US 12,105,020 B2Granted

Gas lens filter systems and methods

AssigneeFLIR Systems, Inc.

InventorsJonas Sandsten, Sten Lindau

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Abstract

Provided are systems and methods to filter infrared spectrum radiation that can be integrated with a compact optical system for an infrared imaging system. The optical system includes an objective lens element configured to receive and transmit infrared (IR) radiation from a scene, where the IR radiation from the scene includes a particular range of wavelengths corresponding to an absorption spectrum or a transmission spectrum of a gas. The optical system also includes a spectral lens element configured to receive the IR radiation transmitted through the objective lens element, where the spectral lens element comprises a first interference filter disposed on a first surface of the spectral lens element. The interference filter is configured to filter the IR radiation transmitted through the objective lens element to a narrower wavelength band that includes the particular range of wavelengths.

Claims20

Dependent claims

A device, comprising:

a three-lens optical system comprising:
an objective lens element configured to receive and transmit infrared (IR) radiation from a scene, wherein the IR radiation from the scene includes a particular range of wavelengths corresponding to an absorption/emission spectrum or a transmission spectrum of a gas;
a subjective lens element;
and
a spectral lens element disposed between the objective lens element and the subjective lens element, wherein the spectral lens element is configured to receive the IR radiation transmitted through the objective lens element, wherein the spectral lens element comprises:
a first interference filter disposed on a first surface of the spectral lens element that is configured to filter the IR radiation transmitted through the objective lens element to a narrower wavelength band that includes the particular range of wavelengths, and
a second interference filter on a second surface opposite the first surface that is configured to filter the IR radiation transmitted through the objective lens element to a second narrower wavelength band that includes the particular range of wavelengths.

4 more elements

A method, comprising:

transmitting, by an objective lens element of a three-lens optical system for a device, infrared (IR) radiation from a scene, wherein the IR radiation from the scene includes a particular range of wavelengths corresponding to an absorption/emission spectrum or transmission spectrum of a gas;
and
receiving, by a spectral lens element of the optical system, the IR radiation transmitted through the objective lens element, wherein receiving the IR radiation comprises:
filtering, by a first interference filter disposed on a first surface of the spectral lens element, the IR radiation to a narrower wavelength band that includes the particular range of wavelengths, and
filtering, by a second interference filter disposed on a second surface opposite the first surface, the IR radiation transmitted through the objective lens element to a second narrower wavelength band that includes the particular range of wavelengths;
and
receiving, by a subjective lens element of the optical system, the filtered IR radiation, wherein the spectral lens element is disposed between the objective lens element and a subjective lens element.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/351,126Filed 17 Jun 2021 · continuation
Priority: 20 Dec 2018
Published: US 2021/0310941 A17 Oct 2021
Granted: 1 Oct 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification25 codes

G01J 5/0014
Radiation pyrometry, e.g. infrared or optical thermometry: for sensing the radiation from gases, flames
G01N 21/3518
For analysing gases, e.g. multi-gas analysis: devices using gas filter correlation techniques; Devices using gas pressure modulation techniques
G01J 5/026
Constructional details: control of working procedures of a pyrometer, other than calibration; Bandwidth calculation; Gain control
G01J 5/048
Casings: protective parts