Image detector with background suppression

Claim 2

A detector for sensing and storing the amplitude of one or more flux samples from a beam of incident photons comprising: a base layer of an intrinsic semiconductor; a pair of separate channels of doped semiconductor formed into said base layer, having exposed surfaces coplanar with one surface thereof, said channels having majority and minority charge carriers of opposite conductivity types; a thin layer of insulating material attached to and covering said coplanar surfaces; at least a first pair of separate but closely adjacent planar gate electrodes mounted on said insulating layer so that each electrode covers an underlying surface portion of a different one of said channels: voltage generating means electrically coupled to each said pair of electrodes for applying alternating bias voltage pulses of opposite polarity thereto relative to the voltage of said base; an opaque structure surrounding said detector including a thin conducting screen substantially spaced from and parallel to said base layer and electrodes, except at the edges thereof, said screen having windows therein adjacent to said underlying said surface portions of only one of said pair of channels, whereby charge carriers of one polarity are periodically generated and stored under electrodes in said one channel in direct proportion to flux samples admitted by said windows and carriers of the opposite polarity are simultaneously stored under electrodes in the remaining channel in direct proportion to the radiation temperature of the screen; said channels being so closely spaced that carriers stored simultaneously under said closely adjacent electrodes are drawn by mutual attraction into said base layer and recombine, leaving substantially only a net charge on one electrode; and readout means electrically coupled to said electrodes to periodically store the amplitude of said net charge.

Claim 3

A detector for sensing and storing the amplitude of one or more flux samples from a beam of incident photons comprising: a base layer of an intrinsic semiconductor; at least a first pair of separate channels of doped semiconductor formed into said base layer, having exposed surfaces coplanar with one surface thereof, said channels having majority and minority charge carriers of opposite conductivity types; a thin layer of insulating material attached to and covering said coplanar surfaces; at least a first pair of separate but closely adjacent planar gate electrodes mounted on said insulating layer so that each electrode covers an underlying surface portion of a different one of said channels; voltage generating means electrically coupled to said pair of electrodes for applying alternating bias voltage pulses of opposite polarity thereto relative to the voltage of said base; a separate planar photoconductor coupled at one end to each of said electrodes having an energy bandgap less then said doped semiconductor; a cyclically operated switch means connected between the remaining end of each of said photoconductors and said base layer for connecting said remaining end to said base when the polarity of said electrode is opposite that of the minority carriers in its underlying channel; means coupled to said base layer to constantly irradiate said base layer with photons having energies greater than the energy bandgap of said doped semiconductor; an opaque structure surrounding at least said photoconductors including a thin heat conducting screen equallly spaced from and parallel to said photoconductors, said screen having a window therein adjacent to the photoconductors associated with only one of said pair of channels, whereby charge carriers of one polarity are periodically generated and stored under electrodes in said one channel in direct proportion to flux samples admitted by said windows and carriers of the opposite polarity are simultaneously stored under electrodes in the remaining channel in direct proportion to the radiation temperature of the screen; said channels being so closely spaced that carriers stored simultaneously under said closely adjacent electrodes are drawn by mutual attraction into said base layer and combine, leaving substantially only a net charge on one electrode; and readout means electrically coupled to said electrodes to periodically store the amplitude of said net charge.

Claim 4

A detector for sensing and storing the amplitude of one or more flux samples from a beam of incident photons comprising: a base layer of an intrinsic semiconductor; at least a first pair of separate channels of doped semiconductor formed into said base layer, having exposed surfaces coplanar with one surface thereof, said channels having majority and minority charge carriers of opposite conductivity types; a thin layer of insulating material attached to and covering said coplanar surfaces; at least a first pair of separate but closely adjacent planar gate electrodes mounted on said insulating layer so that each electrode covers an underlying surface portion of a different one of said channels; voltage generating means electrically coupled to said pair of electrodes for applying alternating bias voltage pulses of opposite polarity thereto relative to the voltage of said base; a separate planar photoconductor coupled at one end to each of said electrodes having an energy bandgap less then said doped semiconductor; a cyclically operated switch means connected between the remaining end of each of said photoconductors and said base layer for connecting said remaining end to said base when the polarity of said electrode is opposite that of the minority carriers in its underlying channel; means coupled to said base layer to constantly irradiate said base layer with photons having energies greater than the energy bandgap of said doped semiconductor; an opaque structure surrounding at least said photoconductors including a thin heat conducting screen equallly spaced from and parallel to said photoconductors, said screen having a window therein adjacent to the photoconductors associated with only one of said pair of channels, whereby charge carriers of one polarity are periodically generated and stored under electrodes in said one channel in direct proportion to flux samples admitted by said windows and carriers of the opposite polarity are simultaneously stored under electrodes in the remaining channel in direct proportion to the radiation temperature of the screen; said channels being so closely spaced that carriers stored simultaneously under said closely adjacent electrodes are drawn by mutual attraction into said base layer and combine, leaving substantially only a net charge on one electrode; and readout means electrically coupled to said electrodes to periodically store the amplitude of said net charge.

Claim 5

A detector for sensing and storing the amplitude of one or more flux samples from a beam of incident photons comprising: a base layer of an intrinsic semiconductor; a pair of separate channels of doped semiconductor formed into said base layer, having exposed surfaces coplanar with one surface thereof, said channels having majority and minority charge carriers of opposite conductivity types; a thin layer of insulating material attached to and covering said coplanar surfaces; at least a first pair of separate but closely adjacent planar gate electrodes mounted on said insulating layer so that each electrode covers an underlying surface portion of a different one of said channels; a planar photoconductor electrically coupled to each of said electrodes; voltage generating means electrically coupled through said photoconductors to said pair of electrodes for applying alternating bias voltage pulses of opposite polarity thereto relative to the voltage of said base; an opaque structure surrounding at least said photoconductors including a thin heat conducting screen equally spaced from and parallel to said photoconductors, said screen having a window therein adjacent to said photoconductors associated with only one of said pair of channels, whereby charge carriers of one polarity are periodically generated and stored under electrodes in said one channel in direct proportion to flux samples admitted by said windows and carriers of the opposite polarity are simultaneously stored under electrodes in the remaining channel in direct proportion to the radiation temperature of the screen; said channels being so closely spaced that carriers stored simultaneously under said closely adjacent electrodes are drawn by mutual attraction into said base layer and recombine, leaving substantially only a net charge on one electrode; and readout means electrically coupled to said electrodes to periodically store the amplitode of said net charge.

Claim 6

A detector for sensing and storing the amplitude of one or more flux samples from a beam of incident photons comprising: a base layer of an intrinsic semiconductor; a pair of separate channels of doped semiconductor formed into said base layer, having exposed surfaces coplanar with one surface thereof, said channels having majority and minority charge carriers of opposite conductivity types; a thin layer of insulating material attached to and covering said coplanar surfaces; at least a first pair of separate but closely adjacent planar gate electrodes mounted on said insulating layer so that each electrode covers an underlying surface portion of a different one of said channels; a planar photoconductor electrically coupled to each of said electrodes; voltage generating means electrically coupled through said photoconductors to said pair of electrodes for applying alternating bias voltage pulses of opposite polarity thereto relative to the voltage of said base; an opaque structure surrounding at least said photoconductors including a thin heat conducting screen equally spaced from and parallel to said photoconductors, said screen having a window therein adjacent to said photoconductors associated with only one of said pair of channels, whereby charge carriers of one polarity are periodically generated and stored under electrodes in said one channel in direct proportion to flux samples admitted by said windows and carriers of the opposite polarity are simultaneously stored under electrodes in the remaining channel in direct proportion to the radiation temperature of the screen; said channels being so closely spaced that carriers stored simultaneously under said closely adjacent electrodes are drawn by mutual attraction into said base layer and recombine, leaving substantially only a net charge on one electrode; and readout means electrically coupled to said electrodes to periodically store the amplitode of said net charge.