Process and device of application of a magnetic track of sound recording on a cinematographic film, and sound film obtained by this process

FRENCH REPUBLIC

Industry and commerce patent d'

SERVICE

iNTELLECTUAL INDUSTRIELLE of the

Gr. 12.

Cl. 2.

Ention No. 1.054.208

Apparatus and method for applying a magnetic track sound [...] on a motion picture film, and film obtained by this method.

Mm. Ernest William FRANCK and Stephen [...][...] residing in the United States of America.

Demanded 8 December 1951, to 10^{m h 17,} to Paris.

.-Issued 7 October 1953 Published the greyhound 1954 9.

The present invention relates to such films cinema-

[...] and more particularly to a method

application of a magnetic stripe recording-

sound member on a film.

According to the present invention, a-e peles

vehicle doctrine magnetic sound recording is-

sounding on a film by casting a material mixture

magnetizable powder with a binder on

wetted areas of the film.

The aim is to create a movie film-

improved confronting its film comprising a track

magnetic sound recording, and a

application method for the track on the film.

Other purposes and advantages of the invention-spring

driving of the following detailed description and of the-

examiner) 104 appended, illustrating, as examples, of the for-

mes the invention. However,

submitted with the latter is not limited to the

details described, various variants, which can be-sheave

related in its frame.

The fig. 1 is a side elevation illustrating the ap-

plication of a sound track on a film-endangered film

graphical.

The is a view like fig. 2, but showing the

opposite side of the application device.

The fig. 3 is a rear view of the device ap-

plication.

The fig. 4 is a horizontal section according to the

line 4-4 of Figure 2.

The fig. 5 is a plane bottom view of the device

application.

The fig. 6,7 and 8 are cross-sections

according to the vertical planes 6-6, 7-7 and 8-8 of the

fig. 2 respectively.

The fig. 9 is a cross-section many

larger scale of a film in the doctrine-

cation thereon a soundtrack according to the invention.

The is a view like fig. 10, but of the film

completed.

3-41555

Figure. II is a plane of a section of the completed film.

The like fig. 12 is a view of a variant.

The like fig. 13 is a view showing another embodiment.

The fig. 14 is a cross-section to much larger scale of a film, illustrating an operation of a variant of the method of applying the magnetic sound track on the film.

The fig. 15 is a view like other operation performed in the process.

The fig. 16 is a view of the film like completed.

Currently, the need most urgent is to provide improved sound track on a 16 mm film. On a film of this width, providing a optical sound track frequently gives rise to the substantially very good. According to the present invention, is created a film having a magnetic track and, although the immediate intention is to apply this sound track on a film of 16 mm, it is obvious that the invention is applicable also to films of 35 mm and may, in fact, be used on all widths of films.

In practicing the method of the present invention, a band comprising magnetic properties or magnetizable material is applied to the film. The strip has a uniform thickness and width, and edges that are at least substantially straight. The tape consists of a mixture sec, or taken, or vulcanized, of a suitable magnetic material and a binder. The magnetic material may be iron oxide or the like to a powdery state, dispersed throughout the binder. Although it is shown herein that the magnetic material is in powder form, is meant thereby describe the state of the material. The material used is very finely divided, or into very fine particles, although the fineness accurate is not critical and is not defined herein.

At the time of application, the mixture is-like the paint or paste. Therefore, there is an allowable range when the viscosity of the mixture of magnetic material and binder. Currently, it is preferred that the aqueous mixture is not, but is of a high consistency to have a low tendency ' Casting of by its own nature, but which can be caused to flow or to extend to a limited extent.

At accompanying drawings, 10 denotes generally an application device by means of which the magnetic strip or sound track is to be applied to the film. This application device is constituted by two elongated mounting plates, rigid, relatively heavy, 11 and 12, arranged in parallel. At their forward ends, these plates are provided with holes coinciding 13 for the passage of a pin or other mounting member or fixing. Two thin plates 14 and 15 are placed between the rear ends of the mounting plates 11 and 12. Plates 14 and 15 are arranged parallel, at a distance, and a front end wall of 16" is disposed between the front ends of these plates and a rear end wall 17 is disposed between the rear portions of these plates. The rear wall 17 is represented, for illustration, of a thickness approximately twice that of the front wall 16. These end walls are represented as being executed in the form of bars of the same width and that the plates 14 and 15, and the mounting plates 11 and 12, are parallel, to a distance from one another. A chamber or container 18, closed at its upper end by a lid C is provided between the side-wall plates 14 and 15 and the end pieces 16 and 17.

The plates 14 and 15 extending beneath the lower edges of the mounting plates 11 and 12 and have their lower edges 19 at the lower end of the front wall 16, and below the lower end of the rear wall 17. The rear wall 17 has steps to its lower end, thereby forming surfaces 20 and 21, the first is the. innermost, is provided at the rear of the chamber 18 and is located in a plane above that of the surface 21. Rivets 22 pass through the support plates 11 and 12, the side-wall plates 14 and 15 of the chamber or container and the end walls 16 and 17 of the container, by fixing all these parts in the relative position above-described.

The lower edges 19 of the ' side-wall plates 14 and 15 are parallel to each other. These side-wall plates are very thin, their thickness being only 0.15 mm and, preferably, thinner according to the material of which they are made. They are, preferably, copper or brass, and are reinforced and held in place to prevent their deformation or warping thereof, because they are applied to the larger portion of their surfaces against the mounting plates stronger 11 and 12, and only their lower edges are discovered below these mounting plates.

The angles lower rear side of the plates 14 and 15 are cut into forming shoulders 23 at the lower surface 21 of the rear end wall 17. The will see which is the purpose of this construction.

In practicing the method of the invention, a film 24 and the application device 10 are arranged relative to each other so that the lower edges 19 of the side-wall plates 14 and 15 of the application device is located on one side of the film and, preferably, against or very near one of its longitudinal edges. In the case of a 16 mm film, the lower edges of the side-wall plates 14 and 15 would otherwise engage the non-perforated film on its edge and on its edge opposite that near which are the perforations provided for the drive wheel.

The mixture M for forming the magnetic track is fed from a container (not shown) placed about 30 cm above the application device in the chamber 18, for example by a connector 25 disposed in its side wall. The mixture, in paste form, descends into the chamber and out through its open lower end, and then on the film 24. At this time, there occurs a relative movement between the applicator and the film in the lengthwise direction thereof. As shown in the drawing, the relative movement is performed allowing the application remain stationary and moving the film in the direction of the arrow 26.

When the relative movement described between the film and the application device occurs, the mixture having magnetic properties is deposited on the film, as shown in Figure 9 to 27. In fact, the height of the bearing material on the film is the height of the material in the chamber or container 18. Furthermore, the binder used in the mixture wets the inner surfaces of the side-wall plates 14 and 15, comes under the lower edges of said plates and serves to wet narrow paths 28 and 29 (Figure 9), extending in the direction of the length of the film and on the edges of the deposited mixture 27. Such paths 28 and 29 are of a width equal to the thickness of the material forming the plated side walls 14 and 15 of the application device, and are disposed directly on the sides of the deposited material, and are rectilinear with uniform edges.

When the relative movement of the device of application and the continuous film in the direction of the length thereof, the film carrying a deposit 27 moves in the rear wall 17 of the chamber or container and the inner step of this wall 20 or prior leveling mixture by operating somewhat as a blade [...] and leaving the material, as shown in Figure 9 to 27.

Furthermore, when the strap of the deposited mixture drops below the step 21 of the rear wall 17 and in front of the cut edges 23 to the lower corners rear side of the wall plates 14 and 15, the mixture is laterally expanded.

The mixture is extended by the surface 21 and the shoulder surfaces 23 substantially on the desired width, but its movement end can be produced by its own nature. It flows easily to the wet sides on the paths 28 and 29, until it forms a strip of uniform thickness sticking the film the outer edge of the path 28 to the outer edge of the path 29. Completed The band produced by the side cast the coating mixture is indicated by 30, to the fig. 10 and 11, and see that it is of the desired width, of uniform thickness and is provided with straight edges, although it is slightly inclined at its corners. The inclined angles do not anneal away or are not broken too easily. The track deposited magnetic material is dried in place. A film may then be used in production of motion pictures for the projection and the sound can be recorded in the magnetic sound track 30.

In order that the film can be wound into a coil to flat sides of substantially equal diameter along each of its sides and prevent the formation of a cone accumulating one on the other of the magnetic layers of the sound tracks 30, is used a device similar to the application device 10 but having an output of reduced width and having a portion of lesser width [...]. The device deposited a strip 31 (fig. 9) to an edge of the film out through the perforations of driving the same and. at the same time, it will form wet paths 32 and 33 along each side of the mixture of a coating deposited. When the deposited coating mixture is supplied in the last part or the scraping edge of the application device, the coating mixture is extended, and then it flows or is caused to flow laterally on the soaked covering and the paths by forming a strip 34 (fig. 101 which is relatively narrow and occupies the space between the hole and the adjacent longitudinal edge of the film. However, the strip 34 is of uniform thickness and the thickness of the strip 30, and then, due to the process used in the formation of the web 34, it also has straight sides, although inclined or with rounded corners at the junction of its side walls and its top.

The fig. 12 illustrates a slightly different process of forming the film 24. A Fig. 12, a film length relatively wide 35 is used having drive rows of perforations 36 and 37 near its respective longitudinal edges. A strip 38, relatively wide, of a magnetic composition, is deposited along the axis of the film 35 by a device similar to that described above and according to the methods proposed. The strip 38 has a uniform thickness and width with straight edges, although inclined at the junction of its top and of its side walls.

Furthermore, narrow strips of the magnetic mixture are deposited along the longitudinal edges of the film 35, outside of its hole, as indicated at 39 and 40. After the deposited material has dried or taken or is vulcanized, the film 35 is split along its axis, as indicated by the dotted line 41, so that two films, each of which corresponds, in its constitution, the film 24 above. That is, the strips 39 and 40 split parts of the film 35 are the equivalent of the web 34 of the film 24, while the divided sections of the strip 38 are each the equivalent of the web 30 of the film 24. Fig. 13 represents a The film 42, comprising rows of feed holes 43 and 44 along the respective longitudinal edges of the. By comparing the fig. 11,12 and 13, is noted that the film 24 having only a single row of perforations 45 is of the type typically used of 16 mm motion picture film. The film 42 body build typically used 35 mm film. Therefore, that the invention is applicable to all films.

By the method of the invention, a strip 46 of a mixture containing a magnetic material in amounts sufficient for the formation of magnetizable strip is deposited on the film 42, immediately inside the feed holes 44. The strip 46 corresponds, for its role and to this constitution, to the-band 30 of the film 24, and the band formed by slitting the strip 38 of the film 35. Furthermore, strips 47 and 48 of a magnetizable mixture are deposited on the film 42 on the outer sides of the rows of perforations 43 and 44 drive. The strips 47 and 48 ensure that the film 42 can be wound into a coil to flat sides; they are of equal thickness and thickness