JP2009064706A - Method of absorbing heat energy from liquid crystal television by heat pipes - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin liquid crystal television of high heat exchange efficiency capable of resolving a problem of treating heat radiation from a light emitting material such as a fluorescent tube or light-emitting diode as its brightness and size become improved. <P>SOLUTION: In a liquid crystal television, a heat transfer material is provided on the back side of a light reflector. The light reflector has pleated convex section to concentrate light from fluorescent tube forward. The heat transfer material is set in the pleated concave section on the opposite side of the light reflector which is the result of formation of the pleated convex section. The heat transfer material is provided separately from the light reflector, and is combined in a body with the light reflector by filling the clearances of the concave portions with a filler of higher thermal conductivity than air or by sealing the openings of the concave portions of the light reflector. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal television having a structure in which heat generated from a fluorescent tube of a liquid crystal screen such as a liquid crystal television is absorbed using a heat transfer body such as a heat pipe.

  Conventionally, a backlight of a liquid crystal television using a small liquid crystal display or the like has a fluorescent tube or an LED (light emitting diode) arranged on at least one side of the four sides of the display, and the entire surface of the liquid crystal display is made using a light guide plate. It was configured to emit light uniformly. In the case of such a liquid crystal display, the heat generated from the fluorescent tube or the LED is radiated from a heat radiating plate or the like on the side where the fluorescent tube or the LED is arranged as in Patent Document 1. Thus, in the case of a small display, since the fluorescent tube, LED, etc. used as a heat generating body are arrange | positioned along the outer periphery of a liquid crystal display, the heat sink etc. were arrange | positioned at the outer periphery of a liquid crystal display.

However, with the recent increase in size of liquid crystal displays, it has become necessary to arrange a plurality of fluorescent tubes, LEDs, and the like on the back surface of the liquid crystal display. As the liquid crystal display becomes larger, the number of fluorescent tubes, LEDs, and the like arranged increases, and the amount of heat generation also increases. Therefore, Patent Document 2 and the like propose a configuration in which heat generated from LEDs arranged on the back surface of the liquid crystal display is dissipated using a heat pipe.
JP-A-11-284379 JP 2006-278041 A

  However, the back panel of the liquid crystal display described in Patent Document 2 has a configuration that uses an LED or the like as a light emitter and does not require a reflector. For this reason, in Patent Document 2, it is possible to arrange a heat pipe directly on a light emitting body such as an LED serving as a heat generating body and let it cool, but in the present invention, since it is a configuration that requires a reflector, it generates heat. A heat pipe cannot be directly placed on a light-emitting body such as an LED or a fluorescent tube to cool the body.

  In view of the above problems, the present invention provides the following liquid crystal television. That is, as a first invention, there is provided a liquid crystal television having a reflector having a heat transfer body made of a heat pipe on the back, the reflector being a bent projection for concentrating light emitted from the fluorescent tube forward And the heat transfer body provides a liquid crystal television arranged in a concave portion on the back side of the reflecting plate generated to form the bent convex portion.

  As a second invention, the heat transfer body is configured as a separate member from the reflector, and the heat transfer body and a filler having higher thermal conductivity than air are disposed in the gap formed between the recesses. A liquid crystal television set forth in the invention is provided.

  As a third invention, the heat transfer body provides the liquid crystal television set according to the first invention or the second invention, which is configured integrally with the reflector by sealing the recess opening of the reflector. .

  According to the present invention, even a large-sized liquid crystal television can realize a liquid crystal television that can efficiently dissipate heat generated from a fluorescent tube or an LED without impairing the thinness that is a feature of the liquid crystal television.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, this invention should not be limited to these embodiments at all, and can be implemented in various modes without departing from the gist thereof.

  The first embodiment mainly relates to claim 1.

  The second embodiment mainly relates to claim 2 and the like.

The third embodiment mainly relates to claim 3 and the like.
<Embodiment 1>
<Summary of Embodiment 1>

  The present embodiment is a liquid crystal television characterized in that a heat transfer body such as a heat pipe for heat dissipation is provided on the back surface of a reflector for reflecting light emitted from a fluorescent tube or the like to a liquid crystal display surface. . By disposing the heat transfer body on the back surface of the reflecting plate, the liquid crystal television of this embodiment can efficiently dissipate heat even if it has a thin shape.

Further, in the liquid crystal television of the present embodiment, the reflector has a bent convex portion for concentrating light emitted from the fluorescent tube forward, and the heat transfer body is a reflection generated to form the bent convex portion. It is characterized by being arranged in a recess on the back side of the plate.
<Configuration of Embodiment 1>

  The liquid crystal television of this embodiment has a reflector having a heat transfer body on the back. In addition, the liquid crystal television of the present embodiment has a bent convex portion for concentrating light emitted from the fluorescent tube arranged on the reflecting plate forward, and the heat transfer body forms the bent convex portion. It arrange | positions in the recessed part of the produced reflector back side.

  FIG. 1 shows a conceptual diagram of a reflector (0102) provided with a heat transfer body (0101) mounted on the liquid crystal television of this embodiment on the back surface. A plurality of light emitters such as fluorescent tubes (0103) are arranged on the surface of the reflector. In the figure, the upper side A is the liquid crystal panel side that irradiates light, and the lower side B is the back side on which the backlight chassis and the like are arranged. The reflector is unevenly formed so as to uniformly irradiate the liquid crystal television display surface with light emitted from the light emitter. This reflector is fixed to the backlight chassis. In FIG. 1, a light emitter such as a fluorescent tube is disposed in a recess (0104) on the surface of the reflector. Light emitted from a light emitting body such as a fluorescent tube is reflected by a bent convex portion (0105) of the reflecting plate to illuminate the liquid crystal panel. At this time, most of the heat generated from the light emitter such as a fluorescent tube is transmitted to the reflector and is transmitted to the back surface of the reflector. Heat generated from the light emitter is transmitted to the back of the reflector and is transmitted to the heat sink by the heat transfer body. At this time, since the liquid crystal panel (0106) is arranged on the upper part A side in the drawing, there is no space for arranging the heat transfer body. For this reason, the heat transfer member cannot be disposed and dissipated in contact with a light emitter such as a fluorescent tube, and is disposed on the opposite side of the light emitter such as a fluorescent tube via a reflector.

  Here, the heat transfer body is one that efficiently transfers heat from an object having a high temperature to an object having a low temperature. Among metals, silver, copper, gold, aluminum, diamond and the like are particularly preferable. In addition, as in a heat pipe, heat transfer due to vaporization and condensation of a substance, or circulation and transfer of heat using a fluid such as gas or liquid as a heat medium, etc.

  The heat transfer body plays a role of obtaining heat generated from the fluorescent tube or the like from the reflecting plate and transmitting it to the heat radiating plate. The heat transfer body may be a heat transfer body that uses liquid vaporization heat, generally called a heat pipe, or may be a device that transfers heat by circulating liquid or gas. FIG. 2 shows a conceptual diagram when the reflector (0201) is viewed from the back side. The example shown to (a) is an example using a heat pipe (0202) as a heat exchanger.

  A heat pipe is a container in which a small amount of liquid (working fluid) is sealed in a sealed container and a capillary structure (0107) is provided on the inner wall. A cross-sectional view of an example of the heat pipe is shown in the circle of FIG. On the inner wall of the heat pipe, grooves and wicks for causing capillary action as shown in the figure are arranged. The liquid (working fluid) sealed inside is water, alternative chlorofluorocarbon, methanol, ethanol, or the like. The airtight container of the heat pipe is made of a material having high heat exchange efficiency such as copper or aluminum. For the type of hydraulic fluid and the material of the sealed container, an appropriate material is selected according to the amount of heat generated.

  The heat pipe is heated on the back surface of the reflector in FIG. 2A, and the internal working fluid evaporates. As the working fluid evaporates, it absorbs heat. The vapor | steam of the hydraulic fluid which generate | occur | produces when a hydraulic fluid evaporates moves to the heat sink which is a low temperature part. In the heat radiating plate, the vapor of the working fluid is condensed and returned to the liquid. Here, heat is released through the heat sink. The working fluid that has been returned to the liquid by condensation moves to the reflecting plate by capillary action. Inside the heat pipe, such a series of phase changes is performed to transfer heat.

  In FIG. 2A, a plurality of heat pipes are arranged in parallel to the longitudinal direction of the liquid crystal television, and heat radiating plates are installed at both ends of the heat pipe. The heat radiating fins of the heat radiating plate are attached in parallel with the heat pipes in the preferred direction. (B) is similar to (a), in which the heat pipes are arranged in the horizontal direction and the heat sinks are installed at both ends of the heat pipes. It is different in the vertical direction. Since the heat radiation fins radiate heat by smoothly flowing air between the fins, when the fins are installed sideways as shown in (a), it is difficult for the air to flow and heat radiation. On the other hand, when the heat dissipating fins are in the vertical direction as shown in FIG. In addition, the heat pipes may be arranged in the horizontal direction as shown in (a) or (b), but may be divided into two on the left and right as shown in (c). . At this time, the heat pipe radiates heat only at one end. Further, the arrangement direction of the heat pipes may be arranged in the vertical direction as shown in (d).

  FIG. 3 shows a cross-sectional view of the reflector of the liquid crystal television of this embodiment. The back surface of the reflective plate (0301) has a reverse pattern of the front surface such that the bent convex portion (0302) on the surface of the reflective plate is a concave portion on the back surface and the concave portion (0303) on the front surface is a convex portion on the back surface. . Heat generated from a light emitting body (not shown) such as a fluorescent tube is transmitted to the back surface of the reflecting plate. For this reason, the liquid crystal television of this embodiment includes a heat transfer body (0304) such as a heat pipe on the back surface of the reflector. It is desirable that the heat transfer body disposed on the back surface of the reflecting plate has a shape and size that can be accommodated in the bent convex portion of the reflecting plate as shown in FIG. When the heat transfer body does not fit in the bent convex part of the reflector as in (b), a gap is generated between the backlight chassis (0305) and a thickness is generated. On the other hand, when the cross section of the heat transfer body is too small as in (c) and (d), there is a possibility that a space may be formed between the reflection plate and the heat transfer body, and the heat of the reflection plate is efficiently transferred. It becomes difficult to be transmitted to the heat body. The heat transfer capacity of a heat transfer body such as a heat pipe varies depending on its diameter. A heat pipe with a large diameter has a large heat transfer capacity, but as shown in FIG. 3 (b), there is a possibility that a thickness may be generated. Therefore, the diameter of the heat pipe is a value of the concave portion on the back surface caused by the bent convex portion of the reflector. The diameter is adjusted to the size and does not protrude significantly from the recess.

  The heat pipe is fixed to the reflector or the backlight chassis by welding or the like. At this time, as shown in FIG. 3A, when welding to the reflector, the positions A and B are welded. Moreover, when welding to a backlight chassis, the position of C and D will be welded. In the case of manufacturing, when welding to a reflecting plate, a heat pipe is welded to the reflecting plate, and the backlight chassis is fixed thereon. In the case of welding to the backlight chassis, a heat pipe is welded to the backlight chassis, and the backlight chassis and the heat pipe integrated together are fixed to the reflector.

  The cross-sectional shape of the heat transfer body may be a shape other than a circle as shown in FIG. For example, as shown in (a), if the cross-sectional shape of the heat transfer body (0401) is a substantially triangular shape along the shape of the bent convex portion (0402), it contacts the bent convex portion of the reflector. The area to be expanded is also increased, and heat exchange is performed efficiently. Moreover, the shape of the bending convex part of a reflecting plate may be shapes other than a substantially triangle. For example, when the shape of the concave portion on the back surface of the reflector is a substantially square shape such as a trapezoid as shown in (b), the cross-sectional shape of the heat transfer body should be a trapezoid as well as the shape of the bent convex portion. The efficiency of heat exchange is improved. Thus, it is desirable that the cross-sectional shape of the heat transfer body be a shape with good heat exchange efficiency in accordance with the shape of the bent convex portion of the reflector.

The material used for the reflecting plate is required to be a material having good heat transfer in order to efficiently transfer heat generated from a light emitter such as a fluorescent tube to the back surface of the reflecting plate. For this reason, it is preferable that the metal plate is made of a thin metal plate such as copper or aluminum.
<Embodiment 1 effect>

The liquid crystal television of this embodiment includes a heat transfer body in the concave portion on the back surface of the reflector. Thereby, even in a large-sized liquid crystal television, it is possible to efficiently dissipate heat generated from a fluorescent tube or an LED without impairing the thinness that is characteristic of the liquid crystal television.
<Embodiment 2>
<Overview of Embodiment 2>

In this embodiment, the heat transfer body and the back surface of the reflector are improved so that the heat exchange efficiency does not change depending on the shape of the recesses on the back surface of the heat transfer body and the reflector, the cross-sectional shape and size of the heat pipe, etc. The liquid crystal television is characterized in that a filler having high thermal conductivity is arranged in a gap formed between the recesses of the liquid crystal display. By disposing a filler with high thermal conductivity in the gap between the heat transfer body and the concave portion on the back of the reflector, it is possible to increase the heat exchange efficiency even if the contact area between the concave portion and the heat transfer body is small. .
<Embodiment 2 configuration>

  In the liquid crystal television of the present embodiment, the heat transfer body is configured separately from the reflector, and a filler having higher thermal conductivity than air is disposed in the gap formed between the heat transfer body and the recess. .

  FIG. 5 shows a cross-sectional view of the reflector of this embodiment. As in the first embodiment, the reflector of the present embodiment is provided with irregularities for concentrating light emitted from a light emitter such as a fluorescent tube forward. At this time, as shown to (a) and (b) of FIG. 4, heat exchange efficiency improves, so that the contact area of a reflecting plate and a heat exchanger is large. However, generally, since the cross-sectional shape of a heat pipe or the like is circular, the contact area with the reflector is small. Therefore, in this embodiment, as shown in FIG. 5A, the gap between the heat transfer body (0501) and the reflector (0502) is filled with a material (0503) having higher thermal conductivity than air. Solves the problem of contact area.

  In this way, by filling the gap between the reflector and the heat transfer body with a material having high thermal conductivity, as shown in FIGS. 5B and 5C, the cross-sectional shape of the heat transfer body Regardless of the heat exchange efficiency.

The filler may be any material that has higher thermal conductivity than air. The gap between the reflector and the heat transfer body may be filled with the same metal powder or fibrous metal as the reflector. For example, the outer periphery of the heat pipe is covered with a metal fiber or the like, and disposed on the reflection plate to fill the gap. In addition, it may be filled with an epoxy-based or ceramic-based high thermal conductive agent containing silver, nickel, ceramic, or the like.
<Embodiment 2 effect>

As in the liquid crystal television of this embodiment, by placing a filler having higher thermal conductivity than air in the gap between the reflector and the heat transfer body, the reflector and the heat transfer can be efficiently transferred regardless of the cross-sectional shape of the heat transfer body. It is possible to exchange heat with the heat element.
<Embodiment 3>
<Overview of Embodiment 3>

The present embodiment is a liquid crystal television characterized in that a space formed by sealing an opening of a concave portion on the back side formed by a bent convex portion of a reflecting plate is used as a heat transfer body. By using the space formed by sealing the opening of the concave portion on the back surface of the reflector as a heat transfer body, heat exchange can be performed most efficiently between the reflector and the heat transfer body.
<Embodiment 3 configuration>

  In the liquid crystal television of the present embodiment, the heat transfer body is configured integrally with the reflecting plate by sealing the recess opening of the reflecting plate.

FIG. 6A shows a cross-sectional view of the reflector (0601) of the liquid crystal television of the present embodiment. In the reflection plate of the liquid crystal television of this embodiment, the opening of the concave portion on the back surface of the reflection plate is sealed, and the space formed by this is a substantially triangular space as the outer frame of the heat transfer body (0602). Thereby, heat exchange can be performed most efficiently between the reflector and the heat transfer body. Further, by changing the shape to be sealed, the cross-sectional shape may be a circle or a rectangle as shown in (b) or (c) in addition to a triangle.
<Embodiment 3 effects>

In the liquid crystal television of this embodiment, the space formed by sealing the recessed opening portion on the back surface of the reflector is used as a heat transfer body. Thereby, heat exchange between the reflector and the heat transfer body can be performed efficiently.
<Specific example>

  FIG. 7 shows a specific example of the present invention. An example shown in FIG. 7 is a reflector used in a liquid crystal television having an aspect ratio of 9:16. The size of the reflector is approximately 380 millimeters in length and approximately 701 millimeters in width. On the reflector, 16 fluorescent tubes (not shown) are arranged in the horizontal direction at equal intervals. On the back surface of the reflecting plate, fifteen heat pipes having a diameter of about 2 millimeters are arranged in parallel with the fluorescent tube as a heat transfer member in a concave portion constituted by a bent convex portion. The height of the recesses in which the heat transfer bodies are arranged is approximately 8 millimeters, and the apex angle is approximately 80 degrees.

Conceptual perspective view for explaining a reflector of a liquid crystal television of Embodiment 1 Conceptual rear view for explaining the reflector of the liquid crystal television of Embodiment 1 Conceptual sectional view for explaining a reflector of a liquid crystal television of Embodiment 1 Conceptual sectional view for explaining a reflector of a liquid crystal television of Embodiment 1 A conceptual sectional view explaining a reflector of a liquid crystal television of Embodiment 2. A conceptual sectional view explaining a reflector of a liquid crystal television of Embodiment 3 Specific examples of the present invention

Explanation of symbols

0101 Heat transfer body 0102 Reflector 0103 Light emitter 0104 Concave part 0105 Bending convex part 0106 Liquid crystal panel 0107 Capillary structure

Claims (3)

A liquid crystal television having a reflector having a heat transfer body made of a heat pipe on the back,
The reflector has a bent protrusion for concentrating the light emitted from the fluorescent tube forward, and the heat transfer body is a liquid crystal arranged in a recess on the back side of the reflector generated to form the bent protrusion. TV set.   The liquid crystal television according to claim 1, wherein the heat transfer body is configured separately from the reflector, and a filler having higher thermal conductivity than air is disposed in a gap formed between the heat transfer body and the recess.   The liquid crystal television according to claim 1, wherein the heat transfer body is configured integrally with the reflection plate by sealing the recess opening of the reflection plate.