KR19980085957A - Video cassette recorder with bad section indexing function - Google Patents

Abstract

The present invention examines a defective section of an image recorded on a video tape during a playback operation, and marks a region identified as a defective section so that the user can refer to the recording and playback operation for the tape. A video cassette recorder having a bad section indexing function of an image recording to provide an indexing function, comprising: a preamplifier 22 for amplifying a reproduced video signal detected by an image head 6 to a predetermined level; An envelope detecting unit 23 for detecting an envelope carrying a predetermined DC voltage from a reproduction signal output from the amplifier 22, an integrating circuit 24 for integrating the envelope waveform detected by the envelope detecting unit 23 at a predetermined time interval, And an A / D converter (25) for converting and outputting an analog signal output from the integrating circuit (24) into a digital signal; A level data storage unit 28 that sets a reference level for determining a defective section with respect to an integrated level of an envelope waveform applied from the A / D converter 25, and a predetermined section of a video tape according to a predetermined control signal. A CTL head HD1 for recording and reading the CTL signal on which the head switching is based, and a counter 35 for detecting the tape feed amount for playback or rewinding / rewinding by the user, and a predetermined control signal during the playback operation. The count value storage unit 36 for storing the count value counted by the counter 35 according to the present invention, and the apparatus as a whole, and based on the reference level set in the level data storage unit 28, the A / The defective section of the tape is determined by comparing the envelope level applied from the D converter 25, and for the defective section, the CTL head is based on the count value counted by the counter 35. And a microprocessor 33 for controlling to record the index data of the duty ratio contracted to a predetermined area of the tape through HD1.

Description

Video cassette recorder with bad section indexing function

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video cassette recorder. In particular, a user can record a tape on a tape by inspecting a bad section of an image recorded on a video tape during playback and marking a region identified as a bad section. And a video cassette recorder having a bad section indexing function of an image recording to provide an indexing function for referencing during a reproduction operation.

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, the video tape may be aged due to long-term use, or the recording surface of the tape may be damaged due to inexperienced operation of the device. Reusing such tape may damage the device every time it is played. As shown in Fig. 2 (d) and (f), the output waveform of the reproduction signal is abnormally detected, such as narrowing the front and rear of the envelope compared to the normal waveform (b), thereby deteriorating the image quality. Will result.

Therefore, the user should watch the bad video and audio of the corresponding section every time the playing operation of the tape, and if recording on such a tape, if the image quality and sound quality of the damaged section is severe, the user will be unable to view the section. It does not mean anything.

The present invention has been made in view of the above circumstances, and when a playback operation (PLAY) is performed, the user checks the defective section of the video recorded on the video tape, and marks the area identified as the defective section by the user. It is an object of the present invention to provide a video cassette recorder having a bad section indexing function of an image recording, which provides an indexing function for reference during recording and playback operations.

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.

Fig. 3 is a block diagram showing a video cassette recorder equipped with a bad section indexing function of video recording according to an embodiment of the present invention.

4 is a diagram illustrating an output state of an OSD subtitle for guiding an index result for an image recording failure section.

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: R / P head drive 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

30: CTL head drive unit 31: amplification unit

32: waveform shaping circuit 34: pulse judgment unit

35: counter 36: count value storage unit

HD1: CTL head

A video cassette recorder having a bad section indexing function of video recording according to the present invention for realizing the above object comprises: a preamplifier 22 for amplifying a reproduced video signal detected by the video head 6 to a predetermined level; Envelope detection unit 23 for detecting an envelope carrying a predetermined DC voltage from the reproduction signal output from preamplifier 22, and integrating circuit 24 for integrating the envelope waveform detected by envelope detection unit 23 at a predetermined time interval. And an A / D converter (25) for converting and outputting an analog signal output from the integrating circuit (24) into a digital signal; A level data storage unit 28 that sets a reference level for determining a defective section with respect to an integrated level of an envelope waveform applied from the A / D converter 25, and a predetermined section of a video tape according to a predetermined control signal. A CTL head HD1 for recording and reading the CTL signal on which the head switching is based, and a counter 35 for detecting the tape feed amount for playback or rewinding / rewinding by the user, and a predetermined control signal during the playback operation. The count value storage unit 36 for storing the count value counted by the counter 35 according to the present invention, and the apparatus as a whole, and based on the reference level set in the level data storage unit 28, the A / The defective section of the tape is determined by comparing the envelope level applied from the D converter 25, and for the defective section, the CTL head is based on the count value counted by the counter 35. And a microprocessor 33 for controlling to record the index data of the duty ratio contracted to a predetermined area of the tape through HD1.

In addition, the video cassette recorder having a bad section indexing function of image recording according to the present invention generates an OSD which outputs a predetermined OSD pattern signal for guiding the result of the bad section indexing operation performed under the control of the microprocessor 33. And a mixer 27 for mixing the output signal and the reproduced video signal of the OSD generator 26 and outputting them to the video output device.

That is, according to the present invention having the above-described configuration, the integral level of the envelope waveform is detected with respect to the reproduced video signal V.RF during the reproduction operation, and the integral level of the envelope waveform is reduced based on the counter value. By checking the interval that is below the fixed position, the index data is recorded in the video recording section by using the CTL signal at the time of the playback stop, so that the user can refer to this when playing or recording the corresponding tape.

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 equipped with a bad section indexing function of video recording according to an embodiment of the present invention, in which components having functions substantially the same as those shown in FIG. The same reference numerals are used, and 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.

Further, reference numeral 28 is a level data storage unit for setting a reference level for determining a defective section with respect to the integration level of the envelope waveform applied from the A / D converter 25, and reference numeral 33 controls the entire apparatus. In addition, by comparing the envelope level applied from the A / D converter 25 on the basis of the reference level set in the level data storage unit 28, the defective section of the tape is determined, and the index data recording function for the section. A microprocessor further comprising: an OSD generator for outputting a predetermined OSD pattern signal for guiding a result of a bad section indexing operation performed under the control of the microprocessor 33, and 27 is an OSD. The output signal of the generator 26 and the reproduced video signal outputted from the amplifier 21 are mixed and output to a video output device such as a TV receiver through an output port P _out . Output mixer.

On the other hand, reference numeral HD1 denotes a CTL head for recording / reading a CTL signal which is the basis of head switching for a contracted section of the video tape, and reference numeral 30 denotes a CTL head according to a control command from the microprocessor 33. CTL head drive unit for controlling drive (HD1), 31 is an amplifier for amplifying the signal read by the CTL head (HD1), 32 is a square wave of the CTL signal amplified to a predetermined level by the amplifier 31 Waveform shaping circuit.

Further, reference numeral 35 denotes a counter for detecting the feeding amount of the tape when playback or rewinding / rewinding is executed by the user, and 36 is counted by the counter 35 under the control of the microprocessor 33 during the reproducing operation. It is a coefficient value storage unit for storing the counted coefficient value.

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 drives the recording / playback head 6 through the R / P head driver 7. By controlling, the playback operation is executed, and the switch contact of the switching unit 8 is controlled to be switched to the P terminal side, so that the video signal output by the playback 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 compares the data level applied from the A / D converter 25 with the reference level set in the level data storage unit 28, and if the signal lower than the reference level is applied, the corresponding section is defective. It is determined as the section, and the current count value counted by the counter 35 is recorded in the count value storage section 36 as the start position of the tape defective section.

On the other hand, when the envelope detection level is restored to the reference value or more, the microprocessor 33 records the count value at the corresponding time point as the end position of the tape defective section in the count value storage unit 36. By repeating, the defective section is confirmed.

Then, when a playback stop command is issued by the user or the playback of the tape is completed, the microprocessor 33 returns the tape to the start position of the defective section based on the information stored in the count value storage unit 36. Then, the contracted index data having a duty ratio of 4: 6 is recorded through the CTL head HD1, and the corresponding index data is also recorded at the end position of the defective tape section in the same manner. .

On the other hand, through the above process, the microprocessor 33 that has completed the indexing function for the defective section of the tape is then subtracted the count value corresponding to the start and end position of the defective section stored in the count value storage section 36 After calculating the quantity of the defective section, and then drive control of the OSD generator 26 based on this, as shown in Figure 4 to output a guide subtitle for the quantity detected in the defective section on the screen.

That is, according to the above embodiment, when the playback operation (PLAY), the user checks the defective section of the video recorded on the video tape and marks the area identified as the defective section so that the user can record and play back the tape. It is possible to realize a video cassette recorder having a bad section indexing function of an image record which is provided with an indexing function for reference.

On the other hand, the present invention is not limited to the above embodiments and can be variously modified without departing from the technical gist of the present invention. Therefore, the above-described tape defect section indexing operation is not executed during the normal reproducing operation. For example, a separate function key (not shown) is additionally provided in the remote control device 1, and the microprocessor 33 allows the user to selectively execute as needed by executing an index operation when the user selects it. It can also be configured to do so.

As described above, according to the present invention, the integral level of the envelope waveform is detected with respect to the reproduced video signal V.RF during the reproduction operation, and the integral level of the envelope waveform is equal to or less than a predetermined value based on the counter value. By checking the section and recording the index data in the video recording section by using the CTL signal at the time of playback stop, the user can not only refer to this when playing or recording the tape later, By allowing the user to identify the defective section of the tape, it is possible to help determine whether to reuse or discard the tape.

Claims (2)

A preamplifier 22 which amplifies the reproduced video signal detected by the image head 6 to a predetermined level, and an envelope detector which detects an envelope carrying a predetermined DC voltage from the reproduced signal output from the preamplifier 22; (23), an integrating circuit 24 for integrating the envelope waveform detected by the envelope detecting section 23 at a predetermined time interval, and A for converting and outputting an analog signal output from the integrating circuit 24 into a digital signal. A video cassette recorder having a / D converter 25; A level data storage unit 28 that sets a reference level for determining a defective section with respect to the integral level of the envelope waveform applied from the A / D converter 25; A CTL head HD1 for recording and reading the CTL signal that is the basis of head switching for a contracted section of the video tape according to a predetermined control signal, A counter 35 for detecting the conveyance amount of the tape with respect to playback or rewinding / rewinding by the user, A count value storage unit 36 for storing count values counted by the counter 35 in accordance with a predetermined control signal during a reproducing operation, and By controlling the overall apparatus and comparing the envelope level applied from the A / D converter 25 based on the reference level set in the level data storage unit 28, the defective section of the tape is determined, and the defective The section includes a microprocessor 33 which controls to record index data of the duty ratio contracted in a predetermined area of the tape through the CTL head HD1 based on the count value counted by the counter 35. A video cassette recorder having a bad section indexing function of a video recording. The OSD generating unit 26 according to claim 1, which outputs a predetermined OSD pattern signal for guiding a result of the defective section indexing operation performed under the control of the microprocessor 33. And a mixer (27) for mixing the output signal with the reproduced video signal and outputting the output video signal to the video output device.