Rotating anti-glare shield

• US 20050180144A1
• Filed: 02/04/2004
• Published: 08/18/2005
• Est. Priority Date: 02/04/2004
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: Guide Corporation (Vehicle Lighting Incorporated)
• Inventors: Lisowski, Michael F., Stout, Bo J.
• Granted Patent: US 7,134,771 B2
• Time in Patent Office: Days
• US Class Current: 362/307
• CPC Class Codes: F21S 41/43 characterised by the shape thereof
• CPC Class Codes: F21S 41/686 Blades, i.e. screens moving in a vertical plane

Abstract

A lamp assembly is provided which reduces the illumination of the foreground area in front of a vehicle so as to reduce reflective glare. A movable glare shield is moved into the portion of the beam of light produced by a lamp assembly that is associated with the foreground area, thereby reducing the illumination level in the foreground area. The shield may be rotatably moved out of the light beam to allow for full illumination when glare is not present.

Claims

1. A method of reducing reflective glare, comprising the steps of:

(a) determining that a potential reflective glare producing condition exists; and

(b) placing a moveable reflective glare reducing shield in the forward beam of a lamp assembly having an illumination field formed by the light exiting the lamp assembly.

2. The method of claim 1, wherein the step of placing a moveable reflective glare reducing shield in the forward beam of a lamp assembly comprising the step of rotating a shield into the forward beam of the lamp assembly, thereby reducing illumination in the foreground area of the illumination field.

3. The method of claim 2, wherein the step of rotating a shield comprises the step of, rotating an opaque shield into the forward beam of the lamp assembly.

4. An automobile lamp assembly comprising:

(a) a reflector having a focal point and an optical axis;

(b) a light source placed such that light from the light source impinges upon the reflector and is reflected in a forward direction;

(c) a lens located forward of the reflector, such that light reflected by the reflector passes through the lens and exits the lamp assembly in the form of a beam producing an illumination field, the illumination field having an upper area and a foreground area; and

(d) a reflective glare reducing shield moveable between a first position and a second position, such that when the shield is in the first position, a first illumination level is produced by the beam of light in the foreground area, and such that when the shield is in the second position, a second illumination level is produced by the beam of light in the foreground area, the second illumination level being less than the first illumination level.

5. The lamp assembly of claim 4, wherein the shield is moveable between a plurality of positions between the first position and the second position, such that when the shield is in each of the plurality of positions, a respective plurality of illumination levels are produced by the beam of light in the foreground area, each of the plurality of illumination levels being greater than the second illumination level and less than the first illumination level.

6. The lamp assembly of claim 5, wherein the shield is moveable by rotation within a plane generally perpendicular to the optical axis.

7. The lamp assembly of claim 6, wherein the shield comprises:

(a) a ring having a vacant center;

(b) teeth arranged about the ring; and

(c) a protuberance arranged upon the ring and protruding into the center of the ring.

8. The lamp assembly of claim 7, wherein the lamp assembly further comprises a means for rotating the shield, the means for rotating engaged with the teeth.

9. The lamp assembly of claim 8, wherein the means for rotating is in a location remote from the shield.

10. The lamp assembly of claim 7, wherein the protuberance is generally in the shape of a partial epicycloid.

11. The lamp assembly of claim 10, wherein the protuberance is opaque.

12. The lamp assembly of claim 7, the lamp assembly further comprising, a cutoff shield having an upper edge, the cutoff shield located between the glare reducing shield and the lens.

13. The lamp assembly of claim 12, wherein when the glare reducing shield is in the first position, the protuberance is lower than the upper edge of the cutoff shield so that the first illumination level is produced, and when the glare reducing shield is in the second position, the protuberance is higher than the upper edge of the cutoff shield so that the second illumination level is produced.

14. A glare producing shield for use in a vehicle headlamp assembly, the shield comprising:

(a) a means for receiving motive force; and

(b) a means for reducing the illumination in the foreground portion of a light beam emitted from a headlamp without significantly altering the illumination in the upper are of the beam, the means for reducing operatively connected to the means for receiving and capable of being installed in a vehicle and moved between a first position and a second position such that when the means for reducing is in the first position, a first illumination level is produced in the foreground portion, and such that when the means for reducing is in the second position, a second illumination level is produced in the foreground portion, the second illumination level being less that the first illumination level.

15. The glare reducing shield of claim 14, wherein the shield comprises a ring having a vacant center, and wherein the means for reducing comprises, a protuberance, projecting toward the vacant center.

16. The glare reducing shield of claim 15, wherein the protuberance is generally in the shape of a partial epicycloid.

17. The glare reducing shield of claim 16, wherein the protuberance is opaque.

18. The shield of claim 16, wherein the means for receiving comprises a plurality of teeth extending away from the ring.

19. The shield of claim 18, wherein the plurality of teeth extend toward the vacant center of the ring.