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.)
RCA Corp
Original Assignee
RCA Corp
Radio Corporation of America
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 RCA Corp, Radio Corporation of AmericafiledCriticalRCA Corp
Application grantedgrantedCritical
Publication of FR726561ApublicationCriticalpatent/FR726561A/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
G03B21/54—Accessories
G03B21/56—Projection screens
G03B21/565—Screens allowing free passage of sound
Landscapes
Physics & Mathematics
(AREA)
General Physics & Mathematics
(AREA)
FR726561D1930-12-051931-11-20Perfectionnements aux écrans pour films cinématographiques sonores
ExpiredFR726561A
(fr)