JPH03108147A - Tension controller - Google Patents

Abstract

PURPOSE:To secure the stability of tension even when tape speed is fluctuated by discriminating the rotating state of a reel, and judging whether or not the latching operation of a multiplication circuit should be performed corresponding to whether the rotating state shows a transient state or a stationary state. CONSTITUTION:The reel 2 is rotated integrally with a reel motor 4, and rotating speed information is detected with a rotating speed information detecting means FG 5. And the information is converted to cycle information at a rotary cycle information conversion means 6. Since the speed of a tape 1 is kept constant, the cycle information outputted from the conversion means 6 is torque information proportional to the radius of the reel 2. Furthermore, it is discriminated whether the rotating state of the reel 2 is set at the transient state or the stationary state with the output of the conversion means 6, and a result is outputted from a comparison means 7. A holding means 9 is provided which latches the output of the multiplication circuit 8 when the output shows the stationary state, and latches no output when it shows the transient state. Thereby, it is possible to secure the stability of the tension even when the speed of the tape 1 is fluctuated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to video tape recorders (hereinafter abbreviated as VTR) and digital audio recorders (hereinafter abbreviated as VTR).
It is abbreviated as DAT. This 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 in order to maintain uniform contact between the tape and the head.

Hereinafter, an example of the above-mentioned conventional tension control device will be described with reference to the drawings.

FIG. 6 is a block diagram showing an example of a conventional tension control device. 12, the tension lever 11 is a tension post installed at -r1 of the tension lever 12;
13 is a spring whose one end is engaged with the other end of the tensile lever 12; 14 is a photocoupler; 15 is a compensation amplifier; 16 is a motor drive circuit; 17 is a tape; 18 is a rotary head for recording and reproducing. A cylinder, 19 is a capstan, 20 is a pinch roller, 21 is a reel that shares an axis with a reel motor and sends out (or winds up) the attached tape 17, 22a, 22b * 22c controls the running path of the tape 17. It is a post that forms. 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 13 and the spring force of the spring 13. To achieve this, tension post 1
The displacement of 1 is detected by the photocoupler 14, and the compensation amplifier 15
After being amplified by the motor drive circuit 16, the reel 21
to control the torque generated by the reel 21. As a result, the displacement of the tension post 11 is kept constant, and the tension applied to the tape 17 becomes a constant value (for example,
Collection of latest technology materials for VTR design (Japan Industrial Center Publishing).

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 11 is in contact with the tape 17 while the tape is running. , the load for running the tape 17 increases.

Further, tension control using a tension lever or the like has a problem in that responsiveness is slow and stable tension control is impossible when the tape running state is in a transient state.

The present invention solves the above-mentioned problems and maintains a stable constant tension on the tape without providing a tension lever, not only when the tape running condition is stable but also when the tape running condition is transient. The purpose of the present invention is to provide a tension control device that provides

Means for Solving the Problems To achieve this object, the tension control device of the present invention comprises a tape, a tape running means for running the tape at a constant speed, a reel around which the tape is wound and for feeding out the tape. A reel driving device for generating rotational torque on the reel, a rotation speed information detection means for outputting rotation speed information of the reel, and a period information conversion means for converting the output of the rotation speed information detection means into period information and outputting it. , a multiplication circuit that multiplies the output of the period information conversion means by a constant and outputs the multiplication result; and a multiplication circuit that determines whether the rotational state of the reel is in a transient state or a steady state from the output of the period information conversion means; A comparison means for outputting the determination result, and latching the output of the multiplier circuit if the rotational state of the reel is in a steady state based on the output of the comparison means;
The configuration includes a hold means that does not perform a latch operation in a transient state, and a drive circuit that receives the output of the hold means and drives the reel drive device.

Effect The present invention has the above-described configuration, so that when the tape speed is in a steady state, the number of rotations of the reel is limited to a range from the minimum radius to the maximum radius of the reel considering the tape winding thickness. It is possible to determine whether the tape speed is within the stable state range from the reel rotation speed. becomes possible.

When the tape speed is stable, the rotational state of the reel is converted into period information by the period information converting means through the rotation speed information detecting means. Since the tape speed is constant, this period information provides information proportional to the radius of the reel. The cycle information is multiplied by a constant by a multiplication circuit and converted into torque information proportional to the reel radius. Therefore, the multiplication circuit outputs reel torque information proportional to the reel radius. Since it is now determined that the tape speed is in a stable state, the hold means receives the output of the comparison means, latches the torque information, and outputs it to the drive circuit. 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, when it is determined that the tape speed is in a transient state, the holding means receives the output from the comparing means and holds the torque information within the limited range without latching. Therefore, even when the tape speed is in a transient state, it is possible to apply stable tension to the tape.

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

FIG. 1 is a block diagram showing the configuration of a tension control device in an embodiment of the present invention. In Figure 1, 1
2 is a tape, 2 is a reel on which the tape 1 is wound and sends out the tape, 3 is a tape running means consisting of a capstan motor etc. that makes the tape 1 run at a constant speed, 4 is a reel 2
5 is an FG that outputs rotation speed information of the reel 2; 6 is a period information conversion means that converts the output of the FG 5 into period information and outputs the same; 8 is an output of the period information conversion means 6; A multiplication circuit that multiplies a constant and outputs the multiplication result; 7 a comparison unit that determines whether the rotational state of the reel 2 is in a steady state from the period information conversion means 6 and outputs the determination result; 9 a comparison circuit; Holding means latches the output of the multiplier circuit 8 when the rotational state of the reel 2 is in a steady state based on the output result of the means 7, but does not perform a latching operation in a transient state. Reference numeral 10 is a drive circuit for driving the reel motor 4.

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

In Fig. 1, in order to keep the tension value applied to tape 1 constant, the radius of reel 2 including the tape winding thickness (hereinafter, the radius of reel 2 refers to the radius including the tape winding thickness). It is sufficient to apply a torque proportional to ) to the reel 2.

Further, the number of rotations of the reel 2 is obtained through the FG 5, and is converted into period information by the rotation period information converting means 6. tape 1
Since the speed of the reel 2 is constant, the period information outputted from the period information conversion means 6 is information proportional to the radius of the reel 2. The multiplication circuit 8 multiplies the cycle information by a constant and outputs torque information proportional to the radius of the reel 2. The number of revolutions of reel 2 when the tape speed is in a steady state is limited to the range from the minimum radius to the maximum radius of reel 2, taking into account the thickness of tape 1 (hereinafter, when we refer to a limited range, it is determined by the thickness of tape 1). (This refers to the rotation speed range from the minimum radius to the maximum radius of the tape loop 2.) Therefore, it is possible to judge whether the tape speed is stable or not.

First, consider the case where the tape speed is stable in a steady state. Now 1. Since it is in a steady state, the output result of the comparison means 7 is always within the limited range, and the output (torque information) of the multiplication circuit 9 is latched by the hold means 9 and output to the drive circuit 10. The reel motor 4 is driven by a drive circuit 10 and is converted into torque proportional to the output data of the holding means 9. 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 8 changes due to fluctuations in the tape speed, but the comparison result of the comparison means 7 is outside the limited range, and the hold means 9 does not perform a new latching operation, so it is latched within the limited range. The output of the last multiplication circuit 8 is held in a hold means 9. Therefore, disturbances in the torque information due to changes in the rotation of the reel 2 do not cause disturbances in the torque applied to the reel 2, 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 according to a second embodiment of the present invention, and FIG. 3 is a waveform diagram showing the operation of each part in FIG.

In FIG. 2, the same parts as in FIG. 1 are given the same numbers and their explanations will be omitted. 63 is a timing generation circuit that receives the output of FG5 and outputs a signal with a minute pulse width compared to this period with a period inversely proportional to the rotation speed; 64 is a falling edge of the signal output from the timing generation circuit 63; e2 is an initial value generation circuit that outputs an initial value when initializing the counter circuit 64, and 61 is a clock for the counter circuit 64 to perform counting operations. 85 is a latch circuit that latches the output of the counter circuit 84 at the rising edge of the signal output from the timing generation circuit 63; 71 is an upper and lower limit value generation circuit that outputs an upper limit value and a lower limit value; 72 73 is a comparator that compares the output of the period information converting means 6 and the upper limit value output from the upper and lower limit value generation circuit 71; A comparator that performs a comparison with a lower limit value, 74 an AND circuit that takes the logical product of the output of the comparator 72 and the output of the comparator 73, 92 a pulse generation circuit, and 93 a comparison means 7.
91 is a D flip-flop circuit that receives the output of the AND circuit 83 and latches the output of the multiplier circuit 8.

Regarding the tension control device configured as above,
The operation will be explained below.

The reel 2 shares a shaft with the reel motor 4 and is detected as one. FG5 outputs a pulse every time the reel 2 rotates by a certain angle. This situation is shown in FIG. 3A. Timing generation circuit 63 receives the output of FG5 and generates a signal. This output is shown in FIG. 3B. The counter circuit 64 takes in the value of the initial value generation circuit 62 at the falling edge of the output signal of the timing generation circuit 63, presets it as an initial value, and performs counting using the output of the clock generation circuit 61. This situation is shown in FIG. 3C. The latch circuit 65 latches the output of the counter circuit 64 at the rising edge of the output signal of the timing generation circuit θ3. This situation can be seen in the third
Shown in the diagram. The comparator 72 includes the periodic information converting means 6
The output of the period information converting means 8 is compared with the upper limit value outputted from the upper limit value lower limit value generation circuit 71, and when the output of the period information converting means 8 is less than the upper limit value, a high level (hereinafter abbreviated as 'H9) is set. In other cases, a low level (hereinafter abbreviated as 'L') is output. The comparator 73 compares the output of the period information conversion means 6 with the lower limit value output from the upper limit value lower limit value generation circuit 71, and when the output of the period information conversion means 6 is equal to or higher than the lower limit value, it "L' in other cases
Output. FIG. 3E shows how this comparison is performed. The AND circuit 74 includes a comparator 72 and a comparator 73
It outputs 'H' only when both outputs are 'Ho', and '6L' in other cases. This situation is shown in FIG. 3F.

The pulse generating circuit 92 generates pulses at a certain constant period. This situation is shown in FIG. 3G. The AND circuit 93 performs a logical product of the pulse generation circuit 92 and the output of the comparison means 7,
Output the result.

This situation is shown in FIG. 3H. D flip-flop circuit 9
1 latches the output of the multiplier circuit 8 at the rising edge of the output of the AND circuit 93 and outputs it to the drive circuit 10. This situation is shown in FIG. 3I. As explained in the first embodiment, when the tape speed is in a transient state (hold interval in FIG. 3), the output of the multiplier circuit 8 in the steady state is held by the D flip-flop circuit 91 due to the output of the AND circuit 93. ing. Therefore, disturbances in the torque information due to changes in the rotation of the reel 2 do not result in disturbances in the torque applied to the reel 2, 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. 4 shows a third embodiment of the present invention.

This will be explained with reference to FIG. FIG. 4 is a block diagram of a tension control device according to a third embodiment of the present invention, and FIG. 5 is an operation waveform diagram of this embodiment, particularly the operation of parts that are different from the second embodiment. FIG.

In FIG. 4, the same parts as in FIGS. 1 and 2 are denoted by the same numbers, and explanations thereof will be omitted. 66 is a timing generation circuit which outputs a latch signal and a reset signal after a certain period of time from the output of the FG5 at a period inversely proportional to the number of rotations. The difference between this embodiment and the second embodiment is that the timing generation circuit generates a reset signal and a latch signal.

FG5 outputs a pulse every time the reel 2 rotates by a certain angle. This situation is shown in FIG. 5J. Timing generation circuit θ6 receives the output of FG5 and generates a latch signal and a reset signal. The latch signal is shown in FIG. 5K, and the reset signal is shown in FIG.

The counter circuit 64 inputs the value of the initial value generation circuit 62 using the reset signal output from the timing generation circuit 66 and performs counting using the output of the clock generation circuit 61. This situation is shown in FIG. 5M. The latch circuit 85 latches the output of the counter circuit 84 with the latch signal output from the timing generation circuit 6θ. This situation is shown in FIG. 5N.

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.

Although only one direction in the tape running direction has been described in the above embodiments, the present invention can be applied to a reel on the tape feeding side regardless of the tape running direction. In addition, although only an example in which the tape running means is configured with a capstan or the like has been described, the same effect can be obtained even in a case where the tape traveling means is configured with a reel motor or the like on the tape winding side, and the present invention is not limited to the embodiments. Needless to say.

Effects of the Invention As described above, the present invention includes a comparison means for determining whether the rotational state of the reel is a transient state or a steady state based on the output of the periodic information conversion means, and outputting the determination result; By providing a hold means that latches the output of the multiplication circuit from the output when the reel rotation state is in a steady state, and does not perform a latching operation when it is in a transient state, it is possible to control the output when the tape speed is running in a transient state or in a steady state. - Tension stability is ensured even when the tape speed fluctuates over time due to load, etc. For example, when used in a DAT or VTR, the mechanism related to tension control can be omitted, making it more compact, and at the same time, there is no load on the tension lever, etc., which reduces the tape running load when the tape runs at high speed.
Tension control with faster response is possible compared to control using a tension lever or the like. As a result, very high-speed tape running can be achieved, and the effect is significant.

[Brief explanation of drawings]

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 type control device according to a second embodiment of the invention, and Fig. 3 shows the operation of the same embodiment. 4 is a block diagram of a tensigine control device according to a third embodiment of the present invention, FIG. 5 is a waveform diagram showing the operation of the same embodiment, and FIG. 6 is a waveform diagram of a conventional tensigine control device. It is a block diagram. DESCRIPTION OF SYMBOLS 1... Tape, 2... Reel, 3... Tape traveling means, 4... Reel drive motor, 5
...Rotation speed information detection means, 6.Period information conversion means, 7.Comparison means, 8.Multiplication circuit,
9... Holding means, lO... Drive circuit.

Claims (3)

[Claims] (1) a tape; a tape running means for running the tape at a constant speed; a reel around which the tape is wound and for feeding the tape; a reel drive device for generating rotational torque on the reel; rotation speed information detection means for outputting rotation speed information of the reel; period information conversion means for converting the output of the rotation speed information detection means into period information and outputting the same; and multiplying the output of the period information conversion means by a constant. , a multiplication circuit that outputs the multiplication result; a comparison unit that determines whether the rotational state of the reel is a transient state or a steady state based on the output of the periodic information conversion means and outputs the determination result; Holding means that latches the output of the multiplication circuit if the rotational state of the reel is in a steady state based on the output of the comparing means, but does not perform a latching operation if it is in a transient state; and a holding means that receives the output of the holding means and drives the reel. A tension control device comprising: a drive circuit for driving the device; (2) The period information conversion means is a timing generation circuit that receives the output of the rotation speed information detection means and outputs a signal having a period of the output signal and a pulse width that is minute compared to the period of the output signal. , a counter circuit that initializes each falling (or rising) edge of a signal output from the timing generation circuit and repeats a counting operation; and an initial value generator that outputs an initial value when the counter circuit initializes. a clock generation circuit that generates a clock for the counter circuit to perform a counting operation; and a latch circuit that latches the output of the counter circuit at a rising (or falling) edge of a signal output from the timing generation circuit. The comparison means includes an upper limit value and lower limit value generation circuit that outputs an upper limit value and a lower limit value, and a comparison means that compares the output of the period information converting means with the upper limit value output from the upper limit value and lower limit value generation circuit. a second comparator that compares the output of the periodic information converting means with the lower limit value output from the upper and lower limit generation circuit; and a second comparator that compares the output of the first comparator and the second comparator. and a first AND circuit that takes a logical product with the output of the holding means, a pulse generating circuit that generates a pulse of a constant period, and a logical product of the output of the pulse generating circuit and the output of the comparing means. The tension control device according to claim 1, comprising: a second AND circuit; and a D flip-flop circuit that receives the output of the second AND circuit and latches the output of the multiplication circuit. (3) a timing generation circuit in which the period information conversion means receives the output of the rotation speed information detection means and outputs a latch signal at the period of the output signal and a reset signal after a minute period of the latch signal; and the timing generation circuit. a counter circuit that initializes and repeats a counting operation for each reset signal output from the counter; an initial value generation circuit that outputs an initial value when the counter circuit initializes; and a counter circuit that performs a counting operation. 2. The tension control device according to claim 1, comprising: a clock generation circuit that generates a clock; and a latch circuit that latches the output of the counter circuit using a latch signal output from the timing generation circuit.