Multi-spectrum imaging

• US 10,171,758 B2
• Filed: 04/14/2016
• Issued: 01/01/2019
• Est. Priority Date: 04/14/2015
• Status: Active Grant

• Current Assignee: Digital Direct IR Inc.
• Original Assignee: Digital Direct IR Inc.
• Inventors: Kaufman, Peter N.
• Primary Examiner(s): Huang, Frank F
• Application Number:
  US15/099,558
• Publication Number:
  US 20170026589A1
• Time in Patent Office: 992 Days
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/021 using plane or convex mirrors, parallel phase plates, or particular reflectors
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 5/44 using change of resonant frequency, e.g. of piezoelectric crystals
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths

Abstract

Multi-spectrum imaging systems and methods are provided to imaging in multiple spectrums, e.g., thermal IR (infrared) at 4 μm and 10 μm wavelengths, near-IR, and visible light, all on a same optical centerline. For example, an imaging system includes a first imager and a second imager. The first imager includes an array of thermal IR detectors, wherein the first imager is configured to receive incident photonic radiation and generate a thermal IR image, wherein each thermal IR detector comprises a photon absorber member that is configured to absorb thermal IR photonic radiation from the incident photonic radiation, and reflect remaining photonic radiation in the incident photonic radiation along an optical path of the imaging system. The second imager is disposed in said optical path of the imaging system, wherein the second imager is configured to receive the remaining photonic radiation reflected from the first imager and generate a second image.

Claims

1. An imaging system, comprising:

a first imager comprising an array of thermal infrared (IR) detectors, wherein the first imager is configured to receive incident photonic radiation and generate a thermal IR image, wherein each thermal IR detector comprises a photon absorber member that is configured to absorb thermal IR photonic radiation from the incident photonic radiation and convert the absorbed thermal IR photonic radiation to thermal energy, and reflect remaining photonic radiation in the incident photonic radiation along an optical path of the imaging system, wherein the photon absorber members within the array of thermal IR detectors collectively form a reflecting surface; and

a second imager disposed in said optical path of the imaging system, wherein the second imager is configured to receive the remaining photonic radiation reflected from the reflective surface collectively formed by the photon absorber members within the array of thermal IR detectors of the first imager and generate a second image;

wherein the first imager comprises;

a substrate, wherein each thermal IR detector is formed on the substrate; and

wherein each thermal IR detector further comprises;

a resonator member configured to generate an output signal having a frequency or period of oscillation; and

wherein the photon absorber member comprises an unpowered detector member that is configured for photon exposure, wherein the unpowered detector member comprises a material having a thermal coefficient of expansion that causes the unpowered detector member to distort due to said photon exposure, wherein the unpowered detector member is further configured to apply a mechanical force to the resonator member due to said distortion of the unpowered detector member, and cause a change in the frequency or period of oscillation of the output signal generated by the resonator member due to said mechanical force applied to the resonator member; and

a thermal insulating member configured to thermally insulate the resonator member from the unpowered detector member; and

digital circuitry configured to (i) determine the frequency or period of oscillation of the output signal generated by the resonator member as a result of the mechanical force applied to the resonator member by the unpowered detector member, and to (ii) determine an amount of said photon exposure based on the determined frequency or period of oscillation of the output signal generated by the resonator member.

2. The imaging system of claim 1, wherein the first imager generates a thermal IR image from thermal IR photonic radiation with a wavelength of about 4 microns or 10 microns.

3. The imaging system of claim 1, wherein the second imager comprise a visible light imager.

4. The imaging system of claim 1, wherein the second imager comprises a near-IR imager.

5. The imaging system of claim 1, further comprising an off-axis parabolic mirror configured to focus the incident photonic radiation received by the first imager.

6. The imaging system of claim 5, further comprising a planar mirror disposed in said optical path between the off-axis parabolic mirror and the first imager.

7. The imaging system of claim 5, further comprising a lens disposed in said optical path between the first imager and the second imager, wherein the lens is configured to focus the remaining photonic radiation reflected from the first imager.

8. The imaging system of claim 1, wherein each thermal IR detector comprises a wedge structure that maintains the thermal IR detector at an angle with regard to a plane of the substrate.