BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a partial cross-sectional view of a projector headlamp system in low beam mode, according to an aspect of the invention;
FIG. 1B is a schematic diagram of a low beam pattern produced by the projector system of FIG. 1A;
FIG. 2A is a partial cross-sectional view of a projector headlamp system in high beam mode, according to an aspect of the invention;
FIG. 2B is a schematic diagram of a high beam pattern produced by the headlamp assembly of FIG. 2A;
FIGS. 3A, 3B, and 4 are schematic views of various components of shield mechanisms;
FIGS. 5 and 6 show side perspective views of various projector systems configured, in accordance with several embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A illustrates a headlamp 10 according to an aspect of the present invention. The headlamp 10 is a projector-style headlamp and comprises a light source 12, a reflector 14, and a lens 16. The headlamp 10 is bi-functional and is configured to selectively provide at least two unique light beam patterns. For example, the headlamp may be configured to provide a high beam pattern and a low beam pattern.
The light source 12 can be any suitable light source that is configured to emit light over an appropriate light spectrum and at an appropriate intensity, for a particular use. Examples of suitable light sources 12 include, but are not limited to, incandescent, halogen, high intensity discharge (“HID”), and light emitting diode (“LED”) light sources. In the embodiment shown in FIG. 1A, the light source 12 is arranged along the optical axis A of the reflector 14 and is disposed generally at a first focal point or plane F1 of the reflector 14.
The reflector 14 may have any shape numerically or otherwise determined to provide the desired light beam pattern, and preferably has an ellipsoidal shape. Reflector 14 is formed so that the light emitted by the light source 12 is reflected by reflector 14 in converging light bundles. Light source 12 and reflector 14 cooperate to form a light pattern at the second focal point or plane F2 of the reflector 14.
The lens 16 is disposed at a predetermined distance from reflector 14. In the embodiment shown in FIG. 1A, lens 16 is formed as a collecting lens and has a first surface 18 and a second surface 20 defined by a body portion 22 therebetween. The lens 16 receives light from the light source 1.2 and the reflector 14 through the first surface 18, transmits the light through the body portion 22, and projects a predetermined beam pattern from the second surface 20. The beam pattern corresponds generally with the light pattern, but is horizontally and vertically inverted with respect to the optical axis A.
The first surface 18 is generally planar and is oriented generally perpendicular to the optical axis A. The second surface 20 has a generally curved contour that may be spherical or aspherical. The contour of the second surface 20 is selected so that light generated by light source 12 and reflected by reflector 14 is deviated during passage through the lens in a predetermined manner. Preferably, the lens 16 is composed of glass, a light permeable synthetic plastic, or any other suitable material.
The headlamp 10 includes a light shield 24 disposed between lens 16 and reflector 14. The light shield 24 comprises a first shade 30 that is moveable between a first position when the headlamp 10 is in a low beam mode, and a second position when the headlamp 10 is in a high beam mode. In FIG. 1A, the headlamp 10 is shown in a low beam mode, wherein a body portion 32 is disposed generally below the optical axis A so that the shade 30 blocks a first portion of the light emitted by the light source 12 and reflected by the reflector 14. The resulting beam pattern, illustrated in FIG. 1B, has a high-intensity light region H and a low-intensity light region L. The upper edge 36 of the beam pattern has a contour that corresponds with the contour of an upper edge 34 of the shade 30.
In FIG. 2A, the headlamp 10 is shown in a high beam mode. In the high beam mode, the first shade 30 is removed from its position between the light source 12 and the lens 16 so that it no longer blocks the first portion of the light pattern. Accordingly, additional light is added to the beam pattern, extending the high-intensity light region H, or “hot zone,” vertically upwards, as shown in FIG. 2B.
At substantially the same time that the first shade 30 is removed, a second shade 40 is moved between the light source 12 and the lens 16, generally above the optical axis A. The shade 40 blocks a second portion of the light emitted by the light source 12 and reflected by the reflector 14, and is configured to remove a portion of the low-intensity light region L, corresponding with the foreground light of the beam pattern. Removal of the foreground portion of the light beam enhances the contrast ratio between the foreground and the hot zone of the beam pattern. This may improve the driver's ability to view the road in the high beam mode, as the driver will tend to focus on the high-intensity portion of the light beam, with less interference from the lower-intensity foreground zone. In FIG. 2B, the lower edge 38 of the beam pattern has a contour that corresponds with the contour of a lower edge 44 of the shade 40.
FIGS. 3A and 3B show the various shades of the light shield 24. In FIG. 3A, a first shade 30 is provided for blocking light in the low beam mode. In the low beam mode, shade 30 is positioned so that an upper edge 34 of the body portion 32 blocks a portion of the light pattern generally below the optical axis. In FIG. 3B, a second shade 40 is provided for blocking light in the high beam mode. In the high beam mode, the shade 40 is positioned so that a lower edge 44 of the body portion 42 blocks a portion of the light pattern generally above the optical axis.
FIG. 4 illustrates another light shield 124 that may be used with the present invention. The light shield 124 comprises a shade 130 for blocking light in the low beam mode and in the high beam mode. In the low beam mode, the shade 130 will be positioned so that an upper portion 132 of the shade blocks a first portion of the light pattern generally below the optical axis. The upper edge of the resulting beam pattern will have a contour that corresponds with the contour of an upper edge 134 of the shade. In the high beam mode, the shade 130 will be positioned so that a lower portion 142 of the shade blocks a second portion of the light pattern generally above the optical axis. The lower edge of the resulting beam pattern will have a contour that corresponds with the contour of a lower edge 144 of the shade. It will be apparent that in the high beam mode, the shade 130 will be positioned so that it does not block the first portion of the light pattern.
FIG. 5 shows a perspective view of a headlamp 210 according to an aspect of the invention. The headlamp 210 has a light source 212, a reflector 214, a lens 216, and a light shield 224, which includes a first shade 230 and a second shade 240. The headlamp 310 further comprises an actuation mechanism 250, which is configured to move the first and second shades 230, 240 between their respective low beam and high beam mode positions. The headlamp 210 is in electrical communication with a control device (not shown) that allows the user to selectively actuate the shades 230, 240 between high beam and low beam modes.
The actuation mechanism 250 preferably comprises a solenoid 252 that is in mechanical communication with the shades 230, 240 via conversion mechanism 254. When the solenoid 252 is in a first position, the light shield 224 is configured so that the first shade 230 blocks a first portion of the light pattern generally below the optical axis, and the headlamp 210 produces a low beam pattern. When the solenoid 252 is in a second position, the light shield 224 is configured so that the first shade 230 is removed from the first portion of the light pattern and so that the second shade 240 blocks a second portion of the light pattern generally above the optical axis. Accordingly, the headlamp 210 produces a high beam pattern.
The actuation mechanism 250 may move the shades 230, 240 independently of each other. Preferably, the first shield 230 and the second shield 240 will move generally simultaneously. For example, in one embodiment of the present invention, the first and second shields 230, 240 may be affixed or may be formed as a single piece. In such an instance, the first shield 230 is attached at a predefined distance from second shield 240 such that a movement of shield 230 out of the light pattern causes movement of second shield 240 into the light pattern.
In FIG. 5, the actuation mechanism 250 is configured to move the shades 230, 240 simultaneously and in a translatory manner. When the high beam function is selected, the shades 230, 240 translate downwardly with respect to the optical axis so that the shade 230 is removed from the light pattern and the shade 240 blocks the light pattern. When the low beam function is subsequently selected, the shades 230, 240 translate upwardly with respect to the optical axis so that the shade 240 is removed from the light pattern and the shade 230 blocks the light pattern.
In FIG. 6, the actuation mechanism 350 is configured to move the shades 330, 340 in a rotational manner. When the high beam function is selected, the shade 340 rotates along an arc into the light pattern and the shade 330 rotates along an arc out of the light pattern. When the low beam function is subsequently selected, the shade 330 rotates into the light pattern and the shade 340 rotates out of the light pattern.
Throughout this specification, various indications have been given as to preferred and alternative embodiments of the invention. However, it should be understood that the invention is not limited to any one of these. 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 appended claims, including all equivalents, that are intended to define the spirit and scope of this invention.
Patent Application
20080025035
