Television – Video display – Projection device
Reexamination Certificate
2000-03-23
2002-09-24
Miller, John (Department: 2614)
Television
Video display
Projection device
C348S749000, C348S748000
Reexamination Certificate
active
06456341
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a cathode ray tube (CRT) assembly of a projection TV system, and more particularly, to a CRT assembly of a projection TV system
All too often, in a CRT assembly for a TV projection system, a coupler which holds the coolant requires an oil cap and an oil cap holder for controlling the pressure of the coolant in the coupler in addition to a separate coolant injection hole for filling the coupler with coolant. Such an arrangement requires two seals and two separate entities for operation of the coupler which is costly, cumbersome, and difficult to manufacture. What is needed is a coupler which holds coolant and is connected to the CRT assembly that uses a single coolant injection hole for both filling the coupler with coolant and for controlling the pressure of the coolant in the coupler.
DESCRIPTION OF THE RELATED ART
Referring to
FIG. 1
, a typical projection TV system is for projecting an image formed by a CRT assembly A installed inside a main body
1
to a rear surface of a screen
3
installed in the front side of the main body
1
by reflecting the image by a reflection mirror
2
.
FIGS. 2 and 3
are a sectional view and an exploded perspective view of a conventional CRT assembly, respectively. Referring to the drawings, the conventional CRT assembly includes a CRT
10
for forming an image, a coupler
20
coupled to the front surface of the CRT
10
, and a projection lens
30
for magnifying and projecting the image formed at the CRT
10
.
The CRT
10
and the projection lens
30
are coupled to the coupler
20
through sealing members
11
and
31
and fixing brackets
12
and
32
. A coolant receiving portion
21
and a coolant injection hole
22
are formed at the coupler
20
. The coolant receiving portion
21
is formed at the center of the coupler
20
and contains coolant C in inner space sealed by the CRT
10
and the projection lens
30
. The coolant injection hole
22
is for injecting coolant C into the sealed space and is sealed by a bolt
23
coupled to the coolant injection hole
22
and a sealing member
24
to prevent leakage of coolant C. Also, the conventional CRT assembly includes a hole
25
, an oil cap
26
and an oil cap holder
27
as a pressure control device, for controlling the pressure of coolant C contained in the coolant receiving portion
21
when the temperature of the CRT
10
increases.
The hole
25
is formed at one surface of the coupler
20
to penetrate the inside and outside of the coolant receiving portion
21
. The oil cap
26
is dome shaped so that a part thereof can be inserted into the inside of the coolant receiving portion
21
. The oil cap
26
is formed of a soft material such that, when the inserted part of the oil cap
26
contacts coolant C and the pressure of the coolant C increases, a convex portion of the oil cap
26
can be deformed to be concave and thus the pressure of coolant C can be absorbed in a direction in which the inner space of the coolant receiving portion
21
increases. The oil cap holder
27
is for fixing the oil cap
26
to the coupler
20
to prevent coolant C from leaking between the oil cap
26
and the hole
25
.
However, in the conventional CRT assembly of a projection TV system, the coolant injection hole
22
, the bolt
23
and the sealing member
24
are needed at the coupler
20
for injecting coolant C and the hole
25
, the oil cap
26
and the oil cap holder
27
are needed for controlling the pressure of coolant C. Thus, as the structures for injecting coolant and for controlling the pressure of coolant are respectively needed, the number of parts increases and the assembly work becomes complicated. Also, in a state in which the oil cap
26
and the oil cap holder
27
are installed at the CRT assembly, the oil cap
26
continues to contact coolant C. Accordingly, when the pressure of coolant C increases excessively due to the heat of the CRT
10
, the oil cap
26
is destroyed by the excessive pressure of coolant C and the coolant C leaks from the coupler
20
.
SUMMARY OF THE INVENTION
To solve the above problems, it is an objective of the present invention to provide a CRT assembly of a projection TV system in which the structure for injecting coolant into the coolant receiving portion of the coupler and controlling the pressure of the coolant is improved.
It is also an object to provide a CRT cooling system that uses a single coolant injection hole to both fill the cooling system with coolant and to control the pressure of the coolant in the cooling system, thus avoiding the need for separate ports for filling the cooling system with coolant and controlling the pressure of the cooling system.
It is also an object to provide a coupler containing coolant for a CRT in a TV projection system that is easy to manufacture and requires fewer parts. Accordingly, to achieve the above objects there is provided a CRT assembly of a projection TV system which comprises a CRT for forming an image, a projection lens for magnifying and projecting the image formed by the CRT, a coupler installed between the CRT and the projection lens, a coolant receiving portion formed at the center of the coupler, having a front surface in contact with the projection lens forming a seal and a rear surface in contact with a front surface of the CRT forming a seal, a coolant injection hole formed to penetrate the side of the coolant receiving portion, through which coolant is filled in the coolant receiving portion, and a pressure control device for controlling the pressure of coolant in the coolant receiving portion while sealing the coolant injection hole.
REFERENCES:
patent: 4717853 (1988-01-01), Ezawa et al.
patent: 4740727 (1988-04-01), Inaida et al.
patent: 4777532 (1988-10-01), Hasegawa
patent: 4780640 (1988-10-01), Hasegawa
patent: 4982289 (1991-01-01), Mitani et al.
patent: 5373394 (1994-12-01), Oh
patent: 5537167 (1996-07-01), Toide et al.
patent: 5877583 (1999-03-01), Meglio et al.
patent: 6130497 (2000-10-01), Takezawa et al.
patent: 6188165 (2001-02-01), Lee
patent: 6384874 (2002-05-01), Ushizaka
patent: 294174 (2000-10-01), None
Bushnell , Esq. Robert E.
Miller John
Samsung Electronics Co,. Ltd.
Yenke Brian
LandOfFree
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