USRE20621E - Device for phonographs with linear phonogram carriers - Google Patents

Description

. Jan. 11, 1938. H.VO'GT ET AL Re: 20,621

DEVICE FOR PHONOGRAPHS WITH LINEAR PHONOGRAM CARRIERS Original Filed March 20. 192 :5 Sheets-Sheet 1 [rave 1650);; V09! F 2 J Alaska/Jew lg- 11m H. VOGT ET AL Jan. 11, 193s.

. DEVICE FOR PHONOGRAPHS WITH LINEAR FHONOGRAM CARRIERS Original Filed March 20, 1922 3 Sheets-Sheet 2 Jan. 11, 1938. H voG-r A Re. 20,621

DEVICE FOR PHONOGRAPHS WITH LINEAR PHONOGRAM CARRIERS on mal Filed March 2 1922 I 3 Sheets-Sheet :5

WITNESSES 1N VENTORS I .Jow /wh oae.

y J' ef17% 'ATTORNEYS Reissued Ja n-11 1938 UNITED STATES PATENT OFFICE DEVICE FOR PHONOGRAPHS WITH LINEAR PHONOGBAM CARRIERS Hans Volt, Berlin- Steglitl, Joseph Massolie, Berlin-Ghenicke, and Josef Engl, Be

Germany, assignors, by means aslottenburg, signmen rim-Charis, to American 'lrl-Ergon Corporation, New York, N. Y., a corporation of New York 6 Claims. (cl. 214-) The recording and the reproduction of sound waves by the use of linear phonogram carriers such as film strips, can only be effected in absolutely satisfactory manner, even after the re- 5 moval of all otheroccurring difilculties, when the speed of the-record carrier is.uniform both for the receiving and the reproduction, and when in both cases no variations of any kind occur. Especially in the case of musical reproductions is the record extremely sensitive to the slightest variations of speed. Consequently, it has hitherto been usual to provide apparatuses such as phonographs and gramophones witth speed regulators. In these apparatuses, however, the problem of the uniform a motion does not assume the same importance as in the case oi sound recording or reproducing apparatus embodying linear 'phonogram carriers, such as photographic sound records on film strips or ribbons because with the former the record carrier consists of a cylinder or disc possessing a somewhat considerable momentum when the desired velocity is imparted thereto which equalizes any small irregularitiesin the motion, such as may be caused, for instance, by-the' driving mechanism. In the latter case, however, that of phonographs with linear records, such as film strips, the portion of the record which is active at a given moment possesses practically no momentum to be taken into consideration. irregularities in the motiomsuch, for instance, as may be caused by the projections, the teeth, the,belts, the connecting places, and so forth, or by the friction, at the guiding point, become consequently very much more important with these-and thus greatly impair the periodicity of thesound recorded. I

According to the present invention, this drawback which attaches to all hitherto known propulsion mechanisms for linear phonogram records is obviated by the arrangement, that the light sound record has given to it at the controlling point the property of. a weighty mass. This is attained by the arrangement that the record carrier (a film strip or the like) is firmly pressed against one or more rollers connecting with a heavy rotating mass, so that the 'record moves in exact conformity with the rollers and the rotating mass.

Also, according to the present invention a dependable and highly efflcient optical system is provided for use in conjunction with moving film strips of the above indicated character.

Various further and also various more specific objects, features and advantages will more clearly appear from the detailed description given below taken in connection with the accompanying drawings, which form a part of this specification.

The invention consists insuch novel features, arrangements .and combinations of parts and methods as may be shown, described and claimed in connection with the embodiments of the invention herein disclosed by wayof example only.

constructional examples of the invention are illustrated in the figures, in which:-

Figure 1 is a side elevation of a linear phonogram carrier.

Figure 2 is a side elevation of a modified form of phonogram carrier,

Figure 3 is a longitudinal section of another form of phonogram carrier.

Figure 4 is an end view of the form of carrier shown in Figure 3.

Figure 5 is a view in elevation of a fly wheel showing an elastic coupling adaptable to the rear side of the fly wheels, the face views of which are shown in various of the other figures.

Figure 6 is a vertical section 01' the same.

Referring to Fig. 1, partially illustrating sound reproducing apparatus, the phonogram carrier, which in these illustrations'is shown as a film strip bearing a photographic sound record, moves over the rollers r, r, suitably coupled by gearing or belting, of which rollers preferably the roller 1" ,directly driven bythe motor is provided with teeth. One or even both rollers are rigidly connected with rotating masses as at m, m", whichgive to the film strip f travelling between them under tension the requisite uniformity of its motion. Between the rollers 1", 1'', there is placed preferably in a casing h thelight-sensitive cell 2 sensitive to electric light, which is influenced by a light my passing from a light source (not shown), through objective 0, and then through the film. The rollers or idles dr, (11'', press the film against the carrier roller r Another construction of theinvention is shown in Fig. 2, in which the little irregularities of movement often caused by the feeding of the film by the teeth on roller r, in the Fig. 1 construction, or which are caused by the mechanical vibrations of the stretches of film between rollers r and 1 in the Fig. 1 construction, are avoided.

The film f is drawn by the sprocket V to the controlling point r and is removed from the con-- trolling point bythe sprocket V. Between these feeding sprockets, the film is guided over the periphery of a larger roller R on which it, rests closely by friction, even during the turning motion. As the roller is rigidly connected with the rotating mass m, or can be constructed so as to be itself the rotating mass, the film moves uni-' formly on in like manner as the surface of the roller R. For the purpose of pressing the film upon the roller R, and for the equalizing'of irregularities of motion, there are provided the spring-supported rollers 'dr', dr'. That is, the

spring pressed rollers engaging the film at points between the feeding rollers and the fiy wheel roller, thus exert resilient pressure against the film to force the film into effective engagement with the flywheel and thereby at the same time the film is deflected from a straight line position,,

. sound record on the film, the light rays pass through the film strip and fall upon the photo cell z preferably placed in the interior of roller,

R. For thispurpose, the roller is either partially transparent, made of glass, for example, or the part of the film bearing the sound record projetlztes beyond the non-transparent parts of the ro r. l

In the hereinbefore described form of execution of the invention the driving of the film sound record is however not efiected directly at the Point of projection but in front or behindthe same. The driving point of the film can however, in a further development of the invention.

' be arranged directly at the point at which light is projected through the record. The driving member can, in this case, be constructed in such a manner that the engaging and disengaging, of the feeding teeth of the film-feeding sprocket with the perforationsof the film, will not affect the speed of the film at the projection point, i. e., at the point at which light falls upon the film in recording, or at which it passes through the film in reproducing.

.l lgures 3 and 4 'show this form of construction by way of example. The shaft a journalled at b and c, carries at one end the feeding-cylinder d which has the customary teeth designed to engage with the perforations of the film, The film I is in contact with one part of the circumference of this cylinder, the length ofv this part corresponding with the distance between the pressure rollers e and 9. Fig. 4. The driving member 1: such as a gear for example, and also the fiy wheel 1, are keyed upon this shaft and designed to communicate to the shai'tand consequently to the cylinder 41, a uniform-revolving speed. The filmwill consequently move also with unlformjspeed, for instance in the direction 9-e. These rollers e-a press the film strip firmly against thecylinder it so that it lies, without possibility ct being shifted, upon the entire peripheral length of cylinder :1 from g to e. because-oi the feed teeth of cylinder d engaging with the perforations of the film. I The engagement and disengagement of the feed teeth on cylinder d, with the perforationsof the film, takes place under the pressure of the rollers g and c, Fig. 4, so that vibrations or Jerky motions of the film band, due to such tooth engagement or disengagement, no

- longer make themselves felt at the point of light projection through the same. The free ends 1-! of the film band are preferably guided by rollers (not shown) for preliminary winding up in the manner well known in picture cinematography. so that they form a loop.

'It will be understood that the invention is intended particularly for use in connection with transparent film records, onwhich-sound is recorded photographically. by causing acoustically modulated light to act upon the film at the control' point. Also that, in reproducing,- light passes through the sound record on the film at the control point, and falls' upon the photo-cell z to set up currents corresponding, in frequency variations, to the sound record through which the light has passed. Also, that the film may pass from a supply reel on which-it is wound, at the starting end, to a reel on which it is progressively wound, at thefinal end, as is usual in cinematography. Further, that the film contemplated may be a talking moving picture film, con-- taining pictures in addition tothe sound record. Sucha record must be fed intermittently past the point at which the pictures are recorded on the film. or at which the projection light shines through the pictures in reproducing. In addition there is need of feeding the film uniformly past the point at which the sound is recorded or reproduced. For such film the loop referred to is preferably formed, between the point of intermittent feed for picture recording or projection, and the point of uniform motion for sound recording or reproducing, the production of such loops in the film being common in cinematography.-

For recording purposes a solid cylinder or roller may be employed in place of the .roller d upon'which the full width of the film strip will bear, sincein recording the acoustically modulated light which is to be recorded need not pass through the film butonly need act upon the,

stance the cell 2 with the cathode l and. anode p.

The cylinder or roller :1 in Figure 3 shows a form ofconstruction byway of example in which the part of the film which carries. the soundrecord projects beyond the edge of the cylinder. The

light collected by the object. glass 0 to a narrow line, comes from a suitablefknown means or source of light projection so arranged. asln'db,

cated for example by the dotted lines in Figs. 3

and 4; that the converged narrow ,line of light is substantially focused or impinges upon the Hares. of translation t on thefilm as a line running transversely of the direction of movement. of the film The sound record as indicated in Fig. 3 may be located at the outer side of one row of perforations in the film. The sound record markings can, however, if desired, be located between the two rows of perforations in the film, in which case only one row of perforations would be utilized for feeding the film, these perforations being engaged by the teethon roller d nearest to the center of cell z. In this .case the sound record portions of the film would still overhang the edge of roller d, the far overhanging edge of the film, moving along either without a special guidance or running over a roller with or without feeding teeth, which roller may be an idler or may be.

specially driven, as desired.

Another feature may advantageously be incorporated in the invention. If the driving shaft of the tone-film revolves with a low number of revolutions andif a rigid drive is used, the-cincumferential speed of fly wheels which can be practically utilized, will, under certain conditions; not be sufficient for compensating the speed fluctuations.

According to the invention the driving of the fly wheel axle is therefore effected with the aid of an elastic coupling, for instance a spring.

This spring can be very feeble as, at constant speed, .it has to overcome only the losses from friction of the drivenpart. As however, at the starting and stopping of the driving mechanism, the inertia of the fiy wheel'has to be overcome, it is advantageous to limit the play of the spring in either direction by a fixed stop.

Figures 5 and 6 show such a form of execution by way of example. The axle l of the wheel with the rotating mass i is separate from the driving shaft (1. Upon the latter a lever 2 is arranged which drives the rotating mass through the intermediary of the spring 8 and of the stud I fixed to the fiy wheel. The studs I which are also fixed on the fiy wheel limitthe stroke of the lever Lat the starting and at the stopping so that the spring 3 is protected againstexcessive tension and against jumping out of position.

While the invention has been described in de- I tall with respect to certain particular preferred examples which give satisfactory results, it will be understood by those skilled in'the art after understanding the invention that various changes and modifications-may be made without departing from the spirit and scope of the invention.

and it is intended therefore in the appended claims to cover all such changes and modifications.

We claim:-

1. An apparatus for reproducing speech, music or the like sounds from vibrations recorded on a film strip, comprising a photoelectric cell, means for imparting to the film an arcuate, rapid and uniform motion longitudinally of the film past,

said cell, a source of light projection for'providing a line oflight in fixed position for translating the sound from the film strip r'noving uniformly past said light, 'and an objective lens in the neighborhood ofthe area of translation on the film strip but spaced, therefrom for collecting said projected light and directing the same as a converging narrow line extending transversely. of

the direction of movement of the film strip and.

passing through the area of translation on the fill; and to said cell.

In combination, optical means for translating sound vibrations to .or from a film record strip by the use of light varied in accordance with the sound,-a' constant speed film feeding xfilm as fed by said feeding roller, said compensating means including a spring pressed roller engaging the film at a point between said feeding roller and said flywheel roller with a resilient pressure causing the film to be deflected a variable amount in passing over said spring pressed roller, the extent of suchdefiection varying with said irregularities of motion.

3. In combination, optical means for translating sound vibrations to or from a film record strip.

by the use oflight varied in accordance with the sound, a constant speedfilm feeding mechanism for moving the film strip uniformly past said light, comprising a continuously rotating feeding roller, a flywheel, a. roller over which the film passes and which roller is operatively connected to said flywheel, means to compensate for variations in the motion of the film arising from small irregularities in the motion of the film as fed by, said feeding roller, said compensating means including a member yieldingly pressing against the film at a. point between said feedingroller and said flywheel roller to variably deflect the film from a straight line path at such point.

strip, the combination are cylinder, a flywheel i therewith, means for rotating said cylinder at uniform speed under control of said flywheel, means for feeding the film record strip onto said cylinder at one point and off therefrom at another point and causing the film strip to adhere closely to the cylinder without'slippage between said points, said film record strip being arranged to overhang one end of the cylinder, 9. photo-electric cell positioned inwardly of the overhanging portion of the film, and means for directing light through said overhanging portion onto said photoelectric cell whereby sound'is translated by the light from the film strip moving uniformly past said light.

5'. An apparatus for reproducing speech, music or the like sounds from vibrations recorded on a film strip, comprising a photoelectric cell, means for imparting to the film an arcuate, rapid and uniform motion longitudinally of the film past said cell, a source of light projection for providing a line of light in fixed position for translating the sound from the film strip moving uniformly past said light, and an objective lens in the neighborhood of the area of translation on the film strip but spaced therefrom for collecting said projected light and directing the same as a converging narrow line extending transversely of the direction of movement of the film strip and passing through the area of translation on the film and to said cell, said means including a flywheel and means operatively connecting said flywheel with the film, which last named means ime parts uniformity of motion of the flywheel to the film in passing through said lineof light.

fi. An apparatus for translating sound vibrations representative of speech, music or the like, to or from a film record stripby the use of a line of light varied in accordance with the sound, which comprises means for imparting to the film an arcuate, rapid and uniform motion longitudiretaining the moving film under tension at the area oitranslation, :1. source of light projection for providing a. line or said light in fixed position, and an objective lens in the neighborhood or said area 01' translation on the film but spaced there- 'Irom for collecting said projected light and directing the same as a converged narrow line impinging dirwtly upon the arcuately moving film 10 at said area .of translation and transversely of 20,621 nally 61 the film past said u e of 1mm, and for the direct on of movement of the film, said means HANS VOGT. OSEPH MASSOLLE'. J OSEF ENGL.

Images