Patent · US Expired

Projection-type system and method of operating the same

US7517093B2 · kind B2 · utility

5Cited by
7References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 15, 2004
Grant dateApr 14, 2009
Priority date
Expiry dateSep 11, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G2320/0633
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An object of the invention is to provide method of operating a projection-type system, which method is capable of suppressing flicker and minimizing gradation disorder at the same time by superimposing a pulse current on a d.c. lamp current to stabilize arc while synchronizing the superimposition of the pulse current on the d.c. lamp current with a predetermined segment. The method of operating a projection-type system configured to pass light emitted from a high-pressure discharge lamp lit by d.c. lighting through divided plural color segments sequentially to project an image onto a screen, includes superimposing a pulse current on a d.c. lamp current in the high-pressure discharge lamp in synchronism with at least one specific color segment.

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