The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jun. 17, 1980

Filed:

Mar. 24, 1978
Applicant:
Inventors:

Masahiro Noda, Inazawa, JP;

Ryoji Takahashi, Inazawa, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03D / ; B66B / ;
U.S. Cl.
CPC ...
361181 ; 361203 ; 340562 ; 340563 ; 307116 ; 49 25 ;
Abstract

A proximity detector comprises a pair of antennae being disposed along the front edge of a door and at a space therebetween, a pair of coils constituting series resonance circuits, together with each electrostatic capacities of the antennae which are connected in series with the coils, an AC power source for supplying voltages to the series resonance circuits; rectifying circuits for rectifying the voltages produced on the antennae by the AC power source, and a differential amplifier circuit for amplifying difference between the outputs of the rectifying circuits, the output of the differential amplifier controlling the movement of the door.


Find Patent Forward Citations

Loading…