KR970011966B1 - Auto-tracking control method using phase error detector for vcr - Google Patents

Abstract

Auto-tracking by VCR phase error detection is operated as follows; (a) Shift from other mode to a play mode. (b) Output the control voltage(VDMC) of drum motor corresponding to the play mode to control the phase and rotating speed of drum and to detect the phase error of drum, and output the control voltage(VCMC) of capstan motor corresponding to play mode to control the phase and rotating speed of capstan and to detect the phase error of capstan. (c) Discriminate whether the phase error of drum is less than the permitted value( M) and the phase error of capstan is less than the permitted value( Ù) or not. (d) If discriminating whether the phase error of drum and capstan is less than permitted value( M, Ù), operates auto-tracking process.

Description

Auto Tracking Method by Phase Error Detection of V-CAL

1 is a flowchart of an operation signal for auto tracking of a general VR.

2 is an explanatory diagram of an auto tracking operation using a video and audio envelope.

3 is a block diagram of V-C to which the auto tracking method of the present invention is applied.

4 is a detailed block diagram of the servo controller in FIG. 2;

(A) and (b) in Fig. 5 are diagrams of tolerances of drums and capstans.

6 is a signal flow diagram for a method of auto-tracking VRC of the present invention.

* Explanation of symbols for main parts of the drawings

10: image signal processing unit, 20: hi-fi signal processing unit,

30: microcomputer, 31: auto tracking control unit,

32: deck control unit, 33: servo control unit,

33A: drum control unit, 33B: capstan control unit,

40: BC Aldek, 41: drum,

42: capstan

The present invention relates to the auto tracking of V-Cal. In particular, the phase of the V-Cal to determine the stability of the servo system based on the phase error of the capstan motor and the phase error of the drum. The present invention relates to an autotracking method by error detection.

The auto tracking control method generally used in VRC will be described with reference to FIG.

When the user sets the play mode using the play key provided in the remote controller or the main body, the system controller converts the tech into the play mode by inches of the key, and controls the rotational speed of the drum and the samson motor to the play mode.

From this, the drum and capstan servometer needs a certain time to stabilize, and after having a delay time for a predetermined time, the actual autotracking operation, that is, the envelope of the video and audio, is detected and the phase of the capstan motor is in an optimal position. To control.

Here, the autotracking operation using the video and audio envelopes will be described briefly with reference to FIG. 2. The video envelope (VE) and the hi-fi audio envelope (AE) are detected while changing the phase of the capstan motor. Let be the positive tracked phase. In this case, there is also a method of referring to the highest point of the video envelope VE in the case of non-hi-fi audio tape, and of the highest point of the audio envelope AE in the case of hi-fi audio tape.

However, in such an autotracking method, the time until the drum and the capstan motor are stabilized is set in advance, and it waits indefinitely for such a time. In this case, if the servo system is stabilized within the set time, it is unnecessary from that time until the preset time. There is a problem of waiting longer, and if the servo system is stabilized after the set time, it detects the video and the HAV envelope in an unstable state, and thus there is a problem in that a desirable autotracking result cannot be obtained.

Accordingly, an object of the present invention is to provide an autotracking method by detecting phase error based on a phase error of a capstan motor and a phase error of a drum, and determining the starting point of the autotracking based on this. have.

In order to achieve the above object, the autotracking method of the present invention outputs the control voltage (V _DMC ) of the drum motor in the play mode to detect the phase error at that time while controlling the rotational speed of the drum, and the tolerance value preset by the phase error. within (α) and outputting the control voltage (V _DMC ) of the capstan to control the rotation speed of the capstan to detect the phase error at that time and perform the autotracking operation for the preset tolerance (β) of the phase error. Is done.

3 is a block diagram of a V-C to which the auto tracking method of the present invention is applied. As shown in FIG. 3, a video signal processor 10 for processing a video signal to generate a video envelope signal and a high-fi audio signal are processed. By using the Hi-Fi signal processing unit 20 to generate an audio envelope signal, and a video and audio envelope signal which is a comparison signal of the auto tracking input from the image signal processing unit 10 and the Ahi-fi signal processing unit 20. The auto tracking control unit 31 for controlling the auto tracking, the deck drive unit 32 for controlling the drive of the V Deck 40, and the servo control unit for controlling the drum and the capstan of the V Deck 40. It consisted of (33).

FIG. 4 is a detailed block diagram of the servo controller 33 in FIG. 3 to output the control voltage V _DMC of the drum motor to the drum 41 to rotate the drum 42. The control voltage V _DMC is compensated based on the speed detection signal DFG and the phase detection signal PG output from the drum 41 side, so that the phase error of the drum 41 falls within the allowable value α. Outputs the control voltage V _DMC of the drum motor to the drum control unit 33A and the capstan 42, and rotates the capstan 42, and the speed detection signal DFG output from the capstan 42 side; The capstan control unit 33B is configured to compensate the control voltage V _DMC based on the phase detection signal CTL and control the phase error of the capstan 42 to fall within the allowable value β. Referring to Figure 7 describes the operation and effect of the present invention in detail.

When the user sets the play mode using the play key provided in the remote controller or the main body, the microcomputer 30 recognizes the key and switches the BC Aldek 40 to the play mode, and the capstan 42 and the capstan 42 The rotation speed of the controller is controlled to play mode.

At this time, the drum control unit 33A outputs the control voltage V _DMC of the drum motor to drive the capstan 42 at a desired speed, and the capstan 42 is rotated, and the speed detection signal detected by the speed detecting means. The phase detection signal PG detected through the DFG and the phase detection means is input to the drum control unit 33A, which is based on the input signals DFG and PG. The control voltage V _DMC is fixed by changing the control voltage V _DMC so that the error of the drum phase is within the allowable value α as shown in FIG. 5A.

In addition, the capstan controller 33B outputs the control voltage V _DMC of the capstan motor in order to drive the capstan 42 at a desired speed, and the capstan 42 is rotated, and the speed detection signal detected by the speed detecting means. The phase detection signal CTL detected through the CFG and the phase detection means is inputted to the capstan control unit 33B, and the capstan control unit 33B is based on the input signals CFG and CTL. The control voltage V _DMC of the capstan motor is fixed when the control voltage V _DMC of the motor is changed to be within the allowable value β as shown in (b) of FIG.

Through the above process, the servo controller 33 detects the phase error of the capstan 42 in the satisfactory region α, and detects the phase error of the capstan 42 to raise the satisfactory region β. Perform auto tracking.

As described in detail above, the present invention may determine the stability of the servo system based on the phase error of the capstan motor and the phase error of the drum, and determine the starting point of the auto tracking based on this. Therefore, it is effective to implement fast and accurate auto tracking.

Claims (1)

The first step of switching from the other mode to the play mode, and outputs the control voltage (V _DMC ) of the drum motor corresponding to the play mode in the play mode to detect the drum phase error while controlling the rotation speed and phase of the drum, A second step of detecting a capstan phase error while outputting a control voltage V _DMC of the capstan motor corresponding to the play mode to control the rotation speed and the phase of the capstan; and a preset tolerance α of the drum phase error. The third step of determining whether or not the phase error of the capstan is a predetermined allowable value β or not; and if the determination result of the third step is not within the allowable values α and β, the third step is repeatedly performed. And a fourth step of performing an autotracking operation within an allowable value (α) or (β).