JP3063384B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic reproducing apparatus, and more particularly to a magnetic reproducing apparatus of the type using a magnetic tape using a rotary head such as a video tape recorder. The present invention provides a means for controlling a spacing amount, and particularly relates to a magnetic reproducing apparatus capable of performing high-density recording, high-speed reproduction, and the like.

[0002]

2. Description of the Related Art FIG. 48 shows, for example, "Introduction to Magnetic Recording Technology".
(Written by Yokoyama, published by Sogo Denshi Publishing Co., page 187).
FIG. 1 is a schematic configuration diagram of a general tape traveling system in a magnetic recording / reproducing apparatus using a rotating head such as R). The traveling path of the magnetic tape T in this traveling system is as follows.

A supply reel 15; a back tension post 36 for detecting a tension caused by a running system of the magnetic tape T; and an eraser for erasing magnetic recording already recorded on at least a portion of the magnetic tape T which is recorded by a rotating head. impedance roller 55 and the guide roller 17 for stabilizing the traveling system of the magnetic tape T;; upper cylinder D ₁ and the lower cylinder D full-width erasing head 37
_A tilting post 18 for tilting the magnetic tape T introduced on the circumference of the head cylinder D constituted by ₂ ; of a head cylinder D with a rotating head (not visible behind the magnetic tape T in this figure); Peripheral edge; inclined post 20 for taking the inclination of magnetic tape T derived from head cylinder D; guide roller 21; impedance roller 70; provided in parallel with the edge of magnetic tape T to record audio information, control information, and the like. Head 7 for erasing information recorded on a linear track for erasing
3; a recording and reproducing head 74 for recording and reproducing information such as audio information and control signals on the linear track;
A capstan 22 driven by a capstan motor (not shown) for running the magnetic tape T at a predetermined speed, and a magnetic tape T between the capstan 22 and the capstan 22.
Pinch roller 75 for pinching the sheet with a certain pressing force; guide roller 80; take-up reel 23.

In the configuration described above, the magnetic tape T is pulled by the rotational force of the capstan 22 at a portion sandwiched between the capstan 22 rotating at a predetermined speed and the pinch roller 75,
It travels on a traveling system from the supply reel 15 to the back tension post 36 to the guide roller 80, and is finally wound up on the take-up reel 23. magnetic recording or reproduction of information to helical tracks is performed by a rotating head that rotates with the upper cylinder D ₁ in attached portion.

On the magnetic tape T, recording / reproducing or erasing by magnetic heads such as the full-width erasing head 37, the erasing head 73, and the recording / reproducing head 74 in addition to the rotary head is performed in the course of the traveling route. That is, when all information recorded on the magnetic tape, such as a video signal, an audio signal, and a control signal, is new, information existing in the entire width of the magnetic tape T is erased by the full-width erasing head 37, and then the recording is performed by the rotating head A video signal, an audio signal, a control signal, and the like are recorded by the reproducing head 74. In addition, at the time of after-recording of audio or when only the control signal is rewritten, only the linear track area of the magnetic tape is erased by the erasing head 73. Recording and reproducing head 74
To record new audio information and control information on this linear track.

As a recording format for recording the above-described video signal, audio signal, control signal, and the like on a helical track or a linear track, a video signal recording method generally known as a VHS method or a β method, It can be adapted to a recording format defined in a digital audio signal recording system generally called DAT.

In this type of magnetic recording / reproducing apparatus, when performing high-density recording / reproducing, it is necessary to keep the spacing between the magnetic head and the magnetic tape constant.
Furthermore, in order to perform special reproduction such as high-speed reproduction and still reproduction without generating noise, it is necessary to keep the spacing amount constant and to make the magnetic head follow the recorded helical track.

That is, in order to perform recording / reproducing or erasing of a magnetic tape in a magnetic recording / reproducing apparatus with good characteristics particularly in a high frequency region, a gap portion of a magnetic head for performing the recording / reproducing or erasing is required. It is widely known that it is necessary to keep the distance from the magnetic tape, that is, the amount of spacing, at a certain small value, and if this condition is not satisfied, the required characteristics cannot be obtained due to spacing loss.

In the magnetic recording / reproducing apparatus described with reference to FIG. 48, the impedance roller 55 of the magnetic tape T is used.
When the tension between the portion sandwiched between the magnetic tape T and the guide roller 17 and the portion sandwiched between the capstan 22 and the pinch roller 75 is increased, the magnetic tape T and the rotating head, the erasing head, and the recording / reproducing head are not The spacing between the air layers between them, that is, the spacing amount is reduced and the high-frequency characteristics are improved. However, if this tension is reduced, the spacing between the magnetic tape T and these magnetic heads is increased and the high-frequency characteristics are deteriorated. Become.

However, if the magnetic tape and the magnetic head come into direct contact with each other because the distance is too small, the contact increases the wear of the magnetic head, lowering the durability and damaging the tape. In addition, in the case of still playback, the same track is continuously played back, which impairs the durability of the magnetic tape.

Therefore, it has been conventionally required to keep the spacing between the magnetic tape and the magnetic head constant, and a method of controlling the back tension applied to the magnetic tape has been known as one of the methods to meet the demand. ing.

FIG. 49 shows an example of a back tension control device applied to the magnetic recording / reproducing device shown in FIG. 48 to control the back tension so as to keep the spacing constant. , Supply reel stand 1
The force required for pulling out the magnetic tape T from the supply reel 15 mounted on 5a, that is, the back tension is controlled so that the tension of the magnetic tape T is kept constant. The supply reel shown and the back tension post shown at 36 are shown in FIG.
Also shown in FIG.

A band brake 76 having one end fixed thereto is provided on the periphery of the supply reel base 15a to suppress the rotation thereof, and the other end is provided on a tension control arm 77 rotatable about a shaft 77a. Is engaged with the pin 77b. At the opposite end of the shaft 77a of the tension control arm 77, the back tension post 36 with which the magnetic tape T is engaged is provided, and one end of a coupling portion 77c provided at an intermediate portion thereof has a tension adjusting lever 79. Tension spring 7 connected to the tip
8 is attached to the other end.

The tension adjusting lever 79 is configured to be rotatable about a shaft 79a. By rotating the adjusting lever 79, the tension force of the tension control arm 77 by the tension spring 78 is changed. Thus, the reference tension of the tension control device can be adjusted.

In the tension control device shown in FIG. 49, when the tension of the magnetic tape T increases, the tension control arm 77 rotates clockwise in the drawing against the tensile force of the tension spring 78, and the peripheral edge of the supply reel base 15a. The pin 77b with which the other end of the band brake 76 is engaged moves rightward in FIG.
6 is loosened, the force regulating the rotation of the supply reel table 15a is weakened, the feeding amount of the magnetic tape T is increased, and the tension of the magnetic tape T is reduced.

Conversely, when the tension of the magnetic tape T decreases, the tension control arm 77 rotates counterclockwise due to the contraction of the tension spring 78, and the supply reel table 1 is rotated.
The pin 77b, which is engaged with the other end of the band brake 76 provided on the periphery of the band 5a, moves to the left in the drawing to increase the braking force of the band brake 76, so that the amount of magnetic tape T sent out decreases. Thus, the tension of the magnetic tape T also increases. Note that the reference tension amount can be adjusted by rotating the adjustment lever 79 as described above.

In the conventional magnetic recording / reproducing apparatus, the tension of the magnetic tape is adjusted by using the above-described mechanism, thereby absorbing a gradual change in the amount of tape tension at the tape supply source. Is kept constant.

In such a conventional system, the amount of spacing between the magnetic tape and the head has not been controlled in relation to the amount of tape tension, and the control of the amount of spacing is solely achieved by making the surface accuracy of the magnetic tape uniform. Or
By strictly controlling the surface characteristics and window shape of the head cylinder, the protrusion amount and the tip shape of the magnetic head in the manufacturing process, the spacing amount is kept constant, and the head contact is secured.

However, it is extremely difficult to control the amount of spacing with the accuracy required when performing high-density recording with high linear recording density on a magnetic tape.
In a device that performs special playback such as playback and search by running a magnetic tape at high speed, the tape running speed fluctuates greatly and a transient tension occurs on the tape. It is virtually impossible to keep the tape tension and the amount of spacing constant.

That is, the control of the spacing amount relying on such a mechanical structure can be applied to a system that requires only a low control band, that is, a system whose recording density is not so high. Attempting high-density recording poses a major problem.

Further, in a magnetic tape device, when a tape having extremely good surface properties such as a vapor-deposited tape is used, the amount of spacing, that is, the accuracy required for a head contact also varies. Therefore, more precise and precise control is required, and it is becoming difficult to respond only by controlling the head contact relying on a mechanical configuration.

On the other hand, in special reproduction such as high-speed retrieval, the tape running speed fluctuates greatly, and a transient tension is generated on the tape. In such a case, it is difficult to keep the tape tension constant and the amount of spacing with a mechanical control system, and the head contact will necessarily deteriorate.

Next, tracking for the magnetic head to trace the helical track will be described. The trace on the magnetic tape by the magnetic head during normal speed (1 × speed) reproduction is performed by keeping the running speed of the magnetic tape and the rotational speed of the rotary head the same as during recording. The angle to the edge of the tape will be the same as the angle of the track being recorded.

However, if the reproduction is performed with the rotation speed of the rotary head being the same as that for recording and the running speed of the magnetic tape alone is different from that for recording, the angle traced by the magnetic head is equal to the angle of the recording track. Since they do not match, a track shift (hereinafter, referred to as a tilt error) occurs, and noise is generated on a reproduction screen.

The helical scan type VT as described above
In a conventional auto-tracking reproducing apparatus for matching the trajectory of a magnetic head with a recording track in R, a magnetic head for reproducing a video signal is usually mounted on an electro-mechanical transducer (hereinafter abbreviated as a head actuator), During reproduction, the head actuator drives the magnetic head in a direction perpendicular to the traveling direction of the recording track or in a direction having a perpendicular component, and performs automatic tracking control so that the magnetic head traces the recording track.

Various methods have been proposed for a so-called auto-tracking control technique for automatically tracking a magnetic head attached to a head actuator on a recording track, and have already been put to practical use.

Regarding the detection of tracking errors, as is well known in, for example, the 8 mm VTR format, several kinds (for example, four kinds) of low frequency tracking pilot signals outside the video signal band are superimposed on the video signal to form several tracks ( (4 tracks) are recorded so that different pilot signals are adjacent to each other. In this pilot system, a tracking error signal is detected at the time of reproduction due to a difference in crosstalk level from right and left tracks.

Also, a 1-inch VTR made by Ampex and a D-2 format digital VTR DVR made by Sony Corporation.
In the wobbling method practically used at -10 or the like, the magnetic head is forcibly vibrated at a constant frequency, that is, a so-called wobbling frequency in the track width direction. The reproduction envelope signal from the magnetic head at that time is synchronously detected at the wobbling frequency, and a tracking error signal is detected.

Further, NV-10 manufactured by Matsushita Electric Industrial Co., Ltd.
000-type VHS-VTR and Mitsubishi Electric Corporation VHS-
In the so-called hill-climbing method that is put into practical use in the HV series of VTRs or the F75 type, a reproduction envelope signal from a magnetic head is sampled and held at the center of a read field, and then a voltage applied to an actuator or a capstan is applied. A series of operations in which the rotation phase of the motor is changed by one step (for example, increased), and then the envelope level of the frame is compared with the sample hold value until the envelope of the next frame becomes smaller. When the envelope of the next frame becomes smaller, the direction of the applied voltage is reversed, and the same operation is continued, so that the reproduction envelope converges toward the maximum value.

A conventional auto-tracking reproducing apparatus is realized by detecting a tracking error by the above-described various tracking error detection methods and feeding back the tracking error to a head actuator built in a head cylinder. .

Generally, such a movable head is used not only for DTF control for correcting a tracking error during normal speed reproduction but also for special reproduction such as high speed reproduction, slow reproduction and still reproduction. There are many.

FIG. 50 shows an example in which such a movable head is used for noiseless special reproduction in a National Technical Report.
t) A schematic diagram of the system published on page 41 of Vol. 28, No. 3 (June 1982) is shown.

Briefly describing these conventional high-speed special reproduction methods, the rotating magnetic head H is driven by a head actuator 14 in a direction perpendicular to the tape running direction in the block diagram of FIG. The tracking error amount is detected by the tracking error detector 16 from the reproduction envelope signal of the magnetic head H.

The tilt correction pattern generator 18 outputs tape speed information from, for example, a frequency generator indicating the rotation speed of the capstan so that the angle at which the magnetic head H scans on the tape matches the angle of the recording track. To perform a tilt correction to generate a tilt correction pattern for causing the magnetic head H to trace a track.

The tracking error signal from the tracking error detector 16 and the tilt correction pattern from the tilt correction pattern generator 18 are added by an adder 410 to move the magnetic head in the direction of travel of the magnetic tape. For driving the head actuator.

More specifically, the angle at which the magnetic head H traces on the tape during normal speed (1 × speed) reproduction is the same as the angle of the recording track. Since the tracing angle does not coincide with the angle of the recording track, a track shift (hereinafter referred to as a tilt error) occurs, and noise is generated on the reproduction screen.

As an example, FIGS. 52 and 53 are schematic diagrams showing the relationship between the recording track pattern on the magnetic tape and the trajectory of the magnetic head. The rotational speed of the rotary head remains the same as during recording. 52 and FIG. 53 show the case of 5 × speed reproduction in which the tape travel speed is set to 5 times the recording speed in the forward direction and the tape is played back in the reverse direction.

FIG. 52A shows the locus of the magnetic head at the time of recording and normal reproduction. When the traveling speed of the magnetic tape is increased by five times in the forward direction, the locus of the magnetic head has an angle. As shown by B, the magnetic head intersects the five tracks (1) to (5) within a period in which the magnetic head crosses the width of the magnetic tape.

FIG. 53 shows the trajectory of the magnetic head when the magnetic tape is run at a speed five times the speed in the direction opposite to the trajectory of the magnetic head during normal reproduction.
The trajectory C having a small angle intersecting with the track of-is drawn.

Even in a special playback mode in which a magnetic tape is run at a speed different from the speed at the time of recording, such as this 5 × speed playback, in order to perform noiseless playback without generating noise on the playback screen, the recorded track must be read. The trajectories B and C must be corrected so that the trajectory of the magnetic head traces.

FIG. 54 shows a VTR of a so-called guard bandless recording system in which signals between adjacent tracks are separated by using azimuth loss without providing a space between adjacent tracks, and two magnetic heads are used. FIG. 9 is a schematic diagram of a tilt error pattern when n-times speed reproduction (n is an arbitrary real number) is performed by a reproducing apparatus using a rotating head having a facing position 180 degrees apart from each other.

Now, let T be a half cycle of the rotation of the movable head,
Assuming that tp is a track pitch, the tilt error at the time of n-times speed reproduction is tp (n-1), and the value of the tilt error is expressed as a function having the reproduction speed ratio n as a parameter. In other words, the tilt error will vary depending on the tape running speed.

The tilt correction pattern generator 18 in FIG. 51 generates a tilt correction pattern by using, for example, an FG signal from a capstan frequency generator or the like as the tape running speed information. When this inclination correction pattern is applied to the head actuator 14 in FIG. 51, the inclination of the trajectory of the magnetic head H is corrected so as to move in parallel with the recording track even at the time of different speed reproduction.

However, if the magnetic head H is simply displaced following the angle of the recording track, a further track deviation occurs due to linearity of the trajectory of the recording track and the magnetic head H or a phase deviation of the track. In order to prevent this track deviation, an automatic tracking control system using a closed loop surrounded by a dotted line in FIG. 51 is usually added.

As a control method of the auto tracking control system, the pilot method, the wobbling method,
Any method such as a hill-climbing method may be applied, but it is necessary to follow the non-linearity of the recording track (hereinafter referred to as track bending) in order to obtain high-quality images even at different speed playback. For this reason, it is desirable to adopt a pilot system or a wobbling system that allows a relatively wide control band. Since the control method and operation of this auto tracking control system are already known, a detailed description will be omitted here.

[0046]

SUMMARY OF THE INVENTION A high-definition signal,
In a digital VTR or the like that records and reproduces a video signal and an audio signal by digitizing the information, the amount of information of the signal to be recorded is greatly increased. Therefore, reproduction technology by high-density recording and high-precision DTF control is indispensable.

In the DTF device of the conventional VTR, the tracking error correction means is only the movable head provided in the head cylinder, so that the DTF control performance is determined by the performance of the head actuator for moving the movable head.

Therefore, a head actuator that is generally used for DTF control of high precision and wide band and has a relatively high frequency, for example, a phase shift from about 1 KHz to several KHz, is selected because of good controllability. In order for a phase shift not to occur at a high frequency, mechanical characteristics that do not resonate at a high frequency are required.

Generally, the primary resonance frequency of the mechanical properties of an actuator is given by the square root of the actuator spring constant divided by the mass of the movable part of the actuator divided by 2π. Is reduced, or the spring constant of the actuator is increased.

As described above, the movable head is generally used not only for DTF control during normal speed reproduction but also for special reproduction. Conventional VT
The high-speed noiseless reproducing apparatus in R corrects a tracking error by moving a magnetic head in the width direction of a recording track by a head actuator. Therefore, the correctable tracking error amount is limited within the movable range of the head actuator.

For this reason, in the conventional configuration, the head actuator must be built in a head cylinder whose outer diameter is determined according to the standard, and a small actuator is inevitably required. The spring with the high resonance frequency is selected to have high rigidity.
Its movable range is narrowly limited. Therefore, high-speed special reproduction performance is reduced.

As described above, in the conventional apparatus, it is physically impossible to simultaneously realize both high-precision and wide-band DTF control with a control band of several hundred Hz and noiseless high-speed reproduction performance of several tens times speed. There was a problem that was impossible.

[0053]

Since the tape tension control mechanism in the conventional magnetic recording / reproducing apparatus is constructed as described above, when a high-speed tape runs, only a certain load is applied in the direction opposite to the tape feed direction. Does not perform special tape tension control. Therefore, the tape cannot be responded to the transient tension fluctuation,
In addition, there has been a problem that an output change occurs due to a change in a contact state between the magnetic head and the tape due to a change in the tension, and the information is likely to deteriorate.

Further, the conventional tension control device has a narrow tension control band and can suppress only a tension fluctuation of several Hz or less. Therefore, digital VT
In a VTR that performs high-density recording / reproduction such as R, it is impossible to always keep an optimum spacing between a magnetic head and a magnetic tape at a desired value, and good recording / reproduction cannot be performed. was there.

Since the conventional magnetic recording / reproducing apparatus is configured as described above, it is possible to maintain the tape tension and secure the head contact in a low band on the tape sending side, but the load fluctuation of the tape running system is possible. However, there is a problem that it is not possible to remove the fluctuation of the tape tension of the head cylinder portion caused by the above. Fluctuations in the amount of spacing between the magnetic tape and the head caused by fluctuations in the tape tension in the head cylinder block the realization of high-density recording, and also cause tape scratches and head wear.

On the other hand, the fluctuation of the spacing amount also occurs due to the eccentricity of the head cylinder, which causes the problem to be further exacerbated. Similarly, in a magnetic disk device or the like, the fluctuation of the spacing amount caused by the disk runout or the like is a serious problem. As described above, in the conventional magnetic recording / reproducing apparatus, it has been important to maintain a constant amount of spacing, enable high-density recording, and improve the reliability of the apparatus and the recording medium.

The present invention has been made in order to solve the above-mentioned problems, and performs noiseless high-speed reproduction such as tens of times speed while performing DTF control in a wide band such as a control band of several hundred Hz at a high speed. It is an object of the present invention to provide a magnetic reproducing apparatus which is realized simultaneously without image deterioration.

Another object of the present invention is to provide a magnetic reproducing apparatus capable of always realizing optimal contact between a head and a tape by high-precision and wide-band tension control, and capable of excellent recording and reproduction.

Further, by controlling the amount of surface pressure received by the magnetic head from the recording / reproducing medium to be constant, the spacing between the magnetic head and the recording / reproducing medium is always controlled to be constant. It is an object of the present invention to provide a magnetic recording / reproducing apparatus capable of realizing recording and greatly improving the reliability of a device and a recording medium.

[0060]

FIG. 1 is a conceptual view showing one of the basic principles of the present invention, in which a head cylinder provided with a rotating head H (in this figure, a rotating surface of the rotating head of the head cylinder). (Only 1 is indicated by reference numeral 1). A pair of entry-side fixing pins 10a ₁ ,
10a ₂ and an input side movable pin 9a are provided, and _two output side fixed pins 10b ₁ and 10b ₂ and an output side movable pin 9b are provided on the outlet side of the head cylinder.

The entry side movable pin 9a is provided with an entry side tape actuator 11a for changing the distance of the entry side movable pin 9a with respect to the line connecting the pair of entry side fixed pins 10a ₁ and 10a _2. Further, the exit side movable pin 9b provided exit side tape actuator 11b for changing the distance of the exit-side movable pin 9b with respect to the pair of output-side fixing pins 10b _1, 10b ₂ a line connecting.

The tension at the head cylinder portion of the magnetic tape T can be controlled by moving the entry movable pin 9a by controlling the entry tape actuator 11a.

When performing reproduction at a speed different from the tape speed at the time of recording, the input side tape actuator 1
Tracking can be performed by differentially moving the output tape actuator 1a and the output tape actuator 11b with respect to each other.

Further, the above-mentioned entrance tape actuator 1
Extremely accurate control can be performed by using a control system including a state estimator that simulates the characteristics of the tape actuators 11a and 11b to control the tape actuator 1a and the output tape actuator 11b.

When a magnetic head movable in the direction of projection toward the recording surface of the recording medium is used, a surface pressure estimator for estimating the surface pressure of the magnetic head based on the displacement of the magnetic head is provided. The surface pressure of the magnetic head can be controlled by a surface pressure control signal obtained based on the difference between the surface pressure estimation value estimated by the surface pressure estimator and the reference surface pressure.

The configuration of a control system for controlling these components of the present invention, in particular, a state estimator that simulates the characteristics of a tape actuator and a surface for estimating the surface pressure of a magnetic head, which are other features of the present invention. The configuration and operation of the pressure estimator will be clarified in the description of the embodiment described below.

As the head cylinder in the present invention, a head cylinder provided with a magnetic head and having a rotating upper cylinder and a non-rotating lower cylinder is used.
Use a known type such as a type in which a rotating drum or disk with a fixed magnetic head is provided between two non-rotating cylinders, or a type in which a magnetic head is provided in a rotating head cylinder. Can be. In addition, as the fixed pin 10 and the movable pin 9, a roller can be used.

[0068]

Referring again to FIG. 1, if the two tape actuators 11a and 11b are driven non-differentially, for example, only the input tape actuator 11a is driven without driving the output tape actuator 11b, the input movable It is apparent that the tension of the magnetic tape in the head cylinder changes in accordance with the vertical movement direction and the amount of the pin 9a. By controlling the tension of the magnetic tape, for example, control of head touch or magnetic recording / reproducing apparatus can be performed. Compensation of the applied acceleration can be performed.

The input tape actuator 11a
If the output tape actuator 11b is driven differentially, that is, in the direction opposite to the vertical direction, the magnetic tape T in the head cylinder portion between the two loops is advanced or retracted in the longitudinal direction. Since the traveling speed of the magnetic tape in the head cylinder changes without affecting other areas of the traveling system, the tape actuator 1 is controlled based on the amount of tracking error.
By driving differentially 1a and 1b, a tracking error can be corrected.

That is, when the magnetic tape is running at the speed of V _C , the movable tape pin 9a on the entry side is moved to the speed V _B.
To move up (+ V _B ) or down (−V _B ), and move the movable tape pin 9b on the exit side down (+ V _B ) at the same speed V _B.
V _B ) or differentially up (−V _B ), 2
The tape speed between the two rollers, that is, the tape speed _VA at the head cylinder portion, is expressed by a linear relational expression as shown in the following expression (1). _{V A = V C + 2V B} ... (1)

Therefore, based on the equation (1), the movable tape pins 9a and 9b on the incoming and outgoing sides are forcibly differentiated by a triangular wave or a sawtooth wave having a frequency Fs synchronized with the rotation frequency of the magnetic head in an open loop based on the equation (1). by operating the tape speed of the head cylinder unit to or slower intermittently fast in the range of V ± V _B relative to periodically normal playback speed V, the tracking is maintained even at the time of trick play A period T can be obtained. This period T is Fs / 2 in an ideal case using a triangular wave, that is, a period of a half cycle of the triangular wave.

If this period is made smaller than Fs / 2 in view of safety from the limit of the response speed of the tape actuator, for example, during one period T during which tracking, which is the rising period of a triangular wave, is maintained. At least one screen of the signal is reproduced, and the reproduced signal is stored in the image memory. During the non-reproducible period during which tracking cannot be performed, such as the falling period of the next triangular wave, the reproduction signal from the image memory is read out. If the video signal is output to the screen, it is possible to perform good signal reproduction although the movement may be somewhat intermittent.

The range of the double speed at which the reproduction speed can be changed by this method is determined by the movable tape pins 9a and 9a on the input side and the output side.
It is determined by the stroke of b and the frequency (hereinafter referred to as cycle frequency) Fs of the triangular wave. For example, in the case of a tape format in which one frame of image data is read out during a period in which the rotary head makes one rotation using a multi-head, the reproducible magnification N, the stroke t of the input side and output side movable tape pins 9a and 9b are set. , And the cycle frequency FS, the period T is set to Fs / 4 in consideration of the safety factor.
, The following equation (2) is obtained. N = (4FsX _PP / V) +1 (2)

[0074]

【Example】

[Schematic of First Embodiment] A first embodiment of the present invention will be described with reference to FIG. 2 which is a schematic block diagram.

In FIG. 2, D is a head cylinder,
T is a magnetic tape; Ha and Hb are one or two magnetic heads attached to a head cylinder D; 4 is a supply reel motor for supplying the magnetic tape T to the head cylinder D; A take-up reel motor for winding the magnetic tape T at a constant speed in a longitudinal direction of the magnetic tape T; and a capstan motor 6 for driving a capstan for feeding the magnetic tape T in the longitudinal direction. A pinch roller 8 for pressing and transmitting the driving torque of the capstan motor 6 to the magnetic tape T;
a is a slant pole on the entrance side of the magnetic tape T of the head cylinder D, and 8b is a slant pole on the exit side of the magnetic tape T of the head cylinder D.

The switch 3 is provided for switching the target of DTF control between a capstan motor and a reel motor. In other words, the tape feed during normal recording / playback or playback up to several times speed is performed by the capstan motor, but when playing back at several tens times speed, such high speed tape feed must be performed by the capstan. Is impossible, the tape is fed by the reel motor on the winding side.

For this reason, the target of tracking error control by the DTF control system is a capstan motor at a tape speed up to several times speed, and a winding-side reel motor at a speed of several tens times speed or more. The switch 3 is provided for switching the target of the DTF control between the capstan motor and the reel motor.

In the case of several tens times speed as described above, since the capstan is separated from the magnetic tape, it is not always necessary to supply power to the capstan motor. Also,
The reel motor is always supplied with DC power according to a mode such as recording / playback, but in this figure, the DC power supply circuit is not shown in order to avoid complication. .

Reference numeral 9a denotes an input side movable tape pin movably provided on the inlet side of the magnetic tape T of the head cylinder D;
Numeral 0a designates collectively two entry-side fixing tape pins provided to face each other on the magnetic tape entrance side of the head cylinder D, and these two fixing tape pins 10a
Is set to be slightly larger than the maximum diameter of the entry-side movable tape pin 9a, and the movement locus of the movable tape pin 9a can change the distance with respect to the line connecting the two entry-side fixed tape pins 10a. Installed.

Similarly, reference numeral 10b denotes two exit-side fixed tape pins movably provided to face each other on the exit side of the head cylinder D, and the interval therebetween is slightly larger than the maximum diameter of the exit-side movable tape pin 9b. And the distance between the line connecting the two output-side fixing tape pins 10b can be changed.

Reference numeral 11b denotes an actuator for driving the output side movable tape pin 9b (hereinafter referred to as an output side tape actuator), and 11a denotes an input side movable tape pin 9a.
(Hereinafter referred to as an entrance tape actuator), 12a is an arm for moving the movable tape pin 9a by rotation of the entrance tape actuator 11a, and 12b is an exit side by rotation of the exit tape actuator 11b. An arm for moving the movable tape pin 9b, 13b is an output tape actuator 11b
A position sensor 13a detects the rotation angle of the entry-side tape actuator 11a, and a position sensor 14 moves the magnetic head H in the width direction of the magnetic tape T (vertical direction in the figure). Head actuator.

Further, in FIG. 2, a state estimator 15a is a state estimator that electrically simulates a "displacement / input voltage" transfer characteristic indicating a relationship between an input voltage of the input side tape actuator 11a and a displacement rotation angle. A tension force applied to the input-side movable tape pin 9a, that is, an acceleration, a speed, and a position applied to the input-side tape actuator 11a are estimated from the input voltage of the input-side tape actuator 11a and its (rotational) displacement angle. The state estimator 15b that receives an input from the actuator 11b has substantially the same configuration and function as the state estimator of the entry-side tape actuator 11a.

The DTF circuit 16 has a magnetic head Ha (H
A tracking error signal is generated from a reproduction envelope signal of the signal reproduced in b), and a high-frequency component of the tracking error signal (indicated by “AC” in the figure)
By driving the head actuator 14 and the low-frequency component (shown as "DC" in the figure) of the output tape actuator 11b, a tracking error is corrected.

The tension servo circuit 17 outputs a control signal to the reel motor 4 and the entry tape actuator 11a so that the acceleration of the entry tape actuator 11a given from the entry state estimator 15a becomes a constant reference value. Tension servo circuit.

The special reproduction signal generator 18 calculates a signal (hereinafter, referred to as a reel motor FG signal) from a reel motor rotation frequency generator indicating the rotation speed of the reel motor from the reel motors 4 and 5. Or a signal from a capstan rotation frequency generator indicating the rotation speed of the capstan motor 6 (hereinafter, capstan FG)
Signal) is converted from the tape speed obtained by frequency-to-voltage conversion.
The triangular waveform described above is output in order to control the tracking at the time of special reproduction such as double-speed reproduction by making the differential operation of 11b.

The adder 19 adds the control signal of the output tape actuator 11b from the DTF circuit 16 and the triangular waveform signal for special reproduction from the special reproduction signal generator 18, and the subtractor 20 A subtractor, which outputs a position error signal by comparing the reference position signal with the estimated position signal of the output tape actuator 11b from the state estimator 15b, and an adder 21, are a DTF signal to the output tape actuator 11b and a state estimator. The adder / subtracter 22 adds the position error signal from the subtractor 20 to the output of the adder 21 and also subtracts the estimated speed from the state estimator 15b. Reference numeral 23 denotes a signal obtained by inverting the reference position signal of the input side tape actuator 11a and D of the output side tape actuator 11b.
An adder / subtractor 24 for adding the TF signal and the estimated position signal from the state estimator 15a is a tension servo circuit 17
This is a subtractor for subtracting the signal from the adder 23 and the estimated speed signal from the state estimator 15a from the tension control signal to the input side tape actuator 11a from the controller.

The reference position voltage input to the subtractor 23 and the subtractor 20 is a fixed voltage such as 0 V, for example. As described below, the input and output tape actuators 11a and 11b are used. Is not spring-supported and therefore has no reference fixed position, so that the reference position is determined, and the tape tension control arm 77 (FIG. 49) is electrically positioned without mechanical spring support. By performing the control, the control arm 77 is electrically supported, so to speak.

[Description of Tape Actuator] FIG. 3 is a schematic perspective view of a tape actuator used in the embodiment of the present invention. FIG. 4 is a cross-sectional view of the actuator, and FIG. 5 is a schematic view for explaining the driving principle. Parts corresponding to those shown in the actuator section of FIG. 2 are denoted by the same reference numerals as in FIG. is there.

This tape actuator is a voice coil type electromagnetic drive actuator having no spring support, which is the same as that practically used as a swing arm actuator which is a tracking actuator of a hard disk drive.

In these figures, reference numeral 11 denotes a tape actuator drive unit of an electromagnetic drive system for rotating and driving the arm 12 provided with the movable tape pins 9, and 401 is magnetized in the extension direction of the rotation shaft. Further, permanent magnets whose magnetization directions are reversed on the left and right, 402 is a yoke made of a soft magnetic material, and 403 is a movable coil that rotates around the rotation axis.

As is apparent from FIG. 5B, the voice coil type electromagnetic drive actuator is magnetized in a direction
A magnetic circuit closed by a permanent magnet 401 and a yoke 402 whose magnetization direction is opposite to the rotating circumferential direction of 03 is constituted by a movable coil arranged in parallel to the permanent magnet 401. A high magnetic flux density can be obtained in a direction perpendicular to the rotation surface of the 403.

When an electric current is applied to the movable coil 403, a rotating shaft is applied to a portion corresponding to the side edge of the movable coil 403 shown in FIGS. The movable coil 403 rotates around. The "displacement angle / frequency" characteristic of the tape actuator having such a configuration is as shown in FIG. 6, where the vertical axis indicates gain and phase, and the horizontal axis indicates frequency.

As is clear from this figure, this actuator has very good controllability because it has no mechanical resonance up to a high frequency range. However, since the mechanical reference position is not determined, FIG. It is necessary to provide a signal for determining the reference position as described.

In the above example, the movable pin 9 is moved by the voice coil type electromagnetic drive actuator. However, the movable pin 9 is rotated or linearly moved by a piezoelectric bimorph or other driving means, and the desired movement is achieved. It is needless to say that a configuration that causes movement is also applicable.

[Explanation of Actuator Displacement Measuring Means]
FIG. 7 shows an example of an optical sensor that measures the displacement of the arm 12 of the tape actuator 11 in order to determine the displacement (rotation angle) of the movable tape pin 9. Reference numeral 404 denotes a light emitting unit configured to collimate the light generated from the laser diode 404a by a collimator lens 404b and further restrict the light beam diameter by a stop. Reference numeral 405a cuts a surface including a rotation axis 405 'of the tape actuator 11. Reference numeral 406 denotes a mirrored reflecting portion, and 406 denotes a light receiving portion constituted by a linear position sensor for detecting the position of the light spot. The rotating shaft 405 'can be provided as an extension of the shaft 405 in FIG. 4, or can be configured in place of a rotating shaft supported by an external bearing.

The optical sensor 40 as shown in FIG.
6 is preferable when the rotation range of the tape actuator 11 is large, but is expensive. For example, when the rotation range is small, the light source LE is less expensive than a laser diode.
D, or a two-part detector that detects a light beam position by dividing the light receiving element at a lower cost into two parts instead of the linear position sensor can be used.

That is, when the rotation range of the tape actuator 11 is small as described above, as shown in FIG. 8A or 8B, the voice coil type electromagnetic drive actuator shown in FIGS. Moving coil 403
A Hall sensor 410 that rotates together with this axis is provided on a rotary shaft 405 of the sensor, and a permanent magnet 411 composed of two magnetized regions having opposite magnetization polarities is attached to a substrate so as to face the sensor 410, Inexpensive magnetic means for detecting the rotational position of the tape actuator 11 based on the output of 410 can be used.

[Description of DTF Control System of First Embodiment] FIG.
Returning to the description, the DTF control system of this embodiment will be described.
In this embodiment, since the rotary tape actuator as described above is used, the input side movable tape pin 9a and the output side movable tape pin 9b driven by the input side and output side tape actuators 11a and 11b, respectively.
Is not a straight line but an arc, so to perform highly accurate tracking, this nonlinear error is
It must be absorbed by the control system.

Therefore, it is necessary to use a feedback control system having higher precision, a wider frequency band, and a wider dynamic range than the conventional DTF control. In addition,
If the open-loop control is performed, a non-linear error occurs in principle, so that it is necessary to perform the feedback control.

In this embodiment, the DTF control based on the low-frequency component of the tracking error signal mainly caused by the tracking error is performed by the output tape actuator 11b having a wide movable range and a high gain in the low-frequency range. The DTF control based on the high-frequency component of the tracking error signal generated based on the non-linear movement path of the movable tape pin 9b drives the magnetic head in a direction perpendicular to the recording track on the magnetic tape. This is performed by the actuator 14.

As described above, the DTF control is constituted by the two-stage coupling of the output tape actuator and the head actuator, and the DC component is made to respond by the capstan motor 6 or the reel motor 5, so that a wide range of operation is achieved. A highly accurate DTF control having a range and being stabilized can be realized.

FIG. 9 shows the tracking control system in the embodiment shown in FIG. 2 as a block diagram based on the flow of physical quantities, and FIG. 10 shows this by a transfer function of control theory. The operation of the DTF control system of this embodiment will be described with reference to these figures.

Elements corresponding to those shown in FIG. 2 in FIGS. 9 and 10 are denoted by the same reference numerals as in FIG. 2, and S in FIG. 10 is a Laplace operator. . A block 25 is a compensator for stably performing a tracking control operation of the head actuator 14, and is a band-pass filter 25a (FIG. 10) which is one of its components.
Is a band-pass filter that cuts the DC component of the tracking error signal and exhibits a first-order integration characteristic in a high frequency range. The amplifier 25b is an amplifier that determines the control band of the tracking control system.

The block 26 is a compensator for stably cooperating the output side tape actuator 11b with the head actuator 14 for tracking. A function 26a (FIG. 10) corresponding to a part of the transfer function is the A transfer function of a secondary filter that electrically simulates the frequency characteristic of "displacement / voltage" of the actuator 14, and 26b is a transfer coefficient indicating the gain of the amplifier.

Block 28 is a compensator comprising a second-order low-pass filter, and its block 28a (FIG. 10)
Is a transfer function indicating the characteristics of a low-pass filter for passing only the low-frequency component of the tracking error signal, and block 28b is a transfer function indicating the gain. These compensators 25, 26, and 27 are included in the DTF circuit 16 in FIG.

Block 27 is a mechanical characteristic showing the displacement ratio in the recording track width direction to the displacement in the length direction of the magnetic tape, and block 29 is a mechanical characteristic showing the displacement ratio in the recording track width direction with respect to the rotation angle of the reel motor 5. . Block 29 shows a transfer function indicating the ratio of the rotation angle of the reel motor 5 (or the displacement angle of the tape actuator 11b) to the displacement of the magnetic tape in the width direction of the recording track.

The block shown as the head actuator 14 in FIG. 9 is a "drive voltage-displacement" characteristic of the head actuator 14, which is shown in FIG. 10 by a transfer function, where K _H τ is a torque constant, R _H Is the coil resistance, m _H is the mass of the movable part, C _H is the viscosity coefficient, and R _H is the transfer coefficient representing the elastic coefficient.

The block 11b in FIG. 9 includes an arm 12b,
It shows the displacement angle (displacement angle / drive voltage) characteristic of the output tape actuator 11b including the movable tape pin 9b (FIG. 2) with respect to the actual drive voltage. In the block 11b of FIG. 10, this characteristic is shown by a transfer function. And 5
0 is a transfer function representing the “torque / voltage” characteristic of the tape actuator, 51 is a transfer function representing the “displacement angle / torque” characteristic of the tape actuator, K _T τ is a torque constant, R _T is a coil resistance, J _T is the inertia of the rotating part,
C _T is the viscosity coefficient of the rotating part.

The subtracter 20 is provided at the output tape actuator 1
1b is a subtractor that compares the reference position of the actuator 1b with the estimated position from the state estimator 15b and outputs a position error signal of the actuator 11b. When a direct current component is applied to the capstan motor 6 or the reel motor 5 in FIG. 2, the position of the actuator is not determined in the DTF operation. Are compared to form a position control system which feeds back and electrically fixes the position of the actuator.

Block 15b is the tape actuator 1.
1b is a state estimator composed of the same-dimensional observer based on modern control theory that electrically simulates the frequency characteristics and dynamic characteristics of “displacement angle / drive voltage”, which will be described in detail later.

In FIG. 10, a block 32 is a transfer function indicating a loop gain of the position control system of the output side tape actuator 11b, a block 33 is a transfer function indicating a loop gain for feeding forward the estimated acceleration from the state estimator 15b, and a block. Reference numeral 34 denotes a transfer function indicating a loop gain for feeding back the estimated speed from the state estimator 15b, and addition / subtraction units 19 _, 21 _, 22, _{1, and} 22 ₂ are transmission blocks each representing addition / subtraction.

Block 5 is a transfer function showing the characteristic of the displacement angle with respect to the input voltage of the reel motor 5 or the capstan motor 6, where K _C τ is a torque constant,
R _C is the coil resistance, and J _C is the inertia of the rotating part. The adder 31 is for obtaining a position in the length direction of the magnetic tape determined by the head actuator 14, the output tape actuator 11b, and the reel motor 5 (or the capstan motor 6).

The subtractor 30 conceptually shows a subtraction for obtaining a difference between the target track position corresponding to the position of the track on the magnetic tape to be tracked and the tracking position from the adder 31. However, in practice, a value indicating an error corresponding to the output of the subtracter 30 can be obtained as a tracking error signal.

The DTF control based on the low-frequency component of the tracking error signal is performed by the output tape actuator 11b, and the tracking error signal is generated based on the fact that the moving path of the movable tape pin 9b is non-linear. DTF by high frequency component
In the two-stage coupling system in which the control is performed by the head actuator 14, the coupling frequency at which the gain of each control loop for the two actuators of the output tape actuator 11b and the head actuator 14 becomes equal is, for example, 7 It is desirable to take the frequency around the cycle frequency Fs of 0.5 Hz.

The basic frequency of the tracking error signal including a non-linear error during high-speed special reproduction such as 5 × speed reproduction requiring a wide tracking operation range is the cycle frequency Fs which is the drive pattern signal of the tape actuator 11. Therefore, the large-amplitude error having a frequency equal to or lower than the cycle frequency is due to the fact that it is reasonable to control and correct the tape actuator 11 itself.

Conversely, if the coupling frequency is set near the cycle frequency Fs, the high frequency component of the tracking error is mainly transmitted to the head actuator 14 having high ability to follow a signal of a high frequency component, and the low frequency component is reduced to the low frequency component. It is possible to configure a two-stage coupling system in which the tape actuator 11 having a large low-frequency torque and a high low-frequency tracking capability is mainly shared.

In such a two-stage coupling system, the two actuators of the tape actuator and the head actuator simultaneously follow one control target, and the control capability for following the target is divided into two frequency bands. Therefore, if the phase difference between the actuator control systems at the coupling frequency is 180 degrees, the total gain becomes −∞dB.
Therefore, in this embodiment, the speed of the actuator 11 is estimated by the state estimator 15b composed of the same dimension observer of the modern control theory for the tape actuator, and the high gain 34 is obtained. As a result, the low frequency characteristic of the "displacement / voltage" frequency characteristic of the tape actuator 11 is improved to a stable primary form, thereby stabilizing the entire system.

In addition, the outlet tape actuator 11b
The disturbance torque estimated by the state estimator 15b is fed forward in order to minimize the position fluctuation due to the disturbance force, that is, the tension torque, which is applied so that the operation is always performed stably regardless of the tape tension.

[Description of State Estimator] The state estimator 15b, which is one of the characteristic components of the present invention, will be described with reference to FIG.

The state estimator 15b simulates the transfer characteristics and dynamic characteristics of the output tape actuator 11b as an electric equivalent circuit, and increases the acceleration, speed, position, disturbance force, etc. of the tape actuator 11b. The estimation can be performed accurately and over a wide frequency band. A state estimator 15a (FIG. 2) for controlling the entry-side tape actuator 11a for a tension control described later.
Has the same configuration and function as the state estimator 15b.

In FIG. 10, reference numeral 100 denotes a transfer function which electrically simulates a transfer function 50 representing the actual "torque / drive voltage" characteristic of the output tape actuator 11b.
Reference numeral 1 denotes a transfer function that electrically simulates the transfer function 51 representing the actual "torque / drive voltage" characteristic of the tape actuator 11b by the equivalent conversion of the control theory together with the transfer function 103.

Blocks 105 and 106 are used to match the dynamic characteristics obtained from the transfer functions 100, 101, and 103 that electrically simulate the characteristics of the tape actuator 11b with the actual characteristics of the output tape actuator 11b. , Block 11 representing the outgoing tape actuator
Position sensor 13b corresponding to output d of b (FIG. 2)
Reference signals and transfer functions 100, 101, 103
Is a transfer function indicating the feedback gain of the observer that is fed back so that the difference from the output of the observer converges to "0", and 102, 104 and 107 are subtractors.

To explain the principle of this state estimator, the transfer function of each element in the state estimator 15b has the value shown in the block of FIG. 10, and the drive function actually input to the output tape actuator 11b. When a voltage is given as an input to the block 100 simulating the coil resistance R and the force constant K, the output b 'of the block 100 is a value obtained by estimating the driving force b of the output tape actuator 11b.

When the values of the blocks 101 and 103 are put together, (1 / J ′S) · (1 / S) = 1 / (J ′S ² ) (3) The mechanical characteristic transfer function 51 of the tape actuator 11b is electrically simulated. If b 'which is the output of the transfer function 100 is input as the input of the block 101, the block 1
The output d 'of 03 should be a value obtained by estimating the rotation angle d of the output side tape actuator 11b.

However, the transfer functions 101 and 1
Numeral 03 has an integrator inside, and in terms of frequency characteristics, the transfer function 51 of the output tape actuator 11b.
However, the dynamic characteristics are not the same due to a difference in the initial value of the integrator or the like.

[0126] Therefore, in this embodiment, the difference e between the estimated value d 'by the displacement amount d and state estimator 15b of the actual exit side tape actuator 11b detected by the position sensor (not shown) with a gain F ₁ and F ₂ Feedback is provided so that not only the frequency characteristics but also the dynamic characteristics coincide with the actual rotation of the tape actuator.

The configuration of the state estimator 15b described above is well known as the configuration of the same-dimensional observer in modern control theory. In this embodiment, the tape actuator 11b
Transfer function 101 including an integrator (1 / S in Laplace transform) in state estimator 15b, which is an electrical model of
When the are you feedback two loop including the gain of the F _1, F ₂ respectively in front of the 103 is to determine freely the convergence of the observer.

Generally, the same-dimensional observer that receives the drive voltage and displacement of the controlled object as inputs is used to extract the estimated speed inside the controlled object. In a state where the static characteristics (frequency characteristics) match, the high gain (F ₁ ) is set so that the observer feedback gains F _{1 and} F ₂ are sufficiently large (negative real numbers are large) compared to the poles to be controlled. _, when the increase) the value of F _2, can be estimated tension, 'the actual displacement amount d and d' displacement output d of the controlled object for dynamic characteristics are consistent ≒ d ... (4) is satisfied.

Further, since the transfer function and its model 100 do not include an integrator, the driving force b ′ ≒ b (5) holds, and the dynamic characteristics of the controlled object and the model in the observer are reduced. Since they match, not only the displacement but also the speed and the acceleration match. Accordingly, c ′ ≒ c (6) holds for the force applied to the arm of the tape actuator 11 which is a value obtained by multiplying the acceleration by J _T.

In the original tape actuator 11b, "drive force b" + "torque a due to tension" = "torque c applied to the tape actuator mechanism" (7). From equation (7), b '+ a = c', and b'-c '= a' (8), that is, a '= a (9).

This means that the signal path a 'in the observer
Represents the disturbance torque due to the tension,
By taking this out, the disturbance torque due to the tension can be detected. As described above, by using the state estimator 15, the position, speed, acceleration, and disturbance of the tape actuator 11 can be detected in a wide band with high accuracy.

[Explanation of DTF Control Operation of First Embodiment] Next, the operation of the DTF control system in the first embodiment constructed using the above state estimator will be described with reference to FIG. explain. The tracking error signal corresponding to the output of the subtractor 30 shown in the upper left of FIG. 10 is obtained from the envelope of the signal reproduced by the magnetic head by the above-described known method such as the pilot method.

This tracking error signal is supplied to the compensator 2
8 has a cut-off frequency of several Hz.
a, the signal is amplified by a third control loop including an output tape actuator 11b described later and an amplifier 28b having a gain selected so that the gain becomes equal at a frequency of several Hz. The DC component of the tracking error is generated by driving the reel motor 5 or the capstan motor 6 according to the running speed of the tape, and moving the magnetic tape in the longitudinal direction through the mechanical characteristics 29 determined by the reel diameter and the track tilt angle. To correct low-frequency errors including

As apparent from the fact that the first control loop operates so that the tracking error is eliminated by the tracking error signal based on the tracking error, the first control loop forms a closed loop.

The above tracking error signal has a compensator 25 having a center frequency of 0. 1 composed of a primary high-pass filter and a low-pass filter, for example. After being phase-compensated by a band-pass filter 25a of a few Hz and amplified to a predetermined gain by an amplifier 25b, it is supplied to a drive amplifier (not shown) of the head actuator 14 to drive the head actuator 14 so that the magnetic head H is tracked. Move in the width direction. Therefore, the second control loop also forms a closed loop similarly to the first control loop.

The output of the amplifier 25b of the compensator 25 is provided, for example, with all the poles of the control system arranged on the left half surface so that the second control loop and the third control loop are stably coupled. After being amplified by an amplifier 26b via a compensator 26a composed of a phase lead / lag filter determined as described above so that the gain of the second loop matches a gain at a certain frequency, the special reproduction signal Outgoing tape actuator 11b via adder 19, speed damping signal subtractor 22, disturbance rejection signal adder 21, etc.
And drives the output tape actuator 11b to move the magnetic tape T in the longitudinal direction via the mechanical characteristics 27, thereby correcting a tracking error.

Therefore, the third control loop is also closed similarly to the first control loop and the second control loop. In this embodiment, DTF control having high accuracy, a wide band, and a wide dynamic resin is realized by the three DTF control loops electrically connected to each other as described above.
It was shown to.

[Explanation of Tension Control System in First Embodiment] However, in this embodiment, the low frequency component of the tracking error is reduced by the output tape actuator 11.
b, the DTF control is performed by dynamically moving the magnetic tape in its length direction.
In principle, the tension of the magnetic tape also varies.

Accordingly, in the embodiment of the present invention, as shown in FIG.
By adding the drive voltage of b to the reference position signal of the position control loop of the input side tape actuator 11a,
For example, in any operation mode such as the normal reproduction mode and the high-speed special reproduction mode, the two tape actuators 11a and 11b are configured to operate differentially with each other so that the tension in the rotary head portion does not fluctuate.

However, if the electrical-mechanical characteristics of these two tape actuators 11 and the mechanical resistance due to the running path of the magnetic tape are completely the same, these two
Even if the above-mentioned variation in tension can be completely suppressed by applying an equal voltage to the two tape actuators 11a and 11b, actually, an equal voltage is applied to the two tape actuators due to various electrical and mechanical variations. It is impossible to operate in exactly the same way.

Therefore, even if the drive voltage of the output tape actuator 11b is added to the reference position signal of the position control loop of the input tape actuator 11a as described above, a tension variation occurs. In this embodiment, the tension control by the closed loop is performed. The system is controlled so as to maintain the optimum tension in any mode by correcting the above-mentioned tension fluctuation by the method.

FIG. 12 is a block diagram showing this tension control system. FIG. 13 shows this tension control system in terms of the transfer function of control theory, and will be described with reference to these figures. Elements corresponding to the elements shown in FIG. 2 in FIGS. 12 and 13 are denoted by the same reference numerals as in FIG. 2, and S in FIG. 13 is a Laplace operator.

In FIG. 12, a block 50 shows electrical characteristics indicating the frequency characteristics of "generated torque / input voltage" of the input tape actuator 11, and a block 51 shows "displacement angle / supply torque" characteristics of the input tape actuator 11a. It is a mechanical characteristic, and the outlet tape actuator 11b
It has the same characteristics as.

A block 52 is a tape rigidity exhibiting a "stress / strain" characteristic in the length direction of the tape, and a block 53 is a mechanical characteristic of a traveling path, and includes a geometrical position between the fixed tape pin 10a and the entrance movable tape pin 9a. It is determined by various characteristics such as the balance of the force between the magnetic tape T and the entry-side movable tape pin 9a and the geometrical positional relationship between the movable tape pin 9a and the rotation axis of the tape actuator driving unit 11a.

The block 15a is a state estimator for electrically estimating the acceleration and speed of the tape based on the drive voltage or drive current input to the input side tape actuator 11a and the amount of displacement detected from the position sensor 13a, and blocks 55 and 56. Is a compensator for feeding back the difference output between the estimated tension value from the tension estimator 15a and the reference tension value, that is, the amount of disturbance tension to the input side tape actuator 11a and the supply reel motor 4 so that the loop is stabilized; The rigidity 52 ′ is a tape rigidity indicating a tape tension variation characteristic caused by a change in the rotation angle of the reel motor 4, and the subtracter 54 is the state estimator 15.
This is a subtractor that takes the difference between the estimated tension value from a and the reference tension value.

The adders 57 and 58 and the subtractor 59 are addition / subtraction blocks indicating the balance of the physical force of the torque. The addition / subtraction unit 24 subtracts the estimated speed and position error from the state estimator 15a into the acceleration control loop. It is for adding.

The sum of the change in the tension value of the magnetic tape detected by the change in the rotation angle of the input side tape actuator 11a and the change in the tension due to the change in the rotation angle of the reel motor is added to the tension disturbance (from the shaft received by the tape and from the head cylinder). The sum of the kinetic friction, the frictional coefficient generated by the tape, and the external disturbance force in the tape length direction is the total tension of the magnetic tape running system, thereby displacing the entry-side tape actuator 11a. Let it.

In FIG. 13 showing this tension control system as a transfer function of control theory, TG indicates a tension disturbance, and block 11a indicates the actual “displacement angle / input voltage” characteristic of the input side tape actuator 11a. It is shown by the transfer function, and its characteristic is 11b in FIG.
Is the same as

A block 52 is a transfer function indicating a transfer characteristic of a change in the tape tension with respect to a change in the rotation angle of the input tape actuator 11a, and a block 53 is a transfer function indicating a transfer characteristic of a torque applied to the input tape actuator 11a by the tape tension. is there.

The block 15a is shown in FIG.
This is a state estimator having the same configuration as the state estimator 15b described with respect to the F control system, and estimates the position, speed, acceleration, and disturbance torque of the tape actuator 11a in a high-precision wide band. Although omitted here, a block 108 is a transfer function indicating the inverse characteristic of the transfer function 53 indicating the transfer characteristic of the torque applied to the input side tape actuator 11a by the tape tension.

A block 55a is a compensator 5 for feeding back a relatively high frequency component in the control band in the tension control system to the input side tape actuator 11a.
A transfer function indicating a band-pass filter which is a part of 5, and a block 55b is a transfer function indicating an amplifier gain for determining a loop gain of a feedback loop for the input side tape actuator 11a.

A block 56a is a transfer function showing a secondary low-pass filter which is a part of the compensation circuit 56 for feeding back a relatively low frequency component within the control band in the tension control system to the supply reel motor 4, and a block 56b. Is a transfer function indicating an amplifier gain for determining a loop gain of a feedback loop for the reel motor 4. The block 4 is a transfer function including the coil resistance _RL of the reel motor 4, the torque constant K _L τ, and the inertia J _{L of the} rotating part.

The adder / subtractor 23 is an operation block for comparing the estimated position signal from the state estimator 15a with the reference position signal and for adding the drive voltage of the output tape actuator 11b. , A transfer function indicating the gain of a loop that feeds back the estimated speed from the state estimator 15a, and the adder / subtractor 24 includes a position control loop and a speed as a tension control loop. This is an operation block for adding and subtracting a control loop signal.

In the conventional tension control system shown in FIG. 49 described above as a conventional example, the tension control arm 77 is stopped when the tension control arm 77 is stopped by the balance of the force of the spring 78 and the tension of the magnetic tape. Assuming that the displacement amount corresponds to the tension, the displacement amount is fed back to the reel motor 4 as a tape tension signal.

However, the displacement of the spring-supported tension control arm 77 is proportional to the tension when the fluctuation frequency of the spring-supported tension control arm 77 is lower than the spring resonance frequency. When the resonance frequency of the spring exceeds the resonance frequency, the phase of the tension fluctuation applied to the tension control arm 77 and the phase fluctuation of the position of the tension control arm 77 are shifted. In practice, it is 90 degrees at the spring resonance frequency and 18 at higher frequencies.
It shifts by 0 degrees.

For this reason, in the conventional tension control, the control frequency band is limited by the phase rotation of the spring support system including the tension control arm 77. This means that
The tension that can be detected by the tension control arm 77 is
This indicates that the frequency must be lower than the spring resonance frequency of the spring support system including the tension control arm 77.

To increase the spring resonance frequency, it is conceivable to reduce the tension control arm or increase the spring constant. However, there is a limit to reducing the tension control arm, and the spring constant is increased. Then, even if there is a variation in tension, the tension control arm 12 does not move much, so that the detection accuracy is deteriorated.

Therefore, in this embodiment, an actuator without spring support as described above with reference to FIGS. 3 to 5 is used, and is input to the subtractor 23 at the upper left of FIG. 2 and the subtractor 20 at the right of FIG. By supplying a voltage for determining the reference positions of the tape actuators 11a and 11b on the side and the exit side, the tape tension control arm 7 is controlled.
7 is electrically supported by a spring by electrically controlling the position without using a mechanical spring. Thus, the tension can be detected in a wide band regardless of the control band of the electrical position control, and the tension control can be performed with high accuracy.

Since the disturbance torque signal from the state estimator 15a is nothing but the tape tension applied to the input side movable tape pin 9a connected to the input side tape actuator 11a, this disturbance torque signal can be treated as a tension signal. it can.

The frequency band in which the tension can be estimated by the state estimator 15a is a function that depends on _two feedback gains F1 _and F2 when the observer performs model matching, and aa ′ = F ₁ / (J _T since ^{_{S 2 + F 2 J T S}} + F 1) · aa ... become (10), if the gain F _1, F ₂ choose high enough, it is possible to the frequency band above 1 KHz.

The tension a estimated as described above
The value a 'is compared with the reference tension TN, which is the optimum value of the tension, by the comparator 54, and the tension error signal TG is detected.

The tension error signal TG is phase-compensated by a compensator 55a composed of a primary band-pass filter having a cutoff frequency of several Hz, which is sufficiently lower than the control frequency band, and then amplified with a predetermined gain by an amplifier 55b. After that, the input side tape actuator 11a is driven via a drive amplifier (not shown) via a tape actuator position control signal adder and a speed damping signal subtractor 24. Thus, the first control loop using the tension as the reference value is closed.

At the same time, the tension error signal TG becomes 2
It is also supplied to a compensator 56a composed of the following low-pass filter, is amplified by an amplifier 56b so as to be stably coupled with the above-mentioned first control loop at several Hz, and is supplied to a reel motor via a drive amplifier (not shown). Drive 4 to keep the tension constant. Thus, the second control loop is also closed.

The reason why the frequency band is divided as described above is that the input side tape actuator 11a generally has a smaller mechanical time constant than the reel motor 4 and is suitable for control in a high frequency band as described above. On the other hand, the movable amount is limited, and it is not suitable for controlling a large tension fluctuation near DC.

In this embodiment, in order to improve the characteristics of the input side tape actuator 11a from the secondary type to the stable primary type, the estimated speed of the state estimator 15a is increased by the amplifier 60 in the same manner as described for the DTF control. , And is fed back to the input side tape actuator 11a with a high gain. At this time, the gain of the amplifier 60 is determined so that the band improved to the primary form is equal to or larger than the tension control band.

In order to fix the position of the entrance tape actuator 11a, a position error signal is generated by comparing the position signal from the state estimator 15a or the position signal from the position sensor 13a with the reference position signal by the subtractor 23. , And the position error signal is converted into a gain G by an amplifier 61.
_After being amplified at ₈ , the signal is fed back to the entry-side tape actuator 11a.

The feedback loop gain G ₈ is
It is desirable to select such that the steady-state deviation of the position control loop of the entry-side tape actuator 11a with respect to the tape tension reference value TN does not become so large as, for example, about several tens to several hundreds μm.

The reason why the phase compensation is not performed in this position control loop is that the characteristics of the input tape actuator 11a have been improved to a stable primary form in the above-described speed damping group.

When the tension is controlled by using the above-described method of estimating the tension disturbance, the estimated magnetic tape tension is accurately detected in a much wider band than in the conventional tension detecting mechanism. Tension control is realized.

According to the tension control system in this embodiment, since the high frequency component of the tension fluctuation is suppressed by the input side tape actuator 11a and the low frequency component of the tension fluctuation is suppressed by the reel motor, the precision of the tension control is improved. Thus, it is possible to obtain a tension control system having a high precision wide band and a wide dynamic range.

As described above, according to the first embodiment of the present invention shown in FIGS. 2 to 13, DTF control and tension control having a high-precision wide band and a wide dynamic range are realized, so In addition, good reproduction can be performed even in the high-speed special reproduction mode.

[Second Embodiment] The second embodiment shown in FIG. 14 to FIG. 16 employs a head touch control circuit 200 and a head touch control circuit 200 for maintaining a constant spacing amount between the magnetic head and the magnetic tape. An adder 201 is provided for adding the head touch control signal from the touch control circuit 200 to the estimated acceleration signal from the state estimator 15a in the tension control loop.

Further, a head actuator for moving the magnetic head in the vertical direction of the track for tracking and a means related thereto are used in order to make the system inexpensive or to reduce the size of the head cylinder. Omitted for clarity.

Therefore, the head touch control will be described first. In the tension control circuit shown in the first embodiment, the tension of the magnetic tape T at the portion of the input side movable tape pin 9a is maintained with high precision and optimal tension over a wide band. However, from the viewpoint of head touch control, what is actually desired to be tension-controlled is the tension of the magnetic head H portion.

That is, if the tension of the magnetic tape at the portion facing the magnetic head H fluctuates due to the eccentricity of the head cylinder D or the mechanical / partial fluctuation of the tension such as the contact between the tape T and the head H, the tape will not move. The high-frequency component of the playback output fluctuates due to the change in head-to-head spacing, which is important for future simplification of mechanical systems, cost reduction of components, or high-density recording. Problem.

FIG. 14 is a conceptual block diagram showing the second embodiment. FIG. 15 is an explanatory diagram showing the flow of physical quantities in the DTF control system, and FIG.
FIG. 18 is a block diagram showing a head touch control circuit.

First, the DTF control system of this embodiment, which has been changed by not using the head actuator, will be described. FIG. 1 shows a DTF control system of this embodiment.
5, FIG. 16 shows the DTF control system of the first embodiment, and FIG.
As is apparent from comparison with FIG. 10, the head actuator is not provided in this embodiment, so that the block 14 showing the transfer function of the head actuator in FIG. 10 is not provided, and the block 5 shown in FIG. As shown, instead of controlling the reel motor of the take-up reel 5, this embodiment is modified to control the capstan motor 6.

The DTF control system of this embodiment controls the tracking error signal based on the high frequency component and the low frequency component in the same manner as in the first embodiment.
b and the capstan motor 6. This embodiment also includes a state estimator 15b as in the first embodiment, improves the low-frequency characteristic of the output tape actuator 11b to a primary form by speed feedback, and performs position control and disturbance elimination control. Also, the same processing as in the first embodiment is performed.

That is, in FIG. 16, the magnetic head H
A tracking error signal (corresponding to the output of the subtractor 30) obtained from the reproduced envelope signal of the above by a method such as a pilot method passes through a low-pass filter 28a whose cutoff frequency of the compensator 28 is several Hz, and is output to a later-described output side. The signal is amplified by an amplifier 28b having an amplification gain selected so as to be coupled to the second control loop by the tape actuator 11b at a frequency of several Hz to 10 Hz. 6 is driven, and the reel motor 5 is driven during high-speed reproduction. It is not always necessary to use the low-pass filter 28a.

The capstan motor 6 (or the reel motor 5) controls the magnetic tape T via the respective mechanical characteristics.
Is moved in the longitudinal direction to correct a low-frequency error including a DC component of a tracking error, so that the first control loop is closed via the tracking error.

The tracking error signal has a cutoff frequency of 0.1. The amplifier 2 is connected via the high-pass filter 25a selected at a frequency lower than the cut-off frequency of the low-pass filter 28a of the compensator 28, such as several Hz.
Amplified to a predetermined amplitude at 5b, special playback signal adder 19, the rate damping signal subtracter 22 _1, disturbance rejection signal adder 21, a drive amplifier (not shown) through a position control signal adder 22 ₂ The output tape actuator 11b is driven.

Since the output tape actuator 11b moves the magnetic tape T in the longitudinal direction through its mechanical characteristics to correct a tracking error, the second control loop is also closed via the tracking error.

In the second embodiment, DTF control with high precision and a wide dynamic range is realized by the two electrically coupled DTF control loops. FIG. 17 shows an example of the open loop characteristics. Show.

A characteristic of the DTF control system of this embodiment is that, as described above, the low-frequency characteristic of the output tape actuator 11b is improved to a primary form and stabilized by speed feedback up to a frequency higher than the DTF control band. It is in. By doing so, it is possible to easily perform coupling with the capstan motor 6 which is a secondary type, and it is possible to stably perform DTF control.

The head touch control of this embodiment will be described. FIG. 18 is a block diagram showing an example of the head touch control circuit 200. 202 is a detection circuit, 203 is a peak hold circuit, 204 is a subtractor, 205 is a limiter, 206 is an absolute value circuit, 207 is a level determiner, 20
8 is an analog switch. FIG. 19 shows signals at points a to d in the figure.

The reproduced signal a reproduced from the magnetic head is detected by the detector 202 to obtain an envelope signal b. When a peak is held by a peak hold circuit 203 for storing the peak value of the envelope signal b, a signal c as shown in FIG. A peak level signal is obtained.

It should be noted that an analog voltage memory or the like can be used as the peak hold circuit 203. This peak value does not actually fluctuate unless the recording conditions and the like change. It is sufficient to reset the hold circuit and update the peak value. In this figure, the peak value c is shown as a substantially constant voltage.

When the envelope signal b is subtracted from the peak level signal c by the subtractor 24, a signal such as d is obtained at the fixed contact of the switch 208, and the idle period of this signal d (the head H scans the tape T In order to cut the output during the non-performing period, the spacing error signal e is obtained by switching with a rotating head phase signal having a duty ratio indicating the rotating phase of the magnetic head of 50%.

The spacing error signal e represents the amount of fall in the output of the envelope signal, so to say, whether the fall is due to track deviation or spacing. No.

In this embodiment, as described above, a highly accurate D
Since the TF is applied, in principle, the track deviation is almost zero and should be a level that does not need to be considered. However, in consideration of safety, in this embodiment, the absolute value of the tracking error signal is set to the absolute value. When the output level exceeds a specified value corresponding to, for example, 10% of the track pitch, the switch 209 is cut off by the output of the level discriminator 207 to cut off the control loop of the head touch control circuit. It is.

If the output of the spacing error signal e from the head touch control circuit is too large, the limiter 205 may suddenly change the tension of the tape and cause serious damage to the tape. This is to prevent output.

The spacing error signal e output from the limiter 205 is added by the adder 201 to the estimated tension signal from the state estimator 15a of the DTF control system as shown in FIG. .

FIG. 18 shows an example in which the head touch control circuit is modified, and the tracking error signal f is converted from the above-mentioned spacing error signal e which indicates the amount by which the output of the envelope signal has fallen. A pure spacing error signal g is extracted by subtraction. FIG. 20 shows an example of a signal at points e, f, and g in FIG. Note that this head touch control method is also effective when DTF control is not used.

The other configuration of the second embodiment is the same as that of the above-described first embodiment, and the description is omitted.

Although the second embodiment has been described with respect to a case where the tension control system is configured as a closed loop, a method of storing the error pattern of the spacing error signal g in a memory and adding the error pattern in a closed loop is also considered. Needless to say, In this case, if the gain to be added is adaptively switched while observing the error pattern of the spacing error signal g, a further effect can be obtained.

According to the second embodiment described above, the DTF control, the tension control and the head touch control can be performed at a low cost with a simple structure, so that the tape is always kept at the optimal tension and a good signal can be obtained. Reproduction becomes possible.

[Third Embodiment] The third embodiment shown in FIG. 21 is obtained by adding the head touch control circuit described in the second embodiment to the first embodiment. Since it is clear from the description of the embodiment and the second embodiment, the description is omitted.

[Fourth Embodiment] FIG. 22 is a schematic diagram showing a fourth embodiment of the present invention. In the figure, reference numeral 250 denotes an acceleration detector added to the third embodiment by the fourth embodiment. This acceleration detector detects the acceleration of the magnetic recording / reproducing deck in the movable direction of the movable pin.

The fourth embodiment is a system assuming that the tape drive system (hereinafter referred to as a deck for convenience) according to the first to third embodiments is installed in a stable place. On the other hand, in this embodiment, in order to maintain a good operation even when an acceleration is applied, such as when the system itself is moved or impacted in an application such as a vehicle, the above-described acceleration is used. The detection means 250 is provided.

In the systems of the first to third embodiments, the tape tension is controlled by the input tape actuator 11.
Although it was detected as the disturbance torque applied to a, this is good even when the deck is stationary, but as assumed in this embodiment, when the deck moves at a certain acceleration, The acceleration of the deck itself is added, and in the above-described embodiment, it is impossible to separate the information based on the disturbance torque from the entrance tape actuator 11a from the information based on the fluctuation of the tension and the information based on the acceleration of the deck.

In this embodiment, the acceleration detector 250
Is for detecting the acceleration applied to the movable pin 9 or the acceleration of the arm to which the movable pin 9 is attached, and the angular acceleration at the entry-side tape actuator 12a,
Specifically, the arm 12 of the entry-side tape actuator 11a
This is for measuring the acceleration in the rotation direction of the arm 12a when d is at the reference position. Then, by subtracting the detection signal representing the obtained acceleration from the estimated tension signal, the influence of the acceleration can be eliminated.

As a device for measuring the acceleration, a commercially available accelerometer that detects the relative movement between the base and the weight using a piezoelectric element or the like can be used. By configuring the system in this manner, accurate tension can be detected even when a sudden disturbance acceleration occurs, for example, when the deck is mounted on a vehicle, so that stable tension control can be realized.

Note that other configurations, operations and effects of this embodiment are the same as those of the first to third embodiments, and therefore description thereof will be omitted.

Fifth Embodiment FIG. 23 is a schematic diagram, FIG. 24 is a block diagram showing physical quantities, and FIG. 25 shows a fifth embodiment using a transfer function.
This is an embodiment in which the outlet tape actuator is omitted. Also in this embodiment, the tension control can be realized by a configuration similar to the method used in the first to third embodiments.

As shown in FIG. 23, the mechanical structure of this embodiment is such that a movable tape pin 3 provided at the tip of a tension detecting arm 300 that rotates about a shaft 300a as a rotation axis.
09 and a pair of fixed tape pins 310a and 310b provided on the entry side of the head cylinder D, a magnetic tape is engaged to form a loop.
00 is urged by a spring 301 in the direction of applying back tension to the magnetic tape, and its rotational position is detected by a sensor 302.

On the other hand, a brake 306 is provided on a reel base 315 on which the supply reel 314 is mounted, and the brake actuator 30 for driving the brake 306 is provided.
5, the brake tension by the brake 306 is changed to control the back tension of the magnetic tape.

The tension control in this embodiment is shown in FIG.
This will be described with reference to FIG. Block 300 is a view illustrating the "rotational displacement / torque" characteristic of the tension detecting arm, the block 310 shown therein is a block for converting the torque of the tension detecting arm speed, J _S is arm rotation The inertia of the part, C, indicates the viscosity coefficient.

As shown in FIG. 23, the position of the balance between the tape tension of the tension detection arm 300 supported by the spring 301 and the restoring force of the spring 301 is observed by the position sensor 302, and is obtained as the output of the block 300. The position information is input to the subtractor 354 of the state estimator 303.

The state estimator 303 electrically simulates the “rotational displacement / torque” frequency characteristic of the tension detecting arm 300 and the dynamic characteristic of the spring 301, and includes the tension detecting arm 300 and the spring 301. The acceleration, velocity, disturbance force and the like of the tension detecting mechanism can be estimated in a wide band with high precision. The configuration and operation principle are basically the same as those shown in the first to fourth embodiments. is there.

Blocks 350, 352 and 353 shown inside the state estimator 303 are transfer functions 310, 311 and 30 of the tension detecting arm 300 and the spring 301.
1 are simulated transfer functions, and the subtractor 354 is a subtractor for determining the difference between the output from the position sensor 302 (FIG. 23) and the outputs from the transfer functions 350 to 353 as described above. Transfer functions 350 to 3 that electrically simulate the characteristics of the tension detection arm 300
This is a transfer function indicating an observer feedback gain that feeds back so that the output difference of the subtractor 354 converges to zero so that the dynamic characteristic at 53 matches the actual tension detection arm 300.

Compared with the state estimator of the first embodiment shown in FIG. 13, the block 50 in FIG. 13 is omitted in the state estimator of this embodiment since the tension detecting arm has no driving member, and , A transfer function 301 newly indicating the spring stiffness because of being changed to the spring support.
Is added and the block 35 simulates this spring.
3 has been added.

The force applied to the tension detecting arm 300 of the tension detecting mechanism is the combined force of the force of the tape tension and the force of the spring 301.
The output indicating the position of the block 300 via the transfer characteristics represented by 311, 301, 312 is detected by the above-mentioned position sensor 302 and applied to the subtraction input terminal of the subtractor 354, while the output is determined based on the reference tension. The output of the transfer function 352 obtained by the blocks 350, 352, 353, 355 of the state estimator 303 simulating the block 300 electrically is applied to the addition input terminal of the subtractor 354.

The output of the transfer function 352 should have estimated the actual position of the position sensor 302.
Since the transfer functions 350 and 352 have an integrator inside, the tension detection mechanisms 300 and 30 have a frequency characteristic.
Even if the transfer characteristics of the integrators 1302 are the same, the dynamic characteristics do not become the same due to the difference in the initial value of the integrator.

Then, as in the above-described embodiment,
The actual displacement position detected by the position sensor 302 (corresponding to the output of the block diagram 300) and the state estimator 3
The difference from the displaced position estimated in step 03 is obtained by subtracting the difference in the subtractor 354 and fed back with the gains F ₁ and F ₂ by the blocks 356 and 357 so that not only the frequency characteristic but also the dynamic characteristic matches the actual mechanical characteristic. I am trying to do it.

The configuration described above is well known as the configuration of the same-dimensional observer in modern control theory. The feedback gains F _{1 and} F ₂ are constants that freely determine the convergence of the observer, and Is selected as the high gain so that the pole of the observer is, for example, about 10 times larger (the value of the negative real part is larger) than the pole of.

In this case, since the characteristics of the state estimator 303 match not only the actual frequency characteristics of the tension detecting mechanisms 300, 301, and 302 but also the dynamic characteristics, the tension fluctuation due to acceleration due to disturbance is detected by the tension detecting mechanism. Can be detected in a wide band without being affected by the mechanical resonance frequency.

The tension fluctuation detected in this way is compensated for in phase compensation gain by the compensator 304 so that the tension control system becomes stable. However, if the brake actuator 305 can operate up to a high frequency without phase rotation. Then, this phase compensation has a first-order low-pass characteristic.

Returning to FIG. 23, the estimated tension signal from state estimator 303 is input to tension servo circuit 304 after the acceleration signal from acceleration detector 250 described in the fourth embodiment is subtracted, and the output is used as the output. A certain tension control signal drives the brake actuator 305 via a drive amplifier (not shown).

As a result, the brake 306 operates to operate the brake on the supply reel base 315 to maintain the tension at the reference value. Since the brake torque characteristic generally has a non-linear characteristic with respect to the displacement of the brake actuator 305, it is desirable to configure the system using a range that can be regarded as linear.

By configuring the tension control system in this way, not only can tension detection be performed in a wide band, but also tension control is realized by a closed loop using an actuator, so that a higher performance than the conventional tension control can be realized. it can.

[Sixth Embodiment] As described above, it is important to always keep the spacing between the magnetic head and the magnetic tape at a predetermined value in high-density recording and the like. In each of the embodiments described above, consideration is given to stabilization of the spacing amount, but since this spacing amount is indirectly controlled through the tension of the tape, it cannot be said that the spacing amount is necessarily sufficient. .

For this reason, it is desirable to move the magnetic head in the direction perpendicular to the surface of the magnetic tape to directly control the amount of spacing. Therefore, first, a configuration example of a rotary head provided with a mechanism for moving the magnetic head in a direction perpendicular to the magnetic tape surface will be described.

In the configuration examples shown in the plan view and the perspective view in FIGS. 26 and 27, respectively, the magnetic head provided on the head cylinder can be moved in the direction perpendicular to the surface of the magnetic tape, that is, in the diameter direction of the head cylinder. 1 shows a configuration of a movable head mechanism used in this embodiment.

[0224] 519 _1, 519 ₂ shows a cross-section of the head cylinder provided with the movable head H, 519 ₁ the shaft portion including the rotation driving unit, 519 ₂ is a wall portion which magnetic tape 516 wraps The movable head H is a head base 525.
Rests above, since the head base 525 is held to the shaft portion 519 ₁ of the head cylinder through a pantograph-shaped leaf spring 524, the air layer on the surface of the movable head H is always magnetic tape 516 Will be pressed through. Since the freedom of movement of the magnetic head H in directions other than the arrows is regulated by the leaf spring 544, the magnetic head H does not move except in a direction perpendicular to the magnetic tape surface.

In the structure shown in FIG. 23, when the sliding surface of the head H is subjected to a surface pressure by the magnetic tape 516, the magnetic head moves inward of the head cylinder in accordance with the surface pressure against the force of the leaf spring 544. The displacement is detected as the output of the Hall element determined by the relationship between the position of the magnet 512 attached to the head base 525 and the position of the Hall element 511.

The term "surface pressure" in the specification and the drawings means the pressure applied to the sliding surface of the magnetic head in the direction in which the magnetic head protrudes from the recording medium by a certain amount of spacing such as an air layer. It is.

If a two-pole magnet as shown in FIG. 27 is used as the magnet 512, a positive or negative signal can be obtained as an output of the Hall element 511 according to the position of the magnet 512. If the control system is configured such that the position at which the output of is equal to "0" is a balancing position, it is possible to configure a control system that is hardly affected by a change in the sensitivity of the Hall element 511.

Seventh Embodiment FIG. 28 is a perspective view showing another example of the structure of the movable head mechanism. Reference numeral 583 denotes a fixing hole 5 in a head cylinder (not shown) in the head cylinder, for example.
The head base 525 on which the head H is mounted is urged by a leaf spring 544 so as to be movable only in a direction protruding from the fixed head base 583. Reflective surface 5 on the side opposite to the head mounting part
48 are formed.

The fixed head base 583 has a light emitting section 546.
And a light receiving unit 547 are provided. The light emitted from the light emitting unit 546 is reflected by the reflection surface 548 of the head base 525 and received by the light receiving unit 547.
Therefore, by using a light receiving element divided into two parts in the figure as the light receiving part 547 and arranging it so that the reflected light at the reference position of the head base 525 is projected on the divided part of the light receiving element, the head base 525 is provided. Can be detected as the difference between the outputs of the two light receiving elements.

FIG. 29 is a perspective view showing another example of the structure in which the amount of displacement of the magnetic head can be controlled in the movable head mechanism shown in the example of the structure shown in FIG. Reference numeral 549 denotes a piezoelectric bimorph provided between the head base 525 and the fixed head base 583. By controlling the voltage applied to the piezoelectric bimorph, the head base 525 supported by the fixed head base 583 by the leaf spring 544 is controlled. By moving the head H, the protrusion amount of the head H can be controlled.

According to such a configuration, the protrusion amount of the head H can be positively controlled, so that the head surface pressure can also be controlled from the head side. It is needless to say that the same operation can be realized by using an actuator such as a voice coil instead of the piezoelectric bimorph 549.

FIG. 30 shows a movable head provided with the above movable head so that the surface pressure of the magnetic head can be controlled. FIG. 14 is a diagram showing a sixth embodiment of the present invention in which the amount of tension of the tape is controlled according to the flow of physical quantity.

As described in the first to fifth embodiments, when the control target 501 which is a movable motor provided on a magnetic tape traveling system or a reel motor for driving a supply reel for supplying a magnetic tape is controlled. The tension of the tape changes, and the surface pressure of the magnetic head changes accordingly, so that the amount of protrusion of the movable head also changes.

The tension surface pressure conversion gain section 502 in FIG. 30 shows the relationship between the amount of change in the tension Tt and the amount of change in the surface pressure Ph of the magnetic head caused by the change in the tension. Head mechanical characteristics 5
Numeral 03 represents the relationship between the amount of change in the surface pressure Ph and the amount of displacement Hm of the movable head caused by the change in the surface pressure. The mechanical characteristics are given by the following equation. Hm = 1 / (mS ² + cS + k) (11)

In the above equation, m is the mass of the movable head, k
Is the spring constant of the spring that holds the movable head, c is the viscosity of the system that holds the movable head, and S is the Laplace operator. The output Hm of the movable head mechanical characteristic 503 is the actual displacement of the movable head, and is measured by the movable head displacement amount measuring means as described above.

The displacement Hm of the movable head measured by the displacement measuring means is input to the surface pressure estimating section 505 to estimate the surface pressure, and is input to the subtraction input terminal of the subtractor 559. Since it is difficult to measure the actual surface pressure of the magnetic head, the surface pressure estimation unit 505 estimates the surface pressure based on the displacement of the movable head. Will be described.

Since the reference surface pressure value Pr is supplied to the addition input terminal of the subtracter 559, the surface pressure error, which is the difference between the reference surface pressure Pr and the estimated surface pressure Pg, is output as the output of the subtractor. The value Pd is obtained. The surface pressure control system compensator 504
A control amount Ct necessary for compensating the surface pressure corresponding to the surface pressure error value Pd is calculated, and a movable pin provided on a reel motor for driving the supply reel or a magnetic tape traveling system as described above is moved. The control is sent to a control target 501 such as an actuator for performing the control. In this embodiment, by using such a feedback control system, the surface pressure of the magnetic head by the magnetic tape can always be kept at a good value.

[Surface Pressure Estimator] The surface pressure estimator 505, which plays a very important role in configuring the above-described surface pressure control system, uses the state estimator described above, in particular, a spring. It has the same configuration and function as the state estimator in the fifth embodiment.

FIG. 31 is a block diagram showing an example of the configuration of the surface pressure estimating section 505 in the configuration of FIG. In the figure, blocks 530, 531 and 534 each simulate the mechanical characteristics of the movable head mechanism 526 as an equivalent circuit. Elements of the simulated mechanical characteristics are shown in these blocks, and a spring constant block 530 is shown. Is the spring constant k, and the mass viscous block 531 is the mass m and the viscosity c.
Are simulated. Note that S
Is the Laplace operator, so block 534, shown as 1 / S, is an integrator.

Blocks 532 and 333 are blocks 53 which electrically simulate the characteristics of the movable head mechanism 526.
0, 531 and 534 of the actual movable head mechanism 5
26 shows observer feedback gains F _{1 and} F ₂ for performing feedback so that the output of the subtractor 354 converges to zero in order to make it equal to 26.

These blocks 530, 531 and 534
Of the movable head is estimated by the subtractor 564.
However, since the output Ps of the surface pressure sensor of the movable head mechanism 526 is input to the subtraction input terminal of the subtracter, the subtractor 564 estimates the actual surface pressure. The difference from the surface pressure is output. Then, the difference output since the feedback gain F _1, F _2, the difference output after a certain time becomes "0".

In such a state, the balance of the force in the movable head mechanism 526 is reproduced in the state estimator, and by taking out the output of the feedback gain block 533 to the outside, the estimated head surface pressure amount Pg is obtained. Obtainable.

The above configuration can be easily configured by a microcomputer or the like, but can also be configured by an analog circuit as described below. FIG.
FIG. 2 is a block diagram when the configuration of FIG. 31 is configured by an analog circuit. Operational amplifiers 531 and 5 in FIG.
Reference numerals 34, 563, and 564 correspond to the mass viscous block 531, the integration block 534, and the calculators 563, 564 of FIG.

The mass viscous block 531 forms a lag lead filter, and the integrating block 534 forms an integrator. Then, the configuration is such that portions corresponding to the feedback loop such as the feedback gain blocks 532 and 533 and the spring constant block 530 are connected.

[0245] However, the surface pressure estimator of the configuration shown in FIG. 31, in the head face pressure estimated quantitatively Pg observation noise included in the output of the head position sensor is F ₂ times the gain of the feedback gain block 533 Therefore, it is necessary to remove the observation noise of this sensor.

FIG. 33 is a block diagram showing an example of the configuration of a surface pressure estimating unit configured so as not to be affected by the observation noise of such a sensor. Reference numeral 584 denotes a pseudo-differential circuit. When the surface pressure sensor output amount Ps is input to the subtractor 564, a signal corresponding to the speed of the movable head mechanism is obtained as the output of the mass viscous block 531. This signal includes the observation noise included in the surface pressure sensor output amount Ps. Is included via the low-pass filter characteristic of the mass viscous block 531.

This velocity signal output, which is the output of the mass viscous block 531, is input to a disturbance estimation observer composed of a Govinas minimum dimension observer in control theory. Generally, this disturbance estimation observer is to input a drive current and a detection speed to estimate a torque disturbance amount or a disturbance force amount.However, when the movable head mechanism has no means such as an actuator for actively driving the movable head. Can be simplified as the drive current amount “0”. The pseudo differentiating circuit 584 is a disturbance estimation observer simplified in this way.

The pseudo-differential circuit 584 outputs the output of the block 584 ₁ having the characteristic of mG ² (where G represents the disturbance estimation band) to the low-pass filter characteristic of 1 / (S + G) in the block 584 ₂ . The signal including noise from the surface pressure sensor passes through two low-pass filter characteristics of 1 / (mS + c) of the mass viscous block 531 and 1 / (S + G) of the block 584 _2. And the estimated value of the surface pressure not including the observation noise from the surface pressure sensor is added to the adder 584 _1.
Can be output to

The block 584 _{4 of the} characteristic mG is shown by the fact that the pseudo differentiator 584 is constituted by the minimum Gobinas observer in the control theory as described above, and includes the block 584 ₄ . Since the path is G≫1 and mG ² ≫mG, and this noise elimination can be ignored, the description is omitted.

FIG. 34 shows an example in which the configuration shown by the transfer function in FIG. 33 is configured by an analog circuit. The surface pressure estimating unit shown in FIGS.
The surface pressure estimating unit 5 is added to the two-head VTR as shown in FIG.
FIG. 35 can be applied as the Ch1 head surface pressure estimating unit 561 and the Ch2 head surface pressure estimating unit 562.
The two-head configuration performs exactly the same function except for the complexity of the configuration and the improvement in performance against observation noise.

[Eighth Embodiment] FIG. 35 shows an embodiment of the surface pressure control system according to the present invention in which the surface pressure is controlled by using a supply reel motor. Two magnetic heads are provided at different positions, and these magnetic heads perform reproduction alternately.
This is for a head type recording / reproducing apparatus.

Each of these two magnetic heads is
A head and a Ch2 head, for example, a Hall element 511 and a magnet 5 as shown in FIG.
12, the displacement of each head H toward the magnetic tape 516 is detected, and the head element pressure sensor output amounts Ch1S and Ch2S are output from these Hall elements 511 for each movable head. Is done.

In the figure, reference numeral 527 denotes a Ch1 sensor amplifier for amplifying the Ch1 head surface pressure sensor output Ch1S, and 528 denotes a Ch2 head surface pressure sensor output Ch2S.
Is amplified based on the output amount Ch1S of the Ch1 head surface pressure sensor from the Ch1 sensor amplifier 27 obtained through the slip ring 529.
A Ch1 head surface pressure estimating unit 562 for estimating the surface pressure amount of the h1 head,
Ch2 based on the output amount Ch2S of the h2 head surface pressure sensor
This is a Ch2 head surface pressure estimating unit that estimates the surface pressure amount of the head.

It should be noted that the Ch1 head surface pressure estimating section 561 and C
Since the h2 head surface pressure estimating unit 562 has the same configuration, here, the Ch1 head surface pressure estimating unit 561 is used.
Is shown in detail.

The changeover switch 535 outputs the output of the Ch1 head surface pressure estimation unit 561 or the Ch2 head surface pressure estimation unit 562.
And a subtractor 559 for subtracting the reference surface pressure Pr from the estimated surface pressure Pg given via the switch 535 to obtain the surface pressure error Pd. A gain compensator for compensating the gain of the surface pressure error Pd from the calculator 559, block 58
Reference numeral 1 denotes a phase compensator for providing phase compensation to the output from the gain compensator 580, and an amplifier 538 is a power amplifier for driving the reel motor 539 with the control amount Ct output from the phase compensator 581.

The block 530 of the Ch1 head surface pressure estimating unit 561 is a plate spring 524 of the movable head mechanism 526.
, A block 531 is a mass-viscosity block constituting a value 1 / (mS + c) corresponding to the mass and viscosity of the movable head mechanism 526, and a block 534 is the above-mentioned spring constant block. 5
The integral block and blocks 532 and 533 that constitute the mechanical model of the movable head mechanism 526 together with the block 30 and the mass viscous block 531 are a Ch1 head surface pressure estimating unit 56.
1 and a feedback gain block using feedback gains F _{1 and} F ₂ as coefficients for constructing the observer in FIG.
A subtractor 563 that subtracts the output Ch1S of the Ch1 head surface pressure sensor from the h1 sensor amplifier 527 and supplies the result to the feedback gain blocks 532 and 533.
Is a computing unit that provides a result obtained by detecting the balance between the output of the feedback gain block 533 and the output of the spring constant block 530 to the mass viscous block 531, and a subtractor 585 calculates the feedback gain block 532 from the output of the mass viscous block 531. Is a subtractor that subtracts the output of the above-mentioned signal and supplies the result to the integration block 534.

As described above, in this embodiment, the Ch1 head H slides on the magnetic tape 516 because the movable head mechanisms 526 including the heads H are mounted on the head cylinder at positions opposed to each other by 180 degrees. The output of the Ch1 head surface pressure estimating section 561 is supplied to the subtractor 559 via the changeover switch 535 in order to obtain the estimated amount of surface pressure during the moving period. Ch2 during the sliding period
The switch 535 is switched every half rotation of the head cylinder so that the output of the head surface pressure estimating unit 562 is supplied to the subtractor 559.

The operation of this embodiment will be described on the assumption that the input on the Ch1 head surface pressure estimating section 561 side is selected by the changeover switch 535. The protruding amount of the head H changes according to the surface pressure applied to the head H by the magnetic tape, and the protruding amount depends on the Hall element 511 and the magnet 512.
, And is given to the Ch1 sensor amplifier 527 and amplified as the Ch1 head surface pressure sensor output amount Ch1S.

Based on the output Ch1S of the Ch1 head surface pressure sensor obtained via the Ch1 sensor amplifier 527, C
In the h1 head surface pressure estimating unit 561, the head surface pressure estimation amount Pg
Is obtained by calculation, and this is given to the subtractor 559 through the changeover switch 535.

In the subtractor 559, the head pressure estimation amount P
g is subtracted from the reference surface pressure amount Pr, the surface pressure error amount Pd is gain-compensated by the gain compensating unit 580, and the phase is compensated by the phase compensating unit 581 including a low-pass filter. It is supplied to a reel motor 539 via an amplifier 538. As a result, the tension amount Tt of the magnetic tape 516 is controlled, and as a result, feedback control is performed so that the surface pressure applied to the head H by the magnetic tape becomes constant.

The head pressure estimating units 561 and 562
The same arithmetic processing as that of the state estimator described in the first to sixth embodiments is performed, and the spring constant block 530, the mass viscous block 531 and the integration block 534 include a spring constant, a mass, An electric circuit simulating the viscosity and the velocity-displacement conversion coefficient is configured, thereby simulating the mechanical characteristics of the movable head.

In this embodiment, since no actuator for controlling the amount of protrusion of the movable head H is mounted, the observer in the head surface pressure estimating units 561 and 562 has no input. However, the estimated displacement amount, which is the surface pressure estimation output, is always compared with the actual displacement amount, and feedback gain blocks 532 and 533 are provided so that the estimation error, which is the result of the comparison, converges after the operation of the observer. I have. By the way,
The feedback gain block 532 corresponds to a term relating to the speed of convergence of the estimation error, and the feedback gain block 533 corresponds to a term relating to the stability of the observer.

In the head surface pressure estimating section 561,
The part where the output of the spring constant block 530 and the output corresponding to the estimated value of the head surface pressure of the feedback gain block 533 are fed back to the mass viscous block 531 through the subtractor 563 is the reaction force of the leaf spring 524 in the movable head mechanism 526. The balance of the force with the head surface pressure that the head H receives from the magnetic tape 516 is reproduced as it is.

In the above description, the operation of the Ch1 head surface pressure estimating section 561 has been mainly described. However, the operation of the Ch2 head surface pressure estimating section 562 is exactly the same. By providing the output of 562 to the arithmetic unit 559, the head contact on the Ch2 head side can be favorably controlled.

Through the above operation, the magnetic tape 51
By changing the tension amount of No. 6, the surface pressure amount of the head H can be controlled, and as a result, the head surface pressure can be controlled to be constant, and the head contact can be favorably maintained.

[Ninth Embodiment] FIG. 36 shows a ninth embodiment of the present invention which is a control system in the case where the amount of protrusion of the movable head can be controlled by an actuator as shown in FIG. It is shown.

A block 506 is an actuator torque constant for giving an actuator torque constant for moving the movable head in the projecting direction, and a block 566 is a head surface pressure Ph.
And an output of the actuator torque constant 506. This surface pressure control actuator is equivalently constituted by an actuator torque constant 506, an adder 566, and a movable head mechanical characteristic 503.

In the structure shown in FIG.
04 is given to the actuator and the torque constant 50 of the actuator shown in block 506 is given.
The force to move the movable head is applied according to 6,
Since the head pressure Ph is also applied to the movable head, a resultant force obtained by adding these forces is applied to the movable head.

The movable head is displaced by receiving the resultant force under the influence of the mechanical characteristics 503 such as its own inertia. The displacement measuring means outputs a displacement Hm corresponding to the displacement.

As in the above-described embodiment, the surface pressure estimating unit 505 estimates the surface pressure received by the movable head from the displacement Hm, and subtracts the reference surface pressure value Pr inputted to the addition input terminal. The estimated value P is input to the subtraction input terminal of the
Enter g.

Therefore, a surface pressure error value Pd, which is the difference between the reference surface pressure Pr and the estimated surface pressure Pg, is obtained as the output of the subtractor. By calculating a control amount Ct necessary for compensating the surface pressure corresponding to the value Pd and supplying the control amount Ct to the actuator for driving the movable head, the head surface pressure estimated value Pg is kept constant according to the reference surface pressure value Pr. Control is performed to keep it.

[Tenth Embodiment] In a tenth embodiment shown in FIG. 37, a movable head is used as a magnetic head, and the surface pressure information obtained from the displacement of the movable head is taken into its tension control system. The configuration is such that highly accurate surface pressure control and tension control are performed simultaneously.

Reference numeral 542 denotes the aforementioned movable pin provided on the entry side of the head cylinder D9. Reference numeral 541 denotes a tension servo circuit for controlling the reel motor 539 for maintaining the tape tension at a predetermined value. Reference numeral 540 denotes the movable pin 542.
Movable pin position control circuit for controlling the position of
Is an arithmetic unit that adds the control amount Ct output from the surface pressure control system compensating unit 504 and the output from the movable pin position control circuit 540 to the tension servo circuit 541 and the movable pin 542, and
82 amplifies the surface pressure sensor output amount Ps obtained by the Hall element 511 of the movable head mechanism 526, and
This is a sensor amplifier that outputs to the surface pressure estimating unit 505 via the control unit 29.

In the above-described configuration, the sensor pressure amplifier 582 amplifies the surface pressure sensor output amount Ps of the head H of the movable head mechanism 526 provided in the head cylinder 519, and the head cylinder via the slip ring 529. It is derived outside and given to the surface pressure estimation unit 505.

As a result, the estimated surface pressure Pg is obtained by the surface pressure estimating section 505, and the estimated surface pressure Pg is obtained.
Is subtracted from the reference surface pressure amount Pr by the computing unit 559, and the obtained surface pressure error amount Pd is input to the surface pressure control system compensator 504.

On the other hand, the position of the movable pin 542 is detected by a position sensor (not shown), and the position of the movable pin
0 is given.

The surface pressure estimating unit 505 and the surface pressure control system compensating unit 504 form a positioning control loop together with the movable pin position control circuit 540. In a state where the movable pin position control circuit 540 controls the positioning, Movable pin 54
The voltage applied to the actuator driving the actuator 2 has a linear relationship in the frequency range within the servo band of the position control system of the movable pin 542 and the tape tension amount of the tape running system.

This is because, when looking at the frequency characteristics from the amount of disturbance at the movable pin 542 received by the tape tension amount to the drive voltage of the control system including the movable pin position control circuit 540, the transmission characteristics of the disturbance and the voltage are controlled by the position control. It is a closed characteristic of the system.

This closed characteristic is generally flat in both the gain characteristic and the phase characteristic up to the vicinity of the control band, and can be easily imagined because there is no change in the frequency characteristic. Therefore, the voltage applied to drive the movable pin 542 in a state where the position control is being performed on the movable pin 542 may be considered to some extent as the detected tension amount of the tape traveling system.

Therefore, after the gain control, gain and phase and compensation of a low-pass filter and the like are performed by the tension control circuit 541 so that the voltage applied to the movable pin 542 becomes constant, the tape tension amount is fed back to the reel motor 539. Can be kept constant.

Here, by adding the output of the surface pressure control system compensator 504 to the position control system of the movable pin 542 by the computing unit 565, the position of the movable pin 542 is controlled and the head H of the movable head mechanism 526 is moved. Control can be performed such that the received head surface pressure becomes constant.

That is, it is possible to keep the amount of tape tension received by the movable pin 542 constant by the reel motor 539, and at the same time, suppress the fluctuation of the head surface pressure having a relatively high frequency received by the movable head mechanism 526 by moving the movable pin 542. It is possible.

By moving the movable pin 542 in the direction of the arrow, it is possible to freely change the amount of tape tension in the tape traveling system, and at the same time, the amount of head surface pressure between the head H and the magnetic tape 516. Needless to say, it can be changed.

Compared to the case where only the reel motor 539 is controlled, the control including the position control of the movable pin 542 is realized by making the movable pin 542 light and highly responsive with high rigidity to form a wider control system. can do.

[Eleventh Embodiment] FIG. 38 is a block diagram showing another example of a surface pressure control system using a reel motor and a movable pin. The actuator torque constant unit 506 is added to the position control system of the movable pin in tension control. A configuration in which a wideband tension control is performed using a disturbance amount as a detection tension amount is illustrated.

In the figure, the block 543 is a movable pin 5
A movable pin tension estimating circuit and an adder for estimating the tension of the movable pin 542 based on the position control signal to the MPU 42 and the position detection signal of the movable pin 542 and outputting the low-frequency component control amount Ctl and the high-frequency component control amount Cth Reference numeral 567 denotes a control amount Ct from the surface pressure control system compensator 504, a control signal from the movable pin position control circuit 540, and a movable pin tension estimating circuit 5.
This is an adder that adds the high frequency component control amount Cth from the P. 43 to generate a position control signal to the movable pin 542. Note that the low-frequency component control amount Ctl from the movable pin tension estimation circuit 543 is provided to the reel motor 539 as a tension control signal.

In the above configuration, the movable pin tension estimating circuit 543 has substantially the same configuration as the Ch1 head surface pressure estimating unit 561 shown in FIG. The amount of tension of the magnetic tape 516 applied to the movable pin 542 is estimated based on the position control signal.

As a result, in the configuration of the tenth embodiment shown in FIG. 37, the tension can be accurately detected only up to the servo band of the position control system of the movable pin 542. It is possible to accurately estimate the tape tension amount even when the
Can be controlled over a wide band.

In this case, the movable pin tension estimating circuit 5
The tape tension amount estimated in 43 is band-divided by a filter or the like, the low-frequency component control amount Ct1 extracted by the low-pass filter or the like is supplied to the reel motor 539, and the high-frequency component control amount Cth extracted by the high-pass filter or the like is movable. The signals are respectively supplied to the pins 542, and the respective frequency bands are shared and controlled.

As described above, in the configuration shown in FIG. 38, the low band tape tension is shared by the reel motor 539, and the wide frequency tension control of a relatively high frequency is shared by the movable pin 542. The target tape tension amount can be maintained in the band.

Further, a signal for controlling the head surface pressure based on the control amount Ct from the surface pressure control system compensator 504 is output to the arithmetic unit 5.
By adding to the position control system of the movable pin 542 at 67, the tension control is performed over a wide band including the rotation frequency of the head cylinder 519, and the variation of the head surface pressure at a higher frequency is further increased using the movable pin 542. By absorbing by the control system, it is possible to maintain good head contact.

[Twelfth Embodiment] FIG. 39 is a block diagram showing still another example of a surface pressure control system for controlling a reel motor and a movable pin. In particular, the tape tension is controlled only by controlling the head surface pressure. This is an example of a case in which a configuration for detecting or estimating the amount of tape tension received by a movable pin and controlling the tension of a traveling system is not included.

In FIG. 29, the surface pressure control system compensating section 504 generates a low-frequency component control amount Ctl and a high-frequency component control amount Cth through a filtering process.
tl is directly supplied to the supply reel 515 as a control signal, and the high frequency component control amount Cth is supplied to the movable pin position control circuit 5 for controlling the movable pin 542 through the calculator 567.
40 is added to the output.

In this case, two or more movable head mechanisms 526 are arranged 180 degrees opposite to each other on the head cylinder 519 so that the amount of surface pressure exerted by the magnetic tape 516 can be detected. 516
38, it is necessary to sample and hold the head surface pressure estimation amount Pg of the surface pressure estimating unit 505 and make it available for use. However, FIG. 39 has a simpler configuration than that of FIG. It has the feature of becoming. And if this condition is satisfied, the head surface pressure can be controlled in a constant and wide band,
Good head contact can be obtained.

FIG. 40 is a block diagram showing a specific circuit configuration of the surface pressure control system compensator 504 in the configuration of FIG. In the figure, reference numeral 556 denotes the surface pressure error amount Pd as K ₀ / (S
+ T ₁ ), a low-pass filter 568, which outputs the output of the low-pass filter 556 as the high-frequency component control amount Cth.
57 indicates the output of the low-pass filter 556 as K ₁ / (S
A low-pass filter 569 for filtering with a transfer function of + T ₂ ) is a driver amplifier that outputs the output of the low-pass filter 557 as the low-frequency component control amount Ct1. As shown in FIG. 39, the high-frequency component control amount Ct
h is sent to the control system of the movable pin, and the low-frequency component control amount Ct
1 is sent to the control system of the reel motor.

In the above-described configuration, in compensating a system having a movable pin control system and a reel motor control system, a low-pass filter 556 secures a low-frequency gain of the movable pin control system and increases the control band. It is determined.

Here, the surface pressure control system of the head corresponds to a kind of force control, that is, acceleration control.
Even if 6 is inserted into the one-stage control loop, the phase of the open loop characteristic turns only 90 degrees, so that the stability of the control system can be secured. Note that even if several low-pass filters are inserted in order to suppress noise in the control system in a frequency region higher than the control band, the phase margin does not significantly decrease. That is, it is acceptable if the phase margin can be maintained at 40 degrees to 60 degrees.

The low-frequency component control amount C to the reel motor
t1 is output via a low-pass filter 557 of one stage so as to control only a lower frequency. This is because the inertia of the reel motor itself is so large that it is not possible to respond very quickly, so that control in a low frequency band is covered. That is, two-stage control is performed by the movable pin and the reel motor according to the frequency band.

In the above example, the reel motor control system obtains the output of the low-pass filter 556 through the low-pass filter 557 to obtain the low-frequency component control amount Ct1, but the surface pressure control system compensator 504 Is divided into two to obtain a high-frequency component control amount Cth through a low-pass filter having a high cutoff frequency,
The configuration may be such that the low-frequency component control amount Ct1 is obtained via a low-pass filter having a low cutoff frequency.

In this case, since each control system is controlled only by a single-stage low-pass filter, there is an advantage that each system can be controlled independently and stably.

In the surface pressure control as in the present invention, the head surface pressure fluctuation amount or disturbance amount often includes many periodic components synchronized with one rotation of the head cylinder or disk. For this reason, the following capability can be enhanced by the configuration shown in the block diagram of FIG.

FIG. 41 shows another example of the surface pressure control system compensator shown in FIG. 40. In FIG.
d is an iterative learning compensator inserted in the input stage. In the above configuration, the periodic component is learned by the repetitive learning compensator 558 for the periodic component. However, in the e- ^LS block, which is a memory for one cycle, the periodic component of the surface pressure fluctuation is ^reduced. is a memory, a filter in order to satisfy the stability of the learning condition 1 / (1 + ST ₃₎ via the K ₃ block is a block with attenuator is positively fed back to the original input.

As a result, since the condition one cycle before is added to the surface pressure error amount Pd, it is possible to perform compensation with good followability.
Since such a configuration includes a memory block, it is difficult to configure with an analog circuit, and it is more effective to apply a digital circuit or a system using a microcomputer.

[Example in which the twelfth embodiment is realized by software] Next, the surface pressure control system compensating section 504 illustrated in FIG. 40 and the surface pressure estimating section illustrated in FIG. A case where the function corresponding to 505 is realized by a control system using software will be described with reference to the flowcharts of FIGS.

FIG. 42 is a software main program. First, in step 101, constants such as a spring constant, a feedback constant, a mass, a gain, various digital parameters, and variables are initialized. In the next step 102, a clock wait of one clock cycle is performed, and a series of subroutines following this, step 10
3 same dimension observer subroutine, step 10
The subroutine for estimating the surface pressure of No. 4 and the subroutine of the compensation system of Step 105 are executed, and the process returns to Step 102 until the control end is detected in Step 106 until the end thereof, and the execution of the subroutine is repeated with the next clock as a trigger.

FIG. 43 is a flow chart showing an example of the observer subroutine in the flow chart of FIG. This subroutine is for realizing the same dimension observer, that is, a function corresponding to the system of FIG. 31. In step 107, the surface pressure sensor output amount Ps is set to the variable a, and in step 108, the variable a is subtracted from the variable b. And set it to the variable c. By the way, this operation is shown in FIG.
A value corresponding to the output of the integration block 534 is set in the variable b, which corresponds to the operation of the first computing unit 564.

Next, at step 109, the value of the variable c is multiplied by the feedback constant F1 and set to the variable d. This operation corresponds to the operation of the feedback gain block 532. On the other hand, in step 110, the value of the variable c is multiplied by the feedback constant F2 and set to the variable e.
This operation corresponds to the operation of the feedback gain block 533.

Next, in step 111, the value of the variable b is multiplied by the spring constant k and set to the variable f. This operation corresponds to the operation of the spring constant block 530. Then, in step 112, the variable f and the variable e are added by sign inversion, and this is set as a variable g. This operation corresponds to the operation of the calculator 563.

In the next step 113, calculation of a digital filter using the variable g as an input is executed, and the output is set to the variable h. This operation corresponds to the operation of the mass viscous block 531. Then, in step 114, the value of the variable d is subtracted from the value of the variable h. This operation corresponds to the operation of the arithmetic unit 585. In the next step 115, a digital filter is calculated with the value of the variable i as an input, and the output is set to the variable b. This operation corresponds to the operation of the integration block 534.

FIG. 44 is a flow chart showing an example of the subroutine for estimating the contact pressure in the flow chart of FIG. This subroutine corresponds to the pseudo differentiating circuit 584 shown in FIG.
That is, this is to realize a function corresponding to the operation of the disturbance estimation block. In step 116, the variable h is multiplied by mG2 and set to the variable j. Next, step 117
Multiplies the variable h by mG and sets it to variable 1.

Then, in step 118, a digital filter is calculated using the value of the variable j as an input, and the output is set to the variable n. Finally, in step 119, the value of variable 1 is subtracted from the value of variable n, and this is set in variable o, and this subroutine ends. Incidentally, the value of the variable o here corresponds to the head pressure estimation amount Pg.

FIG. 45 is a flowchart showing an example of a subroutine of the compensation system in the flowchart of FIG. This subroutine is for realizing a function corresponding to the operation of the configuration shown in FIG. 40. In step 120, a digital filter is calculated using a variable o as an input, and the output is set to a variable p. This operation corresponds to the operation of the low-pass filter 556 in FIG.

At the next step 101, calculation of a digital filter using the variable p as an input is performed, and the output is set to a variable q. This operation corresponds to the operation of the low-pass filter 557. Then, in step 122, output port 1
, The value of the variable p is output, and this output value corresponds to the high-frequency component control amount Cth. Step 123
Outputs the value of the variable q to the output port 2, and this output value corresponds to the low-frequency component control amount Ct1.

Through the above software processing, the high-frequency component control amount Cth to be given to the movable pin control system
And low-frequency component control amount Ct to be given to the reel motor control system
1 can be obtained. Incidentally, the lag-lead filter, that is, the low-pass filter in each subroutine can be generally constituted by a cyclic digital filter.

Note that some of the above software are shown in FIG.
Although a portion corresponding to the operation of the repetitive learning compensator 558 shown in FIG. 5 is not included, it is easy to configure a memory on the microcomputer, and the surface pressure control system compensating unit in FIG. Is easy.

The position control circuit for the movable pin can be generally realized by inputting a position sensor provided on the movable pin, providing gain, and then securing a low-frequency gain and a control band with a low-pass filter. This can be easily realized by providing a new subroutine within one software cycle. In this case, there is only one additional input port for the position sensor of the movable pin, and the position control output may be added to the movable pin control amount in the head surface pressure control output.

In each of the embodiments described above, the case where the movable head is not driven by the actuator is described for the recording / reproducing apparatus using the magnetic tape. However, only the magnetic disk device and the reel motor have no movable head mechanism. In the case of a magnetic tape device, it is necessary to adopt a configuration in which a magnetic head is displaced by an actuator.

In this case, the signal to be given to the movable pin obtained in the subroutine of FIG.
By supplying th to the actuator of the magnetic head displacement mechanism, a similar effect can be obtained.

In this case, the mechanism around the magnetic head becomes complicated, but it is only necessary to move the magnetic head, which is extremely small in mass as compared with a system for controlling the movable pin and the reel motor. Is possible. When a rotary magnetic head is used, a control signal for the magnetic head is supplied via a slip ring or the like that electrically connects the head cylinder to the head cylinder.

The above-described surface pressure control system according to the present invention can be applied to a magnetic disk drive. FIG. 46 shows a first embodiment in which the surface pressure control system of the present invention is applied to a magnetic disk drive.
FIG. 47 is a schematic configuration diagram showing a third embodiment, and FIG. 47 is a perspective view and a sectional view of a holding portion of a head applied to the configuration of FIG.

Referring to FIG. 46, reference numeral 507 denotes a carriage for accessing the head H to the disk 510;
Reference numeral 08 denotes a movable support that is held by the gimbal spring 514 and moves the head H in the protruding direction.
It is movably held in a direction perpendicular to the X-axis and the Y-axis, that is, in the protruding direction via.

FIG. 47 is a perspective view (A) and a sectional view (A) of a holding portion of the head H applied to the configuration of FIG. 46. The head H is mounted on a carriage 507 via a gimbal spring 514 in the X-axis and Y-axis directions. It is movably held in a direction perpendicular to the axis, that is, in a protruding direction.

The protrusion amount of the head H is detected by the magnet 512 provided below the head H and the Hall element 511 fixed on the carriage 507, and sent to the surface pressure estimating unit 505 as the surface pressure sensor output amount Ps. You.

[0324] The pressing force of the head H against the disk 510 is a surface pressure, which can be detected from the position of the head H in the protruding direction with respect to the movable support portion 508. The magnet 512 and the Hall element 511 are provided for this purpose, and the surface pressure sensor output amount Ps is obtained from the magnet 512 by utilizing the fact that the distance between the two corresponds to the surface pressure.

Reference numeral 513 denotes a spindle motor for rotating the disk 510, reference numeral 560 denotes a ceramic actuator for controlling the amount of protrusion of the head H from the disk 510, and reference numeral 559 denotes a head surface pressure estimation amount Pg from the surface pressure estimation unit 505. The arithmetic unit outputs the surface pressure error amount Pd obtained by subtracting from the surface pressure amount Pr to the surface pressure control system compensating unit 504.

In the structure described above, the disk 510 is rotated by the spindle motor 513. On the other hand, the carriage 507 controls the head H to a position corresponding to a predetermined track. Head H is disk 51
0 is recorded and reproduced. In this case, the amount of spacing depends on the reaction force due to the air flow generated between the disk 510 and the head H and the movable support section 8 has a gimbal spring 514.
Is determined by the balance of the force pressing the head H against the disk 510 through the head. In addition, the movable support portion 508
Is driven by the ceramic actuator 560 to the disk 510 side.

The surface pressure sensor output amount Ps obtained through the above configuration is supplied to the surface pressure estimating section 505 to obtain the head surface pressure estimated amount Pg. The estimated head surface pressure amount Pg is compared with a reference surface pressure amount Pr by an arithmetic unit 559, and the surface pressure error P
d, but this surface pressure error amount Pd is
04, and by controlling the ceramic actuator 560 with the control amount Ct obtained as a result, the head surface pressure estimation amount Pg by the surface pressure estimation unit 505 can be kept constant. As a result, the disk of the head H can be maintained. The head contact with 510 can be kept good.

[0328]

As described above, according to the present invention, tension control and DTF control of a magnetic tape can be performed over a wide dynamic range with high accuracy over a wide frequency band. By constructing a control system using a pressure estimator, a better recording / reproducing device can be obtained, so not only good reproduction is possible in normal reproduction, but also noise is generated on the screen even in a wide range of different speed reproduction. There is an advantage that good reproduction can be realized at low cost without performing.

Further, if the surface pressure applied from the magnetic recording medium to the magnetic head is controlled to be always constant, the spacing between the magnetic head and the magnetic recording medium can be maintained accurately and with good responsiveness over a wide band. It is possible to do
The linear recording density can be increased, and even when performing high-density recording, there is no contact between the magnetic tape and the magnetic head, so that their wear can be reduced.

[0330] Since the head contact can be maintained well even when the transient tension fluctuation is severe as in the case of special reproduction such as different speed reproduction, the durability of the magnetic head and the magnetic tape can be improved. A special effect is achieved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing one of the basic principles of the present invention.

FIG. 2 is a schematic block diagram showing a first embodiment.

FIG. 3 is a schematic perspective view of a tape actuator used in the embodiment.

FIG. 4 is a sectional view of a tape actuator used in the embodiment.

FIG. 5 is a schematic diagram for explaining a driving principle of the tape actuator.

FIG. 6 is a diagram showing a “displacement angle / frequency” characteristic of a tape actuator.

FIG. 7 is a diagram illustrating an example of an optical sensor that measures the amount of displacement of an arm of a tape actuator.

FIG. 8 is a diagram showing an example of magnetic means for measuring the displacement of the arm of the tape actuator.

FIG. 9 is a diagram illustrating a tracking control system according to the first embodiment based on a flow of physical quantities.

FIG. 10 is a diagram showing the tracking control system of the first embodiment by using a transfer function of control theory.

FIG. 11 is a diagram illustrating an open loop characteristic of the DTF control system according to the first embodiment.

FIG. 12 is a diagram illustrating a tension control system according to the first embodiment based on a flow of a physical quantity.

FIG. 13 is a diagram illustrating the tension control system of the first embodiment by using a transfer function of control theory.

FIG. 14 is a schematic block diagram showing a second embodiment.

FIG. 15 is a diagram illustrating a DTF control system according to a second embodiment based on a flow of physical quantities.

FIG. 16 is a diagram illustrating a DTF control system according to a second embodiment using a transfer function of control theory.

FIG. 17 is a diagram illustrating an open loop characteristic of the DTF control system according to the second embodiment.

FIG. 18 is a block diagram illustrating a head touch control circuit according to a second embodiment.

FIG. 19 is a waveform diagram of signals in the head touch control circuit of FIG. 19;

20 is a waveform chart of a signal in another operation mode of the head touch control circuit in FIG. 19;

FIG. 21 is a schematic block diagram showing a third embodiment.

FIG. 22 is a schematic block diagram showing a fourth embodiment.

FIG. 23 is a schematic block diagram showing a fifth embodiment.

FIG. 24 is a diagram showing a fifth embodiment based on a flow of physical quantities.

FIG. 25 is a diagram showing the fifth embodiment by using a transfer function of control theory.

FIG. 26 is a plan view showing a configuration of a movable head mechanism provided in a head cylinder.

FIG. 27 is a perspective view showing a configuration of a movable head mechanism provided in a head cylinder.

FIG. 28 is a perspective view showing another example of the configuration of the movable head mechanism.

FIG. 29 is a perspective view showing still another example of the configuration of the movable head mechanism.

FIG. 30 is a diagram showing a sixth embodiment based on a flow of physical quantities.

FIG. 31 is a diagram illustrating a surface pressure estimating unit according to a sixth embodiment using a transfer function of control theory.

FIG. 32 is a block diagram showing an example in which the sixth embodiment is configured by an analog circuit.

FIG. 33 is a diagram illustrating a surface pressure estimating unit according to a seventh embodiment using a transfer function of control theory.

FIG. 34 is a block diagram showing an example in which the seventh embodiment is configured by an analog circuit.

FIG. 35 is a block diagram showing an embodiment of a surface pressure control system according to an eighth embodiment.

FIG. 36 is a block diagram of a ninth embodiment.

FIG. 37 is a schematic view of a tenth embodiment.

FIG. 38 is a schematic view of an eleventh embodiment.

FIG. 39 is a schematic view of a twelfth embodiment.

FIG. 40 is a block diagram showing a circuit configuration of a surface pressure control system compensator in a twelfth embodiment.

FIG. 41 is a block diagram showing another circuit configuration of the surface pressure control system compensator of the twelfth embodiment.

FIG. 42 is a flowchart of a main program when the twelfth embodiment is implemented by software.

FIG. 43 is a flowchart showing an example of an observer subroutine.

FIG. 44 is a flowchart showing an example of a subroutine for estimating surface pressure.

FIG. 45 is a flowchart showing an example of a compensation system subroutine.

FIG. 46 is a schematic view showing a thirteenth embodiment in which the surface pressure control system of the present invention is applied to a magnetic disk drive.

FIG. 47 is a perspective view and a sectional view of a holding portion of a head applied to a thirteenth embodiment.

FIG. 48 is a schematic diagram of a general tape running system in a magnetic recording / reproducing apparatus using a conventional rotary head.

FIG. 49 is a diagram showing an example of a conventional back tension control device.

FIG. 50 is a schematic diagram of a system using a movable head for noiseless special reproduction.

FIG. 51 is a block diagram illustrating an example of a high-speed special reproduction method according to the related art.

FIG. 52 is a diagram for explaining a state of normal speed 5 × speed reproduction.

FIG. 53 is a diagram illustrating a state of 5 × reverse speed playback.

FIG. 54 is a schematic diagram of a tilt error pattern during n-times speed reproduction.

[Explanation of symbols]

H, Ha, Hb Magnetic head D Head cylinder T Magnetic tape 1 Rotating surface of rotating head 4 Supply reel motor 5 Take-up reel motor 6 Capstan motor 7 Pinch roller 8a Inlet slant pole 8b Outlet slant pole 9a Inlet movable pin detecting the 9b exit side movable pin 10a _1, 10a ₂ inlet side fixing pins 10b _1, 10b ₂ exit side rotation angle of the fixing pin 11a inlet side arm 13 tape actuator for moving the tape actuator 11b exit side tape actuator 12 movable pin Sensor 14 Head actuator

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-11719 (JP, A) JP-A-56-11620 (JP, A) JP-A-57-27424 (JP, A) JP-A-2- 246011 (JP, A) JP-A-2-287914 (JP, A) JP-A-56-163552 (JP, A) JP-A-2-185752 (JP, A) JP-A-1-176351 (JP, A) JP-A-1-176352 (JP, A) JP-A-2-78049 (JP, A) JP-A-2-78045 (JP, A) JP-A-1-82356 (JP, A) JP-A-1-25749 (JP, A) JP-A-62-267955 (JP, A) JP-A-2-206053 (JP, A) JP-A-3-173965 (JP, A) JP-A-2-64950 (JP, A) Kaisho 60-65718 (JP, A) JP-A-3-66047 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 15/43

Claims (10)

(57) [Claims] A magnetic recording / reproducing apparatus having a running path from a supply reel to a take-up reel through a head cylinder on which a rotating magnetic head is mounted, and a capstan driven by a capstan motor. , A pair of entry-side fixing pins provided close to the running path of the magnetic tape from the supply reel to the head cylinder, and a distance between a pair of lines connecting the pair of entry-side fixing pins is provided. Entry side movable pin and above entry side movable pin
It is connected to, entry side tape actuator for controlling the distance between the pair of inlet side connecting fixing pins lines and upper fill movable pin
And over motor, the upper fill side the magnetic tape between the pair of input side fixing pins
Engage with the movable pins to form the entry loop of the magnetic tape.
At the same time as the input side
Adjust the distance between the movable pins with the input tape actuator.
To control the tension of this magnetic tape.
A tension control system for generating the tension control signal.
Is the position signal from the input tape actuator.
Based on the above, the characteristics of the entry tape actuator
A magnetic recording / reproducing apparatus comprising a simulated state estimator . 2. A supply reel driving means for rotationally driving a supply reel on which a magnetic tape is wound, and a magnetic tape for moving the magnetic tape from the supply reel at a predetermined speed via a head cylinder on which a rotating magnetic head is mounted. Feed means, a line installed in the running path of the magnetic tape from the supply reel to the head cylinder, and connecting a pair of entry-side fixing pins provided between the supply reel and the head cylinder
An input-side movable pin that changes the distance of the magnetic tape to change the travel path length of the magnetic tape; an input-side tape actuator that drives the movable pin; a position detection unit that detects the position of the movable pin; The output signal from the position detecting means and the input tape
A tension detecting means for detecting a tension of the magnetic tape by calculating a driving voltage or a driving current of the tutor ; and a supply reel driving means alone or the input side tape actuator based on an output signal of the tension detecting means.
And tension control means for outputting a tension control signal to control the tension of the magnetic tape to a predetermined value by over data and cooperate spacing error based on the envelope of the signal reproduced from the magnetic tape by the magnetic head Means for detecting spacing, means for adding a spacing error signal output from the spacing detecting means to the tension control signal, and means for adding the spacing error signal to the tension.
Based on the control signal, the input tape actuator
A magnetic recording / reproducing apparatus, comprising: a tension control system for controlling a movable pin . 3. The spacing detection means outputs a spacing error signal via a limiter for preventing a spacing error signal output from the spacing detection means from exceeding a limited level. 3. The magnetic recording and reproducing apparatus according to claim 2, wherein: 4. The apparatus according to claim 1, wherein the spacing detecting means detects an envelope of a signal reproduced from the magnetic tape by the magnetic head, and detects the signal based on a signal reproduced from the magnetic tape by the magnetic head. Means for obtaining a tracking error signal indicating a relative position error between the magnetic head and a recording track on the magnetic tape; and detecting a spacing amount based on a difference between an output from the envelope detection means and the tracking error signal. 4. A magnetic recording / reproducing apparatus according to claim 2, further comprising means. 5. The spacing detecting means, when it is determined based on the tracking error signal that the tracking error is small, closes the switch means and outputs the spacing error signal from the spacing detecting means. 5. The magnetic recording / reproducing apparatus according to claim 4, further comprising a discriminating unit for determining whether the magnetic recording / reproducing apparatus is in a proper state. 6. The magnetic recording apparatus according to claim 5, wherein said determining means determines the level of the tracking error signal by comparing the amplitude of the tracking error signal with a predetermined voltage. Playback device. 7. A supply reel driving means for rotationally driving a supply reel on which a magnetic tape is wound, and a magnetic tape for moving the magnetic tape at a predetermined speed from the supply reel via a head cylinder on which a rotating magnetic head is mounted. Feeding means, an input-side movable pin installed in a traveling path of the magnetic tape from the supply reel to the head cylinder, and changing a traveling path length of the magnetic tape between the supply reel and the head cylinder; An input tape actuator for driving a movable pin; a position detecting means for detecting a position of the movable pin; an output signal from the position detecting means ;
A tension detecting means for detecting a tension of the magnetic tape by calculating a driving voltage or a driving current of the tutor ; and a supply reel driving means alone or the input side tape actuator based on an output signal of the tension detecting means.
And tension control means for outputting a tension control signal to control the tension of the magnetic tape to a predetermined value by over data and cooperate acceleration detection means for detecting the acceleration of a movable direction of the movable pin, by the acceleration detecting means A magnetic recording / reproducing apparatus, comprising: an adder / subtractor for adding or subtracting the tension control signal based on the detected acceleration signal. 8. A magnetic recording / reproducing apparatus having a running path from a supply reel to a take-up reel via a head cylinder on which a rotating magnetic head is mounted, and a capstan driven by a capstan motor. A pair of entry-side fixed pins provided in the vicinity of the running path of the magnetic tape to the head cylinder, and an entry-side movable pin provided to be able to change the distance with respect to a line connecting the pair of entry-side fixed pins, Entry taper that controls the distance between the line connecting the pair of entry-side fixed pins and the entry-side movable pin.
Together and a actuator, a pair of output side fixing pin provided in proximity to the travel path between the head cylinder and the take-up reel, so as to vary the distance with respect to the pair of output side fixing pins line connecting An output tape actuator for controlling a distance between the output movable pin provided, a line connecting the pair of output fixed pins, and the output fixed movable pin.
And a motor, when performing reproduction at a speed different from the tape speed during recording, the upper fill side tape actuator and egress tape activator
A magnetic recording / reproducing apparatus, characterized in that tracking is performed by moving the actuator differentially with respect to each other. 9. A signal for controlling the delivery side tape actuator is generated by the tracking control system comprising a state estimator which simulates the characteristics of the exit side tape actuator, further comprising a tracking error detecting means for detecting a tracking error , The output tape actuator at the relatively high frequency component of this tracking error signal.
9. The magnetic recording / reproducing apparatus according to claim 8, wherein the capstan motor or the take-up reel motor is controlled by a relatively low frequency component of the tracking error signal. 10. A moving means for moving a magnetic head in a protruding direction toward a recording surface of a recording medium, and a surface pressure between the magnetic head and the recording medium based on a displacement amount of the magnetic head. and a surface pressure estimator to estimate, by the surface pressure control signal obtained based on the difference between the estimated surface pressure value and the reference surface pressure by the surface pressure estimator, and controls the moving means the magnetic head is moved, the magnetic recording and reproducing apparatus is characterized in that so as to control the surface pressure between the magnetic head serial <br/> recording medium constant.