JPH02174385A - Projection type television receiver - Google Patents

Abstract

PURPOSE:To increase the lifetime of a projection type TV receiver by adding a pressure control part containing a lamination of a 1st elastic substance layer which does not contaminate a liquid and a 2nd elastic substance layer which controls the transmission of gas formed from the side bringing into contact with the liquid to a housing. CONSTITUTION:A pressure control part 30 contains a lamination of a silicon rubber layer 30a which does not contaminate a liquid 28 and has a large degree of gas transmittance and an ethylenepropylene rubber-silicon rubber copolymer layer 30b which has a small degree of transmittance and may possibly contaminate the liquid 28 formed from the side bringing into contact with the liquid 28. Then the part 30 is put into a housing 22. Thus the contamination of the liquid 28 filled in the housing 22 is surely prevented and then the consumption of the liquid 28 is also prevented. In such constitution, a projection type TV receiver can be used as long as possible.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is a system in which, for example, a received image projected on the image receiving surface of a cathode ray tube is enlarged via a projection lens system and projected onto a screen. The present invention relates to a television receiver.

(Prior Art) In general, projection type television receivers are of the front type, in which a received image projected on the image receiving surface of a cathode ray tube is enlarged via a projection lens system, and the image projected onto a screen is reflected light. A rear type is known in which the image projected from the back of the screen is viewed.

FIG. 2 shows the above-mentioned rear type television receiver. In the figure, reference numeral 10 denotes a cabinet in which a video projection section 11 is installed. The image projection unit 11 projects the received image, enlarges the received image, and projects it onto the reflecting mirror 12. The reflecting mirror 11 onto which the image is projected by the image projection unit 10 forms an image of the image on a screen 13 provided at the front of the cabinet 12 from the back side.

As shown in FIG. 3, in the image projection unit 11, a projection lens system 21 made of PMMA resin or the like is disposed facing the image surface of a cathode ray tube 20 with a predetermined interval in correspondence with the image surface of a cathode ray tube 20 that projects the received image. . A coupling casing 22 made of die-cast aluminum or the like is disposed between the cathode ray tube 20 and the projection lens system 21. A flange 22a is formed at one end of this housing 22, and this flange 22
a is screwed to a fixed flange 20a provided on the back surface of the cathode ray tube 20 via a screw member 23, a packing 24, etc., and is connected to a sealed structure.

Further, a flange 22b is similarly formed at the other end of the housing 22, and this flange 22b is connected to a fixed flange 25a provided on the cylinder body 25 in which the projection lens system 21 is housed, via a screw member 26, a packing 27, etc. are screwed together to form a sealed structure. The inside of the housing 22 is filled with a colorless and transparent polycrystalline alcohol liquid 28 having a refractive index similar to that of the projection lens system 21, such as a mixed solution of ethylene glycol, glycerin, or water, as a cooling liquid. As a result, when the received image is projected onto the image plane of the cathode ray tube 20, the received image is transferred to the projection lens system 2 by the liquid 28.
1, the light is magnified, and an image is formed on the screen 13 via the reflecting mirror 12.

Furthermore, the pressure adjustment section 1 is provided in the middle part of the housing 22. As shown in FIG. 4, this pressure crab A adjusting section 1 is provided with stepped elastic bodies 1a having a predetermined elastic force.
8 expands, the cathode ray tube 20, the projection lens system 21, and the housing 22 absorb the volumetric expansion and the temperature rises.
In addition to preventing liquid leakage from the gaskets 24, 27, etc. at the connecting part with the projection lens system 21,
To prevent distortion, etc.

However, in the above-mentioned projection type television receiver, since the image projection section 11 is filled with the liquid 28, there is a problem that the pressure adjustment section 1 causes the liquid 28 to be contaminated or consumed. was. That is, in order to adjust and control the pressure of the liquid 28 by absorbing the volumetric expansion of the liquid 28 with the elastic force of the elastic body 1a, the pressure adjustment unit 1 of the image projection unit 11 uses, for example, the elastic body 1a as the elastic body 1a. As shown in Figure 5, a synthetic rubber system of ethylene propylene rubber and silicone rubber copolymer is used, which has a very low gas permeability and almost no consumption of the liquid 28, to achieve high precision in pressure regulation. This causes a problem in that the liquid 28 is heavily contaminated, leading to deterioration of the liquid 28 and making it difficult to use it for a long period of time. Therefore, silicone rubber, which is less likely to contaminate the liquid 28, has been used as the elastic body 1, but according to this, the gas permeability is very high, so the liquid is wasted a lot, and the same problem occurs. A problem arises in that long-term use becomes difficult.

As described above, in the conventional projection type television receiver, if the image projection unit 11 is configured to prevent contamination of the liquid 28, the consumption of the liquid 28 becomes a problem. If configured to prevent this, liquid contamination became a problem.

This situation is not limited to the above-mentioned linear type (the same applies to the front type as well).

(Problem to be solved by the invention + I had a problem with that.

This invention was made in view of the above-mentioned circumstances, and aims to extend the service life as much as possible by having a simple structure and reliably preventing contamination and consumption of the filled liquid. The object of the present invention is to provide a projection type television receiver that provides a projection type television receiver.

[Structure of the Invention] (Means for Solving the Problems) This invention projects a colorless and transparent polyhydric alcohol liquid having a predetermined refractive index onto the image plane of a picture tube through a sealed housing. In a projection type televisigine image receiving device comprising an image projection unit that connects a lens system and optically guides a received image projected on the image plane of the picture tube to the projection lens system via the liquid, the housing A pressure adjusting section is provided in which a first elastic layer that does not contaminate the liquid and a second elastic layer that restricts gas permeation are stacked in order from the side that contacts the liquid. .

(Function) According to the above configuration, the liquid inside the housing is
direct contact with the second elastic layer prevents its contamination, and the second elastic layer prevents gas permeation to the outside air. Therefore, a predetermined amount of liquid can be maintained in the housing without contamination, thereby realizing long-term use.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a pressure adjustment section 30 of a projection television receiver according to an embodiment of the present invention, and the other parts are constructed in the same manner as in FIG. Now, the explanation will be omitted.

That is, first, a first elastic layer, for example, a silicone rubber layer 3 that does not contaminate the liquid 28 and has a high gas permeability, is installed as the pressure adjustment section 30 in a predetermined part of the housing 22.
0a is provided corresponding to the liquid side, and a second elastic layer is provided on the outside air side on the silicone rubber layer 30a, such as ethylene propylene rubber silicone rubber, which has a low gas permeability and may contaminate the liquid 28. Copolymer layer 30b
are stacked on top of each other. As for this formation method, for example, the ethylene propylene rubber/silicone rubber copolymer layer 30b is formed, and then liquid silicone rubber is applied onto the ethylene propylene rubber/silicone rubber copolymer layer 30b to form the silicone rubber layer 30a. is formed.

As a result, the pressure adjusting unit 30 has its silicone rubber layer 30a in contact with the liquid 28 filled in the housing 22 to prevent staining, and the gas that has passed through the silicone rubber layer 30a to be ethylene propylene. The rubber/silicone rubber copolymer layer 30b effectively blocks permeation to ensure a predetermined amount of liquid 28 in the housing 22 without contaminating it.

Then, when the cathode ray tube 20 generates heat and the liquid 28 expands during video reproduction, the silicone rubber layer 30a and the ethylene propylene, rubber/silicone rubber copolymer layer 30b work together to expand the volume of the liquid 28. The pressure inside the housing 22 is adjusted and controlled to be constant, and the cathode ray tube 2
0 and the seal 24.2 of the connection part with the projection lens system 21
In addition to preventing liquid leakage from the projection lens system 7, distortion of the projection lens system 21 due to the increase in pressure is also prevented.

As described above, the projection television receiver has a silicone rubber layer 30a having a high gas permeability that does not contaminate the liquid 28 from the side that comes into contact with the liquid 28, and a silicone rubber layer 30a that has a low gas permeability and does not contaminate the liquid 28. A pressure adjusting section 30 in which a certain ethylene propylene rubber/silicone rubber copolymer layer 30b is sequentially stacked is provided in the housing 22 to reliably prevent contamination of the liquid 28 filled in the housing 22 and to reduce consumption of the liquid 28. By configuring to prevent this, it is possible to use it for as long as possible and extend its life. In the above embodiment, the silicone rubber layer 30a is provided as the first elastic layer, and the silicone rubber layer 30a is provided as the first elastic layer, and the silicone rubber layer 30a is Although the explanation has been made in the case where the ethylene propylene rubber/silicone rubber copolymer layer 30b is provided as the elastic layer, the present invention is not limited to this material and can be applied.

Further, in the above embodiment, as a method for forming the pressure adjustment part 30, first, an ethylene propylene rubber silicone rubber copolymer layer 30b is formed, and a silicone rubber layer is formed on the ethylene propylene rubber pot silicone rubber copolymer layer 30b. Although the case has been described in which the structure is formed by applying 30a, the formation method is not limited to this, and various formation methods are possible.

Therefore, it goes without saying that the present invention is not limited to the above embodiments, and that various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] As detailed above, according to the present invention, with a simple configuration,
In addition, it is possible to provide a projection television receiver that can reliably prevent contamination and consumption of the filled liquid and can extend its life as long as possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main parts of a projection type television receiver according to an embodiment of the present invention, FIG. 2 is a block diagram showing a projection type television receiver to which the present invention is applied, and FIG.
The figure is a cross-sectional view showing the image projection section in FIG. 2 taken out, FIG. 4 is a configuration diagram showing a conventional pressure adjustment section, and FIG. 5 is a characteristic shown to explain the problems of the conventional pressure adjustment section. It is a diagram. 11... Image projection section, 20... Braun tube, 21.
...Projection lens system, 22...Housing, 23°26...
Screw member, 24. 27... Packing, 25... Cylindrical body, 28... Liquid, 30... Pressure adjustment part, 30a...
- Silicone rubber layer, 30b... Ethylene propylene rubber/silicone rubber copolymer layer. Applicant's agent Patent attorney Takehikoma Suzue [hour Figure 5

Claims (1)

[Scope of Claims] A projection lens system is connected via a housing formed by sealing a colorless and transparent polyhydric alcohol liquid having a predetermined refractive index with respect to the image plane of the picture tube, and the image of the picture tube is In a projection type television receiver equipped with an image projection unit that optically guides a received image projected on a surface to the projection lens system via the liquid, the side of the housing that is in contact with the liquid is A projection television receiver comprising a pressure adjusting section in which a first elastic layer that does not contaminate the liquid and a second elastic layer that regulates gas permeation are stacked in this order.