Positional change measurement device, positional change measurement method, and image forming apparatus
US9228825B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2014 |
| Grant date | Jan 5, 2016 |
| Priority date | — |
| Expiry date | Mar 13, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00616
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An objective is to achieve a positional change measurement device which measures positional change of a dynamic measured surface by using speckle patterns while easily reducing influence of fluctuations in a measurement environment temperature. Provided is a positional change measurement device including: a light source; an illuminating optical system configured to guide light from the light source to a measured surface; an imaging optical system; an image pickup device configured to acquire a speckle pattern by receiving reflection light from the measured surface via the imaging optical system; and detected-length compensation means for compensating for fluctuations in a detected length caused by temperature fluctuations. Positional change of the measured surface is measured based on a result of cross-correlation computation performed on multiple speckle patterns acquired at predetermined time intervals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.