JPH0397149A - Tape guide device - Google Patents

Abstract

PURPOSE:To regulate the position of a tape in the width direction by driving a tape guide post without directly regulating the tape mechanically and to stably and surely feed a thin type tape by moving the tape guide post by driving an actuator in a direction intersecting orthogonally to the moving direction of the tape. CONSTITUTION:When the tape is moved from a prescribed position i.e. a feed position as reference to a tape with direction, the fact is detected with a sensor 9, and the post 1 is moved in the width direction of the tape 8 by driving the actuator 10 corresponding to a detection signal. Since no slippage occurs between a feeding tape 8 and the tape guide post 1 rotated with the motion of the tape 8, the tape 8 follows the motion of the tape guide post 1 in the tape width direction. In other words, since the tape 8 is moved in the axial direction of the tape guide post 1, namely, the width direction of the tape 8 with the tape guide post 1, the tape 8 is also moved in the width direction, thereby, the position of the tape 8 in the width direction is corrected. Thereby, it is possible to keep the position of the tape in the width direction constant without regulating a tape edge mechanically and to stably feed the thin type tape without impairing.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a tape guide device that regulates the widthwise position of a tape in a tape running mechanism such as a video tape recorder or an audio tape recorder. More specifically, the present invention relates to a tape guide device suitable for application to a tape running system that requires stable tape running, particularly for use in broadcasting or thin tape running. (Prior art) In video tape recorders, audio table recorders, etc., if the tape moves in the width direction (meaning the direction perpendicular to the tape moving direction) in the tape running mechanism, track misalignment occurs and correct recording and playback cannot be performed. Therefore, the conventional tape running mechanism uses a guide post with a flange that has a constant diameter in the axial direction (tape width direction).
By mechanically and forcibly forcing the upper or lower edge of the tape to align with the flange, the widthwise position of the tape is regulated, and the running position of the tape is adjusted to the normal position. (Problem to be solved by the invention) However, by forcibly aligning the tape edge (end face in the width direction of the tape) with the flange of the tape guide post, the position of the tape in the width direction during tape running is mechanically controlled. Therefore, when the tape is wound unevenly on the cassette reel, the verticality of the tape guide post is poor, or the tape tension is large and the positional fluctuation in the width direction of the tape becomes large, the above-mentioned flange can be used to straighten the tape. Nonlinear friction occurs on the edges. As a result, the tape may run unstable, causing jitter, or in severe cases, may damage the tape edge. This phenomenon becomes more noticeable as the tape becomes thinner, and in some cases, it may become impossible to run. This makes it difficult to increase the storage capacity by reducing the thickness of cassette tapes. SUMMARY OF THE INVENTION An object of the present invention is to provide a tape guide device that can run a thin tape stably without damaging it. More specifically, it is an object of the present invention to provide a tape guide device capable of keeping the widthwise position of the tape constant without mechanically regulating the tape edge. Further, it is an object of the present invention to further reduce the thickness of the tape and realize reliable and stable tape running that prevents the occurrence of jitter, in order to increase the storage capacity.

(Means for Solving the Problems) In order to achieve the above object, the tape guide device of the present invention includes a tape guide post on which a tape is wound, which is attached to an actuator that feeds the tape in a direction orthogonal to the tape movement direction. The post is rotatably attached to the support shaft of the actuator. Further, the tape guide device of the present invention includes a tape displacement sensor that detects whether the tape is in a predetermined position.
The actuator is driven by the output of the sensor. Further, the tape guide post of the tape guide device of the present invention is characterized in that it does not have a flange and is medium-height at the center position in the tape width direction. (Function) Therefore, when the tape moves in the tape width direction from a predetermined position, that is, a reference running position (hereinafter referred to as the reference running position), the sensor detects this and drives the actuator in response to this detection signal to move the post. Move the tape in the width direction. There is no slippage between the running tape and the tape guide post, which rotates as the tape moves, so the tape follows the movement of the tape guide post in the tape width direction. That is, the tape moves together with the tape guide post in the axial direction of the tape guide post, that is, in the width direction of the tape. Therefore, the tape is also moved in the width direction, and the position of the tape in the width direction is corrected. (Example) Hereinafter, the structure of the present invention will be explained in detail based on the embodiment shown in the drawings. Fig. 1 shows an embodiment of the tape guide device of the present invention in a central vertical cross-sectional view. This tape guide device The tape guide post 1 is made up of a roller part 2 around which a tape is wound, a shaft part 3 that rotatably supports the tape guide post 1, and a tape guide post 1 that supports the shaft part 3 of the tape guide post 1 in a direction perpendicular to the tape movement direction (
In other words, the actuator 10 feeds the tape in the tape width direction.
The tape guide post 1 is provided to move the tape guide post 1 in the tape width direction by driving an actuator 10, and a displacement sensor 9 detects when the tape 8 deviates from the reference running position in the width direction. The tape guide post 1 is moved in the tape width direction by driving the actuator 10 to return the tape 8 to the reference running position. In this embodiment, a voice coil motor is used as the actuator 10 for moving the tape guide post 1 in the tape width direction. This voice coil motor is composed of a driving section 11, a speed detecting section 12, etc. The drive section 11 includes a mover section 16 made up of a drive coil 13, a coil bobbin 14, and a shaft 15, and a stator section 22 made up of yokes 18, 19, 20 and a magnet 21 fixed to a mounting plate l7. Become. York 20
A detent pin 23 fixed to the coil bobbin 14 is inserted into a hole 24 of the coil bobbin 14 to prevent the mover section 16 from rotating. The M degree detection section 12 includes a coil section 27 consisting of a sensor coil 25 and a coil bobbin 26;
It is composed of a yoke 30, 31 provided in a shield case 29 held by a mounting plate 28, and a magnet portion 34 consisting of a magnet 32. The coil bobbin 26 is attached to the shaft 15. The @ portion of the shaft 15 abuts against a damper 33 made of rubber or the like, and this abutting position is the original position. The tape guide boss 1 guides a traveling tape 8, and consists of a roller part 2 around which the tape 8 is wound, and a shaft part 3 that rotatably supports the roller part 2, and has a structure in which it rolls into contact with the tape 8. ing. The roller portion 2 of this tape guide boss 1 is a substantially straight cylindrical member without a regulating flange in the tape width direction, or a medium-high barrel shape as shown in FIG.
A radial ball bearing 4 is attached to a shaft portion 3 that is fixed to a shaft 15 of an actuator 10 via a mounting jig 7.
The tape is supported movably in the width direction of the tape via spring washers 6 and 6. In the case of a barrel-shaped guide post, the roller portion 2 is several percent to several tens of percent, preferably several tens of percent, longer than the width of the tape 8 used, and is composed of a curved surface consisting of a gentle arc with a radius of curvature R of 500 to 1000 OOLIII. When using this barrel-shaped roller part 2, the tape 8 running on the roller part 2 constantly tries to move axially on the roller part 2 toward the middle and high part where the diameter is large. The vehicle travels at a fixed position centered on . The surface of the roller portion 2 that comes into sliding contact with the tape 8 may be made of not only non-magnetic metal or plastic, but also a material with a high coefficient of friction such as urethane rubber. A tape displacement sensor 9 is installed near the post 1 to detect whether or not the tape 8 while running is at a predetermined position, that is, a reference running position. As this sensor 9, for example, a sensor for detecting the position of at least one of the upper and lower edges of the tape 8, such as an optical sensor 9, is arranged along the tape bus. In this embodiment, the sensor 9 is an LED bottom type sensor in which an LED is embedded in the bottom. Note that this optical sensor 9 may detect both the upper and lower tape edges. The movement of the tape guide device configured as described above will be explained based on an example of servo control shown in FIG. When the tape 8 moves from the reference running position in the tape width direction, the sensor 9 detects the tape displacement, the displacement detection circuit outputs it as a displacement amount, and the displacement drive circuit outputs it as a voice coil motor wlA dynamic voltage. Feedback is sent to the voice coil 13 of the actuator 10 to move the tape 8 on the tape guide post 1 to the normal position. In the motor 10, when a drive current flows through the drive coil 13, the drive coil 13, coil bobbin 14, and shaft l1 move in the axial direction according to the voltage. At the same time, the sensor coil 25 also moves. This movement of the sensor coil 25 is detected by the magnetic action on the magnet 32 as a current change related to the moving speed of the shaft 11. Therefore, a voltage proportional to the speed is detected from the output of this coil 25,
This voltage is fed back to the drive voltage for the drive coil 13 for post movement, and the tape guide post 1 is moved in the vertical direction, that is, in the tape width direction, while stabilizing the post vertical movement servo. This axial movement of the tape guide post 1 gives the tape 8 a displacement in the tape width direction, making it possible to correct variations in the tape width direction without damaging the edges of the tape 8. It should be noted that, although the above-described embodiment is an example of a preferred embodiment of the present invention, the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, the actuator 10 for moving the tape guide post 1 in the tape width direction is not limited to the above-mentioned voice coil motor, but may also include, for example, a piezoelectric actuator made of multiple layers of piezoelectric elements, or a bimorph type piezoelectric element. , children can use air cylinders, hydraulic cylinders, etc. Piezoelectric actuators are given a mechanical strain, or amount of change, that corresponds to the amount of current applied. Further, as the sensor 9 for detecting the position of the tape 8 in the width direction, a line sensor, a CCD, an optical sensor consisting of a light emitting element and a light receiving element, a magnetic sensor, an ultrasonic sensor, etc. can be used. In addition, the tape guide boss 1 includes a roller portion 2 and a shaft portion 3.
The actuator 10 is not limited to one divided into two parts.
It may be a single member such as a conventional post as long as it is rotatably attached to the shaft. The use of the tape guide device of the present invention in a tape running system is not limited to one location, but multiple devices can be used in combination.
For example, in the case of a VHS type VTR, stable tape running is made possible by replacing the vertical posts on the entrance and exit sides of the drum with the tape guide device of the present invention. Furthermore, if it is desired to further reduce the fluctuations and if necessary, it is effective to replace the tape guide post near the supply reel or take-up reel, such as a limiter post, with the tape guide device of the present invention or a conventional flanged tape guide post. ．． The tape guide device of the present invention can be used in video tape recorders, digital audio tape recorders, computer external storage devices, etc. that require stable tape running control, such as broadcasting or relatively thin tapes. It is suitable if Of course, the tape guide device according to the present invention can be used not only in the above-mentioned helical scan type tape recorder, but also as a tape traveling mechanism such as a normal analog audio tape recorder.

(Effects of the Invention) As is clear from the above description, in the tape guide device of the present invention, the tape guide post is rotatably attached to an actuator, and the actuator is driven to move the tape guide post in a direction orthogonal to the tape moving direction. Since the tape is moved along with the tape guide post in the axial direction of the tape guide post, that is, in the width direction of the tape, the widthwise position of the tape is corrected. That is, the position of the tape in the width direction can be controlled by driving the post without directly regulating the tape mechanically. Moreover, according to the tape guide device of the present invention, the tape guide post is rotated by the movement of the running tape.
While suppressing the increase in tape tension caused by the post, it eliminates tape slippage and improves the ability of the tape to follow the movement of the post. For example, when attempting to correct tape displacement by simply moving the fixed post in the axial direction without rotating it [Fig. 5 (A)], and in the case of the present invention [Fig.
Figure (B)] compares the experimental results with Figure 5. However, Fig. 5 (A) shows the sine wave response from IHz to 0.01 Hz, and Fig. 5 (B) shows the sine wave response from 0.1 Hz to 0.0 Hz.
The sine wave response at 11{z is shown. According to this, if you move the tape guide post without rotating it [Figure 5 (A)], if you move it slowly up and down, the tape will not be able to follow it (in the low frequency range). however,
According to the present invention, as shown in FIG. 5(B), even if the post is moved slowly, the post displacement and the tape displacement are almost linear, that is, the post displacement directly becomes the tape displacement, and the tape movement can be stably controlled. I can understand. In addition, when using a displacement sensor, when the tape running on the post changes in the tape width direction from a predetermined position, that is, a reference running position (hereinafter referred to as the reference running position), the sensor detects this and sends this detection signal. Accordingly, the actuator is automatically driven to move the post in the tape width direction, thereby correcting the tape position.

Therefore, unlike the conventional method of regulating the tape width direction by forcing the tape edge to mechanically align with the flange of the guide post, thin tape is used because nonlinear stress does not act on the tape edge. This allows for extremely stable and reliable running without damaging the tape edge even when the tape edge is damaged.

[Brief explanation of drawings]

Fig. 1 is a central vertical sectional view showing one embodiment of the tape guide device of the present invention, Fig. 2 is a front view showing another embodiment of the tape guide post, and Fig. 3 is the tape guide device of the present invention and a displacement detection sensor. FIG. 4 is a block diagram showing an example of a servo system for tape control using the tape guide device of the present invention, and FIG. 5 is a diagram showing post displacement. FIG. 2 is a graph showing measurement results showing the relationship between This is a sine wave response diagram showing the relationship between the displacement of the barrel-shaped rotating post and the displacement of the tape. 1... Guide post, 2
...Roller part, 3...Shaft part, 9...Displacement sensor, 10...Actuator. Representative of Japan Broadcasting Corporation Sankyo Seiki Seisakusho Co., Ltd. Patent attorney Kazumi Murase

Claims (3)

[Claims] (1) Tape guide post around which the tape is wrapped.
A tape guide device, characterized in that it is attached to an actuator that feeds in a direction perpendicular to a tape moving direction, and the post is rotatably attached to a support shaft of the actuator. (2) The tape guide device according to claim 1, further comprising a tape displacement sensor that detects whether the tape is in a predetermined position, and the actuator is driven by the output of the sensor. (3) the tape guide post does not have a flange;
3. The tape guide device according to claim 1, wherein the tape guide device has a middle height at a center position in the tape width direction.