JPH09141749A - Forming of three-dimensional image and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a high-precision three-dimensional image in a short time and make it possible to apply it to an ultraviolet curing resin. SOLUTION: Three-dimensional image slice data is prepared which consists of a plurality of three-dimensional images obtained by slicing a three-dimensional image to be formed at a specified slicing interval in a specified direction. The three-dimensional image slice data is entered into a digital micromirror device 2, then each of micromirrors is operated in a tilted state in accordance with the three-dimensional slice data, and a reflected light from each of the micromirrors is emitted to a photocuring resin solution 7. Thus a cured film is formed which has a shape corresponding to the three-dimensional image slice data and a thickness equal to a specified slice interval. Further, the cured film is allowed to settle by a specified slice interval. Each of the cured films is laminated by repeating the above sequence of operating steps to form a three-dimensional image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereoscopic image forming method and apparatus, and more particularly to a method and apparatus capable of forming a stereoscopic image with high accuracy.

[0002]

2. Description of the Related Art For example, when a resin molded product is manufactured, a trial production is often carried out before a wooden mold or a metal mold is produced, and various trial production methods have been proposed.

For example, a thin laser beam is emitted from the tip of an optical fiber extending from an ultraviolet laser device,
Based on the data from the three-dimensional CAD, the XY table is moved, a laser beam is scanned so that the image is filled with a pen, and the surface of the ultraviolet curing resin is irradiated to form a cured film. A method of forming a three-dimensional image by repeating the above scanning while descending is known.

Further, a CAD slice image is projected on a transmissive liquid crystal, and the image is collectively projected on the curable resin liquid surface by a light source behind to form a cured film, and a stereoscopic image is formed by repeating such operations. There is also a method.

[0005]

However, in the former modeling method, it takes a whole day and night to model a simple three-dimensional image of a coffee cup, and the modeling time becomes very long, and a complicated interface is required. There was a problem of doing.

In the latter method, although the molding time is short, the liquid crystal used is weak against ultraviolet rays, so that it cannot be applied to the ultraviolet curable resin which is the mainstream at present, and the size of the liquid crystal and the size of the dots are different. However, there is a problem that the precision of the three-dimensional image formed is extremely poor due to the above relationship.

In view of such problems, it is an object of the present invention to provide a three-dimensional image forming method capable of forming a high-precision three-dimensional image in a short time and applicable to an ultraviolet curable resin.

[0008]

In order to solve the problems, therefore, a stereoscopic image forming method according to the present invention creates stereoscopic image slice data by slicing a stereoscopic image to be formed at a predetermined slice interval in a predetermined direction, and creates the stereoscopic image slice data. It is input to a digital micromirror device (hereinafter referred to as DMD), each of the plurality of micromirrors is tilted according to the stereoscopic image slice data, and the reflected light from each of the DMD micromirrors is converted into a photocurable resin liquid in the tank. A hardened film having a shape corresponding to the stereoscopic image slice data and having a thickness of a predetermined slice interval is projected, and the hardened film is allowed to settle at a predetermined slice interval, and the hardened film is laminated by repeating the series of operations described above. The feature is that a three-dimensional image is modeled by using.

The three-dimensional image slice data may be created each time the corresponding cured film is formed, but the work becomes complicated. Therefore, it is preferable that all of the plurality of stereoscopic image slice data be created in advance and be sequentially given to the DMD each time the cured film is formed.

The three-dimensional image slice data may be created based on a three-dimensional image created by three-dimensional CAD, or in the case of modeling another processing device, for example, a skull bone model used in the examination before head surgery. May be created from CT scan or MRI data.

The photocurable resin includes a slow-curing resin and a fast-curing resin. In the case of the slow curing resin, the resin is not cured unless the reflected light from the micro mirror is projected for a predetermined time, for example, about 10 seconds. Therefore, light can be continuously incident on the DMD from the light source, and deterioration of the light source due to frequent ON / OFF of the light source can be prevented. On the other hand, in the case of a quick-curing resin, it is necessary to secure a margin for allowing the resin liquid to cure immediately upon irradiation with reflected light and allowing the cured film to settle. Therefore, it is preferable to tilt all the micromirrors so that the reflected light is not projected onto the photocurable resin liquid after forming the film, or to stop the incidence of light on the micromirrors.

As for the three-dimensional image slice data, the smaller the slice interval is, the higher the modeling accuracy becomes, but the work becomes complicated. Therefore, about 0.1 mm to 0.3 mm is suitable for normal modeling. Further, when slicing one stereoscopic image, a large slice interval can be adopted for a portion where the same shape continues. That is, when one stereoscopic image is formed, the slice interval may be constant or may be sliced at different slice intervals.

The above-described molding method can be performed by a relatively simple device including a light source, a DMD, a photocurable resin liquid tank, and an actuator for supporting and sedimenting a cured film. That is, according to the present invention, the tank in which the photocurable resin liquid is stored and the cured film of the photocurable resin liquid which is provided on the side of the tank and formed by projection of light are supported to be predetermined. An actuator that settles down by a distance and micromirrors are arranged on each memory cell of a two-dimensionally arranged memory array, and the plurality of micromirrors are arranged according to the stereoscopic image slice data input to the memory array. A DMD that tilts and projects reflected light from the plurality of micromirrors onto the photocurable resin liquid in the tank to form a cured film of the photocurable resin liquid into a shape corresponding to stereoscopic image slice data, and the DMD. It is possible to provide a three-dimensional image forming apparatus including a light source that makes light incident on the micro mirror.

The reflected light from the micromirrors of the DMD may be directly projected onto the liquid surface of the photocurable resin liquid, but in order to improve the image forming accuracy, a projection lens is provided to reflect the light reflected from the plurality of micromirrors. Is preferably projected onto the photocurable resin liquid. Further, a hydraulic cylinder, an air cylinder, or the like may be used as the actuator, but since it is desirable to settle down with high accuracy as described above, a so-called Z, which is composed of a ball screw and a motor as shown in the following embodiment, is used. It is good to adopt an axial stage.

[0015]

According to the present invention, the DMD is used to collectively form a sliced shape of a three-dimensional image and the three-dimensional images are laminated to form a three-dimensional image. Compared with the method of filling the sliced surface with a thin laser beam like this, the modeling time can be greatly shortened, and it can be shortened to 1/10 times or less as compared with the most typical conventional modeling method using a He-cd laser. Was confirmed.
Further, since DMD is used, it can be applied to an ultraviolet curable resin.

Regarding the molding accuracy, the number of micromirrors of DMD is about 1.9 million pixels, which is much larger than that of liquid crystal, and there is no large cell partition like liquid crystal, and the contrast is about several times. Well, compared with the conventional liquid crystal system, the molding accuracy can be greatly improved. In the case of the liquid crystal system, the accuracy is generally ± 0.3 mm, while the accuracy is ± 0.1 mm, which is the same level as the laser system. It was confirmed that

Further, regarding the apparatus cost, since the apparatus itself can be simply constructed without requiring a complicated interface unlike the conventional laser system, a significant cost reduction can be achieved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to specific examples shown in the drawings. FIG. 1 shows a preferred embodiment of the present invention. In the figure, a slow-curing photocurable resin liquid 7 is stored in a tank (tank) 6, and a Z-axis stage 8 is erected on the side of the tank 6, and the Z-axis stage 8 is a ball screw. It is composed of a motor and can feed with high precision. This Z-axis stage 8 has a table 9
Is attached and is sent downward by the Z-axis stage 8.
The actuator is configured to support the cured film of the photocurable resin liquid and settle it by a distance equal to the thickness of the cured film.

A DMD 2 and a projection lens 4 are arranged above the tank 6 in the vertical direction and facing the surface of the photocurable resin liquid 7. The DMD 2 has about 1.9 million memory cells arranged two-dimensionally. Memory array, formed by forming aluminum micro mirrors on each memory cell,
The distance between the minute mirrors is about 17 μm. This DMD
The light of the lamp light source 1 is continuously incident on the beam 2 from diagonally below. A light absorbing plate 3 is arranged on the opposite side of the DMD 2, and absorbs light other than the reflected light necessary for image formation by the DMD 2.

Next, the modeling method will be described. FIG. 2 shows the principle of image formation by the DMD 2. First, a three-dimensional image to be modeled is created by three-dimensional CAD, and a plurality of three-dimensional image slice data that is data of an image obtained by slicing a predetermined slice interval, for example, 0.2 mm in the vertical direction of the three-dimensional image. This one stereoscopic image slice data is input to the DMD 2. Here, the DMD 2 is a so-called spatial light modulator that has been recently developed, and is a device that has a large number of micromirrors on its surface, and the angle of each micromirror is changed by an electric signal. Therefore, each of the plurality of micromirrors of the DMD 2 tilts according to the input stereoscopic image slice data. When the light from the lamp light source 1 is incident on the plurality of minute mirrors, a virtual slice original image 1a is formed on the mirror surface composed of the plurality of minute mirrors, and the reflected light is projected on the screen 5 through the projection lens 4. As a result, a slice-shaped image 2a is formed.

Therefore, using the above-described principle, an image corresponding to the three-dimensional slice data is formed on the liquid surface of the photocurable resin liquid 7 instead of the screen 5. Then, only the portion of the projected slice-shaped image 3a of the photocurable resin liquid 7 is cured, and a cured film having a shape corresponding to the stereoscopic image slice data is formed. At this time, the distance between the surface of the table 9 and the liquid surface of the photocurable resin liquid 7 is set to be equal to the slice interval, that is, 0.2 mm, and the photocurable resin liquid 7 between the distances is set. If the irradiation time is set so that the cured film is cured, the thickness of the cured film can be made equal to the slice interval.

When the cured film is formed in this manner, the Z-axis stage 8 is operated to lower the table 9 by the thickness of the cured film to cause the cured film to settle. After that, when the above operation is repeated, the cured film is sequentially formed. It can be stacked to form a three-dimensional image. Since it is important that the distance between the projection lens 4 and the liquid surface of the photocurable resin 7 at this time is constant, the liquid surface position of the photocurable resin 7 is controlled to be constant.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a three-dimensional image forming apparatus according to a preferred embodiment of the present invention.

FIG. 2 is a diagram for explaining the principle of the above device.

[Explanation of symbols]

 1 Lamp Light Source 2 DMD (Digital Micromirror Device) 4 Projection Lens 6 Tank (Tank) 7 Photocurable Resin Liquid 8 Z-Axis Stage (Actuator) 9 Table (Actuator)

Claims (5)

[Claims] 1. A plurality of three-dimensional image slice data obtained by slicing a three-dimensional image to be modeled in a predetermined direction at predetermined slice intervals, inputting the three-dimensional image slice data to a digital micromirror device, and setting each of the plurality of micromirrors. Tilt according to the stereoscopic image slice data, and the reflected light from each micromirror of the digital micromirror device is projected on the photocurable resin liquid in the tank to have a shape corresponding to the stereoscopic image slice data and the predetermined slice. A cured film having an interval thickness is formed, the cured film is allowed to settle by the predetermined slice interval, and the cured film is laminated by repeating the series of operations described above to form the three-dimensional image. How to make a three-dimensional image. 2. The method for forming a three-dimensional image according to claim 1, wherein the photocurable resin liquid is a resin liquid that cures slowly, and light is continuously incident on the digital micromirror device from a light source. 3. The photocurable resin liquid is a resin liquid that is rapidly cured, and all of the micro mirrors are tilted or the micro mirrors are tilted so that reflected light is not projected onto the photo curable resin liquid after film formation. The three-dimensional image forming method according to claim 1, wherein the incidence of light on the mirror is stopped. 4. A tank in which the photocurable resin liquid is stored, and a thickness of the cured film which is provided in the vicinity of the tank and supports the cured film of the photocurable resin liquid formed by projection of light. An actuator that sinks the same distance and micromirrors are arranged on each memory cell of a two-dimensionally arranged memory array, and the plurality of micromirrors are arranged according to the stereoscopic image slice data input to the memory array. Digital micromirror device for tilting the light and projecting the reflected light from the plurality of micromirrors onto the photocurable resin liquid in the tank to form a cured film of the photocurable resin liquid into a shape corresponding to the stereoscopic image slice data. And a light source for making light incident on the micromirrors of the digital micromirror device. 5. The three-dimensional image forming apparatus according to claim 4, further comprising a projection lens that projects reflected light from the plurality of micromirrors onto the photocurable resin liquid in the tank.