JP3147347U - Light guide plate and surface light source device - Google Patents

Abstract

A light guide plate having a light diffusing and condensing structure and a surface light source device using the same.
A light exit surface 211 and a light entrance surface 213 are provided, the light entrance surface being adjacent to the light exit surface, and a plurality of strips protruding from the light exit surface of the light transmit body 21. Each of the plurality of strip-like light diffusion structures 23 includes a plurality of strip-like light diffusion structures having a light exit surface 231 separated from the light exit surface, and the corresponding plurality of strip-like light diffusion structures. A plurality of strip-like light condensing structures 25 respectively projecting from the light exit surface of the structure, wherein each of the plurality of strip-like light condensing structures has a cross-sectional shape at the center of the corresponding strip-like light diffusing structure; A light guide plate 20 is provided that includes a plurality of strip-shaped light diffusion structures that are symmetrical with respect to a normal plane, and wherein the normal plane is parallel to the extending direction of the strip-shaped light diffusion structure. A surface light source device using this light guide plate is also provided.
[Selection] Figure 2

Description

  The present invention relates to a light guide plate and a surface light source device using the same, and more particularly to a light guide plate having an improved light diffusing and condensing structure and a surface light source device using the same.

  In general, a display device that requires a backlight source, for example, a liquid crystal display, needs to provide the required backlight to the liquid crystal display using a surface light source device in order to be able to display the contents of the screen. For example, the backlight module not only needs to provide a backlight light source to the liquid crystal display panel, but also needs to provide a surface light source with sufficient and uniform luminance.

  Conventionally, an edge type backlight module using a light emitting diode as a light source includes a plurality of light emitting diodes and a light guide plate. The plurality of light emitting diodes are usually arranged in a straight line and installed with respect to the light incident surface of the light guide plate. The light guide plate converts the light emitting diode light source into a surface light source by guiding the propagation direction of light from the light emitting diode light source. In order to achieve the purpose of uniforming the light from the light guide plate, one conventional method is to form a microstructure on the light incident side of the light guide plate. Although some light can be dispersed by this method, the problem of bright and dark stripes still exists. Therefore, as described in Patent Document 1, a general method is to make the surface of the light guide plate with respect to the light exit surface a reflective surface, and to provide a V-shaped tank structure on this reflective surface. However, due to the characteristics of the light-emitting diode light source, even if the light-emitting diode light source is combined with a light guide plate having a V-shaped tank reflecting surface, bright and dark stripes still occur at locations close to the light incident surface of the light guide plate. There is no good uniformity of the light from the backlight module.

Patent Document 2 discloses a light guide plate and a backlight module using the same. The light guide plate has a light diffusion structure distributed on the exit surface of the translucent plate, and the light diffusion structure is made of organic filler particles adhered to the exit surface of the light guide plate by an adhesive. However, such a light diffusion structure still cannot solve the problem of light and dark stripes and can only diffuse light, but does not have a function of condensing light.
Taiwan Utility Model No. M269409 Taiwan Patent No. I252938

  An object of the present invention is to provide a light guide plate that is not easily damaged and that can improve the brightness and uniformity of emitted light.

  Another object of the present invention is to provide a surface light source device having good brightness and uniformity of emitted light.

  In addition, other objects and advantages of the present invention can be further known from the technical features disclosed in the present invention.

  In order to achieve one, some or all of the above-mentioned objects or other objects, an embodiment of the present invention includes a light-transmitting body having a light-emitting surface and a light-incident surface adjacent to the light-emitting surface, and a light-transmitting body. A plurality of strip-shaped light diffusing structures protruding from the light-emitting surface of the main body, each of the plurality of strip-shaped light diffusing structures corresponding to a plurality of strip-shaped light diffusing structures each having a light exit surface away from the light-emitting surface A plurality of strip-shaped light condensing structures respectively protruding from the light exit surfaces of the plurality of strip-shaped light diffusing structures, each of the cross-sectional shapes of the plurality of strip-shaped light condensing structures having a corresponding strip-shaped light diffusing structure A plurality of strip-shaped concentrating structures that are symmetric with respect to a normal plane at the center of the strip, wherein the normal plane is parallel to the extending direction (ie, the longitudinal direction) of the strip-shaped condensing structure Provide a light guide plate

  Another embodiment of the present invention provides a surface light source device including a light guide plate and a light source. The light guide plate includes a light transmitting body having a light exit surface and a light incident surface adjacent to the light exit surface, and a plurality of strip-shaped light diffusion structures provided on the light exit surface of the light-transmitting body. Each of the diffusing structures includes a plurality of strip-shaped light diffusing structures having a light exit surface that is separated from the light exit surface, and a plurality of strip-shaped light condensing structures that are respectively provided on the light exit surfaces of the corresponding strip-shaped light diffusing structures. The cross-sectional shape of each of the plurality of strip-shaped light collecting structures includes a plurality of strip-shaped light collecting structures that are symmetric with respect to the normal plane at the center of the corresponding strip-shaped light diffusion structure. The light source is installed on the light incident surface of the light guide plate.

  The embodiment of the present invention uses a strip-shaped light diffusing structure and a strip-shaped condensing structure on the light exit surface of the light guide plate, so that two effects of light diffusion and condensing can be achieved. The brightness and uniformity of light can be improved.

  Reference will now be made in detail to the presently preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, so that the foregoing and other techniques, features and advantages of the present invention may be more readily understood.

  The following description of each embodiment has been made with reference to the accompanying drawings, and is used to illustrate a specific embodiment in which the present invention can be implemented. Also, the directional terms mentioned in the present invention, such as up, down, front, back, left, right, etc., are only for reference to the direction of the attached drawings. Accordingly, the directional terminology used below is used for explanation and is not intended to limit the present invention.

  Please refer to FIG. 1 and FIG. One embodiment of the present invention provides a surface light source device 10. It includes at least a light guide plate 20 and a light source 30. The light guide plate 20 includes a translucent main body 21, a plurality of strip-shaped light diffusion structures 23, and a plurality of strip-shaped light collecting structures 25.

  The translucent body 21 includes a light exit surface 211 and a light entrance surface 213 adjacent to the light exit surface 211. The translucent body 21 may have a plate-like structure (as shown in FIG. 1) or a wedge-like structure, and the material thereof is an optically transparent material such as polypropylene acid resin, carbonate ester, polyethylene resin or polymethyl methacrylate. May be used.

  The plurality of strip-like light diffusing structures 23 are spaced apart from each other on the light exit surface 211 of the translucent main body 21 and project from the light exit surface 211. Each of the plurality of strip-like light diffusion structures 23 may be a columnar lens, and has a light emission surface 231 that is separated from the light emission surface 211 of the translucent main body 21, and the light emission surface 231 is an arch-shaped surface. There may be.

  The plurality of strip-shaped light condensing structures 25 are respectively provided on the light exit surface 231 of the corresponding strip-shaped light diffusing structure 23, and each strip-shaped light condensing structure 25 is provided at the center of the strip-shaped light diffusing structure 23. They are installed symmetrically with respect to the normal plane M (for example, a dotted line as shown in FIG. 2). Here, the normal plane M is parallel to the extending direction (that is, the longitudinal direction) of the strip-shaped light diffusion structure 23. In other words, the cross-sectional shape of each strip-shaped light condensing structure 25 is the same as that of the strip-shaped light diffusion structure 23. Symmetric with respect to the normal plane M at the center. Each strip-shaped condensing structure 25 may be a prism structure with a circular top surface, and includes two opposing side surfaces 251 and a top surface 253 connecting the two side surfaces 251. Here, the two side planes 251 may be parallel to each other, and the top surface 253 is an arched surface. The curvature of the top surface 253 of each strip-shaped light collecting structure 25 is larger than the curvature of the light exit surface 231 of the corresponding strip-shaped light diffusion structure 23.

  The light source 30 is provided on the light incident surface 213 of the light guide plate 20 and is used to provide a required light source to the light guide plate 20. Please refer to FIG. The light source 30 includes a plurality of light emitting diodes arranged linearly, thereby forming a linear light source. The light source 30 is not limited to a linear light source made of a light emitting diode, and may be a cold cathode fluorescent lamp (CCFL). In the case of a light guide plate having a relatively small size, the light source 30 may be a single light emitting diode or other similar point light source.

  In the present embodiment, the light guide plate 20 employs a composite structure in which the strip-shaped light diffusion structure 23 and the strip-shaped light collection structure 25 are provided on the light exit surface 211. By increasing the light output angle of 20 and reducing the light and dark stripes in the vicinity of the light incident surface 213 of the light guide plate 20, the light output uniformity of the entire surface light source device 10 can be improved. The condensing structure 25 condenses part of the light emitted from the light exit surface 231 of the strip light diffusing structure 23, thereby compensating for a luminance drop due to the uniformization of the strip-shaped light diffusing structure 23. Thereby, the two effects which improve the light emission uniformity and the light emission brightness of the surface light source device 10 can be achieved. Further, the provision of the arched top surface 253 of the strip-shaped condensing structure 25 can provide both the light condensing function and the light diffusing function, whereby the luminance distribution of the surface light source device 10 can be made more uniform.

  Further, the strip-shaped light diffusion structure 23 and the strip-shaped light converging structure 25 of the light guide plate 20 disclosed in the embodiment of the present invention are not limited to the above-described structures, and other appropriate structures may be adopted. For example, you may employ | adopt the structure as described in the following Example.

  Please refer to FIG. In this embodiment, a plurality of strip-shaped light diffusion structures 23 and a plurality of strip-shaped light condensing structures 45 are arranged on the light exit surface 211 of the light transmitting body 21 of the light guide plate 40. The plurality of strip-shaped condensing structures 45 are respectively provided on the light exit surface 231 of the corresponding columnar lens, and each strip-shaped condensing structure 45 is a normal plane M at the center of the strip-shaped light diffusing structure 23. (For example, the dotted lines shown in FIG. 3) are arranged symmetrically with respect to each other. In other words, the cross-sectional shape of each strip-like light condensing structure 45 is symmetrical with respect to the normal plane M at the center of the strip-like light diffusion structure 23. It is. Each strip-shaped condensing structure 45 is a circular top prism structure and includes two opposing arched side surfaces 451 and a top surface 453 connecting the two arched side surfaces 451, where the top surface 453 is an arched surface. Surface.

  Please refer to FIG. In this embodiment, a plurality of strip-shaped light diffusion structures 63 and a plurality of strip-shaped light condensing structures 65 are arranged on the light exit surface 211 of the light transmitting body 21 of the light guide plate 60. Each strip-shaped light diffusion structure 63 is a strip-shaped trapezoidal structure, and has a light emission surface 631 that is separated from the light output surface 211. The cross section of each strip-shaped trapezoidal structure is trapezoidal, and according to the shape in the figure, the light emission surface 631 includes two inclined surfaces and a plane connecting the two inclined surfaces. Each strip-shaped condensing structure 65 is projected on the light emission surface 631 of the corresponding strip-shaped trapezoidal structure, and is on a normal plane N (for example, a dotted line shown in FIG. 4) at the center of the strip-shaped light diffusion structure 63. The normal plane N is parallel to the extending direction (longitudinal direction) of the strip-shaped light diffusing structure 63. In other words, the cross-sectional shape of each strip-shaped light collecting structure 65 is the strip shape. Symmetrical to the normal plane N at the center of the light diffusion structure 63, and each strip condensing structure 65 may be a triangular prism structure.

  Please refer to FIG. In this embodiment, a plurality of strip-shaped light diffusion structures 63 and a plurality of strip-shaped light condensing structures 85 are arranged on the light exit surface 211 of the light transmitting body 21 of the light guide plate 80. Each strip-shaped condensing structure 85 is projected on the light emission surface 631 of the corresponding strip-shaped trapezoidal structure, and is on a normal plane N (for example, a dotted line shown in FIG. 5) at the center of the strip-shaped light diffusion structure 63. In other words, the cross-sectional shape of each strip-shaped condensing structure 85 is symmetric with respect to the normal plane N at the center of the strip-shaped light diffusion structure 63, and each strip-shaped concentrating structure 85 is symmetrical. The optical structure 85 may be a columnar lens, and its top surface also has a constant arc degree. Of course, the light guide plate 80 of the present embodiment may adopt the strip-shaped condensing structure 25 or the strip-shaped condensing structure 45 having a circular top surface prism structure shown in FIG. 2 or FIG. Since the detailed structure is the same, the description thereof is omitted here.

  By adopting a composite structure of a strip-shaped light diffusion structure and a strip-shaped light condensing structure on the light exit surface of the light guide plate of the present invention, two effects of light diffusion and light condensing can be achieved. The uniformity and brightness of light can be improved. Further, since the top surface of the strip-shaped condensing structure has a certain arc degree, it is not easily damaged and does not affect the light output quality of the surface light source device.

  Although the present invention has been disclosed above based on the preferred embodiments described above, the preferred embodiments described above are not intended to limit the present invention, and those skilled in the art will recognize the spirit and scope of the present invention. As long as it does not leave, it is possible to make minor changes and coloration to the present invention. Therefore, the protection scope of the present invention is based on what is defined in the attached utility model registration request. Moreover, any embodiment of the present invention or claim for utility model registration need not achieve all the objects, advantages, or features disclosed in the present invention. In addition, the abstract part and the name of the device are only for helping search of patent documents, and do not limit the scope of rights of the present invention.

It is a perspective view of the surface light source device in one Example of this invention. It is a front view of the light-guide plate shown in FIG. It is a front view of the light-guide plate in the other Example of this invention. It is a front view of the light-guide plate in the other Example of this invention. It is a front view of the light-guide plate in the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Surface light source device 20, 40, 60, 80 Light-guide plate 21 Light transmission main body 211 Light emission surface 213 Light-incidence surface 23, 63 Strip-shaped light-diffusion structure 231, 631 Light-projection surface 25, 45, 65, 85 Strip-shaped condensing structure 251 Side plane 253, 453 Top surface 30 Light source 451 Arch-shaped side surface

Claims (22)

A light guide plate,
A light emitting surface and a light incident surface, wherein the light incident surface is adjacent to the light output surface;
A plurality of strip-shaped light diffusing structures each projecting on the light exit surface of the translucent body, wherein each of the plurality of strip light diffuser structures has a light exit surface separated from the light exit surface. Light diffusion structure,
A plurality of strip-shaped light condensing structures respectively projecting from the corresponding light exit surfaces of the plurality of strip-shaped light diffusion structures, each of the cross-sectional shapes of the plurality of strip-shaped light condensing structures being A plurality of strip-like light diffusion structures that are symmetrical with respect to a normal plane at the center of the strip-like light diffusion structure, and wherein the normal plane is parallel to the extending direction of the strip-like light diffusion structure;
Including a light guide plate. Each of the plurality of strip-like light diffusing structures is a columnar lens, and each of the plurality of light exit surfaces is an arched surface,
The light guide plate according to claim 1. Each of the plurality of strip-shaped condensing structures is a circular top prism structure.
The light guide plate according to claim 2. The circular top surface prism structure includes two opposing side planes, and an arched top surface connecting the two side planes,
The light guide plate according to claim 3. The curvature of the arched top surface of the circular top surface prism structure is larger than the curvature of the light exit surface of the corresponding columnar lens,
The light guide plate according to claim 4. The circular top surface prism structure includes two opposing arched side surfaces and an arched top surface connecting the two arched side surfaces,
The light guide plate according to claim 3. Each of the plurality of strip-like light diffusing structures is a strip-like trapezoidal structure, and each of the plurality of light exit surfaces includes two slopes and a plane connecting the two slopes.
The light guide plate according to claim 1. Each of the plurality of strip-shaped condensing structures is a triangular prism structure.
The light guide plate according to claim 7. Each of the plurality of strip-shaped light collecting structures is a columnar lens.
The light guide plate according to claim 7. Each of the plurality of strip-shaped condensing structures is a circular top prism structure.
The light guide plate according to claim 7. The circular top surface prism structure includes two opposing side planes, and an arched top surface connecting the two side planes,
The light guide plate according to claim 10. The curvature of the arcuate top surface of the circular top surface prism structure is greater than the curvature of the light exit surface of the corresponding columnar lens;
The light guide plate according to claim 11. The circular top surface prism structure includes two opposing arched side surfaces and an arched top surface connecting the two arched side surfaces,
The light guide plate according to claim 10. A surface light source device including a light guide plate and a light source,
The light guide plate is
A translucent body having a light exit surface and a light entrance surface adjacent to the light exit surface;
A plurality of strip-shaped light diffusing structures each projecting from the light-emitting surface of the light-transmitting body, each of the plurality of strip-shaped light diffusing structures having a light exit surface separated from the light-emitting surface. Light diffusion structure,
A plurality of strip-shaped light condensing structures respectively projecting from the corresponding light exit surfaces of the plurality of strip-shaped light diffusion structures, each of the cross-sectional shapes of the plurality of strip-shaped light condensing structures being A plurality of strip-shaped condensing structures that are symmetric with respect to a normal plane at the center of the strip-shaped light diffusion structure, and wherein the normal plane is parallel to the extending direction of the strip-shaped light diffusion structure
Including
The surface light source device, wherein the light source is installed on the light incident surface of the light guide plate. Each of the plurality of strip-like light diffusing structures is a columnar lens, and each of the plurality of light exit surfaces is an arched surface,
The surface light source device according to claim 14. Each of the plurality of strip-shaped condensing structures is a circular top prism structure.
The surface light source device according to claim 15. The circular top surface prism structure includes two opposing side planes, and an arched top surface connecting the two side planes,
The surface light source device according to claim 16. The curvature of the arched top surface of the circular top surface prism structure is larger than the curvature of the light exit surface of the corresponding columnar lens,
The surface light source device according to claim 17. The circular top surface prism structure includes two opposing arched side surfaces and an arched top surface connecting the two arched side surfaces,
The surface light source device according to claim 16. Each of the plurality of strip-like light diffusing structures is a strip-like trapezoidal structure, and each of the plurality of light exit surfaces includes two slopes and a plane connecting the two slopes.
The surface light source device according to claim 14. Each of the plurality of strip-shaped condensing structures is a triangular prism structure.
The surface light source device according to claim 20. Each of the plurality of strip-shaped light collecting structures is a columnar lens.
The surface light source device according to claim 20.

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