Profile measuring apparatus

• US 9,335,160 B2
• Filed: 04/26/2011
• Issued: 05/10/2016
• Est. Priority Date: 04/26/2010
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Ito, Yuka, Fujisawa, Haruhiko
• Primary Examiner(s): Satanovsky, Alexander
• Assistant Examiner(s): KUAN, JOHN CHUNYANG
• Application Number:
  US13/064,922
• Publication Number:
  US 20110270562A1
• Time in Patent Office: 1,841 Days
• US Class Current: 1/1
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object
• CPC Class Codes: G01B 21/20 for measuring contours or curvatures, e.g. determining profile
• CPC Class Codes: G01B 9/02055 Reduction or prevention of errors; Testing; Calibration

Abstract

According to one embodiment, a profile measuring apparatus comprises a profile measuring unit, a position acquiring unit, a profile calculating unit, a deflection detecting unit, and a controlling unit. The profile measuring unit has a projecting unit to project a pattern onto a measured object, and an imaging unit to image the pattern. The position acquiring unit acquires a position of the profile measuring unit. The profile calculating unit calculates a profile of the measured object, based on image information from the imaging unit and position information from the position acquiring unit. The deflection detecting unit detects deflection of the projecting unit. The controlling unit executes active correction for the profile measuring unit and/or passive correction for the profile calculating unit, based on the deflection of the projecting unit detected by the deflection detecting unit.

Claims

1. A profile measuring apparatus comprising:

a probe to project a predetermined pattern onto a part of a measured object, and to image the predetermined pattern projected by the probe to produce two-dimensional image information of the predetermined pattern;

a position acquiring unit which acquires a position of the probe;

a deflection detecting unit which detects a deflection of the probe and produces at least one deflection amount; and

a profile calculating unit which is connected so as to be able to communicate with the probe, the deflection detecting unit and the position acquiring unit,

wherein the profile calculating unit corrects the two-dimensional image information on the basis of the at least one deflection amount to produce corrected two-dimensional image information, and

wherein the profile calculating unit calculates a three-dimensional profile of the part of the measured object, based on the corrected two-dimensional image information and position information from the position acquiring unit, after the profile calculating unit corrects the two-dimensional image information.

2. The profile measuring apparatus according to claim 1, further comprising:

a base; and

a moving mechanism unit extending from the base and having a tip coupled to the probe.

3. A profile measuring apparatus comprising:

a probe to project a predetermined pattern onto a part of a measured object, and to image the predetermined pattern projected by the probe to produce two-dimensional image information of the predetermined pattern;

a position acquiring unit which acquires a position of the probe;

a deflection detecting unit which detects a deflection of the probe and produces at least one deflection amount; and

a profile calculating unit which is connected so as to be able to communicate with the probe, the deflection detecting unit and the position acquiring unit, and which calculates a three-dimensional profile of the measured object, based on image information from the probe, position information from the position acquiring unit, and the at least one deflection amount produced by the deflection detecting unit,

wherein the profile calculating unit;

corrects an image position of the predetermined pattern on an image plane obtained by the probe by correcting the two-dimensional image information on the basis of the at least one deflection amount produced by the deflection detecting unit to produce corrected two-dimensional image information;

calculates a position where the predetermined pattern is projected on the measured object from the position of the probe; and

calculates a three-dimensional profile of the part of the measured object based on the calculated position where the predetermined pattern is projected on the measured object and the corrected two-dimensional image information.

4. The profile measuring apparatus according to claim 3, wherein

the deflection detecting unit has at least one of an angular velocity detector to detect an angular velocity of the probe, and an acceleration detector to detect an acceleration of the probe, and

the deflection detecting unit detects the deflection, based on at least one of the angular velocity and the acceleration.

5. The profile measuring apparatus according to claim 4, wherein

the probe has an imaging optical system to form an image of the measured object, and

the imaging optical system is configured so that a plane conjugate with an imaging plane thereof includes an irradiation direction of the predetermined pattern projected from the probe.

6. The profile measuring apparatus according to claim 3, further comprising a controlling unit, which is connected to the deflection detecting unit, which executes comparison of the at least one deflection amount produced by the deflection detecting unit with a predetermined threshold and which controls the profile calculating unit to determine whether the correction in the profile calculating unit is performed or not, according to a result of the comparison.

7. The profile measuring apparatus according to claim 6, wherein correction control of the controlling unit is performed in accordance with the at least one deflection amount produced by the deflection detecting unit.

8. The profile measuring apparatus according to claim 7, wherein

the deflection detecting unit has at least one of an angular velocity detector to detect an angular velocity of the probe, and an acceleration detector to detect an acceleration of the probe, and

the deflection detecting unit detects the deflection, based on at least one of the angular velocity and the acceleration.

9. The profile measuring apparatus according to claim 8, wherein

the probe has an imaging optical system to form an image of the measured object, and

the imaging optical system is configured so that a plane conjugate with an imaging plane thereof includes an irradiation direction of the predetermined pattern projected from the probe.

10. The profile measuring apparatus according to claim 7, wherein the deflection detecting unit detects the amount of the deflection in a scanning direction of the profile measuring unit.

11. The profile measuring apparatus according to claim 10, wherein

the deflection detecting unit has at least one of an angular velocity detector to detect an angular velocity of the probe, and an acceleration detector to detect an acceleration of the probe, and

the deflection detecting unit detects the deflection, based on at least one of the angular velocity and the acceleration.

12. The profile measuring apparatus according to claim 11, wherein

the probe has an imaging optical system to form an image of the measured object, and

the imaging optical system is configured so that a plane conjugate with an imaging plane thereof includes an irradiation direction of the predetermined pattern projected from the probe.

13. The profile measuring apparatus according to claim 6, further comprising a moving mechanism unit which moves the probe relative to the measured object,

wherein the controlling unit executes correction control, based on a difference between the at least one deflection amount produced by the deflection detecting unit and a movement amount the moving mechanism unit moves the probe relative to the measured object.

14. The profile measuring apparatus according to claim 13, wherein

the deflection detecting unit has at least one of an angular velocity detector to detect an angular velocity of the probe, and an acceleration detector to detect an acceleration of the probe, and

the deflection detecting unit detects the deflection, based on at least one of the angular velocity and the acceleration.

15. The profile measuring apparatus according to claim 14, wherein

the probe has an imaging optical system to form an image of the measured object, and

the imaging optical system is configured so that a plane conjugate with an imaging plane thereof includes an irradiation direction of the predetermined pattern projected from the probe.