阅读说明：本技术 面光源装置和液晶显示装置 (Surface light source device and liquid crystal display device ) 是由 陈怡敏 李同 武鹏 于 2021-01-29 设计创作，主要内容包括：本发明揭示了一种面光源装置,包括：第一导光体,具有随着从一端到另一端厚度变小的楔形状,包括第一入射面、由第一入射面的相对两侧分别延伸的第一出射面及第一反射面,该第一反射面与第一出射面相交；第二导光体,包括第二入射面和第二出射面,该第二入射面和第二出射面相交,所述第二入射面可接收来自第一出射面的光线并从第二出射面射出；第一发光体,沿着所述第一导光体的第一入射面侧设置。本发明还揭示了一种液晶显示装置,包括：所述的面光源装置；设置于第二出射面侧的液晶面板。本发明通过在一导光体的至少一侧设置楔形入光头,可以实现高亮度准直且透明度高的优点,适用于多种场景。(The present invention discloses a surface light source device, including: a first light guide body having a wedge shape whose thickness decreases from one end to the other end, including a first incident surface, a first exit surface and a first reflection surface respectively extending from opposite sides of the first incident surface, the first reflection surface intersecting the first exit surface; a second light guide body including a second incident surface and a second exit surface intersecting with each other, the second incident surface being capable of receiving the light from the first exit surface and emitting the light from the second exit surface; a first light emitter disposed along a first incident surface side of the first light guide. The present invention also discloses a liquid crystal display device, comprising: the surface light source device; and a liquid crystal panel disposed on the second emission surface side. According to the invention, the wedge-shaped light inlet head is arranged on at least one side of the light guide body, so that the advantages of high brightness collimation and high transparency can be realized, and the wedge-shaped light inlet head is suitable for various scenes.)

1. A surface light source device, comprising:

a first light guide body having a wedge shape whose thickness decreases from one end to the other end, including a first incident surface, a first exit surface and a first reflection surface respectively extending from opposite sides of the first incident surface, the first reflection surface intersecting the first exit surface;

a second light guide body including a second incident surface and a second exit surface intersecting with each other, the second incident surface being capable of receiving the light from the first exit surface and emitting the light from the second exit surface;

a first light emitter disposed along a first incident surface side of the first light guide.

2. The surface light source device according to claim 1, wherein the second light guiding body further includes a third incident surface, the second incident surface and the third incident surface respectively extending from opposite sides of the second exit surface,

the device still includes:

a third light guide body having a wedge shape whose thickness decreases from one end to the other end, and including a fourth incident surface, a third exit surface and a third reflection surface, the third exit surface and the third reflection surface extending from opposite sides of the fourth incident surface, respectively, the third reflection surface intersecting the third exit surface, the third incident surface being capable of receiving light from the third exit surface and emitting light from the second exit surface;

and a second light emitter provided along a fourth incident surface side of the third light guide.

3. A surface light source device as claimed in claim 2, wherein the second incident surface is disposed adjacent to the first exit surface, and the light entering the second incident surface from the first exit surface does not change its proceeding direction, and/or

The third incident surface is arranged close to the third emergent surface, and the advancing direction of the light rays cannot be changed after the light rays enter the third incident surface from the third emergent surface.

4. A surface light source device according to claim 2, wherein the angle between the first reflecting surface and the first exit surface is less than or equal to 30 °, and/or

And the included angle between the third reflecting surface and the third emergent surface is less than or equal to 30 degrees.

5. The surface light source device according to claim 2, wherein the second light guiding body further includes a bottom surface parallel to the second emission surface,

the second incident surface and the third incident surface are connected between the bottom surface and the second emergent surface.

6. The surface light source device according to claim 2, wherein the first light guide and the third light guide are symmetrically disposed on both sides of the second light guide.

7. The area light source device of claim 1, further comprising an array of deflection prisms distributed on the second exit surface to deflect light.

8. The surface light source device of claim 8, wherein the deflection prism array is bonded to the second light guide body as a single body or formed as a single body.

9. The surface light source device of claim 8, wherein the deflection prism array includes a plurality of prisms arranged in an array,

the distance between the prisms is gradually reduced along the edge of the second emergent surface to the center so as to realize uniform emergent light.

10. A liquid crystal display device, comprising:

the surface light source device of any one of claims 1 to 9;

and a liquid crystal panel disposed on the second emission surface side.

Technical Field

The invention belongs to the technical field of liquid crystal display, and particularly relates to a surface light source device and a liquid crystal display device.

Background

In recent years, liquid crystal displays have been widely used in various display devices, and have become more and more closely related to the life of people. Since the lcd cannot emit light, a backlight module for providing backlight is required. In all special use scenes such as vehicle-mounted display, a large viewing angle is not needed but high brightness is required, and the requirement of a collimation backlight module is met.

In the prior art, a wedge plate and a prism film are generally used for collimating backlight, and the light distribution of the wedge plate is determined by a wedge angle to adjust the uniformity. The light emitted by the wedge-shaped plate has consistency, and the prism film plays a role in deflection and certain collimation. For example, U.S. patent US8403,550B2 discloses a backlight structure, and the design of collimating the backlight using this structure is intended to make the light exit uniformly distributed over the wedge plate, the precision requirement for the wedge angle is high, and the use of the wedge plate for uniformity adjustment sacrifices efficiency and the adjustment space is limited. In addition, due to the requirements of wedge angle and light emission, the larger the size, the thicker the box thickness, and the reflection and non-transparent backlight arranged on the back surface cannot be applied to various scenes.

Therefore, in view of the above technical problems, it is necessary to provide a novel backlight structure.

Disclosure of Invention

The invention aims to provide a surface light source device and a liquid crystal display device, which aim to solve the problems that the wedge angle is high in requirement and cannot be applied to various scenes in the prior art.

In order to achieve the above object, an embodiment of the present invention provides the following technical solutions:

in one embodiment, a surface light source device includes:

a first light guide body having a wedge shape whose thickness decreases from one end to the other end, including a first incident surface, a first exit surface and a first reflection surface respectively extending from opposite sides of the first incident surface, the first reflection surface intersecting the first exit surface;

a second light guide body including a second incident surface and a second exit surface intersecting with each other, the second incident surface being capable of receiving the light from the first exit surface and emitting the light from the second exit surface;

a first light emitter disposed along a first incident surface side of the first light guide.

Preferably, in the above surface light source device, the second light guide further includes a third incident surface, the second incident surface and the third incident surface extend from opposite sides of the second emission surface,

the device still includes:

a third light guide body having a wedge shape whose thickness decreases from one end to the other end, and including a fourth incident surface, a third exit surface and a third reflection surface, the third exit surface and the third reflection surface extending from opposite sides of the fourth incident surface, respectively, the third reflection surface intersecting the third exit surface, the third incident surface being capable of receiving light from the third exit surface and emitting light from the second exit surface;

and a second light emitter provided along a fourth incident surface side of the third light guide.

Preferably, in the above surface light source device, an angle between the second incident surface and the second exit surface is an acute angle, and/or

And the included angle between the third incident surface and the second emergent surface is an acute angle.

Preferably, in the above-described surface light source device, the second incident surface is disposed adjacent to the first exit surface, and the light beam enters the second incident surface from the first exit surface without changing the traveling direction, and/or

The third incident surface is arranged close to the third emergent surface, and the advancing direction of the light rays cannot be changed after the light rays enter the third incident surface from the third emergent surface.

Preferably, in the above surface light source device, an angle between the first reflecting surface and the first emission surface is less than or equal to 30 °, and/or

And the included angle between the third reflecting surface and the third emergent surface is less than or equal to 30 degrees.

Preferably, in the surface light source device described above, the second light guide further includes a bottom surface parallel to the second emission surface,

the second incident surface and the third incident surface are connected between the bottom surface and the second emergent surface.

Preferably, in the above surface light source device, the first light guide and the third light guide are symmetrically disposed on both sides of the second light guide.

Preferably, in the above surface light source device, the second light source further includes a deflection prism array distributed on the second outgoing surface to deflect the light.

Preferably, in the above surface light source device, the deflection prism array and the second light guide are bonded together or integrally molded.

Preferably, in the above surface light source device, the deflection prism array includes a plurality of prisms arranged in an array,

the distance between the prisms is gradually reduced along the edge of the second emergent surface to the center so as to realize uniform emergent light.

In one embodiment, there is also provided a liquid crystal display device including:

comprising the surface light source device; and

and a liquid crystal panel disposed on the second emission surface side.

Compared with the prior art, the wedge-shaped light-in head is arranged on at least one side of the light guide body, so that the advantages of high brightness collimation and high transparency can be realized, and the wedge-shaped light-in head is suitable for various scenes.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic structural diagram and a schematic optical path diagram of a surface light source device according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of a prism structure according to a second embodiment of the present application;

FIG. 3 is a schematic view of a prism structure according to a third embodiment of the present application;

FIG. 4 is a schematic view of a prism structure according to a fourth embodiment of the present application;

fig. 5 is a schematic structural view of a first light guide and a third light guide in a fifth embodiment of the present application;

fig. 6 is a schematic structural diagram of a liquid crystal display device according to an embodiment of the present application.

Detailed Description

The present invention will be described in detail below with reference to embodiments shown in the drawings. The embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to the embodiments are included in the scope of the present invention.

As shown in fig. 1, an embodiment of the present application provides a surface light source device 10 including a light guide and a light emitter that sends light to the light guide.

The light guide body includes a second light guide body 11, and a first light guide body 12 and a third light guide body 13 symmetrically distributed on two opposite sides of the second light guide body 11.

The second light guide 11 mainly transmits light and emits light, and has a second emission surface 111 and a bottom surface 112 arranged in parallel, and a second incident surface 113 and a third incident surface 114 respectively extend from two opposite sides of the second emission surface 111. The second incident surface 113 and the third incident surface 114 are symmetrically formed at both sides of the second emission surface 111.

In a preferred embodiment, the included angles θ between the second incident surface 113 and the third incident surface 114 and the second exit surface 111 are acute angles, and the included angles can be adjusted according to the length and thickness of the second light guide.

The second light guide 11 is preferably a material with low internal light absorption, such as an acrylic sheet and preferably includes acrylate, PMMA (polymethyl methacrylate), PC (polycarbonate), polyethylene, or the like.

The shape of the second light guide 11 may be any shape suitably used, and is not limited to a plate shape, and for example, the bottom surface, the incident surface, and the exit surface thereof may be curved surfaces.

The first light guide body 12 and the third light guide body 13 have the same structure and mainly play a role in shaping a light source, the first light guide body 12 and the third light guide body 13 are respectively arranged at two sides of the second light guide body 11 so as to respectively send shaped and collimated light rays into the second light guide body, and the light rays are transmitted in the second light guide body 11 and then emitted from the second emergent surface.

The structure of the first light guide 12 is explained below, and the structure of the second light guide 13 is the same and will not be described again. The first light guide 12 has a wedge shape whose thickness decreases from one end to the other end, and includes a first incident surface 121, a first exit surface 122 extending from opposite sides of the first incident surface 121, and a first reflection surface 123, and the first reflection surface 123 intersects the first exit surface 122.

In a preferred embodiment, the angle β between the first reflecting surface 123 and the first exit surface 122 is less than or equal to 30 °

The first light guide 12 is preferably made of a plastic-based transparent material such as acryl so as to form a structure having an inclined surface.

The first exit surface 122 of the first light guide 12 faces and is close to the second entrance surface 113 of the second light guide 11, and the light exits from the first light guide 12 and enters the second light guide 11 without changing the traveling direction.

The light emitters include a first light emitter 141 and a second light emitter 142, and the first light emitter 141 and the second light emitter 142 are disposed along the incident surface sides of the first light guide 12 and the third light guide 13, respectively.

In an embodiment, the reflection surface sides of the first light guide 12 and the third light guide 13 are provided with reflection layers 161 and 162, respectively. Taking the reflective layer 161 as an example, the light from the first light emitter 141 is introduced into the first light guide 12, and is reflected by the reflective layer 161 located on the back surface side of the first light guide 12 when it travels in the first light guide 12, and is emitted from the emission surface 122 of the first light guide 12.

The reflective layers 161 and 162 are formed of a high-reflectance material such as aluminum or nickel, and in one embodiment, the reflective layers 161 and 162 are formed on the reflective surfaces of the first light guide 12 and the third light guide 13, respectively, by plating, and in another embodiment, the reflective layers 161 and 162 may be attached to the reflective surface sides of the first light guide 12 and the third light guide 13, respectively, as separate plate-like members.

The second exit surface 111 of the second light guide 11 supports a deflection prism array 17, the deflection prism array 17 includes a plurality of prisms arranged in an array, and the prisms perform a deflection function and a certain collimation function on the exit light of the second exit surface 111.

Referring to fig. 1, in an embodiment, the prism has an inverted trapezoidal structure, the top surface 171 is a light emitting surface, and the side surface 172 is a total reflection surface.

In the technical scheme, the prism acts through total reflection, light entering the prism has a certain range, and due to the arrangement of the inclination angle of the side edge of the prism and the refractive index of the prism, the total reflection of most light can be realized, and a small amount of light leakage is possible.

In one embodiment, the deflection prism array 17 and the second light guide 11 are glued together or integrally formed.

The deflection prism array is preferably of a material with low internal light absorption, such as acrylic sheet and preferably a transparent material comprising acrylate, PMMA (polymethylmethacrylate), polycarbonate, polyethylene, selenium and silver chloride.

In a preferred embodiment, the deflection prism array is made of the same optical material as the second light guide.

The plurality of prisms of the array may be arranged uniformly or non-linearly. In one embodiment, the spacing between the prisms decreases gradually along the edge of the second exit surface towards the center to achieve uniform light exit. The angle of the prism, i.e. the base angle epsilon of the top surface, is determined according to the overall ray angle and the exit requirement of the second light guide body, and is preferably an acute angle.

Referring to fig. 2, in the second embodiment, the prism includes a light emitting surface 181 parallel to the light emitting surface of the second light guiding member and a side surface 182 connected between the light emitting surface and the second light guiding member, the side surface is continuously multi-segmented, each segment is a plane or an arc surface, and the included angle between the segment and the light emitting surface of the second light guiding member is different.

In the third embodiment, as shown in fig. 3, the prism includes a light emitting surface 191 parallel to the light emitting surface of the second light guiding member and a side surface 192 connected between the light emitting surface and the second light guiding member, and the side surface is in an arc shape. The structure has certain processing difficulty, but can solve the problem of light leakage.

Referring to fig. 4, in the fourth embodiment, the prism is a cylindrical body, and includes a light emitting surface 201 parallel to the light emitting surface of the second light guiding member, and a side surface 202 connected between the light emitting surface and the second light guiding member, where the side surface 202 includes a plurality of reflecting surfaces perpendicular to the light emitting surface of the second light guiding member. The two-dimensional structure can further optimize uniformity and improve the visual problem of overlarge one-dimensional spacing.

As shown in fig. 5, in the fifth embodiment, the reflection surfaces 123 of the first light guiding body 12 and the third light guiding body 13 are arc-shaped.

Further referring to fig. 1, the light path trajectory of the light rays (taking the first light guide as an example) is described in detail. The light ray 15 enters from the incident surface of the first light guide 12, and when propagating in the first light guide 12 (for example, n is 1.58), it follows snell's law of refraction:

n1sinθ1＝n2sinθ2

where n1 is the refractive index of medium 1, θ 1 is the incident angle, n2 is the refractive index of medium 2, and θ 2 is the refraction angle.

The angle range of the light entering the first light guide 12 is α ± arcsin (1/1.58) ± 40 °, when the light propagates through the first light guide 12, the angle between the light and the normal of the upper and lower reflective surfaces of the first light guide 12 is 90- α or more than 50 °, and the total reflection angle γ arcsin (1/1.58) ═ 40 °, when the angle of 90- α is more than γ, the light satisfies the total reflection condition, so that the light is not emitted. The angle of the first light guide 12 is β, and the light ray decreases by β from the normal angle of the exit surface 122 of the first light guide 12 after being reflected once, and will exit until the exit condition is satisfied. It is understood that the light entering the second light guiding body 11 from the exit surface 122 exits at an angle close to the total reflection angle, and the directions of the light rays are substantially the same, that is, the directions of the light rays 151 and 152 in the second light guiding body 11 are substantially the same and are large-angle light rays. The light 152 is incident on the second exit surface 111 and is not emitted because the angle is larger than the critical angle. The light rays that do not exit are reflected to the bottom surface 112 and do not exit according to the law of refraction. Light ray 151 enters surface 172 and is totally reflected and exits surface 171. The outgoing light generated by the two light emitters 141 and 142 is concentrated and symmetrical with respect to the normal, and the angle of the surface 171 may be adjusted to overlap the outgoing light from both sides, thereby forming outgoing light with more collimated brightness.

Referring to fig. 6, an embodiment of the present application discloses a liquid crystal display device 100 including the surface light source device 10 shown in fig. 1 to 5, and a liquid crystal panel 20 disposed on the second emission surface side.

In addition, the light emitter and the wedge-shaped light guide body in the present embodiment may be provided in only one set and disposed on one side of the second light guide body.

In summary, the present invention provides a high-brightness transparent collimating backlight scheme, which can be applied to various backlight modules. The collimating function is realized through the design of double-side light incidence and light incidence heads, and uniform light emergence is realized through the design of a light emergence surface microstructure, for example, the light emergence surface microstructure is gradually densified from the edge to the center, so that the characteristics of high brightness and collimation and high transparency are achieved.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.