A light guide plate and its dot design method

Abstract

The present invention discloses a light guide plate and a method for designing a dot thereof, wherein the light guide plate comprises an upper light emitting surface, a lower light emitting surface and a light incident surface, a plurality of dots are arranged on the upper light emitting surface or the lower light emitting surface, the dots are concave dots or convex dots, the dots comprise a top surface, a bottom surface and a light regulating surface, the dots are surrounded by the top surface, the bottom surface and the light regulating surface, the light regulating surface is composed of a plurality of inclined surfaces with different inclination angles, and the inclination angle of each inclined surface is obtained according to the light emitting characteristics, position, size of the LED, based on the law of refraction and the principle of energy superposition. The present invention performs targeted design of the dots of the light guide plate in combination with the light emitting characteristics, position, size, etc. of the LED, and the light regulating surface of the dots of the light guide plate has a plurality of inclined surfaces, which can obtain higher brightness and uniformity.

Description

Technical Field

[0001] The present invention relates to the technical field of light guide plates, and in particular to a light guide plate and a method for designing a mesh point thereof. Background Art

[0002] Liquid crystal materials do not emit light by themselves and require backlight to provide illumination. In order to reduce the thickness of the backlight module, light emitting diodes (LEDs) are usually placed on the side of the LCD screen, and a light guide plate is required to turn the light emitted by the LED from parallel to the LCD screen to perpendicular to the LCD screen. The light guide plate's function of turning light is achieved through the dots on the surface. After the light enters the light guide plate, the dots destroy the total reflection of the light inside the light guide plate. The shape of the dots has a great influence on the brightness and uniformity of the lighting surface light source.

[0003] The existing light guide plate dots are usually frustum, pyramid, prism, ellipsoid, etc., which are usually formed into a continuous light control surface through one-time processing, and the morphology is continuously improved through the effect of actual samples to improve brightness and uniformity. However, the light control surface is continuous, either an inclined surface or a hemispherical surface. Moreover, the design of the dots does not take into account the light-emitting characteristics, position, size, etc. of the LED, resulting in poor effect, high revision cost, and long development cycle. Summary of the invention

[0004] The purpose of the present invention is to provide a light guide plate and a method for designing a light guide dot thereof, and to carry out targeted design of the light guide plate dot in combination with the light-emitting characteristics, position, size, etc. of the LED. The light regulating surface of the light guide plate dot has multiple inclined surfaces, which can obtain higher brightness and uniformity.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A light guide plate comprises an upper light emitting surface, a lower light emitting surface and a light incident surface, wherein a plurality of dots are arranged on the upper light emitting surface or the lower light emitting surface, wherein the dots are concave dots or convex dots, wherein the dots comprise a top surface, a bottom surface and a light regulating surface, wherein the dots are surrounded by the top surface, the bottom surface and the light regulating surface, wherein the light regulating surface is composed of a plurality of inclined surfaces with different inclination angles, wherein the inclination angle of each inclined surface is designed according to the light emitting characteristics, position and size of an LED, based on the law of refraction and the principle of energy superposition.

[0007] Furthermore, the diameter of the long sides of the dots corresponding to the top surface and the bottom surface ranges from 20 μm to 65 μm, and the diameter of the short sides ranges from 0 μm to 25 μm.

[0008] Furthermore, when the network dots are concave dots, the depth of the concave dots is 5 μm to 25 μm, and when the network dots are convex dots, the height of the convex dots is 5 μm to 25 μm.

[0009] The present invention also provides a method for designing a dot of a light guide plate, which is applied to the above-mentioned light guide plate, and designs the inclination angle of the inclined surface of the light regulating surface according to the light emitting characteristics, position, size of the LED based on the law of refraction and the principle of energy superposition, and specifically includes the following steps:

[0010] S1, set the long side diameter of a single dot to L1, the short side diameter to L2, the number of dot slope segments to N, then the horizontal fixed distance of each segment of the dot slope ; The intersection point between each segment is P n , n=0~N-1, the inclination angle of the nth slope is α n ;

[0011] S2, set the distance from the starting point to the side of the light guide plate to D dot , the distance from the LED to the side of the light guide plate is D LED ;

[0012] S3, set the height of the LED light source to H LED , the thickness of the light guide plate is H LGP ;

[0013] S4, discretize the LED light source into M point light sources, each of which is marked as LED m , m=1~M;

[0014] S5, set the light emission angle of the light emitted by the mth LED point light source to the nth intersection of the grid points to θ mn , the position where it enters the light guide plate is P mn ;P mn To P n The vertical distance is p mn1 ;P mn To LED m The vertical distance is p mn2 ; The angle between the light and the horizontal direction is β mn ;

[0015] S6, set the refractive index of the light guide plate to n 1， The refractive index of air is n0; the total reflection angle γ is obtained according to the law of refraction;

[0016] S7, substitute m=1~M into the following formula (1) and repeat it to obtain the range of the inclination angle α0 of the first slope, marked as (α 0min , α 0max );

[0017] ;

[0018] S8, will (α 0min , α 0max ) is discretized, and each discrete angle is marked as α0k ,get:

[0019] ;

[0020] S9, for each α 0k , calculate the angles of each LED point light source reaching the top and bottom points of the first segment, determine whether it satisfies total reflection, accumulate the energy of the light that satisfies total reflection, and the α when the energy is maximum 0k is the inclination of the first segment;

[0021] S10, repeating steps S7-S9 to determine the inclination angle of each inclined surface.

[0022] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the light guide plate and its mesh design method provided by the present invention, mesh points are set on the surface of the light guide plate, and the light guide plate mesh points are designed in a targeted manner in combination with the light-emitting characteristics, position, size, etc. of the LED. The light control surface of the light guide plate mesh points has multiple inclined surfaces, and the angles of different inclined surfaces have an important influence on the control of light. The present invention uses mathematical derivation to calculate the range of the angles, and determines the optimal inclination angle according to the principle of energy superposition. Under the same density distribution, the light source incident on the incident surface is emitted from the light output surface to the greatest extent, thereby effectively improving the brightness while improving the uniformity of light output; in addition, the present invention performs segmented design on the light control surface, and can design the morphology according to specific module parameters, and is applicable to a wide range of modules. At the same time, it can effectively improve energy utilization, reduce optimization processes, shorten research and development cycles, and save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 is a structural schematic diagram of a light guide plate according to an embodiment of the present invention;

[0025] Figure 2a A schematic diagram of design parameters of a network point according to an embodiment of the present invention;

[0026] Figure 2b A schematic diagram of the light direction of the mesh point in an embodiment of the present invention;

[0027] Figure 3a This is the illumination distribution diagram of the existing one-stage network points;

[0028] Figure 3b This is an illumination distribution diagram of a five-segment dot control surface in an embodiment of the present invention;

[0029] Description of reference numerals: 10, light guide plate; 11, grid points; 101, upper light emitting surface; 102, lower light emitting surface; 103, light incident surface. DETAILED DESCRIPTION

[0030] 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.

[0031] The purpose of the present invention is to provide a light guide plate and a method for designing a light guide dot thereof, and to carry out targeted design of the light guide plate dot in combination with the light-emitting characteristics, position, size, etc. of the LED. The light regulating surface of the light guide plate dot has multiple inclined surfaces, which can obtain higher brightness and uniformity.

[0032] 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.

[0033] like Figure 1 As shown, a light guide plate 10 provided by the present invention includes an upper light emitting surface 101, a lower light emitting surface 102 and a light incident surface 103, a plurality of dots are arranged on the upper light emitting surface 101 or the lower light emitting surface 102, the dots 11 are concave dots or convex dots, the dots 11 include a top surface, a bottom surface and a light regulating surface, the dots are surrounded by the top surface, the bottom surface and the light regulating surface, the light regulating surface is composed of a plurality of inclined surfaces with different inclination angles, and the inclination angle of each inclined surface is designed according to the LED light-emitting characteristics, position, size, based on the law of refraction and the principle of energy superposition.

[0034] For example, the light guide plate 10 is a glass plate, the light incident surface 103 is located on the right side of the glass plate, the upper light emitting surface 101 is located on the upper side of the glass plate, and the lower light emitting surface 102 is located on the lower side of the glass plate.

[0035] For example, the top surface and the bottom surface are both circular. The long side diameter of the dots corresponding to the top surface and the bottom surface ranges from 20 μm to 65 μm, and the short side diameter ranges from 0 μm to 25 μm. In addition, the top surface and the bottom surface may also be square, triangular or trapezoidal, which is not limited by the present invention.

[0036] When the network dots are concave dots, the depth of the concave dots is 5 μm to 25 μm, and when the network dots are convex dots, the height of the convex dots is 5 μm to 25 μm.

[0037] For example, the light control surface of the dot is surrounded by N oblique lines of different inclinations, N≧3. Compared with a plane, multiple segments have stronger light control capabilities at different angles and stronger energy control. A cross section of a dot of the light control surface composed of multiple oblique lines is as follows: Figure 2a and Figure 2b As shown, the inclination angle α of different segmented slopes is n Indicated by. The dots are on the upper or lower light-emitting surface; the shapes of the convex and concave dots are described in the same way and are symmetrical.

[0038] The angles of different inclined planes of the light control surface of the dot in the present invention have an important influence on the control of light. The range of the inclination angle is calculated by mathematical deduction, and the optimal inclination angle is determined according to the principle of energy superposition. Figure 2b Take the dot morphology in as an example. It can be seen from the figure that if the inclination angle of the dot is α n If the light incident on the uppermost end of the dot slope can be totally reflected, then the light emitted by the LED and incident on other positions of the dot slope can be totally reflected.

[0039] The present invention also provides a method for designing a dot of a light guide plate, which is applied to the above-mentioned light guide plate, and designs the inclination angle of the inclined surface of the light regulating surface according to the light emitting characteristics, position, size of the LED based on the law of refraction and the principle of energy superposition, and specifically includes the following steps:

[0040] S1, set the long side diameter of a single dot to L1, the short side diameter to L2, the number of dot slope segments to N, then the horizontal fixed distance of each segment of the dot slope ; The intersection point between each segment is P n , n=0~N-1, the inclination angle of the nth slope is α n ;

[0041] S2, set the distance from the starting point to the side of the light guide plate to D dot , the distance from the LED to the side of the light guide plate is D LED ;

[0042] S3, set the height of the LED light source to H LED , the thickness of the light guide plate is H LGP ;

[0043] S4, discretize the LED light source into M point light sources, each of which is marked as LED m , m=1~M;

[0044] S5, set the light emission angle of the light emitted by the mth LED point light source to the nth intersection of the grid points to θ mn , the position where it enters the light guide plate is P mn ;P mn To P n The vertical distance is pmn1 ;P mn To LED m The vertical distance is p mn2 ; The angle between the light and the horizontal direction is β mn ;

[0045] S6, setting the refractive index of the light guide plate to n1 and the refractive index of air to n0; and calculating the total reflection angle γ according to the law of refraction;

[0046] S7, substitute m=1~M into the following formula and repeat it, and you can get the range of the inclination angle α0 of the first section of the slope, marked as (α 0min , α 0max );

[0047] ;

[0048] S8, will (α 0min , α 0max ) is discretized, and each discrete angle is marked as α 0k ,get:

[0049] ;

[0050] S9, for each α 0k , calculate the angles of each LED point light source reaching the top and bottom points of the first segment, determine whether it satisfies total reflection, accumulate the energy of the light that satisfies total reflection, and the α when the energy is maximum 0k is the inclination of the first segment;

[0051] S10, repeating steps S7-S9 to determine the inclination angle of each inclined surface;

[0052] The following is a detailed description of a specific embodiment of the present invention. LGP The distance D between the LED light source and the glass plate is 1.1 mm. LED The distance between the dot and the edge of the light guide plate on the light-incoming side is D dot 14mm, LED height H LED It is 0.8mm, and the refractive index n1 of the light guide plate is 1.5.

[0053] In order to verify the influence of the segmented design of the dot light control surface on the performance of the light guide plate, the optical simulation software was used to simulate the optical performance of the light guide plate, and the illumination and uniformity were evaluated. The upper light-emitting surface was selected to arrange concave dots, with a long side diameter of 56μm, a short side diameter of 20μm, and a depth of 8μm. Table 1 shows the average illumination and uniformity of the dot optical control surface with one, three, five, and eight segments, one segment being the existing light guide plate dots. Figure 3a The illumination distribution diagram of the existing light guide plate with the inclined surface as one section and Figure 3bThis is the illumination distribution diagram of the light control surface with five sections in the present invention. Figure 3a , Figure 3b It can be seen from Table 1 that the light guide plate designed according to the present invention has a higher brightness and a significantly improved uniformity after the dots are designed with multiple bevels.

[0054]

[0055] In summary, the present invention provides a light guide plate and a method for designing a light guide dot thereof. Dots are arranged on the surface of the light guide plate, and the light guide plate dot is designed in a targeted manner in combination with the light-emitting characteristics, position, size, etc. of the LED. The light control surface of the light guide plate dot has multiple inclined surfaces, and the angles of different inclined surfaces have an important influence on the control of light. The present invention calculates the range of the angle by mathematical derivation, and determines the optimal inclination angle according to the principle of energy superposition. Under the same density distribution, the light source incident on the incident surface is emitted from the light output surface to the greatest extent, thereby effectively improving the brightness and the uniformity of the light output. In addition, the present invention performs a segmented design on the light control surface, and can design the morphology according to specific module parameters, and is applicable to a wide range of modules. At the same time, it can effectively improve energy utilization, reduce the optimization process, shorten the R&D cycle, and save costs.

[0056] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas 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. A light guide plate, comprising an upper light emitting surface, a lower light emitting surface and a light incident surface, characterized in that: A plurality of mesh points are arranged on the upper light emitting surface or the lower light emitting surface, the mesh points are concave points or convex points, the mesh points include a top surface, a bottom surface and a light regulating surface, the mesh points are surrounded by the top surface, the bottom surface and the light regulating surface, the light regulating surface is composed of a plurality of inclined surfaces with different inclination angles, and the inclination angle of each inclined surface is designed according to the LED light emitting characteristics, position, size, based on the law of refraction and the principle of energy superposition; The method for designing the dot of the light guide plate includes designing the inclination angle of the inclined surface of the light regulating surface according to the light emitting characteristics, position, size of the LED, based on the law of refraction and the principle of energy superposition, and specifically includes the following steps: S1, set the long side diameter of a single dot to L1, the short side diameter to L2, the number of dot slope segments to N, then the horizontal fixed distance of each segment of the dot slope The intersection point between each segment is P n , n=0~N-1, the inclination angle of the nth slope is α n ; S2, set the distance from the starting point to the side of the light guide plate to D dot , the distance from the LED to the side of the light guide plate is D LED ; S3, set the height of the LED light source to H LED , the thickness of the light guide plate is H LGP ; S4, discretize the LED light source into M point light sources, each of which is marked as LED m , m = 1 ~ M; S5, set the light emission angle of the light emitted by the mth LED point light source to the nth intersection of the grid points to θ mn , the position where it enters the light guide plate is P mn ;P mn To P n The vertical distance is p mn1 ;P mn To LED m The vertical distance is p mn2 ; The angle between the light and the horizontal direction is β mn ; S6, setting the refractive index of the light guide plate to n1 and the refractive index of air to n0; and calculating the total reflection angle γ according to the law of refraction; S7, substitute m=1~M into the following formula (1) and repeat it to obtain the range of the inclination angle α0 of the first section of the slope, marked as (α 0min , α 0max ); S8, (α 0min , α 0max ) is discretized, and each discrete angle is marked as α 0k ,get: S9, for each α 0k , calculate the angles of each LED point light source reaching the top and bottom points of the first segment, determine whether it satisfies total reflection, accumulate the energy of the light that satisfies total reflection, and the α when the energy is maximum 0k is the inclination of the first segment; S10, repeating steps S7-S9 to determine the inclination angle of each inclined surface.

2. The light guide plate according to claim 1, characterized in that: The diameter of the long sides of the dots corresponding to the top and bottom surfaces ranges from 20 μm to 65 μm, and the diameter of the short sides ranges from 0 μm to 25 μm.

3. The light guide plate according to claim 1, characterized in that: When the network dots are concave dots, the depth of the concave dots is 5 μm to 25 μm, and when the network dots are convex dots, the height of the convex dots is 5 μm to 25 μm.

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