Combined optical lens for LCD photocuring 3D printer and LCD photocuring 3D printer

Abstract

The invention provides a combined optical lens for an LCD photocuring 3D printer and the LCD photocuring 3D printer, and relates to the technical field of 3D printing and optical lens, the combined optical lens comprises a free-form surface lens, a reflector, a Fresnel lens and a dodging assembly, a circular groove recessed into a free-form surface lens body is formed in the center of the bottom surface of the free-form surface lens, the circular groove is used for installing an LED light source, firstly, light rays of the light source are limited within a certain angle through forming of the circular groove, the angle is small, light intensity can be fully utilized conveniently, emergent light rays sequentially pass through the reflecting mirror, the Fresnel lens and the light uniformizing assembly, and therefore the light intensity of the LED light source can be fully utilized. Uniform and accurate parallel light is formed, the uniformity of light source emergence is improved, and latticed bright or dark light spots do not exist in light spot distribution. According to the LCD photocuring 3D printer, the combined optical lens is adopted, the light source emitting uniformity is improved, the printing time cannot be prolonged due to uneven light rays, and the printing efficiency and the printing quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing and optical lenses, and more specifically, to a combined optical lens for an LCD light-curing 3D printer and an LCD light-curing 3D printer. Background Art

[0002] 3D printing, also known as "additive manufacturing", is a rapid prototyping technology. Rapid prototyping technology can be divided into many categories according to the materials used, printing process, number of nozzles, etc. Among them, the most common is light curing. Compared with thermal curing, light curing uses ultraviolet light for high energy utilization, which can save up to 90% of energy, and has high precision and low equipment price.

[0003] Taking liquid crystal display (LCD) photocuring 3D printing as an example, the penetration and blocking of ultraviolet light beams are controlled by LCD, combined with the curing reaction of photosensitive resin, a thin layer of a certain thickness is generated each time, and objects are generated layer by layer from the bottom, realizing layer-by-layer printing of three-dimensional models.

[0004] LCD light-curing 3D printers usually use UV LED as the light source, which is efficient, stable and has a long life. At present, most of the products on the market use a whole row of small UV LED lamps as the light source for direct illumination. This method is prone to grid-like bright or dark spots, resulting in large differences in uniformity between different grid areas. Grid spots with large uniformity differences will lead to low printing accuracy and reduce the printing success rate. In addition, due to uneven light, fast printing cannot be achieved, resulting in low printing efficiency. Summary of the invention

[0005] In order to solve the problem of uneven light spot distribution caused by light source irradiation of current LCD light-curing printers, the present invention proposes a combined optical lens for LCD light-curing 3D printers, which uses the combined optical lens to perform secondary light distribution on light to improve the uniformity of light source emission; the present invention also proposes an LCD light-curing 3D printer, which uses the combined optical lens to improve the uniformity of light source emission, improve printing efficiency and print quality.

[0006] To solve the above problems, the technical solution adopted in this application is:

[0007] On the one hand, the present application proposes a combined optical lens for an LCD light-curing 3D printer, comprising: a free-form surface lens, a reflector, a Fresnel lens and a light homogenizing component; a circular groove recessed into the free-form surface lens body is provided at the center of the bottom surface of the free-form surface lens, the circular groove is used to install an LED light source, the inner surface of the circular groove constitutes an incident surface of the LED light source light, after the LED light source light is incident from the incident surface, non-parallel light is emitted through the outer surface of the free-form surface lens, the non-parallel light is reflected by the reflector to the Fresnel lens, and parallel light is obtained, and the parallel light is emitted after being homogenized again by the light homogenizing component.

[0008] According to the above technical solution, the opening of the circular groove limits the light source to a certain angle. The small angle makes it easier to fully utilize the light intensity. The emitted light passes through the reflector, Fresnel lens, and light homogenizing component in sequence to form uniform and precise parallel light, thereby improving the uniformity of the light source emission. There is no grid-like bright or dark spot in the light spot distribution.

[0009] Preferably, the LED light source is a chip-on-board package light source with a wavelength of 370-410 nm.

[0010] Preferably, the outer surface of the free-form surface lens is smooth to ensure the purity of the emitted light without other stray light.

[0011] Preferably, the free-form surface lens is made of high borosilicate glass. High borosilicate glass has a low thermal expansion coefficient, good thermal stability, and high temperature resistance, and is more suitable for internal installation of LED light sources.

[0012] Preferably, the upper surface of the reflector is coated with a high-reflection film to improve the reflectivity of the reflector to light.

[0013] Preferably, the angle between the reflector and the horizontal plane is 45°, and the upper surface coated with the high-reflection film is arranged toward the free-form surface lens.

[0014] Preferably, the Fresnel lens is made of glass.

[0015] Preferably, the light homogenizing component is a light homogenizing film, a diffraction grating or a light homogenizing glass.

[0016] Preferably, the light homogenizing component is arranged in parallel with the Fresnel lens.

[0017] According to the above technical means, the light homogenization component homogenizes the light passing through the Fresnel lens again to improve the uniformity.

[0018] On the other hand, the present application also proposes an LCD light-curing 3D printer, which uses the combined optical lens to adjust the light emitted by the light source.

[0019] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0020] The present invention proposes a combined optical lens for LCD light-curing 3D printer and LCD light-curing 3D printer, wherein a circular groove is provided at the center of the bottom surface of the free-form surface lens, which is concave into the free-form surface lens body, and the circular groove is used to install an LED light source. First, the circular groove limits the light source light within a certain angle, and the angle is small, which is convenient for making full use of the light intensity. The emitted light passes through the reflector, the Fresnel lens, and the light-homogenizing component in sequence to form uniform and precise parallel light, which improves the uniformity of the light source emission, and the light spot distribution does not have a grid-like bright or dark light spot. The LCD light-curing 3D printer proposed by the present invention adopts a combined optical lens, which improves the uniformity of the light source emission, and the printing time will not be extended due to uneven light, thereby improving the printing efficiency and printing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram showing the arrangement of a combined optical lens for an LCD light-curing 3D printer according to an embodiment of the present invention;

[0022] Figure 2 A cross-sectional view showing a free-form surface lens in a combined optical lens for an LCD light-curing 3D printer proposed in an embodiment of the present invention;

[0023] Figure 3 A light path diagram showing the light emission from the combined optical lens proposed in an embodiment of the present invention.

[0024] Among them, 1-free-form surface lens; 11-circular groove; 2-reflector; 3-Fresnel lens; 4-light homogenization component; 5-LED light source DETAILED DESCRIPTION

[0025] The accompanying drawings are only used for illustrative purposes and are not to be construed as limiting the present application;

[0026] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the actual size;

[0027] It is understandable to those skilled in the art that descriptions of certain well-known contents in the drawings may be omitted.

[0028] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0029] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0031] Example 1

[0032] like Figure 1 As shown, this embodiment proposes a combined optical lens for LCD light-curing 3D printer, see Figure 1 , including: a free-form surface lens 1, a reflector 2, a Fresnel lens 3 and a light homogenizing component 4; a circular groove 11 is provided at the center of the bottom surface of the free-form surface lens 1, which is concave into the free-form surface lens body, and the circular groove 11 is used to install the LED light source. The inner surface of the circular groove 11 constitutes the incident surface of the LED light source. After the LED light source is incident from the incident surface, non-parallel light is emitted from the outer surface of the free-form surface lens 1. After the non-parallel light is reflected by the reflector 2 to the Fresnel lens 3, parallel light is obtained. The parallel light is homogenized again by the light homogenizing component 4 and then emitted.

[0033] See also Figure 1 In this embodiment, the reflector, the Fresnel lens 3 and the light homogenizing component 4 in the combined optical lens are arranged in sequence from bottom to top.

[0034] In this embodiment, the circular groove 11 is formed to limit the light source light within a certain angle. The small angle is convenient for fully utilizing the light intensity. The emitted light passes through the reflector 2, the Fresnel lens 3, and the light homogenizing component 4 in sequence to form uniform and precise parallel light, thereby improving the uniformity of the light source emission. There is no grid-like bright or dark light spot in the light spot distribution.

[0035] Specifically, in this embodiment, the LED light source is a chip-on-board package light source with a wavelength of 370-410 nm. Figure 2As shown, the LED light source is indicated by a mark 5, which is a single UV COB LED light source, and is located in a circular groove 11 at the center of the bottom surface of the free-form surface lens 1. The LED light source is a UV light curing 370-410nm COB UV LED ultraviolet 370-410nm wavelength light source, which can emit light for curing liquid photosensitive resin, and is arranged in a straight line distribution to increase the energy and irradiation range of the light. It has the advantages of long life, no heat radiation, life not affected by the number of opening and closing times, high energy, and uniform irradiation, which can effectively improve the printing efficiency of the 3D printer and achieve high-precision product printing details.

[0036] In this embodiment, the outer surface of the free-form surface lens 1 is smooth, ensuring the purity of the emitted light without other stray light. The free-form surface lens 1 of this embodiment is made of high borosilicate glass, and the inner surface of the circular groove 11 in the free-form surface lens 1 is located in the emission direction of the LED light source. High borosilicate glass has a low thermal expansion coefficient, good thermal stability, and high temperature resistance, and is more suitable for internal installation of LED light sources. The free-form surface lens 1 performs secondary light distribution on the ultraviolet light emitted by the LED light source to obtain a rectangular light spot composed of non-parallel light.

[0037] In this embodiment, the reflector 2 of this embodiment is made of glass or plastic. Figure 1 , the angle between the reflector 2 and the horizontal plane is 45°, and the upper surface of the reflector 2 is coated with a high-reflection film. When glass material is used to make the reflector, a layer of metal silver (or aluminum) film is vacuum-coated on the upper surface of the glass as a high-reflection film. The reflector with the high-reflection film not only maintains consistent brightness, but also is accurate and has no deviation. In this embodiment, the upper surface coated with the high-reflection film is arranged toward the free-form surface lens 1, and the light emitted from the outer surface of the free-form surface lens 1 is reflected, thereby improving the reflectivity of the reflector to the light.

[0038] In this embodiment, the Fresnel lens 3 is made of glass and is located above the reflector 2. The Fresnel lens 3 collimates non-parallel light. After the light passes through the Fresnel lens 3, a rectangular light spot composed of parallel light is obtained.

[0039] The light homogenizing component 4 is a light homogenizing film or a diffraction grating or a light homogenizing glass, wherein the light homogenizing film can not only homogenize the light, but also improve the brightness, and the diffraction grating is a kind of grating. It uses a regular structure to make the amplitude or phase (or both) of the incident light subject to periodic spatial modulation. The light homogenizing component 4 of this embodiment uses a light homogenizing glass. The light homogenizing component 4 is located above the Fresnel lens 3 and is arranged parallel to the Fresnel lens 3. The light passing through the Fresnel lens 3 is homogenized again to improve the uniformity of the light.

[0040] Example 2

[0041] This embodiment combines the attached Figure 3 The process of light emission in the combined optical lens is described. Figure 3 As shown, the LED light source located in the circular groove 11 emits light. Under the restriction of the circular groove 11, the light from the light source first emerges at a small angle, emerges through the outer surface of the free-form surface lens 1, and forms a rectangular light spot composed of non-parallel light, and then enters the reflector 2. The high-reflection film on the upper surface of the reflector 2 reflects the light. The reflected light is collimated by the Fresnel lens 3 to form a rectangular light spot composed of parallel light. Figure 3 The Fresnel lens 3 has equidistant teeth on one side of the lens. The design of these teeth makes the lens thinner and lighter, and can also reduce the use of materials while maintaining optical performance. In contrast, ordinary lenses are usually made entirely of optical materials and have no tooth structure, so they are often thicker. The use of Fresnel lenses can also reduce the volume of the combined optical lens, and finally the light is homogenized by the homogenizing component 4, thereby obtaining a more uniform rectangular light spot.

[0042] Example 3

[0043] This embodiment proposes an LCD light-curing 3D printer, which uses the combined optical lens proposed in embodiments 1 to 2 to adjust the light emitted by the light source. Specifically, the combined optical lens includes: a free-form surface lens 1, a reflector 2, a Fresnel lens 3 and a light homogenizing component 4; a circular groove 11 is provided at the center of the bottom surface of the free-form surface lens 1, which is concave into the free-form surface lens body, and the circular groove 11 is used to install the LED light source. The inner surface of the circular groove 11 constitutes the incident surface of the LED light source. After the LED light source is incident from the incident surface, non-parallel light is emitted from the outer surface of the free-form surface lens 1. After the non-parallel light is reflected by the reflector 2 to the Fresnel lens 3, parallel light is obtained, and the parallel light is homogenized again by the light homogenizing component 4 and then emitted.

[0044] In the combined optical lens used by the LCD light-curing 3D printer proposed in this embodiment, the reflector 2, the Fresnel lens 3 and the light homogenizing component 4 are arranged in sequence from bottom to top. In addition, the LED light source is a chip-on-board package light source with a wavelength of 370-410nm. The LED light source of this embodiment is a single ultraviolet COB LED light source, which is located in a circular groove at the center of the bottom surface of the free-form surface lens 1. The LED light source is a COB UV LED ultraviolet 370-410nm light source for UV light curing, which can emit light for curing liquid photosensitive resin and is arranged to be distributed in a straight line to increase the energy and irradiation range of the light. It has the advantages of long life, no heat radiation, life not affected by the number of opening and closing times, high energy and uniform irradiation. The opening of the circular groove 11 limits the light source light within a certain angle, and the angle is small, which is convenient for making full use of the light intensity. The emitted light passes through the reflector 2, the Fresnel lens 3, and the uniform light component 4 in turn to form uniform and precise parallel light, which improves the uniformity of the light source emission. There is no grid-like bright or dark light spot in the light spot distribution, which can effectively improve the printing efficiency of the 3D printer and achieve high-precision product printing details.

[0045] The outer surface of the free-form surface lens 1 is smooth, ensuring the purity of the emitted light without other stray light. The free-form surface lens 1 is made of high borosilicate glass, and the inner surface of the circular groove 11 is located in the emission direction of the LED light source. High borosilicate glass has a low thermal expansion coefficient, good thermal stability, and high temperature resistance, and is more suitable for internal installation of LED light sources. The free-form surface lens 1 performs secondary light distribution on the ultraviolet light emitted by the LED light source to obtain a rectangular light spot composed of non-parallel light.

[0046] The reflector 2 is made of glass or plastic, and the angle between the reflector 2 and the horizontal plane is 45°. The upper surface of the reflector 2 is coated with a high-reflection film. A layer of metal silver (or aluminum) film is vacuum-coated on the upper surface of the glass as a high-reflection film. The reflector with the high-reflection film not only maintains consistent brightness, but also is accurate and has no deviation. The upper surface coated with the high-reflection film is arranged toward the free-form surface lens 1, and reflects the light emitted from the outer surface of the free-form surface lens 1, thereby improving the reflectivity of the reflector to the light.

[0047] The Fresnel lens 3 is made of glass and is located above the reflector 2. The Fresnel lens 3 collimates non-parallel light. After the light passes through the Fresnel lens 3, a rectangular light spot composed of parallel light is obtained.

[0048] The light homogenizing component 4 is a light homogenizing film or a diffraction grating or a light homogenizing glass. The light homogenizing component 4 of this embodiment uses a light homogenizing glass. The light homogenizing component 4 is located above the Fresnel lens 3 and is arranged parallel to the Fresnel lens 3. The light passing through the Fresnel lens 3 is homogenized again to improve the uniformity of the light.

[0049] In summary, under the action of the above-mentioned combined optical lens, the final emission uniformity of the light emitted by the LED light source is improved. The LCD light-curing 3D printer using the combined optical lens has uniform light, so when performing 3D printing, the printing time will not be extended due to uneven light, thereby improving printing efficiency and printing quality.

[0050] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A combined optical lens for LCD light-curing 3D printer, characterized in that: include: A free-form surface lens (1), a reflector (2), a Fresnel lens (3) and a light homogenizing component (4); a circular groove (11) is provided at the center of the bottom surface of the free-form surface lens (1) and is recessed into the free-form surface lens body; the circular groove (11) is used to install an LED light source; the inner surface of the circular groove (11) constitutes an incident surface for the light of the LED light source; after the light of the LED light source is incident from the incident surface, non-parallel light is emitted through the outer surface of the free-form surface lens (1); after the non-parallel light is reflected by the reflector (2) to the Fresnel lens (3), parallel light is obtained; the parallel light is homogenized again by the light homogenizing component (4) and then emitted.

2. The combined optical lens for LCD light-curing 3D printer according to claim 1, characterized in that: The LED light source is a chip-on-board package light source with a wavelength of 370-410nm.

3. The combined optical lens for LCD light-curing 3D printer according to claim 1, characterized in that: The outer surface of the free-form surface lens (1) is smooth.

4. The combined optical lens for LCD light-curing 3D printer according to claim 3, characterized in that: The free-form surface lens (1) is made of high borosilicate glass.

5. The combined optical lens for LCD light-curing 3D printer according to claim 1, characterized in that: The upper surface of the reflector (2) is coated with a high-reflection film.

6. The combined optical lens for LCD light-curing 3D printer according to claim 5, characterized in that: The angle between the reflector (2) and the horizontal plane is 45°, and the upper surface coated with a high-reflection film is arranged toward the free-form surface lens (1).

7. The combined optical lens for LCD light-curing 3D printer according to claim 1, characterized in that: The Fresnel lens (3) is made of glass.

8. The combined optical lens for LCD light-curing 3D printer according to claim 1, characterized in that: The light homogenizing component (4) is a light homogenizing film or a diffraction grating or a light homogenizing glass.

9. The combined optical lens for LCD light-curing 3D printer according to claim 7, characterized in that: The light homogenizing component (4) is arranged in parallel with the Fresnel lens (3).

10. An LCD light-curing 3D printer, characterized in that: The LCD light-curing 3D printer uses the combined optical lens described in any one of claims 1 to 9 to adjust the light emitted by the light source.

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