GB386983A - Improvements relating to the reproduction of sounds from records - Google Patents

Abstract

386,983. Reproducing optical and magnetic records. NAAMLOOZE VENNOOTSCHAP KœCHENMEISTERS INTERNATIONALE MAATSCHAPPIJ VOOR SPREKENDE FILMS, 305, Keizersgracht, Amsterdam. June 26, 1931, No. 18576. Convention date, June 26, 1930. [Class 40 (ii).] Sound is reproduced from optical or magnetic records at any desired pitch which is independent of the speed of the record by the employment of a moving scanning device traversed in the same or the reverse direction to that of the record whereby small portions of the record are omitted or repeated but only to such an extent that the character of the reproduced sound is not seriously impaired. The arrangement is useful for testing synchronism in sound and picture projection in that it permits the two records to be run slowly for inspection of the pictures whilst the reproduced portions of the sound record are reproduced. at the correct pitch. It may also be employed for freak sound reproduction at a different pitch from that of the recorded sound. In one arrangement, an optical record is reproduced by a beam directed through a fixed apertured plate and radial slits in a rotating disc behind which the record is traversed : the pitch of the radial slits in the disc is equal to the width of the aperture, which may be of various shapes. In another arrangement, the slotted disc is replaced by a travelling band 52, Fig. 9, having slits 21<1>, 21<11> .. spaced apart a distance equal to the aperture in a plate 53. A beam directed on the travelling record 50 passes through the apertured plate and one of the slits in the band and is condensed on a light sensitive cell 56 connected with a speaker 57. In another arrangement applicable to a magnetic record, the record 72, Fig. 10, made by a magnet 73 influenced from a microphone 70 is reproduced by a series of pick-up magnets 76<1>, 76<11> .. spaced aparton a travelling band 75, the output current being taken from collector rings to a speaker. The Specification as open to inspection under Sect. 91 describes also the production from a record of another record of different length but with omitted or repeated parts by the use of the apparatus described above for reproducing. This subject-matter does, not appear in the Specification as accepted.