Rotary kinetic fluid motors or pumps – Plural runners supported for relative motion or on separate...
Reexamination Certificate
2002-06-20
2004-05-25
Nguyen, Ninh H. (Department: 3745)
Rotary kinetic fluid motors or pumps
Plural runners supported for relative motion or on separate...
C415S066000, C415S175000, C353S058000, C353S061000
Reexamination Certificate
active
06739831
ABSTRACT:
BACKGROUND OF INVENTION
1. Field of the Invention
The invention relates to a cooling device for a projector, and particularly to a cooling device that direct hot air directly into fan blades to reduce temperature of fan hub.
2. Description of the Prior Art
Please refer to
FIG. 1
that illustrates a prior art of projector
10
, comprising a light source
121
of a light unit
12
inside a casing
11
, the light source
121
creating a high-brightness and high-contrast projecting light ray
122
when acted on by an optical engine
13
m
. A light cut
123
installed on the upper side of the light unit
12
to obstruct the light source
121
of the light unit
12
. In the prior art, heated air is subject to the action of a first fan
157
, air entering the projector
10
through a first air inlet window
151
becomes a first hot current
153
, which after passing a first printed circuit board
141
is separated into a third hot current
155
and a fourth hot current
156
. The third hot current
155
passing a first fan
157
and fan blades
1572
is exhausted out of the projector
10
, and the fourth hot current
156
is directed through the third fan
162
into the light source heat exhausting unit
16
. On the other hand, when subjected to action by the second fan
158
, air enters through the second air inlet window
152
into the projector
10
, creating a second hot current
154
. The second hot current
154
respectively passes an optical engine
13
, a second printed circuit board
142
and a light unit
12
, then through a plurality of fan blades
1582
of the second fan
158
, finally out of the projector
10
.
Due to the action of the second fan
158
, the fourth hot current
156
directed through the third fan
162
into the light source heat exhausting unit
16
passes an air duct
161
to absorb the heat generated by the light source
121
, so the temperature of the fourth hot current
156
rises rapidly. After passing the light cut
123
, the fourth hot current
156
in the prior art of projector
10
is squarely aligned with the second fan
158
, then the second hot current
154
is exhausted out of the projector
10
by the action of the fan blades
1582
of the second fan
158
.
A shortcoming in the prior art of projector
10
lies in that the heat radiating direction of the fourth hot current
156
is squarely in alignment with the second fan
158
or the second fan hub
1581
. The heat generated by the light source
121
of the light unit
12
is the highest in the projector
10
, so the heat carried by the fourth hot current
156
after passing the light cut
123
is also the highest. Accordingly, when the fourth hot current
156
exhaust heat directly against the second fan hub
1581
, the heat will be collected at the front of the second fan hub
1581
before it passes a plurality of second fan blades
1582
and out of the projector
10
, forming a higher average temperature at the front of the second fan hub
1581
. As shown in
FIG. 5
, when the prior art of the projector
10
is operating under room temperature using a light source
12
of approximately 130 Watt, the air temperature at 1 mm position
159
to the front of the center of the second fan hub
1581
will reach as high as 206.6 degrees Fahrenheit, which is higher than the maximum operating temperature of 194 degrees Fahrenheit for the second fan
158
, resulting in adverse effects to the motor bearings, control circuits, rotors, stators and such key components in the hub of the second fan
158
, thereby reducing the working life and reliability of the second fan
158
.
As shown in
FIG. 2
that illustrates another prior art of projector
20
, comprising a casing
21
, a light unit
22
, a light source
221
, an optical engine
23
, a light cut
223
, a first printed circuit board
241
, a second printed circuit board
242
, a cooling device
25
, a first air inlet window
251
, a second air inlet window
252
, a first fan
257
, a light source heat exhausting unit
26
, a third fan
262
, an air outlet
263
and an air inlet
261
, which are the same as the first prior art, but different in that the second fan
258
, the fan hub
2581
and the fan blades
2582
are installed at a rear part of the light source
221
. It has the shortcoming that the heat carried by the fourth hot current
256
is also the highest. As a result, when heat is exhausted in a lower right direction from a specified distance between the fourth hot current
256
and the second fan
258
, the heat will be collected at the front of the second fan hub
2581
before passing the second fan blades
2582
and out of the projector
20
, forming a higher average temperature at the front of the second fan hub
2581
, bringing adverse effects to the motor bearings, control circuits, rotors, stators and such key components in the second fan hub
2581
, reducing the working life and reliability of the second fan
258
and the prior art of the projector
20
.
SUMMARY OF INVENTION
The objective of the invention is to provide a cooling device for projector, to direct hot current directly into fan blades, thereby reducing the temperature of the fan hub, and increasing the working life and reliability of the product.
To achieve the above objective, the present invention involves a light source that provides light to the projector device. With an air duct extending from the light source to a second exhaust fan, so air in the vicinity of the light source is exhausted through the second fan blades and out of the projector, wherein the second exhaust fan comprises a second fan hub and a plurality of second fan blades, the second fan hub being located at a center of the second exhaust fan, the second fan blades respectively connected to a periphery of the second fan hub, thereby the air in the vicinity of the second fan blades in the projector is exhausted through the second fan blades and out of the projector. The air duct is in a closed status at the periphery of the light source, concentrating a direction for exhaustion, and the air outlet is squarely aligned with the second fan blades.
REFERENCES:
patent: 3180981 (1965-04-01), Ulffers
patent: 4925295 (1990-05-01), Ogawa et al.
patent: 6254238 (2001-07-01), Takamatsu
patent: 6443575 (2002-09-01), Miyamoto et al.
patent: 2001242434 (2001-09-01), None
Chou Bor-Bin
Hsu Nien-Hui
Wu Shang-Hsuang
Coretronic Corporation
Hsu Winston
Nguyen Ninh H.
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