KR19980030758U - VSI system with switching pulse error correction during recording - Google Patents

Abstract

The present invention relates to a method for correcting a drum sebum delay error during recording in a VSI system. In the past, a drum sebum value fluctuated due to a voltage fluctuation of a set or a circuit instability of a set after completing a drum sebum error correction. When the switching pulses recorded on the recording tape became inaccurate, it was difficult to ensure the quality of the reproduced picture well.

The present invention has a microcomputer (11) which controls to generate a switching pulse by storing the sebum delay adjustment value in the playback mode and reading the sebum delay value stored in the memory at the time of recording so as to improve such a conventional problem. A switching pulse generator 106 for generating a switching pulse corresponding to a sebum adjustment value under the control of the microcomputer 11, and an AD converter 12 for providing a sebum detection AD conversion value to the microcomputer 11; It is to provide a VSI system having a switching pulse error correction function at the time of recording characterized in that the configuration including a.

Description

VSI system with switching pulse error correction during recording

The present invention relates to a VSI system having a function of correcting an error of switching pulses due to a delay in drum sebum value during tape recording. This is particularly true when a recording operation is performed in a set in which a drum sebum error correction is completed in VSI. In this system, the accuracy of the recording operation can be guaranteed by not causing the phase shift of the switching pulse caused by the instability of the circuit.

The drum of a general V deck deck unit is driven by a drum servo in the system, and a drum sebum for detecting the driving state thereof is attached.

In one example, the shape of the drum servo associated with the drum is illustrated as shown in FIG. 1.

Here, in order to drive the drum, the drum motor is a DC motor, which is more efficient than the AC motor and can easily obtain an arbitrary rotational speed, while the rotational speed changes soon due to the load variation and the voltage variation. Therefore, the servo requires a speed servo that controls the rotation speed in addition to the phase servo that controls the rotation phase.

The phase servo controls the rotational phase of the head as a control system for small fluctuations, and the speed servo constantly controls the number of revolutions of the head as a control system for large fluctuations.

FIG. 1 shows an example of a drum servo using a drum motor by a DC motor as described above, and the drum motor 5 is constituted as shown in FIG.

The drum motor 5 has an FG (Frequency Generator) 55 and a PG (Pulse Generator) 58, and detects an FG pulse of 720 Hz from the FG 55 for speed control. 53 is superposed on the main magnet 55 and magnetized.

In addition, a magnet PG 58 is attached to the rotating part of the drum motor to detect the rotational phase of the video head 52.

Therefore, a comparison signal is generated from these FG pulses and PG pulses to perform speed and phase control.

In FIG. 2, reference numeral 51 denotes an upper drum, 54 denotes an FG substrate, 56 denotes a permanent magnet, 57 denotes a stator coil, and 59 denotes a rotor.

The phase servo system associated with the FG and PG is configured as shown in FIG.

Here, the vertical synchronous separator 31 which separates the vertical synchronous signal from the video signal, the 1/2 divider 34, the large wave shaper 35, the gate 36, the summer 37, and the phase compensator 38 , A DC amplifier 39, and a drum motor 5 are connected to each other, and the 1/2 divider 34 includes an oscillator 32 and a divider 33 which provide a driving clock during regeneration. The sebum 58 head attached to the drum motor 5 is connected to the gate 36 through the pulse amplifier 37.

In addition, the FG 55 is connected to the path of the square wave shaper 41, the monomulti 42, the large wave shaper 43, and the gate 44, and the gate 44 has a gate pulse generator 40. It is connected.

When recording a predetermined video program on a tape in such a drum servo system, the phase is compared with the reference signal made by dividing the 30 Hz PG pulse from the PG 58 head and the vertical synchronization signal of the video signal to be recorded in half, and the phase thereof. The error signal is superimposed on the speed error signal to control the drum motor 5 to control the rotational phase of the head.

During playback, the playback screen is stabilized by rotating the output of the 3.58MHz X-Tal oscillator in synchronization with a reference signal corresponding to the vertical synchronization frequency divided by 1/59712.

In addition, one speed servo system triggers a reference monomulti with an FG pulse of 720 Hz to form a large wave at its output, obtains a speed error signal from the pulse generated from the large wave and the FG pulse, and applies the speed servo to the motor. .

This speed servo enters the square wave shaper 41 after the 720 Hz FG pulse generated by the FG gear of the drum motor 5 is amplified in the FG amplifier, and the monomultiplier 42 is amplified to the driveable level in the FG amplifier. do.

The circuit after the monomulti 42 is supplied with the FG pulse (including the variable component) from the FG amplifier and a constant width pulse of the output of the mono multi 42 so that the difference component is the large wave shaper 43 and the gate 44. Supplied to the circuit. The output of the gate 44 circuit is lowered in FG frequency and narrowed in output pulse when the rotational speed is slower than 720 Hz of normal rotation. In addition, the output pulse becomes wider in FG frequency by higher rotational speed.

In the large wave shaping machine 43, a large wave is generated by the width of the gate pulse. When the pulse width is narrowed, the output level of the large wave is decreased, and when the pulse width is widened, the level of the large wave is also raised, and the large wave is a sample / holder. It is supplied to the circuit to sample the maximum point of the large wave level that varies with the frequency of the FG.

The error voltage obtained in this way is supplied to the control circuit of the motor through the inverting circuit. As a result, if the drum rotation speed becomes slow, the error voltage drops and the control voltage rises, so that the rotation speed of the motor increases. The ground error voltage rises and the control voltage drops, causing the motor to slow down.

As a result, in the speed servo system, the rotation of the drum motor is controlled at 30 revolutions per second so that the frequency of the FG is always 720Hz, and the audio signal listened to with the video signal can be heard.

On the other hand, the sebum 58 attached to the drum as described above is provided in the drum motor 5 as shown in FIG. 2, which is conventionally because the sebum position integrated with these parts cannot be ideally attached when manufacturing the set. The correction for sebum 58 affixation error was calibrated before shipment of the set.

For example, in the related art, as shown in FIG. 3, the set inspector looks at the oscilloscope so that the switching pulse V.SW and the vertical synchronization signal V.SYNC are about 6.5H apart while playing the standard tape of the anti-sushi method. When the variable resistor is adjusted, the analog voltage value adjusted by the variable resistor is provided to the microcomputer as digital data through the AD converter, and the microcomputer is correcting the pico error by correcting the phase value of the switching pulse.

However, in such a prior art, since the sebum error is corrected by using a variable resistor together with an oscilloscope as described above, the sebum delay value is continuously adjusted by a value input through the AD converter in the system. When the input value fluctuated due to unexpected voltage fluctuations or circuit instability, the phase value of the switching pulse recorded on the tape control track was caused by it.

Therefore, when the video signal is recorded in the above state in the system, the phase of the reproduced screen is out of phase, causing the screen quality to be degraded.

The purpose of the present invention is to solve the above problems, and in particular, in such a system, after the set maker stores the sebum adjustment value in the memory through the sebum adjusting means, the sebum value stored in the memory at the time of recording is stored. By reading and generating switching pulses, it is possible to prevent phase error of tape write switching pulses caused by voltage fluctuations or circuit instability of the set.

The present invention implements a microcomputer which controls to generate a switching pulse by storing a sebum delay adjustment value in a reproducing mode and reading a sebum delay value stored in a memory at the time of recording so that the object of the above example can be realized. A switching pulse generator for generating a switching pulse corresponding to a sebum adjustment value, an AD converter for providing a sebum detection AD conversion value to a microcomputer, and a switching pulse error correction function for recording of a configuration including a deck part. It is characterized by VSI system.

Hereinafter, more specific features of the present invention will be understood by describing the same in detail with the accompanying drawings.

1 is a reference diagram showing a drum servo system of a typical VCR (Video Cassette Recorder) system

2 is a reference diagram showing the configuration of a drum motor in FIG.

FIG. 3 is a waveform diagram illustrating a drum PG value correction operation after fabricating a conventional VSI set. FIG.

4 is a system circuit block diagram related to the present invention

5 is an embodiment of a switching pulse error correction processing program during recording according to the present invention

* Explanation of Signs of Major Parts of Drawings *

11. Micro Computer 12. Option Setting Section

13. A / D (Analog / Digital) Converter

14. Delay correction part 15. Motor drive part

16. Deck section 17. Switching pulse detector

18. Key in

100. Switching pulse error correction program during recording

That is, Figure 4 shows a system circuit block of the VSI system according to the present invention.

Here, the key input unit 16 for generating general key command data and the AID converter 12 that detects the sebum analog value from the sebum of the deck unit and converts the digital signal into a digital signal are provided to the microcomputer 11. Is connected to an input port of the microcomputer 11, and a switching pulse is applied to the motor drive unit 14, the deck unit 13, and the tape control track during recording, which drive the drum motor of the deck unit 13, etc. A switching pulse generator 15 for recording is provided.

The system is provided with a switching pulse error correction processing program 100 at the time of recording as shown in FIG.

In this case, the system checks whether the playback mode is in the playback mode (step 101). In playback mode, it is checked whether or not the delayed data value is registered in the memory (step 102). It registers in (step 103).

In step 101, it is checked whether or not the recording mode is in the playback mode (step 104), and in the recording mode, the sebum delay data registered in the memory is extracted (step 105) and a switching pulse based on it is generated (step 106). It consists of a process.

According to the present invention having the above configuration, as shown in FIG. 4, when the playback command is given to the microcomputer 11 through the key input unit 16 in the system, the microcomputer 11 performs the tape playback operation through the deck unit 13.

When the system performs the regeneration operation as described above, the drum motor of the deck unit 13 is driven to detect the sebum pulse on the drum side and convert the digital signal through the AD converter 12 to provide it to the microcomputer 11. do.

When the microcomputer 11 receives the sebum digital data value and adjusts the drum sebum value under the current set state to an optimum value through an oscilloscope, the sebum data is registered in the system memory as a value of the seizure delay correction. .

In this state, when the user operates the set in the recording mode, the system fetches the sebum adjustment value at the time of reproduction registered in the system memory without considering the sebum detection value input from the AD converter 12 as usual. The switching pulse is generated based on this.

Thereafter, the system records the switching pulse on the control track of the tape being recorded in the deck unit 13 through the switching pulse generator 15.

Therefore, even if the output value of the AD converter 12 changes due to the input voltage variation or other circuit instability, the switching pulse is provided to the PD correction value registered in the memory so that a stable and accurate signal can be recorded on the tape during recording. Will be.

Meanwhile, the above operation is performed by the system together with the switching pulse error correction processing program 100 during recording as shown in FIG. 5, which checks whether the system is in the playback mode. It is checked whether it is registered, and if there is no registration of the delayed data value, the delayed data value is adjusted and registered in the memory (steps 101 to 103).

When the recording mode is not the above, it is checked whether or not the recording mode is used. In the recording mode, the sebum delay data registered in the memory is fetched to generate a switching pulse based thereon (steps 104 to 106).

The present invention creates a switching pulse based on the supported delay data value stored in the system when the drum pitch value fluctuates due to a set voltage variation or a circuit instability during recording of the VSI system. It is possible to secure stable records and reliability.

Claims (1)

In a VSI system including a deck unit, a microcomputer, and the like, the system stores a sebum delay adjustment value in the playback mode and controls the microcomputer to generate a switching pulse by reading the sebum delay value stored in the memory during recording. ), A switching pulse generator 106 for generating a switching pulse corresponding to a sebum adjustment value under the control of the microcomputer 11, and an AD converter for providing a sebum detection AD conversion value to the microcomputer 11 ( 12) VSI system having a switching pulse error correction function during recording, characterized by a configuration including a lamp and the like.