Information
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Patent Grant
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6431739
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Patent Number
6,431,739
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Date Filed
Tuesday, February 20, 200123 years ago
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Date Issued
Tuesday, August 13, 200222 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
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CPC
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US Classifications
Field of Search
US
- 362 558
- 362 237
- 362 236
- 362 235
- 362 244
- 362 245
- 362 247
- 362 241
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International Classifications
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Abstract
An illuminating apparatus includes a plurality of light members spaced apart from each other and operable so as to produce forwardly directed parallel light rays, a parabolic reflector disposed in front of the light members for receiving the forwardly directed parallel light rays from the light members, and an integrator unit. The parabolic reflector has a reflecting surface that confronts the light members. The integrator unit has an input side to receive the light rays reflected by the reflecting surface of the parabolic reflector.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an illuminating apparatus for a projection display, more particularly to an illuminating apparatus that utilizes a plurality of light sources to generate input light for a projection display.
2. Description of the Related Art
In a conventional projection display, input light is filtered and separated into color components that are modulated and subsequently recombined to generate an image output. A single light source is commonly used to generate the input light in the conventional projection display. For projection displays with a high requirement of brightness, the single light source will incur a corresponding increase in power requirement. High-power single light sources are disadvantageous in that there is a severe heat dissipation problem that is difficult to resolve when such light sources are in use.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to provide an illuminating apparatus that utilizes a plurality of light sources to generate input light for a projection display.
According to the present invention, an illuminating apparatus comprises:
a plurality of light members spaced apart from each other and operable so as to produce forwardly directed parallel light rays;
a parabolic reflector disposed in front of the light members for receiving the forwardly directed parallel light rays from the light members, the parabolic reflector having a reflecting surface that confronts the light members; and
an integrator unit having an input side to receive the light rays reflected by the reflecting surface of the parabolic reflector.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:
FIG. 1
is a schematic view of the first preferred embodiment of an illuminating apparatus according to this invention; and
FIG. 2
is a schematic view of the second preferred embodiment of an illuminating apparatus according to this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to
FIG. 1
, the first preferred embodiment of an illuminating apparatus
1
according to the present invention is shown to comprise a plurality of light members
32
, a parabolic reflector
3
, and an integrator unit.
The light members
2
are spaced apart from each other and are disposed on a common place. Each of the light members
2
includes a light source
22
and a parabolic reflector
21
. The parabolic reflector
21
has a connecting end
212
for connecting the light source
22
, and an open end
213
opposite to the connecting end
212
. The light parabolic reflector
21
further has a reflecting surface
211
for reflecting light rays that radiate from the light source
22
to produce forwardly directed parallel light rays. In design, the number of the light members
2
depends on the requirement of brightness in a projection display. The light members
2
can be arranged in a ring formation.
The parabolic reflector
3
is disposed in front of the light members
2
for receiving the forwardly directed parallel light rays from the light members
2
. The parabolic reflector
3
has a reflecting surface
31
that confronts the light members
2
, and a focal point
32
.
The integrator unit includes a rod integrator
4
that has an input side
41
to receive the light rays reflected by the reflecting surface
31
of the parabolic reflector
3
. The input side
41
of the rod integrator
4
is coincident with the focal point
32
such that the light rays reflected by the reflecting surface
31
converge at the input side
41
. As such, input light for a projection display (not shown) can be obtained from an output side
42
of the rod integrator
4
.
Because the high power is distributed among the light members
2
, the heat dissipation problem commonly encountered with the use of a high-power single light source as taught in the prior art can be easily overcome. In addition, when one of the light members
2
breaks down, the illuminating apparatus can still work as long as the remaining light members
2
are operable.
FIG. 2
illustrates the second preferred embodiment of an illuminating apparatus
5
according to this invention, which is a modification of the first preferred embodiment. Unlike the previous embodiment, the integrator unit includes a lens array integrator
53
, and a lens
54
. The lens array integrator
53
has an incident end
531
that confronts the reflecting surface
520
of the parabolic reflector
52
, and a radiating end
532
. The lens
54
is disposed between the parabolic reflector
52
and the lens array integrator
53
. The lens
54
has a second focal point
541
that is coincident with the first focal point
521
of the parabolic reflector
52
such that the light rays reflected by the reflecting surface
520
converge at the first and second focal points
521
,
541
and pass through the lens
54
and such that the light rays are radiated in parallel toward the incident end
531
of the lens array integrator
53
.
Like the previous embodiment, because the high power is distributed among the light members
51
, the heat dissipation problem commonly encountered with the use of a high-power single light source as taught in the prior art can be easily overcome.
While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Claims
- 1. An illuminating apparatus comprising:a plurality of light members spaced apart from each other and operable so as to produce forwardly directed parallel light rays; a parabolic reflector disposed in front of said light members for receiving the forwardly directed parallel light rays from said light members, said parabolic reflector having a reflecting surface that confronts said light members, and a first focal point; and an integrator unit having an input side to receive the light rays reflected by said reflecting surface of said parabolic reflector.
- 2. The illuminating apparatus of claim 1, wherein said integrator unit includes a rod integrator having said input side that is coincident with said first focal point such that the light rays reflected by said reflecting surface converge at said input side.
- 3. The illuminating apparatus of claim 1, wherein said integrator unit includes:a lens array integrator having an incident end that confronts said reflecting surface of said parabolic reflector, and a radiating end; and a lens disposed between said parabolic reflector and said lens array integrator, said lens having a second focal point that is coincident with said first focal point such that the light rays reflected by said reflecting surface converge at said first and second focal points and pass through said lens and such that the light rays are radiated in parallel toward said incident end of said lens array integrator.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
5526237 |
Davenport et al. |
Jun 1996 |
A |
5918974 |
Suzuki et al. |
Jul 1999 |
A |
6179439 |
Choate |
Jan 2001 |
B1 |