Toshiba Corporation has developed Dynastron-WD(TM) 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(R) 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.
“Toshiba Dynastron-WD wide dynamic range technology is an industry-leading innovation that exemplifies the company’s commitment to customers building the next generation of mobile handsets. This technology achievement will enable the design of camera phones with superior tonal quality to meet increased consumer demand for higher performance,” said Andrew Burt, vice president of the Imaging and Communications Marketing Group for the ASSP Business Unit at TAEC.
“Previously, image-sensor vendors concentrated on delivering good low-light performance. However, as pixel size shrinks to 2.2 microns and below, there is an emerging need for better image quality under bright-light conditions as well,” Mr. Burt said. He explained that conventional CMOS image sensors could not cover the whole tonal range of an image and image details were lost. For example, he said, 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 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 held its first public exhibition of its Dynastron-WD technology last month at the 3GSM World Congress 2007 in Barcelona, Spain. Mr. Burt noted: “Feedback from our mobile-handset customers in attendance at the conference confirmed that Toshiba Dynastron-WD technology offers observable, unmatched image quality under bright-light conditions. A few customers used their own high-performance, digital-still cameras to make a spot comparison of the same scene and could not achieve image quality equal to the Toshiba Dynastron-WD results.”
About Toshiba CMOS Image Sensor Technology
Toshiba is a pioneer and recognized leader in the development of CMOS image sensors with core competencies in advanced sensor technology and sophisticated signal processing technology. Toshiba Dynastron CMOS image sensors employ a special square-pixel design that enables them to achieve high-quality images with low-power consumption, even in low-light conditions. Dynastron CMOS image sensors have proven their superiority in image-quality comparisons by offering demonstrably better color balance and picture quality.
The latest Toshiba CMOS image-sensor technology breakthrough, Toshiba Dynastron-WD wide dynamic range technology, has a dynamic range from 72dB up to 96dB maximum. 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. CMOS image sensors based on this technology provide excellent tonal quality with the ability to capture image details of both light and dark areas in the same field under both low-light and bright-light conditions.
The company’s newly published white paper, “Toshiba Dynastron-WD(TM) Wide Dynamic Range Technology for CMOS Image Sensors,” can be accessed and downloaded.
Combining quality and flexibility with design engineering expertise, TAEC brings a breadth of advanced, next-generation technologies to its customers. This broad offering includes memory and flash memory-based storage solutions, a broad range of discrete devices, displays, medical tubes, ASICs, custom SOCs, microprocessors, microcontrollers and wireless components for the computing, wireless, networking, automotive and digital consumer markets. TAEC is an independent operating company owned by Toshiba America, Inc., a subsidiary of Toshiba Corp. (Toshiba), Japan’s largest semiconductor manufacturer and the world’s fourth largest semiconductor manufacturer. In more than 130 years of operation, Toshiba has recorded numerous firsts and made many valuable contributions to technology and society.