An image detection apparatus including a field emission array and signal transmission
circuits in communication with pixels of the field emission array. The field emission
array includes a p-type substrate with an array of n-wells therein. Emitter tips,
in communication with the n-wells, protrude from an emission surface of the p-type
substrate. A detection surface of the p-type substrate is located opposite the
emission surface thereof. Each signal transmission circuit of the field emission
array includes a capacitor, a baseline potential transistor, and a signal transmission
transistor. A first side of the capacitor communicates with a corresponding n-well
of the field emission array. A second side of the capacitor communicates with the
baseline potential transistor and the signal transmission transistor. The baseline
potential transistor and the signal transmission transistor may share a drain.
As radiation, such as visible light or near infrared radiation, impinges the detection
surface of the field emission array, electron-hole pairs are created in p-n junctions
between the p-type substrate and the n-wells. As a result, electrons are transferred
from the impinged p-n junctions into the n-well adjacent thereto. The charge created
in the n-well represents the intensity or wavelength of the radiation that has
impinged the p-n junction. A signal representative of the wavelength or intensity
of the impinging radiation is transmitted by the signal transmission circuit, and
may be scanned by a scan circuit. Upon applying a relatively positive potential
to an extraction grid associated with the field emission array, the excess electrons
in n-wells may be emitted from an emitter tip adjacent the n-well. The emitted
electrons may impinge a corresponding display pixel of a display so as to create
a visible image thereon.