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Title:
Chalk screen image projector
United States Patent 3332317
Inventors:
Peckman, Eugene F.
Carlson, Arthur W.
Torrey, Frank R.
Application Number:
US45702765A
Publication Date:
07/25/1967
Filing Date:
05/19/1965
Assignee:
E H SHELDON & COMPANY
Primary Class:
Other Classes:
353/98, 434/408
International Classes:
G03B21/132
View Patent Images:
US Patent References:
3051040Projection cabinet1962-08-28
2522351Plastic chalkboard1950-09-12
2474297Combination televeision receiver and picture projector1949-06-28
1840920Projecting apparatus1932-01-12
1787309Photographic apparatus1930-12-30
1589349Projection apparatus1926-06-22
1242674N/A1917-10-09
Foreign References:
GB572528A1945-10-11