Solid state imaging apparatus
First Claim
1. A solid state imaging apparatus comprising:
- an internal amplification type of light-receiving element which constitutes a picture element;
a signal processing circuit incorporating a pre-amplifier for processing a video signal current of said light-receiving element constituting the picture element;
an internal amplification type reference light-receiving element which is shielded from light;
a feedback loop provided in said pre-amplifier for controlling the gate voltage of said reference light-receiving element such that a current having the same value as that of the video signal current of said light-receiving element which constitutes the picture element is caused to flow to said reference light-receiving element; and
means for discharging the dark current charge accumulated in said reference light-receiving element in the period during which the video signal current from said light-receiving element constituting the picture element is suspended.
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Accused Products
Abstract
A solid state imaging apparatus includes an internal amplification type of light-receiving element which constitutes a picture element, a signal processing circuit incorporating a pre-amplifier for processing a video signal current of the light-receiving element constituting a picture element, an internal amplification type of reference light-receiving element which is shielded from light illumination, a feedback loop provided in the pre-amplifier for controlling the gate voltage of the reference light-receiving element such that a current having the same value as that of the video signal current of the light-receiving element constituting a picture element is caused to flow to the reference light-receiving element, and means for discharging the dark current charge accumulated in the reference light-receiving element in the period during which the video signal current from the light-receiving element constituting the picture element is suspended.
Therefore, the reference light-receiving element functions as a negative feedback element of the pre-amplifier, by means of which the gate voltage of the reference light-receiving element is varied such that a source current which is equivalent to that of the light-receiving element constituting a picture element is caused to flow therethrough under the same bias conditions as in the case of the light-receiving element constituting a picture element, enabling an output which is linear to the quantity of light which is received to be produced as the output of the pre-amplifier.
53 Citations
21 Claims
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1. A solid state imaging apparatus comprising:
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an internal amplification type of light-receiving element which constitutes a picture element; a signal processing circuit incorporating a pre-amplifier for processing a video signal current of said light-receiving element constituting the picture element; an internal amplification type reference light-receiving element which is shielded from light; a feedback loop provided in said pre-amplifier for controlling the gate voltage of said reference light-receiving element such that a current having the same value as that of the video signal current of said light-receiving element which constitutes the picture element is caused to flow to said reference light-receiving element; and means for discharging the dark current charge accumulated in said reference light-receiving element in the period during which the video signal current from said light-receiving element constituting the picture element is suspended. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A solid state imaging apparatus comprising:
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an internal amplification type of light-receiving element which constitutes a picture element; a first differential operational amplifier incorporating a feedback impedance for converting the video signal current of said light-receiving element constituting a picture element to a voltage; a second differential operational amplifier having an inverted input terminal to which the output of said first differential operational amplifier is input through an impedance having the same value as that of said feedback impedance; an internal amplification type reference light-receiving element which is shielded from light illumination and whose gate voltage is controlled by the output voltage of said second differential operational amplifier; a feedback loop of said second differential operational amplifier through which the output current of said reference light-receiving element is input to said inverted input terminal; and means for discharging the dark current charge accumulated in said reference light-receiving element in the period during which the video signal current from said light-receiving element constituting a picture element is suspended. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A solid state imaging apparatus comprising:
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an internal amplification type of light-receiving element which constitutes a picture element; a first differential operational amplifier incorporating a feedback diode for converting the video signal current of said light-receiving element constituting a picture element to a voltage; a second differential operational amplifier having an inverted input terminal to which the output of said first differential operational amplifier is input through a diode having the same characteristics as those of said feedback diode; an internal amplification type of reference light-receiving element which is shielded from light illumination and whose gate voltage is controlled by the output voltage of said second differential operational amplifier; a feedback loop of said second differential operational amplifier through which the output current of said reference light-receiving element is input to said inverted input terminal; and means for discharging the dark current charge accumulated in said reference light-receiving element in the period during which the video signal current from said light-receiving element constituting a picture element is suspended.
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20. A solid state imaging apparatus comprising:
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an internal amplification type of light-receiving element which constitutes a picture element; an internal amplification type of reference light-receiving element which is shielded from light illumination; a first differential operational amplifier for converting the video signal current of said light-receiving element constituting a picture element to a voltage; a second differential operational amplifier for converting the output current of said reference light-receiving element to a voltage, said second differential operational amplifier having the same feedback factor as that of said first differential operational amplifier; a third differential operational amplifier for comparing the outputs of said first and second differential operational amplifiers; a feedback loop to which the output voltage of said third differential operational amplifier is input so as to enable the gate voltage of said reference light-receiving element to be controlled; and means for discharging the dark current charge accumulated in said reference light-receiving element in the period during which the video signal current from said light-receiving element constituting a picture element is suspended.
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21. A solid state imaging apparatus comprising:
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an internal amplification type of light-receiving element which constitutes a picture element; an internal amplification type of reference light-receiving element which is shielded from light illumination; a current input type differential operational amplifier to which the output currents of said light-receiving element constituting a picture element and said reference light-receiving element are input through respective low impedance current inputting circuits; a feedback loop to which the output voltage of said differential operational amplifier is input so as to enable the gate voltage of said reference light-receiving element to be controlled; and means for discharging the dark current charge accumulated in said reference light-receiving element in the period during which the video signal current from said light-receiving element constituting a picture element is suspended.
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Specification