Method for measuring sheet material flatness and method for producing steel sheet using said measuring method
US8459073B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 2012 |
| Grant date | Jun 11, 2013 |
| Priority date | — |
| Expiry date | Apr 11, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/89
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for measuring flatness of a sheet material in which a light and dark pattern composed by a light portion and a dark portion is projected onto a surface of the sheet material running in a longitudinal direction, a pattern image is acquired by photographing the light and dark pattern by an image pickup device having an image pickup visual field larger than a width of the sheet material, and the flatness of the sheet material is measured by analyzing the acquired pattern image. A staggered pattern is used for the projecting step and for light to be specularly reflected for receipt by the image pickup device. Calculating the flatness also includes steps of setting a shape measurement line, averaging picture element concentrations, calculating a distribution of the concentrations, and calculating the flatness based on surface shape using the distribution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.