JPH10207194A - Laminate molding method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate molding method and device capable of precisely molding a three-dimensional object at a high speed, coloring an object and further, molding the object including ceramics and metal except resin as well. SOLUTION: An electrostatic latent image 2 is formed on the surface of a dielectric 1, based on arbitrary cross-sectional shape data of the three- dimensional object. Then, the electrostatic latent image 2 is developed with electrifiable powder 3 and the electrifiable powder 3 is formed like a sheet. The sheet-like electrifiable powder is transferred to a stage. Each of these processes is repeated to laminate the sheet-like electrifiable powder on the stage, so that the three-dimensional object is molded. Further, after the process of developing the electrostatic latent image with the electrifiable powder, the process of transferring this powder to an intermediate transfer body adjacent to the dielectric and forming the electrifiable powder like the sheet on the intermediate transfer body can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional object forming method for forming a three-dimensional object by stacking thin layers formed by forming powder into a sheet shape, and an apparatus therefor.

[0002]

2. Description of the Related Art The lamination molding method has rapidly spread in recent years as a method for molding a three-dimensional object having a complicated shape in a short time. A three-dimensional object created by the additive manufacturing method is used as a model (prototype) of a part of various devices to check the operation and shape of the part. There are various types of additive manufacturing methods, for example, which are described in detail in a special article of "Die Technology", February 1996, published by Nikkan Kogyo Shimbun.

[0003] Specifically, for example, FIG. 11 is a schematic view of a molding method generally referred to as "optical molding method". A laser filled from a top surface is filled with a photo-curable resin which is cured by irradiation with light such as ultraviolet rays. The beam performs two-dimensional scanning in accordance with the cross-sectional shape data of the three-dimensional object, forms a thin layer of cured resin, and forms a three-dimensional object by repeating this process.

FIG. 12 shows a method called a “powder method”, in which a tank in which a thin powder layer is formed is irradiated with laser light to sinter the powder layer into a thin layer having a desired shape. By repeating this process, a three-dimensional object made of a sintered body is formed. According to this method, not only resin but also ceramics and metal can be formed as a three-dimensional object.

FIG. 13 shows a method called “solid base curing method” in, for example, Japanese Patent Application Laid-Open No. 6-55642.
A mask pattern is formed based on the cross-sectional data of the object, the mask is superimposed on the resin layer coated with the photo-curable resin, irradiated with ultraviolet light, and after being sufficiently exposed, the uncured (unexposed portion) resin layer After the wax is filled in the recesses formed by removing the photocurable resin, the wax is cooled, and the hardened resin layer and the wax are repeatedly cut to a predetermined thickness to obtain a desired shape. The three-dimensional model is formed.

[0006]

However, in the stereolithography method, a disadvantage caused by using a liquid called a photocurable resin is that the resolution in the thickness direction is only about 0.2 mm.
In some cases, the time required for the liquid surface to stabilize is long and the productivity is poor. In addition, the use of high-power lasers causes defects such as rapid deterioration of the light source itself and the scanning optical system, difficulty in controlling the energy density and beam diameter, and the amount of deformation due to shrinkage of the photocurable resin during final curing. However, there is a drawback that the accuracy of an object formed large is poor.

[0007] In the powder method, similarly, a problem relating to a high-power laser is also serious. Particularly, a sintering characteristic in the depth direction is not stable, and a molding accuracy in the depth direction is poor. There was a problem that it was difficult to obtain. There is also a disadvantage that it takes time to uniformly spread the powder in the tank and productivity is poor.

[0008] On the other hand, in the solid base curing method, noise is generated in the step of sucking the excess photocurable resin, the resin in the finely shaped portion is sucked in, or the excess resin is left in the details. Therefore, there is a problem that it is difficult to obtain a highly accurate model. Also, since the surface is cut after applying wax, even if a new photocurable resin layer is applied on top of it, the adhesion performance of the upper and lower layers deteriorates, the problem that the final object is easily broken and the equipment is large-scale There is a problem that energy consumption is large.

Further, when checking the design of an apparatus or a part, not only the shape of the object but also the color is often considered.
There are only a few ways to make it possible to color the model. JP-A-7-
In 205551, three types of microcapsules containing a pigment that develops a color only when exposed to a specific wavelength are prepared, and a thin layer made of a mixture of these is sequentially irradiated with laser beams of three types of wavelengths. Is described. However, since this method also belongs to the category of the powder method, it has the problems of the powder method described above.

[0010] The present invention has been made in view of the above-mentioned circumstances, is capable of forming a three-dimensional object with high accuracy and high speed, and is capable of coloring an object in color. It is an object of the present invention to provide an additive manufacturing method and an apparatus therefor, which enable the shaping of an object including the same.

[0011]

According to a first aspect of the present invention, there is provided an additive manufacturing method for forming an electrostatic latent image on a dielectric surface based on arbitrary cross-sectional shape data of a three-dimensional object. A step of developing the electrostatic latent image with a chargeable powder, a step of forming the chargeable powder into a sheet, and a step of transferring the sheet-like chargeable powder to a stage, The method is characterized in that a three-dimensional object is formed by repeatedly stacking sheet-shaped chargeable powder on a stage by repeating each process.

According to the above method, the chargeable powder corresponding to the arbitrary cross-sectional shape data of the three-dimensional object is once formed into a sheet by the sheet forming step. Combined as a single sheet, the density of the object increases and the strength improves, so it is possible to prevent shape collapse during lamination,
A three-dimensional object excellent in accuracy and strength can be formed. In addition, an electrophotographic method can be applied to the step of forming an electrostatic latent image and the step of developing with a chargeable powder, and one section of a three-dimensional object can be formed at high speed.

According to a second aspect of the present invention, there is provided the additive manufacturing method according to the first aspect, wherein a powder made of a thermoplastic resin is used as the chargeable powder, and the step of forming the chargeable powder into a sheet is performed. It is performed by heating.

According to the above method, since a powder made of a thermoplastic resin is used as the chargeable powder and heated, a part of the chargeable powder is melted and bonded to each other, thereby increasing the density of the object. It is formed into one sheet with improved strength. Furthermore, since the film thickness becomes uniform, the accuracy in the laminating direction can be improved, and the surface roughness is reduced, so that lamination and subsequent bonding can be made easy and strong. In addition, the chargeable powder can be arbitrarily selected from thermoplastic resins, and there is no need to use a special material unlike the conventional stereolithography.

[0015] According to a third aspect of the present invention, there is provided the additive manufacturing method according to the first aspect, wherein the thermoplastic resin is a powder containing a metal, ceramics, or a non-thermoplastic resin as the chargeable powder. The step of forming the chargeable powder into a sheet is performed by heating.

According to the above-mentioned method, a powder in which the thermoplastic resin contains metal, ceramics or non-thermoplastic resin is used as the chargeable powder, and the powder is heated. A part is melted and bonded to each other to form a single sheet whose strength is improved by increasing the density of the object. Accordingly, it is possible to form a three-dimensional object having these materials contained in the chargeable powder as a main component. Since the chargeable powder only needs to be insulative even on the surface of the powder, even if it is a non-chargeable material such as a metal, the surface of the chargeable powder is covered with a chargeable resin, so that the main component is a metal.
A three-dimensional object can be formed.

According to a fourth aspect of the present invention, there is provided the additive manufacturing method according to the first aspect, wherein a powder colored in an arbitrary color is used as the chargeable powder.

According to the above method, by using a powder obtained by coloring a resin powder with a pigment or the like as the chargeable powder, a three-dimensional object can be easily colored, and the three-dimensional object to be formed can be easily formed. The appearance of the object can be reproduced better.

According to a fifth aspect of the present invention, there is provided the additive manufacturing method according to the first aspect, wherein the chargeable powder contains a charge control agent.

According to the above method, the specific charge (charge amount / mass) of the chargeable powder can be controlled by introducing a charge control agent. This is nothing less than controlling the mass of the powder developed for a certain electrostatic latent image, so that the thickness of the chargeable powder layer formed on the dielectric after development can be controlled. The molding accuracy of the object can be maintained.

According to a sixth aspect of the present invention, in the method of the first aspect, the step of forming the chargeable powder into a sheet comprises the step of forming the chargeable powder into an intermediate transfer member adjacent to the dielectric. After the transfer to the intermediate transfer member.

According to the above method, the developed chargeable powder on the dielectric is temporarily transferred to the intermediate transfer member. By performing the above-described step of forming a sheet on the intermediate transfer member, it is possible to prevent the deterioration of the characteristics of the dielectric due to the step of forming the sheet (for example, heating).
The molding accuracy can be maintained. Further, if the connection between the dielectric and the intermediate transfer member is temporarily released, the dielectric and the intermediate transfer member do not need to move at the same speed during that time, and the latent image forming step and the developing step performed on the dielectric are not required. And the sheet forming step and the transfer step performed on the intermediate transfer member can be performed independently at different speeds.

According to a seventh aspect of the present invention, in the method of the first aspect, the step of forming the chargeable powder into a sheet comprises the step of forming the chargeable powder into an intermediate transfer member adjacent to the dielectric. After repeating the step of transferring to the intermediate transfer member a plurality of times, the process is performed once on the intermediate transfer member.

According to the above method, a thick chargeable powder layer can be formed at a time, so that the thickness of the sheet-like chargeable powder formed in a sheet can be increased, and the molding speed of a three-dimensional object can be increased. become. In particular, the present invention can be applied to a region where a change in the cross-sectional shape of a three-dimensional object is small. When this method is applied to different types of chargeable powders or chargeable powders of different colors, each chargeable powder is developed in a desired amount in a development step, and then transferred to the same area of the intermediate transfer body in an intermediate transfer step. By transferring, a plurality of types of chargeable powders can be overlaid on the area of the intermediate transfer body, and a mixed layer of chargeable powder having a desired mixing ratio is formed on the area. . Thereafter, in the sheet forming step, a mixed layer of the chargeable powder is formed in a sheet shape, and the sheet-like chargeable powder is sequentially laminated to obtain a composite material having a desired composition ratio or a full-color three-dimensional material. Objects can be shaped and characters and patterns can be drawn.

According to an eighth aspect of the present invention, there is provided the additive manufacturing method according to the sixth or seventh aspect, wherein at least the surface of the chargeable powder is covered with a thermoplastic resin. Is formed on the intermediate transfer member by heating and pressing a heat roll.

According to the above-mentioned method, the chargeable powder is formed into a sheet having good smoothness by heating and pressurizing the heat roller, so that the lamination becomes easier and stronger, and the heat radiation is performed. By defining the distance between the roller and the surface of the intermediate transfer member, it is possible to accurately define the film thickness of the chargeable powder formed in a sheet shape, and to improve the molding accuracy in the laminating direction.
At this time, since the heating and pressurizing are performed on the intermediate transfer member, it is possible to prevent the deterioration of the characteristics of the dielectric material regarding the formation of the latent image.

According to a ninth aspect of the present invention, there is provided an additive manufacturing apparatus, comprising: a dielectric; a latent image forming means for forming an electrostatic latent image on the dielectric based on arbitrary cross-sectional shape data of the three-dimensional object; Developing means for housing the body, charging the chargeable powder, and developing the dielectric having the electrostatic latent image with the chargeable powder; and a sheet for forming the chargeable powder into a sheet. It is characterized by comprising a forming means, a movable stage for mounting a three-dimensional object, and a transfer means for transferring the sheet-shaped chargeable powder to the stage.

According to the above-described apparatus, the chargeable powder corresponding to the arbitrary cross-sectional shape data of the three-dimensional object is formed in a sheet shape, and the three-dimensional object is laminated after the strength is improved by increasing the density of the object. In addition, it is possible to prevent shape collapse at the time of lamination, and it is possible to form a three-dimensional object excellent in accuracy and strength by sequentially laminating the sheet-shaped chargeable powder. In addition, as a configuration for forming an electrostatic latent image and developing it with a chargeable powder, a configuration used in electrophotography can be applied. Can be achieved.

According to a tenth aspect of the present invention, there is provided the additive manufacturing apparatus, comprising: a dielectric;
A latent image forming means for forming an electrostatic latent image based on arbitrary cross-sectional shape data of the three-dimensional object on the dielectric; storing a chargeable powder to charge the chargeable powder; Developing means for developing the dielectric having a latent image with the chargeable powder, an intermediate transfer member adjacent to the dielectric, and transferring the chargeable powder transferred to the dielectric surface to the intermediate transfer member An intermediate transfer means, a sheet forming means for forming the chargeable powder on the intermediate transfer body into a sheet, a movable stage for placing a three-dimensional object, and the sheet-like chargeable powder. And a transfer means for transferring to a stage.

According to the above-mentioned apparatus, by newly providing the intermediate transfer member and the intermediate transfer means, the chargeable powder on the dielectric is temporarily transferred to the intermediate transfer member, and then heated or heated by the sheet forming means. Since they are joined in a sheet shape by pressing or the like, deterioration of the characteristics of the dielectric can be prevented, and the molding accuracy can be maintained. Also, if the connection between the dielectric and the intermediate transfer body is temporarily released, the dielectric and the intermediate transfer body do not need to move at the same speed during that time, and a latent image formation and development performed on the dielectric, Seek performed on the intermediate transfer member
The transfer to the stage and the transfer to the stage can be performed independently at different speeds.

According to an eleventh aspect of the present invention, there is provided the lamination molding apparatus according to the ninth or tenth aspect, wherein the dielectric is made of a photoreceptor, and the latent image forming means is configured to uniformly charge the photoreceptor. It is characterized by comprising charging means and exposure means for selectively irradiating the photosensitive member with light based on arbitrary cross-sectional shape data of the three-dimensional object.

According to the above-mentioned apparatus, since the photoreceptor is used as the dielectric, the initial charging means for forming an electrostatic latent image on the dielectric based on arbitrary cross-sectional shape data of the three-dimensional object. In addition, parts having a good track record in a dry copying machine or the like can be used as the exposure means, so that the apparatus can be practically used and the cost of the apparatus can be reduced.

According to a twelfth aspect of the present invention, there is provided an additive manufacturing apparatus.
In the above-described additive manufacturing apparatus, the exposure means performs light irradiation by scanning with a laser beam.

According to the above-mentioned apparatus, since a laser beam which is used for forming an electrostatic latent image in a digital copying machine, a laser beam printer or the like and has a long track record is used,
It is practical, can reduce the cost of the apparatus, and can perform high-speed drawing.

According to a thirteenth aspect of the present invention, there is provided the additive manufacturing apparatus according to the ninth or tenth aspect, further comprising a plurality of developing means, and a selecting means capable of selecting any of the developing means. And

According to the above apparatus, different charging powders are stored in the respective developing means, and an arbitrary developing means is selected to develop the electrostatic latent image formed on the dielectric material. It is possible to instantaneously switch the image formation using different kinds of chargeable powders or different colors of chargeable powders, or to form a three-dimensional object by arbitrarily mixing a plurality of kinds of chargeable powders.

According to a fourteenth aspect of the present invention, there is provided the additive manufacturing apparatus according to the tenth aspect.
The apparatus according to claim 1, further comprising a plurality of powder layer forming transfer units each including a dielectric, a latent image forming unit, a developing unit, and an intermediate transferring unit, wherein the charge formed in each of the powder layer forming transfer units is provided. The powder layer forming transfer units are arranged so that an image of a powdery material is continuously transferred to a common intermediate transfer member.

According to the above-mentioned apparatus, each of the powder layer forming and transferring sections is arranged so that the image of the chargeable powder formed in each of the powder layer forming and transferring sections is continuously transferred to the common intermediate transfer member. Therefore, a three-dimensional object can be formed at an extremely high speed by arbitrarily mixing chargeable powders of different materials and powders of different colors.

According to a fifteenth aspect of the present invention, there is provided the additive manufacturing apparatus.
In the above described additive manufacturing apparatus, the intermediate transfer body is made of polyimide as a base material, and the surface thereof is coated with a silicone resin or a fluorine resin.

According to the above-described apparatus, since the intermediate transfer member is made of polyimide resin, the intermediate transfer member is excellent in insulation and durability, and is resistant to expansion and contraction and can withstand high temperatures. Furthermore, since the surface of the polyimide resin is coated with a silicone resin or a fluororesin as a release agent, it does not adhere to the sheet-like chargeable powder and has good mold release properties. The conductive powder can be easily transferred.

According to a sixteenth aspect of the present invention, there is provided the additive manufacturing apparatus according to the tenth aspect.
In the above-described lamination modeling apparatus, the chargeable powder is a powder having at least a surface covered with a thermoplastic resin, and the sheet forming unit includes a pair of heat rolls disposed so as to sandwich the intermediate transfer member. It is characterized in that it has roll interval changing means for changing the interval between heat rolls.

According to the above-described apparatus, the chargeable powder on the intermediate transfer member is formed into a sheet having good smoothness by heating and pressing the heat roll, so that the lamination becomes easier and stronger, and the heat transfer is performed. Since the distance between the rolls can be changed, the thickness of the chargeable powder formed in a sheet shape can be accurately defined, and the molding accuracy in the stacking direction can be improved.

According to a seventeenth aspect of the present invention, the stage is movable at the same speed in the same direction with respect to the movement of the dielectric or the intermediate transfer member. It is characterized by having.

According to the above-described apparatus, when the sheet-shaped chargeable powder is transferred to the three-dimensional object on the stage, the stage itself can move at the same speed in the same direction as the dielectric or the intermediate transfer member. The stage and the dielectric or intermediate transfer body can be in contact with each other for a sufficient period of time, and there is no need to temporarily stop the dielectric or intermediate transfer body. Becomes

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the additive manufacturing method according to the present invention will be described with reference to the drawings. FIG. 1 is a conceptual explanatory view showing each step in the additive manufacturing method of the present invention. According to the additive manufacturing method of the present invention, a step of forming an electrostatic latent image on a dielectric surface based on arbitrary cross-sectional shape data of a three-dimensional object, and a step of developing the electrostatic latent image with a chargeable powder Forming the chargeable powder into a sheet, and transferring the sheet-like chargeable powder to a stage, and repeating these steps to stack the sheet-like chargeable powder on the stage. By doing so, a three-dimensional object is formed.

That is, in each of the above steps, first, a two-dimensional electrostatic latent image 2 corresponding to an arbitrary cross-sectional shape data of a three-dimensional object is placed on a dielectric 1 having a certain depth in the front and back directions of the paper.
Is formed (FIG. 1A). Next, a developing means 4 containing the chargeable powder 3 is prepared, and the chargeable powder 3 charged therein is developed near the latent image 2 on the dielectric 1 to develop the entire latent image. The surface is charged with the chargeable powder 3 (FIG. 1B). Subsequently, as a step of forming the chargeable powder into a sheet shape, for example, when a powder of a thermoplastic resin is used as the chargeable powder 3, when the surface of the dielectric 1 is pressed by the heat roll 6, a predetermined process is performed. The charged powder 3 is rolled into the gap between the dielectric 1 and the heat roll 6 and the powder is combined into a sheet to form one sheet-shaped charged powder 3 '(FIG. 1 (c)). )). Then, the stage 7 for mounting the three-dimensional object is raised, pressed on the sheet-shaped chargeable powder 3 ′, and laminated on the lower part of the already formed three-dimensional object 8 (FIG. 1D). By repeating the above steps, a desired three-dimensional object is finally formed.

The sheet-form chargeable powder 3 'formed in the form of a sheet is combined as a single sheet, and the strength is improved by increasing the density of the object. can do. Also, the heat roll 6 and the dielectric 1
By preliminarily defining the interval, the film thickness of the sheet-like chargeable powder 3 'formed by heating and pressurizing the heat roll 6 can be accurately defined, thereby improving the accuracy in the laminating direction. In addition, since the surface roughness can be reduced, the lamination and subsequent joining can be easily and firmly performed. Therefore, by laminating the sheet-shaped chargeable powder 3 ', a three-dimensional object having excellent accuracy and strength can be formed.

As a method of forming the thermoplastic resin powder into a sheet, in addition to a method of heating and pressurizing with a heat roll, a method of radiating heat from a lamp heater or heating with a hot air of a dryer, etc. Can be considered. In these cases,
Since the thermoplastic resin powder is melted by heating to fill the gap between the powders, the density of the object is increased, the strength is improved, and the shape collapse at the time of lamination can be prevented. Also, at this time, the surface of the chargeable powder layer on the dielectric side is smooth because it follows the surface of the dielectric, and one surface side is smooth due to the surface tension of the molten resin. Can be easy and robust.

The step of forming an electrostatic latent image and the step of developing with a chargeable powder can employ an electrophotographic method, and can form one section of a three-dimensional object at high speed. Further, when a chargeable powder containing ceramics, metal, or the like in a chargeable resin is used, it is possible to form a three-dimensional object containing these materials as main components. Further, by coloring the chargeable powder, it is possible to color the three-dimensional object.

Next, an example of an embodiment of the additive manufacturing apparatus according to the present invention will be described with reference to the drawings. FIG. 2 is a configuration explanatory view of the additive manufacturing apparatus according to the present invention.
The additive manufacturing apparatus shown in FIG.
A latent image forming means 15 for forming an electrostatic latent image based on arbitrary cross-sectional shape data of a three-dimensional object, a chargeable powder stored therein, the chargeable powder is charged, and the electrostatic latent image is formed. Developing means 10 for developing the above-mentioned dielectric 11 with a chargeable powder
Forming means 1 for forming a chargeable powder into a sheet shape
4 and movable stage 7 for mounting a three-dimensional object
And a transfer means 16 for transferring the sheet-shaped chargeable powder to the stage. The developing means 10 includes a developing device 12 for storing the chargeable powder and charging the chargeable powder.
And a developing power supply 13 for applying a high voltage to the developing device 12.

According to the above-described additive manufacturing apparatus, the chargeable powder formed on the dielectric 11 based on the cross-sectional shape data of the three-dimensional object is used as the sheet forming means 14 by, for example, the dielectric 1.
When a pair of heat rolls arranged so as to sandwich them are used, they are combined as a single sheet in the sheet forming means 14 and the strength is improved by increasing the density of the object. Can be prevented. Also, by defining the interval between the heaters in advance, the heater
The thickness of the sheet-like chargeable powder 3 'formed by heating and pressurizing the film can be accurately defined, the accuracy in the laminating direction can be improved, and the surface roughness can be reduced. Therefore, lamination and subsequent joining can be easily and firmly performed. Therefore, this sheet-like chargeable powder 3 '
By stacking, a three-dimensional object having excellent accuracy and strength can be formed.

As the configuration for forming the electrostatic latent image and developing with the chargeable powder, the configuration used in electrophotography can be applied, and one section of a three-dimensional object can be formed at high speed. Further, when a chargeable powder containing ceramics, metal, or the like in a chargeable resin is used, it is possible to form a three-dimensional object containing these materials as main components. Further, by coloring the chargeable powder, it is possible to color the three-dimensional object.

Hereinafter, specific examples of each configuration will be described. The dielectric 11 may be basically an insulator. For example, a flexible sheet-shaped insulating belt is used.
The latent image forming means 15 may be a means for applying a high voltage to an array of needle electrodes (multi-stylus head) to induce electrostatic charges on the dielectric surface by discharging, or a means for spraying an ion stream on / off by a modulation electrode. (Ionography) In the case where a photoreceptor is used as the dielectric 11, there are means for selectively irradiating light and charging based on data on the cross-sectional shape of the three-dimensional object. 11 can be arbitrarily selected. As a configuration that has been used in electrophotography and the like, a photoconductor is used as the dielectric 11 and an initial charging unit that uniformly charges the photoconductor is used as the latent image forming unit 15. It is more practical to use one having an exposure means for selectively irradiating light based on the light. As the developing device 12,
A container or the like capable of frictionally charging the chargeable powder while stirring the chargeable powder inside is applicable. As the developing power supply 13, a high-voltage DC power supply of several hundred V to several kV or a power supply in which an alternating voltage is superimposed thereon can be used.

When a thermoplastic resin powder is used as the chargeable powder, the sheet forming means 14 may be any as long as the chargeable powder can be formed into a sheet by pressure or heating. In addition to the configuration in which heating and pressurization are performed by a pair of heat rolls, a configuration in which heating is performed by radiant heat of a lamp heater or warm air of a dryer can be considered. In particular, when a pair of heat rolls is used, Further, if a means for changing the interval between the heat rolls is provided, the film thickness of the sheet-shaped chargeable powder to be formed can be accurately defined according to the application, and the thickness in the stacking direction can be increased. The molding accuracy can be improved, which is preferable. As the stage 7, a stage capable of mounting a three-dimensional object and having a mechanism capable of moving at least in the vertical direction on the paper can be used. As the transfer unit 16, a unit capable of applying heat or electrostatic force to press and transfer a new sheet to the uppermost layer of the three-dimensional object can be used.

Next, another embodiment of the additive manufacturing apparatus according to the present invention will be described with reference to FIG. FIG. 3 differs from FIG. 2 in that an intermediate transfer member 18 that moves adjacent to the dielectric 11 in the same direction and at the same speed and that the chargeable powder that has moved to the surface of the dielectric 11 is transferred to the intermediate transfer member 18. This is the point that the intermediate transfer means 19 is newly provided. The image of the chargeable powder formed on the dielectric 11 is temporarily transferred to an intermediate transfer member 18 by an intermediate transfer unit 19, and is formed into a sheet on the intermediate transfer member 18 by a sheet forming unit 14. As the intermediate transfer member 18, for example, a dielectric belt based on a polyimide film is suitable.
As the intermediate transfer unit 19, a discharge device such as a corotron is applicable.

According to the above-described additive manufacturing apparatus, the intermediate transfer member 1
8 and the intermediate transfer means 19 are newly provided, so that the chargeable powder on the dielectric 11 is once transferred to the intermediate transfer body 18, and then heated or pressed by the sheet forming means 14 to form a sheet. Since the coupling is performed, it is possible to prevent the deterioration of the characteristics of the dielectric 11 with respect to the formation of the latent image, and to maintain the modeling accuracy. Further, if the connection between the dielectric 11 and the intermediate transfer body 18 is temporarily released, the dielectric 11 and the intermediate transfer body 18 do not need to move at the same speed during that time, and the latent image formed on the dielectric 11 is not required. Formation and development, and sheet formation on the intermediate transfer body and transfer to the stage 7 can be performed independently at different speeds.

Hereinafter, more specific embodiments of the additive manufacturing method and apparatus according to the present invention will be described with reference to the drawings. (Embodiment 1) An embodiment of an additive manufacturing method and apparatus according to the present invention will be described with reference to FIG. First, as a dielectric,
A photosensitive drum 17 similar to that used in a copying machine or a printer using an electrophotographic method is prepared. An electrostatic latent image is formed on the photosensitive drum 17 by a latent image forming means 15 including a corotron 21 as an initial charging means and a laser beam 22 as an exposure means. First, the corotron 2 is rotated while rotating the photosensitive drum 17.
1, the photosensitive drum 17 is uniformly charged initially. Here, an organic photoreceptor was used and charged to a surface potential of about -700V. Next, when the laser beam 22 is modulated and scanned in accordance with the cross-sectional shape data of the three-dimensional object, photocharge is generated on the photosensitive drum 17 in the portion irradiated with the laser beam, and the initial charge is neutralized. Therefore, an electrostatic latent image is formed on the surface of the photosensitive drum 17 according to the cross-sectional shape data of the three-dimensional object. (FIG. 4 (a)). As the exposure means, a one-dimensional light-emitting diode array or a one-dimensional liquid crystal shutter array (so-called image bar) may be used instead of laser beam modulation / scanning.

Next, a developing device 12 for storing the charged powder and charging the powder is prepared. The developing unit 12 has a developing power source 1
3 are connected to form the developing unit 10. As the chargeable powder, a powder obtained by pulverizing a thermoplastic resin (mainly composed of polystyrene, butadiene, polyester, or the like) to a diameter of 10 μm to several hundred μm may be used. In order to increase the film thickness of the layer, it is preferable to use a material having a large particle size. When importance is placed on the accuracy in the film thickness direction, it is preferable to use a material having a small particle size. Further, in order to increase or decrease the film thickness of one layer, the potential at the time of forming a latent image, the specific charge of the chargeable powder, or the voltage of the developing power source is changed without changing the particle diameter of the chargeable powder. By controlling, the number of stacked toners may be increased or decreased. In this embodiment, a powder having an average particle size of 50 μm was used.

The developing device 12 charged the chargeable powder 3 by mixing and storing the chargeable powder and the magnetic carrier and stirring the mixture inside. The mixture is brought close to the photosensitive drum 17 on which an electrostatic latent image is formed, and at the same time, a developing bias voltage of −500 V is applied to the developing device 12 from the developing power supply 13. The transfer is performed to the surface of the drum 17 and development is performed (FIG. 4B). In the present embodiment, by adjusting development parameters such as the charge amount and the developing bias voltage, three layers of the developed charged powder 3 were averagely laminated on the photosensitive drum 17.

Next, a dielectric belt 25 based on polyimide is prepared as an intermediate transfer member.
The charging powder 3 is transferred onto the dielectric belt 25 by a transfer charger 26 as an intermediate transfer means while rotating at the same speed in the same direction as the photosensitive drum 17 (FIG. 4 (c)). )). In the moving direction of the dielectric belt 25,
A pair of heat rolls 24 as sheet forming means are arranged, and the chargeable powder on the dielectric belt 25 is formed in a sheet shape (FIG. 4C). In the present embodiment, a rubber roll having a built-in heater at the center is used as a sheet forming means, the distance between the surface of the dielectric belt 25 and the heat roll on the upper side of the paper is set to 50 μm, and an average of three layers (about 150 μm) is used.
Was formed into a sheet-shaped chargeable powder 3 ′ having a thickness of 50 μm. As described above, by using a pair of heat rolls as the sheet forming means and defining the interval in advance, the film thickness of the sheet-like chargeable powder 3 'can be accurately defined. it can.

When the powder layer passes through the gap of 50 μm between the dielectric belt 25 and the heater 24 in the powder state, there are many gaps inside, and a part of the gap is melted and the gap becomes resin. And tightly bonded as one sheet. The gap between the surface of the dielectric belt 11 and the upper heat roll 24 needs to be set to an appropriate value because it depends on the particle size and the sphericity of the chargeable powder 3. It is desirable to set the thickness to 1/2 to 1/3 of the thickness of the conductive powder layer. If the thickness is set too narrow, the thickness of the sheet-shaped chargeable powder 3 'is crushed and becomes larger than the size of the latent image, so that the accuracy in the rolling direction deteriorates. 1/2 to 1 of the chargeable powder layer thickness
If it is set to / 3, the oversize amount of the sheet is about the particle size of the chargeable powder, so that in this embodiment, the accuracy in the rolling direction could be suppressed to about 50 μm. If higher accuracy is required, the oversize amount may be reflected in the exposure data and corrected to be smaller.

Finally, a stage 7 that can be moved up and down on the paper
And the stage 7 is pressed against the sheet-shaped chargeable powder 3 ′ on the dielectric belt 25, thereby laminating the sheet-like chargeable powder 3 ′ on the lower layer of the three-dimensional object 8 on the stage. (FIG. 4D). In this embodiment, the dielectric belt 25 is used.
A heater 27 as a transfer means was provided on the back surface, and the sheet-shaped chargeable powder 3 ′ was pressed and laminated on the lower layer of the three-dimensional object 8 by the heat. At this time, since the sheet-shaped chargeable powder 3 'and the lower layer of the three-dimensional object 8 are formed of the same resin,
Adhesion easily with some heating. On the other hand, the dielectric belt 25 is formed by applying a silicone resin as a release agent to the surface of the polyimide belt so that the sheet-like chargeable powder 3 'is easily peeled off. The transfer to the dimensional object 8 is facilitated.

By repeating the above steps for each of the cross-sectional shape data from the lowermost layer to the uppermost layer of the three-dimensional object, it is possible to form a three-dimensional object having a desired shape excellent in accuracy and strength. The configuration used to form an electrostatic latent image on the photoreceptor drum and develop it with a chargeable powder is applicable to the configuration used in electrophotography, and one section of a three-dimensional object can be formed at high speed. At the same time, the cost of the apparatus can be reduced. Specifically, a three-dimensional object having a length in the stacking direction of about 10 cm can be formed in a few hours.

(Embodiment 2) Another embodiment of the additive manufacturing method and apparatus according to the present invention will be described with reference to FIG. The difference from the first embodiment is that the thermoplastic resin 31 shown in FIG.
Is that a powder having a structure including the ceramics 32 is used as the chargeable powder 3. Alumina, silicon nitride, boron nitride and the like can be used as ceramics, and the particle size can be arbitrarily selected from 10 μm to several hundred μm. Since the surface of the chargeable powder 3 is coated with the thermoplastic resin 31 made of the same material as the thermoplastic resin shown in Example 1, the chargeability is exactly the same.

When the chargeable powder 3 is formed into a sheet, a pair of heat forming means as a sheet forming means described in the first embodiment is used.
When the roll 24 is used, the ceramic at the center is not deformed by heating or pressure, and only the thermoplastic resin 31 on the surface is melted and bonded. Therefore, the gap between the heat rolls 24 is formed by the chargeable powder layer. It is better to set it as wide as 1/2 to 3/4. The sheet-shaped chargeable powder formed in a sheet shape by the pair of heat rolls 24 is sequentially laminated to form a sheet.
Although a three-dimensional object can be formed at this stage, the three-dimensional object has a strength equivalent to that of a plastic resin. Therefore, once 3
If a three-dimensional object is formed and then sintered at a high temperature (not included in the present apparatus), an object having a complicated shape and excellent strength, such as a ceramic turbine, can be manufactured. At this time, if about 1% of zirconia powder coated with a thermoplastic resin is mixed in advance as a sintering aid, the effect of lowering the final sintering temperature and the effect of improving the fracture toughness value are exhibited.

Further, two or more different ceramics 3
2 is charged with a thermoplastic resin 31.
Are weighed in advance and mixed in the developing device 12, a ceramic mixture having a desired composition ratio can be formed. Also, if a chargeable powder containing a metal in the thermoplastic resin 31 is used instead of ceramics, a three-dimensional object mainly composed of a metal can be similarly formed. In this case as well, if a three-dimensional object is formed once and then sintered at a high temperature, an object excellent in strength and closer to the texture and electric characteristics inherent to the material can be formed.

(Embodiment 3) Another embodiment of the additive manufacturing method and apparatus according to the present invention will be described with reference to FIG. The difference from Examples 1 and 2 is that a thermoplastic resin powder colored with a pigment 33 or the like was used as the chargeable powder 3 as shown in FIG. Coloring a thermoplastic resin powder with a pigment or the like has a proven track record in toner coloring in color printers and the like, and can be easily performed by existing techniques. In the method using a photocurable resin described in the prior art, since the color of the three-dimensional object is determined by the color of the resin after curing, it is generally yellow or milky white, and it is difficult to change this. On the other hand, according to the present embodiment, it is possible to form a three-dimensional object colored in a desired color (for example, red, blue, yellow, or the like).

(Embodiment 4) Another embodiment of the additive manufacturing method and apparatus according to the present invention will be described with reference to FIG. The additive manufacturing apparatus shown in the figure includes a photosensitive drum 17 as a dielectric.
A latent image forming means 15 for forming an electrostatic latent image on the photosensitive drum 17; a plurality of developing devices 12 for storing and charging the charged powder; and a developing power supply for applying a high voltage to the developing devices 12 13 and an intermediate transfer member 18 adjacent to the photosensitive drum 17
An intermediate transfer means 19 for transferring the chargeable powder transferred to the surface of the photosensitive drum 17 to the intermediate transfer body 18; and a sheet forming means 14 for forming the chargeable powder on the intermediate transfer body 18 into a sheet. A movable stage 7 on which a three-dimensional object is placed, and a transfer unit 16 for transferring the sheet-shaped charged powder to the stage 7. Further, one of the plurality of developing devices 12 is provided. Arbitrarily selectable means 41. By the selecting means 41, the plurality of developing devices 12
By selecting one of these, the developing power supply 1
Reference numeral 3 denotes a developing unit 1 which is connected to the selected developing device 12 and develops the photosensitive drum 17 having an electrostatic latent image with the chargeable powder.
Since the value is 0, the additive manufacturing apparatus has the same number of the developing units 12 as the four developing units 10. Therefore, the same configuration is obtained when four developing power supplies 13 are provided and connected so as to correspond to each developing device 12.

Each of the four developing units 12 stores thermoplastic resin powder colored yellow (Y), magenta (M), cyan (C), and white (W) by a pigment, and forms a circumferential shape. The selection means 41 is arranged so that any one of the four developing devices 12 can be selected by rotating them. In the present embodiment, the photosensitive drum and laser beam scanning were used as the dielectric and latent image forming means, respectively, as in the first embodiment.

Hereinafter, a method of forming a full-color three-dimensional object using the above-described additive manufacturing apparatus will be described. In this embodiment, four colors of yellow, magenta, cyan, and white are blended in order to form each region with a desired color based on the cross-sectional shape data. The mixing ratio of the four colors is calculated in advance, and the potential when an electrostatic latent image developed by the chargeable powder of each color is formed in the latent image forming unit 15 is set in advance in accordance with the mixing ratio.

First, the latent image forming means 15 forms a latent image corresponding to the density distribution of yellow on the rotating photosensitive drum 17 based on color data relating to one cross-sectional shape data of the three-dimensional object. Then, the yellow (Y) developing device 12 is selected by the selection means 41 and developed with the yellow charging powder 3.
Next, the yellow chargeable powder 3 on the photosensitive drum 17 is transferred to the intermediate transfer member 18 by the intermediate transfer means 19. The yellow charging powder 3 on the intermediate transfer body 18 is
4 and the transfer means 16, but has not yet been rolled into a sheet or laminated on the lower part of the three-dimensional object.

Next, a latent image corresponding to the magenta density distribution is formed on the photosensitive drum 17 and is switched to the magenta (M) developing device 12 by the selection means 41 and developed with the magenta charging powder 3. . Then, the timing of rotation with respect to the intermediate transfer body 18 is measured, and the yellow
Is transferred onto the yellow chargeable powder 3 so as to overlap the same position. In the same manner, similarly, cyan and white chargeable powders are superimposed on the same position on the intermediate transfer member 18 to form a chargeable powder layer composed of a mixture of four kinds of powders.

FIG. 8 shows the appearance of the surface of the mixed chargeable powder layer. As shown in the enlarged view of FIG. 8B, the chargeable powder layer is formed by mixing the chargeable powders of the yellow powder 52, the magenta powder 53, the cyan powder 54, and the white powder 55 with each other. Is formed. Actually, since each of the chargeable powders is substantially spherical, other particles are arranged in a lower layer portion between the particles when viewed from above, but are simply shown here.

After the transfer of the chargeable powder from the photosensitive drum 17 to the intermediate transfer member 18 has been performed four times as described above, the chargeable powder layer is formed into a sheet by the sheet forming means 14 at one time. Thus, a sheet-shaped chargeable powder of a desired color is obtained. At this time, the sheet-shaped chargeable powder is colored in a desired color, and in the same manner as in Examples 1 to 3, in the state of the powder layer, a large number of voids existing inside are partially melted by a resin. Filled and tightly bonded as one sheet. Then, the stage 7 is moved upward, and the sheet-like chargeable powder is transferred and laminated on the lower layer portion of the three-dimensional object 8 on the stage 7 by the transfer means 16, and the above operation is repeated to perform full-color three-dimensional. An object is formed.

In the above description, full color is reproduced by mixing four colors when forming one sheet of chargeable powder. For example, as shown in FIG. In the case where a desired color is reproduced on the side surface of the object, the mixing ratio of each color for reproducing the color is, for example, Y: M: C: W =
When the ratio is 1: 1: 1: 1, each single-color sheet-like chargeable powder 3 'is formed and laminated, and a desired color is formed by a plurality of sheets of the sheet-like chargeable powder 3'. May be reproduced. Because each layer is a thin layer of several tens of micrometers,
This is because each layer cannot be distinguished from the distant position with the naked eye. In this case, it is not necessary to calculate the mixing ratio of each color each time the sheet-shaped chargeable powder is formed, so that the complexity of the molding process can be reduced.

As shown in FIG. 9 (b), when it is desired to draw a yellow circle on the side of the object, for example, on a white background, a sheet-shaped chargeable powder having a yellow circular drawing portion exists. For 3'a, a yellow chargeable powder is used for a circular drawing area, and a white chargeable powder is used for other areas to form a chargeable powder layer and then to form a sheet. However, as for the sheet-like chargeable powder 3'b having no yellow circular drawing portion, the sheet-like chargeable powder may be formed only with the white single-color chargeable powder. 9 (a) and 9 (b), it is necessary to reproduce the desired color by mixing the colors of the sheet of the uppermost layer or the lowermost layer.

In this embodiment, four color powders of yellow, magenta, cyan, and white are used. However, when mixing is performed using five colors including black, a more vivid full-color powder is obtained. Coloring can be applied. Further, it may be performed by another color combination. In particular, when the color does not need to be full color, for example, two types of colored chargeable powders may be used. Furthermore, when focusing only on the color of the surface of the three-dimensional object,
In the cross-sectional data, a charged powder that is colored only in the surrounding area may be used, and an uncolored charged powder may be used in the inner area.

(Embodiment 5) Another embodiment of the additive manufacturing method and apparatus according to the present invention will be described. In the present embodiment, using the same additive manufacturing apparatus (FIG. 6) as in Embodiment 4, a plurality of developing devices 12 each containing a different ceramic 32 or metal as shown in FIG. The body is housed, and these are appropriately selected by the selection means 41 and developed. With this configuration, it is possible to form a three-dimensional object having different components and composition ratios depending on locations. For example, it is possible to easily form a rod having one end made of metal, the other end made of ceramics, and a middle part whose composition gradually changes.

(Embodiment 6) Another embodiment of the additive manufacturing method and apparatus according to the present invention will be described with reference to FIG. The lamination modeling apparatus shown in FIG. 1 is a powder layer forming / transfer comprising a photosensitive drum 17, a latent image forming unit 15, a developing unit 10 including a developing unit 12 and a developing power supply 13, and an intermediate transfer unit 19. A plurality of units 70 are provided, and each developing unit 12 stores, for example, each chargeable powder colored yellow, magenta, cyan, and white. Then, while measuring the timing of the rotation of each photosensitive drum 17 with the intermediate transfer member 18, a latent image corresponding to the mixture ratio of each color in the order of yellow, magenta, cyan, and white is formed. By developing and intermediate-transferring to the same position on the intermediate transfer member 18, a chargeable powder layer having a desired mixing ratio is formed on the intermediate transfer member 18. As compared with the fourth embodiment, not only the developing device 12, but also the photosensitive drum 17, the latent image forming unit 15, the developing power source 13,
Since there are a plurality of powder layer forming transfer sections 70 including the intermediate transfer means 19, four types of chargeable powder can be superimposed during one rotation of the intermediate transfer body 18, and the speed can be increased. .

Further, the present apparatus has a mechanism that allows the stage 7 to move at the same speed in the same direction as the moving direction of the intermediate transfer body 18 as well as in the vertical direction on the paper surface. The transfer means 16 such as a heater is also formed long. Then, the intermediate transfer member 18 is moved while being in contact with the stage 7 and is heated by the transfer means 16 at the same time, so that the three-dimensional object 8 of the sheet-like chargeable powder is moved within the movable range of the stage 7. There was no need to stop the transfer to the intermediate transfer member 18 by completing the transfer and the lamination, and the modeling speed per layer could be made extremely high within several seconds.

[0081]

According to the lamination molding method and apparatus of the present invention, when a three-dimensional object having a desired shape is formed, the chargeable powder layer formed based on each cross-sectional shape data is formed into a sheet. Since it is formed and laminated, a three-dimensional object excellent in accuracy and strength can be formed at high speed. As for the material, not only plastic resin but also an object mainly composed of metal or ceramics or an object made of a composite material thereof can be formed. Further, since the object can be arbitrarily colored, a full-color three-dimensional object can be formed. Further, since the basic configuration of the present apparatus is based on an electrophotographic printer, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a conceptual explanatory view showing each step of the additive manufacturing method of the present invention.

FIG. 2 is a configuration explanatory view of the additive manufacturing apparatus of the present invention.

FIG. 3 is an explanatory diagram of another configuration of the additive manufacturing apparatus of the present invention.

FIG. 4 is an explanatory view of the steps and the configuration of the additive manufacturing method and apparatus of the present invention.

FIG. 5 is a cross-sectional view showing a structural example of a chargeable powder used in the additive manufacturing method and the apparatus therefor according to the present invention.

FIG. 6 is a schematic view showing another example of the structure of the chargeable powder used in the additive manufacturing method and the apparatus according to the present invention.

FIG. 7 is an explanatory view of the configuration of the additive manufacturing apparatus of the present invention.

FIG. 8 is a schematic diagram showing a chargeable powder layer in which chargeable powders of a plurality of colors are mixed.

FIG. 9 is a schematic diagram showing one side of a three-dimensional object formed by the additive manufacturing method of the present invention.

FIG. 10 is an explanatory view of the configuration of the additive manufacturing apparatus of the present invention.

FIG. 11 is an explanatory view showing a conventional stereolithography method.

FIG. 12 is an explanatory view showing a conventional powder method.

FIG. 13 is an explanatory view showing a conventional solid base curing method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dielectric, 2 ... Latent image, 3 ... Chargeable powder, 3 '...
Sheet-shaped chargeable powder, 4: developing means, 6: heat roll, 7: stage, 8: three-dimensional object, 10: developing means, 11: dielectric, 12: developing device, 13: developing power source, 14 ... sheet forming means, 15 ... latent image forming means,
Reference numeral 16: transfer means, 17: photosensitive drum, 18: intermediate transfer body, 19: intermediate transfer means, 21: corotron, 22: laser beam, 24: heat roll,
25: dielectric belt, 26: transfer charger, 27: heater, 31: thermoplastic resin, 32: ceramics,
33: pigment, 41: selection means, 51: chargeable powder layer, 52: yellow powder, 53: magenta powder, 5
4: cyan powder, 55: white powder, 70: powder layer forming transfer unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichi Kawamata 430 Green Tech Nakai, Nakai-cho, Ashigara-kami, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. Inside the corporation

Claims (17)

[Claims] A step of forming an electrostatic latent image on a dielectric surface based on arbitrary cross-sectional shape data of a three-dimensional object; a step of developing the electrostatic latent image with a chargeable powder; Forming a conductive powder in the form of a sheet, and transferring the sheet-shaped charged powder to a stage, and repeating the above steps to stack the sheet-shaped charged powder on the stage. An additive manufacturing method, wherein a three-dimensional object is formed. 2. The method according to claim 1, wherein a powder made of a thermoplastic resin is used as the chargeable powder, and the step of forming the chargeable powder into a sheet is performed by heating. . 3. A process in which a thermoplastic resin containing metal, ceramics or a non-thermoplastic resin is used as the chargeable powder, and the step of forming the chargeable powder into a sheet is performed by heating. The method of claim 1, wherein: 4. The additive manufacturing method according to claim 1, wherein a powder colored in an arbitrary color is used as the chargeable powder. 5. The method of claim 1, wherein the chargeable powder contains a charge control agent. 6. The step of forming the chargeable powder into a sheet shape comprises:
2. The method according to claim 1, wherein the chargeable powder is transferred to an intermediate transfer member adjacent to the dielectric, and is then transferred onto the intermediate transfer member. 7. The step of forming the chargeable powder into a sheet comprises:
2. The method according to claim 1, wherein the step of transferring the chargeable powder to an intermediate transfer member adjacent to the dielectric is repeated a plurality of times, and then performed once on the intermediate transfer member. 8. The step of forming a chargeable powder into a sheet by using a powder having at least a surface covered with a thermoplastic resin as the chargeable powder, wherein the heating and pressurization of a heat roll apply the intermediate transfer member. The method according to claim 6, wherein the method is performed in the above step. 9. A dielectric material, a latent image forming means for forming an electrostatic latent image on the dielectric material based on data of an arbitrary cross-sectional shape of a three-dimensional object, and a chargeable powder stored in the chargeable powder. Developing means for charging the powder and developing the dielectric material having the electrostatic latent image with the chargeable powder, sheet forming means for forming the chargeable powder into a sheet, and a three-dimensional object And a transfer means for transferring the sheet-shaped chargeable powder to the stage. 10. A dielectric material, a latent image forming means for forming an electrostatic latent image on the dielectric material based on arbitrary cross-sectional shape data of a three-dimensional object, and a chargeable powder containing the chargeable powder. Developing means for charging the powder and developing the dielectric having the electrostatic latent image with the chargeable powder, an intermediate transfer member adjacent to the dielectric, and the chargeable powder moved to the dielectric surface An intermediate transfer means for transferring the toner image to the intermediate transfer body, a sheet forming means for forming the chargeable powder on the intermediate transfer body into a sheet, and a movable stage for mounting a three-dimensional object; A transfer means for transferring the sheet-shaped chargeable powder to the stage. 11. A dielectric body comprising a photoreceptor, a latent image forming means comprising: an initial charging means for uniformly charging the photoreceptor;
11. The additive manufacturing apparatus according to claim 9, further comprising an exposure unit for selectively irradiating the photosensitive member with light based on arbitrary cross-sectional shape data of the three-dimensional object. 12. An apparatus according to claim 11, wherein said exposure means irradiates light by scanning with a laser beam. 13. The additive manufacturing apparatus according to claim 9, further comprising a plurality of developing means, and a selecting means for selecting an arbitrary developing means. 14. A plurality of powder layer forming transfer units each comprising a dielectric, a latent image forming unit, a developing unit, and an intermediate transferring unit, wherein the chargeable powder formed in each of the powder layer forming transfer units is provided. 11. The additive manufacturing apparatus according to claim 10, wherein the powder layer forming transfer units are arranged such that a body image is continuously transferred to a common intermediate transfer member. 15. An apparatus according to claim 10, wherein the intermediate transfer member is made of polyimide as a base material, and the surface thereof is coated with a silicone resin or a fluorine resin. 16. The chargeable powder is a powder having at least a surface covered with a thermoplastic resin, and the sheet forming means comprises a pair of heat rolls arranged so as to sandwich the intermediate transfer member.
11. The additive manufacturing apparatus according to claim 10, further comprising a roll interval changing means for changing an interval between said two rollers. 17. The additive manufacturing apparatus according to claim 9, wherein the stage is movable in the same direction and at the same speed with respect to the movement of the dielectric or the intermediate transfer member.