Hyperspectral imaging device

Patent metadata

Field	Value
Publication number	US-12313465-B2
Application number	US-202117996859-A
Country	US
Kind code	B2
Filing date	Apr 21, 2021
Priority date	Apr 22, 2020
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A spectral imaging device comprises:
an optical modifier system (SYS 1 ) to form axial light beams (LB 2 ) from received light beams (LB 1 ), the axial light beams (LB 2 ) being parallel with an optical axis (AX 1 ) of the imaging device ( 500 ), a Fabry-Perot interferometer (FPI) to provide filtered axial light beams (LB 3 ) by filtering light of the axial light beams (LB 2 ), an image sensor (SEN 1 ), and an array (ARR 1 ) of lenses (LNS 0,0 , LNS 0,1 ) to form a plurality of sub-images (S 0,0 , S 0,1 ) on the image sensor (SEN 1 ) by focusing light of the filtered light beams (LB 3 ).

First claim

The invention claimed is:

1. An imaging device, comprising:
a modifier system to form axial light beams from received light beams, the axial light beams being parallel with an optical axis (AX 1 ) of the imaging device,
a Fabry-Perot interferometer to provide filtered axial light beams by filtering light of the axial light beams,
an image sensor, and
an array of lenses to form a plurality of sub-images on the image sensor by focusing light of the filtered light beams,

wherein the modifier system and the Fabry-Perot interferometer are arranged to form an axial filtered light beam from a received light beam such that the axial filtered light beam overlaps a first lens of the array and a second adjacent lens of the array, wherein the first lens focuses light of the axial filtered light beam to the image sensor so as to form a first image point of a first sub-image, wherein the second lens focuses light of the axial filtered light beam to the image sensor so as to form a second image point of a second sub-image, wherein the first image point and the second image point are spatially separate, wherein the first image point and the second image point are images of the same object point.

2. The device of claim 1 , wherein the modifier system is a telecentric lens system.

3. The device of claim 1 , wherein the modifier system is an afocal system which comprises combination of a lens and a limiter unit, wherein the focal length of the lens is negative, and wherein the limiter unit (NAL 2 ) is arranged to prevent propagation of light rays which are outside a predetermined acceptance cone.

4. The device of claim 3 , wherein the limiter unit comprises a fiber optic array.

5. The device according to claim 1 , comprising an optical modulator and a filter array, wherein the filter array comprises a plurality of first filter regions, wherein transmittance of the modulator is modulable so as to alternately enable and disable transmission of light through the first filter regions of the filter array.

6. The device according to claim 1 comprising one or more data processors to receive image data of the sub-images captured by the image sensor, and to stitch image data of the captured sub-images.

7. A method, comprising:
receiving light beams from object points of an object,
forming axial light beams from the received light beams by using an optical modifier system, the axial light beams being parallel with an optical axis of the imaging device,
providing filtered axial light beams from the axial light beams by using a Fabry-Perot interferometer as an optical filter,
using an array of lenses to form a plurality of sub-images on an image sensor by focusing light of the filtered light beams,

wherein the optical modifier system and the Fabry-Perot interferometer are arranged to form an axial filtered light beam from a received light beam such that the axial filtered light beam overlaps a first lens of the array and a second adjacent lens of the array, wherein the first lens focuses light of the axial filtered light beam to the image sensor so as to form a first image point of a first sub-image, wherein the second lens focuses light of the axial filtered light beam to the image sensor so as to form a second image point of a second sub-image, wherein the first image point and the second image point are spatially separate, wherein the first image point and the second image point are images of the same object point.

8. The method of claim 7 comprising forming a spectral image of the object by stitching the sub-images together.

9. The method of claim 7 , wherein the modifier system is a telecentric lens system.

10. The method of claim 7 , wherein the modifier system comprises a negative lens and a limiter unit, wherein the limiter unit prevents propagation of light rays which are outside a predetermined acceptance cone.

11. The method according to claim 7 , comprising:
setting a transmittance peak of the Fabry-Perot interferometer to a first wavelength,
capturing a plurality of first sub-images when the transmittance peak of the Fabry-Perot interferometer is at said first wavelength,
setting a transmittance peak of the Fabry-Perot interferometer to a second wavelength,
capturing a plurality of second sub-images (S when the transmittance peak of the Fabry-Perot interferometer is at said second wavelength,
forming a first spectral image of the object by stitching the first sub-images,
forming a second spectral image of the object by stitching the second sub-images, and
forming a multi-spectral image of the object by combining the first spectral image with the second spectral image.

Assignees

• Teknologian Tutkimuskeskus Vtt Oy

Inventors

• Ojala Kai
• Saari Heikki

Classifications

• G02B13/22

  Telecentric objectives or lens systems · CPC title

• G01J2003/283

  computer-interfaced · CPC title

• G01J3/2823 Primary

  Imaging spectrometer · CPC title

• G01J3/0218

  using optical fibers · CPC title

• G01J3/0208 Primary

  using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction · CPC title