Imaging spectrometer and camera with rotating prism

Patent metadata

Field	Value
Publication number	US-12487122-B2
Application number	US-202318401344-A
Country	US
Kind code	B2
Filing date	Dec 30, 2023
Priority date	Dec 30, 2023
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

A hyperspectral imaging system 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 portion of the light to pass. 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 of the second image plane, and a spatial image of the slit width is imaged along a second axis. A sensor at the second image plane detects the spectrally dispersed light. A rotating prism is located distally to the slit and rotates, thereby rotating the image at the first imaging plane so that the portion of the image transmitted into the spectrometer varies.

First claim

The invention claimed is:

1 . A hyperspectral imaging system comprising:
an optical channel arranged to focus incident light from a scene 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 rotating prism located distally to the slit and adapted to rotate with respect to a central optical axis of the optical channel and by its rotation to rotate the image that is focused onto the first imaging plane so that the portion of the image formed at the slit, and thereby transmitted into the spectrometer, varies as the prism rotates.

2 . The hyperspectral imaging system according to claim 1 further comprising an image processor communicatively coupled to the focal plane array sensor and operable to time sequentially acquire multiple frames each corresponding to a different radial portion of the focused incident light, and accumulate the multiple frames until the complete image from the first image plane has been scanned.

3 . The hyperspectral imaging system according to claim 2 wherein the image processor is further 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.

4 . The hyperspectral imaging system according to claim 3 wherein information from the hyperspectral or multispectral data cube is used to create an image for display to a user which conveys information not easily discernible by white light imaging.

5 . The hyperspectral imaging system according to claim 1 further comprising a collimating lens group arranged between the slit and the dispersive element.

6 . The hyperspectral imaging system according to claim 1 wherein the dispersive element comprises a diffraction grating.

7 . The hyperspectral imaging system according to claim 1 wherein the dispersive element comprises a prism.

8 . The hyperspectral imaging system according to claim 1 wherein the rotating prism is a selected from a group consisting of a Pechan prism, a reversion prism, and a dove prism.

9 . The hyperspectral imaging system according to claim 1 wherein the rotating prism is located between a most proximal lens of the optical channel and the slit.

10 . The hyperspectral imaging system according to claim 1 further comprising a beamsplitter distal to the slit and arranged to redirect a portion of the incident light such that it is imaged onto a third image plane without passing through the slit.

11 . The hyperspectral imaging system according to claim 10 comprising a sensor in the third image plane which collects the redirected portion of incident light and creates a white light image at a frame rate suitable for live video.

12 . The hyperspectral imaging system according to claim 11 comprising an image processor configured to maintain a non-rotating white light image when displayed on an image display.

13 . The hyperspectral imaging system according to claim 10 wherein the rotating prism is located between the beamsplitter and the slit.

14 . The hyperspectral imaging system according to claim 10 wherein the rotating prism is located distal to the beamsplitter.

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 a 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 rotating prism located distally to the slit and adapted to rotate with respect to a central optical axis of the optical channel and by its rotation to rotate the image that is focused onto the first imaging plane so that the portion of the image formed at the slit, and thereby transmitted into the spectrometer, varies as the prism rotates.

16 . The imaging spectrometer camera according to claim 15 wherein the imaging spectrometer camera is adapted to be communicatively coupled to an image processor sensor and operable under control of the image processor to time sequentially acquire multiple frames each corresponding to a different radial portion of the focused incident light, and accumulate the multiple frames until the complete image from the first image plane has been scanned.

17 . The imaging spectrometer camera according to claim 15 wherein the dispersive element comprises a diffraction grating.

18 . The imaging spectrometer camera according to claim 15 wherein the dispersive element comprises a prism.

19 . The imaging spectrometer camera according to claim 15 wherein the rotating prism selected from a group consisting of a Pechan prism, a reversion prism, and a dove prism.

20 . The imaging spectrometer camera according to claim 15 wherein the first rotating prism is located between a most proximal lens of the optical channel and the slit.

21 . The imaging spectrometer camera according to claim 15 further comprising a beamsplitter distal to the slit and arranged to redirect a portion of the incident light such that it is imaged onto a third image plane without passing through the slit.

Assignees

• Storz Karl Imaging Inc

Inventors

• Hale Eric L
• Duckett Iii George E

Classifications

• G01J3/36 Primary

  Investigating two or more bands of a spectrum by separate detectors · CPC title

• G01J2003/1208

  Prism and grating · CPC title

• G01J2003/2813

  2D-array · CPC title

• G01J3/18

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

• G01J3/0248

  using a sighting port, e.g. camera or human eye · CPC title