×

Blind spot detector for vehicles

  • US 4,260,980 A
  • Filed: 04/30/1979
  • Issued: 04/07/1981
  • Est. Priority Date: 04/30/1979
  • Status: Expired due to Term
First Claim
Patent Images

1. Apparatus for detecting the presence of an object moving relative to a vehicle within a location adjacent to said vehicle and hidden from the view of the operator of the vehicle comprising:

  • a first transducer mounted on said vehicle for transmitting continuous ultrasonic signals of a given ultrasonic frequency into said hidden location, a second transducer mounted on said vehicle in spaced relation to said first transducer for receiving ultrasonic signals reflected from an object present in said hidden location, a first high frequency audio amplifier powering said first transducer to cause said first transducer to transmit said ultrasonic signals, a second high frequency audio amplifier for amplifying the ultrasonic signals received by said second transducer, a tuned amplifier coupled to said first high frequency audio amplifier and adapted to receive a portion of the signal amplified by said second high frequency audio amplifier, said tuned amplifier having an output only when there is relative motion between said object and said vehicle, said output of said tuned amplifier being a relatively low audio frequency signal representing a differential frequency between the transmitted signals and the received signals resulting from the change in the transmitted signals as produced by the relative motion between said object and said vehicle, a low frequency audio amplifier for amplifying a portion of the output of said tuned amplifier, and means responsive to the amplified signal from said low frequency audio amplifier for actuating an alarm when said portion of the output from said tuned amplifier exceeds a predetermined value.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×