JPH10154408A - Light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high-intensity illumination by inclining the second side end face adjacent to the first side end face, and utilizing the light sent toward the side end faces in a light source device, provided with a light source and a nearly plate-like light guide member having the first side end face, receiving the light of the light source. SOLUTION: A light guide body 11 is provided with an incidence plane 12 (first side end face) where the light L enters and an outgoing plane 13 where the light L goes out, and it guides the light L of a cold cathode tube 9 in a prescribed direction. A first reflecting plane 16 has a flat surface and reflects the incident light L from the incidence plane 12 to a liquid crystal display element 14 side. A second reflecting plane 17 (second side end face) is inclined to reflect the light of the cold-cathode tube 9 to the liquid crystal display element 14 side. Not only is the light L sent toward the first reflecting plane 16 of the light guide body 11 but also the light sent toward the second reflecting plane 17 is utilized, so that high-intensity illumination can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device, and more particularly to a so-called sidelight type light source device.

[0002]

2. Description of the Related Art Conventionally, various light source devices have been proposed in which light from a light source is guided in a predetermined direction by a light guide (light guide member). Such a light source device, as shown in FIGS. 9 and 10, takes in light L of a light source 3 from an incident surface 2 of a light guide 1 and reflects the light L upward by a reflection surface 4 to guide the light L in a predetermined direction. is there. This light source device is called a sidelight type since a linear light source (for example, a cold cathode tube) or a point light source (for example, a light bulb) is arranged on the side of the light guide 4. Has been used as.

[0003]

However, while the light L traveling toward the reflection surface 4 of the light guide 1 is reflected toward the liquid crystal display element 5, the light L 'traveling toward the side end face 6 of the light guide 1 is not reflected by the liquid crystal. There has been a problem that it cannot contribute to the illumination of the liquid crystal display element 5 because it is not reflected to the display element 5 side. In particular, the light source 3 is a linear light source having a light emitting unit 7 and an electrode unit 8, and the light guide 1 is arranged so that the linear light source is not longer than the incident surface 2 of the light guide 1 in order to reduce the size of the light source device. If the length B of the light emitting portion 7 is shorter than the length A, the portion of the liquid crystal display element 5 near the electrode portion 8 becomes dark because the electrode portion 8 does not emit light (for example, Japanese Patent Application Laid-Open No. 62-168118). No.). The present invention provides a light source device that can obtain high-luminance illumination by using light traveling toward a side end surface.

[0004]

According to the present invention, there is provided a light source device comprising: a light source; and a substantially plate-like light guide member having a first side end face on which light from the light source is incident. A second side adjacent to the first side end surface of the light guide member.
Are inclined.

[0005] The present invention also provides a light source device having a light guide member and a light source disposed on a side of the light guide member.
The light guide member has a first side end surface on which light from the light source is incident, an emission surface from which the light is emitted, a first reflection surface facing the emission surface, and a light source adjacent to the first side end surface. And a second reflecting surface having an inclined second side end surface.

According to the present invention, the first reflecting surface and the second reflecting surface are smoothly connected.

Further, according to the present invention, the light guide member is provided with the first light guide member.
Becomes thinner in accordance with the distance from the side end face of the.

According to the present invention, the light source is a linear light source having a light-emitting portion of a predetermined length.

In the present invention, the length of the first side end surface is longer than the predetermined length.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Light sources 9, 19, 20
In the light source device having the light guide members 11, 23 having the first side end surfaces 12, 24 on which the light L of 19, 20 is incident, the light guide member 1
By inclining the second side end faces adjacent to the first side end faces 12 and 24 of 1 and 23, high-luminance illumination can be obtained.

In the light source device having the light sources 9, 19 and 20 disposed on the side of the light guide members 11, 23, the light guide members 11, 23
The first side end faces 12, 24 on which the light L of the light sources 9, 19, 20 are incident
Outgoing surfaces 13 and 25 through which the light L exits, and first side end surfaces 12 and 25
A second reflecting surface 17, in which a second side end surface adjacent to 24 is inclined;
By providing the light emitting devices 18 and 28, high-luminance illumination can be obtained.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 show the first embodiment.

Reference numeral 9 denotes a cold-cathode tube (linear light source). The cold-cathode tube 9 has a light emitting section 10 having a predetermined length B. Reference numeral 11 denotes a light guide (light guide member). The light guide 11 is made of a translucent resin (eg, acrylic) and guides the light L of the cold cathode tube 9 in a predetermined direction. The light guide 11 has an incident surface 12 (first
Side end surface) and an emission surface 13 from which the light L is emitted.
The emission surface 13 has a rectangular shape corresponding to a liquid crystal display element described later. The length of the incident surface 12 of the light guide 11 is A, and the length A is longer than the length B of the light emitting section 10.
14 is a liquid crystal display element, in which liquid crystal is sealed between a pair of transparent substrates 15, and is a so-called dod matrix type in which pixels are arranged in a matrix.

Next, the light guide 11 will be described in more detail. The light guide 11 has a substantially wedge-shaped plate shape, and gradually becomes thinner according to the distance from the incident surface 12 (see FIG. 2). 16 is the emission surface
13, a first reflecting surface facing the first reflecting surface 16;
Is a plane, and reflects light L incident from the incident surface 12 to the liquid crystal display element 14 side. Reference numeral 17 denotes a second reflecting surface (second side end surface), and the second reflecting surface 17 is inclined so as to reflect the light L ′ of the cold cathode tube 9 toward the liquid crystal display element 14. Therefore, by using not only the light L directed to the first reflecting surface 16 of the light guide 11 but also the light L 'directed to the second reflecting surface 17, high-luminance illumination can be obtained. In order to reduce the size of the light source device, the length of the light-emitting portion 10 is set at the entrance surface with respect to the length B.
Even if the length A is increased, substantially uniform illumination over the entire surface of the liquid crystal display element 14 can be obtained. In other words, even if the length B of the light emitting unit 10 is short, it is possible to obtain substantially uniform large-area illumination. In addition, the first reflecting surface 16 or the second reflecting surface 18 may be subjected to a graining process to be a rough surface (a fine uneven surface), so that more uniform illumination can be obtained.

FIGS. 4 and 5 show a second embodiment. The same portions as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The first reflection surface 16 and the second reflection surface 18 of the light guide 11 are smoothly connected. That is, the second
Has a plane portion 18a and a curved surface portion 18b,
The curved portion 18b smoothly connects the first reflection surface 16 and the flat portion 18a (see FIG. 5). Accordingly, there is no possibility that the luminance changes at the boundary between the first reflection surface 16 and the second reflection surface 18, and more uniform illumination can be obtained. Also,
The first reflection surface 16 and the second reflection surface 18 of the light guide 11 are rough surfaces, so that more uniform illumination can be obtained.

FIGS. 6 to 8 show a third embodiment. The cold cathode tubes 19 and 20 (linear light sources) have light emitting portions 21 and 22, respectively. The light guide 23 (light guide member) guides the light L of the cold cathode tubes 19 and 20 in a predetermined direction. The light guide 23 has a substantially flat plate shape, and has an incident surface 24 (first side end surface) on which the light L of the cold cathode tubes 19 and 20 is incident, and an emission surface 25 on which the light L is emitted. 26
Is a first reflection surface facing the emission surface 25, and the first reflection surface 26 transmits light L incident from the entrance surface 24 to the liquid crystal display element 27.
Reflect to the side. Reference numeral 28 denotes a second reflecting surface (second side end surface), and the second reflecting surface 28 is inclined so as to reflect the light L 'of the cold cathode tubes 19 and 20 to the liquid crystal display element 27 side. . Therefore, high-luminance illumination can be obtained by using the light L ′ traveling toward the second reflection surface 17. Further, even if the length A of the light guide 23 is made longer than the length B of the light emitting portions 21 and 22 of the cold cathode tubes 19 and 20 for downsizing the light source device, Substantially uniform illumination can be obtained. In other words, even if the length B of the light emitting unit 10 is short, it is possible to obtain substantially uniform large-area illumination.

The first reflecting surface 26 and the second reflecting surface 28 of the light guide 23 may be connected smoothly, and the first reflecting surface 26
There is no possibility that the luminance changes at the boundary between the second reflective surface 28 and the second reflective surface 28, and more uniform illumination can be obtained.

In each of the above embodiments, the light source is a cold cathode tube 9, 19, 20 (linear light source), but may be a hot cathode tube, for example. The light source may be a point light source such as a light bulb or a light emitting diode, but a linear light source is preferable for obtaining uniform illumination. In addition, the first embodiment and the third embodiment
In the embodiment, the second reflecting surfaces 17 and 28 are flat, but may be curved. In the third embodiment, the second
Although the reflecting surface 18 has a flat portion 18a and a curved surface portion 18b, the first reflecting surface 16 and the second reflecting surface 18 only need to be connected smoothly, and the second reflecting surface 18 may be a curved surface.

The liquid crystal display elements 14 and 27 and the light guides 11 and 23
And a light-reflecting plate may be disposed between the light source and the light source. Further, a reflection plate may be provided below the light guides 11 and 23, or the first reflection surfaces 16 and 27 of the light guides 11 and 23 may be provided.
Alternatively, a reflective layer (for example, a white printed layer) may be provided on the second reflective surfaces 17, 18, and 28. Further, in each embodiment, the liquid crystal display elements 14 and 28 are illuminated, but other display elements (for example, a transmissive dial) may be illuminated.

Although the light guide 23 may be substantially flat and the light sources may be arranged at two places as in the third embodiment, the light guide 11 may be incident on the light guide 11 as in the first and second embodiments. If the thickness of the light source is reduced according to the distance from the surface, it is only necessary to dispose the light source at one place.

[0021]

According to the present invention, there is provided a light source device comprising a light source and a substantially plate-shaped light guide member having a first side end face on which light from the light source is incident. Since the second side end surface adjacent to the side end surface is inclined, high-brightness illumination can be obtained.

According to the present invention, there is provided a light source device having a light guide member and a light source disposed on a side of the light guide member.
The light guide member has a first side end surface on which light from the light source is incident, an emission surface from which the light is emitted, a first reflection surface facing the emission surface, and a light source adjacent to the first side end surface. A second reflecting surface having a second side end face that is fitted to the second reflecting surface inclined,
High-brightness illumination can be obtained.

Further, in the present invention, the first reflecting surface and the second reflecting surface are smoothly connected, and substantially uniform illumination can be obtained.

Further, according to the present invention, the light guide member may include the first light guide member.
It becomes thinner in accordance with the distance from the side end face, and it is only necessary to dispose the light source in one place.

Further, according to the present invention, the light source is a linear light source having a light emitting portion of a predetermined length, and substantially uniform illumination can be obtained.

Further, according to the present invention, the length of the first side end surface is longer than the predetermined length, and substantially uniform large-area illumination can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a side view of the embodiment.

FIG. 3 is a plan view of the light guide of the embodiment.

FIG. 4 is a perspective view of a light guide according to a second embodiment of the present invention.

FIG. 5 is a plan view of the light guide of the embodiment.

FIG. 6 is a perspective view showing a third embodiment of the present invention.

FIG. 7 is a side view of the embodiment.

FIG. 8 is a plan view of the light guide of the embodiment.

FIG. 9 is a perspective view showing a conventional example.

FIG. 10 is a side view of the conventional example.

[Explanation of symbols]

 9 cold cathode tube (linear light source) 10 light emitting section 11 light guide (light guide member) 12 entrance surface (first side end surface) 13 exit surface 16 first reflection surface 17, 18 second reflection surface (first 2, 20 Cold cathode tube (linear light source) 21, 22 Light emitting part 23 Light guide (light guide member) 24 Incident surface (first side end surface) 25 Outgoing surface 26 First reflecting surface 28 Second reflective surface (second side end surface) B predetermined length

Claims (6)

[Claims] 1. A light source device comprising: a light source; and a substantially plate-shaped light guide member having a first side end surface on which light from the light source is incident, wherein the light guide device is adjacent to the first side end surface of the light guide member. A light source device characterized in that a second side end face is inclined. 2. A light source device comprising a light guide member and a light source disposed on a side of the light guide member, wherein the light guide member has a first side end face on which light from the light source enters, and the light An emission surface from which the light exits, a first reflection surface facing the emission surface, and a second reflection surface in which a second side end surface adjacent to the first side end surface is inclined. Light source device. 3. The light source device according to claim 2, wherein the first reflection surface and the second reflection surface are smoothly connected. 4. The light source device according to claim 1, wherein the light guide member becomes thinner according to a distance from the first side end surface. 5. The light source device according to claim 1, wherein the light source is a linear light source having a light emitting portion having a predetermined length. 6. The light source device according to claim 5, wherein a length of the first side end surface is longer than the predetermined length.