MEANS FOR MEASURING DISTANCE WHEN IT IS CONSIDERED PROBABLE THAT FOREIGN OBJECTS OR PARTICLES ARE BETWEEN THE MEASURING INSTRUMENT AND THE OBJECT TO WHICH THE DISTANCE IS TO BE MEASURED

• US 3,728,026 A
• Filed: 11/08/1971
• Issued: 04/17/1973
• Est. Priority Date: 12/10/1970
• Status: Expired due to Term

• Current Assignee: Anders Persson, Bernt Ling, Erik Idestrom
• Original Assignee: Anders Persson, Bernt Ling, Erik Idestrom
• Inventors: Ling, Bernt, Persson, Anders, Idestrom, Erik
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): Buczinski, S. C.
• Application Number:
  US05/196,324
• Time in Patent Office: 526 Days
• Field of Search: 356/4,5 343/13,7.5 340/1R,1C,1L
• US Class Current: 356/5.08
• CPC Class Codes: G01S 13/103 particularities of the measurement of the distance G01S13/12, G01S13/14, G01S13/16, G01S13/18 and G01S13/20 take precedence

Abstract

An arrangement for measuring distance under conditions when disturbances of various types may be expected to occur between the measuring instrument and the object to which the distance is to be measured comprises an emitter unit arranged to emit a series of electro-magnetic pulses in the direction of the object and a receiver unit, which only registers the very first echo from each single pulse emitted, and the echo which of all those registered has covered the longest distance is considered to comprise a measurement of the distance to the object in question.

Claims

1. Means for measuring distance comprising a signal member including an emitter unit and a receiver unit, said emitter unit including means to emit a series of high frequency pulses towards an object, said receiver unit including means to register only the first echo of each pulse emitted, and means associated with the receiver unit to give an output signal proportional to that echo which of all those registered has covered the longest distance, thereby comprising a measurement of the distance to the object in question.

2. Means according to claim 1, in which said emitter unit comprises a pulsed semi-conductor laser.

3. Means according to claim 1, in which said receiver unit comprises a time-measuring device including means to measure the time which passes between the emission of a pulse from said emitter unit and the receipt of the first echo generated by said pulse, and to emit an output signal in the form of a time pulse which comprises a measurement of the Time measured.

4. Means according to claim 3, in which said receiver unit comprises an output device to which said time pulse is transmitted and which includes means to emit an output signal constituting a measurement of the longest of the time pulses transmitted to the output device, this pulse constituting a measurement of the distance to the object in question.

5. Means according to claim 1, which includes means responsive to the first echo of each pulse to render the receiver unit inoperative to receive any further echoes of such pulse.