JPH04291247A - Liquid crystal projector - Google Patents

Abstract

PURPOSE:To form a cooler for the liquid crystal panel and polarization plate of the liquid crystal projector in cooling structure not affect images on the liquid crystal projector. CONSTITUTION:Heat pipe type coolers 3 and 3 formed by sealing a coolant 32 in a glass vessel 30 are respectively mounted at a liquid crystal panel 1 for light valve and a first polarization plate 21 arranged adjacently to this liquid crystal panel 1, the prescribed amount of the coolant 32 is stocked at the downside of the glass vessel 30, and on the inside of a first glass plate 30a of the glass vessel 30, grooves 300, 300... having fine width are formed to connect the upside and the downside. The coolant in the glass vessel 30 rises up to a prescribed height in the grooves 300, 300 by a capillary phenomenon, and the coolant 32 in these grooves 300, 300... are evaporated from the grooves by absorbing the thermal energy of an object to be cooled. Then, the vapor is dispersed in the glass vessel 30 at high speed. The thermal energy is moved by condensation due to the discharge of the dispersed vapor, and the liquid crystal panel 1 and the first polarization plate 21 are cooled by such a movement of the thermal energy.

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 using a liquid crystal panel as a light valve.

0002

2. Description of the Related Art In recent years, the technology of liquid crystal panels has made remarkable progress, and liquid crystal projectors using liquid crystal panels as light valves have been developed. The liquid crystal projector basically consists of a projection light source, a polarizing plate that polarizes the light emitted by the projection light source, a liquid crystal panel that forms an image, a projection lens that magnifies the image, and a screen that displays the image. Light is irradiated from a projection light source to a liquid crystal panel via a polarizing plate, and an image formed on the liquid crystal panel is enlarged by a projection lens and projected onto a screen.

[0003] In such a liquid crystal projector,
The heat generated by the projection light source and its irradiation light cause the temperature of the liquid crystal panel and the polarizing plate placed close to it to rise.
It was equipped with multiple cooling fans with large airflow to suppress the temperature rise of the liquid crystal panel and polarizing plate. However, such a cooling fan has the drawback of being noisy.

In order to solve the above-mentioned drawbacks, the present inventor devised a heat pipe type cooling structure as shown below (Japanese Patent Application No. 1-264443). FIG. 4 is a sectional view of a liquid crystal assembly equipped with a heat pipe type cooler, and FIG. 5 is a side view of the liquid crystal panel and the cooler. 1 in the figure is a liquid crystal panel, and a first polarizing plate 2 is provided on the incident side of the liquid crystal panel 1.
1, and a second polarizing plate 2 is provided on the output side of the liquid crystal panel 1.
2 are provided. Heat pipe type coolers 5, 5 are provided on the incident surface of the liquid crystal panel 1 and the incident surface of the first polarizing plate 21.
are adhered to each other with a transparent adhesive (eg, silicone adhesive). A condenser lens 4 is attached to the incident side of the cooler 5 attached to the first polarizing plate 21 with a transparent adhesive. Then, LCD panel 1, the first
The polarizing plate 21, the second polarizing plate 22, the coolers 5, 5, and the condenser lens 4 are integrally assembled. Note that the liquid crystal panel 1 is inclined by about 6 degrees with respect to the direction perpendicular to the optical axis A, taking into consideration the preferred viewing angle. The cooler 5 is composed of a sealed glass container 50 made of a pair of flat glasses 50a, 50a and a frame glass 50b, and a heat radiation fin 51 attached to the upper end of the glass container 50. 52 is enclosed.

When the liquid crystal assembly constructed as described above is irradiated with light, the liquid crystal panel 1 and the first polarizing plate 21 absorb the light and generate heat. At this time, the temperature particularly increases in the center of the display area where the amount of light is large. Thermal energy generated by these heat generation is transmitted to the liquid crystal panel 1 and the first polarizing plate 21.
from there to the coolers 5, 5 attached to each other. In the cooler 5, the thermal energy is transferred to the refrigerant 52 via the glass container 50, and the temperature of the refrigerant 32 is increased. The refrigerant 52 is
Due to natural convection, the upper part becomes the hottest and evaporates. The vapor that has absorbed thermal energy during this evaporation moves at high speed inside the glass container 50 to the condensing section 500, which is the part to which the radiation fins 51 are attached, and is condensed in this condensing section 500, becomes liquid, and falls. do. Therefore, the thermal energy absorbed during the evaporation and transferred to the condensing part 500 is released from the radiation fins 51 to the outside. The coolers 5, 5 cool the liquid crystal panel 1 and the first polarizing plate 21 by such heat transfer.

[0006]

However, in the glass container 50 of the cooler 5, thermal energy is transferred by natural convection of the refrigerant 52, so that the glass container 50 of the cooler 5 does not have the flat glasses 50a, 50a.
has a temperature distribution such that the temperature is higher in the central part than in the peripheral part, and due to such temperature distribution, compressive stress acts on the central part and tensile stress acts on the peripheral part, Distortion occurs in the glass container 50. cooler 5,
5 is provided on the incident side of the first polarizing plate 21 and the second polarizing plate 22, so distortion of the glass container 50 affects the polarization of the first polarizing plate 21 and the second polarizing plate 22, For example, when displaying black on a normally open liquid crystal display, the distorted portion of the glass container 50 disrupts the polarization, causing phenomena such as black appearing in the image and deteriorating the contrast of the image. There was a problem with negative effects.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal projector equipped with a cooling structure that does not affect images.

[0008]

[Means for Solving the Problems] A liquid crystal projector according to the present invention includes a heat pipe formed by sealing a working fluid in a thin box-shaped transparent container between a liquid crystal panel for a light valve and a polarizing plate disposed close to the liquid crystal panel. In a liquid crystal projector equipped with a type cooler, a predetermined amount of working fluid is stored in the lower part of the transparent container, and a microscopic liquid crystal is installed inside the mounting part of the transparent container to connect the upper and lower sides. It is characterized by forming a plurality of width grooves.

[0009]

[Operation] The grooves formed inside the mounting part of the transparent container of the cooler are so small that a capillary phenomenon occurs, and the working fluid accumulated on the lower side of the transparent container is The inside of the groove rises to a predetermined height by capillary action. The working fluid in these grooves absorbs the thermal energy of each of the liquid crystal panels (or polarizing plates) and evaporates from the grooves, and the vapor diffuses into the transparent container at high speed. Then, thermal energy is transferred by condensation due to heat radiation of the diffused vapor, and the liquid crystal panel (or polarizing plate) is cooled. In this case, the transparent container is filled with the vapor due to high-speed diffusion of the vapor of the working fluid evaporated from the groove, so that the temperature inside the transparent container is made uniform.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to drawings showing embodiments thereof. FIG. 1 is a sectional view of a liquid crystal assembly equipped with a heat pipe type cooler in a liquid crystal projector according to the present invention, FIG. 2 is a partially cutaway side view of the cooler, and FIG. 3 is taken along line III-III in FIG. FIG.

1 in the figure is a liquid crystal panel, and the liquid crystal panel 1
A first polarizing plate 21 is provided on the incident side of the liquid crystal panel 1.
A second polarizing plate 22 is provided on the output side. Heat pipe type coolers 3, 3 are attached to the incident surface of the liquid crystal panel 1 and the incident surface of the first polarizing plate 21 with transparent adhesive (for example, silicone adhesive), and the liquid crystal panel 1 and Optical cutting is performed between the first polarizing plate 21 and the cooler 3 and between the first polarizing plate 21 and the cooler 3, and heat transfer properties are improved. A condenser lens 4 is attached to the incident side of the cooler 3 attached to the first polarizing plate 21 with a transparent adhesive. Then, LCD panel 1, the first
The polarizing plate 21, the second polarizing plate 22, the coolers 3, 3, and the condenser lens 4 are integrally assembled. Note that the liquid crystal panel 1 is inclined by about 6 degrees with respect to the direction perpendicular to the optical axis A, taking into consideration the preferred viewing angle.

[0012] The cooler 3 includes a first flat glass 30a, a second flat glass 30b, which are a pair of flat glasses arranged opposite to each other, and a frame glass 30 interposed between them.
A thin box-shaped glass container 30 is formed by sealing the flat glasses 30a, 30b and the frame glass 30c with frit glass, and the upper end of the glass container 30 has a glass container 30 with good heat conductivity. It is composed of heat radiation fins 31 attached with adhesive. On the inner surface of the first flat glass 30a of the glass container 30, a large number of grooves 300, 300, . These grooves 300, 300,
The width of ... is such that capillary action occurs. In addition, the liquid level inside the glass container 30 is the same as that of the liquid crystal panel 1.
A refrigerant 32 is sealed so as to be below the lower end of the effective display screen 11, and the sealed refrigerant 32 rises in the grooves 300, 300, .
, 300, . . ., the liquid level is above the upper end of the effective display screen 11. In the cooler 3 having such a configuration, the first flat glass 30a is attached to the liquid crystal panel 1 (or the first polarizing plate 21) so as to be in close contact with the incident surface of the liquid crystal panel 1 (or the first polarizing plate 21). ing.

Next, the operation of the coolers 3, 3 constructed as described above will be explained, taking the cooler 3 attached to the liquid crystal panel 1 as an example. When the liquid crystal assembly is irradiated with light, the black matrix of the liquid crystal panel 1 absorbs the light and generates heat. The thermal energy generated by the liquid crystal panel 1 is
The first flat glass 3 of the cooler 3 is attached via the transparent adhesive.
transmitted to 0a. Thermal energy transferred to the first flat glass 30a raises the temperature of the refrigerant 32 in the grooves 300, 300, . Due to this temperature increase, the refrigerant 32 moves into the grooves 300,
300, ... evaporates from inside, absorbs the heat of vaporization, diffuses at high speed in the space inside the glass container 30 and rises, and the heat dissipating fins 31
It reaches the part where is pasted (hereinafter referred to as the condensation part). The vaporization heat of the refrigerant 32 that has reached the condensation section is released to the outside through the radiation fins 31 and condensed, and the refrigerant 32 that has accumulated on the lower side of the glass container 30 becomes a liquid. to fall. Further, as described above, the grooves 300, 30
0,... by the amount of refrigerant 32 evaporated from inside the glass container 3
The refrigerant 32 accumulated on the lower side of the groove 300, 300,...
will be replenished within.

In this way, in the cooler 3, the grooves 300,
300, ... by transferring thermal energy to the condensing section by the vapor of the refrigerant 32 evaporated from inside, and transferring the thermal energy such that the thermal energy of this vapor is released to the outside via the radiation fins 31 in the condensing section. LCD panel 1
to cool down. Note that the cooler 3 attached to the first polarizing plate 21 also operates in the same manner as described above. In such coolers 3, 3, it falls. Therefore, the thermal energy absorbed during the evaporation and transferred to the condensing section is released from the radiation fins 31 to the outside. The coolers 3, 3 cool the liquid crystal panel 1 and the first polarizing plate 21 by such heat transfer.

[0015] In this way, in the coolers 3, 3, the grooves 300
, 300, ... to evaporate the refrigerant 32 from within the groove 300.
, 300, ... diffuses into the glass container at high speed. Since the vapor diffuses at a high speed in this way, the glass container is filled with the vapor, and the temperature within the glass container is thereby made uniform. does not occur.

[0016]

[Effects of the Invention] In the liquid crystal projector according to the present invention, the working fluid evaporates from within the grooves of a plurality of minute widths connecting the upper and lower sides of the inside of the mounting portion of the transparent container, and the heat of the liquid crystal panel and polarizing plate is reduced. Since the vapor absorbs energy and diffuses at high speed, the transparent container of the cooler is filled with the vapor, and the temperature of the transparent container is made uniform. Since the temperature inside the transparent container is made uniform in this way, distortion does not occur in the transparent container, so the cooling by this cooler does not affect the image, and the present invention has excellent effects.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a liquid crystal assembly including a heat pipe type cooler in a liquid crystal projector according to the present invention.

FIG. 2 is a partially cutaway side view of the cooler.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a cross-sectional view of a liquid crystal assembly with a conventional heat pipe type cooler.

FIG. 5 is a side view of a liquid crystal panel of a liquid crystal assembly including a conventional heat pipe type cooler and its cooler.

[Explanation of symbols]

1.LCD panel 3 Cooler 21 First polarizing plate 30 Glass container 32 Refrigerant 30a First flat glass 300 groove

Claims (1)

[Claims] Claim 1: A liquid crystal projector in which a heat pipe type cooler made of a thin box-shaped transparent container filled with a working fluid is attached to a liquid crystal panel for a light valve and a polarizing plate disposed close to the liquid crystal panel, respectively. , a predetermined amount of hydraulic fluid is stored in the lower side of the transparent container, and a plurality of grooves with a minute width are formed inside the mounting part of the transparent container to connect the upper side and the lower side. LCD projector.