JPH0567367A - Tape tension control device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a tape tension control mechanism capable of controlling a constant tape tension in a tape running device such as a compact cassette tape recorder by using a relatively small and simple member. The purpose is to [Structure] In the tape running device or in a tape cassette used in the tape running device, a contact mechanism for contacting the outer peripheral surface of the tape on the supply side reel is provided, and the load torque is controlled according to the amount of the supply side tape. Then, the tape tension is made constant by adding it to the contact mechanism. Further, the tension of the tape is made constant by controlling the load torque of the supply reel by the displacement of the movable mechanism that can move within a predetermined range due to the fluctuation of tension in the tape cassette. [Effect] Compared to the conventional tape tension control mechanism,
Since it can be easily configured with a small member, the mechanical size can be reduced and the power consumption can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for tape running in a tape running device such as a compact cassette tape recorder while keeping the tape tension constant.

[0002]

2. Description of the Related Art As a conventional technique, a method of detecting a reel base rotation period, calculating a tape winding diameter from this information, controlling a reel motor torque and controlling a back tension from the obtained tape winding diameter is known. FIG. 13 shows a method of controlling the back tension by using a hysteresis plate on the reel stand, and FIG. 15 shows a method of providing a pad material on the head contact portion. Further, FIG. 16 shows a method of detecting and controlling the tension by the tension sensor.

First, in FIG. 13, the magnetic tape running path is constituted by a winding reel 59 at one end and a supply reel 58 at the other end, and a plurality of tape guides 51 are arranged between both ends. And pinch roller 5
The tape 52 is sandwiched between the three and rotated. The tape 52 is taken up by the take-up reel 59, and the back tension F is kept constant by controlling the motor torque T _M of the supply reel motor 57. here,
The supply-side reel 58 is provided with a rotation detection plate 55 fixed to the supply reel shaft 60.
It is rotated together with the rotation of the supply reel 58. The photo sensor 56 is attached to the chassis 50 at a position where the presence or absence of rotation of the detection plate 55 can be detected, and the output of the photo sensor 56 is input to the microcomputer 61. Microcomputer 61
Calculates the tape winding diameter R at the current stage from the output of the photo sensor 56 and the tape speed v. The microcomputer 61 outputs a voltage V necessary for keeping the back tension F constant from the obtained tape winding diameter R to the drive circuit 62, which is transmitted from the drive circuit 62 to the motor 57 to control the constant back tension F. Is done.

Next, FIG. 14 will be described. In FIG. 14, the tape running path and running method are the same as in FIG. The back tension F is generated by the hysteresis load of the hysteresis plate 63 attached to the supply side reel 58, and the tape runs.

FIG. 15 shows an example in which a pad material is provided on the head contact portion. 15, the tape running path and running method are the same as those in FIG. The back tension F is not given by a special mechanism, and is required at the head contact portion 67 by the pad 64 arranged at the center of the leaf spring 65 supporting both ends on the tape back side of the portion 67 where the magnetic head 66 and the tape 52 contact. Obtaining contact pressure.

In the system shown in FIG. 16, the tape 52 is pulled out from the tape cassette 68, the tape guide 51 is arranged so as to be wound around the tension sensor 69 composed of a leaf spring and a tape guide, and the tape is run. The amount of displacement of the tension sensor 69 is transmitted to the supply side reel 58 by the strength of the frictional force of the wire 70, and the tape tension F is kept constant.

[0007]

Problems to be Solved by the Invention The problems in the above-mentioned prior art are listed below. In the method shown in FIG. 13,
Although it is possible to control the back tension F to be constant, the motor 57 dedicated to the supply side reel is required because the back tension F is controlled by the motor torque T _M. The motor is originally a mechanical component of the tape running system,
Since this is a large volume component, it was a major limitation in the compact design of this mechanical part. Further, in controlling the motor torque T _M , the photo sensor 56, the microcomputer 61, and the drive circuit 62 are required, which is a problem in terms of time and effort for circuit design, increase in circuit scale, securing wiring area, and increase in power consumption. Was mentioned.

The system shown in FIG. 14 does not require a motor, a circuit or the like, so that the tape running mechanism can be downsized. Further, the back tension F is also generated only by the hysteresis plate 63, which is advantageous in assembling and adjusting the mechanical portion. However, the control by the hysteresis plate 63 can generate only a constant torque T _H and the back tension F changes with the change of the reel winding diameter R, so that stable tape running is not performed and high-density recording which is a recent movement. Was a big obstacle in.

In the system shown in FIG. 15, when the number of magnetic heads is two or three, as is seen in high-grade tape recorders, the center position of the tape pressing by the pad is set to the head position. A gap is generated in the gap portion, and a stable head touch cannot be obtained, which is a big obstacle particularly in high-density recording.

In the method shown in FIG. 16, it is necessary to pull out the tape from the tape cassette, which is a major obstacle in reducing the mechanical size. Furthermore, it is necessary to design the tape pull-out mechanism required when pulling out the tape. Problems such as the size of the scale are mentioned.

[0011]

A tape tension control mechanism according to the present invention is realized on a tape running device that forms a tape running path by a pair of reels and a tape guide on each of a winding side and a feeding side. To solve the problem, a contact mechanism that contacts the outer peripheral surface of the tape wound on the supply reel regardless of the size of the tape on the tape running device or in the tape cassette, or moves within a predetermined range in the tape cassette due to fluctuations in tension. It is composed of a movable mechanism and the contact mechanism, or a control mechanism for controlling the reel torque by the displacement amount of the movable mechanism.

[0012]

According to the above construction, the magnetic tape is run at a predetermined tape speed after the running path is formed by the running path means. The contact mechanism is arranged on the mechanical chassis or in the tape cassette so that it makes contact with the outer peripheral surface of the tape wound on the supply reel, so that it is pulled by a tension spring or the like in the direction of pressing the contact portion against the outer peripheral surface of the tape. Has been
It can handle changes in reel diameter.

Like the contact mechanism, the control mechanism is arranged on the mechanical chassis or in the tape cassette and generates friction torque on the supply reel. The control mechanism varies and controls the friction torque of the supply reel according to the variation of the contact mechanism, and as a result, is controlled to keep the tape tension constant.

Further, the movable mechanism is arranged in the tape cassette and is constructed so that the roller guide pulled by a spring or the like so as to be located at a predetermined position at a desired tension can be moved by the fluctuation of the tape tension. In this case, the control mechanism is arranged in the tape cassette to generate the friction torque on the supply-side reel as described above. The control mechanism changes and controls the friction torque of the supply reel according to the change of the movable mechanism, and as a result, is controlled to keep the tape tension constant.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In the respective embodiments, parts having the same function are given the same symbols.

(Embodiment 1) FIG. 1 is a plan view of a tape running device having a tape tension control mechanism composed of an abutment mechanism 1 and a control mechanism 2 of the present invention. FIG. 2 is a tape tension control mechanism section. It is the figure which looked at from the side. The tape is wound around a take-up reel 7 and a supply reel 4, and a tape running path is formed between the reels by a tape guide 8. The tape 6 is nipped by a capstan 10 and a pinch roller 9 and runs at a predetermined speed v. ..

Here, a pulley 2c fixed to the reel shaft is attached to the supply reel shaft 3 with the reel shaft as the center, and the chassis is provided on the outer circumference of the pulley by a fixing member 2a at the other end. A wire 2b fixed to 13 is wound. The control mechanism 2 uses the pulley 2c as described above.
It is composed of a fixture 2a and a wire 2b.

The other end of the wire 2b is connected to a tension spring 1d, and the other end of the tension spring is mounted on a movable lever 1b rotatable around a predetermined position 1a on the chassis 13. ing. Movable lever 1
A rotary shaft is attached to b, and a rotary roller 1c is attached to the rotary shaft. The rotation shaft is positioned at a position where the supply reel 4 is located on the rotation orbit when the movable lever 1b is rotated.

The contact mechanism 1 is composed of the tension spring 1d and the movable lever 1b and the rotating roller 1c as described above. The contact mechanism 1 is always pulled in the direction of the supply reel shaft 3 by the tension spring 1d. Cassette 11
Only when mounted is pulled by the mounting lever 5 in the direction opposite to the reel shaft.

On the lower surface of the tape cassette 11, an insertion window 12 for the rotary roller 1c is provided. With the above configuration, the rotating roller 1c can be always brought into contact with the outer peripheral surface 15 of the tape wound on the supply reel 4 regardless of the tape diameter. Further, since the rotating roller 1c is used as the member that comes into contact with the tape, the tape surface is not damaged.

FIG. 3 is a state diagram of the tape tension control mechanism when the tape diameter R of the supply reel 4 is the maximum Rmax when the tape is run by the above mechanism, that is, when the tape running is started. In this case, since the distance between the rotating roller 1c and the reel shaft 3 is long, the force for pulling the wire 2b connected to the tension spring 1d is also strong and the load torque T due to the frictional force generated on the supply side reel becomes maximum.

On the other hand, FIG. 4 shows a state diagram of the tape tension control mechanism in a state where the tape diameter of the supply reel is small, that is, just before the tape running is completed. With the decrease of the supply-side tape winding diameter R, the tape diameter becomes a re-small diameter Rmax, the rotating roller 1c approaches the supply-side reel shaft 3, the pulling force of the wire 2b becomes weak, and the load due to the frictional force generated on the supply-side reel The torque T becomes the minimum.

Looking at the back tension F from the relational expression F = T / R of the load torque T and the tape winding diameter R, the load torque Tmax at the start of tape running, the tape diameter Rmax and the tape running just before the end of tape running. Load torque Tmi
n, tape tension F of tape diameter Rmin is Tmax
By adjusting the torque T so that / Rmax = Tmin / Rmin, the tape tension F can be kept constant. The strength of the load torque T can be adjusted by adjusting the friction coefficient of the portion of the wire 2b that is wound around the pulley 2c, or by adjusting the tension of the length of the working range of the spring. Can be performed by adjusting the spring constant of the tension spring 1d.

In the present embodiment, the movable lever 1b is arranged so as to rotate around a position near the center of the cassette, but the present invention is not limited to this, and the reel on the supply side is placed on the rotation track of the movable lever. It does not matter as long as there is a rotary shaft at the position where is located. The rotating roller 1c is used as the tape outer peripheral surface contact member. For example, a felt like a felt for removing dust on the tape surface is used. It may be one. Further, although the wire 2b is used as the control mechanism, the present invention is not limited to this. For example, a belt-shaped metal plate may be used and a felt material or the like may be attached only to the portion around which the pulley is wound.

(Embodiment 2) FIG. 5A shows a plan view of a tape cassette equipped with a tape tension control mechanism composed of the contact mechanism 1 and the control mechanism 2 of the present invention. The tape cassette 20 is run by a tape running device having two reels on the left and right, and the tape tension is controlled in the same manner as in the first embodiment. In this case, the lower surface of the tape cassette shown in the first embodiment is inserted. The window 12 and the mounting lever 5 are unnecessary, and the wire 2b is wound around the pulley 2c attached to the reel shaft 3 in the first embodiment, but in the present embodiment, the wire 2c is wound around the reel hub 14. It is possible to keep the tape tension constant.

(Embodiment 3) FIG. 6 is a plan view of a tape running device in another embodiment of a tape tension control mechanism composed of a contact mechanism 22 and a control mechanism 23, and FIG. 7 is a tape tension control mechanism of FIG. It is the figure which looked at the part from the side.
In FIG. 6, a tape running path is formed by the tape guide 8 between the take-up reel 4 and the supply reel 7, and the tape 6 is nipped between the capstan 10 and the pinch roller 9 and runs at a predetermined speed v. A control mechanism 23 is supported on the supply reel shaft 3 in such a manner that the control mechanism 23 is wound around the reel shaft 3 and tightened. The control mechanism 23 is fixed so as not to rotate together with the reel shaft, and a torque T due to the tightening force of the control mechanism 23 is generated on the supply-side reel 4 during tape running, resulting in back tension F.

The control mechanism 23 has a tightening portion 23 which is wound around the reel shaft 3 and tightened as shown in the enlarged view of FIG.
c and both ends of the tightening portion are connected in the radial direction of the reel with both arm portions 23a and the tightening portion 23c and both arm portions 23a are connected. Comprised of leaf springs 23b, both arm portions 23a
Guide grooves 23d are provided on the surfaces facing each other. Further, the portion of the tightening portion 23c that comes into contact with the reel shaft is made of a soft material such as felt material.
The coil spring 23cb is wound around a. Further, as shown in FIG. 9, the adjustment spring 22a and the tape diameter transmission rod 22 are provided in the same radial direction as the two arms.
A contact mechanism 22 including b, a roller shaft 22d, and a rotating roller 22c is attached. The contact mechanism 22 is always pulled by the adjusting spring 22a in the reel central axis 3 direction, and is pulled by the cassette mounting lever 5 in the radial direction from the reel central axis 3 only when the tape cassette 11 is mounted.

An insertion window 12 for the rotary roller 22c is provided on the lower surface of the tape cassette 11. With the above configuration, the rotating roller 22c is always in contact with the outer peripheral surface 15 of the tape wound around the supply reel 4 when the tape cassette 11 is mounted. Further, after the tape cassette 11 is mounted, the cassette mounting lever 5 stops the pulling operation, so that the abutting mechanism 22 receives only the force pulled by the adjusting spring 22a in the reel central axis direction.

Therefore, even if the tape winding diameter R changes due to the tape running, the rotating roller 22c can rotate the reel outer peripheral surface 15
It is possible to detect the tape winding diameter R of the supply-side reel 4 by continuing to make contact with the tape and checking the position of the contact mechanism 22.
Further, the tape contact surface can be smoothly contacted by using the rotating roller 22c, and the tape surface is not damaged. On the other hand, the tape diameter transmission rod 22b is supported so as to push open the space between the arms along the guide groove 23d between the arms 23a of the control mechanism 23, whereby the position of the contact mechanism 22 is also supported. There is.

When the tape is made to travel in the above-described configuration, first, a plan view of a state in which the tape winding diameter R of the supply-side reel 4 is large, that is, the positional relationship between the control mechanism 23 and the contact mechanism 22 at the start of tape running. Is shown in FIG. At the start of tape running, the contact mechanism 22 is located at a position distant from the reel center axis 3, so that the tape diameter transmission rod 22b is controlled by the control mechanism 2.
There is almost no amount to push open both arm portions 23a of No. 3, the tightening force of the reel shaft 3 by the tightening portion 23c is in a strong state, and the generated torque T on the supply-side reel 4 is large.

On the other hand, when the tape winding diameter R of the supply reel is small, that is, the control mechanism 2 immediately before the tape running is completed.
FIG. 11 shows a plan view of the positional relationship between the contact mechanism 3 and the contact mechanism 22. The position of the contact mechanism 22 approaches the reel center axis 3 as the tape winding diameter R decreases as compared to when the tape running in FIG. 10 is started.

Therefore, the amount by which the tape diameter transmission rod 22b pushes open both arms 23a of the control mechanism 23 is large, the tightening force of the reel shaft 3 by the tightening portion 23c is weakened, and the torque T generated on the supply side reel 4 is generated. Is small. Here, a relational expression F of back tension F, torque T, and tape winding diameter R
From the equation = T / R, the torque T generated by the tightening portion 23c is also large when the tape diameter R is large at the start of tape running. In addition, the reel diameter R immediately before the end of tape running
The torque T generated by the tightening portion 23c becomes small in a small state, and the back tension F at the start of the tape running and immediately before the end of the tape running can be controlled to be constant.

The back tension F is adjusted by changing the thickness and the frictional force of the felt material 23ca in the tightening portion 23c,
And the spring force of the leaf spring 23b is changed. For example, when the maximum winding radius Rmax is 25 mm, the minimum winding diameter Rmin is 10 mm, and the target back tension F is 20 gf, the torque T that must be generated at the tightening portion is Tmax = R at the maximum winding diameter.
max × F = 2.5 × 20 = 50 gf · cm, and 50 gf is applied to the reel shaft 3 with both arms 23a not opened.
・ Adjust the thickness of the felt material and the frictional force so that a torque of cm is generated.

Next, the required torque Tmin at the minimum tape winding diameter is Tmin = Rmin × F = 1.0 × 20 = 2.
The adjustment of the generated torque at this time is performed by first setting the opening amount between the arms of both arm portions 23a to the same amount as the opening amount at the time of the minimum winding diameter of the tape, and the torque at this time is the target value. The opening amount is set to the coil spring 2 so that it becomes 20 gf · cm.
The spring force of the plate spring 23b transmitted to 3ct may be changed.

By the above adjustment, the back tension F
Is kept constant with changes in tape diameter. Also, FIG.
As shown in FIG. 0 and FIG. 11, the contact mechanism 22 can be reliably supported by providing the both arm portions 23a and the tape diameter transmission rod 22b with taper. (Embodiment 4) FIG. 12 is a plan view of a tape cassette provided with a tape tension control mechanism composed of a movable mechanism 40 and a control mechanism 2 of this embodiment. In FIG. 12, a tape 6 is wound around a take-up reel 7 and a supply reel 4, and a tape path between the reels is formed by a fixed guide 8a and a rotation guide 40a.

The rotation guide 40a is a tension arm 40 which is pulled in a direction opposite to the reel by a fixed spring 40c.
The moving range is determined by the moving groove 41a formed on the cassette half 41, which is attached on b. The movement range is set in this manner in order to prevent tape damage without changing the tape traveling path even when the tape tension suddenly changes due to a defective tape cassette.

A movable spring 40d is attached to the tension arm 40b. As described above, the movable mechanism 40 is composed of the rotation guide 40a, the fixed spring 40c, the tension arm 40b, and the movable spring 40d.

A wire 2b is connected to the other end of the movable spring 40d, and the wire is wound along a wire groove (not shown) formed on the supply reel hub 14 and fixed on the cassette half 41 by a fixture 2a. It

As described above, the control mechanism 2 is composed of the wire 2b, the wire groove formed in the reel hub, and the fixture 2a. The tape cassette 42 having the above mechanism is a pair of left and right reels, capstans, and pinch rollers. The tape is run by mounting it on the configured tape running device. When the tape cassette 42 is moved along the tape, the rotation guide 40a moves within the range of the movement groove 41a due to the change of the tape tension F. As the rotation guide 40a moves, the load torque T due to the friction of the wire 2b connected to the movable spring 40d on the supply-side reel 4 fluctuates, and as a result, the tape tension is kept constant. The tape tension is adjusted by changing the spring force of the fixed spring 40c and the movable spring 40d and the frictional force of the wire 2b. In this embodiment, the tension arm 40b and the fixed spring 40c are used. However, the present invention is not limited to this. For example, a plate spring may be used to cover the role of the tension arm. I can.

In the above-mentioned embodiments 1 to 4, the tape tension control mechanism in which the tape running is in only one direction has been described. However, the tape tension control mechanism of the present invention is applied to both the left and right reels. It becomes possible to correspond to reciprocating traveling by configuring to attach. As an example, a tape tension control mechanism for reciprocating traveling based on the second embodiment is shown in FIG.

As described above, according to the present invention, the traveling device, the contact mechanism for contacting the outer peripheral surface of the tape wound on the supply side reel in the tape cassette, or the fluctuation of the tape tension provided in the tape cassette is detected. By controlling the torque generated by a traveling device or a control mechanism that applies a load torque to the supply side reel provided in the tape cassette, the tape tension is controlled to a constant level.

Therefore, it is not necessary to use electric parts such as a motor and a microcomputer, a great deal of work can be done in designing a circuit and making a circuit, and the mechanism can be simple and miniaturized. The mechanical size can be reduced. Further, since it is not necessary to pull out the tape from the tape cassette, the tape pulling mechanism is not necessary, and the size of the mechanism can be remarkably reduced.

Further, the tape tension can be kept constant, and the tape running and the head touch are improved.

[0044]

As described above, the tape tension control mechanism according to the present invention is mounted on the tape running device and in the tape cassette, and is generated on the supply reel by the change of the tape diameter of the supply reel or the tape tension. By changing the load torque to be applied, it is possible to control to a constant tape tension from the beginning to the end of tape running.

This mechanism is relatively small and is composed of a simple member, and since it is mounted in the tape cassette and it is not necessary to pull out the tape from the tape cassette, the mechanical size can be greatly reduced. It will be possible. Also,
Since it is not necessary to use electric parts such as a motor, a microcomputer, etc., it is possible to save the labor of circuit design, trial manufacture, and adjustment, and to reduce the power consumption. Further, when the contact mechanism is used, it is possible to prevent the slack of the tape and remove dust and the like adhering to the tape surface.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment of a tape traveling device equipped with a tape tension control mechanism including a contact mechanism and a control mechanism.

FIG. 2 is a side view of the first embodiment of the tape tension control mechanism including the contact mechanism and the control mechanism.

FIG. 3 is a positional relationship diagram of the contact mechanism and the control mechanism of the first embodiment when the tape diameter is the maximum.

FIG. 4 is a positional relationship diagram of the contact mechanism and the control mechanism of the first embodiment when the tape diameter is the smallest.

FIG. 5 is a diagram in which a tape tension control mechanism including a contact mechanism and a control mechanism is mounted in a tape cassette.

FIG. 6 is a plan view of a tape traveling device according to a third embodiment in which a tape tension control mechanism including a contact mechanism and a control mechanism is mounted.

FIG. 7 is a side view of a tape tension control mechanism according to a third embodiment, which includes a contact mechanism and a control mechanism.

FIG. 8 is a perspective view of a control mechanism of Example 3.

FIG. 9 is a perspective view of an abutting mechanism according to a third embodiment.

FIG. 10 is a positional relationship diagram of the tape tension control mechanism according to the third embodiment when the tape diameter is large.

FIG. 11 is a positional relationship diagram of the tape tension control mechanism of Example 3 in a state where the tape diameter is small.

FIG. 12 is a plan view of a fourth embodiment of a tape cassette equipped with a tape tension control mechanism by a movable mechanism and a control mechanism.

FIG. 13 is a diagram illustrating an example of a conventional method.

FIG. 14 is a diagram showing an example of a configuration for performing constant tension control with a hysteresis plate.

FIG. 15 is a diagram showing an example of a configuration in which a constant tension control is performed by providing a pad material in the head control unit.

FIG. 16 is a diagram showing an example of a configuration in which a tape tension is detected by a tension sensor and constant tension control is performed.

[Explanation of symbols]

 1 Abutting mechanism of the first example 1a Fixed shaft 1b Movable lever 1c Rotating roller 1d Extension spring 2 Control mechanism of the first example 2a Fixture 2b Wire 2c Pulley 22 Abutting mechanism 22a of the second example Tension spring 22b Tape diameter transmission rod 22c Rotating roller 22d Rotating shaft 23 Control mechanism of Example 3 23a Both arms 23b Leaf spring 23c Tightening 23ca Felt material 23cb Coil spring 23d Guide groove 40 Moving mechanism 40a Rotating guide 40b Tension arm 40c Fixed spring 40d Moving spring 41 Cassette half 41a moving groove 8 tape guide 3 supply side reel shaft 4 supply side reel 5 mounting lever 6 tape 7 take-up reel 11,20,42 tape cassette 15 outer peripheral surface of supply side tape

Claims (2)

[Claims] 1. A tape cassette is mounted on the reel shaft, which has two reel shafts on the left and right, and a tape is formed by a rotational force of the reel shaft or a capstan and a pinch roller provided in a tape traveling path. In a tape tension control device for a device that grips and runs the tape by the rotational force of the capstan and pinch roller, the tape surface of the reel on the supply side is placed in the running device or in the tape cassette used in the running device. A tape tension control device comprising: an abutting unit that abuts against the tape; and a control unit that controls a load torque of the supply reel by a displacement amount of the abutting mechanism due to a change in the supply tape amount. 2. The abutting means has a tape tension detecting function, and the movable means is configured to be movable within a predetermined range by the change of the tape tension, and the load torque of the supply reel is controlled by the displacement of the movable means. 2. The tape tension control device according to claim 1, wherein the control means is provided in the tape cassette.