JPH0449510A - Adjusting device for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To detect the recording pattern deviation of a magnetic tape and to easily obtain real-time linearity information of high precision by recording and reproducing a signal different from a prescribed recording format. CONSTITUTION:A recording test signal processing circuit 26 which records a test signal whose format is different from a prescribed recording signal is provided for recording magnetic heads 4 and 5, and this test signal is reproduced by heads 4 and 5. A reproducing test signal processing circuit 29 and an azimuth time difference detecting circuit 30 are added. Recording tracks 14 and 15 different in azimuth are recorded on a magnetic tape 1. This tape 1 is reproduced, and the time difference between horizontal synchronizing signals taken out from the outputs of heads 4 and 5 by the circuit 29 is read by the circuit 30 to obtain a linearity curve. Thus, linearity information is easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an adjustment device for a magnetic recording/reproducing device used in a VTR or the like, which guarantees mechanical format compatibility and performs linearity adjustment.

Conventional technology In recent years, recording and reproducing devices using magnetic recording have been widely used in VTRs, etc., and as a trend, due to the increase in signal volume due to digitization, etc., the rotation speed of head drum devices is more than three times faster than conventional head drum devices. Progress is being made in rotating magnetic tapes, narrowing tracks, and making magnetic tapes thinner. Under these circumstances, the mechanical issues are: 1) ensuring linearity 2) ensuring tape running stability 3) ensuring that the magnetic head correctly traces the recorded tracks and maintains compatibility between machines Reduction of change 4) Reduction of environmental change is mentioned, and efforts are being made to solve this problem.

Conventionally, in this type of device, the following procedure has been used to ensure mechanical format compatibility.

FIG. 4 shows a recording pattern on a magnetic tape for conventional two-channel divided recording. 1 is a magnetic tape, 2 is a first recording track on which two-channel recording is performed, and 3 is a second recording track.

Note that the recorded signal is a digital signal, and the first recording track 2 and the second recording track 3 have opposite azimuths to prevent adjacent crosstalk. Further, two magnetic heads for recording or reproducing data on the first and second recording tracks are close to each other and form a pair (not shown).

FIG. 5 shows a first conventional example, and is a block diagram of an electrical system for recording and reproducing the first recording track 2 and the second recording track 3 shown in FIG. 4 on the magnetic tape 1. FIG. 2 is a block diagram of a circuit for recording a first recording track 2 and a second recording track 3 on a magnetic tape 1 using recording-only magnetic heads 4 and 5, and reproducing them using a read-only magnetic head 6.7. The recording signal passes through the recording signal processing circuit 20 to the recording amplifier 2.
1 and recorded on the magnetic tape 1 by recording-only magnetic heads 4 and 5. Also, for reproduction, the magnetic tape 1 is reproduced and the reproduction-only magnetic head 6.7
A digital signal is extracted from the magnetic tape 1, amplified by the head amplifier 22, and outputted through the reproduced signal processing circuit 23. At this time, if the playback output of the head amplifier 22 is checked with an oscilloscope, it can be extracted as an envelope. This situation is shown in FIG. 8 is an oscilloscope screen, and 9 is an envelope. If a standard tape for compatibility confirmation is used as the magnetic tape 1, linearity can be measured from the flatness of the envelope.

FIG. 7 shows a second conventional example, in which the bitter method is used for linearity detection and is a linearity curve diagram. 1
1 is linearity deviation, 10 is linearity curve, 12
is the measurement number. In the Bic method, a recorded magnetic tape is developed with a colloid using a magnetic fluid, and the track curvature is measured using a microscope.

Figure 8 shows a third conventional example, in which azimuth time difference detection is used to detect linearity, and since the azimuth direction of the read-only magnetic head 6. Linearity is measured using the time lag. That is, the azimuth time difference detection circuit 24 measures the time difference between the signals between the read-only magnetic heads 6 and 7, and the D/A converter 25 converts the signals from DA to output. FIG. 9 shows how this is output.

13 is detected or is the nearness curve.

As explained above, conventionally, in order to guarantee mechanical compatibility of magnetic recording and reproducing apparatuses, compatible standard tapes are used to determine the envelope 9 and the nearness curve 10 of the reproducing head of the magnetic recording and reproducing apparatus using the Bick method. , mechanical compatibility has been adjusted during playback using the linearity curve 13 based on the azimuth time difference. That is, in order to bring the track deviation from the standard tape within a predetermined standard, mechanical adjustment means (not shown here) is used to make the envelope 9 or linearity curve 10.13 on the oscilloscope screen 8 into a predetermined shape. It will be destroyed.

Problems to be Solved by the Invention However, in the above conventional configuration, since an envelope is used in the first conventional example, there are problems such as instability of the envelope waveform at high frequencies, non-parallelism of the envelope due to differences in head touch, Highly accurate measurements cannot be made due to errors in the bending of the standard tape. In the second conventional example,
Since the Bic method is used, highly accurate measurements are possible, but real-time measurements are not possible, and the number of man-hours required for cutting, developing, and measuring the magnetic tape is impractical.

On the other hand, in the third conventional example, the azimuth time difference is used for linearity detection, and since it is possible to detect high precision or linearity in real time, and it can be handled as a digital value, linearity can be extracted while correcting the bending of the standard tape. is a digital V that handles digital signals.
In VTRs that handle high-band signals such as TRs, the recording-only magnetic head and the read-only magnetic head have different characteristics.
It becomes necessary to detect linearity from the reproduced signal from the read-only magnetic head using the azimuth time difference, making it impossible to detect the recording locus of the write-only magnetic head that actually performs recording. Furthermore, the read-only magnetic head is usually movable for special playback, and is often in an unstable state, resulting in a lack of reliability in detection linearity. On the other hand, in order to produce an eye pattern (RF system) with a recording-only magnetic head, a signal processing circuit dedicated to the recording-only magnetic head is required, and due to the difference in characteristics between the recording-only magnetic head and the read-only magnetic head, a recording-only magnetic head is required. It is very difficult to produce an eye pattern (RF system) for a magnetic head, and crosstalk of high-band signals makes it difficult to obtain a signal with good signal to noise ratio, making it difficult to handle.

The present invention solves the various conventional problems described above, and aims to provide an adjustment device for a magnetic recording/reproducing device that can easily obtain highly accurate and real-time linearity information.

Means for Solving the Problems In order to achieve this object, the adjustment device for a magnetic recording and reproducing device of the present invention comprises a magnetic recording and reproducing device and a predetermined recording format equipped with or added to the magnetic recording and reproducing device. It consists of a signal processing circuit that records or reproduces a second signal different from the signal, and recording pattern shift detection means.

According to the above-described configuration, the present invention records or reproduces a second signal different from a predetermined recording format on a magnetic tape using a recording or reproducing signal processing circuit, and converts the reproduced signal extracted by the signal processing circuit into a recording pattern. Detected by a deviation detection means.

Embodiment An embodiment of the present invention will be explained based on the drawings. FIG. 1 is a block diagram of an embodiment of the invention. In FIG. 1, the difference from the conventional example is that a recording test signal processing circuit 26 for recording a test signal corresponding to a second signal different from a predetermined recording signal is provided in the recording magnetic head 4.5. and the recording signal processing circuit 20 can be selected by the selection 5W 27, as well as a head amplifier 28 for reproducing test signals from the recording magnetic heads 4 and 5, a reproduction test signal processing circuit 29, an azimuth time difference detection circuit 30, and a D/A conversion. This is because a container 31 is added.

For normal digital signal recording and playback, select 5W27 to N.
The recording signal passes through the recording signal processing circuit 20, the recording amplifier 21, and the recording-only magnetic heads 4, 5.
Thus, the recording pattern shown in FIG. 4 is recorded on the magnetic tape 1. On the other hand, during reproduction, the recording pattern of the magnetic tape 1 is reproduced by the reproduction-only magnetic head 6.7, and the signal is outputted via the head amplifier 22 and the reproduction signal processing circuit 23. The playback-only magnetic head 6.7 is on/off for special playback.
It is held on a rotating drum by movable means for the track (not shown).

FIG. 2 shows a recording pattern recorded based on this embodiment, and the magnetic tape 1 has a first recording track 14 and a second recording track 15 recorded in different azimuth directions. Since analog signals are recorded, a plurality of horizontal synchronization signals 16 can be clearly seen.

On the other hand, when confirming linearity, the magnetic tape 1 on which test signals have been recorded in advance is played back, the output from the recording-only magnetic heads 4 and 5 is amplified by the head amplifier 28, and the horizontal synchronization signal is extracted by the playback test signal processing circuit 29. The time difference is read by the azimuth time difference detection circuit 30, and converted from D/A to D/A converter 31 to obtain a linearity curve.

In this embodiment, since the azimuth time difference is used for linearity detection, a synchronization signal is required to detect the time difference due to the track deviation between the first recording track and the second recording track. Y) and color (C), and set one of the two pairs of heads to brightness (Y).
Then, the other color is assigned to color (C), its horizontal synchronization signal is extracted, and the time difference is detected. FIG. 3 shows the horizontal synchronization signal taken out from the reproduction test signal processing circuit 28.

The horizontal synchronization signal 17 read from the first recording track 14 and processed by the reproduction test signal processing circuit 29 and the horizontal synchronization signal 18 read from the second recording track and processed by the reproduction test signal processing circuit 29. A time difference 19 is detected by an azimuth time difference detection circuit 30. This magnetic recording/reproducing device has a pair of heads having azimuth angles in opposite directions, and depending on the direction of deviation from the recording pattern, the horizontal synchronization signal 17 from the first recording track 14 and the second recording track The relative time difference with the horizontal synchronization signal 18 from 15 changes. Since this time deviation 19 is linearly related to the deviation from the track, the track deviation (linearity) is detected from this time deviation 19. Since the test signal is an analog signal, the head amplifier 28 and the signal processing circuit 29 are simple, do not have to be huge like a digital signal processing circuit, consume low power, and can be recorded and reproduced using a recording-only magnetic head 4.5. This makes it possible to accurately verify the linearity of the recording track. Furthermore, if it is simply added as an external jig to a digital VTR such as a recording-only machine that does not have a digital signal processing circuit, a nearness detection system can be constructed using an azimuth time difference, which is very practical.

In this example, the test signal, which is the second signal, is the luminance (Y).
and color (C), but it goes without saying that any signal that includes a synchronization signal will suffice. Further, in this embodiment, a processing circuit for recording and reproducing the test signal is provided, but it goes without saying that it may be added in a removable manner, and it goes without saying that it may be used only for either reproduction or recording. .

In the present invention, a magnetic recording/reproducing apparatus is used which has a separate recording/reproducing head, but it goes without saying that a magnetic recording/reproducing apparatus having a recording/reproducing head may also be used.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, linearity detection of a digital VTR can be performed using an analog signal, and a huge digital signal processing circuit is not required for linearity detection, and a simple analog signal processing circuit can be used for linearity detection. I can handle it,
Even a digital VTR without a playback function, such as a recording-only machine, can easily perform real-time detection using a highly accurate azimuth time difference, and its practical effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an adjustment device for a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a tape format diagram on which analog signals of the present invention are recorded, and FIG. 3 is a waveform of a reproduction synchronizing signal. 4 is a diagram of a conventional tape format, FIG. 5 is a block diagram showing a conventional example of a magnetic recording/reproducing device, and FIG. 6 is a conventional magnetic recording/reproducing method using a first conventional mass time difference or detecting proximity. Device block diagram, No. 9
This figure is an oscilloscope waveform diagram showing a slope linearity curve in azimuth time difference detection in FIG. 8. 26... Recording test signal processing circuit, 27... Selection SW1 28... Head amplifier, 29... Reproduction test signal processing circuit, 30... Azimuth time difference detection circuit, 31... D/A conversion vessel. Name of agent: Patent attorney Shigetaka Awano (1 person)

Claims (1)

[Claims] A magnetic recording/reproducing device having a separate recording/reproducing head for recording/reproducing a predetermined signal in a predetermined recording format on a magnetic recording medium; a signal processing circuit that records or reproduces a second signal different from the signal on the magnetic recording medium; and a deviation from the recording pattern recorded on the magnetic recording medium from the second signal recorded on the magnetic recording medium. An adjustment device for a magnetic recording/reproducing device, comprising a recording pattern shift detection means for detecting a recording pattern shift.