Optical Sensor June 2001

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Balluff's 6K subminiature optical sensor is reportedly smart enough to self-teach target vs. background, even when the target is moving at line speed. The device is said to be the only subminiature optical sensor in the world with microprocessor-based teach capability. The supplier developed software that goes beyond passive teachability. The sensor can determine the optimum trigger point for the target without the aid of an operator. In addition, the self-teaching mode can be activated remotely for a group of sensors with a single pushbutton, or automatically by the machine control. This eliminates the need for the operator to find hidden sensors and manually jog the machine while setting pots for each product change.

The sensor is available in a variety of sensing modes, including diffuse, retroreflective, and thru-beam. It is reportedly the only subminiature sensor to offer models with electronic background suppression and clear-object detection capability. Background suppression models use triangualtion distance measurement to eliminate the influence of shiny backgrounds. Clear object detection is enhanced by low hysteresis and microprocessor-controlled adjustment, while a response time of 0.5 msec and switching frequency of 1,000 Hz make it suitable for high-speed assembly and packaging operations.

The device uses a bright red light source to aid in quick alignment. The visible light is also said to help detect a wider range of colors than possible with infrared. Diffuse models have a sensing range of up to 300 mm (11.8 in). A single membrane-type pushbutton on top of the sensor housing allows programming by hand or switching from light-on to dark-on modes, while eliminating O-rings that can wear out or leak.