CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
FIELD OF THE INVENTION
[0002] The present disclosure relates to a projector headlamp assembly for an automotive
lighting application. More particularly, present disclosure relates to a projector
headlamp assembly incorporating a lens unit which aids in light distribution for low
beam and high beam function.
BACKGROUND OF THE INVENTION
[0003] The subject matter discussed in the background section should not be assumed to be
prior art merely as a result of its mention in the background section. Similarly,
a problem mentioned in the background section or associated with the subject matter
of the background section should not be assumed to have been previously recognized
in the prior art. The subject matter in the background section merely represents different
approaches, which in and of themselves may also correspond to implementations of the
claimed technology.
[0004] Headlamp systems help in illuminating the space in front of an automobile. There
are many kinds of headlamp systems which include reflector headlamps, projector headlamps,
H4 conversions, etc. The main function of a headlamp system is to provide appropriate
light distribution during a low beam and a high beam function.
[0005] In general, projector type vehicle headlamps include a projection lens that is disposed
on an optical axis which extends in a longitudinal direction of a vehicle, a light
source which is positioned such that focus of the light source is on the optical axis
behind the projector lens and a reflector to converge the light to the focal point
of the projection lens.
[0006] In conventional projector-based headlamps, the light distribution during a low beam
and a high beam function is controlled by using a light shield member. Typically,
the light shield member is positioned in front of a light source of the projector
headlamp system. During a low beam function, the light shield member is positioned
in front of the light source to obtain an appropriate light distribution through shielding
of light. However, during a high beam function, the light shield member is moved away
from the light source. When the light shield member is mechanically shifted, a change
in the distribution of light from low beam to high beam occurs which may not be a
smooth transition. Further for different classes of lighting regulation, for example
in two-wheeler for Class B, C and D, there is need for different kind of projector
lamps. Different kinds of projector lamps are also required in four-wheelers suited
for left-hand traffic (LHT) and right-hand traffic (RHT). For different projector
lamps, the light shield member requires a complicated design in order to produce a
change in the amount of light shielded. The complicated design of the light shield
member may increase the space occupied by the light shield member in the projector-based
headlamps.
[0007] Therefore, there exist a need for a projector headlamp assembly which aids in light
distribution for low beam and high beam function. In addition, the projector headlamp
assembly should also be homologated for different classes of regulations across various
countries, e.g., ECE 112, ECE 113 and FMVSS 108 by using suitable combinations of
light source.
SUMMARY OF THE INVENTION
[0008] This summary is provided to introduce concepts related to a vehicle headlamp assembly
and the concepts are further described below in the detailed description. This summary
is not intended to identify essential features of the claimed subject matter nor is
it intended for use in determining or limiting the scope of the claimed subject matter.
[0009] An embodiment of the present disclosure discloses a vehicle headlamp assembly for
an automotive lighting application. The vehicle headlamp assembly includes at least
one light emitting unit; at least one lens unit and at least one projector lens unit.
The at least one lens unit is configured to collect and collimate an emitted light
from the at least one light emitting unit. Further, the at least one lens unit comprises
a dual lens, wherein the dual lens comprises a low beam lens surface and a high beam
lens surface. Further, the low beam lens surface comprises a first part and a second
part. Further, the first part comprises a collimator region and a total internal reflection
region (TIR), and the second part comprises a freeform lens curvature. Further, the
high beam lens surface also comprises a first part and a second part, wherein the
first part comprises a collimator region or a total internal reflection region (TIR),
and the second part comprises a freeform lens curvature. Further, the at least one
projector lens unit is configured to receive the light advanced from the at least
one lens unit, and project it towards to an area in front of the vehicles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing and other features of embodiments of the present disclosure will become
more apparent from the following detailed description of embodiments when read in
conjunction with the accompanying drawings. In the drawings, like reference numerals
refer to like elements.
Figure 1 illustrates an exploded view 100 of a vehicle headlamp assembly, in accordance
with an embodiment of the present disclosure.
Figure 2 illustrates various projections (200) of at least one lens unit for the vehicle
headlamp assembly, in accordance with an embodiment of the present disclosure.
Figure 3 illustrates an exemplary optical design (300) of a low beam lens surface
for a vehicle headlamp assembly, in accordance with an embodiment of the present disclosure.
Figure 4 illustrates an exemplary optical design (400) of a high beam lens surface
for a vehicle headlamp assembly, in accordance with an embodiment of the present disclosure.
Figure 5 illustrates a symmetric low beam light distribution (500) by the vehicle
headlamp assembly, in accordance with an embodiment of the present disclosure.
Figure 6 illustrates an asymmetric low beam light distribution (600) by the vehicle
headlamp assembly, in accordance with an embodiment of the present disclosure.
Figure 7 illustrates a symmetric high beam light distribution (700) by the vehicle
headlamp assembly, in accordance with an embodiment of the present disclosure.
Figure 8 illustrates an asymmetric high beam light distribution (800) by the vehicle
headlamp assembly, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0011] In the following detailed description, reference is made to the accompanying drawings
that form a part hereof, and in which are shown by way of illustration specific embodiments
that may be practiced. These embodiments are described in sufficient detail to enable
a person skilled in the art to practice the present disclosure, and it is to be understood
that other embodiments may be utilized, and that logical, mechanical, and other changes
may be made within the scope of the embodiments. Also, the words "comprising," "having,"
"containing," and "including," and other similar forms are intended to be equivalent
in meaning and be open-ended in that an item or items following any one of these words
is not meant to be an exhaustive listing of such item or items or meant to be limited
to only the listed item or items. The singular forms "a," "an," and "the" include
plural references unless the context clearly dictates otherwise. The following detailed
description is, therefore, not be taken as limiting the scope of the present disclosure,
but instead the present disclosure is to be defined by the appended claims.
[0012] As used herein the term "automobile" is defined as a system for transporting people,
animals or cargo by road. The term is intended to include, but not be limited to,
motorized and non-motorized transportation systems, and is also intended to include
automobiles with two, three, or more wheels. Non-limiting examples of such automobiles
may include bicycles, motorcycles, scooters, cars, trucks and the like.
[0013] The term "low beam function" is used relation to the vehicle headlamp assembly. It
refers to the light projected from the low beam lens surface, where the light projected
is generally short range and the light coverage is approximately 70 m, with limits
on light directed towards the eyes of the other road users as incoming traffic.
[0014] The term "high beam" is used in relation to the vehicle headlamp assembly. It is
defined as the light projected from the high beam lens surface, where the light projected
is generally of long range and the light coverage is approximately 200 m.
[0015] The term "ECE" or "Economic Commission of Europe" is used in relation to the vehicle
headlamp assembly. It provides for a vehicle regulatory framework for member countries
of United Nations.
[0016] The term "FMVSS" or "Federal Motor Vehicle Safety Standards" is used in relation
to the vehicle headlamp. It provides for a specification of the design, construction,
performance and durability requirements for a motor vehicle and its components in
United States of America.
[0017] Figure 1 illustrates an exploded view (100) of a vehicle headlamp assembly, in accordance
with an embodiment of the present disclosure. It must be noted, the vehicle headlamp
assembly may be a projector-based headlamp. The vehicle headlamp assembly may comprise
at least one light emitting unit (102), at least one lens unit (104), and at least
one projector lens unit. Further, the at least one lens unit (104) may be configured
to collect and collimate an emitted light from the at least one light emitting unit
(102). Further, the at least one projector lens unit may be configured to receive
a light advanced from the at least one lens unit (104).
[0018] In one embodiment of the present disclosure, the at least one light emitting unit
(102) may comprise a heat sink (110) and a driver assembly (112). In an embodiment
of the present disclosure, the light unit (102) may comprise at least one light source
soldered into a printed circuit board (PCB) assembly. In one embodiment of the present
disclosure, the light source may be a light emitting diode.
[0019] In an embodiment of the present disclosure, the heat sink (110) may be coupled to
the light unit (102) with thermal paste or thermal tape. In another embodiment of
the present disclosure, the heat sink may use a passive heat transfer mechanism to
suppress the heat generated from the light unit and may transfer the generated heat
to environment by natural convection. Further, the heat sink may enable the light
unit to operate at permissible temperature range and may further allow the light source
to emit the light at optimal efficiency.
[0020] In one embodiment of the present disclosure, the driver assembly (112) may be connected
to the light unit (102). In an alternative embodiment of the present disclosure, the
driver assembly (112) may be coupled to the heat sink (110). In one embodiment of
the present disclosure, the driver assembly (112) may enable the light unit (102)
to operate at a constant current so that there may be no fluctuation in the light
intensity at different input voltage. In another embodiment of the present disclosure,
the driver assembly (112) may assist in fault detection of light source in short or
open condition. For example, the driver assembly may switch off the at least one light
source, when any one of the at least one light source may not functioning properly.
In another embodiment of the present disclosure, the driver assembly (112) may be
also equipped with a noise reducing unit. In one embodiment of the present disclosure,
the noise reducing unit may reduce the electromagnetic noises in order to comply with
Electromagnetic Interference (EMI) and Electromagnetic compatibility (EMC) automotive
regulatory standards.
[0021] In an embodiment of the present disclosure, the projector lens unit may comprise
a projector lens holder (114), a projector lens (116) and a projector lens cover (118).
In an embodiment of the present disclosure, the material of the projector lens (116)
may be plastic. In alternative embodiment of the present disclosure, the material
of the projector lens (116) may be glass.
[0022] In an embodiment of the present disclosure, the at least one lens unit (104) may
comprise a dual lens. Figure 2 illustrates at least one lens unit (104) for the vehicle
headlamp assembly, in accordance with an embodiment of the present disclosure. The
first quadrant (202) and second quadrant (204) in Figure 2 illustrates a side and
front view of the dual lens. The third quadrant (206) and fourth quadrant (208) in
Figure 2 illustrates a top and isometric view of the dual lens. In an embodiment of
the present disclosure, the dual lens together may produce different light beam patterns
for the left-hand traffic and right-hand traffic.
[0023] In one embodiment of the present disclosure, the dual lens may comprise a lens holder
(203). Further, the lens holder (203) may be configured to accommodate low beam lens
surface (210) and high beam lens surface (212). Further, the low beam lens surface
(210) may be integrated with the lens holder (203) as a single piece structure. Further,
the high beam lens surface (212) may comprise a plurality of rib structures (206).
Further, the lens holder (203) may comprise a plurality of extending brackets (214a,
214b). In another embodiment, the plurality of extending brackets (214a, 214b) may
comprise a C-shaped structure. Further, the plurality of rib structures (206) may
engage with the plurality of extending brackets (214a, 214b), which may fixate the
high beam lens surface (212) to the lens holder (203). Further, the high beam lens
surface (212) may be fixated perpendicular to the lens holder (203).
[0024] In another embodiment of the present disclosure, the low beam lens surface (210)
may provide a distribution of light with forward and lateral illumination on road.
The low beam light may be generally used within city and on countryside roads. In
another embodiment of the present disclosure, the high beam lens surface (212) provides
a bright, center-weighted distribution of light. The high beam light is generally
used on highways and with no incoming traffic.
[0025] Figure 3 illustrates an exemplary optical design of the low beam lens surface (210),
in accordance with an embodiment of the present disclosure. In one embodiment of the
present disclosure, the low beam lens surface (210) may comprise a first part (302)
of the low beam lens surface (210) and a second part (304) of the low beam lens surface
(210). Further, the first part (302) may be equipped to the light unit (102), and
the second part (304) may be located at a distal end from the first part (302). Further,
the first part (302) may be configured to collect the light from the light unit (102)
and collimate it to second part (304). The second part (304) may transmit the collimated
light to the projector lens (116). In an embodiment of the present disclosure, the
first part (302) may comprise a collimator region and a total internal reflection
region (TIR). Further, the second part (304) may comprise a freeform lens curvature
to provide a horizontal light pattern and a vertical light pattern for different classes
of lighting regulation. Further, the first part (302) and the second part (304) may
face in a direction of the optical axis. Further, the freeform lens curvature of the
low beam lens surface (210) may be designed in such a manner that amount of low beam
light falling on the high beam lens surface (212) may be minimum.
[0026] Examples of different classes of lighting regulation may include, but not limited
to, ECE 113 Class B, C & D, ECE 112 Class B or FMVSS 108. In an embodiment of the
present disclosure, the low beam lens surface (300), may be designed within the same
dimensions of the projector lens (116), the at least one lens unit (104), the light
unit (102), to make the low beam lens surface (300) suitable across different classes
of lighting regulation.
[0027] Figure 4 illustrates an exemplary optical design of the high beam lens surface (400),
in accordance with an embodiment of the present disclosure. Further, the high beam
lens surface (212) may comprise a first part (402) of the high beam lens surface (212)
and a second part (404) of the high beam lens surface (212). Further, the first part
(402) and the second part (404) may be made up of different type of optical surfaces.
In an embodiment of the present disclosure, the first part (402) may comprise a collimator
region and a TIR (total internal reflection) region. Further, the first part (402)
may be configured to collect the light emitted from the light unit (102). Further,
the second part (404) may concentrate the collimated light from the first part (402)
to the projector lens (116). In an embodiment of the present disclosure, the second
part (404) may comprise a freeform lens curvature to meet the lighting regulation
for different classes of light regulation. Further, the first part (402) and the second
part (404) may face in the direction of the optical axis. Further, the second part
(404) may comprise an elongated structure. Further, the elongated structure may be
configured to direct at least a portion of low beam light incident on the top of the
freeform curvature of the high beam lens surface (400) towards the projector lens
(116). Further, directing of at least a portion of low beam light incident towards
the projector lens (116) may increase the intensity of the low beam light, which may
increase the overall efficiency of the headlamp. In an embodiment of the present disclosure,
the freeform curvature of the high beam lens surface directs remaining portion of
low beam light incident on the top of the freeform curvature of the high beam lens
surface (400) towards the projector lens holder (114). Further, the directing of the
incident low beam light towards the projector lens holder (114). may avoid unnecessary
reflections, thereby eliminating glaring effect. Therefore, the freeform curvature
of the high beam lens surface (400) may act as a shield for the incident low beam
light, which may also eliminate the need of an additional light shielding member.
[0028] Examples of different classes of lighting regulation may include, but not limited
to, ECE 113 Class B, C & D, ECE 112 Class B or FMVSS 108. Within the same boundary
of the lamp system. In an embodiment of the present disclosure, the high beam lens
surface (400), may be designed within the same dimensions of the at least one lens
unit (104), the light unit (102) and the projector lens (116), to make the high beam
lens surface (400) suitable across different classes of lighting regulation.
[0029] In an embodiment of the present disclosure, the material of the low beam and high
beam optical parts may be selected from but not limited to plastic such as poly (methyl
methacrylate) (PMMA), polycarbonate (PC) and the like.
[0030] In an embodiment of the present disclosure, the dual lens together can produce different
versions of low beam and high beam patterns. Now referring to Figures 5 and 6, which
illustrates a symmetric low beam light distribution (500) and an asymmetric low beam
light distribution (600) by the vehicle headlamp assembly, in accordance with an embodiment
of the present disclosure. Further, it may be seen that the low beam light distribution
achieved may fall within the classes of lighting regulation comprising, but not limited
to, ECE 113 Class B, C & D, ECE 112 Class B or FMVSS 108.
[0031] Now referring to Figures 7 and 8, which illustrates a symmetric high beam light distribution
(700) and an asymmetric high beam light distribution (800) by the vehicle headlamp
assembly, in accordance with an embodiment of the present disclosure. Further, it
may be seen that the low beam light distribution achieved may fall within the classes
of lighting regulation comprising, but not limited to, ECE 113 Class B, C & D, ECE
112 Class B or FMVSS 108.
[0032] The foregoing description of the preferred embodiment of the present disclosure has
been presented for the purpose of illustration and description. It is not intended
to be exhaustive or to limit the disclosure to the precise form disclosed. Furthermore,
all examples recited herein are principally intended expressly to be only for pedagogical
purposes to aid the reader in understanding the principles of the present subject
matter and are to be construed as being without limitation to such specifically recited
examples and conditions. Many modifications and variations are possible in light of
the above teachings. It is intended that the scope of the present disclosure not to
be limited by this detailed description.
1. A vehicle headlamp assembly comprising:
at least one light unit (102);
at least one lens unit (104) configured to collect and collimate an emitted light
from the at least one light unit (102), wherein the lens unit (104) comprises a dual
lens (200), wherein the dual lens (200) comprises a low beam lens surface (210) and
a high beam lens surface (212), wherein
the low beam lens surface (210) comprises a first part (302) and a second part (304),
wherein the first part (302) comprises a collimator region and a total internal reflection
region (TIR), and the second part (304) comprises a freeform curvature; and
the high beam lens surface comprises a first part (402) and a second part (404), wherein
the first part (402) comprises a collimator region and a total internal reflection
region (TIR), and the second part (404) comprises a freeform curvature.
2. The vehicle headlamp assembly as claimed in claim 1, further comprising:
a projector lens (116),
wherein the freeform curvature of the high beam lens surface (400) comprises an elongated
structure that directs at least a portion of low beam light incident on the top of
the freeform curvature of the high beam lens surface (400) towards the projector lens
(116).
3. The vehicle headlamp assembly as claimed in claim 2, further comprising:
a projector lens holder (114),
wherein the freeform curvature of the high beam lens surface directs remaining portion
of low beam light incident on the top of the freeform curvature of the high beam lens
surface (400) towards the projector lens holder (114).
4. The vehicle headlamp assembly as claimed in claim 1, wherein the dual lens (200) is
formed by fixating the low beam lens surface (210) and the high beam lens surface
(212) on a lens holder (203).
5. The vehicle headlamp assembly as claimed in claim 1, wherein the low beam lens surface
(210) is directly integrated on the lens holder (203).
6. The vehicle headlamp assembly as claimed in claim 3, wherein the lens holder (203)
comprises a plurality of extending brackets (214a, 214b), and wherein the plurality
of extending brackets (214a, 214b) comprises a C- shaped structure.
7. The vehicle headlamp assembly as claimed in claim 5, wherein the plurality of extending
brackets (214a, 214b) are configured to accommodate the freeform structure of the
high beam lens surface (212).
8. The vehicle headlamp assembly as claimed in claim 1, wherein the high beam lens surface
(212) comprises a plurality of rib structures (216).
9. The vehicle headlamp assembly as claimed in claim 7, wherein the plurality of rib
structures (216) are configured to fit in the plurality of extending brackets (216)
of the lens holder (203).