JP2574738Y2 - Light source device and liquid crystal device - Google Patents

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 used for a pocket television, a wall-mounted television, a projection television, a laptop personal computer, a game machine, and the like, and a liquid crystal device using the same.

[0002]

2. Description of the Related Art Conventionally, in order to incorporate a liquid crystal panel such as a pocket television, it is necessary to construct a small and thin liquid crystal panel. As an example of the countermeasure, a transparent resin plate such as acrylic is used for the light guide from a direct type in which the backlight constituting the liquid crystal panel block is installed directly below the liquid crystal panel glass, and such a light guide, that is, a light guide plate There is proposed a side light system in which a fluorescent tube is disposed on an end face of the light source.

Hereinafter, a conventional panel block structure will be described with reference to the drawings. FIG. 5 shows an example of a conventional panel block structure. In FIG. 5, reference numeral 21 denotes a liquid crystal panel, 22 denotes a light guide plate made of a transparent resin such as acrylic, 23 denotes a fluorescent tube, 24 denotes a diffusion plate provided on the surface of the light guide plate, and 25 denotes light reflection drawn on the back surface of the light guide plate. A pattern, 26 is a reflection plate provided on the back surface of the light guide plate, 27 is a reflection film formed around the fluorescent tube, 28 is a driver for driving the liquid crystal panel, and 29 is a signal to a driver for driving the liquid crystal panel. The supply bus line, 30 indicates a fixed frame made of plastic. Various other forms of the driver for driving the liquid crystal panel are conceivable. Basically, part of the light emitted from the fluorescent tube is once reflected by the reflection film 27, and part of the light is directly incident on the light guide plate 22. The light incident on the light guide plate 22 is radiated in the direction of the liquid crystal panel 21 by the reflection plate 26 on the back surface of the light guide plate. Light applied to the liquid crystal panel 21 is made uniform by the light reflection pattern 25 on the back surface of the light guide plate.

[0004]

In FIG. 5, the fluorescent tube 23 is generally a heating element, and the electrode at the end of the tube is 70 mm.
From 100 to 100 ° C. Such a temperature is transmitted to other parts at a time and raises the temperature of other parts.
A liquid crystal panel generally has a temperature characteristic, and the contrast and other display characteristics of the liquid crystal panel at high and low temperatures differ. In other words, as described above, when the temperature of the fluorescent tube conducts heat to other parts at the time and time, and the temperature of the other parts is raised first, for example, the temperature in the glass of the liquid crystal panel differs depending on the part. turn into. That is, the temperature at the center of the liquid crystal panel is low and the temperature at the corners is high. If the temperature differs depending on the part of the liquid crystal panel as described above, the contrast and display characteristics will differ depending on the part of the liquid crystal panel. Then, the display appearance of the liquid crystal panel becomes extremely poor.

Conventionally, as a measure against this temperature, a radiator plate for releasing heat of the fluorescent tube has been used. However, if the heat radiation plate is carelessly arranged, the lighting startability of the fluorescent tube deteriorates. Therefore, the present invention solves such a drawback and takes measures against heat without deteriorating the lighting startability of the fluorescent tube.

[0006]

According to the present invention, there is provided a light source device having a flat light guide plate, a light source disposed on a side of the light guide plate, and a light guide plate for transmitting light from the end face of the light guide plate to the light guide plate. In a light source device having a reflective film disposed around the light source so as to be incident on the light source plate, a metal heat sink is disposed on one surface side of the light guide plate, and the metal heat sink and the reflective film And a gap is provided between them. The liquid crystal device according to the present invention may further include a light guide plate having a flat plate shape, a light source disposed on a side of the light guide plate, and the light source such that light from the light source is incident on the light guide plate from an end surface of the light guide plate. A reflective film disposed around the light guide plate, a metal radiator plate disposed on one surface of the light guide plate, and a liquid crystal panel disposed on the other surface side of the light guide plate; A gap is provided between the reflective film and the reflective film.

[0007]

1 to 4 show a panel block structure. In the figure, 1 is a liquid crystal panel, 2 is a fluorescent tube, 3 is an acrylic light guide plate for dispersing and irradiating the light of the fluorescent tube 2 to the back surface of the liquid crystal panel 1, and 4 is between the light guide plate 3 and the liquid crystal panel 1. , A light reflection pattern drawn on the back surface of the light guide plate 3, a reflection plate 6 placed on the back surface of the light guide plate 3, and a diffusion plate 7 disposed around the fluorescent tube 2. Reflective film,
Reference numeral 8 denotes a driver for driving the liquid crystal panel 1, 9 denotes a bus line for supplying a driver 8 signal for driving the liquid crystal panel 1, 10 denotes a fixed frame made of plastic, and 11 denotes a heat sink made of metal. The driver 8 for driving the liquid crystal panel 1 may take various other forms. Basically, part of the light emitted from the fluorescent tube 2 is once reflected by the reflection film 7 and partly enters the light guide plate 3 directly. The light incident on the light guide plate 3 is reflected by the reflector 6 on the back surface of the light guide plate 3. Light applied to the liquid crystal panel 1 is made uniform by the light reflection pattern 5 on the back surface of the light guide plate.

The fluorescent tube 2 is generally a heating element, and the temperature of the electrode at the end of the tube increases from 70 to 100 ° C. Such a temperature is transmitted to other parts at a time and raises the temperature of other parts. However, if a metal heat sink exists on the back surface of the light guide plate as in the present invention, and the heat sink is installed close to the fluorescent tube, the heat of the fluorescent tube is reduced by a plastic material having low thermal conductivity. The heat is conducted to the metal heat radiating plate 11 having higher thermal conductivity than the fixed frame 10 and the liquid crystal panel 1. If the heat conduction is low, the temperature of the same part varies depending on the location,
If the thermal conductivity is high, the temperature of the part becomes uniform in a very short time. As in the present invention, in the case of a heat sink with high thermal conductivity, the temperature of the fluorescent tube is fast, and the heat sink conducts heat to the heat sink, and the heat sink absorbs the heat before it reaches the low thermal conductivity plastic etc. . When the temperature of the heat sink arranged on the entire back surface of the light guide plate rises slightly at a uniform temperature over the entire surface, the light guide plate is slightly warmed over the entire surface, and at the same time, the temperature of the panel on the light guide plate is also slightly warmed. . Then, the temperature of the liquid crystal panel 1 rises slightly and almost uniformly, and the temperature at the center and the temperature at the corners of the liquid crystal panel 1 become considerably close.
Then, the contrast and other display characteristics of the liquid crystal panel are uniform within the same panel.

FIG. 1 shows a heat radiating plate having a simple planar shape, and FIG. 2 shows a heat radiating plate whose end is bent at a right angle to improve heat absorption from a fluorescent tube. Further, in FIG. 3, the vicinity of the fluorescent tube of the heat radiating plate is slightly separated from the fluorescent tube, and the heat conduction is slightly hindered. Further, FIG. 4 shows a high thermal conductivity silicon rubber sandwiched between the heat sink and the fluorescent tube below the fluorescent tube, which overcomes the disadvantage of the example shown in FIG.

[0010]

[Effect of the Invention] In the present invention, a metal radiator plate is arranged on one side of the light guide plate, and the radiator plate and the reflective film of the fluorescent tube are separated from each other. As compared with the case, the lighting startability of the fluorescent tube can be improved. In addition, by inserting high thermal conductive silicon between the reflective film and the heat radiating plate, the temperature rise of the light source device can be made uniform without impairing lighting startability and heat radiation. Further, by disposing the liquid crystal panel on the opposite side of the light source device on which the heat radiating plate is disposed, it is possible to suppress display unevenness of the liquid crystal device due to a rise in temperature of the light source device.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example in which a heat sink is used for a light source device.

FIG. 2 is a diagram illustrating an example in which an end of a heat sink of a light source device is bent.

FIG. 3 is a diagram showing an embodiment of the present invention.

FIG. 4 is a diagram showing an embodiment of the present invention.

FIG. 5 is a diagram showing a mounting example of a conventional liquid crystal device.

[Explanation of symbols]

 1,21 liquid crystal panel 3,22 light guide plate 2,23 fluorescent tube 4,24 diffuser plate 5,25 light reflection pattern formed on light guide plate 6,26 reflection plate 7,27 reflection film 8,28 for driving liquid crystal panel Driver 9,29 Bus line 10,30 Plastic fixing frame 11 Metal radiator plate 12 Silicon rubber sheet

Claims (4)

(57) [Scope of request for utility model registration] 1. A light guide plate having a flat shape, a light source disposed on a side of the light guide plate, and a light source disposed around the light source such that light from the light source is incident on the light guide plate from an end face of the light guide plate. In the light source device having the disposed reflective film, a metal heat sink is arranged on one surface side of the light guide plate,
A light source device, wherein a gap is provided between the metal heat sink and the reflection film. 2. The light source device according to claim 1, wherein a high thermal conductive silicon rubber is sandwiched in a gap between the metal heat sink and the reflection film. 3. A light guide plate having a flat plate shape, a light source disposed on a side of the light guide plate, and a light source around the light source such that light from the light source is incident on the light guide plate from an end face of the light guide plate. The reflective film disposed, a metal heat sink disposed on one surface side of the light guide plate, and a liquid crystal panel disposed on the other surface side of the light guide plate, the metal heat sink and the A liquid crystal device, wherein a gap is provided between the reflective film and the reflective film. 4. The liquid crystal device according to claim 3, wherein a high thermal conductive silicon rubber is held in a gap between said metal heat sink and said reflection film.