JPH03275337A - Optical method for forming three-dimensional body - Google Patents

Abstract

PURPOSE:To contrive to save the time and labor for producing optical mask for every horizontal crosssectional shape and to improve illuminance and forming accuracy by a method wherein reducing lens system is provided between an exposure mask and photo-setting resin and, at the same time, exposure region is continuously changed with the exposure mask in response to form data of every horizontal crosssection. CONSTITUTION:Light beam, which sets resin, is irradiated from a light source 4 through an exposure mask 3, which realizes horizontal crosssectional shape, over liquid photo-setting resin 2, which is held in a resin holding container 1, so as to selectively set the photo-setting resin 2 in order to form a three- dimensional shape. In this case, reducing lens system 9 is provided between the exposure mask 3 and the photo-setting resin 2 in order to continuously change an exposure region with the exposure mask 3 in response to form data of every horizontal crosssection. Thus, the time and labor for producing optical mask for every horizontal crosssectional shape are saved and, at the same time, the illuminance given to the resin and the forming accuracy of the obtained molding are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method of exposing and curing a liquid photocurable resin by irradiating it with light to form a three-dimensional three-dimensional shape.

(b) Conventional technology The conventional optical three-dimensional modeling method uses an optical mask commonly used in phosphorography technology, which is widely used in the manufacturing process of semiconductor devices, and repeatedly exposes and hardens each cross section in turn. There is a method of performing three-dimensional modeling, and a method of performing three-dimensional modeling by scanning light energy along the cross-sectional shape of each cross section on the surface of a liquid photocurable resin and selectively curing the resin.

The method using an optical mask is based on the journal of the Institute of Electronics and Communication Engineers (19
81,4vol, J64-CNo, 4P-237-P
-241). This is done by first irradiating an extremely shallow liquid photocurable resin with light from above or below, and then placing an optical mask in front of the photocurable resin with a light-transmitting part corresponding to the horizontal cross-sectional shape of the three-dimensional object to be obtained. By this irradiation, a thin layer cured part with a desired cross-sectional shape is obtained, and for the horizontal cross-sectional shape that continues from this, the depth of the photocuring resin is gradually increased, the optical mask is replaced one after another, and the light irradiation is repeated to obtain the desired shape. The object is to obtain a three-dimensional object.

However, with this method, an optical mask must be manufactured for each horizontal cross-sectional shape of the three-dimensional object to be obtained, which requires time and effort. In particular, in order to obtain a smooth curved surface, it is necessary to increase the number of three-dimensional divisions, and this requires a large number of optical masks, resulting in an enormous amount of manufacturing time and cost.

On the other hand, a method of scanning light energy is disclosed in Japanese Patent Application Laid-open No. 60-2
As disclosed in Japanese Patent Publication No. 47515 (Japanese Patent Publication No. 63-40650), it is possible to house a liquid photocurable resin in a container and move the point of application of light energy three-dimensionally within the container. A planar cured portion is formed by selectively irradiating the liquid photocurable resin with light energy while first relatively moving the point of application of the light energy by the light irradiation means in the horizontal direction. Then, after slightly relatively moving the point of application in the vertical direction, or gradually moving the point relative to each other in the horizontal direction in the same manner as above, the cured portion is laminated, and by repeating this process, the desired three-dimensional object is formed. It is something that creates a shape.

However, in this method, the light irradiation means or the container is operated to move the point of application of the light energy, and the liquid photocurable resin at the point of action is successively cured, so it is not possible to create a model in a short time. In particular, there was a problem in that it was not suitable for modeling large three-dimensional objects.

For this reason, it has been considered to use a liquid crystal shutter or the like to create a three-dimensional object in a short time without having to manufacture an optical mask for each horizontal cross-sectional shape of the three-dimensional object and without moving the point of application of light energy.

(c) Problems to be Solved by the Invention However, with this method, there are problems such as diffusion of light and reduction in illuminance due to passing through the liquid crystal shutter, and the problem that the modeling accuracy is limited by the distance between each dot of the liquid crystal shutter.

B) Means for Solving the Problems The present invention has been made in view of the above points, and includes:
A liquid photocurable resin is placed in a resin storage container, and a light source that cures the resin is irradiated to the photocurable resin through an exposure mask having a horizontal cross section, thereby selectively curing the photocuring resin and forming a three-dimensional shape. In the method, a reduction lens system is provided between the exposure mask and the photocuring resin, and the exposure area of the exposure mask is continuously changed according to each horizontal cross-sectional shape data.

(E) Function Since the present invention uses the above-mentioned means, it is possible to save the effort of manufacturing an optical mask for each horizontal cross-sectional shape, and also to improve illuminance and modeling accuracy.

(F) Examples Examples of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an example of an apparatus for carrying out the method of the invention. Liquid photocurable resin (2) such as modified polyurethane methacrylate or photosensitive polyimide is placed in the resin storage container (1).
), and a reduction lens system (9) for carrying out a service action on the surface of the liquid photocurable resin (2), this lens system (
A liquid crystal shutter plate (3) serving as an exposure mask is provided above the liquid crystal shutter plate (3), and a wavelength capable of curing the liquid photocuring resin (2) is emitted above the liquid crystal shutter plate (3). Ultraviolet light (wavelength 3650), or laser (
A light source (4) with an output of 40 mW and a wavelength of 3250 nm is installed, and a lifting stage (5) that can move up and down inside the cured resin (2) is installed.
) has been established.

The shutter plate (3) is driven by a controller (6), and the controller (6) is driven by a CAD device (
8).

Note that (7) in the figure shows a three-dimensional three-dimensional object that is being formed.

At the bottom of the groove, first move the lifting stage (5) that can move up and down inside the liquid photocurable resin (2) into the liquid photocurable resin (2).
) is submerged by the thickness (2 mm) to be cured in one exposure time (approximately 10 minutes), allowing light to pass through the horizontal section of the desired three-dimensional shape. The liquid crystal shutter plate (3) is operated by the controller (6) to block light from other parts, and the liquid crystal shutter plate (3) is placed on the surface of the liquid photocuring resin (2) without the light being diffused by the lens system. ), the horizontal cross-sectional shape of the first layer is photocured by the thickness on the elevating stage (5).

Next, the elevating stage (5) is further lowered by the thickness that will be cured in one exposure time, and the light transmitting part and light blocking part of the liquid crystal shutter plate (3) are adjusted according to the horizontal cross-sectional shape of the second layer. The controller (6) is operated so that the shape of the light transmitting part of the liquid crystal shutter plate (3) is imaged on the surface of the liquid photocurable resin (2) by the lens system (9), and the shape of the light transmitting part of the liquid crystal shutter plate (3) is
Light cure the layer.

By repeating the same process, a desired three-dimensional object (7) can be easily obtained in a short time by stacking many cured resin layers.

This three-dimensional three-dimensional object (7) was designed with a CAD device (8), and the three-dimensional data of the CAD device (8) is converted into two-dimensional cross-sectional shape data for each horizontal cross-section.
This data is sent to the controller (6). The controller (6) controls a portion of each liquid crystal shutter two-dimensionally arranged on the liquid crystal shutter plate (3) by applying technology used in displays etc. according to each horizontal cross-sectional shape data. The operation of the liquid crystal shutter plate (3) is controlled so that the portion corresponding to the cross-sectional shape transmits light, and the other portions not corresponding to the cross-sectional shape block light.

Note that the surfaces of the liquid crystal shutter plate (3) and the liquid photocurable resin (2) may be in contact with each other, but if they are not, the liquid crystal shutter plate (3) and the liquid photocurable resin may be in contact with each other, taking into account the diffusion of light. (2) It is desirable that the discance with the surface be as small as possible.

Figure 2 shows a lens array (10) installed between the liquid crystal shutter plate (3) and the surface of the liquid photocuring resin (2) to prevent light diffusion. It is. In this case as well, the discance between the liquid crystal shutter plate (3) and the surface of the liquid photocuring resin (2) is preferably as small as possible.

(G) Effects of the Invention According to the optical three-dimensional modeling method of the present invention, a liquid photocurable resin is contained in a resin storage container, and a light source for curing the resin is irradiated onto the photocurable resin through an exposure mask having a horizontal cross section. In the method of selectively curing the photocuring resin to form a three-dimensional shape, a reduction lens system is provided between the exposure mask and the photocuring resin, and the exposure mask is adjusted according to each horizontal cross-sectional shape data. Since the exposure area is continuously changed by changing the exposure area, it is possible to eliminate the trouble of manufacturing an optical mask for each horizontal cross-sectional shape, improve the illumination intensity and improve the modeling accuracy, and realize a practical optical three-dimensional modeling method. Can be provided.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the optical three-dimensional modeling method according to the present invention, and FIG. 2 is a schematic diagram showing a different embodiment of the optical three-dimensional modeling method according to the present invention. (9)...reducing lens system, (10)...lens array.

Claims (1)

[Claims] (1) A liquid photocurable resin is placed in a resin storage container, and the photocurable resin is selectively cured into a three-dimensional shape by irradiating the photocurable resin with a light source that cures the resin through an exposure mask with a horizontal cross section. In the method for forming an optical system, a reduction lens system is provided between the exposure mask and the photocuring resin, and the exposure mask has an exposure area that changes continuously according to each horizontal cross-sectional shape data. Three-dimensional modeling method.