Patent ID: 9645169
Date: 2017-05-09
CPC Classifications: G01Q

Claim:
1. A measurement method in which a sensing unit acquires surface data of a measurement target while scanning the surface of the measurement target, and at least one of the sensing unit and the measurement target is moved in order for the sensing unit to scan the surface along a plurality of fast scan lines on the surface of the measurement target, the measurement method comprising: a first step in which the sensing unit scans a surface along any one fast scan line of the plurality of fast scan lines to acquire the surface data along the any one fast scan line; and a second step in which the sensing unit acquires a surface data along a fast scan line most adjacent to the any one fast scan line while at least one of the sensing unit and the measurement target is moved along the most adjacent fast scan line, after the first step, wherein a scan rate in the second step is determined by using at least the surface data acquired in the first step, and wherein in the second step, the scan rate is determined by using a variation per scan distance in the surface data along the any one fast scan line, wherein the scan rate in the second step is set to decrease from a predetermined time before measurement of a point corresponding to a point at which the variation acquired in the first step is equal to or higher than a predetermined value, and/or wherein the scan rate in the second step is set to increase from a predetermined time after measurement of a point corresponding to a point at which the variation acquired in the first step is equal to or lower than a predetermined value.