Infrared sensor, infrared camera, method of driving infrared sensor, and method of driving infrared camera
First Claim
1. An infrared sensor comprising:
- an imaging area disposed on a semiconductor substrate and including a plurality of infrared detection pixels which detect infrared rays;
row selection lines connected to the infrared detection pixels disposed in a row direction;
a signal line connected to the infrared detection pixels disposed in a column direction;
a constant current source connected to the signal line;
a row selection ciruit applying a voltage to the infrared detection pixels via the row selection line and generating a column voltage in the signal line;
a column amplifier connected to the signal line, the column amplifier including a first amplifying transistor which generates an amplification voltage obtained by amplifying the column voltage and a first clamp ciruit which holds threshold voltage information of the first amplifying transistor in a gate of the first amplifying transistor;
a removing ciruit including a second amplifying transistor which has conductivity opposite to that of the first amplifying transistor and a second clamp ciruit which holds threshold voltage information of the second amplifying transistor in a gate of the second amplifying transistor, the removing ciruit being connected to the column amplifier to remove a bias component generated by a bias current, which flows through the column amplifier, from the amplification voltage; and
a reading ciruit reading an output voltage from the column amplifier, the output voltage being obtained by excluding at least the bias component from the amplification voltage.
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Accused Products
Abstract
An infrared sensor includes an imaging area including infrared detection pixels; row selection lines; a signal line; a row selection circuit generating a column voltage in the signal line; a column amplifier including a first amplifying transistor which generates an amplification voltage obtained by amplifying the column voltage and a first clamp circuit which holds threshold voltage information of the first amplifying transistor in its gate; a removing circuit including a second amplifying transistor and a second clamp circuit which holds threshold voltage information of the second amplifying transistor in its gate, the removing circuit being connected to the column amplifier to remove a bias component from the amplification voltage; and a reading circuit reading an output voltage from the column amplifier, the output voltage is obtained by excluding at least the bias component from the amplification voltage.
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Citations
22 Claims
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1. An infrared sensor comprising:
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an imaging area disposed on a semiconductor substrate and including a plurality of infrared detection pixels which detect infrared rays; row selection lines connected to the infrared detection pixels disposed in a row direction; a signal line connected to the infrared detection pixels disposed in a column direction; a constant current source connected to the signal line; a row selection ciruit applying a voltage to the infrared detection pixels via the row selection line and generating a column voltage in the signal line; a column amplifier connected to the signal line, the column amplifier including a first amplifying transistor which generates an amplification voltage obtained by amplifying the column voltage and a first clamp ciruit which holds threshold voltage information of the first amplifying transistor in a gate of the first amplifying transistor; a removing ciruit including a second amplifying transistor which has conductivity opposite to that of the first amplifying transistor and a second clamp ciruit which holds threshold voltage information of the second amplifying transistor in a gate of the second amplifying transistor, the removing ciruit being connected to the column amplifier to remove a bias component generated by a bias current, which flows through the column amplifier, from the amplification voltage; and a reading ciruit reading an output voltage from the column amplifier, the output voltage being obtained by excluding at least the bias component from the amplification voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A driving method of an infrared sensor, the infrared sensor comprising an imaging area disposed on a semiconductor substrate and including a plurality of infrared detection pixels which detect infrared rays, row selection lines connected to the infrared detection pixels disposed in a row direction, a signal line connected to the infrared detection pixels disposed in a column direction, a constant current source connected to the signal line, a row selection circuit connected to the row selection lines, a column amplifier connected to the signal line, a removing circuit connected to the column amplifier, and a reading circuit connected to an output of the column amplifier,
the method comprising: -
applying a voltage to the infrared detection pixels via the row selection line by using the row selection circuit, thereby generating a column voltage; generating the amplification voltage obtained by amplifying the column voltage in the column amplifier; removing a bias component, which is generated by a bias current flowing through the column amplifier, from the amplification voltage by using the removing circuit, wherein the removing circuit includes a second amplifying transistor which has conductivity opposite to that first amplifying transistor and a clamp circuit which holds threshold voltage information of the second amplifying transistor in a gate of the second amplifying transistor, the removing circuit being connected to the column amplifier to remove a bias component generated by a bias currently, which flows through the column amplifier, from an amplification voltage; and outputting the output voltage, which is obtained by removing the bias component from the amplification voltage, from the column amplifier to the reading circuit. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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21. An infrared camera comprising:
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an imaging area disposed on a semiconductor substrate and including a plurality of infrared detection pixels which detect infrared rays; row selection line connected to the infrared detection pixels disposed in a row direction; a signal line connected to the infrared detection pixels disposed in a column direction; a constant current source connected to the signal line; a row selection circuit applying a voltage to the infrared detection pixels via the row selection line and generating a column voltage in the signal line; a column amplifier connected to the signal line, the column amplifier including a first amplifying transistor which generates an amplification voltage obtained by amplifying the column voltage and a first clamp circuit which holds threshold voltage information of the first amplifying transistor in a gate of the first amplifying transistor; a removing circuit including a second amplifying transistor which has conductivity opposite to that of the first amplifying transistor and a second clamp circuit which holds threshold voltage information of the second amplifying transistor in a gate of the second amplifying transistor, the removing circuit being connected to the column amplifier to remove a bias component generated by a bias current, which flows through the column amplifier, from the amplification voltage; and a reading ciruit reading an output voltage from the column amplifier, the output voltage being obtained by excluding at least the bias component from the amplification voltage.
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22. A driving method of an infrared camera, the infrared sensor comprising an imaging area disposed on a semiconductor substrate and including a plurality of infrared detection pixels which detect infrared rays, row selection lines connected to the infrared detection pixels disposed in a row direction, a signal line connected to the infrared detection pixels disposed in a column direction, a constant current source connected to the signal line, a row selection grit connected to the row selection lines, a column amplifier connected to the signal line, a removing grit connected to the column amplifier, and a reading grit connected to an output of the column amplifier,
the method comprising: -
applying a voltage to the infrared detection pixels via the row selection line by using the row selection grit, thereby generating a column voltage; generating the amplification voltage obtained by amplifying the column voltage in the column amplifier; removing a bias component, which is generated by a bias current flowing through the column amplifier, from the amplification voltage by using the removing circuit, wherein the removing ciruit includes a second transistor which has conductivity opposite to that first amplifying transistor and a clamp ciruit which holds threshold voltage information of the second amplifying transistor in a gate of the second amplifying transistor, the removing ciruit being connected to the column amplifier to remove a bias component generated by a bias currently, which flows through the column amplifier, from an amplification voltage; and outputting the output voltage, which is obtained by removing the bias component from the amplification voltage, from the column amplifier to the reading ciruit; and reading the output voltage from the column amplifier in the reading ciruit.
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Specification