Displays
The technology removes the need for adding external circuit components, according to eMagin. The patented circuit employs a current source operating in a switched mode. The output of the current source is connected to a terminal of the OLED. The current source responds to a combination of a selectively set cyclical voltage signal and a cyclical variable amplitude voltage signal. When the current source is switched on, it supplies the OLED with sufficient current to achieve maximum luminance.
When switched off, the current source blocks the supply of current to the OLED, providing a uniform black level for an OLED display.
Modulating the pulse width of the current controls the apparent luminance of the OLED, effectively varying the length of time that current is supplied to the OLED. By means of a switched mode of operation at the current source, the circuit can employ a larger range of voltages to control the luminance values in a current-driven OLED display.
"The capability to drive brighter OLED displays and to vary the brightness of those displays broadens the technology's utility and the depth of the information content available per pixel - for both see-through and reflective displays," claims Susan Jones, eMagin's chief marketing and strategy officer.
