Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Co
Original Assignee
Minnesota Mining and Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Minnesota Mining and Manufacturing CofiledCriticalMinnesota Mining and Manufacturing Co
Priority to FR31725ApriorityCriticalpatent/FR1446992A/fr
Application grantedgrantedCritical
Publication of FR1446992ApublicationCriticalpatent/FR1446992A/fr
G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
G03B21/00—Projectors or projection-type viewers; Accessories therefor
G03B21/132—Overhead projectors, i.e. capable of projecting hand-writing or drawing during action
Landscapes
Physics & Mathematics
(AREA)
General Physics & Mathematics
(AREA)
FR31725A1965-09-171965-09-17Procédé, appareil et matériaux servant à la projection d'images lumineuses
ExpiredFR1446992A
(fr)