Global Sources
EE Times-India
Stay in touch with EE Times India
EE Times-India > Optoelectronics/Displays

CMOS image sensor offers high image quality

Posted: 15 Sep 2008     Print Version  Bookmark and Share

Keywords:Wide Dynamic Range  CMOS image sensor  Lateral Overflow Integration Capacitor 


Texas Instruments Inc. has introduced a high sensitivity Wide Dynamic Range (WDR) CMOS image sensor for the video surveillance camera market. The TC922 provides a higher-quality image than conventional charge coupled devices (CCD) by keeping the advantages of both sensitivity and wide dynamic range field of vision for improved bright and low-light performance.

The TC922 offers SVGA resolution (800 x 600), which exceeds conventional CCTV cameras in both horizontal and vertical lines, offering 560 TV lines. The TC922 also contains a High Response Amplifier in the pixel and Reset Noise Reduction circuit that provides CCD-level high sensitivity and high signal to noise ratio, which has not been achieved by conventional CMOS sensors. The TC922-based security camera achieves these qualities while the wide dynamic range capability allows for the capture of high resolution, more detailed images in high-contrast lighting conditions. Furthermore, each pixel has a photodiode and a Lateral Overflow Integration Capacitor (LOFIC), which can hold a large number of photoelectrons for very bright lighting conditions. The LOFIC technology enables the sensor's dynamic range to reach 94 decibels (dB). The remarkable electron capability of TC922 is superior to conventional CCD sensors.

With this sensor architecture, the TC922 constantly maintains its dynamic range, which enables it to provide complete information even in environments with severe variations in illumination. Moreover, since the TC922 has large electron capacity and this single exposure concept can provide simultaneity, it does not generate a synthetic gap problem as can be seen in CCD systems. CCD sensors have only a limited electron well capacity and one of the methods for extending dynamic range is to combine two images with different exposure times. The resulting images usually become blurred and the degredation of image quality can be seen.

Additionally, TI will offer an Internet Protocol (IP) network camera reference design with the TC922 based on the TMS320DM355 DaVinci digital media processor. The DM355IPNC-TC922 includes the hardware and software required for developing functions of a Wide Dynamic Range IP network camera in order to reduce the time required for camera design and development. The DM355IPNC-TC922 will be demonstrated in the ObjectVideo booth at ASIS International 2008, Booth # 3235.

The TC922 will be available from TI and TI authorised distributors. Order entry is currently open for the DM355IPNC-TC922 IP network camera reference design and is provided from APPRO Photoelectron Inc. For more information, please visit

Comment on "CMOS image sensor offers high image ..."
*  You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.


Go to top             Connect on Facebook      Follow us on Twitter      Follow us on Orkut

Back to Top