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US5021930A Expired / Lapsed US ⏱️ 0.0 years remaining

Automotive headlamp having reduced chromatic aberration

Assignee: Koito Manufacturing Co Ltd
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Filing: 1990-09-11
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Granted: 1991-06-04
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Expires: 2010-09-11
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Abstract

Abstract The present invention relates to an automotive headlamp construction in which chromatic aberation is substantially eliminated. The headlamp includes an elliptic reflector, a light source disposed at a first focal point of the elliptic reflector, a condenser lens which is focused generally at a second focal point of the elliptic reflector, and an outer lens provided in front of the condenser lens. In accordance with the invention, the radius of curvature of the outer lens is reduced at a vertically middle portion thereof to form an angled portion through which light from the light source passes. The angled portion acts as a lens having a focal length such that chromatic aberration of the condenser lens is canceled out.

Inventors

  • 👤 Masaru Yamada

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 14:05
CPC Classifications
B; B60; B60Q; B60Q1/00; B60Q1/0029; B60Q1/0041; F; F21; F21S; F21S41/00; F21S41/10; F21S41/14; F21S41/162; F21S41/20; F21S41/25; F21S41/255; F21S41/28; F21S41/285; F21S41/29; F21S41/30; F21S41/32; F21S41/321; F21S41/36; F21S41/40; F21S41/43; F21S41/50; F21S41/60; F21S41/67; F21S41/675; F21S43/00; F21S43/50; F21S45/00; F21S45/30; F21S45/33; F21W; F21W2103/00; F21W2103/15

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 107 words
An automotive headlamp comprising: an elliptical reflector; a light source located at a first focal point of said elliptical reflector; a condenser lens focused substantially at a second focal point of said elliptical reflector; a shade provided in front of said reflector for shielding part of light from said light source; and an outer lens provided in front of said condenser lens, said outer lens having an angled portion extending along a vertically middle portion thereof having a radius of curvature smaller than in other portions of said outer lens, said outer lens being positioned such that light from said light source passes through said angled portion.
Claim 2
Dependent Claim 107 words
An automotive headlamp comprising: an elliptical reflector; a light source located at a first focal point of said elliptical reflector; a condenser lens focused substantially at a second focal point of said elliptical reflector; a shade provided in front of said reflector for shielding part of light from said light source; and an outer lens provided in front of said condenser lens, said outer lens having an angled portion extending along a vertically middle portion thereof having a radius of curvature smaller than in other portions of said outer lens, said outer lens being positioned such that light from said light source passes through said angled portion.

References Cited (Backward Citations)

US3578966A Cited
US4928213A Cited
US4914747A Cited
US4953063A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-06-03 1994-12-03 1995-06-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-06-03 1998-12-03 1999-06-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-06-03 2002-12-03 2003-06-04 $7700.00 Window Closed / Lapsed

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