Patent Application
20180112844
The present application relates to vehicle lamps, in particular vehicle lamps in which the light source is a light emitting diode (LED).
The light source in a vehicle lamp is positioned so that light is emitted towards a reflector and then light from the reflector is reflected and projected to a desired light distribution patter in a region in front of the vehicle lamp. However, even if the light source emits a precise beam, like a light emitting diode (LED), there may be some dispersion of light beams. To help inhibit the scattered light beams from being reflected outside the desired light distribution, a shade is positioned adjacent the light source to block the dispersed and scattered light beams.
According to one embodiment, a vehicle lamp is provided with a housing and a transparent lens connected to the housing to define a lamp chamber there between. A reflector is disposed in the lamp chamber for reflecting light through the lens. An electrical board is disposed in the lamp chamber and oriented in relative to the reflector. A light emitting diode (LED) is mounted to the electrical board for emitting light. A shade is soldered to the electrical board at a predetermined orientation relative to the LED to block light rays emitted by the LED.
In another embodiment, the light shade does not contact the reflector.
In another embodiment, the light shade is soldered to the electrical board via a solder pad defined on the electrical board, wherein the light shade is oriented relative to the reflector based on a position of the solder pad.
In another embodiment, the electrical board is a printed circuit board.
In another embodiment, the electrical board comprises a flexible circuit board and a rigidizer.
In another embodiment, the light shade has an appearance surface finished to appear similar to a reflector surface.
According to one other embodiment, a vehicle lamp is provided with a housing and a transparent lens connected to the housing to define a lamp chamber there between. A reflector is disposed in the lamp chamber for reflecting light through the lens. A light assembly is disposed in the lamp chamber. The light assembly has an electrical board oriented relative to the reflector. A light emitting diode (LED) is disposed in the lamp chamber and mounted to the electrical board. A light shade is mounted to the electrical board at a mounting feature defined at a predetermined location relative to the LED to block light rays emitted by the LED, and the light shade does not contact the reflector.
In another embodiment, the light assembly is oriented relative to the reflector by aligning locating features on the electrical board with corresponding locating features the reflector.
In another embodiment, the predetermined location of the light shade is determined based on the locating feature on the electrical board.
In another embodiment, the light emitting diode (LED) is placed on the electrical board at a first mounting feature and the light shade is placed on the electrical board at a second mounting feature at a predetermined location relative to the first mounting feature. The first and second mounting features are based on the locating feature defined on the electrical board thereby ensuring the LED and light shade are positioned at predetermined locations relative to the reflector when the locating features on the electrical board are aligned with the corresponding locating features the reflector.
In another embodiment, the locating features comprise mounting apertures.
In another embodiment, a support structure has a locating pin extending therefrom. The locating pin extends through and aligns the mounting apertures to position the LED and light shade relative to the reflector.
According to one other embodiment a light assembly is provided. An electrical board. A light emitting diode (LED) is mounted to an electrical board. A shade is soldered to the electrical board at a predetermined orientation relative to the LED. The shade forms an enclosure that partially blocks light from the LED from projecting outside the enclosure.
In another embodiment, the enclosure has a blocking surface with a projection-pattern edge. A first portion of light from the LED is projected past the projection-pattern edge and a second portion of light from the LED is blocked by the blocking surface.
In another embodiment, the blocking surface is offset from the electrical board and is not soldered to the electrical board.
In another embodiment, the blocking surface has a projection-pattern edge oriented at a predetermined distance from a focal point of the LED.
In another embodiment, the enclosure is defined by at least four surfaces.
In another embodiment, the shade is soldered to the electrical board along an edge defined by at least three of the enclosure surfaces.
In another embodiment, a method of assembling the light assembly is provided. The method includes placing, with a robotic machine, a light emitting diode (LED) on the electrical board at a first mounting feature. The light shade is placed, with the robotic machine, on the electrical board at a second mounting feature at a predetermined location relative to the first mounting feature.
In another embodiment, the method of assembling the light assembly includes soldering the LED and shade to the electrical board.
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
The vehicle lamp 10 includes a lamp body 22 having a concave portion defining a front opening 24 of the lamp and a transparent cover 26, or lens, closing the front opening 24 of the lamp body 22. An inner space formed between the lamp body 22 and the cover 26 forms a lamp chamber 28.
The vehicle lamp 10 includes a light source assembly 30 positioned in the lamp chamber 28. The light source assembly 30 includes a light emitting diode (LED) 32, an electrical board 34 and the light shade 20. The LED 32 is mounted to the electrical board 34 and connected to the electric board using solder or other suitable method for connecting components to an electrical board 34.
The LED 32 emits light in response to current supplied at the electrical board 34. The electrical board 34 provides an electrical connection to the LED 32 and the electrical board 34 is connected to a vehicle wiring harness at a connector 36. The wiring harness carries power and control signals transmitted by a vehicle control module to the electrical board 34 to activate the LED 32, for example. The electrical board 34 may a printed circuit board or a flexible circuit board. The printed circuit board may be a metal core board or insulated metal substrate consisting of single or double layer circuit boards laminated on a metal sheet. The flexible circuit board may include a rigidizer for forming a generally rigid electrical board.
The electrical board 34 may be mounted on support 38 to dissipate heat generated by the LED. The support 38 may be a heat sink sufficiently sized to dissipate heat. As illustrated in
The light source assembly 30 is arranged so that the LED 32 emits light towards a reflector 50 defined in the lamp chamber 28. The reflector 50 is arranged so that reflection of light rays from the LED 32 is projected toward the lens 26 in a desired light distribution pattern or along a desired emission axis. The reflector 50 may be a parabola-type reflector which has a reflective surface 52 formed based on the revolution of a paraboloid, or any suitable shaped reflector for reflecting light in the desired light distribution pattern based on the type of lamp.
The reflector 50 is positioned adjacent to a top surface 46 of the electrical board 34 and the reflective surface 52 covers the LED 32. The LED 32 may be positioned at the focal point of the reflective surface 52. The reflective surface 52 reflects the light from the LED 32 and irradiates the desired light-distribution pattern toward the lens 26 which projects the light pattern forward.
The direct light emitted by the LED may create glare for a pedestrian or the driver of an oncoming car. So as to not to produce glare, the light shade 20 is positioned adjacent the LED 32 opposite the reflector 50 so that the light shade 20 blocks direct light propagating toward the lens 26. The light shade 20 also blocks scattered or diffuse light from the LED 32 from projecting toward particular regions of the reflector 50 in order to define the desired light-distribution patterns and prevent unwanted light and glare outside the desired light-distribution pattern.
In order to project the desired light-distribution pattern, the LED 32 must be located at a relatively accurate position relative to the reflector 50, such as at the focal point of the reflective surface 52. For example, the LED 32 may be required to be located a predetermined position within a positional tolerance of ±0.3 mm of the focal point of a reflector where the focal point is 15 mm from the reflector 50. Alternatively, the LED 32 may be required to be located at a predetermined position having a positional tolerance of ±0.1 mm to ±0.3 mm.
Likewise and light shade 20 must be located at a relatively accurate position relative to the relative to the LED 32 and the reflector 50 to block direct light while allowing the desired light-distribution pattern. The closer the light shade 20 is located to the LED 32, the greater positional tolerance is required for positioning the light shade 20 at a predetermined location. However, the farther the light shade 20 is located from the LED 32, the light shade 20 blocks more light from the reflector 50 which may adversely affect lamp performance. For example, the light shade 20 may be required to be located at 5 mm from the focal point of the LED 32 at the predetermined position having a positional tolerance of ±0.2 mm. In another example, the light shade 20 may be located at 2.5 mm to the focal point of the LED 32 at the predetermined position having a positional tolerance of ±0.1 mm.
If the light shade 20 can be accurately located relative to the LED 32 with the required tolerances, locating the light shade 20 closer to the LED 32 may improve performance of the lamp 10 while minimizing aesthetic issues with the light shade 20.
In some prior art designs, the LED is positioned relative to the reflector based on one locating feature, and then the light shade is positioned relative to the reflector based on a different locating feature. In these prior art designs, the tolerance stack-up based on multiple locating features can cause the light shade to be misaligned with the LED, resulting in undesirable light distribution. Alternatively, to maintain alignment in prior art designs, the multiple locating features each require tight tolerances which result in high costs of all of the components.
The light source assembly 30, including the LED 32 and light shade 20, are accurately located relative to the reflector 50. Locating apertures 60 are formed on the electrical board 34. The locating apertures 60 are formed at relatively accurate locations on the electrical board 34 to function as datum reference points. For example, the locating apertures 60 may each control two-degrees of freedom. As illustrated in
Similarly, locating apertures 64 are formed on the reflector 50. The locating apertures 64 are formed at relatively accurate locations on the reflector 50 in order to accurately align the electrical board 34 with the reflector 50. For example, the locating apertures 64 may each control two-degrees of freedom and least one locating aperture 66 may control four-degrees of freedom.
The support 38 includes locating pins 58 that extend from the support surface 42. As illustrated, the locating pins 58 extend generally perpendicular from the support surface 42. The locating pins 58 align and extend through the locating apertures 60, 64 to accurately position the light source assembly 30 relative to the reflector 50. Fasteners, such as screws or bolts, may fasten the extend through fastening features formed on the electrical board 34 and support 38 to secure the electrical board 34 to the support 38.
The LED 32, light shade 20 and locating apertures 60 are accurately located on the electrical board 34 of the light source assembly 30 through the manufacturing and assembly process of the electrical board 34. Electrical boards, such as printed circuit boards are manufactured in an extremely clean environment where the air and components can be kept free of contamination and with automated and robotic equipment and so that circuitry and electrical components can be placed with tight tolerances.
For example, during manufacturing, the electrical board is passed through several machines to drill the locating apertures 60 in the substrate and place the electronic components in their proper location in the circuit. An initial process may form the locating apertures 60 and the locating apertures 60 may then serve as datum reference points for subsequent operations. Further, surface mount technology may be used to mount the LED 32 and light shade 20 to the electrical board at mounting points relative to the locating apertures 60. An amount of solder paste is automatically placed at each mounting point and then the LED 32 and light shade 20 may be robotically placed at the accurate mounting point. The components are then soldered to the electrical board. With surface mount technology, the soldering may be done by passing the electrical boards through a reflow process, which causes the solder paste to melt and make the connection.
The LED 32 may be electrically connected to the electrical board 34 by any suitable process that accurately and accurately positions the LED 32 in relation to the electrical circuits formed on the electrical board 34. Similarly, the light shade 20 is connected to the electrical board 34 at an accurate predetermined mounting location.
Unlike the LED 32, the light shade 20 is not required to be in electrical communication with any components on the electrical board 34. As such, the mounting location of the light shade 20 may be connected to the electrical board 34 with a mounting feature other than a solder point. For example, the light shade 20 may be connected to the electrical board 34 with an interference fit, such as a snap-fit, where the light shade is snapped into a mounting aperture formed on the electrical board 34.
The automated process of manufacturing the light source assembly 30 results in the accurate placement of the LED 32 and light shade 20 at predetermined locations on the electrical board 34. In particular, the automated placement of the LED 32 and light shade 20 with robotic machines ensures the accurate placement of the LED 32 and light shade 20 relative to locating features 60 on the electrical board 34.
Turning now to
The light shade 20 has a blocking wall 74 for blocking a portion of the light emitted from the LED 32. The blocking wall 74 may include a projection-pattern edge 76 that is contoured to define the desired light-distribution pattern. The contour of the scroll-pattern edge 76 may vary based on the desired light-distribution pattern, the type of LED light source, the shape of the reflector or other design factors. The projection-pattern edge 76 may be oriented at a predetermined distance from a focal point of the LED 32. For example, the projection-pattern edge 76 may be positioned between 2 mm and 8 mm from the focal point of the LED 32. The closer the light shade 20 is positioned to LED 32, the more accurately the light shade 20 must located relative to the LED 32. The further the light shade 20 is positioned away from the LED 32 the light shade is more visible outside the lamp, and the light shade 20 blocks light reflected from the more of the reflector which may affect lamp performance. The distance of the light shade 20 and edge 76 from the LED 32 may vary depending on the design of the lamp, the size of the LED, the desired light distribution pattern or other variables understood by a person of ordinary skill in the art.
The blocking wall 74 is offset from the electrical board by supporting walls 80. As illustrated in
In one embodiment, the central support wall 82 may be approximately 16 mm wide while the lateral support walls 84 are approximately 10 mm long. The support walls 80 are approximately 6 mm high, thereby offsetting the blocking wall 74 from the electrical board 34 by the height of the support walls 80.
The blocking wall 74 is connected to a first end 90 of the support walls 80 to define the enclosure 86. As illustrated in
In one embodiment, an inner surface 96 of the light shade 20 is disposed adjacent the LED 32 and has an anti-reflective surface to further prevent scattered light from being reflected in an undesirable pattern. For example, the inner surface 96 may be coated with dielectric coating or etched to create an anti-reflective and scattering surface.
As shown in the section view in
As illustrated in
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
