JPH01298563A - magnetic recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing apparatus that records signals on a tape-shaped recording medium using a rotary head or reproduces signals from the recording medium.

[Conventional technology]

This type of magnetic recording/reproducing device includes 8mm VTR and D
AT (digital audio tape recorder)
However, these devices require the rotating head to correctly trace the recording track of the magnetic tape during playback, and conventionally, the capstan motor is controlled based on a tracking error signal generated from the playback signal. There are known methods for controlling the rotational speed, such as making a magnetic head attached to a rotating drum movable by a bimorph element, and controlling the bimorph element using a tracking error signal.

[Problem to be solved by the invention]

However, in the former conventional example, the tape running speed is adjusted using a capstan motor.
The tensile system becomes a load, and a high-torque, low-inertia motor must be used to increase responsiveness. Even so, the response frequency was a few Hz at most, and it could not respond to track bends.

In addition, in the latter conventional example, since the load on the bimorph element that minutely moves the rotary head is small, the Oyabe wave number can be increased to several hundred Hz or more, and it is possible to cope with track bending. However, the driving voltage of the bimorph element is several tens to thousands of volts or more, and this high voltage must be applied to the rotating drum, and a noble metal brush or the like must be used for electrical connection, making stable connection difficult. Furthermore, since the magnetic head is attached to a bimorph element and is in a movable state,
Installation can be troublesome to adjust, and the positional repeatability of the magnetic head becomes a problem especially when recording, so countermeasures such as using a movable head only for playback and using a separate, non-movable head for recording are recommended. It becomes necessary.

In other words, in this conventional example, the cost of parts increases significantly.
Moreover, the workability of assembling becomes poor, and the product becomes very expensive and large.

Furthermore, the demand for high-density recording is increasing, and in particular,
Since digital VTRs have a very large amount of information, there is a strong requirement to reduce track pinch to 10 μm or less.
Considering compatibility, tracking that can follow the undulations of the track is essential.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a magnetic recording/reproducing device that has high tracking responsiveness, can follow track waviness, and can be manufactured inexpensively and compactly.

[Means to solve the problem]

The magnetic recording/reproducing device according to the present invention includes first and second posts located upstream and downstream of the rotating head drum and regulating the running position of the tape-shaped recording medium, and at least the running position of the tape-shaped recording medium. first and second posts having elasticity in the front-rear direction and supporting the first post and the second post, respectively;
a first support means for applying a displacement to the first and second support means, thereby displacing the first and second posts;
and a second driving means.

[Effect]

Since the first and second driving means can be arranged in a non-rotating part rather than in a rotating part such as a rotary head drum, the power supply path thereof can be made inexpensive and stable.

In addition, with the above means, the tape running load does not increase significantly, so the tracking response frequency can be increased, and trunk undulations can also be followed.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view of an embodiment of the present invention, showing a tape traveling mechanism portion. 10 is a rotating head drum;
12 is a tape cassette, 14゜15.16.17.1
8, 19, 20, 21, 22 are guide posts, 24 is a capstan, 26 is a pinch roller, 28 is an erasing head, 30, 31, 32 is a fixed head, 34 is an inlet skate unit, 36 is an outlet Side skate unit, 3
8 is the inlet side catcher 140 is the outlet side catcher 1
42 is the entrance side rail, 44 is the exit side rail, 46.48
is a reel, and 50 is a magnetic tape.

Post 17.20 together with post 18.19 are mounted on skate unit 34.36.

The tape 50 is loaded by moving the skate unit 34, 36, the post 15, 22, and the pinch roller 2'6 by levers (not shown), and the catchers 38, 40 move the skate unit 34, 36, the post 15, 22, and the pinch roller 2'6. Complete by grasping L knits 34 and 36.

This operation is similar to the conventional example. However, rotating head
Post 17, 18 immediately before drum 10 and boss immediately after)
The catchers 38, 40 and the skate units 34, 36 are constructed so as to position the skates 19, 20 with high precision. In the loading complete state shown in Figure 1,
The magnetic tape 50 is helically wound around the rotating head drum 10. Magnetic tape 5 by capstan 24
Recording or reproduction is performed when the zero is run from reel 46 to reel 48. For reference, the loci of movement of the post 15, 22 and the pinch roller 26 in the tape storage state are shown by dashed lines.

In this embodiment, during recording or reproduction, the relative position of the magnetic head with respect to the tape 50 is adjusted by simultaneously moving the posts 17 and 20 in the directions of arrows Y and Y in FIG. Achieve proper tracking.

A mechanism for adjusting the position of post 17.20 will now be described. On the entrance side, reference numerals 51 and 52 denote levers, and with the loading operation, a lever (not shown) rotates the pin 53 on the lever 52 about the shaft 54 in the Xi force direction in the figure. Then, under the action of the torsion spring 55, the lever 51
The skate unit 34 is pressed close to a fulcrum 57 at the base of the arm 56 on which the post 17 is erected. The vicinity of the fulcrum 57 is made of an elastic material. A laminated piezoelectric element 58 is fixed to the lever 51, and power can be supplied to the piezoelectric element 58 from a circuit board 59.

When a driving voltage is applied to the piezoelectric element 58 while the lever 51 is pressed near the fulcrum 57, the arm portion 56 rotates about the fulcrum 57, thereby moving the post 17 to the position Y! in the figure. The IESJI clause can be placed in the direction. Since a laminated piezoelectric element can generally only generate a displacement of several tens of μm at most, the arm portion 56 is used as a lever to increase the amount of displacement by about 10 times.

The exit side has a similar configuration, with 71 and 72 being a lever, 73 being a pin, 74 being a pivot axis of the bin 73, 75 being a torsion spring, 76 being an arm of the skate unit 36, and 77
is a pivot point of the arm portion 76, 78 is a laminated piezoelectric element, and 79 is a circuit board for supplying driving voltage to the piezoelectric element 78. The vicinity of the fulcrum 77 is made of an elastic material, similar to the fulcrum 57.

FIG. 2 shows the tape unload state. The same members as in FIG. 1 are given the same reference numerals. When the lever 52 on the inlet side and the first lever 72 on the outlet side are rotated by the bin 53.73 in the direction opposite to the arrows X□ and X0 in the figure, the lever 51.71 becomes the lever 54.74. protrusion 70.8
0 and rotate, each skate unit 34.
Evacuate to a position that does not interfere with the movement of 36. Of course, pin 53
The movement of .degree. 73 is configured to occur during or after the skate unit 34, 36 is pressed against the cutter 38, 40 and is charged by a spring or the like. The movement of the skate unit (34, 36) is carried out by pushing the bin 61°81 with a lever, etc., but when the loading is completed as shown in Figure 1, the lever 5
Needless to say, the pressure should not be in the opposite direction to the pressing force of 1.71.

Next, the tracking operation during playback will be explained. FIG. 3 shows the track pattern of magnetic tape 50. T in Figure 3
is the recorded track, l is the trajectory of the magnetic head 90, t
is the locus of the center of the track T. Trajectory 1. t has an undulation of several micrometers with respect to a straight line, and at the current technological level, the limit is to suppress it to about 3 to 10 micrometers. Therefore, if the track width is narrower than this, as shown in Figure 3. Also, the magnetic head easily deviates from the desired track. In this embodiment, the magnetic tape 50 is moved as indicated by the arrow 92 in FIG. 3 by adjusting the position of the post 17.20. On the other hand, in the conventional example, the magnetic head 90 is moved as shown by an arrow 94 in FIG.

In general, most trunk undulations have a component of about 1 to 2 cycles per track, and the response characteristic required to make the head follow the track is 1 to 2 times the rotational speed of the rotating head drum. In addition, the swing width of the magnetic tape 50 is determined by setting the trunk inclination angle θ to 66 and the deviation between i and t to 10 μ.
m, -2, 10#mp-p/sin 6 @
"d6μm, about -2, 'boss as mentioned above) 1
7.If the maximum movement distance of 20 is 100 μm, -2, then
You will be able to follow it well.

When moving the head 90 and when moving the tape 50, the head positions on the track are S and S in FIG. 3, respectively.
, S, and appears as a shift in the time axis of the reproduced signal. Therefore, in analog recording type recording and reproducing apparatuses, jitter occurs, which is inconvenient, and it is therefore necessary to take measures such as using a time axis correction circuit or changing the rotational speed of the rotating drum. On the other hand, in the case of digital recording method,
There is no problem since it is common to use a configuration in which data is reproduced using a clock that follows the reproduced signal using a PLL.

FIG. 4 is a configuration block diagram of a recording/reproducing circuit including a circuit configuration for tracking. However, we will take as an example a case where a four-frequency pilot system adopted in an 8 mm VTR is used for tracking. First, the operation during recording will be described. An analog input signal is digitized by an A/D converter 100, and a digital signal processing circuit 102 performs processing such as addition of an error correction code and interleaving. The signal is modulated into a signal suitable for magnetic recording by the modulation circuit 104, appropriately amplified by the recording amplifier 106, and applied to the magnetic head 108 to be recorded on the magnetic tape 50. Needless to say, there may be a plurality of magnetic heads 108. During recording, there is no need to apply voltage to the piezoelectric elements 58, 78.
The capstan 24 may also run the magnetic tape 50 at a constant speed.

During playback, the playback output of the head 108 is sent to the playback amplifier 11.
After being amplified by 0, the waveform is shaped by an equalizer 112,
It is demodulated by the PLL detection demodulation circuit 114 in an operation opposite to that during recording, and the digital signal processing circuit 116 performs error correction and
Performs processing such as deinterleaving. The output of the circuit 116 is converted into an analog signal by a D/A converter 118. Here, a band pass filter (BPF) 120 extracts a pilot signal recorded superimposed on a digital signal in the low frequency range of the reproduced signal, and a tracking error signal generation circuit 122 uses a known signal from the output of the BPF 120. 0 circuit 12 for generating a tracking error signal in the manner of
The tracking error signal output from 2 is the low
The signal is applied to a capstan servo circuit 126 through a bus filter 124, and controls the running speed of the tape 50 through control of the capstan 24.

However, the response frequency of the tracking servo due to the capstan 24 is usually less than a few Hz due to the inertia and load of the capstan motor, and it cannot follow the bending of the track. Even if a low-inertia motor is used to increase response speed, the fixed head in the tape path
This is undesirable because it causes fluctuations in the reproduced signal of No. 2. Therefore, in this embodiment, the BPF 128 extracts the frequency components corresponding to the undulations of the track and the peak from the tracking error signal, boosts the frequency components by the amplifier 130 and the transformer 132, and applies them to the piezoelectric elements 58 and 78. The piezoelectric element 58.78 (boss as described above) 17.2
By simultaneously moving the magnetic tape 50, the magnetic tape 50 can be run with only the load of the sliding resistance between the posts 18, 19, the rotary head drum 10, and the magnetic tape 50.

Furthermore, the reproduced signals of the fixed heads 30, 31, and 32 are not affected.

Piezoelectric elements need to be driven with high voltages of several hundred to several thousand volts, but in this embodiment, only the high frequency component of the tracking error signal needs to be applied to the piezoelectric elements 58, 78, so a transformer can be used. , the cost of the circuit section can be kept low. Since there are no electrical contacts that are opened and closed each time a tape load is performed, unlike brushes, it can be manufactured with inexpensive parts, and there are no problems with longevity.

Although the above embodiment is a case of so-called M loading, the present invention can be applied to any loading type.
In particular, no special measures are required when the movable post does not move in response to the loading operation, but when it moves as in the above embodiment, there is an advantage that no electrical contact is required.

〔Effect of the invention〕

As can be easily understood from the above description, according to the present invention, it is possible to perform tracking that follows track bending with a simple configuration, and it is possible to provide a recording/reproducing device with a narrow track, that is, with high density recording, at a low cost. It becomes like this.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the vicinity of a rotating head drum according to an embodiment of the present invention, FIG. 2 is a plan view of the unloaded state shown in FIG. 1, and FIG. 3 is a schematic diagram of the track pattern of the magnetic tape 50.
FIG. 4 is a schematic block diagram of the recording/reproducing circuit and the tracking control circuit. 10--One rotation head drum 12--Tape cassette 14. 15. 16. 17.
18. 19. 20.21.22-Guide・
Post 24-・Capstan 26-・・Pinch・
Roller 28--Erase heso-42, 44--Rail
46.48-Reel 50-・Magnetic tapeFigure 1Figure 2Figure 3Figure 4

Claims (1)

[Claims] first and second posts located upstream and downstream of the rotating head drum and regulating the running position of the tape-shaped recording medium; first and second support means for supporting the first and second posts; first and second support means for displacing the first and second posts, thereby displacing the first and second posts; 1. A magnetic recording and reproducing apparatus comprising: 2 driving means.