JP3116646B2 - Rotating head cylinder of recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus in which a tape is spirally wound around a rotary cylinder on which a head is mounted, and more particularly to a rotary head cylinder suitable for improving head touch performance. .

[0002]

2. Description of the Related Art A conventional technology of a rotary head cylinder of a recording / reproducing apparatus will be described by taking a helical scan type magnetic recording / reproducing apparatus represented by VTR, DAT and the like as an example.

As shown in FIG. 5, in these magnetic recording / reproducing apparatuses, a signal is recorded on the tape 1 by spirally winding the tape 1 around a cylinder 5 on which a head 8 is mounted. Reproduce. The head 8 slightly protrudes from the outer peripheral surface of the rotating cylinder 5 rotating at high speed,
Recording and reproduction of signals are performed by sliding with the running tape 1. In order to realize good recording and reproduction, it is important to ensure good contact between the tape and the head. Various proposals have been made for realizing the good contact. For example,
In Japanese Patent Application Laid-Open No. 62-132257, a minute protrusion is provided at the upper end of the tape release portion of the fixed cylinder,
A rotary head cylinder has been proposed that reduces the impact (impact jitter) generated when the video head separates from the tape due to the head surface pressure reducing effect of the minute projections, and ensures good head touch performance. I have.

FIGS. 9 and 10 show the prior art disclosed in the above-mentioned prior application. FIG. 9 is a front view of a fixed cylinder of a rotary magnetic head cylinder, and FIG. 10 is a sectional view taken along the line DD of FIG. It is a principal part cut-away perspective view of the fixed cylinder.

In FIGS. 9 and 10, reference numeral 51 denotes a fixed cylinder of a rotary magnetic head cylinder, and 52 denotes a fixed cylinder 51.
, A tape running surface formed on the outer peripheral surface of the fixed cylinder 51, and a tape running surface 5 of the fixed cylinder 51.
5, a bulge 54 is formed on the tape release side, and the bulge 54 is formed between the lead 52 and the tape running surface 5.
5 and the fixed cylinder 5
It is formed by leaving a part of the upper end portion of the outer periphery of 1 slightly. Reference numeral 1 denotes a magnetic tape wound around the rotary magnetic head cylinder device over a predetermined angle and traveling in the direction of arrow F.

[0006] Such a bulge 54 is fixed to the fixed cylinder 51.
Is formed on the side where the tape is released from the tape 1 so that the video head 8 of the rotary cylinder is released from the tape 1
The impact applied to the tape 1 when the video head 8 separates can be mitigated by the head surface pressure reducing action due to the bulge 54 contacting the tape 1, thereby suppressing the tape vibration on the tape separating side and recording / reproducing characteristics. There is an effect that can be improved.

[0007]

The bulge 54 according to the prior art disclosed in the above-mentioned prior application has a great effect in suppressing the vibration of the tape on the tape releasing side. However, further improvement in the reliability of the contact between the head and the tape immediately before the magnetic head separates from the tape has not been considered, and there is room for improvement in further improving the head touch. .

[0008] Further, with the advancement of the performance of the recording / reproducing apparatus, a vapor-deposited tape (hereinafter, referred to as an ME tape) has begun to spread, in contrast to a coating tape (hereinafter, referred to as an MP tape) which has been more widely used than before. These two types of tapes have significantly different rigidities. The ME tape has a higher rigidity than the MP tape, and the magnetic layer has a hard composition. Therefore, the state of contact between the head and the tape during tape running is significantly different. FIGS. 5 and 6 are side views showing the head abutting state of tapes having different rigidities. In the low-rigidity MP tape 58, since the tape is deformed so as to enclose the head, good head touch is obtained. Although the performance is easy to obtain, in the ME tape 59 having high rigidity, since the tape is hardly deformed so as to enclose the head, only a part of the tape is brought into contact with the head, so that it is likely to be in a state of one end. This tendency is particularly noticeable in the vicinity immediately before the tape detachment portion where the tape floating amount is small. That is, in the case of a highly rigid ME tape, it is more difficult to secure the head touch performance on the delivery side.

An object of the present invention is to solve such a problem,
It is an object of the present invention to provide a rotary head cylinder capable of uniformly achieving good head touch with any of the MP / ME tapes having different tape rigidities.

[0010]

In order to solve the above-mentioned problems, in the present invention, a concave portion is formed on a tape running surface across a winding portion and a non-winding portion with a tape winding end interposed therebetween. In addition, a configuration is adopted in which a fixed cylinder in which the step area S of the concave portion in the tape detachment portion is set in the range of 0.005 mm ² to 0.05 mm ² is provided.

[0011]

By forming a minute concave portion lower than the tape running surface across the winding portion and the non-winding portion with the tape winding end interposed therebetween, an air bypass effect of the concave portion is generated. The output side has a negative pressure according to the theory of the foil bearing, but in the output side where the tape floating amount is small, the air pressure near the concave portion communicating with the outside of the tape winding range is increasing. The resulting tape lifting force lifts the tape on the side where the head piece comes into contact by reducing the negative pressure, and has the effect of improving the head piece contact. At this time, in the case of a low-rigidity tape in which the head piece does not contact, there is a difference in the floating state of the tape, but it does not significantly affect the shape of the head wrapping, so that the head touch performance does not significantly deteriorate. The concave cross-sectional area S and the flying height of the tape are correlated, and by setting the concave cross-sectional area S to the optimum range with respect to the relative speed V of the head and the tape, the head touch performance of MP / MEs having different rigidities can be compatible. realizable.

[0012]

An embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view showing the force applied to the tape by the concave portion of the fixed cylinder, FIG. 2 is a perspective view showing a state in which the tape is wound around a rotary head cylinder, FIG. 3 is a front view of the fixed cylinder, and FIG. 3 is a perspective view of a fixed cylinder cut along a line CC of FIG. 3, FIG. 5 is a schematic plan view of a recording / reproducing apparatus equipped with a rotary head cylinder device of the present invention, and FIG. 6 shows a running state of an MP tape. FIG. 7 is a cross-sectional view of a main part, showing a running state of the ME tape, FIG. 8 is a view showing a relationship between a cross-sectional area S of the concave portion in the tape detachment part and a waveform ratio, and FIG.
FIG. 10 is a front view of a conventional fixed cylinder, and FIG.
It is a principal part cut-away perspective view of the fixed cylinder cut | disconnected along the D line.

Hereinafter, an outline of the entire apparatus will be described with reference to FIG. The tape 1 is composed of a supply reel 3 in the cassette 2, a first input pin 12, a tension pin 10 erected on a tension arm 11, and an impeller erected on a chassis 16.
After passing through a dance roller 9, a guide roller 7 set on a guide base 30, and an inclined pin 6 set on the guide base 30, it is wound around a cylinder 5 having a rotating head at a predetermined angle.
Next, the tape 1 that has exited the cylinder 5 is
5, an inclined pin 13, a guide roller 14, a pinch roller 17, and a drawer arm 20, which are also erected.
The paper is held between the capstan 15 and the pinch roller 17 through the pull-out guide 19 set up in the cassette 2, and is driven at a constant speed while being taken up by the take-up reel 4 in the cassette 2. During this time, signals are recorded / reproduced on / from the tape 1 by the head 8 in the cylinder 5. The guide plate 25 is provided with grooves 26 and 27 for guiding the guide bases 30 and 35, and is screwed to the chassis 16.

Next, the loading operation will be described. When the loading motor 21 is turned on to load the tape 1 in the unloaded state in which the guide bases 30 and 35 are stored in the cassette opening, the rotation of the motor 21 is performed. Is transmitted to the gear portion of the loading ring (not shown) through the torsion gears 60 and 61 by means such as a known gear train, and the guide bases 30 and 35 engaged with the loading ring are connected to the loading ring. The guide plate 25 starts to move along the grooves 26 and 27 of the guide plate 25.

Further, as the rotation of the loading ring progresses, the guide bases 30 and 35 move to the cylinder base 4.
No. 0 guide guide grooves 43 and 44,
A part of the boss holding the guide rollers 7 and 14 of the rollers 30 and 35 abuts on the V-grooves of the catching parts 41 and 42,
The movement of the guide bases 30, 35 stops. In this state, one of the two-layered torsion gears 60 and 61 for driving the loading ring further rotates by a predetermined angle, and the spring (not shown) built in the torsion gears 60 and 61 is twisted. The urging force of this spring is transmitted to the loading ring and becomes a pressing force in the direction of arrow B in FIG.
The switches 30, 35 are positioned at predetermined positions. Thus, the loading completed state shown in FIG. 4 can be maintained. During unloading, the above-described loading motor 21 rotates in a direction opposite to the direction at the time of loading.
Dingling also rotates in the opposite direction. As a result, the pressure-bonded state of the guide bases 30, 35 to the catching portions 41, 42 is released, and the guide bases 30, 35 are again entrained by the loading ring and moved, and are stored in the cassette openings. It returns to the unload state.

FIG. 2 is a perspective view showing a state in which the tape is wound around the rotary head cylinder device. FIG. 3 shows a state in which a tape is wound around the rotary head cylinder device of the present embodiment and travels. In the figure, 52 is a lead formed on the outer peripheral surface of the fixed cylinder for guiding the lower end of the tape 1,
Numeral 55 is a tape running surface formed on the outer peripheral surface of the fixed cylinder 51. The tape running surface 55 is formed to have substantially the same outer shape as the outer peripheral surface (tape running surface) 57 of the rotary cylinder 56. Then, the tape 1 wound around the outer periphery of the rotary head cylinder over a predetermined angle (for example, approximately 226 °) by the inclined pins for guiding the tape, the guide rollers 13, 14, 6, and 7 is arrowed by the capstan motor. F is driven to travel in the direction F, and travels from the tape entry side P of the rotary head cylinder to the tape release side (tape exit side) Q while being guided by the lead 52.
, And recording and reproduction are performed. In this embodiment, at the upper end of the tape running surface 55 of the fixed cylinder 51 and on the tape releasing side Q, a convex portion 54 (bulge) slightly projecting from the tape running surface and a concave portion slightly recessed from the tape running surface are provided. 53 (grooves) are provided. The tape upstream side of the concave portion 53 is inside the tape winding portion, and the tape downstream side of the concave portion is formed outside the tape winding portion, and this concave portion passes through the lower side of the convex portion from the tape upstream side to the downstream side. Are formed continuously. Here, the surface pressure of the head is reduced by lifting the tape at the convex portion provided on the tape releasing side, and the impact when the head is released from the tape is reduced.

FIG. 1 shows the force applied to the tape by the recess of the fixed cylinder. Since the concave portion is continuous outside the tape winding range, it is possible to increase the air pressure near the concave portion immediately before the tape is released by the bypass effect. As shown in FIG. 1, in the vicinity of the concave portion communicating with the outside of the tape winding, the tape 1 is lifted by the tape lifting force 62 due to this pressure difference, and the tape 1 floats. It is possible. The flying height of the tape is proportional to the cross-sectional area S, 63 of the concave portion of the tape separating portion. M
In the case of the P tape, if this tape lifting force acts within a predetermined value, the tape wrapping effect in the head portion is maintained and the head touch is not deteriorated. However, in a tape running state in which the tape below the head is lifted to such an extent that the tape wrapping effect in the head cannot be maintained, head touch deterioration occurs in the MP tape as well. On the other hand, in the case of the ME tape, the tape on the head contact side is lifted by the tape lifting force, and the tape is deformed in a direction in which the head contact is improved. This causes head touch deterioration. That is, the sectional area S of the recess of the fixed cylinder is MP /
It must be set within the compatible range of the head touch performance of the ME tape.

FIG. 8 is a cross-sectional area S of the concave portion at the tape releasing portion.
And the relationship between the waveform rate and the waveform rate. In the figure, the waveform ratio of the MP / ME tape with respect to the cross-sectional area S of the concave portion shows performance curves having different maximum values. Head touch stable region, i.e. the tolerance of the waveform factor when within -3 dB, concave cross-sectional area S of the tape leaving portions of the fixed cylinder portion is a range of 0.005~0.05mm ^2.
In other words, by setting the concave cross-sectional area S within the above range, it is possible to achieve both head touch performances of tapes having different rigidities. Although the present embodiment discloses an 8 mm video system having a relative speed of about 3 m / s, the relative speed between the head and the tape is 3 to 6 m / s.
Within this range, a similar effect can be obtained.

In this embodiment, the fixed cylinder portion is provided with a convex portion (bulge). Regardless of the presence or absence of the convex portion, the same effect is obtained with respect to the compatibility of the head touch performance of the ME / MP tape. Needless to say, it can be demonstrated.

[0021]

As described above, according to the present invention, for the MP / ME tape having a large difference in rigidity, the concave cross-sectional area S is set to an optimum range with respect to the relative speed V between the head and the tape. By eliminating the head and tape hitting,
Compatibility of MP / ME head touch performance can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a force applied to a tape by a recess of a fixed cylinder according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which a tape is wound around a rotary head cylinder in one embodiment of the present invention.

FIG. 3 is a front view of a fixed cylinder in one embodiment of the present invention.

FIG. 4 is a perspective view of an essential part of the fixed cylinder cut along the line CC of FIG. 3 in one embodiment of the present invention;

FIG. 5 is a schematic plan view of a recording / reproducing apparatus equipped with a rotary head cylinder of the present invention in one embodiment of the present invention.

FIG. 6 is a sectional view of a main part showing a running state of an MP tape in one embodiment of the present invention.

FIG. 7 is a sectional view of a main part showing a running state of the ME tape in one embodiment of the present invention.

FIG. 8 is a diagram showing a relationship between a cross-sectional area S of a concave portion and a waveform ratio in a tape detachment portion in one embodiment of the present invention.

FIG. 9 is a front view of a fixed cylinder in a conventional example.

FIG. 10 is a perspective view of a main part of a fixed cylinder cut along a line DD of FIG. 9 in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tape, 8 ... Head, 51 ... Fixed cylinder, 53 ... Concave part, 54 ... Convex part, 58 ... MP tape, 59 ... ME tape, 63 ... Concave section area S

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyasu Sawano 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi Media Media Research Laboratory (72) Inventor Masanori Kawachi 1410 Inada, Katsuta-shi, Ibaraki Hitachi, Ltd. (72) Inventor Kuniaki Hirayama 1410 Inada, Katsuta-shi, Ibaraki Prefecture Hitachi, Ltd.AV Equipment Division (72) Inventor Eijiro Tazawa 1410, Inada, Katsuta-shi, Ibaraki Hitachi, Ltd.AV Equipment Division ( 56) References JP-A-64-30051 (JP, A) JP-A-4-298846 (JP, A) JP-A-1-229449 (JP, A) JP-A-64-24542 (JP, U) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) G11B 15/61

Claims (1)

(57) [Claims] 1. A head for recording a signal on a tape or reproducing a signal from the tape, a rotary cylinder on which the head is mounted, a tape guide lead formed on the outer periphery, and a tape spiraled over a predetermined angle on a tape running surface. And a concave portion is formed on the tape running surface across the winding portion and the non-winding portion with the tape winding end interposed therebetween, and the cross-sectional area S of the concave portion in the tape separating portion is 0.005 mm ^2. From 0.0
And a fixed cylinder set within a range of 5 mm ² .