JPS60253050A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To execute stably high speed reproduction of odd times by forming helically a track on a magnetic tape by using a rotary head, and using tracking information used for an automatic tracking (ATF) system. CONSTITUTION:A motor 5 is rotated at a constant speed by converting an output of a frequency generator varied in accordance with a revolving speed of its motor 5, to a voltage by an F-V converter 8, and applying it to a driving circuit 10, and also brought to rotation control so that an output of a tracking detecting circuit 11 is applied to a driving circuit 10 through an adder 9, and heads 1a, 1b execute an on-track to a track recorded on a magnetic tape 12. A speed control loop of the motor 5 works so that an input signal frequency of the F-V converter 8 becomes constant, therefore, when a frequency division of a frequency dividing circuit 7 is 1/N, a rotating speed of the motor 5 becomes N times as high as the regular reproducing time. Even in this case, an output of the tracking detecting circuit 11 is applied to the driving circuit 10 through the adder 9, and the track recorded on the magnetic tape 12 and the heads 1a, 1b are brought to on-track control, as well.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording and reproducing device that can be used in digital audio tape recorders (hereinafter abbreviated as DAT) and the like.

Conventional configuration and problems The video tape recorder (hereinafter referred to as VTR) is a device that forms helical tracks on a conventional magnetic tape.
(abbreviated)). Regarding tape tracking, a VTR is equipped with a control head exclusively for tracking. During recording, the control head records a reference signal on the magnetic tape, and during playback, the control head reproduces the reference signal on the magnetic tape, and the control head is used to record the reference signal on the magnetic tape. The usual method was to control the capstan motor so that the phase of the reproduced signal was synchronized with the frequency to ensure tracking.

This method has a problem in that the control head installation tends to be distorted due to accuracy, temperature changes, and changes over time, and there are large variations among manufacturers.

In order to solve the above problem, the control head is omitted and instead, like an 8mm IJ VTR, a pilot signal is recorded as tracking information in the form of FM modulation over the entire video track during distribution, and during playback. Tracking is performed by controlling the capstan motor so that the amplitudes of the two difference frequency signals detected from the two pilot signals leaking from the tracks on both sides adjacent to the reproduction track and the pilot signal of the own track are equal. An automatic tracking method (hereinafter referred to as the ATF method) has been proposed. Especially for DAT etc. 7il, broadband f
j [+ Recording information is required, so please record & record gig information.
, lλ-dio digital data and a plurality of receiving sections on one chic.

Although this ATF system allows reproduction at the same speed as recording, it is extremely difficult to reproduce at high speeds such as 3x or 5x speed.

OBJECTS OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing apparatus that can stably perform high-speed reproduction of odd number times using tracking information used in the ATF method.

DESCRIPTION OF THE INVENTION The magnetic recording and reproducing apparatus of the present invention is a magnetic recording and reproducing apparatus that records and reproduces information by forming a helical pattern on a magnetic tape using a rotary helical 1'.

A tracking detection circuit detects tracking information of a magnetic tape recorded with a tracking information area provided at a predetermined position of each track, a drive means for running the magnetic tape, and a rotation speed of the drive means. a frequency dividing circuit that divides the output frequency information of the speed detecting means into a predetermined odd number, and a frequency-voltage converter (hereinafter referred to as
The driving means is controlled by using both outputs of the tracking detection circuit and the F-V converter.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of the main parts for explaining the tracking method (ATF) of the magnetic recording and reproducing device of the present invention.
1-digit rotating magnetic head (hereinafter referred to as head) 1a, 1b
a cylinder for holding and rotating at high speed, a motor for rotating the double cylinder 1, a position detector for detecting the rotational phase of the 3Vi cylinder 1 and detecting the rotational position of the head 1& and the head 1b, A phase control circuit constitutes a phase control loop with the four motors 2 and the position detector 3, and the motor 2, that is, the seven cylinders 1, is rotationally controlled in phase synchronization 1- with reference frequency fs.

6 is a capstan motor for driving the magnetic tape 12; 6 is a frequency generator (speed detection means) that outputs a signal with a frequency proportional to the number of rotations of the capstan motor 5; 7 is the output of the frequency generator 6. A frequency dividing circuit that divides B
1. , + y-v Kono/・-ta, 9 is the power DH device, 1o
is a drive circuit that rotates the capstan motor 5. Note that the motor 6 (!: drive circuit 10 constitutes a drive means. The head 1a,
This is a tracking detection circuit for detecting the tracking information of 1b.

The output of a frequency generator 6, which changes according to the rotation speed of the motor 5, is converted into a voltage by an F-V converter 8 and applied to a drive circuit 10 to rotate the motor at a constant speed. The output of the circuit 11 is applied to the drive circuit 10 via the adder 9, and the output is applied to the magnetic tape 12.
The rotation of the heads 1a and 1b is controlled so that the heads 1a and 1b are on track on the track recorded above. The frequency dividing circuit divides the frequency of the output No. 3 of the frequency generator 6, but since the speed control loop of the motor 5 works so that the input signal frequency of the F-V converter 8 is constant, the frequency dividing circuit 7 divides the frequency of the output signal No. 3 of the frequency generator 6. Frequency division is /N
At this time, the rotational speed of the motor 5 is N times that during normal reproduction. Even in this case, the output of the tracking detection circuit 11 is applied to the drive circuit 10 through the adder 9, and the output from the tracking detection circuit 11 is also applied to the tracks recorded on the magnetic tape 12 and the heads 1&
, 1b are under on-track control.

Here, a more detailed explanation will be given by giving an example of a specific recording of tracking pufferfish information and an example of a dragging detection circuit. FIG. 2 shows an example of a track TR and a tracking information area on the magnetic tape 12, and Fl and F2 are This indicates the tracking information area, and the area indicates the area containing other data information. Although the example in FIG. 2 shows the tracking information area or both ends of the trunk TH, other examples are of course possible.

FIG. 3 shows a specific recording example of the tracking information area F1 in FIG. In the example of FIG. 3, trunks are formed alternately at two different azimuth angles, and each track A1. A2... has the same azimuth as the head 11L, and track B1... has the same azimuth as the head 11L. B2... has the same azimuth as the head 1b. As shown in Figure 3, truck person 1, A2...
The groups "Guru Lake" and Trunk B1, B2... are recorded in different patterns, and the frequencies fh and fb are recorded as shown in 3V. A signal of the same frequency is recorded in the notched part.
indicates the double gap of head 1J1b, which moves in the direction of arrow AR.

FIG. 4 shows a specific example of the tracking detection circuit 11,
It can be used for the example tracking information area shown in FIG.

FIG. 6 is an operational waveform diagram of the tracking detection circuit of FIG. 4, and FIG. 6 is a tracking error characteristic diagram.

In FIG. 4, 13 is an RF amplifier;
, 1b are amplified. 14 and 17 are filters, each of which receives the frequency f2L from the output of the RF amplifier 13.
, fb are left and other unnecessary signals are deleted. Filter 14
．． The output of 17 is as shown in A and C of FIG. Here, the frequency f&.

fb is set so that fa has a small azimuth, and fbi has a small azimuth loss. - As shown in Figure 5, fb only plays its own tracks! - Also, in Figure 4, 15.18
is an amplitude detector which rectifies the output of the filter 14°170 and outputs a number 18 such as t, +r, = in FIG. The output of the amplitude detector 18 is set to a large amplitude by the tube regulator 19, and the sample and hold circuit 1
6, hold the output of the amplitude detector 15 (corresponding to the voltage G in Figure 6: 1). At the rising edge of the comparator 19, create the pulse E in Figure 6 via the monostadal multivib break 2o. , the output of the amplitude detector 16 is held in the sample and hold circuit 21 (corresponding to the voltage H in FIG. 5).

Therefore, in the fourth sample and hold circuit 16.21,
A voltage proportional to the overlap of the head gap to the adjacent track is held. In FIG. 4, 22 is a subtracter, which outputs the difference between the outputs of the sample and hold circuits 16 and 22.

Therefore, the tracking error characteristic showing the output with respect to the tracking error of the tracking detection circuit 11 of FIG. 4 is as shown in FIG. 6. That is, when the tracking error is zero, the output of the tracking detection circuit is zero, and if a tracking error occurs, a positive or negative voltage is output depending on the direction of the tracking error.

6, the control circuit of the capstan motor shown in FIG. Can move accurately on the track.

Here, if the frequency division ratio of the frequency divider circuit shown in FIG. Therefore, the tracks TR formed on the magnetic tape 12 and the trajectories of the heads 1a and 1b are parallel to each other and k. FIG. 7 is a diagram schematically showing the track TR and the trajectories A and B of the heads 1a+1b in this case. In FIG. 7, if the frequency dividing ratio of the frequency dividing circuit 7 is 1. When there is no frequency division by 1, normal reproduction is performed, and after the head 1a passes through the track A3, the head 1b passes through the track B2. However, if the frequency dividing ratio of the frequency dividing circuit is poor, as shown in FIG. 7, when the head 1& passes through the track A3, the head 1b passes through the trunk B1, and the inclination of the track and the head trajectory are no longer parallel. Even in this case, if there is only one tracking information area in the track TR (Fl in FIG. 7), the tracking information area F1 is almost completely on-track due to the action of the tracking information area F1. , the horizontal head 1a can pass over the track A3, making it possible to reproduce data. Of course, the same applies to the head 1b.

The above explanation is based on the case where there is one tracking information area per track on the track TR, but if there are multiple tracking information areas on one track, the tracking error will be zero in all of the tracking information areas. It is not possible.

First, each tracking information area becomes stable with some tracking error occurring in the tracking error characteristics shown in FIG. For example, if there are two tracking information areas as shown in Figure 2, area F1Vi plus
This results in an offset such as the area F2 minus, and good controllability cannot be obtained.

FIG. 8 shows an example of the tracking detection circuit 11 in which when there are two tracking information areas on one track, only one of them is used. In FIG. 8, components having the same functions as those of the tracking detection circuit 11 in FIG. 4 are designated by the same reference numerals, and the explanation of the operation will be omitted here. 1. FIG. 9 is an operating waveform diagram of FIG. 8.

In FIG. 8, reference numeral 23 denotes a selection circuit which selects the tracking information area F1. It has the function of selecting only one of F2.

This selection circuit 23 will be explained in more detail.

In FIG. 8, PG is the output of the position detector 3 (see FIG. 1), which outputs pulses twice per rotation corresponding to the heads 1a and 1b. 231 is a monostable multivibrator, 232i-, iRS flip-flop circuit, 2
33, 234, and 238 are AND circuits, 236, 237 are inverters, and 235 is an OR circuit. The monostable multi-by-break 231 outputs a high level for a certain period of time after a pulse is generated in the PG. The input of the monostable multi-by-break 231 is shown in section 9, and its output is shown in section 9 in FIG. When a pulse is generated at PO, the RS flip-flop circuit 232 is reset and the output QH becomes low level. The output Q of this RS flip-flop circuit 232 is shown in FIG.

If a pulse is generated in the PG and the comparator 19 outputs a pulse while the output of the monostable multivibrator 231 is at a no-low level (see 1 in FIG. 9), the AND circuit 238 outputs a high-level output. Then, RS
Flip-flop circuit 232 is set to output QVi
Becomes a no-evil level.

When the output Q of the RS flip-flop circuit 232 becomes the /.-E level, all the inputs of the AND circuit 233 become the No.-E level, and a pulse is generated as the output of the selection circuit 23 via the OR circuit 236. Once the output of the RS flip-flop circuit 232 becomes low level, the output of the stable multivibrator 231 becomes low level, and the output of the AND circuits 233 and 234 no longer becomes the low level, and the comparator Even if the output signal 19 outputs a pulse, the selection circuit 23 does not output an output signal.

In other cases, after a pulse is generated in the PG, the output of the monostable multivibrator 231 becomes Halbel (
71) If the inter-ni comparator 19 does not output a pulse, the RS flip-flop circuit 232 is not set, so the output QH corrobel is 11. At this time, when the comparator 19 outputs a pulse when the output of the monostable multivibrator 231 is at a low level, the inputs of the AND circuit 234 become Halvel, so the selection circuit 23 generates an output pulse via the OR circuit 236. do.

Monostable multivibrator 231 outputs...
Just head 1& while leveling.

1b or point A of each track, it is possible to distinguish whether the output of the monostable multi-by-break 231 is at a high level, or at the first half or the second half of a low level cathedral. In this case, if the comparator 19 outputs a pulse in the first half of the track, that pulse is outputted via the selection circuit 23, but the output pulse of the comparator 19 in the second half of the track is outputted by the selection circuit 2a.
Vi does not pass. Conversely, when the comparator 19 does not output a pulse in the first half of the track, the output pulse of the comparator 19 in the second half of the track becomes the output of the selection circuit 23. If the selection circuit 23 does not output a pulse, the sample and hold circuits 16 and 22 continue to hold the value of 1, so tracking information is not used.

As described above, when there are two tracking information areas in one track, the tracking detection circuit 11 uses only the trunking information area in the first half of the track by the selection circuit 23 in FIG. When signal detection is not possible, tracking detection can be performed using the tracking information area in the latter half.

In order to operate the tracking detection circuit using one tracking information area in one track, for example, in the case of triple speed playback, the navel as shown in Figure 7)'
It can be controlled so that the trajectories 1a and tb become the trajectories A and B (same as one tracking information area for one trunk).

Furthermore, it is clear from the above description that even if the recorded magnetic tape is damaged and the first half of the tracking information area is lost, it is still possible to use the second half of the tracking information area.

Further, although an example has been described in which the frequency division ratio of the frequency dividing circuit 7 (FIG. 4) is almost the same, that is, only for triple speed reproduction, as long as the frequency division ratio is an odd numbered speed, the heads 1&, 1b will each track 1. Since it passes through A2... and track 131°B2..., the same effect as triple speed can be obtained. (At even multiple speeds, after the head 1a passes through the track A1, the head 1b also passes through the tracker 3, etc., and no reproduction output is obtained.) Furthermore, the selection circuit 23 in FIG. This is an example in the case of the tracking information area, but the present invention applies only to this ft1l. Needless to say, there is no such thing.

In particular, if the address information of the track is recorded in the data area immediately adjacent to the tracking information area in FIG. 2, high-speed address retrieval becomes possible using the high-speed playback of the present invention.

Effects of the Invention As described above, the magnetic recording and reproducing apparatus of the present invention
Moreover, it is possible to perform high-speed playback of an odd number times. In particular, even if there are multiple tracking information areas in one track, high-speed playback is possible even if the magnetic tape is scratched and some tracking information areas are lost. It becomes possible.

Therefore, triple reproduction and high-speed address search are possible in digital, audio, tape recorders, etc., and the effects of the present invention are great.

[Brief explanation of the drawing]

1''A is a block diagram of the main part to explain the tracking method of the magnetic recording/reproducing apparatus of the present invention, FIG. 2 is a pattern diagram showing an example of tracks and tracking information areas on a magnetic tape, and FIG. FIG. 4 is a block diagram showing an example of the configuration of the tracking detection circuit, FIG. 5 is its operating waveform diagram, FIG. 6 is a characteristic diagram of the tracking detection circuit, and FIG. 7 is a pattern diagram showing an example of recording of the tracking information area. Figure 8 is a relationship diagram of the track head trajectory of magnetic tape+ at 3x speed.
9 is an operational waveform diagram of the tracking detection circuit of FIG. 8. 1a, 1b co-rotating head, 12, magnetic tape, TR,
A1. B1. A2. B2. A3 ,,,,,,
i-rack, Fl, F2 Tosikkinog information area, 11
, tracking detection circuit, 6, 10. drive means, 6
・Speed detection means, 7 frequency divider circuit, 8 frequency voltage converter. Name of agent: Patent attorney Toshio Nakataku and 1 other person 2nd
Figure 3 (2) Figure 5 6 - Figure 6 Figure 7 Figure 9 -

Claims (2)

[Claims] (1) A device for recording and reproducing information by forming tracks in a helical forest shape on a C magnetic tape using a rotating head, and the magnetic tape is recorded with a tracking information area provided at a predetermined position on each track. A tracking detection circuit that detects trunking information, a drive means that rotates to drive the magnetic tape, a speed detection means that detects the number of rotations of the drive means as frequency information, and an output of the speed detection means. The tracking detection circuit and the frequency-voltage converter include a frequency dividing circuit that divides frequency information into a predetermined total number, and a frequency-voltage converter that converts an output signal of the frequency dividing circuit into a voltage signal. 1. A magnetic recording/reproducing device characterized in that the driving means is rotationally controlled using the Ryokawa force of the converter. (2) Tracking information is detected using only one piece of tracking information among a plurality of pieces of tracking information on each track of a magnetic tape recorded by providing tracking information areas on each track at a plurality of predetermined positions on each track. ]・When tracking information cannot be detected from the dragging information area selected for detecting racking information, one racking detection circuit is configured to detect tracking information from other trunking information areas of each track Lj Here and there! P! A magnetic recording/reproducing device according to claim (1), wherein the magnetic recording/reproducing device has an f characteristic.