Self-scanned phototransistor array employing common substrate

Claim 2

A photosensitive transistor array comprising: a body of photosensitive semiconductive material having a surface, said body being of one type conductivity, means defining a plurality of transistors in said body, said means comprising a plurality of first regions of conductivity type opposite to that of said body in said body adjacent to said surface and a second region of said one type conductivity within each of said first regions, the material of said body constituting a common region for all of said transistors, first conductive means extending adjacent to said first regions, channel means of controllable conductivity in said body adjacent to said surface and extending between each of said first regions and said first conductive means, a coating of insulating material on said surface over each channel means, a metal field electrode on said insulating coating over each channel means and contacting said first conductive means, and second conductive means coupled only to said second regions.

Claim 3

A photosensitive transistor array as defined in claim 1 wherein said first conductive means comprises diffused regions of conductivity type opposite to that of said body in said body adjacent to said first region.

Claim 4

A photosensitive transistor array as defined in claim 2 wherein each insulating coating and each field electrode extend in overlapping relation to each first region.

Claim 5

A photosensitive transistor array as defined in claim 2 wherein said transistors are arranged in a two-dimensional matrix and Wherein said first conductive means extend parallel to one direction of said matrix and said second conductive means comprises a plurality of metal bars extending parallel to the other direction of said matrix.

Claim 6

A photosensitive transistor array comprising a body of semiconductive material having a surface, said body being of relatively low conductivity of one type, means defining a plurality of phototransistors in said body, said means comprising a plurality of base regions of conductivity type opposite to that of said body in said body adjacent to said surface and an emitter region within each said base region and defining an emitter-base junction therewith, the material of said body constituting a common collector region for all of said phototransistors, means for normally applying to said base regions a voltage having a polarity and magnitude sufficient to maintain said emitter-base junctions in reverse-biased condition and for selectively removing the reverse-biasing voltage from at least one of said phototransistors whereby the base region of said one phototransistor is effectively isolated, and means coupled to said phototransistors for deriving outputs which are functions of the photocurrent flowing in each selected transistor.

Claim 7

A photosensitive transistor array comprising a body of semiconductive material having a surface, said body being of relatively low conductivity of one type, means defining a plurality of phototransistors in said body, said means comprising a plurality of base regions of conductivity type opposite to that of said body in said body adjacent to said surface and an emitter region within each said base region and defining an emitter-base junction therewith, the material of said body constituting a common collector region for all of said phototransistors, means for normally applying to said base regions a voltage having a polarity and magnitude sufficient to maintain said emitter-base junctions in reverse-biased condition and for selectively removing the reverse-biasing voltage from at least one of said phototransistors whereby the base region of said one phototransistor is effectively isolated, and means coupled to said phototransistors for deriving outputs which are functions of the photocurrent flowing in each selected transistor.

Claim 8

A photosensitive transistor array as defined in claim 5 wherein said phototransistors are arranged in a plurality of rows and columns, said means for removing reverse bias being adapted to be coupled to all the transistors in a selected column and including a plurality of column connector regions of low resistivity of conductivity type opposite to that of said body in said body adjacent to said surface, each of said column connector regions extending parallel to and spaced from the base regions of the transistors in one of said columns, a coating of insulating material on said surface over the space between the column connector regions and said base regions, and a plurality of metal electrodes, each of which is in contact with a column connector region and extends over said insulating coating in field applying relation to the space between said column connector region and said base region.

Claim 9

A photosensitive transistor array as defined in claim 5 wherein said insulating coating and each of said metal electrodes extends in overlying relation to a base region.

Claim 10

A photosensitive transistor array as defined in claim 5 wherein said means for deriving outputs comprises a plurality of transistors formed in said body, each of said transistors being electrically coupled to an emitter region of one of said phototransistors.

Claim 11

A photosensitive transistor array comprising a body of monocrystalline silicon having a pair of opposed major surfaces, said body being of relatively low conductivity of one type, means in said body defining a plurality of phototransistors arranged in rows and columns, said means comprising a plurality of base regions of conductivity type opposite to that of said body in said body adjacent to one of said major surfaces and an emitter region within each said base region and defining an emitter-base junction therewith, the material of said body constituting a common collector region for all of said phototransistors, a plurality of elongated diffused connector regions of low resistivity of conductivity type opposite to that of said body in said body adjacent to said one major surface, each of said connector regions extending parallel to and spaced from the base regions of the transistors in one of said columns, a coating of insulating material on said surface over the space between said connector regions and said base regions, a plurality of metal electrodes, each of which is in contact with a connector region and extends over said insulating coating in field applying relation to the space between said connector region and said base region, and a plurality of conductive bars on said insulating coating and extending in the row direction parallel to each row of saId phototransistors, said bars each being coupled to the emitter regions of the transistors in a row.

Claim 12

A photosensitive transistor array comprising a body of monocrystalline silicon having a pair of opposed major surfaces, said body being of relatively low conductivity of one type, means in said body defining a plurality of phototransistors arranged in rows and columns, said means comprising a plurality of base regions of conductivity type opposite to that of said body in said body adjacent to one of said major surfaces and an emitter region within each said base region and defining an emitter-base junction therewith, the material of said body constituting a common collector region for all of said phototransistors, a plurality of elongated diffused connector regions of low resistivity of conductivity type opposite to that of said body in said body adjacent to said one major surface, each of said connector regions extending parallel to and spaced from the base regions of the transistors in one of said columns, a coating of insulating material on said surface over the space between said connector regions and said base regions, a plurality of metal electrodes, each of which is in contact with a connector region and extends over said insulating coating in field applying relation to the space between said connector region and said base region, and a plurality of conductive bars on said insulating coating and extending in the row direction parallel to each row of saId phototransistors, said bars each being coupled to the emitter regions of the transistors in a row.

Claim 13

A photosensitive transistor array as defined in claim 9 further comprising means for making contact to the common collector region of said transistors, said means comprising a diffused region of low resistivity of the same type as said body in said body adjacent to the other of said major surfaces.

Claim 14

A photosensitive transistor array as defined in claim 10 further comprising a plurality of sense transistors in said body, each of said sense transistors comprising a diffused emitter region of conductivity type opposite to that of said body in said body adjacent to said one surface thereof, and an annular diffused collector region of conductivity type opposite to that of said body in surrounding relation to each of said emitter regions, said material of said body constituting a common base region for all of said sense transistors.

Claim 15

A photosensitive transistor array as defined in claim 11 wherein said sense transistors are spaced from said phototransistors by a distance sufficiently great to produce a substantial resistance between the base material of said sense transistors and the collector material of said phototransistors.

Claim 16

A photosensitive transistor array as defined in claim 12 further comprising elongated diffused regions of low-resistivity material of conductivity type opposite to that of said body in said body in the space between said sense transistors and the balance of said array, said diffused regions serving to increase the resistance between the base regions of said sense transistors and the balance of the array.