Inspecting apparatus based on hyperspectral imaging

Patent metadata

Field	Value
Publication number	US-11037283-B2
Application number	US-201916444719-A
Country	US
Kind code	B2
Filing date	Jun 18, 2019
Priority date	Dec 11, 2018
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

Provided is a hyperspectral imaging (HSI)-based inspection apparatus capable of quickly and stably performing two-dimensional (2D) HSI for an inspection object, and accordingly, capable of quickly and accurately inspecting the inspection object. The HSI-based inspection apparatus includes: a stage on which an inspection object is arranged; an optical system configured to allow light to be incident on the inspection object and emit the light reflected from the inspection object; a scan mirror configured to reflect the emitted light from the optical system while rotating; and a hyperspectral camera configured to obtain an image having a wavelength direction and a line direction as two axes for light reflected from the scan mirror, wherein, by using the rotation of the scan mirror, the hyperspectral camera is configured to perform the 2D HSI for the inspection object.

First claim

What is claimed is:

1. A hyperspectral imaging (HSI)-based inspection apparatus, the apparatus comprising:
a stage on which an inspection object is arranged;
an optical system configured to allow an input light to be incident on the inspection object and to emit reflected light reflected from the inspection object;
a scan mirror configured to rotate and to reflect light emitted from the optical system while rotating; and
a hyperspectral camera configured to obtain an image having a wavelength direction and a line direction as two axes for light reflected from the scan mirror,
wherein, by using rotation of the scan mirror, the hyperspectral camera is configured to perform a two-dimensional (2D) HSI for a sample area of the inspection object,
wherein the optical system comprises an illumination optical system configured to input the input light from a light source to the inspection object, and an imaging optical system configured to output the reflected light reflected from the inspection object to the scan mirror,
wherein the illumination optical system comprises a condensing lens and at least one mirror,
wherein the imaging optical system comprises a tube lens, a splitter, and an objective lens,
wherein the input light from the illumination optical system is input to the inspection object via the splitter and the objective lens, and
wherein the reflected light reflected from the inspection object is input to the scan mirror via the objective lens, the splitter, and the tube lens.

2. The apparatus of claim 1 ,
wherein the scan mirror is controlled at an angular displacement having a step shape based on a settling response time at a level of micro-seconds, and
wherein the 2D HSI for a first sample area of the inspection object is performed by the hyperspectral camera through the rotation of the scan mirror.

3. The apparatus of claim 2 ,
wherein the sample area is moved to a second sample area of the inspection object by a movement of the stage, and
wherein the 2D HSI for the second sample area of the inspection object is performed by the hyperspectral camera through the rotation of the scan mirror.

4. The apparatus of claim 1 , wherein the scan mirror comprises a Galvano mirror.

5. The apparatus of claim 1 ,
wherein the hyperspectral camera comprises a slit plate, a first concave mirror, a second concave mirror, a spectroscopic element, and an image sensor,
wherein the light reflected from the scan mirror is converted to light of a line shape by the slit plate and is incident on the spectroscopic element through reflection of the first concave mirror, and
wherein the light incident on the spectroscopic element is dispersed by the spectroscopic element and is input to the image sensor through reflection of the second concave mirror.

6. The apparatus of claim 1 ,
wherein the hyperspectral camera comprises a slit plate, first through third concave mirrors, a dichroic mirror, a first spectroscopic element, a second spectroscopic element, a first image sensor, and a second image sensor,
wherein the light reflected from the scan mirror is converted to light of a line shape by the slit plate and is incident on the dichroic mirror to be divided into two light beams,
wherein a first beam of the two light beams is dispersed in a first spectral element and is input to the first image sensor via the second concave mirror, and
wherein a second light beam of the two light beams is dispersed in a second spectral element and is input to the second image sensor via the third concave mirror.

7. The apparatus of claim 6 , wherein the dichroic mirror is configured to transmit or reflect incident light incident on the dichroic mirror with respect to each wavelength band, and to separate the incident light into two light beams.

8. The apparatus of claim 1 , further comprising:
a first polarizing plate in the illumination optical system, or
a first polarizing plate in the illumination optical system and a second polarizing plate in the imaging optical system.

9. A hyperspectral imaging (HSI)-based inspection apparatus, the apparatus comprising:
a light source;
a stage on which an inspection object is arranged;
an illumination optical system configured to input light from the light source to the inspection object;
an imaging optical system configured to output light reflected from the inspection object to a scan mirror;
the scan mirror configured to rotate and to reflect light output from the imaging optical system while rotating;
a hyperspectral camera configured to obtain an image having a wavelength direction and a line direction as two axes for light reflected from the scan mirror; and
a first polarizing plate in the illumination optical system or a first polarizing plate in the illumination optical system and a second polarizing plate in the imaging optical system,
wherein, by using rotation of the scan mirror, the hyperspectral camera is configured to perform a two-dimensional (2D) HSI for the inspection object.

10. The apparatus of claim 9 ,
wherein the scan mirror is controlled at an angular displacement having a step shape based on a settling response time at a level of micro-seconds, and
wherein the 2D HSI for at least two sample areas of the inspection object is performed by the hyperspectral camera through the rotation of the scan mirror and a movement of the stage.

11. The apparatus of claim 9 , further comprising:
a relay lens arranged at least one portion between the scan mirror and the imaging optical system and between the scan mirror and the hyperspectral camera.

12. The apparatus of claim 9 ,
wherein the hyperspectral camera comprises a slit plate, a first concave mirror, a second concave mirror, a spectroscopic element, and an image sensor,
wherein light reflected from the scan mirror is converted to light of a line shape by the slit plate and is incident on the spectroscopic element via reflection of the first concave mirror, and
wherein the light incident on the spectroscopic element is dispersed by the spectroscopic element and is input to the image sensor through reflection of the second concave mirror.

13. The apparatus of claim 9 ,
wherein the hyperspectral camera comprises a slit plate, first through third concave mirrors, a dichroic mirror, a first spectroscopic element, a second spectroscopic element, a first image sensor, and a second image sensor,
wherein light reflected from the scan mirror is converted to light of a line shape by the slit plate and is incident on the dichroic mirror to be divided into two light beams,
wherein a first beam of the two light beams is dispersed in a first spectral element and is input to the first image sensor via the second concave mirror, and
wherein a second light beam of the two light beams is dispersed in a second spectral element and is input to the second image sensor via the third concave mirror.

14. A hyperspectral imaging (HSI)-based inspection apparatus, the apparatus comprising:
an optical system configured to allow input light to be incident on an inspection object and to emit light reflected from the inspection object;
a scan mirror configured to rotate and to reflect light emitted from the optical system while rotating; and
a hyperspectral camera configured to obtain an image having a wavelength direction and a line direction as two axes for light reflected from the scan mirror,
wherein the hyperspectral camera comprises:
a slit plate, a first concave mirror, a second concave mirror, a first spectroscopic element, and a first image sensor, or
the slit plate, the first concave mirror, the second concave mirror, a thir

Assignees

• Samsung Electronics Co Ltd

Inventors

• Jang Sung-Ho
• Hidaka Yasuhiro
• Park Young-Kyu
• Park Ye-Eun
• Yang Yu-Sin

Classifications

• G01J3/2823 Primary

  Imaging spectrometer · CPC title

• H04N23/10

  for generating image signals from different wavelengths · CPC title

• G02B26/105

  with one or more pivoting mirrors or galvano-mirrors (G02B26/101 takes precedence) · CPC title

• G01N2201/068

  Optics, miscellaneous · CPC title

• G01N21/8806 Primary

  Specially adapted optical and illumination features · CPC title