Patent · US Expired

Light emitting device, driving method for the same and electronic apparatus

US6661180B2 · kind B2 · utility

172Cited by
13References
28Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 21, 2002
Grant dateDec 9, 2003
Priority date
Expiry dateMar 21, 2022

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10K59/12
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

It is a problem to provide a light-emitting device capable of obtaining a constant brightness without being affected by deterioration in an organic light-emitting layer or temperature change, and of making desired color display. The towering in OLED brightness due to deterioration is reduced by causing the OLED to emit light while keeping constant the current flowing through the OLED instead of causing the OLED to emit light while keeping constant the OLED drive voltage. Namely, OLED brightness is controlled not by voltage but by current thereby preventing against the change in OLED brightness due to deterioration of OLED. Specifically, the drain current Id of a transistor for supplying a current to the OLED is controlled in a signal line drive circuit thereby keeping constant the drain current Id without relying upon the value of a load resistance.

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