KR980011195A - How to switch the audio output mode of the video cassette recorder - Google Patents

Abstract

The present invention relates to a method for converting an audio mode of a video cassette recorder, the method comprising the steps of: (a) detecting whether a playback mode has been changed during playback; and (b) Converting the audio output mode into a general audio signal output mode, and (c) automatically tracking the hi-fi audio track of the cassette tape and switching the audio output mode back to the hi- Respectively. Therefore, in the present invention, the audio output mode is changed from the Hi-Fi audio output mode to the general audio output mode at the time of the change of the playback mode, the audio joining occurring at this time is reduced, There is an advantage that it is possible to switch to the pi audio output mode and listen to the Hi-Fi audio signal.

Description

How to switch the audio output mode of the video cassette recorder

1 is a schematic block diagram of a video cassette recorder for carrying out the present invention;

2 is a flowchart of a method of switching an audio output mode of a video cassette recorder according to a preferred embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

10: Micom 12: Deck part

14: Audio signal processing unit 16: Hi-fi signal processing unit

18: Switching part 20: Speaker

22: Envelope detection part 24:

The present invention relates to a method for reproducing an audio signal of a video cassette recorder, and more particularly, to a method and apparatus for reproducing an audio signal of a video cassette recorder by switching a Hi-Fi audio mode to a normal audio mode and reproducing it, And a method of switching the audio output mode of the video cassette recorder.

As the performance of a video cassette recorder has been dramatically developed, a method of recording and reproducing an audio signal of high fidelity (HI-FI) by employing a rotary head method for an audio signal was developed in 1983 Developed. In this hi-fi audio system, the same shape as that of the video head is mounted on the same circumference as the video head of the head drum, and a signal obtained by FM (frequency modulation) modulation of the audio signal is deeply recorded on the video track for reproduction And an audio signal is recorded and reproduced in an audio track in a conventional manner. In other words, the FM-modulated audio signal is recorded deep on the video track, and the video signal is recorded on the surface (the chroma signal of the video signal is recorded down to the deep layer because of the low frequency, but its level is 10 decibel It does not reach enough to erase the audio signal at the low level). That is, surface recording and deep recording were performed to record a video signal and an audio signal on the same track, and two channels (stereo), that is, an L channel and an R channel, were distinguished as FM carriers of 1.3 MHz and 1.7 MHz .

Therefore, such a hi-fi audio system maintains compatibility with a method of recording and reproducing a general audio signal recorded on an audio track using a conventional fixed head, and does not impair picture quality and has a remarkable improvement in sound quality come.

By the way, when a cassette tape in which such hi-fi audio is recorded is reproduced, There may occur a case where the playback speed is changed from SP (standard play) mode to LP (long play) mode and LP mode to SP mode. At this time, the CTL signal recorded on the cassette tape and the tape transport speed of the capstan motor The audio output will be muted.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the conventional problems in the hi-fi audio reproduction, and it is an object of the present invention to provide a hi-fi audio reproduction apparatus, The present invention provides a method of switching the audio output mode of V. AL to change the audio output mode to reduce the occurrence of a noise and then to perform auto tracking to change the audio output mode back to the Hi-Fi audio mode have.

According to a preferred embodiment of the present invention for achieving such an object, there is provided a video cassette recorder for reducing a joint of an audio output caused by a change of a reproduction mode during reproduction of a cassette tape in which an audio signal is recorded as Hi- A method for switching an audio output mode of a video cassette recorder, comprising the steps of: (a) determining whether a playback mode has been changed during playback; (b) if the playback mode has been changed in Audio signal output mode; and (c) automatically tracking the high-pitched audio track of the cassette tape and switching the audio output mode back to the high-pitched audio signal output mode when the auto-tracking is completed do.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic block diagram of a general V. S. Al for carrying out the present invention. 2, the audio signal processing unit 14, the Hi-Fi signal processing unit 16, the audio signal processing unit 14, A switching unit 18, a speaker 20, an envelope detecting unit 22, and a comparing unit 24. The switching unit 18, When the user inputs a playback key signal from a key input unit (not shown), the microcomputer 10 generates a control signal for playback by the deck unit 12, and accordingly, the deck unit 12 loads the cassette tape Playback is executed.

When a reproduction is performed in the deck unit 12, a general audio head (not shown) reproduces an audio signal from an audio track, and a Hi-Fi audio head reproduces a Hi- And outputs it to the signal processing unit 14 and the high-fi signal processing unit 16. [ The audio signal processing unit 14 processes a general audio signal provided from the deck unit 12, that is, a mono audio signal, and outputs the processed signal to the switching unit 18. The hi-fi signal processing unit 16 processes the hi-fi signal, for example, a stereo signal, reproduced from the hi-fi reproducing head of the deck unit 12, And provides a high or low signal to the microcomputer 10 depending on whether the hi-fi signal is provided from the deck unit 12. The microcomputer 10 also provides a high or low signal to the switching unit 18,

The microcomputer 10 generates a switching control signal to the switching unit 18 in response to the high or low signal provided from the hi-fi signal processing unit 16 so that the switching unit 18 outputs a general audio signal or high- Signal to the speaker (20). For example, when a high signal indicating that the hi-fi audio signal is provided from the hi-fi signal processing unit 16 is provided, the microcomputer 10 generates a control signal to the switching unit 18 and outputs the control signal to the hi-fi signal processing unit 16 Output signal of the audio signal processing unit 14 is supplied to the speaker 20 and a control signal is generated by the switching unit 18 when a low signal is provided, To be supplied to the speaker (20) through the switching unit (18).

In the present invention, when the cassette tape on which the hi-fi audio signal is recorded is reproduced, the microcomputer 10 controls the switching unit 18 in accordance with the high signal provided from the hi-fi signal processing unit 16 The signal output from the hi-fi signal processing unit 16 generates a control signal to the switching unit 18 so that the output signal of the hi-fi signal processing unit 16 is supplied to the speaker 20 through the switching unit 18. [ .

When the playback speed, that is, the playback mode, changes from the SP mode to the LP mode or from the LP mode to the SP mode or the like in response to key input by the user during playback, the microcomputer 10 controls the switching unit 18, So that the output signal of the audio signal processing unit 14 is provided to the speaker 20. At the same time, the envelope detecting section 22 detects an envelope of the reproduced hi-fi audio signal provided from the deck section 12 and provides the envelope to the comparing section 24, And provides a comparison signal to the microcomputer 10 when the output signal of the envelope detector 22 is equal to or higher than a reference level as compared with a preset reference signal. That is, in detail, when the reproduction mode is changed, auto-tracking is performed, and a signal indicating the completion of the auto-tracking is provided to the microcomputer 10.

Accordingly. The microcomputer 10 generates a control signal to the switching unit 10 and then switches the switching unit 18 so that the output signal of the hi-fi signal processing unit 16 is supplied to the speaker 20 through the switching unit 18. [ .

2 is a flowchart of a method for switching the audio output mode of V.AUD according to a preferred embodiment of the present invention.

First, if playback is performed in step S10, it is determined in step S20 whether the playback mode has been changed. If the playback mode is changed in step S20, the flow advances to step S30. Then, in step S30, the audio output mode is switched to the general audio signal output mode, thereby reducing the generation of the joint due to the change of the reproduction mode.

Thereafter, in step S40, auto-tracking is performed on the hi-fi signal. When the auto-tracking is completed, that is, when the hi-fi signal is detected and the signal exceeding the reference level is detected, the process proceeds to step S50 .

Then, in step S50, the flow is ended after switching the general audio output mode back to the hi-fi audio output mode. Therefore, the present invention can reduce the audio coupling occurring at this time by switching the audio output mode from the hi-fi audio output mode to the general audio output mode when the playback mode is changed to V And after a time, it is switched to the hi-fi audio output mode so that the hi-fi audio signal can be heard.

While the present invention has been particularly shown and described with reference to certain preferred embodiments thereof, those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the invention as set forth in the following claims.

Claims (1)

A method of switching an audio output mode of a video cassette recorder for reducing a joint of an audio output caused by a change of a playback mode during playback of a cassette tape in which an audio signal is recorded in a Hi-Fi format in a video cassette recorder, Determining whether the playback mode has been changed during execution; (B) converting the audio output mode into the general audio signal output mode if the playback mode is changed in the step (a); (C) auto-tracking the hi-fi audio track of the cassette tape and switching the audio output mode back to the hi-fi audio signal output mode when the auto-tracking is completed . ※ Note: It is disclosed by the contents of the first application.