Image sensor and image capture apparatus

An imaging apparatus comprising:

• an image sensor;
• and
• an optical imaging system,
• wherein the image sensor comprises:
• a plurality of pixel sections in which pixels are arranged two-dimensionally, each of the pixels connecting to a common amplifier transistor, the common amplifier transistor being connected to a power voltage and having a gate into which voltages of signal charges, generated by photoelectric conversion areas included in the pixels, are respectively input;
• and
• AD conversion circuits that axe provided for the plurality of pixel sections respectively, wherein each of the AD conversion circuits includes:
• a reference transistor that has a gate into which a ramp signal having a voltage that changes at a constant rate is input;
• and
• a constant current source that is connected to the reference transistor and the common amplifier transistor,
• wherein the common amplifier transistor and the reference transistor form a current mirror circuit.

An imaging apparatus comprising:

• an image sensor;
• an image memory that stores digital signals transfer from the image sensor;
• and
• a processor that applies noise reduction process to the digital signal stored in the image memory,
• wherein the image sensor comprises:
• a plurality of pixel sections in which pixels are arranged two-dimensionally, each of the pixels connecting to a common amplifier transistor, the common amplifier transistor being connected to a power voltage and having a gate into which voltages of signal charges, generated by photoelectric conversion areas included in the pixels, are respectively input;
• and
• AD conversion circuits that are provided for the plurality pixel sections respectively, wherein each of the AD conversion circuits includes:
• a reference transistor that has a gate is to which a ramp signal having voltage that changes at a constant rate is input;
• and
• a constant current source that is connected to the reference transistor and the common amplifier transistor,
• wherein the common amplifier and the reference transistor form a current mirror circuit, and
• wherein the image memory stores the digital signals transferred from the AD conversion circuits.