← Back to Patent Explorer
US5322998A Expired / Lapsed US ⏱️ 0.0 years remaining

Conical blur filter for reducing artifacts in imaging apparatus

Assignee: Intellectual Ventures Fund 83 LLC
•
Filing: 1993-03-31
•
Granted: 1994-06-21
•
Expires: 2013-03-31
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract An optical blur filter having a substantially conical shape is used in imaging apparatus to limit high spatial frequencies incident upon an image sensor, and thereby to reduce undersampling artifacts. By having a conical shape, the filter images a circular blur pattern upon an array of adjacent photosites. A conical shape with a distinct vertex images an annular pattern, and a flattened vertex fills in the central region of the pattern.

Inventors

  • 👤 Todd A. Jackson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 09:52
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/42; G02B27/46

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 81 words
An imaging apparatus for generating an image signal from incident image light having its higher spatial frequencies limited to reduce undersampling artifacts, said apparatus comprising: an image sensor for generating the image signal from an array of photosites; and an optical section having an optical filter with a substantially conical shape that includes a base and a vertex region, said optical filter interposed in the path of the incident image light so as to output a blurred image upon said photosites.
Claim 2
Dependent Claim 81 words
An imaging apparatus for generating an image signal from incident image light having its higher spatial frequencies limited to reduce undersampling artifacts, said apparatus comprising: an image sensor for generating the image signal from an array of photosites; and an optical section having an optical filter with a substantially conical shape that includes a base and a vertex region, said optical filter interposed in the path of the incident image light so as to output a blurred image upon said photosites.
Claim 3
Dependent Claim 31 words
An imaging apparatus as claimed in claim 1 wherein said optical section includes a lens positioned between said optical filter and said photosites for imaging the blurred image upon said photosites.
Claim 4
Dependent Claim 112 words
An imaging apparatus for generating an image signal from incident image light having its higher spatial frequencies limited to reduce undersampling artifacts, said apparatus comprising: a substantially transparent conical filter having a base and a vertex located along a conical axis defined therebetween, said conical filter having its conical axis directed toward the incident image light so as to output a circular blur pattern for each input point source; an image sensor for generating an image signal from a two-dimensional array of photosites; and a lens positioned between said conical structure and said image sensor for imaging the blur pattern upon a plurality of photosites to thereby limit the higher spatial frequencies.
Claim 5
Dependent Claim 112 words
An imaging apparatus for generating an image signal from incident image light having its higher spatial frequencies limited to reduce undersampling artifacts, said apparatus comprising: a substantially transparent conical filter having a base and a vertex located along a conical axis defined therebetween, said conical filter having its conical axis directed toward the incident image light so as to output a circular blur pattern for each input point source; an image sensor for generating an image signal from a two-dimensional array of photosites; and a lens positioned between said conical structure and said image sensor for imaging the blur pattern upon a plurality of photosites to thereby limit the higher spatial frequencies.
Claim 6
Dependent Claim 34 words
An imaging apparatus as claimed in claim 3 wherein said conical filter produces an annular blur pattern for each input point source that is imaged through said lens upon a two-dimensional array of photosites.
Claim 7
Dependent Claim 22 words
An imaging apparatus as claimed in claim 3 wherein the vertex of said conical filter is oriented toward the incident image light.
Claim 8
Dependent Claim 20 words
An imaging apparatus as claimed in claim 3 wherein the vertex of said conical filter is oriented toward said lens.
Claim 9
Dependent Claim 130 words
An imaging apparatus for generating an image signal from incident image light having its higher spatial frequencies limited to reduce undersampling artifacts, said apparatus comprising: a substantially transparent conical filter having a conical surface defined relative to a conical axis and a vertex flattened at the tip thereof, said conical filter having its conical axis directed toward the incident image light as to output a circular blur pattern for each input point source, said blur pattern having an annular component dependent upon the conical surface and a central component dependent upon the flattened vertex; an image sensor for generating an image signal from a two-dimensional array of photosites; and a lens for imaging the circular blur pattern upon a combination of said photosites to thereby limit the higher spatial frequencies.
Claim 10
Dependent Claim 130 words
An imaging apparatus for generating an image signal from incident image light having its higher spatial frequencies limited to reduce undersampling artifacts, said apparatus comprising: a substantially transparent conical filter having a conical surface defined relative to a conical axis and a vertex flattened at the tip thereof, said conical filter having its conical axis directed toward the incident image light as to output a circular blur pattern for each input point source, said blur pattern having an annular component dependent upon the conical surface and a central component dependent upon the flattened vertex; an image sensor for generating an image signal from a two-dimensional array of photosites; and a lens for imaging the circular blur pattern upon a combination of said photosites to thereby limit the higher spatial frequencies.
Claim 11
Dependent Claim 22 words
An imaging apparatus as claimed in claim 7 wherein the flattened vertex of said conical filter is oriented toward the incident light.
Claim 12
Dependent Claim 21 words
An imaging apparatus as claimed in claim 7 wherein the flattened vertex of said conical filter is oriented toward said lens.

References Cited (Backward Citations)

US4101929A Cited
US4111561A Cited
US4518864A Cited
US4896217A Cited
US4998800A Cited
US4989959A Cited
JPH0365922A Cited
JPH03248695A Cited
US5140469A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-06-20 1997-12-20 1998-06-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-06-20 2001-12-20 2002-06-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-06-20 2005-12-20 2006-06-21 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag