Revolutionary Pixel Design Enables Improved Performance in Consumer Imaging Devices

ROCHESTER, N.Y., February 4, 2008 -- Eastman Kodak Company (NYSE:EK) is enabling a new level of performance in consumer imaging devices by redesigning the basic building block used to collect light in imaging devices.

The KODAK TRUESENSE CMOS Pixel improves on the design of standard CMOS image sensors by providing improved color performance and clearer images under low light. The KODAK TRUESENSE CMOS Pixel is first being deployed in the 5 Megapixel KODAK KAC-05020 Image Sensor, which will be demonstrated by Kodak at the GSMA Mobile World Congress held next week in Barcelona, Spain.

A key driver in consumer imaging markets is the need to provide ever-higher sensor resolutions in small optical formats, requiring the use of smaller and smaller pixels. As pixel sizes shrink, however, the overall performance of image sensors tends to decline, leading to high-resolution sensors that provide poor imaging performance -- especially under low light conditions. The KODAK TRUESENSE CMOS Pixel changes this equation by improving the fundamental performance of the pixel element itself, enabling a new generation of high performance, small pixel imaging devices.

"Camera phones and other small pixel consumer imaging devices often suffer from poor performance, particularly under low light conditions," said Chris McNiffe, General Manager of Kodak's Image Sensor Solutions business. "The KODAK TRUESENSE CMOS Pixel was developed specifically to address this problem, enabling CCD-level performance in a CMOS design. As this technology is integrated into cameras and camera phones, consumers will enjoy a level of imaging performance that was previously unavailable from CMOS devices."

The KODAK TRUESENSE CMOS Pixel is a re-envisioning of the fundamental design and architecture of traditional CMOS pixel designs. In a standard CMOS pixel, signal is measured by detecting electrons that are generated when light interacts with silicon of the sensor. As more light strikes the sensor, more electrons are generated, resulting in a higher signal at each pixel. In the KODAK TRUESENSE CMOS Pixel, however, the underlying "polarity" of the silicon is reversed, so that the absence of electrons is used to detect a signal. This change - similar to detecting air bubbles flowing through water, rather than a stream of water flowing through the air -- enables a series of improvements to the design and structure of the pixel that ultimately results in CMOS imaging performance that rivals that available from CCD image sensors.

With an amplifier circuit available in each pixel, CMOS designs are well suited to the detection of these "holes", which have less mobility in silicon than electrons. Because charge is converted at each pixel, holes are not required to travel long distances, and the "hole-transfer" efficiency of the sensor can be kept very high. By detecting holes rather than electrons, it is also possible to change from n-type to p-type silicon base wafers, allowing for the design of CCD-like collection structures in the CMOS sensor to improve imaging performance and reduce sensor noise while keeping manufacturing and circuit design costs down.

The results of implementing this new architecture are significant. Quantum Efficiency -- the ability of a pixel to convert light into charge -- is improved by 10. Crosstalk -- the unintended detection of light by a neighboring pixel -- is reduced three-fold. And Dark Current -- a measure of the background signal detected by the sensor in the absence of any incident light -- is reduced by 30 times or more compared to current CMOS pixel designs. All of these combine to redefine the capabilities of CMOS image sensors, bringing them in line with the performance available from comparable CCD devices today.

The KODAK KAC-05020 Image Sensor, the first product to leverage this new pixel architecture, sets a new standard for CMOS image sensors as the industry's first 1.4 micron, 5 Megapixel, High ISO device. Light sensitivity in the KAC-05020 is enhanced through use of the KODAK TRUESENSE Color Filter Pattern, which adds panchromatic, or "clear," pixels to the red, green and blue pixels already on the sensor. Since these pixels are sensitive to all wavelengths of visible light, they collect a significantly higher proportion of the light striking the sensor. This provides a 2x to 4x increase in sensitivity to light (from one to two photographic stops) compared to current sensor designs, which improves performance when taking pictures under low light and reduces motion blur when imaging moving subjects. When combined with the KODAK TRUESENSE CMOS Pixel, these technologies allow the KAC-05020 to provide a new level of imaging performance that surpasses what is available from current devices using larger, 1.75 micron pixel designs.

With over 30 years experience in the design and manufacture of electronic image sensors, Kodak is a world leader in the development and commercialization of both CMOS and CCD image sensor technology. Kodak's imaging legacy includes invention of the "Bayer Pattern" arrangement of color pixels commonly used today for one-shot color image capture, development of the first prototype digital camera, commercialization of the first megapixel imager, and the design of KODAK PIXELUX technology, a 4-transistor, pinned photodiode, shared pixel CMOS architecture that is today used extensively throughout the industry. The TRUESENSE Color Filter Pattern and TRUESENSE CMOS Pixels are the latest additions to this legacy, enabling a new generation of products that provide advanced levels of performance, resolution, and image quality.

For additional information regarding this technology, please contact Image Sensor Solutions, Eastman Kodak Company at (585) 722-4385 or by email at [email protected]. For more information on Kodak's entire image sensor product line, please visit www.kodak.com/go/imagers.

About Eastman Kodak Company
As the world's foremost imaging innovator, Kodak helps consumers, businesses, and creative professionals unleash the power of pictures and printing to enrich their lives. To learn more, visit www.kodak.com, and our blogs: 1000words.kodak.com, and 1000nerds.kodak.com.