MICROBOLOMETER FOCAL PLANE ARRAY WITH TEMPERATURE COMPENSATED BIAS

• US 20070029484A1
• Filed: 09/11/2006
• Published: 02/08/2007
• Est. Priority Date: 10/07/1999
• Status: Active Grant

• Current Assignee: Fluke Corporation (Fortive Corp.)
• Original Assignee: Infrared Solutions, Inc. (Fortive Corp.)
• Inventors: Anderson, Shane, McManus, Timothy
• Granted Patent: US 7,417,230 B2
• Time in Patent Office: Days
• US Class Current: 250/338.100
• CPC Class Codes: G01J 5/22 Electrical features thereof
• CPC Class Codes: G01J 5/24 Use of specially adapted circuits, e.g. bridge circuits
• CPC Class Codes: H04N 25/671 for non-uniformity detection or correction
• CPC Class Codes: H04N 25/673 by using reference sources
• 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

A readout circuit for an array of substrate-isolated microbolometer detectors includes a bias source that varies in accordance with changes in substrate temperature as detected by a temperature sensor that has temperature characteristic that resembles the temperature characteristic of the microbolometer detector array so as compensate detector measurements for temperature induced errors in the microbolometer focal plane array read out.

Claims

1. A readout circuit arrangement for a microbolometer imaging apparatus including an array of selectable substrate-isolated microbolometer detectors, each detector having a resistance value Rpixel_n associated with the nth detector, D_n, and wherein an electrical bias source is coupled to each detector, and wherein a readout circuit is provided for sequentially establishing a corresponding output signal, Sout_n, representative of the resistance value, Rpixel_n, associated with the detector at a given instant, the readout circuit comprising:

a temperature sensor, thermally coupled to the substrate of said array, for substantially sensing the temperature of said substrate, and ahving an elecctrical sensor parameter that has a temperature characteristic behavior resembling the temperature characteristic behavior of said array of detectors in response to changes in substrate temperature;

first circuit means for sequentially establishing an electrical pixel parameter as a function of said electrical bias source and said detector resistance, Rpixel_n, for selected ones of said detectors;

second circuit means responsive to said electrical pixel parameter for providing an electric signal output signal, Sout_n, as a function of said electrical pixel parameter;

bias source generating means for generating said electrical bias source as a function of said electrical sensor parameter of said temperature sensor.

2-21. -21. (canceled)