WB

William F. Butterfield

PO Polaroid: 2 patents #349 of 898Top 40%
🗺 Massachusetts: #42,150 of 88,656 inventorsTop 50%
Overall (All Time): #2,274,536 of 4,157,543Top 55%
2
Patents All Time

Issued Patents All Time

Showing 1–2 of 2 patents

Patent #TitleCo-InventorsDate
5689371 Filter assembly — 1997-11-18
4747674 Contrast enhancement filter Kuang-Chou Chang, Edmund J. McLelland, Leonard Polizzotto 1988-05-31