CORTLAND, N.Y. A new approach to CMOS image sensor design offers unprecedented image quality by eliminating fixed pattern noise from the equation, according to Photon Vision Systems LLC.
The sensor innovation places a unity gain amplifier at each pixel so that the signal generated at the pixel site remains intact and at full strength, with no fixed pattern noise (FPN) generated. The architecture results in a CMOS image sensor that has CCD quality output, the company claims.
While CMOS image sensors are a lower-cost alternative to CCDs, CMOS image quality has lagged because of the inability to create a single reference voltage for all pixels in an array, which is the problem that produces FPN.
Photon Vision Systems has designed the amplifier-per-pixel approach into a line of single-chip cameras that also use a specially designed on-chip video bus. The resulting chips can output video with a signal-to-noise ratio of 60 decibels at 60 MHz, the company claims.
The single-chip cameras leverage such other CMOS imaging advantages as a digitally programmable shutter and the ability to selectively read out regions of interest in the image.