Projection type vehicular headlamp

• US 5,091,830 A
• Filed: 06/11/1991
• Issued: 02/25/1992
• Est. Priority Date: 06/19/1990
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Suzuki, Yoshinobu
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): Cole: Richard R.
• Application Number:
  US07/713,201
• Time in Patent Office: 259 Days
• Field of Search: 362/61, 362/80, 362/294, 362/351, 362/373
• US Class Current: 362/539
• CPC Class Codes: F21S 41/295 specially adapted to projection lenses
• CPC Class Codes: F21S 41/43 characterised by the shape thereof
• CPC Class Codes: F21S 41/47 Attachment thereof achieving variable light distribution by movable screens F21S41/683
• CPC Class Codes: F21S 45/33 specially adapted for headlamps
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes

Abstract

A projection type vehicular headlamp having a projection unit including a reflector accommodating therein a light source, a tubular lens holder engaged with the front opening of the reflector, and a projection lens supported by the lens holder as one unit, with a clear cut forming shade provided inside the lens holder in such a manner that the shade blocks substantially the lower half of the section of the optical path in the projection unit. In the vehicular headlamp, the shade has an opening in the lower end portion thereof through which spaces fore and rear sides of the shade are communicated with each other.

Claims

1. A projection type vehicular headlamp comprising:

a light source;

an elliptic reflector having a front opening and a first and second focal points for reflecting light beam emitted from said light source into an optical path;

a tubular lens holder having a first opening fixedly secured with said front opening of said reflector and a second opening, said tubular lens holder being unbroken between said first and second openings;

a projection lens fitted on said second opening of said lens holder for collimating the light beam reflected by said reflector, said tubular lens holder enclosing a space between said lens and said reflector; and

a shade for forming a required cut-off line of projected light beam, said shade being provided inside said lens holder in such a manner that said shade blocks substantially a lower half of the optical path in said projection type headlamp, said shade having an opening formed therein at a lower portion of said shade.

2. The projection type vehicular headlamp of claim 1, wherein said shade comprises a shade body and a bent portion extending from said shade body toward a lower portion of said lens.

3. The projection type vehicular headlamp of claim 2, wherein said bent portion of said shade is unitarily formed with said holder.

4. The projection type vehicular headlamp of claim 1, wherein said light source is a light bulb having a filament positioned at said first focal point of said reflector.

5. The projection type vehicular headlamp of claim 1, wherein said second opening of said lens holder comprises a block wall protruding upwardly from a lower edge portion thereof.

6. The projection type vehicular headlamp of claim 1, wherein said reflector is formed of aluminum die cast.

7. The projection type vehicular headlamp of claim 1, wherein said holder is formed of aluminum die cast.

8. The projection type vehicular headlamp of claim 1, wherein said reflector, said holder and said lens are unitarily formed and constitute a projection lamp unit.

9. The projection type vehicular headlamp of claim 1, further comprising a lamp body, an outer cover fitted on said lamp body at one end thereof and a back cover fixed to said lamp body at the other end thereof, said lamp body, said outer cover and said back cover accommodates therein said reflector, said holder and said lens.