Measurement device for obtaining amplitude information of an object

Patent metadata

Field	Value
Publication number	US-10001405-B2
Application number	US-201414784744-A
Country	US
Kind code	B2
Filing date	Mar 20, 2014
Priority date	Apr 16, 2013
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

A complex amplitude information measurement apparatus ( 10 ) according to the present invention includes pixel sensor groups for generating a difference from one pixel sensor group to another in the optical distance of object light traveling from a measurement object ( 100 ); a camera ( 15 ) provided with an image sensor for recording, with a single-shot exposure, the object light that has passed through or been reflected from the pixel sensor groups to obtain intensity information of the measurement object; and a computer ( 16 ) for computing, on the basis of the intensity information, phase information of the measurement object ( 100 ).

First claim

The invention claimed is:

1. A measurement apparatus comprising:
a plurality of pixel sensor groups for generating a difference from one pixel sensor group to another in optical distance of object light traveling from a measurement object,
an image sensor for recording, with a single-shot exposure, the object light that has passed through or been reflected from the plurality of pixel sensor groups to obtain intensity information of the measurement object, and
a phase information computing unit for computing, on the basis of the intensity information, phase information of the measurement object,
wherein the phase information computing unit comprises:
an extraction section for extracting, on the basis of the intensity information, pixel values obtained by recording the object light that has passed through or been reflected from the plurality of pixel sensor groups so as to generate extracted data corresponding to the respective pixel sensor groups;
an interpolation section for interpolating each of the extracted data to generate interpolated data; and
a calculation section for obtaining the phase information from each of the interpolated data.

2. The measurement apparatus according to claim 1 , wherein the calculation section obtains the phase information on the basis of transport of intensity equation.

3. The measurement apparatus according to claim 1 , wherein the calculation section obtains the phase information on the basis of Fourier transformation.

4. A measurement apparatus comprising:
a plurality of pixel sensor groups for generating a difference from one pixel sensor group to another in optical distance of object light traveling from a measurement object, wherein pixel sensors of the pixel sensor groups that differ from each other in the optical distance are alternately arrayed in the lengthwise and crosswise directions,
an image sensor for recording, with a single-shot exposure, the object light that has passed through or been reflected from the plurality of pixel sensor groups to obtain intensity information of the measurement object, the image sensor corresponding to each pixel sensor of the pixel sensor groups; and
a phase information computing unit for computing, on the basis of the intensity information, phase information of the measurement object,
wherein the phase information computing unit comprises a calculation section for obtaining the phase information from a combination of different and adjacent pixel values included in the intensity information, the different and adjacent pixel values corresponding to the respective pixel sensor groups.

5. A measurement apparatus comprising,
a plurality of pixel sensor groups for generating a difference from one pixel sensor group to another in optical distance of object light traveling from a measurement object;
an image sensor for recording, with a single-shot exposure, the object light that has passed through or been reflected from the plurality of pixel sensor groups to obtain intensity information of the measurement object;
a phase information computing unit for computing, on the basis of the intensity information, phase information of the measurement object; and
between the measurement object and an image plane of the image sensor:
a polarizer for converting object light from the measurement object into linearly polarized light;
a wave plate having a refractive index that varies with an vibration direction of light incident thereon, the wave plate being for separating light that has been transmitted through the polarizer into linearly polarized light components that are perpendicular to each other; and
a micro-polarizer array including first regions that allow only a slow axis component of the linearly polarized light components to be transmitted therethrough and second regions that allow only a fast axis component of the linearly polarized light components to be transmitted therethrough,
wherein the plurality of pixel sensor groups consist of a first pixel sensor group and a second pixel sensor group; and the first regions overlap with pixel sensors constituting the first pixel sensor group; and the second regions overlap with pixel sensors constituting the second pixel sensor group.

6. A measurement apparatus, comprising
a plurality of pixel sensor groups for generating a difference from one pixel sensor group to another in optical distance of object light traveling from a measurement object;
an image sensor for recording, with a single-shot exposure, the object light that has passed through or been reflected from the plurality of pixel sensor groups to obtain intensity information of the measurement object; and
a phase information computing unit for computing, on the basis of the intensity information, phase information of the measurement object;
wherein the object light is linearly polarized light, the apparatus comprising, between the measurement object and an image plane of the image sensor, a wave plate having a refractive index that varies with an vibration direction of light incident thereon, the wave plate being for separating the linearly polarized light into linearly polarized light components that are perpendicular to each other; and
a micro-polarizer array including first regions that allow only a slow axis component of the linearly polarized light components to be transmitted therethrough and second regions that allow only a fast axis component of the linearly polarized light components to be transmitted therethrough,
wherein the plurality of pixel sensor groups consist of a first pixel sensor group and a second pixel sensor group; and the first regions overlap with pixel sensors constituting the first pixel sensor group; and the second regions overlap with pixel sensors constituting the second pixel sensor group.

7. A measurement apparatus comprising,
a plurality of pixel sensor groups for generating a difference from one pixel sensor group to another in optical distance of object light traveling from a measurement object;
an image sensor for recording, with a single-shot exposure, the object light that has passed through or been reflected from the plurality of pixel sensor groups to obtain intensity information of the measurement object;
a phase information computing unit for computing, on the basis of the intensity information, phase information of the measurement object; and
between the measurement object and an image plane of the image sensor:
a polarizer for converting object light from the measurement object into linearly polarized light; and
a wave plate array including first regions and second regions,
the first regions having a refractive index that varies with an vibration direction of light incident thereon, such that a linearly polarized light component in a first vibration direction experiences the highest refractive index,
the second regions having a refractive index that varies with an vibration direction of light incident thereon, such that a linearly polarized light component in a second vibration direction, which is different from the first vibration direction, experiences the highest refractive index,

wherein the plurality of pixel sensor groups consist of a first pixel sensor group and a second pixel sensor group; and the first regions overlap with pixel sensors constituting the first pixel sensor group; and the second regions overlap with pixel sensors constituting the second pixel sensor group.

8. A measurement apparatus, comprising
a plurality of pixel sensor groups for generating a difference from one pixel sensor group to another in optical distance of object light traveling from a measurement object;
an image sensor for recording, with a single-shot exposure, the object light that has passed through or been reflected

Assignees

• Nat Univ Corp Kyoto Inst Technology

Inventors

• Awatsuji Yasuhiro
• Xia Peng

Classifications

• G02B21/14

  affording illumination for phase-contrast observation · CPC title

• G01J1/0429 Primary

  using polarisation elements · CPC title

• G02B21/0016

  Technical microscopes, e.g. for inspection or measuring in industrial production processes · CPC title

• G01B11/24 Primary

  for measuring contours or curvatures · CPC title

• G01J1/44

  Electric circuits {(for command of an exposure part G03B7/02)} · CPC title