Electric signal processing circuit employing capacitively scanned phototransistor array

Claim 2

An electrical signal processing circuit comprising: a phototransistor of the type including emitter, base, and collector regions; a first PN-junction between the emitter and base regions, and a second PN-junction between the base and collector regions, said junctions serving as photodetectors which are electrically responsive to an external electromagnetic input; charge storage means comprising a capacitor serially coupled to said base region; and means for applying voltages to said circuit so as to reversebias said junctions.

Claim 3

An electrical signal processing circuit according to claim 1, wherein said capacitor has a value greater than the inherent capacitance of said first and second PN-junctions.

Claim 4

An electrical signal processing circuit according to claim 2, wherein the value of said capacitor is independent of voltage.

Claim 5

An electrical signal processing circuit according to claim 2, further including: a plurality of row conductors and a plurality of column conductors, each one of said row conductors being positioned transverse to each one of said column conductors at an insulated intersection therebetween; a plurality of phototransistor-capacitor combinations, with each one of said combinations located at one of said intersections; the base region of each one of said phototransistors being serially coupled through said capacitors to either said row or column conductor at said intersection; and either the emitter region or the collector region of each one of said phototransistors connected to the other of said column or row conductor at said intersection.

Claim 6

An electrical signal processing circuit according to claim 4, further comprising the other of the collector region or the emitter region of each one of said phototransistors connected to a common electrode.

Claim 7

An electrical signal processing circuit according to claim 4, further comprising means for sequentially applying a scan pulse to said row conductors and a scan pulse to said column conductors.

Claim 8

A solid-state image sensor element, comprising: a phototransistor formed in a semiconductor body having a major surface; said transistor including emitter, base, and collector regions of alternate conductivity type, with a PN-junction between the emitter and base region, and a PN-junction between the base and collector region; and means defining a capacitor serially coupled to said base region at said surface, said capacitor having a value greater than the inherent capacitance of said PN-junctions.

Claim 9

A solid-state image sensor element, comprising: a phototransistor formed in a semiconductor body having a major surface; said transistor including emitter, base, and collector regions of alternate conductivity type, with a PN-junction between the emitter and base region, and a PN-junction between the base and collector region; and means defining a capacitor serially coupled to said base region at said surface, said capacitor having a value greater than the inherent capacitance of said PN-junctions.

Claim 10

A solid-state image sensor element according to claim 7, wherein portions of each region and each junction extend to said surface.

Claim 11

A solid-state image sensor element, comprising: a phototransistor formed in a semiconductor body having a major surface; said transistor including emitter, base, and collector regions of alternate conductivity type, with a PN-junction between the emitter and base regions, and a PN-junction between the base and collector regions, a portion of each region and each junction extending to said surface; an insulating coating overlying said surface; and a layer of conductive material overlying that portion of said insulating coating adjacent said base region, so that said conductive layer, said insulating coating, and a portion of said base region at said surface, form a capacitor serially coupled to said base region.

Claim 12

A solid-state image sensor element, comprising: a phototransistor formed in a semiconductor body having a major surface; said transistor including emitter, base, and collector regions of alternate conductivity type, with a PN-junction between the emitter and base regions, and a PN-junction between the base and collector regions, a portion of each region and each junction extending to said surface; an insulating coating overlying said surface; and a layer of conductive material overlying that portion of said insulating coating adjacent said base region, so that said conductive layer, said insulating coating, and a portion of said base region at said surface, form a capacitor serially coupled to said base region.

Claim 13

A solid-state image sensor array, comprising: a plurality of phototransistors arranged in an array of rows and columns in a semiconductor body having a major surface; each said transistor including an emitter, base, and collector region of alternate conductivity type, with a PN-junction between the emitter and base region, and a PN-junction between the base and collector region, a portion of each region and each junction extending to said surface; an insulating coating overlying said surface, said coating having a plurality of apertures with each aperture exposing a portion of one of said emitter regions at said surface; a plurality of row conductive layers disposed on said coating, each row conductor interconnecting the emitter regions in the corresponding row through the apertures in said coating; and a plurality of column conductive layers disposed on said coating, each said column conductor overlying that portion of said coating adjacent to the base region of each phototransistor in the corresponding column.

Claim 14

A solid-state image sensor array, comprising: a plurality of phototransistors arranged in an array of rows and columns in a semiconductor body having a major surface; each said transistor including an emitter, base, and collector region of alternate conductivity type, with a PN-junction between the emitter and base region, and a PN-junction between the base and collector region, a portion of each region and each junction extending to said surface; an insulating coating overlying said surface, said coating having a plurality of apertures with each aperture exposing a portion of one of said emitter regions at said surface; a plurality of row conductive layers disposed on said coating, each row conductor interconnecting the emitter regions in the corresponding row through the apertures in said coating; and a plurality of column conductive layers disposed on said coating, each said column conductor overlying that portion of said coating adjacent to the base region of each phototransistor in the corresponding column.

Claim 15

A solid-state image sensor array according to claim 10, wherein said column conductive layers are disposed transversely to, and insulated from said row conductor metal layers.

Claim 16

A solid-state image sensor array according to claim 10, further comprising said phototransistors formed in a semiconductor body, and wherein said body comprises a common electrode for one of the regions in said phototransistors.