DE1055840B - Method and device for the simultaneous magnetic recording or scanning of two signals lying in the same frequency range - Google Patents

Description

It has been proposed to produce magnetograms on a flat recording medium in such a way that that by a symmetrically divided recording magnetic head two adjacent., in Their phase is offset by 180 ° from each other with recordings of the same modulation with which The aim is to use a symmetrically subdivided magnetic head for scanning, its partial windings are wound in opposite directions to each other., and thus against magnetic fields, which the two Assert parts in phase, becomes insensitive.

This arrangement can be used to have two different magnetograms on the same support to be recorded simultaneously in superposition and to be separated from each other again during scanning.

It is known when recording with high frequency magnetization the useful frequency in push-pull, while the high frequency is recorded in phase with the aim of suppressing interference during playback that occurs between the High frequency and the higher harmonics of the useful frequency arise. With this procedure is so there is only one recording channel.

In the present method, however, two useful signals are recorded, which are in the same frequency range lie, and can be scanned separately from each other without influencing each other.

Although there are also methods known, the two separate modulations on top of each other on the same Record carrier, e.g. B. two columns can be used whose directions are 90 ° to each other are twisted. However, with this method the two recordings take place one after the other; so that through the second gap or its stray field a part of the already recorded by the first gap Modulation is deleted again. In the present procedure, the record of both takes place Modulations take place simultaneously through the same gap, so that subsequent deletion is excluded.

In a method for simultaneous magnetic recording or scanning of two in the same Frequency range signals by means of split magnetic heads are used to avoid "the disadvantages the known method according to the invention at the same time in two adjacent on the signal carrier Tracks - the first signal on both tracks in phase and the second in the same / frequency range - Lying signal recorded on both tracks in opposite phase in superposition, -and; the The first magnetogram is recorded in a known manner by means of a simple, the second by means of a double ear head reproduced with coils connected against one another. -_ ■ --_ ■ - - ■: ■ _- ■ .ν- -. - .-. -. ■ .-. ".:"

Method and device

for simultaneous magnetic

Recording or sampling

two in the same frequency range

lying signals

Applicant:

Oswald Scharfenberg,
Wiesbaden, Walkmühlstr. 9

Oswald Scharfenberg, Wiesbaden,
has been named as the inventor

The simultaneous recording of the two magnetograms can thus be achieved, for example be that a symmetrically divided into two separate magnets arranged close together is used whose windings are wound in opposite directions, so that they are in the of them excited partial magnets produce magnetic fluxes which are offset from one another in their phase by 180 ° Record two identical, but anti-phase tracks of the same modulation on the signal carrier. These Traces then induce in the series-connected, the signal voltage again under opposing windings of a likewise subdivided scanning head, remain 'on a non-subdivided, normal' scanning head without effect. Conversely, two in-phase recorded partial tests induce, by co-winding the two partial magnets of the Aufsprechkopfes are obtained in the subdivided headset with against one another Windings do not have any voltage, but can be connected in series with a headphone in the same direction Windings or a normal, non-subdivided headset. "■ -

It is therefore ¹ - possible by a divided Aufsprechkopf two different modulations in super position at the same _time: record and scan then separated in time and space with separate, miscellaneous-Jtrtig switched heads the two Magnetogramme- "; by the recording head similarly constructed reproducing head Both tracks can also be removed at the same time, but separately from each other. '

909 507/273

Fig. 1 shows an example of the playback head with separate coil pairs. Each of the partial cores 1 and 2 carries two windings. The one connection 3 belonging to the path I is located in the winding 4 on the partial core 1, is by means of the connection 5 to the corresponding winding 6 on the second Partial core 2 connected; the windings 4 and 6 are wound in opposite directions. The other port 7 the winding 6 also belongs to path I. The second pair of windings is the one belonging to path II Terminal 8 connected to winding 9 on partial core 1; the winding 9 is via the line 10 connected to the winding 11 on the lower partial core 2. The two windings 9 and 11 are in Connected in series. The connection 12 of the winding 11 also belongs to path II.

The double modulation, which is caused by the two halves of the magnetic head with the same and opposite directions arranged windings is recorded or scanned, enables a further downward a ° Setting the interference voltage in relation to the useful voltage in that one of the two tracks, for example the magnetically in the same direction stores a control signal, which increases the gain during scanning regulates in the playback channel. Registers this control signal, for example in the case of a sound recording, the respective position of the manually or automatically operated volume control in the actual Modulation path, while this modulation is recorded on the other, anti-phase track, for example, when the recording is played back, the control track can be a control device in the playback path the modulation in such a way that the dynamics originally present during the recording are restored will; So it is possible, for example, to have a piece of music in the forte and piano parts with the same To store the amplitude on the recording medium and when playing with the aid of the control track restore the original volume balance. This means that the recording and playback process works across the entire volume range constant with the greatest possible signal-to-noise ratio. With the previous procedures, however, remained the The absolute value of the interference level was constant, and the ratio of useful voltage to interference voltage changed with the amplitude of the useful voltage. The ratio of the maximum useful voltage to the interference voltage is with the previous methods about 50 to 56 db (1: 300 to 1: 600). Through the specified procedure the signal-to-noise ratio can be increased again. By appropriately dimensioning the control device you can use it to set any desired playback dynamics at the same time. When playing around The control impulses can also be used advantageously on sound film or record the cardboard cover for film or the transport of the recorder for the record recording of the respective Control volume accordingly.

The recorded frequency range can easily be expanded. To this end z. B. those after dividing the entire frequency range into two or more sections Sections that are normally no longer transmitted through auxiliary frequencies (transposition frequencies), which are recorded at the same time as a second modulation; in the cheapest normal area relocated and recorded separately on the same recording medium, sampled separately and after sampling by the transpose frequency recorded relocated the relocated sections back to the original area.

The double modulation method according to the invention is also advantageous with frequency or phase modulation Realize: Become the two simultaneously recorded signal tracks by two preferably same-frequency alternating currents (carrier frequency) generated, their frequency or phase position are shifted against each other by the signal to be recorded, then one of the known Frequency or phase detector circuits the useful signal from the two sampled frequency or out of phase voltages are recovered. This method allows a frequency range to be transmitted, the lower limit of which begins at direct current values and the upper limit of which is only given by the level of the recorded and sampled carrier frequency. Become at In this way, amplitude limiters are switched into the two carrier frequency channels all interference generated by amplitude modulation is suppressed during playback.

The invention is not limited to the sound drawing, but can also be used for any storage magnetic signals, e.g. B. in the pulse storage for program control of machines, such as Machine tools, or for storing television pulses.

Claims (6)

Patent claims: 1. Method for simultaneous magnetic recording or scanning of two in the same Signals lying in the frequency range by means of split magnetic heads, characterized in that at the same time the first signal is recorded in two adjacent tracks on the signal carrier both tracks in phase and the second signal in the same frequency range both tracks are recorded out of phase in superposition and the first magnetogram is recorded in known way by means of a simple, the second by means of a double headset with mutually connected Coils is played. 2. Device for carrying out the reproduction method according to claim 1, characterized in that that the reproduction of the two signal tracks is carried out simultaneously by means of a single, split headset, which is used for the separate Reproduction of both signals on each core part carries two windings, and one winding of the one core part with the corresponding winding of the other core part in the same direction one behind the other - and the "two other windings are connected against each other. 3. The method according to claim 1, characterized in that the two superimposed on each other Recording tracks contain independent signals. 4. The method according to claim 1, characterized in that the two superimposed on each other Recording tracks contain two conditionally dependent signals, e.g. B. Dynamics Control of the magnetogram recorded in antiphase by one on the in-phase track recorded control signal, or control of the clear tone diaphragm of a Liehttonaufaufnahmegerätes at Copying from magnetic tape to optical sound film. "- 5. The method according to claim 1, characterized in that recorded on the two one above the other Recording tracks signals are registered which, scanned separately from one another, give the original signal only after they have been put together, e.g. B. Record a transposed frequency band as the first and the transpose frequency as second track. 6. The method according to claim 5, characterized in that that the two superimposed on each other Magnetograms sinusoidal or any * - ξ-hold staged pulse trains of the same frequency, which are shifted in phase from one another by the signal to be recorded ui after their separate sampling, roughly in a discriminator relationship with the original borrowed signal can be combined. Considered publications:
U.S. Patent No. 2,497,654. 1 sheet of drawings © 909- 507/273 4.59