Toshiba Develops Sensors to Clarify Phone Cameras

Pictures that are taken by mobile phones just don’t have the resolution of full-fledged digital cameras. However, they may be getting closer. Toshiba America Electronic Components, Inc. just let us know about the development of the Dynastron-WD wide dynamic range technology for CMOS image sensors used in mobile-handset applications such as camera cell phones. This new innovation can extend the dynamic range of a CMOS image sensor up to 96 decibels (dB) maximum, compared to the 60dB dynamic range of the current Toshiba Dynastron technology. Toshiba Dynastron-WD CMOS image sensors can capture high-quality image details over the entire tonal range, even in low-light or bright-light conditions. The company plans to launch its first products based on the new technology in the second half of 2007. According to Toshiba, conventional CMOS image sensors could not cover the whole tonal range of an image and image details were lost. For example, when shooting a well-lit subject near a doorway or by a window exposed to direct sunlight, dark parts became deep shadows or bright parts of the scene bleached out. With a wider dynamic range of 72dB to 96dB, Toshiba Dynastron-WD CMOS image sensors overcome these clipping artifacts and capture more image detail than conventional CMOS image sensors. Toshiba Dynastron CMOS image sensors employ a special square-pixel design that enables them to achieve high-quality images with low-power consumption. Compared to other dynamic-range technologies, Dynastron-WD is frame-memory free, achieves a smaller pixel size and provides low noise and linear signals. To achieve the optimal dynamic range, Dynastron-WD technology incorporates four stages of operation : dual exposure operation on the photodiode, separate readout operation, linear-conversion synthesis operation and high-signal compression.