Patent · US Expired

Shielded discharge-type automotive head lamp

US4794297A · kind A · utility

6Cited by

7References

11Claims

0Family size

Assignee

Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH · DE

Inventors

Manfred Gaugel · Fürstenfeldbruck, DE
Ju vom Scheidt · Taufkirchen, DE
Ewald Wurster · Grünwald, DE

Key dates

Filing date	Dec 30, 1986
Grant date	Dec 27, 1988
Priority date	—
Expiry date	Dec 30, 2006

Classification

Technology area (CPC H)Electricity
CPC primaryH01J61/35
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

To provide light distribution required by legal and safety requirements for utomotive head lamps from a discharge lamp, a discharge vessel or bulb (2, 12) is retained within an outer bulb (7, 17), which outer bulb is made of hard glass and is coated at the outside with a visible light radiation absorbing coating (8, 18) directly applied to the outer bulb, and placed thereon to provide the desired light distribution. Thus, standard silicon iron oxide black can be used for the coating. Preferably, the inside of the outer bulb has a coating of infrared absorbing, visible light transmitting material applied thereto.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.