JP3127419U - Surface emitting light guide plate and surface emitting device - Google Patents

Abstract

A prism sheet is eliminated when manufacturing a light guide plate of a surface light-emitting device.
In a light guide plate in which an irregular reflection part for irregularly reflecting light is formed by laser processing within the thickness of an integrated transparent plate, the irregular reflection part 3 is composed of a plurality of layers overlapping in the thickness direction of the transparent plate 2. It consists of prism row layers 4 and 5, and each prism row layer 4 and 5 presents ridges 41 and 51 in adjacent diffuse reflection layers 42, 42, 52 and 52, and the ridges 41, 41, 51 and 51 are parallel to each other. Adjacent prism row layers 4 and 5 are formed so that the ridges 41 and 51 cross each other, and a reflective layer 6 is provided on the back surface of the transparent plate 1. It is formed by laser irradiation.
[Selection] Figure 1

Description

  The present invention relates to a surface emitting light guide plate used for a backlight of a liquid crystal screen and the like, and an edge light type surface light emitting device using the light guide plate.

  In this seed light emitting plate, a prism sheet is attached to the front surface (light emitting surface) of the transparent plate to form a diffused light reflection layer to improve the light use efficiency and increase the brightness. (Patent Document 1).

The edge light type surface light emitting device is indispensable for reducing the thickness of equipment using the edge light type surface emitting device.
However, since the transparent plate also serves as a core material for maintaining the shape of the light guide plate, there is a limit to reducing the thickness. As a result, the light guide plate becomes thicker by the thickness of the prism sheet, which hinders thinning.
In addition, the prism sheet is expensive and requires time and labor for manually bonding to the transparent plate.
Further, when the prism sheet having the uneven surface of the prism sheet is used on the outside, dust accumulates on the uneven surface and is easily contaminated.
The present invention clarifies a light guide plate that can solve the above problems and an edge light type surface light emitting device that uses the light guide plate.

JP 2001-307530 A

  In the light guide plate in which the irregular reflection part for irregularly reflecting light is formed by laser processing within the thickness of the integral transparent plate, the irregular reflection part (3) is arranged in the thickness direction of the transparent plate (2). The prism row layers (4) and (5) are composed of a plurality of overlapping prism row layers (4) and (5). Each of the prism row layers (4) and (5) is inclined by adjacent irregular reflection layers (42) (42), (52), and (52). A prism row layer that exhibits strips (41), (51), and that the strips (41), (41), (51), (51) are continuous in parallel, and overlaps in the thickness direction of the transparent plate (2) ( 4) and 5), the ridges (41) and (51) cross each other, and a reflective layer (6) is provided on the back surface of the transparent plate (2), and each prism row layer (4) (5) is provided. ) Is formed by laser irradiation.

  Claim 2 is the light guide plate in which the irregular reflection part for irregularly reflecting light is formed by laser processing within the thickness of the integral transparent plate, and the irregular reflection part (3) is inclined and adjacent to the two irregular reflection layers (42) (42) presents a ridge (41), and the first prism row layer (4) in which the ridges (41) are continuous in parallel, and the same inclination as the first prism row layer (4) Then, the adjacent two irregular reflection layers (52) and (52) form a ridge (51), and the second prism layer (5) in which the ridge (51) is continuous in parallel with each other in the same plane. Ridges (41) and (51) intersect, a reflective layer (6) is provided on the back surface of the transparent plate (2), and the prism row layers (41) and (51) are formed by laser irradiation. .

  According to a third aspect of the present invention, in the light guide plate of the first or second aspect, the reflective layer (6) includes a row of grooves (61) directly applied to the transparent plate (1) by laser irradiation.

The light guide plate (1) according to claim 1 forms a diffuse reflection part (3) within the thickness of the transparent plate (2), so that a prism sheet is used as compared with a conventional case where a prism sheet is attached to a transparent body. The light guide plate can be thinly formed for the thickness of the sheet.
The irregular reflection portion (3) is inclined and adjacent to the irregular reflection layers (42), (42), (52), and (52) to form ridges (41) and (51), and the ridges (41), (41), ( 51) (51) is a continuous form in parallel, and adjacent prism row layers (4) (5) are formed so that the ridges (41) (51) cross each other. In other words, the irregular reflection portion (3) has the same arrangement as the arrangement of the prism rows of the conventional prism sheet, and can increase the irregular reflection efficiency of light and contribute to uniform surface emission and luminance improvement.
The reflective layer (6) provided on the back surface of the transparent plate often includes a groove array (61) formed by laser processing. However, the laser processing for forming the groove array (61) and the irregular reflection portion (3) are formed. The laser processing for this can be carried out on the same processing line in which the necessary number of laser irradiation devices are arranged, and the labor of attaching the prism sheet manually can be saved.
Since the light emitting surface of the transparent plate (2) may be a smooth surface, it is possible to solve the problem that dust tends to accumulate as in the case where the prism sheet is attached to the transparent plate with the prism surface facing up.

  The light guide plate (1) according to claim 2 is further reduced in thickness as compared with the light guide plate according to claim 1, since the prism row layers (4) and (5) forming the irregular reflection portion (3) are in the same plane. Can be achieved.

[Light Guide Plate of First Embodiment] (FIGS. 1 to 4)
The irregular reflection portion (3) and the diffusion layer (7) are formed by laser processing in the thickness of the integral transparent plate (2).
The transparent plate (2) is a highly transparent acrylic resin plate.
The irregular reflection part (3) is located closer to the front side than the diffusion layer (7).

The irregular reflection portion (3) is composed of a plurality of prism row layers (4) and (5) overlapping in the thickness direction of the transparent plate (2).
Each prism row layer (4), (5) is inclined and adjacent to the irregular reflection layers (42), (42), (52), (52) to form ridges (41), (51), and the ridges (41 ) (41), (51) and (51) are continuous in parallel.
The prism row layers (4) and (5) overlapping in the thickness direction of the transparent plate (1) are formed such that the ridges (41) and (51) cross each other at right angles.

Each of the irregular reflection layers (42) and (52) of the prism row layers (4) and (5) is formed of a set of dot-like or linear alteration portions caused by laser irradiation.
The peak heights of the ridges (41) and (51) of the prism row layers (4) and (5) and the mountain angle (the angle formed by the adjacent irregular reflection layers in the same prism row layer) are the height of the previous prism sheet, It may be the same as the mountain angle.
In the case of the example, the mountain height is about 200 μm and the mountain angle is 100 °.
In the drawings, the size of the ridges (41) and (51) of each prism row layer (4) and (5) is exaggerated, and the drawing shows the thickness of the transparent plate (2) and the reflection layer described later. It must not be used for comparison with the size of the groove row (61) in (6).

  The diffusion layer (7) is also formed by a collection of dot-like or linear alterations caused by laser irradiation, and has an action of diffusing light passing through the thickness of the transparent plate (2).

A reflective layer (6) is provided on the back surface (opposite side of the light emitting surface) of the transparent plate (1).
The reflective layer (6) includes a groove row (61) formed directly on the light guide plate (1) and a reflective sheet (6) covered so as to hide the groove row (61).
The groove row (61) is formed by laser processing.

FIG. 4 shows a surface light emitting device (9) in which a light source (8) such as a bar-shaped light (81) or LED (light emitting diode) array is provided on the end face of the light guide plate (1) and is covered with a reflector (80). ing.
Since the light guide plate (1) forms the irregular reflection portion (3) within the thickness of the transparent plate (2), the prism plate thickness is compared with the conventional case where the prism sheet is adhered to the transparent plate. Can thinly form the light guide plate.
The light from the light source (8) enters from the end face of the light guide plate (1), and is repeatedly reflected and diffused by the groove array (61), the diffusion layer (7) or the irregular reflection part (3) of the reflection layer (6). Most of the incident light finally passes through the irregular reflection portion (3) and exits from the light emitting surface of the light guide plate (1).

  The irregular reflection part (3) exhibits the ridges (41), (51) at the adjacent irregular reflection layers (42), (42), (52), (52), and the ridges (41), (41), (51) ( 51) is formed in parallel and is formed so that the ridges (41) and (51) of the overlapping prism row layers (4) and (5) cross each other, that is, the arrangement of the prism rows of the conventional prism sheet Similar arrangements can increase the efficiency of irregular reflection of light and contribute to uniform surface emission and improved luminance.

  Laser processing of the groove row (61) constituting a part of the reflective layer (6) provided on the back surface of the transparent plate and the irregular reflection portion (3) should be performed on the same processing line in which the necessary number of laser irradiation devices are arranged. Is possible.

  Since the light emitting surface of the transparent plate (2) may be a smooth surface, it is possible to solve the problem that dust tends to accumulate as in the case where the prism sheet is attached with the prism surface facing up.

[Light Guide Plate of Second Embodiment] (FIGS. 5 and 6)
The irregular reflection portion (3) and the diffusion layer (7) are formed by laser processing in the thickness of the integral transparent plate (2).
The transparent plate (2) is a highly transparent acrylic resin plate.
The irregular reflection part (3) is located closer to the light emitting surface (front) than the diffusion layer (7).

The irregular reflection portion (3) is a first prism row layer (4) in which two irregular reflection layers (42) and (42) adjacent to each other are inclined to form a ridge (41), and the ridge (41) is continuous in parallel. ), And the first prism row layer (4), the two irregularly reflecting layers (52) and (52) adjacent to each other are inclined to form a ridge (51), and the ridge (51) continues in parallel. The second prism layer (5) is formed such that the ridges (41) (51) intersect each other in the same plane.
The irregular reflection portion (3) can also be expressed as pyramid-shaped square pyramids that are stacked on each other without any gap between the vertical and horizontal axes, with the slopes of each other overlapping.

  The diffusion layer (7) and the reflection layer (6) are formed in the same manner as in the first embodiment.

  In the light guide plate (1) of the second embodiment, the prism row layers (4) and (5) forming the irregular reflection portion (3) are in the same plane, and therefore, compared to the light guide plate of the first embodiment, Further thinning can be achieved.

  The description of the above embodiment is for explaining the present invention, and should not be construed to limit the invention described in the claims of the utility model registration or to reduce the scope. Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and various modifications can be made within the technical scope described in the claims of the utility model registration.

  For example, in the first embodiment, the irregular reflection portion (3) can be formed by overlapping three or more prism row layers (4) and (5).

It is a partially expanded perspective view of the transparent plate of 1st Example. It is sectional drawing which follows FIG. 1A-A line. It is sectional drawing which follows FIG. 1B-B line. It is principal part sectional drawing of a surface light-emitting device. It is a board part expanded slope view of the transparent board of 2nd Example. It is sectional drawing which follows FIG. 5C-C line. It is sectional drawing which follows FIG. 5D-D line.

Claims (4)

  In the light guide plate in which the irregular reflection portion for irregularly reflecting light is formed by laser processing within the thickness of the single transparent plate, the irregular reflection portion (3) is a plurality of layers of prisms overlapping in the thickness direction of the transparent plate (2). Each prism row layer (4) (5) is composed of row layers (4) and (5), and each of the prism layer layers (4) and (5) is inclined and adjacent to the irregular reflection layers (42) (42), (52) and (52). Prism row layer (4) (5) having a shape (51) in which the ridges (41) (41), (51) (51) are continuous in parallel and overlap in the thickness direction of the transparent plate (2) Are crossed with each other's ridges (41) and (51), a reflective layer (6) is provided on the back surface of the transparent plate (2), and the prism row layers (4) and (5) are formed by laser irradiation. A formed light guide plate for surface light emission.   In the light guide plate in which the irregular reflection part for irregularly reflecting light is formed by laser processing within the thickness of the integral transparent plate, the irregular reflection part (3) is inclined and adjacent to the two irregular reflection layers (42) (42) (42) ) And the first prism row layer (4) in which the ridges (41) are continuous in parallel with each other, and in the same manner as the first prism row layer (4), the first prism row layer (4) is inclined and adjacent to each other. Two diffusely reflecting layers (52) and (52) form a ridge (51), and the second prism layer (5) in which the ridge (51) is continuous in parallel with each other in the same plane. ) (51) intersect, a reflective layer (6) is provided on the back surface of the transparent plate (2), and each prism array layer (41) (51) is formed by laser irradiation. Light guide plate.   The light guide plate according to claim 1 or 2, wherein the reflection layer (6) includes a groove array (61) directly applied to the transparent plate (2) by laser irradiation.   4. A surface light emitting device comprising a light source (8) disposed on an end surface of the light emitting plate (1) for surface light emission according to any one of claims 1 to 3.

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