Patent · US Active

Method and apparatus to measure light intensity

US8575845B2 · kind B2 · utility

1Cited by

2References

13Claims

0Family size

Assignee

TEXAS INSTRUMENTS INCORPORATED · US

Inventors

Tobin Hagan · Plano, US
David L. Freeman · McKinney, US
Marco Corsi · Little Elm, US

Key dates

Filing date	Dec 14, 2011
Grant date	Nov 5, 2013
Priority date	—
Expiry date	May 28, 2032

Classification

Technology area (CPC H)Electricity
CPC primaryH05B45/39
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A method for controlling a light emitting diode (LED) is provided. Initially, the LED, which had been active, is deactivated, and a voltage for a current that corresponds to the persistence of the LED is generated. The voltage is then integrated so as to generate an integrated voltage, and the integrated voltage is compared to a threshold. When the integrated voltage is less than the threshold, the LED is then activated.

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