JPH0252724A - Optical shaping method - Google Patents

Abstract

PURPOSE:To efficiently form a comparatively thick belt-shaped solid of desired shape with high dimension accuracy by one scanning by using laser with light amount distribution having a ring large light amount area or a section vertical to the optical axis as irradiation light. CONSTITUTION:Ring laser is irradiated to a photosetting fluidized substance and scanned at given speed. The set section width (X1) based on the ring laser irradiation is considerably larger than the set section width (X2) of TEMoo model laser irradiation, and therefore, a belt-shaped set section thicker than existing laser having the light amount distribution represented by Gaussian function can be formed with same power consumption. The dimension accuracy of the belt-shaped set section peripheral edge based on laser irradiation is lowered by using a diffused TEMoo model laser, and for instance, a solid of complicated shape cannot be formed. Said defects can be eliminated by using the ring laser to form a solid of complicated shape with high dimension accuracy efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical shaping method using light and a photocurable fluid material to form a solid body of a desired shape.

Conventional technology and its problems Traditionally, models corresponding to the product shape required during mold production, or models for tracing control in cutting or die-sinking electrical discharge machining electrodes, have been produced by hand processing or using an NC milling machine. This was done by NC cutting using, etc. However, when using manual machining, there is a problem in that it requires a lot of time and skill, and when using NC machining, it is necessary to create a complicated machining program that takes into account replacement to change the shape of the cutting edge of the blade, wear, etc. In addition, there is a problem in that additional finishing machining may be required to remove steps formed on the machined surface.

In order to solve these problems, the present inventor has proposed the following optical modeling method.

In this method, the photocurable fluid material (A) is placed in a container (not shown).
The base plate (2) housed in the container and supported by the support rod (3) is irradiated with light from above to a depth such that a continuous hardened portion extending from the upper surface of the fluid substance (A) to the upper surface of the base plate (2) is obtained. Submerged in a fluid substance (A) as shown in (
(see FIG. 7(a)), selectively irradiates light from above the fluid material (A) through a light converging device (4) such as a convex lens, and from the top surface of the fluid material (A) onto the base plate (2). (See Figure 7(b))
Furthermore, the base plate (2) is coated with a fluid substance (A) to a depth corresponding to the above-mentioned depth on the hardened portion (5).
) (see Figure 7(e)), and the fluid material (A
) is selectively irradiated with light from above to cure the hardened portion'' (5).
A hardened portion (6) extending continuously upward is formed from the base plate (see Fig. 7(d)), and the settling of the base plate (2) and the formation of the hardened portion are repeated to form a solid having a desired shape. (Japanese Patent Application Laid-Open No. 60-247517).

The proposed optical modeling method forms a solid body in a desired shape by a simple operation of selectively irradiating light while adjusting the depth of the photocurable fluid material, and does not require manual processing as described above. It eliminates the need for labor and skill when using N
This has the effect of eliminating the need for changing blades, creating complex machining programs, and adding finishing machining when using C-cutting.

However, when selectively irradiating light, if the light beam is converged with a lens, for example, in the case of laser light, it is possible to concentrate all the light energy to a diameter of 1 μm or less, and to obtain a solid with good dimensional accuracy. However, there is a problem in that the solid that can be obtained in one scan is limited to a thin strip corresponding to the diameter of the light beam.

In order to deal with this problem, it is possible to emit laser light as a thick beam, or to expand the diameter of the beam using a lens, etc., but the intensity of the laser beam is determined based on the cross section of the beam, for example centered on the optical axis. Since the material is attenuated toward the periphery like a Gaussian distribution, there is a problem that the degree of hardening in the periphery becomes unstable and the dimensional accuracy of the obtained solid deteriorates.

An object of the present invention is to solve the above-mentioned problems, and to provide an optical modeling method that can form a relatively thick band-shaped solid with high dimensional accuracy in one scan of light irradiation, and can efficiently form a solid of a desired shape. It is about providing law.

Means for Solving the Problems The above object of the present invention is to house a photocurable fluid material that hardens with light in a container, and while irradiating the fluid material with light, irradiating the irradiated area with respect to the container. In an optical modeling method in which a solid body having a desired shape is formed by relative movement according to the shape of the object to be modeled in the horizontal and vertical directions, when performing the light irradiation, the light intensity distribution in a cross section perpendicular to the optical axis is annular. This is achieved by an optical modeling method characterized in that a laser oscillated in a mode having a region is used as the light.

As a method for forming a solid in a desired shape to which the present invention can be applied,
In addition to the optical modeling method described in JP-A No. 60-247515 mentioned above, a hollow or solid bottomed body having translucency in the vertical direction is placed in the photocurable fluid material in the container. The substance is housed at a depth between the bottom surface of the bottomed body and the top surface of the container bottom such that a continuous hardened portion extending over the top and bottom surfaces of the substance is obtained by irradiation with light from above by immersion. , by selectively irradiating light from above the bottomed body to form a hardened portion extending over the upper and lower surfaces of the substance between the bottom surface and the top surface, and then slightly pulling up the bottomed body or pulling down the hardened portion; A fluid material around the bottomed body is added between the upper surface of the hardened portion and the bottom surface of the bottomed body so as to have a depth corresponding to the depth, and light is selectively emitted from above the bottomed body. An optical modeling method may also be mentioned in which irradiation is performed to form a cured part that extends continuously from the cured part, and the addition of a photocurable substance and the formation of the cured part are repeated (Japanese Patent Application Laid-Open No. 1983-1999). 101408), this method has the advantage that since the liquid level of the photocurable material to be cured is covered by the bottom of the pot, it is possible to prevent the influence of the atmosphere in the container, such as components in the air and dust. can get.

As the photocurable substance, various substances that are cured by light irradiation can be used, such as modified polyurethane methacrylate, oligoester acrylate, etc. Examples include urethane acrylate, epoxy acrylate, photosensitive polyimide, and amino alkyd.

The photocurable fluid substance may be mixed with a modifying material such as pigment, ceramic powder, metal powder, etc. in advance.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows the laser beam used as irradiation light when performing light irradiation in the optical modeling method described in, for example, the above-mentioned Japanese Patent Application Laid-Open No. 60-247515 and Japanese Patent Application Laid-Open No. 62-101408. , which shows the light intensity distribution in a cross section perpendicular to the optical axis. The laser shown in FIG. 1 is a so-called annular laser which is oscillated in a mode having a multi-light coarse region from its front axis to the periphery of its optical axis. The annular laser can be oscillated from the laser oscillator in a known manner by appropriately selecting a resonant mirror within the laser oscillator.

The above-mentioned photocurable fluid material does not have a clear threshold for the amount of light to start curing, and if a sufficient amount of light is not given,
It gradually hardens based on continued light irradiation. The initial light intensity curing value at which the fluid substance starts to harden is shown in FIG. 1(b),
It is assumed that the fluid substance is reliably cured with an amount of light equal to or higher than the light intensity (a). Therefore, in the figure, the light intensity (a) and (b
) The photocurable fluid material irradiated with light of an amount between 1 and 2 is in a semi-cured state under short-term light irradiation.

Under the above conditions, when the annular laser is scanned at a constant speed while irradiating the photocurable fluid material, the width of the hardened portion of the fluid material is represented by (Xl), and the width of the semi-hardened portion is (Rx
Indicated by +). In addition, the diameter of the luminous flux of the annular laser is (R1)
(See Figure 4) In order to compare the irradiation of the annular laser to the photocurable fluid material, T as shown in Figure 2 is used.
A conventionally used laser having an EMoo mode light intensity distribution in a cross section perpendicular to the optical axis, and the T E Moo
A laser having a mode light intensity distribution diffused by a light diffuser or the like (see FIG. 3) was scanned while irradiating each photocurable fluid material (see FIGS. 5 and 6). The traveling speed is the same as when the annular laser is scanned. Note that the annular laser and the TEMoo mode laser are oscillated from laser oscillators that differ only in the shape of the resonant mirror, and the input power of the laser oscillators is the same.

FIG. 5 shows the width of the hardened portion of the fluid material after scanning with the TEMoo mode laser irradiation as (X2), the width of the semi-hardened portion as (Rx2), and the diameter of the light beam as (R2). The diameter (R2) of the TEMoo mode laser is the diameter (R2) of the annular laser (
Same as R1).

In addition, a diffused T E Mo o mode laser (see Fig. 3), which is a diffusion of the T E Mo o mode laser described above, is used.
After scanning the irradiation, the width of the hardened portion of the fluid material is (X3), the width of the semi-hardened portion is (Rx3), and the diameter of the light beam is (R3).
As shown in Fig. 6.

As can be seen from FIGS. 4, 5, and 6, the width of the cured portion (Xl
) is the width of the cured portion of TEMoo mode laser irradiation (X2
), and therefore, compared to a conventional laser having a light intensity distribution expressed by a Gaussian function, a thicker band-shaped cured part can be formed with the same power consumption by using the above-mentioned annular laser.

In addition, the width of the cured portion (X
3) can be made the same as the cured portion width (Xl) formed based on annular laser irradiation, but the semi-cured portion width (RXa) is the same as the semi-cured portion width (Xl) formed based on annular laser irradiation.
Rx1).

Therefore, when a diffused TEMoo mode laser is used, the dimensional accuracy of the peripheral edge of the band-shaped cured portion obtained by the laser irradiation decreases, and, for example, it is impossible to form a solid having a complicated shape. The use of an annular laser eliminates these drawbacks and makes it possible to efficiently form complex-shaped solids with high dimensional accuracy.

Effects of the Invention As is clear from the above, according to the present invention, when irradiating a photocurable fluid material with light, the light amount distribution in a cross section perpendicular to the optical axis is oscillated in a mode having an annular multi-optical tooth region. Since a laser is used as the irradiation light, a relatively thick band-shaped solid can be formed with high dimensional accuracy in one scan of the light irradiation, and this optical modeling method can efficiently form a solid of a desired shape. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a graph showing an example of the light intensity distribution in a cross section perpendicular to the optical axis of the annular laser used for light irradiation in carrying out the method of the present invention, and FIG.
A graph showing an example of the light intensity distribution in a cross section perpendicular to the optical axis of an o-mode laser. Figure 3 is a graph showing an example of the light intensity distribution in a cross section perpendicular to the optical axis of a diffused TE Moo mode laser obtained by diffusing a TEMoo mode laser. A graph showing an example, FIG. 4 is a plan view showing a hardened portion of the photocurable fluid material after scanning with annular laser irradiation, and FIG. 5 is TEMo. FIG. 6 is a plan view showing the hardened portion after scanning of the diffuse T E Moo mode laser irradiation, and FIGS. 7(a) to (b) are the conventional hardened portions. FIG. 2 is an explanatory diagram schematically showing an optical modeling method. (X+), (X2), (Xa)...Group, hardened portion width (Rx+), (RX2), (RX3)...Group
Semi-cured portion width (R+), (R2), (R3)... Laser beam diameter (or more) Fig. Fig. Fig. Fig. (b) (C) (d)

Claims (1)

[Claims] [1] A photocurable fluid material that is hardened by light is placed in a container, and while irradiating light into the fluid material, the irradiation area is directed horizontally and vertically to the container according to the shape of the object to be modeled. In an optical modeling method in which a solid body having a desired shape is formed by relative movement, the light irradiation is performed using a laser that is oscillated in a mode in which the light intensity distribution in a cross section perpendicular to the optical axis has an annular high-light-intensity region. An optical modeling method characterized by its use as a