Blur film assembly for infrared optical applications

• US 5,867,307 A
• Filed: 11/13/1996
• Issued: 02/02/1999
• Est. Priority Date: 11/13/1996
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Brunton, Daniel W., Saccketti, Nicholas B., Smith, David R., Myers, James R., Sparrold, Scott W., Jensen, Stephen M., Westhoven, Lawrence A.
• Primary Examiner(s): Spyrou, Cassandra C.
• Assistant Examiner(s): Schuberg, Darren E.
• Application Number:
  US08/748,586
• Time in Patent Office: 811 Days
• Field of Search: 359/350, 359/353, 359/557, 359/599, 250/332, 250/350, 250/351
• US Class Current: 359/350
• CPC Class Codes: G02B 23/12 with means for image conversion or intensification
• CPC Class Codes: G02B 26/0875 by means of one or more refracting elements
• CPC Class Codes: G02B 3/0031 Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: G02B 5/0215 the surface having a regular structure
• CPC Class Codes: G02B 5/0278 used in transmission
• 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
• CPC Class Codes: Y10T 156/1039 Surface deformation only of sandwich or lamina [e.g., embossed panels]

Abstract

A blur film is made of a polymeric film material transmissive to infrared energy of a selected waveband, which is affixed to a surface of a substrate transmissive to energy of the same selected infrared waveband. The blur film has a texture or a plurality of lenslets thereon, where the surface of each lenslet is a surface of revolution. In a spatial-filter wheel application, the blur film and substrate are affixed to a support, which in turn is rotatably mounted on a drive. The support is structured such that a portion of its circumference is covered by the blur film and a portion of its circumference is not covered by the blur film. The spatial-filter wheel is rotated in front of a detector to produce alternating blurred and direct images on the detector.

Claims

1. A blur film assembly, comprising:

a blur film made of a film material transmissive to a selected waveband of incident infrared energy, the blur film having a surface texture thereon comprising a pattern of peak-and-valley features having an amplitude in the direction perpendicular to the surface of the blur film and a lateral dimension parallel to the surface of the blur film that are each no less than a midpoint wavelength of the selected waveband of incident infrared energy.

2. The blur film assembly of claim 1, wherein the peak-and-valley features are lenslets.

3. The blur film assembly of claim 1, further including

a substrate made of a substrate material transmissive to infrared energy of the same selected infrared waveband as the blur film, wherein the blur film is affixed to a surface of the substrate.

4. The blur film assembly of claim 3, further including a spatial-filter wheel to which the blur film is affixed, the spatial-filter wheel having a circumferentially extending first sector covered by the blur film and a circumferentially extending second sector not covered by the blur film.

5. A blur film assembly, comprising

a blur film made of a film material transmissive to a selected waveband of infrared energy, a surface of the blur film comprising a plurality of lenslets, wherein each lenslet comprises a surface shaped as a surface of revolution.

6. The blur film assembly of claim 5, wherein the plurality of lenslets comprise a regular array of lenslets.

7. The blur film assembly of claim 5, wherein the film material is a polymer.

8. The blur film assembly of claim 5, further including

a substrate made of a substrate material transmissive to infrared energy of the same selected infrared waveband as the blur film, wherein the blur film is affixed to a surface of the substrate.

9. The blur film assembly of claim 8, further including a spatial-filter wheel to which the blur film is affixed, the spatial-filter wheel having a circumferentially extending first sector covered by the blur film and a circumferentially extending second sector not covered by the blur film.

10. A blur film assembly, comprising:

a blur film made of a film material transmissive to energy of a selected infrared waveband, the film having a plurality of lenslets thereon, each lenslet comprising a locally curved surface of revolution;

a support to which the blur film is affixed to form a spatial-filter wheel, the spatial-filter wheel having a circumferentially extending first sector covered by the blur film and a circumferentially extending second portion not covered by the blur film; and

a rotational drive affixed to the spatial-filter wheel.

11. The blur film assembly of claim 10, further including a detector for energy of the selected infrared waveband, and wherein the spatial-filter wheel is positioned between the detector and an infrared energy source.

12. The blur film assembly of claim 10, wherein the blur film material is a polymer.

13. The blur film assembly of claim 10, wherein the plurality of lenslets comprise a regular array of lenslets.

14. The blur film assembly of claim 10, wherein each lenslet comprises a surface of revolution.