SU710068A1 - Method of monitoring the process of iclined linewise recording - Google Patents

Description

(54) METHOD FOR CONTROLLING THE PROCESS OF INCLINED LINE RECORDING

one

The invention relates to instrumentation engineering, in particular, to recording signals on a magnetic tape, where slope recording is used.

The known method and apparatus for determining the recording level of magnetic rotating heads used in video recorders, according to which the level of the reproduced signal of the additional rotating head 1 is measured.

The disadvantage of this method is the lack of continuous monitoring of the recording level at the nominal speed of the recording medium.

The closest in technical essence to the present invention is a method for controlling the process of oblique-line recording, including the operation of simultaneous reproduction of signals along the direction of rectilinear movement of a tape carrier by means of a fixed magnetic head, amplification and measurement of parameters of a reproduced signal 2.

An additional magnetic head magnetizes the magnetic tape with a constant field before starting the measurement. After the process

recordings by rotating magnetic heads from a continuous longitudinal recording track, there remain areas of magnetization between the transverse recording tracks, which are reproduced by a fixed magnetic head.

However, this method cannot determine the recording level of rotating heads. In addition, at the intersection of the inclined lines with the longitudinal path, the quality of the reproduced signal is impaired.

The aim of the invention is to control the recording level of a rotating magnetic head.

To do this, according to the proposed method, the dotted sections of the recorded control waveform are located at the intersection of the inclined lines and the longitudinal geometric line of the tape carrier, highlight the maximum value of the received pulse sequence and measure its value.

Claims (2)

FIG. 1 shows a device that implements the proposed method; in fig. 2 - the signal during sequential reproduction of video tracks by the head with a solid line shows the waveform at a low recording level, and the dotted one at a large one. The device comprises a stationary reproducing head 1, an amplifier 2, a measuring device 3, a magnetic tape 4, a block 5 of rotating recording heads with heads 6 and a recording amplifier 7. When the phase of the recorded signal at the same height of the tape is unequal, and in the presence of transverse vibrations of the tape the short circuit changes when the nth number of transverse video tracks intersects and cyclically takes values from zero to the maximum. The EMF of the magnetic head 1 changes accordingly. The condition of cycling the EMF of the head in modern video recorders is always fulfilled, because, first, the phase of the recorded signal of the video tracks at the equal height of the tape from the edge changes, secondly, the magnitude of the transverse displacements of the tape far exceeds wavelength signal. The device works as follows. The drives are turned on (not shown) by pulling the magnetic tape 4 and rotating the block 5 with magnetic heads 6. Magnetic heads 6 are connected to recording amplifier 7 and recorded on magnetic tape 4. Reproducing magnetic head 1 mounted in a rack 8 , reproduces the signals from transverse magnetic tracks 9, corresponding to the recording level, to the magnetic flux of the tape 4 of the working gap of the magnetic head 1. Signals amplified by amplifier 2 are fed to measuring device 3, such as an oscilloscope. The amplitude of the reproduced signals is then measured. The maximum value of the reproduced signal corresponds to the maximum recording level for a particular rotating magnetic head and a particular magnetic tape. The use of the invention will allow continuous monitoring of the recording level. Claims The method of controlling the process of downlink recording, including the operation of simultaneous reproduction of signals along the direction of linear motion of a tape carrier by means of a fixed magnetic head, amplification and measurement of parameters of the reproduced signal, characterized in that, in order to control the recording level, reproduce t point portions of the recorded control waveforms located at the intersections of the inclined lines and the longitudinal geometric line of the tape carrier, the selection m is the maximum value of the received pulse sequence and its value is measured. Sources of information taken into account in the examination 1. Japan Patent JVb 51-37765, cl. 102 E 31, published. 1976. 2. Japanese Patent No. 51-30455, cl. 102 E 95, published. 1976 (prototype).