JP3796882B2 - Stereolithography equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical modeling apparatus, and more particularly to shape processing of a workpiece using an optical modeling method.
[0002]
[Prior art]
There is known an optical modeling method in which a three-dimensional model is formed by irradiating an ultraviolet curable resin with ultraviolet rays and curing a light irradiated portion. In this stereolithography method, based on the cross-sectional shape data of the first layer of the three-dimensional model to be manufactured, the liquid surface of the UV curable resin is irradiated with an ultraviolet light spot (scanning spot) or optical pattern, The first layer portion is cured. Next, the first layer portion is immersed in the ultraviolet curable resin liquid, and the second layer portion is cured by irradiating the liquid surface of the ultraviolet curable resin with ultraviolet rays based on the cross-sectional shape data of the second layer. In the same manner, a modeled object having a predetermined three-dimensional shape is formed by sequentially curing and laminating each layer portion.
[0003]
[Problems to be solved by the invention]
As described above, in the conventional optical modeling apparatus using the optical modeling method, light irradiation is performed at a constant incident angle substantially perpendicular to the planar liquid surface of the ultraviolet curable resin, and is cured in a planar shape. A three-dimensionally shaped object is formed by laminating each layer portion.
By the way, in the field of artificial bone molding, for example, in order to further fine-tune the surface shape of artificial bone formed using an optical modeling method, an ultraviolet curable resin is applied to a local region that needs fine adjustment, Research is being carried out to irradiate the surface with ultraviolet rays for fine processing. In this case, for example, if the surface shape of the locally depressed region of the artificial bone is to be finely adjusted using a conventional stereolithography apparatus, a desired angle (orientation) with respect to the complicated surface of the applied ultraviolet curable resin ) Cannot be irradiated, and as a result, the desired shape processing may not be performed.
[0004]
The present invention has been made in view of the above-described problems, and an object thereof is to provide an optical modeling apparatus capable of efficiently performing fine shape processing even on a workpiece having a complicated surface shape. To do.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a light pattern forming means for forming a light pattern having a predetermined shape,
An objective optical system for condensing light from the light pattern to form an image of the light pattern on the surface of the workpiece;
Light incident on the surface of the workpiece in order to change the angle of incident light with respect to the surface of the workpiece without substantially changing the formation position of the image of the optical pattern on the surface of the workpiece. An optical path switching means for switching the optical path of
There is provided an optical modeling apparatus characterized in that the workpiece is shaped according to a light intensity distribution of an image of the optical pattern formed on the surface of the workpiece.
[0006]
According to a preferred aspect, the optical path switching means switches an optical path of light incident on the surface of the workpiece by changing a position of a light transmitting portion through which incident light from the light pattern is transmitted. In this case, it is preferable that the light pattern forming unit switches the shape of the image of the light pattern formed on the surface of the workpiece by changing the shape of the light pattern.
[0007]
According to another preferred aspect, the light pattern forming unit forms a plurality of light patterns spatially separated from each other, and the light path switching unit spatially separates from each of the plurality of light patterns. By selectively transmitting the light incident along the separated optical path and guiding it to the surface of the workpiece, the optical path of the light incident on the surface of the workpiece is switched. In this case, it is preferable that the light pattern forming unit forms a plurality of different light patterns and switches the shape of the image of the light pattern formed on the surface of the workpiece by the action of the optical path switching unit. .
[0008]
Furthermore, it is preferable that the optical path switching means is disposed in the vicinity of the pupil plane of the objective optical system.
Further, based on light from the surface of the workpiece through the objective optical system along an optical path substantially different from an optical path of light incident on the surface of the workpiece, an image of the optical pattern is obtained. It is preferable that an observation system for observing the surface of the formed workpiece is further provided.
Furthermore, the objective optical system is a multifocal optical system having a different focal length depending on a region through which light passes, and the optical pattern formed on the surface of the workpiece by the action of the optical path switching unit. It is preferable to switch the imaging position in the optical axis direction of the image.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the optical shaping apparatus of the present invention, for example, an optical pattern is formed by an optical pattern forming means such as an LED array, light from the optical pattern is condensed through an objective optical system, and the optical pattern is formed on the surface of the workpiece. Form an image of Then, the optical path of the light incident on the surface of the workpiece is switched by the optical path switching means, and the incident light on the surface of the workpiece is substantially changed without substantially changing the formation position of the optical pattern image on the surface of the workpiece. The angle (orientation) can be changed.
[0010]
As a specific example, the optical path switching means is composed of a light valve such as a liquid crystal display element arranged in the vicinity of the pupil plane of the objective optical system, for example, and the position of the light transmitting portion through which incident light from the light pattern is transmitted. By changing, the optical path of the light incident on the surface of the workpiece is switched. In this case, the light pattern forming means can change the shape of the image of the light pattern formed on the surface of the workpiece by changing the shape of the light pattern.
[0011]
According to another specific example, the light pattern forming unit has, for example, a plurality of LED arrays, and forms a plurality of light patterns spatially separated from each other. The optical path switching means is composed of, for example, a light valve disposed in the vicinity of the pupil plane of the objective optical system or an aperture stop having a plurality of openings. Thus, the surface of the workpiece is selectively transmitted by the optical path switching means along the optical paths spatially separated from each of the plurality of light patterns and guided to the surface of the workpiece. The optical path of the light incident on is switched. In this case, the shape of the image of the light pattern formed on the surface of the workpiece can be switched by forming different light patterns for each LED array.
[0012]
Thus, in the stereolithography apparatus of the present invention, the angle (direction) of incident light with respect to the surface of the workpiece can be changed by switching the optical path of the light incident on the surface of the workpiece. Therefore, for example, an image of a predetermined light pattern is formed by irradiating light at a desired angle (orientation) on the surface of the ultraviolet curable resin applied to a local region of a workpiece having a complicated surface shape such as artificial bone. Can be formed. Then, fine scanning according to the light intensity distribution of the optical pattern image can be efficiently performed while scanning the optical pattern image as necessary.
[0013]
Further, in the stereolithography apparatus of the present invention, light is generated based on light from the surface of the workpiece through the objective optical system along an optical path substantially different from the optical path of light incident on the surface of the workpiece. The surface of the workpiece on which the pattern image is formed can be observed. Furthermore, a multifocal optical system having a different focal length according to the region through which the light passes is used as the objective optical system, and the optical pattern image formed on the surface of the workpiece by the action of the optical path switching means is connected in the optical axis direction. The image position can be switched.
Therefore, in the present invention, by appropriately switching the angle (orientation) of incident light with respect to the surface of the workpiece, the shape of the image of the optical pattern, the imaging position in the optical axis direction, etc. while observing the surface of the workpiece, Complex and fine shape processing can be performed more efficiently while scanning an optical pattern image as required.
[0014]
Embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view schematically showing a configuration of an optical modeling apparatus according to an embodiment of the present invention.
The apparatus of the present embodiment includes a light source 41 that emits ultraviolet light. As the light source 41, for example, an ultraviolet light emitting laser such as an Ar laser can be used. The light emitted from the light source 41 enters the pattern mask 47a through a collimator lens and a diffusion plate (not shown) as uniform light having no uneven illuminance. The pattern mask 47a includes a transparent portion and an opaque portion, and light transmitted through the transparent portion forms a light pattern having a predetermined shape.
[0015]
The pattern light transmitted through the pattern mask 47 a is incident on the inclined surface 43 a of the hexagonal truncated pyramid prism 43. The light reflected downward in the figure by the inclined surface 43a of the prism 43 enters a light valve 44 made of, for example, a liquid crystal display element. The light that has passed through the light transmitting portion 44a of the light valve 44 is collected via the objective optical system 45 and guided along the optical path 49a to a workpiece 46 such as artificial bone. An ultraviolet curable resin is applied to a predetermined region of the workpiece 46. Thus, a pattern image of the pattern mask 47a is formed on the surface of the ultraviolet curable resin applied to a predetermined region of the workpiece 46. In FIG. 1, for the sake of clarity, the light valve 44 is disposed closer to the light source than the objective optical system 45. In general, the light valve 44 is positioned near the pupil plane of the objective optical system 45. It is preferable. However, when the light pattern is one small spot pattern, it can be arranged at a position away from the pupil plane of the objective optical system 45, for example, closer to the workpiece than the objective optical system 45.
[0016]
The workpiece 46 is supported by a stage 50 that can move three-dimensionally. The stage 50 includes, for example, an XY stage that can move two-dimensionally in a plane perpendicular to the optical axis of the objective optical system 45, and a Z stage that can move in the optical axis direction of the objective optical system 45. Therefore, the workpiece 46 can be moved three-dimensionally by driving the stage 50, and the predetermined region to be shape-processed of the workpiece 46 can be positioned at a desired position with respect to the objective optical system 45. Further, if necessary, a pattern image is two-dimensionally displayed on the surface of a predetermined region of the workpiece 46 by moving the workpiece 46 two-dimensionally in a plane perpendicular to the optical axis of the objective optical system 45. Can also be scanned.
[0017]
The apparatus of this embodiment also includes a light emitting element 47b capable of forming a two-dimensional light pattern made of ultraviolet rays. As the light emitting element 47b, for example, a CRT, LED array, DMD (digital micromirror device), or the like can be used. Light from the light pattern formed on the light emitting element 47 b is incident on the inclined surface 43 b of the hexagonal truncated pyramid prism 43. The light reflected downward in the drawing by the inclined surface 43b of the prism 43 passes through the light transmitting portion 44b of the light valve 44, and is then condensed through the objective optical system 45, along an optical path 49b different from the optical path 49a. Guided to work piece 46. Thus, a pattern image of the light emitting element 47b is formed on the surface of the ultraviolet curable resin applied to a predetermined region of the workpiece 46.
[0018]
The pattern image formed on the surface of the ultraviolet curable resin applied to a predetermined region of the workpiece 46 and the light from the periphery thereof are along an optical path 48 different from the optical paths 49a and 49b, along the objective optical system 45. In addition, the light enters the prism 43 through a light transmission portion 44 c formed at the center of the light valve 44. The light incident on the prism 43 passes through the upper surface 43c and the bottom surface 43d, and forms an image on the imaging surface 42 of an imaging device such as a CCD. Thus, based on the output signal of the CCD, an image of the shape processing region of the workpiece 46 on which the pattern image is formed is reproduced. That is, the shape processing region of the workpiece 46 can be observed at any time through the observation system including the objective optical system 45, the light valve 44, the prism 43, and the CCD.
[0019]
In the apparatus of the present embodiment, the pattern light from the pattern mask 47a passes through the light transmitting portion 44a of the light valve 44 and reaches the workpiece 46 along the optical path 49a. On the other hand, the pattern light from the light emitting element 47b passes through the light transmitting portion 44b of the light valve 44 and reaches the workpiece 46 along the optical path 49b.
Therefore, when the light pattern forming means is constituted by the light source 41 and the pattern mask 47a and uses only the pattern light from the pattern mask 47a, the position of the light transmitting portion 44a is changed by the action of the light valve 44 as the optical path switching means. Thus, the optical path 49a of the light incident on the workpiece 46 can be switched.
[0020]
Further, when the light pattern forming means is constituted by the light emitting element 47b and only uses the pattern light from the light emitting element 47b, by changing the position of the light transmitting portion 44b by the action of the light valve 44 as the optical path switching means, The optical path 49b of the light incident on the workpiece 46 can be switched.
That is, in any case, the optical path of the light incident on the workpiece 46 is switched, and the formation position of the pattern image on the surface of the workpiece 46 is not substantially changed. The angle (direction) of incident light can be changed.
[0021]
Further, when the light pattern forming means is composed of the light source 41, the pattern mask 47a, and the light emitting element 47b, and uses both the pattern light from the pattern mask 47a and the pattern light from the light emitting element 47b, as an optical path switching means. By selecting only one of the light transmission part 44a and the light transmission part 44b by the action of the light valve 44, the optical path of the light incident on the workpiece 46 is switched between the optical path 49a and the optical path 49b. be able to. That is, even when light from two light patterns spatially separated from each other is used, the optical path of light incident on the workpiece 46 is switched to change the pattern image formation position on the surface of the workpiece 46. The angle (orientation) of incident light with respect to the surface of the workpiece 46 can be changed without substantially changing.
[0022]
In the apparatus of the present embodiment for shape processing, an ultraviolet curable resin is applied to a predetermined area of the workpiece 46 to be shape processed, and the predetermined area of the workpiece 46 is moved to the objective optical system 45 by driving the stage 50. Position. Thus, a predetermined pattern image is formed on the surface of the ultraviolet curable resin applied to a predetermined region of the workpiece 46. As described above, by the action of the light valve 44 as the optical path switching means, the optical path of the light incident on the surface of the workpiece 46 is switched, and the angle (direction) of the incident light with respect to the surface of the workpiece 46 is changed. It can be changed appropriately. Therefore, for example, a pattern image can be formed by irradiating light at a desired angle (orientation) on the surface of an ultraviolet curable resin applied to a local region of a workpiece having a complicated surface shape such as artificial bone. it can. And fine shape processing according to the light intensity distribution of a pattern image can be performed efficiently, scanning a pattern image as needed.
[0023]
By the way, in the apparatus of the present embodiment, when only the pattern light from the pattern mask 47a is used, the shape of the pattern image formed on the surface of the workpiece 46 is changed by changing the shape of the light pattern of the pattern mask 47a. Can be switched. When only the pattern light from the light emitting element 47b is used, the shape of the pattern image formed on the surface of the workpiece 46 can be switched by changing the shape of the light pattern of the light emitting element 47b. Further, when both the pattern light from the pattern mask 47a and the pattern light from the light emitting element 47b are used, light patterns having different shapes are formed on the pattern mask 47a and the light emitting element 47b, thereby serving as an optical path switching means. By the action of the light valve 44, the shape of the pattern image formed on the surface of the workpiece 46 can be switched.
[0024]
FIG. 2 is a diagram illustrating variations of the light pattern formed in the pattern mask 47a or the light emitting element 47b of the present embodiment, and the corresponding light intensity distribution is shown on the right side of each light pattern.
In this way, by switching the shape of the optical pattern and switching the shape of the pattern image formed on the surface of the workpiece 46, it becomes possible to perform more complicated and fine shape processing and shape processing having various surface roughnesses. .
[0025]
FIG. 3 is a diagram illustrating a variation of the light transmission portion formed in the light valve 44 of the present embodiment.
In general, for example, when a light valve made of a liquid crystal display element is used, the formation position and shape of the light transmission part can be changed as needed. Therefore, by changing the formation position of the light transmission part, the angle (orientation) of the incident light with respect to the surface of the work piece is changed, as well as by changing the shape of the light transmission part, the light is incident on the work surface. It is possible to adjust the numerical aperture of the luminous flux to be adjusted, and thus the depth of focus of the objective optical system (depth of field in the observation system). In addition, the intensity of the light beam incident on the surface of the workpiece can be adjusted by changing the transmittance of the light transmitting portion.
[0026]
Also, a multifocal optical system with a slightly different focal length depending on the region through which light passes is used as the objective optical system, and the pattern image formed on the surface of the workpiece by the action of the light valve is formed in the optical axis direction. It can also be configured such that the position can be switched. In this case, while observing a predetermined region of the workpiece on which the pattern image has been formed through the observation system, the workpiece is switched by switching the focal length of the objective optical system along the optical path of the light incident on the workpiece. The pattern image can be sharpened without moving.
[0027]
As described above, in the apparatus of the present embodiment, the angle (orientation) of incident light with respect to the surface of the workpiece, the shape of the pattern image, and the optical axis direction while observing a predetermined region of the workpiece through the observation system. By appropriately switching the image forming position, the numerical aperture and intensity of the incident light beam, etc., it is possible to more efficiently perform complicated and fine shape processing while scanning the pattern image formed on the surface of the workpiece as necessary. Can do.
In the above-described embodiment, the stage is composed of the XY stage and the Z stage. However, when the workpiece is rotationally symmetric as a whole with respect to the optical axis of the objective optical system, the stage is light of the objective optical system. It is preferable to provide a θ stage that can rotate around an axis. Further, it is advantageous to perform a complicated and fine shape processing by adding a stage function capable of rotating around another axis as required.
[0028]
In the above-described embodiment, an apparatus having one observation image plane is illustrated. However, an observation system having a plurality of observation image planes can be configured along a plurality of different optical paths.
Furthermore, in the above-described embodiment, the apparatus of the present invention is applied to shape processing of a local region of a modeled object such as artificial bone. However, like the conventional apparatus, even if the stereolithography apparatus of the present embodiment is used, a predetermined three-dimensional structure is obtained by irradiating a pattern image onto the liquid surface of the ultraviolet curable resin and sequentially curing and laminating each layer portion. A shaped object having a shape can be formed.
[0029]
In the above-described embodiment, a light valve made of, for example, a liquid crystal display element is used as the optical path switching means. However, when using a plurality of light patterns, an aperture stop having a plurality of openings is used instead of the light valve. It can also be used.
Further, in the above-described embodiment, the optical modeling apparatus is fixed and the workpiece is movable. However, contrary to the configuration of the present embodiment, the optical modeling apparatus can be movable and the workpiece can be fixed.
[0030]
【effect】
As described above, in the present invention, the angle (direction) of incident light with respect to the surface of the workpiece can be changed by switching the optical path of the light incident on the surface of the workpiece. The surface of the ultraviolet curable resin applied to the local area of the workpiece having a complex surface shape is irradiated with light at a desired angle (orientation) to form an image of a predetermined light pattern. Fine shape processing can be efficiently performed while scanning an image as necessary.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a configuration of an optical modeling apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a variation of a light pattern formed in the pattern mask 47a or the light emitting element 47b of the present embodiment, and a corresponding light intensity distribution is shown on the right side of each light pattern.
FIG. 3 is a diagram illustrating a variation of a light transmission portion formed in the light valve 44 of the present embodiment.
[Explanation of symbols]
41 Light source 42 CCD imaging surface 43 Hexagonal frustum prism 44 Light valve 45 Objective optical system 46 Work piece 47b Light emitting element 47a Pattern mask 50 Stage

Claims (5)

A light pattern forming means for forming a light pattern having a predetermined shape;
An objective optical system for condensing light from the light pattern to form an image of the light pattern on the surface of the workpiece;
Light incident on the surface of the workpiece in order to change the angle of incident light with respect to the surface of the workpiece without substantially changing the formation position of the image of the optical pattern on the surface of the workpiece. An optical path switching means for switching the optical path of
An optical modeling apparatus, wherein the workpiece is shaped according to a light intensity distribution of an image of the optical pattern formed on the surface of the workpiece. 2. The optical path switching unit switches an optical path of light incident on the surface of the workpiece by changing a position of a light transmitting portion through which incident light from the light pattern is transmitted. Stereolithography equipment. The optical modeling apparatus according to claim 2, wherein the optical pattern forming unit switches a shape of an image of the optical pattern formed on a surface of the workpiece by changing a shape of the optical pattern. . The light pattern forming means forms a plurality of light patterns spatially separated from each other;
The optical path switching means selectively transmits the light incident along the optical paths spatially separated from each of the plurality of light patterns and guides the light to the surface of the workpiece. The optical modeling apparatus according to claim 1, wherein the optical path of light incident on the surface is switched. The light pattern forming means forms a plurality of different light patterns,
The optical modeling apparatus according to claim 4, wherein the shape of the image of the optical pattern formed on the surface of the workpiece is switched by the action of the optical path switching unit.

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