KR19980087076A - Magnetic recording and playback device - Google Patents

Abstract

The magnetic recording and reproducing apparatus has a supply reel and take-up reel around the magnetic tape to be wound. The first tape guide is provided near the rotary head on the supply reel side and the second tape guide is provided near the rotary head on the take-up reel side. The first and second tape guides can be moved in the width direction of the magnetic tape. The detector detects the height of each of the first and second tape guides. The calculated value according to the detected height is obtained by the counter. At least the height of the first or second tape guide is adjusted such that the calculated value is equal to the reference value. The calculated value is set to a specific value when the detected height becomes a reference height corresponding to the reference value after the magnetic tape is wound around the supply and take-up reel.

Description

Magnetic recording and playback device

The present invention relates to a magnetic recording and reproducing apparatus having a mechanism for adjusting the height of a guide pole (tape guide) provided on the supply and take-up reel side.

It is known that the track patterns formed on the magnetic tape are different from each other according to the rotational trajectory of the magnetic rotating head. This phenomenon occurs even when the track pattern is formed by a magnetic recording apparatus of the same recording and reproducing standard due to the difference in the allowed mechanical tolerances.

In this case, the recorded data sometimes damages the data reproduced by the magnetic recording device which coexists with other magnetic recording devices. The narrower the track pattern of the high density recording, the more serious the problem may occur.

For example, a W-VHS video tape recorder (VTR) has been proposed for recording and reproducing high visual-image data simultaneously recorded in three parallel track patterns each having a width of 19 μm-. Two of the three parallel track patterns are used for video signal recording and reproduction with two rotating magnetic heads having azimuth angles in opposite directions. In contrast, the other track pattern is used for recording and playing back audio signals with an audio rotating magnetic head that can be used after recording.

The tolerance of the curve on one track pattern of the W-VHS VTR is determined to be about 7 μm. This tolerance is such that the track pattern of the magnetic tape recorded by the first W-VHS VTR and the second W- coexist with the first W-VHS VTR when the next recording is performed by the second W-VHS VTR. A maximum 14 μm-deviation can occur between the rotary tracks of the rotary magnetic heads of the VHS VTR.

If the 14 μm-deviation occurs, the audio rotary magnetic head for later recording of the second W-VHS VTR will be displaced by 14 μm from the audio track pattern on the magnetic tape to adjacent video track patterns each having 19 μm-width. will be. This results in the recording of the audio signal for later recording over the 14 μm-width portion of the video track pattern, each having a 19 μm-width.

Thus, the reproduced video signal is degraded because only 5 μm-width portions remain as the video signal.

It is an object of the present invention to provide a magnetic recording and reproducing apparatus which can eliminate the difference in allowable mechanical tolerances affecting the track pattern on the magnetic tape.

The present invention provides a magnetic recording and reproducing apparatus comprising: a supply reel and a take-up reel around a magnetic tape to be wound; A first tape guide provided near the rotating head of the supply reel side; A second tape guide provided near the rotating head of the take-up reel side, the first and second tape guides can be moved in the width direction of the magnetic tape; A first detector for detecting a height of each of the first and second tape guides; A counter for obtaining a calculated value corresponding to the detected height; An adjuster for adjusting the height of at least the first or second tape guide so that the calculated value corresponds to the reference value; Means for setting the calculated value to a specific value when the detected height becomes a reference height corresponding to the reference value after the magnetic tape is wound around the supply and take-up reel.

The present invention also provides a magnetic recording and reproducing apparatus comprising: a supply reel and a take-up reel around a magnetic tape to be wound; A tape guide provided near the rotating head of the supply reel and take-up reel side, the tape guide can be moved in the width direction of the magnetic tape; A driver for moving the tape guide in a tape width direction; Detecting the height of each of the tape guides, generating a first reference signal when at least one of the tape guides is moved from the first direction to the first reference height, wherein at least one of the tape guides A detector for generating a second reference signal when moved to a second reference height in a second direction opposite the first direction; Memory for storing the first pulse number calculated when the first reference signal is generated and for storing the second pulse number calculated when the second reference signal is generated, the driver further comprising at least a second value between the first and second pulse numbers; 1 Move at least one tape guide based on the difference.

The present invention also provides a magnetic recording and reproducing apparatus comprising: a supply reel and a take-up reel around a magnetic tape to be wound; A tape guide provided near the rotating head of the supply reel and take-up reel side, the tape guide can be moved in the width direction of the magnetic tape; A driver for moving the tape guide in a tape width direction; A counter for calculating the number of pulses generated while the at least one tape guide is moved; A detector for detecting the number of calculations of pulses when the at least one tape guide moves at a specific speed and then stops, the driver moves at least one tape guide based on the number of calculations of the detected pulses.

1 is a block diagram of a magnetic recording and reproducing apparatus according to the present invention;

2A to 2C are explanatory diagrams for explaining the disadvantages of the conventional magnetic recording and reproducing apparatus.

3 is a perspective view illustrating an embodiment of a magnetic recording and reproducing apparatus according to the present invention while a tape is loaded.

4 is a perspective view for explaining an embodiment of a magnetic recording and reproducing apparatus according to the present invention when tape loading is completed;

Fig. 5 is a perspective view illustrating another embodiment of the magnetic recording and reproducing apparatus according to the present invention while the tape is loaded.

6A-6C are explanatory diagrams of a guide foul provided on the foul base;

7A to 7C are explanatory diagrams of gear coupling.

8A and 8B are explanatory diagrams for explaining the operation of the reference position sensor.

9A and 9B are explanatory diagrams of a guide foul provided on the foul base;

10A to 10C are flowcharts illustrating the operation of the magnetic recording and reproducing apparatus according to the present invention.

11A to 11C are flowcharts illustrating another operation of the magnetic recording and reproducing apparatus according to the present invention.

12 is a time flow diagram illustrating a magnetic recording and reproducing apparatus according to the present invention;

13A and 13B are plan and cross-sectional views of the fouling base.

14A to 14C are explanatory diagrams for explaining the movement of the sole base;

15A to 15C are other explanatory diagrams for explaining the motion of the foul base;

16A to 16C are still another explanatory diagram for explaining the motion of the foul base.

17 is an explanatory diagram for explaining the operation of the operation of the height adjustment cam;

18A and 18B are explanatory diagrams for explaining the movement of the guide roller while the tape is loaded.

19 is a cross-sectional view of a guide roller.

20 is a sectional view of another guide roller;

21 is a sectional view of another guide roller;

22A and 22B are explanatory diagrams of a guide foul provided on the foul base;

23A-23C are explanatory diagrams of another guide pole provided on the foul base;

24A and 24B are explanatory diagrams of yet another guide foul provided on the foul base;

25A-25C are explanatory views of yet another guide foul provided on the foul base;

26A-26C are explanatory diagrams of yet another guide foul provided on the foul base;

Fig. 27 is a perspective view for explaining an embodiment of the magnetic recording and reproducing apparatus according to the present invention while the tape is loaded.

28A-28C are explanatory diagrams of a guide foul provided on a foul base;

29 is an explanatory view of yet another guide foul provided on the foul base;

30 is a perspective view of a height adjustment mechanism in a fixed section of the magnetic recording and reproducing apparatus according to the present invention.

31A and 31B are perspective views of another height adjustment mechanism in the fixed section of the magnetic recording and reproducing apparatus according to the present invention.

32A and 32B are cross sectional and top views of guide rollers provided on a fouling base;

33 is an explanatory view of a guide roller and an opening of a cassette;

34A and 34B are explanatory diagrams of a guide roller.

Explanation of symbols for the main parts of the drawings

1: input terminal 2: output terminal

3: rotating magnetic head 4: recording and playback processor

5: envelope detector 6: controller

7: reference positioning sensor 8: rotary encoder

9: control motor 10: reference positioning sensor

11: rotary encoder 12: control motor

13: drum controller 14: tape movement controller

15: loading controller

Suitable embodiments according to the present invention are described with reference to the accompanying drawings. Throughout the drawings, elements in similar or identical embodiments use the same reference signs or reference numerals.

1, the signal to be recorded is supplied to the recording and reproducing processor 4 via the input terminal 1. The signal is processed by the processor 4 and recorded on a magnetic tape (not shown) via the rotating magnetic head 3.

In reproduction, the recording signal is reproduced from the magnetic tape via the rotating magnetic head 3. The reproduced signal is processed by the recording and reproducing processor 4 and output through the output terminal 2.

During reproduction, the recording and reproducing processor 4 supplies the reproduced frequency-modulated signal to the envelope detector 5 which outputs the envelope signal to the controller 6.

The controller 6 controls the overall function of the recording and reproducing apparatus of FIG. 1 in response to a control signal supplied through the input terminal 17. The controller 6 may include CPUs, ROMs, RAMs, counters, up / down counters, and the like.

The envelope signal indicates how much the magnetic track of the recording signal on the magnetic tape is curved. The envelope signal may also be provided with first and second guide poles arranged on the feed and take-up reel sides, respectively, along the tape movement path by closed-loop automatic control that meets the magnetic track with the rotating track of the rotating magnetic head. Tape guide).

The controller 6 supplies control data to the drum controller 13 and the tape movement controller 14. The controller 13 rotates the drum drive motor (to be described later) at a predetermined rotational speed and phase. The controller 14 is controlled to move the magnetic tape at a predetermined moving speed and phase. The controller 6 also controls the loading controller 15 which will be described later.

The reference positioning sensor 7, the rotary encoder 8 and the control motor 9 constitute a first height adjustment mechanism for adjusting the height of the first guide pole provided on the supply reel side.

On the other hand, the reference positioning sensor 10, the rotary encoder 11 and the control motor 12 constitute a second height adjustment mechanism for adjusting the height of the second guide pole provided on the take-up reel side.

The first and second height adjustment mechanisms will be described with reference to FIGS. 2A to 2.

2C shows the upper drum Du, the lower drum Dd and the drum base DB. In addition, the first and second pole bases PB1 and PB2 shown in FIG. 2C are provided in the loading mechanism.

The first guide pole GP1 and the first sloped foul SP1 and the second guide pole GP2 and the second sloped pole SP2 are provided on the base poles PB1 and PB2, respectively. The guide poles GP1 and GP2 may be moved in a direction perpendicular to the bases PB1 and PB2, respectively. The guide poles GP1 and GP2 are moved to the predetermined positions of the feed and take-up reel sides, respectively, when loaded by the completed loading mechanism.

FIG. 2A is a plan view showing the state of the upper drum Du and its periphery when the loading operation is completed. FIG.

The upper and lower drums Du and the magnetic tape T have data recording on a continuous straight track such as an alignment tape (adjustable reference tape), and the magnetic tape T is wound by more than 180 degrees (drum center angle). When the heights of the guide poles GP1 and GP2 are both predetermined reference heights during the movement along Dd), the envelope of the reproduction frequency-modulated signal reproduced by the rotating magnetic head 3 has a rectangular shape.

However, if the heights of the guide poles GP1 and GP2 are not the predetermined reference heights, the envelope of the reproduction frequency-modulated signal is determined even when the magnetic tape T has data recording on the continuous straight track. Has a wave as shown in FIG. 2B depending on the height of GP1 and GP2).

Further, even when the height of the guide poles GP1 and GP2 is the predetermined reference height, when the magnetic tape T has recording data on the curved track as shown in Fig. 2C, the reproduction frequency-modulated signal is The envelope also has a wave in the shape as shown in FIG. 2B.

The present invention provides a closed-loop automatic guide pole-height control system that forms a track on a magnetic tape that meets a rotating track of a rotating magnetic head.

Specifically, the closed-loop control system detects the curved data in accordance with a change in the envelope of the frequency-modulated signal reproduced from the magnetic tape for generating the height control signal. The curved data indicates how curved both ends of the data-recording track are. The height of the guide pole is adjusted based on the height control signal so that the reproduction frequency-modulated signal has a rectangular shape.

3, 4 and 5, the upper and lower drums Du and Dd on the drum base DB form a drum body (assembly) DA. The drum base DB is mounted on the fixed end face of the recording and reproducing apparatus. The drum drive motor Md is provided to the upper drum Du, the rotor of which is fixed to the upper drum Du. The upper drum Du is a rotating drum as described below.

The plate 18 is provided above the drum body DA on which the starter of the drum drive motor Md is fixed with screws (screws) 20, 21. The central shaft 19 of the drum body DA is fixed on the central portion of the lower drum Dd fixed on the drum base DB. The drum base DB is also provided with two bass catchers BC (only one shown for brevity).

The upper and lower drums Du and Dd are arranged to have a gap G therebetween, and a magnetic rotating head 3 is provided just above the gap G. The magnetic rotating head 3 forms a rotating track at a predetermined position with respect to the fixed end face of the recording and reproducing apparatus.

A plurality of magnetic rotating heads may be provided according to the recording and reproducing method employed by the recording and reproducing apparatus.

The loading mechanism is provided with both first guide poles GP1 mounted on the first pole base PB1 and both second guide poles GP2 mounted on the first sloped pole SP1 and the second pole base PB2. And a second inclined fouling SP2.

The loading mechanism removes the magnetic tape from the cassette (not shown) in the loading operation. And when the magnetic tape is wound around the predetermined outer surfaces of the upper and lower drums Du and Dd upon completion of the loading operation, the fouling base PB1 is formed of a first guide pole GP1 and a first sloped foul SP1. ) Moves along the tape runway to the feed reel side, whereas the foul base PB2 has a second guide pole GP2 and a second sloped pole SP2 along the tape runway Move to position

The first and second pole bases PB1 and PB2 are fixed, for example, on a link (not shown) of the loading mechanism and can move along a guide rail (not shown).

Upon completion of the loading operation, the foul bases PB1 and PB2 are engaged with the base catchers BC1 and BC2, respectively. Thus, upon completion of the loading operation, the pole bases PB1 and PB2 are located in cavities having a predetermined positional relationship in the left and right and up and down directions with respect to the fixed end face of the magnetic recording and reproducing apparatus.

In view of this, in Figs. 3, 4 and 5 only the second guide pole GP2, the sloped pole SP2 and the sole base PB2 are shown for the sake of brevity. The first guide fouling GP1, the inclined foaming SP1 and the fouling base PB1 are present on opposite sides of the drum body DA.

6A to 6C show the structure of the guide pole GP1, but it is commonly applied to the guide poles GP1 and GP2.

The end portion of the shaft 22 is inserted into a hole 55 formed on the fouling base PB1 that limits the direction of translation of the shaft 22. The lower flange 23 is fixed around the shaft 22 with the gear 23g at the lower outer surface of the flange 23. Further, a male screw (screw) 23a is formed around the boss outer surface of the gear 23g. The gear 23g is a secondary gear that meshes with the primary (drive) gear of the first height control mechanism provided in the fixed end face of the magnetic recording and reproducing apparatus, and will be described later to rotate to allow rotation of the primary gear. do.

The male screw 23a is screwed into a female screw 24 provided on the fouling base PB1. The female screw 24 is larger than the male screw 23a, so that when the shaft 22 is rotated, the guide pole GP1 is moved in the direction along the center line L of the shaft 22. The male screw 23a may be formed around the outer surface of the shaft 22.

An elastic ring 26, such as a rubber ring, is provided around the shaft 22 and between the gear 23g and the upper end portion 25 of the fouling base PB1. The elastic ring 26 always pushes the gear 23g upwards so that the screws 23a and 24 are firmly engaged with each other. Thus, the gear 23g is rotated only by the force given by the primary gear of the first height control mechanism.

An upper flange 27 having a protrusion 27a fixed around the shaft 22 is provided above the lower flange 23. The roller 28 is provided between the flanges 23 and 27 having the same length as the width of the magnetic tape. The semi-circular shield plate 29 is mounted on the upper surface of the protrusion 27a by the screw 30.

3, 4 and 5, a photointerpreter (photointerrupter) 31 is provided to work with the shield plate 29 as part of the reference position detector 7 (10).

3, 4, and 5, the rotary encoder 8 (11) generates a pulse that carries data indicating the rotational speed and the rotational direction of the shaft 32 of the control motor 9 (12). The rotary encoder 8 (11) is manufactured by a shield vane plate 33, and a photointerpreter 34 is provided around the shaft 32 of the control motor 9 (10).

In addition, a gear 35 that meshes with the gear 36 with the rotating shaft 38 of the power transmission system is provided around the shaft 32. Gear 37 is mounted over gear 36 and meshes with gear 39 with a rotating shaft 40. The gear 39 is the primary gear of the fixed-side height adjustment mechanism provided in the fixed end face of the magnetic recording and reproducing mechanism.

In the loading operation, the fouling base PB1 (2) is moved from the cassette to the drum body DA side along a predetermined moving path. Next, when the loading operation is completed, the end portion of the fouling base {PB1 (2)} moves the secondary gear 23g of the first (second) height adjusting mechanism provided on the fouling base side of the fixed-side height adjusting mechanism. The base catcher BC1 (2) engages to engage the primary gear 39.

The vertices of each tooth of the gears 23g and 39 are the base and the catcher base as shown in Figs. 7B and 7C to avoid full engagement and also incomplete engagement as shown in Fig. 7A. It may be formed without any flat portion for engagement between {BC1 (2)}.

8A and 8B illustrate reference position detection by the reference position sensor 7 (10) with the shield plate 29 and the photo interpreter 31. The sensor 7 (10) is also provided with a light emitting element 41 and a light receiving element 42. The sensor 7 generates a position signal when the shield 29 is inserted between and exits the light emitting and light receiving elements 41 and 42.

The shield 29 may be in the form of a reflection in which a beam of light emitted from the light emitting element 41 is received by the light receiving element 42. Further, the reference position sensor 7 (10) may be a magnetic tape having permanent magnets and magnetic detection elements such as Hall-effect elements instead of the optical position sensors shown in Figs. 8A and 8B.

As shown in Fig. 6B, the semi-circular shield plate 29 is fixed by screws 30 on the upper surface of the protrusion 27a of the upper flange 27 of the guide pole GP1 (2). In the semicircular shield plate 29, the guide surface (the upper surface of the lower flange 23 or the lower surface of the upper flange 27 of the guide pole {GP1 (2)) is magnetic in the recording and reproducing operation. When positioned at a predetermined reference height in order to achieve high compatibility of the recording and reproducing apparatus, as shown in FIG. 8B, the position corresponding to the instant when the beam of light generated from the light emitting element 41 is received by the light receiving element 42 is achieved. 8B illustrates a reference position at which the shield plate 29 is inserted into the photointerpreter 31 in its deepest state.

The guide surface of the guide pole GP1 (2) is detected by the number of pulses generated by the signal generated by the reference position sensor 7 (10) and the rotary encoder 8 (11). Specifically, the reference rotational phase of the shield plate 29 is determined as its position corresponding to the instant when the beam of light generated from the light emitting element 41 is received by the light receiving element 42. Also, the reference position of the guide surface of the guide pole GP1 (2) is determined as the height of the guide pole GP1 (2) when the shield plate 29 is positioned on the reference rotation. Next, the positional deviation or the difference in height of the guide surface of the guide pole {GP1 (2)} from the reference position in the vertical direction is obtained by the reference position and the number of pulses from the rotary encoder {8 (11)}. . The cumulative number of pulses is given by the up and down counters with addition in the up deviation of the guide pole GP1 (2) and subtraction in the down deviation.

The guide pole GP1 (2) can move in the vertical direction by the rotation of the gear 23g engaged with the gear 39. And, thereby, it is sometimes moved upward or downward by an external force even when the gear 23g is not engaged with the gear 39. And, if the guide pole {GP1 (2)} is rotated one or more times after the shield plate 29 is adjusted to be positioned on the reference rotation, the reference rotation phase is the guide surface of the guide pole {GP1 (2)}. Does not correspond to the height of

To overcome this drawback, the elastic ring (or spring) 26 described with respect to FIGS. 6B and 6C is suitable for a guide pole {GP1 (2)} that does not rotate even when no external force is provided. In addition, the stopper may be provided along the path of the shield plate 29 for the guide pole GP1 (2) that does not rotate more than once. In addition, slots may be formed on the shield plate 29 to secure the shield plate 29 by screws after being adjusted on a reference rotation.

As described above, upon completion of the magnetic tape loading operation, the guide surfaces of the first and second guide poles GP1 and GP2 are adjusted to predetermined heights for recording and playback. And, in reproducing, the guide surface is also provided with the first and second guide poles GP1 and GP2 obtained on the basis of the signal reproduced from the magnetic tape to match the track with the rotating track on the rotating drum for obtaining proper reproduction. Adjustment is made by a height adjustment mechanism having a height control signal generated by curved data indicative of a track proximate to.

In this respect, the tracks on the magnetic tape are mostly curved like U or S. In the case of the S-shaped curvature, the first and second guide poles GP1 and GP2 for erasing the curved track effect on the reproduction signal by the height control mechanism having the control signal obtained based on the curvature data as described above. The height of the guide surface of the can be adjusted in the opposite direction, i.e. one at the top and the other at the bottom.

The envelope of the frequency-modulated signal reproduced from the magnetic tape has a wave shape corresponding to the S-shaped curvature characteristic of the track. After amplitude demodulation of the reproduced frequency-modulated signal, a sampling for the envelope signal corresponding to the continuous track reproduced by amplitude demodulation is produced to extract the head envelope signal portion, the intermediate envelope signal portion and the end envelope signal portion. .

Based on the head and intermediate envelope signals, the controller 6 has a first height indicating the size and direction for adjusting the height of the lower flange 23 of the first guide pole GP1 provided on the supply reel side. Generate a control signal.

Further, based on the end and intermediate envelope signal sections, the controller 6 adjusts the size and direction for adjusting the height of the lower flange 23 of the second guide pole GP2 provided on the take-up reel side. Generate a second height control signal to indicate.

The first and second height control signals are supplied to the control motors 9 and 12 of the height control mechanism for the first and second guide poles GP1 and GP2, respectively.

The amplitude of the intermediate envelope signal portion does not change significantly even if the heights for the first and second guide poles GP1 and GP2 are adjusted. The height adjustment data is obtained by comparing successive sampling values on the same position of the envelope signal corresponding to the frequency-modulated signal reproduced from the magnetic tape. The control motors 9 and 12 are rotated by the rotational speed according to the first and second height control signals in the normal direction or the opposite direction, respectively, by the drive signals corresponding to the first and second height control signals.

The control motors 9, 12 transmit a force to the primary gear 39 via the gears 35 and the gears 36, 37 fixed to the rotary shaft 32. The force is also directed to the secondary gear 23g which meshes with the primary gear 39 which rotates in the normal or reverse direction. At this time, the first and second guide poles GP1 and GP2 are moved along the center line of the shaft 22, so that the lower flange 23 of the shaft 22 is vertically moved.

In the magnetic recording and reproducing apparatus shown in Fig. 5, the first and second guide poles GP1 and GP2 are provided on the fouling bases PB1 and PB2, respectively, so that they are magnetic in the recording and reproducing operation. Vertical sliding is performed with the aid of the elastic ring 26 within the range of the predetermined upper and lower regions relative to the predetermined reference height in order to achieve high compatibility of the recording and reproducing apparatus.

The positioning of the foul bases PB1, PB2 is performed by engaging the base features BC1, BC2, respectively. More specifically, the positioning is provided in the horizontal direction by engaging the concave portion (V-cutting portion) 43 having the portion 44 shown in Fig. 5, and the position provided on each of the pole bases PB1 and PB2. This is performed in the vertical direction by engaging the protrusion 45 having the determining portion (not shown).

The first and second guide fouls GP1 and GP2 are provided on the fouling bases PB1 and PB2, respectively, as described above. The height of the guide surface of each guide pole is adjusted to the height determined by the height control mechanism at the fixed cross-section side and the foul base side due to the engagement of the respective base and the base catcher and other elements of the height control mechanism.

9A and 9B, the engaging portion 46a is formed in the lower flange 46 of the shaft 22 of the guide pole GP1 (2). The engaging portion 46a is engaged with the engaging slot 47b formed in the boss of the gear 47 of the fixed side height control mechanism.

Moreover, the recessed part 49 is formed in the upper part of the fouling base DB1 (2). The spring 50 is wound around the guide pole shaft 22 between the bottom face of the lower flange 46 and the recess 49. The spring 50 always pushes up the lower and upper flanges 46, 47 and the rollers 28 provided therebetween.

The washer 52 is fixed to the lower end of the shaft 22 by the screw 53 of the cavity 51 as it protrudes from the lower end of the shaft 22. This limits the upper deviation of the guide pole GP1 (2). The screw 48g is formed around the outer surface of the lower portion of the gear 47 shaft 48. The screw 48g is engaged with the screw 54g formed in the protrusion 54 of the drum base DB.

5 shows an intermediate state of the loading operation. When the loading operation is completed from the intermediate state, the engaging portion 46a of FIG. 9A formed in the head of the lower flange 46 engages with the engaging slot 47b formed in the boss of the gear 47.

The lower flange 46 is one of the components making up the height adjustment mechanism at the foul base side. In contrast, the gear 47 is one of the components constituting the fixed side height adjustment mechanism.

The engagement portion 46a formed in the head of the lower flange 46 is characterized by a V-shape in the cross section as shown in FIG. 9B. The engagement slot 47b formed in the boss of the gear 47 also features a V-shape in its cross section to engage the engagement portion 46a until the completion of the loading operation.

In Fig. 5, upon completion of the loading operation, a recording or reproducing operation is started and the controller 6 supplies a height control signal to the control motor 9 (12). The control motor 9 (12) rotates the gear 47 through the gears 35, 36 and 37 of the power transmission system. Rotation of the gear 47 causes the screw 48g to rotate while engaging the screw 54g. This exerts a force to move the shaft 48 of the gear 47 in the vertical direction along the direction of rotation.

While the shaft 48 of the gear 47 is rotated, the shield plate 29 of the reference position sensor 7 (10) rotates so that the photointerpreter 7 of the reference position sensor 7 outputs a position signal. do. In addition, the shaft 48 is rotated and moved in the vertical direction, and the engaging portion 46a that engages with the engagement slot 46b can also be moved in the vertical direction. Thus, the guide pole GB1 (2) is moved in the vertical direction with respect to the rotation of the control motor 9 (12).

How the reference heights of the guide poles GP1 and GP2 are set when manufacturing the magnetic recording and reproducing apparatus shown in FIGS. 3, 4 and 5 will be described with reference to FIGS. 10A to 10C.

In the flowchart shown in FIG. 10A for height adjustment in shipping (product), first in step a1, the control motor 9 (12) is moved in the vertical direction to adjust the guide surface to a predetermined height by a measuring device. In order to move the guide pole {GP1 (2)}. Here, the guide surface is the upper surface of the lower flange, the lower surface of the upper flange or the roller surface. The predetermined height is a reference height predetermined to achieve high compatibility of the magnetic recording and reproducing apparatus in the recording and reproducing operation. Next, in step a2, the calculated value of the counter is stored in the external nonvolatile memory 16 of FIG.

In another flow chart shown in FIG. 10B for height adjustment in shipping (product), first in step b1, the control motor 9 (12) is guided in the vertical direction to adjust the guide surface to a predetermined height. It is driven to obtain a flat envelope of the frequency-modulated signal reproduced from the reference tape to move {GP1 (2)}.

In detail, the reference tape having no bends on the track is loaded into the recording and reproducing apparatus in step b1.

The control motor 9 of the first height control mechanism for the guide pole GP1 on the supply reel side is provided while the counter (not shown) of the controller 6 counts the number of pulse outputs by the rotary encoder 8. The reference position sensor 7 is rotated in the normal or opposite direction until the reference position signal outputs a corresponding reference position signal on the reference rotation of the shield plate 29. The number of pulses indicates the time until the reference position signal is output. The counter is then preset to zero when a predetermined number, for example a reference position signal, is output.

Next, on the take-up reel side, the control motor 12 of the second height control mechanism for the guide pole GP2 is pulsed by the rotary encoder 11 with another counter (not shown) of the controller 6. While counting the output, the reference position sensor 10 is rotated in the normal or opposite direction until the reference position signal outputs a corresponding reference position signal on the reference rotation of the shield plate 29. The counter is then preset to zero when a predetermined number, for example a reference position signal, is output.

The reference tape then moves to detect the frequency-modulated signal reproduced by the envelope detector 5 under a stable moving state. The detector 5 provides sampling for the envelope signal of each reproduced frequency-modulated signal, and extracts the head envelope signal portion, the intermediate envelope signal portion and the end envelope signal portion to the track on the reference tape. Corresponds. The extracted signal portion is converted into a digital signal and supplied to the controller 6.

The controller 6 adjusts the height of the first guide pole GP1 at the supply reel side within the range adjustable by the control motor 9 and detects an envelope signal. The controller 6 also calculates the magnitude (envelope value) of the envelope signal that changes with the change in the height of the guide pole GP1 (the change in the value calculated by the counter). The calculated value is stored in a memory (not shown) of the controller 6.

The controller 6 reads the envelope values from the memory obtained within the adjustable range and compares them with each other to find a first output value corresponding to the envelope value indicating the flattest track on the reference tape. The first calculated value for the guide pole GP1 is stored in an external nonvolatile memory 16.

The controller 6 then adjusts the height of the second guide pole GP2 on the take-up reel side within the adjustable range by the control motor 12 and detects the envelope signal. The controller 6 also calculates the magnitude (envelope value) of the envelope signal that changes with the change in the height of the guide pole GP2 (the change in the value calculated by the counter). The calculated value is stored in a memory (not shown) of the controller 6.

The controller 6 reads the envelope values from the memory obtained within the adjustable range and compares them with each other to find a second calculated value corresponding to the envelope value indicating the flattest track on the reference tape. The second calculated value for the guide pole GP2 is stored in an external nonvolatile memory 16.

The first and second calculated values stored in the memory 16 as reference height data of the first and second guide poles GP1 and GP2 correspond to the standard heights of the guide poles GP1 and GP2, respectively. The standard height is predetermined to obtain high compatibility of the magnetic recording and reproducing apparatus in the recording and reproducing operation.

Thus, by adjusting the heights of the first and second guide poles GP1 and GP2 to correspond to the first and second calculated values, the heights of the guide poles GP1 and GP2 that can be adjusted to the standard height are determined.

Next, in Fig. 10C, the recording and reproducing of the magnetic tape by the magnetic recording apparatus according to the present invention is performed by the magnetic recording apparatus according to the present invention of another magnetic tape recorded as data by another magnetic recording apparatus. Guide height adjustment in regeneration is explained.

First, in recording and reproducing a magnetic tape by the magnetic recording apparatus according to the present invention, in step c1 of FIG. 10C, the magnetic tape is loaded into the magnetic recording apparatus according to the present invention.

Next, in step c2, the control motor 9 of the first height adjustment mechanism for the guide pole GP1 on the supply reel side is external to the number of pulses generated by the rotary encoder 8 calculated by the counter. It is rotated in the normal or reverse direction until it equals the calculated value stored in the nonvolatile memory 16. The control motor 9 is stopped when the number of pulses is equal to the stored value.

Also in step c2, the control motor 12 of the second height adjustment mechanism for the guide pole GP2 on the take-up reel side is external to the number of pulses generated by the rotary encoder 11 calculated by the counter. It is rotated in the normal or opposite direction until it is equal to the other calculated value stored in the nonvolatile memory 16. The control motor 12 is stopped when the number of pulses equals the stored value.

The method of step c2 adjusts the guide surfaces of the guide poles GP1 and GP2 to correspond to the standard guide pole heights. Then, after completion of step c2, the heights of the guide poles GP1 and GP2 become standard heights.

Next, in step c3, it is determined depending on whether or not the work mode is to be reproduced. If not, or if the mode is write, the method terminates.

In contrast, if the mode is playback, the method proceeds to step c4. The frequency-modulated signal is reproduced from the magnetic tape. In addition, the envelope signal is detected by the envelope detector 5. Sampling is then performed for each envelope signal to extract the head envelope signal portion, the intermediate envelope signal portion, and the end envelope signal portion. The extracted signal portion is converted into a digital signal and supplied to the controller 16 such as curved data. The controller 6 drives the control motors 9 and 12 in the normal or opposite direction according to the bend data to adjust the height of the guide poles GP1 and GP2 to correct for the bend track on the magnetic tape. The method then terminates.

Further, the reproduction by the magnetic recording and reproducing apparatus according to the present invention of another magnetic tape recorded with data by another magnetic recording apparatus will be described.

Although steps c1 and c2 are as described above, the guide poles GP1 and GP2 are adjusted to a standard height. Thus, when the magnetic tape recorded by another magnetic recording and reproducing apparatus is recorded by the magnetic recording and reproducing apparatus according to the present invention having the adjusted guide pole, the magnetic tape is appropriately reproduced by the other magnetic recording and reproducing apparatus. Can be.

Next, in step c3, the magnetic tape recorded by the other magnetic recording and reproducing apparatus is reproduced. In addition, in the same step c4 as described above, the controller 6 controls the normal and the opposite direction according to the curved data for adjusting the height of the guide poles GP1 and GP2 for correction of the curved track on the magnetic tape. To drive the control motors 9 and 12.

Thus, even if the recorded magnetic tape has a curved track, a stable signal can be reproduced in the same manner as reproduction from a magnetic tape having a straight track.

The shield plate 29 of the reference position sensor 7 (10) is provided with a photo when the guide surfaces of the guide poles GP1 and GP2 are adjusted to the standard height as described above with reference to FIGS. 8A and 8B. It has a positional relationship with the light-emitting and light-receiving elements of the interpreter 31.

However, the shield plate 29 is provided to be moved in the loading operation, while the photointerpreter 31 is provided at the fixed end portion. As a result, sometimes the rotation trajectory of the photointerpreter 31 deviates from the reference rotation trajectory due to vibration or collision.

In order to prevent this phenomenon, the control motor 9 (12) is configured to vertically guide the guide poles GP1 and GP2 within a predetermined range such that the reference positions of the guide poles GP1 and GP2 correspond to the counter values. Can be rotated in the normal or opposite direction upon completion of the loading operation.

As described above, in the magnetic recording and reproducing apparatus shown in Figs. 3, 4 and 5, reference position sensors 7 and 10 provided in the first and second height adjustment mechanisms provided on the supply and take-up reel sides. Each generate a reference position signal supplied to the controller 6. In addition, the rotary encoders 8 and 11 generate pulses carrying data in the rotational direction and the amount is also supplied to the controller 6. The envelope detector 5 also generates an envelope signal in response to the frequency-modulated signal reproduced from the magnetic tape, and supplies the envelope signal to the controller 6.

Next, the controller 6 drives the guide poles GP1 and GP2 to drive the control motors 9 and 12 of the first and second height adjustment mechanisms for adjusting the heights of the guide poles GP1 and GP2, respectively. To generate a height control signal on the height of?).

Here, the first (second) height adjustment mechanism is a closed-loop automatic height control system and includes a control motor {9 (12)}, a reference position sensor {7 (10)}, a rotary encoder {8 (11)}, and a control. Motor {9 (12)}, gears 23g, 35 to 37, 39 in FIGS. 3 and 4 or gears 35 to 37 and 47, guide poles GP1 and GP2 and controller 6 in FIG. ).

When the guide poles GP1 and GP2 are adjusted to the reference height, it is indicated by the calculated value of the up-down counter which calculates the number of pulses generated by the rotary encoder 8 (11). In contrast, the calculated value, that is, the reference height, is stored in advance in the external nonvolatile memory 16. Thus, the deviation of the height of the guide poles GP1 and GP2 from the reference height can be detected as the difference between the calculated value of the up-down counter and the calculated value previously stored in the external nonvolatile memory 16.

Thus, according to the magnetic recording and reproducing apparatus shown in Figs. 3, 4 and 5, by the calculated value of the counter, the guide surfaces of the guide poles GP1 and GP2 are adjusted to the reference height by the automatic height control system. Can also be changed exactly.

11A to 11C are flowcharts for explaining the operations for measuring the backlash amount of the gears of the power transmission system, respectively. FIG. 11B is a flow chart for a method of enforcement executed in Zone 1 in FIG. 11A. FIG. 11C is a flow chart for another method of enforcement implemented in Zone 2 in FIG. 11A.

At the beginning of the flowchart shown in FIG. 11A, the controller 6 first reads the reference position signal S1 (S4) output from the reference position sensor 7 (10) in step S1 in S1 (S4), The process proceeds to S1 (S4) = 0 in step a2. In step a2, it is determined whether the reference position signal S1 (S4) read in step a1 is zero or one.

In the state where the reference position signal S1 (S4) is 0, the shield plate 29 of the reference position sensor 7 (10) is provided to the photointerpreter 31 of the reference position sensor {7 (10)}. It exists in the optical path between the light emitting element 41 and the light receiving element 42 as shown in FIG.

In contrast, the state in which the reference position signal S1 (S4) is 1 indicates that the shield plate 29 exists outside the optical path between the light emitting element 41 and the light receiving element 42.

In step a2, when it is determined that the reference position signal S1 (S4) is 0, the method starts the operation of measuring the amount of backlash of the gear of the power transmission system performed in the step following step a8. Proceed to CNT = 0. On the contrary, in step a2, when it is determined that the reference position signal S1 (S4) is 1, this means that the rotational phase of the shield plate 29 of the reference position sensor 7 (10) is the backlash amount of the gear of the power transmission unit. Indicates an unsuitable state for measurement. Thus, the method proceeds to Out REVDRV in step a3, in which the control motor 9 (12) is dynamic, and the procedure proceeds to in S1 (S4) in step a4.

In step a4, the reference position signal S1 (S4) output from the reference position sensor 7 (10) is read, and the procedure goes to step a5. In step a5, it is determined whether the reference position signal S1 (S4) read in step a4 is zero or one. When the reference position signal is 1, the procedure returns to step a4. Next, the operation of step a4 and the operation of step a5 are repeated until the determination result that the reference position signal read in step a4 is 1 obtained by the determination in step a5 is obtained.

In step a5, when it is determined that the reference position signal S1 (S4) is 0, the procedure proceeds to TIMER in step a6, where time is extinguished by a timer for a while. At this time, the procedure goes to OUT STPDRV of step a7 in which the control motor 9 (12) stops. The procedure proceeds to CNT1 = 0 in step a8 to commence the operation of measuring the amount of backlash of the gear of the power transmission portion which is carried out in a subsequent step after step a8.

At CNT = 0 in step a8, the calculated value of the counter provided to the controller 6 is set to 0, and the procedure then proceeds to OUT FORDRV in step a9. In step a9 the control motor 9 (12) is driven normally. In the passage of time shown in FIG. 12, the state of time t0 represents the time when the time disappears for a while after the control motor 9 (12) starts its normal rotation. In the zone 1 from step a8 to step a12, the intermittent method is performed by the pulse S2 (S5) generated from the rotary encoder 8 (11). The coefficient of the regulation method is shown in Fig. 11B.

In in S1 (S4) of step b1 in FIG. 11B, the reference position signal S1 (S4) is read. At S4 = 0 in step b2, it is determined whether the reference position signal S4 read in step b1 is 0 or 1. In the inc CNT1 of step b3, the calculated value of the counter 1 (not shown) provided to the controller 6 is increased by one.

That is, when the interruption is affected by the pulse {S2 (S5)} generated from the rotary encoder 8 (11) of the zone 1, the reference position signal S1 (S4)} is read in step b1. The procedure proceeds to step b2 of determining whether the reference position signal S1 (S4) read in step b1 is zero or one. If S1 (S4) = 0, the procedure returns, and if S1 (S4) = 1, the procedure proceeds to step b3, where the calculated value of the counter 1 is increased by 1, and The procedure returns.

In the operation of measuring the backlash amount of the gear of the power transmission system stored in step a8, the shield plate 29 of the reference position sensor {7 (10)} at the time when the measurement operation starts (times to t1 in FIG. 12). ) Is present in the optical path between the light emitting element 41 and the light receiving element 42 provided in the photointerpreter 31 of the reference position sensor 7 (10). Therefore, the reference position signal S1 (S4) generated from the reference position sensor 7 (10) during the above-described period is in the zero state as in the period of time to t1 in FIG.

Accordingly, in the pulse {S2 (S5)} generated from the rotary encoder {8 (11)} during the above-described time to t1 of FIG. 12, P1 to P5 are not counted by the counter 1, but the guide The fouls GP1 and GP2 continue the upward displacement for the above-described period (see Fig. 12 {S3 (S6)}).

When judged at time t1 in Fig. 12, the reference position signal S1 (S4) generated from the reference position sensor 7 (10) is changed to 1 in step b2 in the intermittent method, and the counter 1 The counting operation is started at step b3 of the intermittent method.

In the main routine shown in Fig. 11A, the control motor 9 (12) is stopped at OUT STDRV in step a12. In the main routine shown in FIG. 12A, the reference position signal S1 (S4) is read in in S1 (S4) of step a10. In step S11 (S4) = 0, it is determined whether the reference position signal S1 (S4) read in step a11 is 0 or 1.

In the TIMER of step a13, all the time assumes that the control motor 9 (12) is in a fully stopped state and waits until the procedure proceeds to CNT2 = 0 in step a14. In CNT2 = 0 in step a14, the calculated value of the counter 2 (not shown) provided to the controller 6 is set to 0, and the procedure goes to OUT REVDRV in step a15. In step a15, the control motor 9 (12) is inverted by the motor drive signal S3 (S6).

In the zone 2 from step a14 to step a18, the interruption method is performed by the pulse S2 (S5) generated from the rotary encoder 8 (11). The content of the enforcement method is shown in Fig. 11C.

In Fig. 11C, in reference S1 (S4) in step c1, the reference position signal S1 (S4) is read. At S1 (S4) = 0 in step c2, it is determined whether the reference position signal S1 (S4) read in step c1 is 0 or 1. In the inc CNT2 of step c3, the calculated value of the counter c (not shown) provided to the controller 6 is increased by one.

That is, when the interruption is affected by the pulse {S2 (S5)} generated from the rotary encoder 8 (11) of the zone 2, the reference position signal S1 (S4) is read in step c1. The procedure proceeds to step c2 for determining whether the reference position signal S1 (S4) read in step c1 is 0 or 1. If S1 (S4) = 0, the procedure returns, and if S1 (S4) = 1, the procedure proceeds to step c3, where the calculated value of the counter 1 is increased by one, and the procedure is To return.

At the starting time of zone 2 (times t2 to t3 in FIG. 12), the shield plate 29 of the reference position sensor PS is provided to the photointerpreter 31 of the reference position sensor 7 (10). It exists in the optical path between 41 and the light receiving element 42 in the state outside. Therefore, the reference position signal S1 (S4) generated from the reference position sensor 7 (10) during the above-described period is in the state of 1 as shown in FIG. Therefore, P6 to P17 of the pulses {S2 (S5)} generated from the rotary encoder 8 (11) in FIG. 1 are calculated by the counter 2.

During the time t3 to t4 of FIG. 12, the drive motor 9 (12) is rotated, but rotational force is not transmitted to the guide poles GP1 and GP2 due to the presence of a back flash in the gears of the power transmission system. There is a period of time. In that period, no change occurs in the heights of the guide poles GP1 and GP2. However, the end point of the period in which the rotational force is not transmitted due to the presence of backlash cannot be detected.

At time t4 in FIG. 12, the shield plate 29 of the reference position sensor 7 (10) is configured such that the reference position sensor {changes from state 1 to 0 so that the reference position signal S1 (S4) changes from state 1 to zero. 7 (10)} is introduced into the optical path between the light emitting element 41 and the light receiving element 42 provided in the photo interpreter 31.

At time t4, in the zone 2 shown in Fig. 11C, the interruption routine interrupts the counting operation of the counter 2. Therefore, the pulses P18, P19, ..... after the time t5 from the pulse {S2 (S5)} generated from the rotary encoder 8 (11)} are not calculated by the counter 2.

In addition, in the main routine shown in FIG. 11A, the control motor 9 (12) is stopped by OUT STDRV in step a18. In the main routine shown in FIG. 11A, in reference S1 (S4) of step a16, the reference position signal S1 (S4) is read. In S1 (S4) = 0 in step a17, it is determined whether the reference position signal S1 (S4) read in step a11 is 0 or 1.

In BRA = CNT2-CNT1 of step a19, the calculated value of the counter 2 is subtracted from the calculated value of the counter 1 to obtain a measurement result of the backlash amount of the gear of the power transmission system.

Next, the result of measuring the backlash amount of the gear of the power transmission system obtained in step a19 will be described later by the time flow chart shown in FIG. In the example shown in Fig. 12, the number of pulses S2 (S5) generated from the rotary encoder {8 (11)} is 2, for example, P6 and P7, and the calculated value of the counter 1 is a reference position sensor. From the time t1 when the reference position signal S1 (S4) generated from the {7 (10)} changes from 0 to 1, the time t3 at which the control motor {9 (12)} is reversed in normal rotation through the stop. It is 2 in the period until.

The number of pulses {S2 (S5)} generated from the rotary encoder {8 (11)} is 10 from the pulses P8 to P17, and the calculated value of the counter 2 is calculated by the control motor {9 (12)}. The reference position signal S1 (S4) generated by the reference position sensor 7 (10)} from the time point t3 of 10 becomes 10 in the period from the time point t4 at which it changes from 1 to zero.

The calculated value 2 of the counter 1 corresponds to the height position of the guide poles GP1 and GP2 which are much higher than the reference position.

Accordingly, the amount of backlash of the gear of the power transmission system is determined by the value of the counter 1 at the calculated value 10 of the counter 2 which counts the number of pulses S2 (S5) generated from the rotary encoder 8 (11). It is obtained as an 8-pulse part obtained by subtracting the calculated value (2).

The amount of backlash of the power transmission gear obtained as described above is stored in the external nonvolatile memory 16, and the amount of backlash stored therein is read in preference to the recording and reproducing operation as described above. Next, the value of the pulse {S2 (S5)} generated from the rotary encoder {8 (11)} is corrected to correct the error of the position caused by the backlash, and thus the guide pole GP1, The height position of GP2) can be set to the standard height (a regular height predetermined to achieve compatibility with the magnetic recording and reproducing operation).

Next, another mode for correcting the error of the backlash position will be described. For example, with the guide poles GP1 and GP2 displaced in the predetermined direction, the value counted by the counter of the controller 6 with respect to the number of output pulses of the rotary encoder {8 (11)} is determined by the guide pole GP1. , GP2). Further, in a state in which the guide poles GP1 and GP2 are displaced in a direction opposite to the above-described displacement direction, the amount of rotation of the drive zone such as the control motor 9 (12) is stored calculated corresponding to the backlash of the power transmission system. It is increased by the amount corresponding to the value.

For example, the control motor 9 (12) is configured to guide guides GP1 and GP2 to a stored calculated value A corresponding to a backlash of a power transmission system and a numerical value B smaller than the calculated value A. ) Is rotated by the amount of rotation corresponding to the numerical value of (A + B), obtained by adding up to the target height position in the state displaced in the predetermined direction. Further, the control motor 9 (12) is rotated by the amount of rotation corresponding to the numerical value of (A-B).

Although the supply of the drive signal supplied to the control motor {9 (12)}, as shown in FIG. 12, the reference position signal {S1 (S4)} generated from the reference position sensor {7 (10)} is equal to zero. The light emitting element 41 and the light receiving element 42 provided with the shield plate 29 of the reference position sensor {7 (10)} are provided to the photointerpreter 31 of the reference position sensor {7 (10)} so as to change to one. Pulses P6 and P7 are output from the rotary encoder {8 (11)} even when stopped at a time t2 after a slight time has elapsed from the time t1 changing from the optical path in between This occurs based on the overrun of the control motor 9 (12).

The number of output pulses S2 (S5) is controlled from the time when the reference position signal S1 (S4) generated from the reference position sensor 7 (10)} changes from 0 to 1 as shown in FIG. From the rotary encoder {8 (11)} until the time when the motor {9 (12)} starts to operate in the direction opposite to the conventional rotation direction generated based on the overrun of the control motor {9 (12)}. Is output.

Therefore, the calculated value of the number of output pulses S2 (S5)} can be used as data on the overrun amount of the control motor 9 (12). Similarly, the overrun amount occurs when the control motor {9 (12)} rotates in the direction opposite to the rotation direction as described above, so that the data of the overrun amount is the normal rotation and the opposite of the control motor {9 (12)}. Each is measured for rotation and stored in an external nonvolatile memory 16.

In the magnetic recording and reproducing apparatus, when adjusting the height of the guide poles GP1 and GP2 to a standard height (a regular height predetermined to achieve compatibility with the magnetic recording and reproducing operation) or during the recording and reproducing operation. In the operation for controlling the height positions of the GP1 and GP2, the data of the overrun amount stored in the external nonvolatile memory 16 is targeted when the actual height positions of the guide poles GP1 and GP2 are adjusted. The height position is the number of output pulses {S2 (S5)} outputted from the rotary encoder {8 (11)} of the pulse stored as the data of the overrun amount of the external nonvolatile memory 16 with the height position of the guide poles GP1 and GP2. It is used to set the number of pulses smaller than the number of pulses needed to make the target height position actually set by the number.

13A and 13B show the execution of the fouling base PB and the guide roller GR (guide fouling) corresponding to the fouling bases PB1 and PB2 and the guide poles GP1 and GP2, respectively, as shown in FIG. An example is shown. The guide roller GR has an upper flange UF and a lower flange LF fixed to the shaft Sf to rotatably sandwich the roller R. The lower flange LF has a lever LF1 facing the travel direction and a rear stop bar LF2.

The lower side Sf1 of the shaft Sf is smoothly assembled into the hole PB1a of the fouling base PB to form a guide that is smoothly displaced in the height direction. A spring SPa is always provided between the lower flange LF and the fouling base PB to upwardly press the roller guide GR. The stop bar LF2 of the lower flange LF is stopped by the hooks St1 and St2 of the stopper St on the fouling base PB, and the roller guide GR continues at a constant height HL. . The base portion LF3 of the stop bar LF2 is assembled in the slit PB3a of the retaining portion PB2a of the foul base PB to effect whirl-stop.

14A-16C show the operating state of the fouling base PB shown in FIGS. 13A and 13B. Throughout the figures, reference numerals have been indicated for simplicity only those elements directly related to the operating state of the fouling base PB.

14A to 14C show recording and normal playback states after tape loading is completed. The lever LF1 of the lower flange LF is in contact with the flat surface of the adjustment cam Ca, which will be described later in detail, and the roller guide GR is lower than the intermediate height of loading. The height is the normal height Hn indicating the recording and normal reproduction states.

15A to 15C show a state when the roller guide GR is displaced upward. The adjusting cam Ca rotates in the counterclockwise direction, and the guide roller GR is displaced upward along the cam face at the upper height Hu.

16A to 16C show a state when the guide roller GR is displaced downward. The control cam Ca The control cam Ca rotates in a clockwise direction, and the guide roller GR is displaced downward along the cam surface at a lower height Hd.

Height adjustment of the adjustment cam (Ca) will be described with reference to FIG. 14B. The cam gear Cg is rotatably assembled into the shaft L1 of the drum base DB and is always inclined upward by the spring CSP. The shortest end of the shaft (L1) is formed by a screw, the height of the cam gear (Cg) can be adjusted by rotating the nut (Cn). After the height of the nut Cn is adjusted, the nut Cn is fastened by stopping the set screw S1. Since the nut Cn and the set screw S1 can be adjusted from the top, the adjustment of the height is easily performed with an automatic machine. The normal position is flat and has a certain width, so that the position of the sensor does not need to be fixed.

17 is an exemplary view of the height adjustment cam Ca. The overall height of the adjustment cam Ca is adjustable in the range from the dashed-dotted line X to the dashed-dotted line Y. Specifically, the overall height of the adjustment cam Ca is the line NN (normal position) when the top LF1a of the lower flange LF lever LF1 abuts the flat surface of the adjustment cam Ca in the area Zf. It is adjusted to be at the height shown by. The regions Zd and Zu respectively describe a state in which the top LF1a of the lever LF1 contacts the rising and falling surface portions indicated by the straight line M of the adjustment cam Ca.

The lower drum Dd is provided with a lid around it, and the lid has relief at its head and end portions, so that when band correction for lowering the guide roller GR is performed, excessive force is applied. This is not provided for the magnetic tape recorded by another magnetic reproducing apparatus suitable for the magnetic reproducing apparatus according to the present invention.

The height of the fouling base PB during tape loading is described with reference to FIGS. 18A and 18B. In these figures, reference numerals are used only for elements directly related to the height change of the foul base PB.

At the start of loading, the guide roller GR is lifted upward by the spring CSP and stopped by the stopper St as shown in Fig. 18A (loading height H10). On the contrary, when the loading is completed, the height of the guide roller GR in the normal position is displaced upward and downward, and the height of the lower flange LF is lower than the hook St1 of the stopper St. Naturally, the height of the guide roller GR observed from the foul base PB is lower than when loading is started as shown in Fig. 18B (normal height Hn).

The height of the fouling base PB changes (Hi) so that the height of the magnetic tape T does not change just before the tape loading is terminated. By doing so, it is possible to avoid damage to the magnetic tape which will occur when the height of the guide roller GR is the same from the start of loading to the end of loading. In this case, the magnetic tape T is operated or dropped on the upper flange UF or the lower flange LF.

19 shows another embodiment of the guide roller GR1. The adjustment cam Ca1 has a structure for urging the upper flange UF1 of the guide roller GR1 downward. Such a structure shows that the upper flange UF1 is more inclined than that shown in Figs. 13A to 16C on the adjustment cam Ca1 where the guide roller GR1 is adjusted to move up and down by the upper flange UF1. Except that, the same as in Figure 13a to 16c.

20 shows another embodiment of the guide roller GR2. In this embodiment, the stopper Sta is located laterally in the portion where the shaft Sf1 diameter is small.

21 shows another embodiment of the guide roller GR3. The spring SPb is provided under the foam base PBa so as to always press down the guide roller GR3 between the spring base SH and the press base PBa pressed into the lower end of the shaft Sf2. The base portion SHa of the spring holder SH is assembled in the slit of the fouling base PBa to effect swing-stop. In the height direction, the displacement direction and the height of the fouling base upon loading are opposite to the directions described above. 19 through 21, reference numerals are used only for the elements featured in this embodiment for simplicity.

Another embodiment of a guide pole (tape guide) provided on the feed and take-up reel sides will be described with reference to FIGS. 22A-26B.

Guide poles GPa shown in FIGS. 22A and 22B are provided with a lower flange 700 and a gear 70g. On a portion of the gear 70g, the shield plate 130 is mounted by a screw 270 through the slot 280 of the shield plate 130 after being adjusted to a predetermined rotation. The lower flange 700 is secured around the shaft 500 through the foul base PBa formed with the guide pole GPa and the female screw 800. The male screw 70a formed on the other side of the boss of the gear 70g is engaged with the female screw 800. The female screw 800 should be larger than the male screw 70a so as to deviate to the center line of the shaft 500 while the guide pole GPa is rotated.

Stud 290 is provided in cavity 310 at the lower end portion of shaft 500. The spring 300 is provided between the top surface of the stud 290 and the top wall of the cavity 310. The spring 300 always pushes the guide pole GPa downward to achieve complete engagement of the screws 70a and 800. Thus, the gear 70g provided as the secondary gear of the height adjustment mechanism on the sole base side is never rotated by any external force. The gear 70g is rotated only by engaging the primary gear provided in the height adjustment mechanism of the fixed section.

Next, as shown in FIGS. 23A and 23B, a guide pole GPb is provided with the upper flange 111. The shield plate 131 is mounted on the protrusion 111a of the upper flange 111. The guide pole GPb is also provided with the stopper 321 such that the operation portion 321a of the stopper 321 is in the orbit of the shield plate 131. The stopper 321 limits the movement of the shield plate 131 to rotate only once.

As shown in FIGS. 24A and 24B, a guide pole GPc is provided with the lower flange 702. The shield plate 132 is mounted on the lower surface of the gear 72g formed in the lower flange 702. In addition, the stopper 332 is provided with a fluctuation of the shield plate 132. The stopper 331 also limits the movement of the shield plate 132 to rotate only once.

Next, as shown in FIGS. 25A-25C, a guide pole GPd is provided with a male screw 73a formed around the lower protrusion of the lower flange 703 formed around the shaft 503. The male screw 73a is engaged with a female screw (not shown) formed in the center hole of the gear 373g. The shield plate 133 is mounted on the gear 373g by the screw 273 through the slot 283 of the shield plate 133 after being adjusted to a predetermined rotation. The shaft 503 penetrates through the lower flange 703 and the upper flange 113, and is provided with a stud 353 at its lower end portion. The stud 353 is provided with protrusions 353a and 353b as pivot-stops. The lower end portions of the shaft 503 and the stud 353 protrude from the cavity 383 of the foul base PBd. The protrusions 353a and 353b are loosely inserted into the slits 393 and 403 respectively.

A spring 363 is provided between the upper surface of the stud 353 and the upper wall portion of the cavity 383 provided in the foul base PBd. The spring 363 always presses the guide pole GPd downward to completely engage the male screw 73a formed in the center hole of the gear 373g. Therefore, the gear 373g provided as the secondary gear of the height adjustment mechanism at the foul base side is never rotated by any external force. The gear 373g is rotated only by engaging the primary gear provided in the height adjusting mechanism of the fixed section.

Next, a guide pole GPe as shown in FIGS. 26A-C is provided with the shaft 504. The lower end portion of the shaft 504 protrudes from the bottom of the foul base PBe. The gear 54a formed around the lower end portion of the shaft 504 meshes with a female screw (not shown) formed in the center hole of the gear 374g. Shield plate 134 is mounted on the gear 374g by screw 274 through a slot of shield plate 134 after being adjusted to a predetermined rotation. The shaft 504 passes through the lower flange 704 and the upper flange 114. The pivot-stop 444 is provided in the hole 74b formed in the lower surface of the lower flange 704 and also in the hole 454 of the foul base PBe.

A spring 434 is provided between the lower portion of the convex portion 424 and the lower surface of the lower flange 704 formed on the upper surface of the foul base PBe. The spring 434 always pushes up the guide pole GPe to achieve a complete engagement of the female and male threads 54a formed in the center hole of the gear 374g. Here, the gear 374g provided as the secondary gear in the height adjusting mechanism of the fouling base side never rotates by any external force. The gear 374g is rotated by engaging only the primary gear provided in the height adjustment mechanism of the fixed section.

With reference to FIGS. 22A-26C, only the elements that the embodiment features are described.

27 shows another embodiment of the magnetic recording and reproducing apparatus according to the present invention. The difference between FIG. 27 and FIGS. 3-5 is that the electron has a gear 515 that meshes with the gears 185, 195.

28A to 28C show the fouling base PBf in the magnetic recording and reproducing apparatus shown in FIG. The shaft 125 of the guide pole GPf has a lower portion inserted into the hole formed in the pole base PBf, and the shaft 125 is slidably movable while guided in the direction of movement by the wall surface of the hole. have.

The upper flange 115 is fixed to the shaft 125 and the roller 135 has a length equal to the width of the magnetic tape. The lower flange 545 is formed with an engaging portion 55b that can engage the shortest portion of the screw 525g provided near the upper end of the rotary shaft 525 of the gear 465 of FIG. 27.

The engaging portion 55b is such that the shortest portion provided near the upper end of the rotating shaft 535 of the gear 535g in the tape loading operation can be easily engaged with the lower surface of the engaging portion 55b of the lower flange 545. It is provided with the inclination part 55b1. The collar 605 is fixed to the lower end of the shaft 125. The collar 605 is provided with protrusions 65a and 65b as pivot-stops.

The lower end of the shaft 125 for the guide sole GPf and the stop 605 protrudes into a cavity 595 provided in the sole base PBf, the protrusions 65a and 65b respectively being in the pole base PBf. Loosely assembled in the provided slits 615,625. The spring 565 is provided between the top surface of the stop 605 and the top wall of the cavity 595. The guide pole GPf is always inclined downwardly by the spring 565. The screw 525g meshes with an internal screw 535g formed in the protrusion 535 of the drum base DBf.

When the magnetic recording and reproducing apparatus is shifted from the intermediate state of the state in which the loading operation is completed (not shown), the shortest part of the fouling base PBf is the magnetic base PBf magnetically recording. And a base catcher BCf so as to be set at a cavity position having a predetermined positional relationship with respect to the fixed region of the reproduction device.

Assuming that the magnetic recording and reproducing apparatus has completed the loading operation, the lower surface of the engaging portion 55b formed at the shortest end of the lower flange 545 is the screw of the upper surface of the rotating shaft 525 of the gear 465. (525g) Assume the engaged state with the shortest part. Here, the lower flange 545 is used as a member that functions as part of a constituent member provided on the foul base side of the height control mechanism. In contrast, the gear 465 is used as a member that functions as a constituent member provided on the fixed side of the height adjustment mechanism.

In the magnetic recording and reproducing apparatus according to the present invention shown in Fig. 27, the recording and reproducing operation is started after the loading operation by the loading mechanism is completed. Next, when the motor Mg is rotated, the gear 465 is rotated through the gears 185, 515, 195 and 205 of the power transmission system. When the gear 465 is rotated, the screw 525g formed on the rotary shaft 525 of the gear 465 meshes with the screw 535g formed on the protrusion 535 of the drum base DBf. Accordingly, the rotation shaft 525 of the gear 465 moves up and down in the rotational direction.

When the rotary shaft 525 rotates, the shield plate 135 of the position sensor PSf mounted on the lower portion of the rotary shaft 525 is rotated, and the position signal is the photointerpreter 245 of the position sensor PSf. Is output from Further, when the rotary shaft 525 moves up and down while rotating, the engaging portion 55b formed at the shortest end of the lower flange 545 also moves up and down as the rotary shaft 525 moves up and down. do. Thus, the guide pole GPf moves up and down by the rotation of the motor Mgf.

Next, the embodiment shown in FIG. 29 will be described. The guide fouling GPg shown in FIG. 29, which may be provided to the magnetic recording and reproducing apparatus of FIG. 27, has a shape in which the inclined surface 116b is formed on the upper surface of the guide flange GPg upper flange 116. In the shape shown in Fig. 29, when the magnetic recording and reproducing apparatus of Fig. 27 completes the loading operation, the inclined surface 116b of the upper surface of the guide flange GPg upper flange 116 is fixed to the height control mechanism. It is in engagement with the engagement inclined surface 636g of the engagement member 636 provided on the rotating shaft 476 of the gear 466 used as the member serving as a constituent member provided on the side.

When the recording and reproducing operation is started, the motor Mgf of FIG. 27 is rotated, and the gear 466 corresponding to the gear 465 of FIG. 27 is rotated through the gears 185, 515, 195, 205 of FIG. 27 of the power transmission system. do. At this time, the screw 476g formed in the lower portion of the rotary shaft 476 is engaged with the internal screw 536g formed in the protrusion 536 in the drum base DBf of FIG. 27 for rotation. Thus, the engagement member 636 provided on the rotation shaft 525 of the gear 466 is moved up and down in the direction of rotation. Therefore, as the engagement member 636 moves up and down, the guide pole GPg moves up and down by the rotation of the motor Mgf.

30, 31A and 31B show an example of the component member provided on the fixed area of the height control mechanism. The component member is used to control the height of the guide pole GPf shown in Figs. 28A to 28C.

First, FIG. 30 shows the projection 536 formed in the drum base DB and the L-shaped bracket 646. A hole 656 provided in the lower portion of the L-shaped bracket 646 is positioned in communication with the holes 706 and 716 provided in the protrusion 536 of the drum base DB, and the L-shaped bracket 646 is a drum. Coupling with the protrusion 536 of the base (DB). Pin 696 is inserted through the holes 706, 656, 716. Thus, the L-shaped bracket 646 is rotatably connected to the protrusion 536 of the drum base DB with the pin 696 as a rotating shaft.

In FIG. 30, the shield plate 136 of the reference position sensor PS is fixed to one end of the rotation shaft 476 of the gear 466. The screw 476g is inserted through the spring and then engages with an internal screw 686 formed in the protrusion 536 of the drum base DB.

When the screw 476g of the rotation shaft 476 of the gear 466 rotates in engagement with the internal screw 686 formed in the protrusion 536 of the drum base DB, the protrusion of the drum base DB L-shaped bracket 646 rotatably connected to 536 rotates about pin 696, such that the shortest end 646a of L-shaped bracket 646 moves laterally.

Assuming that the magnetic recording and reproducing apparatus has completed the loading operation, the lower surface of the engaging portion 55b formed at the shortest end of the lower flange 545 of Figs. 28A to 28C is provided on the fixed side of the height adjustment mechanism. Engages with the face of the shortest end 646a of the L-shaped bracket 646 used as a member that functions as a constituent member.

After the loading operation by the loading mechanism is completed, when the recording and reproducing operation starts to rotate the motor Mgf, the gear 46 passes through the gears 185, 515, 195, 205 of the power transmission system of Fig. 27 as described above. Is rotated. The L-shaped bracket 646 when the screw 476g of the rotation shaft 475 of the gear 466 rotates while engaging the internal screw 686 formed in the protrusion 536 of the drum base DB. The engaging portion 55b formed at the shortest end of the lower flange 545 of Figs. 28A to 28C in contact with the surface of the shortest end 646a also moves up and down. Therefore, the guide pole GPf is moved up and down by the rotation of the motor Mgf. In addition, when the gear 465 rotates, the rotation shaft 525 of the gear 465 rotates. Next, the shield plate 135 of the reference position sensor PSf mounted on the lower portion of the rotary shaft 525 rotates, and the position signal is output from the photointerpreter 246 of the position sensor PSf.

Next, FIGS. 31A and 31B show protrusions 537 formed in the drum base DB and the rack plate 737. The rack 77L is provided on the rack plate 737. The shield plate 137 of the reference position sensor PS is also mounted on the rack plate 737. The inclined surface 747 is configured on the end of the rack plate 737. The upper surface of the rack plate 737 functions as a component member provided on the fixed side of the control mechanism. Also provided is a photointerpreter 247 of the position sensor PS. The rack plate 737 is slidably mounted in the recess 757. Pinion 727 engages rack 77L of rack plate 737. Gear 197 is mounted on rotating shaft 217 of pinion 727.

The gear 197 meshes with a gear 187 mounted on the rotating shaft 157 of the motor Mg. The shield blade 167 constituting a part of the rotary encoder RE is also mounted on the rotary shaft 157 of the motor Mg. The photo interpreter 177 constitutes a part of the rotary encoder RE.

Assuming that the magnetic recording and reproducing apparatus has completed the loading operation, the lower surface of the engaging portion 55b formed at the shortest end of the flange 545 in Figs. 28A to 28C is provided on the fixed side of the height adjustment mechanism. It is engaged with the upper surface of the rack plate 737 used as the member to function as the member.

After the loading operation by the loading mechanism is completed, when the recording and reproducing operation starts to rotate the motor Mg, the pinion 727 may be moved as described above so that the rack engaged with the pinion 727 moves up and down. 27 through gears 185 and 195 of the power transmission system. Therefore, the engaging portion 55b formed at the shortest end of the lower flange 545 in contact with the upper surface of the rack plate 737 also moves up and down. Therefore, the guide pole GP is moved up and down by the rotation of the motor Mg. In addition, when the pinion 727 rotates such that the rack engaged with the pinion 727 moves up and down, the shield plate 137 of the position sensor PS mounted on the rack plate 737 also rotates, and the position The signal is output from the photo interpreter 247 of the position sensor PS.

Next, an example of the guide roller GR (guide pole) according to the present invention will be described.

The shield plate 158 shown in Figs. 32A and 32B is integrally molded from resin. Top flange 168 and shaft 508 are pressurized internally. The assembling portion 158a of the shield plate is assembled into the shortest portion 58a of the shaft 508 after the phase with respect to the reference position sensor is adjusted. The large diameter portion of the shield plate 158 is smaller than the outer diameter of the upper and lower flanges 168, 178. The outer diameter of the gear 188 is also smaller than the outer diameter of the upper and lower flanges 168, 178.

FIG. 33: is explanatory drawing about the opening part and cassette Ct of the guide roller GR of FIG. 32A and 32B.

33 shows a cassette Ct, a magnetic tape T, a side opening Msup, a side opening Mtu, and a drum Dd. 33 also shows the unloading position UL and the loading completion position LE of the guide roller GR.

When the cassette Ct is mounted, the guide roller GR has an opening Msup of the cassette Ct having a small gap between the upper and lower flanges 168 and 178, the wall of the cassette Ct and the magnetic tape T. , Mtu).

If the large diameter portion of the shield plate 158 and the outer diameter of the gear 188 according to FIGS. 32A and 32B are larger than the outer diameters of the upper and lower flanges 168 and 178, they often have a cassette Ct and a magnetic tape ( Rub the walls of T). However, they are smaller than the outer diameters of the upper and lower flanges 168 and 178 as described above, so no friction occurs.

The reference position sensor on the fixed area is located near the detection end of the guide roller GR shield plate 158 after completion of the loading to be in the normal position.

34A shows an embodiment of the guide roller GR shown in FIGS. 32A and 32B in which the assembling portion 159a of the shield plate 158 is pressed into the small diameter portion 169 of the upper flange 168 of FIG. 32A. 34B shows an embodiment in which the assembly 159b of the shield plate 158 is pressed into the inner diameter 169 of the upper flange 168.

The shield plate 158 may be manufactured as a compressed sheet metal or other material having a resin assembly portion and a sheet metal plate portion, in addition to the resin.

According to the present invention described above, the reference height data of the tape guide (guide pole or guide roller) obtained according to the standard height for compatibility in recording and reproduction is stored in the memory. The height adjustment mechanism detects the height of the tape guide when the tape loading is completed and adjusts its height to the standard height with respect to the stored data. Thus, high compatible recording and reproducing can be achieved between magnetic recording and reproducing apparatuses having the same recording and reproducing standards.

Further, according to the present invention, the height of the tape guides provided on the feed reel and take-up reel sides, respectively, can be adjusted by the closed-loop automatic control under control signals generated based on the curve data on the track recorded on the standard magnetic tape. Can be. This can be achieved by automatic tape guide height adjustment only by reproducing standard magnetic tapes in the loading adjustment.

Further, according to the present invention, the amount of backlash of the power transmission system gear of the magnetic recording and reproducing apparatus is measured as the number of pulses generated by the rotary encoder and used to correct the height of the tape guide. This achieves accurate tape guide height adjustment.

Further, according to the present invention, the tape guides provided on the feed reel and take-up reel sides, respectively, are displaced to a height for correcting the track band, where during recording and normal reproduction of the displacement mechanism for displacing the tape guide in the height direction. The position of can be adjusted, and the position is always sustained during recording and normal playback. Since the adjustment cam has a flat surface width, the position of the sensor need not be precise.

Therefore, the present invention can achieve a magnetic recording and reproducing apparatus for correcting a track band by solving the problems in the conventional magnetic recording and reproducing apparatus as follows: (1) Recording and normal reproduction position of the tape guide Can be changed on the premise of accurate detection of the sensor and will change after elapse of time; (2) the reproducibility of recording and normal reproducing positions may be degraded due to the play and backlash of the drive gear; (3) When the rotation detection disk is mounted on the tape guide, the recording and normal playback positions cannot detect whether the tape guide rotates more than once.

Further, according to the present invention, the large diameter portion of the shield plate for detecting the position of the tape guide and the outer diameter of the gear for driving the tape guide are made smaller than the diameters of the upper and lower flanges of the tape guide. This shape makes it possible to prevent damage on the tape guide and cassette when the cassette is inserted or removed or when the shield plate or drive gear is in contact with the cassette wall.

Further, according to the present invention, the mounting position of the shield plate for detecting the position of the tape guide is formed of an elastic body, which is pressed into the small diameter portion of the upper flange of the tape guide and assembled into the shaft or extended into the shaft extending over the upper flange. And by assembling. This shape increases the number of steps for engaging the screw; The screw head protrudes onto the shield plate; In addition, since the screw hole penetrates the flange, it is possible to solve the problem in the conventional magnetic recording and reproducing apparatus that the compression tolerances for the upper flange and the shaft cannot be taken.

Claims (21)

A supply and take-up reel around the magnetic tape to be wound; A first tape guide provided near the rotating head of the supply reel side; A second tape guide provided near the rotating head of the take-up reel side, wherein the first and second tape guides can be moved in the width direction of the magnetic tape; A first detector for detecting a height of each of said first and second tape guides; A counter for obtaining a calculated value corresponding to the detected height; An adjuster for adjusting the height of at least the first or second tape guide so that the calculated value matches the reference value; And means for setting the calculated value to a specific value when the detected height becomes a reference height corresponding to the reference value after the magnetic tape is wound around the supply and take-up reel. 2. The apparatus of claim 1, further comprising a second detector for detecting an envelope of a signal reproduced from the magnetic tape, and a regulator for adjusting the height of at least the first or second tape guides so that the envelope is flat. Magnetic recording and playback device. A supply reel and take-up reel around the magnetic tape to be wound; A tape guide provided near the rotating head of the supply reel and take-up reel side, and movable in the width direction of the magnetic tape; A driver for moving the tape guide in a tape width direction; Detecting the height of each of the tape guides, generating a first reference signal when at least one of the tape guides is moved from the first direction to the first reference height, wherein at least one of the tape guides A detector for generating a second reference signal when moved to a second reference height in a second direction opposite the first direction; A counter for counting the number of pulses generated while the at least one tape guide is moved; And a memory for storing the first pulse number calculated when the first reference signal is generated and the second pulse number calculated when the second reference signal is generated, wherein the driver is configured to store the first and second pulse numbers. A magnetic recording and reproducing apparatus for moving at least one tape guide based on at least a first difference therebetween. 4. The magnetic recording and reproducing apparatus according to claim 3, wherein the driver moves at least one tape guide in a first direction based on the number of first and second pulses or in a second direction based on a first difference. 4. The method of claim 3, wherein the driver moves the at least one tape guide in a first direction based on a particular number less than a first difference or in a second direction based on a first difference and a second difference between the specific number. Magnetic recording and playback device. A supply reel and take-up reel around the magnetic tape to be wound; A tape guide provided near the rotating head of the supply reel and take-up reel side, and movable in the width direction of the magnetic tape; A driver for moving the tape guide in a tape width direction; A counter for calculating the number of pulses generated while the at least one tape guide is moved; A detector for detecting the number of calculations of the pulses when the at least one tape guide moves at a particular speed and then stops, wherein the driver is configured to move the at least one tape guide based on the number of calculations of the detected pulses. Magnetic recording and playback device. 7. The apparatus of claim 6, wherein the detector detects the first pulse count when the at least one tape guide is stopped at the first direction after the at least one tape guide is moved at a particular speed and the at least one tape guide is moved at a particular speed. Detect a second pulse count when stopped in a second direction opposite to the first direction of magnetic tape width, and the driver moves at least one tape guide based on the first and second pulse counts Magnetic recording and reproducing apparatus. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the adjuster has inclined means for tilting each tape guide in one direction and a stopper for sustaining each tape guide at a fixed height. The tape guide according to claim 1, wherein each tape guide is provided on a foul base and the adjuster changes the height of at least one tape guide in the first case of initiating loading of the magnetic tape and further from the first case. A magnetic recording and reproducing apparatus for changing the height of the foul base in the second case just before the loading is terminated to maintain a certain height of the magnetic tape up to the second case. 2. The magnetic recording apparatus of claim 1, wherein the adjuster has an inclined surface, the flat surface being in contact with a portion of the tape guide to adjust the height of each tape guide or in contact with a portion of each tape guide in reproduction and reproduction. Playback device. 2. A magnetic recording and reproducing apparatus as set forth in claim 1, wherein each tape guide is provided on the foul base with a stopper to limit the rotation of the tape guide to one time. 2. The magnetic recording and reproducing apparatus as set forth in claim 1, wherein each tape guide is provided with a rotating shaft formed with a screw engaged with the adjuster gear, the apparatus further comprising means for preventing backlash of the screw. The magnetic recording and reproducing apparatus according to claim 1, wherein each tape guide is adjustable in its axial direction on its upper and lower portions. 14. The magnetic recording and reproducing apparatus according to claim 13, wherein each tape guide is adjustable through springs on upper and lower portions. 2. The tape of claim 1, wherein each tape guide is provided with a shield plate that acts with a photointerpreter of a first detector for detecting its height, and is formed with an upper and a lower flange, the diameter of the shield plate. A magnetic recording and reproducing apparatus whose diameter is smaller than the diameter of the upper and lower flanges. 2. The tape guide according to claim 1, wherein each tape guide is provided with a rotating shaft formed with a screw that engages an adjuster gear, and is also formed with an upper and a lower flange, the diameter of which is greater than the diameter of the upper and lower flanges. Small magnetic recording and playback device. 2. The tape guide according to claim 1, wherein each tape guide is provided with a shield plate formed of an elastic body which acts with a photointerpreter of the first detector for detecting its height, and is formed with an upper and a lower flange, A magnetic recording and reproducing apparatus, wherein the shield plate is pressed and assembled into a specific diameter portion of the upper flange. The tape guide according to claim 1, wherein each tape guide is provided with a shield plate and a rotating shaft formed of an elastic body that acts together with the photointerpreter of the first detector for detecting its height, and also formed with the upper and lower flanges. And the shield plate is pressed and assembled into a portion of the shaft extending over the upper flange. 2. The magnetic recording and reproducing apparatus as set forth in claim 1, wherein each tape guide is provided with a shield plate which works with a photointerpreter of the first detector for detecting its height, and the shield plate is made of resin. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein each tape guide is provided with a shield plate which works with a photointerpreter of the first detector for detecting its height, and the shield plate is made of metal. 10. The method of claim 1, wherein each tape guide is provided with a shield plate that acts with a photointerpreter of the first detector for detecting its height, the shield plate being made of a metal and a fixing portion made of resin. Magnetic recording and reproducing apparatus having a plate portion.