Optical lens, optical lens design method and application thereof

Abstract

The present invention relates to an optical lens, belonging to the field of backlight display, the optical lens comprises a first surface microstructure, a first total reflection surface, a second surface microstructure, a first refractive surface, a second refractive surface and a second total reflection surface. The present invention also requests protection for a design method of the optical lens and an application of the optical lens in a liquid crystal display backlight module. The optical lens of the present invention has a plurality of refractive surfaces and total reflection surfaces, and is combined with a micron-level surface microstructure, so as to obtain satisfactory uniformity under a smaller light mixing distance and a larger LED spacing.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal display, and in particular to an optical lens used in a liquid crystal display backlight module. Background Art

[0002] Liquid crystal displays occupy an important position in the field of flat panel displays and have been developing in the direction of being light, thin, and low in power consumption. Direct-type backlight modules have the advantages of high cost performance and high energy utilization, but they need to be used with secondary lenses to reduce the light mixing distance, thereby reducing the thickness of the backlight module. Existing secondary lenses are divided into refractive and reflective types. Compared with reflective lenses, refractive lenses have high light utilization, but the light mixing distance is relatively large. Regardless of whether it is a refractive lens or a reflective lens, it is difficult to achieve high uniformity requirements at a small light mixing distance, so it is difficult to use it in an ultra-thin backlight module. This patent proposes a new lens structure for the case where the optical distance (OD) is small, which can achieve high uniformity at a small light mixing distance and meet the requirements of an ultra-thin backlight module. Summary of the invention

[0003] The object of the present invention is to provide an optical lens having multiple refractive surfaces and total reflection surfaces, and combined with a micrometer-level surface microstructure, which can achieve satisfactory uniformity at a smaller light mixing distance and a larger LED spacing.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] An optical lens, comprising: a first surface microstructure, a first total reflection surface, a second surface microstructure, a first refractive surface, a second refractive surface, and a second total reflection surface;

[0006] The two second total reflection surfaces are symmetrically arranged, and one ends of the two second total reflection surfaces are connected;

[0007] The other ends of the two second total reflection surfaces respectively have the first surface microstructure, and the two first surface microstructures are symmetrical; the two first surface microstructures are located in the same plane;

[0008] The other ends of the two first surface microstructures respectively have the first total reflection surface;

[0009] The other ends of the two first total reflection surfaces respectively have the first refractive surfaces;

[0010] The other ends of the two first refractive surfaces respectively have the second surface microstructure;

[0011] The second refractive surface is provided between two of the second surface microstructures;

[0012] The two first refractive surfaces, the two second surface microstructures and the second refractive surface form a groove.

[0013] Optionally, the first surface microstructure is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5 μm to 20 μm, and the height is 10 μm to 20 μm.

[0014] Optionally, the second surface microstructure is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5 μm to 20 μm, and the height is 10 μm to 20 μm.

[0015] Optionally, the cross-sections of the first total reflection surface and the second total reflection surface are curved surfaces with a curvature of 0° to 45°.

[0016] A method for designing an optical lens, the method comprising:

[0017] Determine a first total reflection surface and a first refraction surface according to the light source;

[0018] determining the first surface microstructure according to the first total reflection surface;

[0019] determining a second refractive surface and a second surface microstructure according to the light source;

[0020] A second total reflection surface is determined according to the light emitted by the light source at the second refractive surface and the second surface microstructure.

[0021] Optionally, determining the first total reflection surface and the first refractive surface according to the light source includes:

[0022] The position of the light source is set to (x0, y0), the height of the optical lens is set to H, and the coordinates of the intersection of the first refractive surface and the horizontal axis are set to (x1, y1); the light source is located in the middle of the intersection of the two first refractive surfaces and the horizontal axis;

[0023] Divide the range [θ2,90°] into M points with a step length of △θ to obtain a series of angles θ i , i = ~M; set coefficient α;

[0024] According to the angle θ i ,use Get the corresponding coordinate point (x 4i, y 4i ), where β is the inner surface deflection angle; In and Out are the inner surface incident vector and outgoing vector respectively; N is the value of the P i Normal vector of the point; n In represents the refractive index of air; n Out Represents the refractive index of the optical lens; P i and Pi+ is the adjacent point where the light is incident on the first refractive surface;

[0025] According to the corresponding coordinate point (x 4i, y 4i ),use Get the corresponding coordinate point (x 2i ,y 2i ), wherein a, b, and c represent angles respectively; and n is the refractive index of the optical lens.

[0026] Optionally, determining the second refractive surface and the second surface microstructure according to the light source includes:

[0027] Determine the second refractive surface within the light range of [0,θ1];

[0028] The second surface microstructure is determined within the light range of [θ1, θ2].

[0029] Optionally, the first surface microstructure is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5μm to 20μm, and the height is 10μm to 20μm; the second surface microstructure is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5μm to 20μm, and the height is 10μm to 20μm.

[0030] Optionally, determining the second total reflection surface according to the light emitted by the light source on the second refractive surface and the second surface microstructure specifically includes:

[0031] The second total reflection surface is set so that the cross-section of the second total reflection surface is a curved surface with a curvature of 0° to 45°. The second total reflection surface is divided into N segments, where N≥2. The curvature of each segment is adjusted according to the light emitted from the second refractive surface and the second surface microstructure until the light emission requirements are met.

[0032] An application of an optical lens, wherein the optical lens is applied to a liquid crystal display backlight module.

[0033] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0034] The optical lens of the present invention has multiple refractive surfaces and total reflection surfaces, and is combined with a micrometer-level surface microstructure, so that satisfactory uniformity can be obtained under a smaller light mixing distance and a larger LED spacing. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 is a surface diagram of the optical lens of the present invention;

[0037] Figure 2 is the optical path diagram of the present invention;

[0038] Figure 3 The surface design diagram of the optical lens of the present invention;

[0039] Figure 4 is a structural diagram of the first surface microstructure;

[0040] Figure 5 is a structural diagram of the second surface microstructure;

[0041] Figure 6 This is the LightTools point light source simulation effect diagram. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The object of the present invention is to provide an optical lens which can obtain higher uniformity when the light mixing distance is small.

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Figure 1 This is a surface diagram of the optical lens of the present invention, which comprises: a first surface microstructure 1, a first total reflection surface 2, a second surface microstructure 3, a first refractive surface 4, a second refractive surface 5 and a second total reflection surface 6. The LED light source is located at the center of the lens.

[0046] The specific structure of the optical lens is:

[0047] The two second total reflection surfaces 6 are symmetrically arranged, and one ends of the two second total reflection surfaces 6 are connected; the other ends of the two second total reflection surfaces 6 respectively have first surface microstructures 1, and the two first surface microstructures 1 are symmetrical; the cross-sections of the two second total reflection surfaces 6 are curves; the two first surface microstructures 1 are located in the same plane; the other ends of the two first surface microstructures 1 respectively have first total reflection surfaces 2; the other ends of the two first total reflection surfaces 2 respectively have first refractive surfaces 4; the other ends of the two first refractive surfaces 4 respectively have second surface microstructures 3; there are second refractive surfaces 5 between the second surface microstructures 3; the two first refractive surfaces 4, the two second surface microstructures 3 and the second refractive surface 5 form a groove.

[0048] Figure 4 is the structural diagram of the first surface microstructure, Figure 5 The first surface microstructure 1 and the second surface microstructure 3 are both periodic triangles, with an angle of 45° to 90°, a period length of 5 μm to 20 μm, and a height of 10 μm to 20 μm.

[0049] The optical lens of the present invention has multiple refractive surfaces and total reflection surfaces, and is combined with a micrometer-level surface microstructure, so that satisfactory uniformity can be obtained under a smaller light mixing distance and a larger LED spacing.

[0050] The optical lens of the present application can be used in a liquid crystal display backlight module, and can obtain higher uniformity at a smaller light mixing distance, meeting the requirements of an ultra-thin backlight module.

[0051] Figure 2 This is the optical path diagram of the optical lens of the present invention. For the light emitted from the light source at an angle of [0, θ1], it first enters the second refractive surface 5, and then is reflected by the second total reflection surface 6 and then emitted to the target receiving surface through the first total reflection surface 2; the light emitted from the light source at an angle of [θ1~θ2] first enters the second surface microstructure 3, and then is reflected by the second total reflection surface 6 and then emitted to the target receiving surface through the first total reflection surface 2; the light emitted from the light source at an angle of [θ2~90°] first enters the first refractive surface 4, and then is reflected by the first total reflection surface 2 to the first surface microstructure 1, and then is reflected by the first surface microstructure 1 to the bottom reflection plate, and then is reflected by the bottom reflection surface to the target receiving surface.

[0052] The optical lens of the present invention is based on Figure 3 The method specifically includes:

[0053] Step 1, set the position of the light source to (x0, y0), the height of the optical lens to H, and the coordinates of the intersection of the first refractive surface 4 and the horizontal axis to (x1, y1); the light source is located in the middle of the intersection of the two first refractive surfaces 4 and the horizontal axis.

[0054] Divide the range [θ2,90°] into M points with a step length of △θ to obtain a series of angles θ i , i=1~M; set coefficient α.

[0055] According to the angle θ i ,use Get the corresponding coordinate point (x 4i ,y 4i ), where β is the inner surface deflection angle; In and Out are the inner surface incident vector and outgoing vector respectively; N is the value of the P i Normal vector of the point; n In represents the refractive index of air; n Out Represents the refractive index of the optical lens; P i and P i+1 is the adjacent point where the light is incident on the first refractive surface 4.

[0056] According to the corresponding coordinate point (x 4i ,y 4i ),use Get the corresponding coordinate point (x 2i ,y 2i ) i ; Wherein, a, b, c represent angles respectively; n is the refractive index of the optical lens.

[0057] Step 2, determining the first surface microstructure 1 according to the first total reflection surface 2; the first surface microstructure 1 is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5μm to 20μm, and the height is 10μm to 20μm.

[0058] Step 3, in the light range of [0, θ1], the second refractive surface 5 is set to a curve with a curvature of 0° to 45°. In the light range of [θ1, θ2], the second surface microstructure 3 is determined; the second surface microstructure 3 is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5μm to 20μm, and the height is 10μm to 20μm.

[0059] Step 4, set the second total reflection surface 6 so that the cross-section of the second total reflection surface 6 is a curve with a curvature of 0° to 45°, divide the second total reflection surface 6 into N segments, N≥2, and adjust the curvature of each segment according to the light emitted from the second refractive surface 5 and the second surface microstructure 3 until the requirement of light emission uniformity is met.

[0060] Figure 6This is the simulation effect diagram of the Light Tools point light source. The optical lens height is 1.5mm, the optical lens diameter is 1.48mm, and when the OD is 3mm, the spot diameter reaches 20mm and the uniformity reaches 92%. The above simulation results verify that the optical lens of the present invention can achieve high uniformity at a small mixing distance and meet the requirements of the ultra-thin backlight module.

[0061] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0062] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, 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 present invention.

Claims

1. An optical lens, characterized in that: The optical lens comprises: a first surface microstructure (1), a first total reflection surface (2), a second surface microstructure (3), a first refractive surface (4), a second refractive surface (5) and a second total reflection surface (6); The two second total reflection surfaces (6) are symmetrically arranged, and one ends of the two second total reflection surfaces (6) are connected; The other ends of the two second total reflection surfaces respectively have the first surface microstructure (1), and the two first surface microstructures (1) are symmetrical; the two first surface microstructures (1) are located in the same plane; The other ends of the two first surface microstructures (1) respectively have the first total reflection surfaces (2); The other ends of the two first total reflection surfaces (2) are respectively provided with the first refractive surfaces (4); The other ends of the two first refractive surfaces (4) are respectively provided with the second surface microstructure (3); The second refractive surface (5) is provided between the two second surface microstructures (3); The two first refractive surfaces (4), the two second surface microstructures (3) and the second refractive surface (5) form a groove.

2. The optical lens according to claim 1, characterized in that: The first surface microstructure (1) is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5 μm to 20 μm, and the height is 10 μm to 20 μm.

3. The optical lens according to claim 1, characterized in that: The second surface microstructure (3) is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5 μm to 20 μm, and the height is 10 μm to 20 μm.

4. The optical lens according to claim 1, characterized in that: The cross-sections of the first total reflection surface and the second total reflection surface are curved surfaces with a curvature of 0° to 45°.

5. A method for designing the optical lens according to claim 1, characterized in that: The method comprises: Determining a first total reflection surface (2) and a first refraction surface (4) according to a light source; Determining the first surface microstructure (1) according to the first total reflection surface (2); Determining a second refractive surface (5) and a second surface microstructure (3) according to the light source; A second total reflection surface (6) is determined based on the light emitted by the light source at the second refractive surface (5) and the second surface microstructure (3).

6. The method for designing an optical lens according to claim 5, characterized in that: The step of determining the first total reflection surface (2) and the first refraction surface (4) according to the light source comprises: The position of the light source is set to (x0, y0), the height of the optical lens is set to H, and the coordinates of the intersection of the first refractive surface (4) and the horizontal axis are set to (x1, y1); the light source is located in the middle of the intersection of the two first refractive surfaces (4) and the horizontal axis; Divide the range [θ2, 90°] into M parts with a step length of △θ, and obtain a series of angles θi, i = 1 to M; set the coefficient α; According to the angle θi, using Obtain the corresponding coordinate point (x4i, y4i) of the light source on the first refractive surface (4); wherein β is the inner surface deflection angle; In and Out are the inner surface incident vector and the exit vector, respectively; N is the normal vector through the Pi point; nIn represents the refractive index of air; nOut represents the refractive index of the optical lens; Pi and Pi+1 are adjacent points where the light is incident on the first refractive surface (4); According to the corresponding coordinate point (x4i, y4i) of the light source on the first refractive surface (4), using The corresponding coordinate points (x2i, y2i) on the first total reflection surface (2) are obtained; wherein a, b, and c represent angles respectively; and n is the refractive index of the optical lens.

7. The method for designing an optical lens according to claim 6, characterized in that: The determining of the second refractive surface (5) and the second surface microstructure (3) according to the light source comprises: Determine the second refractive surface (5) within the light range of [0, θ1]; The second surface microstructure (3) is determined within the light range of [θ1, θ2].

8. The method for designing an optical lens according to claim 7, characterized in that: The first surface microstructure (1) is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5μm to 20μm, and the height is 10μm to 20μm; the second surface microstructure (3) is a periodic triangle, the angle of the triangle is 45° to 90°, the period length is 5μm to 20μm, and the height is 10μm to 20μm.

9. The method for designing an optical lens according to claim 8, characterized in that: The step of determining the second total reflection surface (6) according to the light emitted by the light source from the second refractive surface (5) and the second surface microstructure (3) specifically comprises: The second total reflection surface (6) is set so that the cross section of the second total reflection surface (6) is a curved surface with a curvature of 0° to 45°, and the second total reflection surface (6) is divided into N sections, N ≥ 2, and the curvature of each section is adjusted according to the light emitted from the second refractive surface (5) and the second surface microstructure (3) until the light emission requirements are met.

10. An application of the optical lens according to any one of claims 1 to 4, characterized in that: The optical lens is applied to a liquid crystal display backlight module.

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