JPH02156458A - Tape tension detection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a tape tension detection device used in a magnetic recording and reproducing apparatus that records and reproduces information using a magnetic tape as a recording medium.

2. Description of the Related Art Various proposals have been made in the past regarding methods of detecting tape tension during running of a magnetic tape.

A conventional tape tension detection device will be described below with reference to the drawings.

FIGS. 4 and 6 are a side view and a plan view showing an outline of a conventional tape tension detection device. In Figures 4 and 5,
9 is a magnetic tape, 8 is a post in contact with the magnetic tape 9, and 10 is an L-shape with the post 8 attached to one end and the other end rotatably attached to a substrate 13 around a support shaft 11. 12 is a clockwise direction of the arm 10;
That is, it is a spring that biases the post 8 in a direction in which it comes into closer contact with the magnetic tape 9. A rotating body 14 is attached to the rotating shaft of a capstan motor that pulls and drives the magnetic tape 9 in the direction indicated by the arrow, and causes the magnetic tape 9 to run in the direction indicated by the arrow by being pressed against the pinch roller 16. Reference numeral 18 denotes a reel stand on which a reel on which the magnetic tape 9 is wound is mounted, and is coaxial and rotates at the same time as the reel. A band 17 is made of felt or the like and is used to tighten the reel stand 18 and apply a brake. One end of the band 17 is fixed to the fixed part 13a, and the other end is attached to the support shaft 11 of the arm 1o. The spring 12 is attached to the opposite side of the body using a metal fitting 16.

With the above configuration, in the conventional tape tension detection device, the magnetic tape 9 is driven in the direction of the arrow by the rotating body 14 attached to the rotating shaft of the capstan motor. At this time, the magnetic tape 9 is pulled and runs in the direction of the arrow, and at the same time there is a pulling force acting in the opposite direction, the direction of the arrow F, so a certain tension is generated in the magnetic tape 9, and this tension causes the post A force in the direction of arrow E is acting on 8. There is a proportional relationship between this tape tension and the force of arrow E. Therefore, when the tape tension increases, it overcomes the force of the spring 12 and the post 8
moves in the direction of arrow E. At this time, the arm 10 also rotates counterclockwise about the support shaft 11 at the same time as the post 8 moves. Therefore, when attaching the band 17, the metal fitting 16 also rotates counterclockwise, and the band 17 tightens the reel stand 18.
When tightening, the torque decreases, which causes the braking force acting in the direction of arrow F to decrease, and therefore the force in arrow F to decrease. This reduces the tape tension, and the tape tension is always stabilized at a preset constant value.

Problems to be Solved by the Invention However, in the conventional configuration as described above, the relationship between the tape tension and the amount of post movement is affected by changes in the spring force, and the post attachment is affected by the axial load of the fulcrum of the metal fitting and the friction coefficient of the band. The problem is that the tape tension changes over time and due to changes in environmental conditions, making it extremely unstable and making it impossible to accurately detect the tape tension.

Means for Solving the Problems In order to solve the above problems, the tape tension detection device of the present invention includes a semiconductor element that detects pressure by a change in resistance value using the piezoresistance effect of a silicon semiconductor, and a semiconductor element that detects pressure by a change in resistance value. a cylindrical rotating body rotatably attached to the column for transmitting running tension of the magnetic tape to the semiconductor element as pressure; and a side surface opposite the column to which the semiconductor element is attached. It is equipped with a shock absorber made of felt or the like attached to the side surface.

Effect: With the above-described configuration, the present invention detects the pressure of the tape pressing the support column directly through the cylindrical rotating body using the semiconductor element in proportion to the tape tension, so there is no mechanical damage due to changes over time or environment. Stability elements can be removed and accurate pressure can be detected at all times. Furthermore, since the magnetic tape is wound around a rotating cylindrical rotating body while directly contacting the semiconductor element or indirectly contacting the semiconductor element,
There is no problem with the running of the magnetic tape, and even if excessive acceleration is applied to the rotating body due to a fall, etc., the cushioning material is placed on the support, so that the shock from this rotating body is reduced from being applied to the semiconductor element. , semiconductor devices are indestructible.

EXAMPLE Hereinafter, an example of the tape tension detection device of the present invention will be described with reference to the drawings.

FIG. 1 is a plan sectional view of one embodiment of the present invention, and FIG. 2 is a side sectional view of the same. FIG. 3 is a diagram simply showing the movement when an impact is applied.

In FIGS. 1 and 2, 4 is a semiconductor element configured to change resistance depending on pressure by utilizing the piezoresistance effect of a silicon semiconductor; 3 is in contact with the semiconductor element;
A spherical rigid body for transmitting pressure; 1 is a support having a concave portion 1a on its side for housing the semiconductor element 4 and the rigid body 3; 2 is a cylindrical rotating body arranged to rotate around the support 1; , 6 is a buffer layer made of a feather A/) or the like provided on the opposite side of the support 1 from the semiconductor element 4. The support column 1 is fixed to the substrate 6 so that the outer peripheral portion of the rotating body 2 facing the semiconductor element 4 comes into contact with the running magnetic tape 7.

In this embodiment, when the tape is driven, the magnetic tape 7 wraps around the rotating body 2 at a certain angle and travels, as shown in FIG. The magnetic tape 7 applies pressure to the rotating body 2, and this pressure is applied to the semiconductor element 4 via the rotating body 2 and the rigid body 3. As a result, if there is running tension of the magnetic tape 7, the semiconductor element 4 outputs a signal based on a change in resistance value in accordance with the pressure.

Now, when the magnetic tape 7 is removed from the state shown in FIG. 1, that is, when it is not in use, if an impact is applied to the board 6 in the direction of the arrow in FIG. The positional relationship is such that the rotating body 2 is in contact with the rigid body 3 on the opposite side. At this time, if there is no buffer layer 5 made of felt or the like and the support 1 and the rotating body 2 have high hardness,
When the positional relationship shown in FIG. 3A is reached, the rotating body 2 rebounds due to the impact, and the rotating body 2 collides with the rigid body 3 as shown in FIG. 3. The acceleration of the rotating body 2 at that time is very close to the acceleration when the impact is applied to the substrate 6 for the first time. Also, depending on the acceleration at that time, it will look like Figure 3 C,
Repeat this positional relationship between the mouth and C in Figure 3 many times. In the positional relationship shown in FIG. 3, a force equal to the weight of the rotating body 1 and the rigid body 3 multiplied by acceleration is applied to the semiconductor element 4, which may cause breakage or the like. Therefore, by arranging the buffer layer 6 as shown in FIGS. 1 and 2, the impact caused by the acceleration at times A or C in FIG. , the impact caused by the rotating body 2 is greatly reduced. In addition, as long as the impact applied to the semiconductor element 4 at the end of FIG. It is small enough.

Effects of the Invention As described above, the tape tension detection device of the present invention utilizes the piezoresistance effect of a silicon semiconductor, and a semiconductor element that detects pressure by a change in resistance value is installed in the support, and the tension is detected by the running tension of the magnetic tape. Pressure is detected by the semiconductor element via a rotating body and a rigid body. Pressure can be directly detected without intervening mechanical elements, and the running tension of the tape can be stably detected. Furthermore, even when a shock is applied due to excessive acceleration due to a fall, etc., the shock can be softened by the buffer, and the semiconductor element can be prevented from being destroyed.

[Brief explanation of the drawing]

Fig. 1 is a plan sectional view showing a tape tension detection device according to an embodiment of the present invention, Fig. 2 is a sectional view of the same side, and Fig. 3 is a rotating body relative to a support when acceleration such as falling is applied to the device. FIG. 4 is a side view showing a conventional tape tension detection device, and FIG. 6 is a plan view thereof. 1... Support column, 2... Rotating body, 3...
... Rigid body, 4 ... Semiconductor element, 6 ...
- Buffer layer, 6...Substrate, 7...Magnetic tape. Name of agent: Patent attorney Shigetaka Awano and 1 other person 2nd
Figure f・-4 (2-Rotating body 5-41 total j also □C figure figure figure figure figure

Claims (1)

[Claims] a circular support with a recess formed on a side surface; a cylindrical rotating body rotatably fitted to the outside of the support; and disposed within the recess of the support so as to abut against an inner wall of the rotating body. a semiconductor element whose resistance value changes depending on the strain applied, and a buffer layer provided on a side surface of the pillar opposite to the recess,
A tape tension detection device characterized in that the support column is arranged so that a running magnetic tape comes into contact with an outer circumferential portion of the rotating body facing the semiconductor element.