JPH04315853A - Tape running height correction device for tape path system - Google Patents

Abstract

PURPOSE:To restrict the total lap angle of a fixing guide for correcting the tape running height and to reduce a tape running load. CONSTITUTION:Fixing guides 10 and 12 are provided on the intake side and outtake side of a tape 4 with different running heights. The respective fixing guides 10 and 12 are tilted respectively in the tape running direction of the intake side or the outtake side, the tape 4 between the fixing guides 10 and 12 is arranged so as to have large shifting angles in the same direction, a rotary guide 11 is provided between the fixing guides 10 and 12, and the rotary guide 11 is arranged perpendicular to the tape 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape running height correction device for a tape pass system, which corrects the running height of a tape in a tape pass system such as a VTR.

0002

2. Description of the Related Art For example, in a VTR, a tape is wound around a helical scan drum, so the running height of the tape is different between the entrance and output of the drum. On the other hand, since the tape height is the same on the cassette supply side and take-up side, there is a tape running height that corrects the tape running height in sections of the tape path system where the tape running height is different from the cassette side. A correction device is provided.

[0003] There are two methods of correcting the running height of the tape: one using a fixed guide and the other using a rotating guide. The former means arranges the fixed guide to be inclined parallel to the tape (azimuthal inclination). Although this means has a short correction span and stable running, it has the disadvantage that the tape running load increases due to friction with the tape.

[0004] In the latter means, the rotation guide is arranged so as to be inclined in a direction perpendicular to the tape. This means has almost no friction with the tape, so the tape running load does not become too large, but it has the disadvantage that the tape running is unstable because an external force is applied in the width direction of the tape. Also, it is not possible to make large angle corrections.

[0005] Therefore, when the correction span cannot be shortened and there is a large correction angle, for example, in a VTR in which the wrap angle to the drum is 180° or more, a fixed guide is generally used.

[0006]

However, the disadvantage of using a fixed guide as described above is that the tape running load increases, and this tape running load increases approximately in proportion to the wrap angle of the tape. The total wrap angle is approximately half that when configuring with two fixed guides than when configuring with one fixed guide, but when configuring with three or more fixed guides, The total lap angle is not much different.

Therefore, in the past, when there was a large correction angle, a correction device was constructed with two fixed guides, but it was not possible to suppress the tape running load to an extent that would ensure stable running.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a tape pass type tape running height correction device that reduces the tape running load by keeping the total wrap angle of the fixed guide small.

[0009]

[Means for Solving the Problems] In order to achieve the above object, there is provided a tape running height correction device for a tape path system according to the present invention, in which a tape of a tape path system is wound around a rotating guide and fixed guides on both sides of the tape. each fixed guide is arranged to be inclined along the tape running direction on the entrance side or the exit side, so that the tape between the two fixed guides has a large tilt angle in the same direction, The present invention is characterized in that the rotation guide is disposed perpendicularly to the tape having a large tilt angle.

0010

[Operation] The rotation guide changes direction at the tape position where there is a large tilt angle, and the tape height is corrected by the vertical component of this direction change, so only a small amount of height correction by the fixed guides on both sides is sufficient, so both fixing The total wrap angle of the guide can be small.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 8 show examples in which the present invention is applied to a tape pass system of a VTR.

FIG. 2 shows a schematic plan view of the VTR in a tape loading state. In FIG. 2, three types of cassettes, L, M, and S, can be used as the cassette 1, and in this embodiment, the L cassette is used. A supply reel 2 and a take-up reel 3 are rotatably supported within the cassette 1, and the tape 4 discharged from the supply reel 2 returns to the take-up reel 3 through a tape path system.

The tape path system is constructed from a large number of guides as shown below. That is, the tape 4 discharged from the supply reel 2 passes through a guide 5, a full erase head 6, and a guide 7, and is wound around a guide 8 for tension detection. The tension detection guide 8 is rotatable about point a and detects the tape tension on the supply side of the tape path system.

The tape 4 that has come out of the tension detection guide 8 is wound around three guides 10, 11, 12 of the tape running height correction device 9 according to the present invention, where the tape height is adjusted downward ( (direction with a descending angle with respect to the reference horizontal plane). The detailed structure, correction angle, etc. of the tape running height correction device 9 will be explained in detail below.

The tape 4 is attached to the inclined rotation guide 13.
Then, it is corrected upward (in a direction having an upward angle with respect to the reference horizontal plane) by the inclined fixed guide 14 and enters the drum 15. The tape 4 is wound along a lead (not shown) of a drum 15, and the tape 4 exiting the drum 15 is corrected horizontally (parallel to a reference horizontal plane) by an inclined fixed guide 16. Therefore, it is now at the same height as each reel 2, 3 of the cassette 1, and there is no inclination.

After this, the tape 4 passes through the two guides 17, 1
8 through the fixed head 19 and the capstan shaft 20
and pinch roller 21. The tape 4 is driven by a driving force from a capstan shaft 20 during play mode and the like.

Capstan shaft 20 and pinch roller 21
The tape 4 that has come out passes through a guide 22, a tension detection guide 23, and a guide 24 and returns to the take-up reel 3. The tension detection guide 23 detects the tape tension on the winding side of the tape path system.

FIG. 3 shows a side view of the tape pass system viewed from the direction of arrow A in FIG. In FIG. 3, the tape 4 between the guide 8 on the supply side and the fixed guide 10 on the entrance side of the tape running height correction device 9 and the tape 4 between the guide 16 and guide 18 on the winding side are at the same height and are not tilted. do not have. tape 4
A tape running height correction device 9 is used to wind the tape around the drum 15.
The running direction of the tape 4 is lowered at .

FIG. 4 is a perspective view of the tape running height correcting device 9, and FIG. 1 is a diagram illustrating the arrangement of the guides 10, 11, 12. In FIG. 4, reference holes 27 and 28 are formed in two places in the mounting block 26, and reference pins on the base (not shown) side are inserted into these reference holes 27 and 28, so that the mounting block 26 is attached to the base. Positioned. Furthermore, fastening holes 29 are formed at three locations in the mounting block 26, and fastening screws are inserted into the fastening holes 29 to attach the mounting block 26 to the base.

The rotary guide 11 and the fixed guides 10 and 12 on both sides thereof have their lower ends supported by a mounting block 26, and in this embodiment, the tape running height correcting device 9 is integrated into one block. Therefore, it is easy to assemble,
Furthermore, the assembly accuracy of each guide 10, 11, 12 is also good.

As shown in FIG. 1, the fixed guide 1 on the entrance side
0 along the tape running direction on the entrance side, and the fixed guide 12 on the exit side being inclined (azimuth inclination) along the tape running direction on the exit side.
2 are arranged in a substantially V-shape.

Since the tilt angle (angle of inclination with respect to the reference vertical plane) of the tape 4 increases in proportion to the azimuth angle, the azimuth angle of the fixed guides 10 and 12 should be made as large as possible so that the tape between the fixed guides 10 and 12 4 are configured to have large tilt angles in the same direction. However, if the azimuth angle is 45 degrees or more, it is difficult to put it into practical use, so it is set at an angle less than 45 degrees.

The rotation guide 11 is arranged perpendicularly to the tape 4 having a large tilt angle. That is, tape 4
The azimuth angle and the tilt angle are set to be as close to 0 degrees as possible, and as shown in FIG. 1, the contact projection surface b of the tape 4 with respect to the rotating guide 11 is configured to have a rectangular shape.

In order to satisfy the setting conditions between the rotating guide 11 and the fixed guides 10 and 12 on both sides, each guide 10
, 11, 12 so that their central axes c intersect at one point. In this embodiment, the design is slightly different due to the assembly conditions of the automatic assembly machine.

The operation of the above configuration will be explained below. When play mode is selected, tape 4 is placed on supply reel 2.
It runs from the side to the take-up reel 3 side. In this running process, the running height of the tape 4 does not change until it reaches the fixed guide 10 on the entrance side of the tape running height correction device 9, but the tape 4 that has left the fixed guide 12 on the exit side is the standard. The vehicle is changed to run at a predetermined descending angle (θ) with respect to the horizontal plane.

Since the fixed guide 10 on the entrance side is inclined with an azimuth angle, the running direction of the tape 4 is corrected downward by an angle θ1 with respect to the reference horizontal plane, and the fixed guide 12 on the exit side is also tilted at an azimuth angle. The running direction is corrected downward by an angle θ3.

Furthermore, since the rotating guide 11 changes the tape running direction with a wrap angle (α) for the tape 4 having a tilt angle, the running direction is corrected downward by the vertical component (angle θ2) of the changing angle. do.

Therefore, the tape running height correcting device 9 can lower the tape running by θ1+θ2+θ3=θ in total. The tape running load occurs on the fixed guides 10 and 12 on both sides, but the fixed guides 10 and 12 on both sides
The total wrap angle required for the correction angle of θ1+θ3 is sufficient, so the tape running load is reduced compared to the conventional method.

[0029] Here, we will consider specific numerical values. A case will be explained in which the fixed guide 12 on the injection side has an azimuth angle of 33° and a wrap angle of 9°, and the tape 4 is ejected from the fixed guide 12 on the injection side with a descending angle of 9.6° and a tilt angle of 4.6°. .

FIGS. 5 to 8 show respective characteristic diagrams when the wrap angle α of the rotation guide 11 is used as a parameter, and the descending angle and tilt angle in FIGS. 7 and 8 are relative to the reference horizontal and vertical planes. It is.

As shown in FIG. 5, the fixed guide 1 on the entrance side
The larger the azimuth angle of 0, the more the rotating guide 11
The wrap angle α becomes larger, and the swing angle of the fixed guide 10 on the input side also becomes larger as shown in FIG. 8, so that the correction angle by the rotating guide 11 can be increased. However, as described above, the azimuth angle cannot be greater than 45°.

Furthermore, as shown in FIG. 6, it can be seen that it is preferable that the wrap angle of the rotary guide 11 is larger because the wrap angle of the fixed guide 10 on the incident side is also smaller. However, if the wrap angle of the fixed guide 10 on the input side is small (the wrap angle of the rotating guide 11 is large), the descending angle of the fixed guide 10 on the input side will naturally become small.

[0033] The azimuth angle of the fixed guide 10 on the incident side is set to 3
9 degrees and the wrap angle is 22 degrees, the descending angle and tilt angle with respect to the reference horizontal and vertical planes having values as shown in FIG. 1 can be obtained from the characteristics shown in FIGS. 5 to 8. Fixed guide 10 on the entrance side
The correction angle of the rotation guide 11 is 2°, the correction angle of the rotation guide 11 is 6.6°,
The correction angle on the exit side is 1°, and the rotation guide 11 provides a large correction angle.

[0034]The total wrap angle of the two fixed guides 10 and 11 is only 31°, and if an attempt is made to correct it using only the two fixed guides under the same conditions, the total wrap angle will be 6.
4° (20° + 44°), and if an attempt is made to correct it using only one fixed guide, the wrap angle becomes 129.6°, which shows that the tape running load is significantly reduced compared to the conventional case.

Further, the rotation guide 11 is not arranged at an angle with respect to the tape 4 to correct the tape running direction, but is arranged perpendicularly to the tape 4 to correct the tape running direction. Therefore, no external force is applied in the width direction of the tape 4 as in the conventional case, and the tape runs stably.

[0036]

Effects of the Invention As described above, according to the present invention, fixed guides are provided on the entrance side and exit side of tapes having different running heights, and these fixed guides are arranged along the tape running direction on the entrance side or the exit side. and the tape between the two fixed guides is arranged so as to have a large tilt angle in the same direction, and a rotation guide is provided between the two fixed guides, and the rotation guide is rotated with respect to the tape. Since the rotating guides are arranged vertically, the tape running direction is also corrected, so that the total wrap angle of the fixed guides can be kept small and the tape running load can be reduced.

[Brief explanation of drawings]

FIG. 1 is a diagram (embodiment) illustrating the arrangement of each guide of a tape running height correction device.

FIG. 2 is a schematic plan view (embodiment) of a VTR in a tape loading state.

FIG. 3 is a side view (embodiment) of the tape pass system seen from the direction of arrow A in FIG. 2;

FIG. 4 is a tilted view of the tape running height correction device (embodiment).

[Figure 5] Characteristic diagram of the azimuth angle of the fixed guide on the input side (
Example).

FIG. 6 is a characteristic diagram of the wrap angle of the fixed guide on the incident side (example).

FIG. 7 is a characteristic diagram (example) of the descending angle of the tape that exits the fixed guide on the incident side.

FIG. 8 is a characteristic diagram (example) of the tilt angle of the tape that exits the fixed guide on the incident side.

[Explanation of symbols]

4... Tape, 9... Tape running height correction device, 10, 12
...Fixed guide, 11...Rotating guide.

Claims (1)

[Claims] [Claim 1] A tape path system tape is provided so as to be wrapped around a rotating guide and fixed guides on both sides thereof, and each fixed guide is arranged at an angle along the tape running direction on the entrance side or the exit side. , a tape path system characterized in that the tape between the two fixed guides is configured to have a large tilt angle in the same direction, and the rotating guide is arranged perpendicularly to the tape having the large tilt angle. tape running height correction device.