Automotive projector-type headlamp
US4945455A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1989 |
| Grant date | Jul 31, 1990 |
| Priority date | — |
| Expiry date | Nov 30, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21S41/338
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The inner reflecting surface of the concave mirror of the projector-type headlamp is composed of a central spherical area and a composite ellipsoidal surface of revolution formed by parts of a plurality of different ellipsoidal surfaces of revolution, smoothly joined to each other for junction with the central spherical area, having a common focus at the center of the spherical area and other foci, respectively, at positions spaced ahead of a predetermined distance from the common focus. The lamp bulb is so disposed so as to have the center thereof located near the common focus, and the convex lens is so disposed as to have the focus thereof located near the common focus. The ellipsoidal surfaces of revoltion are so shaped geometrically as to reflect in directions toward their respective other foci the rays emitted from the lamp bulb and incident upon the ellipsoidal surrfaces of revolution, and the convex lens is so designed as to have the focus thereof located near the common focus of the ellipsoidal surfaces of revolution at which the lamp bulb is located. Thereby, it is possible to decrease the total length of the optical system, design compact the entire structure of the proje…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.