Illumination – Supported by vehicle structure – Light modifier
Reexamination Certificate
1999-07-21
2001-02-13
Husar, Stephen (Department: 2875)
Illumination
Supported by vehicle structure
Light modifier
C362S539000, C362S508000, C362S270000, C362S277000, C362S538000, C362S513000
Reexamination Certificate
active
06186651
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to automotive headlamps, and more particularly to HID (high intensity discharge) automotive headlamps.
2. Disclosure Information
HID headlamps are commonly used nowadays in automotive applications, in large part because of the quality of light produced and because of the longevity, energy efficiency, and reliability of the lamp bulbs. Conventional automotive applications of HID projector-type headlamps are disclosed in U.S. Pat. Nos. 5,180,218 to Ohshio 5,709,451 to Flora et al., both of which are incorporated herein by reference.
FIG. 8
(taken from FIG. 1 of the aforementioned Flora et al. patent) illustrates a representative prior art approach for constructing an HID headlamp for low beam conditions, which includes a light shield
20
with its top edge
22
positioned immediately beneath the second focal point F
2
of the elliptical reflector
10
.
In conventional HID automotive headlamp applications, the common practice is to provide two of such headlamps on each of the left-hand and right-hand front areas of the vehicle; one of these two headlamps per side would be a low beam headlamp similar to
FIG. 8
, while the other headlamp would be an essentially similar high beam headlamp that would not include a light shield
20
. Besides the fact that the low beam headlamp has a light shield while the high beam does not, another difference between low and high beam headlamps is the respective forward-projected points in space (“hot spots”) that each must be aimed at, as well as glare and intensity requirements. These requirements are specified by the Federal Motor Vehicle Safety Standard (FMVSS) and other automotive vehicle standards of the U.S. and other countries.
Although there are significant benefits in utilizing HID-type lighting systems in automotive applications, one drawback is the need for two headlamps per vehicle side. It would be desirable to provide an HID-based lighting system for automotive headlamp applications which requires the use of only a single headlamp per vehicle side.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of the prior art approaches by providing a projector headlamp for projecting light in a forward direction generally along a horizontal axis selectably between high beam and low beam conditions which requires only one headlamp per vehicle side. One embodiment of the projector headlamp comprises: (a) a generally elliptical reflector having a reflector axis, first and second focal points located along the reflector axis, and a forward-facing reflector opening; (b) a light source from which light waves may emanate, the light source being located substantially at the first focal point; (c) a light shield disposed generally beneath the second focal point and having a top edge; (d) a condenser lens having a condenser axis, the condenser lens being disposed forward of the reflector opening and spaced apart from the second focal point effective to substantially collimate the light waves generally in the forward direction; and (e) means for selectably moving at least one of the light shield, the reflector, the condenser lens, and the light source between the low beam and high beam conditions. In the low beam condition, the reflector and condenser axes are substantially collinear and substantially parallel to the horizontal axis, and the light shield is oriented in a first position wherein the top edge is positioned immediately beneath the second focal point. In the high beam condition, the reflector and condenser axes are substantially collinear and raised by an angle A with respect to the horizontal axis, and the light shield is oriented in a second position wherein the top edge is lowered away from the second focal point. Other embodiments of the present invention are also provided.
It is an object and advantage that the present invention requires only one projector headlamp for accommodating both high and low beam lighting conditions, while providing for the difference in hot spot aiming between these two conditions.
Another advantage is that the HID projector headlamp of the present invention requires much less vehicle space than is required for conventional HID projector headlamps.
These and other advantages, features and objects of the invention will become apparent from the drawings, detailed description and claims which follow.
REFERENCES:
patent: 5180218 (1993-01-01), Ohshio
patent: 5339226 (1994-08-01), Ishkawa
patent: 5414301 (1995-05-01), Davenport et al.
patent: 5423127 (1995-06-01), Deslandres
patent: 5436807 (1995-07-01), Kobayashi
patent: 5539625 (1996-07-01), Turley, Jr. et al.
patent: 5709451 (1998-01-01), Floras et al.
patent: 5899559 (1999-05-01), Lachmayer et al.
patent: 5902039 (1999-05-01), Futami
patent: 5906431 (1999-05-01), Chinale et al.
patent: 5911502 (1999-06-01), Zillgitt et al.
patent: 5915829 (1999-06-01), Kaize et al.
Cejnek Milan
Chinniah Jeyachandrabose
Cruz Jose M.
Erion Jeffrey Allen
Patel Balvantrai
Alavi Ali
Husar Stephen
Shelton Larry I.
Visteon Global Technologies Inc.
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