Movable condenser lens

#The present invention relates generally to automotive lamps. In particular, the present invention relates to an assembly for moving the light beam pattern of a headlamp.

#Generally, conventional automotive headlamps utilize a reflector of parabolic shape and an incandescent lamp. However, a projector headlamp, which has recently come into use more widely in the United States, is an automotive headlamp that typically utilizes a reflector of elliptical shape and may include a high intensity discharge gas lamp. A projector headlamp also generally requires the use of a condensing lens, which is located in front of the lamp and the reflector, to focus the light emitted by the assembly into a concentrated beam pattern which meets applicable automotive lighting requirements.

#In response to changing driving conditions, it can become desirable to move the beam pattern relative to the vehicle. For example, when a vehicle is being driven around a corner, it may be desirable for the beam pattern of that vehicle's forward lighting system to be adjusted, axially and/or laterally, such that the emitted light better illuminates the area in the direction the vehicle is turning. Additionally, adverse weather conditions or an increase or decrease in a vehicle's speed may also result in circumstances where adjustment of the vehicle's forward lighting beam pattern may become desirable. Automotive headlamps that can be adjusted in this manner are generally known in the industry as adaptive front lighting systems (“AFS”).

#FIG. 1A is a schematic top plan view of one exemplary embodiment of the invention.

#FIG. 1B is a schematic top plan view of the embodiment of the invention shown in FIG. 1A with the condenser lens in an alternative position.

#FIG. 2A is a schematic top plan view of an alternative exemplary embodiment of the invention using a elliptical reflector.

#Referring now to FIG. 1A, a schematic top plan view of one exemplary embodiment of the invention is shown. Headlamp assembly 100, which is installed in a vehicle, comprises reflector 102 having a reflector axis 104. Reflector 102 has focal point F1 and forward-facing reflector opening 106. Light source 108 is located substantially at focal point F1. Condenser lens 110 is disposed forward of reflector opening 106. For purposes of explanation, point A is positioned at the approximate center of mass of condenser lens 110. Accordingly, a light beam (not shown) is projected forward from reflector 102 and focused by condenser lens 110 so as to provide illumination in front of the vehicle.

#Referring now to FIG. 1B, headlamp assembly 100 is shown with condenser lens 110 in an alternate position in accordance with the present invention when the vehicle is turning to the left. The approximate center of mass of condenser lens 110 when condenser lens 110 is in the alternate position is indicated by point B. In this embodiment, the linear distance from F1 to point A shown in FIG. 1A is equal to the linear distance from F1 to point B in FIG. 1B. When condenser lens 110 is in this alternate position, condenser lens 110 focuses the light beam in a direction to the left of the direction of the light beam produced in the configuration of FIG. 1A above. The movement of condenser lens 110 is accomplished by rotating the lens with respect to a point that is not co-located with point A. Accordingly, the path followed by condenser lens 110 from one position to another position about the point of rotation may be described as being arcuate.

#Those of skill in the art will recognize that the present invention may be practiced with a number of variations. For example, the point of rotation need not be substantially near to the focal point of the reflector. Furthermore, the arcuate path may be of any curvilinear shape such as, but not limited to, generally circular or elliptical. These and other variations being within the scope of the present invention.