JPH0622822Y2 - Backlight device with heat sink and reflector - Google Patents

Description

[Detailed Description of the Invention] "Industrial application field" The present invention relates to a backlight device with a reflector that also serves as a heat sink.

“Prior Art” In a conventional backlight device, as shown in FIG. 6, a light source 2 is arranged outside both end surfaces of a transparent substrate 1, and the light source 2 except for the end surface side of the transparent substrate 1 is cross-sectioned. It is surrounded by a U-shaped reflector 3. The reflective plate 3 has the opening end portion of the transparent substrate 1
Secure to the end of. A reflective sheet 4 is attached to the back surface of the transparent substrate 1. A liquid crystal panel 6 is attached to the surface of the transparent substrate 1 with a translucent diffusion sheet 5 interposed. Then, when the light source 2 is turned on, the emitted light from the light source 2 enters the inside from the end surface of the transparent substrate 1. Transparent substrate 1
The light that has entered the inside is reflected by the reflection sheet 5 to reach the diffusion sheet 5, is diffused by the diffusion sheet 5 so that the amount of light is uniform over the front surface, and then is incident on the liquid crystal panel 6.

[Problems to be Solved by the Invention] However, the above-mentioned conventional backlight device uses the light source 2
Is sealed by the reflection plate 3 and the surface area of the reflection plate 3 is small, so that there is a problem that the heat generated from the light source 2 is trapped in the reflection plate 3 and the temperature further rises. When the temperature inside the reflection plate 3 becomes high, the transparent substrate 1 may be deformed depending on the material such as acrylic, and the liquid crystal panel 6 receives heat from the light source 2 and causes deterioration such as accelerated deterioration. Has become.

Therefore, in view of the above circumstances, an object of the present invention is to provide a backlight device with a reflection plate that also serves as a heat dissipation plate that can effectively dissipate heat from a light source.

"Means and Actions for Solving the Problem" In order to achieve the above object, the present invention provides a transparent substrate attached to a liquid crystal panel, a light source arranged on the end face side of the transparent substrate, and a transparent substrate. In a backlight device comprising a reflection plate provided on the back surface, the light source except for the end face side of the transparent substrate is surrounded by a light source reflection plate, and the light source reflection plate is attached to the back surface of the transparent substrate. A light source reflection plate and a main reflection plate, which are integrally formed with a plate, and in which the light source reflection plate and the main reflection plate are made of a material having good thermal conductivity, and which integrally generate heat from the light source and have a large area. It is intended to be released to the outside through.

[Embodiment] An embodiment of a backlight device with a heat sink and a reflector according to the present invention will be described below with reference to the drawings. 1 and 2, 11 is a transparent substrate and 12 is a reflector. The reflector 12 is made of a material such as aluminum having a good thermal conductivity and a high heat dissipation effect. Reflector 12
Has a light source receiving portion 13 whose both ends are curved, and rising walls 12a are integrally formed at the front edge and the rear edge. The reflection layer 14 is formed on the back surface of the reflection plate 12 over the front surface by means such as coating with a paint or printing. By fitting the transparent substrate 11 between the rising wall portions 12a,
The transparent substrate 11 is attached to the reflection plate 12. Light sources 15 are arranged in the light source receiving portions 13 at both ends of the reflection plate 12. A liquid crystal panel 17 is attached on the transparent substrate 11 with a translucent diffusion sheet 16 interposed. Diffusion sheet 16
Is to diffuse the heat radiation from the transparent substrate 11 uniformly over the front surface by using a satin-shaped or milky white translucent sheet. The liquid crystal panel 17 has a well-known configuration for displaying characters and pictures by liquid crystal.

Then, in the backlight device having the above-described configuration, the transparent substrate 11, the light source 15 and the like are assembled on the basis of the reflector 12.
When the transparent plate 11 is mounted between the rising wall portions 12a and the light source 15 is arranged in the light source receiving portion 13 as described above, and the assembling is performed, the transparent substrate 11 and the light source 15 can be easily positioned and attached. Therefore, it is very suitable for manufacturing by a series of flow operations. The liquid crystal panel 17 is attached to the transparent substrate 11 with the diffusion sheet 16 interposed.

When the light source 15 is turned on, diffused light from the light source 15 enters the transparent substrate 11 from the end face, and the light entering the transparent substrate 11 is reflected by the reflective layer 14 of the reflector 12 and diffused. The light is incident on the liquid crystal panel 17 through the sheet 16. In the diffusion sheet 16, the light emitted from the transparent substrate 11 is made uniform over the front surface and then is incident on the liquid crystal panel 17. The liquid crystal panel 17 is the diffusion sheet 1
The light passing through 6 is illuminated so that the displayed contents can be read. On the other hand, the heat generated from the light source 15 heats the light source receiving portion 13 of the reflecting plate 12, but since the reflecting plate 12 itself is made of a material having good thermal conductivity such as an aluminum plate, the light source receiving portion is formed. The heat of 13 is conducted to other parts, and accordingly, the heat is diffused from the wide-area reflection plate 12 to the outside, and the temperature rise in the light source receiving part 13 is prevented.

FIG. 3 shows the dot-shaped reflective layer 19 screen-printed with high-reflectivity ink on the surface of the transparent substrate 11 in contact with the reflective plate 12. The transparent substrate 11 has a reflective layer 19
When screen-printing, the printed surface is formed into an extremely fine rough surface that does not reach a satin finish. The size of the dots of the reflective layer 19 is made larger as the distance from the light source 15 is increased, that is, the area of the reflective layer 19 per unit area is increased as the emitted light from the light source 15 increases the distance. It is made larger according to the degree of attenuation.

In this embodiment, when the radiated light from the light source enters the transparent substrate 11 from the end, the light is repeatedly reflected between the front and back surfaces of the transparent substrate 11, and at this time, a part of the light is reflected from the back surface of the reflection plate 1.
2, the light is reflected by the reflection plate 12 and enters the liquid crystal panel 17 through the transparent substrate 11 and the diffusion sheet 16. In addition, the light repeatedly reflected between the front and back surfaces of the transparent substrate 11 is reflected by the reflection layer 1.
When it reaches 9, the light is diffusely reflected by the reflective layer 19 and the transparent substrate 11
Enters the liquid crystal panel 17 through the diffusion sheet 16. Since the shape of the dots in the reflective layer 19 is increased as the distance from the light source 15 increases, the amount of light added by the light reflected by the reflective plate 12 and the light reflected by the reflective layer 19 is a transparent substrate. The light is uniform over the entire area of the surface of 11. The radiated light from the transparent substrate 11 is provided to the liquid crystal panel 17 as a backlight after being made into a soft light that does not flicker by the diffusion sheet 16.

FIG. 4 shows a third embodiment, in which a reflective stripe 18 is formed on the surface of the transparent substrate 11 in contact with the reflection plate 12 with ink having high reflectance.
Is screen-printed. When screen-printing the reflective stripes 18, the printed surface of the transparent substrate 11 is made to be a very fine rough surface that does not reach a satin-like shape. The reflective stripes 18 are denser as the distance from the light source 15 is increased. . The reflection stripe 18 is a line having a predetermined width, but it may be screen-printed so that the line width becomes thicker as the distance from the light source 15 increases. In this embodiment, the light from the light source 15 enters the transparent substrate 11. Then, the incident light is reflected by the reflection stripes 18 and radiates from the surface of the transparent substrate 11 toward the liquid crystal panel 17. Incidentally, the reflective layer 19 of the second embodiment.
Alternatively, the reflective stripe 18 of the third embodiment can be used by using a binder such as a viscous and transparent synthetic resin mixed with reflective particles such as tin and aluminum that have heat resistance and good reflectance.

FIG. 5 shows a fourth embodiment in which the light source 15 is provided only on one surface side of the transparent substrate 11. The transparent substrate 11 is adapted to be assembled by being fitted into the reflection plate 20 having the rising wall 20a on the peripheral portion except the side where the light source 15 is disposed, and the second and third embodiments. As described above, a dot-shaped reflective layer 19 or reflective fringes 18 may be formed. The light source 15 is surrounded by the reflection plate 21. Reflector 2
1 has a ring-shaped cross section with a part cut away, and the open end thereof is screwed to the transparent substrate 11 on the surface on which the reflection plate 20 and the diffusion sheet 16 are placed. Light emitted from the light source 15 enters the transparent substrate 11 as in the above-described embodiments, is reflected by the reflection plate 20 to the reflection layer 19 and the reflection stripes 18, and then is diffused through the diffusion sheet 16 to the liquid crystal panel 17 as a backlight. The heat generated from the light source 15, which is provided as the above, is conducted from the reflection plate 21 to the reflection plate 20 and diffused to the outside like a wide area heat dissipation plate.

The light source receiving portion 13 and the reflection plate 21 of the reflection plate 12 of each of the above-described embodiments are also used as a holder to which the light source 15 is attached.

[Advantage of Device] As described above, according to the backlight device with a heat dissipation plate and a reflection plate of the present invention, the reflection plate is made of a material having a good heat dissipation effect to serve also as a wide area heat dissipation plate, and The heat can be effectively diffused, the abnormal temperature rise of the transparent substrate and the liquid crystal panel can be prevented, and the life can be extended, which is convenient for use.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a first embodiment of a backlight device with a heat sink and a reflector according to the present invention, FIG. 2 is a sectional view of the backlight device of FIG. 1, and FIG. 3 is a second embodiment. FIG. 4 is a back view of the transparent substrate with a part of the enlarged view, FIG. 4 is a back view of the transparent substrate of the third embodiment, FIG. 5 is a sectional view of a backlight device showing the fourth embodiment, and FIG. It is sectional drawing of the conventional backlight apparatus. 11 ... Transparent substrate 12, 20, 21 ... Reflector 13 ... Light source receiving part, 14 ... Reflective layer 15 ... Light source, 16 ... Diffusing sheet 17 ... Liquid crystal panel, 18 ... Reflective stripes 19 ... Reflective layer

Claims (1)

[Scope of utility model registration request] 1. A backlight device comprising a transparent substrate attached to a liquid crystal panel, a light source disposed on an end face side of the transparent substrate, and a reflection plate provided on the back surface of the transparent substrate, wherein the transparent substrate is a transparent substrate. The light source except for the end face side is surrounded by a light source reflection plate, the light source reflection plate is integrally formed with a main reflection plate attached to the back surface of the transparent substrate, and the light source reflection plate and the main reflection plate are formed. A backlight device with a reflecting plate that also serves as a heat dissipation plate, characterized in that the plate is formed of a material having good thermal conductivity.