JP2008293817A - Backlight unit and display device with the same backlight unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backlight unit having a cooling means for cooling a light source by intercepting it from the open air. <P>SOLUTION: The backlight unit 15 has the light sources organized by cold-cathode tubes 17<SB>1</SB>-17<SB>6</SB>and the like, and an airtight container 16 for storing the light sources. The airtight container 16 is formed by a light-transmitting window 16B at one side and a main case 16A where a space with a designated capacity is arranged, and the light sources organized by the cold-cathode tubes 17<SB>1</SB>-17<SB>6</SB>, a heat sink 19 for radiating heat generated from the light sources, and convection fans 20<SB>A</SB>, 20<SB>B</SB>for making air in the airtight container 16 circulate are stored in the main case 16A. Further, the inside of the airtight container 16 is intercepted from the open air by exposing a heat-radiating section 19B of the heat sink 19 to the outside of the airtight container 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a backlight device provided with a cooling means for suppressing temperature rise inside and a display device provided with the backlight device.

A flat type display panel is often used for a display device of a general electronic / electric apparatus, and most of the display panel is a liquid crystal panel. This liquid crystal panel is provided with a backlight device that irradiates the display screen because the display image is difficult to see in a dark place because the liquid crystal is a non-light emitting substance.

In recent years, since a brighter screen display is required for the liquid crystal panel, a backlight device having a higher luminance is required. As a light source of the backlight device, a fluorescent lamp, a cold cathode tube, a light emitting diode (LED), or the like is usually used. In order to increase luminance using these light sources, it is necessary to increase the number of light sources. However, when the number of these light sources is increased, the amount of heat generated from the light sources increases, so that the temperature in the housing case housing the light sources rises.

This tendency appears remarkably when using a light source such as a fluorescent lamp or a cold cathode tube whose surface is hot. The temperature rise in the housing case adversely affects the operation characteristics of the liquid crystal panel, the semiconductor elements that control the panel, and other electronic components, and the normal operation characteristics cannot be obtained, or the deterioration thereof is accelerated and the failure occurs. It may cause.

Therefore, in a liquid crystal display device provided with such a high-brightness backlight device, a cooling means is provided in the backlight device (see, for example, Patent Documents 1 and 2 below).

For example, a liquid crystal display device described in Patent Document 1 includes a backlight unit in which an exhaust opening is formed in an upper part of a case that houses a light source, and an intake opening is formed in a lower part.
In the backlight unit, when the air inside the case is heated by the heat generated by the light source, the heated air rises and is discharged from the upper exhaust opening. On the other hand, cold air is sucked from the lower intake opening, and the temperature rise inside the case is suppressed by natural convection of air.

FIG. 6 is a cross-sectional view of a main part of the liquid crystal display device described in Patent Document 2 below.

The liquid crystal display device 30 includes a liquid crystal panel 31, a backlight casing 32 that houses a plurality of fluorescent lamps that irradiate the liquid crystal panel, a liquid crystal driving circuit board 33 that drives the liquid crystal panel, and a backlight casing 32. Ventilation members 34, 34 provided on the upper surface portion and the lower surface portion. The ventilation members 34 and 34 are formed with ventilation holes 34 a and 34 a communicating with the backlight housing 32.

In the liquid crystal display device 30, outside air is sucked from the lower ventilation member 34, and the sucked cold air passes through the backlight housing 32 and is exhausted from the upper ventilation member 34. At this time, heat generated in the backlight housing 32 is released to the outside. This document 2 also discloses a technique for forcibly cooling by arranging a forced air cooling fan on the upper and lower ventilation members.
JP 2002-189207 A (FIG. 1, paragraphs [0019] to [0021]) JP-A-10-96898 (FIG. 1, paragraphs [0019], [0020])

The backlight unit disclosed in Patent Document 1 exhausts air heated inside the case from an exhaust opening provided on the case. However, in this backlight unit, air intake and exhaust into the case is performed by natural convection of air, so the flow rate and flow velocity at this time depend on the natural convection of air, and they can not be adjusted, The cooling capacity is naturally limited. For this reason, it is difficult to apply to a display device that requires a larger cooling capacity. Also, since the intake and exhaust openings are always open,
Dust, dust, cigarette smoke, or the like enters from the opening, and adheres to the backlight light source to reduce the brightness thereof, and water or the like may enter and cause a failure.

In addition, the liquid crystal display device disclosed in Patent Document 2 has the same problem as the backlight unit described above, because intake and exhaust into the backlight housing is performed by natural convection of air. This Patent Document 2 also discloses a technique in which a forced air cooling fan is disposed on the upper and lower ventilation members to perform forced cooling. However, outside air is forcibly introduced into the backlight housing from the ventilation members. Since dust, dust, tobacco smoke, water, and the like are brought together at the same time, the same problem as the backlight unit disclosed in Patent Document 1 is latent.

On the other hand, as a characteristic of the liquid crystal panel, the light transmittance is extremely low, and the light transmittance of one liquid crystal panel is usually 10% or less. When the light transmittance is low, in a display device in which a plurality of liquid crystal panels are stacked, such as a multi-layer display device or a stereoscopic display device, the light transmittance decreases in inverse proportion to the number of stacked liquid crystal panels. . Therefore, in a display device in which one liquid crystal panel is further laminated on one liquid crystal panel, the light transmittance is further reduced, for example, 0.1% or less. In addition, since the multi-layer display device is usually used by laminating at least two color liquid crystal panels and a sheet for preventing moire is inserted between the liquid crystal panels, the light transmittance as described above is used. The decrease in the remarkably appears.

For this reason, a backlight device for a multi-layer display device or a stereoscopic display device needs a light source with higher luminance. For example, even a medium-sized liquid crystal panel
Furthermore, when a structure in which one liquid crystal panel of the same type is stacked, about 10 for a single liquid crystal panel is used.
A light source having a brightness twice as high (for example, 2 to 30,000 cd / m ² ) is required, and when a fluorescent lamp or a cold cathode tube is used as the light source, the temperature in the housing case for storing the light source rises to around 100 ° C. . However, since the cooling means of the backlight device disclosed in Patent Documents 1 and 2 relies on air convection, the cooling capacity is naturally limited and the ingress of contaminants from the outside is suppressed. Therefore, it is extremely difficult to apply to a display device that requires a high-intensity light source as described above.

The present invention has been made in order to solve the problems of the prior art, and an object of the present invention is to provide a backlight device including a cooling unit that cools the light source and the like by blocking it from outside air, and the backlight device. It is providing the display apparatus provided with.

Another object of the present invention is to provide a backlight device including a cooling means having a high cooling capacity and a display device including the backlight device.

In order to achieve the above object, a backlight device according to the present invention includes a light source and a storage case for storing the light source, wherein the storage case has a light transmission window on one side and a predetermined volume on the inside. Is formed in a sealed container provided with a space, and in the sealed container, the light source,
A heat sink that radiates heat generated from the light source and a convection fan that convects the air in the sealed container are housed, and a heat radiating portion of the heat sink is exposed to the outside of the sealed container, and the inside of the sealed container is outside air. It is characterized by being blocked.

According to the backlight device of this aspect, the light source and the heat sink are housed in the sealed container,
Since the inside of the container is shut off from the outside air, the heat generated in the sealed container can be dissipated to the outside without blowing the outside air through a vent or the like, and the temperature rise inside can be suppressed. In addition, since the inside of the sealed container is shielded from the outside air, dust, dust or cigarette smoke does not enter from the outside of the sealed container, so that it is possible to prevent functional deterioration due to contamination of members such as the light source. .

In the backlight device according to the present invention, the light source is surrounded by a casing, and the heat sink is fixed to the casing.

According to the backlight device of this aspect, since the light source is surrounded by the casing and the heat sink is fixed to the casing, the heat generated from the light source can be efficiently conducted to the heat sink through the casing and dissipated. .

The backlight device of the present invention is characterized in that, in the above-described backlight device, the sealed container has a reflective member disposed below the light source, and the heat sink is fixed to the reflective member.

According to the backlight device of this aspect, since the reflecting member is disposed below the light source and the heat sink is fixed to the reflecting member, the heat generated from the light source is efficiently conducted to the heat sink via the reflecting member. It can dissipate heat.

The backlight device according to the present invention is the above backlight device, wherein the light source is a linear fluorescent lamp or a cold cathode tube, and a convection fan is provided at at least one end in the longitudinal direction of the fluorescent lamp or the cold cathode tube. Is provided.

According to the backlight device of this aspect, a linear fluorescent lamp or a cold cathode tube is used as a light source, and a convection fan is disposed at at least one end in the longitudinal direction of the fluorescent lamp or the cold cathode tube. Therefore, the air blown from the convection fan flows in contact with substantially the entire surface of the fluorescent lamp. Therefore, the fluorescent lamp or the cold cathode tube can be efficiently cooled.

Further, when a convection fan is disposed at both ends of the fluorescent lamp or the cold cathode tube and the convection fan is rotated so as to generate air in the same direction, a ventilation circulation path in the same direction is formed in the sealed container. . Therefore, the air cooled by the heat sink is blown to the fluorescent lamp or the cold cathode line side, the heat of the fluorescent lamp surface is taken away by this blow, and the air warmed by this heat is blown to the heat sink and radiated from the radiation fins. . Thus, since the cooling of the heat sink of the blown air and the heating cycle on the fluorescent lamp or cold cathode tube side are repeated, the fluorescent lamp or the cold cathode tube is efficiently cooled, so that the temperature rise in the sealed container is reduced. Can be suppressed.

Further, the backlight device of the present invention is the above backlight device, wherein the heat sink includes a fixed portion having a predetermined area, and a plurality of radiating fins protruding from the fixed portion with a predetermined interval, It is characterized by being formed of a material having good thermal conductivity.

According to the backlight device of this aspect, the heat sink is formed of a material having good thermal conductivity, which includes a fixed portion having a predetermined area and a plurality of heat radiation fins protruding from the fixed portion in one direction with a predetermined length. The heat conducted from the fixed part can be efficiently dissipated by the plurality of heat dissipating fins.

In the backlight device according to the present invention, in the backlight device, the heat sink extends between the plurality of radiating fins by extending the plurality of radiating fins by a predetermined length, and is adjacent to the radiating fins in the middle of the extended plurality of radiating fins. Are connected to each other by a partition portion, and the outer periphery of the partition portion is extended to be a flange portion, and the flange portion of the heat sink is airtightly fixed to an opening provided in the sealed container. Features.

According to the backlight device of this aspect, the heat radiation area is increased because the plurality of heat radiation fins are extended for a predetermined length, and the flange portion is provided in the partition portion, so that it can be easily fixed to the sealed container. Become.

The display device of the present invention is characterized in that a display panel is mounted on the light transmission window of any one of the backlight devices.

According to the display device of this aspect, since the backlight device used in this display device has the above-described effects, it can be applied to various display devices, particularly multi-layer display devices that require high-intensity irradiation. Brightness can be displayed on the screen.

Hereinafter, the best embodiment of the present invention will be described with reference to the drawings. However, the embodiment shown below is a backlight device for embodying the technical idea of the present invention, and a display device provided with the backlight device, and a three-dimensional video display device or a two-screen video display device, and is used for this. And is not intended to limit the invention to these, and other embodiments within the scope of the claims are equally applicable. .

FIG. 1 is a schematic cross-sectional view of a three-dimensional video display device including the backlight device according to the first embodiment. FIG. 2 is a plan view of the backlight device. 3 is a cross-sectional view taken along line X ₁ -X ₁ of FIG. FIG. 4 is a cross-sectional view of the heat sink cut along line X ₂ -X ₂ in FIG. FIG. 5 is a schematic cross-sectional view of a two-screen video display device provided with the backlight device of the second embodiment.

First, with reference to FIG. 1, an outline of a three-dimensional video display device including the backlight device according to the first embodiment will be described.

The three-dimensional image display device 1 includes a polarizing plate 8, a barrier cell 2 made of a transmissive liquid crystal element that electronically generates a parallax barrier, a spacer glass 7, a liquid crystal image display cell 9, and a polarizing plate 14. And a backlight device 15 that irradiates a liquid crystal image display cell or the like.

The barrier cell 2 is configured by sequentially stacking an upper glass substrate 2A, a common electrode 3, a spacer 4, a liquid crystal layer 5, a pixel electrode 6, and a lower glass plate 2B. When three-dimensional display is performed by the barrier cell 2, a voltage is selectively applied between the electrodes 3 and 6 to change the orientation of the liquid crystal molecules in the liquid crystal layer 5 to generate a barrier having an arbitrary shape. The voltage application control is obtained by an electronic circuit such as a microcomputer. When displaying 2D images, stop the generation of barriers,
The entire video display area is controlled to be colorless and transparent.

A spacer glass 7 may be disposed between the barrier cell 2 and the liquid crystal image display cell 9, or an air layer may be provided between the barrier cell 2 and the liquid crystal image display cell 9. The spacer glass 7 is used to adjust the distance between the liquid crystal image display cell 9 and the barrier cell 2 and may not be used depending on the size of the three-dimensional image display device 1. The liquid crystal image display cell 9 is configured by arranging an upper glass substrate 9A, a common electrode 10, a spacer 11, a liquid crystal 12, and a lower glass substrate 9B having pixel electrodes 13 in this order.
A predetermined distance is placed behind the spacer glass 7. In the liquid crystal image display cell 9, an image for the right eye and an image for the left eye are alternately displayed corresponding to the barrier generated by the barrier cell 2 during the 3D video display. A backlight device 15 is provided behind the polarizing plate 14. Illumination light from the backlight device is transmitted through the liquid crystal image display cell 9, and the image light is guided to the left and right eyes of the observer to provide a stereoscopic image. The

  Next, the configurations of the backlight device and the heat sink will be described with reference to FIGS.

The backlight device 15 includes a plurality of, for example, a light source consisting of six cold cathode tubes ₁₇ 1-17 _6, a lamp housing 18 that accommodates these cold cathode tubes ₁₇ 1-17 _6, the back cover of the housing A heat sink 19 that radiates heat generated inside the housing case to the outside and a pair of convection fans 20 _A and 20 _B that convect the air in the sealed container 16, and these members are contained in the sealed container 16. It is configured to be housed and sealed and shielded from outside air. The cold cathode tubes 17 _{1 to} 17 ₆ as light sources are each composed of a long thin tube, and known ones are used.

The heat sink 19 includes a fixed portion 19 _A to be fixed to the back cover of the lamp housing 18, and a heat radiating portion 19 _B that protrude from one surface of the fixed portion, having good thermal conductivity material, e.g., aluminum or It is made of an aluminum alloy or the like.

Fixing portion 19 _A is formed in a plate-like body having a predetermined area and thickness so as to be fixed in contact with the flat surface of the lamp housing 18 the back cover. Radiating portion 19 _B is made of a flat radiating fins 19 ₁ ~ 19 _n of a plurality of hanging down perpendicularly from one surface of the fixed portion, these radiating fins are substantially equally spaced fixing portion 19 _A at substantially the same length are parallel bristled fixed at a clearance 19 _0. This gap 19 ₀ represents the distance that wind is blown. Each radiating fin 19 ₁
~19n is relatively long extended, are separated by connecting the gaps of the fins adjacent to the substantially middle portion in the longitudinal direction, the partitioned portion is in the partition portion 19 _C.

The partition portion 19 _C, the outer periphery is extended to the slightly outward flange portion 19 _D is formed. This flange portion 19 </ b> _D serves as a fixing portion to the sealed container 16. Radiation fin 19
_{1 to} 19 _n are provided with a partition portion 19 _{C in the} middle to partition the partition portion 19 _C.
The upper and lower air blowing paths B ₁ and B ₂ are formed between the radiation fins 19 _{1 to} 19 n with the boundary as a boundary.
Upper air passage B ₁ represents becomes a blowing path through the air in the vessel be in the closed vessel 16 to be described later, also, the air blowing path B ₂ The lower, in the outside of the sealed container 16, exposed to the air It becomes a ventilation path.

Next, with reference to FIG.2 and FIG.3, the structure of the airtight container 16 is demonstrated. The sealed container 16 is constituted by a main body case 16A having an opening 16 ₀ upwards, a lid 16B made of a light transmissive material for closing the opening portion of the main body case. The main body case 16A is formed of a metal material, a synthetic resin, or a molded body of these composite materials. The lid 16B is made of a glass material.

The main body case 16A includes, for example, six cold cathode tubes 17 _{1 to} 17 ₆ , a lamp housing 18,
It has a size that can accommodate the heat sink 19 and the two convection fans 20 _A and 20 _B. The main body case 16A is provided with spaces S ₁ and S _{2 in} which convection fans 20 _A and 20 _B are disposed at both ends in the longitudinal direction. Further, the cold cathode tubes ₁₇ 1-17 ₆ is accommodated in the lamp housing 18 is disposed at a substantially central portion of the body case 16A. The body case 16A is closed and the bottom plate portion 16 ₁ of the rectangle having a predetermined width dimension and length, a side plate portion 16 _{2-16 5} by a predetermined height vertically arranged in the same direction from the outer periphery of the bottom plate, the and, upward it is formed in the box-shaped body of shallow that the opening 16 ₀ that is open.

Opening 16 ₀ of the body case 16A can be relatively large opening, the display panel with light emitted is in the monkey light transmission window irradiation through the opening. The main body case 16A is provided with support means for fixing the lamp housing 18 in which the cold cathode tubes 17 _{1 to} 17 ₆ are accommodated. Although illustration of the support means is omitted, these support means are fixed to the side wall of the case using a known member using a fixing means such as a screw.

Further, a substantially central portion of the bottom plate portion 16 ₁ of the main body case 16A, the bottom opening 16a for mounting the heat sink 19 is formed. The main body case 16A has cold cathode tubes 17 ₁ to 17 ₁ inside.
17 _6, after the storage such as a lamp housing 18 and heat sink 19, the openings 16 ₀
Is covered with a glass plate of the lid 16B, and the inside is shut off from the outside air and sealed. Lid 16B is formed of a glass plate having a size to close the opening 16 ₀ of the body case 16A.

Next, an example of an assembly process of the backlight device 15 and a cooling method in the sealed container 16 will be described. First, the heat sink 19 is assembled and fixed to the main body case 16A. Fixing of the heat sink 19, by inserting the heat radiation portion 19 _B of the heat sink 19 to the bottom opening 16a of the body case 16A, sticking of known flange portion 19 _D provided on the heat radiating fins ₁₉ 1 ～19N of the heat radiating portion to the opening peripheral edge Use a means to seal tightly. At this time, each radiation fin 19 _{1 to} 19n
They are each fin gaps 19 ₀ fixed so as to coincide with the longitudinal direction of the long cold cathode tubes ₁₇ 1-17 _6.

The main body case 16A includes convection fans 20 _A , 2, respectively, in the vicinity of opposite side wall surfaces.
0 _B is fixed. Thereafter, previously housed a plurality of elongated cold cathode tubes ₁₇ 1-17 ₆ the lamp housing 18 in the body case 16A, the lamp housing 18 the body case 16A
Secure to. At this time, each elongated cooling both ends of the cathode tubes ₁₇ 1-17 ₆ and the convection fan ₂₀ A,
20 _B is accommodated so as to face.

During accommodation of the lamp housing 18, it is fixed by contacting the fixing portion 19 _A of the heat sink 19 on the back cover of the lamp housing 18. Thereafter, an opening 16 ₀ of the body case 16A fixed closed with a lid member 16B made of a glass plate, to cut off the sealed inside and outside air. This sealed container 1
6, lead wires connected to the cold cathode tubes 17 _{1 to} 17 ₆ and the convection fans 20 _A and 20 _B are led out, and this lead-out portion is also hermetically sealed using a known sealing member. With such a configuration, a thin backlight device 15 can be obtained.

It should be noted that the airtight container only needs to prevent outside air from entering the inside, and does not necessarily need to be completely shut off from the outside air to be airtight.

The assembled backlight device 15 is used as the three-dimensional image display device 1 (see FIG. 1) by placing and fixing the liquid crystal image display cell 9 on the lid body 16B forming the light transmission window of the sealed container 16. . The backlight device 15 attached to the three-dimensional image display device 1 rotates the convection fans 20 _A and 20 _B in one direction by a drive motor (not shown) when the display device is used. By this rotation of the fan, within the sealed container 16, for example, the circulation path of the air indicated by the arrow W ₁ in FIG. 3 is formed.

In this circulation path, air flowing upward from the lamp housing 18 with the lamp housing 18 as a boundary contacts the individual cold cathode tubes 17 _{1 to} 17 ₆ , and heat H generated from the lamp is taken away by this air. . The air warmed by this heat flows to the back side of the lamp housing 18, and when it passes through the gaps between the heat radiation fins 19 _{1 to} 19 n of the heat sink 19, heat is taken away to become cold air, and again the lamp housing 18. To each of the cold cathode tubes 17 ₁ again.
The to 17 ₆ to cool. Thereafter, it is continued similar cycle, heat generated in the cold cathode tubes 17 _{1-17 6} is radiated to the outside through the heat sink 19.

The heat sink 19, because the fixing portion 19 _A is fixed to the back cover of the lamp housing 18, heat generated from the cold cathode tube is the heat radiation is conducted to the heat sink 19 by thermal conduction through the back cover . The heat sink 19 can efficiently dissipate heat in the upper and lower air passages B ₁ and B ₂ , and can prevent the temperature inside the sealed container 16 from rising.

Therefore, according to the backlight device 15 of the embodiment, the light source comprising a cold cathode tubes 17 _{1-17 6,} and isolated from the atmosphere by accommodating the heat sink 19 to the sealed container 16, the outside air through such vent into the closed vessel 16 Therefore, the heat generated in the sealed container 16 can be efficiently cooled by the heat sink, and the temperature rise in the sealed container 16 can be prevented. The sealed container 16
Inner, since it is isolated from the atmosphere, dust from outside the closed container 16, without the like from entering the smoke dust or tobacco, never light source made of the cold cathode tubes 17 _{1-17 6} is contaminated Therefore, it is possible to prevent functional degradation due to contamination of the light source.

Next, with reference to FIG. 5, an outline of a two-screen video display device 1A including a backlight device according to the second embodiment of the present invention will be described. In FIG. 5, the configuration of the backlight device 15 is the same as that of the backlight device 15 in the 3D video display device 1 of the first embodiment, and thus detailed description thereof is omitted.

The two-screen video display device 1A includes a polarizing plate 8, a first transmissive liquid crystal display element 9a, and a second
The transmissive liquid crystal display element 9b, the polarizing plate 14, and the backlight device 15 are provided.
A moire countermeasure sheet 25 is disposed between the first transmissive liquid crystal display element 9a and the second transmissive liquid crystal display element 9b.

The first transmissive liquid crystal display element 9a and the second transmissive liquid crystal display element 9b have substantially the same configuration, and both can display different images. The first transmissive liquid crystal display element 9a and the second transmissive liquid crystal display element 9b are:
Both have substantially the same configuration as the transmissive liquid crystal display element 9 of the first embodiment. Therefore, in FIG. 5, the same reference numerals are given to the same components as those of the transmissive liquid crystal display element 9 of the first embodiment, and the subscript “a” is added to the first transmissive liquid crystal display element 9a. "Is attached to the second transmissive liquid crystal display element 9b, and the detailed description thereof is omitted.

The two-screen video display device 1A displays a front image by the first transmissive liquid crystal display element 9a, displays a rear image by the second transmissive liquid crystal display element 9b, and displays a pseudo three-dimensional display. It is. Therefore, the stereoscopic effect is inferior to the 3D image display device 1 of the first embodiment, but the stereoscopic effect changes depending on the distance between the observer and the display screen as in the 3D image display device 1 of the first embodiment. This is no longer the case. This two-screen video display device 1A is used, for example, in a ball game machine.

In such a two-screen image display device 1A, the first transmissive liquid crystal display element 9a and the second transmissive liquid crystal display element 9b use liquid crystal display elements for color display. Therefore, the first
The transmission factor of the transmissive liquid crystal display element 9a is the same as that of Example 1 for generating a simple black-and-white barrier.
Compared with the barrier cell 2 used in the three-dimensional image display apparatus 1 of FIG. Therefore, in the two-screen video display device 1A, the moire countermeasure sheet 25 may be used, and the two-screen video display device 1A has a higher brightness than the backlight used in the three-dimensional video display device 1 of the first embodiment. Needed.

Therefore, according to the screen display device 1A of the second embodiment, even if the backlight device 15 has a high luminance, it is unlikely to reach a high temperature. Therefore, the first transmission type liquid crystal display element 9a and the second transmission type are used. A high-luminance screen can be displayed without adversely affecting the liquid crystal display element 9b.

The present invention is not limited to the backlight device and the display device shown in this embodiment, and can be modified as appropriate. For example, the light source is not limited to the cold cathode tube, and may be another light source, for example, a fluorescent lamp or a light emitting diode. A reflective member may be used instead of the lamp housing, and a heat sink may be fixed to the reflective member. Furthermore, the display panel can use other display panels instead of the liquid crystal panel.

3 is a schematic cross-sectional view of a three-dimensional video display device including a backlight device according to an embodiment of Example 1. FIG. It is a top view of a backlight apparatus. It is a cross-sectional view of the _X 1 -X ₁ line in FIG. It is a cross-sectional view of the cut heat sink _X 2 -X ₂ line in FIG. 6 is a schematic cross-sectional view of a two-screen image display device including the backlight device of Example 2. FIG. It is sectional drawing of the liquid crystal display device of a prior art.

Explanation of symbols

1: three-dimensional image display device 1A: two-screen display device 2: barrier cell 5: liquid crystal layer 7: spacer glass 8: polarizing plate 9, 9a, 9b: liquid crystal image display cell 14: polarizing plate 15
: Backlight device 16: Airtight container 16A: Main body case 16B: Lid 17 _{1 -1}
7 ₆ : Cold cathode tube (light source) 18: Lamp housing (housing) 19: Heat sink 19
_A : Fixed part 19 _B : Heat radiating part 19 _{1 to} 19 n: Radiating fin 19 c: Partition part 19 _D
: Flange 20 _A , 20 _B : Convection fan 25: Moire countermeasure sheet

Claims (7)

In a backlight device comprising a light source and a housing case that houses the light source,
The housing case is formed of a light-transmitting window on one side surface and a sealed container provided with a predetermined volume space therein, and the light source, a heat sink that radiates heat generated from the light source, and the sealed container The backlight device is characterized in that a convection fan for convection of the air is housed, a heat radiating portion of the heat sink is exposed to the outside of the sealed container, and the inside of the sealed container is blocked from outside air. The backlight device according to claim 1, wherein the light source is surrounded by a casing, and the heat sink is fixed to the casing. The backlight device according to claim 1, wherein the sealed container includes a reflective member disposed below the light source, and the heat sink is fixed to the reflective member. 2. The light source includes a linear fluorescent lamp or a cold cathode tube, and a convection fan is disposed at at least one end in the longitudinal direction of the fluorescent lamp or the cold cathode tube.
The backlight apparatus in any one of -3. The heat sink has a fixed part having a predetermined area and a plurality of heat radiation fins protruding at a predetermined interval from the fixed part, and is formed of a material having good thermal conductivity. The backlight device according to claim 1. The heat sink includes a plurality of radiating fins extending a predetermined length, connecting adjacent radiating fins in the middle of the extended radiating fins with a partition portion, and extending an outer periphery of the partition portion. 6. The backlight device according to claim 5, further comprising a flange portion, wherein the flange portion of the heat sink is airtightly fixed to an opening provided in the sealed container. A display device, wherein a display panel is mounted on the light transmission window of the backlight device according to claim 1.

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