Optics: image projectors – Temperature control – Blower
Reexamination Certificate
2000-06-28
2002-10-29
Adams, Russell (Department: 2851)
Optics: image projectors
Temperature control
Blower
C353S060000, C353S061000, C353S119000, C349S005000
Reexamination Certificate
active
06471357
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to projection display devices for projecting to screens or the like images obtained by applying light from light sources to light valves.
2. Description of the Related Art
Projection display devices are prepared for the market, which comprise light valves using liquid-crystal panels, for example, and separates white light emitted from a light source into the three primary colors of red (R), green (G) and blue (B) before modulating the three liquid-crystal panels based on an image signal. Modulated lights are subjected to color synthesis, and then projected enlargedly on a screen through a projection lens for display.
FIGS. 9-10
show a conventional projection display device. The projection display device
1
is provided with an optical unit
2
, an axial flow fan
3
for cooling the optical unit
2
, and an exterior cabinet or casing
4
having the optical unit
2
, the axial flow fan
3
, etc. mounted thereto.
The optical unit
2
is provided with a light source or lamp
21
, a fly-eye lens group
22
, a P-polarization/S-polarizabon (P/S) converter element
23
, color separating mirrors or dichroic mirrors
25
,
26
, reflecting mirrors
24
,
27
,
28
,
29
, three condenser lenses
30
R,
30
G,
30
B, three sets of light valves
35
R,
35
G,
35
B (refer simply to as
35
in some instances) each
25
comprising an incident side deflection plate
36
, liquid-crystal panels
31
R,
31
G,
31
B and an outgoing side deflection plate
37
, a cross prism or dichroic prism
32
for color synthesis, a projection lens
33
, and a unit frame
34
.
The P/S converter element
23
is formed out of rectangular glasses with a coated dielectric film bonded to each other by an adhesive. Moreover, on the incident side of the liquid-crystal panels
31
R,
31
G,
31
B, the incident side deflection plates or films
36
are bonded to the condenser lenses
30
R,
30
G,
30
B through thin glass plates, respectively. On the outgoing side of the liquid-crystal panels
31
R,
31
G,
31
B, the deflection plates
37
are bonded to the cross prism
32
through thin glass plates, respectively.
Illumination light applied from the light source
21
is equalized by the fly-eye lens group
22
, and is adjusted in the deflection direction by the P/S converter element
23
, which is then separated into R, G and B by the reflecting mirrors
24
,
27
,
28
,
29
and the color separating mirrors
25
,
26
.
Color lights applied to the liquid-crystal panels
31
R,
31
G,
31
B through the condenser lenses
30
R,
30
G,
30
B and the deflection plates
36
are modulated by an image signal, and the permeability of each is controlled through the deflection plate
37
. In such a way, images formed on the liquid-crystal panels
31
R,
31
G,
31
B are color composed by the cross prism
32
, and are projected to an external screen (not shown) through the projection lens
33
.
When passing through the deflection plates
36
,
37
, light is partly absorbed by the deflection plates to produce a temperature rise thereof. There are arranged cooling means for retraining this temperature rise, which comprise intake openings
38
R,
38
G,
38
B arranged in the lower side of the unit frame
34
to face the three liquid-crystal panels
31
R,
31
G,
31
B and the deflection plates
36
,
37
, and exhaust openings
39
R,
39
G,
39
B arranged in the upper side of the unit frame
34
to face the intake openings
38
R,
38
G,
38
B.
The axial flow fan
3
is disposed below the optical unit
2
, i.e. roughly beneath the cross prism
32
, and serves to blow cooling air on the three liquid-crystal panels
31
R,
31
G,
31
B, the deflection plates
36
,
37
, etc. through the intake openings
38
R,
38
G,
38
B arranged in the unit frame
34
, which is then exhausted outside from an exhaust port, (not shown) arranged in the exterior cabinet
4
through the exhaust openings
39
R,
39
G,
39
B.
Next, the shape or configuration of the exterior cabinet of the projection display device will be described. Referring to
FIGS. 15-17
, when viewing from the shape of their exterior cabinets, the projection display devices can be classified into a vertically lengthened projection display device
1001
wherein the direction of separating and synthesizing light emitted from the light source is defined as the vertical direction, and a horizontally lengthened projection display device
2001
wherein the direction of separating and synthesizing light emitted from the light source is defined as the horizontal direction. In recent years, for achieving a size and weight reduction of the device, the vertical projection display device is often used which allows a reduction in size of the optical system for separation and synthesis of light emitted from the light source, since the liquid-crystal panels are of the shorter vertical length than the horizontal length.
Referring to
FIGS. 15-16
, the conventional vertical projection display device
1001
is provided with an optical unit
102
, an axial flow fan or cooling fan
103
for cooling the optical unit
102
, and an exterior cabinet or casing
104
having the optical unit
102
, the axial flow fan
103
, etc. mounted thereto.
The optical unit
102
is provided with a light source or lamp
121
, a fly-eye lens group
122
, a P/S converter element
123
, color separating mirrors or dichroic mirrors
125
,
126
, reflecting mirrors
124
,
127
,
128
,
129
, three condenser lenses
130
R,
130
G,
130
B, three sets of light valves
135
R,
135
G,
135
B (refer simply to as
135
in some instances) each comprising an incident side deflection plate
136
, liquid-crystal panels
131
R,
131
G,
131
B and an outgoing side deflection plate
137
, a cross prism or dichroic prism
132
for color synthesis, a projection lens
133
, and a unit frame
134
.
The optical unit
2
is disposed in the vertical exterior cabinet
104
with the light source
121
side down and the light valves
135
side up.
The P/S converter element
123
is formed out of rectangular glasses with a coated dielectric film bonded to each other by an adhesive. Moreover, on the incident side of the liquid-crystal panels
131
R,
131
G,
131
B, the incident side deflection plates or films
136
are bonded to the condenser lenses
130
R,
130
G,
130
B through thin glass plates, respectively. On the outgoing side of the liquid-crystal panels
131
R,
131
G,
131
B, the deflection plates
137
are bonded to the cross prism
132
through thin glass plates, respectively.
Illumination light applied from the light source
121
is equalized by the fly-eye lens group
122
, and is adjusted in the deflection direction by the P/S converter element
123
, which is then separated into red (R), green (G) and blue (B) by the reflecting mirrors
124
,
127
,
128
,
129
and the color separating mirrors
125
,
126
.
Color lights applied to the liquid-crystal Panels
131
R,
131
G,
131
B through the condenser lenses
130
R,
130
G,
130
B and the deflection plates
136
are modulated by an image signal, and the permeability of each is controlled through the deflection plates
137
. In such a way, images formed on the liquid-crystal panels
131
R,
131
G,
131
B are color composed by the cross prism
132
, and are projected to an external screen (not shown) through the projection lens
133
.
When passing through the deflection plates
136
,
137
, light is partly absorbed by the deflection plates to produce a temperature rise thereof. There are arranged cooling means for retraining this temperature rise, which comprise, as shown in
FIG. 16
, intake openings
138
R,
138
G,
138
B arranged in one side
134
a
of the unit frame
134
to face the three liquid-crystal panels
131
R,
131
G,
131
B and the deflection plates
136
,
137
, and exhaust openings
139
R,
139
G,
139
B arranged in another side
134
b
of the unit frame
134
to face the intake openings
138
R,
138
G,
138
B.
The axial flow fan
103
is disposed roughly just beside the cross prism
132
of the optical
Hara Nobuyuki
Ohkubo Takuji
Adams Russell
Frommer William S.
Frommer & Lawrence & Haug LLP
Kessler Gordon
Koval Melissa
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