KR100236111B1 - Fade control apparatus of a vcr - Google Patents

Abstract

The present invention relates to a recording apparatus of a video cassette recorder, and more particularly, to a fade control apparatus of a video cassette recorder for fade control of an overlap section occurring during recording.

To this end, the present invention provides a video cassette recorder for recording an input video signal on a magnetic tape, comprising: an automatic gain control unit for adjusting and providing a gain value of an input level of an input video signal; A signal separator which separates and provides a luminance signal and a color signal from an image signal provided by an automatic gain control unit; A color signal processor configured to process and provide a color signal provided separately from the signal separator; A luminance signal processor for mixing and providing a first frequency modulated signal obtained by frequency modulation the luminance signal provided separately from the signal separator and a second frequency modulated signal provided; A mixing unit for mixing and providing a color signal and a luminance signal provided by the color signal processing unit and the luminance signal processing unit; A signal amplifying unit amplifying a mixed signal of the color signal and the luminance signal provided by the mixing unit and providing the amplified signal to the magnetic tape; An oscillator for oscillating the second frequency modulated signal corresponding to the oscillation control signal provided to the luminance signal processor; And a microcomputer that provides an oscillation control signal for oscillating the second frequency modulated signal to the oscillator, thereby reproducing a natural screen.

Description

Fade control unit of video cassette recorder

The present invention relates to a recording apparatus of a video cassette recorder, and more particularly, to a fade control apparatus of a video cassette recorder for fade control of an overlap section occurring during recording.

As is well known, with the economic growth and the growing cultural needs of people, each home is equipped with video equipment such as a video cassette recorder.

Such a video cassette recorder records a composite video signal applied from a tuner that tunes a broadcast signal received through an antenna to a desired channel to a magnetic tape using a head or a video signal input from the outside to a magnetic tape through a head. It has a recording function for recording and a reproduction function for reproducing a composite video signal recorded on a magnetic tape and displaying it on a monitor of a television, allowing viewers to watch a program they want to watch at any time.

However, a video cassette recorder is a tape structure that has already been recorded by a distance difference between a full erase head for erasing all the signals recorded on the magnetic tape during recording and a video head for recording the provided image signal on the magnetic tape. When the signal is again recorded on the picture, i.e., when another signal is recorded on the signal that is not erased by the full width erasing head, a section where the screen overlaps, that is, an overlap section occurs.

In the overlap section, overlapping occurs in a section corresponding to about 4 to 5 seconds when the recording speed mode is the SP mode and about 12 to 15 seconds when the recording mode is the SP mode, and the screen overlaps and is reproduced. .

On the other hand, the fade control function is one of the switching methods used for changing the scene of the video, and there is a black fade that lowers the video signal level electrically and finally increases the video signal level up to 100 IRE. Performing green playback using the fade control function has the effect of close-up of the screen during playback and the smooth connection of tape editing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a fade control apparatus for a video cassette recorder for reproducing a natural screen by adding a fade control function during an overlap occurrence period at the beginning of recording. To provide.

A feature of the present invention for achieving the above object is a video cassette recorder for recording an input video signal on a magnetic tape, comprising: an automatic gain control unit for adjusting and providing a gain value of an input level of the input video signal; A signal separator which separates and provides a luminance signal and a color signal from an image signal provided by the automatic gain control unit; A color signal processor configured to process and provide a color signal provided separately from the signal separator; A luminance signal processing unit for mixing and providing a first frequency modulated signal frequency-modulated with the luminance signal provided separately from the signal separation unit and a second frequency modulated signal provided; A mixing unit which mixes and provides a color signal and a luminance signal provided by the color signal processing unit and the luminance signal processing unit; A signal amplifying unit amplifying a mixed signal of a color signal and a luminance signal provided by the mixing unit and providing the amplified signal to the magnetic tape; An oscillator for oscillating the second frequency modulated signal corresponding to the oscillation control signal provided to the luminance signal processor; And a microcomputer providing an oscillation control signal for oscillating the second frequency modulated signal to the oscillator.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

1 is a block diagram showing the configuration of a fade control device of a video cassette recorder according to a preferred embodiment of the present invention.

2 is a view showing a waveform of a luminance signal according to a preferred embodiment of the present invention

* Description of the symbols for the main parts of the drawings *

10: key input unit 20: micom

30: oscillation unit 40: automatic gain control unit

50: signal separation unit 60: color signal processing unit

70 luminance signal processor 71 frequency modulation (FM) unit

72: first mixing unit 80: second mixing unit

90: signal amplifier

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

1 is a block diagram showing a configuration of a fade control device of a video cassette recorder according to the present invention, which is provided by a key input unit 10 and a key input unit 10 for providing a signal and recording information on a recording key pressed by a user. Provides a recording control signal corresponding to the recording information, and oscillates the oscillation frequency corresponding to the oscillation control signal provided from the microcomputer 20, the microcomputer 20 for providing an oscillation control signal for oscillating the frequency modulation signal Luminance from the image signal provided by the oscillator 30, the automatic gain controller (AGC: Auto Gain Controller) 40, which adjusts and provides the gain value of the input level of the input image signal. The signal separation unit 50 which separates the signal from the color signal and provides the color signal processing unit 60 and the signal separation unit 50 to process and provide the color signal provided by the signal separation unit 50. A mixing unit 80 and a mixing unit 80 which mix and provide a color signal and a luminance signal provided by the luminance signal processing unit 70, the color signal processing unit 60, and the luminance signal processing unit 70 to process and provide the luminance signal. It consists of a signal amplification unit 90 to amplify the luminance signal and the color signal provided by the provided to the video head.

A detailed description of the operation of the fade control device of the video cassette recorder according to the present invention configured as described above is as follows.

The key input unit 10 is generally composed of key metrics to provide a predetermined key signal pressed by the user, and provides a signal for the recording key or the recording information to the microcomputer 20.

At this time, the microcomputer 20 provides the oscillation control signal to the oscillator 30 when the signal provided from the key input unit 10 is a signal for the recording key. A control signal for oscillating up to a set point or more, and a control signal for oscillating the oscillation frequency, that is, the frequency of the white level and the gray level, and the control signal for stopping the oscillation in the period of the synchronization signal, the oscillator 30 To provide.

That is, the oscillator 30 oscillates the frequency corresponding to the oscillation control signal provided from the microcomputer 20 to a predetermined section, that is, a point where the full width erasing head and the video head meet or more, and thus, the first mixing unit 72. As shown in the description below, the modulation frequency corresponding to the predetermined step is oscillated and provided to the first mixing unit 72.

On the other hand, the automatic gain control unit 40 adjusts the gain value of the input level of the input image signal to the signal separation unit 50, the signal separation unit 50 is adjusted by the automatic gain control unit 40 The luminance signal and the color signal are separated from the provided image signal and provided to the color signal processor 60 and the luminance signal processor 70.

At this time, the color signal processing unit 60 low-converts the color signal provided from the signal separation unit 50 and provides it to the second mixing unit 80.

In addition, the luminance signal processing unit 70 is composed of a frequency modulator 71 and a first mixing unit 72, as shown in the same figure, the frequency modulator 71 in the signal separation unit 50 A first frequency modulated signal obtained by frequency modulating the provided luminance signal is provided to the first mixing unit 72, and the second mixing unit 72 includes a first frequency modulated signal and an oscillating unit (provided by the frequency modulating unit 71). A second frequency modulated signal provided at 30), that is, a frequency signal of 4.4 MHz, which is a frequency corresponding to 100 IRE, which is a white level, as shown in FIG. 2, is mixed and provided to the second mixing unit 80.

That is, the first mixer 72 mixes the first frequency modulated signal provided by the frequency modulator 71 and the second frequency modulated signal provided by the oscillator 30, and thus, the first mixer 72 provided by the oscillator 30. The 2 frequency modulated signal is provided with a frequency of 4.2 MHz corresponding to a gray level of 50 IRE at a frequency of 4.4 MHz, which is a frequency corresponding to 100 IRE, and an overlap period or more predetermined intervals as shown in FIG. A section) is faded.

At this time, the oscillator 30 oscillates the 3.54 MHz frequency, which is the tip frequency of the sync signal. As described above, the oscillator 30 stops oscillation under the control of the microcomputer 20 to generate a sync signal at the time of reproduction. To be detected.

Meanwhile, the second mixing unit 80 receives the color signal provided from the color signal processing unit 60 and the faded luminance signal received from the luminance signal processing unit 70 and mixes the same to the signal amplification unit 90. .

Therefore, the signal amplifier 90 provides the color signal and the luminance signal provided from the second mixer 80 to the video head.

As described above, the fade control apparatus of the video cassette recorder according to the present invention performs a fade process from the initial recording time point to the overlap occurrence period, that is, the point where the full width erasing head and the video head meet or more, Close up the screen during playback by mixing the first frequency modulated signal frequency-modulated with the luminance signal separated from the video signal and the second frequency modulated signal provided by oscillation, and mixing the mixed luminance signal and the color signal and recording them on a magnetic tape. (close-up) and seamlessly connect the screen when editing tapes.

While the invention has been shown and described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various modifications, changes and omissions can be made without departing from the spirit and scope of the invention.

Claims (5)

A video cassette recorder for recording an input video signal on a magnetic tape, An automatic gain adjusting unit which adjusts and provides a gain value of an input level of the input video signal; A signal separator which separates and provides a luminance signal and a color signal from an image signal provided by the automatic gain control unit; A color signal processor configured to process and provide a color signal provided separately from the signal separator; A luminance signal processing unit for mixing and providing a first frequency modulated signal frequency-modulated with the luminance signal provided separately from the signal separation unit and a second frequency modulated signal provided; A mixing unit which mixes and provides a color signal and a luminance signal provided by the color signal processing unit and the luminance signal processing unit; A signal amplifying unit amplifying a mixed signal of a color signal and a luminance signal provided by the mixing unit and providing the amplified signal to the magnetic tape; An oscillator for oscillating the second frequency modulated signal corresponding to the oscillation control signal provided to the luminance signal processor; And And a microcomputer for providing an oscillation control signal for oscillating the second frequency modulated signal to the oscillator. 2. The apparatus of claim 1, wherein the luminance signal processor comprises: a frequency modulator for frequency modulating a luminance signal provided separately from the signal separator, a first frequency modulated signal provided from the frequency modulator, and the oscillator; A fade control device for a video cassette recorder, characterized in that it comprises a first mixing section for mixing the provided second frequency modulated signal. The fading control apparatus of a video cassette recorder according to claim 1, wherein the oscillation control signal provided by the microcomputer is a control signal for oscillating a frequency corresponding to a white level. The apparatus of claim 1, wherein the oscillation control signal provided by the microcomputer is a control signal not to provide the oscillation frequency in a period of a synchronization signal. The oscillation control signal provided by the microcomputer is configured to a point where the full width erasing head removing the signal recorded on the magnetic tape and the video head recording the image signal on the magnetic tape meet or exceed a predetermined section. A fade control device for a video cassette recorder, characterized in that oscillation is performed.

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