CHEESE. This new "camera on a chip" measures just a quarter-inch in width.

Soon, for less than $50, you too will be able to buy a marble-size video camera that rivals any spy's. Vanguard International Semiconductor Corporation has just licensed from Lucent Technologies' Bell Laboratories the technology to create cameras on single quarter-inch silicon chips.

The chip itself is nothing new. It's made using the CMOS (complementary metal oxide semiconductor) technology behind today's computer chips. But its imaging array employs an improved version of the active-pixel approach introduced in the 1970s. The array holds more than 100,000 pixels, each of which generates a small charge when illuminated. Amplifiers at each pixel serve to minimize distortion. In addition, the Bell Labs researchers corrected for so-called "fixed-pattern noise," which results from differences in individual amplifiers and long plagued CMOS-based cameras in development.

The new cameras have several advantages over traditional ones using CCD (charged coupled device) technology. They are much smaller and use less power. Whereas a nine-volt battery will power a CCD camera for only 30 minutes, it will run a CMOS camera for five hours. Vanguard expects the new cameras will be used first for videoconferencing and surveillance.