JP3379121B2 - Projection device for projection television - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a projection device for projecting an image on a screen of a projection television.

[0002]

2. Description of the Related Art A conventional projection television projection apparatus will be described with reference to FIG.

In FIG. 1, 1 is a projection tube and 3 is a concave lens. The projection tube 1 and the concave lens 3 are fixed to a bracket 2 made of a material having good heat conduction via packings 10 and 11, respectively, and are optically coupled. A cooling liquid is sealed in the cooling chamber 2a of the bracket 2 located between the projection tube 1 and the concave lens 3.

As a projection device for a projection television, as shown in Japanese Utility Model Publication No. 2-41979, the packing between the projection tube and the bracket has an enlarging portion having a circular cross-section and a groove in the bracket. It is known that the flat peripheral portion is formed of a flat portion that is connected to the enlarged portion that is pressed against the projection tube. A sectional view of the packing is shown in FIG.

[0005]

As shown in FIG. 2, the packing 10 is pressure-contacted between the projection tube and the bracket, the enlarged portion 10a is deformed, and the packing tube 10 is water-tight due to the contact area with the projection tube surface and the bracket groove portion 2a. Make a state.

In the conventional packing 10 as shown in FIG. 3, since the cross section 10a of the enlarged portion is circular, the enlarged portion is relatively difficult to be deformed and the area of the watertight portion is also relatively small. In such a case, when a foreign substance such as dust is caught in the watertight portion, the watertight state is broken and the coolant leakage is relatively likely to occur.

According to the present invention, in a projection television projection device, the projection tube and the bracket are pressed against each other.
That packing improves, and an object thereof is to provide a projection apparatus that reduce coolant leakage due to narrowing sandwiched foreign matter such as dust.

[0008]

A feature of the present invention is that a groove is formed on a surface of a projection tube of a bracket, a packing is placed in the groove, and an enlarging portion is inserted into the groove. The flat portion connected to this is formed, and a groove is further provided in the enlarged portion.

[0009]

By providing the groove in the enlarged portion, the enlarged portion is relatively easily deformed, the area of the watertight portion becomes large, and even if foreign matter such as dust is caught in the packing portion, the leakage of the cooling liquid is prevented. It can be hard to occur.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the drawings. The one shown is one of the three monochromatic projection tubes that make up the projection television.

In the figure, the projection tube 1 is attached to a bracket 2 made of aluminum die casting through a packing plate 10 by a pressing plate 6.
Fixed to. The pressing plate 6 is provided with a screw 7 via a spring 13.
The screw 7 is screwed into the bracket 2 by being pressed by. The concave lens 3 is packed 1 by the pressing plate 4.
It is fixed to the bracket 2 via 1. The screw 14 is screwed into the bracket 2 to fix the pressing plate 4. A cooling liquid is sealed in the cooling chamber 2a of the bracket 2 to optically couple the projection tube 1 and the concave lens 3 to each other.

In the bracket 2, the groove portion 2 into which the enlarged portion 10a of the packing 10 is fitted on the projection tube side surface thereof.
b is provided so that the packing 10 can be positioned. Flat portion 1 connected to the enlarged portion 10a
0b is sandwiched between the flat portion of the bracket around the groove 2b and the projection tube surface so that the bracket and the projection tube do not come into direct contact with each other, and the projection tube is prevented from being damaged by the impact.

In the packing, a groove 10'c is provided in the expanded portion 10'a as shown in FIG. Therefore, in FIG.
The enlarged portion 10'a shown in Fig. 3 is easily deformed as compared with the enlarged portion 10a shown in Fig. 3 having a circular cross section, and the contact areas between the projection tube and the bracket and the enlarged portion increase. It is possible to prevent the cooling liquid from leaking due to the inclusion of foreign matter such as dust into the watertight portion.

In the packing of the embodiment shown in FIG. 4, four grooves are provided. However, in this shape, since the packing is difficult to release from the mold during molding, the packing is easily damaged and the yield is poor. There is a drawback that.

A solution to this problem is shown in FIG. 5, in which the packing is a surface 2 in contact with the projection tube and the bracket.
Grooves 10'c are provided at the locations. With such a shape
This facilitates mold release .

[0016]

As described above in detail, according to the present invention, it is possible to prevent the leakage of the cooling liquid due to the inclusion of foreign matter such as dust into the packing portion.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a projection device.

FIG. 2 is a partially enlarged view of a cross section of the projection device.

FIG. 3 is a cross-sectional view showing a conventional packing example.

FIG. 4 is a sectional view showing an example of packing.

FIG. 5 is a sectional view showing an example of packing.

[Explanation of symbols]

1 ... Projection tube, 2 ... bracket, 3 ... concave lens, 4, 6 ... Presser plate, 5,7,14 ... screws, 10, 11, 12 ... Packing.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04N 5/74 G02B 7/02

Claims (3)

(57) [Claims] 1. A cooling liquid is mounted between the lens and the projection tube by mounting the lens in a watertight state on one surface of the bracket and by mounting the projection tube in a watertight state on the other surface of the bracket through an annular rubber packing. In the projection device for a projection television, the bracket has an annular groove formed on the surface on the projection tube side.
Is the packing is provided with a large portion to be fitted into the annular groove of the bracket, projection device in projection television is characterized in that a groove is formed bulging most. 2. The enlarging part is the projection tube of the packing.
The method according to claim 1, wherein the contact surface is also provided.
Projection device in the projection television described. 3. Watertightly attach the lens to one side of the bracket.
A rubber ring packing on the other side of the bracket
The projection tube is installed in a watertight manner via
With a cooling liquid enclosed between the projector and the projection tube.
In projection devices for projection television, The bracket has an annular groove on the projection tube side.
And the packing fits in the annular groove of the bracket.
And an enlarged portion having a groove formed in the center thereof and the expansion
With a flat flange portion formed continuously on the large part, The bulge of the packing is in the annular groove of the bracket
Is crushed with
Is pressed into contact with the flat portion of the projection tube and the projection tube.
Projection device for projection television.