CN217196980U - Projection device with double convex matrix optical lenses and 3D printer - Google Patents

Abstract

The utility model discloses a biconvex matrix optical lens's projection arrangement and 3D printer, this projection arrangement includes: the LED array, the biconvex matrix optical lens and the LCD are sequentially arranged from bottom to top along the light path; the LED array is composed of a plurality of rows and columns of point light sources of UV ultraviolet LED chips; the biconvex matrix optical lens is composed of biconvex lenses which have the same arrangement mode and the same quantity as the point light sources; the LED array is matched with the biconvex matrix optical lens; the 385-405nm ultraviolet light emitted by the point light source passes through the corresponding double convex lens to form parallel light to be projected to the LCD. The projection device adopts the biconvex matrix optical lens, the consistency of light spots caused by the splicing seams arranged on the lens matrix is high, and the uniformity of the whole light spots is improved; make 385 ~ 405 nm's LED light energy refraction back, become the less accurate parallel light of angle, help the 3D printer to promote and print success rate and efficiency.

Description

Projection device with double convex matrix optical lenses and 3D printer

Technical Field

The utility model relates to a UV photocuring 3D printer and 3D print technical field, especially relate to a projection arrangement and 3D printer of biconvex matrix optical lens.

Background

Currently, there are three types of photocuring 3d printers, namely SLA, DLP, LCD and other technical forming machines. The SLA technique is applied by irradiating the photosensitive resin with laser light. The method adopts a laser G code, scans the lasers of each model layer one by one from point to line, and then irradiates a photosensitive resin fast laser with the lasers. The light source for DLP technology applications originates from a projector. The projector irradiates the model portion as a planar image into the resin solution to solidify. With this method, the surface is formed at one time, and the printing time depends only on the height of the object to be printed. LCD technique photocuring 3D printer, the advantage is the precision height, and equipment low price.

The problem that the LCD technology photocuring 3D printer exists in the industry at present is that latticed bright light spots or dark light spots appear in splicing seams in the middle of matrix arrangement, so that the uniformity of the whole light spots is low, the accuracy is low due to uneven light energy, rapid printing cannot be achieved, and the printing efficiency is low and the cost is high.

If the uniformity of the light energy projected onto the exposure screen is insufficient, the 385-405nm light energy received in the liquid resin box is different, so that the printing precision is reduced; the printing time of the portion with lower light energy is prolonged.

In addition, the 3D printer UV photocuring needs to penetrate through high and uniform light energy and accurate parallel light to realize high-precision printing, so that the requirement for the uniformity and small angle of the whole light spot is a great pain point in the current industry to realize the effect that the whole machine can realize high-precision and rapid printing.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide a projection apparatus and a 3D printer with a lenticular optical lens for at least partially solving the above technical problems.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

in a first aspect, an embodiment of the present invention provides a projection apparatus with biconvex matrix optical lens, including: the LED array, the biconvex matrix optical lens and the LCD are sequentially arranged from bottom to top along the light path;

the LED array is composed of a plurality of rows and columns of point light sources of UV ultraviolet LED chips;

the biconvex matrix optical lens is composed of biconvex lenses which have the same arrangement mode and the same number as the point light sources; the LED array is matched with the biconvex matrix optical lens;

and forming parallel light to project to the LCD through the 385-405nm ultraviolet light emitted by the point light source through the corresponding biconvex lens.

Further, the UV LED chip is solidified on an aluminum substrate or a copper substrate;

the aluminum substrate or the copper substrate is fixed on the radiator;

the radiator is also provided with a bracket; the biconvex matrix optical lens is fixed on the bracket.

Further, the UV LED chip is an LED with 50% of light intensity and 60-degree or 90-degree angle.

Further, the material of the biconvex matrix optical lens is optical-grade PMMA.

Further, the position of the point light source coincides with the focal point of the corresponding lenticular lens.

Furthermore, the curvatures of the light incident surface and the light emergent surface of the biconvex lens are different, and the curvature of the light incident surface is smaller than that of the light emergent surface.

Furthermore, the thickness of the biconvex lens is 5 mm-25 mm, and the thickness is uniformly transited from the edge to the center.

Further, the size of the LCD liquid crystal display screen is the same as the size of the LED array.

In a second aspect, the present invention provides a 3D printer, a projection apparatus using the lenticular matrix optical lens according to any one of the above embodiments.

The utility model provides a biconvex matrix optical lens's projection arrangement, include: the LED array, the biconvex matrix optical lens and the LCD are sequentially arranged from bottom to top along the light path; the LED array is composed of a plurality of rows and columns of point light sources of UV ultraviolet LED chips; the biconvex matrix optical lens is composed of biconvex lenses which have the same arrangement mode and the same number as the point light sources; the LED array is matched with the biconvex matrix optical lens; and forming parallel light to project to the LCD through the 385-405nm ultraviolet light emitted by the point light source through the corresponding biconvex lens. The projection device adopts the biconvex matrix optical lens, the consistency of light spots caused by the splicing seams arranged on the lens matrix is high, and the uniformity of the whole light spots is improved; the LED light energy of 385-405nm is refracted and then becomes accurate parallel light with a smaller angle, and the 3D printer is helped to improve the printing success rate and efficiency.

Drawings

Fig. 1 is a schematic structural diagram of a projection apparatus with biconvex matrix optical lenses according to an embodiment of the present invention;

fig. 2 is a perspective view of a projection apparatus with a biconvex matrix optical lens according to an embodiment of the present invention;

fig. 3a is a plan view of a projection apparatus with biconvex matrix optical lenses according to an embodiment of the present invention;

FIG. 3b is a cross-sectional view taken along line AA in FIG. 3 a;

FIG. 3c is a cross-sectional view taken along line BB of FIG. 3 a;

fig. 4 is a schematic view illustrating the position of a point light source and the coincidence of the focal points of corresponding lenticular lenses according to an embodiment of the present invention;

fig. 5 is a schematic view of an optical path provided by an embodiment of the present invention.

Detailed Description

In order to make the technical means, creation features, achievement purposes and functions of the present invention easy to understand, the present invention is further described below with reference to the following embodiments.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element to which the reference is made must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, and for example, "connected" may be either fixedly connected or detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1:

referring to fig. 1, the utility model provides a pair of biconvex matrix optical lens's projection arrangement can realize carrying out large tracts of land distribution at the exposure screen to 3D printer UV photocuring's curing light source's light energy, becomes the parallel light as far as possible, and it is better that the angle is little more, and the light efficiency is the purpose that the higher is better.

The projection device includes: the LED array 1, the biconvex matrix optical lens 2 and the LCD liquid crystal display 3 are sequentially arranged from bottom to top along a light path;

the LED array 1 is composed of point light sources of a plurality of rows and columns of UV ultraviolet LED chips 11; the lenticular matrix optical lens 2 is composed of lenticular lenses 21 which are arranged in the same manner as the point light sources and have the same number; the LED array is matched with the biconvex matrix optical lens and corresponds to the biconvex matrix optical lens in number and position one by one; the curvatures of the light incident surface and the light emergent surface of the biconvex lens are different, and the curvature of the light incident surface is smaller than that of the light emergent surface; the thickness of the biconvex lens is 5 mm-25 mm, and the thickness is evenly transited from the edge to the center. The 385-405nm ultraviolet light emitted by the point light source passes through the corresponding double convex lens 21 to form parallel light to project to the LCD liquid crystal display screen 3, and the size of the LCD liquid crystal display screen is the same as that of the LED array.

The working principle of the components of the 3D printer, such as the UV light curing light source, namely the LED array 1, the biconvex matrix optical lens 2, the exposure screen, namely the LCD liquid crystal display screen 3, and the like, is shown in FIG. 2. Technology using LCD as light source, that is, LCD mask photocuring: 385-405nm ultraviolet light (like DLP) is used, and an LCD panel is used as a selective light transmission technology (mainly a black and white LCD panel).

In the embodiment, a plurality of single-point light sources emit light simultaneously, and the double convex matrix optical lens can change the multi-point light source into parallel light, so that light spots with high uniformity and high light efficiency are projected to the LCD. The 385-405nm point light sources of the array can emit light-sensitive resin capable of solidifying liquid, and a plurality of the point light sources are arranged and distributed in a linear array mode so as to improve the energy and the irradiation range of light. UVLED (point light source) have long-lived, do not have the thermal radiation, the life-span is not influenced by the number of times of opening and closing, the energy is high, shine even improvement production efficiency, do not contain the advantage that the poison material is safer, more environmental protection than traditional array point light source.

The UV light curing has important application in 3D printing, and mainly adopts ultraviolet light to scan the surface of liquid photosensitive resin, a thin layer with a certain thickness is generated each time, and an object is generated layer by layer from the bottom. UV light cured 3D printing is accomplished by the transition of the polymer from liquid to solid state.

The projection device adopts the biconvex matrix optical lens, the consistency of light spots caused by the splicing seams arranged on the lens matrix is high, and the uniformity of the whole light spots is improved; the LED light energy of 385-405nm is refracted and then becomes accurate parallel light with a smaller angle, and the 3D printer is helped to improve the printing success rate and efficiency.

Further, as shown in fig. 1, the UV ultraviolet LED chip 11 is cured on an aluminum substrate or a copper substrate 12; and the aluminum substrate or copper substrate 12 is fixed on the heat sink 13; a black support 22 is further arranged above the heat sink, and the lenticular lens 21 of the lenticular matrix optical lens 2 is fixed on the black support 22; the black color is selected for light absorption, and light absorption lines can be arranged on the black color. The material of the biconvex matrix optical lens can be optical-grade PMMA (polymethyl methacrylate), is a high polymer, is also called as acrylic or organic glass, has the advantages of high transparency, low price, easy machining and the like, can replace common glass, has lighter quality compared with glass, and has higher light transmittance than glass.

As shown in fig. 3a-3b, a lenticular optical lens, which is a UV light curing light source for 3D printing, is fixed on top of a black support. The black support is fixed on the aluminum profile radiator, and the MCPCB (aluminum substrate) is fixed on the aluminum profile radiator; the optical lens is manufactured by adopting a CNC (computerized numerical control) mould ultra-precision machining process and then an ultra-precision injection molding process.

After the optical design is completed, a Monte Carlo method can be adopted to perform light simulation, and light energy distribution of 405nm on an exposure screen is obtained. The light energy distribution on the whole exposure screen has the uniformity of more than 95 percent; the uniformity of illumination of the exposure screen (black and white LCD) is the minimum illumination value/average illumination value, and the minimum illumination value is calculated according to a point-by-point calculation method.

Further, the UV ultraviolet LED chip 1 can be an LED with a 50% light intensity angle of 60 ° or 90 °, and can achieve the following three purposes in combination with the above-mentioned double convex matrix optical lens:

a. through a biconvex matrix optical lens of a UV curing light source for 3D printing, light energy of 60-degree and 90-degree UV385-405nm LEDs is refracted and then changed into parallel light or nearly parallel light energy with a left-right angle smaller than 1.5 degrees (the smaller the angle is, the better the angle is).

b. Meanwhile, uniform 385-405nm light energy distribution is obtained on the exposure screen. The uniformity of the light machine is actually measured to be more than 90%. The defect of 3D printing photocuring of the traditional LCD is overcome; meanwhile, the double convex matrix optical lens is adopted, so that the collimation and uniformity of light are successfully solved, and the uniformity of the optical machine reaches over 90 percent.

c. Compared with the traditional plano-convex matrix optical lens, the biconvex matrix optical lens can obtain higher light energy utilization rate, and is beneficial to saving energy or obtaining higher 3D printing efficiency.

Further, in the implementation of the specific embodiment, the position of the point light source may be coincident with the focal point of the corresponding lenticular lens, as shown in fig. 4:

firstly, designing a biconvex collimating lens according to the Snell's law of light rays, determining the propagation directions of incident light rays and refracted light rays when the light rays are refracted through an interface of two media, wherein a plane formed by the incident light rays and an interface normal line passing through an incident point is called an incident plane, included angles between the incident light rays and the refracted light rays and the normal line are respectively called an incident angle and a refraction angle, the incident angle and the refraction angle are expressed by thetai and thetat, the refracted light rays are in the incident plane, the ratio of sine of the incident angle to sine of the refraction angle is a constant, and the refraction index is expressed by n: sin θ i/sin θ t ═ n. The focal point of a biconvex matrix optical lens of the 3D printing UV light curing light source coincides with a point light source position of 385-405nm, so that parallel light is generated.

In addition, according to the current UV light curing 3D printer industry, machines in different fields have different requirements on uniformity and energy of light source light spots, and for consumer machines, the requirements on uniformity are generally more than 80%, and the energy is more than 3500 uW/CM. The cost control requirement of consumer products is high, the maximum single plano-convex matrix parallel light source in the industry at present is made to be below 28mm, and the single 28mm is the limit.

In order to promote the price/performance ratio of light source, the embodiment of the utility model provides a can accomplish below the biggest 42mm to single lens, the facula homogeneity and the transmittance that can't satisfy realization UV photocuring 3D printer trade are arranged to this big. But the effect of large size and high uniformity can be realized according to UV packaging precision and double-sided optical refraction, and the special requirements on the industry are realized through high-precision optical design, ultra-precision mould processing and ultra-precision injection molding, so that the biconvex matrix light source is specially developed.

Moreover, according to the LCD screens with different specifications and sizes in the industry, different customers have different requirements on energy and uniformity and the cost of the light source. The embodiment of the utility model provides a screen that accessible two-sided optics realized same specification and dimension can reduce the LED single branch of academic or vocational study quantity about up to 35% and realize higher light energy utilization.

As shown in fig. 5, the 385-405nm ultraviolet LED chip at the focal position emits light with a 50% light intensity angle of 60 degrees, the light energy is refracted for the first time through the optical light incident surface of the biconvex lens, the biconvex aspheric optical surface is beneficial to the convergence of the light energy to the exposure screen, and the utilization rate of the LED light energy of the system is improved. The collimated 385-405nm light is projected to an exposure screen, and an extremely small angle, uniformity and high light efficiency are obtained. In order to reduce the error of STP file conversion during the production process of the lenticular optical lens, such as when the lenticular optical lens is also realized by 3D printing, an optical surface equation can be adopted for manufacturing an optical mold.

Example 2:

based on same utility model the design, the embodiment of the utility model provides a still provide a 3D printer, use the projection arrangement of biconvex matrix optical lens as above embodiment 1 provides, its theory of operation as follows:

1. 385-405nm of light energy is emitted from the LED, and the LED with 50% light intensity angle of 60 or 90 degrees is selected as the LED;

2. the light energy passes through the lower surface of the lens to form first refraction and enters the biconvex optical lens;

3. the light energy passes through about 20mm and then is refracted out of the lens to form parallel light, and the device is characterized in that: high uniformity and high luminous efficiency;

4. the uniform parallel light is projected to a black-and-white LCD with high transmittance;

5. the unshielded 385-405nm light can enter the liquid resin box after passing through the black and white LCD.

6. 385 ~ 405nm light energy solidifies the resin at the same position of liquid resin box, realizes the 3D and prints the function: the liquid resin at the designated position becomes solid; the part which is not irradiated by 385-405nm light energy is kept unchanged. And 3D object printing is completed by matching with the lifting device.

In the embodiment, after the light emitted by the 385-405 nm-LED array penetrates through the biconvex matrix optical lens, the distance between the light path propagation direction vertical to the LCD liquid crystal display screen and the liquid level of the light curing material is less than 5 cm. The utility model discloses can promote the printing success rate and the efficiency of product under reduction in production cost's prerequisite.

The basic principles and the main features of the invention and the advantages of the invention have been shown and described above. The optical principles and functions of the present invention are illustrated herein using specific examples, and the above description is only for the purpose of aiding understanding of the methods and core concepts of the present invention, and, at the same time, it should be understood that the disclosed devices, in several of the embodiments provided by the present invention, can be implemented in other ways. For example, the above-described embodiments of the apparatus are merely illustrative, and for example, the above-described division of the units is only one type of division of logical functions, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. To the general technical personnel in this field, according to the thought and the method of the utility model, all have the change part on concrete implementation and application, so the utility model content should not be understood as the restriction of the utility model, as long as thought and method are close or identical, all are applicable to the coverage of the utility model.

Claims (9)

1. A projection apparatus having a lenticular optical lens, comprising: the LED array, the biconvex matrix optical lens and the LCD are sequentially arranged from bottom to top along the light path;

the LED array is composed of a plurality of rows and columns of point light sources of UV ultraviolet LED chips;

the biconvex matrix optical lens is composed of biconvex lenses which have the same arrangement mode and the same quantity as the point light sources; the LED array is matched with the biconvex matrix optical lens;

and the 385-405nm ultraviolet light emitted by the point light source passes through the corresponding biconvex lens to form parallel light to be projected to the LCD.

2. The projection apparatus of claim 1, wherein the UV LED chips are cured on an aluminum substrate or a copper substrate;

the aluminum substrate or the copper substrate is fixed on the radiator;

the radiator is also provided with a bracket; the biconvex matrix optical lens is fixed on the bracket.

3. The projection apparatus of claim 2, wherein the UV LED chip is an LED with 50% intensity angle of 60 ° or 90 °.

4. The projection apparatus of claim 1, wherein the material of the lenticular optical lens is optical grade PMMA.

5. A projection apparatus of a lenticular optical lens according to claim 1, wherein the point light source is located to coincide with the focal point of the corresponding lenticular lens.

6. The projection apparatus of claim 1, wherein the curvatures of the light incident surface and the light emergent surface of the lenticular lens are different, and the curvature of the light incident surface is smaller than that of the light emergent surface.

7. A projection unit of a lenticular optical lens according to claim 1, wherein the lenticular lens has a thickness of 5mm to 25mm, and the thickness is uniform from the edge to the center.

8. The projection apparatus of claim 1, wherein the LCD display screen has the same size as the LED array.

9. A 3D printer characterized by a projection apparatus using the lenticular matrix optical lens according to any one of claims 1 to 8.

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