|
US2042619A
|
|
Noiseless recording
|
|
US1987205A
|
|
Light coupled projector
|
|
US2039182A
|
|
Reproducing system
|
|
US1955084A
|
|
Solid surface area illuminator
|
|
US1993616A
|
|
Apparatus and method for recording sound accurately
|
|
US1943984A
|
|
Photo-electric tube
|
|
US1888328A
|
|
Recording glow lamp
|
|
US1850467A
|
|
Monitor method of recording sound on film
|
|
US1935369A
|
|
Floating cathode amplifier
|
|
US1949217A
|
|
Harmonic neutralizing amplifier
|
|
US1882336A
|
|
Pick-up apparatus for magnetic films
|
|
US1928760A
|
|
Amplifier system
|
|
US1899712A
|
|
Electrostatic potential control from photoelectric cells
|
|
US1767547A
|
|
Apparatus for photographically recording and reproducing sound
|
|
US1889758A
|
|
Means for transforming light impulses into current impulses
|
