FEBRUARY 21--Designers can now take a "drop in" approach to adding color sensing capabilities to their new products with an integrated red, green, and blue (RGB) color sensor with a digital-compatible interface from Texas Advanced Optoelectronic Solutions Inc. (TAOS; Plano, TX; www.taosinc.com). This color sensor integrates RGB filters on a single die. It is built on a light-to-frequency converter platform that enables 10--12 bits or better resolution per color channel without the need for expensive analog-to-digital converters.
The TCS230 Programmable Color Light-to-Frequency Converter is well suited to use in colorimeter measurement applications such as color printers, medical diagnostics, computer color monitor calibration, process controls, and color-matching applications with paints, textiles, cosmetics, and printed materials.
The TCS230 achieves its full RGB color sensing through a 64-photodiode grid that consists of four types of photodiodes: red, green, blue, and clear for overall intensity information. The four types (colors) of photodiodes are interdigitated to minimize the effect of nonuniformity of incident irradiance. All 16 photodiodes of the same color are connected in parallel and the color selected for use by the TCS230 during operation is dynamically selectable via two programming pins. The device is capable of responding to light over a 250,000-to-1 dynamic range, with a typical output frequency range of 2 Hz to 500 kHz. In addition, with two other programming pins, the user can select output scaling factors of 100%, 20%, or 2%, or a power-down mode.
The TCS230 also provides assembly benefits because its single-die configuration helps simplify mounting and optics. Much more accurate measurement is ensured because all three color filters are on the same optical plane.
