Illumination – Light fiber – rod – or pipe – With ventilating or cooling or thermally controlled light guide
Reexamination Certificate
2001-01-31
2003-02-11
O'Shea, Sandra (Department: 2875)
Illumination
Light fiber, rod, or pipe
With ventilating or cooling or thermally controlled light guide
C362S035000, C362S294000, C362S373000
Reexamination Certificate
active
06517229
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a spread illuminating apparatus used as an illuminating means for signboards, various kinds of reflection-type display devices and so on, and more particularly to a spread illuminating apparatus used as an illuminating means for a liquid crystal display device.
2. Description of the Related Art
A demand for a liquid crystal display device as a display device mainly for computers has been increased since the liquid crystal display device which operates on low power consumption is characterized by being thin and lightweight. Since a liquid crystal which is a component of the liquid crystal display device does not emit light by itself unlike a light emitting element such as a picture tube, an illuminating means for viewing an image is required. In particular, in the recent demand for thinner devices, there is a growing tendency to employ a thin plate-like spread illuminating apparatus of side light type (light conductive plate type) as an illuminating means for illuminating the liquid crystal display device.
An example of such a side light type spread illuminating apparatus is shown in
FIGS. 4 and 5
.
In
FIGS. 4 and 5
, a spread illuminating apparatus
1
is generally composed of a transparent substrate
2
made of a light-transmissible material and a bar-like light source
3
disposed close to an end surface
2
a
of the transparent substrate
2
. A liquid crystal display device (not shown) is disposed at a lower surface of the transparent substrate
2
, and the spread illuminating apparatus
1
is used as an auxiliary illuminating apparatus for the liquid crystal display device.
The transparent substrate
2
is formed in a wedge-shape, in which as the distance from the end surface
2
a
increases, the thickness of the transparent substrate
2
gradually decreases.
The light source
3
is generally composed of a light conductive member
4
and a spot-like light source
6
. The light conductive member
4
is made of a transparent material, formed in a triangular long plate-shape and disposed close to and along the end surface
2
a
of the transparent substrate
2
, and the spot-like light source
6
is disposed facing an end
4
a
of the light conductive member
4
and is mounted on a printed wiring board
5
such as PCB, FPC or the like.
In addition, a surface (second surface of light conductive member)
4
c
of the light conductive member
4
opposing a surface (first surface of light conductive member)
4
b
that faces the transparent substrate
2
is slanted in plan view with respect to the first surface
4
b
of the light conductive member. The second surface
4
c
of the light conductive member is provided with an optical path conversion means
7
comprised of grooves
7
a
substantially triangular in section and plane portions
7
b
each formed between two adjacent grooves
7
a
, whereby although the spot-like light source
6
is disposed on the end
4
a
, light beams entering the light conductive member
4
at the end
4
a
are emitted uniformly from the first surface
4
b
of the light conductive member.
A light reflection pattern
8
is formed on a surface
2
b
of the transparent substrate
2
(the upper side in
FIG. 4
, and hereinafter referred to as upper surface), whereby the brightness is almost uniform everywhere on the transparent substrate
2
irrespective of the distance from the light conductive member
4
.
The spot-like light source
6
is disposed on the printed wiring board
5
and a terminal of the board (not shown) is connected to a copper foil (not shown) by soldering.
Further, a light reflection member
11
, which is made of a resin film and U-shaped, is disposed in such a manner as to cover longitudinal surfaces of the light conductive member
4
except the surface facing the transparent substrate
2
(the first surface
4
b
of the light conductive member) [covered are the surface opposing the first surface
4
b
of the light conductive member
4
(the second surface
4
c
of the light conductive member), and two substantially triangular surfaces extending in the longitudinal direction and orthogonal to and continuous with the second surface
4
c
of the light conductive member (the one on the upper side in
FIG. 4
is referred to as third surface
4
d
of the light conductive member and the one on the lower side in
FIG. 4
is referred to as fourth surface
4
e
of the light conductive member)] and a transparent substrate proximal portion
10
, that is, a portion toward the end surface
2
a
of the transparent substrate
2
.
In
FIG. 5
, adhesive
12
is applied to an area covering from the upper part of the spot-like light source
6
to the upper part of the light reflection member
11
and an area covering from the lower part of the printed wiring board
5
to the lower part of the light reflection member
11
, and thus these components are bonded together.
In the spread illuminating apparatus, it is desired that heat generated by the spot-like light source be efficiently radiated in order, for example, to ease specifications for the spot-like light source and peripheral components thereof. This also applies to the conventional technique described above referring to
FIGS. 4 and 5
.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above, and an object of the present invention is therefore to provide a spread illuminating apparatus with an enhanced efficiency of radiating heat generated by a spot-like light source.
According to a first aspect of the present invention, there is provided a spread illuminating apparatus in which a bar-like light source is disposed in the vicinity of an end surface of a transparent substrate made of a light-transmissible material, wherein the bar-like light source is composed of a light conductive member which is formed of a bar-like transparent material and disposed close to and along at least one of end surfaces of the transparent substrate, and a spot-like light source which is disposed on at least one end of the light conductive member and mounted on a printed wiring board, and wherein the spot-like light source is enclosed by an enclosure made of a material having a high heat conductivity.
According to a second aspect of the present invention, the spread illuminating apparatus of the first aspect of the invention comprises a frame which covers the light conductive member, further extends to a part in the vicinity of the end surface of the transparent substrate to hold fixedly the transparent substrate, and which includes the enclosure at its end.
According to a third aspect of the present invention, in the spread illuminating apparatus of the second aspect of the invention, the frame and the enclosure are integrally formed.
According to a fourth aspect of the present invention, in the spread illuminating apparatus of any one of the first to third aspects of the invention, the printed wiring board is composed of a substrate on which the spot-like light source is mounted and a cover portion which extends from the substrate in such a manner as to cover the spot-like light source and is provided with dummy patterns.
REFERENCES:
patent: 5528474 (1996-06-01), Roney et al.
patent: 5590945 (1997-01-01), Simms
patent: 6102559 (2000-08-01), Nold et al.
patent: 6286970 (2001-09-01), Egawa et al.
patent: 6293683 (2001-09-01), Okada
patent: 6305813 (2001-10-01), Lekson et al.
Suzuki Shingo
Toyoda Koichi
Minebea Co. Ltd.
Negron Ismael
O'Shea Sandra
Oliff & Berridg,e PLC
LandOfFree
Spread illuminating apparatus having heat sink function does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spread illuminating apparatus having heat sink function, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spread illuminating apparatus having heat sink function will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3132345