1. Field of the Invention
The invention relates generally to a headlamp assembly and a headlamp module for use in a motor vehicle. More specifically, the invention relates to a headlamp module having an internally-reflecting trough for directing light rays in a forward direction and a headlamp assembly having a plurality of headlamp modules, at least one of which includes an internally-reflecting trough for directing light rays in a forward direction.
2. Related Technology
Conventional headlamp assemblies typically include one or more sets of headlamp modules cooperating with each other to provide illumination for a motor vehicle. For example, one set of headlamp modules may define a low beam, another set of headlamp modules may define a high beam, and another set of headlamp modules may define a turn signal.
Each of the headlamp modules typically includes a housing and a lens cooperating to define a cavity, a light element that is generally centrally located within the cavity, and a reflector positioned near a rear portion of the cavity to reflect light rays from the light element towards the front of the cavity and out through the lens. Often, the light element is a light emitting diode connected to the headlamp module by a support arm. Furthermore, the reflector is typically a component made of a generally reflective material, such as polished metal or highly-reflective plastic that covers all or most of the rear wall of the cavity.
Because the light element is positioned in a generally closed cavity, the housing and the components defining and providing electricity to the light element are potentially exposed to undesirable heat levels from light element. Therefore, this type of design typically requires temperature mitigating components, such as a heatsink supporting the light element with respect to the housing and cooling channels formed by the housing itself. Even if these structures are able to consistently prevent undesirably high heat levels, the temperature mitigating components generally increase the complexity and the part cost of this type of headlamp module.
Due to their highly reflective nature and centralized location, the light element, the components supporting the light element, and the reflector are all highly visible components. More specifically, these components are particularly visible when the light element is not emitting light, causing the unlit headlamp module to have a generally undesirable aesthetic appearance.
Another known type of headlamp module is an internal reflector module. In this design, a light source is spaced apart from the base of a translucent block for directing light rays into the body of the translucent block. More specifically, the light source is positioned along a central axis of the translucent block so that the light rays exit the light source, travel across an air gap, and then enter the translucent block. The light rays are then reflected internally by the inner surfaces of the translucent block in a desired direction. However, as with the above described design, the centralized location of the light source creates a generally aesthetically undesirable appearance. Furthermore, the air gap may cause undesirable light loss or an unsecured connection between the light source and the translucent block.
It is therefore desirous to provide a headlamp module having a decreased complexity and part cost and an aesthetically desirable appearance.
In overcoming the limitations and drawbacks of the prior art, a headlamp module is provided, including a light source for emitting light rays and a translucent member for supporting the light source and directing the light rays in a forward direction. More specifically, the light element is positioned so that the light rays enter the translucent member and are internally reflected in a forward direction by a reflection surface. The light rays then pass through an exit surface of the translucent member as a light beam.
In one aspect of the present invention, the support portion is positioned with respect to the exit surface such that a projection of the support portion along a line parallel to the light ray axis is located adjacent to or outside of a periphery of the exit surface. Therefore, the light source is discretely positioned with respect to the exit surface so as to be substantially hidden to an observer examining the unlit headlamp module from the front of the vehicle.
In another aspect of the present invention, the translucent member includes top and bottom surfaces that each intersect respective portions of the exit surface and the support portion is defined by the top surface. More specifically, the top surface extends generally perpendicularly from a top portion of the exit surface and defines a relief for supporting the light element.
In another aspect, the bottom surface extends in a direction that is not perpendicular with the exit surface so that the light rays are focused into a beam exiting the exit surface. More specifically, the bottom surface generally defines a parabola and the light source is positioned adjacent to a focus thereof so that the light rays are vertically focused into a beam.
The headlamp module also includes first and second side surfaces that intersect: the top surface, the bottom surface, and the exit surface. The side surfaces each preferably include a tapered portion extending in a direction not parallel to the light ray axis so that the light rays are horizontally focused into a beam exiting the exit surface. The tapered portion may be generally linear or arcuate.
In another aspect of the present invention, the translucent member includes a reflective coating defining at least a portion of the reflection surface to prevent light rays from exiting the translucent member through surfaces other than the exit surface.
In yet another aspect, the headlamp module includes a plurality of light sources supported by a second support portion of the translucent member.
In another aspect of the present invention, the light source emits light rays through an outer surface and at least a portion of the outer surface is engaged by a support portion of the translucent member so that light rays emitted through the outer surface of the light source are able to immediately enter the translucent member. This configuration reduces light losses that may occur when the light rays from traveling through different mediums.
In one design, the light source is a light emitting diode and the outer surface is at least partially defined by a translucent protective coating. Additionally, the support portion preferably completely engages the outer surface of the translucent protective coating. Furthermore, the translucent protective coating is preferably connected to the support portion by a form-fitting engagement.
In another aspect of the present invention, a headlamp assembly for a motor vehicle includes a plurality of headlamp modules cooperating to provide illumination for the motor vehicle. In one design, at least one of the plurality of headlamp modules is a trough module cooperating with at least one other trough module to define a set of trough modules. The headlamp assembly may also include a set of projector modules cooperating with the set of trough modules to generate a low beam. The headlamp assembly may also include a high beam module configured to generate a high beam and a turn signal module configured to generate a light signal beam.
Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification.
Referring now to the drawings,
As shown in
The trough 14 shown in the figures is a single, unitary solid body component defining a top surface 32, a pair of side surfaces 34, 36, and a bottom surface 38 that each intersect the exit surface 16 along edges thereof. More specifically, the top surface 32 and the exit surface 16 are both generally planar surfaces positioned generally perpendicular to each other (see
The LED 12 is supported by a support portion 46 of the trough 14 positioned with respect to the exit surface 16 such that a projection of the support portion 46 along a line 60 parallel to the light ray axis 48, is located adjacent to or outside of a periphery 62 of the exit surface 16, thereby substantially hiding the LED 12 to an observer examining the unlit trough-type headlamp module 10 from the front of the vehicle. This configuration is illustrated in
The support portion 46 in the figures is a recess formed in the top surface 32 of the trough 14 so that the light rays entering the trough 14 are directed towards the bottom surface 38 (as best shown in
The above-described positioning of the LED 12 with respect to the trough 14 offers many advantages that are discussed in more detail below. First of all, the positioning of the LED 12 adjacent to the focus 56 of the parabolic paths 40, 42, 44 causes the light rays that exit the LED to be focused into a beam that exits the exit surface 16. Secondly, as mentioned above, the positioning of the LED 12 along the top surface 32 of the trough improves the aesthetic appearance by minimizing the perception of the LED 12, of the trough-type headlamp module 10 for an observer viewing the module 10 from the front of the vehicle. Thirdly, the orientation of the LED 12 shining light rays in the downward direction minimizes glare to occupants of on-coming vehicles.
The support portion 46 shown in the figures conforms to the shape of the LED 12 to minimize or eliminate any air gaps between the LED outer surface and the trough 14. The form-fitting configuration between the outer surface of the LED 12 and the trough 14 securely connects the components 12, 14 to each other and reduces the likelihood of undesirable separation thereof. Furthermore, the form-fitting configuration reduces or prevents relative movement between the components 12, 14, thereby reducing premature part wear. The LED 12 may be coupled with the trough 14 by a form-fitting engagement or by another appropriate connection means, such as an adhesive or a mechanical fastener. However, direct contact between the LED chip 18 and the trough 14 may cause damage or premature wear to the LED 12. Therefore, the translucent protective coating 20 surrounds the chip 18 to provide protection and to increase the product life of the LED 12.
The elimination of air gaps between the LED outer surface and the trough 14 may also reduce light losses within the trough-type headlamp module 10. It is a natural principle that light traveling between different mediums may undergo light losses due to reflection. Thus, it is generally desirable to minimize the number of different mediums that the light rays must travel through before exiting the trough-type headlamp module 10. It is therefore more specifically desirable to minimize air gaps that the light rays must travel through.
As mentioned above, the light rays 30 entering the trough 14 are directed towards the bottom surface 38 and substantially internally reflected in a forward direction towards the exit surface 16. More specifically, some of the light rays (the reflected rays 30a) are reflected towards the exit surface 16 while the remaining light rays (the refracted rays 30b) may exit the trough 14 through the bottom surface 38.
As is a generally known natural principle, when a light ray intersects a boundary of a medium at a relatively large angle of incidence, a substantial percentage of the light ray will be reflected within the medium and the small, remaining percentage of the light ray will be refracted while exiting the medium through the boundary. Conversely, when a light ray intersects a boundary of a medium at a relatively small angle of incidence, a substantial percentage of the light ray will be refracted while exiting the medium through the boundary and the small, remaining percentage of the light ray will be reflected within the medium. Therefore, resultant light rays typically include both reflected components and refracted components. However, for illustrative purposes, resultant light rays are referenced by and depicted with their dominant components. As used herein, the term “reflected rays 30a” refers to rays each have a higher percentage of light that is reflected towards the exit surface 16 than light that is refracted through the bottom surface 38 of the trough 14. Similarly, as used herein, the term “refracted rays 30b” refers to rays each have a higher percentage of light that is refracted as it exits the bottom surface 38 than light that is reflected towards the exit surface 16.
The above principle is demonstrated with respect to the present invention in
As mentioned above, the bottom surface 38 of the trough 14 defines a parabolic path 44. More specifically, the parabolic path 44 is configured such that the reflected rays 30a are generally evenly spread in a vertical direction when shining through the exit surface 16. The positioning of the LED 12 adjacent to the focus 56 of the parabolic path 44 of the bottom surface 38 further improves the concentration of the reflected rays 30a in the vertical direction.
However, due to the light losses from the refracted rays 30b, the light rays 30 only exit a lower portion 54 of the exit surface 16, thereby only illuminating a lower portion of the trough-type headlamp module 10. As used herein, the illuminated portion 54 is defined as the portion of the exit surface 16 that receives a substantial amount of light rays when the LED is illuminated. Similarly, a non-illuminated portion 58 is defined as the portion of the exit surface 16 that receives little or no light when the LED is illuminated. Although the non-illuminated portion 58 may receive trace amounts of light that are remnants of the refracted rays 30b, this light is not necessarily sufficient enough to effectively illuminate an area in front of the trough-type headlamp module 10.
The parabolic path 44 is also configured such that the rays 30a reflected by the bottom surface 38 are directed so as to be parallel with each other and to define a light beam extending generally along a light ray axis 48. Although some of the reflected rays 30a may extend in a direction not parallel to the axis 48, the headlamp beam is substantially focused to extend along the axis 48.
As mentioned above, the side surfaces 34, 36 of the trough 14 also define parabolic paths 40, 42. More specifically, the parabolic paths 40, 42 are configured such that the reflected rays 30a are generally evenly spread in a horizontal direction when shining or passing through the exit surface 16 (as best shown in
However and as shown in
The respective paths 40, 42, 44 of the trough 14 can be altered from those shown in
Furthermore, as discussed above, the location of the LED 12 along the top surface 32 of the trough 14 also improves the aesthetic appearance of the trough-type headlamp module 10 to an observer viewing the trough-type module 10 from the front of the vehicle. Because the LED 12 is positioned generally adjacent or in-line with the periphery 62 of the exit surface 16 rather than centrally with respect to of the exit surface 16, an observer is less likely to see and notice the LED 12 through the exit surface 16. Furthermore, because the upper portion of the exit surface 16 is the non-illuminated portion 58, an opaque trim portion may be disposed over the non-illuminated portion 58 to further conceal the LED 12.
The downward-facing orientation of the LED 12 generally minimizes glare from distracting the vehicle occupants. For example, the refracted rays 30b exit the trough 14 in the downward direction.
The trough 14 is preferably formed of a generally transparent material having a relatively high luminous transmittance to minimize light losses within the trough. For example, the trough 14 is preferably made from one of the following materials: glass, polymethyl methacrylate (PMMA), polycarbonate resins, polystyrene resins, styrene-acrylonitrile (SAN) resins, cellulose acetate, or any other material having a relatively high light transmission percentage.
It may also be desirable for the trough 14 to be formed of an easily moldable material, such as resin, to simplify the manufacturing process and reduce manufacturing costs. Although it may be desirable for the resin to have a particular color so that the light beam is colored, the resin is preferably colorless or lightly tinted so as to further minimize light losses. Alternatively, the trough 14 may be substantially colorless with a tinted portion defining the exit surface 16. In this design, it may be advantageous to form the trough of two, differently-colored sections that are connected with each other.
Referring to
Although the projector-type headlamp modules 5, the high beam module 6, the turn signal modules 7a, 7b, and the park light modules 8 shown in
It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.
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