US 4,143,267 AGranted

Digital distance measuring instrument

OwnerLonnie G. Johnson, John M. Ledererinventors

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Abstract

An apparatus for making distance measurements with a high degree of accuracy and a means for interpreting and displaying the results on a digital readout. A binary encoded scale which exhibits a one to one correspondence with discrete locations on said scale and the coded information at those locations is used in making the measurements. The scale is made using photographic reducing techniques. An optical detection system, comprising a magnifying lens, a plurality of light conducting fibers and phototransistors is used to read digital information from the binary encoded scale. An electronic circuit accepts digital code from the optical detection system, decodes it and displays the resulting information on a digital readout.

Claims6

Dependent claims

An improved device for providing a digital readout of distance measurements, said device comprising:

a. a first member, a second member and a coded scale, said coded scale being fixed to said first member, said second member being moveably coupled to said first member in a manner which facilitates the measurement of distance by said device by positioning said second member at a location on said coded scale corresponding to the magnitude of the distance being measured, said coded scale exhibiting a one to one correspondence with discrete distance magnitudes, discrete locations on said coded scale and the coded information at those locations;
b. an optical detection system attached to said second member for reading said coded scale, said optical detection system comprising a lens, and a plurality of light conducting fibers and phototransistors, said lens being focused on said coded scale so that it magnifies the image of the code at the location of said coded scale with which said second member is aligned, the alignment of said second member corresponding to the alignment of said lens, said light conducting fibers being positioned for optically coupling the image magnified by said lens to said phototransistors, said phototransistors being operative for converting the image magnified by said lens into electrical signals;
c. a signal conditioning circuit connected to said phototransistors, said signal conditioning circuit receiving electrical signals from said phototransistors and generating conditioned, electrical signals in response thereto;
d. a latching circuit, said latching circuit receiving electrical signals being output from said signal conditioning circuit by means of electrical connections, said latching circuit synchronizing the loading of information into its output with correct alignment of said optical detection system with a row of code being read and holding the information last read when alignment is off;
e. a decoder and a digital display, said decoder being connected to said latching circuit and interpreting the information being output therefrom and supplying driving signals by means of electrical connections to said digital display for digital readout of information representative of that read from said coded scale;
f. said device incorporating integrated circuits in order to form a compact unit having all associated electrical circuitry physically located inside said device and having said digital display physically attached to said device.

3 more elements

Dependencies are inferred from the claim text.

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Abstract

An improved device for providing a digital readout of distance measurements, said device comprising:

a. a first member, a second member and a coded scale, said coded scale being fixed to said first member, said second member being moveably coupled to said first member in a manner which facilitates the measurement of distance by said device by positioning said second member at a location on said coded scale corresponding to the magnitude of the distance being measured, said coded scale exhibiting a one to one correspondence with discrete distance magnitudes, discrete locations on said coded scale and the coded information at those locations;
b. an optical detection system attached to said second member for reading said coded scale, said optical detection system comprising a lens, and a plurality of light conducting fibers and phototransistors, said lens being focused on said coded scale so that it magnifies the image of the code at the location of said coded scale with which said second member is aligned, the alignment of said second member corresponding to the alignment of said lens, said light conducting fibers being positioned for optically coupling the image magnified by said lens to said phototransistors, said phototransistors being operative for converting the image magnified by said lens into electrical signals;
c. a signal conditioning circuit connected to said phototransistors, said signal conditioning circuit receiving electrical signals from said phototransistors and generating conditioned, electrical signals in response thereto;
d. a latching circuit, said latching circuit receiving electrical signals being output from said signal conditioning circuit by means of electrical connections, said latching circuit synchronizing the loading of information into its output with correct alignment of said optical detection system with a row of code being read and holding the information last read when alignment is off;
e. a decoder and a digital display, said decoder being connected to said latching circuit and interpreting the information being output therefrom and supplying driving signals by means of electrical connections to said digital display for digital readout of information representative of that read from said coded scale;
f. said device incorporating integrated circuits in order to form a compact unit having all associated electrical circuitry physically located inside said device and having said digital display physically attached to said device.

3 more elements