Abstract: A tamper-resistant security system for and method of operating and installing the same are disclosed for electronically controlling an access device such as a garage door. A manual keyboard encoder mounted exteriorly on a garage door jamb is operative for generating coded electrical signals, including a predetermined sequence of coded electrical signals required to move the garage door from a closed to an open position. A control-processor unit mounted within the interior garage area is operative for detecting the coded signals, and for moving the garage door from the closed to the open position in response to detection of the predetermined coded signal sequence. A single pair of electrical conductors interconnects the encoder and the control-processor unit. The transmission of the predetermined coded signal sequence over the single pair of conductors deters intruders from compromising system security, and also simplifies the installation.

Abstract: An array of laser generating elements is mounted upon at least one substrate in a one-dimensional band, with essentially one laser emitting surface facing two lens assemblies, the first being an array of plano-cylindrical inner lenses, equal in number to the number of bands of laser elements with their focal axes parallel to such bands, and the second being a single plano-cylindrical outer lens having its focal axis perpendicular to those of the lenslets. Advantageously, the substrates are assembled such that each laser element is in essentially precise alignment with its corresponding lenslet for its preselected operating temperature. Also advantageously, the curved surfaces of each inner lens and of the outer lens are formed to a slightly acylindrical shape for essentially complete collimation of the laser radiation. Further advantageously, a heat removal system may be incorporated in the mounting substrate which is formed with an expanded rear face, having a coolant applied thereto.

Abstract: A marine obstacle avoidance system for and method of alerting a helmsman of a marine vehicle to the danger of maritime collision with floating and/or submerged objects. The system includes an optical transmitter, an optical receiver, and an alarm. The transmitter transmits an incident light beam towards the waterline, whereupon a reflected light beam and a refracted lightbeam are generated. An obstacle in the path of either the incident and/or reflected and/or refracted beams is detected by reflecting the light back towards the receiver which, in turn, sounds the alarm.