JPH0721627A - Detection of tape tension and detector therefor - Google Patents

Abstract

PURPOSE:To exactly detect the tension of a traveling tape with a less traveling load on the tape and at a high response speed by bringing a detecting element into contact with the traveling tape under prescribed pressure and detecting the reaction of the tape. CONSTITUTION:The detecting element 2 is brought into contact with the bottom edge of the tape 1 on which the tension is applied. The reaction of the tension is determined by the bending rigidity of the tape, the tension acting on the tape and the pressing amt. of the detecting element on the tape. The tension of the tape is determined by measuring the reaction of the tape acting on the detecting element if the bending rigidity of the tape and the pressing amt. of the detecting element are fixed. The traveling route of the tape is simplified and the traveling load of the tape is decreased, the response speed is made high, and the tension of the tape is identified with good accuracy by this method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape tension detecting method for a tape device for recording and reproducing information and its detecting device.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional tape tension detecting device. Reference numeral 1 is a tape, 22 and 23 are guide rollers for guiding the tape, 25 is an arm which rotates around a rotation support shaft 24, and 26 is a detection post which is erected on the arm 25. Reference numeral 27 is a spring, 28 is a light emitting diode, 29 is a photodiode for receiving the light of the light emitting diode 28, and 30 is a light shielding plate attached to the arm 25.

The spring 27 gives a torque that tends to rotate the arm 25 clockwise. However, the detection post 2
Since the component of the tension T of the tape 1 acts on 6,
The arm 25 is also given a counterclockwise torque. Spring 2
At the position where the clockwise torque given from 7 and the counterclockwise torque received from the tape 1 become equal,
5 is stationary. That is, the stronger the tension of the tape 1, the more the arm 25 rotates counterclockwise, and the weaker the tension of the tape 1, the more the arm 25 rotates clockwise.

Here, the light shield plate 30 attached to the arm 25 blocks more light from the light emitting diode 28 when the arm 25 rotates counterclockwise, and the amount of light received by the photodiode 29 decreases. Therefore, the higher the tension of the tape 1, the more the photodiode 29
The amount of received light is reduced.

The tension of the tape 1 can be detected by setting the strength of the spring 27 to an appropriate value and measuring the photocurrent of the photodiode 29. As described above, in the conventional tape tension detection method, the detection post 26 is pressed against the tape 1, and the reaction force due to the tape tension acting on the detection post 26 is measured by the position of the detection post 26.

[0006]

However, according to the above-mentioned conventional configuration, it is necessary to sandwich the tape 1 between the detection post 26 and the guide rollers 22 and 23, which complicates the tape path and increases the tape running load. Since the detection post 26 and the arm 25 supporting the detection post are pressed against the tape 1 by the spring force, the response speed is slow and the resonance of the spring-mass system is likely to occur.

There is a problem that An object of the present invention is to provide a tape tension detecting method and a detecting device therefor, in which the tape running load is small, the response speed is fast, and the tape tension can be accurately detected.

[0008]

A tape tension detecting method according to claim 1, wherein a detector is brought into contact with the tape in a direction perpendicular to a traveling direction of the tape with a predetermined pressing force, and a reaction force of the tape applied to the detector is applied. Is the tape tension measured. The tape tension detection device according to claim 2, wherein a detector that is in contact with the traveling tape in a direction perpendicular to the traveling direction with a predetermined pressing force, and a strain gauge that detects the reaction force of the tape applied to the detector. And an output means for outputting the detection signal of the strain gauge.

[0009]

According to the structure of the present invention, when the detector is brought into contact with the tape under tension and a small amount is pushed from there, the tape is deformed in the width direction and a component force is generated on the tape, and the tape is attached to the detector. The reaction force of. The reaction force of the tape is
The bending stiffness of the tape and the tension acting on the tape,
It depends on how much the detector is pushed into the tape. Therefore, if the bending stiffness of the tape and the amount by which the detector is pressed are constant, the tension of the tape can be obtained by measuring the reaction force of the tape applied to the detector.

[0010]

【Example】

First Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1A is a perspective view showing a tape tension detecting device in the first embodiment. 1
Is a tape, 8 and 9 are guide posts, 2 is a detector for measuring the reaction force at the edge of the tape 1, and is a cantilever made of an aluminum material to which the semiconductor strain gauge 4 is bonded.
FIG. 1B is a schematic cross-sectional view taken along the line AA of FIG. 7
Is the XYZ stage. When the detector 2 is brought into contact with the lower edge portion of the tape 1 and a small amount is pushed in the width direction of the tape 1 from there, the reaction force of the tape 1 bends the detector 2 and a resistance change occurs in the semiconductor strain gauge 4. . This change in resistance is detected by the strain amplifier 5, and this output is output to the oscilloscope 6
To measure. The strain amplifier 5 and the oscilloscope 6 constitute an output means.

2A and 2B and FIGS. 3A and 3B,
Tape 1 under tension in Figure 1 (a)
The detector 2 is brought into contact with the lower edge portion of the
FIG. 4 is a front view and a cross-sectional view showing the relationship of forces acting when a small amount is pushed in in the width direction of FIG. At this time, tape 1
Movement in the width direction is regulated by the guide posts 8 and 9.

2 (a) and 2 (b) show the relationship of forces when the detector 2 is pushed into the lower edge portion of the tape 1 and the tape 1 is not deformed in the thickness direction. When the tension applied to the tape 1 is T, the detector 2 is a resultant force of a component force T ₁ applied by the tension T in the width direction of the tape 1 and an elastic restoring force N due to bending deformation of the tape 1. The reaction force F of the tape 1 is applied.

FIGS. 3 (a) and 3 (b) show the relationship of forces for deforming the tape 1 in the thickness direction when the detector 2 is pushed into the lower edge portion of the tape 1. As shown in FIG.
A component force T ₁ in the width direction component of the tape 1 of the tension T shown in (a), the component force S ₁ in the width direction component of the tape 1 of the tension S shown in FIG. 3 (b), by the bending deformation tape 1 The reaction force F of the tape 1, which is the resultant force with the elastic restoring force N, is applied.

When the detector 2 is brought into contact with the lower edge portion of the tape 1 and pushed in by a very small amount, the detector 2 moves the tape 1
The force pushing the lower edge portion and the reaction force F of the tape 1 are in equilibrium. The reaction force F of the tape 1 becomes large when the tension of the lower edge portion of the tape 1 is strong, and becomes small when the tension is weak.

FIG. 4 shows the relationship between the reaction force F of the tape 1 shown in FIGS. 2 and 3 and the tension T at the lower edge portion of the tape 1. Thus, if the relationship between the tension T and the reaction force F of the tape 1 is obtained in advance by an experiment, the tension T can be calculated from the measured reaction force F of the tape 1 arbitrarily. In the embodiment, the detector 2 is pressed in the width direction of the tape 1 to measure the reaction force, but the detector is pressed in the tape thickness direction to measure the reaction force of the tape. May be.

Second Embodiment FIG. 5 is a schematic view showing a tape tension detecting device according to a second embodiment of the present invention. 2 and 3 are detectors, 7
Is the XYZ stage. Similar to the first embodiment, the reaction force F ₁ of the tape 1 at the lower edge portion of the tape 1 is obtained.
Also at the upper edge of the tape 1, the detector 3 is pushed into the upper edge portion of the tape 1 by a small amount (the same amount as the lower edge of the tape 1), and the reaction force F ₂ of the tape 1 at the upper edge portion of the tape 1 is obtained. . In this way, the tension T _{1 at} the lower edge portion of the tape 1 and the tension T ₂ at the upper edge portion of the tape 1 can be obtained from the reaction forces F ₁ and F ₂ of the tape 1.

In the tape device, the distribution of tension in the width direction is an important factor for the stable running of the tape, but it could not be measured conventionally. According to this embodiment, this is possible, and by incorporating it into the tape device or using it for adjustment during manufacturing, the tape running performance of the tape device can be greatly improved. Third Embodiment FIG. 6 is a schematic diagram showing a tape tension detecting device according to a third embodiment of the present invention. This embodiment relates to a magnetic recording / reproducing apparatus in which a tape is wound around a drum for helical scan recording / reproducing at a predetermined angle. 15 and 16 are mounts to which the detectors 2 and 3 are fixed, 1
Reference numeral 0 is a drum, 11 is a head for recording and reproducing information on the tape 1, and the tape 1 is regulated by guide posts 8 and 9 and runs in the direction of arrow B. 7 is a sectional view of the detector 2 and the mounting base 15 in FIG. 6, and FIG.
3 is a cross-sectional view of the detector 3 and the mounting base 16 in FIG. 12 is an electronic micro, 17 and 18 are pins having a threaded portion, 19 is a hole through which the pin 18 passes, and 20 and 21 are mounting bases 15 and 16.
Is the mounting surface. As shown in FIG. 6, the detector 2 is installed immediately before the tape 1 contacts the drum 10. Figure 7
By rotating the pin 17 to finely adjust the height of the mounting surface 20, the detector 2 is pushed into the lower edge portion of the tape 1 by a small amount, and the reaction force of the tape 1 is measured. Similarly, FIG.
As shown in, the detector 3 is installed immediately after the tape 1 leaves the drum 10. In FIG. 8, the pin 18 is rotated and the height of the mounting surface 21 is finely adjusted, so that the tape 1 is pushed into the upper edge portion by a small amount and the reaction force of the tape 1 is measured. At this time, the change in height of the mounting surfaces 20 and 21 is measured by the electronic micro 12. With the above configuration, the tension T ₂ the upper edge of the tension T ₁ and tape 1 of the lower edge of the tape 1 can be measured.

According to this embodiment, the tension of the tape 1 which largely influences the contact state between the tape 1 and the head 11 which determines the recording density of information, and the tension of the tape 1 at the drum entrance side are the portions where the head 11 enters the tape 1. The tension T ₁ at the lower edge portion of the tape 1 can be measured with high accuracy, and the tension T ₂ at the upper edge portion of the tape 1 where the head 11 separates from the tape 1 on the drum exit side can be measured with high accuracy. Therefore, it is possible to adjust the contact between the tape 1 and the head 11 that determines the information recording density to the optimum state.

The detector may be provided on only one of the drum input side and the drum output side.

[0020]

According to the tape tension detecting method and the tape tension detecting device of the present invention, when the detector is brought into contact with the tape under tension and a small amount is pushed from there, the tape is deformed in the width direction and divided into the tape. A force is generated and the reaction force of the tape is applied to the detector. The reaction force of the tape is determined by the bending stiffness of the tape, the tension acting on the tape, and the amount by which the detector is pressed into the tape. Therefore, if the bending stiffness of the tape and the amount by which the detector is pressed are constant, the tension of the tape can be obtained by measuring the reaction force of the tape applied to the detector. In this way, the tape tension is obtained by the reaction force applied to the detector pressed against the tape, so that the tape traveling path is simplified, the tape traveling load is small, the response speed is fast, and the tape tension can be accurately detected. can get.

[Brief description of drawings]

FIG. 1 is a perspective view and a sectional view of a tape tension detecting device according to a first embodiment of the present invention.

2A and 2B are a front view and a sectional view for explaining a tape tension detecting operation of the first embodiment of the invention.

3A and 3B are a front view and a sectional view for explaining the tape tension detecting operation of the first embodiment of the invention.

FIG. 4 is a characteristic curve diagram showing the relationship between tape reaction force and tape tension in the first embodiment of the present invention.

FIG. 5 is a sectional view of a tape tension detecting device according to a second embodiment of the present invention.

FIG. 6 is a plan view of a tape tension detecting device according to a third embodiment of the present invention.

FIG. 7 is a partial sectional view of a tape tension detecting device according to a third embodiment of the present invention.

FIG. 8 is a partial sectional view of a tape tension detecting device according to a third embodiment of the present invention.

FIG. 9 is a plan view of a conventional example.

[Explanation of symbols]

 1 Tape 2, 3 Detector 4 Semiconductor strain gauge 5 Strain amplifier 6 Oscilloscope 7 XYZ stage 8, 9 Guide post

Claims (2)

[Claims] 1. A tension of the tape is obtained by contacting a detector with a predetermined pressing force in a direction perpendicular to the traveling direction of the traveling tape and measuring a reaction force of the tape applied to the detector. Tape tension detection method. 2. A detector that is in contact with a running tape in a direction perpendicular to the running direction with a predetermined pressing force, and a strain gauge that detects a reaction force of the tape applied to the detector.
A tape tension detecting device having an output means for outputting a detection signal of the strain gauge.