Projection head lamp for cars

• US 5,339,226 A
• Filed: 06/01/1993
• Issued: 08/16/1994
• Est. Priority Date: 06/03/1992
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Ishikawa, Masaaki
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): LEE, Y MY QUACH
• Application Number:
  US08/069,358
• Time in Patent Office: 441 Days
• Field of Search: 362/61, 362/66, 362/80, 362/277, 362/282, 362/284, 362/319, 362/321, 362/322, 362/324, 362/351
• US Class Current: 362/539
• CPC Class Codes: B60Q 1/14 having dimming means
• CPC Class Codes: F21S 41/43 characterised by the shape thereof
• CPC Class Codes: F21S 41/698 Shaft-shaped screens rotating along its longitudinal axis

Abstract

A projection head lamp for vehicles comprises a substantially elliptical reflector 14, a light source located at the first focal point of the reflector 14, a projection lens 16 disposed in front of the reflector 14, and a shade 20 located at a position near to the second focal point and the focal point of the projection lens 16, the shade 20 intercepting light beams going from the reflector 14 toward the projection lens 16. The shade 20 may be turned about the horizontal shaft. To adjust the beam distribution pattern, the shade 20 is turned. The shade 20 consists of left and right shades 21 and 22, which are separated and horizontally extended when seen from the point right under the optical axis. The shades 21 and 22 have pairs of shade plates 212 and 213, and 222 and 223, of which the extended parts extending along the horizontal shaft overlap with one another.

Claims

1. A projection type headlamp, comprising:

a substantially oval reflector;

a light source disposed at a first focal point of said reflector;

a projection lens disposed in front of said reflector; and

shade means for cutting at a predetermined position a part of light beam emitted from said light source and reflected by said reflector to form a desired light distribution pattern, said shade means being provided between said reflector and said projection lens in the vicinity of a second focal point of said reflector and substantially at a focus point of said projection lens, said shade means via motor and gear means rotating along a horizontal axis thereof which is perpendicular to an axis of said light source, said shade means comprising;

a first shade member having at least two plates spaced apart from each other by a predetermined angle; and

a second shade member having at least two plates spaced apart from each other by a predetermined angle,

said blades of said first and second shade members successively positioning at said predetermined position during the rotation of said shade means, whereby said part of light beam reflected by said reflector always cutting generally by one of said plates.

2. The projection lamp of claim 1, wherein said first and second shade member rotate along said horizontal axis of said shade means independently from each other.

3. The projection lamp of claim 1, wherein each of said first and second shade member comprises a cylindrical body member having a center axis coincide with said horizontal axis of said shade means, and each of said plate comprises a pair of a base part and an extension part, said base parts protruding radially from said body member and each of said extension parts extending axially from each of said base parts.

4. The projection lamp of claim 3, wherein said extension parts of said first and second shade members overlap with said base parts of said second and first shade members respectively.

5. The projection lamp of claim 3, wherein said pair of base parts of each of said first and second shade members spaced apart from each other by an angle of 90°

.

6. The projection lamp of claim 3, wherein at least one of said extension parts is inclined by 15°

with respect to an outer edge of the base part from which said at least one of said extension part extends, and an outer edge of at least one other of said extension parts is stepped up by an angle of 45°

with respect to another outer edge of the base part from which said at least one other of said extension part extends.

7. The projection lamp of claim 1, wherein said first and second shade members are arranged laterally along said horizontal axis of said shade means and adjacent to each other.

8. The projection lamp of claim 1, further comprising a first motor operatively engaging with said first shade member through gear means and a second motor operatively engaging with said second shade member through gear means.