Three-dimensional printing projection objective lens system based on liquid crystal screen
By designing a three-dimensional printing projection objective system based on LCD screen, the high contrast effect is achieved by using lens combination and the flip of LCD screen, the problems of thermal accumulation and low contrast in the prior art are solved, and the imaging quality and reliability of LCD screen are improved. sex.
Patent Information
- Application Number
- CN202420744769.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-11
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-04-11
AI Technical Summary
In the existing three-dimensional photocuring printing technology, the LCD screen display solution leads to thermal accumulation damage, and the DLP projection solution generally has low contrast, making it difficult to achieve efficient and high-definition imaging.
Design a three-dimensional printing projection objective lens system based on the LCD screen, including the first lens set, the second lens set, the seventh lens, the eighth lens, the ninth lens, the focus lens and the LCD screen, through the turn of the aperture and the LCD screen Achieve high contrast effect, avoid thermal accumulation, and improve imaging clarity.
It achieves the advantages of high integration, small size, easy manufacturing, low cost and high imaging quality, improves the service life and reliability of the LCD screen, and has high contrast and clarity imaging effects.
Smart Images
Figure CN222135970U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of optical lenses, in particular to a three-dimensional printing projection objective lens system based on a liquid crystal screen. Background Art
[0002] 3D printing technology, as a rapid prototyping technology, its special production and manufacturing method has realized people's pursuit of efficient, fine, personalized and customized products. The technology has been developed to provide more than just models for industrial design or machinery manufacturing industries. Its application involves jewelry, food, industrial design, architecture, engineering, automobiles, aerospace, medical industry, education, geographic information systems, civil engineering, military and other fields. The principle of light-curing 3D printing technology is that the activation energy generated by ultraviolet light with the highest energy in the spectrum can break the CC bond of unsaturated polyester resin and generate free radicals to solidify the resin.
[0003] The existing 3D printing technology solutions of the light-curing technology route are mostly LCD display solutions and DLP projection solutions. Among them, the LCD display solution has the advantages of low cost and high contrast. The release film is tightly attached to the LCD screen, and the photosensitive resin is cured by ultraviolet light on the release film. The backlight irradiation of the LCD screen and the curing of the photosensitive resin both generate a large amount of heat accumulation, which greatly affects the service life and reliability of the LCD screen.
[0004] The DLP projection solution has the advantages of high efficiency and high definition. The image generator is a DMD chip, which controls the direction of light at the corresponding pixel position through a micro-mirror. The on and off of the pixel corresponds to the flip angle of the micro-mirror. The flip of the micro-mirror alone cannot completely intercept the light in the pixel off state, resulting in a generally low contrast ratio in the implementation cases of this solution. Therefore, it is very necessary to design a 3D printing projection lens system based on an LCD screen. Utility Model Content
[0005] The purpose of the utility model is to provide a three-dimensional printing projection lens system based on a liquid crystal screen, which has a series of advantages such as high integration, small size, easy manufacturing, reasonable tolerance, low cost and high imaging quality, and has high practical application value.
[0006] To achieve the above purpose, the utility model provides the following solutions:
[0007] A three-dimensional printing projection objective lens system based on a liquid crystal screen, which includes, along the optical axis from the object plane to the imaging plane, a first lens group G13, a second lens group G46, a seventh lens G7, an eighth lens G8, a ninth lens G9, a focusing lens and a liquid crystal screen;
[0008] The first lens group G13 includes a first lens G1 and a glued lens G2 / 3, and the glued lens G2 / 3 is composed of a second lens G2 and a third lens G3;
[0009] The second lens group G46 includes a fourth lens G4, a fifth lens G5 and a sixth lens G6, and a stop is disposed between the fourth lens G4 and the fifth lens G5.
[0010] Optionally, the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, and the ninth lens G9 are all made of glass.
[0011] Optionally, the ratio of the length L of the first lens G1 to the ninth lens G9 to the length BFL from the rear surface of the ninth lens G9 to the liquid crystal screen is 3.5<|L / BFL|<5.5.
[0012] Optionally, the ratio of the first lens group G13 to the second lens group G46 is 0.8<|G13 / G46|<1.2, the focal powers of the first lens G1, the third lens G3, the fourth lens G4 and the sixth lens G6 are positive, and the angles of the second lens G2 and the fifth lens G5 are negative.
[0013] Optionally, the eighth lens G8 and the ninth lens G9 are both bent toward the liquid crystal screen, and a ratio of a focal length f8 of the eighth lens G8 to a focal length f9 of the ninth lens G9 is 2<|f8 / f9|<2.5.
[0014] Optionally, the focal length f of the focusing lens c is 90mm, the focal length F of the 3D printing projection lens system and the focal length f of the focusing lens c The ratio is 1.0<|F / f c |<1.6.
[0015] Optionally, the refractive index n2 and the Abbe constant v2 of the second lens G2 satisfy:
[0016]
[0017] The refractive index n3 and the Abbe constant v3 of the third lens G3 satisfy:
[0018]
[0019] The refractive indexes of the second lens G2 and the third lens G3 are arranged in order of high and low, and the Abbe constants are arranged in order of low and high.
[0020] According to the specific embodiments provided by the utility model, the utility model discloses the following technical effects: the utility model provides a three-dimensional printing projection objective system based on a liquid crystal screen, the system includes a first lens group G13, a second lens group G46, a seventh lens G7, an eighth lens G8, a ninth lens G9, a focusing lens and a liquid crystal screen. The system adopts a liquid crystal screen to implement a projection scheme. There is a large air gap between the release film in the light-cured three-dimensional printing architecture and the projection objective system, which avoids the problem of heat accumulation damaging the liquid crystal screen in the liquid crystal display scheme. The system adopts an objective projection system to better map the pixels of the liquid crystal screen at the receiving surface, thereby improving the clarity and resolution. The image generator is a liquid crystal screen, and the light is passed and intercepted by liquid crystal flipping, which is the principle of light valve, thereby achieving a high contrast effect of the projection objective system. The liquid crystal screen is adopted, and the cost is disclosed. The system has a series of advantages such as high integration, small size, easy manufacturing, reasonable tolerance, low cost and high imaging quality, and has high practical application value. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0022] Figure 1 This is a schematic diagram of the structure of a three-dimensional printing projection lens system based on a liquid crystal screen according to an embodiment of the utility model;
[0023] Figure 2 This is a schematic diagram of the MTF of the 3D printing projection objective system;
[0024] Figure 3 Schematic diagram of relative illumination of 3D printing projection objective system.
[0025] Figure numerals: 1. focusing chip; 2. LCD screen. DETAILED DESCRIPTION
[0026] The purpose of the utility model is to provide a three-dimensional printing projection lens system based on a liquid crystal screen, which has a series of advantages such as high integration, small size, easy manufacturing, reasonable tolerance, low cost and high imaging quality, and has high practical application value.
[0027] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0028] like Figure 1As shown, the three-dimensional printing projection objective lens system based on the liquid crystal screen provided by the embodiment of the utility model includes, along the optical axis from the object plane to the imaging plane, a first lens group G13, a second lens group G46, a seventh lens G7, an eighth lens G8, a ninth lens G9, a focusing lens 1 and a liquid crystal screen 2;
[0029] The first lens group G13 includes a first lens G1 and a glued lens G2 / 3, and the glued lens G2 / 3 is composed of a second lens G2 and a third lens G3;
[0030] The second lens group G46 includes a fourth lens G4, a fifth lens G5 and a sixth lens G6. An aperture is arranged between the fourth lens G4 and the fifth lens G5. The aperture is placed in the center of the lens combination of the objective lens system, which effectively reduces the chromatic aberration of the system.
[0031] The first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8 and the ninth lens G9 are all made of glass.
[0032] The ratio of the length L of the first lens G1 to the ninth lens G9 to the length BFL from the rear surface of the ninth lens G9 to the liquid crystal screen 2 is 3.5<|L / BFL|<5.5, which can control the total length of the optical lenses and their air gaps, effectively compress the total length of the optical system, and realize the miniaturization of the optical system.
[0033] The ratio of the first lens group G13 to the second lens group G46 is 0.8<|G13 / G46|<1.2, the focal powers of the first lens G1, the third lens G3, the fourth lens G4 and the sixth lens G6 are positive, and the angles of the second lens G2 and the fifth lens G5 are negative, the first lens group G13 and the second lens group G46 are two consecutive groups of three-piece lens groups with positive and negative focal powers, and the positive and negative focal powers are arranged in a nearly symmetrical manner, which can effectively balance aberrations and control the system aperture within an enlarged range to achieve high efficiency of the optical system.
[0034] The eighth lens G8 and the ninth lens G9 are both bent toward the liquid crystal screen 2, with the same bending direction. The ratio of the focal length f8 of the eighth lens G8 to the focal length f9 of the ninth lens G9 is 2<|f8 / f9|<2.5. The two lenses are similar in shape and material, and their function is to reasonably distribute the optical focal length, thereby achieving the rationality of the lens bending shape and easy processing.
[0035] The focal length f of the focusing lens 1 c is 90 mm, the focal length F of the 3D printing projection lens system and the focal length f of the focusing lens 1 c The ratio is 1.0<|F / f c|<1.6, the focal length of the objective lens system is slightly larger than the focusing lens 1, which avoids the problem of large aberrations caused by unbalanced distribution of system optical power, and at the same time reduces the distance to the gap between the liquid crystal panels, further compressing the length of the system.
[0036] The refractive index n2 and the Abbe constant v2 of the second lens G2 satisfy:
[0037]
[0038] The refractive index n3 and the Abbe constant v3 of the third lens G3 satisfy:
[0039]
[0040] The refractive indexes of the second lens G2 and the third lens G3 are arranged in order of high and low, and the Abbe constants are arranged in order of low and high.
[0041] The 3D printed projection objective system is suitable for LCD screens with a maximum size of 4 inches and can achieve a maximum Nyquist sampling frequency of 11 line pairs per millimeter for identifying LCD screens.
[0042] The parameters of the 3D printing projection objective system are shown in Table 1;
[0043] Table 1 Specific parameters of 3D printing projection lens system
[0044]
[0045]
[0046] The MTF (Modulation Transfer Function) index is the most accurate and scientific evaluation standard for lenses. The vertical axis represents contrast. The closer it is to 1, the better the lens imaging. The horizontal axis represents resolution, in units of line pairs per millimeter. The projection image pixel size used in the embodiment of the present application is 23μm, and the corresponding limiting Nyquist frequency is about 11 line pairs per millimeter. Projection lenses generally require that the MTF value of each field of view is at least 0.3 at the design resolution, such as Figure 2 As shown, the MTF values within the optical zoom focal length of the embodiments of the present application are all above 0.8, with extremely excellent imaging quality.
[0047] Relative illumination refers to the ratio of the illumination at different coordinate points on the image plane to the illumination at the center point. The ordinate represents the normalized illumination value, and the abscissa represents the field of view angle of the lens. Under the same conditions, a smooth transition of the relative illumination curves of each field of view represents uniform illumination within the projection frame. The closer the relative illumination value of each field of view is to 1, the higher the final projection brightness. The relative illumination diagram of this application is shown in the figure below. Figure 3 shown.
[0048] This application uses a liquid crystal screen as an image generator and implements a receiving surface display solution by projection. The LCD screen pattern is mapped to the receiving surface, and the radiation energy surface carrying the image information realizes a photocuring reaction of a specific pattern. It can be seen from the embodiments that the MTF (modulation transfer function) of the lens at low, medium and high frequencies are all very good, and it can be analyzed that it has a high resolution effect.
[0049] The utility model provides a three-dimensional printing projection lens system based on a liquid crystal screen, the system comprises a first lens group G13, a second lens group G46, a seventh lens G7, an eighth lens G8, a ninth lens G9, a focusing lens and a liquid crystal screen, the system adopts a liquid crystal screen to realize a projection scheme, there is a large air gap between a release film in a light-cured three-dimensional printing structure and the projection lens system, the problem of heat accumulation damaging the liquid crystal screen in a liquid crystal display scheme is avoided, the system adopts an objective lens projection system, better maps pixel points of the liquid crystal screen at a receiving surface, and realizes an improvement in clarity and resolution, wherein an image generator is a liquid crystal screen, and light is passed and intercepted by liquid crystal flipping, which is a light valve principle, thereby realizing a high contrast effect of the projection lens system, adopting a liquid crystal screen, and cost disclosure, the system has a series of advantages such as high integration, small size, easy manufacturing, reasonable tolerance, low cost and high imaging quality, and has high practical application value.
[0050] This article uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the method and core ideas of the utility model. At the same time, for those skilled in the art, according to the ideas of the utility model, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the utility model.
Claims
1. A three-dimensional printing projection lens system based on a liquid crystal screen, characterized in that: The optical axis includes, from the object plane to the imaging plane, a first lens group G13, a second lens group G46, a seventh lens G7, an eighth lens G8, a ninth lens G9, a focusing lens and a liquid crystal screen; The first lens group G13 includes a first lens G1 and a glued lens G2 / 3, and the glued lens G2 / 3 is composed of a second lens G2 and a third lens G3; The second lens group G46 includes a fourth lens G4, a fifth lens G5 and a sixth lens G6, and a stop is disposed between the fourth lens G4 and the fifth lens G5.
2. The three-dimensional printing projection lens system based on a liquid crystal screen according to claim 1, characterized in that: The first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8 and the ninth lens G9 are all made of glass.
3. The three-dimensional printing projection lens system based on a liquid crystal screen according to claim 1, characterized in that: The ratio of the length L of the first lens G1 to the ninth lens G9 to the length BFL from the rear surface of the ninth lens G9 to the liquid crystal screen is 3.5<|L / BFL|<5.
5.
4. The three-dimensional printing projection lens system based on a liquid crystal screen according to claim 1, characterized in that: The ratio of the first lens group G13 to the second lens group G46 is 0.8<|G13 / G46|<1.2, the focal powers of the first lens G1, the third lens G3, the fourth lens G4 and the sixth lens G6 are positive, and the angles of the second lens G2 and the fifth lens G5 are negative.
5. The three-dimensional printing projection lens system based on a liquid crystal screen according to claim 1, characterized in that: The eighth lens G8 and the ninth lens G9 are both bent toward the liquid crystal screen, and a ratio of a focal length f8 of the eighth lens G8 to a focal length f9 of the ninth lens G9 is 2<|f8 / f9|<2.
5.
6. The three-dimensional printing projection lens system based on a liquid crystal screen according to claim 1, characterized in that: The focal length f of the focusing lens c is 90mm, the focal length F of the 3D printing projection lens system and the focal length f of the focusing lens c The ratio is 1.0<|F / f c |<1.
6.
7. The three-dimensional printing projection lens system based on a liquid crystal screen according to claim 2, characterized in that: The refractive index n2 and the Abbe constant v2 of the second lens G2 satisfy: The refractive index n3 and the Abbe constant v3 of the third lens G3 satisfy: The refractive indexes of the second lens G2 and the third lens G3 are arranged in order of high and low, and the Abbe constants are arranged in order of low and high.