CH561434A5CH579474ACH579474ACH561434A5CH 561434 A5CH561434 A5CH 561434A5CH 579474 ACH579474 ACH 579474ACH 579474 ACH579474 ACH 579474ACH 561434 A5CH561434 A5CH 561434A5
Authority
CH
Switzerland
Application number
CH579474A
Original Assignee
Ritzerfeld Gerhard
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 Ritzerfeld GerhardfiledCriticalRitzerfeld Gerhard
Publication of CH561434A5publicationCriticalpatent/CH561434A5/xx
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)
Overhead Projectors And Projection Screens
(AREA)
Non-Portable Lighting Devices Or Systems Thereof
(AREA)