KR19980030878A - Video cassette recorder with video playback status display - Google Patents

Abstract

The present invention relates to a video cassette recorder having an image playback state display function that allows a user to visually display a current playback state through a predetermined OSD pattern during a tape playback operation. A preamplifier for amplifying the detected reproducing video signal to a predetermined level, an envelope detector for detecting an envelope carrying a predetermined DC voltage from the reproduced signal output from the preamplifier, and an envelope waveform detected by the envelope detector for a predetermined time interval. The integrating circuit integrating the signal, the A / D converter converting and outputting the analog signal output from the integrating circuit into a digital signal, and the OSD driving data for each reproduction state corresponding to the level data detected by the A / D converter. Level data storage unit, the predetermined OSD panel corresponding to the playback state in accordance with the predetermined control signal An OSD generator for outputting a signal, a mixer for mixing the output signal of the OSD generator with the reproduced video signal and outputting the same to an image output device, and controlling the overall apparatus, and according to the data level applied from the A / D converter. And a controller configured to read OSD control data according to a current playback state from the level data storage and drive the OSD generator based on the readout.

Description

Video cassette recorder with video playback status display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video cassette recorder, and more particularly, to a video cassette having a video playback state display function, which allows a user to visually display a current playback state through a predetermined OSD pattern during a tape playback operation. It is about a recorder.

Widely used in general audio equipment, including video cassette recorders (hereinafter referred to as VCRs), magnetic tape is made by magnetizing a thin film uniformly coated with a magnetic material with a contracted electromagnetic signal corresponding to predetermined data. It is to be recorded or read in the reverse order, even in the case of the tape is already recorded video or audio data can be initialized and used in a relatively simple way through the magnetization process described above.

Fig. 1 is a functional block for explaining the recording function of a conventional general VCR having the above-mentioned functions. A receiving unit for receiving the infrared signal and converting it into an electrical code signal, 3 is a microprocessor as a control unit for controlling the operation of the entire apparatus based on the code signal output from the receiving unit (2).

In addition, reference numeral 4 is a supply reel for conveying the tape wound while rotating in a constant direction, 5 is a rewind reel to rewind the tape released from the supply reel (4), 6 is from the microprocessor (3) A recording / playback head for recording a video signal or reading out recorded video data from a tape conveyed from the supply reel 4 according to a predetermined control signal of the head; A head driving unit for driving control of the synchronization signal detecting head 22 to be described later, 8 is a switching unit for performing switching switching according to the execution of the recording or reproducing operation based on a predetermined control signal from the microprocessor (3). .

On the other hand, reference numeral P _in denotes a video signal input terminal for receiving a video signal applied from a TV receiver or a camcorder connected to a VCR, and reference numeral 9 is applied to the inside of the apparatus through this video signal input terminal P _in . YC separation unit for separating and outputting the video signal to be divided into the luminance signal (Y) and the color tone signal (C), 10 is a frequency modulation (FM) of the luminance signal (Y) separated and output from the YC separation unit (9) FM modulation circuit, 11 is a frequency low-frequency conversion circuit for converting and outputting the tone signal (C) which is separated from the luminance signal in the YC separation unit 9 into a low-band frequency signal, 12 is the FM modulation circuit 10 and A mixer (MIXER) for mixing the luminance signal (Y) and the color tone signal (C) respectively output from the frequency low-frequency conversion circuit 11, 13 amplifies the video signal mixed in the mixer 12 to a predetermined level A signal for supplying the amplified signal to the fixed terminal (R; recording) of the switching unit (8) It's a wealth.

Reference numeral 14 denotes a recording erasing head for erasing previously recorded video and audio data prior to the recording operation of the recording / reproducing head 6, and 15 denotes a predetermined control from the microprocessor 3; A recording erasing head driver for driving control of the recording erasing head 14 according to a signal, and 22 is a preamplifying part for amplifying and outputting a reproduction signal applied to the fixed terminal P side of the switching unit 8 during a reproduction operation. .

Reference numeral 16 denotes a high pass filter (HPF) for detecting only the luminance signal Y among the reproduction signals output from the preamplifier 22, and 17 denotes this high band pass filter 16 ( FM demodulation circuit for demodulating the luminance signal output from the HPF), 18 is a low pass filter LPF for detecting only the hue signal C among the reproduction signals output from the preamplifier 22; Low Pass Filter), 19 is a frequency high-frequency conversion circuit for converting a color tone signal output from the low pass filter 18 (hereinafter referred to as LPF) into a high frequency signal of a predetermined frequency band, and 20 is the FM demodulation circuit. Mixer (MIXER) for combining the luminance signal (Y) output from the furnace (17) and the color tone signal (C) output from the frequency high-frequency conversion circuit (19), 21 is the image reproduction synthesized by this mixer 20 an amplification section for amplifying the signal to a predetermined level, a reference numeral P _out is the amplification section 21 An output terminal for outputting a video reproduction signal amplified up toward the video display device such as a TV.

That is, in the conventional general VCR having the above-described configuration, in response to a user inputting a recording execution command through the remote control device 1, the conventional VCR is installed in front of the recording / reproducing head 6 before the recording execution. The recording head (also called full-width erasing head) 14 is used to erase all existing video and audio recordings. With all data erased, the audio signal is controlled at the top of the track based on the video signal. The signals CTL are recorded at the bottom of the track, respectively.

On the other hand, since the VCR is operated while the comprehensive mechanical mechanisms are interlocked with each other precisely, even a small adjustment point has a great influence on the output state of the reproduction signal, that is, the image quality state. If the guide post (GUIDE POST), which is in close contact, is inaccurately adjusted, the position where the video recording surface of the video tape contacts the slits of the head is distorted, and the playback as shown in (d) and (f) of FIG. The output waveform of the signal is abnormally detected, such as narrowing the front and rear of the envelope compared to the normal waveform, resulting in a deterioration in image quality.

At this time, it is difficult for the general user to find out whether the reason for the poor screen state is caused by a defect in the TV itself or a problem in the playback state. Manipulations often provide a cause for greater failure.

The present invention has been made in view of the above circumstances, and has a video playback state display function that allows the user to visually display through a predetermined OSD pattern so that the user can recognize the current playback state at a glance during a tape playback operation. Its purpose is to provide a video cassette recorder.

1 is a block diagram for explaining recording and reproducing operations of a conventional video cassette recorder (VCR).

Fig. 2 is a waveform diagram for explaining and comparing output waveforms of a video signal according to a playback state during tape playback.

Figure 3 is a block diagram showing the internal configuration of a video cassette recorder with a video playback status display function according to an embodiment of the present invention.

Fig. 4 is a diagram illustrating an example screen output of a predetermined OSD pattern indicating a playback state.

******* Explanation of symbols on the main parts of the drawings *******

1: Remote controller 2: Receiver

3, 33: microprocessor 4: supply reel

5: Rewind 6: Head for recording / playback

7 head driving unit 8 switching unit

9: Y-C separation unit 10: FM modulation circuit

11: frequency low frequency conversion circuit 12, 20: mixer

13, 21: amplifier 14: record erase head

15: Record erase head drive unit 16: HPF (High Pass Filter)

17: FM demodulation circuit 18: LPF (Low Pass Filter)

19: frequency high frequency conversion circuit 22: preamplifier

23: envelope detection unit 24: integrating circuit

25: A / D converter 26: OSD generator

27: Mixer 28: Level data storage

A video cassette recorder having a video playback state display function according to the present invention for realizing the above object comprises a preamplifier for amplifying a reproduced video signal detected by a head to a predetermined level, and a playback signal output from the preamplifier. An envelope detection unit for detecting an envelope carrying a predetermined DC voltage, an integration circuit for integrating the envelope waveform detected by the envelope detection unit at a predetermined time interval, and an A / D for converting and outputting an analog signal output from this integration circuit into a digital signal Converter, a level data storage unit for storing OSD driving data for each playback state corresponding to the level data detected by the A / D converter, and an OSD for outputting a predetermined OSD pattern signal corresponding to the playback state according to a predetermined control signal. A generator for mixing the output signal of the OSD generator with the reproduced video signal and outputting the mixed output signal to an image output device; And a control unit which controls the entire device and reads the OSD control data according to the current reproduction state from the level data storage unit according to the data level applied from the A / D converter, and drives the OSD generation unit based on this. Characterized in that configured to include.

That is, according to the present invention having the above-described configuration, by detecting the integral level of the envelope waveform with respect to the reproduced video signal (V.RF) and outputting a predetermined OSD pattern indicating the current reproduction state on the screen, It is possible to visually indicate whether the current playback operation is being executed normally at a glance.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention.

FIG. 3 is a block diagram showing an internal configuration of a video cassette recorder having a video playback state display function according to an embodiment of the present invention. The same reference numerals refer to the same elements as those shown in FIG. The numbers will be omitted and the detailed description thereof will be omitted.

In FIG. 3, reference numeral 23 denotes an envelope detector for detecting an envelope carrying a predetermined DC voltage from a reproduction signal V. RF output from the preamplifier 22, and 24 denotes an envelope detected by the envelope detector 23. In FIG. An integrating circuit for integrating waveforms at predetermined intervals, 25 is an A / D converter for converting and outputting an analog signal output from the integrating circuit 24 into a digital signal.

In addition, reference numeral 33 denotes a microprocessor which controls the entire apparatus and additionally includes an OSD display function according to the current playback state based on the digital data applied from the A / D converter 25. A level data storage unit for storing OSD driving data for each reproduction state corresponding to the level data detected by the A / D converter 25, reference numeral 26 is reproduced in accordance with a predetermined control signal from the microprocessor 33. An OSD generator which outputs a predetermined OSD pattern signal corresponding to a state, and 27 is an output port P _out by mixing the output signal of the OSD generator 26 and the reproduced video signal output from the amplifier 21. The mixer outputs to an image output device such as a TV receiver.

Next, the operation of the device having the above configuration will be described.

When the user selects a play button (not shown) provided in the remote control device 1, the microprocessor 33 plays back by controlling the recording / playback head 6 through the head driving unit 7. In addition to performing the operation, by switching the switch contact of the switching unit 8 to the P terminal side, the video signal output by the reproducing operation is sent to the preamplifier 22 side.

On the other hand, the reproduced video signal amplified by the preamplifier 22 to a predetermined level has only a low pass filter (LPF) 18 and a luminance signal Y that separate only the hue signal C for a normal reproduction operation. The separation is applied to the high pass filter (HPF) 16, the envelope detector 23 is output from the preamplifier 22, as shown in (b) and (c) of FIG. The envelope waveform V.ENV carrying a predetermined DC voltage is detected from the reproduced video signal V.RF.

The envelope waveform detected by the envelope detector 23 is integrated by the integrating circuit 24 at predetermined time intervals, and the calculation result is converted into digital data by the A / D converter 25. The microprocessor 33 reads the OSD control data corresponding to the playback state from the level data storage 28 according to the data level applied from the A / D converter 25, and generates the OSD based on this. The drive section 26 is drive controlled.

As a result, in the mixer 27, a predetermined OSD pattern signal for displaying the current playback state on the screen is mixed with the playback video signal, and the mixed signal is outputted through the output port P _out . As a result, it is transmitted to the output device. As a result, a predetermined OSD pattern indicating the current playback state is output on the CRT screen as illustrated in FIG.

That is, according to the embodiment, by detecting the integral level of the envelope waveform with respect to the reproduced video signal (V.RF) and outputting a predetermined OSD pattern indicating the current reproduction state on the screen, the user is currently proceeding. It is possible to visually indicate whether the playing operation is normally performed at a glance.

On the other hand, the present invention is not limited to the above embodiments and can be variously modified within the scope not departing from the technical gist of the present invention, for example, the form of the OSD pattern output on the screen is good / normal / bad, etc. It can also be configured to be represented in a simplified form of.

As described above, according to the present invention, the tape can be visually displayed through a predetermined OSD pattern so that the user can recognize the current playback state at a glance.

Claims (1)

A preamplifier for amplifying a reproduced video signal detected by the head to a predetermined level; An envelope detector for detecting an envelope carrying a predetermined DC voltage from a reproduction signal output from the preamplifier; An integrating circuit for integrating the envelope waveform detected by the envelope detecting section at predetermined time intervals, An A / D converter which converts and outputs an analog signal output from the integrating circuit into a digital signal, A level data storage unit for storing OSD driving data for each reproduction state corresponding to the level data detected by the A / D converter; An OSD generator for outputting a predetermined OSD pattern signal corresponding to a reproduction state according to a predetermined control signal; A mixer for mixing the output signal of the OSD generating unit with the reproduced video signal and outputting the mixed video signal to the video output device; And a control unit which controls the entire apparatus and drives the OSD generator based on the readout of the OSD control data according to the current playback state from the level data storage unit according to the data level applied from the A / D converter. And a video cassette recorder having a video playback status display function.