Optical turning film structure for LCD backlight

Abstract

The utility model discloses an optical turning film structure for LCD backlight, and belongs to the technical field of liquid crystal display screens. Comprising a diaphragm base material arranged right above the backlight module at intervals, the diaphragm base material is provided with a light-in lower surface and a light-out upper surface, a plurality of light steering units are evenly arranged on the light-out upper surface, the distance between every two adjacent light steering units in the horizontal direction is defined as w, the light steering units are used for refracting and steering all or part of light emitted by the backlight module and then emitting the light to the liquid crystal screen. According to the optical steering film structure, steering of the angle of emergent light of the module and adjustment of the steering light proportion can be achieved, and the requirements for different observation angles in the display period of a liquid crystal screen are met.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid crystal display screens, in particular to an optical turning film structure used for LCD backlight. Background Art

[0002] With the rapid development of electronic information technology, display devices are being used more and more widely. These display devices mainly include three categories: LED display screens, LCD display screens and OLED display screens. Among them, LCD is the most widely used due to its mature technology and low cost.

[0003] Backlight is a common component in LCD display screens, which includes light source, diffusion film, and brightness enhancement film. Most of the light emitted by it is located near the direction of 90 degrees to the display screen, so when viewed in the normal direction of the screen surface, the maximum brightness can often be obtained. For LCD display devices equipped with such backlight, people need to view the maximum brightness in the direction perpendicular to the display plane, and the brightness of the picture will decrease when viewed at a certain angle. Sometimes, for some special needs, people need to rotate the viewing angle range of the LCD display screen from a certain angle perpendicular to the screen. Utility Model Content

[0004] The purpose of the utility model is to provide an optical turning film structure for LCD backlight, aiming to solve at least one of the technical problems existing in the above-mentioned prior art. To achieve the above-mentioned purpose, the technical solution adopted by the utility model is as follows:

[0005] An optical deflection film structure for LCD backlight, comprising a film substrate arranged at intervals just above a backlight module, wherein the film substrate has a light-incoming lower surface and a light-emitting upper surface, and a plurality of light deflection units are evenly arranged on the light-emitting upper surface, wherein the horizontal spacing between two adjacent light deflection units is defined as w, and the plurality of light deflection units are used to refract and deflect all or part of the light emitted by the backlight module and then emit it onto a liquid crystal screen.

[0006] As a further solution of the utility model: the light deflection unit includes two symmetrically arranged right triangles, the long side surface of the right triangle is defined as S1, the long side surface S1 is perpendicular to the light-emitting upper surface of the membrane substrate, the short side surface of the right triangle is defined as S3, the short side surface S3 overlaps with the light-emitting upper surface of the membrane substrate, the hypotenuse surface of the right triangle is defined as S2, and one side of the two hypotenuse surfaces S2 overlaps.

[0007] As a further solution of the present invention: the length of the short side surface S3 in the horizontal direction is defined as a, 20≤a≤50μm.

[0008] As a further solution of the present invention: the acute angle between the bevel surface S2 and the light emitting upper surface of the film substrate is defined as θ, 36°≤θ≤72°.

[0009] As a further solution of the utility model: 0≤w≤15μm.

[0010] As a further solution of the utility model: the refractive index n1 value of the membrane substrate is between 1.49 and 1.6.

[0011] As a further solution of the utility model: the refractive index n2 of the light redirecting unit is between 1.52-1.67.

[0012] The utility model has the following beneficial effects:

[0013] The utility model arranges a layer of film substrate at intervals just above the common backlight module, and evenly arranges a plurality of light redirection units on the light-emitting upper surface of the film substrate. The light emitted by the backlight module enters the film substrate from the light-incidence lower surface, and is emitted from the light-emitting upper surface of the film substrate to enter the light redirection unit. The light is redirected after passing through the light redirection unit. The horizontal spacing between two adjacent light redirection units is w. The proportion of light a3 in the direction of the angle of 90° with the light-emitting upper surface of the film substrate in the total emitted light can be controlled by adjusting the spacing w, so as to adjust the proportion of redirected light.

[0014] The light redirection unit in the utility model includes two symmetrically arranged right triangles, and the length of the short side surface S3 in the horizontal direction is defined as a, 20≤a≤50μm, and the length of the light redirection unit in the horizontal direction is 2a. The acute angle between the hypotenuse surface S2 and the light-emitting upper surface of the film substrate is defined as θ, 36°≤θ≤72°. By adjusting the spacing w, the length of the short side surface S3 in the horizontal direction as a, and the acute angle between the hypotenuse surface S2 and the light-emitting upper surface of the film substrate as θ, the module output light angle can be redirected and the proportion of the redirected light can be adjusted to meet the requirements of different observation angles during the LCD display. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The utility model is further described below in conjunction with the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the structure of an optical turning film used for LCD backlight in the utility model;

[0017] Figure 2 This is a schematic diagram of the light redirection unit structure of the utility model when w=0;

[0018] Figure 3 This is a schematic diagram of the light redirection unit structure of the utility model when w>0;

[0019] Figure 4 is a schematic diagram of the refraction and redirection of light in the light redirection unit;

[0020] Figure 5 3 is a schematic diagram of a concave curve structure in which the contour of the hypotenuse surface S2 is close to a straight line.

[0021] In the figure: 1, backlight module; 11, light emitting surface; 2, film substrate; 21, light incident lower surface; 22, light emitting upper surface; 23, light redirecting unit; 24, right triangle. DETAILED DESCRIPTION

[0022] 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. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] See also Figure 1-5 As shown, the utility model provides an optical redirecting film structure for LCD backlight, including a film substrate 2 arranged at intervals just above a backlight module 1, the backlight module 1 having a light emitting surface 11, from which light is emitted into the film substrate 2, the film substrate 2 having a light incident lower surface 21 and a light emitting upper surface 22, a plurality of light redirecting units 23 are evenly arranged on the light emitting upper surface 22 of the film substrate 2, the light emitted from the backlight module 1 enters the film substrate 2 from the light incident lower surface 21, and is emitted from the light emitting upper surface 22 of the film substrate 2 into the light redirecting unit 23, and the light is redirected in its emitting direction after passing through the light redirecting unit 23.

[0024] See also Figure 3 As shown, the horizontal spacing between two adjacent light redirection units 23 is defined as w, 0≤w≤15μm, when w=0, refer to Figure 2 As shown, all the light is refracted and redirected by the light redirection unit 23. When w>0, please refer to Figure 3 As shown, after the light a3 passes through the light emitting upper surface 22 of the film substrate 2, it does not enter the light redirecting unit 23, so the light a3 does not change its propagation direction and is emitted directly, while the light a1 and the light a2 enter the light redirecting unit 23 and are refracted and redirected to be emitted.

[0025] Therefore, the spacing w can be adjusted to control the proportion of light a3 in the total emitted light at an angle of 90° to the light emitting upper surface 22 of the film substrate 2, thereby adjusting the proportion of the turned light and meeting the requirements for different viewing angles during LCD display.

[0026] See also Figure 3 As shown, in one embodiment, the light redirecting unit 23 includes two symmetrically arranged right triangles 24, and the long side surface of the right triangle 24 is defined as S1, and the long side surface S1 is perpendicular to the light-emitting upper surface 22 of the film substrate 2. The short side surface of the right triangle 24 is defined as S3, and the short side surface S3 overlaps with the light-emitting upper surface 22 of the film substrate 2. The hypotenuse surface of the right triangle 24 is defined as S2, and one side of the two hypotenuse surfaces S2 overlaps.

[0027] It is worth noting that the length of the short side surface S3 in the horizontal direction is defined as a, 20≤a≤50μm, and the length of the light redirecting unit 23 in the horizontal direction is 2a. The acute angle between the hypotenuse surface S2 and the light emitting upper surface 22 of the film substrate 2 is defined as 36°≤θ≤72°.

[0028] It should be noted that the refractive index of the film substrate 2 is n1, preferably n1 is 1.57, but it can also fluctuate between 1.49-1.6 as needed, and the refractive index of the light redirecting unit 23 is n2, preferably n1 is 1.58, and it can fluctuate between 1.52-1.67 as needed. The surrounding environment is air, and the refractive index of air is defined as n0.

[0029] The light redirecting unit 23 may be made of a photosensitive resin material or other similar materials. The photosensitive resin material is extruded and formed through a specific structure, and the formed photosensitive resin material is cured.

[0030] It is worth noting that the profile of the hypotenuse surface S2 of the right triangle 24 may also be changed. The profile of the hypotenuse surface S2 may be Figure 5 The concave curve shown as being close to a straight line may also be a convex curve close to a straight line.

[0031] The working principle of this utility model:

[0032] See also Figure 4As shown, the light a1 is emitted vertically from the light-emitting surface 11 of the backlight module 1, passes through the lower light-incident surface 21 of the film substrate 2 and the upper light-emitting surface 22 of the film substrate 2 in sequence, enters the light-redirecting unit 23 from the short side surface S3, and is incident on the hypotenuse surface S2. When the acute angle θ between the hypotenuse surface S2 and the upper light-emitting surface 22 of the film substrate 2 meets the total reflection angle condition of the light from the material of the light-redirecting unit 23 to the air (i.e.), the light a1 is totally reflected on the hypotenuse surface S2, and then is incident on the long side surface S1, and after passing through the spacing w, enters the long side surface S1 of the adjacent light-redirecting unit 23 again, and finally is refracted by the hypotenuse surface S2 of the adjacent light-redirecting unit 23 and then is emitted. The light a2 is similar to the light a1. After being refracted by the light-redirecting unit 23, it is finally deflected and emitted at a certain angle to the incident direction, completing the change of the light propagation direction. After passing through the light emitting upper surface 22 of the film substrate 2 , the light a3 does not enter the light redirecting unit 23 , and thus does not undergo a change in propagation direction and is emitted directly.

[0033] In summary, the utility model provides an optical redirecting film structure for LCD backlight, in which a layer of film substrate 2 is spaced apart just above a common backlight module 1, and a plurality of light redirecting units 23 are evenly arranged on the light emitting upper surface 22 of the film substrate 2. The horizontal spacing w between two adjacent light redirecting units 23 can be adjusted to control the proportion of light a3 in a direction at an angle of 90° to the light emitting upper surface 22 of the film substrate 2 in the total emitted light, thereby achieving adjustment of the proportion of redirected light and meeting the requirements for different observation angles during LCD display.

[0034] The above detailed description of the preferred embodiments of the utility model should not be considered to limit the scope of implementation of the utility model. All equivalent changes and improvements made within the scope of application of the utility model should still fall within the scope of the patent coverage of the utility model.

Claims

1. An optical turning film structure for LCD backlight, characterized in that: The invention comprises a film substrate (2) arranged at intervals just above a backlight module (1), wherein the film substrate (2) has a light-entering lower surface (21) and a light-emitting upper surface (22), and a plurality of light-redirecting units (23) are evenly arranged on the light-emitting upper surface (22), wherein the interval between two adjacent light-redirecting units (23) in the horizontal direction is defined as w, and the plurality of light-redirecting units (23) are used to refract and redirect all or part of the light emitted by the backlight module (1) and then emit it onto a liquid crystal screen.

2. The optical turning film structure for LCD backlight according to claim 1, characterized in that: The light deflection unit (23) comprises two symmetrically arranged right triangles (24), wherein the long side surface of the right triangle (24) is defined as S1, and the long side surface S1 is perpendicular to the light-emitting upper surface (22) of the film substrate (2); the short side surface of the right triangle (24) is defined as S3, and the short side surface S3 overlaps the light-emitting upper surface (22) of the film substrate (2); the hypotenuse surface of the right triangle (24) is defined as S2, and one side of the two hypotenuse surfaces S2 overlaps.

3. The optical turning film structure for LCD backlight according to claim 1, characterized in that: The length of the short side surface S3 in the horizontal direction is defined as a, 20≤a≤50 μm.

4. The optical turning film structure for LCD backlight according to claim 1, characterized in that: The acute angle between the bevel surface S2 and the light-emitting upper surface (22) of the film substrate (2) is defined as 36°≤θ≤72°.

5. The optical turning film structure for LCD backlight according to claim 1, characterized in that: 0≤w≤15μm.

6. The optical turning film structure for LCD backlight according to claim 1, characterized in that: The refractive index n1 of the membrane substrate (2) is between 1.49 and 1.

6.

7. The optical turning film structure for LCD backlight according to claim 1, characterized in that: The refractive index n2 of the light redirecting unit (23) is between 1.52 and 1.67.

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