JPS63110879A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To securely realize a horizontal H-arrangement and to obtain a video with a higher quality even at the time of azimuth overwriting by recording in different recording and reproducing heads and obtaining the recording timing of an information signal based on a reproduced synchronizing signal. CONSTITUTION:A drive circuit 10 controlled in a CPU18 controls the accumulating and reading action of a solid-state image pickup device 1. Recording signals from a processing circuit 3 are alternately supplied to the recording and reproducing heads H1 and H2 through an Amp 4, a change-over switch 5 and a switching circuit 12. A reproduced luminance signal Y from a process circuit 7 is transmitted to a timing comparator 17 through a vertical synchronizing separator 9. A PG pin on a rotary magnetic sheet 13 is detected in a PG head and PG pulses are transmitted to the CPU18 and the circuit 17. Said circuit 17 measures time from the PG pulse to the vertical synchronizing signal, detects deviation from the prescribed quantity of the measured value, and transmits a detected result to the CPU18. It transmits the recording timing of the information signal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording and reproducing device, and in particular to a magnetic recording and reproducing device that uses a rotating magnetic sheet to sequentially form concentric tracks of information signals such as video signals at different azimuth angles. The present invention relates to a magnetic recording/reproducing device using an azimuth recording method.

[Prior Art] A magnetic recording/reproducing device that forms concentric tracks on a disk-shaped rotating magnetic sheet is conventionally known. This device generally uses one track on one television screen.
It records one field. To record one frame, the tracks are formed into two trees, and the two tracks are made into a pair.

Figure 5 shows a recording format in which concentric tracks are formed while forming guard bands (gaps between tracks), where TI is the track for the first field and T2 is the track for the second field. It is a truck,
These two tracks Tl and T2 form the above-mentioned one frame. In order to realize the recording format shown in FIG. 5 in a magnetic recording and reproducing apparatus A that does not have a field memory, two recording and reproducing heads H1 and H2 are used as shown in FIG. For example, it can be placed inline. Now, if the width of the head is HW, the track width is (TW) =) IW, and the width of the card band is G.
It becomes W. Since it is an inline type, when one frame is recorded, the horizontal synchronization signal is 1 between the two tracks T1 and D2.
/2H (where H is the horizontal synchronization period).

Additionally, devices using this type of recording method have guard bands between recording tracks, so if you want to further increase the recording density, you should use a home VTR (video tape).
It is conceivable to adopt azimuth overwriting, which is also used in recorders).

Figure 7 shows a method for realizing frame recording by azimuth overwriting while maintaining compatibility with a recording/playback device that uses a recording format that performs field recording while sequentially forming guard bands as shown in Figure 5 with one head. An example of a recording format is shown below. In this case, since the first field track TI and the second field track T2 are adjacent to each other, a so-called H arrangement is performed in which the timing of the horizontal synchronizing signal is the same for both.

FIG. 8 shows the arrangement of heads for realizing the recording format of FIG. 7. Here, Hl is an O azimuth head for recording and reproducing the first field, and the head width is 1 (assuming that W is equal to the track width TW.
It is assumed that the head is for field recording and reproduction, and has, for example, a + (plus) azimuth angle. The head width of the head H2 is the same as the old head <)IW. Also,
In the track length direction, it has a staggered shape with a distance d difference between the centers of the gaps of both heads) II and Hl, and d = (n + -) ・l (L
-(1) However, there is a relationship between tL: length n20 in the track length direction corresponding to the IH light period and a positive integer.

To realize the recording format shown in Figure 7,
In the above formula (1), it is good to set n=0 and d=1/21. However, the length HL in the track length direction, which corresponds to the IH bright period, varies depending on the recording radius of the track, but generally the area where recording tracks exist is concentrated in a large radius area with good magnetic recording characteristics. Therefore, even if d is actually fixed to this value, the error will hardly cause any problem between the outermost and innermost peripheries.

[Problems to be Solved by the Invention] Now, after one frame image is recorded by the two heads H1 and H1 arranged as shown in the upper part of FIG. Consider the case where recording is performed at a track pitch TW+GW (for example, in the inner circumferential direction). Recording start timing is generally obtained based on a certain predetermined angular position of the magnetic sheet. In this example, a PG pin for generating a synchronization signal (pulse) made of a permanent magnet fixed on a magnetic sheet is used as a reference. Therefore, when all the tracks on one magnetic sheet jacket are formed by one magnetic recording/reproducing device, the above-mentioned hi between frames-recorded tracks is properly performed and does not pose a problem. When recording is performed using another magnetic recording/reproducing device, due to errors in the installation of the PG detection head that detects the passage of the PC bin and the recording/reproducing head, An H arrangement is not necessarily performed at the boundary.

Head l (1, 1 (2 and head) 11' in Fig. 8,
82' are for different magnetic recording/reproducing devices, and if there is an error in the installation as described above, the position of the horizontal synchronizing signal will be relatively shifted by t.

The problems caused by the lack of H alignment will be described in more detail below. Typically, the horizontal synchronization signal is FM modulated with a modulation carrier along with the luminance signal. At this time, the horizontal synchronization signal is modulated to the lowest frequency side of the frequency deviation, and the highest white beak of the luminance signal is modulated to the lowest frequency side of the deviation. Here, when crosstalk is mixed into the FM signal wave, the damage prevention component appearing in the demodulated signal is as follows. That is, according to the principle of triangular noise, crosstalk of frequency components close to the carrier becomes small after demodulation, but frequency components far from the carrier become large damage prevention components. Therefore, crosstalk in the horizontal synchronization signal portion is likely to become a problem.

The one shown in Figure 8 is for compatibility with a conventional magnetic recording/reproducing device that forms a guard band, but apart from this, the two recording/reproducing heads each have a positive and a negative azimuth angle. A high-density recording system is also conceivable. FIG. 9 shows an example of the recording method, but in this case as well, there is an error in the attachment of the PG detection head and the recording/reproducing head between the two devices when compatibility is established with another magnetic recording/reproducing device, as described above. Then, as shown in Figure 9, t
A problem arises in that the H signal (horizontal synchronization signal) is relatively shifted.

In view of the above-mentioned problems, the present invention reliably realizes H alignment at the boundary between new locations of the magnetic recording and reproducing devices even when recording tracks are azimuthally overwritten across a plurality of magnetic recording and reproducing devices. The object of the present invention is to provide a magnetic recording/reproducing device that can perform the following functions.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a first recording/reproducing head having a first azimuth angle and a second recording/reproducing head having a second azimuth angle. In a magnetic recording and reproducing device that records and reproduces information signals by facing a rotating magnetic sheet, a track recorded by a second recording and reproducing head is reproduced by a first recording and reproducing head, and the synchronization obtained by reproduction is performed. The present invention is characterized by comprising a control means for obtaining the recording timing of the information signal based on the signal. - [Function] In the present invention, the track recorded by the second recording/reproducing head is reproduced by the first recording/reproducing head, and the recording timing of the information signal is obtained based on the synchronization signal obtained thereby. , across multiple magnetic recording and reproducing devices,
Even when azimuthal overwriting is performed on a single magnetic sheet, it is possible to reliably achieve H alignment in which the timing of the horizontal synchronization signal is the same on both sides at the boundary where the device is changed. There is no crosstalk caused by signals, and higher quality images can be obtained.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the basic configuration of an embodiment of the present invention. Here, a
is a first recording/reproducing head having a first azimuth angle;
b is a second recording/reproducing head having a second azimuth angle, C is a rotating magnetic sheet, and the heads a and b are opposed to the rotating magnetic sheet C to record and reproduce information signals.

d is a control means, which reproduces the track recorded by the above-mentioned second recording/reproducing head b with the first recording/reproducing head a;
Based on the synchronization signal obtained by this reproduction, the recording timing of the above-mentioned information signal is obtained.

FIG. 2 shows a circuit configuration of an embodiment of the present invention. In this figure, 1 is a solid-state imaging device (image sensor) that captures an image of a subject through an optical system (not shown), and 2 is the device 1
3 is a recording process circuit that processes the output of amplifier 2, 4 is an amplifier that amplifies the output of process circuit 3, and 5 is a changeover switch that connects the output of amplifier 4 to the B terminal. . 6 is an amplifier connected to the A terminal of the selector switch 5; 7 is a reproduction process circuit that processes the output of the amplifier 6; 8 is a monitor that displays the output of the reproduction process circuit 7 as an image; 9 is the reproduction process circuit 7. This is a vertical synchronization separation circuit that separates the vertical synchronization signal from the output.

10 is a solid-state image sensor drive circuit that drives and controls the solid-state image sensor, 11 is a head drive circuit that controls the drive of the old head H2, and 12 is a switching circuit that connects to the switch 5, and the head H1 is connected to the A terminal. The head H2 is connected to the B terminal. 13 is a magnetic sheet, 14 is a drive motor that rotates the magnetic sheet 13, and 5 is a motor 1.
4 is a motor drive circuit that drives and controls the PG head, 16 is an amplifier that amplifies the PG pulse of the PG head, and 17 is a timing comparison circuit that performs recording timing. The PG pulse from 6 is input. 18 is a CPU (central processing unit) that performs control operations according to the control procedure shown in FIG.
9 is a release circuit having a release button.

In the above configuration, the solid-state imaging device 1 such as a CCD (charge-coupled device) has operations such as storage and readout controlled by the solid-state imaging device drive circuit 10 which is controlled by the PU 18. is input manually to the recording process circuit 3 via the amplifier 2,
Various signal processing is performed so that the signal form required for recording by this circuit 3 is obtained. This recording process circuit 3
A recording signal outputted from the recording amplifier 4 is inputted to the B terminal of a changeover switch 5 via a recording amplifier 4. Then,
The recording signal is led from the switch 5 to the switching circuit 12, and is alternately supplied to the two recording/reproducing heads H1 and H2 by this circuit 12 under the control of CI'tllB.

The heads H1 and H2 are located on the rotating magnetic sheet 13, and form recording tracks using the azimuth overwriting recording mode explained in FIGS. 8 and 9.

The magnetic sheet 13 is rotationally driven by a magnetic sheet rotation drive motor 14, and the motor 14 is rotationally controlled by a motor drive circuit 15 controlled by CP018.

The signal reproduced from the magnetic sheet 13 is sent from the switching circuit 12 to a regenerative amplifier (amplifier) via terminal A of the changeover switch 5.
6. The output of the amplifier 6 is sent to the reproduction process circuit 7.
Finally, the signal is processed into a signal format that can be displayed by a motor (video machine) 8. The reproduced luminance signal Y as an output signal of the reproduction process circuit 7 is supplied to a vertical synchronization signal separation circuit 9, and the vertical synchronization signal output from this separation circuit 9 becomes one input signal of the timing comparison circuit 17.

Further, the PG pin on the rotating magnetic sheet 13 is detected by the PG head, and the detection pulse (PG
The pulse) is supplied via an amplifier 18 to the CPII 18 and the timing comparison circuit 17 as the other human input signal.

The timing comparison circuit 17 measures the period from the PG pulse to the vertical synchronization signal, detects a deviation of the measured value from a predetermined value, and supplies the detection result to the CP018. Further, the output of the release circuit 19 is also supplied to the CPt 118, and the recording timing is obtained by the above.

Next, referring to FIG. 3, the above-mentioned timing comparison circuit 17
Explain the operation.

In this figure, PG indicates the timing of the PG pulse, and f
, indicates the timing of the reproduced horizontal synchronizing signal from a track previously recorded by another magnetic recording/reproducing device, and fv indicates the timing of the vertical synchronizing signal obtained by the vertical synchronizing separation circuit 9. fH′ indicates the timing of the horizontal synchronization signal originally recorded by the current magnetic recording/reproducing device;
V' indicates the timing of the vertical synchronization signal originally recorded by the current magnetic recording/reproducing device.

In the embodiment of the present invention, the period from the PG pulse to the fv pulse is, for example, 2H as shown in FIG. 3, and this is defined as the time length T. If the previously recorded track had a period from the PG pulse to the fv pulse (Tit), then the difference t corresponds to the positional error in the mounting of the PG head and the recording/reproducing heads H1 and H2 mentioned above. become.

Next, referring to the flowchart in FIG.
The control operation (algorithm) in 8 will be explained. Note that 51 to 515 represent steps of the control procedure.

First, when it is detected that the mode has been switched to recording mode (S
l) Drive the head drive circuit 11 to drive the head 111
and move H2 to the next position to be recorded (S2)
. At that time, if the first field recording/reproducing head H1 is a head as shown in FIG. The position will be overwritten by (TW-GW) so that
Similarly, in a head such as that shown in FIG. 9, the overwriting position is (HW-TW).

Next, when a release signal is manually input from the release circuit 19 (S3), the rotation of the magnetic sheet rotation drive motor 14 is started (S4). Next, when the magnetic sheet 13 reaches steady rotation (S5), the mode is switched to the playback mode (P/B mode) (S6), the changeover switch 5 is set to the A terminal side, and the changeover circuit 12 is set to overwrite with the old head. The switch is made to the A terminal side in order to obtain a video signal to be reproduced from the width corresponding to that width (S7).

Next, as explained in FIG.
To measure the period (T+t) (S8), after detecting the amount of deviation t, return the playback mode to the recording mode again (S9), and switch the selector switch 5 to the B terminal (510).

Thereafter, if the PG pulse is detected (Sll), the recording timing is corrected by the time detected in step S8, and the first field is recorded by head II (512).

Next, the switching circuit 12 is set to the B terminal side (513), and the next second field is similarly corrected by the time t, and the head H2
(514). When recording for one frame is completed in this way, the head 111.) 12 is moved eight times by the track pitch "rp" (515), and waits for the next instruction.

In this embodiment described above, during recording, the head H2 is moved to the next new recording position (step S2 in FIG. 4), but the playback track width in the overlapping area is narrow and sufficient S/ If the N ratio cannot be obtained, temporarily move the head H1 directly onto the track recorded with the previous head H1,
Sequence control may be performed in which after obtaining a reliable reproduction signal, the track pitch TP is sent and the next recording position is moved eight times.

[Effects of the Invention] As explained above, according to the present invention, a track recorded by the second recording/reproducing head is reproduced by the first recording/reproducing head, and an information signal is generated based on the synchronization signal obtained thereby. Even when azimuthal overwriting is performed on a single magnetic sheet across multiple magnetic recording and reproducing devices, the timing of the horizontal synchronization signal is maintained at the boundary where the devices are changed. Since it is possible to reliably realize the H arrangement in which both are the same, crosstalk due to the H signal does not appear on the playback screen, and higher quality images can be obtained.

[Brief explanation of the drawing]

1 is a block diagram showing the basic configuration of an embodiment of the present invention; FIG. 2 is a block diagram showing a circuit configuration of an embodiment of the present invention; FIG. 3 is a timing chart showing the operation of the timing comparison circuit of FIG. 2; Figure 4 is a flowchart showing the recording operation procedure of the CPU in Figure 2, Figure 5 is a diagram showing a recording format with a card band, Figure 6 is a principle diagram showing a recording method with a card band, and Figure 7 is a diagram showing the recording format with a card band. FIG. 8 is a diagram showing the principle of a recording method that performs azimuth overwriting. FIG. 9 is a diagram showing the principle of another recording method that performs azimuth overwriting. ) 11... First recording/playback head, H2... Second recording/playback head, 3... Recording process circuit, 5... Changeover switch, 7... Playback process circuit, 8... Monitor, 9... Vertical synchronization separation circuit, 11... Head drive circuit, 12... Switching circuit, 13... Rotating magnetic sheet, 17... Timing comparison circuit, 18... CPU. An arrow diagram showing the basic construction method of the actual V2fl+ Fig. 1 Pq A word recorder with a force (force) index Figure 5 A three-note spindle with a force Figure 6: A diagram showing the principle of Azimuth overwriting and recording 7 large nulls.

Claims (1)

[Claims] A first recording/reproducing head having a first azimuth angle;
In a magnetic recording and reproducing apparatus that records and reproduces information signals by arranging a second recording and reproducing head having a second azimuth angle to face a rotating magnetic sheet, the track recorded by the second recording and reproducing head is 1. A magnetic recording/reproducing apparatus comprising a control means for reproducing the information signal with a first recording/reproducing head and obtaining the recording timing of the information signal based on a synchronization signal obtained by the reproduction.