Large area thin film circuits employing current driven, illumination enhanced, devices

摘要

A thin film circuit comprises a plurality of thin film transistors, wherein the output response of the circuit is dependent on at least first (36) and second (34, 22) of the transistors. The first thin film transistor (36) is, in use, exposed to a source of illumination (2) and the second thin film transistor (16) is shielded from the source of illumination. The first thin film transistor (36) is operated in use as an analogue switch which provides an analogue output in response to a control input. The illumination of this transistor reduces the effect of dynamic threshold voltage variations, which can be a limitation to circuit performance.

主权项

1. A thin film circuit, comprising:
a plurality of thin film transistors,
wherein an output response of the thin film circuit is dependent on at least a first one and a second one of the plurality of thin film transistors,wherein the first thin film transistor is positioned below a source of illumination, said first thin film transistor discharging a storage capacitor;wherein the second thin film transistor is shielded from the source of illumination by being positioned in a shielded outside perimeter area surrounding an area of illumination of said source of illumination and switching a drive voltage; andsaid first thin film transistor is positioned in an area along an inner edge of the shielded outside perimeter area within said area of illumination, the first thin film transistor being operated as an analogue device which provides an analogue output sensitive to a threshold voltage in response to a control input.