JPS63131361A - Tape drive controller - Google Patents

Abstract

PURPOSE:To apply required tension to a tape without inflecting damage on the tape by using an electric means to apply retension servo without using a mechanical mechanism. CONSTITUTION:A pulse signal as a rotational speed signal detected by 1st and 2nd drive detectors 31, 32 is fed to an arithmetic controller 30 comprising a microcomputer, and the arithmetic controller 30 applies a prescribed arithmetic operation based on a pulse ratio of supplied pulse signals to calculate a tape radius wound on the reel bases 11, 12. Then a drive signal in response to the calculated radius of the tape is outputted from the arithmetic controller 30, it is supplied to the drive motors 21, 22, which drive the reel bases 11, 12 by a prescribed torque respectively. Thus, a prescribed tension is applied even to a very delicate tape without inflicting damage on the tape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for driving and controlling the tape of a tape recorder, for example, and particularly to a means for making the tape tension constant during tape winding.

[Conventional technology]

A conventional tape drive control device of this type is generally equipped with a tension servo mechanism as shown in FIG. In FIG. 5, 1 is a supply reel stand, 2 is a take-up reel stand, 3 is a tape, 4 and 5 are tape guides, and 6 is a tension servo mechanism.

During tape fast forwarding operations such as during high speed access, it is necessary to run the tape 3 at high speed.

In such high-speed running, cab drive is not possible and reel drive is normally used. In this case, in order to prevent damage to the tape 3 and to prevent uneven winding, the tension servo mechanism 6 is operated to control the tape tension to be constant even if the tape winding radius changes. was.

[The problem that the invention attempts to solve]

The conventional device described above has the following problems.

For very delicate tapes such as recent DATs and 8mrn video tape recorders, which have a narrow tape width and a thin tape thickness, the mechanical tension servo mechanism 6 shown in Fig. This is not practical because it will cause damage and it is necessary to secure a space for installing the tension servo mechanism 6, which is quite large.

Therefore, the present invention makes it possible to apply the required constant tension to the tape without damaging the tape, even for extremely delicate tapes with narrow tape width and thin tape thickness, and which takes up an extremely large installation space. It is the object of the present invention to provide a tape drive control device that does not require security.

[Means for solving problems]

In order to solve the above-mentioned problems and achieve the object, the present invention takes the following measures. That is, the first one detects the rotational speed of the supply reel stand and the take-up reel stand. A second rotational speed detector is provided, and the maximum tape winding is determined based on the ratio of the rotational speed signal detected by the first rotational speed detector and the rotational speed signal detected by the second rotational speed detector. A calculation controller is provided to calculate the radius and each tape radius of the supply reel table and the take-up reel table at a given time, and each reel table is controlled with a predetermined torque according to each tape radius calculated by the calculation controller. A driving means is provided.

[Effect]

By taking such measures, the following effects are achieved. Since the tension servo is performed by electrical means rather than a mechanical mechanism, delicate tension adjustment such as soft start is possible. Therefore, even if the tape is extremely delicate with a narrow tape width and a thin tape thickness, a required constant tension can be applied to the tape without damaging the tape. Moreover, it can be achieved by simply attaching a rotational speed detector to the drive motor and providing an arithmetic controller consisting of a microcomputer, etc., resulting in a small and lightweight device, and there is no need to secure a particularly large installation space. Become.

〔Example〕

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. 11
1 is a supply reel stand, 12 is a take-up reel stand, 13 is a tape, and 14 and 15 are tape guides. 2'1 is a direct drive motor on the supply side, and 22 is a direct drive motor on the winding side. A first rotation detector 31 is directly connected to the direct drive motor 21 on the supply side, and a second rotation detector 32 is directly connected to the direct drive motor 22 on the winding side.

FIG. 2 is a diagram showing the configuration of the control system. Pulse signals as rotation speed signals detected by the first and second rotation detectors 31 and 32 are supplied to an arithmetic controller 30 consisting of a microcomputer. The calculation controller 30 performs a predetermined calculation based on the pulse ratio of the supplied pulse signal,
The radius of the tape wound on each reel stand 11, 12 is calculated. The arithmetic controller 20 then outputs a rotational drive signal corresponding to the calculated tape radius, which is applied to each of the drive motors 21 and 22. Thus, each drive motor 21, 22 drives each reel stand 11, 11, 22 with a respective predetermined torque.
12 is driven to rotate. Therefore, the tape 13 is driven to run while maintaining a required constant tension.

Next, the content of calculation control in the calculation controller 30 will be explained with reference to FIGS. 3 and 4.

As shown in FIG. 3, the maximum tape winding radius is Ra, and the minimum tape winding radius (radius of the tape winding portion of the reel stand) is ra. Further, the output of the first rotational speed detector 31 is assumed to be fl, and the output of the second rotational speed detection $32 is assumed to be f2.

"≠-Calculation of maximum winding radius Ra" The tape maximum winding radius Ra is not constant depending on the thickness and length of the tape 13, but is an unknown quantity. On the other hand, the minimum tape winding radius ra, that is, the radius ra of the tape winding portion of the reel stand is a known number based on standards or design. Therefore, at the initial stage of tape winding, if the tape 13 is wound a little to prevent it from loosening, a rotation drive signal having a frequency of fl; f2 is output from the rotation speed detectors 31 and 32. The frequency fl in this rotational speed signal
, f2 are inversely proportional to the tape radius, so Ra can be determined by the formula Ra-ra.f2/f1-(1).

"Calculation of Tape Radius at Any Time" At any time when the tape 13 is running, the tape winding radius on the supply side changes from Ra to Rb as shown in FIG.
The tape winding radius on the winding side changes from "a" to "b".
Suppose that it changes to . Assuming that the tape 13 is always running under a certain amount of tension and does not loosen, the area of the tape winding portion is the same as that of the fourth section even in the case of FIG.
Even in the case of the figure, it is constant and does not change, so π(Ra2-ra2) -yr (Rb2-r a2) +π(r b2-r a2) ,', Ra2=Rb2+ r b2-r a2-(2)
becomes. In addition, when the tape is not slack and is stretched with sufficient tension, the tape speeds of both reel stands 11 and 12 are equal, so the tape speed is set to V.
, the angular velocity of the supply reel stand 11 is ω1, and the take-up reel stand 1 is
If the angular velocity of 2 is ω2, V-Rb・ω1-rb skewer ω
2-(3). Therefore, Rb can be obtained as follows. From the above formula (3), rb-Rb ・ωl/ω2-Rb-f 1/f 2 Substituting this into formula (2), Rb2=Ra2+ r a2-r b2Rb2-Ra2
+ "a2-Rb211α2,', Rb= (Ra
+ra2)/(1+a2)...(4). However, it is α-f 1/f 2. Thus (
4) Rb can be determined using the formula. Further, rb is determined as follows. From equation (3), Rb-11rb@ω2/ω1abrb/α Substituting this into equation (2), r b2-Ra2+ r a2-Rb2 "b2mlIR
a2+ra2-rb2/α2,', rb-Ra+ra)/(1+1/a2)...
(5) It becomes. In this way, rb can be determined using equation (5).

From the above, the maximum tape winding diameter Ra, the minimum tape winding diameter ra, the □ both - small rotational speed ratio α at any time
From, we can calculate the tape radius at any point and get ′.

The torques applied to the reel stands 11 and 12 are TI and T, respectively.
2 and the tape tension is F, then the tape radius R
The torque required for b and rb is T1 Rb-F
...(6) T 2 = r b - F
=-(7). Therefore, in order to obtain the necessary tape tension F, torque TI must be applied to each reel stand 11, 12.

It is sufficient to give each T2.

In this manner, in this embodiment, the tension servo is performed by electrical means rather than a mechanical mechanism, so that delicate tension adjustments such as soft start, for example, are possible.

Therefore, even if the tape 13 is a narrow, thin, and extremely delicate tape, a required constant tension can be applied to the tape 13 without damaging the tape 13. Moreover, since it can be constructed by simply attaching the rotational speed detector 31, 32 to the drive motor 21, 22 and providing the arithmetic controller 30 consisting of a microcomputer or the like, the device is small and lightweight, and an extremely large installation space is secured. It turns out there's no need.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

According to the present invention, the first rotation speed of the supply reel stand and the take-up reel stand is detected. A second rotational speed detector is provided, and the maximum tape winding is determined based on the ratio of the rotational speed signal detected by the first rotational speed detector and the rotational speed signal detected by the second rotational speed detector. An arithmetic controller is provided to calculate the radius and each tape radius of the supply reel stand and the take-up reel stand at an arbitrary point in time, and each reel stand is controlled with a predetermined torque in accordance with each tape radius calculated by the arithmetic controller. Since a driving means is provided, it is possible to apply the required constant tension to the tape without damaging the tape, even for extremely delicate tapes with narrow tape width and thin tape thickness. It is possible to provide a tape drive control device that does not require a particularly large installation space.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention, and FIG.
This figure shows the configuration of the control system of the same embodiment, and FIGS. 3 and 4 are diagrams for explaining the contents of calculation control by the calculation controller. FIG. 5 is a diagram showing a conventional example. 11... Supply reel stand, 12... Take-up reel stand,
13... Tape, 21... Supply side direct drive motor, 22... Winding side direct drive motor, 30
...Arithmetic controller (microcomputer), 31...
・First rotational speed detector, 32...Second rotational speed detector, Applicant's representative Patent attorney Atsushi Tsuboi Figure 1 Figure 2

Claims (1)

[Claims] First and second rotational speed detectors that detect the respective rotational speeds of the supply reel stand and the take-up reel stand, and the rotational speed signal detected by the first rotational speed detector and the second rotational speed detector. an arithmetic controller that calculates the maximum tape winding radius and each tape radius of the supply reel stand and the take-up reel stand at a given time based on the ratio with the rotational speed signal detected by the arithmetic controller; A tape drive control device comprising means for driving each reel stand with a predetermined torque in accordance with each tape radius.