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:
Aug. 17, 2010
Filed:
Sep. 30, 2005
Masahiro Ohishi, Itabashi-ku, JP;
Fumio Ohtomo, Itabashi-ku, JP;
Masahiro Ohishi, Itabashi-ku, JP;
Fumio Ohtomo, Itabashi-ku, JP;
Kabushiki Kaisha TOPCON, Tokyo, JP;
Abstract
A time difference measuring device can accurately measure a time difference between two pulse signals generated with a predetermined time difference by measuring the two pulse signals by one measurement. The time difference measuring device measures a time difference between a start signal (M) and a stop signal (M). The device has a reference signal generation unit () for generating two reference signals (S, S) having a π/2 phase difference. According to corresponding amplitude values (A, A) and (A, A) of the reference signals (S, S) at each generation timing of the start signal (M) and the stop signal (M), a phase difference detection unit () calculates a phase difference Δθ (=θstop−θstart) between the generation timings of the pulse signals (M, M). According to the detected phase difference Δθ and the cycle (Ts) of the reference signals (SS), a time difference calculation unit () calculates the generation time difference Δt between the pulse signals (m, M).