Liquid crystal lens
By adding optimized electrodes to the liquid crystal lens, the problem that existing liquid crystal lenses cannot achieve high imaging quality and large zoom range at the same time when driving in the full voltage range is solved, and the effect is closer to the ideal voltage distribution is achieved and the application range is expanded.
Patent Information
- Application Number
- CN202421206576.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-29
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-05-29
Smart Images
Figure CN222580375U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of liquid crystal lenses, and more specifically, to a liquid crystal lens. Background Art
[0002] Lenses have always played a key role in many fields, such as medicine, lasers, and film and television. Many fields have explored the imaging quality, portability, and zoomability of lenses. Among them, since the electrically controlled variable-focus liquid crystal lens can adapt to scenarios where there is a need for changes in the focal length of the lens, it has a very large research value compared to the traditional non-variable-focus lens. Among them, liquid crystal lenses with a large zoom range and high imaging quality have better applicability in corresponding application scenarios. For example, endoscopes used in medicine have obvious requirements for the weight, size, and zoom performance of the lens. The characteristics of liquid crystal lenses with a large zoom range and high imaging quality can meet this requirement, so the liquid crystal lens has important research value.
[0003] For the existing ordinary high-resistance layer electrode liquid crystal lens (HRLE-LCL), when the alternating current U is applied, the electric potential along the edge of the liquid crystal layer gradually decreases, forming a potential gradient distribution with high, medium and low edges. For optically positive liquid crystal materials, the effective refractive index distribution of light incident from the vertical lens in the liquid crystal layer forms a gradient distribution with low edges and high middle. The liquid crystal lens is a positive lens, equivalent to a convex lens, which plays the role of converging light beams. Changing the amplitude and frequency of the driving voltage can adjust the refractive index distribution of the liquid crystal lens to achieve the purpose of zooming. For the electrically controlled ordinary HRLE-LCL, the voltage amplitude effective value U of the liquid crystal lens is set at the focal length (such as the focal length is 200mm) rms , the distribution curve is similar to a quadratic parabola distribution. However, in the entire effective refractive index range n o -n e , the effective value of the driving voltage amplitude applied to the liquid crystal layer is U rms (At this time, the voltage range is the full voltage range, which is 0-11V in this model rms ) and refractive index n eff For an electrically controlled liquid crystal lens, the ideal effective refractive index distribution under a set focal length is a standard quadratic parabola curve.
[0004] For the common HRLE-LCL, if the full voltage range is applied to the lens, due to U rms With n effThe overall nonlinear relationship between the upper electrode layer and the lower electrode layer is that no matter how the driving conditions (such as the effective value of the driving voltage amplitude and the frequency of the driving voltage) are adjusted, the liquid crystal lens cannot obtain the ideal effective refractive index distribution. If the full voltage range is applied to the liquid crystal lens, the actual lens refractive index distribution will seriously deviate from the ideal effective refractive index distribution, and the imaging quality of the liquid crystal lens will be seriously reduced; if the full voltage range is not applied, the applied voltage range is reduced, such as the voltage range of the applied interval, then U rms -n eff The relationship is approximately linear, and the effective refractive index distribution of the liquid crystal lens can be close to the ideal effective refractive index distribution. The liquid crystal lens can maintain good imaging quality, but reducing the applied voltage range means reducing the effective refractive index difference between the center and the edge of the lens (n center -n periphery ), that is, the focusing range of the liquid crystal lens is reduced, so that the application range of the liquid crystal lens is limited. Utility Model Content
[0005] In order to overcome the defects in the prior art, the utility model provides a liquid crystal lens, which can achieve a large zoom range of HRLE-LCL while maintaining the high imaging quality of the liquid crystal lens.
[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is:
[0007] A liquid crystal lens comprises, from bottom to top, a first glass layer, a lower electrode layer, a first liquid crystal orientation layer, a liquid crystal layer, a second liquid crystal orientation layer, an upper electrode layer, and a second glass layer, wherein the upper electrode layer is electrically connected to the lower electrode layer; and a plurality of optimization electrodes concentrically arranged with the lens are also arranged on the upper electrode, and each of the optimization electrodes is electrically connected to the lower electrode layer.
[0008] According to the above technical means, when driving in the full voltage range, the V rms -n eff The relationship curve is nonlinear, and high imaging quality and a large zoom range cannot be taken into account at the same time. The utility model adds optimized electrodes on the basis of ordinary HRLE-LCL, so that the HRLE-LCL type liquid crystal lens can have high imaging quality and a large zoom range at the same time.
[0009] Furthermore, the shape of the optimization electrode is a ring structure which is the same as the shape of the lens.
[0010] Furthermore, at least three optimization electrodes are provided, one of which is located at the center of the lens, and the radius of the optimization electrode adjacent to the center is greater than or equal to 0.5 mm. The number of optimization electrodes is not limited. For example, the aperture of the liquid crystal lens is 4 mm. Generally speaking, the number of optimization electrodes should not exceed 5 or more. This is because too many additional optimization electrodes will increase the number of lead wires of the optimization electrodes and thus increase the area of the lead wires. The lead wires of the optimization electrodes will affect the electric field distribution in the liquid crystal region, which is not conducive to the imaging quality of the lens. The radius position of the innermost optimization electrode (except the optimization electrode in the center) is generally not less than 0.5 mm. Generally, no optimization electrode is required from r = 0.5 mm to the center of the lens, and its voltage amplitude effective value distribution is close to the ideal distribution.
[0011] Furthermore, the line width of each optimization electrode is less than 50 um. The line width of each optimization electrode should be less than 50 um. If the line width of the optimization electrode is too large, it will affect the electric field distribution in the liquid crystal region and thus affect the lens imaging.
[0012] Furthermore, the upper electrode layer includes a circular hole electrode and a high resistance layer which are arranged concentrically with the lens; the circular hole electrode is electrically connected to the lower electrode layer. The material of the high resistance layer is generally zinc oxide (ZnO), and can also be TiOx, ZnS, SnO, Sb-Sn-O, ZrO, etc. Combining the conductivity and relative dielectric constant of the material, the high resistance layer selects a material with a higher resistance value, which can achieve better results.
[0013] The high resistance layer is electrically connected to the upper electrode layer, and a certain voltage can be increased between the upper electrode layer and the lower electrode layer, so that an equivalent circuit is formed between the upper electrode layer and the lower electrode layer. The high resistance layer forms an equivalent resistor, and the liquid crystal layer forms an equivalent capacitor. By adjusting the voltage amplitude and frequency, the liquid crystal orientation of the liquid crystal layer can be changed, and the refractive index can be made closer to the ideal electric field, thereby further improving the imaging effect.
[0014] Furthermore, the line width of the circular hole electrode is less than 50 um; and the radius of the circular hole electrode is 2 mm to 5 mm.
[0015] Furthermore, the optimized electrode and the circular hole electrode are electrically connected to the lower electrode layer through electrode lead wires; the line width of the electrode lead wires is less than 30um; and the spacing between two adjacent electrode lead wires is greater than or equal to 30um.
[0016] Furthermore, the thickness of the first glass layer and the second glass layer is 100um to 550um; the thickness of the first liquid crystal alignment layer and the second liquid crystal alignment layer is 0.5um to 1um. The material of the first glass layer and the second glass layer is generally soda lime glass, quartz glass, etc. The material of the first liquid crystal alignment layer and the second liquid crystal alignment layer is polyimide.
[0017] Furthermore, the thickness of the liquid crystal layer is 25um to 50um. The liquid crystal layer is generally a mixed liquid crystal formed by mixing several nematic liquid crystals, and has a higher Δn (birefringence) and a lower threshold voltage.
[0018] Furthermore, the thickness of the upper electrode layer and the lower electrode layer is 150nm-300nm; the thickness of the high resistance layer is 0.01um-0.1um. The upper electrode layer and the lower electrode layer are generally indium tin oxide (ITO), and can also be other transparent and conductive film materials.
[0019] Compared with the prior art, the beneficial effect is that the liquid crystal lens provided by the utility model adds optimized electrodes on the basis of the ordinary HRLE-LCL, so that the HRLE-LCL type liquid crystal lens can have high imaging quality and a large zoom range at the same time. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a structural schematic diagram of the liquid crystal lens of the utility model.
[0021] Figure 2 It is a connection schematic diagram of the upper electrode, the optimized electrode and the lower electrode of the utility model.
[0022] Figure 3 is a schematic diagram of the electrode lead wire of the optimized electrode.
[0023] Figure numerals: 1. first glass layer; 2. lower electrode layer; 3. first liquid crystal orientation layer; 4. liquid crystal layer; 5. second liquid crystal orientation layer; 6. upper electrode layer; 61. optimized electrode; 62. circular hole electrode; 63. resistive layer; 7. second glass layer; 8. electrode lead wires. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The utility model is described in one of the embodiments in combination with the specific implementation methods. Among them, the drawings are only used for exemplary descriptions, and only schematic diagrams are shown, not physical drawings, and cannot be understood as limitations on the utility model; in order to better illustrate the embodiments of the utility model, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.
[0025] In the description of the present utility model, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, it is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for exemplary explanations and cannot be understood as limitations on the present utility model. For ordinary technicians in the field, the specific meanings of the above terms can be understood according to specific circumstances. In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text is to include three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that satisfy both A and B.
[0026] Embodiment 1:
[0027] The present embodiment provides a liquid crystal lens, which includes, from bottom to top, a first glass layer 1, a lower electrode layer 2, a first liquid crystal orientation layer 3, a liquid crystal layer 4, a second liquid crystal orientation layer 5, an upper electrode layer 6, and a second glass layer 7, wherein the upper electrode layer 6 is electrically connected to the lower electrode layer 2; a plurality of optimization electrodes 61 concentrically arranged with the lens are also provided on the upper electrode, and each of the optimization electrodes 61 is electrically connected to the lower electrode layer 2.
[0028] According to the above technical means, when driving in the full voltage range, the V rms -n eff The relationship curve is nonlinear, and high imaging quality and a large zoom range cannot be taken into account at the same time. The utility model adds an optimized electrode 61 on the basis of the ordinary HRLE-LCL, so that the HRLE-LCL type liquid crystal lens can have both high imaging quality and a large zoom range.
[0029] like Figure 2 As shown, the shape of the optimization electrode 61 is a ring structure which is the same as the shape of the lens.
[0030] Specifically, at least three optimization electrodes 61 are provided, one of which is located at the center of the lens, and the radius of the optimization electrode 61 adjacent to the center is greater than or equal to 0.5 mm. The number of optimization electrodes 61 is not limited. For example, the aperture of the liquid crystal lens is 4 mm. Generally speaking, the number of optimization electrodes 61 should not exceed 5 or more. This is because too many additional optimization electrodes 61 will increase the number of lead wires of the optimization electrodes 61 and thus increase the area of the lead wires. The lead wires of the optimization electrodes 61 will affect the electric field distribution in the liquid crystal region, which is not conducive to the imaging quality of the lens. The radius position of the innermost optimization electrode 61 (except the optimization electrode 61 in the center) is generally not less than 0.5 mm. Generally, the optimization electrode 61 is not required from r = 0.5 mm to the center of the lens, and its voltage amplitude effective value distribution is close to the ideal distribution.
[0031] The line width of each optimization electrode 61 is less than 50 um. The line width of each optimization electrode 61 should be less than 50 um. If the line width of the optimization electrode 61 is too large, it will affect the electric field distribution in the liquid crystal region and thus affect the lens imaging.
[0032] like Figure 1 As shown, the upper electrode layer 6 includes a circular hole electrode 62 and a high resistance layer 63 which are arranged concentrically with the lens; the circular hole electrode 62 is electrically connected to the lower electrode layer 2. The material of the high resistance layer 63 is generally zinc oxide (ZnO), and can also be TiOx, ZnS, SnO, Sb-Sn-O, ZrO, etc. In combination with the conductivity and relative dielectric constant of the material, the high resistance layer 63 is selected from a material with a higher resistance value, which can achieve a better effect.
[0033] The high resistance layer 63 is electrically connected to the upper electrode layer 6, and a certain voltage can be increased between the upper electrode layer 6 and the lower electrode layer 2, so that an equivalent circuit is formed between the upper electrode layer 6 and the lower electrode layer 2. The high resistance layer 63 forms an equivalent resistor, and the liquid crystal layer 4 forms an equivalent capacitor. By adjusting the voltage amplitude and frequency, the liquid crystal orientation of the liquid crystal layer 4 can be changed, and the refractive index can be made closer to the ideal electric field, thereby further improving the imaging effect.
[0034] In this embodiment, the line width of the circular hole electrode 62 is less than 50 um; the radius of the circular hole electrode 62 is 2 mm to 5 mm.
[0035] The optimized electrode 61 and the circular hole electrode 62 are both electrically connected to the lower electrode layer 2 via electrode lead wires 8; the line width of the electrode lead wires 8 is less than 30 um; and the spacing between two adjacent electrode lead wires 8 is greater than or equal to 30 um.
[0036] Specifically, the thickness of the first glass layer 1 and the second glass layer 7 is 100um to 550um; the thickness of the first liquid crystal orientation layer 3 and the second liquid crystal orientation layer 5 is 0.5um to 1um. The material of the first glass layer 1 and the second glass layer 7 is generally soda-lime glass, quartz glass, etc. The material of the first liquid crystal orientation layer 3 and the second liquid crystal orientation layer 5 is polyimide.
[0037] In addition, the thickness of the second liquid crystal layer 4 is 25um to 50um. The liquid crystal layer 4 is generally a mixed liquid crystal formed by mixing several nematic liquid crystals, and has a higher Δn (birefringence) and a lower threshold voltage.
[0038] The thickness of the upper electrode layer 6 and the lower electrode layer 2 is 150nm-300nm; the thickness of the high resistance layer 63 is 0.01um-0.1um. The upper electrode layer 6 and the lower electrode layer 2 are generally indium tin oxide (ITO), or other transparent and conductive film materials.
[0039] Example 2
[0040] The other structures of this embodiment are the same as those of Embodiment 1, except that, in this embodiment, the liquid crystal lens is a circular structure; the circular hole electrode 62 in the upper electrode layer 6 is a liquid level circular ring structure; and the optimization electrode 61 is a circular ring structure arranged concentrically with the liquid crystal lens.
[0041] Example 3
[0042] The liquid crystal lens structure of this embodiment is the same as that of Embodiment 2. In this embodiment, the diameter of the liquid crystal lens is 4 mm; the hole radius of the circular hole electrode 62 is 2 mm; in this embodiment, 5 optimized electrodes 61 are set, and the radii of the optimized electrodes 61 are respectively: 0 mm, 0.55 mm, 0.77 mm, 1.16 mm, and 1.76 mm.
[0043] The electric field simulation of the liquid crystal lens provided in this embodiment is performed by the finite element method, and the ideal voltage amplitude effective value distribution, optimized voltage amplitude effective value distribution and non-optimized voltage amplitude effective value distribution of the lens at three focal lengths (f=200, f=300, f=400) are obtained. At the three focal lengths, the voltage amplitude effective value of the optimized liquid crystal lens is closer to the ideal voltage amplitude effective value than the non-optimized one. Here are the standard deviations of the voltage amplitude effective values of the non-optimized and optimized liquid crystal lenses and the ideal voltage amplitude effective value at the three focal lengths:
[0044] f=400mm:
[0045] Unoptimized: 0.2569;
[0046] Optimized: 0.0246;
[0047] f=300mm:
[0048] Unoptimized: 0.2835;
[0049] Optimized: 0.0267;
[0050] f=200mm:
[0051] Unoptimized: 0.2784;
[0052] Optimized: 0.0452.
[0053] If a driving voltage is applied to the liquid crystal lens, the voltage amplitude effective value distribution in the lens is the same as the ideal voltage amplitude effective value at a certain focal length, then the effective refractive index distribution of the liquid crystal lens is the same as the ideal effective refractive index distribution at the focal length. At this time, the lens has no aberration at the focal length and the imaging quality is extremely high. In actual situations, the closer the voltage amplitude distribution of the lens is to the ideal voltage amplitude effective value, the higher the imaging quality.
[0054] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0055] Obviously, the above embodiments of the utility model are only examples for clearly explaining the utility model, and are not intended to limit the implementation methods of the utility model. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the protection scope of the claims of the utility model.
Claims
1. A liquid crystal lens, characterized in that: The invention comprises, from bottom to top, a first glass layer (1), a lower electrode layer (2), a first liquid crystal orientation layer (3), a liquid crystal layer (4), a second liquid crystal orientation layer (5), an upper electrode layer (6), and a second glass layer (7), wherein the upper electrode layer (6) is electrically connected to the lower electrode layer (2); and a plurality of optimization electrodes (61) are arranged concentrically with the lens on the upper electrode, and each of the optimization electrodes (61) is electrically connected to the lower electrode layer (2).
2. The liquid crystal lens according to claim 1, characterized in that: The shape of the optimization electrode (61) is a ring structure which is the same as the shape of the lens.
3. The liquid crystal lens according to claim 2, characterized in that: At least three optimization electrodes (61) are provided, one of the optimization electrodes (61) is located at the center of the lens, and the radius of the optimization electrode (61) adjacent to the center is greater than or equal to 0.5 mm.
4. The liquid crystal lens according to claim 2, characterized in that: The line width of each optimized electrode (61) is less than 50 um.
5. The liquid crystal lens according to claim 2, characterized in that: The upper electrode layer (6) comprises a circular hole electrode (62) and a high resistance layer (63) which are arranged concentrically with the lens; the circular hole electrode (62) is electrically connected to the lower electrode layer (2).
6. The liquid crystal lens according to claim 5, characterized in that: The line width of the circular hole electrode (62) is less than 50 um; and the radius of the circular hole electrode (62) is 2 mm to 5 mm.
7. The liquid crystal lens according to claim 5, characterized in that: The optimized electrode (61) and the circular hole electrode (62) are both electrically connected to the lower electrode layer (2) via electrode lead wires (8); the line width of the electrode lead wires (8) is less than 30 um; and the spacing between two adjacent electrode lead wires (8) is greater than or equal to 30 um.
8. The liquid crystal lens according to any one of claims 1 to 7, characterized in that: The thickness of the first glass layer (1) and the second glass layer (7) is 100 um to 550 um; the thickness of the first liquid crystal orientation layer (3) and the second liquid crystal orientation layer (5) is 0.5 um to 1 um.
9. The liquid crystal lens according to any one of claims 1 to 7, characterized in that: The thickness of the liquid crystal layer (4) is 25 um to 50 um.
10. The liquid crystal lens according to any one of claims 5 to 7, characterized in that: The thickness of the upper electrode layer (6) and the lower electrode layer (2) is 150nm to 300nm; the thickness of the high resistance layer (63) is 0.01um to 0.1um.