Patent GB-378013-A (GB)
Title: Improvements in or relating to a method of and apparatus for recording sound in synchronism with a moving picture record
IPC: G03B31/00
Filed: 1931-03-26
Abstract: 378,013. Producing and recording sound in association with kinematography. SYNCHROCIN•, 63, Avenue des Champs s Elysees, Paris. March 26, 1931, No. 9294. Convention date, March 26, 1930. [Classes 40 (ii) and 88 (ii).] Comprises a method of recording a synchronous sound accompaniment for a previously photographed picture film. A control strip is unwound synchronously with the projection of the pictures and marks are made on the strip according to the projected picture events to indicate the appropriate sound accompaniment, and finally the control strip is unwound at a speed corresponding to the normal film projection speed and the sound recording effected in accordance with the markings thereon. As shown diagrammatically in Fig. 1, a control strip 1 is driven, in synchronism with the picture projection, past a series of marking devices 3 adapted to be actuated by keys 13<1> .. 17<1>. The marking device 13, for example, may be used to indicate the commencement and end of phrases or sentences whilst the marker 14 may make indications to assist in the composition of a musical accompaniment. The intermediate markers are used for indicating on the band the instants when incidental noises are to occur. If desired, the intermediate markers may be arranged to perforate the control strip, the perforations being afterwards employed to control the operation of the various incidental sound-producing means. After the completion of this preliminary operation, the complete text to be subsequently spoken and recorded is written in on the control strip and the sound record is made by unwinding the strip, in view of the actors, at a speed corresponding to the picture projection speed, the actors speaking the text in accordance with the indications on the strip. To assist a musician in the composition of a musical score which shall be in exact synchronism with the picture projection, use is made of the previously marked control strip, whereon the strong beats of the music have been marked by the indicator 14<1>, in co-operation with a composition table as shown in Fig. 4. The composition table comprises a platform 18 on which are mounted two rollers 19, 21 between which the strip 1 is wound. A board 22 having thereon a series of parallel lines 23, 23', &c. and 26, 26<1>, &c., each marked with equidistant divisions 24, 24<1>, &c., is slid underneath the strip 1 until the divisions of one of the lines coincide with the beat marks on the strip 1. A scale 25 then shows the metronomic time which must be observed so that the beats of the music will be spaced in accord with the actions of the picture. Each series of lines 23, 23<1> &c. and 26, 26<1>, &c. corresponds to a different musical time, e.g. 4/4 time, 3/4 time, which time is arbitrarily selected by the musician. The control strip, or a reproduction thereof, may be perforated to actuate a luminous metronome, Fig. 6, situated on the conductor's table wherein a red lamp 37 serves to indicate the approach of a musical item and four white lamps 38 .. 41 are illuminated momentarily in succession, in the case of 4/4 time to indicate the beats of the music. In the case of 2/4 time it is arranged that the lamps 38, 39 are illuminated in succession. A modified form of the observation table, shown diagrammatically by Fig. 1, is illustrated by Fig. 8 wherein the control strip 52 is wound over a table 50 from a drum 51 to a drum 53. The strip 53 passes beneath marking devices which each comprise a roller 57 carried by a rod 56 connected to a pivoted lever 55. The levers 55 are controlled by electromagnets 59 energized by depressing keys 62 on a control keyboard. Between each roller 57 and the strip 52 is an ink ribbon. A platform 54 is mounted on four rods 64 which are slidable in sockets 65 and vertically displaceable by means of a pedal 66. By depressing the pedal 66, the operator is able to raise the rollers 57 from the strip 52 when he desires to make manual inscriptions on the strip. A further pedal is provided which enables the starting, stopping and speed of the picture projection to be controlled. A lazytongs device, Fig. 9, is adapted to be mounted on the top of the composition table of Fig. 4 in such manner that vertical rulers 68 extend transversely above the control strip 1. Under the rulers 68 is a fixed scale 69 which bears indications of metronome divisions so that, if the first ruler 68<1> is placed against the division indicative of the metronome time previously ascertained, the equal distances apart of the rulers 68<1> will represent on the control strip the duration of the musical bars, the staves of which can then be marked in pencil on the strip 1. The recording table comprises a casing 70, Fig. 10, which is provided with a window 72 across which the control strip is passed to give the necessary indications to the conductor and actors. A number of such tables may be provided. The control strip is driven by an electric motor 74 synchronously with the film projector. To ensure exact agreement of the film and control strip at the start of recording, an aperture is made in the film and a mark is made at a corresponding part of the control strip. Between the motor 74 and the driving sprocket of the control strip is an electromagnetic clutch, Fig. 12, a coupling 78, 78<1> of which permits of relative longitudinal sliding of the parts 78, 78<1> thereof while a coupling 79, 79<1> is engaged when an electromagnet 76 is energized, by the film aperture passing over a contact device, to cause sliding movement of the armature 77. Thus the control strip starts to be fed past the window 72 at the moment when the film aperture passes the contact, the control strip having been set initially with reference to the starting mark thereon.