CN113715325A

CN113715325A - Photocuring three-dimensional printing method, system, equipment and computer readable medium

Info

Publication number: CN113715325A
Application number: CN202010440612.8A
Authority: CN
Inventors: 侯锋
Original assignee: Prismlab Information Technology Ltd; PRISMLAB CHINA Ltd
Current assignee: Prismlab Information Technology Ltd; PRISMLAB CHINA Ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2021-11-30

Abstract

The application provides a photocuring three-dimensional printing method, a photocuring three-dimensional printing system, photocuring three-dimensional printing equipment and a computer readable medium. The photocuring three-dimensional printing method comprises the following steps: obtaining a three-dimensional data model of a printing object; dividing the three-dimensional data model into a plurality of layers; and performing contraction processing on at least one edge in the horizontal direction of the bottom layers of the preset number of the three-dimensional data models. According to the method, the bottom edge of the three-dimensional data model of the printing object is subjected to shrinkage treatment, so that a printing model finished product can be taken out from the forming platform base plate more conveniently.

Description

Photocuring three-dimensional printing method, system, equipment and computer readable medium

Technical Field

The present application relates to the field of three-dimensional printing technologies, and in particular, to a method, a system, a device, and a computer readable medium for photocuring three-dimensional printing.

Background

In the photocuring three-dimensional printing, the printing process is carried out on a forming platform, and after the printing is finished, a printing model finished product needs to be taken out of the forming platform. Some printing models can be placed on the forming platform in a suspended mode by using a supporting tool, and the printing models can be taken out conveniently after printing is completed. However, some printing models cannot be suspended by using a supporting tool and can only be directly placed on the bottom plate of the forming platform in a bottom-attached mode. Thus, the printing model product and the forming platform may be combined too tightly, which may make it difficult to cut into and take out the piece by using a tool such as a scraper after printing.

Disclosure of Invention

The technical problem to be solved by the application is to provide a photocuring three-dimensional printing method, a photocuring three-dimensional printing system, photocuring three-dimensional printing equipment and a computer readable medium, wherein a printing model finished product can be conveniently taken out from a forming platform bottom plate.

In order to solve the technical problem, the present application provides a photocuring three-dimensional printing method, including: obtaining a three-dimensional data model of a printing object; dividing the three-dimensional data model into a plurality of layers; and performing contraction processing on at least one edge in the horizontal direction of the bottom layers of the preset number of the three-dimensional data models.

Optionally, the shrinkage distance of each bottom layer decreases from the lowest layer to the top layer.

Optionally, the predetermined number is less than or equal to the quotient of the light transmission depth divided by the average layer thickness of the predetermined number of bottom layers.

Optionally, the layers of the predetermined number of bottom layers are equal in thickness.

Alternatively, the contraction distance of each bottom layer from the lowest layer up is linear.

Optionally, a line where the shrunk edge of the layer with the smallest shrinking distance and the shrunk edge of the bottommost layer are located intersects with the horizontal plane at the bottom of the three-dimensional data model, so that a smallest positive included angle formed by the intersection of the line and the horizontal plane at the bottom of the three-dimensional data model is 15-40 degrees.

In order to solve the above technical problem, the present application further provides a photocuring three-dimensional printing system, including: the model acquisition module is used for acquiring a three-dimensional data model of the printing object; the layering module is used for dividing the three-dimensional data model into a plurality of layers; and the contraction module is used for performing contraction processing on at least one edge of the bottom layers of the three-dimensional data model in the horizontal direction, wherein the bottom layers are in the preset number.

In order to solve the technical problem, the present application further provides a photocuring three-dimensional printing apparatus, including a printing mechanism and a controller, where the controller is configured to control the printing mechanism to execute the photocuring three-dimensional printing method as described above.

To solve the above technical problem, the present application also provides a computer readable medium storing computer program code, which when executed by a processor, implements the photocuring three-dimensional printing method as described above.

Compared with the prior art, the method has the following advantages:

the bottom edge of the three-dimensional data model of the printing object is subjected to shrinkage treatment, so that a printing model finished product can be taken out from the forming platform bottom plate more conveniently.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the principle of the application. In the drawings:

fig. 1 shows a schematic flow chart of a photocuring three-dimensional printing method according to an embodiment of the application.

FIG. 2 shows a schematic diagram of a photocured three-dimensional printing model according to an embodiment of the present application.

Fig. 3 shows a schematic flow chart of a photocuring three-dimensional printing method according to an embodiment of the application.

FIG. 4 shows a bottom layer edge shrink schematic of a photocured three-dimensional printed model according to an embodiment of the present application.

Fig. 5A shows a schematic internal configuration diagram of a photocuring three-dimensional printing model according to an embodiment of the application.

Fig. 5B shows a schematic diagram of an internal configuration of a photocuring three-dimensional printing model according to another embodiment of the present application.

Fig. 5C shows a schematic view of the internal configuration of a photocured three-dimensional printing model according to yet another embodiment of the present application.

FIG. 6 shows a block diagram of a photocuring three-dimensional printing system according to an embodiment of the present application.

Fig. 7 shows a controller architecture diagram of a photocuring three-dimensional printing apparatus according to an embodiment of the present application.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways than those described herein and thus is not limited to the specific embodiments disclosed below.

As used in this application and the appended claims, the terms "a," "an," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

It will be understood that when an element is referred to as being "on," "connected to," "coupled to" or "contacting" another element, it can be directly on, connected or coupled to, or contacting the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to" or "directly contacting" another element, there are no intervening elements present. Similarly, when a first component is said to be "in electrical contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and/or other components that allow current to flow even without direct contact between the conductive components.

Fig. 1 illustrates a basic structure of a photo-curing type Three-Dimensional (3D) printing apparatus according to an embodiment of the present application. This 3D printing apparatus 100 includes a material tank 110 for containing a light curing resin, an image exposure system 120 for curing the light curing resin, and an elevating table 130 for attaching a molded workpiece. The elevating table 130 is movable up and down in a vertical direction. The image exposure system 120 is located above the material tank 110, and irradiates a beam image to cure a layer of the light-curable resin on the liquid surface of the material tank 110. After the image exposure system 120 irradiates a beam image each time to cure a layer of light-cured resin, the lifting platform 130 drives the formed layer of light-cured resin to slightly descend, and the light-cured resin is uniformly spread on the top surface of the cured workpiece through the scraper 131 to wait for the next irradiation. The squeegee 131 is movable in the horizontal direction. And circulating the steps, and obtaining the three-dimensional workpiece formed by layer-by-layer accumulation.

The image exposure system 120 may irradiate a beam image onto the photocurable resin to form a desired exposure pattern. The image exposure system 120 may use various known techniques capable of forming a beam image, which is not limited in this application.

For example, in one embodiment, the image exposure system 120 may use Digital Light Processing (DLP) projection technology. DLP projection imaging is implemented using a Digital Micromirror Device (DMD) to control the reflection of light. The digital micromirror device can be considered as a mirror. This mirror is composed of hundreds of thousands or even millions of micromirrors. Each micromirror represents a pixel from which an image is constructed.

In another embodiment, the image exposure system 120 may also use Liquid Crystal (LCD) projection technology. The liquid crystal panel comprises a plurality of pixels, each pixel can independently control the polarization direction of polarized light, and the polarized light filters on two sides of the liquid crystal panel are matched to control whether light rays of a certain pixel pass or not, so that light beams passing through the liquid crystal panel system are imaged.

The light curing type 3D printing apparatus 100 inputs a three-dimensional data model of a printing object and decomposes the three-dimensional data model into a plurality of two-dimensional images. Each two-dimensional image represents a layer of the print object. The photocurable 3D printing apparatus 100 sends these two-dimensional images to the image exposure system 120, which projects the two-dimensional images.

FIG. 2 shows a schematic diagram of a photocured three-dimensional printing model according to an embodiment of the present application. The light source-up type photocuring three-dimensional printing device is taken as an example for explanation in the application. It should be noted that the photocuring three-dimensional printing method referred to in the present application is also applicable to a light source underneath type photocuring three-dimensional printing apparatus, and will not be described herein. As shown in fig. 2, the print model may be divided into a plurality of layers, each layer having a layer thickness D; the light beam of the 3D printing apparatus penetrates into the resin to a depth H. The depth of light transmission H should be greater than the layer thickness D, otherwise the portion of a layer greater than the depth of light transmission H will not receive light. The material strength of the photocuring three-dimensional printing model finished product is in positive correlation with the irradiation strength received by the photocuring resin. That is, the material strength of the region with higher irradiation intensity is higher than the material strength of the region with lower irradiation intensity.

Fig. 3 shows a schematic flow chart of a photocuring three-dimensional printing method according to an embodiment of the application. As shown in fig. 3, the photo-curing three-dimensional printing method includes the steps of:

301, obtaining a three-dimensional data model of a printing object;

step 302, dividing the three-dimensional data model into a plurality of layers; and

step 303, performing a shrinking process on at least one horizontal-direction edge of a preset number of bottom layers of the three-dimensional data model.

The three-dimensional data model obtained in step 301 is an original three-dimensional data model of the printing object, which has not been subjected to the bottom edge contraction process.

In step 303, the light-curing type 3D printing apparatus performs a shrinking process on at least one edge in the horizontal direction of a preset number of bottom layers of the three-dimensional data model. The contraction process means that the edge of one layer of the three-dimensional data model is contracted by a certain distance in the horizontal direction toward the inner direction of the three-dimensional data model. The shrinking process may be performed in one horizontal direction, or may be performed in a plurality of horizontal directions as needed, which is not limited in the present application. The shrinking distance can be adjusted by an operator according to factors such as printing material, and the like, which is not limited in the present application.

FIG. 4 shows a bottom layer edge shrink schematic of a photocured three-dimensional printed model according to an embodiment of the present application. As shown in fig. 4, the three-dimensional data model has a predetermined number N of bottom layers, which are D1, D2, … …, Dn from the bottom layer upwards; the shrinkage distance X (dashed line) of each bottom layer is X1, X2, … …, Xn, respectively, where N is 1, 2, … …, N. After the bottom layer is shrunk, the image exposure system of the photo-curing type 3D printing device does not irradiate the shrunk part any more when the bottom layer is printed. Because the layer thickness D of each layer is less than the optical transmission depth H, when a layer is irradiated, it is still possible to receive irradiation if one or more layers below the layer are still within the optical transmission depth H. When the light beam passes through the light-curing resin, the intensity of the light beam gradually decreases along with the increase of the penetration distance. Therefore, the layers below this layer receive a lower intensity of light than the currently printed layer that is receiving the light, and the hardness of the light-curable resin after curing is also lower. That is, the light-curable resin of fig. 4, in which the bottom layers are within the range of the shrinkage distance X, still receives radiation when the upper layer receives radiation, but the intensity of the received radiation is lower than that of normal printing, and the hardness after curing is correspondingly lower. Therefore, the finished three-dimensional model product subjected to bottom shrinkage treatment is still complete in appearance, but the material strength of the bottom edge area is low, and the combination with the bottom plate of the forming platform is weak, so that the workpiece can be conveniently cut into and taken out. The cutting-in and taking-out can be performed by using a tool such as a scraper knife, and the tool used for cutting-in and taking-out is not limited in the application.

Fig. 5A shows a schematic internal configuration diagram of a photocuring three-dimensional printing model according to an embodiment of the application. The black area and the gray area in fig. 5A constitute a three-dimensional model, where the black area is a normal print area and the gray area is an area subjected to the contraction processing. Compared with the black area, the gray area has lower material strength and is weaker to be combined with the forming platform bottom plate. Therefore, when the workpiece is taken out using a cutting tool such as a blade with the gray area as the cutting position, the workpiece can be easily cut. Fig. 5B shows a schematic diagram of an internal configuration of a photocuring three-dimensional printing model according to another embodiment of the present application. Similarly to the embodiment of fig. 5A, the black area and the gray area in fig. 5B constitute a three-dimensional model, where the black area is a normal print area and the gray area is an area subjected to the contraction processing. Fig. 5A and 5B are merely examples of the internal structure of the three-dimensional printing model, and the shape of the contraction region is not limited in the present application.

Alternatively, the predetermined number N may be less than or equal to the light transmission depth H divided by the average layer thickness of the predetermined number of bottom layers

Quotient of (1), i.e

Optionally, each of the predetermined number of bottom layers has an equal layer thickness D. When the layer thicknesses of the layers of the bottom layer are equal, the average layer thickness

Equal to the layer thickness D. That is, the predetermined number N may be less than or equal to the quotient of the optical transmission depth H divided by the layer thickness D of the bottom layer, i.e., N ≦ H/D. By limiting the number of bottom layers according to the light transmission depth and the average layer thickness of the bottom layers, all the bottom layers can be ensured to receive irradiation, and the problem that the shrinkage area of part of the bottom layers cannot be cured due to insufficient irradiation is avoided.

Alternatively, the shrinkage distance X of each bottom layer may decrease from the bottommost layer up in sequence. By gradually reducing the contraction distance X from the bottommost layer upwards, the material strength of an area with a cross section similar to a triangle on the edge of the three-dimensional model is lower, and the cutting-in and taking-out are more convenient.

Alternatively, the contraction distance X of each bottom layer from the lowest layer up may be linear. At the moment, the cross section of the low-strength area of the edge of the three-dimensional model is closer to a triangle, so that the cutting-in and taking-out of the workpiece are more convenient. Fig. 5C shows a schematic view of the internal configuration of a photocured three-dimensional printing model according to yet another embodiment of the present application. Similarly to the embodiment of fig. 5A and 5B, the black area and the gray area in fig. 5C constitute a three-dimensional model, where the black area is a normal print area and the gray area is an area subjected to the contraction processing. In this case, the shape of the area subjected to the shrinking process is more triangular, and the cutting into the workpiece is more facilitated.

Preferably, a straight line where the shrunk edge of the layer with the smallest shrinking distance and the shrunk edge of the bottommost layer are located intersects with the horizontal plane at the bottom of the three-dimensional data model, so that a smallest positive included angle formed by the intersection of the straight line and the horizontal plane at the bottom of the three-dimensional data model can be 15-40 degrees. Taking the three-dimensional data model shown in fig. 4 as an example, the Dn layer is the layer with the smallest contraction distance, and a point a on the contracted edge and a point B on the contracted edge of the bottommost layer D1 of the model are on a straight line, and the straight line intersects with the horizontal plane of the bottom to form the smallest positive included angle α. Cutting into the pick is most facilitated when the included angle alpha is between 15-40 degrees.

After the above-described shrinkage processing of the bottom layer of the three-dimensional data model is completed, the photocuring-type 3D printing apparatus may start to print the three-dimensional model layer by layer. The printing process of the photo-curing type 3D printing apparatus is not described herein.

FIG. 6 shows a block diagram of a photocuring three-dimensional printing system according to an embodiment of the present application. As shown in fig. 6, the stereolithographic system 400 includes a model acquisition module 410, a layering module 420, and a shrinking module 430. The model obtaining module 410 is configured to obtain a three-dimensional data model of a printing object; the layering module 420 is used for dividing the three-dimensional data model into multiple layers; and a shrinking module 430 for shrinking at least one horizontally oriented edge of a preset number of bottom layers of the three-dimensional data model. The steps executed by the modules can refer to the description of the

steps

301 and 303 in the foregoing embodiments, and will not be further described herein.

The application also provides a photocuring three-dimensional printing device which comprises a printing mechanism and a controller, wherein the controller is configured to control the printing mechanism to execute the photocuring three-dimensional printing method.

Fig. 7 shows a controller architecture diagram of a photocuring three-dimensional printing apparatus according to an embodiment of the present application. Referring to fig. 7, a controller 700 of the stereolithographic apparatus may include a memory 710 and a processor 720. Memory 710 is used to store instructions that are executable by processor 720. Processor 720 is configured to execute instructions to implement the photocuring three-dimensional printing method described above.

In some embodiments of the present application, the controller 700 further includes a communication port 730, an input/output device 740, and an internal communication bus 750.

The communication port 730 may be responsible for data communication between the controller 700 and an external device (not shown). The input/output device 740 may support input/output data streams and image streams between the controller 700 and other components. By way of example, the input/output device 740 may include one or more of the following components: input devices such as a keyboard, mouse, camera, display, scanner, touch screen, handwriting input pad, and microphone, or any combination thereof. The input/output device 740 may input various data of numeric type or various data of non-numeric type, such as graphics, images, voice, etc., to the controller 700. The internal communication bus 750 may enable data communication between various components in the controller 700.

It is understood that a photocuring three-dimensional printing method of the present application is not limited to be implemented by one photocuring three-dimensional printing device, but may be cooperatively implemented by a plurality of online photocuring three-dimensional printing devices. The online photocuring three-dimensional printing device can be connected and communicated through a local area network or a wide area network.

Further implementation details of the three-dimensional printing apparatus of the present embodiment may refer to the embodiments described in fig. 1 to 6, and are not expanded herein.

The present application also provides a computer readable medium having stored thereon computer program code which, when executed by a processor, implements a photocuring three-dimensional printing method as described above.

In an embodiment of the present application, the computer program code may implement the above-mentioned photocuring three-dimensional printing method when executed by the processor 720 in the controller 700 shown in fig. 7.

For example, a photocuring three-dimensional printing method of the present application can be implemented as a program of the photocuring three-dimensional printing method, stored in the memory 710, and loaded into the processor 720 for execution to implement the method of the present application.

The stereolithographic method, when implemented as a computer program, may also be stored in a computer-readable storage medium as an article of manufacture. For example, computer-readable storage media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD)), smart cards, and flash memory devices (e.g., electrically Erasable Programmable Read Only Memory (EPROM), card, stick, key drive). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media (and/or storage media) capable of storing, containing, and/or carrying code and/or instructions and/or data.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Aspects of the methods and systems of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, micro-code, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. The processor may be one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), digital signal processing devices (DAPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or a combination thereof. Furthermore, aspects of the present application may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips … …), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD) … …), smart cards, and flash memory devices (e.g., card, stick, key drive … …).

A computer readable signal medium may comprise a propagated data signal with computer program code embodied therein, for example, on a baseband or as part of a carrier wave. The propagated signal may take any of a variety of forms, including electromagnetic, optical, and the like, or any suitable combination. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code on a computer readable signal medium may be propagated over any suitable medium, including radio, electrical cable, fiber optic cable, radio frequency signals, or the like, or any combination of the preceding.

Additionally, the order in which elements and sequences of the processes described herein are processed, the use of alphanumeric characters, or the use of other designations, is not intended to limit the order of the processes and methods described herein, unless explicitly claimed. While various presently contemplated embodiments of the application have been discussed in the foregoing disclosure by way of example, it should be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments of the application. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

Although the present application has been described with reference to the present specific embodiments, it will be recognized by those skilled in the art that the foregoing embodiments are merely illustrative of the present application and that various changes and substitutions of equivalents may be made without departing from the spirit of the application, and therefore, it is intended that all changes and modifications to the above-described embodiments that come within the spirit of the application fall within the scope of the claims of the application.

Claims

1. A photocuring three-dimensional printing method, comprising:

obtaining a three-dimensional data model of a printing object;

dividing the three-dimensional data model into a plurality of layers; and

and performing contraction processing on at least one edge of the preset number of bottom layers of the three-dimensional data model in the horizontal direction.

2. The method of claim 1, wherein the shrinkage distance of each bottom layer decreases from the lowest layer to the top layer in a layer-by-layer manner.

3. The method of claim 1, wherein the predetermined number is less than or equal to the quotient of the light transmission depth divided by the average layer thickness of the predetermined number of bottom layers.

4. The method of claim 1, wherein the layers of the predetermined number of bottom layers are equal in thickness.

5. The method of claim 2, wherein the contraction distance of each bottom layer from the bottommost layer up is linear.

6. The method of claim 1, wherein a line between a shrunk edge of the layer with the smallest shrinking distance and a shrunk edge of the bottommost layer intersects a horizontal plane at the bottom of the three-dimensional data model to form a smallest positive included angle of between 15 and 40 degrees.

7. A photocuring three-dimensional printing system comprising:

the model acquisition module is used for acquiring a three-dimensional data model of the printing object;

the layering module is used for dividing the three-dimensional data model into a plurality of layers; and

and the contraction module is used for performing contraction treatment on at least one edge of the preset number of bottom layers of the three-dimensional data model in the horizontal direction.

8. A photocuring three-dimensional printing apparatus comprising a printing mechanism and a controller configured to control the printing mechanism to perform the photocuring three-dimensional printing method of any one of claims 1-6.

9. A computer readable medium having stored thereon computer program code which, when executed by a processor, implements the photocuring three-dimensional printing method of any one of claims 1-6.