No Image Blur
In camera applications, the less there is light the longer exposure times are required. Unfortunately the longer the exposure time is the more easily the image is spoiled by image blur due to camera or subject movements. The image blur can be avoided by reading-out the image sensor several times during a long exposure and by afterwards discarding data that is corrupted. However, in present CCD and CMOS technologies, the more often the sensor is read-out during the long exposure the higher the image noise and the poorer the image quality will be. Therefore, in present camera applications, the produced image or video is often a balance between two artifacts, image noise and image blur.
In Pixpolar’s image sensor technology the more often the image sensor data is read-out the smaller the image noise and the better the image quality will be. Therefore by utilizing Pixpolar’s image sensor technology blur-free images can be obtained with minimum image noise and maximum possible exposure time. If all data is saved into a memory the image blur can even be corrected with intelligent algorithms increasing significantly the maximum possible exposure time.
High Dynamic Range
Dynamic range is the ratio between the brightest and the darkest pixel value. Often, a single image contains areas that are very bright and areas that are extremely dark. With Pixpolar’s image sensor technology, dynamic range can be enhanced by using pixel-specific exposure times. Very short exposure time can be used for bright pixels so that they won’t be overexposed and very long exposure time can be used for dark pixels to get better signal-to-noise ratio in dark areas.
Dynamic range can be further enhanced with logarithmic read-out. In very bright illumination conditions MIG pixel shifts from a linear read-out region into a logarithmic read-out region where the output signal depends logarithmically on the illumination level. Logarithmic read-out is a build in feature in MIG pixels.
Very High Sensitivity
Sensitivity of an image sensor tells how efficiently the available light can be utilized. The better the sensitivity of a sensor is the shorter the exposure time can be set to get an image with desired exposure value. Pixpolar’s image sensor technology delivers very high sensitivity thanks to the novel MIG pixel structure.
MIG Pixel Structure
In the Figure below, single MIG pixel transistor is shown. The structure is backside illuminated with fully depleted substrate delivering 100% fill factor, great quantum efficiency and extremely low cross talk. The thickness of the sensor can be optimized based on the wavelength and therefore MIG technology can be utilized in many different applications needing optical, near-infrared, ultra-violet or X-ray detection capabilities.
With only one transistor per pixel one can achieve all the functionality found in a standard 4 transistor CMOS image sensor pixel. One single transistor on top of the charge collection area means that pixels can be scaled down without sacrificing full well capacity and dynamic range. If one additional transistor is included, Non-Destructive Correlated Double Sampling (NDCDS) is enabled, which means that one can take multiple very low-noise samples during single exposure without sacrificing the signal-to-noise ratio.