US1871761A - Paper roll phonograph record - Google Patents

Description

g 15,1933 J. WEINBERGER ,3

PAPER ROLL PHONOGRAPH RECORD Filed Oct. 27. 1925 Fgj 7 BYCIZ A G UST/LZA6RAP/l mi 7455 INVENTOR JUUUS WElNBERGER TORNEY Patented Aug. 16, 1932 j UNITED STATES PATENT: OFFICE JULIUS WEINBERG-ER, OF NEW YORK, N. Y., ASSIGNOR TO RADIO CORPORATION OF AMERICA, CORPORATION OF DELAWARE PAPER ROLL PHONOGRAPH RECORD Application filed October 27, 1925. Serial No. 65,131.

The invention concerns phonograph records and :a process of making them andhas for its principal object to provide a nonbreakable record of unlimited playing time.

A further object of the invention is to provide a phonograph record consisting of a roll of paper or other flexible material on which representations of the sound waves to be reproduced are printed.

Still another object of the invention is to provide a phonograph record consisting of a roll of paper or other flexible material on which representations of the sound waves to be reproduced are printed by first converting the sound waves into correspondingly modulated high frequency currents and recording the current fluctuations in graphical form. V

The great majority of phonograph records made up to the present time consist of wax discs or cylinders on whose surfaces are engraved grooves having indentations or undulations corresponding to the recorded sounds. The indentations may be either lateral or normal to the face of the record and serve to cause vibrations in a reproducing stylus following the grooves of frequencies correspondingto those of the original sounds. The vibrations of. the stylus are transferred to a mechanical vibrating member, usually a diaphragm, which thereupon sets up sound waves of substantially the same frequency and intensity as those originally recorded on the record. There are numerous objections to these records. In the first place the process of manufacture is very expensive. Moreover the records are easily broken and their playing time is extremely limited, about four or five minutes being the maximum playing time which has been found practicable.

I propose to decrease the cost of manufacture, indefinitely increase the playing time and provide a non-breakable record by registering markings corresponding to the sound waves to be reproduced on a paper roll. Replicas of the original record can then be made by ordinary printing or photographic processes and the original sounds reproduced by photo-electric methods or by the use of heat waves transmitted through or reflected from the printing on the paper. The master record under this system can be made ina number of ways. Electrical high frequency oscillations may be modulated in accordance with the sound waves to be recorded and a photo-graphic representation of the modulated high frequency oscillations ob tained by means of an oscillograph, or an engraving of the modulated oscillations may be obtained by means of an electro-ma-gnetic,

piezo-electrical crystal or condenser recorder.

Again the sound waves may be. recorded photographically by purely optical processes such as varying the intensity or size of a shaft of light falling upon a moving strip of paper having a sensitized surface. What-. ever" method is used the completed record will be in the form of a roll of paper or otherfiexiblematerial which will be practically unbreakable and which can be made as longas desired.

The invention in several different forms isillustrated by way of example in the ac- V companying drawing in which,

Figs. 1 and 2 show two modifications of the process making use of. modulated high frequency oscillations and Fig. 3 shows a portion of a record roll made according to the invention.

Referring to Fig. 1. of the drawing a vacuum tube is indicated at 4 which may be arranged in any suitable manner for generating high frequency oscillations. Sound waves to be recorded are impressed on the device l for conversion into variable electric currents. The device 1 is coupled to the grid filament circuit of the oscillator by means of the transformer 3 and a battery 2 is provided in the circuit of the device 1 to supply the necessary electrical energy. The current variations resulting from the operation of the device 1 by the sound waves are thus transferred to the input circuit of the oscillator 4 and serve to modulate the high frequency oscillations generated by the oscillator. The output circuit of the oscillator contains a source ofenergy 5 and an inductance 6 and an oscillograph .7 is connected across the terminals of the inductance 6. The

voltage drop across the inductance 6 will be proportional to the modulated high frequency oscillations generated by the oscillator i and these voltage drops will be impressed on the operating mechanism of the oscillograph. A photographic representation of themodulated high frequencywaves on a moving photographic film or a strip of paper having a sensitized surface may thus be obtained from the oscillograph and this film may be used as a' master record from which photographic prints may bemade. .to form other records.

A short section of aphonograph record- 'formed in this manner is shown in Fig. 3 in wh1ch11 indicates the strlpot paper or flexible material iforming therecord and the curve printed 1thereon represents the sounds to be reproduced. The curve 15is in reality av graph of .the'high frequency oscillations ofthe oscillator dimo'dui'ated in accordance with the sound waves impressed on the device-1. The envelope of the curve 15 lS'.8. graphical representation of the sound waves impinging on the device 1.

Such a record could be reproduced by photo electric methods or by the use oi heat wavesinstead of light waves transmit through or reflected from the printing on the .2' 1 record. 'In the former case a band of light could be directed against the moving record of suii'icient width to cover the widest fluctuations-ofthecurve 15. The curve15 would have the efiectof varying the intensity of the I band of'lightin accordance withthe modulations of the curve and the intensity of the light after passing through the record wouldbeproportional to the sound waves originally causing the tracing of the curveon the record. Sucha band oflight of variable intensity could-be made to affect a light-sensitive cellconnectcd'in circuit-with a suitable electric or electro-magnetic reproducing system whereby the reproducing system would .1 give a true and accurate reproduction'of the sounds-originally causing the tracing of the V curveon the record.

A modification of the deviceis shown in Fig. 2 in which the oscillator 4 and device 1 aresimilar to those in Fig. 1 but in which the oscillograph has been replaced by a recorder 10, the details of which are disclosed in my application, Ser. No."65,135 filed concurrently herewith. The recorder 10 has a suitable stylus 16 to execute vibrations corresponding to the varying currents impressed on the recorder. This stylus 16 is arranged to rest lightly on a strip 11 of paper or other flexible material which by means of the" rollers 12 or other devices is caused to move at a steady rate beneath the stylus. The strip 11 may be provided with an opaque coating of such a nature as to be scraped ofi? by the engraving stylus 16 in its vibrations. -The vibrating styluswill thereupon trace a curve ted.

similar to that shown in 15 of Fig. 3 on the record and this record may be used as a master record from which photographic or other replicas may be made.

Instead of forming an opaque coating on the'record 11; toruse in connection with the system shownl .in .Fig. .2: the surface-lot the record can be sensitized with any suitable chemical responsive to light. The vibration of the stylus in this case will serveto scratch 0d the sensitizing material and the record canthenbe subjected to the action of light rays and'dev'eloped to obtain the master rec- 0rd from whichduplicates may be obtained as before.

l/Vhile I have' described :n1y:invention-:particularly :asxapplied to electrical recording systems, it is quite obvious that itcan be carried v out :by purely optical or '.-mechanical means in which case the-1narkingswill be formed onthe. record. either by purelymechanical means or :bywa traveling; beam-of light or a band of light of varyingxwidth or the record with an opaque coating'yvibrating the stylus at a modulated superaudible: frequency, and scraping off i axportion of the opaque coating by said stylus.

8. The m'ethod of recording sound on ia flexible record which consists in applying: an opaque coating to a master record,'scraping off a portion of said coating byan engraving stylus vibrated atza modulated superaudible frequency; and photogra ahing other records bypassing light thruzt e porti'oncofz-zsaid master record from which'the opaque coating was scraped. 7

1. The method-0t reproducing sound on a flexible record which: consistsxin providing the record with. a j light: sensitive vsurface, scratching off avportion of the sensitizingimaterial with an engraving stylus vibratedat a modulated superaudiblei frequency,=.and subjecting :the record toa developing treatment.

JULIUS WEINBERGER.

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