Uncooled optical imaging device

• US 20040155195A1
• Filed: 06/19/2003
• Published: 08/12/2004
• Est. Priority Date: 07/15/2002
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Maurel, Gilles
• Granted Patent: US 7,091,488 B2
• Time in Patent Office: Days
• US Class Current: 250/351
• CPC Class Codes: H04N 23/52 Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

Optical sensors, more particularly infrared sensors, use an array of MEM micromirrors to chop a light beam impinging on an array of sensors of an imaging device to minimize the influence of thermal noise. The array of micromirrors preferably switches the beam impinging on the array of sensors between an image to be analyzed and an image of a reference black body at a clearly defined temperature. These sensors are not cooled and require no cryogenic devices.

Claims

1. An optical imaging device that is not cooled and in which an optical image is transported along an optical path onto an array of optical sensors and an array of MEM micromirrors is inserted into said transfer optical path outside locations of intermediate images to chop the light beam infringing on said array of sensors.

2. The device claimed in claim 1 wherein said array of micromirrors is disposed in the vicinity of a real pupil.

3. The device claimed in claim 1 wherein said array of micromirrors when in a first state directs onto said array of sensors an image to be analyzed and when in a second state directs onto said array of sensors an image of a black body at a clearly defined temperature.

4. The device claimed in claim 3 wherein said array of micromirrors when in a plurality of separate states directs onto said array of sensors images of a plurality of separate black bodies having different characteristics.

5. The device claimed in claim 1 including a plurality of arrays of micromirrors associated side by side.

6. The device claimed in claim 1 including an afocal optical system for associating an entry image, an array of micromirrors, and an array of analyzers with different dimensions.

7. The device claimed in claim 6 wherein said entry image and said array of sensors have substantially equal dimensions and said array of micromirrors has linear dimensions substantially twice those of said sensor and said entry image.