U.S. patent application number 13/845247 was filed with the patent office on 2013-08-29 for automotive signal light employing multi-focal length light pipes.
The applicant listed for this patent is Chad D. Lambert, James R. McFadden. Invention is credited to Chad D. Lambert, James R. McFadden.
Application Number | 20130223088 13/845247 |
Document ID | / |
Family ID | 42352578 |
Filed Date | 2013-08-29 |
United States Patent
Application |
20130223088 |
Kind Code |
A1 |
Lambert; Chad D. ; et
al. |
August 29, 2013 |
AUTOMOTIVE SIGNAL LIGHT EMPLOYING MULTI-FOCAL LENGTH LIGHT
PIPES
Abstract
An automotive signal light is taught which employs multi-focal
length light pipes to collect, collimate and direct, as needed,
light emitted from one or more semiconductor light sources. Each
multi-focal length light pipe includes at least one light
transmission structure, each of which has a light receiving port to
receive light emitted from a semiconductor light source spaced from
the light receiving port by an air gap. The light transmission
structure includes at least two superimposed parabolic reflecting
surfaces, each having a common focal point at the light receiving
port but having different focal lengths, and the superimposed
parabolic reflectors operate to receive, collimate, spread and
transmit the light from the semiconductor light source to a light
emitting surface of the light pipe which is located adjacent to a
lens of the signal light. The aesthetic arrangement of the light
pipes is not particularly limited and a wide range of signal light
functionalities can be provided.
Inventors: |
Lambert; Chad D.;
(Belleville, CA) ; McFadden; James R.; (Oxford,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lambert; Chad D.
McFadden; James R. |
Belleville
Oxford |
MI |
CA
US |
|
|
Family ID: |
42352578 |
Appl. No.: |
13/845247 |
Filed: |
March 18, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12690441 |
Jan 20, 2010 |
8398283 |
|
|
13845247 |
|
|
|
|
61205558 |
Jan 21, 2009 |
|
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Current U.S.
Class: |
362/511 |
Current CPC
Class: |
F21S 43/243 20180101;
G02B 6/0096 20130101; F21W 2103/20 20180101; F21S 43/14 20180101;
F21W 2103/00 20180101; F21W 2103/35 20180101; F21S 43/249 20180101;
F21Y 2115/10 20160801; F21S 43/237 20180101 |
Class at
Publication: |
362/511 |
International
Class: |
F21V 8/00 20060101
F21V008/00 |
Claims
1. An automotive signal light, comprising: a housing; a transparent
lens connected to said housing; at least one light source assembly
mounted within said housing; a multi-focal length light pipe
disposed within said housing in proximity to said at least one
light source assembly; and at least one light transmission
structure formed as part of said multi-focal length light pipe such
that light produced by said at least one light source assembly
transfers through said at least one light transmission structure of
said multi-focal length light pipe to produce a desired beam
pattern.
2. The automotive signal light of claim 1, said at least one light
source assembly further comprising a plurality of semiconductor
light sources.
3. The automotive signal light of claim 2, each of said plurality
of semiconductor light sources further comprising a light emitting
diode (LED).
4. The automotive signal light of claim 1, said at least one light
transmission structure further comprising at least one light
receiving port for receiving light from said at least one light
source assembly mounted within said housing.
5. The automotive signal light of claim 4, wherein said at least
one light receiving port is substantially conic in shape such that
said at least one light receiving port substantially surrounds said
at least one light source assembly to receive substantially all of
the light from said at least one light source assembly.
6. The automotive signal light of claim 4, said further comprising
at least two parabolic reflector shapes formed as part of said at
least one light transmission structure, each of said at least two
parabolic reflector shapes having a focal point at said at least
one light receiving port, and each of said at least two parabolic
reflector shapes having a different focal length such that light
received from said at least one light receiving port is collimated,
focused, and spread to create said desired beam pattern.
7. The automotive signal light of claim 1, wherein said at least
one light transmission structure is scalloped in shape.
8. The automotive signal light of claim 1, said housing further
comprising a back panel.
9. The automotive signal light of claim 8, further comprising: a
heat sink which transfers heat away from said at least one light
source assembly; and a plurality of fins formed as part of said
heat sink, said plurality of fins extend through said back panel of
said housing for releasing heat from said heat sink.
10. The automotive signal light of claim 8, wherein said back panel
is an integral back panel formed as part of said housing.
11. The automotive signal light of claim 8, wherein said back panel
is formed by a portion of said vehicle to which said signal light
is mounted.
12. The automotive signal light of claim 1, wherein said at least
one light transmission structure directs light through said
multi-focal length light pipe through total internal
reflection.
13. The automotive signal light of claim 1, wherein said housing is
made from one selected from the group consisting of polyvinyl
chloride (PVC), polycarbonate, and combinations thereof.
14. The automotive signal light of claim 1, wherein said
multi-focal length light pipe is made of a clear, acrylic
material.
15. The automotive signal light of claim 1, further comprising: an
emitter surface formed as part of said multi-focal length light
pipe; and said multi-focal length light pipe includes an elongate
axis, wherein light emitting from said emitter surface is primarily
directed parallel to said elongate axis.
16. The automotive signal light of claim 1, wherein a first focal
length of said multi-focal length light pipe provides running light
functionality, a second focal length of said multi-focal length
light pipe provides brake light functionality, and a third focal
length of said multi-focal length light pipe provides back-up light
functionality.
17. An automotive signal light, comprising: a housing; a
transparent lens connected to said housing; a plurality of
semiconductor light source assemblies mounted within said housing;
a multi-focal length light pipe disposed within said housing; a
plurality of light transmission structures formed as part of said
multi-focal length light pipe, each of said plurality of light
transmission structures having one focal length, and each of said
plurality of light transmission structures receives light from one
of said plurality of semiconductor light source assemblies; and an
emitter surface formed as part of said multi-focal length light
pipe such that light is received by said plurality of light
transmission structures and is directed out of said emitter
surface, and each of said plurality of light transmission
structures produces a desired beam pattern,
18. The automotive signal light of claim 17, each of said plurality
of light transmission structures further comprising: at least one
light receiving port for receiving light from one of said plurality
of semiconductor light sources; and at least two parabolic
reflector shapes having a different focal length, and each of said
at least two parabolic reflector shapes having a focal point
located in proximity to said at least one light receiving port such
that light received from said at least one light receiving port is
collimated, focused, and spread by said light transmission
structure to create said desired beam pattern emitted from said
emitter surface.
19. The automotive signal light of claim 18, wherein said at least
one light receiving port is substantially conic in shape such that
said at least one light receiving port substantially surrounds a
respective one of said plurality of semiconductor light source
assemblies to receive substantially all of the light from said
respective one of said plurality of light sources assemblies.
20. The automotive signal light of claim 17, further comprising: a
heat sink which removes heat from said plurality of light source
assemblies; and a plurality of fins formed as part of said heat
sink, said plurality of fins extending out of said housing for
releasing heat from said heat sink.
21. The automotive signal light of claim 20, said housing further
comprising an integral back panel, wherein said plurality of fins
formed as part of said heat sink extend out of said back panel.
22. The automotive signal light of claim 20, said housing further
comprising a back panel formed by a portion of said vehicle to
which said signal light is mounted, wherein said plurality of fins
formed as part of said heat sink extend out of said back panel.
23. The automotive signal light of claim 17, wherein each of said
plurality of light transmission structures directs light through
said multi-focal length light pipe through total internal
reflection.
24. The automotive signal light of claim 17, wherein said housing
is made from one selected from the group consisting of polyvinyl
chloride (PVC), polycarbonate, and combinations thereof.
25. The automotive signal light of claim 17, wherein said
multi-focal length light pipe is made of a clear, acrylic
material.
26. The automotive signal light of claim 17, said multi-focal
length light pipe further comprising an elongate axis, wherein
light emitting from said emitter surface is primarily directed
parallel to said elongate axis.
27. The automotive signal light of claim 17, wherein a first focal
length of said multi-focal length light pipe provides running light
functionality, a second focal length of said multi-focal length
light pipe provides brake light functionality, and a third focal
length of said multi-focal length light pipe provides back-up light
functionality.
28. The automotive signal light of claim 17, wherein said at least
one light transmission structure is scalloped in shape
29. The automotive signal light of claim 17, wherein each of said
plurality of semi-conductor light source assemblies is a light
emitting diode (LED).
30. An automotive signal light comprising: a substantially weather
proof volume defined by at least a housing and a lens; at least one
semiconductor light source and heat sink assembly located within
the volume; and at least one multi-focal length light pipe located
within the volume having at least one light transmission structure
with a light receiving port positioned adjacent a respective
semiconductor light source to receive light emitted by said one
semiconductor light source, the light transmission structure
including at least two superimposed parabolic reflecting structures
each having a common focal point at the light receiving port and
each having a focal length differing from the focal length of the
other such that the light transmitting structure receives,
collimates, directs and spreads and transmits the light received at
the light receiving port to a light emitting surface of the light
pipe adjacent the lens to from a desired output light pattern.
31. An automotive signal light in accordance with claim 30,
comprising at least two multi-focal length light pipes located
within the volume.
32. An automotive signal light in accordance with claim 31, wherein
each multi-focal length light pipe provides a different signal
function.
33. An automotive signal light in accordance with claim 30, wherein
the signal light includes at least two semiconductor light sources
and the multi-focal length light pipe includes a corresponding
number of light transmission structures.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 12/690,441, filed Jan. 20, 2010 and which claims the benefit of
U.S. Provisional Application No. 61/205,558, filed Jan. 21, 2009.
The disclosure of the application is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an automotive signal light
which employs semiconductor light sources. More specifically, the
present invention relates to an automotive signal light which
employs semiconductor light sources and at least one multi-focal
length light pipe to produce a desired output light pattern.
BACKGROUND OF THE INVENTION
[0003] It is known to employ semiconductor light sources, in
particular light emitting diodes (LEDs), in automotive signal
lights. For example, tail lights on some vehicles include an array
of red light-emitting and/or amber light-emitting LEDs which are
positioned between a reflector and a lens to provide the desired
signal patterns. It is also known to have signal lamps wherein one
or more LEDs are arranged in a direct view wherein the output of
the LED passes directly through the lens of the signal light.
[0004] While known signal lights employing LEDs provide advantages
over signal lights employing incandescent bulbs, they still suffer
from some problems. For example, available LEDs emit limited
amounts of light relative to incandescent lamps. Due to these lower
emitted levels of light and/or the inefficiency of a conventional
reflector and lens in transmitting the light produced by the LEDs,
a large number of LEDs must often be employed to produce sufficient
signal lighting to meet regulatory requirements. Further, this
large number of LEDs must be appropriately spaced about the signal
light to provide the lighted surface area required to meet
regulatory requirements and thus the aesthetic design of such
signal lights is limited.
[0005] As will be apparent, next to regulatory and safety concerns,
aesthetic design can be one of the most significant considerations
for the designer of a vehicle and, to date, the range of aesthetic
design available for signal lamps using semiconductor light sources
has been limited.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a novel
signal light utilizing semiconductor light sources with at least
one multi-focal length light pipe to obviate or mitigate at least
one disadvantage of the prior art.
[0007] According to a first aspect of the present invention, there
is provided an automotive signal light comprising: a substantially
weather proof volume defined by at least a housing and a lens; at
least one semiconductor light source and heat sink assembly located
within the volume; and at least one multi-focal length light pipe
located within the volume having at least one light transmission
structure with a light receiving port positioned adjacent a
respective semiconductor light source to receive light emitted by
said one semiconductor light source, the light transmission
structure including at least two superimposed parabolic reflecting
structures each having a common focal point at the light receiving
port and each having a focal length differing from the focal length
of the other such that the light transmitting structure receives,
collimates, directs and spreads and transmits the light received at
the light receiving port to a light emitting surface of the light
pipe adjacent the lens to from a desired output light pattern.
[0008] The present invention provides an automotive signal light
which employs at least one multi-focal length light pipe to
collect, collimate and direct, as needed, light emitted from one or
more semiconductor light sources. The light emitted from the
semiconductor light sources is collimated, focused and spread by
the multi-focal length light pipe to obtain a desired output light
pattern while allowing for a wide range of aesthetic designs and a
wide range of signal light functionalities which can be
provided.
[0009] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0011] FIG. 1 is a FIG. 1 shows a perspective view of the front of
an automotive signal light in accordance with the present
invention;
[0012] FIG. 2 shows a perspective exploded view of the signal light
of FIG. 1;
[0013] FIG. 3 shows a perspective view of the lighting components
of the signal light of FIG. 1;
[0014] FIG. 4A shows an end view of a pair of multi-focal length
light pipes and a light source and heat sink assembly for the
signal light of FIG. 1;
[0015] FIG. 4B shows a side view of a multi-focal length light pipe
and light source and heat sink assemblies for the signal light of
FIG. 1;
[0016] FIG. 5A shows a side view of a multi-focal length light pipe
for the signal light of FIG. 1;
[0017] FIG. 5B shows a more detailed cut away perspective view of
the portion of the multi-focal length light pipe identified in
circle A of FIG. 5B; and
[0018] FIG. 50 shows a more detailed cut away perspective view of
the portion of the multi-focal length light pipe identified in
circle B of FIG. 5B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0020] An automotive signal light in accordance with the present
invention is indicated generally at 20 in the accompanying Figures.
As best seen in FIGS. 1 and 2, signal light 20 comprises a housing
24, which fabricated from any appropriate material such as PVC,
polycarbonate, etc. and a transparent lens 28, which in the
illustrated embodiment is clear. As will be apparent to those of
skill in the art, lens 28 is fabricated from any suitable
transparent material, such as polycarbonate, and tinted one or more
colors or clear.
[0021] Housing 24 includes an integral back panel, or the portion
of the vehicle to which signal light 20 is mounted forms a back
panel, such that the interior volume of signal lamp 20 receives the
lighting components (described below) in a substantially weather
proof manner.
[0022] Signal light 20 further comprises at least one light source
assembly 32 comprising a heat sink and at least one semiconductor
light source 40. Each semiconductor light source 40 is mounted to
the heat sink such that waste heat produced by the operation of the
semiconductor light sources 40 is transferred to the heat sink,
which in turn radiates that waste heat to the surrounding
atmosphere via a set of fins 44 (best seen in FIG. 4A). Preferably,
to enhance the transfer of heat from the heat sinks to the
surrounding atmosphere, fins 44 of each heat sink extend through
the back panel outside of the enclosed volume of signal light
20.
[0023] In the present embodiment, semiconductor light sources 40
are surface mounted, domed light emitting diodes (LEDs), such as
(for example) the Luxeon Rebel.TM. surface mounted LEDs sold by
Philips Lumileds Lighting Company, 370 West Trimble Road, San Jose,
Calif.
[0024] As discussed below, depending upon the color of the light
required to be output by signal light 20, semiconductor light
sources 40 selected to produce light of a corresponding color, such
as red, amber or white. Each semiconductor light source 40 is
mounted to an electrical circuit board 46 (best seen in FIGS. 5B
and 5C) and connected thereby to an appropriate electrical power
supply (not shown) as will be apparent to those of skill in the
art.
[0025] Signal light 20 further comprises at least one multi-focal
length light pipe 48, each of which receives light emitted by at
least one semiconductor light source 40. In the illustrated
embodiment, each light pipe 48 receives the light emitted by five
semiconductor light sources 40. However, the present invention is
not limited to light pipes 48 receiving light from five
semiconductor light sources 40 and light pipes 48 can receive light
emitted from one or more semiconductor light sources 40 depending
upon the size of light pipe 48 and the amount of light required to
be emitted from light pipe 48, as will be apparent to those of
skill in the art.
[0026] Multi-focal length light pipe 48 is shown in more detail in
FIGS. 4A and 4B, and in FIGS. 5A, 5B and 5C. As shown, light pipe
48 includes an emitter surface 52 and at least one (and in the
illustrated embodiment, five) light transmission structure 56. The
number of light transmission structures 56 required on a light pipe
48 depends on the output levels of light emitted by semiconductor
light sources 40 and the desired level of light output from light
emitting surface 52, and corresponds to the number of light sources
40 used to illuminate the light pipe 48. Semiconductor light
sources 40 with higher levels of emitted light can reduce the
number of light transmission structures 56 which would other wise
be required.
[0027] Light pipe 48 is preferably fabricated from an optically
clear material, such as acrylic, to ensure that a substantial
percentage of the light entering structures 56 is transmitted
through transmission structures 56 and out of light emitting
surface 52 with minimal transmission losses.
[0028] To ensure that a substantial portion of the light emitted by
semiconductor light sources 40 is usefully received within
structures 56, each structure 56 includes a light receiving port 60
which is generally conic in shape and which surrounds and
encompasses the light emitting surface of light source 40. A small
air gap (on the order of one millimeter or less) is also provided
between light receiving port 60 and the light emitting surface of
semiconductor light source 40, as best seen in FIG. 5C.
[0029] Light received from light source 40 at input port 60 is
transferred from input port 60 through structure 56 to emitter
surface 52 by total internal reflection through structure 56. Each
structure 56 is designed with at least two parabolic reflector
shapes, superimposed upon one another, with each parabolic
reflector shape having its focal point at input port 60 but having
a different focal length, such that light received at input port 60
is collimated, focused and spread to create the desired output
light pattern at light emitter surface 52.
[0030] To reduce the amount of material required to form structures
56, material which is otherwise unnecessary, due to the
superimposition of the parabolic shapes, can be omitted from
structures 56 in a manner similar to that employed with Fresnel
lens, etc. In such a case, structures 56 have a "scalloped" shape,
as shown in FIGS. 5A, 5B and 5G. While it is presently preferred to
omit such unnecessary material when fabricating light pipes 48, the
present invention is not so limited and structures 56 can be
fabricated with unnecessary material in place, as shown in FIGS. 2
and 4B.
[0031] In the illustrated configuration, the light from each
structure 56 is focused and shaped within structures 56 such that a
generally elongated overall light pattern is formed at emitter
surface 52, with the emitted light primarily directed parallel to
the elongate axis of multi-focal length light pipe 48. Depending
upon the design of the superimposed parabolic reflector shapes in
structures 56, other patterns of output light can be created, as
will be apparent to those of skill in the art.
[0032] The shape of multi-focal length light pipe 48 is not
particularly limited and, while in illustrated embodiment light
pipe 48 is shown as having light transmission structures 56
arranged in a substantially straight line and light emitting
surface 52 being gently curved, the present invention is not so
limited and curved configurations of light transmission structures
56 and/or different shapes for light emitting surface 52 can be
employed as may be desired for aesthetic or other design
purposes.
[0033] Further, while in the illustrated embodiment two multi-focal
length light pipes 48 are employed, the present invention is not so
limited and additional multi-focal length light pipes 48 can be
included if desired and the multi-focal length light pipes 48 need
not all be the same size or shape. Further still, while in the
present embodiment multi-focal length light pipes 48 are shown as
being arranged horizontally across signal light 20, the present
invention is not so limited and vertical, diagonal or other
arrangements of multi-focal length light pipes 48 can be employed
as desired.
[0034] For aesthetic purposes one or more bezels 64 can be provided
about multi-focal length light pipes 48 to complete the design of
signal light 20.
[0035] As will be apparent to those of skill in the art, signal
light 20 can be configured to provide a variety of signal light
functions, as desired. For example, if signal light 20 is intended
to server as a tail light of an automobile, it can provide running
light functionality by illuminating the semiconductor light sources
40 emitting light for one of multi-focal length light pipes 48 at
reduced brightness levels and can provide brake light functionality
by selectively illuminating those same semiconductor light sources
40 at full brightness when braking.
[0036] Similarly, turn signal functionality can be by provided by
alternately illuminating and extinguishing the semiconductor light
sources 40 emitting light for the other multi-input light pipe 48.
As will be apparent to those of skill in the art, a wide variety of
other signal light functionalities can be similarly provided. For
example, signal light 20 can have a third multi-focal length light
pipe (not shown) included within housing 24 which is illuminated by
white LEDs to provide a back up light, or license plate
illumination, function.
[0037] As will now be apparent to those of skill in the art, the
present invention teaches an automotive signal light 20 which
employs at least one multi-focal length light pipe 48 to collect,
collimate, spread and direct, as needed, light emitted from
semiconductor light sources. Each multi-focal length light pipe 48
includes at least one light transmission structure, each of which
has a light receiving port 60 to receive light emitted from a
semiconductor light source 40 spaced from the light receiving port
60 by an air gap. The received light is collimated, spread and
transmitted to a light emitting surface 52 which is located
adjacent to a lens 28 of the signal light 20. The aesthetic
arrangement of the light pipes 48 is not particularly limited and a
wide range of signal light functionalities can be provided.
[0038] The description of the invention is merely exemplary in
nature and, thus, variations that do not depart from the essence of
the invention are intended to be within the scope of the invention.
Such variations are not to be regarded as a departure from the
spirit and scope of the invention.
* * * * *