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:
Dec. 17, 2013
Filed:
Dec. 18, 2009
Masahiro Ohishi, Tokyo, JP;
Yoshikatsu Tokuda, Tokyo, JP;
Masahiro Ohishi, Tokyo, JP;
Yoshikatsu Tokuda, Tokyo, JP;
Topcon Corporation, Tokyo, JP;
Abstract
A distance measuring apparatus and method that enable high-precision and high-speed measurement by canceling variations of a delay circuit in the apparatus are provided. Pulsed light is branched into first and second reference light, and transmitted measurement light, and the difference in detection time among the first reference light along a first path with no optical variations, the second reference light along a second path with an optical delay, and received measurement light from an object to be measured is measured. The received measurement light and the first reference light are temporally separate, distance is calculated from the difference in detection time between the received measurement light and the first reference light. When the received measurement light and the first reference light are not temporally separate, distance is calculated from a difference in detection time between the first reference light and the second reference light and a difference in detection time between the received measurement light and the second reference light.