JP2000147472A - Liquid crystal panel and projector using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance cooling effects of substrates of a liquid crystal panel and polarizing plates. SOLUTION: A liquid crystal panel 7 is constituted by sealing liquid crystal in between two sheets of transparent substrates 5, 5 and by arranging polarizing plates 9, 9 at outsides of respective substrates 5, 5. The both substrates 5, 5 are held by holding cases 8, 8 and openings 81 permitting the transmission of lights to the substrates 5, 5 are openedly provided in the holding cases 8, 8. Moreover, fins 80 for heat radiation are integrally provided at the outsides of the cases 8, 8 and the polarizing plates 9, 9 are provided outside or inside the fins 80 for heat radiation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel and a projection device for irradiating the panel with strong light to irradiate an image on a screen.

[0002]

2. Description of the Related Art Conventionally, there is known a projection apparatus which irradiates an image on a screen by irradiating a liquid crystal panel (7) with strong light, and FIG. 8 is a side view showing a basic configuration of such a projection apparatus. It is. The light from the light source (2) is converged by the first and second integrator lens bodies (41) and (42) and the condenser lenses (43) and (44), and then irradiates the liquid crystal panel (7). FIG.
FIG. 3 is a cross-sectional view of the liquid crystal panel (7) as viewed from the side. The liquid crystal panel (7) has a liquid crystal (51) sealed between two transparent substrates (5) and (5) slightly separated from each other. (5) The peripheral portion between (5) is closed with a sealant (50). Outside each of the substrates (5) and (5), a polarizing plate (9) that allows passage of only one of the indeterminate polarized lights.
(9) is provided. Since the light from the light source (2) is strong, the substrates (5) and (5) and the polarizer (9) are easily overheated,
As a result, the image function may be deteriorated, and the durability may be reduced. Therefore, the substrates 5 and 5 and the polarizing plate 9 are usually air-cooled from below or from the side.

[0003]

In recent years, such devices have been required to have higher luminance, and the light emitted from the light source (2) has become stronger. Therefore, the substrates (5) and (5) and the polarizing plate
(9) is more susceptible to thermal damage, and is required to improve the cooling effect. Generally, to increase the air cooling effect,
It is conceivable to attach a heat radiation member. Applicant:
It was conceived that if the portions other than the portions irradiated with the substrates (5) and (5) were covered with the heat radiation member, the cooling effect would be high. The present invention
The object is to enhance the cooling effect of the substrates (5) and (5) of the liquid crystal panel (7) or the polarizing plate (9).

[0004]

A liquid crystal panel (7) has a liquid crystal (51) sealed between two transparent substrates (5) and (5), and each of the substrates (5) is sealed.
Polarizing plates (9) and (9) are arranged outside of. Both substrates
(5) and (5) are held by holding cases (8) and (8), and each holding case (8) and (8) has an opening (81) that allows light to pass through to the substrates (5) and (5). ) Has been established. A radiation fin (80) is integrally provided outside the holding case (8), and the polarizing plate (9) is provided outside or inside the radiation fin (80).

[0005]

[Functions and Effects] The substrates (5) and (5) are sandwiched between holding cases (8) and (8) integrally formed with heat radiation fins (80).
The polarizing plate (9) is provided outside or inside the heat radiation fin (80). Therefore, even if the substrates (5) and (5) of the liquid crystal panel (7) and the polarizing plate (9) are irradiated with strong light from the light source (2), the substrates (5) and (5) of the liquid crystal panel (7) can be irradiated. Alternatively, overheating of the polarizing plate (9) is prevented, and heat damage can be prevented. In particular, if the opening (81) of the holding case (8) is made as small as possible in accordance with the minimum irradiation area of the substrate (5), the air cooling effect of the radiating fin (80) is further improved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of the present invention will be described in detail with reference to the drawings. The same reference numerals are used for the same configuration as the conventional one. FIG. 5 is a plan view of the projection device. The projection device irradiates three liquid crystal panels corresponding to the three primary colors of light, R, G, and B, with strong light, and then combines the light to form a screen. Project an image. A cabinet (3) for holding three liquid crystal panels (7), (7a) and (7b) is provided in the cabinet (6), and a projection lens (67) is provided at a front end of the chassis (3). ing. A prism body (30) is provided in the chassis (3) coaxially with the optical axis of the projection lens (67).
Liquid crystal panels (7a) and (7b) corresponding to R and B are provided with (0) therebetween. The prism body (30) includes a reflection layer (31) inside, and a liquid crystal panel (7) corresponding to G is provided on the opposite side of the projection lens (67) across the prism body (30). .
A light source (2) is provided at the entrance of the chassis (3), and a total reflection mirror (75) (76) (77) (78) and a dichroic mirror (45) (46) are inclined on the optical path on the optical path. Has been deployed. In the following description, the direction in which light is emitted from the light source (2) and heads toward the prism body (30) is defined as forward.

The light from the light source (2) is converged by the first and second integrator lens bodies (41) and (42) and the condenser lens (43), and then reflected by the total reflection mirror (75). The dichroic mirror 45 allows R to pass through and reflects G and B. R is reflected by the total reflection mirror (76) and irradiates the liquid crystal panel (7a) corresponding to R. G is reflected by the dichroic mirror (46) and enters the prism body (30). B is reflected by the reflection layer (31) in the prism body (30) after being reflected by the total reflection mirrors (77) and (78), and enters the projection lens (67). R, G, B with prism body (30)
Are combined and projected on the screen (68).

(First Embodiment) FIG. 1 is an exploded perspective view of a liquid crystal panel (7), and FIG. 2 is a sectional view of the same, cut along the line AA. The liquid crystal panel (7) includes holding cases (8) and (8) which abut each other, and sandwiches two transparent substrates (5) and (5) opposed to each other by the holding cases (8) and (8). are doing. A liquid crystal (51) is sealed in a gap between the two substrates (5) and (5), and a peripheral portion between the two substrates (5) and (5) is closed with a sealant (50). On the outside of the holding case (8), a plurality of projections (84), (84) are formed in a row to form a heat dissipating fin (80), and the holding case (8) and the heat dissipating fin (80) are formed by aluminum die casting. Alternatively, they are integrally formed by processing a copper plate. Aluminum or copper is used as the material of the holding case (8) and the radiating fin (80). The thermal conductivity of aluminum is 236 (1 / W · m ⁻¹ · K ⁻¹ ), and the thermal conductivity of copper is Is 403 (1 / W · m ⁻¹ · K ⁻¹ ), which is due to its higher thermal conductivity and higher heat dissipation effect than other metals such as iron.

An opening (81) is formed at the center of the radiating fins (80) (80).
Light from the outside enters the two substrates (5) and (5) through the opening (81). LCD panel as before
(7) includes polarizing plates (9) and (9), and the polarizing plates (9) and (9) are attached to the tips of the heat radiation fins (80) and cover the opening (81).
As is well known, the polarizers (9) and (9) have polarization directions orthogonal to each other, and when power supply and cutoff to the liquid crystal (51) sealed between the substrates (5) and (5) are switched, light is emitted. The mode is switched between blocking and passing, and an image is displayed.

Since the light source (2) irradiates with strong light, it tends to overheat. However, in this example, the holding case having the heat dissipating fins (80) is provided on the substrates (5) and (5) and the polarizing plate (9).
(8) is attached to enhance the cooling effect. Therefore,
Strong light from the light source (2), the substrate (5) of the liquid crystal panel (7)
Irradiation of (5) and the polarizing plate (9) prevents overheating of the substrates (5) and (5) and the polarizing plate (9), thereby preventing thermal damage. In particular, if the opening (81) is made as small as possible in correspondence with the minimum irradiation area of the substrate (5), the air cooling effect of the radiating fin (80) is further improved. Note that a transparent conductive film (not shown) may be formed on the substrate (5) to further increase the thermal conductivity. Also,
As shown by the dashed line in FIG. 2, instead of providing the polarizing plates (9) and (9) outside the holding case (8), the polarizing plates (9) and (9) are provided inside the holding case (8) in contact with the substrate (5). Is also good. Further, a leaf spring (82) is provided on the inner surface of one holding case (8) to
(5) may be pressed against the other holding case (8).

FIG. 6 is a longitudinal sectional view showing a state in which the liquid crystal panel (7) is mounted on the chassis (3). An opening (32) is formed below the liquid crystal panel (7) on the chassis (3),
A fan (33) is provided below the opening (32). The liquid crystal panel (7) is air-cooled by the fan (33), and the cooling effect is enhanced by the radiating fins (80). In this case, as shown in FIG. 5, three liquid crystal panels (7), (7a) and (7b) are provided on the chassis (3), and an opening (32) is formed in each liquid crystal panel (7). (7a) It is established corresponding to (7b). The fan (33) cools the three liquid crystal panels (7), (7a) and (7b) through the openings (32), (32) and (32). The cooling air from the fan (33) is used for heat dissipation. It rises between the projections (84) of the fins (80). Thus, the liquid crystal panels of the three liquid crystal panels (7), (7a) and (7b) can be cooled by one fan (33). That is, as shown in FIG. 5, each liquid crystal panel (7) (7a) (7b)
The mounting position of each of the liquid crystal panels is different from that of the adjacent liquid crystal panel by 90 degrees.
When installed on the side of (7b), three liquid crystal panels (7) (7a)
It is difficult to cool (7b) at once. Therefore, fans (3
3) was installed below the liquid crystal panels (7), (7a) and (7b).

(Second Embodiment) FIG. 3 is a plan sectional view of a liquid crystal panel (7) according to another embodiment. This is the substrate (5)
(5) Attach a transparent glass plate (55) (55) for dustproof,
This is sandwiched between holding cases (8) and (8). By forming the glass plates (55) and (55) from sapphire glass or the like having a high thermal conductivity, the heat of the substrate (5) is transferred to the glass plate (5).
5) Through the (55), the heat is easily transmitted to the radiating fins (80), and the cooling effect is enhanced. Here, although the thermal conductivity of sapphire glass varies depending on the glass component ratio,
0.55-0., Which is the thermal conductivity of general soda glass.
This value is larger than 75 (1 / W · m ⁻¹ · K ⁻¹ ), and the cooling effect is greater than forming the glass plates 55 and 55 with soda glass. The substrate (5) may be made of sapphire glass. Further, a transparent conductive film (not shown) may be formed on the glass plate (55) to further increase the thermal conductivity. Furthermore,
As described above, a transparent conductive film may be formed on the substrate (5), or the polarizing plates (9) and (9) may be provided inside the holding case (8) instead of being provided outside the holding case (8). May be provided in contact with the substrate (5).

(Third Embodiment) FIG. 4 is a plan sectional view of a liquid crystal panel (7) according to another embodiment. In this example,
The periphery of the two substrates (5) and (5) is a plastic frame
(52) (see FIG. 7), and outside each of the substrates (5) and (5),
An intermediate member (95) formed of a transparent and high thermal conductivity material such as sapphire glass is in contact with the intermediate member. The intermediate member
On the outside of (95), the center part is open (81), and a mountain-like projection (84)
A first radiating fin (80) formed by connecting the first radiating fin (80) to the outside in a lateral direction is attached, and a second radiating fin (80) having the same shape as the first radiating fin (80) is mounted outside the first radiating fin (80). Fins (83) are attached. First heat dissipation fin (80) and second heat dissipation fin
In (83), the apexes of the protrusions (84) abut each other, and a closed space (85) is formed between the protrusions (84) and the adjacent protrusions (84). Cooling air flows up and down the closed space (85). As described above, the first heat radiating fin (80) and the second heat radiating fin (83) are provided to increase the area of the portion that comes into contact with air, thereby enhancing the cooling effect. A glass plate (86) is provided outside the second heat radiating fin (83), and is located inside the opening (81) of the second heat radiating fin (83) on the inner surface of the glass plate (86). A polarizing plate (9) is attached. Incidentally, the polarizing plate (9) may be directly attached to the outside of the second radiating fin (83).

The description of the above embodiments is for the purpose of illustrating the present invention and should not be construed as limiting the invention described in the appended claims or reducing the scope thereof. Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a liquid crystal panel.

FIG. 2 is a plan sectional view of the same.

FIG. 3 is a plan sectional view of a liquid crystal panel in another embodiment.

FIG. 4 is a plan sectional view of a liquid crystal panel in another embodiment.

FIG. 5 is a plan view of the projection device.

FIG. 6 is a longitudinal sectional view showing a positional relationship between a liquid crystal panel on a chassis and a fan.

FIG. 7 is a perspective view of a substrate supported by a frame.

FIG. 8 is a side view showing a basic configuration of the projection device.

FIG. 9 is a side sectional view of a liquid crystal panel.

[Explanation of symbols]

 (2) Light source (3) Chassis (5) Substrate (7) Liquid crystal panel (9) Polarizer (51) Liquid crystal (55) Glass plate (80) Heat dissipation fin

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H052 AC18 AC27 AD34 2H088 EA15 HA01 HA13 HA18 HA23 HA24 HA28 MA20 2H089 HA40 JA07 QA06 TA12 TA15 TA16 TA17 TA18 2H091 FA05Z FA08X FA08Z FA21X FA26X FA26Z FA29Z FA41Z04FBFD

Claims (4)

[Claims] A liquid crystal (51) between two transparent substrates (5) (5).
And a polarizing plate (9) (9) provided outside each substrate (5), the two substrates (5) and (5) have holding cases (8) and (8). )
Each holding case (8) (8) is provided with an opening (81) that allows light to pass through to the substrates (5) (5). Outside the holding case (8), a radiating fin (80) is provided. Wherein the polarizing plate (9) is provided outside or inside the heat radiating fins (80). 2. A glass plate (55) made of sapphire glass having a large thermal conductivity among glass materials is attached to at least one of the heat radiation fin (80) and the substrate (5). The liquid crystal panel according to 1. 3. A light source (2) and a light source in a chassis (3).
A spectroscopic means for dispersing the light from (2) into R, G, and B;
Liquid crystal panels (7), (7a) and (7b) corresponding to the G and B lights,
The liquid crystal panels (7), (7a), and (7b), comprising a combination means for combining light irradiated thereon, and a projection lens (67) for projecting the combined light,
The liquid crystal panels (7), (7a) and (7b) are two transparent substrates (5) (5)
A liquid crystal (51) is sealed in between, and a polarizing plate (9) is provided outside each substrate (5).
In the projection device provided with (9), the substrates (5) and (5) of each of the liquid crystal panels (7) (7a) (7b) have a peripheral edge at a holding case (8) (8). At each holding case
(8) An opening (8) that allows transmission of light to the substrates (5) and (5) is provided in (8).
1) was opened, and a radiating fin (80) was provided integrally on the outside of the holding case (8), and the polarizing plate (9) was provided on the outside or inside of the radiating fin (80). Characteristic projection device. The radiating fin (80) has a plurality of projections (84) (8).
4. The air blower according to claim 3, wherein the air from the fan (33) is arranged in a horizontal line, and the air from the fan (33) arranged on the lower side of the chassis (3) flows upward between the protrusions (84). Projection device.