JP2005044394A - Rotary head drum unit and recording and reproducing apparatus using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary head drum which can secure a stable head output by suppressing tape lifting from a drum surface caused by the high-speed rotation of the drum, and improving contact performance between a tape and a head in all extent of tape volume attachment to the drum, and to provide a recording and reproducing apparatus using it. <P>SOLUTION: In a rotary head drum which consists of a fixed upper drum, a rotating center drum, and a fixed lower drum, a taper processing by which an outer diameter becomes smaller in coming nearer to the rotating center drum is set on an external perimeter of the fixed upper drum, and when a relief amount of the taper processing at a tape winding and entering position is set as α, and a relief amount of the taper processing at a retreat position of the tape is set as β, the relation of α>β is satisfied. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary head drum device that rotates a head to record or reproduce a signal on a tape-shaped recording medium, and a recording / reproducing device using the same.
[0002]
[Prior art]
In a conventional recording / reproducing apparatus such as a VTR, a video camera, a tape streamer, etc., a magnetic tape is obliquely wound around the outer peripheral surface of a rotating drum, and the magnetic tape is obliquely scanned by a plurality of magnetic heads provided on the rotating drum. In general, a helical scan method for recording or reproducing the image is employed. Under such circumstances, with the trend of longer time, higher image quality, and digitization, it is required to increase the amount of recorded information (higher density) and to increase the data transfer speed, increase the drum rotation speed, and head tape It is in the direction to increase the relative speed. When the rotational speed of the drum increases, the air on the surface of the rotating drum is caught between the magnetic tape and the contact state between the tape and the head (hereinafter referred to as tape / head contact) is deteriorated, which affects the recording / reproducing performance. Further, the force that the tape receives in the head scanning direction (upward in the tape width in a general VTR) increases, and there is a concern about the influence on the tape running performance.
[0003]
For example, Japanese Patent Application Laid-Open No. 2004-133867 discloses a technique for rotating the middle drum rotating method in which only the width of a part including the head of the upper rotating drum is rotated in order to minimize the surface area of the drum rotating portion. A drum structure is described in which the entire rotating drum is fixed and only the head is rotated. Further, Patent Document 2 takes advantage of the characteristics of the upper fixed drum structure, and processes and deforms a part of the upper fixed drum to give a tape tension distribution in the width direction, thereby improving the tape / head contact performance. A technique for maintaining and stabilizing the recording / reproducing waveform is described.
[0004]
[Patent Document 1]
JP-A-7-182740 (paragraph numbers 0017, 0019, FIG. 1, FIG. 3)
[Patent Document 2]
JP-A-9-320153 (paragraph numbers 0018 to 0025, FIGS. 1 and 2)
[0005]
[Problems to be solved by the invention]
In the conventional technique using the rotating drum, the air film thickness between the drum and the tape increases on the tape entrance side of the drum, and the contact surface pressure at the tape / head contact decreases. As a result, output deterioration and fluctuation are caused in the drum entrance side portion and drum exit side portion of the reproduction output waveform, and the head output is deteriorated. In addition, the structure using the upper fixed drum increases the effect of suppressing tape floating, but it is still insufficient in terms of ensuring the tape / head contact performance in order to cope with a wide variety of tapes including ultra-thin tapes. is there. In other words, even if the tape entry side of the drum is set to an appropriate head / tape contact condition, the head / tape contact condition is deviated from the appropriate condition on the drum exit side, resulting in a large tape deformation at the head. The contact surface pressure may not be obtained at the gap portion of the head.
[0006]
An object of the present invention is to make it possible to ensure a stable head output even when an ultra-thin tape or the like is used as a recording medium in a recording / reproducing apparatus in view of the above-described state of the prior art.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the present invention, basically, the rotary head drum device has an upper drum and a lower drum, each of which has a fixed structure, and an intermediate drum of the rotary structure is provided between the upper drum and the lower drum. The head is mounted on the middle drum so that it can rotate, and the outer peripheral surface of the fixed upper drum is provided with a taper on the side close to the middle drum. Change.
[0008]
Specifically, (1) a taper portion is provided on the outer peripheral surface of the fixed upper drum so that the outer diameter dimension U of the fixed upper drum gradually decreases as the rotating drum approaches the drum. The taper portion escape amount α at the entrance position of the medium and the taper portion escape amount β at the medium exit position are in a relationship satisfying α> β within an angle range in which the recording medium is wound. To do. (2) In the above (1), the taper portion is configured such that the escape amount from the entry position to the withdrawal position of the medium continuously changes at least within an angle range around which the tape-shaped recording medium is wound. . (3) In the above (2), the amount of relief of the tapered portion is in the range of about 5 to 10 μm at the end portion position of the fixed upper drum at the entry position of the tape-like recording medium.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a mechanism portion of a recording / reproducing apparatus equipped with a rotating head drum device of the present invention. The tape cassette is indicated by a virtual line for convenience of explanation. FIG. 1 shows a state when tape loading is completed, and it is assumed that a tape as a recording medium is spirally wound around a rotary head drum device within a predetermined angle range. The present embodiment shows an example of an M loading type tape running system generally adopted for a VHS type VTR. The recording / reproducing apparatus includes a signal processing circuit as signal processing means for performing signal processing of a reproduction signal from the head of the rotary head drum device or a recording signal to the head in addition to the mechanism unit.
[0010]
In FIG. 1, 1 is a tape such as a magnetic tape as a tape-shaped recording medium, 2 is a rotary head drum device, 3 is a tape cassette, 4 is a supply reel in the tape cassette 3, 5 and 9 are inclined pins in the tape running system, 6, 7 and 10 are also guide rollers, 8 is also a tension control guide, 11 is a capstan, 12 is a tape guide, 13 is a pinch roller, 14 is a take-up reel in the tape cassette 3, and 15 is a mechanical chassis. The rotary head drum device 2 includes a fixed upper drum, a fixed lower drum, a middle rotary drum on which the head is mounted, and a drum driving motor (not shown) that rotationally drives the middle rotary drum. The capstan 11 is driven by a capstan motor (not shown). The supply reel 4 and the take-up reel 14 are also driven by a reel driving motor (not shown).
[0011]
In this configuration, the tape 1 fed out from the supply reel 4 of the tape cassette 3 is taken up by the take-up reel 14 in the tape cassette 3 through the tape running path by the tape running system and the rotary head drum device 2. On the tape entry side of the rotary head drum device 2, a tape running path is formed by a tape running system as a recording medium running means such as the inclined pin 5, the guide rollers 6 and 7, and the tension control guide 8. On the tape withdrawal side of the rotary head drum device 2, a tape traveling path is formed by a tape traveling system as recording medium traveling means such as the inclined pin 9, the guide roller 10, the capstan 11, and the tape guide 12. At the time of recording or reproduction, the tape 1 is sandwiched between the capstan 11 and the pinch roller 13 and the capstan 11 rotates at a constant speed, so that the tape 1 fed out from the supply reel 4 moves along a predetermined traveling path at a constant speed. And is taken up on the take-up reel 14.
[0012]
In the case of this embodiment, the rotary head drum device 2 rotates in the direction of arrow A, and the tape 1 runs in the direction of arrow B in the normal recording / reproducing mode, and runs in the direction of arrow C in the reverse running mode (rewinding etc.). . Further, since the M loading type tape running system is used, one inclined pin 5 and 9 is provided on each of the tape entry side and the tape withdrawal side, and the tape running height is regulated within a certain range in the vicinity thereof. Guide rollers 6 and 10 are provided. In this embodiment, the tape drive method using a capstan is described as a premise. However, the tape drive method is not limited to this, and there is a problem even if other methods such as a tape reel direct drive are adopted. There is no.
[0013]
2 is a developed side view of the tape running system of the recording / reproducing apparatus of FIG. 1 when viewed from the direction of arrow G in FIG. 1a is the upper end of the tape 1, 1b is the lower end, 5 and 9 are inclined pins, 6 and 10 are guide rollers, 6a and 6b are upper flanges of the guide rollers 6, and lower flanges 10a and 10b are upper portions of the guide rollers 10, respectively. A flange, a lower flange, 16 is a fixed upper drum, 17 is a rotating drum, 18 is a recording / reproducing head mounted on the rotating drum 17, 19 is a fixed lower drum, and 20 is for guiding the running of the tape 1. A lead portion provided on the outer peripheral surface of the fixed lower drum 19, U is an outer diameter dimension of the fixed upper drum 16, and M is an outer diameter dimension of the rotating drum 17. Usually, a plurality of heads 18 are mounted on the rotating drum 17. Here, in order to stabilize the tape running, the outer diameter dimension M of the rotating drum 17 and the outer diameter dimension U of the fixed upper drum 16 are configured such that M <U.
[0014]
Reference numeral 16a denotes a tapered portion formed on the outer peripheral surface of the fixed upper drum 16, and has a shape such that the outer diameter U of the fixed upper drum 16 becomes smaller as it approaches the drum 17 side during rotation. Further, in the present invention, the taper portion is formed so that the escape amount from the surface of the fixed upper drum 16 is different between the entry side and the withdrawal side in the winding range of the tape 1 around the rotary head drum device 2. Specifically, the relationship between the escape amount α on the entry side of the tape 1 and the escape amount β on the exit side is α> β, and the escape amount is continuously from the entry side to the exit side. It is going to change. The taper portion 16a in the present embodiment is formed at substantially the same angle so that the taper angle does not change abruptly. As a result, the taper portion height Hα on the entry side of the tape 1 and the withdrawal side are formed. The relationship of the taper portion height Hβ at Hα> Hβ.
[0015]
However, the taper angle is not limited to the present embodiment. For example, as shown in FIG. 3, the height of the taper portion 16 a is a substantially constant value H within the winding range of the tape 1, and only the escape amount enters the tape 1. A shape that changes from α to β on the side and the exit side is also possible. In this case, in the winding range of the tape 1 around the rotary head drum device 2, the taper angle θ decreases continuously as θi → θo. What is necessary is just to select the optimal shape corresponding to a system.
[0016]
The taper portion 16 of the present embodiment has a shape with a relatively gentle taper angle while leaving the straight portion γ on the outer peripheral surface of the fixed upper drum 16. Note that the boundary portion between the straight portion γ and the tapered portion 16a is formed with a smooth curvature so as not to have a sharp angular shape. Although various methods can be used for the taper-shaped machining direction, general cutting is advantageous in terms of reducing the machining cost.
[0017]
Here, for example, a metal or vapor deposition type tape having a width of 8 mm and a thickness of 4 to 8 μm is used, the protruding amount from the outer peripheral surface of the rotating drum 17 is about 20 μm, and the outer diameter U of the fixed upper drum 16 is the rotating drum 17. The taper portion 16a of the fixed upper drum 16 has a clearance α of about 5 to 10 μm at the end position of the fixed upper drum at the entry position of the tape 1 winding range. It is desirable to set the range. In that case, the escape amount β on the exit side is set to about 2 to 5 μm, and a reduced setting than that on the entrance side can provide a good result.
[0018]
In such a configuration, when the drum 17 is rotating during rotation and the tape 1 is traveling by the tape traveling system, a transition force (arrow I) for regulating the tape is generated in the rotating head drum device 2, and as a result, the lead 20, the lower end 1 b of the tape 1 is stably regulated in height. As a result, the tape lift on the tape withdrawal side in the rotary head drum device 2 can be suppressed, and the tape running can be stabilized. Therefore, in the guide rollers 6 and 10, it is possible to set the contact force between the upper end 1a of the tape 1 and the upper flanges 6a and 10a for restricting the tape width as small as possible. Moreover, the lower end 1b of the tape 1 is made not to contact the lower flanges 6b and 10b for restricting the tape width. Thereby, out-of-plane deformation such as curling does not occur in the tape 1, and in particular, occurrence of tape damage at the upper end of the tape in a mode such as repeated running can be suppressed.
[0019]
FIG. 4 and FIG. 5 are explanatory diagrams for improving the head and tape contact performance. 4 is an enlarged view of the head and tape contact portion (a portion) on the tape entry side in FIG. 2, and FIG. 5 is an enlarged view of the head and tape contact portion (b portion) on the tape withdrawal side in FIG.
[0020]
In FIG. 4, on the tape entry side, the head 18 mounted on the rotating drum 17 is set to a predetermined protruding amount P from the outer surface of the rotating drum 17. Further, a tapered portion 16a is formed on the outer peripheral surface of the fixed upper drum 16, and the amount of protrusion from the end of the tapered portion 16a of the fixed upper drum 16 is Pi. On the other hand, on the tape withdrawal side, as shown in FIG. 5, the protruding amount from the end of the taper portion 16a of the fixed upper drum 16 is Po. As described above, the amount of relief of the tapered portion 16a in the present application is α on the tape entry side and β on the tape withdrawal side, and there is a relationship of α> β. Therefore, the relationship between the head protrusion amount Pi and Po from the end of the tapered portion 16a is Pi> Po.
[0021]
Thereby, on the tape entry side, since the tape tension is relatively small and the tape floating amount from the drum surface is relatively large, the tape 1 is moved from the head 18 by increasing the protruding amount Pi as in this embodiment. It is easy to envelop the tape, and it is possible to secure an appropriate surface pressure of the head and tape. On the other hand, on the tape withdrawal side, the tape tension from the drum surface is relatively small due to the relatively large tape tension, and conversely, the head gap portion (head width central portion) due to excessive wrapping of the tape 1 with respect to the head 18. It is easy for the tape to float. Therefore, by reducing the protruding amount Po as in the present embodiment, such tape floating can be suppressed, and as a result, an appropriate surface pressure of the head and the tape can be ensured as well as on the tape entry side. . Due to the above effects, it is possible to ensure a good reproduction waveform in the entire winding range of the tape.
[0022]
FIG. 6 shows an example of the head output waveform obtained by this embodiment. In the conventional structure, as shown by a waveform 21 ′ (indicated by a solid line), output deterioration ΔV is seen at the left end (tape entry position) and right end (tape withdrawal position). In the structure of the present embodiment, the deterioration can be recovered and close to a good waveform such as the waveform 21 (indicated by a broken line).
[0023]
In the present embodiment, the outer surface of the fixed upper drum 16 protrudes from the outer surface of the drum 17 during rotation. However, the outer surface of the fixed upper drum 16 does not necessarily protrude, and the outer surfaces of both are substantially the same. The same performance can be secured even in the same plane, and is not limited to the scope of the present embodiment.
[0024]
Further, the specific configuration of the tape guide in the tape running system is not limited to this embodiment, and the same effect can be obtained by applying the gist of the present invention to other similar tape running systems. Needless to say.
[0025]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a rotary head drum device capable of ensuring a stable head output and a recording / reproducing apparatus using the rotary head drum device.
[Brief description of the drawings]
FIG. 1 is a plan view showing a tape running mechanism portion on which a rotary head drum of the present invention is mounted.
FIG. 2 is a drum side view showing a drum taper shape according to an embodiment of the present invention.
FIG. 3 is a drum side view showing a drum taper shape of another embodiment of the present invention.
4 is an enlarged view of the head portion on the tape entry side (a portion) in FIG. 2. FIG.
5 is an enlarged view of the head portion on the tape withdrawal side (b portion) in FIG. 2. FIG.
FIG. 6 is a head output waveform diagram according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Tape 2 ... Rotary head drum 3 ... Cassette 4 ... Supply reel 5, 9 ... Inclined pin 6, 7, 10 ... Guide roller 6a, 10a ... Upper flange 6b 10b ... Lower flange 8 ... Tension control guide 11 ... Capstan 12 ... Tape guide 13 ... Pinch roller 14 ... Take-up reel 15 ... Mechanical chassis 16 ... Fixed Upper drum 16a ... taper 17 ... rotating drum 18 ... head 19 ... fixed lower drum 20 ... lead 21 ... reproduction output waveform (good state)
21 ′ ・ ・ ・ Reproduction output waveform (degraded state)

Claims (6)

A rotary head drum device for rotating a head to record or reproduce a signal on a tape-like recording medium,
A fixed lower drum in which a lead for guiding the tape-shaped recording medium is formed on the outer periphery;
A fixed upper drum arranged coaxially facing the fixed lower drum and guiding the tape-shaped recording medium;
A rotating drum which is mounted between the fixed lower drum and the fixed upper drum and is rotatable around a central axis, the head being mounted thereon;
A taper portion is provided on the outer peripheral surface of the fixed upper drum so that the outer diameter dimension U of the fixed upper drum gradually decreases as the drum approaches the rotating drum, and an angular range around which the tape-shaped recording medium is wound. In which the relief amount α of the taper portion at the entrance position of the medium and the relief amount β of the taper portion at the exit position of the medium are configured so as to satisfy α> β. Rotating head drum device. 2. The rotary head according to claim 1, wherein the taper portion has a clearance amount that continuously changes from an entry position to a withdrawal position of the medium at least within an angle range around which the tape-shaped recording medium is wound. Drum equipment. 3. The taper portion according to claim 1 or 2, wherein the taper portion has an escape amount in a range of about 5 to 10 [mu] m at an end portion position of the fixed upper drum at an entry position of the tape-shaped recording medium. Rotating head drum device. A recording / reproducing apparatus for recording and reproducing signals on a tape-like recording medium using a rotary head drum device,
A fixed lower drum in which a lead for guiding the tape-shaped recording medium is formed on the outer periphery;
A fixed upper drum arranged coaxially facing the fixed lower drum and guiding the tape-shaped recording medium;
A rotating drum on which a head is mounted and which is arranged between the fixed lower drum and the fixed upper drum and is rotatable around a central axis;
A taper portion is provided on the outer peripheral surface of the fixed upper drum so that the outer diameter dimension U of the fixed upper drum gradually decreases as the drum approaches the rotating drum, and an angular range around which the tape-shaped recording medium is wound. A rotary head drum device configured such that the amount of relief α of the tapered portion at the medium entry position and the amount of relief β of the taper portion at the medium withdrawal position satisfy α> β.
Medium running comprising a guide member arranged before and after the rotary head drum device to guide the tape-like recording medium, and running the tape-like recording medium along a predetermined path through the outer periphery of the rotary head drum device Means,
A recording / reproducing apparatus comprising: signal processing means for performing signal processing of a reproduction signal from the head or a recording signal to the head. The taper portion of the rotary head drum device has an escape amount that continuously changes from an entry position to a withdrawal position of the medium at least within an angle range around which the tape-shaped recording medium is wound. 5. The recording / reproducing apparatus according to 4. 5. The taper portion of the rotary head drum device has an escape amount in a range of about 5 to 10 [mu] m at an end portion position of the fixed upper drum at an entry position of the tape-shaped recording medium. The recording / reproducing apparatus according to claim 5.

Images