U.S. patent application number 14/370292 was filed with the patent office on 2016-10-06 for backlight module and backlight system using same.
The applicant listed for this patent is SHENZHEN CHINA STAR OPTOELECTRONICS TECHNOLOGY CO., LTD. Invention is credited to Yongyuan QIU.
Application Number | 20160291234 14/370292 |
Document ID | / |
Family ID | 51669306 |
Filed Date | 2016-10-06 |
United States Patent
Application |
20160291234 |
Kind Code |
A1 |
QIU; Yongyuan |
October 6, 2016 |
BACKLIGHT MODULE AND BACKLIGHT SYSTEM USING SAME
Abstract
The present invention discloses a backlight module including a
solar collector, a number of fibers, a light bar, an optical mixing
block and a light guide plate. Each of the fibers includes a light
incident end and a light output end. The solar light collector
traces the sun and collects the solar light. The light incident
ends are connected to the solar light collector and transmits the
collected solar light to the light output end. The light bar
includes a number of point light sources. The point light sources
and the light output ends of the fibers are set on the light bar.
The solar light collected by the solar light collector enters the
optical mixing block to mix via the light output ends of the fibers
and emits into the light guide plate to be spread as an even
surface light source.
Inventors: |
QIU; Yongyuan; (Shenzhen,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHENZHEN CHINA STAR OPTOELECTRONICS TECHNOLOGY CO., LTD |
Shenzhen |
|
CN |
|
|
Family ID: |
51669306 |
Appl. No.: |
14/370292 |
Filed: |
December 24, 2013 |
PCT Filed: |
December 24, 2013 |
PCT NO: |
PCT/CN2013/090376 |
371 Date: |
July 2, 2014 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 6/00 20130101; H05B
35/00 20130101; H05B 45/20 20200101; Y02B 20/46 20130101; H01L
31/055 20130101; Y02B 20/40 20130101; G02B 6/0011 20130101; G02B
6/0028 20130101; G02B 6/0068 20130101; G02B 6/0066 20130101; Y02E
10/52 20130101; H05B 47/00 20200101; H05B 45/10 20200101; G02B
6/264 20130101; F21S 19/005 20130101; H05B 47/11 20200101; H05B
45/22 20200101; H01L 35/30 20130101; G02B 6/0008 20130101; G02B
6/0031 20130101; G02B 6/0023 20130101 |
International
Class: |
F21V 8/00 20060101
F21V008/00; H05B 33/08 20060101 H05B033/08; H05B 37/02 20060101
H05B037/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 26, 2013 |
CN |
201310613076.7 |
Claims
1. A backlight module, comprising: a solar light collector tracing
the sun and collecting the solar light; a plurality of fibers, each
of the fibers comprising a light incident end connecting the solar
light collector and a light output end, the light incident end
transmitting the collected solar light to the light output end; a
light bar comprising a plurality of point light sources; a optical
mixing block; and a light guide plate; wherein the point light
sources and the light output ends of the fibers are set on the
light bar, the solar light collected by the solar light collector
enters the optical mixing block to mix via the light output ends of
the fibers and emits into the light guide plate to be spread as a
even surface light source, and the point light sources give out a
light to compensate lacks of chromaticity and brightness of the
collected solar light.
2. The backlight module of claim 1, wherein the point light sources
and the light output ends of the fibers are alternately set on the
light bar along a longitudinal direction of the light bar.
3. The backlight module of claim 2, wherein an arrangement of the
point light sources is alternately spaced blue point light sources
and white point light sources.
4. The backlight module of claim 2, wherein an arrangement of the
point light sources is orderly spaced red point light sources,
green point light sources, and blue point light sources.
5. The backlight module of claim 1, wherein the optical mixing
block comprises a light incident surface, a light output surface,
and a refection surface connecting the light incident surface and
the light output surface, the light come out from the point light
source and the light output end of the fiber enters into the
optical mixing block via the light incident surface, and the light
strike on the reflection surface from inside of the optical mixing
block is reflected back into the optical mixing block.
6. The backlight module of claim 5, wherein the optical mixing
block is a orthogonal trapezoidal quadrangular which comprises an
upper surface, a lower surface parallel to the upper surface and
similar to the upper surface in shape, a front surface, a back
surface parallel to the front surface but having different size
with the front surface, an incline side surface obliquely
connecting with the front surface and the back surface, and a rear
surface perpendicularly connecting with the front surface and the
back surface, the back surface is functional as the light incident
surface, the rear surface is functional as the light output
surface, the upper surface, the lower surface, the front surface
and the incline side surface are functional as the reflection
surface, the rear surface faces a incident side of the light guide
plate, and a light emitting direction of the point light source and
the light output end of the fiber on the light bar faces the back
surface.
7. The backlight module of claim 5, wherein the optical mixing
block is an orthogonal triangular prism which comprises a pair of
rectangular side walls perpendicular to each other, a rectangular
incline side wall obliquely connected to the rectangular side walls
and a pair of triangular side walls correspondingly perpendicularly
connected to the rectangular side walls and the incline side wall,
the incline side wall is divided into an upper light output area
and a lower light incident area, the incident surface of the light
guide plate corresponds to the light output area, a width of the
light output area is the same as the thickness of the light guide
plate, the light guide plate is perpendicular to the incline side
wall, the light bar is set below the light guide plate, a light
emitting direction of the light bar is aligned with the light
incident area of the incline side wall, the rectangular side walls
and the triangular side walls are function as the reflection
surface.
8. A backlight system comprising: a backlight module comprising: a
solar light collector tracing the sun and collecting the solar
light; a plurality of fibers, each of the fibers comprising a light
incident end connecting the solar light collector and a light
output end, the light incident end transmitting the collected solar
light to the light output end; a light bar comprising a plurality
of point light sources; a optical mixing block; and a light guide
plate; wherein the point light sources and the light output ends of
the fibers are set on the light bar, the solar light collected by
the solar light collector enters the optical mixing block to mix
via the light output ends of the fibers and emits into the light
guide plate to be spread as a even surface light source, and the
point light sources give out a light to compensate lacks of
chromaticity and brightness of the collected solar light; and a
controlling module comprising: a setting unit setting chromaticity
coordinates of backlight, a brightness standard value and error
ranges of the chromaticity coordinates and the brightness standard
value; a detecting unit detecting chromaticity coordinates and
brightness value of the light from the light guide plate; a
comparing unit comparing a threshold of the error range of the
chromaticity coordinates with the chromaticity coordinates of the
light from the light guide plate and comparing a threshold of the
error range of the standard brightness value with the brightness
value of the light from the light guide plate; and a regulating
unit controlling the color of the point light source to shine
according to the comparison between the chromaticity coordinates of
the light from the light guide plate and the preset error range of
the chromaticity coordinates to compensate the chromaticity
deviation of the solar light and controlling the brightness of the
point light source according to the comparison between the
brightness of the light from the light guide plate and the standard
brightness value to compensate lack of brightness of the solar
light.
9. The backlight system of claim 8, wherein the chromaticity
coordinates is (0.28, 0.29), and the error range of the
chromaticity coordinates is (0.28+0.05, 0.29+0.05).
10. The backlight system of claim 8, wherein the brightness
standard value is 5000 nits, and the error range of the brightness
standard value is .+-.5%.
11. The backlight system of claim 8, wherein the point light
sources and the light output ends of the fibers are alternately set
on the light bar along a longitudinal direction of the light
bar.
12. The backlight system of claim 11, wherein an arrangement of the
point light sources is alternately spaced blue point light sources
and white point light sources.
13. The backlight system of claim 11, wherein an arrangement of the
point light sources is orderly spaced red point light sources,
green point light sources, and blue point light sources.
14. The backlight system of claim 8, wherein the optical mixing
block comprises a light incident surface, a light output surface,
and a refection surface connecting the light incident surface and
the light output surface, the light come out from the point light
source and the light output end of the fiber enters into the
optical mixing block via the light incident surface, and the light
strike on the reflection surface from inside of the optical mixing
block is reflected back into the optical mixing block.
15. The backlight system of claim 14, wherein the optical mixing
block is a orthogonal trapezoidal quadrangular which comprises an
upper surface, a lower surface parallel to the upper surface and
similar to the upper surface in shape, a front surface, a back
surface parallel to the front surface but having different size
with the front surface, an incline side surface obliquely
connecting with the front surface and the back surface, and a rear
surface perpendicularly connecting with the front surface and the
back surface, the back surface is functional as the light incident
surface, the rear surface is functional as the light output
surface, the upper surface, the lower surface, the front surface
and the incline side surface are functional as the reflection
surface, the rear surface faces a incident side of the light guide
plate, and a light emitting direction of the point light source and
the light output end of the fiber on the light bar faces the back
surface.
16. The backlight system of claim 14, wherein the optical mixing
block is an orthogonal triangular prism which comprises a pair of
rectangular side walls perpendicular to each other, a rectangular
incline side wall obliquely connected to the rectangular side walls
and a pair of triangular side walls correspondingly perpendicularly
connected to the rectangular side walls and the incline side wall,
the incline side wall is divided into an upper light output area
and a lower light incident area, the incident surface of the light
guide plate corresponds to the light output area, a width of the
light output area is the same as the thickness of the light guide
plate, the light guide plate is perpendicular to the incline side
wall, the light bar is set below the light guide plate, a light
emitting direction of the light bar is aligned with the light
incident area of the incline side wall, the rectangular side walls
and the triangular side walls are function as the reflection
surface.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a backlight module and a backlight
system using same.
BACKGROUND OF THE INVENTION
[0002] A current liquid crystal display usually employs a number of
light emitting diodes (LEDs) as a backlight module. However, the
LED is an electroluminescent device and wastes a lot of energy for
a long time use. Nature sunlight is environmental free energy and
should be considered being used as a backlight resource of liquid
crystal display. However, solar energy is not available at night or
in cloudy days and the color temperature of sunlight is 6000K, far
from a color temperature range of normal backlight resource from
10000K to 20000K, which influences a display effect.
[0003] Therefore, it is desirable to provide a means which can
solve the above-mentioned problems.
SUMMARY OF THE INVENTION
[0004] To solve the above-mentioned problem, the present invention
provides a backlight module including a solar collector, a number
of fibers, a light bar, an optical mixing block and a light guide
plate. Each of the fibers includes a light incident end and a light
output end. The solar light collector traces the sun and collects
the solar light. The light incident ends are connected to the solar
light collector and transmits the collected solar light to the
light output end. The light bar includes a number of point light
sources. The point light sources and the light output ends of the
fibers are set on the light bar. The solar light collected by the
solar light collector enters the optical mixing block to mix via
the light output ends of the fibers and emits into the light guide
plate to be spread as an even surface light source. The point light
sources give out a light to compensate lacks of chromaticity and
brightness of the collected solar light.
[0005] Wherein the point light sources and the light output ends of
the fibers are alternately set on the light bar along a
longitudinal direction of the light bar.
[0006] Wherein an arrangement of the point light sources is
alternately spaced blue point light sources and white point light
sources.
[0007] Wherein an arrangement of the point light sources is orderly
spaced red point light sources, green point light sources, and blue
point light sources.
[0008] Wherein the optical mixing block includes a light incident
surface, a light output surface, and a refection surface connecting
the light incident surface and the light output surface. The light
come out from the point light source and the light output end of
the fiber enters into the optical mixing block via the light
incident surface. The light strike on the reflection surface from
inside of the optical mixing block is reflected back into the
optical mixing block.
[0009] Wherein the optical mixing block is a orthogonal trapezoidal
quadrangular which includes an upper surface, a lower surface
parallel to the upper surface and similar to the upper surface in
shape, a front surface, a back surface parallel to the front
surface but having different size with the front surface, an
incline side surface obliquely connecting with the front surface
and the back surface, and a rear surface perpendicularly connecting
with the front surface and the back surface. The back surface is
functional as the light incident surface. The rear surface is
functional as the light output surface, the upper surface. The
lower surface, the front surface and the incline side surface are
functional as the reflection surface. The rear surface faces a
incident side of the light guide plate, and a light emitting
direction of the point light source and the light output end of the
fiber on the light bar faces the back surface.
[0010] Wherein the optical mixing block is an orthogonal triangular
prism which includes a pair of rectangular side walls perpendicular
to each other, a rectangular incline side wall obliquely connected
to the rectangular side walls and a pair of triangular side walls
correspondingly perpendicularly connected to the rectangular side
walls and the incline side wall. The incline side wall is divided
into an upper light output area and a lower light incident area,
the incident surface of the light guide plate corresponds to the
light output area. A width of the light output area is the same as
the thickness of the light guide plate. The light guide plate is
perpendicular to the incline side wall, the light bar is set below
the light guide plate. A light emitting direction of the light bar
is aligned with the light incident area of the incline side wall,
the rectangular side walls and the triangular side walls are
function as the reflection surface.
[0011] A backlight system includes a backlight module and a
controlling module to control the backlight module. The backlight
module including a solar collector, a number of fibers, a light
bar, an optical mixing block and a light guide plate. Each of the
fibers includes a light incident end and a light output end. The
solar light collector traces the sun and collects the solar light.
The light incident ends are connected to the solar light collector
and transmits the collected solar light to the light output end.
The light bar includes a number of point light sources. The point
light sources and the light output ends of the fibers are set on
the light bar. The solar light collected by the solar light
collector enters the optical mixing block to mix via the light
output ends of the fibers and emits into the light guide plate to
be spread as an even surface light source. The point light sources
give out a light to compensate lacks of chromaticity and brightness
of the collected solar light. The controlling module includes a
setting unit, a detecting unit, a comparing unit, and a regulating
unit. The setting module set chromaticity coordinates of backlight,
a brightness standard value and error ranges of the chromaticity
coordinates and the brightness standard value. The detecting unit
detects chromaticity coordinates and brightness value of the light
from the light guide plate. The comparing unit compares a threshold
of the error range of the chromaticity coordinates with the
chromaticity coordinates of the light from the light guide plate
and compares a threshold of the error range of the standard
brightness value with the brightness value of the light from the
light guide plate. The regulating unit controls the color of the
point light source to shine according to the comparison between the
chromaticity coordinates of the light from the light guide plate
and the preset error range of the chromaticity coordinates to
compensate the chromaticity deviation of the solar light and
controls the brightness of the point light source according to the
comparison between the brightness of the light from the light guide
plate and the standard brightness value to compensate lack of
brightness of the solar light.
[0012] Wherein the chromaticity coordinates is (0.28, 0.29), and
the error range of the chromaticity coordinates is (0.28+0.05,
0.29+0.05).
[0013] Wherein the brightness standard value is 5000 nits, and the
error range of the brightness standard value is +5%.
[0014] Wherein the point light sources and the light output ends of
the fibers are alternately set on the light bar along a
longitudinal direction of the light bar.
[0015] Wherein an arrangement of the point light sources is
alternately spaced blue point light sources and white point light
sources.
[0016] Wherein an arrangement of the point light sources is orderly
spaced red point light sources, green point light sources, and blue
point light sources.
[0017] Wherein the optical mixing block includes a light incident
surface, a light output surface, and a refection surface connecting
the light incident surface and the light output surface, the light
come out from the point light source and the light output end of
the fiber enters into the optical mixing block via the light
incident surface, and the light strike on the reflection surface
from inside of the optical mixing block is reflected back into the
optical mixing block.
[0018] Wherein the optical mixing block is a orthogonal trapezoidal
quadrangular which includes an upper surface, a lower surface
parallel to the upper surface and similar to the upper surface in
shape, a front surface, a back surface parallel to the front
surface but having different size with the front surface, an
incline side surface obliquely connecting with the front surface
and the back surface, and a rear surface perpendicularly connecting
with the front surface and the back surface. The back surface is
functional as the light incident surface. The rear surface is
functional as the light output surface, the upper surface. The
lower surface, the front surface and the incline side surface are
functional as the reflection surface. The rear surface faces a
incident side of the light guide plate, and a light emitting
direction of the point light source and the light output end of the
fiber on the light bar faces the back surface.
[0019] Wherein the optical mixing block is an orthogonal triangular
prism which includes a pair of rectangular side walls perpendicular
to each other, a rectangular incline side wall obliquely connected
to the rectangular side walls and a pair of triangular side walls
correspondingly perpendicularly connected to the rectangular side
walls and the incline side wall. The incline side wall is divided
into an upper light output area and a lower light incident area,
the incident surface of the light guide plate corresponds to the
light output area. A width of the light output area is the same as
the thickness of the light guide plate. The light guide plate is
perpendicular to the incline side wall, the light bar is set below
the light guide plate. A light emitting direction of the light bar
is aligned with the light incident area of the incline side wall,
the rectangular side walls and the triangular side walls are
function as the reflection surface.
[0020] The backlight system of the embodiments of the present
invention employs the collected sunlight as backlight, with a help
of blue point light sources to compensate blue lack of the sunlight
and make use of white point light source to compensate a brightness
of the sunlight. Thus, the energy is saved with a good backlight
quality.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to illustrate technical schemes of the present
invention or the prior art more clearly, the following section
briefly introduces drawings used to describe the embodiments and
prior art. Obviously, the drawing in the following descriptions
just is some embodiments of the present invention. The ordinary
person in the related art can acquire the other drawings according
to these drawings without offering creative effort.
[0022] FIG. 1 is a schematic structural view of a backlight system
in accordance with a first embodiment of the present invention;
[0023] FIG. 2 is an enlarged view of II portion of FIG. 1;
[0024] FIG. 3 is a schematic structural view of an optical mixing
block of FIG. 1;
[0025] FIG. 4 is a schematic structural view of a backlight system
in accordance with a second embodiment of the present invention;
and
[0026] FIG. 5 is a schematic structural view of an optical mixing
block of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The following sections offer a clear, complete description
of the present invention in combination with the embodiments and
accompanying drawings. Obviously, the embodiments described herein
are only a part of, but not all of the embodiments of the present
invention. In view of the embodiments described herein, any other
embodiment obtained by the person skilled in the field without
offering creative effort is included in a scope claimed by the
present invention.
[0028] Referring to FIG. 1, a backlight system provided by a first
embodiment of the present invention includes a backlight module 10
and a controlling module 12 used to control the backlight module
10. The backlight module 10 includes a solar light collector 100, a
number of fibers 110, a light bar 120, an optical mixing block 130,
and a light guide plate 140. Each of the fiber 110 includes a light
incident end 110a and a light output end 110b opposite to the light
incident end 110a. The solar light collector 100 traces the sun and
collects the solar light. The light incident end 110a is connected
to the solar light collector 100 for transmitting the solar light
to the light output end 110b. There are a number of point light
sources 121 and the light output ends 110b of the fibers 110 set on
the light bar 120. The solar light collected by the solar light
collector 100 emits into the optical mixing block 130 to mixture
and then enters the light guide plate 140 to be spread as a surface
light source. The controlling module 12 controls the point light
sources 121 to give out the light to compensate lacks of
chromaticity and brightness of the collected solar light.
[0029] The solar collector 100 includes a lens group 101, a light
sensor 102, and a driving device 103. The lens group 101 is used to
converge the solar light. The light sensor 102 senses an
orientation of the sun according to the collected solar light. The
driving device 103 drives the lens group to face the sun according
to the orientation of the sun. The light incident ends 110a of the
fibers 110 is connected with the lens group 101 to transmit the
collected light to the optical mixing block 130. The light sensor
102 determines the orientation of the sun according to a shadow of
a mark on which the sun shines or an energy distribution of the sun
on a predetermined plane. The principle and embodiment of the light
sensor 102 is not recited here in detail.
[0030] Also referring to FIG. 2, the point light sources 121 and
the light output ends 110b of the fibers 110 are alternately set on
the light bar 120 along a longitudinal direction of the light bar
120. The light bar 120 defines a number of receiving through holes
123 between each two adjacent point light sources 121. A periphery
of each receiving through hole 123 at a light emitting side of the
point light sources 121 extends out a pair of receiving side walls
124. The light bar 120 clamps the light output end 110b of the
fiber 110 received between the receiving side walls 124 by screwing
a nut on an outer surface of the receiving side walls 124. An
arrangement of the point light sources 121 may be, but is not
limited to, alternately spaced blue point light sources 121 and
white point light sources 121, or orderly spaced red point light
sources 121, green point light sources 121, and blue point light
sources 121. In this embodiment, the arrangement of the point light
source 121 is alternately spaced blue point light sources 121 and
white light sources 121.
[0031] In this embodiment, the point light sources 112 are a number
of light emitting diodes (LEDs). It is understood that, in an
alternative embodiment, the point light sources 121 also may be, a
number of organic light emitting diodes (OLEDs) and a number of
lamps.
[0032] The optical mixing block 130 includes a light incident
surface 131, a light output surface 132, and a refection surface
133 connecting the light incident surface 131 and the light output
surface 132. The light come out from the point light source 121 and
the light output end 132 of the fiber 110 enters into the optical
mixing block 130 via the light incident surface 131. A reflector or
a reflecting layer with high reflectivity is set on the light
output surface 133. The light output surface 133 also includes a
number of micro scattering structures 134 formed thereon to scatter
the light, such as a number of concave dots arranged as a matrix.
The micro scattering structures 134 on the reflection surface 133
scatter the light to different direction when reflects the light
back into the optical mixing block 130. The light is evenly mixed
in the optical mixing block 130, and then is emitted out from the
light output surface 132. The optical mixing block 130 is made of a
material has good translucency, such as polymethyl methacrylate
(PMMA).
[0033] Also referring to FIG. 3, in this embodiment, the optical
mixing block 130 is a orthogonal trapezoidal quadrangular which
includes an upper surface 130a, a lower surface 130b parallel to
the upper surface 130a and similar to the upper surface 130a in
shape, a front surface 130c, a back surface 130d parallel to the
front surface 130c but having different size with the front surface
130c, an incline side surface 130e obliquely connecting with the
front surface 130c and the back surface 130d, and a rear surface
130f perpendicularly connecting with the front surface 130c and the
back surface 130d. The back surface 130d is functional as the light
incident surface 131. The rear surface 130f is functional as the
light output surface 132. The other surfaces are functional as the
reflection surface 133. The micro scattering structures 134 are set
on the incline side surface 130e. Because the incline side surface
130e located before the back surface 130d, most of light entered
from the back surface 130d is scattered by the micro scattering
structure 134 when is reflected by the incline side surface 130e to
mix the light evenly. The light strikes on the upper surface 130a,
the lower surface 130b and the front surface 130c are all reflected
back into the optical mixing block unit come out from the rear
surface 130f.
[0034] It is understood that the light incident surface 131 is not
limited to the back surface 130d of the orthogonal trapezoidal
quadrangular and may be the other surfaces, such as the optical
mixing block 130 includes two light incident surfaces 131 of the
front surface 130c and the back surface 130d, or includes three
light incident surfaces 131 of the front surface 130c, the back
surface 130d and the incline surface 130e. Each of the light
incident surfaces 131 is correspond to one light bar 120 to provide
the incident light source.
[0035] The light output surface 132 of the optical mixing block 130
faces the light incident side of the light guide plate 140. A light
emitting direction of the point light source 121 and the light
output end 110b of the fiber 110 on the light bar 120 faces the
light incident surface 131 of the optical mixing block 130. In this
embodiment, the light emitting direction of the light bar 120 is
perpendicular to a normal line of the light output surface 132.
That is, a light path of the backlight module 10 is the light from
the light bar 120 is turned 90 degrees by the optical mixing block
130 and then enters into the light guide plate 140.
[0036] The light guide plate 140 includes an incident surface 142
and an output surface 144. The incident surface 142 is similar to
the light output surface 132 of the optical mixing block 130 in
shape and size to accept as much as possible light from the light
come out from the optical mixing block 130. The light guide plate
140 may be a rectangular plate with a stable thickness or a wedge
with the thickness gradually reducing from one end to the other
end. In this embodiment, the light guide plate 140 is the
rectangular plate with the stable thickness. A side wall
corresponding to one of short side is the incident surface 142. A
top surface perpendicular to the side wall is the output surface
144.
[0037] The controlling module 12 includes a setting unit 121, a
detecting unit 122, a comparing unit 123 and a regulating unit 124.
The word "module", as used therein, refers to logic embodied in
hardware or firmware, or to a collection of software instructions,
written in a programming language. The software instructions may be
embedded in firmware or stored in any type of storage device and
executed by a processor to implement a particular function.
[0038] The setting unit 121 sets chromaticity coordinates of
backlight, a brightness standard value and error ranges of the
chromaticity coordinates and the brightness standard value. The
chromaticity coordinates, the brightness standard value and the
corresponding error ranges is used as a reference to regulate the
light from the point light source 121. In this embodiment, the
chromaticity coordinates is (0.28, 0.29), the error range of the
chromaticity coordinates is (0.28+0.05, 0.29+0.05). The brightness
standard value is 5000 nits. The error range of the brightness
standard value is +5%.
[0039] The detecting unit 122 includes a chromaticity detector 122a
and a brightness detector 122b. The chromaticity detector 122a and
the brightness detector 122b are set beside the output surface 144
of the light guide plate 140 to detect the chromaticity coordinates
and the brightness of the light from the light guide plate 140.
Because nature sunlight lacks of blue wave band, in order to meet a
chromaticity requirement of the backlight, the point light sources
121 needs to give out blue light to regulate the collected
sunlight. At night or in a cloudy day, the brightness of the
collected sunlight also cannot meet the display requirement, and
the point light source 121 needs to give out white light to
compensate the brightness of the collected sunlight. The
chromaticity coordinates and the brightness value of the light from
the light guide plate 140 is used as a parameter to regulate the
lighting of the point light source 121.
[0040] The comparing unit 123 compares a threshold of the error
range of the chromaticity coordinates with the chromaticity
coordinates of the light from the light guide plate 140 to
determine how much lack of blue light in the light from the light
guide plate 140. The comparing unit 123 compares a threshold of the
error range of the standard brightness value with the brightness
value of the light from the light guide plate 140 to determine
whether or not the brightness of the light from the light guide
plate 140 meet the brightness requirement of the backlight.
[0041] The regulating unit 124 controls the blue point light source
121 to shine according to the comparison between the chromaticity
coordinates of the light from the light guide plate 140 and the
preset error range of the chromaticity coordinates. If the
chromaticity coordinates of the light from the light guide plate
140 is within the error range of the chromaticity coordinates, the
regulating unit 124 transmits a turn off instruction to the light
bar 120 to turn off the blue point light source 121. If the
chromaticity coordinates of the light from the light guide plate
140 is out of the error range of the chromaticity coordinates
towards a direction of blue side, the regulating unit 121 transmits
a compensating instruction to the light bar 120 to turn on the blue
point light source to compensate the blue light. The chromaticity
coordinates of the output light deviate further from the error
range, and the blue point light source is controlled to shine
brighter to increase the compensation strength of blue light. The
regulating unit 124 controls the white point light source 121 to
shine according to the comparison between the brightness of the
light from the light guide plate 140 and the standard brightness
value. If the brightness of the light from the light guide plate
140 is less than a minimum value of the error range of the standard
brightness value, the regulating unit 124 transmits a brightness
compensating instruction to the light bar 120 to turn on the white
point light source 121 for compensating the backlight brightness.
It is understood that if the arrangement of the point light sources
121 is alternately spaced the red point light source 121, the green
point light source 121 and the blue point light source 121, the
light bar 120 turns on the red point light source 121, the green
point light source 121 and the blue point light source 121 at a
same time when receives the brightness compensating
instruction.
[0042] Referring to FIGS. 4 and 5, a structure of a backlight
system in accordance with a second embodiment of the present
invention is similar to that of the backlight system 1 of the first
embodiment with a difference that the optical mixing block 230 is
an orthogonal triangular prism. The optical mixing block 230
includes a pair of rectangular side walls 230a perpendicular to
each other, a rectangular incline side wall 230b obliquely
connected to the rectangular side walls 230a and a pair of
triangular side walls 230c correspondingly perpendicularly
connected to the rectangular side walls 230a and the incline side
wall 230b. The incline side wall 230b is divided into an upper
light output area 2300b and a lower light incident area 2301b along
a direction perpendicular to the lateral edge. The light output
area 2300b is functional as the light output surface 232 of the
optical mixing block 230. The light incident area 2301b is
functional as the light incident surface 231 of the optical mixing
block 230. The incident surface 242 of the light guide plate 240
corresponds to the light output area 2300b. A width of the light
output area 2300b is the same as the thickness of the light guide
plate 240. The light guide plate 240 is perpendicular to the
incline side wall 230b. The light bar 220 is set below the light
guide plate 240. A light emitting direction of the light bar 220 is
aligned with the light incident area 2301b of the incline side wall
230b. The rectangular side walls 230 and the triangular side walls
230 are function as the reflection surface 133.
[0043] The backlight system 1 of the embodiments of the present
invention employs the collected sunlight as backlight, with a help
of blue point light sources 121 to compensate blue lack of the
sunlight and make use of white point light source 121 to compensate
a brightness of the sunlight. Thus, the energy is saved with a good
backlight quality.
[0044] What is said above are only preferred examples of present
invention, not intended to limit the present invention, any
modifications, equivalent substitutions and improvements etc. made
within the spirit and principle of the present invention, should be
included in the protection range of the present invention.
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