DE1050659B - - Google Patents

Description

GERMAN

In the case of sound-image films, the magnetic sound method is also used to record the sound used. For this purpose, the films, especially 16 mm narrow films, are made with high quality Magnetic sound edge tracks are provided, which are arranged on one side or on both sides of the image can. For many purposes, the raw image film is already made with the magnetic sound edge track or tracks before exposure Mistake.

For films recorded in a single line, there are sometimes difficulties with cutting and with Connecting or gluing together different film scenes, as it is sometimes impossible to avoid that the film junction of the edge track contains a continuous tone modulation. When scanning the playback head cannot momentarily follow the thickness fluctuation of the material, and there is a short but audible interruption in the sound reproduction and under certain circumstances also a kuack noise.

In order to avoid these disadvantages, in the case of a splice switch for films with magnetic sound edge tracks, according to the invention, the sound reproduction takes place on the normal edge track with the standardized image-sound offset of 28 images and on the compensation edge track with the image-sound offset of 28 + (4 + x) Images simultaneously recorded modulation, the magnetic sound scanning during the expected film connection passage without changing the film and the two image / sound offset sections alternatively and intermittently on the compensation edge track free of the film connection point.

The new device has the advantage that any types of film connection points or adhesive parts, for example from 16 mm films, by any method, including with regard to the Called for the smallest possible frequency modulation caused by wow and flutter without affecting the edge track magnetite layer or its position on the gloss or Consideration must be given to the emulsion side.

For example, the drawing shows schematically the structure of a splice switch for 16 mm narrow film with one edge track on both sides of the image. The recording takes place on both tracks at the same time, the tape head II for the compensating track is offset by a certain distance to tape head I of the 16 mm standard track in (+) or against (-) the direction of film travel. Shortly before the passage of the film joint or film splice F to be expected at the normal head I, the scanning is switched to the compensation track by a relay R with drop-out delay until the film joint or film splice F am

Splice switch for films with magnetic sound edge marks

Applicant: Südwestfunk, Baden-Baden, Hans-Bredow-Straße

Dipl.-Ing. Otto Rabe, Steinbach near Baden-Baden, has been named as the inventor

Normalkopf I walked by. Then the switch back takes place depending on the time setting of the relay the auxiliary equalizer or auxiliary amplifier output voltage of + 6 db to the normal equalizer or normal amplifier output voltage of + 6 db via changeover contacts without interruption.

An optical sound device, which is mostly present in the film recorder, provides the impulse for the relay R. A voltage sufficient to operate the relay R can be achieved at the photocell amplifier output through a narrow, preferably oval, hole L punched in the direction of travel in the 2.5 mm wide magnetite track. In the case of cemented film ends, the film thickening can also be used to generate impulses. The drop-out delay time of the relay R has an image before and an image behind the film joint or -klebestelleF to ² / 2s seconds or because of the inertia of the relay R approximately in the middle corresponding to five images on ^l Ii second set shorter least accordingly.

The drawing shows, among other things, the timing of the sound scanning of a part of the film Glue again:

1. Standard gauge from

2. standard track cd

3. Switching from tape head I to tape head II d- e

4. compensation track ef

5. Switching from tape head II to tape head I fg

6. standard gauge gh

^{1 &}

When switching from one track to the other, the level equality must be checked by a second level meter A ₂ . Since with 16-mtn-Fiknen the balancing track is only

809 749/146

Claims (2)

0.8 mm compared to the 2.5 mm wide standard gauge, the gain after equalization is at least three times greater and thus the signal-to-noise ratio also deteriorates by about 10 db. If two glued points should be so close to each other that one of them falls within the scanning of the compensation track, a glued menstrual disturbance is inevitable. However, this coincidence can be countered during the editing of the cut. It must be noted that the splice switch only works properly for films that are finally cut for demonstration. After the two-track recording, these films may no longer be subject to editing. Since both tracks are recorded at the same time, in the event of a failure of the standard-gauge amplification, one has the option of reproducing the magnetic sound recording via the compensating-track amplifier II by continuously actuating the relay R via the compensating-track amplifier II - but then with film connection or splice faults - without any significant deterioration in quality. In order to keep the quality and the level ratios within limits for the intermittent scanning of the compensating track as favorable as possible, the compensating track head II must be electrically, magnetically and mechanically similar to the normal track head I. Even if the reproduction on the equalization track is worse than on the normal track, one may use the highly developed, practically hum-free amplifier (possibly without mains-fed tubes or with transistors) and with the use of a fast-switching relay, furthermore under the use of a flawless compensating track head arrangement, unaffected by the perforation, assume that the operation via this magnetic track adhesive switch, which is independent of film connecting parts or adhesive parts of any kind, is more advantageous than all previous methods and also a risk-free, ίο financially acceptable expense due to the components used in television studio technology and sound radio means. PΛ T H XT A N S P Ρ, Γ C Ii Ε: 1. splice switch for films with magnetic sound edge tracks, characterized in that the sound reproduction of the normal edge track with the normalized image-sound offset of 28 images and on the compensation edge track with the image-sound offset of 28 + + images simultaneously recorded modulation the magnetic sound scanning takes place alternately and intermittently on the compensation edge track free of film connection points without changing the film and the two image-sound offset sections during the expected film connection point run. 2. splice switch according to claim 1, characterized in that the switching between the two sound modulations amplified at the same level takes place via a relay (R) which is controlled with a drop-out delay of at least ² / »5 seconds by the photocell provided for the light tone scanning. 1 sheet of drawings © 809 749/146 2.59