Imaging spectrometer and camera with sliding lens group

Patent metadata

Field	Value
Publication number	US-2025216258-A1
Application number	US-202318401342-A
Country	US
Kind code	A1
Filing date	Dec 30, 2023
Priority date	Dec 30, 2023
Publication date	Jul 3, 2025
Grant date	—

Abstract

A hyperspectral imaging device includes an optical channel arranged to focus light at a first image plane. A spectrometer includes a slit formed at the first image plane to allow a slit-shaped portion of the light pass through. A dispersive element receives light from the slit and spectrally disperses it along a direction perpendicular to a width of the slit. A focusing lens focuses the spectrally dispersed light at a second image plane such that the spectral dispersion is imaged along a first axis thereof, and a spatial image of the slit width is imaged along a second axis for detection by a sensor. A sliding lens group between the optical channel and the first image plane moves to direct the incident light, scanning the entire image over the slit such that multiple frames acquired by the sensor each correspond to a horizontal line of the image.

First claim

1 . A hyperspectral imaging device comprising:
an optical channel arranged to focus incident light at a first image plane to form an image at the first image plane; a spectrometer comprising:
a slit formed in an optical stop at the first image plane to allow a slit-shaped portion of the incident light pass through;
a dispersive element constructed and arranged to receive incident light from the slit and spectrally disperse it along a direction perpendicular to a width of the slit;
a focusing lens arranged to focus the spectrally dispersed light at a second image plane such that the spectral dispersion is imaged along a first axis of the second image plane, and a spatial image of the slit width is imaged along a second axis of the image plane; and
a focal plane array sensor at the second image plane operable to detect the spectrally dispersed light; and
a sliding lens group arranged between the optical channel and the first image plane and adapted to move linearly in a direction perpendicular to an optical axis of the imaging channel and perpendicular to a length of the slit, to direct the incident light in a varying offset position thereby scanning the entire image over the slit such that multiple frames acquired time sequentially by the focal plane array sensor each correspond to a horizontal line of the image.

2 . The device according to claim 1 further comprising an image processor communicatively coupled to the focal plane array sensor and operable to process the multiple frames into a hyperspectral or multispectral data cube comprising data sufficient for a 2D image of the scene at a multiplicity of spectral bands.

3 . The device according to claim 2 wherein the image processor is further operable to create an image based on the hyperspectral or multispectral data cube for display to the user which conveys information not easily discernible by white light imaging.

4 . The device according to claim 1 wherein the imaging objective is telecentric.

5 . The device according to claim 1 wherein the sliding lens group is afocal.

6 . The device according to claim 1 wherein a distal lens surface of the sliding lens group is convex and a proximal lens surface is concave.

7 . The device according to claim 6 wherein the sliding lens group comprises a cemented doublet with an overall meniscus shape.

8 . The device according to claim 1 further comprising a collimating lens group optically arranged between the slit and the dispersive element.

9 . The device according to claim 1 wherein the dispersive element comprises a diffraction grating.

10 . The device according to claim 9 , wherein the diffraction grating is a blazed diffraction grating.

11 . The device according to claim 1 wherein the dispersive element comprises a prism.

12 . The device according to claim 1 further comprising a beamsplitter upstream from the slit adapted to redirect a portion of incident light from the scene such that it is imaged onto a third image plane without passing through the slit.

13 . The device according to claim 12 further comprising a sensor in the third image plane which collects the redirected portion of light and creates a white light image at a frame rate suitable for live video.

14 . The device according to claim 12 wherein the sliding lens group is between the beamsplitter and the slit.

15 . An imaging spectrometer camera adapted to receive incident light from a medical scope, comprising:
an optical channel receiving and focusing incident light at a first image plane to form an image at the first image plane; an imaging spectrometer positioned downstream from the optical channel and comprising:
a slit formed in an optical stop at the first image plane to allow a slit-shaped portion of the incident light pass through;
a dispersive element constructed and arranged to receive incident light from the slit and spectrally disperse it along a direction perpendicular to a width of the slit;
a focusing lens arranged to focus the spectrally dispersed light at a second image plane such that the spectral dispersion is imaged along a first axis of the second image plane, and a spatial image of the slit width is imaged along a second axis of the image plane; and
a focal plane array sensor at the second image plane operable to detect the spectrally dispersed light; and
a scanning system comprising a sliding lens group arranged in the optical channel upstream of the first image plane and adapted to move linearly in a direction perpendicular to an optical axis of the imaging channel and perpendicularly to length of the slit, to direct the incident light in a varying offset position thereby scanning the entire image over the slit such that multiple frames acquired time sequentially by the focal plane array sensor each correspond to a horizontal line of the image.

16 . The imaging spectrometer camera according to claim 15 wherein the imaging objective is telecentric.

17 . The imaging spectrometer camera according to claim 15 wherein the sliding lens group is afocal.

18 . The imaging spectrometer camera according to claim 15 wherein a distal lens surface of the sliding lens group is convex and a proximal lens surface is concave.

19 . The imaging spectrometer camera according to claim 15 wherein the sliding lens group comprises a cemented doublet with an overall meniscus shape.

Assignees

• Storz Karl Imaging Inc

Inventors

• Duckett Iii George E

Classifications

• G01J2003/064

  Use of other elements for scan, e.g. mirror, fixed grating · CPC title

• G01J3/04

  Slit arrangements {slit adjustment} · CPC title

• G01J3/0208

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

• G01J3/18

  using diffraction elements, e.g. grating (gratings per se G02B) · CPC title

• G01J3/14

  using refracting elements, e.g. prisms (G01J3/18, G01J3/26 take precedence {prisms per se G02B5/04}) · CPC title