U.S. patent application number 12/371751 was filed with the patent office on 2009-08-20 for diffuser with light condensing function.
Invention is credited to Wen-Hao LIU, Whey-Bin LOR, Kuang-Lin YUAN.
Application Number | 20090207497 12/371751 |
Document ID | / |
Family ID | 40954874 |
Filed Date | 2009-08-20 |
United States Patent
Application |
20090207497 |
Kind Code |
A1 |
LOR; Whey-Bin ; et
al. |
August 20, 2009 |
Diffuser with Light Condensing Function
Abstract
One face of a substrate of a diffuser with a light condensing
function is disposed with a plurality of prism rods; at least one
inclined face of parts of prism rods is disposed with a rough
diffusion face; the diffusion face may be positioned on any
position of the inclined face of the prism rod; the diffusion face
is disposed with a plurality of irregularly arranged raised and
indented stripes perpendicular, not perpendicular or parallel to a
crest line of the prism rod; chromatic dispersion can be reduced
and stripes of the prism rods can be atomized effectively by
utilizing the diffusion face to eliminate the occurrence of moire
fringes and elevate the yield factor.
Inventors: |
LOR; Whey-Bin; (Jhubei City,
TW) ; YUAN; Kuang-Lin; (Taichung City, TW) ;
LIU; Wen-Hao; (Kaohsiung City, TW) |
Correspondence
Address: |
BRUCE H. TROXELL
SUITE 1404, 5205 LEESBURG PIKE
FALLS CHURCH
VA
22041
US
|
Family ID: |
40954874 |
Appl. No.: |
12/371751 |
Filed: |
February 16, 2009 |
Current U.S.
Class: |
359/599 |
Current CPC
Class: |
G02B 5/0278 20130101;
G02B 5/0221 20130101; G02B 5/045 20130101; G02B 5/0231
20130101 |
Class at
Publication: |
359/599 |
International
Class: |
G02B 5/02 20060101
G02B005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 14, 2008 |
TW |
097202707 |
Claims
1. A diffuser with a light condensing function, comprising a
substrate and a plurality of longitudinally arranged long
strip-typed prism rods; one surface of said substrate being
disposed with said plurality of prism rods; each said prism rod
being provided with a crest line, a first inclined face and a
second inclined face; said crest line being positioned at the
highest position of said prism rod; said first inclined face and
said second inclined face being respectively extended from two
sides of said crest line to said substrate; at least one inclined
face of said first inclined face and said second inclined face of
each of parts of said prism rods being disposed with a diffusion
face; said diffusion face is disposed with a plurality of
irregularly arranged raised and indented stripes.
2. The diffuser with a light condensing function according to claim
1, wherein a width of said diffusion face is a value between 2% and
90% of a width of said inclined face.
3. The diffuser with a light condensing function according to claim
1, wherein said plurality of raised and indented stripes are
perpendicular to said crest line.
4. The diffuser with a light condensing function according to claim
1, wherein said plurality of raised and indented stripes are
parallel to said crest line.
5. The diffuser with a light condensing function according to claim
2, wherein said plurality of raised and indented stripes are
perpendicular to said crest line.
6. The diffuser with a light condensing function according to claim
2, wherein said plurality of raised and indented stripes are
parallel to said crest line.
7. The diffuser with a light condensing function according to claim
5, wherein said diffusion face is close to said substrate.
8. The diffuser with a light condensing function according to claim
5, wherein said diffusion face is close to said crest line.
9. The diffuser with a light condensing function according to claim
6, wherein said diffusion face is close to said substrate.
10. The diffuser with a light condensing function according to
claim 6, wherein said diffusion face is close to said crest
line.
11. The diffuser with a light condensing function according to any
one of claims 1, wherein a width of said diffusion face is randomly
varied.
12. The diffuser with a light condensing function according to any
one of claims 7, wherein a width of said diffusion face is randomly
varied.
13. The diffuser with a light condensing function according to any
one of claims 8, wherein a width of said diffusion face is randomly
varied.
14. The diffuser with a light condensing function according to any
one of claims 9, wherein a width of said diffusion face is randomly
varied.
15. The diffuser with a light condensing function according to any
one of claims 10, wherein a width of said diffusion face is
randomly varied.
16. The diffuser with a light condensing function according to any
one of claims 1, wherein a width of said diffusion face is
regularly varied.
17. The diffuser with a light condensing function according to any
one of claims 7, wherein a width of said diffusion face is
regularly varied.
18. The diffuser with a light condensing function according to any
one of claims 8, wherein a width of said diffusion face is
regularly varied.
19. The diffuser with a light condensing function according to any
one of claims 9, wherein a width of said diffusion face is
regularly varied.
20. The diffuser with a light condensing function according to any
one of claims 10, wherein a width of said diffusion face is
regularly varied.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an optical film, and more
particularly to an optical film with a plurality of prism rod
structures required for a backlight system of a liquid crystal
display or other electronic devices.
[0003] 2. Description of Related Art
[0004] Please refer to FIG. 1. A backlight system of a general
liquid crystal display (LCD) comprises a cold cathode fluorescence
lamp (CCFL) 11, light guiding plate (LGP) 12, bottom diffuser 13,
prism sheet 14, top diffuser 15 and reflector 16.
[0005] Please refer to FIG. 2. A conventional prism sheet is
constituted by a plurality of triangular prism rods 141 with their
longitudinal axes parallel to each other and a substrate 142. The
prism rods 141 are coupled to one side of the substrate 142. A
height and a width of each prism rod 141 are the same, and the
height of a peak of the prism rod 141 is not varied, a course of
the peak is a straight line, two inclined faces at two sides of the
peak are symmetrical. The conventional prism sheet 14 is provided
with a surface structure constituted by a plurality of regular
prism rods 141.
[0006] Please refer to FIG. 3. There are three optical path modes
of the prism sheet 14:
[0007] 1. Total Reflection (TRI) Recycle:
[0008] When a light beam 143 is projected from an inside of a prism
approximately within .+-.4.degree. relative to a virtual
perpendicular axis 140 perpendicular to a bottom face of the prism
rod 141, it is influenced by total reflection phenomena of inclined
faces of the prism rod 141, recycled toward a back light source
after two total reflections and diffused, propagated and utilized
continuously;
[0009] 2. Second Reflection Recycle:
[0010] After a light beam 144 is refracted by two prism rods 141,
it is then recycled to the back light source and diffused,
propagated and utilized continuously;
[0011] 3. Directed Reflective:
[0012] A beam 145 is refracted out through an inclined face of the
prism rod 141, this optical path mode have light gathering
function; only light beams refracted out within the range of a
vision angle 80.degree. of the prism rod 141 can be utilized, as
shown in FIG. 3.
[0013] Chromatic dispersion and moire fringes will be easily
yielded when a upper layer material film such, as a upper differ 15
or another prism sheet is stacked on the prism sheet 14.
Furthermore, a face of the prism sheet 14 provided with the
plurality of prism rods parallel to each other is rather smooth. If
there are defects, they are easy to be found and thus, the prism
sheet 14 is considered as a flaw product.
[0014] There are many prism sheets with a diffuser layer, for
example, a prism sheet disclosed by U.S. Pat. No. 5,844, 720 has a
plurality of triangular prism rods with their longitudinal axes
almost parallel to each other on one side and has the other side
roughened. The prism sheet is free from interference fringes, safe
from scratching and uniform and high in brightness, being thus
useful for liquid crystal display. Furthermore, a prism sheet
disclosed by Taiwan Patent No. M293442 comprises a substrate; one
side of the substrate comprises a light diffusing layer with raised
or indented coarse structure, in which the light diffusion layer
has diffusivity of 5% to 90%.
[0015] The prism sheets with a light diffusing layer mentioned
above are mostly manufactured by allowing a manufactured prism
sheet to be further fabricated with a coarse face layer on a bottom
thereof; it is rather wastes the labor time. Moreover, a face of
the prism sheet with the plurality of parallel prism rods is rather
smooth, if there are defects thereon, they are easily found and the
prism sheet is considered as a flow product.
[0016] A diffusing prism sheet disclosed by Taiwan Patent
Application No. 95133798 is provided with a long striped-type
coarse diffusion face between two adjacent prism rods. Chromatic
dispersion and fringes of prism rods can be respectively
effectively eliminated and atomized, moire fringes are reduced and
the yield factor of prism sheets can be increased by mixing light
diffused from a diffusion face between two adjacent prism rods and
light projected from prism rods. Moreover, a substrate, a plurality
of long strip-typed prism rods with longitudinal axes parallel to
each other and long strip-typed coarse diffusion faces may be
formed into one body such that the prism sheet is easily
manufactured.
[0017] A diffusing prism sheet disclosed by Taiwan Patent
Application No. 96108016 is manufactured by allowing rough coarse
portions to be respectively disposed on tops of peaks of a
plurality of prism rods and/or two sides of each prism rod so as to
reduce block, chromatic dispersion and moire fringes yielded when
the diffusing prism sheet is stacked with the other material
film.
[0018] However, if the substrate, the plurality of long strip-typed
prism sheets with longitudinal axes parallel to each other and the
long strip-typed coarse diffusing faces want to be formed into one
body, it is rather difficult. Generally, the coarse diffusion face
is formed by means of abrasion blasting after the prism rods are
formed; the two manufacturing processes are needed, it increases
the production time and cost.
SUMMARY OF THE INVENTION
[0019] For allowing a diffuser with a light condensing function to
have a new structure to enable it to be manufactured easier, the
present invention is proposed.
[0020] The main object of the present invention is to propose a
diffuser with a light condensing function, allowing it to be
manufactured easily to save the production cost and capable of
being free from chromatic dispersion when the diffuser and the
other material are stacked with each other.
[0021] Another object of the present invention is to provide a
diffuser with a light condensing function, capable of atomizing
stripes of prism rods and helpful for elevating the yield factor of
the diffuser and shielding defects of a backlight module.
[0022] Still another object of the present invention is to provide
a diffuser with a light condensing function, capable of reducing
moire fringes yielded when the diffuser is stacked with the other
material film.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The present invention can be more fully understood by
reference to the following description and accompanying drawings,
in which:
[0024] FIG. 1 is a schematic of a conventional backlight system of
a display;
[0025] FIG. 2 is a schematic view of a conventional prism
sheet;
[0026] FIG. 3 is a schematic view of various light refraction modes
of a conventional prism sheet.
[0027] FIG. 4 is a schematic view, showing a diffuser of a first
preferred embodiment of the present invention;
[0028] FIG. 5 is a side view, showing a diffuser of the first
embodiment according to the present invention;
[0029] FIG. 6 is a schematic view, showing diffusing light of a
diffuser of the first embodiment according to the present
invention;
[0030] FIG. 7 is a schematic view, showing a diffuser of a second
preferred embodiment according to the present invention;
[0031] FIG. 8 is a schematic view, showing a diffuser of a third
preferred embodiment according to the present invention; and
[0032] FIG. 9 is a schematic view, showing a diffuser of a fourth
preferred embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Please refer to FIGS. 4, 5 and 6. A diffuser with a light
condensing function of the present invention is used for
eliminating chromatic dispersion of prism rods and the occurrence
of moire fringes. A diffuser 20 of a first preferred embodiment
according to the present invention comprises a substrate 21 used
for allowing light to be penetrated through; one surface of the
substrate 21 is disposed with a plurality of longitudinally
arranged long strip-typed prism rods 22; each prism rod is provide
with a crest line 221, a first inclined face 222 and a second
inclined face 223; the crest line 221 is positioned at the highest
position of the prism rod 22; the first inclined face 222 and the
second inclined face 223 are respectively extended from two sides
of the crest line 221 to the substrate 21; each of bottoms of the
first inclined faces 222 and/or the second inclined faces of parts
of prism rods 22 close to the substrate 21 is disposed with a rough
diffusion face 224; the diffusion face 224 is disposed with a
plurality of irregularly arranged raised and indented stripes 225;
the plurality of stripes 225 are perpendicular to the crest line
221. As shown in FIG. 5, a width "a" of the diffusion face 224 is a
value between 2% and 90% of a width "b" of the first inclined face
222 or the second inclined face 223. There is only one
manufacturing process needed to form the prism rods 22 and the
diffusion face 224 simultaneously for the diffuser 20. Thus, the
production time and cost can be reduced.
[0034] The diffuser 20 of the present invention can reduce
chromatic dispersion and atomize stripes of the prism rods 22
effectively by mixing light 31 diffused out from the diffusion face
224 with light 32 projected out from the prism rod 22 as shown in
FIG. 6, and in the meantime, reduce moire fringes. Moreover,
because the prism rod 22 is provided with the long strip-typed
coarse diffusion face 224, the entire outlook of the diffuser 20 is
not a completely smooth face, even if other defects are yielded on
the first inclined face 222 and/or the second inclined face 223,
they cannot be found easily to cause the diffuser 20 to be
considered as a flaw product thereby capable of elevating the yield
factor of the prism sheets 20.
[0035] Please refer to FIG. 7. A diffuser 30 of a second preferred
embodiment according to the present invention also comprises a
substrate 31 and a plurality of prism rods 32. Each prism rod 32
has a crest line 321, a first inclined face 322 and a second
inclined face 323. But, upper ends of the first inclined face 322
and/or the second inclined face of the plurality of prism rods 32
close to the crest lines 321 are disposed with rough diffusion
faces 324; each diffusion face 324 is disposed with a plurality of
irregularly arranged rough stripes 325; the plurality of rough
stripes 325 are perpendicular to the crest line 321; a width of the
diffusion face 324 is a value between 2% and 90% of a width of the
first inclined face 322 or the second inclined face 323. There is
only one manufacturing process needed to form the prism rods 32 and
the diffusion face 324 simultaneously for the diffuser 30. Thus,
the production time and cost can be reduced. Moreover, the diffuser
30 has the other functions held by the diffuser 20 mentioned
above.
[0036] Please refer to FIG. 8. A diffuser 40 of a third preferred
embodiment according to the present invention also comprises a
substrate 41 and a plurality of prism rods 42. Each prism rod 42
has a crest line 421, a first inclined face 322 and a second
inclined face 423. But, lower ends of the first inclined face 422
and/or the second inclined face of the plurality of prism rods 42
close to the substrate 41 are disposed with rough diffusion faces
424; each diffusion face 424 is disposed with a plurality of
irregularly arranged rough stripes 425; the plurality of rough
stripes 425 are parallel to the crest line 421; a width of the
diffusion face 424 is a value between 2% and 90% of a width of the
first inclined face 422 or the second inclined face 423. There is
only one manufacturing process needed to form the prism rods 42 and
the diffusion face 424 simultaneously for the diffuser 40. Thus,
the production time and cost can be reduced. Moreover, the diffuser
40 has the other functions held by the diffuser 20 mentioned
above.
[0037] Please refer to FIG. 9. A diffuser 50 of a fourth preferred
embodiment according to the present invention also comprises a
substrate 51 and a plurality of prism rods 52. Each prism rod 52
has a crest line 521, a first inclined face 522 and a second
inclined face 523. But, upper ends of the first inclined face 522
and/or the second inclined face of the plurality of prism rods 52
close to the crest lines 521 are disposed with rough diffusion
faces 524; each diffusion face 524 is disposed with a plurality of
irregularly arranged rough stripes 525; the plurality of rough
stripes 525 are parallel to the crest line 521; a width of the
diffusion face 524 is a value between 2% and 90% of a width of the
first inclined face 522 or the second inclined face 523. There is
only one manufacturing process needed to form the prism rods 52 and
the diffusion face 524 simultaneously for the diffuser 50. Thus,
the production time and cost can be reduced. Moreover, the diffuser
50 has the other functions held by the diffuser 20 mentioned
above.
[0038] Each of inclined faces of a plurality of prism rods of a
diffuser of the present invention may be disposed with a rough
diffusion face; a width of the diffusion face is a value between 2%
and 90% of a width of the inclined face of the prism rod. All two
inclined faces of the prism rod may respectively be disposed with a
diffusion face or only one inclined face thereof is disposed with a
diffusion face. The diffusion face may be positioned on any
position of the inclined face of the prism rod, the diffusion face
is disposed with a plurality of irregularly arranged rough stripes
and the irregularly arranged rough stripes may be perpendicular,
not perpendicular or parallel to a crest line of the prism rod. The
width of the diffusion face may be randomly or regularly varied.
The diffusion face of the diffuser of the present invention maybe
utilized to eliminate chromatic dispersion and atomize the stripes
of the prism rods, and reduce moire fringes to elevate the yield
factor. Besides, one single diffuser of the present invention can
be used to replace the prism sheet 14 plus the upper diffuser 15
shown in FIG. 1 so as to attain to the two films coupling effect
and reduce a thickness of the backlight module to reduce the cost
expense.
[0039] A diffuser of the present invention can attain to the
following effects: [0040] 1. capable of reducing the production
time and cost; [0041] 2. capable of eliminating chromatic
dispersion of prism rods; [0042] 3. atomizing stripes of prism
rods, reducing occurrence of moire fringes; [0043] 4. atomizing
stripes of prism rods, helpful for elevating the yield factor; and
[0044] 5. atomizing stripes of prism rods, shielding defects of a
backlight module.
[0045] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
* * * * *