Abstract: A vehicle detector and method for detecting the presence of a vehicle. The vehicle detector includes an array of ultrasonic transducers to direct and receive ultrasonic beams to and from a target. Further, the vehicle detector includes a control system for turning on and off the ultrasonic transducers and for generating data corresponding to the distance between the vehicle detector and the target, the speed of the target, and the direction of motion of the target; and for comparing the generated data to stored data to determine whether or not a vehicle is present. Finally, the vehicle detector includes output circuitry that directs a signal to an external device whether or not a vehicle is present.

Abstract: A system to prevent the improper installation of a safety circuit used to keep an automatic door from closing on an obstruction includes an automatic door operator for opening and closing the automatic door. A sensor system is provided for allowing the automatic door operator to close the automatic door whenever no obstruction is under the automatic door. The sensor system further prevents the automatic door operator from closing the automatic door whenever an obstruction is under the automatic door. Further, the sensor system prevents the automatic door operator from closing the automatic door when the sensor system is improperly installed such that an obstruction under the automatic door is undetectable.

Abstract: A method for increasing the contrast between reflected and background luminescent on an object to be scanned comprising the following steps: targeting a signal on an object to be scanned for luminescence; varying the wavelength and/or intensity of the signal to produce a contrast between the luminescence on the object and any background luminescence; and processing the return signal to remove the background luminescence.