SHAPE MEASURING DEVICE AND METHOD, AND PROGRAM

• US 20100328454A1
• Filed: 09/07/2010
• Published: 12/30/2010
• Est. Priority Date: 03/07/2008
• Status: Abandoned Application

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: YAMADA, Tomoaki
• Application Number:
  US12/876,928
• Publication Number:
  US 20100328454A1
• Time in Patent Office: Days
• US Class Current: 348/135
• 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: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light

Abstract

The invention relates to a shape measuring device and method, and a program therefor, that allow measuring the shape of a test object, more simply and reliably, using a single-chip color sensor.

An optical low-pass filter (24) expands a slit beam reflected on a test object (12), in a direction perpendicular to a baseline direction. A CCD sensor (25) has R, G and B pixels arranged in a Bayer array, and the CCD sensor (25) outputs image signals that are obtained by the pixels receiving the slit beam. On the basis of image signals of the G pixels, an image processing unit (26) detects the timing at which the slit beam passes over a site of the test object (12) that is pre-set for the G pixels and, on the basis of image signals of the R pixels and the B pixels, controls a projection unit (22) to adjust the intensity of the slit beam. A dot group computing unit (27) computes the position of the test object (12) on the basis of the timing detected for the G pixels. The invention can be used in a three-dimensional shape measuring device.

Claims

1. A shape measuring device comprising:

light beam projection means for projecting a measurement light beam of a predetermined wavelength having a long pattern in one direction, onto a test object;

image capture means for receiving a reflected light beam of the measurement light beam and outputting an image signal; and

shape measuring means for measuring the shape of the test object on the basis of the image signal,

wherein the image capture means is configured in such a manner that first pixels that receive light of a specific wavelength band including the predetermined wavelength, and second pixels having a lower light-reception sensitivity than that of the first pixels with respect to light of the predetermined wavelength, are alternately arrayed, and both the first pixels and the second pixels receive the reflected light beam, from a same site of the test object, whereby mutually different image signals are outputted; and

the shape measuring means comprises a signal processing unit for processing image signals from each of the first pixels and the second pixels, and for measuring the shape of sites on the test object.

2. The shape measuring device according to claim 1, further comprising:

adjustment means for adjusting the intensity of the measurement light beam that is projected by the light beam projection means, on the basis of a signal from the second pixels of the image capture means, from among the image signals.

3. The shape measuring device according to claim 1,

wherein the signal processing unit includes:

a saturation detection unit that detects saturation in the image signal corresponding to the first pixels; and

a computation unit that interpolates and computes values corresponding to light intensity received by the first pixels on the basis of an image signal from the second pixels, when saturation is detected by the saturation detection unit; and

wherein the shape of sites on the test object is measured on the basis of the values calculated by the computation unit.

4. The shape measuring device according to claim 1,

wherein the first pixels and the second pixels are arrayed in a direction that is perpendicular to a transverse direction of the pattern.

6. The shape measuring device according to claim 2,

wherein the first pixels and the second pixels are arrayed in a direction that is perpendicular to a transverse direction of the pattern.

7. The shape measuring device according to claim 3,

wherein the first pixels and the second pixels are arrayed in a direction that is perpendicular to a transverse direction of the pattern.

5. A shape measuring method, comprising:

a step of projecting a measurement light beam of a predetermined wavelength having a long pattern in one direction, onto a test object;

a step of acquiring an image signal relating to an image of a test object onto which the measurement light beam is projected, by way of an image capture means;

comprising first pixels that receive light of a specific wavelength band including the predetermined wavelength; and

second pixels having a lower light-reception sensitivity than that of the first pixels with respect to light of the predetermined wavelength, the first pixels and the second pixels being alternately arrayed in the predetermined direction, both the first pixels and the second pixels receiving the reflected light beam from a same position at the test object;

an adjustment step of adjusting the intensity of the measurement light beam that is projected, on the basis of a signal from the second pixels, from among image signals obtained through reception of the reflected light beam; and

a shape measurement step of measuring the shape of the test object on the basis of an image signal relating to the image of the test object onto which the adjusted measurement light beam is projected.

8. A program for causing a computer to execute a process, the process comprising:

a step of projecting a measurement light beam of a predetermined wavelength having a long pattern in one direction, onto a test object;

a step of acquiring an image signal relating to an image of a test object onto which the measurement light beam is projected, by way of an image capture means;

comprising first pixels that receive light of a specific wavelength band including the predetermined wavelength, and second pixels having a lower light-reception sensitivity than that of the first pixels with respect to light of the predetermined wavelength, the first pixels and the second pixels being alternately arrayed in the predetermined direction, both the first pixels and the second pixels receiving the reflected light beam from a same position at the test object;

an adjustment step of adjusting the intensity of the measurement light beam that is projected, on the basis of a signal from the second pixels, from among image signals obtained through reception of the reflected light beam; and

a shape measurement step of measuring the shape of the test object on the basis of an image signal relating to the image of the test object onto which the adjusted measurement light beam is projected.