CONTACT TYPE SHAPE MEASURING APPARATUS

• US 20120125088A1
• Filed: 11/09/2011
• Published: 05/24/2012
• Est. Priority Date: 11/24/2010
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Miyata, Akinori
• Granted Patent: US 9,016,106 B2
• Time in Patent Office: Days
• US Class Current: 73/104
• CPC Class Codes: G01B 21/045 Correction of measurements G01B9/02055 takes precedence
• CPC Class Codes: G01B 5/008 using coordinate measuring machines

Abstract

An acting force is applied to a probe on the basis of a target speed serving as a probe speed in a stable copy scanning state of a target surface to be measured and a probe speed error serving as a difference between the target speed and a probe speed.

Claims

1. A shape measuring apparatus comprising:

a moving member configured to move three-dimensionally;

a probe supported movably relative to the moving member;

a position measuring unit configured to measure a position of the probe;

a probe-speed calculation unit configured to calculate a probe speed serving as speed information in a moving direction of the probe on the basis of position information about the position of the probe obtained by the position measuring unit;

a target-speed calculation unit configured to calculate a probe target speed with reference to probe speed information during scanning of a target object to be measured;

an acting-force calculation unit configured to calculate an acting force that reduces a probe speed error serving as a different between the probe target speed and the probe speed on the basis of the probe speed error; and

a force generating unit configured to generate, in the probe, a force in the moving direction of the probe in accordance with the calculated acting force;

wherein the shape measuring apparatus measures a shape of the target object by scanning a surface of the target object and measuring the position of the probe while the probe is in contact with the target object.

2. The shape measuring apparatus according to claim 1, wherein the target-speed calculation unit sets the target speed with reference to past information about the probe speed.

3. The shape measuring apparatus according to claim 1, wherein the acting-force calculation unit calculates the acting force by multiplying the probe speed error by a proportionality coefficient when the probe speed error exceeds a threshold value.

4. The shape measuring apparatus according to claim 1, wherein the acting-force calculation unit calculates a fixed acting force when the probe speed error exceeds a threshold value.