Reflective Sensor distinguishes degrees of color.

Press Release Summary:

Color Sensor Assembly combines white LED with reflective color sensor chip in miniature plastic housing. Self-correcting LED illuminates surface of object or liquid being sensed, while sensor chip measures hue, saturation, and luminance values of light reflected from surface. Assembly housing is 1.08 x 0.675 x 0.26 in. with 18 in. wiring harness. Applications include pill sorting, ink and/or paper color detection for office machines, paint, textiles, and cosmetics.

Original Press Release:

OPTEK Develops Reflective Sensor Assembly To Distinguish Degrees of Color

CARROLLTON, TX (July 28, 2005) - Providing design engineers with the means to electronically detect color differences in liquids or solids, TT electronics OPTEK Technology has developed a high resolution color sensor technology that promises to bring a new level of accuracy to automated color selection/detection. Introduced at the 2005 Sensors Expo, held on June 6 - 9 in Chicago, the color sensor assembly was incorporated into an active display that automatically sorted 'M&M'S®' candies by color as they were fed down a tube.

OPTEK's color sensor assembly combines a white LED with a reflective color sensor chip in a miniature plastic housing less than one quarter of a cubic inch. The white LED (self-correcting to minimize the effect of non-uniform ambient light sources) is used to illuminate the surface of the object or liquid being sensed, while the color sensor chip measures the HSL value (hue, saturation, luminance) of the light reflected from that surface. By processing this value through a programmable algorithm, the sensor has the ability to distinguish between several different colors and intensities.

"Our color sensor gives design engineers the ability to reliably sort or match items by color with the use of automated equipment," said Steve Coble, engineering manager for OPTEK Technology. "The sensor's ability to distinguish colors can be enhanced by advanced signal processing electronics that can be incorporated into the assembly that can further analyze the sensor's digital output."

According to Coble, the new color sensor technology extends the range of OPTEK's sensing capability to encompass the visible spectrum, as a natural extension of the company's work with infrared sensor technologies. "Our ability to offer customers a packaged or custom assembly to automatically sense color means that we can help them with a wider range of applications," he added.

Some other applications where the color sensor is being implemented include pill sorting machinery in pharmaceutical applications, ink and/or paper color detection for office machines, color printer calibration sensors, as well as color-match sensing in paint, textile and cosmetic manufacturing. The sensor is also being used by an appliance manufacturer to differentiate between different flavors of coffee and/or hot drinks by identifying the color of a ring on the coffee filter pack.

In its initial design, the sensor assembly housing is approximately 1.08" by 0.675" by 0.26" tall (2704mm by 17.1mm by 6.6mm) with an 18" (45.7cm) wiring harness, making it small enough to be incorporated into almost any application.

Pricing and lead times for the color sensor technology will be determined by each application's requirements (as a custom assembly).

For more information about OPTEK's color sensor technology, contact TT electronics' OPTEK Technology at 1645 Wallace Dr., Carrollton, TX, 75006; call 972-323-2200, e-mail at or visit OPTEK on the web at

OPTEK Technology is a leading manufacturer of standard and application-specific sensors using infrared, visible, magnetic and fiber optic technologies focused on applications in office machines, industrial equipment, encoders, automotive electronics, military and high-reliability applications, and medical diagnostic equipment. Headquartered in Carrollton, TX, the company is ISO/TS16949:2002 and BS EN ISO 9001:2000 certified, as well as ITAR registered. OPTEK Technology was acquired by TT electronics in December 2003.

TT electronics plc is a global electronics company manufacturing a broad range of advanced electronic components, assemblies and sensor modules for the automotive, industrial, telecommunication, computer and aerospace markets.

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