April 13, 2005, Palo Alto, CA--Agilent Technologies has introduced a CMOS (complementary metal-oxide semiconductor) color sensor that is only 5 x 5 x 1 mm in size. The new color sensor can detect the presence of a certain color and identify its exact coordinate across the full color spectrum.
Key applications for the device include color measurement in blood glucose monitoring and other medical instruments, the detection of stains in yarns during textile manufacturing, and in LCD display for controlling the color point of red, green and blue (RGB) LED backlighting. There are many other applications in industries such as paint, pigment and coating, cosmetics, and food and beverage.
Agilent's color sensor converts colored light to proportional RGB voltage outputs. It is a monolithic CMOS IC solution with integrated RGB color filters combined with three interleaved sets of 3 x 3 photodiode arrays, which minimizes the effects of contamination and optical aperture misalignment. The photodiodes convert the RGB light components into photocurrents, and the transimpedance amplifiers then convert the photocurrent to analog voltages. The voltage output of each channel (R, G and B) increases linearly with increasing light intensity, and the gain of each channel can be independently set.
The sensor integrates color filters, photodiode arrays, amplifiers and gain selection in a single, compact package. It features uniform color filter arrays throughout the photodiode active area, which help to resolve potential inaccuracies caused by light gradient, optical aperture misalignment and tilting and irregularities of the package surface. Agilent's new color sensor provides operation over the -40 C to +85 C temperature range and is supplied in a QFN (quad flat no leads) lead-free package. It operates from a single 5volt power source.