JP2008293818A - 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 and a display device having the same backlight unit. <P>SOLUTION: The backlight unit 15 has the light source, a reflecting member for making light of the light source reflect in a designated direction, and a storage case for storing the light source and the reflecting member. The storage case is formed by a light-transmitting window at one side, and an airtight container 16 where a space with a designated capacity is arrange in its inside, and stores the light sources 17<SB>1</SB>-17<SB>6</SB>, the reflecting member 18, and a cooling piping 19 in the airtight container. The inside of the airtight container is intercepted from the open air by exposing a supplying and discharge section of the cooling piping 19 to the outside of the airtight container. <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. In addition, since the intake and exhaust openings are always open, dust, dust, or cigarette smoke enters through the openings, and these adhere to the backlight light source and the like to reduce the brightness. May enter and cause malfunctions.

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, cigarette smoke, water, and the like are brought together, 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 of the present invention includes a light source composed of a cold cathode tube or a fluorescent lamp, a reflecting member that reflects light from the light source in a predetermined direction, and a housing that houses the light source and the reflecting member. And a storage device, wherein the housing case is formed of a light-transmitting window on one side and a sealed container having a space of a predetermined volume therein, and the cooling pipe, the light source, and the reflection are formed in the sealed container. The member is housed, and at least one end of the cooling pipe is led out of the sealed container and connected to a cooling means, so that the inside of the sealed container is shut off from outside air.

According to the backlight device of this aspect, the light source, the reflection member, and the cooling pipe are accommodated in the sealed container to block the inside of the container from the outside air, and at least one end of the cooling pipe is led out of the sealed container to be cooled. Since it is connected to the means, it is possible to radiate the heat generated in the sealed container to the outside without blowing the outside air through the vent or the like, thereby suppressing the temperature rise inside. Further, 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, in the backlight device, the light source and the reflection member are disposed in this order in the sealed container below the light transmission window, and below the reflection member. The cooling pipe is provided.

According to the backlight device of this aspect, by disposing the cooling pipe below the reflecting member, the light from the light source is reflected and effectively used, and the heat generated from the light source disposed above the reflecting member. Can be absorbed by the cooling pipe and radiated to the outside.

In the backlight device of the present invention, in the backlight device described above, the reflecting member is formed in a corrugated shape in which a top portion and a bottom portion alternately appear at a predetermined interval, and is formed between adjacent top portions of the corrugated shape. The light source in a recess, the cooling pipe in the space opposite the top,
It is characterized by being arranged respectively.

According to the backlight device of this aspect, the light from the cold cathode fluorescent lamp or the fluorescent lamp is efficiently reflected from the side wall surface that forms the depression, and there is a wave-shaped top between the adjacent cold cathode fluorescent lamps or fluorescent lamps. Since the light reflected from the vicinity of this top part is irradiated, the vicinity of this top part does not become darker than other parts. That is, the location where the cold cathode fluorescent lamp or the fluorescent lamp exists and the vicinity of the top of the reflecting member have substantially the same luminance, and the lamp image phenomenon in which the vicinity of the top becomes dark does not occur. Further, since the cooling pipe is close to the cold cathode tube or the fluorescent lamp, the heat from the cold cathode tube or the fluorescent lamp can be efficiently absorbed and radiated.

In the backlight device according to the present invention, the cooling pipe is a heat pipe.

According to the backlight device of this aspect, since the heat pipe is a tubular member that is known to have very good thermal conductivity, a movable member such as a pump is provided, or a ventilation hole is provided in the sealed container. Even if the outside air is not blown through, the heat from the light source can be favorably absorbed and radiated to the outside.

Further, in the backlight device according to the present invention, in the backlight device, the cooling pipe is a hollow pipe through which a cooling medium is circulated, and both ends of the hollow pipe are connected to the pump and the cooling means outside the sealed container. It is characterized by being connected to each other.

According to the backlight device of this aspect, the temperature of the sealed chamber is increased by supplying the cooling medium from the outside of the sealed container to the refrigerant pipe without blowing the outside air through the ventilation hole or the like into the sealed container. Can be suppressed.

In the backlight device according to the present invention, the cooling medium is any one of water, air, and an organic solvent.

According to the backlight device of this aspect, by using water, air, an organic solvent, or the like as the cooling medium, cooling in the sealed chamber corresponding to the characteristics of each medium can be performed.

In the backlight device of the present invention, the cooling means is a heat sink or a combination of a heat sink and a forced cooling means.

According to the backlight device of this aspect, the cooling effect by the cooling means can be dramatically increased.

In the backlight device according to the present invention, the cooling pipe is arranged in parallel to the light source.

According to the backlight device of this aspect, the arrangement direction of the cooling pipe is arranged so as to be parallel to the light source such as the cold cathode tube or the fluorescent lamp, so that the convection of the air around the light source is not disturbed. This improves the cooling effect. At this time, if an air circulation fan is arranged in the backlight device, the cooling efficiency is further improved.

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

According to the display device of this aspect, the backlight device used in the display device has the above-described effects. Therefore, even when 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 XX of FIG. FIG. 4 is a piping diagram showing a refrigerant circulation path of the cooling pipe. 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 the liquid crystal image display cell 9 and 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 configuration of the backlight device will be described with reference to FIGS.

The backlight device 15 includes a light source 17 including a plurality of, for example, six cold cathode tubes 17 _{1 to} 17 ₆ , a reflecting member 18 that reflects light from these cold cathode tubes 17 _{1 to} 17 ₆ upward, A cooling pipe 1 that is disposed below the reflecting member and cools heat generated from the cold cathode tubes 17 _{1 to} 17 _6.
9. The cold cathode tubes 17 _{1 to} 17 ₆ , the reflecting member 18, and the cooling pipe 19 are housed in the sealed container 16 and are blocked from the outside air. Cold cathode tube 17
Light source 17 consisting of _{1-17 6} is the respective elongated tubular shaped, known are used.

The reflection member 18 is formed of a folded body obtained by folding a plate-like body whose surface is a reflection surface into a bellows shape. That is, this folding body has a width substantially the same as or slightly longer than the lengths of the cold cathode tubes 17 _{1 to} 17 ₆ , and a plate-like body having a predetermined length with a predetermined unit width length L from one end in the longitudinal direction. Folded in a bellows shape. The folded body has a top portion 18 ₁ and a bottom portion 18 ₂ by folding, and the entire shape is formed in a corrugated shape. The unit width length L is determined by the cold cathode tubes 17 _{1 to} 17 ₆ and the cooling pipe 1.
The cold cathode fluorescent lamps 17 ₁ to 17 ₁ are formed in substantially V-shaped grooves formed to be longer than the diameter of 9 and folded at respective widths L.
17 ₆ is adapted to position. By positioning the cold cathode tubes 17 _{1 to} 17 ₆ in the V-shaped grooves, the light emitted from the cold cathode tubes 17 _{1 to} 17 ₆ is efficiently reflected from the reflecting surface of the reflecting member and irradiated to the outside. Is done.

Since the wave-shaped top portion 18 ₁ is located between the adjacent cold cathode tubes 17 _{1 to} 17 _{6 and} the reflected light is irradiated from the vicinity of the top portion, the vicinity of the top portion does not become darker than the other portions. That is,
The location where the cold cathode tubes 17 _{1 to} 17 ₆ exist and the vicinity of the top of the reflecting member have substantially the same luminance, and the lamp image phenomenon in which the vicinity of the top becomes dark does not occur. The cooling pipe 19 is positioned in the lower part of the top portion 18 ₁ of the corrugated. That is, each of the cold cathode tubes 17 _{1 to} 17 ₆ and the cooling pipe 1
9 is a shape arranged substantially in parallel. Thereby, the wave-shaped top part 18 of the reflecting member 18 is obtained.
_The area where the inner wall surface of ₁ and the cooling pipe contact or face each other is increased, and the reflecting member 18 can be efficiently cooled. Further, an air circulation fan (not shown) is provided in the backlight device 15.
The cooling efficiency is further improved by arranging

The reflecting member 18 is made of a synthetic resin plate, a metal plate, or a composite plate thereof, and includes a cold cathode tube 17 ₁ to 17 _1- .
17 ₆ is the reflecting surface is formed on a surface disposed. For example, the reflective surface is coated with white paint,
It is formed by sticking a white polyester film or aluminum vapor deposition. This reflecting member 18
The good thermal conductivity metal, for example, using aluminum or aluminum alloy, the heat from the cold cathode tubes 17 _{1-17 6} the efficiency to better conducted to the cooling pipe 19 via the good thermal conductivity of the reflecting member 18 be able to.

The cooling pipe 19 is a long pipe having a hollow inside, and is formed of a material having good thermal conductivity, for example, a copper pipe or an aluminum pipe. The cooling pipe 19 is bent to reflect the reflecting member 18.
The end portion is exposed to the outside of the sealed container 16. The exposed end portions are a cooling medium feeding unit 20A and a discharging unit 20B. That is, the cooling pipe 19 is
Figure 4 As shown in, reflected is bent as corrugated disposed below the top 18 ₁ of the member 18, the pump P to the feeding portion 20A, the cooling means 21 is piping to the discharge unit 20B L ₁ , L ₂ . This loop constitutes a circulation path. As the cooling medium, any cooling medium such as water, air, and other organic solvents is used.

As the cooling means 21, a simple heat sink alone can be provided with sufficient heat dissipation capability if the heat dissipation area is increased. If the outside air is forcibly blown onto the heat sink, the cooling efficiency is further improved. Furthermore, the heat radiation efficiency can be further improved by combining other forced cooling means, for example, a thermo module such as a Peltier element.

Closed container 16 is composed of 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. Opening 16 ₀ of the body case 16A is covered with a lid made of glass material, and has a light transmitting window. The main body case 16A includes six cold cathode tubes 17 _{1 to} 17 _6.
The reflecting member 18 and the cooling pipe 19 can be accommodated. This body case 16
A has a 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 upright from the outer periphery in the same direction of the bottom plate portion, the upper Opens and opens 16
It is formed of a shallow box-shaped body with _zero .

The main body case 16A is provided with support means (not shown) for supporting the cold cathode tubes 17 _{1 to} 17 ₆ , the reflecting member 18 and the cooling pipe 19. Also, the main body case 16
In A, a feeding portion 20A and a discharge portion 20B to the cooling pipe 19 are projected. The sealed container 16, the cold cathode tubes ₁₇ 1-17 ₆ to the main body case 16A, after accommodating the reflective member and the coolant tube, covers the opening 16 ₀ of the main body case with a glass plate of the cover 16B, inside the outside air And shut off.

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.

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 cooling pipe 19 bent into a predetermined shape is disposed in the main body case 16 </ b> A, and the reflecting member 18 is disposed on the cooling pipe 19. In this case, it is located between the respective bottoms 18 ₂ of the reflecting member 18 of each cooling pipe ₁₉ 1-19 _5. Cooling pipe 19 and reflecting member 18
Is fixed to the main body case 16A by a fixing means (not shown). Thereafter, the reflective bottom of the member 18, i.e., folded by arranging cold cathode tubes ₁₇ 1-17 ₆ in each of the bottom corrugated, the cold cathode tubes ₁₇ 1-17 ₆ not shown fixing means To fix the main body case 16A.

Finally, an opening 16 ₀ of the body case 16A is sealed covered with lid 16B made of a glass plate, to cut off the inner container and the outside air. In addition, from this airtight container 16, each cold-cathode tube 17 _{1 -1}
7 ₆ feeding portion 20A and the discharge section 20B of the connected leads and cooling pipe 19 is derived, but hermetically sealed using known sealing means also those deriving unit. With such a configuration, a thin backlight device 15 can be obtained. The assembled backlight device 15
The liquid crystal image display cell 9 is placed and fixed on a lid 16B that forms a light transmission window of the sealed container 16, and is used as the three-dimensional image display device 1 (see FIG. 1).

The backlight device 15 includes a light source 17 made from the cold cathode tubes ₁₇ 1-17 _6, the reflecting member 1
8 and the cooling pipe 19 are housed in the sealed container 16 and shut off from the outside air, so that the cooling medium is supplied from the outside of the sealed container 16 to the cooling pipe 19 to cool the heat generated in the sealed container 16 to a temperature. The rise can be prevented. Further, the sealed container 16, because it is isolated from the atmosphere, from the outer sealed container 16 dust, without such from entering the smoke dust or tobacco, such as the light source 17 made from the cold cathode tubes 17 _{1-17 6} The member is not contaminated, and function deterioration due to contamination can be suppressed.
Further, since the cooling pipe 19 is disposed below the reflecting member 18, heat generated from the light source disposed above the reflecting member 18 can be efficiently cooled.

Further, the reflecting member 18 is formed into a corrugated shape in which the top portion 18 ₁ and the bottom portion 18 ₂ alternately appear at a predetermined interval, and a cold cathode tube is formed in a recess formed between the adjacent top portions 18 _{1 of the} corrugated shape. 17 ₁
Having disposed -17 _6, light from the cold cathode tubes ₁₇ 1 to 17 ₆ is efficiently reflected from the side wall surface to form a recess. In addition, a wave-shaped top portion 18 ₁ between adjacent cold-cathode tubes 17 _{1 to} 17 ₆ is used.
There Due to the position, because the light reflected on the reflecting member is emitted from the top 18 near _1, never near the top portion becomes darker than the other portions. That is, the cold cathode tubes 17 ₁ to 1
7 ₆ substantially the same brightness as the position of presence and near the top ₁₈₁ of the reflecting member 18, a top 18 ₁
There is no longer a lamp image phenomenon that darkens the vicinity.

The cooling pipe 19, because it is disposed in a space formed on the opposite side of the top portion 18 ₁ of the reflecting member 18, is close to the cold cathode tubes 17 _{1-17 6,} the cold cathode tubes 17 _{1-17 6}
Can efficiently absorb and dissipate heat.

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 image display device 1A, the moire countermeasure sheet 25 may be used, and a higher brightness than the backlight used in the three-dimensional image display device of Example 1 is required. It is said.

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 a cold cathode tube, and may be another light source, for example, a fluorescent lamp or a light emitting diode, and a heat pipe may be used as the cooling pipe 19. In particular, when a heat pipe is used as the cooling pipe 19, the heat pipe is a tubular member known to have a very good thermal conductivity. Can be played. Further, as the display panel, another display panel can be used instead of the liquid crystal panel.

1 is a schematic cross-sectional view of a three-dimensional video display device that includes the backlight device of Example 1. FIG. It is a top view of a backlight apparatus. It is sectional drawing of the XX line of FIG. It is the piping figure which showed the circulation path of the refrigerant | coolant of cooling piping. 6 is a schematic cross-sectional view of a two-screen video display device that includes the backlight device of Embodiment 2. FIG. It is principal part sectional drawing of the liquid crystal display device of a prior art.

Explanation of symbols

1: 3D image display device 1A: 2 screen image 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
-17 ₆ : Cold cathode tube (light source) 18: Reflective member 18 ₁ : Top portion 18 ₂ : Bottom portion 19: Cooling piping 20A: Feeding portion 20B: Discharge portion 21: Cooling means 25: Moire countermeasure sheet P: Pump

Claims (9)

In a backlight device comprising a light source composed of a cold cathode tube or a fluorescent lamp, a reflecting member that reflects light from the light source in a predetermined direction, and a housing case that houses the light source and the reflecting member,
The housing case is formed of a light-transmitting window on one side surface and a sealed container having a space of a predetermined volume therein, and houses the cooling pipe, the light source, and the reflecting member in the sealed container, and includes at least the cooling pipe. A backlight device characterized in that one end is led out of the sealed container and connected to a cooling means, and the inside of the sealed container is shut off from outside air. 2. The sealed container according to claim 1, wherein the light source and the reflection member are arranged in this order below the light transmission window, and the cooling pipe is arranged below the reflection member. The backlight device described. The reflection member is formed in a corrugated shape in which a top portion and a bottom portion alternately appear at a predetermined interval, and the light source is placed in a recess formed between adjacent top portions of the corrugation, and a space opposite to the top portion. The backlight device according to claim 1, wherein the cooling pipes are respectively arranged in the interior. The backlight device according to claim 1, wherein the cooling pipe is a heat pipe. The said cooling piping consists of hollow piping with which a cooling medium distribute | circulates inside, The both ends of the said hollow piping were mutually connected outside the said airtight container via the pump and the said cooling means. The backlight apparatus in any one. The backlight device according to claim 5, wherein the cooling medium is water, air, or an organic solvent. The backlight device according to claim 1, wherein the cooling unit is a heat sink or a combination of a heat sink and a forced cooling unit. The backlight device according to claim 1, wherein the cooling pipe is arranged in parallel with the light source. 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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