JPH1049943A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a magnetic recording and reproducing device capable of obtaining a satisfactory reproduced output by constituting a gap smaller than a specific μm between the lower edge of the slidable contact surface of a lower drum and a lead ring. SOLUTION: The deterioration of reproduced outputs from rotary magnetic heads when the gap Ga between the lower edge of the slidable surface of a lower drum Dd and a read ring Lr changed is shown from experimental results. Black round marks show measured values obtained at the fast-rewinding reproducing operation of a seven-fold speed using a rotary magnetic head whose head track width is 58μm and black square marks show measured values obtained at the fast-forwarding reproducing operation of a seven-fold speed using a rotary magnetic head whose track width is 58μm. In both cases, when gaps between the lower edge of the slidable contact surface of the lower drum Dd and the lead ring Lr are <=150μm, deterioration of reproduced outputs is <=-2db and when the gaps are >=150μm, the deterioration of the reproduced outputs is made to be larger. Thus, the satisfactory reproduced output is obtained by constituting the gap Ga smaller than 150μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating magnetic head by changing the spatial position of a rotating locus surface of a rotating magnetic head in accordance with a change in a running speed of a magnetic tape running in sliding contact with a part of a peripheral surface of a drum. The present invention relates to a magnetic recording / reproducing apparatus which enables a head to track a recording trace satisfactorily.

[0002]

2. Description of the Related Art A magnetic tape wound around a part of a peripheral surface of a drum composed of an upper drum and a lower drum is run at a predetermined running speed, and a recording / reproducing operation is performed using a rotary magnetic head. As a typical example of the so-called helical scan type magnetic recording / reproducing apparatus, a video tape recorder (VTR) [or a video cassette recorder (V
CR)]. And the VT
In using the R and VCR, in addition to normal reproduction (normal reproduction) in which recorded information is reproduced at the same magnetic tape traveling speed as during recording, the traveling speed and traveling direction of the magnetic tape during recording are defined as follows. Trick play in which a reproducing operation is performed by running (including stopping) a magnetic tape at different running speeds and running directions is also widely performed.

However, the pattern of the recording trace formed on the magnetic tape according to the rotation locus of the rotating magnetic head of the helical scan type magnetic recording / reproducing apparatus described above is as follows.
It is determined by various conditions such as the diameter of the drum, the number of rotations of the rotating magnetic head, the rotating direction of the rotating magnetic head, the running speed of the magnetic tape, the running direction of the magnetic tape, the track angle, the head track width, the recording area width of the magnetic tape, and the like. When the operation mode (normal reproduction mode, various trick play operation modes) of the magnetic recording / reproducing apparatus is changed, for example, the conditions such as the running direction and the running speed of the magnetic tape are changed, the magnetic tape is rotated by the rotating magnetic head. The pattern of the rotation trajectory of the rotary magnetic head depicted in FIG.

For example, when the magnetic recording / reproducing apparatus in the VHS (registered trademark) system is in the SP mode, the diameter is 62 m.
m rotating drum mounted on a rotating drum
The recording / reproducing operation is performed in a state where the magnetic tape wound around a part of the outer circumference of the drum is transported in the forward direction at a feed speed of 33.35 mm per second. The rotation trajectory of the rotary magnetic head drawn on the magnetic tape during traveling by the magnetic head has an angle of 5 ° 58'9.9 ”with respect to the reference edge of the magnetic tape,
Further, for example, in a magnetic recording / reproducing apparatus of the VHS (registered trademark) system, a rotating magnetic head attached to a rotating drum having a diameter of 62 mm is rotated at 1800 revolutions per minute,
When the recording / reproducing operation (double speed reproduction in the forward direction) is performed while the magnetic tape wound around a part of the outer periphery of the drum is transported in the forward direction at a feed speed of 66.7 mm per second, the rotation is performed. The rotation trajectory of the rotary magnetic head drawn on the magnetic tape during traveling by the magnetic head has an angle of 6 ° 2′19.2 ″ with respect to the reference edge of the magnetic tape.

Further, for example, in a magnetic recording / reproducing apparatus of the VHS (registered trademark) system, a rotary magnetic head mounted on a rotary drum having a diameter of 62 mm is rotated at 1,800 revolutions per minute and wound around a part of the outer periphery of the drum. When the recording / reproducing operation (double speed reproduction in the reverse direction) is performed with the magnetic tape being transported in the reverse direction at a feed rate of 66.7 mm per second, the rotating magnetic head applies the magnetic tape during traveling. The rotation locus of the rotating magnetic head to be drawn has an angle of 5 ° 54'6.2 ”with respect to the reference edge of the magnetic tape. In the magnetic recording / reproducing apparatus of the VHS (registered trademark) system described above, the rotation locus having a diameter of 62 mm is used. The rotating magnetic head attached to the drum is rotated at 1800 revolutions per minute,
With the magnetic tape wound around a part of the outer periphery of the drum stopped, the rotation locus of the rotary magnetic head drawn on the magnetic tape by the rotary magnetic head is 5 ° 56 ′ with respect to the reference edge of the magnetic tape. The angle is 7.4 ".

Therefore, during normal recording / reproducing (normal recording / reproducing), the rotating locus of the rotating magnetic head drawn on the magnetic tape by the rotating magnetic head, and the rotating magnetic track drawn on the magnetic tape by the rotating magnetic head during trick play. The rotation locus of the head intersects. Therefore, the signal level of the frequency modulated wave signal of the reproduced signal reproduced at the time of trick play changes greatly every time the rotating magnetic head crosses the recording trace, and the frequency modulated wave of the reproduced signal in one vertical scanning period is changed. Looking at the signal envelope, large undulations occur during one vertical scanning period. Therefore, as a reproduced image at the time of trick play, only a reproduced image of poor quality having noise bars in the image can be obtained. . In particular, in a consumer digital VTR,
Since the data amount of the video signal is compressed and recorded by the high-efficiency encoding method, the rotating magnetic head performs the reproducing operation across the recording track of the magnetic tape, such as during fast forward playback or rewind playback. In this case, an image may not be reproduced at all depending on the arrangement state of the blocks of data arranged in a mosaic pattern.

[0007] In order to solve the above-mentioned problems, it is only necessary to make the rotation trajectory of the rotary magnetic head coincide with the recording trace of the magnetic tape, and it has been conventionally used as an actuator in an open loop control circuit or a closed loop control circuit. A rotating magnetic head is mounted on the electro-mechanical conversion element to be used, and the rotating magnetic head is displaced by the electro-mechanical conversion element so that the rotating magnetic head can be traced to the recording mark of the magnetic tape. As disclosed in JP-A-34126 and JP-A-61-158633, the rotating drum on which the rotating magnetic head is mounted and the lower drum are integrally tilted so that the rotating magnetic head records magnetic tape. It is possible to trace the trace, for example, as disclosed in JP-B-61-22378,
By changing the height of guides for restricting the height in the width direction of the magnetic tape provided on the side where the magnetic tape enters the drum and on the side where the magnetic tape separates from the drum, the rotating magnetic head moves the magnetic tape. And the reference edge of the magnetic tape at the time of high-speed reproduction is provided at the portion of the lead guide provided on the lower drum on the side where the magnetic tape enters the drum and on the side where the magnetic tape separates from the drum. Various solutions have been proposed, such as providing a guide surface to the user.

However, in the VTR in which the rotation locus of the rotary magnetic head is controlled by using the electromechanical transducer used as the actuator as described above, an electric motor for controlling the rotation locus of the rotary magnetic head is used. -Since the mechanical conversion element must be provided in a narrow space inside the rotating drum, a small-sized electro-mechanical conversion element is required. It is difficult to apply a large displacement to the rotating magnetic head, and the structure is such that the state of the head touching the magnetic tape does not deteriorate even when the rotating magnetic head displaced by the electro-mechanical transducer is displaced. VT that performs good recording / reproducing operation using a small actuator exhibiting good operating characteristics And it is difficult to make a rotating magnetic head track a recording track with a small width on a magnetic recording medium on which high-density recording is performed. is there.

Among the magnetic recording / reproducing apparatuses in which the rotating drum and the lower drum are integrally inclined so that the rotating magnetic head can track the recording mark of the magnetic tape, Japanese Utility Model Publication No. 63-34126 discloses the same. In the magnetic recording / reproducing apparatus disclosed in the above, since the guide portion of the reference edge of the magnetic tape only contacts the reference edge of the magnetic tape in a state close to a point contact, so to speak, When the reference edge position of the tape is greatly displaced and the magnetic tape is recorded at a low recording density, that is, when the recording mark width is large, normal reproduction is barely good. However, during trick play, the magnetic tape is running in a state where the reference edge of the magnetic tape is not correctly guided by the guide section, so fast forward In either case the playback returns Birth and winding, it can not be performed satisfactorily remove the noise bars becomes a problem.

Further, in the magnetic recording / reproducing apparatus in which the rotating drum and the lower drum are integrally inclined so that the rotating magnetic head can track the recording trace of the magnetic tape, the magnetic recording / reproducing apparatus is disclosed in JP-A-61-158633. In the magnetic recording / reproducing apparatus disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, a member (guide section) capable of guiding a portion of a predetermined length at a reference edge of a magnetic tape formed separately from the lower drum is fixed to a fixing section of the apparatus. Therefore, the change in the position of the reference edge of the magnetic tape, which has occurred in the magnetic recording and reproducing apparatus disclosed in Japanese Utility Model Publication No. 63-34126, can be prevented from occurring at least at the time of normal reproduction operation. If the rotating drum on which the magnetic head is mounted and the lower drum are integrally tilted to perform a fast-forward playback operation or a rewind playback operation, The magnetic tape running while being in sliding contact with the sliding surfaces of the upper and lower drums having the contact surfaces is inclined together with the upper and lower drums while being in sliding contact with the sliding surfaces of the upper and lower drums. With the inclination of the upper and lower drums, the reference edge of the magnetic tape may be displaced away from a member (guide portion) for guiding the reference edge of the magnetic tape. Occur. Therefore, when the rotating drum on which the magnetic head is mounted and the lower drum are integrally tilted in order to perform a fast-forward playback operation or a rewind playback operation, etc., with the inclination of the upper and lower drums, There is a portion where the reference edge of the magnetic tape is not guided by the above-mentioned member (guide portion) for guiding the reference edge of the magnetic tape, and the position of the reference edge of the magnetic tape in that portion fluctuates to cause noise bars. May occur.

Also, Japanese Patent Publication No. 61-223
Also in the high-speed reproducing device described in Japanese Patent Publication No. 78, the height of a guide for limiting the width in the width direction of the magnetic tape provided on the side where the magnetic tape enters the drum and on the side where the magnetic tape separates from the drum. Is changed, and the reference edge of the magnetic tape when the recording mark of the magnetic tape is traced by the rotating magnetic head is guided by only a very small portion specially provided at the end of the lead guide provided on the lower drum. As a result, a stable running state of the magnetic tape cannot be obtained, and the position of the reference edge of the magnetic tape may fluctuate to generate a noise bar. In particular, in recent years, in order to reduce the size and lengthen the length of a magnetic tape, the recording track width (track width) has been reduced, and a thin material having low rigidity has been used as a base member. Therefore, it is not possible to obtain a high-speed playback image in a noiseless state by using the high-speed playback apparatus having the configuration disclosed above.

As means for solving the above problems, the present applicant has firstly provided an upper drum provided with a sliding contact surface for a magnetic tape wound around a part of the peripheral surface of the upper and lower drums;
A rotating magnetic head, a magnetic drum sliding contact surface located on an extended surface of the magnetic tape sliding contact surface of the upper drum, and a lower drum coaxially provided with the upper drum; First tilt drive means for tilting the central axes of the upper and lower drums and the rotary magnetic head by a predetermined angle when the rotational trajectory surface of the rotary magnetic head coincides with the formed recording trace A guide portion for a reference edge of a magnetic tape, which is configured separately from the upper and lower drums and is arranged in a state of approaching the outer peripheral surface of the small diameter portion formed below the lower drum. Position regulation surface)
A guide member for regulating the traveling position of the magnetic tape comprising:
A magnetic recording / reproducing apparatus comprising: a second tilt drive unit that tilts the guide member for regulating the traveling position of the magnetic tape so that the position regulating surface of the magnetic tape coincides with the reference edge position of the magnetic tape. And its implementation has yielded good results.

FIG. 8 and FIG. 9 are diagrams showing a schematic configuration of a magnetic recording / reproducing apparatus already proposed by the present applicant. FIG. 8 shows a pair of the upper drum Du and the upper drum Du. Lower drum Dd provided (see FIG. 9)
A guide member Lr for regulating the running position of the magnetic tape for regulating the position of the reference edge Te of the magnetic tape T (hereinafter, a guide member for regulating the traveling position of the magnetic tape for regulating the position of the reference edge Te of the magnetic tape T is provided. (May be described as a ring Lr).
FIG. 9 is a perspective view showing a schematic configuration of an example of a tape driving system and a mechanism section of a VTR provided with a VTR. FIG. 9 shows a rotation locus drawn on the magnetic tape T by the rotary magnetic heads H1 and H2. 3 shows an example of the configuration of a mechanism that enables control to be at a predetermined angle with respect to a reference edge Te of the tape T. In FIG. 8, reference numeral 1 denotes a supply reel table, and 2 denotes a take-up reel table. A cassette case 3 wound around a supply reel 4 and a take-up reel 19 provided in a cassette case 3 and storing a magnetic tape T therein. Is mounted on the VTR, the supply reel 4 in the cassette case 3
0, and the take-up reel 19 in the cassette case 3 is connected to the take-up reel table 2 provided in the machine base 20.

When the magnetic tape T is pulled out of the cassette case 3 by loading poles (vertical guide rollers) 9 and 14 provided in a parallel loading type loading mechanism, the magnetic tape T is transferred to the tension pole 5 and the guide. The upper drum Du, which is driven and rotated at a predetermined rotation speed via a pole 6, a full width erasing head 7, an impedance roller 8, a loading pole (vertical guide roller) 9, an inclined guide (slant pole) 10, etc., and a stationary state After being wound around a part of the peripheral surface of the lower drum Dd while the reference edge Te of the magnetic tape is being guided, the inclined guide (slant pole) 13 and the loading pole
(Vertical Guide Roller) 14, audio control head 15, guide pole 16, capstan 18, pinch roller 17 and the like. 22 in the figure
s is a supply pole base and 22t is a take-up pole base.

In a state where the rotary magnetic head provided on the upper drum Du is driven and rotated at a predetermined rotation speed,
The control information is provided from the main control unit according to the running direction and the running speed of the magnetic tape T set in the main control unit provided in the VTR in accordance with various operation modes. The tilt control unit (not shown) is configured to control the center line 21 of the drum structure DA including the upper drum Du, the lower drum Dd (see FIG. 9), and the lead ring Lr in the drum structure DA.
Is tilted by a predetermined amount in the direction of arrow 21a (or 21b) in FIG. 9, and the lead ring Lr is also tilted by a predetermined amount in a predetermined direction under the control of the tilt control unit. Is done. Thereby, the pattern of the rotation trajectory drawn on the magnetic tape T by the rotation trajectory of the rotary magnetic head is brought into a state in which it coincides with the recording trace of the magnetic tape, and the guide of the lead ring is moved along the movement trajectory of the reference edge Te of the magnetic tape. The part G (position regulation surface) is brought into a state where they match.

After the loading operation by the loading mechanism has been performed as described above, the magnetic tape T traveling on the magnetic tape traveling path set between the supply reel 4 and the take-up reel 19 becomes the tension pole 5 → It travels in a horizontal state on a traveling path in the section of guide pole 6 → full width erasing head 7 → impedance roller 8 → loading pole (vertical guide roller) 9, and then inclined guide
When the running direction of the magnetic tape T is changed by the (slant pole) 10, the magnetic tape T is driven and rotated at a predetermined rotational speed by the upper drum Du and the lower drum D.
It is wound around the guide portion G provided on the lead ring Lr over a range of a center angle slightly more than 180 degrees with respect to both of d and d.

As described above, the upper drum Du and the lower drum D
The magnetic tape T wound over a range of slightly more than 180 degrees with respect to d.
After the running direction of the magnetic tape T is returned to the running direction of the horizontal state again, the loading pole (vertical guide roller) 14 → the audio control head 15
The guide tape 16 is wound around the take-up reel 19 while traveling on the magnetic tape traveling path in the section such as the capstan 18 and the pinch roller 17. An arrow a in FIG. 8 indicates the rotation direction of the upper drum Du, and an arrow b indicates the transport direction of the magnetic tape T in the forward direction. It goes without saying that the transfer direction of the magnetic tape T in the reverse direction is the direction opposite to the direction of the arrow b in FIG. In FIGS. 8 and 9, a drum motor for driving and rotating the upper drum Du at a predetermined number of rotations is omitted for simplification of the drawings. For example, a motor having a configuration in which a rotor is fixed to the upper drum Du as illustrated in FIGS. 11 and 12 may be used. When the drum motor having the above configuration is used, the upper drum Du is used.
Is rotatably supported by a bearing bearing with respect to the center axis of the drum structure DA.

Next, the operation of a mechanism for controlling the rotation trajectory drawn on the magnetic tape T by the rotary magnetic head so as to be at an arbitrary predetermined angle with respect to the reference edge Te of the magnetic tape T. FIG. 9 showing the principle will be described. In FIG. 9, DB is a drum base, and a drum structure DA including an upper drum Du, a lower drum Dd, and a lead ring Lr is supported by the drum base DB. The upper drum Du is rotatably supported with respect to the center axis of the drum structure DA by a bearing (not shown) mounted on the center axis (49 in FIGS. 11 and 12) of the drum structure DA. In addition, lower drum D
d is fixed to the center axis of the drum structure DA.
The lead ring Lr functioning as a guide for the reference edge Te of the magnetic tape T is formed separately from the lower drum Dd, close to the outer peripheral portion below the lower drum Dd, and A knife edge 23 provided on the inner periphery is coaxially fitted with the lower projection of the lower drum Dd.

During the recording operation, the lower drum Dd has four rotation fulcrums whose bottom surface protrudes from the drum base DB (two of the four rotation fulcrums in the figure). Only the pivot points 25 and 26 are shown, and two pivot points (not shown) correspond to the pivot points 2 shown in the figure.
5 and 26 are provided one by one on a line perpendicular to the paper surface, which are indicated by reference numerals 35 and 36 in FIG. 10), and are also provided with a read ring during a recording operation. Lr denotes only four pivot points (only two pivot points 27 and 28 out of the four pivot points) protruding from the lead ring Lr.
The two rotation fulcrums (not shown) are provided one by one on a line perpendicular to the plane of the drawing at the positions of the rotation fulcrums 27 and 28 shown in the figure. Although indicated by reference numerals 37 and 38, the lower drum Dd
Is pressed against the bottom of the drum. Springs (springs 44 and 45, springs 4 in FIGS. 11, 12, and 10) are provided between the lead ring Lr and the drum base DB and between the lower drum Dd and the drum base DB, respectively.
6 and 47) are attached so that the above-mentioned components are connected to each other in a predetermined connection state. [For a specific configuration example, the mutual connection status of the components when a recording operation is performed is determined. Illustrated in FIG. 11].

When fast forward reproduction (FF) is performed in the same running direction as the running direction of the magnetic tape during the recording operation, the screw 29 is driven so as to push up the bottom surface of the lower drum Dd. 30 is driven in a direction away from the bottom surface of the lower drum Dd, and two of the four rotation fulcrums (the rotation fulcrum 25 shown in FIG. One rotation fulcrum provided on a line perpendicular to the paper surface at the position of the rotation fulcrum 25, which is shown in FIG. 10, is in contact with the bottom surface of the lower drum Dd.
The upper drum Du is defined by using the above-mentioned two pivot points as pivot points.
The center axis of the lower drum Dd is rotated in the direction of arrow 21a in FIG. 9 (and FIG. 12). [Specific configuration examples in the case where fast forward reproduction is performed in the forward direction] FIG. 12 shows an example of how the components are connected to each other. In the figure, 49 is a central axis, and 21 is a center line].

In the case where fast reverse reproduction (REW) is performed in the running direction opposite to the running direction of the magnetic tape during the recording operation, the screw 30 is driven so as to push up the bottom surface of the lower drum Dd. At the same time, the screw 29 is driven in a direction away from the bottom surface of the lower drum Dd, and two of the four pivots protruding from the drum base DB (the pivots 26 and Rotating fulcrum 26 shown in the figure
, One rotation fulcrum provided on a line perpendicular to the paper surface at position... 36) in contact with the bottom surface of the lower drum Dd, and using the two rotation fulcrums as the rotation fulcrum. The center axis of the upper drum Du and the lower drum Dd is indicated by an arrow 21 in FIG.
It is made to rotate in the direction of b. The screw 29 described above,
The above-described drive operation of the drive unit 30 is performed by the operation of a drive mechanism operating under the control of a tilt control unit (not shown). The drive mechanism includes a motor 40 serving as a power source as shown in an exploded perspective view of FIG. 10, a reduction mechanism 41 including a plurality of gears, and a rotary encoder 4.
2. It comprises a position detector 43 and the like.

The running direction and running speed of the magnetic tape T are controlled by the main control unit according to various operation modes set in the main control unit provided in the VTR. The tilt control unit to which the information is given moves the center axis of the drum structure DA including the upper drum Du, the lower drum Dd (see FIG. 9), and the lead ring Lr in the drum structure DA to an arrow 21a (or 21b) in FIG. The drive mechanism is controlled so that the screws 29 and 30 are advanced and retracted in such a manner as to incline by a predetermined amount in the direction of (2).
When fast-forward playback (FF) is performed in the same running direction as the running direction of the magnetic tape during the recording operation, two of the four rotating fulcrums projecting from the lead ring Lr are used. (The rotation fulcrum 27 and one rotation fulcrum provided on a line perpendicular to the paper surface at the position of the rotation fulcrum 27 shown in the drawing... 37 in FIG. 10) The center axis of the lead ring Lr is turned by a predetermined amount in the direction of the arrow 21a in FIG. 9 (and FIG. 12), in contact with the bottom surface of the lower drum Dd and using the two turning fulcrums as turning fulcrums. The two screws 31 and 32, which are screwed into the lead ring Lr and are provided in a state where the tips abut on the bottom surface of the lower drum Dd, respectively, are rotated in opposite directions so as to be in a specific state. Fast forward playback in the forward direction Mutual bonding state of each component is illustrated in Figure 12 when dividing.

Further, when rewinding (REW) is performed in the running direction opposite to the running direction of the magnetic tape during the recording operation, four rotating fulcrums projecting from the lead ring Lr. Of the two rotation fulcrums (the rotation fulcrum 28)
And one rotation fulcrum provided on a line perpendicular to the paper surface at the position of the rotation fulcrum 28 shown in FIG.
38) is in contact with the bottom surface of the lower drum Dd.
The lead ring Lr is screwed into the lead ring Lr such that the center axis of the lead ring Lr is rotated by a predetermined amount in the direction of the arrow 21b in FIG. , Two screws 31 and 32 provided in a state where the tip portions abut against the bottom surface of the lower drum Dd, respectively.
Are rotated in opposite directions.

The above-mentioned driving operation for the screws 31 and 32 is also performed by the operation of the above-mentioned driving mechanism which operates under the control of the tilt control unit (not shown). In response to the direction and the traveling speed being set in the main control unit provided in the VTR in accordance with various operation modes, the inclination control unit to which the control information is given from the main control unit includes: The drive mechanism is controlled so that the lead ring Lr is inclined by a predetermined amount in the direction of arrow 21a (or 21b) in FIG.
Move 1,32 forward and backward. In the above description, in order to facilitate understanding of the operation, the tilting operation of the center axis of the drum assembly by the forward and backward operations of the screws 29 and 30 and the tilting operation of the central axis of the lead ring Lr by the forward and backward operations of the screws 31 and 32 are described. Were explained as if they were performed independently.

However, as shown in FIG. 12, the screws 29 and 32 are simultaneously driven and rotated by a common power transmission mechanism, and the screws 29 and 31 are simultaneously driven. Are driven and rotated at the same time by a common power transmission mechanism, the tilting of the center axis of the drum assembly by the reciprocating motion of the screws 29, 30 and the lead ring Lr by the reciprocating motion of the screws 31, 32. Is performed simultaneously with the tilting operation of the central axis. FIG. 11 showing a specific configuration of the magnetic recording / reproducing apparatus already proposed is a longitudinal sectional view in a direction of 90 degrees to 180 degrees.
FIG. 12 is a longitudinal sectional view in the 0-180 degree direction.
FIG. 11 shows the state of the magnetic recording / reproducing apparatus at the time of the recording operation. FIG. 12 shows the state of the magnetic recording / reproducing apparatus at the time of the fast-forward reproduction, that is, the drum structure D.
A state in which the center line 21 of A is inclined in the direction of the arrow 21a in the figure is shown. In FIG. 10 showing a partial exploded perspective view, the illustration of the upper drum Du and the drum motor 50 is omitted.

In FIGS. 11 and 12, reference numeral 49 denotes a center shaft fixed to the lower drum Dd, and bearings 51 and 52 are fitted into the center shaft 49. Also, upper drum D
u is the center shaft 49 described above by the bearings 51 and 52.
Are rotatably supported. H1 and H2 are rotary magnetic heads provided on the upper drum Du. The rotor 50r of the drum drive motor 50 is fixed to the upper drum Du. Also, the drum drive motor 50
Is fixed to the central shaft 49 described above. Reference numeral 48 denotes a rotary transformer mounted on the lower drum Dd, and reference numeral 53 denotes a rotary transformer mounted on the upper drum Du.

FIGS. 11, 12 and 10 and FIGS.
In the magnetic recording / reproducing apparatus proposed by the present applicant described with reference to FIG. 9, the rotation trace surface of the rotary magnetic head is expected to coincide with the recording trace formed on the magnetic tape. First tilt drive means for tilting the central axes of the upper and lower drums and the rotary magnetic head by an angle, and a separate structure from the upper and lower drums, and a lower portion of the lower drum; The reduced diameter portion 39 (FIG. 1)
1, FIG. 12 and FIG. 10), a position regulating guide member (lead ring) Lr for a magnetic tape having a regulating surface G at the position of the reference edge of the magnetic tape disposed close to the outer peripheral surface of the magnetic tape. The upper and lower drums and the position regulating surface G of the reference edge of the magnetic tape are formed by the second inclination driving means for inclining the position regulating guide member of the magnetic tape so as to coincide with the reference edge position of the magnetic tape. The rotation trajectory of the rotary magnetic head coincides with the recording trace formed on the magnetic tape by inclining the read ring Lr provided with The guide edge Te of the magnetic tape T can be favorably guided by the position regulating surface G of the lead ring Lr. As described above, the expected effect can be obtained by the above-described proposed magnetic recording / reproducing apparatus.

[0028]

However, in the magnetic recording / reproducing apparatus proposed by the present applicant described with reference to FIGS. 8 to 12, the magnetic recording / reproducing apparatus is configured separately from the lower drum Dd. The lead ring Lr is shown in FIGS.
As shown in FIG. 4, the lower drum Dd and the lead are opposed to the small-diameter portion 39 provided below the portion where the sliding surface RF of the lower drum Dd is formed, and between the lower drum Dd. Even when the ring Lr and the ring Lr perform a tilting operation, the lower edge db of the sliding surface RF of the lower drum Dd and the upper end of the lead ring Lr are formed so that an accident such as a collision does not occur. Reference edge T of magnetic tape T
A predetermined gap Ga (approximately 500
FIG. 14 shows the vicinity of the reference edge Te of the magnetic tape T in contact with the regulation surface G at the position of the reference edge Te of the magnetic tape T formed on the upper surface of the lead ring Lr. As shown in FIG. 7, the state is separated from the sliding contact surface RF formed on the lower drum Dd. Therefore, the magnetic tape T wound around the peripheral surface of the drum at a center angle range of slightly more than 180 degrees travels in a state where the wide portions near the reference edge Te at both ends are not supported by the sliding surface of the lower drum Dd. May cause vibration and adversely affect the playback state.
In the case where the magnetic tape T used at the time of recording / reproducing is configured by using a base film having a small mechanical strength, a mechanical tape is attached to the reference edge Te of the magnetic tape T at the time of trick play. The problem of causing distortion has been a problem, and a solution to the above problems has been sought. Note that ub in FIG. 13 indicates the lower edge of the sliding contact surface of the upper drum Du.

[0029]

SUMMARY OF THE INVENTION The present invention provides an upper drum having a sliding surface for a magnetic tape wound around a part of the peripheral surface of the upper and lower drums, a rotating magnetic head, and a magnetic head. It has a sliding surface for magnetic tape that is located on the extended surface of the sliding surface of the tape, and also has a lower drum coaxially provided with the upper drum and a recording mark formed on the magnetic tape. First tilt drive means for tilting the central axes of the upper and lower drums and the rotary magnetic head by a predetermined angle when the rotation locus surfaces of the rotary magnetic head coincide with each other; Are formed separately, are arranged in a state of approaching the outer peripheral surface of the small diameter portion formed at the lower portion of the lower drum, and have a position regulating surface of the reference edge of the magnetic tape at the upper end portion. Proposal for restricting running position of magnetic tape A magnetic recording / reproducing apparatus comprising: a member; and a second tilt drive unit for tilting the guide member for regulating the running position of the magnetic tape so that the position regulating surface of the magnetic tape coincides with the reference edge position of the magnetic tape. When the magnetic recording and reproducing apparatus operates in the same running state of the magnetic tape as the running state of the magnetic tape during the recording operation,
The portion of the lower drum that slides on the lower drum at a portion corresponding to the portion between the two rotation fulcrums set to be used during the tilting operation of the guide member for regulating the traveling position of the magnetic tape. The lower edge of the surface and the position regulating surface of the reference edge of the magnetic tape in the guide member for regulating the traveling position of the magnetic tape are brought into contact with each other, and a large gap is formed in portions other than the above. A magnetic recording / reproducing apparatus comprising: a lower edge of a sliding surface of the magnetic tape in the lower drum; and a position regulating surface of a reference edge of the magnetic tape in a guide member for regulating a running position of the magnetic tape. provide.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific contents of a magnetic recording / reproducing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
FIGS. 1 and 4 are side views of the main parts of different embodiments of the magnetic recording / reproducing apparatus of the present invention, and FIG. 2 is a diagram of the magnetic recording / reproducing apparatus of the present invention shown in FIG. FIG. 3 is a side view when the magnetic recording / reproducing apparatus of the present invention shown in FIG. 1 is performing a fast-forward reproduction operation (rewind reproduction operation) in the reverse direction, and FIG. FIG. 5 is a side view of the magnetic recording and reproducing apparatus of the present invention shown in FIG. 4 performing a fast forward reproducing operation in the forward direction. FIG. 6 is a side view of the magnetic recording and reproducing apparatus of the present invention shown in FIG. FIG. 7 is a side view when the fast forward reproduction operation (rewind reproduction operation) is performed.

FIGS. 1 (FIGS. 2 and 3) and FIG. 4 (FIGS. 5 and 6) showing the magnetic recording / reproducing apparatus according to the present invention. Although only the parts necessary for explaining the operation of the magnetic recording / reproducing apparatus of the present invention are illustrated, the magnetic recording / reproducing apparatus shown in FIGS. 1 (FIGS. 2 and 3) and FIG. 4 (FIGS. 5 and 6) are used. The specific configuration of the components other than the characteristic components of the device is the same as that of the magnetic recording / reproducing device described above with reference to FIGS. 10 to 12 and the like. 1 (FIGS. 2 and 3) and FIG. 4 (FIGS. 5 and 6) will be described with reference to FIGS. 10 to 12 and the like.

First, the magnetic recording / reproducing apparatus of the present invention shown in FIGS. 1 (FIGS. 2, 3) and 4 (FIGS. 5, 6) has already been described with reference to FIGS. Similarly to the magnetic recording / reproducing apparatus described above, a component portion including an upper drum Du, a lower drum Dd, and a lead ring Lr is a drum base (FIG. 1).
1 (see DB in 1). Upper drum D
u is rotatably supported with respect to the central axis by a bearing mounted on the central axis (49 in FIGS. 11 and 12), and the lower drum Dd is supported by the central axis. It is fixed. Reference edge T of magnetic tape T
The lead ring Lr functioning as a guide portion of the lower drum D is formed separately from the lower drum Dd.
It is arranged near the outer peripheral portion 39 below d, and coaxially fits with the lower protruding portion of the lower drum Dd by the knife edge 23 provided on the inner periphery of the lead ring Lr.

The lower drum Dd during the recording operation of the magnetic recording / reproducing apparatus shown in FIGS. 1 (FIGS. 2 and 3) and FIG. 4 (FIGS. 5 and 6) has a drum base (FIG. 11). DB) are supported by four pivot points (indicated by reference numerals 25, 26, 35 and 36 in FIG. 10). The magnetic recording / reproducing apparatus shown in FIG. 4 (FIGS. 5 and 6) has four rotations projecting from the lead ring Lr during the recording operation shown in FIG. 4 (the state shown in FIG. 4). A fulcrum (indicated by reference numerals 27, 28, 37, 38 in FIG. 10)
Is pressed against the bottom surface of the lower drum Dd.
Therefore, the lead ring Lr of the magnetic recording / reproducing apparatus at the time of the recording operation shown in FIG. 4 is configured such that the lower edge db of the sliding contact surface of the lower drum Dd and the position regulating surface G of the lead ring Lr cover the predetermined section. It will be in contact.

The read ring Lr provided in the magnetic recording and reproducing apparatus shown in FIG. 1 (FIGS. 2 and 3) is the same as the read ring in the magnetic recording and reproducing apparatus shown in FIG. 4 (FIGS. 5 and 6). Unlike the Lr, the read ring Lr in the magnetic recording / reproducing apparatus shown in FIG. 4 (FIGS. 5 and 6) described above.
In this embodiment, the four pivot points provided in the first embodiment are not provided. Then, during a recording operation in the magnetic recording / reproducing apparatus shown in FIG. 1 (FIGS. 2 and 3) (state shown in FIG. 1).
As shown in FIG. 1, the lower edge db of the sliding contact surface of the lower drum Dd and the position regulating surface G of the lead ring Lr are in contact with each other over a predetermined section, as shown in FIG. Is done.

In the recording operation of the magnetic recording / reproducing apparatus, the predetermined section is set so that the lower edge db of the sliding contact surface of the lower drum Dd and the position regulating surface G of the lead ring Lr are brought into contact with each other. 1 (FIGS. 2 and 3), the upper and lower drums Du and Dd
The rotation fulcrum areas (surrounded by circles in FIG. 1) set at both ends of the area where the magnetic tape T is wound around the sliding contact surface (for example, the area of 190 degrees at the central angle of the lower drum Dd). (The part indicated by the arrow). FIG. 7 shows FIG.
FIG. 5 is a development view of a portion of a lower drum Dd and a lead ring Lr in a state where the magnetic recording and reproducing apparatus shown in FIG. In FIG. 7, a predetermined section where the lower edge db of the sliding contact surface of the lower drum Dd and the position regulating surface G of the lead ring Lr are brought into contact with each other is a sliding contact between the upper and lower drums Du and Dd. Magnetic tape T against the surface
Is wound, that is, a region where the central angle of the lower drum Dd is 190 degrees (−5 degrees to +185 degrees in FIG. 7).
Are within the range of +5 degrees to +175 degrees. In FIG. 7, a portion in the range of -5 degrees to +5 degrees,
The portion in the range of +175 degrees to +185 degrees is a region that functions as a pivot point of the lead ring Lr.

In the magnetic recording and reproducing apparatus shown in FIG. 4 (FIGS. 5 and 6), the lower edge db of the sliding contact surface of the lower drum Dd and the position regulating surface G of the lead ring Lr are in contact with each other during the recording operation. The section predetermined in advance is set to the pivots 27 (37), 2 provided on the lead ring Lr.
8 (38) (rotation fulcrum 37 indicated by reference numerals 37 and 38,
38 (see FIG. 10) (corresponding to the fulcrum spacing in FIG. 4). In both the magnetic recording / reproducing apparatus shown in FIGS. 1 (FIGS. 2 and 3) and the magnetic recording / reproducing apparatus shown in FIGS. 4 (FIGS. 5 and 6), the lower surface of the lower drum Dd is slid during the recording operation. The portion excluding a section predetermined so that the edge db and the position regulating surface G of the lead ring Lr are in contact with each other has a shape that does not contact the lower edge db of the lower drum Dd during high-speed playback operation. Is done.

Next, when the magnetic recording / reproducing apparatus shown in FIGS. 1 and 4 performs the fast forward reproduction (FF) in the same traveling direction as the traveling direction of the magnetic tape during the recording operation, FIGS. 12, the center axis 21 of the upper drum Du and the lower drum Dd is shifted from the state of FIG. 1 to the inclined state of FIG. 2 and from the state of FIG. The state changes to the tilt state of 5 by the operation of the tilt drive mechanism of the central axis. 9 to 12 when the magnetic recording / reproducing apparatus shown in FIGS. 1 and 4 performs the rewinding (REW) in the running direction opposite to the running direction of the magnetic tape during the recording operation. As in the case of the magnetic recording and reproduction described above with reference to the above, the upper drum Du and the lower drum Dd
The central axis 21 from the state of FIG. 1 to the inclined state of FIG.
The state is changed from the state shown in FIG. 4 to the tilted state shown in FIG. 6 by the operation of the tilt drive mechanism for the central axis.

FIG. 1 (FIGS. 2 and 3) and FIG.
In the magnetic recording / reproducing apparatus shown in FIGS. 5 and 6, the illustration of the above-mentioned center axis tilt drive mechanism is omitted, but FIGS. 1 (FIG. 2 and FIG. 3) and FIG. , FIG. 6), a center axis tilt drive mechanism similar to the center axis tilt drive mechanism described above with reference to FIGS. 9 to 12 may be used. The center axis 21 of the upper drum Du and the lower drum Dd is shifted from the state of FIG.
FIGS. 9 to 12 show the operation in the case where the operation is changed by the operation of the inclination driving mechanism of the central axis from the state shown in FIG. 3 to the state shown in FIG. 3 and from the state shown in FIG. 4 to the state shown in FIG. The description is as follows.

The magnetic recording / reproducing apparatus shown in FIGS.
When fast-forward playback (FF) is performed in the same running direction as the magnetic tape during the recording operation, the screw 29 is driven so as to push up the bottom surface of the lower drum Dd, and the screw 30 is moved downward. Driving in a direction away from the bottom surface of the drum Dd,
Two of the rotation fulcrums (the rotation fulcrums 25 and 35 in FIG. 10) are in contact with the bottom surface of the lower drum Dd, and the two rotation fulcrums are used as a rotation fulcrum. The center shaft 21 of the upper drum Du and the lower drum Dd is rotated from the state of FIG. 1 to the state of FIG. 2 and from the state of FIG. 4 to the state of FIG.

When the magnetic recording / reproducing apparatus shown in FIGS. 1 and 4 performs the fast reverse reproduction (REW) in the running direction opposite to the running direction of the magnetic tape at the time of the recording operation, the screw 30 is turned off. The bottom surface of the lower drum Dd is driven to be pushed up, and the screw 29 is driven in a direction away from the bottom surface of the lower drum Dd, so that two of the four pivot points projecting from the drum base DB. The rotation fulcrums (the rotation fulcrums 26 and 36 in FIG. 10) contact the bottom surface of the lower drum Dd,
The upper drum Du is defined by using the above-mentioned two pivot points as pivot points.
The center axis 21 of the lower drum Dd is moved from the state of FIG.
4 and from the state of FIG. 4 to the state of FIG. The above-described driving operations for the screws 29 and 30 are performed by the operation of a driving mechanism that operates under the control of a tilt control unit (not shown). The drive mechanism includes a motor 40 serving as a power source as shown in an exploded perspective view of FIG. 10, a speed reduction mechanism 41 including a plurality of gears, a rotary encoder 43, a position detector 42, and the like. Have been.

As described above, the running direction of the magnetic tape T,
When the traveling speed is set in the main control unit provided in the VTR in accordance with various operation modes, the tilt control unit to which control information is given from the main control unit includes a drum structure. The center axis 21 of the upper drum Du and the lower drum Dd (see FIG. 9) in DA is shown in FIG. 2 (or FIG. 3), FIG.
As shown in FIG. 5 (or FIG. 5), the drive mechanism is controlled to advance and retreat the screws 29 and 30 so that each of them is inclined by a predetermined amount.

Next, when the magnetic recording / reproducing apparatus shown in FIG. 4 performs the fast-forward reproduction (FF) in the same traveling direction as the traveling direction of the magnetic tape during the recording operation, the magnetic recording / reproducing apparatus is protruded from the read ring Lr. Two of the four rotation fulcrums (the rotation fulcrum 27 and the one provided on a line perpendicular to the paper surface at the position of the rotation fulcrum 27 shown in the drawing). The rotation fulcrum 37) in FIG. 10 is in contact with the bottom surface of the lower drum Dd, and the two rotation fulcrums are used as the rotation fulcrum.
The center axis 21 of the lead ring Lr is screwed into the lead ring Lr so that the center axis 21 is rotated in the direction shown in FIG. 5, and the leading end is provided in a state of contacting the bottom surface of the lower drum Dd. Two screws 31 and 3
2 are rotated in opposite directions.

When the magnetic recording / reproducing apparatus shown in FIG. 4 performs the rewinding (REW) in the running direction opposite to the running direction of the magnetic tape during the recording operation, the magnetic recording / reproducing apparatus projects from the read ring Lr. 2 of the four pivot points
10. The number of rotation fulcrums (the rotation fulcrum 28 and one rotation fulcrum provided on a line perpendicular to the paper surface at the position of the rotation fulcrum 28 shown in the drawing... 38 in FIG. 10) The lead ring Lr is in contact with the bottom surface of the lower drum Dd so that the center axis 21 of the lead ring Lr is rotated in the direction shown in FIG. And three screws 3 which are screwed into the lower end of the lower drum Dd.
1, 32 are rotated in opposite directions.

Next, when the magnetic recording / reproducing apparatus shown in FIG. 1 performs fast-forward reproduction (FF) in the same traveling direction as the traveling direction of the magnetic tape during the recording operation, the magnetic recording / reproducing apparatus shown in FIG. The fulcrum area shown in the range of 185 degrees (FIG.
Of the lead ring Lr
The center shaft 21 is screwed into the lead ring Lr so that the center shaft 21 is rotated in the direction shown in FIG. 2, and the leading end portions are provided in a state of contacting the bottom surface of the lower drum Dd, respectively. The two screws 31, 32 are rotated in opposite directions. In the case where the magnetic recording / reproducing apparatus shown in FIG. 1 performs the rewind reproduction (REW) in the running direction opposite to the running direction of the magnetic tape during the recording operation, FIG.
The fulcrum region shown in the range of -5 degrees to +5 degrees in FIG.
Of the lead ring Lr
The center shaft 21 is screwed into the lead ring Lr so that the center shaft 21 is rotated in the direction shown in FIG. 3, and the leading end portions are provided so as to abut against the bottom surface of the lower drum Dd. The two screws 31, 32 are rotated in opposite directions.

The above-described driving operation for the screws 31 and 32 is also performed by the operation of the above-described driving mechanism operating under the control of the tilt control unit (not shown). In response to the direction and the traveling speed being set in the main control unit provided in the VTR in accordance with various operation modes, the inclination control unit to which the control information is given from the main control unit includes: The drive mechanism is controlled so that the lead ring Lr is tilted by a predetermined amount to the state shown in FIGS. 2, 3, 5, and 6, and the screws 31 and 32 are advanced and retracted. In the above description, in order to facilitate understanding of the operation, the tilting operation of the center axis of the drum assembly by the forward and backward operations of the screws 29 and 30 and the tilting operation of the central axis of the lead ring Lr by the forward and backward operations of the screws 31 and 32 are described. However, as described in FIG. 12, each of the screws 29 to 32 has the same power transmission mechanism as the screw 29 and the screw 31 as shown in FIG. And the screw 30 and the screw 32 are simultaneously driven and rotated by the common power transmission mechanism. Therefore, the tilting operation of the center axis of the drum assembly by the advancing and retreating operation of the screws 29 and 30 is performed. And the tilting operation of the center axis of the lead ring Lr by the forward and backward movements of the screws 31 and 32 are performed simultaneously.

As is apparent from the above description, FIG.
In the magnetic recording / reproducing apparatus shown in FIGS. 2 and 3, a magnetic tape T is wound around a lead ring Lr used as a component of the magnetic recording / reproducing apparatus with respect to the sliding surfaces of the upper and lower drums Du and Dd in the lead ring Lr. The area to be turned (for example, lower drum D
The portion other than the rotation fulcrum regions (the portions indicated by circles in FIG. 1) set at both ends of the central angle d (the region of 190 degrees at the central angle of d) is the recording operation of the magnetic recording / reproducing apparatus. In the state where the time is running, the predetermined interval is set so that the lower edge db of the sliding contact surface of the lower drum Dd and the position regulating surface G of the lead ring Lr are brought into contact with each other. On both sides of a predetermined section, an area functioning as a rotation fulcrum of the read ring Lr is provided, and when the magnetic recording / reproducing apparatus performs a fast-forward reproduction operation or a rewind reproduction operation, the read ring Lr A portion that contacts the lower edge of the sliding surface of the lower drum Dd in the region that functions as a rotation fulcrum is operated as a rotation fulcrum of the lead ring Lr, and the magnetic field shown in FIG. 4 (FIGS. 5 and 6). In the recording and playback device A lead ring Lr used as a constituent member thereof is connected to pivot points 27 (37) and 28 (38) provided on the lead ring Lr (the pivot points 37 and 38 shown by reference numerals 37 and 38 in the drawings). FIG.
(A distance shown as a fulcrum interval in FIG. 4) corresponds to the lower edge db of the sliding contact surface of the lower drum Dd and the position regulating surface G of the lead ring Lr during the recording operation. The gap Ga between the lower edge of the sliding surface of the lower drum Dd and the lead ring Lr is formed as a predetermined section to be brought into contact with the lower drum Dd in the above-described conventional magnetic recording apparatus. Since the gap Ga between the lower edge of the sliding contact surface of Dd and the lead ring Lr can be made smaller, the problem that has occurred in the conventional apparatus does not occur in the magnetic recording and reproducing apparatus of the present invention.

FIG. 15 shows how the reproduction output from the rotary magnetic head changes when the gap Ga (gap in FIG. 15) between the lower edge of the sliding surface of the lower drum Dd and the lead ring Lr is changed. FIG. 4 is a table of experimental results showing whether the recording medium deteriorates, and black circles in the figure show measured values during a 7 × speed rewind reproduction operation using a rotating magnetic head having a head track width of 58 μm. A black square mark in the middle indicates a measured value at the time of a 7x speed fast-forward reproduction operation using a rotating magnetic head having a head track width of 58 micrometers. According to the experimental results shown in FIG. 15, the lower edge of the sliding surface of the lower drum Dd and the lead ring L in both the fast-forward playback operation and the rewind playback operation.
When the gap Ga (gap in FIG. 15) with respect to r is 150 μm or less, the deterioration of the reproduction output is −2 dB or less, and when the gap Ga (gap in FIG. 15) is 150 μm or more, the reproduction output is small. It is shown that the deterioration has increased. Therefore, in the predetermined section where the lower edge db of the sliding contact surface of the lower drum Dd and the position regulating surface G of the lead ring Lr are brought into contact with each other as described above in the magnetic recording / reproducing apparatus of the present invention, Between the lower edge of the sliding surface of the drum Dd and the lead ring Lr, 15
It can be seen that good results can be obtained even when the magnetic recording / reproducing apparatus of the present invention is implemented so as to form the gap Ga of 0 μm or less.

[0048]

As is apparent from the above description, in the magnetic recording / reproducing apparatus of the present invention, the lead ring used as a component of the magnetic recording / reproducing apparatus is provided on the sliding surfaces of the upper and lower drums in the lead ring. On the other hand, a rotation fulcrum region (indicated by being surrounded by a circle in FIG. 1) is set at both ends of a region where the magnetic tape is wound (for example, a region of 190 degrees at the central angle of the lower drum Dd). In the state where the magnetic recording / reproducing device is performing the recording operation,
The lower edge of the sliding surface of the lower drum and the position regulating surface of the lead ring are defined as a predetermined section so as to be brought into contact with each other, and the rotation of the lead ring is provided on both sides of the predetermined section. The magnetic recording / reproducing apparatus is provided with an area functioning as a moving fulcrum, and is slidably contacted with the lower drum Dd in the area functioning as a rotation fulcrum in the lead ring during a fast-forward reproduction operation or a rewind reproduction operation. A portion that contacts the lower edge of the surface may be operated as a rotation fulcrum of the lead ring, or a portion corresponding to the distance from the rotation fulcrum provided on the lead ring may be in sliding contact with the lower drum Dd during the recording operation. The lower edge of the sliding surface of the lower drum and the lead ring are formed as a predetermined section so that the lower edge of the surface and the position regulating surface of the lead ring are brought into contact with each other. Can be made smaller than the gap between the lower edge of the sliding surface of the lower drum and the lead ring in the conventional magnetic recording apparatus described above, so that the problem that has occurred in the conventional apparatus, that is, the upper surface of the lead ring, Vibration occurs because the wide part near the reference edge of the magnetic tape that contacts the regulation surface at the position of the reference edge of the magnetic tape formed on the tape is running without being supported by the sliding surface of the lower drum. If the magnetic tape used during recording / reproducing has a bad influence on the reproducing state or has been formed using a base film having a low mechanical strength, the reference edge of the magnetic tape T during trick play. Does not cause a problem of causing mechanical distortion in the portion of the lower drum, and in the magnetic recording / reproducing apparatus of the present invention, the lower edge of the sliding contact surface of the lower drum and the lead ring Lr In the position regulating surface and is predetermined to be in abutment section,
Between the lower edge of the sliding surface of the lower drum Dd and the lead ring,
By providing a gap of 150 micrometers or less, it is possible to provide a magnetic recording / reproducing apparatus capable of obtaining a good reproduction output.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a magnetic recording / reproducing apparatus of the present invention during a recording operation.

FIG. 2 is a side view of a main part when the magnetic recording / reproducing apparatus of the present invention performs a fast forward reproduction operation in a forward direction.

FIG. 3 is a side view of a main part when the magnetic recording / reproducing apparatus of the present invention is performing a fast-forward reproduction operation (rewind reproduction operation) in a reverse direction.

FIG. 4 is a side view of a main part of the magnetic recording / reproducing apparatus of the present invention during a recording operation.

FIG. 5 is a side view of a main part when the magnetic recording / reproducing apparatus of the present invention performs a fast forward reproduction operation in a forward direction.

FIG. 6 is a side view of a main part when the magnetic recording / reproducing apparatus of the present invention is performing a fast forward reproduction operation (rewind reproduction operation) in a reverse direction.

FIG. 7 shows a lower drum Dd and a lead ring L in a state where the magnetic recording / reproducing apparatus shown in FIG. 1 is performing a recording operation.
It is a development view of the part with r.

FIG. 8 is a perspective view of a traveling system of the magnetic recording / reproducing apparatus.

FIG. 9 is a side sectional view of a tilt drive unit of the magnetic recording / reproducing apparatus.

FIG. 10 is an exploded perspective view of a main part of the magnetic recording / reproducing apparatus.

FIG. 11 is a vertical sectional side view of a main part of the magnetic recording / reproducing apparatus.

FIG. 12 is a vertical sectional side view of a main part of the magnetic recording / reproducing apparatus.

FIG. 13 is a side view of a main part of the magnetic recording / reproducing apparatus.

FIG. 14 is a vertical sectional side view of a part of the magnetic recording / reproducing apparatus.

FIG. 15 is a diagram showing experimental results showing how the reproduction output from the rotary magnetic head deteriorates when the gap between the lower edge of the sliding contact surface of the lower drum Dd and the lead ring is changed. .

[Explanation of symbols]

DB: drum base, Dd: lower drum, Du: upper drum, DA: drum assembly, T: magnetic tape, Te: reference edge of magnetic tape T, RF: sliding surface, Lr: lead ring,
G: guide portion provided on the lead ring Lr (position regulating surface of the reference edge of the magnetic tape formed on the magnetic tape position regulating guide member) 1 ... supply reel stand, 2 ... take-up reel stand, 3 ... cassette case, 4 ... supply reel, 5 ...
Tension pole, 6, 16 Guide pole, 7 Full width erasing head, 8 Impedance roller, 9, 14 Loading pole (vertical guide roller), 10, 13 Slant guide (slant pole), 15 Control head, 17 ... Pinch roller, 18 ... Capstan, 19 ...
Take-up reel, 20: machine stand, 21, 49: central axis, 25
~ 28, 35-38 ... pivot point, 29-32 ... screw,

Claims (4)

[Claims] 1. An upper drum having a sliding surface for a magnetic tape wound around a part of a peripheral surface of an upper and lower drum, a rotating magnetic head, and an extension of a sliding surface of the magnetic tape on the upper drum. A lower drum provided coaxially with the upper drum, and a rotational locus surface of a rotary magnetic head with respect to a recording mark formed on the magnetic tape. The first inclination driving means for inclining the central axes of the upper and lower drums and the rotary magnetic head by a predetermined angle when the states coincide with each other, and the upper and lower drums are configured separately. The magnetic tape is provided so as to be close to the outer peripheral surface of the small-diameter portion formed at the lower portion of the lower drum, and has a position regulating surface of a reference edge of the magnetic tape at an upper end portion. A guide member and the magnetic tape A second tilt drive means for tilting the guide member for regulating the running position of the magnetic tape so that the position regulating surface of the tape coincides with the reference edge position of the magnetic tape. When the magnetic recording / reproducing apparatus operates in the same running state of the magnetic tape as the running state of the magnetic tape at the time, the two positions set to be used during the tilting operation of the guide member for controlling the running position of the magnetic tape described above. The position corresponding to the lower edge of the sliding surface of the magnetic tape on the lower drum and the reference edge of the magnetic tape in the guide member for regulating the running position of the magnetic tape in a portion corresponding to the portion between the rotation fulcrums of the magnetic tape. The lower edge of the magnetic tape sliding contact surface of the lower drum and the magnetic tape Magnetic recording and reproducing apparatus, characterized in that for constituting the position restricting surface of the reference edge of the magnetic tape in the row position restricting guide member. 2. An upper drum having a sliding surface for a magnetic tape wound around a part of a peripheral surface of an upper and lower drum, a rotary magnetic head, and extension of a sliding surface of the magnetic tape on the upper drum. A lower drum provided coaxially with the upper drum, and a rotational locus surface of a rotary magnetic head with respect to a recording mark formed on the magnetic tape. The first inclination driving means for inclining the central axes of the upper and lower drums and the rotary magnetic head by a predetermined angle when the states coincide with each other, and the upper and lower drums are configured separately. The magnetic tape is provided so as to be close to the outer peripheral surface of the small-diameter portion formed at the lower portion of the lower drum, and has a position regulating surface of a reference edge of the magnetic tape at an upper end portion. A guide member and the magnetic tape A second tilt drive means for tilting the guide member for regulating the running position of the magnetic tape so that the position regulating surface of the tape coincides with the reference edge position of the magnetic tape. When the magnetic recording / reproducing apparatus operates in the same running state of the magnetic tape as the running state of the magnetic tape at the time, the two positions set to be used during the tilting operation of the guide member for controlling the running position of the magnetic tape described above. The position corresponding to the lower edge of the sliding surface of the magnetic tape on the lower drum and the reference edge of the magnetic tape in the guide member for regulating the running position of the magnetic tape in a portion corresponding to the portion between the rotation fulcrums of the magnetic tape. 15 between faces
A gap of 0 micrometers or less is formed,
A magnetic recording / reproducing apparatus characterized in that a large gap is formed in a portion other than the above. 3. An end of a portion of the lower drum where the lower edge of the sliding surface of the magnetic tape in contact with the sliding surface of the magnetic tape is in contact with the position regulating surface of the reference edge of the magnetic tape in the guide member for regulating the running position of the magnetic tape. 3. The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic recording / reproducing apparatus is used as a rotation fulcrum to be used at the time of a tilting operation of the tape running position regulating guide member. 4. The magnetic recording apparatus according to claim 1, wherein the guide member for regulating the running position of the magnetic tape is provided with a rotation fulcrum used when the guide member for regulating the running position of the magnetic tape is tilted. Playback device.