VEHICLE LOCATOR SYSTEM

• US 3,783,445 A
• Filed: 09/11/1972
• Issued: 01/01/1974
• Est. Priority Date: 09/11/1972
• Status: Expired due to Term

• Current Assignee: Kent A. Penwarden
• Original Assignee: Kent A. Penwarden
• Inventors: Penwarden, Kent A.
• Primary Examiner(s): Cooper, William C.
• Assistant Examiner(s): Kundert, Thomas L.
• Application Number:
  US05/287,631
• Time in Patent Office: 477 Days
• Field of Search: 340/22,23,24 178/18,19 200/159,46
• US Class Current: 340/990
• CPC Class Codes: G08G 1/13 the indicator being in the form of a map

Abstract

A compression type matrix switch comprising rows of parallel horizontal conductors in one plane and columns of parallel vertical conductors in a second plane parallel to the first plane and spaced therefrom by a resilient mat having apertures therethrough at the crossover points of the horizontal and vertical conductors is located behind a beat map overlay in a police patrol car. One end of each conductor is connected to a different sensor that monitors the electrical continuity between conductors at associated horizontal and vertical crossover points. The location of the car is selected for transmission to a monitor facility by firmly pressing the map at the crossover point nearest the actual location of the car. This electrically connects a pair of horizontal and vertical conductors through an aperture in the mat so that the output signals of only the two associated sensors indicate continuity at the crossover point. The outputs of all the sensors comprise a binary code signal uniquely defining the location of the car. This code signal is coupled, together with a binary code signal identifying the car, through a shift register to a transceiver for transmission to the monitor facility. Binary signals received at the monitor facility are processed in a logic circuitry for presenting on a map a visual indication of the location of the patrol car.

Claims

1. Apparatus for identifying the instantaneous location of a mobile unit at a remote station, said mobile unit comprising a first map overlay disposed in a first plane and depicting a geographic area in which said mobile unit is located, a compressive-type switch under said map overlay actuatable by finger-type force applied to said overlay at the point representative of the location of said mobile unit, said switch comprising a first set of spaced parallel conductors in a second plane parallel to said first plane and a second set of spaced parallel conductors in a third plane parallel to and spaced from said second plane, the conductors of the first set extending transversely of the conductors oF the second set and defining therewith crossover points at which electrical contact is made between conductors of the two sets in response to said finger-type compressive force, means for electrically energizing said first set of conductors, each conductor of the second set being energized only by the conductor of the first set in electrical contact therewith, sensor means responsive to the electrical continuity of each conductor of said first and second sets and producing a first binary digit for each conductor in contact with another conductor and a second binary digit for each conductor not in contact with another conductor, means responsive to said first and second binary digits for generating a binary word uniquely defining the selected position of contact between conductors of said first and second sets, a radio frequency transmitter, and means responsive to said binary word for modulating said transmitter to transmit same to said remote station, said remote station comprising means for receiving said binary word, and display means responsive to said receiving means comprising a plurality of illuminatable points adapted to be illuminated to form a pattern corresponding to the pattern of said crossover points of said mobile unit switch with one of said illuminatable points at each position corresponding to a crossover point, and a second map overlay substantially the same as said first map overlay optically superimposed on said illuminatable points and oriented relative thereto as said first map overlay is oriented relative to the crossover points of said switch whereby a finger-type compressive force applied to one location on said first map overlay causes illumination of a point at the same location on said second map overlay.

2. Apparatus according to claim 1 in which said illuminatable points comprise light emitting elements.

3. Apparatus according to claim 1 in which said illuminatable points comprise portions of the screen of a cathode ray tube.

4. Apparatus according to claim 1 in which said mobile unit includes means for generating a second binary word representing the identity of the particular transmitting mobile unit, indication means responsive to said transmitting means for indicating transmission of said binary words, said remote station having a transmitter responsive to said receiving means for transmitting an acknowledgment signal upon reception of said binary words, the indicator means at said mobile unit also being responsive to said acknowledgment signal for indicating reception by the remote station of said binary words.