Image sensor

An image sensor comprising:

• a pixel array comprising a pixel area and a dummy area, the pixel area comprising a plurality of pixels;
• a row driver configured to output a driving signal to the pixel array;
• and
• a detection circuit configured to receive a plurality of row output signals from the dummy area, and receive the driving signal and a clock signal,
• wherein the detection circuit comprises:
• a signal selection circuit configured to select an Nth row output signal from among the plurality of row output signals;
• a counter circuit configured to generate an Nth count result value by counting cycles of the clock signal during a time interval of the Nth row output signal based on the driving signal;
• a difference circuit configured to generate an Nth difference value between the Nth count result value and an (N−1)th count result value;
• and
• a comparison circuit configured to detect a defect of the Nth row output signal by comparing the Nth difference value with a reference value, and
• wherein the time interval comprises a delay interval in which the Nth row output signal is delayed based on the driving signal.

A method of operating an image sensor, the method comprising:

• receiving a driving signal;
• receiving a plurality of row output signals;
• selecting an Nth row output signal from among the plurality of row output signals;
• generating an Nth count result value by counting cycles of a clock signal during a delayed time interval between the driving signal and the Nth row output signal;
• generating an Nth difference value between the Nth count result value and an (N−1)th count result value;
• comparing the Nth difference value with a reference value;
• and
• detecting that the Nth row output signal is faulty based on the Nth difference value being greater than the reference value.