Highly sensitive HARP image sensor with Spindt-type field emitter array

A compact ultrahigh-sensitivity image sensor consisting of a Spindt-type field emitter array (FEA) equipped with an active-matrix drive circuit and a high-gain avalanche rushing amorphous photoconductor (HARP) target was fabricated. The image sensor has a 640 × 480-pixel active-matrix Spindt-type FEA, which is equivalent to the VGA format. Experiments showed that the prototype sensor could obtain clear images with little noise under illumination on a level equivalent to moonlight, with sufficient resolution as a VGA image sensor while consuming far less power than current ultrahigh-sensitivity pickup tubes.