Image sensor and method of processing image data with multiple differential ramping up/down signals, and image processing device including the image sensor

A device comprising an image sensor, wherein the image sensor comprises:

• a pixel configured to generate a pixel signal;
• and
• a signal processing circuit configured to perform a first correlated double sampling (CDS) operation on the pixel signal by using a first ramping up/down signal among a plurality of ramping up/down signals in a reset interval, and to perform a second CDS operation on the pixel signal by using a selected ramping up/down signal among the plurality of ramping up/down signals in an image interval,
• wherein the signal processing circuit includes:
• a signal generator configured to generate the plurality of ramping up/down signals;
• a selection circuit configured to output the selected ramping up/down signal in response to at least one control signal;
• and
• a comparison circuit configured to perform a correlated double sampling of the pixel signal, to perform a correlated double sampling of the first ramping up/down signal, to compare the correlated double sampled pixel signal with the correlated double sampled first ramping up/down signal at one or more sampling times between the reset interval and the image interval, and to generate the at least one control signal according to a result of the comparison.

A signal processing device for processing a pixel signal produced by a pixel of an image sensor, the signal processing device comprising:

• a signal generator configured to generate a plurality of ramping up/down signals;
• a selection circuit configured to receive the plurality of ramping up/down signals and to output a selected ramping up/down signal among the plurality of ramping up/down signals in response to at least one control signal;
• and
• a correlated double sampling circuit configured to perform a correlated double sampling operation on the pixel signal and the selected ramping up/down signal, and to output a correlated double sampled output signal having a first level when a correlated double sampled pixel signal is greater than a correlated double sampled selected ramping up/down signal, and to output the correlated double sampled output signal having a second level when the correlated double sampled pixel signal is less than the correlated double sampled selected ramping up/down signal,
• wherein the correlated double sampling circuit is configured to perform the correlated double sampling operation on the pixel signal and the selected ramping up/down signal, and to output the correlated double sampled output signal, at least once between a reset interval of the pixel and an image interval of the pixel,
• wherein the correlated double sampling circuit is further configured to perform the correlated double sampling operation of the pixel signal and the selected ramping up/down signal at least once during the image interval of the sensor, and
• wherein the correlated double sampled output signal which is output by the correlated double sampling circuit between the reset interval of the pixel and the image interval of the pixel generates the at least one control signal for the selection circuit while the correlated double sampling circuit performs the correlated double sampling operation on the pixel signal and the selected ramping up/down signal during the image interval of the pixel.