Patent Application
20160107567
The instant invention relates to an instrument cluster, and more particularly, to an instrument cluster having a printed circuit board (PCB) having a light source and a light conductor mounted directly on the PCB.
Instrument clusters having printed circuit boards (PCBs) are used in the automobile industry, among others. For example, European Patent Application Publication EP 2235482, incorporated herein by reference, discloses an instrument cluster having a printed circuit board which holds a pointer drive source and an illumination source for a pointer. Additionally, light guides for an instrument cluster are known. See, for example of U.S. Pat. No. 7,592,972 to Eckardt et al. (“the '972 patent”), incorporated herein by reference. Referring now to
Additionally, European Patent Application Publication No. EP 2 587 121 A1 to Kerpe (the '121 reference) discloses LED-based lighting with a reflector mounted on a PCB. In the '121 reference, a plurality of LEDs are mounted to a PCB. Furthermore, a surface mount reflector of a metal sheet with punched out reflector surfaces is located on the PCB. According to the '121 reference, the surface mount reflector and the PCB are held together within a frame.
What is needed is an improved design for lighting an instrument cluster using a light conductor directly attached to a PCB, in order to eliminate the need for a frame structure or light housing.
It is accordingly an object of this invention to provide an instrument cluster system that overcomes the disadvantages of the prior art. In one particular embodiment of the invention, an instrument cluster is provided wherein a light conductor is provided that is directly attached to the printed circuit board (PCB) near or adjacent to a light source on the PCB. In another embodiment of the invention, the light conductor provided is a light weight, non-rigid light guide. In a further particular embodiment, a light guide is directly mounted to the PCB using adhesive.
Although the invention is illustrated and described herein as embodied in an instrument cluster including a PCB mounted light conductor, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction of the invention, however, together with the additional objects and advantages thereof will be best understood from the following description of the specific embodiments when read in connection with the accompanying drawings.
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements and in which:
Referring now to
In the preferred embodiment of the invention, the light conductor 20 is attached directly (i.e., without a support frame or light housing) to the PCB 50. More particularly, a rear face of the light guide 20 is adhered directly to, and in full contact with, a front face of the PCB 50. In one particular embodiment of the invention, the light conductor 20 is adhered directly to the PCB 50 using an adhesive. Use of a light conductor 20 directly attached to the PCB 50 will eliminate a plastic part (frame or light housing) used in current assemblies and simplifies the design, thus creating new possibilities cosmetically, in illumination and in decorative features.
Referring more particularly to
In one particular embodiment of the invention, light from the light sources 60 enter the light collecting faces 40 of the light conductor 20 and is emitted from the emitting surface 30 of the light conductor 20, while the faces 22 of the light conductor 20 reflect light within the light conductor 20. In one particular embodiment, the faces 22 could be painted white, if desired, so as to increase the reflection of light within the light conductor 20 and emission from the emitting surface 30. Additionally, the bottom surface of the light conductor 20 (i.e., the face that is attached directly to the PCB 50, includes a white coating, in order to improve reflection from the emitting surface 30. Such a white coating can be applied to the bottom surface by painting or application of a foil or some other process, as desired. Additionally, if desired, marks or reflecting surfaces (such as indicator line 25) can be placed on or in the body of the light conductor 20. For example, the upper surface or emitting face 30 of the light conductor 20 (i.e., the face not in direct contact with the PCB 50) can be made to include reflecting surfaces, such as dots (in silicone light conductors 20) and/or microstructures (in plastic or glass light conductors 20) that can reflect the light as described more particularly in col. 5 of the '972 patent, lines 5-54, (that reference being previously incorporated herein, by reference in its entirety). Other types of structures can be used as well in plastic and/or glass, such as eroded structures (i.e., formed by VDI and/or Charmilles Technologies™ erosion processes).
The present invention simplifies the manufacture and design of instrument clusters by adhering the light conductor 20 directly to the PCB 50 near the light sources 60 without an extra piece, light housing or frame structure being required. This results in thinner instrument clusters having less weight and costing less to produce.
Although the invention is illustrated and described herein as embodied in an instrument cluster including a PCB mounted light conductor, it is nevertheless not intended to be limited to only these details shown. As can be seen, various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
