US 2013/0093931 A1 · METHOD FOR ACQUIRING DATA WITH AN IMAGE SENSOR

Abstract

To avoid reset noise in a CMOS chip for direct particle counting, it is known to use Correlative Double Sampling: for each signal value, the pixel is sampled twice: once directly after reset and once after an integration time. The signal is then determined by subtracting the reset value from the later acquired value, and the pixel is reset again. In some embodiments of the invention, the pixel is reset only after a large number of read-outs. Applicants realized that typically a large number of events, typically approximately 10, are needed to cause a full pixel. By either resetting after a large number of images, or when one pixel of the image shows a signal above a predetermined value (for example 0.8×the full-well capacity), the image speed can be almost doubled compared to the prior art method, using a reset after acquiring a signal.

Claims10

Dependent claims

A method for acquiring data with an image sensor, the sensor showing a multitude of pixels, the sensor using a reset to bring the pixels to a predetermined state, the method comprising:

resetting the voltage of a pixel;
reading the voltage of the pixel a first time, resulting in a first read-out value for the pixel;
reading the voltage of each pixel a second time, resulting in a second read-out value for the pixel;
and
determining a first signal by subtracting the first read-out value from the second read-out value of the pixel;
reading the voltage of the pixel a third time, resulting in a third read-out value;
between reading the voltage of the pixel a second time and reading the voltage of the pixel a third time no reset occurs;
and
determining a second signal by subtracting the second read-out value from the third read-out value.

6 more elements

Dependencies are inferred from the claim text.

Method for acquiring data with an image sensor

Life of this patent

Method for acquiring data with an image sensor

Life of this patent

Abstract

Claims10