JPH10128856A - Method and apparatus for processing optically shaped data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for processing data in order to shape data optically and precisely at a high speed by optical shaping. SOLUTION: When a region S(n+1) enclosed with respective contour lines of the (n+1)th contour data and the n th contour data for a contour data group of a model shape is projected on Sn, in the case where a process wherein a difference S sef between Sn and a logical product of Sn and S(n+1) (Sn AND S(n+1)) is compared with a specific value C1, a process wherein an area of a region obtained by offsetting the contour of Sn by a specific value C2 inside is compared with the specific value, and a process for discrimination of truth or falsehood of logical products of both processes are executed and when the discrimination judge result is true, the judged result that liquid surface stabilizing time from application of uncured resin for shaping a part of the n th contour data to start of exposure is made longer than a first set time, is outputted. In the case of falsehood, the judge result that the liquid surface stabilizing time is set at the first setting time, is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereolithography method and an apparatus for producing a three-dimensional resin model by curing an ultraviolet-curable resin by laser irradiation, and more particularly to a stereolithography product having excellent dimensional accuracy in a short time. And a device therefor.

[0002]

2. Description of the Related Art An optical molding technique is known as a technique for creating a shape model from three-dimensional CAD data in a short time. As shown in Japanese Patent Publication No. 6-69726 and Japanese Patent Publication No. 6-69724, the UV curing resin is irradiated with a UV laser in accordance with the contour data converted by cutting the CAD shape data into a circle. The molding is performed by repeating the hardening and lamination.

[0003]

In stereolithography, a photocurable resin is cured and laminated at a predetermined pitch. In order to laminate at a predetermined pitch, it is necessary that every time the layer is further cured, it is submerged in the uncured resin by the lamination pitch, and the uncured resin is applied on the cured layer at a constant thickness. For this reason, the uncured resin is once thickly applied and the excess is scraped off with a squeegee. However, the photocurable resin is viscous and does not provide a desired uncured layer thickness to be defined by a squeegee. In particular, there is a problem that a difference occurs between the liquid level of the surrounding uncured resin and the height of the applied surface on the hardened layer having a large area. If exposure curing is performed in this state, the difference in liquid level is fixed, and the end of the molding surface is inclined or rounded, so that high-precision molding cannot be performed. For this reason, after scraping with a squeegee, it is necessary to provide a predetermined waiting time as a liquid level stabilization time so that the liquid level becomes uniform. However, since the viscosity of the resin is high, this time is required for 20 to 60 seconds per layer, and there is a problem that a lot of dead time is generated in the optical molding in which several hundreds to thousands of layers are stacked.

In the prior art, it is impossible to achieve both high-precision molding and molding in a short time.

In addition, it is possible to manually determine which layer is to be set to have a longer liquid surface stabilization time while considering the shape, but it takes a great deal of time and mistakes are inevitable. There's a problem. A data processing method that automatically determines the setting of the liquid level stabilization time when exposing and curing the n-th layer from the data and outputs a determination result, and automatically performs the liquid level stabilization based on the determination result. An object of the present invention is to provide an optical shaping apparatus capable of setting and controlling the length of the lithography time.

[0006]

When an uncured resin is applied, cured by exposure, and sequentially laminated, even if the layer has a large area, if the layer is not the upper surface of the model, the When the next layer is applied and cured, there is no problem in accuracy because the roundness and the inclination of the end portion generated when the layer is cured are buried when the next layer is applied and cured. The roundness or inclination of the end remains, which causes a problem in accuracy when the layer is the upper layer of the model.

Therefore, the upper surface is first detected by means for detecting the upper surface from the model shape data. Among the detected upper surfaces, the surface area is small, and when the uncured resin is applied, there is also an upper surface in which the height of the liquid level equilibrates with the surrounding liquid surface in a short time. There is no need to set it long. This can be achieved by identifying whether or not a point having a large area and being separated from the end by a predetermined value or more exists in the surface by the shape identification means on the upper surface.

For this reason, for the contour data group converted at a predetermined pitch P from the model shape data, the nth contour data and the (n + 1) th contour data in the contour data group are compared, and the contour lines of both contour data are compared. Are defined as Sn and S (n + 1), respectively, and when S (n + 1) is projected on Sn, Sn to Sn and S (n + 1)
AND (Sn AND S (n + 1)) is larger than a predetermined value A (a large area appears on the upper surface), and S
Achieved by performing data processing for automatically determining that the area of a region formed by offsetting the outline of n by a predetermined value C inward is positive (no inversion: a point separated from the outline by a predetermined value exists). it can. Based on the judgment result, the judgment result is true (it takes a long time to stabilize the liquid surface because it takes time to equilibrate the liquid surface around the outside of the end and the liquid surface of the resin applied on the upper surface. Required), a determination result is output in which the liquid surface stabilization time from the application of the uncured resin for forming the part of the n-th contour data to the start of exposure is longer than the first set time. In other cases, a determination result for setting the liquid level stabilization time to the first set time is output.

The stereolithography apparatus is provided with a liquid level stabilization time variable control means controlled by the data processing and the result, thereby controlling the liquid level stabilization waiting time control means to form a layer other than the upper surface. When forming a layer that has a small area even on the upper surface and can quickly stabilize the liquid level, the liquid level stabilization time is set and controlled to a short first set time, and then formed. On the other hand, if the discrimination result is the top surface and the result is that the surface area is large and the liquid surface stabilization requires time, the liquid level stabilization wait time control means is controlled to set the liquid surface stabilization time to a long second setting. The model is controlled by setting the time.

As a result, the dimensional accuracy can be improved on the upper surface related to the dimensional accuracy, and the liquid surface stabilization time can be shortened in other portions, and both high accuracy and modeling in a short time can be achieved.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a P of the data processing method according to an embodiment of the present invention.
FIG. The process is started, and initial settings such as specification of a shape data file and setting of a lamination pitch for contour line conversion are performed. Next, all the patch data representing the shape are read and converted into a contour data group having a pitch P.

For these contour data groups, as shown in FIG. 2, the n-th contour data and the (n + 1) -th contour data are compared, and the regions surrounded by the contour lines of both contour data are Sn and S ( n + 1) and S (n +
When 1) is projected onto Sn, from Sn to Sn and S (n
When the difference S def from the logical product (Sn AND S (n + 1)) of (+1) is larger than the predetermined value C1, it can be understood that the n-th layer is formed as the upper surface of the model. Furthermore, as shown in FIG. 3, by determining that the area of the region formed by offsetting the contour line of Sn inward by the predetermined value C2 is positive (not inverted), the surface is wide and the area outside the model is determined. It can be identified that it takes time to stabilize the liquid level between the liquid level and the liquid level above the model. This identification determination result is
The liquid level stabilization time until the start of exposure after the application of the uncured resin for forming the part of the n-th contour data is output as a determination result that is longer than the first set time, and in other cases, This is output as a determination result of setting the liquid level stabilization time to the first set time.

By setting the liquid surface stabilization time of the optical shaping apparatus based on this output, it is possible to form a model with high accuracy and high speed.

FIG. 4 is an explanatory view of an optical shaping apparatus according to an embodiment of the present invention. UV curable resin 1 is injected into UV curable resin tank 2. The squeegee 3 is mounted on a slide rail 4 provided in parallel with the liquid surface of the UV curable resin 1.
It is configured to be able to move in contact with the liquid surface of the V-cured resin 1. The work table 7 for stereolithography is controlled by the work table Z-axis moving means 8 to move in the Z-axis (depth) direction in the UV-curable resin tank 2 while keeping the liquid level of the UV-curable resin 1 parallel. The UV laser light 9 is emitted to a laser oscillator 10 and irradiates the liquid surface of the UV curable resin 1 via a galvanometer mirror (X axis, Y axis) 11. The galvanomirror 11 is controlled by a galvanomirror control circuit 12 so that the laser beam 9 can scan the liquid surface of the UV curable resin 1.
The squeegee driving means 5, the galvanomirror control circuit 12, and the worktable moving means 8 are a stereolithography system control circuit 13.
Is controlled by The stereolithography system control circuit 13 operates the galvanomirrors 11 of the X and Y axes via the galvanomirror control circuit 12 according to the contour drawing data 14, and the laser beam 9 scans the liquid surface of the UV curable resin 1. The portion of the UV curable resin 1 irradiated with the laser beam 9 is immediately cured. When the scanning for one layer is completed, the optical shaping system control circuit 13 reads the contour drawing data 14 'of the next layer, and moves the work table 7 through the work table Z-axis moving means 8 further deeper by the stacking pitch P.
Submerge from the liquid surface of V-cured resin 1.

A new layer of uncured UV curable resin is placed on the already cured layer. Thereafter, by moving the squeegee 3, the uncured resin portion applied thicker than the prescribed liquid level is removed. FIG. 7 shows that after the n-th layer is cured, the work table 7 is sunk by P, and the uncured resin layer 1 is placed thereon.
5 has been applied. Insufficiency of application occurs in a portion where the width of the hardened layer on the application bottom surface is wide, and an uncured resin is applied thickly in the narrow portion 18 or the end portion 19. As a result,
As shown in FIG. 8, portions to be cured with a predetermined thickness (reference line 21) have portions that are too thin and portions that are too thick, which causes a problem of reduction in dimensional accuracy.

FIG. 5 is a PAT diagram of the shaping process, in which the liquid surface stabilization time is determined from the shape data to determine whether the shaping surface is the model upper surface and the set time is long when the area is large.
The liquid surface stabilization time is set, and in other cases, the first liquid surface stabilization time is set short, and the exposure, curing, and lamination are sequentially repeated to form the object.

The PAT diagram of FIG. 6 does not make a judgment for each layer as shown in FIG.
The molding is performed by repeating the application, the liquid surface stabilization, and the exposure and curing, and the judgment can be performed collectively before the molding.

FIG. 9 automatically detects that there is a large area on the molding upper surface by the processing of FIGS. 5 and 6, and sets the liquid level stabilization time longer than the first liquid level stabilization time (5 seconds). FIG. 8 is a diagram showing a state of the liquid surface when the stabilization time is automatically switched to the liquid surface stabilization time (60 seconds). The difference in liquid level between the resin on the cured portion and the surrounding resin could be eliminated. As shown in FIG. 10, even when exposed to light, the cured surface is flat, has good dimensional accuracy, and can form a shape model with high accuracy.

If it is not the upper surface, as shown in FIG. 11, the surface is flattened by setting the liquid surface stabilization time sufficiently long, and the non-upper surface is formed at high speed, and the upper surface is formed with high precision. High precision high speed molding was achieved.

[0020]

According to the present invention, when the lamination is repeated, the liquid level stabilization time after application of the uncured resin for each layer is controlled for a longer or shorter time regardless of the dimensional accuracy. Layers can be automatically detected from the build data. The liquid level stabilization time can be automatically set and controlled based on this detection data.

For this reason, the liquid level stabilization time is lengthened only when necessary and high precision is achieved without repeating an unnecessarily long liquid level stabilization time, thereby achieving both high precision and high speed molding. I can do it. In addition, since the determination of the length of the liquid level stabilization time and the control can be automatically performed,
There is no need for human judgment, and there is no mistake or mistake.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of data according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of processing.

FIG. 3 is an explanatory diagram of a process.

FIG. 4 is an explanatory view of an optical shaping apparatus according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a process of the optical shaping apparatus of the present invention.

FIG. 6 is an explanatory diagram of a process of the optical shaping apparatus of the present invention.

FIG. 7 is an explanatory diagram of the operation of the present invention.

FIG. 8 is an explanatory diagram of the operation of the present invention.

FIG. 9 is an explanatory diagram of the operation of the present invention.

FIG. 10 is an explanatory diagram of the operation of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... UV curable resin, 2 ... UV curable resin tank, 3 ... Squeegee, 4 ... Slide rail, 5 ... Squeegee drive means, 7 ... Work table, 8 ... Z axis moving means, 9 ... UV laser light, 10 ... Laser oscillator Reference numeral 11: Galvanometer mirror; 12, Galvo mirror control circuit; 13, Stereolithography system control circuit; 14, Contour line drawing data.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Norio Goto, Inventor 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Multimedia Systems Development Headquarters, Hitachi, Ltd. (72) Inventor Kiyoshi Wada Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa (292) Inventor Masayuki Muranaka 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo, Japan Hitachi, Ltd.

Claims (2)

[Claims] 1. An uncured U layer is formed on a cured photocurable resin layer.
A V-cured resin is applied to a predetermined thickness, the uncured resin is exposed and cured according to contoured shape data, and a new cured layer is repeatedly laminated on the already-cured layer. In stereolithography, the shape model data is converted into a contour data group having a predetermined pitch P, and the n-th contour data and (n +
The 1) -th contour data is compared, and the areas surrounded by the contour lines of both contour data are defined as Sn and S (n + 1), respectively, and S
When (n + 1) is projected onto Sn, the logical product of Sn and S (n + 1) from Sn (Sn AND S (n + 1))
Is larger than the predetermined value A and the area of the region formed by offsetting the contour line of Sn inward by the predetermined value C is positive, the uncured portion for forming the part of the n-th contour data First time to stabilize the liquid surface of resin after coating with resin
A stereolithography data processing method, comprising: outputting a determination result that is longer than the set time, and outputting a determination result that sets the liquid level stabilization time to the first set time in other cases. 2. An optical shaping apparatus according to claim 1, further comprising variable control means for the liquid surface stabilization time, wherein the control setting value of the liquid surface stabilization time is set and controlled to a longer or shorter time based on the judgment result of the data processing means. .