JP2001069452A - Recording and reproducing device, and input/output device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect character information and a copy guard signal and to effectively utilize a high definition OSD circuit by detecting character information, which is superimposed on the vertical blanking period of an analog video signal at the time of recording, encoding the character information and recording it on a recording medium while superimposing it on a digital signal from which the character information is removed. SOLUTION: This recording and reproducing device is newly provided with a path for outputting a video signal, which is compressed/expanded in a recording mode, to a monitor screen regardlessly of analog/digital signal, namely, provided with a digital EE path for outputting the signal through a video decoder 9, a digital IF 10, an MPEG2 encoder 11, an MPEG decoder 13, an OSD circuit 18, a digital IF 19, an adder circuit 27, a video encoder 20 and a switch 21. By providing such a digital EE path, a present recording picture quality can be confirmed and the digital OSD circuit 18 can output a high definition OSD picture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus and an input / output apparatus for performing digital compression / expansion on an input analog video signal or the like, and more particularly to a compression / expansion processing and suitable for such information as copy guard information and character information. It concerns processing technology.

[0002]

2. Description of the Related Art Conventionally, in a home analog VTR, as the number of soft tapes increases, the problem of illegal copying and the like becomes remarkable. From the standpoint of copyright protection, a pseudo sync pulse is used as a copy guard signal in a vertical blanking period. To prevent the AGC circuit from malfunctioning (compression operation) during dubbing on a VTR and to greatly disturb the recorded image to prevent copy.

[0003] In recent years, DVDs (Digital
In addition to the pseudo sync pulse, a copy protection signal called a color stripe has been added to a soft tape of the Video Disc standard. This is a system that synchronizes a signal used as a reference for color signal processing with a burst signal of an input signal at the time of recording, such as a VTR, by inverting the phase of a color burst signal at a certain line interval near the center of the burst by 180 degrees. In such a device, the hue is largely disturbed and a horizontal streak-like hue defect is generated. This is a measure for further enhancing copyright protection.

Such a copy protection function is provided by an analog VTR.
Works effectively, but no effect is obtained in a digital VTR or the like. In Japanese Patent Application Laid-Open No. Hei 9-102929, a device is devised so that a copy protection function works even between digital VTRs. In particular, a disturbance signal generation flag is set for a disturbance signal such as a pseudo sync pulse or a color stripe signal. The information is stored in a newly secured area, and based on this information, this information is propagated also in restoration of a disturbed signal at the time of reproduction and signal transmission / reception through a digital interface, thereby realizing copy protection.

On the other hand, in a home digital VTR,
In recent years, stationary VTRs of the DV standard using magnetic tapes having a width of 6 mm have been commercialized. These digital VTRs use an image compression / expansion technology to extend the recording time, and perform such compression / expansion processing. Is home V
TR is becoming mainstream. In addition to the conventional home analog VTR mode, a digital VTR mode is newly added, and a VTR that is upwardly compatible with the conventional analog VTR has been commercialized. In addition, a VTR compatible with digital broadcasting that directly records a bit stream signal from a digital tuner called an IRD has appeared. As described above, a signal obtained from a digital tuner includes a lot of information such as character information, and a digital OSD (short for on-screen display)
In many cases, a high-definition OSD screen can be configured by a circuit, which is different from a conventional analog VTR.

[0006]

In the digital VTRs shown in the above-mentioned known examples, a copy protection technique is shown, but details of a home VTR to which the technique is applied are not mentioned much. . That is, it does not describe the details of a home VTR or the like utilizing the compression / decompression technique.

Furthermore, in the above-mentioned known example, only the description relating to the copy guard signal is provided, and the recording process of the closed caption signal (character information) superimposed in the vertical blanking period on the digital device and the reproduction process from the digital device are performed. Is not specifically described.

In general, a recording / reproducing apparatus such as a VTR outputs an EE (output to a monitor passing only through an electrical path) screen to a monitor television even during recording. There are problems such as differences between the image quality recorded in the recording / reproducing device (which changes considerably due to compression) and the monitored EE image quality. The image quality check allows the recording image quality to be monitored as necessary. There is also a need for functionality.

It is also necessary to consider the specific processing of information superimposed during the vertical blanking period, such as a copy guard signal, on the EE output signal at the time of the image quality check function.

[0010] Further, in a digital device to which the digital compression / expansion technique is applied, there arises a problem that it is difficult to control the image quality recorded in the recording / reproducing apparatus due to a change in the recording transmission rate.

In order to provide a recording / reproducing apparatus with good cost performance, it is necessary to effectively use the high-definition OSD circuit not only for bit stream recording but also for external video input recording and reproduction signals. , Applications and the like are not particularly shown.

[0012] Further, a tape containing copy guard information of only a pseudo sync like a soft tape of a VTR, a soft tape in which a part of the copy guard information is missing due to an illegal device such as a copy guard signal elimination device, and the like. There is a possibility that the copy guard function exists, so it is necessary to consider that the copy guard function works sufficiently with only the pseudo sync or the color stripe signal.

An object of the present invention is to solve such a problem,
It is an object of the present invention to provide a high-quality apparatus with high cost performance by realizing protection of character information and a copy guard signal and effective use of a high-definition OSD circuit in a recording / reproducing apparatus and an input / output apparatus employing a compression / expansion technique.

[0014]

In order to achieve the above object, according to the present invention, there are provided means for converting an input analog video signal into a digital signal, recording means for recording the converted digital signal on a recording medium, and recording. In a recording / reproducing apparatus having a reproducing means for reproducing a digital signal from a medium and a converting means for converting the reproduced digital signal into an analog video signal, the character information superimposed during the vertical blanking period of the analog video signal during recording is read. There is provided a detecting means for detecting, and a superimposing means for encoding the detected character information and superimposing it on a digital signal from which the character information has been removed, so that the superimposed signal is recorded on a recording medium.

Further, according to the present invention, means for converting an input analog video signal into a digital signal, recording means for recording the converted digital signal on a recording medium, reproducing means for reproducing the digital signal from the recording medium, In a recording / reproducing apparatus having a converting means for converting a reproduced digital signal into an analog video signal, a extracting means for extracting character information from a digital signal read from a recording medium at the time of reproduction, and a reproducing process for the extracted character information Adding means for adding the digital video signal to a predetermined position of the digital video signal, and outputting an analog video signal obtained by converting the digital video signal after the addition by the conversion means.

Further, according to the present invention, means for converting an input analog video signal into a digital signal, compression means for compressing the signal, recording means for recording the compressed digital signal on a recording medium, In a recording / reproducing apparatus having a reproducing means for reproducing the digital signal thus obtained and an expanding means for expanding the compressed digital signal, the first digital signal before compression and the second digital signal which has been compressed and expanded are A switching means for switching and an converting means for converting the output to an analog video signal are provided, and the converted analog video signal is output to the image display device.

Further, according to the present invention, means for converting an input analog video signal into a digital signal, compression means for compressing the signal, recording means for recording the compressed digital signal on a recording medium, A recording / reproducing apparatus having a reproducing means for reproducing the compressed digital signal and an expanding means for expanding the compressed digital signal, a converting means for converting the compressed and expanded second digital signal into an analog video signal, Switching means for switching between a first analog signal before conversion into a signal and a second analog signal that has been compressed and expanded, and outputs this analog video signal to the image display device, and the vertical analog signal that is deleted in the process of compression and expansion. Detecting means for detecting information superimposed during the blanking period at a stage prior to the compression means; and encoding the detected information to encode the information. A superimposing means for superimposing on the signal, and an adding means for adding the superimposed information to the signal decompressed by the decompressing and decompressing means, so that an output obtained by the adding means is obtained as the second analog signal. did. Here, the information extracted by the detection means is preferably sent to the addition means via a microcomputer.

Further, according to the present invention, a converting means for converting an inputted analog video signal into a digital signal, a compressing means for compressing the same, a recording means for recording the compressed signal on a recording medium, and a digital signal from the recording medium In a recording / reproducing apparatus having a digital mode for recording and reproducing having a reproducing means for reproducing and a decompressing means for decompressing a compressed signal, and an analog mode for recording and reproducing an input analog video signal in an analog signal state, Converting means for converting the expanded second digital signal into an analog video signal, and switching means for switching between the first analog signal before encoding and the compressed and expanded second analog signal; To the image display device and compress the information superimposed during the vertical blanking period, which is deleted in the process of compression and decompression. Detecting means for detecting the information at a stage preceding the stage, superimposing means for encoding the detected information and superimposing the information on the compressed signal, and adding means for adding the superimposed information to a signal expanded and extracted by the expanding means The output obtained by the adding means is obtained as the second analog signal.

Here, it is preferable that the compression means has a variable transmission rate, and uses the second analog signal as a check mode for performing the optimal setting of the transmission rate which affects image quality.

Further, in the present invention, a digital OSD (abbreviation of an on-screen display) circuit is provided at a stage subsequent to the decompression means, so that compression is always performed during reproduction in a digital mode, input of an external composite signal, and reproduction in an analog mode. The expanded second analog signal is fixed at the output, and a digital OSD screen is displayed.

In the present invention, the path for obtaining the second analog signal is a video decoder for demodulating an analog video signal into a luminance signal and a color difference signal, a compression circuit for compressing the output thereof, and a decompression signal. A decompression circuit, an addition circuit for adding the information, and a video encoder for converting an output of the decompression circuit into an analog video signal, a switch circuit for switching between the video decoder output and the output of the decompression circuit at a stage subsequent to the decompression circuit, A digital OSD circuit is arranged in the stage, and the signal which is always passed through the digital OSD circuit as the second analog signal and switched between a compressed / expanded signal and a video decoded / encoded signal is switched.

According to the present invention, there is provided an A / D converter for converting an input analog video signal into a digital signal, a compressor for compressing the output of the A / D converter, and a recorder for recording the output of the compressor on a recording medium. A reproducing unit for reproducing a digital signal from the recording medium, an expanding unit for expanding an output of the reproducing unit, and a DA converting unit for converting an output of the expanding unit into an analog video signal; Detecting means for detecting first copy guard information superimposed on the vertical blanking period of the input analog video signal and second copy guard information superimposed on the color burst signal; and the two copies detected by the detecting means Adding means for adding guard information to the signal expanded by the expansion means, and in a mode other than the reproduction mode by the reproduction means, The output of the serial compression means were to be supplied to the expansion means.

It is preferable that the copy guard information extracted by the detecting means is sent to the adding means via a microcomputer. Further, it is preferable that the microcomputer matches a delay amount of the signal generated in the process of the compression and decompression with a delay amount of the copy guard information extracted by the detection unit.
Preferably, the second copy guard information is detected based on a signal obtained by demodulating an incoming modulated color signal on the BY axis.

The recording / reproducing apparatus may further comprise: an analog recording means for recording an input analog video signal on a recording medium as an analog signal in addition to the recording / reproduction of a digital signal; and an analog reproducing means for reproducing an analog signal from the recording medium. . The second copy guard signal is an APC (Auto-Automatic Clock) included in the analog recording means for phase-locking a color burst signal included in an input analog video signal and a color subcarrier used as a reference signal of the analog recording means. It is preferable to detect based on information from a phase control circuit.

Also, in the present invention, A / D conversion means for converting an input analog video signal into a digital signal, compression means for compressing the output of the A / D conversion means, decompression means for decompressing the compressed signal, and output of the decompression means And a DA conversion means for converting a signal into an analog video signal.
The output of the compression means is supplied to the decompression means for detecting first copy guard information superimposed on a vertical blanking period of the input analog video signal and second copy guard information superimposed on a color burst signal. A detection unit; and an addition unit that adds the two pieces of copy guard information detected by the detection unit to the signal expanded by the expansion unit.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a system configuration diagram of a digital VTR equipped with an MPEG encoder / decoder.
In this embodiment, a system in which a conventional analog VTR mode and a digital VTR mode are mixed will be described as an example. First, the analog mode will be described. Reference numeral 2 denotes an analog VTR (AVTR in the figure) signal processing circuit. The composite video signal input from terminal 1 is A
After being made constant amplitude by a GC (Auto Gain Control) circuit 3, it is separated into a luminance signal and a chrominance signal by a YC separation circuit 6, processed by a recording processing circuit 26, and recorded on a magnetic tape via a magnetic head. . After the signal reproduced from the magnetic tape is processed by the reproduction signal processing circuit 5, the reproduction luminance signal and the reproduction color signal are converted to the terminals 23 and 24 via the switches 7 and 21.
Respectively. Similarly, during recording, the outputs (luminance signal and chrominance signal) of the YC separation circuit 6 are output to the terminals 23 and 24 via the switches 7 and 21, respectively.

In the digital mode, a signal YC separated at the time of recording is input to a video decoder 9 via a switch 7 and converted into a digital signal by an AD converter at an input stage, and then converted into a luminance signal and a color difference signal by a decoder. Demodulated, digital interface 10 (hereinafter referred to as digital IF)
Then, the clock rate is converted to the clock rate of the MPEG2 encoder 13 and the signal is transmitted to the MPEG2 encoder 11. MP
The output of the EG2 encoder 11 is a DVTR (digital VT).
The signal is recorded by a DVTR signal processing circuit 15 via an interface (hereinafter abbreviated as DVTR_IF) 14 and recorded on a magnetic tape.

Here, information inserted in the vertical blanking period will be described with reference to FIG. FIG. 6 shows N
It is a figure which shows the waveform of the vertical blanking period of a TSC system video signal, and the CGMS_A42 and 21H which perform the copy management to the pseudo sync 41 and 20H for copy guard in 10-17H (H is a horizontal scanning period), and the character information to 21H Is inserted in FIG. 1 (abbreviated as CC in FIG. 1). Of these information, CGM
S_A is information that may be rewritten after copying, but is otherwise information that must not change during the recording and reproduction of the VTR. The information detected by the recording time detection circuit 16 is encoded and transmitted through the microcomputer 17. MPEG2 encoder 1
One part is stored together with the video signal, and is played back in MPEG2
The information is sent to the adder circuit 27 by the microcomputer 17 in the decoder 13 by the decoder 13 and is added to the MPEG2-decoded video signal. Although not shown in FIG. 6, there is a so-called color stripe as a copy guard signal for a color signal. For example, this signal is obtained by inverting a color burst signal every 21 lines for four lines in the middle of the burst signal. Thus, a dubbing machine such as a VTR works to disturb the hue. The information of the color stripe is also detected by the detection circuit 16 and restored by the addition circuit 27 at the time of reproduction. Generally, in order to transfer the data from the video decoder 9 to the MPEG2 encoder 11, the digital IF 10 converts the signal into a signal compliant with ITU-R Recommendation 601. ITU-R Recommendation 601
Is a luminance signal and a color difference signal (Cr, Cb) of 4: 2: 2.
In the form of time division multiplexing at a data rate of 27 Mhz, the information of the synchronization signal in the horizontal blanking period and the vertical blanking period is encoded and Video timing reference codes
Since the information superimposed during the vertical blanking period at this point disappears, the information is detected by the detection circuit 16 before the digital IF 10.
And the MPEG2 encoder 1 via the microcomputer 17
It is necessary to superimpose information again in the part of 1. Thereafter, the signal is delayed and recorded in the DVTR signal processing circuit 15.

The signal reproduced from the magnetic tape is a DVTR
After being reproduced by the signal processing circuit 15, it is expanded by the MPEG2 decoder 13, passed through the OSD circuit 18, and furthermore, in the digital IF 19, information of a synchronization signal of a horizontal blanking period and a vertical blanking period superimposed as video timing reference codes. After converting it to a signal form that is easy to decode, such as by extracting
The information to be inserted in the vertical blanking period, such as the copy guard signal, closed caption signal, and CGMS_A extracted by the G2 decoder 13 is added by the addition circuit 27, and then the luminance signal and the color signal are added by the video encoder 20. , And output to the output terminals 23 and 24 via the switch 21. Although omitted in FIG. 1,
It is assumed that a DA converter for converting a digital signal into an analog signal is built in an output stage of the video encoder.

The basic operation of recording / reproducing has been described above. In this embodiment, a path for outputting a video signal which has been compressed / expanded in the recording mode irrespective of analog / digital to a monitor screen is additionally provided. That is, a video decoder 9, a digital IF 10, an MPEG2 encoder 1
1. The digital EE path provided via the MPEG decoder 13, the OSD circuit 18, the digital IF 19, the adder circuit 27, the video encoder 20, and the switch 21 is provided. Providing such a digital EE path has the following advantages. First, MPEG
The encoder generally makes the transmission rate variable, and sets the transmission rate according to the purpose. Decreasing the transmission rate increases the recording time while deteriorating the image quality, but increasing the rate decreases the recording time while improving the image quality. Therefore, the provision of the EE pass has an advantage that the current recording image quality can be confirmed. By using this function, it is possible to provide a user-friendly VTR that allows the user to select, for example, a switch provided in the set or a change in the setting of the transmission rate on a menu screen. Second, in a digital VTR for home use utilizing image compression / expansion, various character information and the like are superimposed on a digital signal from a digital tuner (not shown in FIG. 1) such as an IRD, so that high definition is achieved. Digital OSD
The function is being added. Therefore, the digital E
By outputting the E path to the monitor screen, digital O
There is also an advantage that the SD circuit 18 can output a high-definition OSD screen. However, what should be noted at this time is the same as the state where the copy guard signal or closed caption signal superimposed during the vertical blanking period lost in the process of compressing and expanding the image is input as described above. Information needs to be restored. FIG. 6A shows an input video signal, and FIG. 6B shows a waveform when information is not restored. When such a signal is output from the EE output, copying is performed freely. Therefore, the condition is that the pseudo sync 44, the CGMS_A 45, and the closed caption signal 46 are restored again and output to the EE output as shown in FIG. The above is the description of the EE output when an external signal is input. In the present embodiment, when recording and reproduction are performed in the analog mode, the normal reproduction signal is output via the switch 7 and the switch 21 to the output terminal. 23, 24. In this case, the OSD circuit is an analog OS.
D (not shown), and cannot be as high-definition as the digital OSD in reality. Therefore, a high-definition OSD screen cannot be obtained through a normal output path. Therefore, a high-definition digital OSD circuit 18 can be used for a reproduction signal in the analog mode by passing the switch 7 and then selecting and outputting the white side with the switch 21 via the compression / decompression path. become.

FIG. 2 shows the switching between the switches 7 and 21 shown in FIG. 1, and shows the connection of the switches to the black and white contacts. Regardless of analog recording or digital recording, the EE output can switch between a through signal and a signal that has passed through an MPEG2 encoder / decoder. Normal playback output and MPE
A signal that has passed through the G2 encoder / decoder can be switched. The CODEC output in the figure means a signal that has passed through an MPEG2 encoder / decoder, that is, a compressed / decompressed signal. Also, "reproduction->CODEC" means a signal obtained by compressing and expanding a reproduced analog signal, and "MPEG_DEC" means a signal expanded by an MPEG2 decoder.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 shows a recording / reproducing apparatus using a DVD_RAM, which has only digital recording / reproducing unlike a VTR in which the analog mode and the digital mode are mixed. Parts similar to those in FIG. 1 are omitted. Unlike the digital VTR shown in FIG. 1, it does not have an analog VTR signal processing block, so the AGC circuit 31 is set independently. The signal processing after passing through the AGC is almost the same as that of FIG. 1 except that the switch 7 is deleted. Also, MP
The interface connected to the EG2 encoder 11 and the MPEG2 decoder 13 is a DVD interface 32
1 in that a DVD signal processing circuit 33 is connected to the end. FIG. 4 shows the mode switching of the switch 21 shown in FIG. As mentioned above,
Even in a device having only digital recording / reproducing, a signal path which has been compressed / expanded is output as an EE output, so that FIG.
In the same manner as in the embodiment, advantages such as confirmation of the recording image quality, setting of the image quality by the user, and realization of a high-definition digital OSD screen can be obtained.

Next, a third embodiment will be described with reference to FIG. FIG. 5 is different from the embodiment of FIG. 1 in that a switch 35 is provided in a stage preceding the OSD circuit 18 to switch the output signal of the digital IF 10 and the output of the MPEG2 decoder 13. As described above, the digital OSD circuit can generate an extremely high-definition OSD screen as compared with the conventional analog OSD circuit, and always passes through the EE pass and the reproduction path in the analog mode to improve the quality of the set. Can be enhanced. However, the signal that has passed through the MPEG2 encoder 11 and the MPEG2 decoder 13 causes some degradation in image quality due to compression and decompression even if the transmission rate is increased. This embodiment is a means for preventing such image quality deterioration and providing a high-definition OSD screen. By connecting the switch 35 to the black side,
A signal that does not pass through the PEG2 encoder 11 and the MPEG2 decoder 13, that is, does not undergo compression
The video encoder 20 can convert the analog video signal into an analog video signal via the SD circuit 27 and output the analog video signal. This makes it possible to output a high-quality analog video signal capable of high-definition and high-definition OSD display to a monitor. On the other hand, the image quality during recording can be checked by connecting the switch 35 to the white side.

Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG. This embodiment is a detailed embodiment relating to the detection of the pseudo sync pulse and the color stripe signal and the additional circuit in the digital EE path as compared with FIG. A pseudo sync pulse is detected by the detector 51 from the luminance signal output from the switch circuit 7,
A closed caption signal, a CGMS_A signal, and the like are detected, and the detection information is sent to the microcomputer 53. The color stripe information is detected by the color stripe detection circuit 52 from the color signal, and the detected information is sent to the microcomputer 53. As described above, the digital EE path includes the video decoder 9,
Digital interface 10, MPEG2 encoder 11, MPEG2 decoder 13, digital OSD circuit 1
8. Sent to the video encoder via the digital IF 54. Here, the process of being sent from the digital IF 54 to the video encoder and being converted into a video signal will be described in detail. The input of the digital IF 54 is ITU-R recommendation 601
Since the luminance signal and the chrominance signal (Cr, Cb) are transmitted in a time-division multiplexed format at a data rate of 27: 2: 2 27 Mhz, the digital IF is, for example, 13.5 Mhz.
, And a color difference signal (Cr, Cb), which are sent to the addition circuit 58 and the burst addition circuit 56, respectively. The information of the synchronization signal in the horizontal blanking period and the vertical blanking period is encoded and is used as a video timing reference.
Since they are superimposed as codes, they are separated and sent to the pulse generation circuit 59 as synchronization signal information (e), and based on this, a composite synchronization signal and a burst gate pulse at the time of adding a burst are generated and added. The gate pulses (g) and (f) are sent to the circuit 58 and the burst addition circuit 56, respectively. Also, copy guard information and the like detected before the video encoder are sent to the pulse generation circuit via the microcomputer 53,
(h) and (I) add the luminance signal and the color difference signal to the addition circuit 5
8. A burst addition circuit 56 adds the data again.
As for the luminance signal, the output of the addition circuit 58 is output to the output terminal 24 via the switch circuit 21. For the color signal, the output of the burst addition circuit 56 is modulated into the fsc band by the color encoder 57 and output to the output terminal 23 via the switch circuit 21.

Next, a means for detecting a color stripe signal will be described with reference to FIGS. FIG. 8 shows an outline of the color stripe. FIG. 7A is an enlarged view of a normal burst signal, and the phase is continuous during the entire period. FIG. 11B shows a burst portion to which a color stripe signal is added. The second half has a normal phase, whereas the first half is 180 degrees out of phase, that is, the phase is inverted. A phase discontinuity occurs in the vicinity. Such a burst signal is transmitted by 17H as shown in FIG.
There is a type in which a discontinuous burst for a 4H period is inserted after a normal phase continues for a period. What is shown here is N
This is an example of the TSC broadcasting standard.
There is also a color stripe signal of a line normal phase burst and a two line discontinuous burst.

FIG. 9 shows a specific configuration of the color stripe detection circuit 52. As shown in FIG. 11A, in the color signal of the NTSC broadcasting standard, the burst signal B has a phase of 180 degrees with respect to the BY axis, and a color is represented by a phase difference between the burst B and the color signal C. . When such a signal is multiplied by a carrier signal in the BY axis direction and demodulated, a state as shown in FIG. In order to correct this axis deviation, it is possible to correct the axis deviation by controlling the result of multiplication with the carrier signal in the RY axis direction so that Br becomes zero, and as shown in FIG. Will be located above. This state is R
-The Y-axis component is always located at zero, and the BY-axis component is always located at 180 degrees. For example, if the burst signal is inverted, the BY-axis component will be located at 0 degrees,
Therefore, the BY component can be used for color stripe determination. FIG. 9 shows a circuit for realizing this.
Are multiplied by the color subcarriers of 0 degree phase and 90 degree phase by the multipliers 62 and 67,
As a result, a BY axis component (Bb) and an RY axis component (Br) are obtained. At this time, only Br is compared with a constant (K = 0) given by the burst gate pulse (d) period coefficient unit 71, and the difference is smoothed by the LPF 70 to control the fsc oscillator 68. Control is applied in the direction to eliminate the deviation. In this state, the relationship between the input modulated color signal (a) and the Bb signal (e) is as shown in FIG. Assuming that the pulse generation circuit has a gate pulse (b) for checking the first half of the burst and a gate pulse (c) for checking the second half of the burst, the output (e) of the sign determination circuit 63 becomes the normal burst signal 75. For the discontinuous burst signals 77 to 80, the first half has a positive polarity and the second half has a negative polarity. It is counted in the field, and if the count value becomes a certain number or more, it can be determined that there is a color stripe. The determination result is output to the terminal 65 and sent to the microcomputer. Here, the signal input from the terminal 73 to the pulse generation circuit 72 is a composite signal separated from the input luminance signal.

As described above, the presence / absence of the color stripe information has been determined based on the phase information of the burst signal. However, the information of the color stripe control (hereinafter APS) added to the same line as the CGMS_A described above has been determined. Call it)
Of course, it is necessary to manage based on. The information is composed of 2 bits. 00 is a color stripe off, 01 is a 1-line color stripe, 10 is a 2-line color stripe, and 11 is a 4-line color stripe (the configuration described in FIG. 8). Become. Therefore, the color stripe information is added by looking at the result of the color stripe presence determination and the APS information. As described above, by detecting the color stripe information, it is possible to add a copy guard signal to the digital EE output even for a signal having no APS information and only the color stripe information.

Although the present embodiment has been described with reference to a digital VTR as an example, the same applies to a disk device such as a DVD based on FIG. 3, which is within the scope of the present invention.

Hereinafter, a fifth embodiment of the present invention will be described with reference to FIGS. This embodiment differs from FIG. 7 in the method of detecting a color stripe signal, and has the same purpose. The embodiment shown in FIG. 12 is a VTR in which an analog VTR mode and a digital VTR mode are mixed,
Generally, in a conventional analog VTR for home use, an APC (Auto Ph.D.) is used to lock a phase of a reference signal (color subcarrier) used for recording with a burst signal of an input color signal.
ase Control) circuit. Therefore, the above AP
The color stripe signal is detected using the phase comparison output in the C circuit. In FIG. 12, the phase comparison output obtained from the recording processing circuit 26 in the analog VTR processing 2 is input to the color stripe detection circuit 85, and a signal (k) for determining the presence or absence of a color stripe is sent to the microcomputer 53. . At this time, the APC circuit generally responds slowly with a long time constant to some extent, and the phase comparison signal itself is information smoothed by the LPF. Therefore, only the digital recording mode that requires detection of a color stripe is used. The control is performed by the control signal (j) from the microcomputer 25 so that the time constant is increased.

FIG. 13 shows a specific configuration of the detection circuit.
The color signal (a) input from the terminal 91 to the recording processing circuit 26 of the analog VTR is converted by the phase comparator 92 into the color subcarrier f transmitted from the crystal oscillator 93 and the voltage controlled oscillator 94.
The phase is compared with sc, and the phase error (e1) is input to the LPF 98, which is a loop filter, and is returned to the voltage controlled oscillator 94 with a certain time constant to perform phase control. Here, the pulse generator 103 receives the composite synchronization signal input from the terminal 104, generates a burst gate pulse (d), sends it to the phase detector 92, and performs phase comparison only during the burst period. Analog VTR processing circuit
It is generally C-shaped, and it is difficult to directly obtain a phase detection output. In general, the output of the LPF 98 is output from a terminal. Therefore, if the time constant during the normal APC operation is maintained, the phase error is smoothed and the detection becomes difficult as shown in FIG. 14 (e2). Therefore, the time constant of the LPF 98 is reduced by the digital mode “High” control signal input from the terminal 97, and the LPF 98 is input to the color stripe detection circuit 85 with a large phase error as shown in (e2 ′). In response to this signal, the input stage of the color stripe detection circuit 85
6, the comparator 100 compares the signal (e3) with the threshold Vth of the threshold generator 99 by the color stripe determination circuit 101 to determine whether or not the signal (e3) is present. Output to As shown in FIG. 14 (e1), a large phase error occurs in the burst portion where the phase is inverted, and the color stripe is determined based on the large phase error. As described above, as the color stripe determination circuit, a newly configured example as shown in FIGS. 7 and 9 and an analog VT as shown in FIGS.
An example in which the configuration is made using the R portion can be considered.

As described above, in the present embodiment, the D is mainly equipped with the MPEG2 codec (general term including encoder / decoder).
Although the description has been made by taking a VTR as an example, the present invention is applied to a digital VTR of a DV standard using a 6-mm-width magnetic tape which performs another compression process, a device for recording / reproducing a medium other than a magnetic tape, and a signal input / output device. However, the present invention can be similarly applied, and is within the scope of the present invention. In this embodiment, NT
Although the SC broadcast standard has been described as an example, the PAL broadcast standard can be applied similarly to the NTSC broadcast standard, and is within the scope of the present invention.

[0042]

As described above, according to the present invention,
The recording processing means for the digital device and the reproduction processing means from the digital device can be realized without damaging the character information and the like superimposed during the vertical blanking period.

Also, by outputting the signal compressed and decompressed in the recording / reproducing apparatus to a monitor television as an EE (output to a monitor passing only through an electric path) screen, the image quality recorded / reproduced by the digital device is recorded. A function that can be checked can be realized. Further, it is also possible to manage the recording image quality of the recording / reproducing apparatus based on a change in the recording transmission rate during digital compression / expansion.

Also, pseudo sync information and color stripe information deleted in the process of compression and decompression are detected and added to the signal after MPEG decompression to obtain the compressed and expanded digital E.
In the E path, an analog video signal to which the same pseudo sync and color stripe signal as the input are added is obtained, and even in a device having the digital EE output, the copy guard function can be operated for an external device.

Further, by effectively utilizing the high-definition digital OSD circuit not only for bit stream recording but also for external video input recording and reproduction signals, a recording / reproducing apparatus with good cost performance can be provided.

Further, by independently detecting the pseudo sync and the color stripe signal, there is an effect that a sufficient copy protection function can be realized even for an input signal corresponding to only one of them. Color stripe information
It can be easily realized by detecting the BY axis component of the incoming modulated color signal. Further, in a device in which the analog recording mode and the digital recording mode are mixed, an APC (Automatic Print Control) having the color stripe information in the analog recording mode is used.
Phase control) can be easily realized by the information of the circuit, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a recording / reproducing apparatus showing a first embodiment of the present invention.

FIG. 2 is a diagram showing mode switching in the first embodiment.

FIG. 3 is a block diagram of a recording / reproducing apparatus showing a second embodiment of the present invention.

FIG. 4 is a diagram showing mode switching in a second embodiment.

FIG. 5 is a block diagram of a recording / reproducing apparatus showing a third embodiment of the present invention.

FIG. 6 is a diagram showing information superimposed during a vertical blanking period.

FIG. 7 is a block diagram of a recording / reproducing apparatus showing a fourth embodiment of the present invention.

FIG. 8 is a diagram schematically showing a color stripe signal.

FIG. 9 is a diagram illustrating a color stripe detection circuit according to a fourth embodiment.

10 is a signal waveform of each part at the time of detecting a color stripe in FIG. 9;

FIG. 11 is a vector diagram showing a state of demodulation of a modulated color signal.

FIG. 12 is a block diagram of a recording / reproducing apparatus showing a fifth embodiment of the present invention.

FIG. 13 is a diagram illustrating a color stripe detection circuit according to a fifth embodiment.

14 is a signal waveform of each part at the time of detecting a color stripe in FIG.

[Explanation of symbols]

2: Analog VTR signal processing circuit, 9: Video encoder, 10, 19: Digital interface, 1
1 ... MPEG2 encoder, 13 ... MPEG2 decoder, 18 ... OSD circuit, 27,58 ... Addition circuit,
16 ... detection circuit, 20 ... video encoder, 14 ...
Digital VTR interface, 15 ... Digital V
TR signal processing circuit, 17, 25 microcomputer, 7, 2
1, 35: switch circuit, 32: DVD interface, 33: DVD signal processing circuit, 41, 44: pseudo sync pulse, 42, 45: CGMS_A signal,
43, 46 ... Closed caption signal, 52, 8
5: color stripe detection circuit, 56: burst addition circuit, 59: pulse generation circuit, 57: color encoder, 66, 68 ... oscillator, 63: sign determination circuit,
64, 101 ... color stripe judgment circuit, 92 ...
Phase detector.

Continued on the front page (72) Inventor Hiroo Okamoto 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Digital Media Development Division, Hitachi, Ltd. 5C053 FA13 FA21 FA24 GA11 GA13 GB12 GB38 JA16 JA26 JA28 KA07 KA24 KA25 5D044 AB07 AB09 BC01 CC01 CC04 DE49 DE50 GK08 GK11 GK17

Claims (22)

[Claims] A means for converting an input analog video signal into a digital signal; a recording means for recording the converted digital signal on a recording medium; a reproducing means for reproducing a digital signal from the recording medium; A recording / reproducing apparatus having a converting means for converting a digital signal into an analog video signal, a detecting means for detecting character information superimposed during a vertical blanking period of the analog video signal at the time of recording, and encoding the detected character information. And a superimposing means for superimposing the superimposed signal on the digital signal from which the character information has been removed, and recording the superimposed signal on a recording medium. 2. A means for converting an input analog video signal into a digital signal; a recording means for recording the converted digital signal on a recording medium; a reproducing means for reproducing a digital signal from the recording medium; A recording / reproducing apparatus having conversion means for converting a digital signal into an analog video signal; a extracting means for extracting character information from a digital signal read from a recording medium at the time of reproduction; A recording / reproducing apparatus, comprising: adding means for adding a video signal to a predetermined position, and outputting an analog video signal obtained by converting the digital video signal after the addition by the converting means. 3. A means for converting an input analog video signal into a digital signal, a compression means for compressing the signal, a recording means for recording the compressed digital signal on a recording medium, and a digital signal compressed from the recording medium. In a recording / reproducing apparatus having a reproducing means for reproducing a signal and a decompressing means for decompressing a compressed digital signal, a switching means for switching between a first digital signal before compression and a compressed and decompressed second digital signal And a converting means for converting the output to an analog video signal, and outputting the converted analog video signal to an image display device. 4. A means for converting an input analog video signal into a digital signal, a compression means for compressing the digital signal, a recording means for recording the compressed digital signal on a recording medium, and a digital signal compressed from the recording medium. A recording / reproducing apparatus having a reproducing means for reproducing a signal and a decompressing means for decompressing a compressed digital signal; a converting means for converting the compressed and decompressed second digital signal into an analog video signal; Switching means for switching between a first analog signal before compression and a second analog signal after compression and expansion, outputting the analog video signal to the image display device, and a vertical blanking period deleted in the process of compression and expansion. Detecting means for detecting the information superimposed on the compressed signal at a stage preceding the compressing means; encoding the detected information to superimpose the information on the compressed signal Recording means comprising superimposing means, and adding means for adding the superimposed information to the signal expanded by the extracting and expanding means, and obtaining an output obtained by the adding means as the second analog signal. Playback device. 5. The recording / reproducing apparatus according to claim 4, wherein the information extracted by said detecting means is sent to said adding means via a microcomputer. 6. A conversion means for converting an input analog video signal into a digital signal, a compression means for compressing the signal, a recording means for recording the compressed signal on a recording medium, and a reproduction for reproducing a digital signal from the recording medium. And a digital mode for recording and reproducing by inputting and outputting an analog video signal in the form of an analog signal. Conversion means for converting the two digital signals into an analog video signal, and switching means for switching between a first analog signal before encoding and a compressed / expanded second analog signal. The information superimposed on the vertical blanking period, which is output to the device and deleted during the compression / decompression process, is detected at the preceding stage of the compression means Detecting means for encoding, the superimposing means for encoding the detected information and superimposing the information on the compressed signal, and adding means for adding the superimposed information to the signal expanded by the extracting and expanding means. A recording / reproducing apparatus, wherein an obtained output is obtained as the second analog signal. 7. The compression means has a variable transmission rate,
6. The third analog signal according to claim 3, wherein the second analog signal is used as a check mode for performing an optimal setting of the transmission rate that affects image quality.
And the recording / reproducing apparatus according to claim 6. 8. A digital OSD (abbreviation of an on-screen display) circuit is provided at a subsequent stage of the decompression means, and is always compressed and decompressed during reproduction in a digital mode, input of an external composite signal, and reproduction in an analog mode. 7. The recording / reproducing apparatus according to claim 3, wherein an output of the second analog signal is fixed and a digital OSD screen is displayed. 9. A path for obtaining the second analog signal includes a video decoder for demodulating an analog video signal into a luminance signal and a color difference signal, a compression circuit for compressing the output thereof, and a decompression circuit for decompressing the compressed signal. An expansion circuit for adding the information, a video encoder for converting the output to an analog video signal, a switch circuit for switching between the video decoder output and the output of the expansion circuit at a stage subsequent to the expansion circuit, and a digital circuit at the subsequent stage. 4. The system according to claim 3, wherein an OSD circuit is arranged to switch between a compressed / expanded signal and a video decoded / encoded signal while constantly passing through the digital OSD circuit as the second analog signal. The recording / reproducing apparatus according to any one of claims 4, 5, 6, and 7. 10. An A / D converter for converting an input analog video signal into a digital signal, a compressor for compressing an output of the A / D converter, a recorder for recording an output of the compressor on a recording medium, and the recorder. A recording / reproducing apparatus comprising: reproducing means for reproducing a digital signal from a medium; expanding means for expanding the output of the reproducing means; and DA converting means for converting the output of the expanding means to an analog video signal. Detecting means for detecting the first copy guard information superimposed on the signal during the vertical blanking period and the second copy guard information superimposed on the color burst signal; and detecting the two copy guard information detected by the detecting means. Adding means for adding to the signal expanded by the expansion means, and in a mode other than the reproduction mode by the reproduction means, Force recording and reproducing apparatus characterized in that it is supplied to the expansion means. 11. The recording / reproducing apparatus according to claim 10, wherein the copy guard information extracted by said detecting means is sent to said adding means via a microcomputer. 12. The recording / reproducing apparatus according to claim 11, wherein the microcomputer matches a delay amount of a signal generated in the process of the compression / expansion with a delay amount of the copy guard information extracted by the detecting means. 13. The apparatus according to claim 10, wherein the second copy guard information is detected based on a signal obtained by demodulating an incoming modulated color signal on the BY axis. The recording / reproducing apparatus as described in the above. 14. The recording / reproducing apparatus according to claim 10, further comprising: an analog recording means for recording an input analog video signal on a recording medium as an analog signal; and an analog reproducing means for reproducing an analog signal from said recording medium. A recording / reproducing apparatus comprising: 15. An APC (APC) included in said analog recording means for phase-locking a color burst signal contained in an input analog video signal and a chrominance subcarrier used as a reference signal of said analog recording means. A
2. The method according to claim 1, wherein the second copy guard signal is detected based on information from an auto phase control circuit.
5. The recording / reproducing apparatus according to 4. 16. An analog-to-digital converter for converting an input analog video signal into a digital signal, a compressor for compressing an output of the analog-to-digital converter, an expander for expanding a compressed signal, and an output of the expander for analog video. An input / output device having DA conversion means for converting the signal into a signal, wherein the output of the compression means is supplied to the decompression means, and the first copy guard information and color which are superimposed during a vertical blanking period of the input analog video signal. Detecting means for detecting second copy guard information superimposed on the burst signal, and adding means for adding the two copy guard information detected by the detecting means to the signal expanded by the expansion means. Characteristic input / output device. 17. The input / output device according to claim 16, wherein the copy guard information extracted by said detecting means is sent to said adding means via a microcomputer. 18. The input / output device according to claim 17, wherein the microcomputer matches a delay amount of the signal generated in the process of the compression and decompression with a delay amount of the copy guard information extracted by the detecting means. 19. The apparatus according to claim 16, wherein said second copy guard information is detected based on a signal obtained by demodulating an incoming modulated color signal on the BY axis. I / O device as described. 20. A recording / reproducing apparatus comprising: a conversion circuit for converting an input analog video signal into a digital signal; and a recording circuit for recording the digital signal converted by the conversion circuit on a recording medium. A detecting circuit for detecting information superimposed during the vertical blanking period, and a superimposing circuit for encoding the detected information and superimposing the information on the digital signal, and recording the superimposed signal on a recording medium. Characteristic recording / reproducing device. 21. A recording / reproducing apparatus having a reproducing circuit for reproducing a digital signal from a recording medium and a conversion circuit for converting the reproduced digital signal into an analog video signal and outputting the analog video signal, wherein the signal reproduced from the recording medium is provided. 1. A recording / reproducing apparatus comprising: a detection circuit for detecting predetermined information from a video signal; and an addition circuit for adding the information detected by the detection circuit to a vertical blanking period of the analog video signal. 22. A first conversion circuit for converting an input analog video signal into a digital signal, a second conversion circuit for converting the digital signal converted by the first conversion means into an analog video signal and outputting the converted signal. A detection circuit for detecting information superimposed on a vertical blanking period of the input analog video signal, and an analog video signal obtained by converting the information detected by the detection circuit by the second conversion circuit. An input / output device having an addition circuit for adding during a signal vertical blanking period.