U.S. patent application number 13/677530 was filed with the patent office on 2013-03-21 for multicolored linear light source.
This patent application is currently assigned to I2IC CORPORATION. The applicant listed for this patent is Manas Alekar, Balaji Ganapathy, Sanat Ganu, Manohar Joshi, Udayan Kanade, Gaurav Kulkarni, Karthikk Sridharan. Invention is credited to Manas Alekar, Balaji Ganapathy, Sanat Ganu, Manohar Joshi, Udayan Kanade, Gaurav Kulkarni, Karthikk Sridharan.
Application Number | 20130069519 13/677530 |
Document ID | / |
Family ID | 40226611 |
Filed Date | 2013-03-21 |
United States Patent
Application |
20130069519 |
Kind Code |
A1 |
Kanade; Udayan ; et
al. |
March 21, 2013 |
MULTICOLORED LINEAR LIGHT SOURCE
Abstract
A multicolored linear light source is disclosed. In an
embodiment, the multicolored linear light source comprises a linear
light source emanating light of a first spectrum, and regions of
photoluminescent material. The light of the first spectrum
interacts with regions of photoluminescent material to give light
of a different spectrum. The composition of different regions of
photoluminescent material is different, providing light of
different spectra in different regions. Coupled to each region of
photoluminescent material is a columnar light guide such that light
produced by the regions traverses respective columnar light guides
and gets extracted.
Inventors: |
Kanade; Udayan; (Pune,
IN) ; Kulkarni; Gaurav; (Pune, IN) ;
Sridharan; Karthikk; (Minneapolis, MN) ; Alekar;
Manas; (Irvine, CA) ; Joshi; Manohar; (Pune,
IN) ; Ganu; Sanat; (Pune, IN) ; Ganapathy;
Balaji; (Atlanta, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kanade; Udayan
Kulkarni; Gaurav
Sridharan; Karthikk
Alekar; Manas
Joshi; Manohar
Ganu; Sanat
Ganapathy; Balaji |
Pune
Pune
Minneapolis
Irvine
Pune
Pune
Atlanta |
MN
CA
GA |
IN
IN
US
US
IN
IN
US |
|
|
Assignee: |
I2IC CORPORATION
Foster City
CA
|
Family ID: |
40226611 |
Appl. No.: |
13/677530 |
Filed: |
November 15, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12667526 |
Jul 9, 2010 |
8333494 |
|
|
13677530 |
|
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Current U.S.
Class: |
313/485 |
Current CPC
Class: |
H01J 61/48 20130101;
H01J 61/35 20130101; G02B 6/001 20130101; H01J 1/74 20130101 |
Class at
Publication: |
313/485 |
International
Class: |
H01J 61/48 20060101
H01J061/48 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 5, 2007 |
IN |
1284/MUM/2007 |
Claims
1. An apparatus comprising: a light source emanating light of a
first spectrum, a plurality of regions of photoluminescent material
disposed on the surface of the light source, and a plurality of
light guides situated perpendicular to the light source, wherein
least a first region of photoluminescent material and a second
region of photoluminescent material emanate light of different
spectra.
2. The apparatus of claim 1, wherein the light source is a gas
discharge tube.
3. The apparatus of claim 1, wherein the light source comprises a
light guide, diffuser particles and a second light source.
4. The apparatus of claim 1, further comprising a mirror partially
covering the surface of the light source, wherein the plurality of
regions of photoluminescent material is disposed in an area where
the mirror is not disposed on the surface of the light source.
5. The apparatus of claim 1, wherein each light guide of the
plurality of light guides is situated closed to a particular region
of the plurality of regions of photoluminescent material.
6. The apparatus of claim 1, wherein each light guide of the
plurality of light guides further comprises means of extracting
light.
7. The apparatus of claim 6, wherein the means of extracting light
comprises particles that scatter light.
8. The apparatus of claim 1, wherein the light source comprises a
second light guide, and a second light source situated near the end
of the second light guide, the second light guide comprising means
of extracting light.
9. The apparatus of claim 5, wherein the means of extracting light
comprises particles that scatter light.
10. The apparatus of claim 6, further comprising a display lighted
by the plurality of light guides.
Description
[0001] This patent is a continuation of U.S. patent application
Ser. No. 12/667,526 entitled "MULTICOLORED LINEAR LIGHT SOURCE"
filed on Jul. 9, 2010, which in turn claims priority from
provisional patent number 1284/MUM/2007 titled "Multicolored Linear
Light Source" filed on the 5th of Jul. 2007 in Mumbai, India.
TECHNICAL FIELD
[0002] The present invention relates to a source of illumination.
Particularly, the invention relates to an apparatus and method for
a source of illumination producing multiple colors.
BACKGROUND ART
[0003] A source of illumination is used for lighting purposes. A
linear light source may be used as a source of illumination to
provide light in the backlights of display systems. In color
transmissive display systems such as liquid crystal displays, the
backlights are designed to provide light into the liquid crystal
sheet. The light emanating from the liquid crystal sheet passes
through a sheet of color filters. The color filter sheet allows
only light of a particular color to pass through and blocks light
of other colors. So, a significant proportion of light emanating
from the backlight is blocked by the color filter sheet, reducing
the efficiency of the display.
[0004] There exists prior art wherein a color display is lighted by
column sources of light, each column carrying light of a particular
color. A multicolored light source is needed so that light of
various colors is coupled into the various columns. The
multicolored linear light sources known in art are cumbersome and
costly to produce. Thus, there is a need for a simple and cheaper
multicolored linear light source.
[0005] A photoluminescent tube (usually known as a fluorescent
tube) is used as a source of illumination for backlights in
displays. A photoluminescent tube is made of a gas discharge tube
coated with photoluminescent material on the surface of the tube.
When a high voltage is applied across the tube, ionization of the
gases occurs. These ions emit photons which hit the
photoluminescent materials on the surface. The photoluminescent
materials on the surface emit light of a particular spectrum.
Photoluminescent material is any material which absorbs photons and
hence emits photons. Photoluminescent materials include fluorescent
materials, phosphorescent materials and scintillators.
SUMMARY
[0006] A multicolored linear light source is disclosed. In an
embodiment, the multicolored linear light source comprises a linear
light source emanating light of a first spectrum, and regions of
photoluminescent material. The light of the first spectrum
interacts with regions of photoluminescent material to give light
of a different spectrum. The composition of different regions of
photoluminescent material is different, providing light of
different spectra in different regions.
[0007] The above and other preferred features, including various
details of implementation and combination of elements are more
particularly described with reference to the accompanying drawings
and pointed out in the claims. It will be understood that the
particular methods and systems described herein are shown by way of
illustration only and not as limitations. As will be understood by
those skilled in the art, the principles and features described
herein may be employed in various and numerous embodiments without
departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings, which are included as part of the
present specification, illustrate the presently preferred
embodiment and together with the general description given above
and the detailed description of the preferred embodiment given
below serve to explain and teach the principles of the present
invention.
[0009] FIG. 1 illustrates a block diagram of a multicolored linear
light source, according to an embodiment.
[0010] FIG. 2 illustrates a block diagram of a multicolored linear
light source comprising a mirror, according to an embodiment.
[0011] FIG. 3 illustrates a cutaway diagram of a multicolored
linear light source comprising a light guide and diffuser,
according to an embodiment.
[0012] FIG. 4 illustrates a cutaway diagram of a multicolored
linear light source comprising a light guide, a diffuser and a
mirror, according to an embodiment.
[0013] FIG. 5 illustrates a block diagram of extraction of light
from a multicolored light source, according to an embodiment.
[0014] FIG. 6 illustrates a block diagram of a light source
comprising column sources of light, according to an embodiment.
DETAILED DESCRIPTION
[0015] A multicolored linear light source is disclosed. In an
embodiment, the multicolored linear light source comprises a linear
light source emanating light of a first spectrum, and regions of
photoluminescent material. The light of the first spectrum
interacts with regions of photoluminescent material to give light
of a different spectrum. The composition of different regions of
photoluminescent material is different, providing light of
different spectra in different regions.
[0016] FIG. 1 illustrates a block diagram of a multicolored linear
light source 199, according to an embodiment. The inner surface of
a gas discharge tube 100 is coated with different photoluminescent
materials as shown in the figure to give a multicolored
photoluminescent tube. The photoluminescent materials 102, 104, 106
are such that, light emanating from them are of different spectra.
In an embodiment, the gas discharge tube is a cold cathode lamp. In
another embodiment, the gas discharge tube is a hot cathode
lamp.
[0017] FIG. 2 illustrates a block diagram of a multicolored linear
light source 299 comprising a mirror, according to an embodiment.
The outer surface of the photoluminescent tube 200 is partially
covered by a mirror 208. In a region where the mirror is not
present, photoluminescent material 202, 204 and 206 are provided.
Light produced by low pressure gas in the photoluminescent tube
falling on the mirror 208 gets reflected once or more times, till
it falls on one of the photoluminescent materials 202, 204 or 206.
Light falling on the photoluminescent materials 202, 204 and 206
causes light emanation. The photoluminescent materials 202, 204,
206 are such that, light emanating from them are of different
spectra.
[0018] FIG. 3 illustrates a cutaway diagram of a multicolored
linear light source 399 comprising a light guide and diffuser,
according to an embodiment. Light source 310 emanates light into
light guide 300. The light traveling through light guide 300 is
scattered by diffuser particles 312 present inside it. The surface
of the light guide 300 is coated with different photoluminescent
materials 302, 304 and 306. Light scattered by the diffuser
particles 312 reaches the photoluminescent materials, causing light
emanation from the photoluminescent materials. The photoluminescent
materials 302, 304, 306 are such that, light emanating from them
are of different spectra.
[0019] FIG. 4 illustrates a cutaway diagram of a multicolored
linear light source 499 comprising a light guide, a diffuser and a
mirror, according to an embodiment. Light source 410 emanates light
into light guide 400. The light traveling through the light guide
400 is scattered by diffuser particles 412 present inside it. The
surface of the light guide 400 is partially covered by a mirror
408. In a region where the mirror is not present, photoluminescent
materials 402, 404 and 406 are provided. Light scattered by the
diffuser particles 412 falling on the mirror 408 gets reflected
once or more times, till it falls on one of the photoluminescent
materials 402, 404 or 406. Light falling on the photoluminescent
materials 402, 404 and 406 causes light emanation. The
photoluminescent materials 402, 404, 406 are such that, light
emanating from them are of different spectra.
[0020] FIG. 5 illustrates a block diagram of extraction of light
from a multicolored light source 599, according to an embodiment.
Exemplary, light ray 514 passes through the light guide 500. The
light ray 514 undergoes scattering when it impinges on a particle
of the diffuser 512. The light ray 514 then gets reflected from the
mirror 508 and may again get scattered by diffuser particles. When
the light ray 514 falls on the photoluminescent material 518,
photoluminescent material 518 emanates light 520 of a particular
spectrum.
[0021] FIG. 6 illustrates a block diagram of a light source 699
comprising column sources of light, according to an embodiment. A
multicolored linear light source 600 has regions of
photoluminescent material 602, 604, 606 on the surface emanating
light of different spectra. Coupled to each region of
photoluminescent material, is a columnar light guide such as light
guides 612, 614 and 616. The light produced by the regions 602, 604
and 606 traverses respective light guides and gets extracted over
the entire length of the light guide by light scattering due to
small particles, or other extraction methods. The light guides 612,
614 and 616 may have cladding material of lower refractive index
between them. They may also have mirrors between them, or behind
them.
[0022] A multicolored linear light source is disclosed. It is
understood that the embodiments described herein are for the
purpose of elucidation and should not be considered limiting the
subject matter of the present patent. Various modifications, uses,
substitutions, recombinations, improvements, methods of production
without departing from the scope or spirit of the present invention
would be evident to a person skilled in the art.
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