JPH06305032A - Method for forming three dimensional shape - Google Patents

Abstract

PURPOSE:To provide a method wherein a required real image model of a three dimensional image is formed in a short time and accurately by using a hologram without difficult procedures and processings. CONSTITUTION:A monochromic ultraviolet laser light is made into a wide beam having a parallel phase face and is divided into a reference light 6 and an irradiation light 7 by means of a beam splitter and an aimed three dimensional body 1 is irradiated with the irradiation light 7. Then, a photosensitive plate 2 is irradiated with the reflected light 8 from a body 1 with the reference light 6 to form interference fringes (hologram). Then, when the developed photosensitive plate 2 is irradiated with the reference light, a three dimensional real image 10 of the aimed three dimensional body is formed and when a nucleus 9 is arranged at the position and a photocurable resin 12 is dropped down on the nucleus 9, the resin is cured at the actual image part where the light is focused to formed a real image model of a solid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine processing method, and more particularly to a high precision three-dimensional shape forming method.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a three-dimensional shape called stereolithography or stereolithography, there is a method of scanning a photocurable material while irradiating it with laser light. (Laser Research Vol. 18, No. 7, Journal of Precision Engineering 58/3/1992, etc.). That is, by irradiating the liquid surface of the resin with the laser beam and sweeping the irradiation spot, a thin plate-shaped cured layer is formed. Arbitrary three-dimensional shapes can be formed by sequentially laminating the hardened layers.

[0003]

However, in the above method, since the layers are laminated one by one, the forming time is very long, and a step having a thickness of one layer is formed, so that a highly accurate three-dimensional shape cannot be formed. There is such a problem. The present invention has been made in view of the above-mentioned problems, and utilizes the coherence and monochromaticity of a laser to form a spatial light intensity distribution (real image) by using diffraction. It is intended to realize a three-dimensional shape with high accuracy in a short time by chemically changing the photo-curable material according to the intensity distribution of.

[0004]

In order to solve the above-mentioned problems, the structure of the first invention is a three-dimensional shape forming method for irradiating a photo-curable material with light to selectively solidify an irradiation area. The three-dimensional intensity distribution of light emitted from the three-dimensional object is a hologram forming step of forming at least one hologram, an image reproducing step of reproducing a three-dimensional real image of the three-dimensional object with the hologram, and a material supply means. And a solidifying step of solidifying the photo-curable material by applying the stereoscopic real image to the supplied photo-curable material. The configuration of the first related invention is characterized in that the material supplying means is a means for dropping the photocurable material from above onto a sufficiently small nucleus provided at the real image position. The configuration of the second related invention is characterized in that the hologram forming step is a step of obtaining a light emission distribution intensity pattern of the three-dimensional object by a computer to form a sensitive plate.

According to the structure of the second invention, in the three-dimensional shape forming method of irradiating the material to be processed with light to selectively decompose the irradiation area, the three-dimensional intensity distribution of the light emitted from the three-dimensional object to be formed. , A hologram forming step of forming at least one hologram, an image reproducing step of reproducing a three-dimensional real image of the three-dimensional object with the hologram, and the intensity of the work material and light at the position of the reproduced three-dimensional real image. And a processing medium which reacts with each other, and a processing step of piercing the shape of the real image.

[0006]

First, a laser beam (a monochromatic laser that causes a diffraction phenomenon, that is, a laser having coherence) is applied to an object having a target shape existing in a real space, and at the same time, a coherent reference beam (reference beam) is emitted. When the sensitive plate arranged at a predetermined position is irradiated, the light scattered from the object and the reference light interfere with each other, and a diffraction pattern is formed on the sensitive plate.
Will be recorded. The pattern formed on this sensing plate is a three-dimensional spatial image data subjected to spatial Fourier transform,
The pattern corresponds to the data in the reciprocal space. Next, when the pattern formed on the touch panel is irradiated with the reference light again, it is equivalent to performing the Fourier retransformation on the real space pattern, and the three-dimensional image of the original object is restored, and the stereoscopic real image is placed at a predetermined position. As the light is condensed.

If a photo-curable material that cures according to the intensity of light is arranged at the position where the three-dimensional real image is condensed, a three-dimensional shape is realized by solidifying the photosensitive material. Further, if a processing medium and a material to be processed that cause a reaction corresponding to the intensity of light are arranged at this position (for example, etching, deposition, etc.), a shape that reflects the intensity distribution of this light is processed. The point to be taken into consideration in the present invention is that, for example, if the photosensitivity of the photocurable material is too high, it may be solidified by a certain intensity of light even if it is not condensed. Needs some help. Therefore, it is important to select the most suitable photo-curable material, but as one method, in the related invention, a very small nucleus is placed in the light-collecting part, and the photosensitive material is dropped from the top of this to form the core. The photosensitive material is always present only on the surface, and even if it solidifies, the photosensitive material is always supplied to this surface. By doing so, since the photosensitive material does not exist in the area where light is not originally collected, the photosensitive material does not solidify at an extra position and a desired shape is obtained.

It is not always necessary to form an actual hologram on the touch panel for recording the hologram pattern, and it is sufficient that the pattern is completed on the touch panel. Therefore, a computer can perform Fourier transform calculation from an ideal three-dimensional shape. Go to find the reciprocal space pattern and draw out the pattern directly to make a touch panel.

Further, in the case of reproducing an image using a plurality of holograms, the reproduced images can be overlapped by allocating different wavelengths to different holograms. A stereoscopic real image with strong contrast can be formed. A photosensitive material is supplied to the real image by the above method. Alternatively, as in the second invention, a three-dimensional shape is formed by using a translucent photosensitive material and reproducing a three-dimensional real image in the volume of the material to solidify it.

[0010]

Since the real image to be reproduced is a stereoscopic image in which the original object shape is reproduced as it is, there is a trade-off relationship between the forming time and the forming accuracy as in the conventional method of scanning and solidifying the laser beam one by one. In addition, the entire three-dimensional shape can be formed at once in a short time, and highly accurate formation is possible. Instead of forming the pattern on the touch panel using diffraction, a computer is used to calculate the intensity distribution pattern in the reciprocal space to form the touch panel, which is then used to focus the light. If so, not only the desired shape can be obtained without using an actual product, but there is an advantage that an arbitrary shape can be obtained. Further, there is an advantage that an optical means can be applied to the image reproducing process to enlarge and reduce the image freely, and even a minute target shape that is difficult to form can be realized with a model of a size that is easy to handle.

[0011]

EXAMPLES The present invention will be described below based on specific examples. (First Embodiment) FIG. 1 schematically shows steps for carrying out the three-dimensional shape forming method of the present invention. FIG. 1A shows a hologram forming step, which is a well-known means for forming a hologram.
Most of the required photo-curing resins are those that are cured by ultraviolet light, so the laser beam from the monochromatic ultraviolet laser light source 3 is converted into a wide beam having parallel phase planes by using the optical system 4 and the reference is made by the beam splitter 5. Light 6 and irradiation light 7 are used. This irradiation light 7 is applied to the target three-dimensional object 1. Then, the reflected light 8 from the object 1 is irradiated onto the sensitive plate 2 together with the reference light 6 to form interference fringes (hologram) on the sensitive plate. After exposure, the pattern is fixed by developing the photograph. It should be noted that this step is performed in a dark room so that the photosensitive plate 2 is not exposed to excessive light.

Next, as shown in FIG. 1 (b), when the developed photosensitive plate 2 is irradiated with the reference light 6, a stereoscopic real image 10 of a target three-dimensional object is formed at a predetermined position. (Note that Figure 1
The position of the real image 10 in (b) does not show the position of the image created in FIG. 1 (a). ) A nucleus 9 for fixing the photocurable resin is arranged at that position, and the photocurable resin 12 is dropped from the resin supply unit 11 to the nucleus 9, and the resin is removed in the real image portion where the light is condensed. Harden. The photo-curing resin 12 is continuously supplied, and solidification continues until the light intensity becomes equal to or lower than the photosensitivity threshold of the resin to form a solid real image model.

The photocurable resin starts to cure instantly when it is exposed to ultraviolet rays, and completely cures in a predetermined amount within a few seconds. However, depending on the photo-curable resin selected, the surface layer that is irradiated is cured rather than substantially in volume. The amount of curing is determined by the amount of light energy applied, and it takes time to complete a certain amount of solidification with a laser having a small energy density. That is, it takes time to solidify in a region where light is not collected. Therefore, a stereoscopic real image area having a high energy density by condensing can create the whole image in a short time. On the contrary, if the reproduced image is continuously irradiated more than necessary, the solidification of the resin proceeds to the area around the real image and the spatial resolution is lowered. for that reason,
The laser irradiation time for the selected photo-curable resin has a finite value, but the detailed conditions are determined by various combined experiments. When the resin 12 is dropped from the top of the core 9, there is no problem even if the resin 12 is continuously poured as shown in FIG. 2 for the above reason, and the solidified portion 13 grows so that the core becomes thick and the real image becomes a substantial image. Will be transformed. However, since the dropping of the resin utilizes gravity and is supplied in one direction, it is better to arrange the nucleus 9 at the bottom of the real image. Further, in order to save waste, the resin is not dropped onto the area above the real image.

The photo-curable resin is mixed with a photo-polymerizable pre-oligomer (oligomer), a photo-polymerizable monomer (monomer), a photo-polymerization initiator and the like. Generally, when the amount of the oligomer is large, the viscosity becomes high and a fine structure is formed. Some of them include a monomer as a diluent because they are difficult to form.
The fineness of formation is determined by the physical properties such as viscosity of the photosensitive material used, but as a limit, it is possible up to the size of the molecular cluster of the resin used or the level of the wavelength of the reproduction light.

(Second Embodiment) Further, as in the hologram pattern sensitive plates 30, 32 and 34 of FIG. 3, a plurality of sensitive plates may be used to reproduce a real image from a polygonal surface. In this case, the three-dimensional shape of the object is reproduced not only from one direction but also from many directions, so that the three-dimensional shape can be perfectly reproduced, and since the real images are superposed, the brightness of the real image is increased. Have a synergistic effect on. Therefore, in this case, since the reproduced image has high contrast, the transparent container 3
Even when the photocurable resin 38 having a low photosensitivity is placed in 6 and placed at the real image reproducing position to reproduce a stereoscopic real image, only the surface of the real image portion is cured to quickly form a desired shape in detail, It is possible to prevent the curing from reaching the periphery. The laser irradiation may be pulsed to control the solidification rate. At this time, if holograms are formed on different patterned plates at different wavelengths, they will not interfere with each other during reproduction, and a type of photo-curing resin that cures by photoexcitation of two or more waves will be used. Then, the shape of only the superimposed real image portion can be formed without paying much attention to the photosensitivity of the photocurable resin. The bottom of the position where the real image is formed is the bottom of the container, or the model stand 37 as shown in the figure is required.

(Third Embodiment) Further, the photo-excited etching block 40 as a processing material for the reproduction model and the entire block base 44 are soaked in the reactive solution 42, and the block 40 is placed at a position where a stereoscopic real image is formed. And the hologram real image is reproduced, an etching reaction occurs only in the real image portion where the light is condensed, and the block 40 is eroded to form the block 40 in which the three-dimensional real image shape is hollowed (FIG. 4). In this case, the laser for causing etching is not limited to ultraviolet rays. In order for the etching reaction to continue, the block is made of a material that is transparent to the laser light and has a refractive index that does not differ significantly from that of the etching liquid, and the etching start end is located on the surface of the block. is necessary. In addition, in the third embodiment, the entire block 40 and the block base 44 are immersed in the reactive solution 42, but the reactive solution is not limited and any reactive medium such as a reactive gas may be used.

Besides, in any of the methods, when an optical system such as a lens is used, this hologram reproduced image can be freely magnified.
Since it can be reduced, for example, make a model with a reasonable size,
If a hologram is created based on this model and then reduced by an optical system during image reproduction, there is an advantage that a minute model that is difficult to form can be instantly formed.

The hologram formed in the hologram forming step is not only formed by an actual optical operation based on an actual object or a model, but also a three-dimensional object which is calculated by a computer or the like and directly drawn is Fourier-transformed to be inversed. It may be a hologram in which a spatial pattern is calculated and the pattern is formed on a touch panel, and therefore, it can be applied to the case where a real object is complicated and it is difficult to form a hologram. Furthermore, even if there is no real thing or model, it is possible to create an arbitrary shape from the drawing and model it, and it is possible to expand and contract freely.

As described above, a method for forming a desired three-dimensional stereoscopic image substantial model using a hologram with high precision in a short time without requiring difficult procedures and steps has been shown.

[Brief description of drawings]

FIG. 1 is a main process diagram of a first embodiment to which the present invention is applied.

FIG. 2 is a detailed perspective view of essential parts of a first embodiment to which the present invention is applied.

FIG. 3 is a main part process chart of a second embodiment to which the present invention is applied.

FIG. 4 is a main part process chart of a third embodiment to which the present invention is applied.

[Explanation of symbols]

 1 3D Object 2 Hologram Pattern Sensitive Plate 3 Monochromatic Laser Light Source 4 Optical System 5 Beam Splitter 6 Reference Light (Reference Light) 7 Irradiation Light 8 Scattered Light 9 Nucleus 10 Reproduced Stereoscopic Image 11 Photocuring Resin Supply Unit 12 Photocuring Resin 13 Nucleus Resin solidified above 30, 32, 34 Hologram pattern sensitive plate 36 Transparent container 37 Model stand 38 Photocurable resin 40 Transparent block 42 Transparent reaction solution 44 Block stand

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Claims (4)

[Claims] 1. A three-dimensional shape forming method of irradiating a photo-curable material with light to selectively solidify an irradiation area, wherein at least one three-dimensional intensity distribution of light emitted from a three-dimensional object to be formed is at least one sheet. A hologram forming step of forming a hologram of the three-dimensional object, an image reproducing step of reproducing a three-dimensional real image of the three-dimensional object with the hologram, and applying the three-dimensional real image to the photocurable material supplied by a material supplying unit to perform the photocuring. A three-dimensional shape forming method comprising: a solidifying step of solidifying a conductive material. 2. The three-dimensional structure according to claim 1, wherein the material supplying means is a means for dropping the photocurable material from above onto a sufficiently small nucleus placed at the real image position. Shape forming method. 3. The hologram forming step is a step of forming a sensitive plate by obtaining a light emission distribution intensity pattern of the three-dimensional object by a computer.
The method for forming a three-dimensional shape according to. 4. A three-dimensional shape forming method in which a material to be processed is irradiated with light to selectively decompose an irradiation area, and a three-dimensional intensity distribution of light emitted from a three-dimensional object to be formed is determined by at least one sheet. A hologram forming step of forming a hologram, an image reproducing step of reproducing a three-dimensional real image of the three-dimensional object with the hologram, and a processing medium which reacts at the position of the reproduced three-dimensional real image with the material to be processed and the intensity of light. And a processing step of arranging to form the shape of the real image, the three-dimensional shape forming method.