SU36679A1 - Sound recorder - Google Patents

Description

In the proposed device for recording sound on a film, a Relay disk is used, placed in a sound field. As is known, if a Relay placed in a sound field consisting of a light movable plate, for example, a mica, equipped with a light mirror and mounted on two pairs of highly tensioned threads, direct the light beam to the disk, then the light beam reflected from the mirror will shift depending on the speed of sound vibrations. The magnitude of the "reflected light beam on the scale, located at a distance d from the relay disk, as you know, is equal to

 d

l 45.6 10E g 62

where / is the length of the thread,

R is the radius of the disk relay,

V is the speed of oscillation

E is the modulus of elasticity of the material of the thread,

g-radius of the thread,

b is the distance between parallel threads.

In the schematic drawing of FIG. 1 is a horizontal cross section of the instrument; FIG. 2-vertical section.

Putting the above-mentioned system with a Relay disk into a metal box sealed with sound-absorbing material so that the sound entering through the opening 4 inside the receiver, when meeting the walls, is completely absorbed (i.e., there are no standing waves inside the device). film vibrations in the location of this device. Disk 1 The relay will be, at a large natural frequency ,. what is achieved by the tension of the thread, precisely follow instantaneous changes in sound intensity (more precisely, instantaneous changes in the square of the oscillation velocity), and thereby change the direction of the beam coming from the illuminator with a slit located in the plane of oscillation of the light beam through hole 5, mirror 7, a pocket mirror 8, a pocket mirror of a disk 1 Relay, a pocket mirror 9 and a hole 6 to a tape-drive mechanism of conventional construction. Since the light source is slit, the image obtained at | tape, has the shape of this slot; while on the path of the beam, the diaphragm, also in the form of a slit located in the plane of oscillation of the beam, when the film moves and if there are sound vibrations, a transverse phonogram is obtained on the latter.

In order to shoot, it is necessary to shift the aperture relative to the latent beam in the following way: In the absence of sound, the beam did not fall into the aperture slot; then, as the sound power increases, the beam will oscillate in increasing limits and thus more and more, and more to overlap the aperture slit, and hence the film. In this case, the oscillation frequency is light; The beam will be equal to the frequency of variation of the square of the oscillation velocity (twice the frequency compared to the frequency of the oscillation velocity), and the amplitude is proportional to the strength of the sound. Thus, the soundtrack on the tape will be exactly the same as the instantaneous values of the square of the velocity oscillation. Since such a record differs from the usual one in that the magnitude of the ordinates is proportional to the square of the oscillation velocity, when demonstrating it is necessary to work not on the linear characteristic of the photocell, but on the quadratic (national ratio proportional to the square root of illumination), which is quite easy to implement change photocell mode of operation.

With this system, it is possible to get a regular recording, rather than a quadratic one, if in addition to the alternating current of light energy we add an empty note, a much larger nerve, but this causes inconvenience in regard to the operation of the device.

The subject matter of the invention.

A device for recording sound, for example, on a film by means of

the light beam cast by the oscillating mirror is different

using a light disk 1 fitted with a light mirror and installed in the field of sound vibrations, mounted on highly tensioned threads x 2 and serving to direct the light: about the navel from the source of light at the slits; the diaphragm installed in front of the tape drive mechanism the purpose of directly supplying sound pressure to disk 1 is the latter enclosed in a box 3, the cavity of which communicates with the environment through the opening 4.

With $ 3g. one

Srig. S