Three-dimensional printing device, three-dimensional printing system and three-dimensional printing method

Desired designated sections are selectively extracted from a color image to be printed, the extracted designated sections are converted into a solid black image having a high thermal energy absorbency, and the solid black image is printed on the foaming layer surface of a supplied thermal expansion sheet. Next, thermal energy is applied by a halogen lamp in a thermal expansion processing unit, causing the solid black image section to expand and rise. Furthermore, in an ink jet printer unit, a prescribed color that is a background color is printed on the entire foaming layer surface of the thermal expansion sheet including the raised sections. Furthermore, the color image to be printed is printed thereon by an ink jet recording method to obtain color image three-dimensional printed material.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Japanese Patent Application No. 2011-038184, filed Feb. 24, 2011, the entire disclosure of which is incorporated by reference herein.

FIELD

This application relates generally to a three-dimensional printing device, three-dimensional printing system and three-dimensional printing method that creates printed material in which desired sections of a color image are made three-dimensional.

BACKGROUND

In the past, three-dimensional printing has been realized through Braille printing, a layering technique through UV ink, a physical pressing method, a three-dimensional printer and/or the like. For example, a method of forming three-dimensional images by using thermal expansion sheets made of thermal expansion microspheres of material with a low boiling point microencapsulated by thermoplastic resin, forming an image using for example black toner with a high thermal energy absorbency on this thermal expansion sheet, exposing the entire surface uniformly to strong light and selectively heating parts of the image through differences in light absorption to create a three-dimensional image has been known in Unexamined Japanese Patent Application KOKAI Publication No. S54-089638. However, with this pioneering technology, essentially no mention is made of coloring the three-dimensional image.

Hence, in Unexamined Japanese Patent Application KOKAI Publication No. 2001-150812, besides forming a planar image such as a color image on the surface of a foam sheet, a light-absorbing pattern for shaded images is formed on the back surface of the base layer of the foam sheet on the basis of distant image data in which a three-dimensional shape related to the planar image is expressed. A foam molding method is proposed through a printed foam sheet with a high degree of freedom in the bulge amount by shining light on this from the base layer side, generating heat in accordance with the shading of the image, and causing the foam sheet to expand and bulge in accordance with distant image data.

However, the conventional three-dimensional image formation methods described in the above-described Unexamined Japanese Patent Application Kokai Publication No. S54-089638 and Unexamined Japanese Patent Application Kokai Publication No. 2001-150812 have a variety of problems, such as requiring time to create three-dimensional printing, having numerous processes and requiring much labor, and accordingly, the devices become complicated and costs increase.

Not only that, but the three-dimensional image formation methods of the above-described Unexamined Japanese Patent Application KOKAI Publication No. S54-089638 and Unexamined Japanese Patent Application KOKAI Publication No. 2001-150812 all produce the image surface by first forming the image and then causing thermal expansion, so cracks can form in the surface of the image after expansion. As a result, the problem exists that the image quality of the three-dimensional image drops markedly.

SUMMARY

In consideration of the foregoing, it is an object of the present invention to provide a three-dimensional printing device, a three-dimensional printing system and a three-dimensional printing method compatible with color images that can create printed material in which desired section of a color image are made three-dimensional at high quality, easily and at low cost.

In order to achieve the above-described objective of this invention, the three-dimensional printing device according to this invention comprises an image extractor that extracts selectively designated section from an image to be printed; an image converter that converts the designated section extracted by the image extractor into an image with a color having a higher thermal energy absorbency than section other than the designated section; a converted image printer that prints the converted image converted by the image converter onto a foaming layer surface of a thermal expansion sheet; a sheet surface raiser that applies thermal energy to the thermal expansion sheet on which the converted image is printed by the converted image printer, and causes the printed section of the converted image to expand and rise; a background color printer that prints a prescribed color that is a background color on the surface of the foaming layer surface of the thermal expansion sheet containing section raised by the sheet surface raiser; and an image printer that prints the image to be printed on the surface on which the prescribed color was printed by the background color printer.

The three-dimensional printing device according to the present invention comprised as described above is comprised such that the image in the color having the higher thermal energy absorbency is a solid black image and the prescribed color is white.

In addition, in the three-dimensional printing device according to the present invention comprised as described above, the image to be printed is a color image.

In addition, the three-dimensional printing device according to the present invention comprised as described above further comprises a sheet supplier that supplies the thermal expansion sheet.

In order to achieve the above-described objective of this invention, the three-dimensional printing system according to this invention comprises an image extractor that extracts selectively designated section from an image to be printed; an image converter that converts the designated section extracted by the image extractor into an image with a color having a higher thermal energy absorbency than section other than the designated section; a converted image printer that prints the converted image converted by the image converter onto a foaming layer surface of a thermal expansion sheet; a sheet surface raiser that applies thermal energy to the thermal expansion sheet on which the converted image is printed by the converted image printer, and causes the printed section of the converted image to expand and rise; a background color printing device that prints a prescribed color that is a background color on the surface of the foaming layer surface of the thermal expansion sheet containing section raised by the sheet surface raiser; and an image printing device that prints the image to be printed on the surface on which the prescribed color was printed by the background color printer.

In addition, the three-dimensional printing system according to the present invention comprised as described above is comprised such that the image in the color having the higher thermal energy absorbency is a solid black image and the prescribed color is white.

In addition, the three-dimensional printing system according to the present invention comprised as described above is preferably comprised such that the image to be printed is a color image.

In order to achieve the above-described objective of this invention, the three-dimensional printing method according to this invention is a three-dimensional printing method comprising: extracting selectively designated section from an image to be printed; converting the designated section that were extracted into an image with a color having a higher thermal energy absorbency than section other than the designated section; printing the converted image that was converted onto a foaming layer surface of a thermal expansion sheet; applying thermal energy to the thermal expansion sheet on which the converted image is printed, and causing the printed section of the converted image to expand and rise; printing a prescribed color that is a background color on the surface of the foaming layer surface of the thermal expansion sheet containing section that were raised; and printing the image to be printed on the surface on which the prescribed color was printed.

In addition, the three-dimensional printing method according to the present invention comprised as described above is comprised such that wherein the image in the color having the higher thermal energy absorbency is a solid black image and the prescribed color is white, and furthermore the image to be printed is a color image.

In order to achieve the above-described objective of this invention, the three-dimensional printing device according to this invention comprises an image extractor that extracts selectively designated sections having differing degrees of rising from an image to be printed; an image converter that converts the designated sections extracted by the image extractor into a first color image having a higher thermal energy absorbency than section other than the designated sections, and a second color image having a higher thermal energy absorbency than the first color image; a converted image printer that prints the converted image converted by the image converter onto a foaming layer surface of a supplied thermal expansion sheet; a sheet surface raiser that applies thermal energy to the thermal expansion sheet on which the converted image is printed by the converted image printer, and causes the printed sections of the converted image to expand and rise; a background color printer that prints a prescribed color that is a background color on the surface of the foaming layer surface of the thermal expansion sheet containing sections raised by the sheet surface raiser; and an image printer that prints the image to be printed on the surface on which the prescribed color was printed by the background color printer.

Furthermore, the three-dimensional printing device according to the present invention comprised as described above is comprised such that the first color image is a solid gray image, the second color image is a solid black image and the prescribed color is white.

In addition, the device should be comprised such that the image to be printed is a color image. In addition, the three-dimensional printing device according to the present invention comprised as described above further comprises a sheet supplier that supplies the thermal expansion sheet.

In addition, the three-dimensional printing system according to this invention comprised as described above comprises an image extractor that extracts selectively designated sections having differing degrees of rising from an image to be printed; an image converter that converts the designated sections extracted by the image extractor into a first color image having a higher thermal energy absorbency than section other than the designated sections, and a second color image having a higher thermal energy absorbency than the first color image; a converted image printing device that prints the converted image converted by the image converter onto a foaming layer surface of a thermal expansion sheet; a sheet surface raising device that applies thermal energy to the thermal expansion sheet on which the converted image is printed by the converted image printer, and causes the printed sections of the converted image to expand and rise; a background color printing device that prints a prescribed color that is a background color on the surface of the foaming layer surface of the thermal expansion sheet containing sections raised by the sheet surface raiser; and an image printing device that prints the image to be printed on the surface on which the prescribed color was printed by the background color printer.

In addition, in the three-dimensional printing system according to this invention comprised as described above, the first color image is a solid gray image, the second color image is a solid black image and the prescribed color is white. Furthermore, the image to be printed is a color image.

In order to achieve the above-described objective of this invention, the three-dimensional printing method according to this invention is a three-dimensional printing method comprising: extracting selectively designated sections having differing degrees of rising from an image to be printed; converting the designated sections that were extracted into a first color image having a higher thermal energy absorbency than section other than the designated sections, and a second color image having a higher thermal energy absorbency than the first color image; printing the converted image that was converted onto a foaming layer surface of a thermal expansion sheet; applying thermal energy to the thermal expansion sheet on which the converted image is printed, and causing the printed sections of the converted image to expand and rise; printing a prescribed color that is a background color on the surface of the foaming layer surface of the thermal expansion sheet containing raised sections; and printing the image to be printed on the surface on which the prescribed color was printed.

In addition, the three-dimensional printing method according to this invention comprised as described above is comprised such that the first color image is a solid gray image, the second color image is a solid black image and the prescribed color is white.

In addition, the image to be printed is preferably a color image.

In this manner, with the three-dimensional printing device, three-dimensional printing system and three-dimensional printing method according of the present invention, it is possible to create printed material in which desired sections of a color image are made three-dimensional at high quality, easily and at low cost.

DETAILED DESCRIPTION

FIG. 1is a cross-sectional view schematically showing the internal composition of a three-dimensional printing device according to an embodiment of the present invention. As shown inFIG. 1, the three-dimensional printing device1is composed of a solid image printing unit2at the very bottom, a thermal expansion processing unit3above this, and an ink jet printer unit4at the very top.

The solid image printing unit2in this example utilizes an electronic photograph image creation method. Furthermore, in the internal center of a device casing5, an endless transfer belt6is provided, extending in the horizontal direction. The transfer belt6is looped over a drive roller7and a following roller8while being stretched by an unrepresented stretching mechanism, is driven by the drive roller7, and moves cyclically in a counterclockwise direction as indicated by an arrow “a” in the drawing.

A photosensitive drum11of an image creation unit9is positioned touching the top cyclical moving surface of the transfer belt6. A developing roller12is positioned adjacent to the photosensitive drum11so as to enclose the surface thereof, and is connected to a cleaner, initializing charger and optical writing head omitted from the drawing.

The above-described developing roller12is positioned at the side opening of a toner container13. Inside the toner container13, black toner K is stored. The black toner K is made up of non-magnetic component toner.

The above-described developing roller12has on the surface a thin layer of the black toner K stored in the toner container13, and develops an image of black toner K on an electrostatic latent image formed on the surface of the photosensitive drum11by an optical writing head.

A primary transfer roller14is pressed against the bottom of the photosensitive drum11via the transfer belt6, and here a primary transfer unit is formed. A bias voltage is supplied from an unrepresented bias power source to the primary transfer roller14.

The primary transfer roller14in the primary transfer unit impresses on the transfer belt6the bias voltage supplied from the bias power source, and transfers to the transfer belt6an image in the black toner K developed on the surface of the photosensitive drum11.

A secondary transfer roller15is pressed against the following roller8over which the transfer belt6is looped on the right end in the figure via the transfer belt6, and here a secondary transfer unit is formed. A bias voltage is supplied from an unrepresented bias power source to the secondary transfer roller15.

The secondary transfer roller15in the secondary transfer unit impresses on the transfer belt6the bias voltage supplied from the bias power source, and transfers the image in black toner K primarily transferred to the transfer belt6to the thermal expansion sheet17conveyed from the bottom in the figure as shown by the arrow along an image creation conveyance route16.

The thermal expansion sheet17has encapsulated thermally expansive microspheres on a base sheet, and for example it is possible to use a sheet available on the market on which thermally expansive spheres 10-30 μm in diameter in which propane, butane or some other substance with low boiling point is microencapsulated with a thermoplastic resin such as vinylidene chloride acrylonitrile, methacrylate ester-acrylate copolymer, vinylidene chloride-acrylate ester copolymer, are coated and dried on a base sheet using a thermoplastic coating such as a vinyl acetate polymer or an acrylate polymer.

The above-described thermal expansion sheet17is loaded and stored in a thermal expansion sheet storage unit18composed of a paper cassette and/or the like, and the topmost sheet is taken out by an unrepresented paper roller and/or the like, is sent to the image creation conveyance route16, is further conveyed along an image creation conveyance route19, and the image in black toner K is transferred thereto while the sheet traverses the above-described secondary transfer unit.

The thermal expansion sheet17that has traversed the secondary transfer unit while the image in black toner K is transferred is conveyed to a fixing unit21along a fixing conveyance route19. The thermal expansion sheet17is interposed between a heating roller22and a pressing roller23in the fixing unit21and is conveyed while being heated and pressed.

Through this, the thermal expansion sheet17has the secondarily transferred image in black toner K fixed to the paper surface and is further conveyed by the heating roller22and the pressing roller23. Conveyance is handed over to the fixing unit discharge roller pair24and the sheet is discharged to the thermal expansion processing unit3above. The conveyance speed of the thermal expansion sheet17in the fixing unit21is relatively fast, so the black toner printing portion of the thermal expansion sheet does not expand due to the heat of the heating roller22.

The thermal expansion processing unit3has a medium conveyance route25formed on the top, and four sets of conveyor roller pairs26(26a,26b,26cand26d) are positioned along this medium conveyance route25. Furthermore, a heat and light radiation unit27is positioned below substantially the center of the medium conveyance route25.

The heat and light radiation unit27is composed of a halogen lamp27aand a reflective minor27bof substantially semicircular cross-section surrounding the bottom half of this halogen lamp27a.

In this example, a 900 W halogen lamp27ais used and is positioned at a location separated by4cm from the surface of the thermal expansion sheet17being conveyed along the medium conveyance route25. The conveyance speed of the conveyor roller pairs26conveying the thermal expansion sheet17is 20 mm/sec. Under these conditions, the thermal expansion sheet17is heated to 100° C. to 110° C., and the black-printed portion of the thermal expansion sheet17thermally expands.

The conveyance speed of the thermal expansion sheet17in the solid image printing unit2is quick while the conveyance speed of the thermal expansion sheet17in the thermal expansion processing unit3is slow, but thermal expansion sheets17are conveyed one at a time from the thermal expansion sheet storage unit18, so successive conveyance is not accomplished until conveyance in the thermal expansion processing unit3is finished.

Accordingly, the thermal expansion sheet17conveyed in the thermal expansion processing unit3does not create troubles in conveyance as a whole by staying for a short time in a state bent by the conveyance route b between the fixing unit discharge roller pair24of the solid image printing unit2and the first conveyor roller pair26aof the thermal expansion processing unit3.

The thermal expansion sheet17that rises by the black solid printed part thermally expanding in the thermal expansion processing unit3is carried to the ink jet printer unit4along a conveyor route c.

The above-described conveyor roller pairs26may be composed of long roller pairs extending in the widthwise direction of the thermal expansion sheet17orthogonal to the direction of conveyance, or may be composed of short roller pairs that convey the thermal expansion sheet17by both sides thereof being interposed in between.

FIG. 2is a perspective view showing the composition of the ink jet printer unit4. The ink jet printer unit4shown inFIG. 2has an internal frame37shown inFIG. 2positioned between the conveyor route c shown inFIG. 1and a medium discharge opening28on the outside of which a paper discharge tray29is provided.

The ink jet printer unit4is provided with a carriage31mounted so as to be capable of moving back and forth in a direction indicated by the bidirectional arrow d orthogonal to the direction of paper conveyance. Attached to the carriage31are a print head32for executing printing and ink cartridges33(33w,33c,33mand33y) for storing ink.

The cartridges33w,33c,33mand33ystore colored ink in white W, cyan C, magenta M and yellow Y, respectively. These cartridges are composed independently or with each ink chamber integrated in a single casing, and are connected to the print head32having nozzles for respectively spraying various colored ink.

In addition, the carriage31is supported in one direction by a guide rail34so as to be free to slide, and in the other direction is anchored to a toothed drive belt35. Through this, the print head32and the ink cartridges33(33w,33c,33mand33y) move back and forth with the carriage31in a direction orthogonal to the paper conveyance direction indicated by the bidirectional arrow d in the drawing, that is to say in the primary scanning direction of printing.

Between the print head32and a below-described control device of the three-dimensional printing device1, a flexible communication cable36is connected via an internal frame37. Through this flexible communication cable36, print data and control signals from the control device are sent to the print head32.

Facing this print head32, a platen38is provided, extending in the above-described primary scanning direction of the print head32and comprising a portion of the paper conveyance route on the bottom side of the internal frame37.

Contacting this platen38, the thermal expansion sheet17is conveyed intermittently in the printing auxiliary scanning direction indicated by an arrow e in the drawing by a paper supply roller pair39(the bottom roller of which is not visible in the drawing, being in the shadow of the thermal expansion sheet17) and a paper discharge roller pair41(the bottom roller of which is similarly not visible in the drawing, being in the shadow of the thermal expansion sheet17).

During the periods of stoppage during the intermittent conveyance of this thermal expansion sheet17, the print head32prints on the paper surface by spring ink droplets in a condition close to the thermal expansion sheet17while being driven by a motor42via the toothed driving belt35and the carriage31. By repeating this intermittent conveyance of the thermal expansion sheet17and the printing during back-and-forth movement by the print head32in this manner, printing is accomplished on the entire surface of the thermal expansion sheet17.

When printing by overlaying full-color printing on a white coating as described below, the white-printed thermal expansion sheet17is conveyed in the reverse direction of the printing auxiliary scanning direction indicated by the arrow e, and full-color printing is then accomplished while this sheet is again conveyed in the direction of the arrow e.

FIG. 3is a circuit block diagram including the control device of the three-dimensional printing device1having the above-described composition. As shown inFIG. 3, the circuit block is centered on a CPU (central processing unit)45, and an I/F_CONT (interface controller)46, a PR_CONT (printer controller)47and an image cutting unit48are connected via respective data buses to this CPU45.

A printer printing unit49is connected to the above-described PR_CONT47. In addition, the image cutting unit48is connected in the other direction to the I/F_CONT46also. In this image cutting unit48, an image processing application similar to those loaded in a personal computer and/or the like is loaded.

A ROM (read only memory)51, an EEPROM (electrically erasable programmable ROM)52, an operation panel53of a main body operation unit and a sensor unit54into which output from sensors positioned in various units is input are connected to the CPU45. The ROM51stores system programs. The operation panel53is provided with a touch-type display screen.

The CPU45reads a system program stored in the ROM51and accomplishes processing by controlling each unit in accordance with the system program read.

That is to say, in each unit, first the I/F_CONT46converts print data supplied from host equipment such as a personal computer, for example, into bitmap data and deploys this to a frame memory55.

In the frame memory55, memory areas are set up corresponding to the print data of the black toner K and the respective print data of the white W, cyan C, magenta M and yellow Y colored ink, and the print data of images in each of the above-described colors are deployed to this memory area. The deployed data is output to the PR_CONT47and is output from the PR_CONT47to the printer printing unit49.

The printer printing unit49is an engine unit, and under control from the PR_CONT47controls the impressed voltage on the photosensitive drum11of the solid image printing unit2shown inFIG. 1, the rotational drive system including the primary transfer roller14, the initializing charger omitted from the drawing inFIG. 1and the image creation unit9having driven units such as read/write heads and/or the like, and the process load such as driving of the transfer belt6and the fixing unit21.

Furthermore, the printer printing unit49controls driving of the four sets of conveyor roller pairs26in the thermal expansion processing unit3shown inFIG. 1and light-emitting driving of the heat and light radiation unit27, and the timing thereof. Furthermore, the printer printing unit49further controls the actions of each part of the ink jet printer unit4shown inFIGS. 1 and 2.

Furthermore, the image data in black toner K output from the PR_CONT47is supplied to an optical writing head omitted from the drawing in the image creation unit9of the solid image printing unit2shown inFIG. 1from the printer printing unit49.

In addition, the respective image data of the white W, cyan C, magenta M and yellow Y color ink output from the PR_CONT47is supplied to the print head32shown inFIG. 2.

FIGS. 4A,4B and4C are drawings showing a basic overview for creating a three-dimensional surface on the thermal expansion sheet17in a first embodiment of the three-dimensional printing device1having the above-described composition.FIG. 4Ais a drawing showing the composition of the thermal expansion sheet17used in Embodiment 1,FIG. 4Bis a drawing explaining the principle of processing by selectively foaming and causing partial bulging of the thermal expansion sheet17, andFIG. 4Cis a cross-sectional view showing the processing results.

As shown inFIG. 4A, the thermal expansion sheet17is composed of a base material56, and a foaming resin layer57including a thermal foaming agent coated on this base material56. The base material56is not particularly limited in the type of substance used, and may be composed of paper, a cloth such as canvas cloth and/or the like, or a panel material such as plastic and/or the like. For the thermal expansion sheet17composed of this base material56and the foaming resin layer57including a thermal foaming agent, it is possible to use a commonly known product available in the market (for example, one sold by Matsumoto Yushi-Seiyaku Co. Ltd. of Japan).

A below-described black toner solid image58is printed in the solid image printing unit2ofFIG. 1in the part where the foaming resin layer57of this thermal expansion sheet17is to become three-dimensional. Furthermore, the surface of the foaming resin layer57of the thermal expansion sheet17on which the black toner solid image58is printed is heated by a heat-source heater59, as shown inFIG. 4B.

FIG. 4Bis a drawing showing a basic overview, and although the composition differs from that of the thermal expansion processing unit3shown inFIG. 1, the principle is the same. That is to say, as shown inFIG. 4Bthe thermal expansion sheet17is anchored by being mounted on a mounting stand61, the surface on which the black toner solid image58is printed facing upward.

Guide grooves62(62a,62b) are formed on both side ends of the mounting stand61, and following these guide grooves62, heat-source heater support pillars63(63a,63b) capable of moving back and forth as indicated by a bidirectional arrow f are established.

The heat-source heater59supported on both ends by these heat-source heater support pillars63moves in accordance with the movement of the heat-source heater support pillars63, while emitting thermal radiation to the surface of the foaming resin layer57of the thermal expansion sheet17. That is to say, while the thermal expansion sheet17and the heat-source heater59are moving relative to each other, thermal radiation is emitted toward the surface of the foaming resin layer57.

Through this, the black toner solid image58absorbs the thermal radiation and transmits that heat to the thermal foaming agent included in the foaming resin layer57, and the thermal foaming agent causes a thermal expansion reaction, so that the part G on which the black toner solid image58is printed in the thermal expansion sheet17expands and rises.

In this manner, the printing surface of the thermal expansion sheet17that has been heated by the heat-source heater59becomes three-dimensional, only the foaming agent of the part G that has been printed with black toner foaming due to the difference in heat absorption rates between the part G on which black toner in printed and a part H on which such has not been printed.

The above-described heat-source heater in the present example is a heat and light radiation unit27composed of a halogen lamp27aand a reflective mirror27bas described above, and the above-described relative motion of the thermal expansion sheet17and the heat-source heater59in the thermal expansion process unit3of the present example is accomplished by the heat and light radiation unit27being anchored and the thermal expansion sheet17moving by being conveyed by the conveyor roller pair26.

FIGS. 5A to 5Gare drawings for explaining the processing procedures of three-dimensional image printing executed by the control device of the three-dimensional printing device1having the above-described composition. The CPU45of the control device first takes in image data of a digital image photographing a three-wheeled motorcycle65stopped on a road with two large roadside trees64(64a,64b) in the background, for example as shown inFIG. 5A, as original image data from the outside, through the I/F_CONT46.

Next, through the image cutting unit48the CPU45cuts off the images of the three-wheeled motorcycle65and the two roadside trees64(64a,64b) that are the images selected and indicated as parts to be made three-dimensional from the original image data via the operation panel by a user of the three-dimensional printing device1, as shown inFIG. 5B. This cutting of the desired image is prepared with a general image processing application at present.

In addition to cutting the selected part manually as described above, image cutting includes automatically cutting by setting a threshold value for remote data on the order of two stages and setting a high-low difference because remote data is included in the image shot by the three-dimensional camera, for example.

Next, the CPU45converts the above-described cut-out image into a solid black image66, as shown inFIG. 5C. Conversion to this solid black image66can also be easily executed by an image processing application loaded in the image cutting unit48.

The image data of this solid black image66is sent to the printer printing unit49via the I/F_CONT46and the PR_CONT47. The printer printing unit49controls the solid image printing unit2and prints the solid black image66on the surface of the thermal expansion sheet17, as shown inFIG. 5D.

Printing of the solid black image66in the present example consists of printing with black toner through an image creation device having an electronic photography format, but this may also be done by printing in black ink using an ink jet printer.

Next, the CPU45controls the thermal expansion processing unit3, projects heat and light rays68as shown inFIG. 5Eby means of the heat and light radiation unit27toward the thermal expansion sheet17conveyed by the four sets of conveyor roller pairs26, and causes the solid black image printing part G (the solid black image66inFIG. 5E) to expand, as shown inFIG. 4C.

Next, the CPU45controls the ink jet printer unit4and prints solid white67, as shown inFIG. 5F, by white W colored ink in the cartridge33wonto the surface of the thermal expansion sheet17whose solid black image66part has risen.

Next, the CPU45drives the paper supply roller pair39and the paper discharge roller pair41in reverse, conveying the thermal expansion sheet17on which solid white was printed in a direction opposite that of the printing auxiliary scanning direction indicated by the arrow e. Furthermore, while again being conveyed in the direction of the arrow e, full-color printing is accomplished on the surface of the thermal expansion sheet17whose entire surface became solid white67, including the risen portion of the solid black image66part.

With this process, printing is accomplished on the basis of the former original image from which selection pieces were cut off, using cyan C, magenta M and yellow Y colors in of the ink cartridges33c,33mand33y.

The thermal expansion sheet17on which full color printing has finished is discharged onto the paper discharge tray29via the medium discharge opening28.FIG. 5Gshows a three-dimensional image discharged onto the paper discharge tray29.

This three-dimensional image is such that the two roadside trees64aand64band the three-wheeled motorcycle65rise more than the other parts, although such is not definitely visible in the drawing. Furthermore, because printing of the image occurred after this rising, there is no cracking such as cracking of the risen part.

In the present embodiment, the surface of the thermal expansion sheet17is uneven due to the risen part of the solid black image66part, so as the printing method at least when accomplishing full-color printing, an ink jet recording method capable of printing without contact on the uneven surface is preferably used.

In addition, in the above-described Embodiment 1, as an after process a varnish coating and/or the like may be applied either manually or automatically by the printer to the surface of the thermal expansion sheet17after printing has finished in order to impart luster.

FIGS. 6A to 6Care drawings showing the basic principle of the process in Embodiment 2, in the three-dimensional printing device1.FIG. 6Ais a planar view of the thermal expansion sheet17with the surface having the foaming resin layer57on top andFIG. 6Bis a cross-sectional view taken along line A-A′. On the surface of the foaming resin layer57, the concentration of the black printing changes, so that a solid black image71and a solid gray image72are printed.

Because the concentration of black differs between the solid black image71and the solid gray image72, the heat absorbency differs as well. Accordingly, when the heating and foaming process is conducted on this thermal expansion sheet17, the part L of the solid black image71of the foaming resin layer57rises greatly through thermal expansion, as shown inFIG. 6C.

Furthermore, the part N of the solid gray image72rises through thermal expansion but rises less than the part L of the solid black image71, so overall a two-level three-dimensional object is obtained. In this explanation of the basic principle, two levels are used, but this is not limited to two levels. If the concentration of black is three or more levels, a three-dimensional object of three or more levels can be obtained.

FIG. 7is a figure in which the image cut out from the digital original image data shown inFIG. 6Ais converted into two-level solid concentration image data of solid gray and solid black when accomplishing two-level three-dimensional printing on an image, and is an image in which that two-level solid concentration image is printed on the thermal expansion sheet17. The process procedures thereafter are the same as in Embodiment 1.

In this embodiment, the motorcycle as a whole becomes three-dimensional and by having a black printing part of high concentration, the tire part, tank part, spokes part and headlight part are further made three-dimensional along with the central leafy part of the roadside trees, thereby making such jump forward and be emphasized, as shown inFIG. 7.

In the embodiments of the present invention for creating three-dimensional printed objects, with the above-described embodiments an example was explained of a three-dimensional printing device1in which a device body illustrated as a solid image printing unit2in the bottom-most part, a thermal expansion processing unit3above such, and an ink jet printer unit4in the top-most part are integrated, as shown inFIGS. 1 to 3, but these various parts may be respectively independent devices, and a printing system may be comprised by linking these various devices.

That is to say, in the above-described embodiments the image cutting unit48is provided in the solid image printing unit2, but these processes may be accomplished by host equipment such as a personal computer, and the solid image printing unit2and the ink jet printing unit4may respectively be a stand-alone electronic photography printer and ink jet printer, and a system may be composed with the thermal expansion processing unit3also an independent device.

In this case, it is possible to compose the system by linking the various devices that should execute the procedures for creating the three-dimensional printed material, and naturally human intervention between the various procedures is possible.