Quantum Scientific Imaging QSI 540ci Cooled Interline Single Shot Color CCD Camera with 4.2 Megapixel KAI-04022 Image Sensor, Electronic Shutter and RGB Bayer Filter

The QSI 540ci model camera employs a Kodak KAI-04022 4.2 megapixels interline transfer CCD image sensor with microlens technology. The integral RGB Bayer color filter mask allows Single-Shot color imaging. The KAI-04022M sensor has a photoactive array of 2048W x 2048H pixels. It has excellent quantum efficiency between 350nm and 1000nm with significant enhancement at the blue end of the spectrum. Low dark current and high pixel charge capacity result in a dynamic range exceeding 74db. The sensor employs a vertical overflow drain that provides both antiblooming protection and a fast electronic shutter. Micro lenses cover the surface of the CCD to focus the light into each pixel to increase optical response.

Single-Shot color imaging is made possible by overlaying the pixels on the CCD with an alternating red, green and blue color filter matrix at the time of manufacture. This is also how the vast majority of color video and still cameras create color images. The raw image from the camera requires further processing to extract the color and luminance information and create a final image. Most CCD image acquisition software, including MaxIm LE and MaxIm DL, has special processing for just this purpose.

The 540ci utilizes the electronic shutter built into the KAI-04022 CCD image sensor to control exposures. Shutter timing is very precise and can range from as short as 100 microseconds up to 240 minutes. The very fast acting shutter is possible due to two key features of the interline transfer architecture. 1) Any existing electrons can be removed from the pixels instantly with a single electronic pulse, beginning the exposure. 2) After the specified exposure duration, the entire image field can be instantaneously moved into a light-shielded holding area on the CCD. The image is then read out at the normal rate without being contaminated by any light still illuminating the CCD surface.