Patent · US Expired

Selective illumination

US4225808A · kind A · utility

67Cited by
5References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 5, 1978
Grant dateSep 30, 1980
Priority date
Expiry dateJun 5, 1998

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02B20/40
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

Different portions of an area are selectively highlighted in response to observer proximity. An adjustable dimmer establishes the non-highlight illumination level for each area. The dimmer is overridden by observer-sensing circuitry to produce the highlight illumination level.

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