A chopper for an imaging system includes a frame and a sheet that have different coefficients of thermal expansion. The frame has a space within it, and has at least one opening that allows radiation to pass through the space. The sheet has structure which influences radiation passing through the sheet, and the sheet is movably disposed within the space in the frame, in a manner so that the sheet can expand and contract relative to the frame in a direction approximately parallel to the sheet. The frame prevents any significant movement of the sheet in a direction transverse to the sheet.

Title
Method and apparatus for modulating infrared radiation
Application Number
10/458879
Publication Number
20040184130
Application Date
June 10, 2003
Publication Date
September 23, 2004
Inventor
Paul D Felts
Plano
TX, US
Alexander L Kormos
Fairview
TX, US
Agent
Baker Botts
TX, US
Agent
Jerry W Mills Esq
TX, US
IPC
G02B 07/02
G02B 26/02
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