Imaging device, method for operating the same, and electronic device

An imaging device comprising:

• a pixel;
• a first circuit configured to convert an analog signal into a digital signal, the first circuit electrically connected to the pixel;
• a second circuit configured to detect a difference between image data of a first frame and image data of a second frame, the second circuit electrically connected to the first circuit;
• a third circuit configured to control frequency of a clock signal, the third circuit electrically connected to the second circuit;
• and
• a fourth circuit comprising a first transistor, a second transistor, a third transistor, a fourth transistor and a seventh circuit, the fourth circuit electrically connected to the third circuit,
• wherein the fourth circuit is electrically connected to the first circuit,
• wherein a gate of the first transistor is electrically connected to one of a source and a drain of the third transistor,
• wherein a gate of the second transistor is electrically connected to one of a source and a drain of the fourth transistor,
• wherein the other of the source and the drain of the third transistor is electrically connected to the other of the source and the drain of the fourth transistor,
• wherein the seventh circuit comprises:
• an inverter circuit comprising a power supply potential input terminal, an input terminal and an output terminal;
• a fifth transistor;
• and
• a sixth transistor,
• wherein a gate of the fifth transistor is electrically connected to one of a source and a drain of the first transistor,
• wherein a gate of the sixth transistor is electrically connected to one of a source and a drain of the second transistor,
• wherein the output terminal of the inverter circuit is electrically connected to one of a source and a drain of the fifth transistor,
• wherein the output terminal of the inverter circuit is electrically connected to one of a source and a drain of the sixth transistor,
• wherein the input terminal of the inverter circuit is electrically connected to the other of the source and the drain of the fifth transistor,
• wherein the other of the source and the drain of the fifth transistor is electrically connected to the other of the source and the drain of the sixth transistor, and
• wherein the input terminal of the inverter circuit is electrically connected to the output terminal of the inverter circuit.

A method for operating an imaging device, comprising:

• a first step of supplying a first clock signal to an A/D converter circuit;
• a second step of imaging a first frame and converting imaged analog data into digital data with the A/D converter circuit;
• a third step of storing most significant bit data of the first frame in a comparison circuit;
• a fourth step of supplying a second clock signal to the A/D converter circuit;
• a fifth step of imaging a second frame and converting imaged analog data into digital data with the A/D converter circuit;
• a sixth step of transmitting least significant bit data of the second frame to the comparison circuit;
• a seventh step of determining whether or not a logic signal of the most significant bit data of the first frame is the same as a logic signal of the least significant bit data of the second frame with the comparison circuit;
• and
• after the seventh step, performing the first step when the two logic signals are the same and performing the fifth step when the two logic signals are different.