JPH02287947A - Tension controller - Google Patents

Abstract

PURPOSE:To give the stable prescribed tension even in the case a tape running state is stable and in the case it is in a transient state by detecting the speed-of- revolution information of a reel, and also, discriminating whether a speed of the tape is in a stable state or not. CONSTITUTION:Since a speed of a tape 1 is constant, periodic information outputted from a periodic information converting means 7 is information being proportional to a radius of a reel 2. From a multiplying circuit 9, torque information being proportional to the radius of the reel 2 is outputted by multiplying the periodic information by a constant. In this case, since a tape speed is in a stationary state, from a result of output of a comparing means 8, an output (torque information) of the multiplying circuit 9 is latched by a holding means 10, and outputted to a driving circuit 11. A reel driving device 4 is driven by the driving circuit 11, and an output of the holding means 10 is converted to torque. Accordingly, tension applied to the tape 1 becomes constant irrespective of the radius of the reel 2. Also, in the case the tape speed is in a transient state, by a result of output of the comparing means 8, the output of the multiplying circuit 9 latched at the time of a stable state is held by the holding means 10.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a video tape recorder (hereinafter abbreviated as VTR).
or digital audio tape recorder (hereinafter referred to as DAT)
The present invention relates to a tape tension control device in a tape running system such as the following.

Conventional technology In recent years, recording and reproducing devices that use tape have become smaller.

As recording densities continue to increase, higher performance control is required. For example, tape tension control is essential to maintain uniform contact between the tape and the head.

An example of the above-mentioned conventional tension control device will be described below with reference to the drawings.

FIG. 7 is a block diagram showing an example of a conventional tension control device, in which the tension lever 14 is a tension post installed at one end of the tension lever 15;
17 is a photocoupler; 18 is a compensation amplifier; 19 is a motor drive circuit; 20 is a tape; 21 is a cylinder; 22 is a capstan; 23 is a pinch roller; 25a, 25b, and 25c are bosses that form the running path of the tape 20. The reel 25a, 25b, and 25c is a reel that winds the tape 20 attached to the reel motor so as to share a shaft. The operation of the tension control device configured as described above will be described below.

The principle of operation of the tension control device shown in FIG.
The purpose is to maintain a balance between the tension applied to the spring 16 and the spring force of the spring 16. To achieve this, Tension Bost 1
The displacement of 4 is detected by the photocoupler 17, and the compensation amplifier 18
After being amplified by the motor drive circuit 19, the reel 24
Controls the torque generated. As a result, the displacement of the tension post 14 is kept constant, and the tension applied to the tape 20 becomes a constant value (for example, VTR design latest technical data collection, published by Hon Kogyo Center).

Problems to be Solved by the Invention However, the above configuration requires a tension lever and a photocoupler, which not only hinders miniaturization, but also because the tension post 14 is in contact with the tape 20 while the tape is running. The load for running the tape 20 increases.

Further, there is a problem in that stable tension control is impossible when the tape running state is in a transient state.

The present invention solves the above-mentioned problems, and allows stable constant tension even when the tape running state is stable as well as when the tape running state is transient, without providing a tension lever. The object of the present invention is to provide a tension control device for applying tension to a tape.

Means for Solving the Problems To achieve this object, the tension control device of the present invention includes a first reel around which a tape is wound, and a tension control device that drives the first reel so that the tape runs at a constant speed. a reel driving means, and a first reel that outputs rotation speed information of the first reel.
a rotational speed information detecting means, a first periodic information converting means for converting the output of the first rotational speed information detecting means into periodic information, a second reel around which the tape is wound, and a second reel on which the tape is wound; A reel driving device for driving the reel, a second rotation speed information detection means for outputting rotation speed information of the second reel, and converting the output of the second rotation speed information detection means into cycle information and outputting it. a second periodic information converting means; a multiplication circuit that multiplies the output of the second periodic information converting means by a constant and outputs the result; and a multiplication circuit that calculates the periodic information output from the first and second periodic information converting means. , a calculation means for outputting tape speed information; a comparison means for determining whether the tape speed is in a steady state from the output of the calculation means and outputting a result; It is comprised of a hold means which latches the output of the multiplier circuit if the output is present, but does not perform a new latching operation if it is in an unsteady state, and a drive circuit which receives the output of the hold means and drives the reel drive device.

Effect of the present invention With the above-described configuration, the rotational state of the second reel is converted into periodic information by the second periodic information converting means through the second rotational speed information detecting means.

Since the tape speed is constant, this period information provides information about the radius of the reel. The period information is multiplied by a constant by a multiplication circuit and converted into torque information. When the tape speed is stable, the torque information is latched by the hold means and output as is. The reel drive device is driven by a drive circuit and generates a torque proportional to the torque information. Since this torque is proportional to the radius of the reel, the tension applied to the tape is constant regardless of the radius of the reel. Further, based on the output of the comparison means for determining whether the tape speed is in a steady state, the holding means holds steady state torque information when the tape speed is in a transient state. Therefore, even when the tape speed is in a transient state, stable tension is applied to the tape.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a tension control device in an embodiment of the present invention. In FIG. 1, 1 is a tape, 2a,
2b is a first and second reel around which the tape 1 is wound; 4 is a reel drive device for driving the second reel 2b; 5 is a reel drive device for driving the second reel 2b;
a, 5b are the first. The first and second rotation speed information detecting means output the rotation speed information of the second reels 2a and 2b; The first one converts the output of the second rotation speed information detection means 5 al 5 b into period information and outputs it. A second periodic information converting means 12 is a first periodic information converting means. Second period information conversion means 6, 7
8 is a calculation means for calculating period information output from the calculation means 12 and outputting speed information of the tape 1; 8 is a comparison means for determining whether the speed of the tape 1 is in a steady state by the calculation means 12 and outputting the result; 9 is a comparison means for outputting the result. A multiplier circuit 10 multiplies the output of the periodic information converting means 7 by a constant and outputs the result, and a multiplier 10 latches the output of the multiplier circuit 9 when the speed of the tape 1 is in a steady state, depending on the output result of the comparing means 8. 11 is a drive circuit that drives the reel drive device 4; 31 is a target value generation circuit that outputs target speed information of the tape 1; and 34 is a target value generation circuit 31 and arithmetic operation. 33 is a reel drive device for driving the first reel 2a; 32 is a drive circuit for driving the reel drive device 33;

The operation of the tension control device of this embodiment configured as described above will be explained below.

In this embodiment, the first reel 2a takes up the tape 1.
The second roll 2b feeds the tape 1. That is,
The tape 1 is fed from the second reel 2b toward the first reel 2a. (Hereinafter, unless the direction of the tape 1 is specifically described, it is assumed that the tape 1 is fed in the direction from the second glue 2b to the first glue 2a.) In FIG.
In order to keep the tension value constant, the radius of the second reel 2b including the tape winding thickness (hereinafter referred to as the radius of the first and second reels 2a and 2b is the radius including the tape winding thickness). It is sufficient to apply a torque proportional to ) to the second guide wheel 2b. Further, the first rotation speed information detection means 5a transmits information proportional to the rotation of the first reel 2a, and the second rotation speed information detection means 5b transmits information proportional to the rotation of the first reel 2b.
Information proportional to the rotation of can be obtained. 1st. Second
The output of the rotation speed information detection means 5 al 5 b of the first. The second period information converting means 6 and 7 convert it into period information and output it. This first. The period information outputted from the second period information conversion means 6, 7 is calculated by the calculation means 12 and converted into tape 19 speed information. Therefore, by determining the speed information of the tape 1 outputted from the calculation means 12, the comparing means 8 can determine whether the speed of the tape 1 is in a steady state. Also,
The subtracter 34 subtracts the speed information of the tape 1 outputted from the calculating means 12 and the target speed information outputted from the target value generation circuit 31, and outputs the amount of speed error of the tape 1 to the drive circuit 32. The reel drive device 33 is a drive circuit 32
, and generates a torque proportional to the speed error of the tape 1. The first reel 2a is rotated by a reel drive device 33 to wind up the tape 1. Since torque is generated by the reel drive means 33 until the speed of the tape 1 reaches the target value and the error amount becomes O, it becomes possible to run the tape 1 at a constant speed at the target speed.

First, consider the case where the tape speed is stable in a constant steady state. Since the speed of the tape 1 is constant, the periodic information outputted from the second periodic information converting means 7 is information proportional to the radius of the tape 2. The multiplication circuit 9 multiplies the cycle information by a constant and outputs torque information proportional to the radius of the reel 2. Since it is now in a steady state, the output (torque information) of the multiplication circuit 9 is latched by the holding means 10 based on the output result of the comparison means 8, and is output to the drive circuit 11. The reel drive device 4 is driven by a drive circuit 11, and the output of the holding means 10 is converted into torque. Since this torque is proportional to the radius of the reel 2, the tension applied to the tape 1 is constant regardless of the radius of the reel 2.

Next, consider the case where the tape speed is in a transient state. At this time, the output of the multiplier circuit 9 changes due to fluctuations in the tape speed, but the output result of the comparison means 8 determines the output of the hold means 10.
Since no new latching operation is performed, the output of the multiplier circuit 9 latched in the steady state is held in the hold means 10. Therefore, disturbances in the torque information due to changes in the rotation of the second girdle 2b do not cause disturbances in the torque applied to the second girdle 2b, making it possible to apply stable tension.

As mentioned above, even in the transient state of tape speed,
Even when the speed of the tape 1 changes over time due to a load or the like during running in a steady state, it is possible to keep the tension value applied to the tape 1 constant.

Next, FIG. 2 shows a second embodiment of the present invention.

This will be explained with reference to FIG. FIG. 2 is a block diagram of a tension control device in a second embodiment of the invention. In FIG. 2, the same parts as in FIG. 1 are given the same numbers and their explanations will be omitted. 63 is a first timing generation circuit that receives the output of the first rotation speed information detection means 5a and outputs a signal that is inversely proportional to the rotation speed and has a minute pulse width compared to the period; 64 is a first timing generation circuit; A first counter circuit 62 initializes each falling edge of the signal output from the circuit 63 and repeats the counting operation, and a first counter circuit 62 outputs an initial value when the first counter circuit 64 initializes. An initial value generation circuit; 61 is a first clock generation circuit that generates a clock for the first counter circuit 64 to perform a counting operation; 65 is a first timing generation circuit 63;
a first latch circuit 73 that latches the output of the first counter circuit 64 at the rising edge of the signal output from the first latch circuit 73;
74 is a second timing generation circuit that receives the output of the second rotation speed information detection means 5b and outputs a signal that is inversely proportional to the rotation speed and has a minute pulse width compared to the period; and 74 is a second timing generation circuit. A second counter circuit 73 initializes and repeats the counting operation every falling edge of the signal output from 73, and 72 a second initializer that outputs an initial value when the second counter circuit 74 initializes. A value generation circuit 71 is a second clock generation circuit that generates a clock for the second counter circuit 74 to perform a counting operation. A second latch circuit latches the output of the counter circuit 74, 81 is an upper limit/lower limit generation circuit that outputs an upper limit value and a lower limit value, and 82 is an upper/lower limit value generation circuit that outputs the output of the calculation means 12 and the upper/lower limit value generation circuit 81. 83 is a second comparator that compares the output of the calculation means 12 with the lower limit value output from the upper and lower limit generation circuit 81; 84 is the first comparator; 82 and the second comparator 83, and 101 is a D latch circuit.

FIG. 5 is a waveform diagram showing the operation of each part in FIG. 2.

The operation of the tension control device configured as described above will be explained below.

The first reel 2a is rotating together with the reel driving device 33, and the first rotation speed information detection means 5a detects the rotation speed information of the reel 2a. First rotation speed information detection means 5a
outputs a pulse every time the reel 2a rotates by a certain angle. This situation is shown in FIG. 5A. The first timing generation circuit 63 receives the output of the first rotation speed information detection means 5a and generates a signal. This output is shown in FIG. 5B. The first counter circuit 64 inputs the first initial (value of the IF generation circuit 62) at the falling edge of the output signal of the first timing generation circuit 63, and starts counting at the output of the first clock generation circuit 61. This situation is shown in FIG. The second reel 2b is rotating together with the reel drive device 4, and the second rotation speed information detecting means 5b detects the rotation speed information of the second reel 2b. The rotation speed information detecting means 5b outputs a pulse every time the second reel 2b rotates by a certain angle.This situation is shown in FIG. 5E.The second period information converting means 7 converts the first period information. The operation similar to that of the means 6 is performed to convert the output of the second rotational speed information detection means 5b into period information.This situation is shown in FIG. (FIG. 5D) and the output of the second cycle information converting means 7 (FIG. 5F) are calculated to output speed information of the tape 1.

This situation is shown in FIG. 5G. The first comparator 82 compares the output of the calculation means 12 with the upper limit value output from the upper limit value lower limit value generation circuit 81, and when the output of the calculation means 12 is less than or equal to the upper limit value, the first comparator 82 is at a high level (hereinafter referred to as rHJ). omitted)
is low level (hereinafter abbreviated as rLJ) in other cases.
Output. The second comparator 83
The output of the calculation means 12 is compared with the lower limit value outputted from the upper and lower limit generation circuit 81, and if the output of the calculation means 12 is equal to or higher than the lower limit value, rHJ is output, and otherwise, rLJ is output.

The AND circuit 84 outputs rHJ only when the outputs of the first comparator and the second comparator are both rHJ, and outputs rLJ in other cases. This situation is shown in FIG. 5H. The D latch circuit 101 outputs the output of the multiplier circuit 9 as is when the output of the AND circuit 84 is rHJ, and when the output of the AND circuit 84 is rLJ, the output of the AND circuit 84 is the last one that was "I("). The output of the multiplier circuit 9 is held. This situation is shown in FIG. The output of the multiplication circuit 9 in a steady state is held by the D latch circuit 101.

Therefore, disturbances in the torque information due to changes in the rotation of the second reel 2b do not result in disturbances in the torque applied to the second reel 2b, making it possible to apply stable tension.

As mentioned above, even in the transient state of tape speed,
Even when the speed of the tape 1 changes over time due to a load or the like during running in a steady state, it is possible to keep the tension value applied to the tape 1 constant.

Next, FIG. 3 shows a third embodiment of the present invention.

This will be explained with reference to FIG. FIG. 3 is a block diagram of a tension control device in a third embodiment of the present invention. In FIG. 3, the same parts as in FIGS. 1 and 2 are given the same numbers, and their explanations will be omitted. 66.76 is the 1st.
This is a timing generation circuit that outputs a latch signal and a reset signal after a certain period of time from the output of the second rotational speed information detection means 5a, 5b at a period inversely proportional to the rotational speed. The difference between this embodiment and the second embodiment is that the timing generation circuit generates a reset signal and a latch signal.

FIG. 6 is a waveform diagram showing the operation of different parts between this embodiment and the second embodiment, and the operation will be explained below.

The first rotation speed information detection means 5a is a first IJ-rule 2a.
Outputs a pulse every time it rotates by a certain angle.

This situation is shown in FIG. 6J. The first timing generation circuit 86 receives the output of the first rotation speed information detection means 5a and generates a latch signal and a reset signal.

The latch signal is shown in FIG. 6K, and the reset signal is shown in FIG. The first counter circuit 64 inputs the value of the first initial value generation circuit 62 using the reset signal output from the first timing generation circuit 66, and inputs the value of the first initial value generation circuit 62.
Count the output of . This situation is shown in FIG. 6M.

The first latch circuit 65 latches the output of the first counter circuit 64 with the latch signal output from the first timing generation circuit 66. This situation is shown in FIG. 6N.

Further, the second periodic information converting means 7 also performs the same operation as the first periodic information converting means 6.

As described above, in this embodiment, as in the first embodiment, even when the tape speed is in a transient state, or when the speed of the tape 1 changes from time to time due to load etc. during running in a steady state, , it becomes possible to keep the tension value applied to the tape 1 constant.

Next, a tension control device according to a fourth embodiment of the present invention will be described with reference to FIG. 4.

FIG. 4 is a block diagram of a tension control device in a fourth embodiment of the present invention. In FIG. 4, the same parts as in FIG. 1 are given the same numbers and their explanations will be omitted. 121
is an adder that adds the output of the first periodic information converting means 6 and the output of the second periodic information converting means 7.

The operation of the tension control device of this embodiment configured as described above will be described below.

The first period information conversion means 6 outputs the period information of the first rail 2a, and the second period information conversion means 7 receives the period information of the second rail 2a.
The period information of the tape 2b is outputted, and the speed information of the tape 1 can be easily obtained by adding the period information.

In this embodiment, as in the first embodiment, even if the tape speed is in a transient state or while running in a steady state - even if the speed of the tape 1 fluctuates due to load or the like, the steady state multiplication Since the output of the circuit 9 is held by the holding means 10, a disturbance in the torque information due to a change in the rotation of the second reel 2b does not result in a disturbance in the torque applied to the second reel 2b, and the torque applied to the tape 1 is not disturbed. It becomes possible to keep the tension value constant.

Although the embodiment has been described only in the case where the hold means is constituted by a D latch circuit, similar effects can be obtained even if the hold means is constituted by a D flip-flop circuit. Furthermore, although only the case where the calculation means 12 is configured with an adder has been described, the same effect can be obtained even if the calculation unit 12 is configured to square the period information and perform the addition, for example. Also, the running direction of the tape 1 is set to the second reel 2b.
Although only the case of the first rail 2a has been described, the same effect can be obtained even in the opposite direction. Therefore, it goes without saying that the present application is not limited to the examples only.

Effects of the Invention As described above, the present invention detects rotation speed information of the second reel to control the second reel, and determines whether the tape speed is in a steady state to control the second reel. The control state is set, and the tension can be controlled without depending on the tape winding thickness without providing a tension lever. In addition, stability is ensured when the tape speed changes over time due to load or the like during a tape speed transient state or during running in a steady state. For example, DAT and V
When used in a TR, a mechanism related to tension control can be omitted, resulting in a smaller size, and at the same time, tension control can be performed without contacting the tape, reducing the tape running load when the tape is running at high speed.

As a result, higher-speed tape running can be realized, and the effect is significant.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a tension control device according to an embodiment of the present invention, FIG. 2 is a block diagram of a tension control device according to a second embodiment of the present invention, and FIG. 3 is a block diagram of a tension control device according to a second embodiment of the present invention. 4 is a block diagram of the tension control device in the fourth embodiment of the present invention, FIG. 5 is a waveform diagram showing the operation of the second embodiment, and FIG. 8 is a block diagram of the tension control device in the fourth embodiment of the present invention. Waveform diagram showing the operation of Example 3, No. 7
The figure is a block diagram of a conventional tension control device. 1...Tape, 2a, 2b...Reel, 3
... Reel driving means, 4... Reel driving device,
5a, 5b... rotation speed information detection means, 6,
7... Cycle information conversion means, 8... Comparison means, 9
...Multiplication circuit, lO...Holding means, 1! ...
drive circuit, 12... calculation means; Name of agent: Patent attorney Shigetaka Awano Haka 1 person! -Cheve no tape 0 2I2 convex---Shi, shi Fig. 10--Munoside, coagulation factor 2/-m-tape 8-11 ratio-1'te tear lO---O\-rudote J9/- --Tates 9 2 Must Sand - Sea, υ 6- Lee A/Shield moves, Curse - Bind Xun

Claims (4)

[Claims] (1) A first reel around which a tape is wound, a reel driving means for driving the first reel so as to run the tape at a constant speed, and outputting rotation speed information of the first reel. a first rotational speed information detection means; a first periodicity information conversion means for converting the output of the first rotational speed information detection means into periodicity information and outputting the same; and a second reel around which the tape is wound. , a reel driving device for driving the second reel, a second rotation speed information detection means for outputting rotation speed information of the second reel, and an output of the second rotation speed information detection means. a second periodic information converter that converts and outputs periodic information; a multiplication circuit that multiplies the output of the second periodic information converter by a constant and outputs the result; and the first and second periodic information converters. a calculation means for calculating cycle information output from the calculation means and outputting speed information of the tape; a comparison means for determining whether the speed of the tape is in a steady state based on the output of the calculation means and outputting a result; holding means that latches the output of the multiplier circuit if the speed of the tape is in a steady state based on the output of the comparing means, but does not perform a new latching operation if the speed of the tape is in an unsteady state; A tension control device comprising: a drive circuit that drives the reel drive device. (2) The first and second period information conversion means include a timing generation circuit that outputs a signal having a pulse width that is inversely proportional to the rotation speed and is minute compared to the period from the output of the rotation speed information detection means, and the timing a counter circuit that initializes each falling edge of a signal output from a generation circuit and repeats a counting operation; an initial value generation circuit that outputs an initial value when the counter circuit initializes; and the counter circuit It consists of a clock generation circuit that generates a clock for performing a counting operation, and a latch circuit that latches the output of the counter circuit at the rising edge of the signal output from the timing generation circuit, and the comparison means compares the upper and lower limits. an upper and lower limit generation circuit that outputs a value; a first comparator that compares the output of the calculation means with the upper limit output from the upper and lower limit generation circuit; and a first comparator that compares the output of the calculation means and the upper limit. The hold means comprises a second comparator that performs a comparison with the lower limit value output from the value lower limit value generation circuit, and an AND circuit that takes the logical product of the output of the first comparator and the output of the second comparator. 2. The tension control device according to claim 1, wherein: comprises a D latch circuit. (3) The first and second period information converting means include a timing generation circuit that outputs a latch signal and a reset signal after a certain period of time of the latch signal at a period inversely proportional to the rotation speed from the output of the rotation speed information detection means. , a counter circuit that initializes each reset signal outputted from the timing generation circuit and repeats a counting operation; an initial value generation circuit that outputs an initial value when the counter circuit initializes; and the counter circuit The tension control device according to claim 1, comprising: a clock generation circuit that generates a clock for performing a counting operation; and a latch circuit that latches the output of the counter circuit using a latch signal output from the timing generation circuit. (4) The tension control device according to claim 1, wherein the calculation means comprises an adder that adds the output of the first period information conversion means and the output of the second period information conversion means.