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.
Patent No.:
Date of Patent:
May. 11, 1993
Filed:
Mar. 04, 1992
Yukio Ohmamyuda, Sagamihara, JP;
Shigeru Kimura, Yokohama, JP;
Toru Tanabe, Machida, JP;
Kazuhisa Iwasaki, Yokohama, JP;
Takao Seto, Yokohama, JP;
Hideki Kitamura, Yokohama, JP;
Kazuhiko Sugimura, Yokohama, JP;
Yasushi Senoo, Yokohama, JP;
Stanley Electric Co., Ltd., Tokyo, JP;
Abstract
An optical distance measuring apparatus operable in accordance with a phase difference detecting process, comprises a processing system including a central processing unit and first and second local oscillating circuits which serve to detect and calculate a phase difference between the electrical phase of a modulated signal outputted from a reference oscillator electrically connected to a light source via a modulating circuit and the electrical phase of a demodulated signal outputted from a demodulating circuit electrically connected to a light receiving portion so as to determine a distance between the apparatus and an object to be measured based on the detected phase difference with reference to the electrical phase of a reference signal outputted from the reference oscillator. A first local oscillating signal is outputted from the first local oscillating circuit and it is then subjected to frequency conversion together with the demodulated signal in a mixer so as to output a first intermediate frequency, while a second local oscillating signal is outputted from the second local oscillating circuit and it is then subjected to frequency conversion in a mixer together with the demodulated signal so as to output a second intermediate frequency signal. One of the first and second intermediate frequency signals is selected depending on the present distance between the apparatus and the object to be measured.