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. 15, 2012
Filed:
Sep. 01, 2011
Isao Minegishi, Tokyo, JP;
Masahiro Ohishi, Tokyo, JP;
Naoto Miki, Tokyo, JP;
Yuichi Yoshimura, Tokyo, JP;
Isao Minegishi, Tokyo, JP;
Masahiro Ohishi, Tokyo, JP;
Naoto Miki, Tokyo, JP;
Yuichi Yoshimura, Tokyo, JP;
Kabushiki Kaisha Topcon, Tokyo, JP;
Abstract
A distance measuring device measures a distance from a phase difference of beaten down processing signals even when fluctuations occur in a frequency of an oscillator. The distance measuring device includes a laser unit, a dividing device, a reference light receiving unit, and a measuring light receiving unit. The distance measuring device further includes an oscillator, a first mixer, a second mixer, a fourth filter, a fifth filter, a third mixer, a sixth filter, a second filter, a phase difference measuring unit, and a distance measuring unit. The phase difference measuring unit measures a phase difference of the two beat signals extracted by the sixth filter and the second filter. The distance measuring unit measures a distance based on the phase difference measured by the phase difference measuring unit.