Patent · US Expired

Lighting system for controlling the color temperature of artificial light under the influence of the daylight level

US5721471A · kind A · utility

221Cited by
6References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 1, 1996
Grant dateFeb 24, 1998
Priority date
Expiry dateMar 1, 2016

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05B47/10
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A lighting system having at least one light source for supplying artificial light and a control unit for controlling the light source. The light source is of the type having an adjustable color temperature. The control unit is provided with a control signal from a signal generator. The signal generator is dependent on the mean daylight level. The control unit is arranged to adjust the color temperature of the light source in dependence on a predetermined relationship between the mean daylight level and the color temperature of the artificial light. The lighting system will provide artificial light which will when the daylight level, as measured on an office desk, increases from approximately 400 lux to approximately 800 lux, increase the color temperature from approximately 3300 K to approximately 4300 K.

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