JPH03212862A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To securely execute recording always under the optimum condition even when a magnetic recording medium specified as any optimum recording current is used by measuring the optimum recording current of the magnetic recording medium and setting automatically the recording current based on the measured result. CONSTITUTION:Upon receipt of an instruction signal for commencing recording, an output of an oscillator 7 is supplied to a magnetic head 4 and recorded to one track on a magnetic tape 3. A regenerative signal on this recording track is fetched to a calculator 10, and an envelope of the regenerative signal converted into a digital signal is detected, and then an optimum recording current value I is calculated to be measured. A recording current value capable of recording under the optimum condition for the using magnetic tape 3 is evaluated from the measured optimum recording current value I, and an output of the calculator 10 is converted into an analog voltage signal in a D/A converter 11, and this voltage signal is inputted to a VCA 12 to adjust automatically and set a recording signal level. By this method, even when a magnetic medium specified as any optimum recording current is used, the recording can securely be executed always under the optimum condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a helical scan type magnetic recording and reproducing apparatus, such as a video tape recorder that records and reproduces video signals.

[Prior Art] Figure 5 is a schematic diagram of the recording system of a conventional magnetic recording/reproducing device. In the figure, (1) is a recording amplifier that amplifies the recording signal, and (2) is a recording amplifier that adjusts the recording current. (3) is a magnetic tape which is an example of a magnetic recording medium; (4) is a magnetic head, which is attached to a rotating drum (13).

Next, the operation of the above configuration will be explained.

The recording signal is input to the amplifier (1) via the recording current adjustment volume (2), where it is amplified and then recorded on the magnetic tape (3) via the magnetic head (4).

The recording current at this time is the recording current adjustment volume (
2) is set by manual adjustment.

[Problems to be Solved by the Invention] Since the conventional magnetic recording/reproducing device is configured as described above, it is necessary to adjust the recording current supplied to the magnetic head so as to make full use of the characteristics of the magnetic recording medium. Therefore, when recording on a magnetic recording medium with a different optimum recording current, recording under the optimum conditions may not be possible due to forgetting to manually adjust the recording current, or it may be necessary to readjust the recording current manually. In some cases, it is difficult to perform recording on the palm of the hand under optimal conditions according to the characteristics of the magnetic recording medium, such as requiring a lot of time and effort, and it may not be possible to take full advantage of the characteristics of the magnetic recording medium. Ta.

This invention was made to solve the above-mentioned problems, and it provides a magnetic recording and reproducing system that can always perform recording under optimal conditions, no matter what magnetic recording medium with optimal recording current is used. The purpose is to provide equipment.

[Means for Solving the Problems] A magnetic recording/reproducing apparatus according to the present invention is configured to measure the optimum recording current of a magnetic recording medium and automatically set the recording current based on the measurement result. Features.

[Function] According to the present invention, the optimum recording current can be measured for each magnetic recording medium used, and the recording current passed through the magnetic recording medium used can be automatically set based on the measurement results. Therefore, no matter what magnetic recording medium is used, recording can always be performed under optimal conditions and its characteristics can be fully utilized.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the configuration of a magnetic recording and reproducing apparatus according to an embodiment of the present invention, and in the same figure, (1)
(3), (4), and (13) are the same as the conventional example shown in FIG. 5, so the corresponding parts are given the same reference numerals and detailed explanation thereof will be omitted.

In Figure 1, (5) and (8) are switches, and (7) is an oscillator for measuring the recording current.
7), when the switch (5) is switched to the ■ side, its output is supplied to the magnetic head (4) through the recording amplifier (1).

(8) is a playback amplifier, (9) is an A/D converter, (
10) is a calculator, and when the switch (6) is set to the ■ side, the playback signal that is amplified by the playback amplifier (8) and converted into a digital signal by the A/D converter (9) is output. The optimum recording current for the magnetic tape (3) is measured, and the optimum recording current for the magnetic tape (3) is determined from the value of the measured optimum recording current.

(11) is the D/A converter, and (12) is the voltage converter.
A control amplifier (hereinafter referred to as VCA) outputs the output from the calculator (10) and connects it to the D/A converter (11).
The level of the recording signal is automatically adjusted using the voltage converted into an analog signal. In addition, the above switch 1' (5
) and (6) are automatically switched to the ■ side after the level adjustment by the VCA (12), and a transition is made to normal recording operation.

Next, the operation of the above configuration will be explained.

When receiving the instruction signal to start recording, first press the switch (5).
is switched to the ■ side, and the output of the oscillator (7) is supplied to the magnetic head (4) via the recording amplifier (1) and recorded on one track on the magnetic tape (3). The recording current at this time has a waveform having an amplitude A and a period B as shown in FIG.

Next, the switch (6) is switched to the ■ side by the signal to start playback, and the playback signal picked up by tracing the recording track on the magnetic tape (3) is amplified by the playback amplifier (8). /D converter (9)
The signal is converted into a digital signal and taken into a calculator (lO).

Here, this calculator (10) operates according to the flowchart shown in FIG. That is, step 521 detects the envelope of the reproduced signal converted into a digital signal.
), the time C of the reproduced output waveform as shown in FIG. 3 is determined (step 522), and the optimum recording current value I is calculated and measured using the following equation (step 323).

1 =AX (2-C) /B Next, from the measured optimum recording current value I, a recording current value that allows recording to be performed on the magnetic tape (3) in use under optimal conditions is determined (step 524), and the setting data is Output to the D/A converter (11) (step 525).

Next, the D/A converter (11) converts the output from the calculator (lO) into an analog voltage signal, and inputs the voltage signal to the V CA (12), thereby automatically adjusting the recording signal level. Adjust and set.

Thereafter, the switches (5) and (6) are respectively switched to the ■ side to perform normal recording operations.

In the above embodiment, the recording current is set before the start of the recording operation, but the magnetic tape (3)
The same effects as in the above embodiments can be obtained by setting the recording current only once immediately after replacing the disc, or by providing an external switch and setting the recording current by arbitrarily operating this switch.

Furthermore, in the above embodiment, the target signal is overwritten without erasing the track in which the optimal recording current measurement signal is recorded, but preferably, a rotating erasing head or the like is used. It is desirable to erase the track and then record the desired signal.

[Effects of the Invention] As described above, according to the present invention, the optimum recording current is measured for each magnetic recording medium to be used, and the recording current is passed through each magnetic recording medium. ! Since the current can be automatically set, no matter what kind of magnetic recording medium is used, the optimum recording current can always be recorded under the optimum conditions, and the characteristics of each magnetic recording medium can be adjusted. can be fully utilized.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are waveform diagrams of recording current and reproduction output, and FIG. 4 is a flowchart showing the operation of a calculator. , FIG. 5 is a schematic diagram of a recording system of a conventional magnetic recording/reproducing apparatus. (3)...Magnetic tape, (4)...Magnetic head, (
5). (6)...switch, (7)...oscillator, (10)
...Calculator, (12)...VCA. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A helical scan type magnetic recording and reproducing device for recording and reproducing signals, which includes means for measuring the optimum recording current of a magnetic recording medium, and means for automatically setting the recording current based on the measurement results. A magnetic recording/reproducing device comprising: