JPS61278073A - Reel driving device - Google Patents

Abstract

PURPOSE:To execute the control of a control force corresponding to the quantity of a tape-shaped body wound to a reel and to suppress a damage to the tape- shaped body by controlling a rotation driving means by a control signal corresponding to the rotating state of the reel. CONSTITUTION:A comparing signal corresponding to the rotating speed of a supply side reel receiving base 1 is outputted from a comparing signal generator 2, and a counter 4 counts a reference pulse inputted from a reference pulse generator 3 between the leading of the comparing signal and the next leading, and outputs a count data to a latch circuit 5. When a damping trigger is inputted, a latch pulse is outputted from a damping controlling circuit 6, and a reading-out circuit 7 outputs a read-out use address designating signal. A damping data corresponding to the rotation speed of the reel pedestal 1 is stored in advance in a memory 8, an outputted damping data is inputted to a damping control signal generator 10 through a D/A converter, controls a torque of a reel motor 13 through a switch 11 and a motor controlling circuit 12, and the running of a tape is damped smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reel drive device in a mechanism for running a tape-like body between two reels.

[Summary of disclosure]

This specification and the drawings disclose a technology in which a braking control signal is generated in accordance with the rotational state of a reel in a reel drive device, and the rotation of the reel is braked by the control signal during braking.

[Conventional technology]

Conventionally, in a mechanism that runs a tape-shaped body between two reels, when braking the rotation of the reel, for example, in a recording/playback device such as a VTR or audio tape recorder, the rotation of the reel holder on the winding side is stopped. At the same time, a mechanical braking device such as a plunger presses a pad or the like against the supply reel holder with a constant force to brake the rotation of the reel.

In addition, in a so-called direct drive tape-like material traveling mechanism in which the take-up side reel pedestal and the supply-side reel pedestal are directly driven by separate motors, when the tape material stops traveling, the take-up side At the same time as the reel pedestal drive motor was stopped, a constant torque was generated in the supply side reel pedestal drive motor in the opposite direction to the direction in which it had been rotating, thereby braking the rotation of the reel.

[Problem that the invention seeks to solve]

In these conventional systems, the braking force is not controlled according to the rotational state of the reel, and the rotational state of the reel changes moment by moment according to the amount of tape-like material wound on the reel. Since the rotation of the reel was braked by generating a certain amount of reverse torque in the reel's rotational drive means, sudden braking was applied, especially when the reel was rotating at high speed, resulting in the inertia of the reel or the impact of the braking. This can cause damage to the tape-like material wound around the guru, such as stretching or loosening.For example, in recording and reproducing devices, it is recommended to reduce the thickness of the tape-like material in order to record and play back for a long time. This has become an obstacle to attempts to do so.

The present invention has been made in view of the above circumstances, and by detecting the rotational state of the reel and controlling the braking force on the reel accordingly, it is possible to perform control according to the amount of tape-shaped material wound on the reel. It is an object of the present invention to provide a reel drive device that can control power and prevent damage to a tape-like body.

[Means to solve the problem]

The reel drive device of the present invention includes a reel rotation drive means,
A means for controlling the rotational drive means, a means for detecting the rotational state of the reel, a means for outputting a control signal for braking according to the rotational state, and a means for supplying the control signal to the control means during braking. It is something that

[For production]

In the above configuration, the rotation state of the reel is detected, and during braking, the rotation of the reel is braked by controlling the rotation drive means using a control signal for braking according to the rotation state.

〔Example〕

Examples of the present invention will be described below.

Figure 1 shows a VT system using a direct drive system in which the reel holders on the winding side and the supply side are each directly driven.
This is an example in which the present invention is applied to an R tape running mechanism.

FIG. 2 is a timing chart showing the operation waveforms of FIG. 1 above.

In the tape running mechanism of a VTR as shown in Figure 1, when the tape is running, the reel pedestal drive motor on the tape supply side does not lack torque, and the tape is running while maintaining a constant tension by the pack tension servo. There is.

At this time, a plurality of small pieces of magnets, etc. are attached at equal intervals on the circumference of the supply side reel holder 1, a fixed big-up head is installed, and the output thereof is input to the comparison signal generator 2. The comparison signal generator 2 outputs a comparison signal corresponding to the rotational speed of the reel holder 10 as shown in FIG. 2(B) to the counter 4.

The reference pulse (b) generated by the reference pulse generator 3 is input to the counter 4 together with the comparison signal (a). The reference pulse (reference pulse) is set at a frequency sufficiently higher than that of the comparison signal (a), and the counter 4 detects the rising edge of the comparison signal (b)) until the next rising edge. The number of rising edges of the reference pulse being detected is counted.

The counted data signal is then input to the next latch circuit 5, but since the latch operation of this latch circuit 5 is controlled by the latch pulse described later,
The count data input until this pulse is input is reset and rewritten with new count data every time a rising edge of the comparison signal (b) is detected.

A latch pulse for controlling the latch circuit 5 is generated by a brake control circuit 6. The braking control circuit 6 receives a comparison signal (
a) is input, and when a braking trigger (c) is input as a braking command for tape running, the #braking control circuit 6 outputs a latch pulse (d) synchronized with the comparison signal (a).
) is output, and each time the latch circuit 5 detects the rising edge of the latch pulse (d), the signals (e, ) to (e4) in FIG. 2 are output.
The count data shown in is sequentially latched into the memory readout circuit 7.

The read circuit 7 generates a read address designation signal based on the input count data as described above and inputs it to the memory 8.

The memory 8 stores braking data corresponding to the rotational speed of the supply reel holder, and is read out and output in response to the address designation signal. In other words, since the address designation signal corresponds to the rotation speed of the supply side reel cradle,
The braking data read thereby also corresponds to the rotational speed of the reel pedestal.

The braking data outputted from the memory 8 as described above is input to a digital-to-analog (D/A) converter 9, where the digital braking data is converted into an analog braking signal. When this braking signal is input to the next braking control signal generator 10, the braking control signal generator 10 sends a motor control signal, which will be described later, so that the tape is braked without causing damage such as elongation or loosening during braking. A brake control signal controlling circuit 12 is generated and applied to switch 1.

The switch 1) switches the control signal supplied to the motor control circuit 12 between normal tape running and braking.
Its operation is controlled by the brake trigger mentioned above. That is, the switch 1) is normally connected to the B side shown in FIG. 1, and as shown in FIG. The torque of the supply reel motor 13 during normal tape running is controlled by the motor control signal, so that the tape runs while maintaining a constant tension.

Here, as described above, when the brake trigger (c) is input to switch 1) as a brake command for tape running, switch 1) is connected to the A side shown in Figure 1, and a brake control signal is generated as described above. A brake control signal generated from the motor control circuit 10 is supplied to a motor control circuit 12.
generates a motor control signal that controls the torque of the supply reel motor 13 so that smooth braking is performed without causing damage to the tape such as elongation or loosening when braking the tape, and this signal causes the tape to run smoothly. is braked.

By the way, in this embodiment, a memory was used as a means for outputting a control signal during braking according to the rotational state of the reel, but instead of the memory, braking data is calculated according to the rotational speed of the supply side reel holder. □ An arithmetic circuit may be used.

Although the embodiment has been described as a reel drive device for a VTR, the present invention is applicable not only to VTRKs but also to audio tape recorders, industrial paper winding machines, etc. as long as the device runs a tape-shaped body between two reels. It can be used.

〔Effect of the invention〕

As described above, according to the present invention, as a reel drive device as described at the beginning, it is possible to prevent damage to the tape-like body and brake the rotation of the reel with a simple configuration, and is extremely effective in this type of reel drive device. It is beneficial.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electric circuit in the case where the present invention is applied to a reel drive device of a VTR as an embodiment of the present invention. FIG. 2 is a timing chart showing the timing of each operation in the professional diagram of FIG. 1... Supply side reel holder 2... Comparison signal generator 4
...Counter 7...Readout circuit 8...
Memory 6... Brake control circuit 10... Brake control signal generator

Claims (3)

[Claims] (1) A mechanism for running a tape-like body between two reels, which includes a reel rotation drive means, a control means for the rotation drive means, a means for detecting the rotation state of the reel, and a means for detecting the rotation state of the reel. means for outputting a control signal for braking;
and means for supplying the control signal to a control means during braking. (2) The reel drive device according to claim (1), wherein the means for outputting the control signal includes an arithmetic circuit that calculates control data according to information from the means for detecting the rotational state of the reel. . (3) The means for outputting the control signal includes a memory means holding control data according to information from the means for detecting the rotational state of the reel, and a control data held in the memory means. The reel drive device according to claim 1, further comprising means for reading out information according to information from the detection means.