Light source control method, device, three-dimensional printing equipment and non-volatile storage medium

Abstract

The present invention discloses a light source control method, device, three-dimensional printing equipment and non-volatile storage medium. The method includes: obtaining a target projection image, wherein the target projection image is used for three-dimensional printing; dividing the position of the selective light-transmitting screen into a projection area and a non-projection area according to the target projection image; controlling the first LED unit corresponding to the projection area to emit light according to a first preset power, and controlling the second LED unit corresponding to the non-projection area to emit light according to a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material, and the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material. The present invention solves the technical problem that the details of the three-dimensional printed object are unclear or distorted because the LCD screen in the related art may also cure the material in the non-projection area.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional printing, and in particular to a light source control method and device, a three-dimensional printing device, and a non-volatile storage medium. Background Art

[0002] In existing technology, 3D printing involves using an LCD (Liquid Crystal Display) screen to display the desired pattern. The photocurable material above the LCD screen solidifies according to the pattern, forming a layer of the 3D object. The LCD screen then updates the displayed pattern, and the next layer of the 3D object is cured based on the previous layer, until the 3D model is completely printed. When the LCD screen displays a projected image, a light source shines onto the liquid photosensitive resin. The pixels on the LCD selectively block or transmit light according to the image requirements. The transmitted light is focused by a lens onto the liquid photosensitive resin, causing it to solidify and take shape.

[0003] Even if the grayscale of the LCD screen is set to the minimum value, there will still be a weak light intensity from the light source of the LCD screen that passes through the screen, which may cause the material to solidify in the non-projected area, resulting in unclear or distorted details in the printed result.

[0004] To address the above-mentioned problems, no effective solutions have been proposed so far. Summary of the Invention

[0005] Embodiments of the present invention provide a light source control method, apparatus, three-dimensional printing equipment, and non-volatile storage medium to at least address the technical problem in related technologies of unclear or distorted details of three-dimensional printed objects caused by the possibility of solidifying materials in non-projected areas of the LCD screen.

[0006] According to one aspect of an embodiment of the present invention, a light source control method is provided for a three-dimensional printing device, the three-dimensional printing device including a selective light-transmitting screen and a light source, the light source including a plurality of LED units, light emitted by the light source is projected onto a photocurable material through the selective light-transmitting screen, the light source control method comprising: acquiring a target projection image, wherein the target projection image is used for three-dimensional printing; dividing the position of the selective light-transmitting screen into a projection area and a non-projection area according to the target projection image; controlling a first LED unit corresponding to the projection area to emit light according to a first preset power, and controlling a second LED unit corresponding to the non-projection area to emit light according to a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material, and the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material.

[0007] Optionally, the method includes: determining the power after light intensity calibration as a first preset power; and adjusting the first preset power according to a preset coefficient to obtain a second preset power.

[0008] Optionally, the preset coefficient is determined by: obtaining the number of printing layers required to print a three-dimensional printed object, wherein the projection of the slice model of the three-dimensional printed object includes a target projection image; determining the critical exposure required for curing of the photocurable material; determining the initial dynamic contrast of the three-dimensional printing device, and the curing interface exposure per unit area of the three-dimensional printing device in the projection area, wherein the initial dynamic contrast is the ratio of the light intensity projected by the three-dimensional printing device in the projection area to the light intensity projected in the non-projection area; and determining the preset coefficient based on the number of printing layers, the critical exposure, the initial dynamic contrast, and the curing interface exposure.

[0009] Optionally, determining the critical exposure amount of the exposure amount required for curing the photocurable material includes: obtaining printing parameters when three-dimensional printing is performed using the photocurable material, and physical parameters of the printed part formed; inputting the printing parameters and physical parameters into a pre-trained deep learning model, and the deep learning model outputs the critical exposure amount corresponding to the photocurable material, wherein the deep learning model is trained through training samples, and the training samples include sample critical exposure amounts corresponding to sample materials, as well as sample printing parameters and sample physical parameters when three-dimensional printing is performed using the sample materials.

[0010] Optionally, the range of the preset coefficient is configured to be in the interval [0, COE C / nE0); where C0 is the initial dynamic contrast, E C is the critical exposure, n is the number of printing layers, and E0 is the exposure of the curing interface.

[0011] According to another aspect of an embodiment of the present invention, a light source control device is also provided for use in a three-dimensional printing device, the light source control device comprising: a selectively light-transmitting screen for selectively transmitting light; a light source comprising a plurality of LED units, the light emitted by the plurality of LED units being projected onto a photocurable material through the selectively light-transmitting screen; a power control mechanism electrically connected to each LED unit, for controlling a first LED unit corresponding to a projection area of the selectively light-transmitting screen to emit light according to a first preset power, and controlling a second LED unit corresponding to a non-projection area of the selectively light-transmitting screen to emit light according to a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material, and the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material.

[0012] Optionally, any one of the multiple LED units includes an LED lamp and a collimating component, wherein the collimating component is correspondingly arranged on the light-emitting side of the LED lamp, and the collimating component is used to focus the light emitted by the LED lamp.

[0013] Optionally, the collimating component is any one of the following: a convex lens, a Fresnel lens, and a total internal reflection lens.

[0014] Optionally, any one of the multiple LED units further includes a light source reflection component, wherein the light source reflection component is arranged on the backlight side of the LED lamp to focus the light emitted by the LED lamp.

[0015] Optionally, any one of the multiple LED units further includes a light blocking component, wherein the light blocking component is arranged on the light emitting side of the LED lamp to block the light emitted by the LED lamp toward the location of other LED lamps.

[0016] Optionally, the power control structure includes: an LED driving circuit, wherein the LED driving circuit is connected to a plurality of LED units and is used to control any one of the plurality of LED units to emit light independently.

[0017] Optionally, the LED driving circuit includes an LED driving chip and a control chip, wherein the control chip is connected to the LED driving chip, multiple LED units are arranged in an array, and the LED driving chip includes multiple anode pins and multiple cathode pins, any one of the multiple anode pins is connected to the anode of the LED unit located in the same column, and any one of the multiple cathode pins is connected to the cathode of the LED unit located in the same row.

[0018] Optionally, the LED driving circuit includes an LED driving chip and a control chip, wherein the control chip is connected to the LED driving chip, the LED driving chip includes a plurality of driving pins, and the plurality of LED units are correspondingly connected to the plurality of driving pins.

[0019] According to another aspect of an embodiment of the present invention, a three-dimensional printing device is also provided, including a forming platform; a material tray for holding a photocurable material; and a light source control device as described above. The photocurable material is formed layer by layer on the forming platform under the irradiation of the light source to obtain a three-dimensional object.

[0020] According to another aspect of an embodiment of the present invention, a non-volatile storage medium is provided. The non-volatile storage medium includes a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute any one of the above-mentioned light source control methods.

[0021] In an embodiment of the present invention, a point light source is used to provide light intensity to the LCD screen. By setting the luminous intensity for the non-projected area according to the light-curing characteristics of the material, the purpose of preventing the light intensity in the non-projected area from solidifying the material is achieved, thereby achieving the technical effect of improving the accuracy of printing three-dimensional printed objects, and further solving the technical problem of unclear or distorted details of the three-dimensional printed object caused by the fact that the LCD screen in the non-projected area may also solidify the material in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 A hardware structure block diagram of a computer terminal for implementing a light source control method is shown;

[0024] Figure 2 is a flow chart of a light source control method according to an embodiment of the present invention;

[0025] Figure 3 is a structural diagram of a light source control device provided according to an embodiment of the present invention;

[0026] Figure 4 This is a structural diagram of an LED unit provided according to an optional embodiment of the present invention;

[0027] Figure 5 is a structural schematic diagram of another LED unit provided according to an optional embodiment of the present invention;

[0028] Figure 6 is a schematic structural diagram of another LED unit provided according to an optional embodiment of the present invention;

[0029] Figure 7 is a structural schematic diagram of another light source control device provided according to an optional embodiment of the present invention;

[0030] Figure 8 is a structural schematic diagram of another light source control device provided according to an optional embodiment of the present invention;

[0031] Figure 9 is a schematic diagram of a driving circuit provided according to an optional embodiment of the present invention;

[0032] Figure 10 is a schematic diagram of another driving circuit provided according to an optional embodiment of the present invention;

[0033] Figure 114 is a structural block diagram of a three-dimensional printing device provided according to an embodiment of the present invention.

[0034] The accompanying drawings are numbered as follows: 31, selective light-transmitting screen; 32, LED unit; 33, power control mechanism; 41, LED lamp; 42, collimation component; 51, light source reflection component; 61, light blocking component; 71, LED driving circuit; 81, light intensity calibration component; 82, miniature probe; 111, forming platform; 112, material tray; 113, light source control device. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0037] According to an embodiment of the present invention, an embodiment of a method for controlling a light source is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0038] The method embodiment provided in the first embodiment of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 1 FIG1 shows a hardware structure block diagram of a computer terminal for implementing a light source control method. Figure 1As shown, the computer terminal 10 may include one or more (illustrated as 102a, 102b, ..., 102n in the figure) processors (the processor may include but is not limited to a microprocessor MCU or a programmable logic device FPGA and other processing devices), a memory 104 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the BUS bus), a network interface, a power supply and / or a camera. It will be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 1 More or fewer components than shown, or with Figure 1 Different configurations shown.

[0039] It should be noted that the one or more processors and / or other data processing circuits described above may generally be referred to herein as "data processing circuitry." The data processing circuitry may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuitry may be a single, independent processing module, or may be incorporated in whole or in part into any of the other components of the computer terminal 10. As described in the embodiments of the present application, the data processing circuitry serves as a processor control (e.g., selection of a variable resistor terminal path connected to an interface).

[0040] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the light source control method in the embodiment of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, implementing the light source control method of the above-mentioned application. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include a memory remotely located relative to the processor, and these remote memories may be connected to the computer terminal 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0041] The display may be, for example, a touch screen liquid crystal display (LCD) that enables a user to interact with a user interface of the computer terminal 10 .

[0042] When performing 3D printing, you can first create a 3D model of the print part, and then slice the 3D model of the print part layer by layer. When printing, you can start from the first layer of the sliced model. Based on the successful printing of the previous layer of sliced model, each layer of the sliced model is printed in sequence, and finally a complete 3D model of the print part is obtained, which is the final three-dimensional object. When printing each layer of the sliced model, a projection image can be generated according to the shape of this layer of sliced model. The light-emitting mechanism can illuminate the projection image on the printing area in the material tray filled with light-curing material. Under the irradiation of the light emitted by the light-emitting mechanism, the light-curing material will solidify between the molding platform and the construction surface to form a solid or semi-solid polymer that matches the projection image. Then the solid or semi-solid polymer can be separated from the construction surface, and the next layer of the sliced model can be printed.

[0043] Among them, when an LCD screen is used as a light-emitting mechanism to illuminate the projected image onto the photocurable material, there are many small pixels on the LCD screen, and each pixel can control the transmission or blocking of light by controlling the voltage. During the printing process, the light source is irradiated onto the photocurable material, and the pixels on the LCD screen selectively block or transmit light according to the projected image. The transmitted light is focused onto the liquid photosensitive resin through a lens, causing it to solidify and form. In order to improve the uniformity of light transmittance of the LCD liquid crystal screen component, an initial grayscale mask can be superimposed on the projected image of the LCD screen. However, when using a grayscale mask during 3D printing, even if the grayscale of the LCD screen is set to 0, a weak light intensity from the bottom light source will still pass through the screen, which may cause the material in the non-printing area to solidify, resulting in problems such as increased residue in the material tray and screen aging. It can also cause surface quality abnormalities such as unclear or distorted details of the printed three-dimensional model.

[0044] In response to the above problems, this application proposes a light source control method for a three-dimensional printing device. The three-dimensional printing device includes a selective light-transmitting screen and a light source. The light source includes multiple LED units. The light emitted by the light source is projected onto a light-curing material through the selective light-transmitting screen. Figure 2 FIG. 1 is a flow chart of a light source control method according to an embodiment of the present invention. Figure 2 As shown, the method includes the following steps:

[0045] Step S202: Acquire a target projection image, wherein the target projection image is used for three-dimensional printing.

[0046] In this step, the target projection image is a projection image corresponding to a certain layer of the slice model of the printed three-dimensional object, and can be generated according to the shape of the slice model of this layer.

[0047] Step S204 : dividing the position of the selective light-transmitting screen into a projection area and a non-projection area according to the target projection image.

[0048] In this step, after determining the target projection image, the screen can be divided into a projection area and a non-projection area according to the position where the target projection image is projected on the selectively transparent screen. The screen can be divided into a non-projection area and a projection area according to the grayscale value of the target projection image. Specifically, the screen area with an image grayscale value not equal to 0 can be set as the projection area, and the screen area with other grayscale values of 0 can be set as the non-projection area.

[0049] In step S206, the first LED unit corresponding to the projection area is controlled to emit light according to a first preset power, and the second LED unit corresponding to the non-projection area is controlled to emit light according to a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material, and the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material.

[0050] In this step, the light source involved in three-dimensional printing includes a plurality of LED units that can emit light independently, and the light-emitting power can be adjusted. Among the plurality of LED units, the light-emitting power of the first LED unit corresponding to the projection area can be controlled to be different from the light-emitting power of the second LED unit corresponding to the non-projection area. Specifically, the first LED unit can be controlled to emit light at a first preset power, wherein the first preset power is a power sufficient for the photocurable material to cure, that is, the first LED unit emits light so that the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material; the second LED unit can also be controlled to emit light at a second preset power, wherein the second preset power is a power insufficient for the photocurable material to cure, and specifically can be determined based on the critical exposure at which the photocurable material just begins to form a solid or semi-solid, that is, the second LED unit emits light so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material.

[0051] Through the above steps, the technical effect of improving the accuracy of printing three-dimensional printed objects can be achieved, thereby solving the technical problem of unclear or distorted details of the three-dimensional printed objects caused by the fact that the LCD screen in the non-projection area in the related technology may also solidify the material.

[0052] As an optional embodiment, the preset coefficient is determined by: obtaining the number of printing layers required to print a three-dimensional printed object, wherein the projection of the slice model of the three-dimensional printed object includes a target projection image; determining the critical exposure required for curing of the photocurable material; determining the initial dynamic contrast of the three-dimensional printing device, and the curing interface exposure per unit area of the three-dimensional printing device in the projection area, wherein the initial dynamic contrast is the ratio of the light intensity projected by the three-dimensional printing device in the projection area to the light intensity projected in the non-projection area; and determining the preset coefficient based on the number of printing layers, the critical exposure, the initial dynamic contrast, and the curing interface exposure.

[0053] As an optional embodiment, the range of the preset coefficient is configured to be in the interval [0, COE C / nE0); where C0 is the initial dynamic contrast, E C is the critical exposure, n is the number of printing layers, and E0 is the exposure of the curing interface.

[0054] Optionally, the preset coefficient may be determined in advance according to the light-curing material, and the specific determination steps may be: first, obtaining the critical exposure E of the light-curing material C , where E C It is the critical exposure dose at which the photocurable material just begins to form a solid or semi-solid state. When the photocurable material is a resin, E C It is the critical exposure that just makes the resin start to form gel. For light-curing printing technology, in the extreme case (without considering the disturbance of the resin), it is necessary to ensure that the cumulative exposure of the non-projected area of the screen during the entire printing process is less than E C value to ensure that no additional solidified residue is generated in the non-projected area of the screen during printing, that is, to ensure that formula (1) is established:

[0055] nE1<E C (1)

[0056] Where E1 is the exposure of the curing interface in the non-projected area, and n is the total number of exposure layers required for printing the three-dimensional object. In addition, the dynamic contrast ratio C of the device can be used to determine E1, that is, formula (2):

[0057] E1=E0 / C (2)

[0058] Among them, E0 is the exposure amount of the curing interface in the projection area, that is, the dynamic contrast ratio C of the device is the ratio of the light intensity projected in the projection area of the screen to the light intensity projected in the non-projection area of the screen. When the irradiation of the light-curing material per unit area is limited, the dynamic contrast ratio C of the device can be the ratio of the exposure amount of the curing interface in the projection area of the screen to the exposure amount of the curing interface in the non-projection area of the screen.

[0059] Substituting formula (2) into formula (1) yields formula (3):

[0060] n E0 / C<E C (3)

[0061] Where n, E0, E C It is all related to the requirements of the slice model itself and the properties of the material. Therefore, the dynamic contrast value of the device required in this case is extremely high, that is, C>n E0 / E C .

[0062] While meeting the light intensity requirements for the screen projection area, minimizing the light intensity in the non-projection area is an effective way to improve the dynamic contrast ratio of the device. By lighting the light source (second LED unit) corresponding to the non-projection area of the screen with a preset coefficient α, where α is a value between 0 and 1, the light intensity in the non-projection area can be reduced, thereby improving the dynamic contrast ratio of the device, that is, meeting the following requirements:

[0063] C1=C0 / α (4)

[0064] Among them, C1 is the dynamic contrast of the light source in the non-projection area of the device after being illuminated with a preset coefficient α, and C0 is the initial dynamic contrast of the device.

[0065] Therefore, by substituting formula (4) into formula (3), we can obtain the following formula:

[0066] α<C0E C / n E0 (5)

[0067] Therefore, it can be determined that the configuration range of the preset coefficient α is [0, C0E C / n E0).

[0068] It should be noted that formula (5) only provides a specific method for determining the preset coefficient α. On this basis, the configuration range of the preset coefficient α can be further limited in combination with actual conditions such as the performance of the LED lamp or the disturbance of the resin.

[0069] As an optional embodiment, determining the critical exposure amount of the exposure amount required for curing a photocurable material includes: obtaining printing parameters when three-dimensional printing is performed using the photocurable material, and physical parameters of the resulting print; inputting the printing parameters and physical parameters into a pre-trained deep learning model, and the deep learning model outputting the critical exposure amount corresponding to the photocurable material, wherein the deep learning model is trained through training samples, and the training samples include sample critical exposure amounts corresponding to sample materials, as well as sample printing parameters and sample physical parameters when three-dimensional printing is performed using the sample materials.

[0070] Optionally, the preset coefficient α can be calculated based on the specific material parameters, resulting in very precise control. However, in actual use, some photocurable materials may have unknown properties. To improve the compatibility and broad applicability of the method disclosed herein, for photocurable materials with unknown material parameters, relevant experimental data can be obtained through printing measurements and analyzed using a deep learning model to determine the critical exposure per unit area required for curing the material.

[0071] Among them, the deep learning model needs to be trained in advance. During training, some light-curing materials with known material parameters can be selected for printing measurement and relevant parameters can be collected. For example, known materials can be used for printing, and the exposure time, light source power, thickness of the print at fixed exposure, print molding height, print surface quality, mechanical properties, material viscosity, printing size accuracy and other printing parameters can be recorded. After obtaining the printing parameters of the known material parameters, the critical exposure required for the material to cure per unit area is used as the label of the printing parameters. The printing parameters and the corresponding labels are used to train the original neural network model, and finally a trained deep learning model is obtained.

[0072] Based on the above training process, when using the trained deep learning model, relevant experimental data can be obtained by printing and measuring unknown materials, and the relevant experimental data can be input into the deep learning model for calculation to automatically generate the critical exposure required for unit area curing of the corresponding material.

[0073] Furthermore, a larger deep learning model can be constructed, or the aforementioned deep learning model can be further trained. This model can then automatically calculate a preset coefficient α based on the current printed model's shape, size, layer thickness, area, and other parameters, thereby controlling the LED unit's light emission. This deep learning model can achieve intelligent adaptive printing of unknown materials, achieving high printing efficiency and wide applicability.

[0074] It should be noted that for the aforementioned method embodiments, for simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should be aware that the present invention is not limited by the order of the actions described, because according to the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0075] Through the description of the above embodiments, those skilled in the art can clearly understand that the light source control method according to the above embodiment can be implemented by means of software plus the necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0076] According to an embodiment of the present invention, there is also provided a light source control device for performing three-dimensional printing based on the above light source control method. Figure 3 FIG. 1 is a structural diagram of a light source control device according to an embodiment of the present invention. Figure 3 As shown, the light source control device includes: a selective light-transmitting screen 31 for selectively transmitting light; a light source including a plurality of LED units 32, wherein light emitted by the plurality of LED units is projected onto the photocurable material through the selective light-transmitting screen; a power control mechanism 33, electrically connected to each LED unit, for controlling a first LED unit corresponding to a projection area of the selective light-transmitting screen to emit light according to a first preset power, and controlling a second LED unit corresponding to a non-projection area of the selective light-transmitting screen to emit light according to a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material, and the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material.

[0077] The light source may include multiple LED units, which are located on the same plane and can be arranged in an array. Figure 3 This is a cross-sectional view of a light source control device. Each LED unit projects light onto a selectively transparent screen, which selectively transmits light. The selectively transmitted light is then projected onto the photocurable material. A power control mechanism controls the first LED unit corresponding to the projection area of the selectively transparent screen to emit light at a first preset power, and controls the second LED unit corresponding to the non-projection area to emit light at a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material.

[0078] Optionally, Figure 4 : is a schematic structural diagram of an LED unit provided according to an optional embodiment of the present invention, such as Figure 4 As shown, any one of the multiple LED units includes an LED lamp 41 and a collimating component 42, wherein the collimating component is correspondingly arranged on the light-emitting side of the LED lamp, and the collimating component is used to focus the light emitted by the LED lamp.

[0079] Each LED unit may include an LED lamp for emitting light, and a collimating component for focusing. The LED lamp is usually an ultraviolet LED lamp or a visible light LED lamp. The LED lamp has the characteristics of high brightness, low power consumption and long life. The function of the collimating component is to further focus the light as it passes through, thereby improving the collimation of the light. Optionally, the collimating component is any one of the following: a convex lens, a Fresnel lens, and a total internal reflection lens. The collimating structure generally adopts a convex lens, a Fresnel lens, or a total internal reflection lens (TIR) lens, so that the light can be more concentrated.

[0080] Optionally, Figure 5 is a structural diagram of another LED unit provided according to an optional embodiment of the present invention, such as Figure 5 As shown, any of the multiple LED units further includes a light source reflector assembly 51, which is disposed on the backlight side of the LED lamp and is used to focus the light emitted by the LED lamp. A reflector assembly can be disposed at the bottom (backlight side) of the LED lamp. The shape and material of the reflector assembly can affect the collimation of the light. A focusing design is generally used to concentrate the light in a single direction.

[0081] Optionally, Figure 6 is a schematic structural diagram of another LED unit provided according to an optional embodiment of the present invention, such as Figure 6 As shown, any of the multiple LED units further includes a light-blocking assembly 61, which is disposed on the light-emitting side of the LED lamp and is used to block light emitted by the LED lamp from the locations of other LED lamps. The light-blocking assembly prevents crosstalk between the light emitted by each LED unit. The light from each LED unit is only responsible for illuminating the corresponding area and will not affect adjacent units, achieving precise illumination and improving the contrast of the screen.

[0082] Optionally, Figure 7 is a structural schematic diagram of another light source control device provided according to an optional embodiment of the present invention; Figure 8 is a structural diagram of another light source control device provided according to an optional embodiment of the present invention, such as Figure 7 As shown, the power control structure includes: an LED driving circuit, wherein the LED driving circuit is connected to a plurality of LED units and is used to control any one of the plurality of LED units to independently emit light, and the plurality of LED units are located below the selective light-transmitting screen at a distance of 0.001 to 10 mm. Figure 8 As shown, the light intensity calibration component 81 can also be used to calibrate the light intensity of the selective light transmission screen-light source assembly. Usually, the micro probe 82 in the light intensity calibration component corresponds to the position area and number of the LED units in the light source.

[0083] Optionally, Figure 9 is a schematic diagram of a driving circuit provided according to an optional embodiment of the present invention, such as Figure 9As shown, the LED driver circuit includes: an LED driver chip (i.e., LED Driver IC) and a control chip (i.e., MCU), wherein the control chip is connected to the LED driver chip, and multiple LED units are arranged in an array. The LED driver chip includes multiple anode pins (i.e., OUT0-OUTn) and multiple cathode pins (i.e., LINE0-LINEn). Any one of the multiple anode pins is connected to the anode of the LED unit located in the same column, and any one of the multiple cathode pins is connected to the cathode of the LED unit located in the same row.

[0084] Based on the total number of LED lamps to be driven, multiple LED units can be designed into a matrix arrangement of multiple rows and columns. In this case, the connection relationship between the LED driver chip and multiple LED units can be: the anodes of the LEDs in the same column are connected to the OUT0-OUTn pins of the LED driver chip; the cathodes of the LEDs in the same row are connected to the LINE0-LINEn pins of the LED driver IC.

[0085] To illuminate an LED, simply connect the corresponding OUT and LINE lines to a conduction level based on the row and column number of the LED. During each frame, the driver chip sequentially accesses each LINE at a very high refresh rate, quickly illuminating the required LEDs for a short period of time. This creates a visual effect consistent with all LEDs being illuminated simultaneously when viewed over a longer timeframe.

[0086] Specifically, the control chip MCU in the circuit maintains clock synchronization with the driver chip IC by outputting the serial control clock SCLK signal; data communication with the driver IC is completed through the serial signal SIN. In addition, the driver IC has a SOUT serial signal output, which allows multiple driver ICs to be cascaded, that is, the SOUT of the previous chip is connected to the SIN of the next chip, thereby controlling multiple driver ICs through the MCU's single data output signal cascade. In this way, when the number of LEDs to be driven is large and the bus number of a single driver IC is insufficient, multiple driver ICs can be used to form a cascade. Figure 7 Of course, you can also use the MCU's multi-channel serial interface to separately control multiple driver ICs and connect them in parallel. That is, multiple driver ICs are directly connected to the MCU instead of receiving signals from the MCU through other driver ICs.

[0087] Optionally, Figure 10 is a schematic diagram of another driving circuit provided according to an optional embodiment of the present invention, such as Figure 10As shown, the LED driving circuit includes: an LED driver chip (i.e., LED Driver IC) and a control chip (i.e., MCU), wherein the control chip is connected to the LED driver chip, the LED driver chip includes multiple driving pins, and multiple LED units are correspondingly connected to the multiple driving pins.

[0088] Figure 10 The following diagram shows another driver circuit for array LEDs. Unlike the previous drive method, each individual or small string of lamps is driven by a separate pin on the driver chip (i.e., LED Driver). The lamps do not affect each other, eliminating the need for high-refresh-rate scanning for display. The actual current flowing through each lamp is a stable DC current, without flickering. A single driver chip can be configured with 4, 8, 32, or other channels. The appropriate channel number can be selected based on the desired number of LEDs. The driver chip can be connected to the controller in series via the DIN and DOUT pins, and controlled using the MCU's single data output signal to achieve the desired display effect.

[0089] According to an embodiment of the present invention, a three-dimensional printing device for implementing the above light source control method is also provided. Figure 11 is a structural block diagram of a three-dimensional printing device provided according to an embodiment of the present invention, such as Figure 11 As shown, the three-dimensional printing device includes: a forming platform 111, a material tray 112 and any one of the above-mentioned light source control devices 113, wherein the material tray is used to hold photocurable material; the photocurable material is formed layer by layer on the forming platform under the irradiation of the light source to obtain a three-dimensional object.

[0090] A three-dimensional printing device may include a memory and a processor.

[0091] Among them, the memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the light source control method and device in the embodiments of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, realizing the above-mentioned light source control method. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include a memory remotely arranged relative to the processor, and these remote memories can be connected to the computer terminal via a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network and a combination thereof.

[0092] The processor can call the information and application stored in the memory through the transmission device to perform the following steps: obtaining a target projection image, wherein the target projection image is used for three-dimensional printing; dividing the position of the selective light-transmitting screen into a projection area and a non-projection area according to the target projection image; controlling the first LED unit corresponding to the projection area to emit light according to a first preset power, and controlling the second LED unit corresponding to the non-projection area to emit light according to a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material, and the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material.

[0093] Optionally, the method includes: determining the power after light intensity calibration as a first preset power; and adjusting the first preset power according to a preset coefficient to obtain a second preset power.

[0094] Optionally, the preset coefficient is determined by: obtaining the number of printing layers required to print a three-dimensional printed object, wherein the projection of the slice model of the three-dimensional printed object includes a target projection image; determining the critical exposure required for curing of the photocurable material; determining the initial dynamic contrast of the three-dimensional printing device, and the curing interface exposure per unit area of the three-dimensional printing device in the projection area, wherein the initial dynamic contrast is the ratio of the light intensity projected by the three-dimensional printing device in the projection area to the light intensity projected in the non-projection area; and determining the preset coefficient based on the number of printing layers, the critical exposure, the initial dynamic contrast, and the curing interface exposure.

[0095] Optionally, determining the critical exposure amount of the exposure amount required for curing the photocurable material includes: obtaining printing parameters when three-dimensional printing is performed using the photocurable material, and physical parameters of the printed part formed; inputting the printing parameters and physical parameters into a pre-trained deep learning model, and the deep learning model outputs the critical exposure amount corresponding to the photocurable material, wherein the deep learning model is trained through training samples, and the training samples include sample critical exposure amounts corresponding to sample materials, as well as sample printing parameters and sample physical parameters when three-dimensional printing is performed using the sample materials.

[0096] Optionally, the range of the preset coefficient is configured to be in the interval [0, COE C / nE0); where C0 is the initial dynamic contrast, E C is the critical exposure, n is the number of printing layers, and E0 is the exposure of the curing interface.

[0097] An embodiment of the present invention provides a light source control solution. By using a point light source to provide light intensity to an LCD screen, the luminous intensity in non-projected areas is set based on the light-curing properties of the material. This prevents the light intensity in non-projected areas from causing the material to solidify, thereby improving the accuracy of 3D printed objects. This solves the technical problem in related technologies where the LCD screen may solidify the material in non-projected areas, resulting in unclear or distorted details in the 3D printed object.

[0098] A person skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a non-volatile storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0099] The embodiment of the present invention further provides a non-volatile storage medium. Optionally, in this embodiment, the non-volatile storage medium can be used to store the program code executed by the light source control method provided in the above embodiment.

[0100] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group.

[0101] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: obtaining a target projection image, wherein the target projection image is used for three-dimensional printing; dividing the position of the selective light-transmitting screen into a projection area and a non-projection area according to the target projection image; controlling the first LED unit corresponding to the projection area to emit light according to a first preset power, and controlling the second LED unit corresponding to the non-projection area to emit light according to a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material, and the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material.

[0102] Optionally, the method includes: determining the power after light intensity calibration as a first preset power; and adjusting the first preset power according to a preset coefficient to obtain a second preset power.

[0103] Optionally, the preset coefficient is determined by: obtaining the number of printing layers required to print a three-dimensional printed object, wherein the projection of the slice model of the three-dimensional printed object includes a target projection image; determining the critical exposure required for curing of the photocurable material; determining the initial dynamic contrast of the three-dimensional printing device, and the curing interface exposure per unit area of the three-dimensional printing device in the projection area, wherein the initial dynamic contrast is the ratio of the light intensity projected by the three-dimensional printing device in the projection area to the light intensity projected in the non-projection area; and determining the preset coefficient based on the number of printing layers, the critical exposure, the initial dynamic contrast, and the curing interface exposure.

[0104] Optionally, determining the critical exposure amount of the exposure amount required for curing the photocurable material includes: obtaining printing parameters when three-dimensional printing is performed using the photocurable material, and physical parameters of the printed part formed; inputting the printing parameters and physical parameters into a pre-trained deep learning model, and the deep learning model outputs the critical exposure amount corresponding to the photocurable material, wherein the deep learning model is trained through training samples, and the training samples include sample critical exposure amounts corresponding to sample materials, as well as sample printing parameters and sample physical parameters when three-dimensional printing is performed using the sample materials.

[0105] Optionally, the range of the preset coefficient is configured to be in the interval [0, COE C / nE0); where C0 is the initial dynamic contrast, E C is the critical exposure, n is the number of printing layers, and E0 is the exposure of the curing interface.

[0106] An embodiment of the present invention further provides a computer program product, including a computer program, which implements the steps of the light source control method in each embodiment of the present application when the computer program is executed by a processor.

[0107] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0108] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0109] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0110] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0111] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0112] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, and other media that can store program code.

[0113] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A light source control method, characterized in that: Used in a three-dimensional printing device, the three-dimensional printing device includes a selective light-transmitting screen and a light source, the light source includes a plurality of LED units, the light emitted by the light source passes through the selective light-transmitting screen and is projected onto a light-curable material, the light source control method includes: Acquiring a target projection image, wherein the target projection image is used for three-dimensional printing; According to the target projection image, the position of the selective light-transmitting screen is divided into a projection area and a non-projection area, wherein the screen area with a non-zero grayscale value is the projection area, and the screen area with a zero grayscale value is the non-projection area; The first LED unit corresponding to the projection area is controlled to emit light according to a first preset power, and the second LED unit corresponding to the non-projection area is controlled to emit light according to a second preset power, so that the cumulative exposure of the non-projection area is less than the critical exposure of the photocurable material, and the cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material.

2. The method according to claim 1, characterized in that The method comprises: Determining the power after light intensity calibration as the first preset power; The first preset power is adjusted according to a preset coefficient to obtain the second preset power.

3. The method according to claim 2, characterized in that The preset coefficient is determined by: Obtaining a number of printing layers required to print a three-dimensional printed object, wherein a projection of a slice model of the three-dimensional printed object includes the target projection image; determining a critical exposure required for curing of the light-curable material; Determining an initial dynamic contrast ratio of a 3D printing device and a cured interface exposure per unit area of the 3D printing device within a projection area, wherein the initial dynamic contrast ratio is a ratio of the light intensity projected by the 3D printing device within the projection area to the light intensity projected within a non-projection area; The preset coefficient is determined according to the number of printing layers, the critical exposure, the initial dynamic contrast and the curing interface exposure.

4. The method according to claim 3, characterized in that The critical exposure amount for determining the exposure amount required for curing the photocurable material includes: Obtaining printing parameters when three-dimensional printing is performed using the light-curing material, as well as physical parameters of the resulting print; The printing parameters and physical parameters are input into a pre-trained deep learning model, and the deep learning model outputs a critical exposure corresponding to the photocurable material, wherein the deep learning model is trained through training samples, and the training samples include a sample critical exposure corresponding to a sample material, as well as sample printing parameters and sample physical parameters when the sample material is used for three-dimensional printing.

5. The method according to claim 3, characterized in that The range of the preset coefficient is configured to be in the interval [0, C0E C / nE0); Wherein, C0 is the initial dynamic contrast, E C is the critical exposure, n is the number of printing layers, E0 is the exposure amount of the cured interface.

6. A light source control device, characterized in that: For a three-dimensional printing device, the light source control device includes: Selective light transmission screen, used for selective light transmission; a light source comprising a plurality of LED units, wherein light emitted by the plurality of LED units is projected onto the light-curable material through the selective light-transmitting screen; a power control mechanism electrically connected to each LED unit, configured to control a first LED unit corresponding to a projection area of the selective light-transmitting screen to emit light according to a first preset power, and to control a second LED unit corresponding to a non-projection area of the selective light-transmitting screen to emit light according to a second preset power, so that a cumulative exposure of the non-projection area is less than a critical exposure of the photocurable material, and a cumulative exposure of the projection area is greater than or equal to the critical exposure of the photocurable material; The screen area where the image grayscale value is not 0 is the projection area, and the screen area where the image grayscale value is 0 is the non-projection area.

7. The light source control device according to claim 6, wherein: Any one of the plurality of LED units includes an LED lamp and a collimating component, wherein the collimating component is correspondingly arranged on the light-emitting side of the LED lamp, and the collimating component is used to focus the light emitted by the LED lamp.

8. The light source control device according to claim 7, wherein: The collimating component is any one of the following: a convex lens, a Fresnel lens and a total internal reflection lens.

9. The light source control device according to claim 7, wherein: Any one of the plurality of LED units further comprises a light source reflecting component, wherein the light source reflecting component is arranged on the backlight side of the LED lamp and is used to focus the light emitted by the LED lamp.

10. The light source control device according to claim 7, wherein: Any one of the plurality of LED units further comprises a light blocking component, wherein the light blocking component is arranged on the light emitting side of the LED lamp and is used to block the light emitted by the LED lamp toward positions where other LED lamps are located.

11. The light source control device according to claim 7, wherein: The power control mechanism includes: an LED driving circuit, wherein the LED driving circuit is connected to the plurality of LED units and is used to control any one of the plurality of LED units to emit light independently.

12. The light source control device according to claim 11, wherein: The LED driving circuit includes an LED driving chip and a control chip, wherein: The control chip is connected to the LED driver chip, the multiple LED units are arranged in an array, and the LED driver chip includes multiple anode pins and multiple cathode pins. Any one of the multiple anode pins is connected to the anode of the LED unit located in the same column, and any one of the multiple cathode pins is connected to the cathode of the LED unit located in the same row.

13. The light source control device according to claim 11, wherein: The LED driving circuit includes an LED driving chip and a control chip, wherein: The control chip is connected to the LED driver chip, the LED driver chip includes a plurality of drive pins, and the plurality of LED units are correspondingly connected to the plurality of drive pins.

14. A three-dimensional printing device, characterized in that: include: Forming platform; A material tray, the material tray is used to hold the light-curing material; And the light source control device according to any one of claims 6 to 13, wherein the light-curable material is formed layer by layer on the forming platform under the irradiation of the light source to obtain a three-dimensional object.

15. A non-volatile storage medium, characterized in that: The non-volatile storage medium includes a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute the light source control method according to any one of claims 1 to 5.

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