KR940005853B1 - Control device of capstan - Google Patents

Abstract

The controller for generating the phase control signal by itself rather than reproducing it from the tape comprises a generator providing CFG signals with different frequencies according to the tape running mode, and a generator providing CTL signals dividing the frequency with different division ratio according to the tape running mode, and having the constant frequency at each mode.

Description

Capstans and their controls

1 is a schematic diagram showing a tape driving mechanism.

2 is a schematic diagram showing a part of a conventional capstan motor.

3 is a schematic view showing a part of a capstan motor according to the present invention.

4 is a waveform diagram of signals generated in the apparatus of FIG.

* Explanation of symbols for main parts of the drawings

10: microcomputer 20: drum

30: capstan 70, 90: rotor

80, 100: Hall element

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capstan for controlling tracking in a VCR and a control device thereof. In particular, the capstan phase is generated by directly generating a control signal from a capstan motor without using a CTL signal on a tape. A capstan to adjust and its control apparatus are related.

In general, in order to reproduce data recorded on a tape in a VHS VCR, a motor of a head-mounted drum and a capstan motor driving the tape must operate at a constant frequency. In addition, the phase relationship between the head and the tape must also have a constant relationship. Keeping the number of revolutions of the drum and capstan motor constant and maintaining the phase relationship between the head and the tape so that the head tracks straight on the track of the tape is called tracking. In order to perform such tracking, the tape running speed at the time of data reproduction must match the speed of the data proxy. Therefore, when data is recorded on the tape, control signals for determining the running speed and phase of the tape are recorded together, and the control signals are reproduced at the time of data reproduction so that the same condition as that of the data proxy is achieved. Thus, correct tracking can be performed to obtain good picture and sound.

As described above, in the conventional capstan control apparatus, in order to adjust the phase of the capstan, the control signal recorded on the tape is reproduced and used during data recording. That is, when the control signal recorded on the tape is reproduced and transmitted to the microcomputer, the microcomputer adjusts the phase of the capstan in accordance with the control signal. In this case, depending on the quality or condition of the tape is greatly affected when recording and reproducing the control signal, a malfunction may occur in the capstan control and an unstable phenomenon in which the screen or voice may become unstable during reproduction.

Accordingly, an object of the present invention is to provide a capstan and its control apparatus for generating a capstan motor in a device for controlling the capstan to perform tracking, without generating a control signal for adjusting the capstan phase on the tape. .

A feature of the present invention for achieving the above object is a capstan of a servo system for recording or reproducing image data on a tape, comprising: means for generating CFG signals having different frequencies according to the traveling mode of the tape, and The capstan comprises means for dispensing at different frequency divisions in accordance with the running mode of the tape and for generating a CTL signal having a constant frequency in each mode.

A further aspect of the present invention is a capstan control apparatus for a system for recording or reproducing image data on a tape, the apparatus comprising: means for generating CFG signals having different frequencies according to the traveling mode of the tape, and running of the tape Capstan, which has a means for distributing at different division ratios according to modes and having a CTL signal having a constant frequency in each mode, and means for determining a driving mode of a tape by receiving a VED signal from the Youngsan signal processor of the system. And a means for controlling the driving of the capstan by receiving the CFG signal and the CTL signal of the capstan and the VED signal of the driving mode determining means.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 shows a tape driving mechanism including a capstan phase control signal CTL generated by the apparatus according to the present invention and input to the microcomputer 10. The capstan motor 30 generates a CFG (Capstan Frequency Generator) signal having a different frequency according to the operation mode of the VCR. That is, the capstan motor 30 is 1,080 Hz in the SP (Standard Play; below SP) mode, 540 Hz in the LP (Long Play; below LP) mode, SLP (Super Long Play; below SLP) In mode, it generates a 360Hz CFG signal.

As the CFG signal is input to the microcomputer 10, the operation of the capstan is controlled, and thus the running speed of the tape is determined. In addition, the capstan motor 30 generates a CTL signal having a constant frequency of 30 Hz in all modes and applies it to the microcomputer 10 so that the phase of the capstan is always kept constant. A drum motor that rotates the head mounted drum 20 generates a DFG (Drum Frequency Generator) signal, and also referred to as a DPG (Drum Phase-Pulse Generator) for adjusting the phase of the drum. ) Signal is generated. In addition, the video signal processing unit 50 outputs a VED (Video Envelope Detect) signal indicating a screen state and is supplied to the microcomputer 10. This VED signal represents a good or bad state of the screen displayed as a signal having a constant level of voltage.

In the present invention, the running mode of the tape is determined using this VED signal. Meanwhile, the microcomputer 10 receives and processes the control signals as described above, and outputs a CEV (Capstan Error Voltage; CEV) signal and a DEV (Drum Error Voltage; DEV) signal. Control the speed of rotation. That is, when the play mode is changed, the CEV and DEV signals are supplied to match the rotational speed of the capstan and drum to the corresponding mode. The CEV signal and the DEV signal are supplied as compensation signals for errors, respectively.

As can be seen in FIG. 1, the CTL signal for controlling the capstan phase is generated directly from the capstan motor 30 and supplied to the microcomputer 10. FIG. In the conventional apparatus, the tracking is independent of the tape by reproducing the CTL signal recorded on the tape 40 to control the phase of the capstan, and generating the signal controlling the speed and phase of the capstan directly from the capstan motor. To be performed.

In order to perform tracking, a signal having the same frequency as that of a CTL signal of 30 Hz, which is recorded on a tape and generated during reproduction in a conventional apparatus, must be output from the capstan motor. In FIG. 2 a portion of a conventional capstan motor is shown and in FIG. 3 a portion of a capstan motor according to the invention is shown. In the capstan motor of FIG. 2, only the CFG signal for controlling the capstan speed is generated. That is, when the rotor 70 composed of a plurality of permanent magnets rotates about the axis 60, an induced current is generated in the hall element 80 due to the change of magnetic flux, thereby generating a CFG signal. In this manner, the conventional capstan motor generates only the CFG signal, and the CTL signal is reproduced from the tape and supplied.

The capstan motor of FIG. 3 includes a rotor 90 having a plurality of layers 91, 92, 93, and 94 made up of a plurality of permanent magnets, and a plurality of Hall elements 101 in which induced current is generated from each layer of the rotor. 102, 103, and 104 are provided. A timing diagram of such a capstan motor generating a CFG signal and a CTL signal in the SP, LP and SLP modes is shown in FIG. 4 (a), 4 (b) and 4 (c) show the SP, LP and SLP modes, respectively.

The capstan motor generates a CFG signal having a different frequency according to each mode. In FIG. 4, FIG. 4 (a) shows CFG = 1,080 Hz as the SP mode, FIG. 4 (b) shows CFG = 540Hz as the LP mode, and FIG. 4 (c) shows CFG = 360Hz as the SLP mode.

Such a CFG signal is obtained by generating an induced current in the CFG Hall element 104 also positioned at the bottom by the rotation of the CFG layer 94 located at the bottom of the rotor 90 in FIG. At this time, since the rotation speed of the rotor 90 around the axis 60 according to each mode is different, CFG signals of different frequencies are generated. In this way, the CFG signal changes the frequency of the capstan by varying the frequency according to each mode, so that the running speed of the tape is determined to match the mode. However, even if the modes are different, the phase of the capstan must be constant so that the CTL signal should always have a constant frequency (30 Hz). Thus, in order to generate a CTL signal having a constant frequency of 30 Hz in all modes, three layers 91, 92, and 93 made up of different numbers of permanent magnets as shown in FIG. 3 are additionally mounted to the rotor of the capstan motor. And three Hall elements 101, 102, 103 for generating an induced current from each layer are provided.

First, in the SP mode, as the rotor 90 rotates, a CFG signal of 1,080 Hz is generated in the CFG Hall element 104 by the magnetic flux change of the CFG layer 94, and the CTL signal output terminal is a SP Hall element. In connection with 103, the CTL signal corresponding to the current tape mode is selected by the microcomputer and outputs the CTL signal induced by the SP layer 93 of the rotor. As shown in FIG. 4 (a), a CTL signal of 30 Hz can be obtained by generating one pulse for every 36 pulses in a CFG signal of 1,080 Hz. Here, the frequency ratio of the CFG signal to the CTL signal is the number of permanent magnets constituting the CFG layer 94 in the rotor 90 and the number of permanent magnets constituting the SP, LP, and SLP layers 93, 92, and 91. Is determined by the ratio of

Secondly, in the LP mode, the CFG signal is converted to 540 Hz as shown in FIG. 4 (b). The CTL signal output terminal is connected to the LP Hall element 102 to output a CTL signal induced by the LP layer 92 of the rotor. In this case, the CTL signal has a frequency of 30 Hz by generating one pulse for every 18 pulses of the CFG signal.

Third, in the case of the SLP mode, the CFG signal is converted to 360 Hz as shown in FIG. 4 (c). The CTL signal output terminal is connected to the SLP hall element 101 and outputs a CTL signal induced by the SLP layer 91 of the rotor. In this case, the CTL signal has a frequency of 30 Hz by generating one pulse for every 12 pulses of the CFG signal.

As described above, the capstan control apparatus according to the present invention does not need to record the CTL signal from the tape by directly generating the capstan motor and the CTL signal for controlling the capstan phase as well as the CFG signal for controlling the capstan speed. Can be utilized, and there is no need to provide a separate device for reading the CTL signal from the tape. In addition, since the capstan control is performed independently of the tape, it is possible to prevent a malfunction in the control and a hunting phenomenon of the screen and sound, which may occur when the quality of the tape or the CTL signal recording state is not good.

Claims (6)

1. A capstan of a servo system for recording or reproducing image data on a tape, said capstan comprising: means for generating a CFG signal having a different frequency in accordance with a traveling mode of the tape; And means for dividing at different frequency division ratios according to the running mode of the tape, and generating a CTL signal having a constant frequency in each mode. The capstan according to claim 1, wherein the CTL signal generating means comprises a rotor fixed to a rotation shaft of the capstan motor and having a plurality of permanent magnets, and a Hall element generating an induced current as the rotor rotates. The method of claim 1, wherein the CTL signal generating means is fixed to the rotation axis of the capstan motor and the rotor having a different number of permanent magnets so that each has a different division ratio and the induction current as the plurality of rotors rotate Capstan, characterized in that consisting of Hall element for generating a. A capstan control apparatus of a system for recording or reproducing image data on a tape, the apparatus comprising: means for generating a CFG signal having a different frequency according to the running mode of the tape, and at a different division rate according to the running mode of the tape; A capstan having means for dividing and generating a CTL signal having a constant frequency in each mode at all times; Means for determining a running mode of the tape by receiving a VED signal from an image signal processor of the system; And a means for controlling the driving of the capstan by receiving the CFG signal and the CTL signal of the capstan and the VED signal of the driving mode determining means. 5. The capstan according to claim 4, wherein the CTL signal generating means comprises a rotor fixed to a rotating shaft of the capstan motor and having a plurality of permanent magnets, and a Hall element generating an induced current as the rotor rotates. Control unit. 5. The method according to claim 4, wherein the CTL signal generating means is fixed to the rotating shaft of the capstan motor and guided by the rotation of the plurality of rotors and the rotors having different numbers of permanent magnets, each having a different division ratio. Capstan control device comprising a plurality of Hall elements for generating a current.