The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 26, 2008
Filed:
Aug. 04, 2005
Rolf W. Biernath, Wyoming, MN (US);
Robert L. Brott, Woodbury, MN (US);
William Ward Merrill, White Bear Lake, MN (US);
John S. Huizinga, Dellwood, MN (US);
William B. Black, Eagan, MN (US);
Rolf W. Biernath, Wyoming, MN (US);
Robert L. Brott, Woodbury, MN (US);
William Ward Merrill, White Bear Lake, MN (US);
John S. Huizinga, Dellwood, MN (US);
William B. Black, Eagan, MN (US);
3M Innovative Properties Company, Saint Paul, MN (US);
Abstract
An optical low pass filter or blur filter, and method of making the filters, using an article having a birefringent surface for refracting incoming light when used with an image sensor. The birefringent surface of the article, such as a film, is structured or tilted such that, when the blur filter is placed within an optical path between a lens and the image sensor, the birefringent surface causes refraction of a light signal in the optical path into multiple light signals each being incident upon different sub-pixels within the pixels in the image sensor to prevent or reduce artifacts, such as undesirable color moiré effects, in the resulting digital image. The structures on the surface have a variable pitch or angles. The variable pitch can include a periodic, aperiodic, or quasi-aperiodic pitch, to reduce diffractive artifacts in the resulting image.