JP2001315214A - Method and apparatus for photo fabrication, and recording medium having photo fabrication program recorded therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the setting of fabrication conditions and to improve the precision of fabrication by using a theoretical expression for presuming curing characteristics precisely. SOLUTION: First, dimensional precision is determined (S201). Next, a preliminary experiment is done to correct the depth of permeation DP, the energy of critical curing Ec, and Rp indicating the facility of curing in the width direction in a fabrication surface (S202) to obtain those correction coefficients. Next, a space disintegration capacity is determined (S203). The capacity is determined by the depth of curing Cd and the width of curing LW. Next, with the use of corrected DP', Ec' and Rp', the optimum conditions of laser power PL, a beam radius Wf and a scanning speed V are calculated (S204). Next, testing fabrication is done (S205), a curing shape is measured (S206), slice data are prepared (S207), actual fabrication is done (S208), the shape of fabricated article is evaluated (S209), and a process is completed (S210).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical shaping method, an optical shaping apparatus, and a recording medium on which an optical shaping program is recorded.
In particular, the present invention relates to an optical shaping method, an optical shaping apparatus, and a recording medium on which an optical shaping program is recorded with improved dimensional accuracy.

[0002]

2. Description of the Related Art Stereolithography is a method of producing a three-dimensional object by gradually solidifying a photo-curable resin that becomes a solid from a liquid when irradiated with light. , Ion beam machining, electric discharge machining, etc.)
Has features.

[0003] An arbitrary micro three-dimensional shape can be integrally formed.

Since a large-scale facility is not required, construction on a laboratory level is possible.

[0005] Stereolithography can be classified as follows according to the liquid level and the method of light irradiation.

The liquid level control is classified into a free liquid level system and a regulated liquid level system, and the method of curing the liquid resin is classified into a one-photon absorption type and a two-photon absorption type.

[0007] Light irradiation methods are classified into a laser light scanning method and a surface exposure method.
It is classified into a galvanometer mirror type and a stepping motor type.

In the galvanomirror system and the stepping motor system, there are a case where the laser beam is a parallel beam and a case where the laser beam is a convergent beam. Note that light using a lamp may be used instead of laser light.

FIG. 1 shows the classification of the one-photon absorption type and the two-photon absorption type of the optical shaping method.

Here, a regulated liquid level system of a stepping motor system when a laser beam is used will be described.

In the free liquid level method, the liquid level fluctuates due to vibration or the like, and the liquid level rises due to surface tension or the like, so that precise modeling is difficult. On the other hand, in the regulated liquid level method, the thickness can be more precisely controlled, and a more precise three-dimensional shape can be created.

Further, the stepping motor is a motor whose rotation angle is proportional to the number of input pulses, and which can accurately perform positioning and speed control. The stepping motor method is a method in which the movement of the object and the scanning of the laser beam are performed using a stepping motor.

The shaping principle of the regulated liquid level system of the stepping motor system will be described with reference to FIGS.

FIG. 2A shows a personal computer. In this method, stereolithography is performed by controlling such a personal computer. For example, a three-dimensional object on the left side in FIG. 2B is manufactured by stacking slices on the right side in FIG. 2B. The three-dimensional object and the slice layer are formed by CAD (Computer)
Aided Design) / CAM (Computer Aided Manufactu)
ring).

For example, a three-dimensional object is created by CAD,
The AM creates an arbitrary number of slice layers. Note that the slice layer has two-dimensional coordinate data.

FIG. 3 shows an example of a molding process.

FIG. 3A shows a setup state. The container 10 is filled with a UV curable liquid 11 that cures when irradiated with UV (ultraviolet light). Lifting table 1
An ultraviolet light source 14 is irradiated from below through the glass 12. Ultraviolet rays can scan the surface by scanning in the X-axis direction and the Y-axis direction under the control of the personal computer in FIG. The lift 13 moves up and down according to the scanning of the light source under the control of the personal computer in FIG.

In FIG. 3B, the elevator 13 is raised by the thickness of the slice in order to form the first layer. Then, the UV curable liquid 11 flows into the space. Light source 1
4 scans the lower surface of the elevator 13 in the X-axis direction and the Y-axis direction. According to the scanning of the light source 14, the UV-curable liquid 11 is cured to generate a solid. As a result, a first slice layer is generated. When the first slice layer is generated, FIG.
As shown in (D), the lift 13 is raised by the thickness of the slice under the control of the personal computer. As a result, the UV curable liquid 11 flows into the space. As in FIG. 3C, the light source 14 scans in the X-axis direction and the Y-axis direction to generate a second slice layer. By repeating this, N slice layers are generated. FIG. 3 (F) shows the final product.

The slices of each layer are matched to the final product,
By having a predetermined shape, the final product becomes a three-dimensional object having a desired shape.

In the stereolithography method, the main parameters used for analysis are as follows.

Regarding the modeling parameters,
Laser illuminance H [mW / mm² ] On the modeling surface of convergent light
Beam radius W_f[Mm], laser scanning speed (irradiation
Time) V [mm / sec] (t [s]), on the molding surface
Laser power P_L[MW], half of beam of irradiation laser light
Diameter W_O[Mm] to determine the cured shape of the UV curable resin.
And use the curing depth Cd [mm] and curing width LW [mm]
In terms of curing parameters for UV-curable resins,
Degree DP [mm], Critical curing energy Ec [mJ / mm]
^Two ] Is used. Note that P_L= (Π / 2) W_O ²H or P
_L= (Π / 2) W _f ²H and W_OIs for parallel light
And W_fIs the case of convergent light.

Next, the analysis procedure will be described.

First, as shown in FIG. 4A, parallel light one-point exposure is performed. As a result, a conical cured shape is obtained. As will be described later, several cone-shaped samples are generated, and the critical curing energy Ec and the penetration depth DP, which are the characteristic values of the cured resin, are calculated.

The actual shaping is performed by parallel light scanning or convergent light scanning as shown in FIGS. 4B and 4C. At this time, modeling conditions (V, P _L , W _f, or W _O ) are calculated using E _C , D _P obtained in FIG.

In the following description, scanning with convergent light will be mainly described. However, with respect to scanning with parallel light, analysis and modeling can be performed in accordance with scanning with convergent light, and a description thereof will be omitted.

In the parallel light single-point exposure, the curing depth Cd and the curing width LW can be expressed as follows. (For example, Society of Manufacturin
Paul published by g Engineers
F. "Rapid Protot" by Jacobs
4th of “yping & Manufacturing”
See chapter "Basics and theory of stereolithography". ) Hardening depth Cd = Dp × ln (Ht / Ec) (1) Hardening width LW = {2 × W0 × {ln (Ht / Ec)} ^1/2 ... (2) Ht is the exposure amount Emax on the modeling surface.

Next, the curing depth Cd and the curing width LW in the parallel light scanning are obtained. Curing depth C in parallel light scanning
The d and the curing width LW are derived as follows (see the above “Rapid Prototyping & Manu”).
facting ").

[0028]

(Equation 1) Next, the curing depth Cd and the curing width LW in the convergent light scanning.
Ask for. The curing depth Cd and the curing width LW in the convergent light scanning are represented by W0 in equations (3) and (4) of the parallel light scanning:
It can be obtained by substituting the following Wf.

[0029]

(Equation 2) As shown in FIG. 5, f is the focal length of the lens [m
m] and d are the thickness of the quartz glass [mm], θ is the incident angle of the laser beam on the modeling surface [deg], and l is the focal position [mm] when the refraction between the liquid resin and the quartz glass is ignored.
Is shown.

Accordingly, the curing depth Cd in the convergent light scanning is
And the curing width LW are as follows.

[0031]

(Equation 3) In conventional stereolithography, it is a parameter necessary for analysis,
Further, the penetration depth DP and the critical curing energy Ec, which are curing parameters of the ultraviolet curable resin, were determined as fixed values by experiments.

That is, as shown in FIG. 4A, parallel light single-point exposure is performed, and several manufactured cone-shaped cured samples are produced. From this sample, the cure depth Cd of each sample is measured and plotted against the exposure as shown in FIG. Assuming that the curing depth Cd and the exposure amount can be expressed by a linear relationship, an approximate straight line A is obtained.

The penetration depth DP is obtained as the slope of the approximate straight line A, and the critical curing energy Ec is obtained as the intersection of the straight line A and Cd = 0.

A procedure for producing a three-dimensional shape in a conventional example will be described with reference to FIG. First, a three-dimensional object is designed using CAD / CAM (S100). For this purpose, the dimensional accuracy is determined in consideration of the use of the manufactured object and the like (S101). The spatial resolution is determined based on the dimensional accuracy (S102).
The spatial resolution is determined by the curing depth Cd and the curing width LW. Next, a search for molding conditions is performed by trial and error (S10).
3). By substituting the penetration depth DP and the critical curing energy Ec obtained from FIG. 6 into equations (6) and (7) for convergent light scanning,
Laser power PL, beam radius Wf, scan speed V
Is obtained on a trial basis. Test molding is performed with this trial value (S104). The dimensions of the test molding are measured, and it is determined whether or not the molding was performed with the expected dimensions. If the predetermined size has not been obtained, the molding condition is searched again by trial and error (S103). This is repeated several tens of times to obtain the desired dimensions. The slice data is created under the conditions (S
105). The actual modeling is performed using this data (S
106). If the formed dimensional accuracy is lower than the expected accuracy, the process returns to step 102 and starts over.

If the formed dimensional accuracy is higher than the expected accuracy, the process is completed (S107).

[0036]

In the stereolithography method, it is essential to set molding conditions optimally in order to rapidly produce a three-dimensional shape with high dimensional accuracy.

However, since the setting items are diversified, it is very difficult to uniquely determine the optimum conditions.

Several theoretical formulas for calculating the optimum conditions, including the formulas (6) and (7), have been reported so far, but none of them has sufficient accuracy in predicting the curing of the liquid resin. .

As a result, when the stereolithography is actually performed, it is necessary to perform many trial and errors (for example, in FIG. 7, it is necessary to perform several tens of trial and errors).
There was a problem that he had to rely on his experience at key points.

The present invention has been made in view of the above problems, and has as its object to simplify the setting of molding conditions and improve the molding accuracy by using a theoretical formula for estimating the curing characteristics with high accuracy. .

[0041]

According to a first aspect of the present invention, there is provided a stereolithography method for producing a three-dimensional object by irradiating a liquid photocurable resin with light. Obtain the cure depth, which is the depth dimension of the cure corrected by the illuminance, and the cure width, which is the width dimension on the modeling surface corrected by the illuminance, and estimate the dimensional accuracy of the three-dimensional object based on the cure depth and the cure width. hand,
It is characterized by performing stereolithography.

According to a second aspect of the present invention, in the stereolithography method according to the first aspect, the degree of ease of curing of the photo-curable resin is determined as a function of the illuminance of light, and the curing width is determined. It is characterized in that it is a function of the degree of ease of curing of the photocurable resin.

According to a third aspect of the present invention, there is provided a stereolithography method for producing a three-dimensional object by irradiating a liquid photocurable resin with light, wherein a correction term based on the illuminance of the curing depth, which is a depth dimension of curing. And a step of performing a preliminary experiment for obtaining a correction term based on the illuminance of a curing width, which is a width dimension on a modeling surface, or a degree of ease of curing of the photocurable resin.

According to a fourth aspect of the present invention, there is provided a control device,
A light source, a scanning unit, a moving unit, and a container for containing a liquid photocurable resin, wherein the control unit is at least an optical shaping device that controls the scanning unit and the moving unit; As a curing parameter of the cured resin, a curing depth, which is a depth dimension of curing that has been corrected by illuminance, and a curing width, which is a width dimension on a modeling surface that has been corrected by illuminance, are determined based on the curing depth and the curing width. It is characterized in that control is performed to produce a three-dimensional object.

According to a fifth aspect of the present invention, in the stereolithography apparatus according to the fourth aspect, the control device obtains a degree of easiness of curing of the photocurable resin as a function of illuminance of light. The curing width is obtained as a function of the degree of ease of curing of the photocurable resin.

According to a sixth aspect of the present invention, there is provided a computer-readable recording medium having recorded thereon a program for producing a three-dimensional object by irradiating a liquid light curable resin with light, and determining a dimensional accuracy. Preliminary experiments to determine the correction term based on the illuminance of the curing depth, which is the depth dimension of curing, the correction term based on the illuminance of the curing width, which is the width dimension on the modeling surface, or the degree of ease of curing of the photocurable resin , A step of determining a spatial resolution, a step of calculating an optimum molding condition, a step of creating slice data, and a molding step, and a computer-readable recording medium recording a program for causing a computer to execute the It is.

[0047]

Next, embodiments of the present invention will be described with reference to the drawings.

First, the calculation formula used in the present invention will be described.

Conventionally, it has been assumed that the curing depth Cd is linear in the logarithmic value of the product of the laser illuminance H and the irradiation time t. In contrast, in the present invention, it is assumed that the depth of cure Cd is linear in the logarithmic value of the product of the power of the laser illuminance H and the irradiation time t.

[0050]

(Equation 4) The following relationship is derived from equation (9).

[0051]

(Equation 5) Here, γ is an index representing nonlinearity.

From the experimental results described later, the expression (10)
The constants α and β in can be expressed as follows.

Α = α1 × EXP (α2Cd) (11) β = β1 + β2 Cd (12) From the above equation, the following equation is derived. .

[0054]

(Equation 6) By comparing the coefficients of the equation (13) and the conventional equation (1), a new penetration depth DP 'and a new critical curing energy Ec' can be obtained. Also, regarding the curing width LW ',
It can be calculated using a similar technique. Further, as a characteristic value of the resin, Rp 'indicating the ease of curing in the width direction when receiving ultraviolet rays was newly introduced.

[0055]

(Equation 7) In the conventional formula, Rp 'indicating the ease of curing in the width direction when receiving ultraviolet rays is a fixed value (for example,
1) was assumed.

Equations (14) to (16) are obtained by adding a non-linear term to the conventional curing parameter penetration depth D _P , critical curing energy E _C , and ease of curing R _P in the width direction. . That is, the nonlinear term reflects laser scattering / refraction, the reaction speed of the cured resin, the difference in light absorptivity between the uncured resin and the cured resin, and the like.

Next, how to find the coefficients α ₁ , α ₂ and β ₁ , β _{2 in} the present invention will be described. FIG. 8A is the same as FIG. Since the exposure amount is affected by the laser illuminance and the irradiation time, FIG. 8B is plotted with respect to the laser illuminance instead of the exposure amount. FIG. 8C is a graph plotted against irradiation time instead of the exposure amount.

In the present invention, instead of the exposure amount shown in FIG. FIG.
In (C), when the time exceeds 10 seconds, a phenomenon in which the curing depth is saturated is observed. This is considered to be due to an effect such as a reduction in efficiency because the cured resin absorbs laser light. In actual stereolithography, it is rare to perform irradiation for 10 seconds or longer, so there is no problem even if the point of 10 seconds or longer is ignored.

FIG. 9D shows a graph of irradiation time and curing depth Cd when irradiation for 10 seconds or longer is ignored. FIG. 9 (D) is rewritten to show the relationship between laser illuminance and irradiation time with respect to several curing depths Cd.
(E) is shown. Furthermore, the slope and intercept (H = 1 [mW] of the straight line in FIG.
/ Mm ² ]) is shown in FIG. 10 (F).

From FIG. 10 (F), the coefficients α ₁ and α ₂ and β ₁ and β ₂ can be obtained. The coefficients α ₁ and α
₂ and β ₁ , β ₂ are determined by performing such preliminary experiments.

The parameters for the curing width LW are obtained in the same manner.

FIG. 1 shows the procedure for producing a three-dimensional shape according to the present invention.
1 will be described. First, a three-dimensional object is designed using CAD / CAM (S200). Next, dimensional accuracy is determined in consideration of the use of the manufactured object and the like (S201). In the present invention, prior to actual modeling, a preliminary experiment is performed to determine the coefficients α ₁ , α ₂ and β ₁ , β ₂ in the present invention (S2).
02). This preliminary experiment is an experiment for determining the characteristics of the resin, and the resin that has already undergone the preliminary experiment can be handled by using the data of the previous preliminary experiment. Therefore, in this case, the step of this preliminary experiment can be jumped to the step of determining the spatial resolution.

Next, the spatial resolution is determined based on the dimensional accuracy (S203). Spatial resolution is the cure depth C
Determined by d and curing width LW.

Next, the optimum molding conditions are calculated using the data obtained as described above (S204). First,
The penetration depth DP, the critical curing energy Ec, and the curing are calculated based on the penetration depth DP ', the critical curing energy Ec', and Rp ', which indicates the ease of curing in the width direction on the molding surface. It is substituted as Rp, which indicates the ease of operation. Then, the optimum laser power PL, beam radius Wf, and scan speed V are obtained. Next, test molding is performed (S20).
5). The dimensions of the test molding are measured, and it is determined whether or not the molding was performed with the expected dimensions. If the predetermined dimensions have not been obtained, the search for the molding conditions is performed again by trial and error (S2).
06). However, in the present invention, since almost desired dimensions can be obtained, there is almost no need to search for molding conditions again. When a predetermined size is obtained, slice data is created under the conditions (S207). The actual modeling is performed using this data (S208). The shape of the modeled object is evaluated (S209). If the dimensional accuracy of the modeled object is lower than the desired accuracy, the process returns to step 203 and the modeling is performed again.

When the dimensional accuracy of the molded object is equal to or more than the expected accuracy, the object is completed (S210).

FIGS. 12 to 14 are diagrams for explaining the details of FIG. Since the flow is clear from the description of FIG. 11 and the contents described in FIGS. 12 to 14, the description is omitted.

FIG. 15 illustrates an example of an optical molding system according to the present invention.

The system shown in FIG. 15 has a metal container (resin tank) 20 provided with a hardened glass that allows ultraviolet rays to pass therethrough, a laser light source 21 for generating an ultraviolet laser, and a shutter for passing or blocking ultraviolet rays mechanically or electrically. 22, Z stage 2
3, a stepping motor 24, an XY stage 25 controlled by the stepping motor, a host computer 26 having a CAD / CAM function, a collimator 27, and a power controller 28.

The power of the ultraviolet light is controlled by the power controller 2
8 is performed. The laser light generated by the ultraviolet light source 21 is irradiated and scanned from the lower portion of the metal container 20 having a quartz glass window at the bottom via a power controller 28, a shutter 22, and a collimator 27.

The position control of the Z stage and the XY stage 25 for laser scanning uses a stepping motor 24 having a resolution of 1 μm. The laser light source 21 has a wavelength of 325.
nm, single mode with a maximum output of about 12 mW (TEM0
0) He-Cd ultraviolet laser is used. For switching between irradiation and non-irradiation of laser light, an electric shutter having a response speed of 10 msec or less may be used. The power controller 28 can perform real-time power control in the range of 0.1 μW to 1 mμW by combining two ND filters. Further, the stepping motor 24, the electric shutter 22, and the power controller 2
8 is controlled by the host computer 26.

The host computer operates as shown in FIG.
To control the entire flow of the stereolithography shown in FIG. Therefore,
The host computer is loaded with a program for controlling the entire flow of the optical molding shown in FIG. 11 or FIGS. In addition, all or a part of the program for controlling the entire flow of the optical molding shown in FIG. 11 or FIGS. 12 to 14 can be stored externally as a recording medium.

A computer-readable recording medium in which a program for producing a three-dimensional object by irradiating light to a liquid photo-curable resin is installed in a computer, and can be used as an optical shaping apparatus of the present invention. .

FIG. 16 shows a comparison between the conventional example and the present invention in which parallel light is exposed at one point. (A) is a 100-percentage of the error (the difference between the calculated value and the value of the actual molded article with respect to the irradiation time at the curing depth Cd; the same applies hereinafter). (B) is the percentage error of the laser illuminance at the curing depth Cd. (C) is the percentage of error with respect to the irradiation time in the curing width LW.
(D) is a percentage of an error with respect to the laser illuminance in the curing width LW.

In any case, it can be seen that the present invention is superior to the conventional example.

FIG. 17 shows a comparison between the conventional example and the present invention when convergent light is scanned. (A) shows a plot of the curing depth Cd with respect to the laser beam radius using the scanning speed V of the laser beam as a parameter. (B) shows the error of 10 for the laser beam radius at the curing depth Cd.
0 fraction. (C) shows a plot of the curing width LW with respect to the laser beam radius using the scanning speed V of the laser beam as a parameter. (D) is the percentage of error with respect to the laser beam radius at the curing width LW.

In any case, it can be seen that the present invention is superior to the conventional example.

FIG. 18 shows an actual model produced by the present invention.

[0078]

According to the present invention, it is possible to estimate the curing characteristics of the resin with an error of about 10% or less by using the newly calculated equation.

Further, compared with the estimation accuracy of the conventional example, 10
Up to 20%.

Further, the optical shaping apparatus of the present invention can automatically or semi-automatically set the optimum shaping conditions for a desired dimensional accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram showing a classification of an optical molding method.

FIG. 2 is a diagram showing a procedure for creating data for stereolithography.

FIGS. 3A and 3B are a diagram for explaining a shaping principle of a regulated liquid level system of a stepping motor system and a diagram showing an example of a shaping process.

FIG. 4 is a diagram illustrating an analysis procedure.

FIG. 5 is a diagram for explaining Wf.

FIG. 6 is a diagram for obtaining a penetration depth DP and a critical curing energy Ec in a conventional example.

FIG. 7 is a flowchart showing a procedure for producing a three-dimensional shape in a conventional example.

FIG. 8 is a diagram (part 1) illustrating a method of obtaining a correction parameter in the present invention.

FIG. 9 is a diagram (part 2) illustrating a method of obtaining a correction parameter according to the present invention.

FIG. 10 is a diagram (part 3) illustrating a method of obtaining a correction parameter in the present invention.

FIG. 11 is a flowchart showing a procedure for producing a three-dimensional shape according to the present invention.

FIG. 12 is a flowchart (part 1) showing a detailed three-dimensional shape preparation procedure of the present invention.

FIG. 13 is a flowchart (part 2) showing a detailed three-dimensional shape preparation procedure of the present invention.

FIG. 14 is a flowchart (part 3) showing a detailed three-dimensional shape preparation procedure of the present invention.

FIG. 15 is a diagram illustrating an example of an optical molding system according to the present invention.

FIG. 16 is a diagram showing a comparison between a conventional example and the present invention in the case of parallel light single-point exposure.

FIG. 17 is a diagram showing a comparison between the conventional example and the present invention in the case of convergent light scanning light.

FIG. 18 is a view showing an actual model produced by the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Container 11 UV curable liquid 12 Glass 13 Lifting table 14 Light source 20 Metal container (resin tank) 21 Laser light source 22 Shutter 23 Z stage 24 Stepping motor 25 XY stage 26 Host computer 27 Collimator 28 Power controller

Claims (6)

[Claims] In a stereolithography method for producing a three-dimensional object by irradiating a liquid photocurable resin with light, a curing depth of a photocurable resin, which is a depth dimension of curing corrected by illuminance, is set as a curing parameter. Obtaining a curing width that is a width dimension on a molding surface corrected by illuminance, based on the curing depth and the curing width, estimating a dimensional accuracy of a three-dimensional object, and performing optical molding by performing optical molding. . 2. The photolithography method according to claim 1, wherein a degree of easiness of curing of the photocurable resin is obtained as a function of illuminance of light, and the curing width is determined by the easiness of curing of the photocurable resin. Stereolithography characterized by a function of the degree of roughness. 3. A stereolithography method for producing a three-dimensional object by irradiating a liquid photocurable resin with light, wherein a correction term based on the illuminance of a curing depth, which is a depth dimension of curing, and a width dimension on a molding surface. A stereolithography method comprising a step of performing a preliminary experiment for obtaining a correction term based on illuminance of a curing width or a degree of easiness of curing of a photocurable resin. 4. An optical shaping apparatus for controlling at least the scanning unit and the moving unit, the control unit including a control device, a light source, a scanning unit, a moving unit, and a container for containing a liquid photocurable resin. In the control device, as a curing parameter of the photocurable resin,
Determine the curing depth, which is the depth dimension of the curing corrected by illuminance, and the curing width, which is the width dimension on the modeling surface, corrected by the illuminance, based on the curing depth and the curing width,
An optical shaping apparatus that performs control so as to produce a predetermined three-dimensional object. 5. The optical shaping apparatus according to claim 4, wherein the control device obtains a degree of ease of curing of the photocurable resin as a function of illuminance of light, and determines the curing width of the photocurable resin. An optical shaping apparatus characterized in that it is determined as a function of the degree of easiness of curing. 6. A computer-readable recording medium having recorded thereon a program for producing a three-dimensional object by irradiating a liquid photo-curable resin with light. Performing a preliminary term to determine the correction term based on the illuminance of depth, the correction term based on the illuminance of the curing width, which is the width dimension on the modeling surface, or a preliminary experiment to determine the degree of ease of curing of the photocurable resin; A computer-readable recording medium recording a program for causing a computer to execute a determining step, a step of calculating an optimum molding condition, a step of creating slice data, and a molding step.