Compact light sensor

Patent metadata

Field	Value
Publication number	US-11159750-B2
Application number	US-202016844908-A
Country	US
Kind code	B2
Filing date	Apr 9, 2020
Priority date	Mar 21, 2014
Publication date	Oct 26, 2021
Grant date	Oct 26, 2021

Abstract

Provided are methods and systems for concurrent imaging at multiple wavelengths. In one aspect, a hyperspectral/multispectral imaging device includes a lens configured to receive light backscattered by an object, a plurality of photo-sensors, a plurality of bandpass filters covering respective photo-sensors, where each bandpass filter is configured to allow a different respective spectral band to pass through the filter, and a plurality of beam splitters in optical communication with the lens and the photo-sensors, where each beam splitter splits the light received by the lens into a plurality of optical paths, each path configured to direct light to a corresponding photo-sensor through the bandpass filter corresponding to the respective photo-sensor.

First claim

What is claimed is:

1. An imaging device, comprising:
a lens disposed along an optical axis and configured to receive light, wherein the lens has a fixed focal distance;
one or more photo-sensors;
an optical path assembly in optical communication with the lens and the one or more photo-sensors; and
at least two projectors, wherein the at least two projectors are configured to project a composite image onto a surface positioned in front of the lens, wherein:
when the surface is located at the fixed focal distance from the lens along the optical axis, the composite image forms a first pattern of light onto the surface, and
when the surface is located at a distance other than the fixed focal distance from the lens along the optical axis, the composite image forms a pattern of light that is different than the first pattern of light onto the surface.

2. The imaging device of claim 1 , wherein each of the at least two projectors are configured to project a same respective individual pattern of light such that:
when the surface is located at the fixed focal distance from the lens along the optical axis, the respective individual pattern of light projected from each of the at least two projectors converge on the surface, and
when the surface is located at a distance other than the fixed focal distance from the lens along the optical axis, the respective individual pattern of light projected from each of the at least two projectors do not converge on the surface.

3. The imaging device of claim 2 , wherein the each of the at least two projectors are configured to project a same respective circular pattern of light.

4. The imaging device of claim 1 , wherein the each of the at least two projectors are configured to project different respective individual pattern of light such that:
when the surface is located at the fixed focal distance from the lens along the optical axis, the respective individual pattern of light projected from each of the at least two projectors form a first composite pattern of light on the surface, and
when the surface is located at a distance other than the fixed focal distance from the lens along the optical axis, the respective individual pattern of light projected from each of the at least two projectors do not form the first composite pattern of light on the surface.

5. The imaging device of claim 4 , wherein the first composite pattern of light comprises a closed framing guide.

6. The imaging device of claim 5 , wherein the imaging device is configured such that the closed framing guide indicates all or substantially all of the area of the surface that would be imaged by the imaging device when the surface is located at the fixed focal distance from the lens along the optical axis.

7. The imaging device of claim 1 , wherein the first pattern of light is a reticle.

8. The imaging device of claim 1 , wherein the first pattern of light is a cross-hair.

9. The imaging device of claim 1 , wherein:
the one or more photo-sensors comprise a plurality of photo-sensors;
the imaging device further comprises an optical path assembly comprising a plurality of beam splitters in optical communication with the lens and the plurality of photo-sensors;
the imaging device further comprises a plurality of multi-bandpass filters, wherein each respective multi-bandpass filter in the plurality of multi-bandpass filters covers a corresponding photo-sensor in the plurality of photo-sensors thereby selectively allowing a different corresponding spectral band of light, from the light received by the lens and split by the plurality of beam splitters, to pass through to the corresponding photo-sensor;
each respective beam splitter in the plurality of beam splitters is configured to split the light received by the lens into at least two optical paths;
a first beam splitter in the plurality of beam splitters is in direct optical communication with the lens and a second beam splitter in the plurality of beam splitters is in indirect optical communication with the lens through the first beam splitter, and
the plurality of beam splitters collectively split light received by the lens into a plurality of optical paths, wherein each respective optical path in the plurality of optical paths is configured to direct light to a corresponding photo-sensor in the plurality of photo-sensors through the respective multi-bandpass filter covering the corresponding photo-sensor.

10. The imaging device of claim 9 , wherein the plurality of multi-bandpass filters are dual bandpass filters.

11. The imaging device of claim 9 , further comprising a first light source and a second light source, wherein the first light source and the second light source are configured to shine light so that a portion of the light is backscattered by the surface and received by the lens.

12. The imaging device of claim 11 , wherein:
the first light source emits light that is substantially limited to a first spectral range, and
the second light source emits light that is substantially limited to a second spectral range.

13. The imaging device of claim 12 , wherein:
the first light source is a first multi-spectral light source covered by a first bandpass filter, wherein the first bandpass filter substantially blocks all light emitted by the first light source other than the first spectral range, and
the second light source is a second multi-spectral light source covered by a second bandpass filter, wherein the second bandpass filter substantially blocks all light emitted by the second light source other than the second spectral range.

14. The imaging device of claim 12 , wherein:
each respective multi-bandpass filter in the plurality of multi-bandpass filters is configured to selectively allow light corresponding to either of two discrete spectral bands to pass through to the corresponding photo-sensor;
a first of the two discrete spectral bands corresponds to a first spectral band that is represented in the first spectral range and not in the second spectral range; and
a second of the two discrete spectral bands corresponds to a second spectral band that is represented in the second spectral range and not in the first spectral range.

15. The imaging device of claim 12 , wherein:
the first spectral range comprises 520 nm, 540 nm, 560 nm and 640 nm wavelength light and does not include 580 nm, 590 nm, 610 nm and 620 nm wavelength light, and
the second spectral range comprises 580 nm, 590 nm, 610 nm and 620 nm wavelength light and does not include 520 nm, 540 nm, 560 nm and 640 nm wavelength light.

16. The imaging device of claim 15 , wherein the imaging device is portable and electrically independent of a power grid during the illuminating (A) and the illuminating (D), and wherein the illuminating (A) occurs for less than 300 milliseconds and the illuminating (D) occurs for less than 300 milliseconds.

17. The imaging device of claim 12 , further comprising a controller configured to capture a plurality of images from the plurality of photo-sensors by performing a method including:
(A) illuminating the object a first time using the first light source;
(B) capturing a first set of images with the plurality of photo-sensors during the illuminating (A), wherein the first set of images includes, for each respective photo-sensor in the plurality of photo-sensors, an image corresponding to a first spectral band transmitted by the corresponding multi-bandpass filter, wherein the light falling within the first spectral range includes light falling within the first spectral band of each multi-bandpass filter in

Assignees

• Hypermed Imaging Inc

Inventors

• Darty Mark Anthony
• Tilleman Michael
• Meenen Peter
• Yudovsky Dmitry

Classifications

• G01J3/0294 Primary

  Multi-channel spectroscopy · CPC title

• G01J3/0291 Primary

  Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements · CPC title

• H04N23/56

  provided with illuminating means · CPC title

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N23/74

  by influencing the scene brightness using illuminating means · CPC title