SU1115104A1 - Method of measuring parameters of recording tracks of phonograms - Google Patents

Abstract

A METHOD FOR MEASURING PARAMETERS OF PHONOGRAM RECORDS, including recording phonograms on recording tracks, a different method that, in order to improve its accuracy, the base edge of the magnetic recording medium is magnetized, the measuring magnetic head is shifted along the recording tracks, at a constant speed perpendicular to the recording tracks, and at the same time, the reproducing magnetic head was played along the reproducing tracks of the recording magnetic head, along with a constant speed perpendicular to the recording tracks, and simultaneously playing the reproducing magnetic head to the recording tracks, simultaneously playing the perpendicular recording tracks, simultaneously reproducing the magnetic recording head, simultaneously playing the recording tracks, simultaneously reproducing the magnetic measuring head perpendicular to the recording tracks, simultaneously reproducing the magnetic recording head and reproducing the recording tracks. magnetic head and measure the time intervals between the reproduced signals.

Description

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The invention relates to a technique of magnetic recording, in particular to methods of control and measurement in the production of tape recorders and video recorders.

Methods are known for measuring the parameters of recording tracks of phonograms, which consist of the following operations of magnetic recording of phonograms, visualization of recording tracks and measuring parameters of tracks (for example, the width of tracks and their location relative to the base edge of the magnetic recording medium).

A known method for measuring the parameters of recording tracks of phonograms, in which bismuth-containing ferritic garnet films are used for visualization, and a polarizer of light, a translucent mirror, a microscope and a polar analyzer Lll are used for measurements.

The disadvantage of this method is the need to use complex, expensive equipment and insufficient measurement efficiency.

Closest to the present invention is a method for measuring the parameters of recording tracks of phonograms, in which the method of visualization using magnetic powder is used. For this, a carrier with photograms recorded on it is developed in a suspension of magnetic powder (for example carbonyl iron) and an easily evaporating neutral liquid (gasoline, heptane), after which measurements are made using an C-3 instrumental microscope.

The disadvantages of this method are the uncertainty of measurement, as well as the complexity of the visualization and measurement processes.

The purpose of the invention is to improve the measurement accuracy.

This goal is achieved by the fact that according to the method of measuring the parameters of recording tracks of phonograms, which include recording phonograms on recording tracks, the base edge of the magnetic recording medium is magnetized, transferring measuring magnetic head with constant speed perpendicular to the recording tracks, simultaneously measuring magnetic signals head and measure

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time intervals between the reproduced signals.

The proposed method is based on the fact that when recording phonograms with 5 longitudinal magnetization, which is used in tape recorders and. VCRs, in the residual magnetization of the magnetic recording medium, are perpendicular and transverse 10 components, the latter of which makes it possible to obtain a signal containing information about the time of intersection by the measuring magnetic head, moving perpendicular to the tracks of the edges of these tracks.

The speed of movement of the measuring magnetic head allows, instead of direct measurements of such track parameters as the track width and its position relative to the carrier’s base edge, to measure the time intervals between the reproduced signals at 25 moments of intersection of the tracks by the measuring magnetic head, as well as measuring time intervals It is produced with great accuracy, the measurement accuracy of the mentioned parameters of 30 meters of recording tracks can be significantly increased.

Figure 1 shows the magnetic recording medium, figure 2 - structural diagram of the device that implements the method; in fig. 3 - oscilloscope signal.

On the magnetic recording medium 1 (Fig. 1), magnetic recording heads 2-4 record the tracks of phonograms 5-7. In addition, FIG. 1 shows the source 8 of magnetization of the base edge 9 of the carrier and the measuring magnetic head 10. The direction of movement of the carrier during recording and the direction of movement of the measuring magnetic head 10 are respectively Vy and Vr, and the recording track width h. 50

As a device implementing the method (Fig.2), for example, the Frame-ZPM serial video recorder can be used, and the video head of the rotating video head unit of the video recorder can serve as the measuring head of the 55 magnetic head. 31 The operations of the proposed method are carried out as follows. The VCR is included in the Record mode and on the magnetic recording medium 1 (magnetic tape) produced recording heads 2-4 (Figures 1 and 2) recording tracks of phonograms 5-7. A permanent magnet can serve as the source 8 for magnetizing the base edge of the carrier. As generators of recorded signals, DC generators 11-13 are used (Fig. 2). After rewinding the recorded section of the carrier from the receiving coil 14 to the supply coil 15, the video recorder is switched to Play mode. The measuring magnetic head 10 of the rotating video head assembly 16 reproduces the signals from the magnetic recording medium driven by the drive shaft 17. These signals through the amplifier 18 are fed to the input of the meter 19 time intervals, for example, an oscilloscope having a calibrated delayed scan. . FIG. 3 shows the signal observed on the oscilloscope screen when the measuring magnetic head 10 crosses one recording track with a width h. The times t3 correspond to the moments of intersection of the track of the recorded phonogram by the measuring magnetic head, and at a constant linear velocity of movement of the measuring magnetic head Vf, the difference is proportional to the width of the track h. The proposed method for measuring the parameters of recording tracks of phonograms when measuring on the base object of a VCR Frame-ZPM ensures a precision increase of no less than two times as compared with the known method with a significant reduction in the measurement time.

Claims (1)

METHOD FOR MEASURING PHONOGRAM RECORDING WAYS PARAMETERS, including recording phonograms on recording tracks, characterized in that, in order to increase its accuracy, the base edge of the magnetic recording medium is magnetized, the measuring magnetic head is moved at a constant speed perpendicular to the recording tracks, and the signals are transmitted by the measuring magnetic head and simultaneously measure the time intervals between the reproduced signals. FIG. 1