JP5887557B2 - Light guide member - Google Patents

Description

  The present invention relates to a light guide member that emits introduced light to the outside.

  A light guide member used in a light emitting device is disclosed in Patent Document 1 and the like. The light guide member has a light guide part and a reflection part, and the light introduced into the light guide part is reflected by the reflection part and emitted from an emission surface formed on the side opposite to the reflection part of the light guide part. It is provided as follows.

JP 2012-89442 A

  In the conventional light guide member, the reflection part for reflecting light was formed using materials, such as a white material. However, it is difficult to say that the reflection part formed in this way is sufficient in terms of light diffusivity, and thus there is a problem that it is difficult to improve the light extraction efficiency from the emission surface. This is because if the light diffusibility at the reflecting portion is low, the proportion of the reflected light that is totally reflected at the exit surface increases, and the light extraction efficiency decreases accordingly.

  This invention is invented in view of the said problem, Comprising: Let it be a subject to improve the extraction efficiency of the light from a light guide member.

In order to solve the above-described problems, the present invention provides a rod-shaped light guide member in which a large number of end portions in the short direction perpendicular to the longitudinal direction are reflected in the resin material so that incident light is reflected. The light diffusion part in which the bubbles are contained , the other part is a light guide part formed integrally with the light diffusion part using the same resin material as the light diffusion part, the light guide part, has an exit surface of the light reflected by the light diffusing portion is emitted, and said molded from the exit surface to have a more narrow closer to the light diffusing section, the light diffusing section, said light guide portion It is characterized by being formed wider than the narrowest end .

  Further, in the present invention, a neck portion that is recessed from the periphery is formed at a boundary portion between the light diffusion portion and the light guide portion adjacent thereto, and the neck portion engages with a predetermined holding case. It is preferable that it is a portion to be processed.

  According to the present invention, since the reflection part is formed by the light diffusion part in which a large number of bubbles are contained, there is an effect that the light extraction efficiency from the light guide member can be improved.

It is a side view of the light guide member of one embodiment of the present invention. It is the XX sectional view taken on the line of FIG. FIG. 3 is an enlarged view of a main part of FIG. 2. It is the schematic of the holding case which hold | maintains a light guide member same as the above.

  The present invention will be described based on embodiments shown in the accompanying drawings. FIG. 1 shows a light guide member 2 according to an embodiment of the present invention. This light guide member 2 is a rod-like long member whose longitudinal direction is the left-right direction in FIG. 1, and more specifically, a transparent material such as polymethyl methacrylate resin (PMMA) or polycarbonate (PC). An organic glass formed using a resin material.

  In the light guide member 2, one end portion in the short direction b orthogonal to the longitudinal direction a is a light diffusion portion 4 in which a large number of bubbles are mixed in a resin material, and the other portions are not mixed with bubbles. The light guide 6 is made of a resin material. This light diffusion part 4 is a reflection part in this embodiment. The light diffusing unit 4 and the light guiding unit 6 use the same resin material, and the light diffusing unit 4 and the light guiding unit 6 are integrally formed. An exit surface 8 for emitting light is formed on the surface of the light guide unit 6 opposite to the side where the light diffusion unit 4 is formed (the lower side in FIG. 1).

  Both the light diffusion part 4 and the light guide part 6 are formed over the entire region of the light guide member 2 in the longitudinal direction a. That is, a transparent light guide 6 is formed over the entire area of the light guide member 2 in the longitudinal direction a, and at one end in the short direction b of the light guide 6 over the entire area of the longitudinal direction a. The light diffusion part 4 in which many fine bubbles are inherently formed. A flat emission surface 8 is formed at the other end of the light guide portion 6 in the short direction b over the entire length direction a of the light guide member 2.

  Both end surfaces in the longitudinal direction a of the light guide 6 are introduction surfaces 10 for introducing light from the outside. In the vicinity of the introduction surfaces 10 on both sides, a light emitter 12 for making light incident on each introduction surface 10 is installed. The light emitter 12 is composed of an LED disposed at a position facing the introduction surface 10.

  2 is a cross-sectional view taken along line XX of FIG. As shown in FIG. 2, the light guide part 6 that forms the main part of the light guide member 2 is formed so that the one end part 14 in the short direction b is widest, and the end face of the wide one end part 14 is the exit surface 8. It has become. A portion 16 of the light guide portion 6 other than the one end portion 14 is formed narrower than the one end portion 14 via a stepped portion.

  This portion 16 of the light guide 6 is formed so as to gradually become narrower as it moves away from the emission surface 8 in the short direction b (in other words, closer to the light diffusion portion 4). The end opposite to 8 is the narrowest. The light guide unit 6 and the light diffusing unit 4 are adjacent to each other in the short direction b with the narrowest portion as a boundary.

  The light diffusion portion 4 is formed wider than the narrowest end portion of the light guide portion 6. Thereby, between the light guide part 6 and the light-diffusion part 4, the neck part 20 dented from the both sides of the width direction is formed. The width direction here is a direction orthogonal to the longitudinal direction a and the short direction b of the light guide member 2.

  The light guide member 2 of this embodiment is accommodated in the holding case 22 shown in FIG. 4 and constitutes a light emitting device. The holding case 22 is provided with a storage space 24 having a dimension and shape into which the light guide member 2 is fitted. That is, on the inner surface of the accommodation space 24, an engaging portion 26 having a size and shape that engages with the neck portion 20 is formed corresponding to the neck portion 20 of the light guide member 2. The light guide member 2 is held in the holding case 22 by engaging the convex engaging portions 26 with the concave neck portion 20 from both outer sides in the width direction. In the state where the light guide member 2 is held by the holding case 22 as described above, only the widest one end portion 14 having the emission surface 8 is exposed to the outside from the holding case 22.

  As described above, the light guide member 2 of the present embodiment has the reflection portion that reflects the incident light and the emission surface 8 from which the light reflected by the reflection portion is emitted. It is formed by the light diffusing portion 4 in which many bubbles are contained.

  According to the light guide member 2 of the present embodiment, when light introduced from an external light source is reflected by the light diffusing unit 4 having a large number of bubbles, it is also diffused over a wide range of angles. This is because, since each of the bubbles in the light diffusing unit 4 is a fine spherical shape, the light reflected by the light diffusing unit 4 in which many bubbles are present is the light reflected by the flat reflecting surface. This is because it is diffused over a wider range of angles (see FIG. 3). As described above, when the light diffusibility at the time of reflection is low, the ratio of the reflected light that is totally reflected by the exit surface 8 increases. However, according to the light guide member 2 of the present embodiment, the light diffusion is performed. The proportion of the light reflected by the portion 4 that is totally reflected by the exit surface 8 is reduced, and the light extraction efficiency is improved accordingly.

  Further, the light guide member 2 of the present embodiment is shaped so as to become narrower as it approaches the light diffusion portion 4 from the emission surface 8.

  Thereby, since the volume of the light-diffusion part 4 can be suppressed and the number of the bubbles to mix can be decreased, manufacture of the light guide member 2 becomes easy.

  In addition, the light guide member 2 of the present embodiment has a neck portion 20 that is formed to be recessed from the periphery at the boundary portion between the light diffusion portion 4 and the light guide portion 6 adjacent thereto. The neck portion 20 is a portion engaged with a predetermined holding case 22.

  As a result, the light guide member 2 can be directly attached to the holding case 22, which contributes to a reduction in manufacturing cost and simplification of the structure of a light emitting device configured using the light guide member 2.

  Although the present invention has been described based on the embodiments shown in the accompanying drawings, the present invention is not limited to the above-described embodiments, and appropriate design changes may be made within the intended scope of the present invention. Is possible.

2 Light guide member 4 Light diffusion part 6 Light guide part 8 Output surface 20 Neck part 22 Holding case

Claims (2)

It is a rod-shaped light guide member, and one end portion in the short direction perpendicular to the longitudinal direction is a light diffusion portion in which a large number of bubbles are contained in the resin material so that incident light is reflected , The other part is a light guide unit formed integrally with the light diffusion unit using the same resin material as the light diffusion unit , and the light reflected from the light diffusion unit is emitted from the light guide unit. It has an emission surface and is shaped so as to become narrower as it approaches the light diffusion portion from the emission surface, and the light diffusion portion is shaped wider than the narrowest end of the light guide portion. A light guide member characterized by being made .   It has a neck part which is dented from the periphery at the boundary part between the light diffusion part and the light guide part adjacent thereto, and the neck part is a part engaged with a predetermined holding case. The light guide member according to claim 1.

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