JPH0843785A - Liquid crystal projector - Google Patents

Abstract

PURPOSE:To efficiently cool a liquid crystal display element and a light source. CONSTITUTION:In a single plate type liquid crystal projector 1; a suction port 31 and an exhaust port 39 for cooling air are formed in an equipment case 2, and a fan 33 for generating the cooling air is provided in the case 2. An air current path 30 leading to the exhaust port 39 from the suction port 31 through a liquid crystal display panel 12 and a light source 6 is formed in the case 2, and further a cooling air division means 40 dividing the cooling air at least to the display panel 12 side and the light source 6 side in the path 30 is installed. The division means 40 is a cooling air separation plate arranged nearly parallel with the display panel 12 between the display panel 12 and the light source 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector, and more particularly to a cooling structure for a liquid crystal projector such as a liquid crystal projection television.

[0002]

2. Description of the Related Art Light from one light source is converted into an R (red) component,
The light is decomposed into three lights of G (green) component and B (blue) component, and the corresponding three liquid crystal display panels are irradiated, and each of the liquid crystal display panels is decomposed into three colors of R, G, and B and displayed. There is a three-plate type liquid crystal projector in which a color image such as a television image thus generated is combined by reflection and transmission and enlarged and projected on a screen by one projection lens. There is also a single-plate type liquid crystal projector using one liquid crystal display panel with a color filter.

Then, in the display window on the front surface of the case containing the light source, the liquid crystal display panel, the projection lens and the reflection mirror, there is provided the rear screen provided with the transmissive screen for enlarging and displaying the image displayed by the liquid crystal display panel by the projection lens. There is a liquid crystal projection television as a projection type projector device. Here, in a rear projection type projector device including such a liquid crystal projection television, a reflection mirror is arranged in a case so as to be oblique, and the image light passing through the projection lens is reflected by the reflection mirror to display a screen. Since the projection distance is enlarged and the linear distance between the screen and the projection lens can be shortened, the device becomes thin.

In the liquid crystal projector as described above,
Conventionally, a liquid crystal display element and a light source are cooled by providing a device case or a fan in the device case to suck the outside air into the device case or exhaust the air in the device case.

[0005]

However, as in the prior art, if a fan is used to simply suck the outside air into the equipment case or discharge the air inside the case, the fan cannot be operated. There was a problem that the liquid crystal display element and the light source were not cooled well, despite the ability.
This is because the inhaled outside air diffuses inside the case,
This is because sufficient cooling air does not reach the target point, and as a result, the liquid crystal display element and the light source cannot be cooled well.

An object of the present invention is to efficiently cool a liquid crystal display element and a light source in a liquid crystal projector.

[0007]

In order to solve the above problems, the present invention provides a liquid crystal display panel for displaying an image, a light source for irradiating the liquid crystal display panel with light, and an image displayed on the liquid crystal display panel. In a liquid crystal projector that houses a projection lens that projects light on the screen,
Forming an inlet and an outlet for cooling air in the equipment case,
A fan for generating cooling air is provided in the equipment case,
An air flow path from the suction port to at least the liquid crystal display panel and the light source to the discharge port is formed in the device case, and the cooling air flows to at least the liquid crystal display panel side in the air flow path. The structure is characterized in that a cooling air dividing means is provided separately from the light source side.

The above liquid crystal projector is, for example, a single-plate type liquid crystal projector, and the cooling air dividing means is, for example, substantially parallel to the liquid crystal display panel between the liquid crystal display panel and the light source. It is a cooling air separation plate arranged in.

Further, in the liquid crystal projector according to claim 1 or 2, the liquid crystal display panel is exposed to the inside of the air flow passage, for example, protruding to one surface side of a liquid crystal display module including a shield case. It also features a configuration.

[0010]

According to the present invention, in the device case of the liquid crystal projector, the cooling air generated by the fan is cooled by the cooling air dividing means in the air flow passage extending from the suction port to at least the liquid crystal display panel and the light source to the discharge port. Since at least the liquid crystal display panel side and the light source side are divided, the liquid crystal display element and the light source can be efficiently cooled.

In the single-plate type liquid crystal projector, the cooling air can be easily separated between the liquid crystal display panel side and the light source side by the cooling air separating plate which is arranged substantially parallel to the liquid crystal display panel between the light source and the light source.

Further, the cooling efficiency of the liquid crystal display element is improved by projecting the liquid crystal display panel on one surface side of the liquid crystal display module including the shield case and exposing the liquid crystal display panel in the air flow passage.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a liquid crystal projector according to the present invention will be described below with reference to FIGS. First, FIG. 1 shows a liquid crystal projection television as an example of a liquid crystal projector to which the present invention is applied. Reference numeral 1 is a liquid crystal projection television as a liquid crystal projector, 2 is a device case, and 3 is a screen. As shown in the figure, the liquid crystal projection television 1 is provided with a screen 3 for displaying a projection image from the rear side on the upper half of the front side of a vertically long device case 2.

2 and 3 showing the internal cooling structure of such a liquid crystal projection television 1, 5 is a power source, 6 is a light source, 9 is a dichroic mirror,
10 is a liquid crystal display module, 16 is a wind control wall (incident side polarization plate), 20 is a projection lens, 21 is a wind control wall (lens surface),
30 is an air flow passage, 31 is an inlet, 32 is a filter, 3
3 is a fan, 34, 35, 36, 37, 38 are baffle plates,
39 is an outlet, 40 is a cooling air dividing means (cooling air separating plate), 41 is a partition plate, and 42 is an outlet. That is, as shown in FIG. 2, the power source 5 is installed on the lower right pedestal 4 and the light source 6 is installed on the left side in the lower half of the device case 2. The light source 6 is a lamp 7 that emits white light.
Is arranged at the focal point of the reflector 8, and the lamp 7 is supplied with electric power from the power source 5.

As shown in the figure, the light source 6 reflects the white light emitted from the lamp 7 by the reflector 8 and irradiates it to the right in the figure, and the dichroic mirror 9 is arranged on the optical axis thereof. . This dichroic mirror 9
Is, for example, 3 of R, G, and B of white light from the light source 6.
The color components are reflected upward, and therefore, in the drawing, they are arranged at an angle of 45 ° to the upper right. The liquid crystal display module 10 is disposed on the optical axis reflected upward by the dichroic mirror 9.
Further, above the liquid crystal display module 10, a projection lens 20 that projects the image light transmitted through the liquid crystal display module 10 is arranged. The lens surface 21 of the projection lens 20 is parallel to the liquid crystal display module 10, and also serves as a wind control wall as described later.

The liquid crystal display module 10 is shown in detail in FIG.
As shown in FIG. 1, the liquid crystal display panel 12 is housed in the shield case 11. That is, the liquid crystal display panel 12 that displays an image by driving the liquid crystal display element is formed by enclosing a liquid crystal between two glasses, and the liquid crystal on the incident side located on the lower surface side of the liquid crystal display panel 12 in the drawing. Display panel glass surface (hereinafter abbreviated as LCD glass surface) 1
As shown in the figure, 3 is recessed in the liquid crystal display module surface (hereinafter abbreviated as LCM surface) 14 on the incident side of the liquid crystal display module 10 including the shield case 11.

Further, an incident side polarization plate 16 is attached in parallel to the lower surface side of the liquid crystal display module 10 in the drawing through support pins 15, 15, 15, ..., This incident side polarization plate 16 will be described later. As such, it also serves as a windbreak wall. Further, on the upper surface side of the liquid crystal display module 10 in the drawing, an outgoing side polarizing plate 18 is attached in parallel via support pins 17, 17, .... As described above, the liquid crystal projection television 1 is illuminated by the light source 6 to be dichroic mirror 9
The light reflected upward enters the liquid crystal display panel 12 of the liquid crystal display module 10, and the image light transmitted through the liquid crystal display panel 12 is driven upward by the driving of the liquid crystal display element and is projected upward by the projection lens 20. A projection image is displayed on the screen 3 from the back side through the reflection by the mirror.

In the liquid crystal projection television 1 described above, as shown in FIGS. 2 and 3, the power source 5, the light source 6 and the liquid crystal display module 1 are provided in the lower half of the device case 2.
An air flow passage 30 for cooling 0 is formed.
That is, in FIG. 2 and FIG. 3, the air flow passage 30 is provided with an intake port 31 that opens to the right side surface of the lower half of the device case 2.
And a discharge port 39 opening to the left side of the lower half of the device case 2.
And a discharge port 4 that opens below the suction port 31.
It is configured to connect two.

Inside the suction port 31, a filter 32 for purifying the outside air and a fan 33 for generating cooling air are arranged in this order, and in the equipment case 2, the fan 33 passes from the suction port 31 through the filter 32. Front and rear baffle plates 34, 35 for guiding the cooling air sucked in by the to the exhaust port 39 are arranged. Furthermore, in the device case 2, a fan 3
A vertical air guide plate 36 for guiding the cooling air flowing from 3 toward the liquid crystal display module 10 side in front of the projection lens 20.
And an oblique air guide plate 37 for guiding the cooling air passing through the liquid crystal display module 10 toward the lower light source 6 side, and an oblique air guide plate 38 parallel to the lower side of the dichroic mirror 9. ing.

Further, below the liquid crystal display module 10, a cooling air separating plate 40 as a cooling air dividing means for partitioning the space between the light source 6 side and the light source 6 side is provided in parallel with the incident side polarizing plate 16 which also serves as the wind control wall. It is located in. The cooling air separating plate 40 has an opening through which the light emitted from the light source 6 and reflected upward by the dichroic mirror 9 passes. Further, the cooling air separating plate 40 is arranged with a gap provided between the cooling air separating plate 40 and the upper portion of the oblique air guide plate 38 along the dichroic mirror 9. Further, while partitioning between the suction port 31 and the discharge port 42 therebelow,
A partition plate 41 for partitioning the power source 5 from the filter 32 and the fan 33 is arranged. This partition board 4
1 is also arranged with a gap between it and the upper part of the air guide plate 38 that is oblique along the dichroic mirror 9.

As described above, since the cooling structure of the liquid crystal projection television 1 as one type of liquid crystal projector is used, the fan 3 can be operated when the power is turned on.
By keeping 3 in the operating state, the air flow passage 3
Power source 5, light source 6 and liquid crystal display module 1 arranged in 0
0 can be individually and effectively cooled. That is, as shown by the arrows in FIGS. 2 and 3, the fan 33
The outside air flowing into the air flow passage 30 in the device case 2 from the suction port 31 is first cleaned by removing dust by the filter 32 and then flows toward the liquid crystal display module 10 through the fan 33.

For this liquid crystal display module 10,
Cooling is performed by the cooling air flowing between the lens surface 21 of the upper projection lens 20 and the lower cooling air separating plate 40. At this time, the cooling air flowing in front of the projection lens 20 is
The vertical air guide plate 36 prevents the straight movement and flows toward the liquid crystal display module 10 side below. In particular, in the liquid crystal display module 10, the upper projection lens 2
Since the lens surface 21 of 0 is the wind-control wall and the lower incident-side polarization plate 16 is the wind-control wall, the cooling air flows in a rectified state during this period, and as shown in FIG. The shield case 11 is cooled, and the liquid crystal display panel 12 therein is cooled.

Further, the cooling air generated by the fan 33 is further cooled by the cooling air separating plate 40 and the air guide plate 38.
Flows from the dichroic mirror 9 toward the light source 6 through a gap between and. At this time, after the liquid crystal display module 10 has been cooled as described above, the oblique air guide plate 37 prevents the liquid crystal display module 10 from going straight and flows toward the lower light source 6 side. Therefore, in particular, the light source 6 including the lamp 7 and the reflector 8 is effectively cooled. In this way, the cooling air after individually cooling the liquid crystal display module 10 and the light source 6 merges and is discharged to the outside of the device case 2 through the discharge port 39.

The cooling air generated by the fan 33 also flows to the power source 5 side through the gap between the partition plate 41 and the air guide plate 38. Therefore, the power source 5 for supplying power to the light source 6 can be cooled. The cooling air after cooling the power supply 5 in this way is discharged from the device outlet 2 to the outside of the device case 2.

As described above, in the air flow passage 30 in the equipment case 2, the cooling air generated by the fan 33, especially the cooling air separating plate 40, is used for the liquid crystal display module 10.
Since it is divided into the (liquid crystal display panel 12) side and the light source 6 side, the liquid crystal display element and the light source 6 enclosed in the liquid crystal display panel 12 can be individually and efficiently cooled.
Therefore, a small fan can be used as the fan 33, which can contribute to reduction of power consumption and noise of the fan. Moreover, in the single-panel liquid crystal projection TV 1,
In the embodiment, the cooling air separating plate 40 arranged in parallel with the liquid crystal display panel 12 between the light source 6 allows the cooling air to be easily separated into the liquid crystal display panel 12 side and the light source 6 side, thus simplifying the configuration. Can be achieved.

By the way, in the above embodiment, the liquid crystal display module 10 in which the LCD glass surface 13 is concave in the LCM surface 14 is used, but as shown in FIG. 5, the LCD glass surface 13 is convex from the LCM surface 14. Then, the cooling efficiency can be increased. That is, in the embodiment shown in FIG.
By exposing the liquid crystal display panel 12 to the outside from the shield case 11 and providing the liquid crystal display module 10 with the LCD glass surface 13 protruding from the LCM surface 14, the liquid crystal display panel 12 is exposed in the air flow passage 30. Become.

Next, in the liquid crystal display module 10, the temperature of the central portion of the liquid crystal display panel 12 was replaced with a dummy, and the temperature of the central portion thereof was measured by a thermocouple. In the following table, the LCM surface 14 shown in FIGS. 4 and 5 is the A surface, the LCD glass surface 13 is the B surface, and the distance between the A surface and the B surface is changed to keep the outside air temperature constant. The result of the experiment is shown. The LCM surface 14
The convex state of the LCD glass surface 13 (the B surface) from the (A surface) is represented by plus, and the concave state is represented by the minus.

[0028]

As can be seen from the above experimental results, LCM
As the liquid crystal display module 10 in which the LCD glass surface 13 is projected from the surface 14, the liquid crystal display panel 12 is exposed in the air flow passage 30, so that the cooling efficiency for the liquid crystal display element can be improved. Like

In the above embodiments, the single plate type liquid crystal projection television is used, but the present invention is not limited to this, and other single plate type liquid crystal projectors and projection televisions other than the projection television are applicable. It may be a three-panel liquid crystal projector including the above. Further, in the embodiment, the cooling air separating plate is used as the cooling air dividing means, but the invention is not limited to this, and it is optional, and the configuration of the air flow passage including the intake port and the exhaust port, the location of the fan, etc. It is needless to say that the detailed structure and the like can be appropriately changed.

[0031]

As described above, according to the liquid crystal projector of the present invention, the cooling air is divided into at least the liquid crystal display panel side and the light source side by the cooling air dividing means in the air flow passage in the equipment case. Therefore, the liquid crystal display element and the light source can be efficiently cooled, and as a result, a small fan can be used, and power consumption and noise of the fan can be reduced.

According to the second aspect, in the case of the single-plate type liquid crystal projector, the cooling wind is separated from the liquid crystal display panel side by the cooling wind separation plate arranged substantially parallel to the liquid crystal display panel with the light source. And the light source side can be easily separated, and the configuration can be simplified.

Further, as described in claim 3, if the liquid crystal display panel is projected to one side of the liquid crystal display module and the liquid crystal display panel is exposed in the air flow passage, the cooling efficiency of the liquid crystal display element is improved. can do.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a liquid crystal projection television as an example of a liquid crystal projector to which the present invention is applied.

FIG. 2 is a rear view of an internal cutaway showing an internal cooling structure of the liquid crystal projection television of FIG.

3 is a cross-sectional plan view showing an internal cooling structure of the liquid crystal projection television of FIG.

4 is an enlarged side view of a unit portion including the liquid crystal display module shown in FIG.

5 shows a modified example of a unit portion including the liquid crystal display module shown in FIG. 2, and is an enlarged side view of a state where a liquid crystal display panel is projected to one surface side of the liquid crystal display module.

[Explanation of symbols]

 1 Liquid Crystal Projector 2 Device Case 3 Screen 4 Pedestal 5 Power Supply 6 Light Source 7 Lamp 8 Reflector 9 Dichroic Mirror 10 Liquid Crystal Display Module 11 Shield Case 12 Liquid Crystal Display Panel 13 LCD Glass Surface 14 LCM Surface 16 Incident Side Polarizing Plate (Wind Control Wall) 18 Emission side polarizing plate 20 Projection lens 21 Lens surface (wind control wall) 30 Air flow passage 31 Inlet 32 Filter 33 Fan 34, 35, 36, 37, 38 Baffle plate 39 Exhaust 40 40 Cooling air splitting means (cooling air separation) Plate) 41 Partition plate 42 Discharge port

Claims (3)

[Claims] 1. A liquid crystal display panel for displaying an image, a light source for irradiating the liquid crystal display panel with light, and a projection lens for projecting image light displayed on the liquid crystal display panel onto a screen are housed in a device case. In the liquid crystal projector, a cooling air inlet and an outlet are formed in the device case, and a fan for generating the cooling air is provided in the device case. At least the liquid crystal display panel is provided in the device case from the intake port. And an air flow passage extending through the light source to the outlet, and in the air flow passage, cooling air dividing means for dividing the cooling air into at least the liquid crystal display panel side and the light source side is provided. LCD projector characterized by. 2. A single-plate type liquid crystal projector, wherein the cooling air splitting means is a cooling air separating plate arranged between the liquid crystal display panel and the light source and substantially parallel to the liquid crystal display panel. The liquid crystal projector according to claim 1, 3. The liquid crystal display panel according to claim 1, wherein the liquid crystal display panel projects to one side of a liquid crystal display module including a shield case and is exposed in the air flow passage. projector.