Image sensor array with threshold voltage detectors and charged storage capacitors

Claim 2

A sensor array for measuring intensity of an incoming signal, the array having a plurality of sensors colocated on a single integrated circuit chip, each sensor comprising: a transducer for sensing a portion of the incoming signal and for providing an output current related to the sensed incoming signal; a capacitor receiving the transducer output current and storing charge associated with the transducer output current, the capacitor integrating current to provide a capacitor output voltage; a detector receiving the capacitor output voltage, the detector generating an output pulse when the capacitor output voltage exceeds a threshold voltage and a reset signal for discharging the stored charge in the capacitor, the detector generating a stream of output pulses having a pulse frequency representative of the intensity of said portion of the sensed incoming signal.

Claim 3

A sensor array as claimed in claim 1 wherein each transducer is a photodetector comprising a p-n junction.

Claim 4

A sensor array as claimed in claim 1 wherein the capacitor has a capacitance of less than about 1 pF.

Claim 5

A sensor array as claimed in claim 1 wherein the capacitor comprises an intrinsic capacitance associated with the transducer, the intrinsic capacitance storing substantially all charge associated with the transducer output current.

Claim 6

A sensor array as claimed in claim 1 wherein the detector is an inverter.

Claim 7

A sensor array as claimed in claim 1 wherein the detector is a comparator having a tunable threshold voltage.

Claim 8

A sensor array as claimed in claim 1 wherein each detector output pulse also serves as a reset signal.

Claim 9

A sensor array as claimed in claim 1 wherein the incoming signal is capable of varying over a range of 10 5 or more.

Claim 10

A sensor array as claimed in claim 1 wherein each sensor further comprises a switch coupled to the capacitor, the switch being responsive to the reset signal for discharging the stored current in the capacitor.

Claim 11

A sensor array as claimed in claim 1 further comprising a series arrangement of buffers connected to the detector output for buffering each output pulse.

Claim 12

A photosensor array for measuring intensity of incoming radiation, the array having a plurality of photosensors colocated on a single integrated circuit chip, each photosensor comprising: a photodetector for sensing a portion of the incoming radiation and for providing an output current related to the intensity of the sensed incoming radiation; a intrinsic capacitor associated with the photodetector, the intrinsic capacitor directly receiving the photodetector output current and storing substantially all charge associated with the photodetector output current, the capacitor integrating current to provide an output voltage; a detector receiving the capacitor output voltage, the detector generating an output pulse when the capacitor output voltage exceeds a threshold voltage and a reset signal for discharging the stored charge in the capacitor, the detector generating a stream of output pulses having a pulse frequency representative of the intensity of said portion of the sensed incoming radiation.

Claim 13

A photosensor array for measuring intensity of incoming radiation, the array having a plurality of photosensors colocated on a single integrated circuit chip, each photosensor comprising: a photodetector for sensing a portion of the incoming radiation and for providing an output current related to the intensity of the sensed incoming radiation; a intrinsic capacitor associated with the photodetector, the intrinsic capacitor directly receiving the photodetector output current and storing substantially all charge associated with the photodetector output current, the capacitor integrating current to provide an output voltage; a detector receiving the capacitor output voltage, the detector generating an output pulse when the capacitor output voltage exceeds a threshold voltage and a reset signal for discharging the stored charge in the capacitor, the detector generating a stream of output pulses having a pulse frequency representative of the intensity of said portion of the sensed incoming radiation.

Claim 14

A photosensor array as claimed in claim 11 wherein the intrinsic capacitor has a capacitance of less than about 1 pF.

Claim 15

A photosensor array as claimed in claim 11 wherein the incoming radiation is capable of varying in intensity over a range of 10 5 or more.

Claim 16

A photosensor array as claimed in claim 11 wherein each photosensor further comprises a switch coupled to the capacitor, the switch being responsive to the reset signal for discharging the stored current in the capacitor.

Claim 17

A sensor comprising: a transducer for providing an output current responsive to an incoming signal; a intrinsic capacitor associated with the transducer for storing substantially all charge from the transducer output current, the capacitor integrating current to provide an output voltage; a detector receiving the capacitor output voltage, the detector providing an output pulse when the capacitor output voltage exceeds a threshold voltage and a reset signal for discharging the stored current in the capacitor, the detector generating a stream of output pulses having a pulse frequency which is representative of a property of the incoming signal.

Claim 18

A sensor comprising: a transducer for providing an output current responsive to an incoming signal; a intrinsic capacitor associated with the transducer for storing substantially all charge from the transducer output current, the capacitor integrating current to provide an output voltage; a detector receiving the capacitor output voltage, the detector providing an output pulse when the capacitor output voltage exceeds a threshold voltage and a reset signal for discharging the stored current in the capacitor, the detector generating a stream of output pulses having a pulse frequency which is representative of a property of the incoming signal.

Claim 19

A sensor as claimed in claim 15 further comprising a switch coupled to the capacitor, the switch being responsive to the reset signal for discharging the current in the capacitor.

Claim 20

A sensor as claimed in claim 15 wherein the transducer is a photodetector comprising a p-n junction.

Claim 21

A sensor as claimed in claim 15 wherein the intrinsic capacitor has a capacitance of less than about 1 pF.

Claim 22

A sensor as claimed in claim 15 wherein the detector is an inverter.

Claim 23

A sensor as claimed in claim 15 wherein the detector is a comparator having a tunable threshold voltage.

Claim 24

A sensor as claimed in claim 15 wherein each detector output pulse also serves as a reset signal.

Claim 25

A sensor as claimed in claim 15 wherein the pulse frequency is proportional to an intensity of the incoming signal.

Claim 26

A sensor as claimed in claim 15 further comprising a series arrangement of buffers connected to the detector output for buffering each output pulse.

Claim 27

A sensor as claimed in claim 15 wherein the sensor is formed on a single integrated circuit chip.

Claim 28

A sensor as claimed in claim 15 wherein the incoming signal is capable of varying over a range of 10 5 or more.

Claim 29

A single-chip photosensor comprising: a photodetector for sensing incoming light and for providing an output current related to the sensed light; a intrinsic capacitor associated with the photodetector and directly receiving the photodetector output current for storing substantially all charge from the received photodetector output current, the capacitor integrating current to provide an output voltage; a detector receiving the capacitor output voltage, the detector generating an output pulse when the capacitor output voltage exceeds a threshold voltage and a reset signal for discharging the stored current in the capacitor, the detector generating a stream of output pulses having a pulse frequency representative of the intensity of the sensed incoming light.

Claim 30

A single-chip photosensor comprising: a photodetector for sensing incoming light and for providing an output current related to the sensed light; a intrinsic capacitor associated with the photodetector and directly receiving the photodetector output current for storing substantially all charge from the received photodetector output current, the capacitor integrating current to provide an output voltage; a detector receiving the capacitor output voltage, the detector generating an output pulse when the capacitor output voltage exceeds a threshold voltage and a reset signal for discharging the stored current in the capacitor, the detector generating a stream of output pulses having a pulse frequency representative of the intensity of the sensed incoming light.

Claim 31

A photosensor as claimed in claim 26 further comprising a switch coupled to the capacitor, the switch being responsive to the reset signal for discharging the current in the capacitor.

Claim 32

A photosensor as claimed in claim 26 wherein the photodetector comprises a p-n junction.

Claim 33

A photosensor as claimed in claim 26 wherein each detector output pulse also serves as a reset signal.

Claim 34

A photosensor as claimed in claim 26 wherein the intrinsic capacitor has a capacitance of less than about 1 pF.

Claim 35

A photosensor as claimed in claim 26 wherein the incoming light is capable of varying over a range of 10 5 or more.

Claim 38

A method as claimed in claim 32 further comprising providing a switch coupled to the capacitor, the switch being responsive to the reset signal for discharging the stored current in the capacitor.

Claim 39

A method as claimed in claim 32 wherein the transducer comprises a photodetector.

Claim 40

A method as claimed in claim 32 wherein the intrinsic capacitor has a capacitance of up to about 1 pF.

Claim 41

A method as claimed in claim 32 wherein the frequency of the output pulses is proportional to an intensity of the input signal.

Claim 42

A method as claimed in claim 32 wherein the transducer, capacitor and detector are colocated on a single integrated circuit chip.

Claim 45

A method as claimed in claim 38 further comprising providing a switch coupled to the capacitor, the switch being responsive to the reset signal for discharging the stored current in the capacitor.

Claim 46

A method as claimed in claim 38 wherein the incoming light is capable of varying in intensity over a range of 10 5 or more.