.
The transport roller pair 26 may be constituted by a long roller pair extending in the width direction of the thermally expandable sheet S orthogonal to the transport direction, or only on both side ends of the thermally expandable sheet S. It is also possible to constitute a pair of short rollers that sandwich and convey the roller.

FIG. 2 is a perspective view showing the configuration of the inkjet printer unit 4 in the embodiment of the present invention.
In the inkjet printer unit 4 shown in FIG. 2, an internal frame 37 shown in FIG. 2 is disposed between the conveyance path c shown in FIG. 1 and the medium discharge port 28 provided with a paper discharge tray 29 outside.

  The ink jet printer unit 4 includes a carriage 31 provided so as to be capable of reciprocating in a direction indicated by a double arrow d orthogonal to the paper transport direction. A print head 32 that performs printing and an ink cartridge 33 (33w, 33c, 33m, 33y) that contains ink are attached to the carriage 31.

  The cartridges 33w, 33c, 33m, and 33y contain color inks of white W, cyan C, magenta M, and yellow Y, respectively. Each of these cartridges has a configuration in which each ink chamber is integrated into one housing, and is connected to a print head 32 having respective nozzles for ejecting each color ink.

  On the one hand, the carriage 31 is slidably supported by the guide rail 34, and on the other hand, it is fixed to the toothed drive belt 35. As a result, the print head 32 and the ink cartridges 33 (33w, 33c, 33m, 33y) are driven to reciprocate together with the carriage 31 in a direction orthogonal to the paper conveyance direction indicated by the double arrow d in FIG. The

  A flexible communication cable 36 is connected via an internal frame 37 between the print head 32 and a control unit (to be described later) of the stereoscopic image forming apparatus 1. Print data and control signals are sent from the control unit to the print head 32 through the flexible communication cable 36.

A platen 38 that faces the print head 32 and extends in the main scanning direction of the print head 32 and forms a part of the sheet conveyance path is disposed at the lower end portion of the internal frame 37.
Further, the thermally expandable sheet S is in contact with the platen 38 and the pair of paper feed rollers 39 (the lower roller is behind the thermally expandable sheet S and cannot be seen in FIG. 2) and the discharge roller pair 41 (lower roller) Is not seen in the same manner), and is intermittently conveyed in the printing sub-scanning direction indicated by arrow e in FIG.

  During the period during which the intermittent conveyance of the thermally expandable sheet S is stopped, the print head 32 is driven by the motor 42 via the toothed drive belt 35 and the carriage 31 while being in close proximity to the thermally expandable sheet S. Is printed on the paper surface. Thus, printing (printing) is performed on the entire surface of the thermally expandable sheet S by repeating the intermittent conveyance of the thermally expandable sheet S and the printing during the reciprocating movement by the print head 32.

  In order to suppress the density difference of the above-described heat absorbing portion, which is an image of the black toner K printed by the black toner printing portion 102, first, the density difference suppression using white ink as an example on the thermally expandable sheet S is suppressed. The part is formed so as to overlap at least the heat absorption part. The shade difference suppressing unit will be described later.

  Full color printing may be superimposed on the shade difference suppressing portion. In this case, the thermally expandable sheet S on which the density difference suppressing portion is formed is reversely conveyed in the direction opposite to the printing sub-scanning direction indicated by the arrow e, and full color printing is performed while being conveyed again in the arrow e direction.

FIG. 3 is a circuit block diagram including a control unit of the stereoscopic image forming apparatus 1 according to the embodiment of the present invention.
As shown in FIG. 3, the circuit block is centered on a central processing unit (CPU) 45, and the CPU 45 is connected to an I / F_CONT (interface controller) 46, PR_CONT (printer controller) 47, via a data bus, respectively. In addition, an image cutout unit 48 is connected.

  A printer printing unit 49 is connected to the PR_CONT 47 described above. The image cutout unit 48 is also connected to the I / F_CONT 146 on the other side. The image cutout unit 48 includes an image processing application similar to that mounted on a personal computer or the like.

  Also connected to the CPU 45 are a ROM (read only memory) 51, an EEPROM (electrically erasable programmable ROM) 52, an operation panel 53 of the main body operation unit, and a sensor unit 54 to which outputs from sensors arranged in each unit are input. Has been. The ROM 51 stores a system program. The operation panel 53 includes a touch-type display screen.

The CPU 45 reads the system program stored in the ROM 51 and controls each part according to the read system program to perform processing.
That is, in each unit, first, the I / F_CONT 46 converts print data supplied from a host device such as a personal computer into bitmap data and develops it in the frame memory 55.

  In the frame memory 55, storage areas corresponding to the print data of the black toner K and the print data of the color inks of white W, cyan C, magenta M, and yellow Y are set, and the image of each color is stored in this storage area. The print data is expanded. The expanded data is output to the PR_CONT 47, and is output from the PR_CONT 47 to the printer printing unit 49.

  The printer printing unit 49 is an engine unit, and is a rotational drive system including the photosensitive drum 11 and the primary transfer roller 14 of the black toner printing unit 2 shown in FIG. 1 under the control of the PR_CONT 47, which is shown in FIG. The voltage applied to the image forming unit 9 having a driven portion such as an initialization charger and an optical writing head, and the drive output to a process load such as driving of the transfer belt 6 and the fixing portion 21 are controlled.

  Further, the printer printing unit 49 controls the driving of the four pairs of transport rollers 26 of the thermal expansion processing unit 3 shown in FIG. 1, the light emission driving of the light source unit 27, and their timing. Further, the printer printing unit 49 controls the operation of each unit of the inkjet printer unit 4 shown in FIGS. 1 and 2.

  Then, the image data of the black toner K output from the PR_CONT 47 is supplied from the printer printing unit 49 to the optical writing head (not shown) of the image forming unit 9 of the black toner printing unit 2 shown in FIG. Also, the image data of the white W, cyan C, magenta M, and yellow Y color inks output from the PR_CONT 47 is supplied to the print head 32 shown in FIG.

<Stereoscopic image forming method>
FIG. 4 is a flowchart for explaining the three-dimensional image forming method according to the embodiment of the present invention.

  First, a heat absorbing portion forming step (step S11) for forming the heat absorbing portion 71 (the image of the black toner K described above) on the surface of the heat expandable sheet S, and radiating heat energy to the heat expandable sheet S The thermal energy radiation process (step S12) to be performed will be described with reference to FIG.

FIGS. 5A to 5E are explanatory views for explaining the heat absorption part forming step (step S11) and the thermal energy irradiation step (step S12) in the embodiment of the present invention.
The heat-expandable sheet S absorbs more heat energy as the density (for example, area gradation) of the heat absorption part 71 formed of black toner is higher. Since the foaming height of the foamed resin layer 57 has a positive correlation with the amount of heat absorbed by the foamed resin layer 57, the foamed height of the thermally expandable sheet S is eventually increased in the portion where the concentration of the heat absorbing portion 71 is deeper. The height is high.

  Therefore, one of the information used when forming the heat absorbing portion 71 is the information whose density is determined so as to correspond to the target height of the three-dimensional shape formed by the expansion of the thermally expandable sheet S. The first gray level information 72 is as follows. It can be said that the first density information 72 has a correlation with the target height at which the thermally expandable sheet S foams when the thermally expandable sheet S receives thermal energy. The first density information 72 is formation information of the heat absorption part 71.

  In FIG. 5A, the image corresponding to the first grayscale information 72 has the same target height throughout the image (fish-shaped region), and therefore the density is also assumed to be constant. Only illustrated. However, the target height may be varied depending on the position in the image, and the density may vary.

  Here, the photothermal irradiation temperature distribution of the light source unit 27 shown in FIGS. 5C and 5D is the center of the longitudinal direction of the light source unit 27 (the short side direction of the thermally expandable sheet S having a rectangular shape) g. It becomes high as it approaches the both ends of the longitudinal direction g. In addition, the length along the longitudinal direction g of the light source unit 27 is longer than the length of the short side of the thermally expandable sheet S, and the light source unit 27 has the entire length direction g (the short side of the thermally expandable sheet S). Thermal energy is radiated to the thermally expandable sheet S over a longer range than the length.

  Thereby, the amount of heat that the unit area of the thermally expandable sheet S receives per unit time may decrease as it approaches both ends from the center in the longitudinal direction g of the light source unit 27. As a result, the foam height may be lower in the region corresponding to both ends of the light source unit 27 than in the region corresponding to the center portion even if the target height of the thermally expandable sheet S is constant. It was.

Therefore, when the density of the heat absorption unit 71 is determined according to the first density information 72 in which the density is determined according to the target height, the longitudinal direction of the light source unit 27 is used in the thermally expandable sheet S even in the portion where the density is the same. The foam height is lower at both end portions than at the central portion in g.
Therefore, in order to control the amount of heat absorbed by the thermally expandable sheet S so as to be substantially equal regardless of the position in the longitudinal direction g of the light source unit 27, from the center side in the longitudinal direction g of the light source unit 27. The information of which the density is determined so that the density of the heat absorption unit 71 becomes deeper as it approaches the both end sides, the second density information 73 which is another information used when forming the heat absorption unit 71, and To do. The second light / dark information 73 can be regarded as light / dark information corresponding to the thermal energy radiation characteristic when the thermally expandable sheet S receives heat energy. The second density information 73 is formation information of the heat absorption part 71.

  As described above, the density of the heat absorption unit 71 is determined by adding the density determined by the second density information 73 to the density determined by the first density information 72. That is, when the density of the heat absorption unit 71 is compared with the density (first density information 72) determined according to the target foaming height, the longitudinal direction g of the light source unit 27 is corrected by the correction based on the second density information 73. As the distance from the center 71a to the both ends 71b increases, the density increases.

  In addition, as the light / dark information corresponding to the thermal energy radiation characteristic, the second light / dark information 73 corresponding to the characteristic that the light source unit 27 is high in the central part in the longitudinal direction g and becomes low as it approaches both ends in the longitudinal direction g has been described. . However, in the process of moving the light source unit 27 in the moving direction (long side direction of the thermally expandable sheet S) f orthogonal to the longitudinal direction g, the light source unit 27 or the thermally expandable sheet S, the thermally expandable sheet S. The amount of heat received per unit time by the unit area of the thermally expandable sheet S increases as it approaches the end point side from the start point side in the moving direction f of the light source unit 27 due to heat storage of the mounting table 60 or the like on which the light source unit is mounted. It can also be considered.

  Therefore, in order to control the amount of heat received by the thermally expandable sheet S as second density information so as to be substantially equal regardless of the position of the light source unit 27 in the movement direction f, the movement direction f of the light source unit 27 is determined. It is also possible to use light / dark information in which light / dark is determined so that the heat absorption portion 71 has a lighter density as it approaches the end point from the start point side.

FIG. 5B is a cross-sectional view before foaming along the longitudinal direction g of the light source unit 27 of the thermally expandable sheet S on which the heat absorbing portion 71 is formed.
As shown in FIG. 5 (b), the thermally expandable sheet S includes a base material 56 and a thermal foaming agent (thermally expandable microcapsule) in a binder that is a thermoplastic resin provided on the base material 56. And a foamed resin layer 57 arranged in a dispersed manner.

  The base material 56 is made of a cloth such as paper or canvas, a panel material such as plastic, and the material is not particularly limited. As such a heat-expandable sheet S, a known commercial product can be used.

  Of the surface (the upper surface in FIG. 5B) of the foamed resin layer 57 of the thermally expandable sheet S, the above-described heat absorbing portion 71 is formed in a portion to be three-dimensionalized. 5C and 5D, the surface of the foamed resin layer 57 of the thermally expandable sheet S on which the heat absorbing portion 71 is formed is heated by the heat source heater 59.

  The configurations of FIGS. 5B and 5C are diagrams showing the basic concept, and thus the principle is the same, although the configuration is different from the configuration of the thermal expansion processing unit 3 shown in FIG. That is, as shown in FIGS. 5C and 5D, the thermally expandable sheet S is placed on the placing table 60 with the printed surface of the heat absorbing portion 71 facing upward, and the sheet supporting frame 62 The position is fixed.

  In the mounting table 60, guide grooves (not shown) are formed on both side end surfaces in the longitudinal direction g of the light source unit 27, and reciprocating movement is possible along the guide grooves as indicated by a double arrow f. Heat source heater support columns 63 (63a, 63b) are provided upright.

  While the heat source heater 59 supported at both ends by these heat source heater support columns 63 moves in accordance with the movement of the heat source heater support columns 63, heat radiation (thermal energy) is applied to the surface of the foamed resin layer 57 of the thermally expandable sheet S. An example). That is, heat radiation is emitted to the surface of the foamed resin layer 57 while the thermally expandable sheet S and the heat source heater 59 move relatively.

  As a result, the heat absorbing portion 71 absorbs the heat radiation and transfers the heat to the thermal foaming agent contained in the foamed resin layer 57, causing the thermal foaming agent to undergo a thermal expansion reaction, as shown in FIG. As shown, the portion of the thermally expandable sheet S where the heat absorbing portion 71 is formed expands and rises. In FIG. 5 (e), it is illustrated that the height (foaming) height P of the portion where the heat absorbing portion 71 is formed is set to be the same.

  Thus, in the thermally expandable sheet S heated by the heat source heater 59, only the thermal foaming agent of the portion where the heat absorbing portion 71 is printed foams and the printing surface becomes three-dimensional. Even if the portion of the surface of the thermally expandable sheet S where the heat absorbing portion 71 is not formed absorbs heat energy, the amount of heat is kept sufficiently small and the height does not change substantially, The change in height is sufficiently small as compared with the portion where the absorbing portion 71 is formed.

  As shown in FIG. 5 (d), the heat source heater 59 constitutes a light source unit 27 having a halogen lamp 27 a and a reflecting mirror 27 b, and the heat expandable sheet S and the heat source heater 59 are relative to each other. In the thermal expansion processing unit 3 described above, the light source unit 27 is fixed, and the thermally expandable sheet S is transported and transported by the transport roller pair 26.

  Next, the density difference suppression unit forming step (steps S13 and S14) illustrated in FIG. 4 will be described. First, the control unit used to generate pattern data of the density difference suppression unit that suppresses the density difference of the heat absorption unit 71. Will be described. The control unit may be a control unit disposed in the apparatus housing of the image forming apparatus 1 described with reference to FIG. 3, but here, is disposed outside the apparatus housing of the image forming apparatus 1. A control unit connected to the inside of the apparatus housing by wire or wireless will be described. It can be said that the image forming apparatus 1 also includes a control unit arranged outside the apparatus housing of the image forming apparatus 1.

FIG. 6 is a hardware configuration example of a computer 100 that can operate as a control unit in the embodiment of the present invention.
A computer 100 illustrated in FIG. 6 includes a CPU (Central Processing Unit) 101, a storage unit 102, an input unit 103, a display unit 104, an interface unit 105, and a recording medium driving unit 106. These components are connected via a bus line 107 and exchange various data with each other.

  The CPU 101 is an arithmetic processing unit that controls the operation of the entire computer 100. The CPU 101 generates pattern data by reading and executing a program for generating pattern data of the shading difference suppressing unit.

The storage unit 102 includes a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, and the like.
The ROM is a read-only semiconductor memory in which a predetermined basic control program is recorded in advance. Note that as the ROM, a memory such as a flash memory in which stored data is nonvolatile when power supply is stopped may be used.

The RAM is a semiconductor memory that can be written and read at any time and used as a working storage area as necessary when the CPU 101 executes various control programs.
The hard disk stores various control programs executed by the CPU 101 and various data.

  The input unit 103 is, for example, a keyboard device or a mouse device. When operated by a user of the computer 100, the input unit 103 acquires various input information from the user associated with the operation content, and the acquired input information is stored in the CPU 101. Send to.

The display unit 104 is a display, for example, and displays various texts and images.
The interface unit 105 manages the exchange of various information with various devices.
The recording medium driving unit 106 is a device that reads various control programs and data recorded on the portable recording medium 108. The CPU 101 can perform each process of pattern data generation by reading and executing a predetermined control program recorded on the portable recording medium 108 via the recording medium driving unit 106.

  Examples of the portable recording medium 108 include a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), and a flash memory provided with a USB standard connector.

  In order to operate such a computer 100 as a control unit, first, a control program for causing the CPU 101 to perform each process is created. The created control program is stored in advance in the hard disk device or the portable recording medium 108 of the storage unit 102. Then, when a predetermined instruction is given to the CPU 101, the control program is read and executed. Thereby, the computer 100 operates as a control unit.

Returning to the flowchart shown in FIG. 4, the density difference suppressing portion forming step (steps S <b> 13 and S <b> 14) will be described with reference to FIG. 7.
FIGS. 7A to 7D are explanatory diagrams for explaining the density difference suppressing portion forming step in the embodiment of the present invention.

  In the present embodiment, the density difference suppression unit is formed of white ink by the inkjet printer unit 4 shown in FIGS. First, the entire surface is white-printed on the surface (the surface on which the heat absorbing portion 71 is formed as shown in FIG. 7A) of the thermally expandable sheet S that has been foamed and expanded (step S13 in FIG. 4). .

  When the printing of the entire solid white image as the density difference suppressing portion is performed on the surface of the thermally expandable sheet S in this way, as shown in FIG. Covering makes it difficult to see the difference in shading. Note that the entire solid white image is an image having no gradation difference (gradation) over the entire image.

  However, as described with reference to FIG. 5, the heat absorbing member 71 before white printing on the entire surface is corrected so that the density is higher at both end portions 71 b than the center 71 a in the longitudinal direction g of the light source unit 27. . Therefore, the heat absorption part 71-1 after white printing on the entire surface is also more likely to be exposed at a darker position at both end parts 71-1b than the center 71-1a in the longitudinal direction g of the light source unit 27.

  Therefore, in order to further eliminate the density difference of the heat absorption unit 71-1 after the entire white printing, the entire white gradation image is printed as the density difference suppressing unit (step S <b> 14). The gradation of the density is determined based on, for example, the first density information 72 and the second density information 73 of the heat absorption unit 71 illustrated in FIG. That is, regarding the first density information 72, the density of the black density is determined according to the information that the density is determined so as to correspond to the target height of the three-dimensional shape formed by the expansion of the thermally expandable sheet S. Without determining the density of the white density. As for the second light / dark information 73, the light / dark information in which both ends 73b are darker than the center 73a in the longitudinal direction g of the light source unit 27 is closer to both ends 73b from the center 73a in the longitudinal direction g of the light source unit 27. Instead of increasing the black density, as shown in white gradation information 74 shown in FIG. 7C, the white density is changed so as to increase from the center 74a in the longitudinal direction g of the light source unit 27 toward both ends 74b. It is good to use. In FIG. 7C, the dark black portion indicates that the white concentration is high. At this time, the white density of the density difference suppression part may be the same density as the black density of the corresponding heat absorbing part 71 formed above the density difference suppression part. In addition, the white density of the density difference suppressing unit may be calculated by multiplying the corresponding black density of the heat absorbing unit 71 by a predetermined coefficient, or derived based on a desired table. Alternatively, the effect of suppressing the difference in light and shade may be optimized.

As shown in FIG. 7D, the heat absorbing portion 71-2 after the entire white gradation printing is performed appears to be a gray color that is almost uniform white.
In this way, when forming the shade difference suppressing portion by performing the entire white gradation printing in addition to the entire white printing, the shade difference suppressing portion is arranged at the center 71a (first first) of the heat absorbing portion 71 shown in FIG. It becomes darker in the part overlapping both end portions 71b (an example of the second absorbent part having a higher concentration than the first absorbent part) than the part overlapped with the absorbent part (an example of the absorbent part). Uniformly formed.

  Then, the color printing process (step S14) shown in FIG. 4 is performed by the inkjet printer unit 4 shown in FIGS. In this color printing process, for example, printing is performed based on the original image data used for forming the thermally expandable sheet S.

  In the present embodiment, the density difference suppressing portion forming step is performed by dividing the entire white printing (step S13 in FIG. 4) and the entire white gradation printing (step S14) into two times. The white density to be printed on the image may be added once. The added white density is obtained by increasing the density of the entire white gradation 74 shown in FIG. 7C by the density of the entire white printing (step S13).

  Furthermore, when the position information is included in addition to the density information such as the first density information 72 and the second density information 73 as the formation information of the heat absorption section 71 acquired by the control section, the heat absorption section 71 is formed. The white gradation printing in step S14 may be performed only on the region that has been made. Also in this case, if the foamed resin layer 57 is white, the difference in density between the portion where the white gradation printing is performed and the other portion, that is, the portion where only the whole surface white printing is performed on the foamed resin layer 57 is suppressed. Is done.

  In the present embodiment described above, based on the formation information of the heat absorption part 71 (for example, the density information such as the first density information 72 and the second density information 73 and the position information), the density difference suppression unit is at least The pattern data is generated so as to overlap the heat absorption part 71 and so that the density difference suppressing part is formed non-uniformly (for example, the density is non-uniform) on the surface of the thermally expandable sheet S.

  In this way, by forming the density difference suppressing portion non-uniformly on the surface of the thermally expandable sheet S, the density difference suppressing portion having the same density on the surface of the thermally expandable sheet S is uniformly formed as a whole. Even if the consumption of the material (white ink) of the density difference suppression part is reduced, the density difference can be suppressed by determining the density distribution of the density difference suppression part based on the formation information of the heat absorption part 71. become. Therefore, when a color image is printed after the formation of the density difference suppressing portion, it is possible to prevent the dark portion of the heat absorbing portion 71 from appearing dark, thereby forming a high-quality stereoscopic image on the thermally expandable sheet S. can do.

  Moreover, in this Embodiment, as shown to Fig.5 (a), the heat absorption part 71 is both ends rather than the center 71a (an example of a 1st absorption part) in the longitudinal direction g of the light source unit 27 (refer FIG. 1). The density is high at 71b (an example of the second absorption part). Then, the pattern data of the density difference suppression unit is based on at least the density information of the heat absorption unit 71, and the density of the density difference suppression unit is darker in the portion overlapping the both ends 71 b than in the portion overlapping the center 71 a of the heat absorption unit 71. Is generated as follows.

  In this way, at both end portions 71b having a higher concentration than the center 71a of the heat absorption portion 71, the density difference suppression portion is made thicker so that the density difference is suppressed by reducing the material in accordance with the concentration of the heat absorption portion 71. Even if it is a part, the shading difference of the heat absorption part 71 can be suppressed.

  Further, in the present embodiment, the density information of the heat absorbing unit 71 has a correlation with the target height at which the thermally expandable sheet S foams when the thermally expandable sheet S receives thermal energy, and the thermally expandable sheet S. 5 includes the first gray-scale information 72 shown in FIG. 5A corresponding to the target height of the three-dimensional shape formed by foaming and expanding. Alternatively, the density information of the heat absorption unit 71 is illustrated in FIG. 5A corresponding to thermal energy radiation characteristics (for example, the above-described temperature distribution generated in the light source unit 27) when the thermally expandable sheet S receives thermal energy. Second density information 73 is included.

  Therefore, the density difference suppression unit that reduces the material in accordance with the density of the heat absorption unit 71 by generating the pattern of the density difference suppression unit based on at least one of the first density information 72 and the second density information 73. Even so, the difference in light and shade of the heat absorption part 71 can be suppressed.

FIG. 8 is a flowchart for explaining a stereoscopic image forming method according to a modification of the embodiment of the present invention.
FIGS. 9A and 9B are explanatory diagrams for explaining the density difference suppressing portion forming step in the modification of the embodiment of the present invention.

  In this modified example, the density difference suppressing part is not formed unevenly from the viewpoint of density by making the density of the density difference absorbing part non-uniform on the surface of the thermally expandable sheet S as described above. By forming the density difference absorption part (the density may be uniform) only on a part of the surface of the conductive sheet S, the density difference absorption part is non-uniformly formed from a positional viewpoint.

  The heat absorption part forming process (step S21), the thermal energy radiation process (step S22), and the color printing process (step S24) shown in FIG. Since it can be performed in the same manner as the energy emission process (step S12) and the color printing process (step S14), the density difference suppressing portion forming process (step S23) will be described.

  When the black or gray heat absorption part 81 is formed in the thermally expansible sheet S as shown to Fig.9 (a), the above-mentioned control part at least overlaps with the heat absorption part 81, and the thermal expansive sheet S of The pattern data of the shading difference suppressing portion is generated so as to be formed on a part of the surface.

  In the example of FIG. 9B, in order to minimize the consumption of the white ink that is the material of the density difference suppression unit, the heat-expandable sheet S2 has a heat absorption function based on the positional information of the heat absorption unit 81. In the same area where the portion 81 is formed, the shade difference suppressing portion 82 having the same size is formed. In FIG. 9B, a portion having a high black density (for example, a black density of 100%) indicates that the white density is high (for example, the white density is 100%).

  The white density of the density difference suppressing unit 82 may be uniform or non-uniform, but when the density of the heat absorbing unit 81 is non-uniform, the black density distribution of the heat absorbing unit 81 is changed to white. Is replaced with the density distribution of the heat absorption unit 81, the white density of the density difference suppression unit 82 is increased in a portion where the black density of the heat absorption unit 81 is high, and the white density of the density difference suppression unit 82 is set in a portion where the black density of the heat absorption unit 81 is low. Should be thin. As a result, the density can be made more uniform and the density difference can be suppressed more efficiently with a smaller amount of white ink consumed.

  As in the present modification, by forming the light / dark difference absorbing portion 82 on a part of the surface of the thermally expandable sheet S, that is, the portion where the heat absorbing portion 81 is formed, the light / dark difference absorbing portion 82 is positioned in terms of position. Even if it is formed unevenly, the consumption of the material (white ink) of the light / dark difference suppressing portion is reduced compared to the case where the light / dark difference suppressing portion 82 is formed on the entire surface of the thermally expandable sheet S. be able to. Therefore, as in the case where the density difference suppressing portion is formed non-uniformly from the viewpoint of density as described above, a high-quality stereoscopic image can be formed while suppressing the consumption of the material of the density difference suppressing portion.

  In addition, in the above-mentioned embodiment and modification, although the color of the heat absorption parts 71 and 81 and the light and shade difference suppression part 82 was black and white, it is not restricted to this. In other words, if the lightness difference suppression part 82 is lighter than the heat absorption parts 71, 81, the lightness difference of the heat absorption parts 71, 81 is formed by forming the lightness difference suppression part 82 as described above. The difference can be suppressed.

  As mentioned above, although embodiment of this invention was described, this invention includes the invention described in the claim, and its equivalent range. The invention described in the scope of claims at the beginning of the filing of the present application will be appended.

[Appendix 1]
On the surface of the medium that expands and expands according to the amount of heat absorbed, a heat absorption part forming means that forms a heat absorption part that absorbs heat energy more easily than the medium;
Thermal energy radiation means for radiating thermal energy to the medium;
Based on the formation information of the heat absorption part, the density difference suppression part that suppresses the density difference of the heat absorption part overlaps at least the heat absorption part, and the density difference suppression part is not present on the surface of the medium. A control unit for generating pattern data generated so as to be formed uniformly;
A density difference suppression unit forming means for forming the density difference suppression unit corresponding to the pattern data;
An image forming apparatus comprising:

[Appendix 2]
The heat absorption part includes the first absorption part and a second absorption part having a concentration higher than that of the first absorption part,
The formation information of the heat absorption part includes shading information of the heat absorption part,
The control unit is based on at least the shade information of the heat absorption unit, so that the density of the shade difference suppression unit is higher in the portion overlapping the second absorption portion than in the portion overlapping the first absorption portion, Generating the pattern data;
The image forming apparatus as set forth in appendix 1, wherein:

[Appendix 3]
The shading information of the heat absorption part is correlated with the target height at which the medium foams when the medium receives heat energy, and the target height of the three-dimensional shape formed by the foam expansion of the medium. Including corresponding first shade information,
The control unit generates the pattern data based on at least the first density information.
The image forming apparatus according to appendix 2, wherein

[Appendix 4]
The shade information of the heat absorption unit includes second shade information corresponding to thermal energy radiation characteristics when the medium receives thermal energy,
The control unit generates the pattern data based on at least the second density information.
The image forming apparatus according to appendix 2 or 3, characterized by the above.

[Appendix 5]
The formation information of the heat absorption part includes position information of the heat absorption part,
The control unit generates the pattern data based on at least the position information of the heat absorption unit so that the density difference suppression unit is formed on a part of the surface of the medium.
The image forming apparatus according to any one of appendices 1 to 4, characterized in that:

[Appendix 6]
On the surface of the medium that expands and expands according to the amount of heat absorbed, a heat absorption part that absorbs heat energy more easily than the medium is formed,
Radiating thermal energy to the medium,
Based on the formation information of the heat absorption part, the density difference suppression part that suppresses the density difference of the heat absorption part overlaps at least the heat absorption part, and the density difference suppression part is not present on the surface of the medium. Forming the shading difference suppressing unit corresponding to the pattern data generated so as to be formed uniformly;
An image forming method.

[Appendix 7]
When generating the pattern data of the density difference suppressing part that suppresses the density difference of the heat absorbing part that absorbs heat energy more easily than the medium formed on the surface of the medium that expands and expands according to the amount of heat absorbed by the computer, Based on the formation information of the heat absorption part, the density difference suppression part overlaps at least the heat absorption part, and the density difference suppression part is formed unevenly on the surface of the medium. Generate pattern data,
A pattern data generation method characterized by the above.

[Appendix 8]
Causes the computer to generate pattern data of the density difference suppression unit that suppresses the density difference of the heat absorption part that absorbs heat energy more easily than the medium formed on the surface of the medium that expands and expands according to the amount of heat absorbed. At the time, based on the formation information of the heat absorption part, so that the shade difference suppression part overlaps at least the heat absorption part, and the shade difference suppression part is formed unevenly on the surface of the medium, Causing the computer to execute processing for generating the pattern data;
A program characterized by that.

DESCRIPTION OF SYMBOLS 1 Stereoscopic image forming apparatus 2 Black toner printing part 3 Heating apparatus 4 Inkjet printer part 27 Light source unit 27a Halogen lamp 27b Reflector 32 Print head 56 Base material 57 Foamed resin layer 71 Heat absorption part 71a Center 71b Both ends 72 First density information 73 2nd density information 73a center 73b both ends 81 heat absorption part 82 shade difference suppression part 100 computer 101 CPU

Claims (8)

On the surface of the medium that expands and expands according to the amount of heat absorbed, a heat absorption part forming means that forms a heat absorption part that absorbs heat energy more easily than the medium;
Thermal energy radiation means for radiating thermal energy to the medium;
Based on the formation information of the heat absorption part, the density difference suppression part that suppresses the density difference of the heat absorption part overlaps at least the heat absorption part, and the density difference suppression part is not present on the surface of the medium. A control unit for generating pattern data generated so as to be formed uniformly;
A density difference suppression unit forming means for forming the density difference suppression unit corresponding to the pattern data;
An image forming apparatus comprising: The heat absorption part includes the first absorption part and a second absorption part having a concentration higher than that of the first absorption part,
The formation information of the heat absorption part includes shading information of the heat absorption part,
The control unit is based on at least the shade information of the heat absorption unit, so that the density of the shade difference suppression unit is higher in the portion overlapping the second absorption portion than in the portion overlapping the first absorption portion, Generating the pattern data;
The image forming apparatus according to claim 1. The shading information of the heat absorption part is correlated with the target height at which the medium foams when the medium receives heat energy, and the target height of the three-dimensional shape formed by the foam expansion of the medium. Including corresponding first shade information,
The control unit generates the pattern data based on at least the first density information.
The image forming apparatus according to claim 2. The shade information of the heat absorption unit includes second shade information corresponding to thermal energy radiation characteristics when the medium receives thermal energy,
The control unit generates the pattern data based on at least the second density information.
The image forming apparatus according to claim 2, wherein the image forming apparatus is an image forming apparatus. The formation information of the heat absorption part includes position information of the heat absorption part,
The control unit generates the pattern data based on at least the position information of the heat absorption unit so that the density difference suppression unit is formed on a part of the surface of the medium.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. On the surface of the medium that expands and expands according to the amount of heat absorbed, a heat absorption part that absorbs heat energy more easily than the medium is formed,
Radiating thermal energy to the medium,
Based on the formation information of the heat absorption part, the density difference suppression part that suppresses the density difference of the heat absorption part overlaps at least the heat absorption part, and the density difference suppression part is not present on the surface of the medium. Forming the shading difference suppressing unit corresponding to the pattern data generated so as to be formed uniformly;
An image forming method. When generating the pattern data of the density difference suppressing part that suppresses the density difference of the heat absorbing part that absorbs heat energy more easily than the medium formed on the surface of the medium that expands and expands according to the amount of heat absorbed by the computer, Based on the formation information of the heat absorption part, the density difference suppression part overlaps at least the heat absorption part, and the density difference suppression part is formed unevenly on the surface of the medium. Generate pattern data,
A pattern data generation method characterized by the above. Causes the computer to generate pattern data of the density difference suppression unit that suppresses the density difference of the heat absorption part that absorbs heat energy more easily than the medium formed on the surface of the medium that expands and expands according to the amount of heat absorbed. At this time, based on the formation information of the heat absorbing portion, the light intensity difference suppressing portion overlaps at least the heat absorbing portion, and the light intensity difference suppressing portion is formed unevenly on the surface of the medium. , Causing the computer to execute processing for generating the pattern data,
A program characterized by that.