JPH05101305A - Method for recording copying number of times - Google Patents

Abstract

PURPOSE:To provide a method for recording copying number of times recording a signal indicating how many order of generation of a copy is copied at the time of recording in an analog HD-VTR. CONSTITUTION:An index signal read at the time of reproducing is signal processed by an index signal process circuit 18 and copying number of times information recorded on the index signal recording area of a tape is detected. An optimum value is read from a ROM 19 recording respective signal process constants and a reproducing system video signal process circuit 20 is controlled so as to signal process suitably for the detected copying number of times. The reproducing processes of the adjustment of the limitter threshold value of a noise reducer, the adjustment of a frequency characteristic and the emphasis of an edge, etc., are performed. By the reproducing processes, the degradation of S/N by repeating a copy is prevented and an image suitable for enjoying is reproduced automatically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, when recording with a video tape recorder (hereinafter referred to as VTR), records an identification signal indicating the generation of the copy on a tape and automatically performs signal processing. Regarding how to choose.

[0002]

2. Description of the Related Art In a conventional VTR, there is no information regarding the source at the time of recording, and it is not possible to automatically select a signal processing suitable for the case where the image quality is deteriorated by copying.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to detect the number of times a tape recorded on a VTR has been copied, and to automatically select a signal process suitable for the case in which the image quality is degraded by copying. To do.

[0004]

SUMMARY OF THE INVENTION According to the present invention, when recording, an identification signal indicating the number of copies counted from the master tape is recorded on the tape at the same time and reproduced according to the number of copies. The feature is that the system video signal processing is changed.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS To explain the present invention, the structure of a general consumer analog HD-VTR will be described. FIG. 5 shows a block circuit diagram of the analog HD-VTR. In the figure, a video signal consisting of a luminance signal Y, a blue color difference signal P _B , and a red color difference signal P _R is input to the A / D converter 1, converted into a digital signal, and input to the vertical non-linear emphasis circuit 2. .. This emphasized signal is encoded into a TDM signal in the frame memory 3 and shuffled. The output of the frame memory 3 is emphasized by the horizontal non-linear emphasis circuit 4 and converted into an analog signal by the D / A conversion circuit 5. This analog video signal is emphasized by the main emphasis circuit 6, modulated by the frequency modulation circuit 7, amplified by the recording amplifier 8 and recorded on the magnetic tape 9.

On the other hand, in the reproduction of the video signal recorded on the magnetic tape 9, the signal read by the head is amplified by the reproduction amplifier 10 and demodulated by the FM demodulator 11 in FIG. It is de-emphasized by the emphasis circuit 12 and converted into a digital signal by the A / D conversion circuit 13. This digital signal is de-emphasized by the horizontal non-linear de-emphasis circuit 14, deshuffling processing is performed by the frame memory 15 and decoding of the TDM signal is performed, de-emphasized by the vertical non-linear de-emphasis circuit 16, and then the D / A conversion circuit 17. The luminance signal and the color difference signal are converted into analog signals and reproduced and output.

According to the present invention, in the above analog HD-VTR, an identification signal indicating the copy number (generation number) at the time of recording is simultaneously recorded on the tape, and the image quality is deteriorated by copying. There is a point to automatically select a signal processing suitable for the time, and the mode will be described below.

FIG. 2 shows a format of a tape pattern and an index area of a consumer analog HD-VTR. In FIG. 2A, each segment S
There is an index area I between the areas of the G video signal V and the audio signal A.
Various signals are recorded in. The index area I
2 part of the data area, for example, a part of any of PACK1 to 5 forming the data area as shown in FIG. Or 4 bits.

The present invention detects the number of copies recorded as described above and automatically selects signal processing. The signal processing will be described below. FIG. 1 shows an example of a block circuit for reading the number of times of copying recorded in the index area of the tape at the time of reproduction and performing signal processing suitable for the number of times of copying. In the figure, the index signal read at the time of reproduction is subjected to signal processing by the index signal processing circuit 18, the copy number information recorded in the index area I is detected, and signal processing suitable for this copy number is performed. The optimum value is read from the ROM 19 in which each signal processing constant is recorded, and the reproduction system video signal processing circuit 20 is controlled. In the signal processing circuit 20, adjustment of a threshold value of a limiter which constitutes a noise reducer using inter-frame correlation, adjustment of f gain,
Reproduction processing such as adjustment of edge emphasis is performed, S / N deterioration due to repeated copying is prevented, and an image suitable for viewing is automatically reproduced.

As means for counting and recording the number of times of copying, a method of forming a transmission line for transmitting information of the index signal, connecting VTRs and exchanging information of the number of times of copying in the video, It can be designed as needed, such as transmitting a code on the signal during the vertical blanking period of the signal.

Next, as another example of recording the number of times of copying,
It is also possible to record the number of times of copying on the control track (CTL track). For example, as shown in FIG. 3A, the duty ratio can be changed and recorded in the same manner as in a system that records indexing index data and address index data on a CTL track. That is, the duty ratio is changed according to the number of times of copying, and as shown in FIG. 3B, the number of times of copying data is recorded in 4 bits next to the header (11 bits) of the CTL track. This recording is repeated several times to prevent errors. The reading of the copy count and the like can be processed by the circuit shown in FIG.

Further, it is also possible to record in a reserve area of a TDM (time division multiplex) signal as an area for recording the number of copies. Figure 4 shows the analog HD-VTR T
The waveform diagram of the DM signal is shown. In this waveform diagram,
It is also possible to record the number of copies in a reserve area E of about H / 3 behind the level correction reference lamp. In this case, it does not need to be written in all segments, at least 1
It is enough to be in a segment.

[0013]

By knowing the number of times of copying, it is possible to estimate the degree of deterioration of the image quality, and it is possible to perform signal processing for making the screen easy to see. It can also be used as a simple copy guard by transmitting the number of copies.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of recording the number of copies in an index area.

FIG. 3 is an explanatory diagram for recording the number of copies on a CTL track.

FIG. 4 is a waveform diagram of a TDM signal.

FIG. 5 is a block circuit diagram of a consumer analog HD-VTR.

[Explanation of symbols]

18 ... Index processing circuit 19. ROM storing each signal processing constant 20. Playback video signal processing circuit

Claims (1)

[Claims] 1. When recording with a video tape recorder, an identification signal indicating the number of copies from the master tape is simultaneously recorded on the tape, and the reproduction system video signal processing is changed according to the number of copies. Characteristic copy count recording method.