US2655564A

US2655564A - Method of obtaining stereophonic sound

Info

Publication number: US2655564A
Application number: US245149A
Authority: US
Inventors: Holt-Seeland Aage
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-11-10
Filing date: 1951-09-05
Publication date: 1953-10-13
Anticipated expiration: 1970-10-13

Description

Oct. 13, 1953 HQLT-SEELAND 2,655,564

METHOD OF OBTAINING STEREOPHONIC SOUND I Filed Sept. 5, 1951 f 2 Sheets-Sheet 1 Ounclaunu Patented Oct. 13, 1953 UNITED STATES PATENT OFFICE,

METHOD OF OBTAINING. STEREOPHONIC SOUND Aage Holt-Seeland, Los'Angeles, Calif.

Applicationseptember 5, 195.1,,SerialNo. 245,149

Norway November 10,1950

4 Claims. 1

This invention relates to cinema performance and more particularly to a device for connecting tape or track and the sound from another sound source or group of sources on another sound tapeor track and so forth. Each of these tapes or tracks was then provided with a complete sound reproduction set and with one loudspeaker at a predetermined place in the cinema. This arrangement gave a realistic performance with a highwstereophonic effect.

The method was, however, so expensive that it has not been repeated. If thetracks should be placed at the edge'of the-film 'in the above case four trackswere used-each of them. would be too narrow to be practical. A- special tape for the sound tracks was thereforechosen thus raising the costs of the films. In addition the performance requires that the cinema is disposing; of several sound reproducing equipments.

The object of the present invention is to solve this problem in such a way that a film with a usual sound track can be employed giving a satisfactory result, at the same time as the costs of the necessary equipment are low.

According to the-present invention each' loudspeaker or group of loudspeakers is switched on or. off. by means of a stepwise movement of a perforated sheet of non-conducting material in such a way that certain loudspeakers are on when the perforated sheet is in one position, other loudspeakers being switched on by the movement of the sheet. The stepwise movement of the sheet is caused by mechanical or electrical impulses given by marks on the edge of the film. These marks may be arranged by the person operating the sound recorder or by cutting and handling of the finished film. The marks may be of different types e. g. a black strip which on the film positive will give a white strip. If a beam of light i directed upon the edge of the film this beam will only pass through every time a white (transparent) mark is crossing the beam, thus influencing a photoelectric cell placed behind the film so that the cell will give an impulse which by means of an amplifier and an electric motor or the like would move theperforated sheet one step.

Another way of marking the film consists in stamping out a bit from the edge of the film and passingthe film through a spring contact, thus giving anelectric impulse to the motor or the like which movesr the perforated sheet eachtime such a mark on the film edge passes the spring- These are only examples of how the contact. him may bemarked and how these marks may cause the movements of the perforatedsheet.

When the film edge is provided with a mark the member of the corresponding loudspeaker or loudspeakers which are to be connected for this part of the film is recorded. In this way therewill be obtained a scheme-with the numbers of the loudspeakers giving the succession for the connection of the corresponding loudspeakers. If the contacts for the loudspeakers are placed side byside laterally to the direction of motion of the sheet, the sheet may be perforated between thecontacts for the loudspeaker to be connected.

Thus, accordingto the present invention, an

arrangement for obtaining stereophonicsound- 1 by sound film performances comprising a plurality of loudspeakers which automatically are connected or disconnected in order thatv the starting point .ofthe-sound inside or outside the screen area shall be adaptedto' the pictures displayed at any time is characterized by a device for connecting or disconnecting the loudspeakers comprising a. sheet of electric insulating material having. perforations that determine the connection of. the loudspeaker to be connected; said sheet having a stepwise movement caused by optical'ormechanical marks on the film itself, said.

marks by the movement ofthe film through the projecting apparatus being capable of giving impulses to an adequate driving device, thus connecting or disconnecting the desired loudspeakers in relation to the movement of the film through the projector.

Another feature of the present invention consists therein that the film strip is provided with the impulse giving marks during cutting or setting up of the finished film, or simultaneously with the sound recording.

The invention will now be described by way of example with reference to the accompanying drawings.

In Fig. 1 is diagrammatically illustrated the layout of five loudspeakers.

Fig. 2 is a sectional view on the line I--I in Fig. 1.

Figs. 3 and 4 show film strips with different marks.

In Fig. 1, l is an ordinary film strip with a sound track 2. 3 is an ordinary play back head transforming the picture of the sound waves into electric oscillations which are amplified in the amplifier 4 and are transformed into sound by the loudspeakers ll, I2, l3, l4 and [5. Between the amplifier 4 and the loudspeakers is provided a contact table 5 where the loudspeakers can be connected or disconnected by means of the contacts 6, I, 8, 9 and [0. The strip or sheet l6 consists of an electric non-conducting material and is inserted between the contacts in such a way that Without perforations in the strip or sheet; all the loudspeakers would be disconnected. The sheet I6 is, however, provided with perforations so that at any time the desired loudspeakers are connected. For instance at the plate indicated by the transverse line I! only the contact 9 will be connected and only the loudspeaker M will be functioning. If, however, the sheet I6 is moved one step further so that the line I8 will be under the contacts, the contact 9 will be disconnected and the contact 8 connected and only the loudspeaker 13 will be functioning.

In the next position [9 the contact 8 will still be connected but simultaneously the contacts 6 and I will be connected so that the loudspeakers ll, l2 and [3 are in function at the same time. In the position 20 is the contact 6 disconnected but the

contacts

1 and 8 are still connected so that the loudspeakers l2 and 13 are functioning.

The film l is provided with suitable marks 2| which by passing a suitable device 22, for instance a spring contact or an optical device like the play back head 3, are giving impulses to the motor 23 thus moving the sheet I6 predetermined distances.

In Fig. 2, 5 is the contact table with the perforated sheet l6 inserted between the table 5 and the

spring contacts

24, 25, 26, 21 and 2B. In this figure it is seen how the

spring contacts

24, 26 and 21 through perforations in the sheet [6 are connecting the corresponding loudspeakers with the table 5 which again is electrically connected to the amplifier, the

contacts

25 and 28 and the corresponding loudspeakers being disconnected.

In Figs. 3 and 4 is shown film strips with two different kind of marks on the films. The strip in Fig. 3 is provided with notches 2| and by using such marks the device 22 (Fig. 1) could consist of a spring contact device which is connected in all the notches but is disconnected by the film itself.

The film strip shown in Fig. 4 is marked with black parts (black on the negative and trans- 4 parent on the print) and the device 22 (Fig. 1) could be an ordinary optical play back head.

Instead ofas mentioned aboveusing an electric non-conducting sheet IS, the sheet could of course consist of a conducting material thus disconnecting the loudspeakers by perforations.

By employing the method according to the present invention it would be suitable to make a scheme for placing the loudspeakers in a cinema giving the loudspeakers international numbers and places.

I claim:

1. A system for the reproduction of sound to obtain stereophonic sound from a film strip having a sound track by means of a plurality of loudspeakers selectively connected into the amplifier of the system according to the starting point of the sound inside or outside of the screen area so that the sound will be adapted to the pictures displayed from the film strip at any time, comprising means including a perforated strip of electric insulating material, a contact means operatively associated with said perforated strip and connected into said amplifier, said contact means including a contact terminal for each of said loudspeakers adapted to be connected through to said amplifier when a perforation in said sheet is moved into alignment with said terminal, said film strip being provided with marks located thereon, and means responsive to said marks on the film strip for advancing said perforated strip relative to said contact means thereby efiecting connection of the desired ones of said loudspeakers with the amplifier.

2. A system as claimed in claim 1 in which the marks on the film strip comprise notches in an edge of the film strip.

3. A system as claimed in claim 1 in which the marks on the film strip comprise transparent portions in a dark strip on the edge of the film strip.

4. A system as claimed in claim 1 in which the perforated strip comprises electrically conductive material in which the perforations constitute means for disconnecting the loudspeakers in cooperation with the contact means.

AAGE HOLT-SEELAND.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,909,370 Mallina May 16, 1933 1,953,538 Mittell Apr. 3, 1934 2,022,665 Halstead Dec. 3, 1935 2,361,490 Mueller Oct. 31, 1944 2,405,246 Watson Aug. 6, 1946