JP2002354500A - Video recording and reproducing device and controlling method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the difference in image quality feeling between a video signal (recording system) which is obtained by reproducing and delaying an inputted signal by arbitrary time and video signal (bypass system) which is obtained by only passing through the inputted signal, while temporarily recording the input signal at the time of observing the signals while switching them. SOLUTION: A video signal processing equivalent to a processing executed in the recording system including a compressing means, a recording means and an expanding means is executed by a video adjusting circuit of the bypass system to adjust the image quality of the bypass system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a first branch for recording input video information on a recording medium and outputting a video signal reproduced from the recording medium, and recording the input video information on the recording medium. Recording / reproducing apparatus having a second branch that outputs the data without any error.

[0002]

2. Description of the Related Art In recent years, development of digital technology for remarkably compressing the amount of information of a video signal, such as MPEG, has been advanced. Also, a hard disk (HDD) as one of the media for temporarily recording a compressed digital signal
The capacity of has been remarkably increasing. Therefore, by combining these technologies, it is sufficiently possible to compress the information amount of the video signal using MPEG or the like and temporarily record the information on the hard disk. Therefore, a device that reads information temporarily recorded on a hard disk, decompresses the compressed information, restores the original video signal, and projects it on a CRT (cathode ray tube) or the like has been put to practical use. The time required for writing (recording) on the hard disk and the time required for reading (reproducing) have both been shortened. Also,
The time required to compress and expand the video signal has also been reduced.

Therefore, a video signal input in real time is compressed, written (recorded) to a hard disk, and read (reproduced) from the hard disk almost simultaneously.
A device that expands in real time and outputs it as a video signal has been put to practical use. When writing / reading to / from the hard disk is performed almost simultaneously, the time required for the input video signal to be output as a video signal through compression, writing / reading to / from the hard disk, and decompression processing (delay time) Can be executed in a few seconds (3 to 6 seconds).

[0004] Therefore, by performing readout from the hard disk at an arbitrary timing, it can be output as an image signal at an arbitrary timing, and can be used as an image signal delay device having a delay time of several seconds to tens of seconds. is there. Furthermore, we record video signal for several hours on hard disk,
The hard disk can also be used as a device having a function equivalent to that of a conventional magnetic tape VCR.

[0005] In recent years, copyright issues relating to video and the like have been highlighted. DVD (Digita
l Versatile Disc), if the recorded video or the like is to be protected by copyright, a CGMSA (Serial Copy Ge)
Nation Management System
If (Analog) is an NTSC video signal, Lin
e21 is encoded and recorded. Further, a macro vision signal is added to the vertical synchronizing signal of the video signal to perform copy protection (copyright protection).
The copy protection by the macro vision signal is performed by a conventional magnetic tape commercially available in the general market.
In many cases, it is also added to a CR soft tape (soft tape in VHS). When these copy-protected video signals are input, recording these video signals on an HDD or the like even temporarily should not be performed from the viewpoint of copyright protection.

Therefore, it is necessary to provide a bypass branch for simply passing an input video signal, in addition to a recording / reproducing branch for performing compression, writing / reading / expansion in the HDD, and expansion.

When a video signal transmitted on a broadcast network is received, a video signal obtained when the broadcast radio wave is weak (a weak electric field) often contains a lot of noise. is there. Even a video signal obtained from a cable television network often contains a lot of noise depending on the state of the transmission system.

If these video signals contain much noise, the recording / reproducing system branches of compression, writing / reading by HDD, and decompression may not function well. Since the recording / reproducing system branch cannot be used, a bypass system branch that simply passes through the input video signal is provided, and a video signal containing much noise is output through the bypass system branch. Is done. Finally, each signal of the recording route and the bypass route is selected by the signal switching unit and output as a video output signal.

A conventional video recording / reproducing apparatus will be described with reference to FIG. The conventional example of the video recording / reproducing apparatus has a first branch 601, a second branch 602, and a switching unit 603. The first branch 601 and the second branch 602 are provided with an NTSC signal (analog signal) input from the input terminal 604.
And outputs a processed video signal. The switching unit 603 receives the output signal of the first branch 601 and the output signal of the second branch 602 and selectively outputs one of them according to the switching control signal 606.

The first branch 601 is connected to the sink AGC 61
1, burst AGC 612, A / D converter 613, luminance signal / color signal separation means 614, demodulator 615, compression means 616, recording means 617, recording medium 618, reproduction means 6
19. Decompression means 620, modulator 621 and adder 62
2. It has a D / A converter 623.

The first branch 601 will be described. Sync AG
C611 receives an NTSC signal, and amplifies and outputs the NTSC signal so that the level (sink level) of the horizontal synchronization signal becomes a constant value (40IRE) (a wide frequency range from low to high frequencies). And a broadband amplifier having a flat amplification factor.).

A burst AGC 612 receives an NTSC signal and receives a burst signal (a signal of about 3.58 MHz).
Amplifier that amplifies and outputs only the color signal so that the amplitude level of the burst signal becomes a constant value (40 IRE) (amplifies only the frequency from 3 MHz to 4 MHz so that the amplitude level of the burst signal becomes a constant value, and 3 MHz or less) Amplifier having no amplification factor in the band of (1). Burst A
The GC 612 includes, for example, a circuit for separating a luminance signal and a chrominance signal,
It is composed of an automatic gain control circuit for color signals (a circuit that amplifies the burst signal so that the amplitude level of the burst signal becomes a constant value), and an addition circuit of a luminance signal and a color signal with a constant amplitude level of the burst signal. You. A /
The D converter 613 receives an NTSC signal having a fixed sync level and a fixed burst level, and converts it into a digital signal. The luminance signal / color signal separating means 614 separates the digitally converted NTSC signal into a luminance signal and a chrominance signal. The demodulator 615 receives a color signal having a burst signal of a constant amplitude level and receives two color difference signals (R
-Y, BY).

A compression means 616 receives a luminance signal and a color difference signal (RY, BY), which are digital signals, compresses and multiplexes the information amounts, and outputs the multiplexed digital signal. I do. The recording unit 617 inputs the multiplexed digital signal and records the digital signal on the recording medium 618. The recording medium 618 is an HDD medium.

The reproducing means 619 controls the recording medium 61 during reproduction.
The multiplexed digital signal recorded in 8 is reproduced and transmitted to the decompression means 620. The decompression means 620 separates the multiplexed digital signal into a luminance signal and two color difference signals (RY, BY) whose information amounts are compressed, and compresses the compressed luminance signal and color difference signal (R-Y). Y, BY) are decompressed and output.

The modulator 621 receives two color difference signals, performs quadrature quadrature modulation with a subcarrier of about 3.58 MHz, and outputs a modulated color signal. The adder 622 receives the luminance signal and the chrominance signal, adds them, and adds the added signal (NTS
C signal) to the D / A converter 623. The D / A converter 623 receives an NTSC signal which is a digital signal,
The signal is converted into an analog signal, and the analogized NTSC signal is transmitted to the input terminal 632 of the switching unit 603.

The second branch 602 is a bypass route for directly transmitting the NTSC signal input to the input terminal 604 to the input terminal 631 of the switching means 603. N entered
If the TSC video signal can be copied and has a signal / noise ratio (S / N ratio) that allows digital processing such as compression, the switching unit 603 inputs the signal to the input terminal 632 according to the switching control signal 606. The output signal of the first branch is output. If the input NTSC video signal is a signal for which copying is prohibited or a signal having an S / N ratio that is so low that digital processing such as compression cannot be performed, the switching means 6
03 is an input terminal 631 according to the switching control signal 606.
And outputs the output signal of the second branch input to the second branch.

[0017]

In the conventional video recording / reproducing apparatus, however, the bypass (second branch) and the recording / reproducing branch (first branch) are switched by the signal switching means. However, when observed on a CRT (cathode ray tube) or the like, the two may feel a difference in image quality (bright / dark, colored / good / bad, etc.).

If the NTSC video signal is described as a representative,
The level (magnitude) of the horizontal synchronization pulse of the input video signal is the set value (401RE) of the standard NTSC video signal
If they are deviated from each other, when the selection of the route is switched, the two may feel a difference in image quality (bright / dark, etc.).

The recording system route is a digital signal processing system, and an input video signal is A / D converted. Generally, when performing A / D conversion, a sink AGC (Auto) is performed prior to A / D conversion in order to perform A / D conversion optimally.
The processing of “Matic Gain Control” is performed. In the processing of the sync AGC, if the level of the horizontal synchronization pulse of the input video signal deviates from the standard setting value, the level is adjusted to the standard horizontal synchronization pulse level.
Adjusts the overall level of the input video signal. This difference in the presence or absence of the signal level adjustment is observed as a difference in texture between the output signal of the recording branch including the processing of the sync AGC and the output signal of the bypass branch including no processing.

If the level (magnitude) of the burst signal of the input video signal deviates from the set value of the standard NTSC video signal, the selection of the route is switched. Then, the user may feel a difference in the sense of image quality (good / bad coloring).

This is because when a recording medium such as a hard disk is used as the recording means, only the part of the actual video signal is actually written on the hard disk in order to increase the efficiency of use of the recording medium. Pulse, vertical blanking period signal (equalization pulse, horizontal / vertical sync pulse,
Etc.), the color burst signal is not written on the hard disk or the like, but is added after the decompression processing by the decompression means. (So-called sync and burst replacements are performed.)

In performing the burst replacement, it is necessary to adjust the burst signal level of the input color signal to a standard set value (401RE). In other words, if the level of the color burst signal of the input video signal deviates from the standard setting, a process of changing the overall level of the input color signal (so-called burst AGC) to match the level of the standard color burst signal is performed. Is going. In the recording / reproducing branch including the burst AGC processing and the bypass branch including no processing, a difference (good / bad coloring, etc.) occurs in the sense of image quality of both output signals.

Here, an input signal deviating from the setting of the standard NTSC video signal is input, writing / reading to / from the hard disk is performed almost simultaneously, and an output video signal of the recording / reproducing system branch is obtained with a delay time of several seconds. If the user selects and switches the route while the user is in the area, the difference in the image quality between the two is particularly easily felt. If the delay time is several seconds, the scenes of the transmitted images are almost the same in many cases, and the difference in switching is easily felt.

In particular, when a video signal transmitted on a broadcast network is received, the level of the horizontal synchronization pulse and the level of the burst pulse of the received video signal are set to the standard NTSC.
It often deviates from the set value (401RE) of the video signal. Also, the level deviation from the standard setting value may differ between the received television broadcast channels. This means that the difference in the sense of image quality when the route is switched is different between the broadcast channels. Even if you switch between the recording route and the bypass route,
A video signal output from the same device is converted to a cathode ray tube (CRT).
When observing with the like, a difference in the sense of image quality due to switching should not be caused.

[0025]

In order to solve the above problems, the present invention has the following arrangement.

According to a first aspect of the present invention, there is provided a first video signal processing branch, a second video signal processing branch, and signal switching means, wherein the signal switching means has a first input terminal. A second input terminal, and an output terminal for selectively outputting a video signal input to the first input terminal or a video signal input to the second input terminal according to a switching control signal; Has,
The first video signal processing branch includes an input unit for inputting a video signal, a first video adjustment unit for adjusting the input video signal for an arbitrary element, and an input unit for inputting the adjusted video signal. Compression means for compressing the information amount and outputting a compressed video signal; recording means for recording the compressed video signal on a recording medium; and reproducing the compressed video signal from the recording medium. Playback means, and expansion means for expanding the compressed video signal output by the compression means or the reproduction means, and transmitting the expanded video signal to the first input terminal of the signal switching means. And the second video signal processing branch includes the input unit, the first video adjustment unit, and the adjusted video signal output by the first video adjustment unit. Transmitting to the second input terminal. Having a transmission means, that the video recording and reproducing apparatus according to claim.

According to a second aspect of the present invention, there is provided a first video signal processing branch, a second video signal processing branch, and signal switching means, wherein the signal switching means has a first input terminal. A second input terminal, and an output terminal for selectively outputting a video signal input to the first input terminal or a video signal input to the second input terminal according to a switching control signal; Has,
The first video signal processing branch includes an input unit for inputting a video signal, a first video adjustment unit for adjusting the input video signal for an arbitrary element, and an input unit for inputting the adjusted video signal. Compression means for compressing the information amount and outputting a compressed video signal; recording means for recording the compressed video signal on a recording medium; and reproducing the compressed video signal from the recording medium. Playback means, and expansion means for expanding the compressed video signal output by the compression means or the reproduction means, and transmitting the expanded video signal to the first input terminal of the signal switching means. Wherein the second video signal processing branch adjusts the input section and the input video signal with respect to the element, and applies the adjusted video signal to the second input terminal of the signal switching means. The second video to be transmitted And a integer unit, it is a video recording and reproducing apparatus according to claim.

According to a third aspect of the present invention, the first image adjusting means extracts image quality information from the input image signal, and the second image adjusting means extracts the input image signal based on the image quality information. The signal is adjusted.
2. The video recording / reproducing apparatus according to item 1.

According to a fourth aspect of the present invention, the first video adjusting means or the first video adjusting means and the second video adjusting means may adjust the level of a horizontal synchronizing signal of the input video signal substantially. At least one of a first amplifier for amplifying the signal so as to be constant and a second amplifier for amplifying a color signal in the input video signal so that the level of the color burst signal is substantially constant. A video recording / reproducing apparatus according to claim 1 or 2, wherein:

According to a fifth aspect of the present invention, the first video adjusting means and the second video adjusting means amplify the input video signal so that the level of the horizontal synchronizing signal is substantially constant. 4. The video recording / reproducing apparatus according to claim 3, further comprising one amplifier, wherein the image quality information includes level information of a horizontal synchronization signal of the video signal.

According to a sixth aspect of the present invention, the first image adjusting means and the second image adjusting means convert a color signal in the input image signal into a substantially constant color burst signal level. Including a second amplifier that amplifies
4. The video recording / reproducing apparatus according to claim 3, wherein the image quality information includes level information of a color burst signal of the video signal.

According to a seventh aspect of the present invention, there is provided a control method of a video recording / reproducing apparatus for selectively executing a first video signal processing step and a second video signal processing step, wherein the first video signal processing step comprises the steps of: The processing step includes an inputting step of inputting a video signal, a first video adjusting step of adjusting the input video signal for an arbitrary element thereof, and inputting the adjusted video signal and compressing the information amount. And a compression step of outputting a compressed video signal, a recording step of recording the compressed video signal on a recording medium, and expanding the compressed video signal to output an expanded video signal. Decompressing step, wherein the second video signal processing step includes an input step of inputting a video signal, adjusting the input video signal with respect to the element, and outputting the adjusted video signal. A second image adjusting step, the of, that is a control method of a video recording and reproducing apparatus according to claim.

According to the present invention, in the first image adjusting step, image quality information is extracted from the input image signal, and in the second image adjusting step, the image quality information is extracted based on the image quality information. The control method of a video recording / reproducing apparatus according to claim 7, wherein the video signal is adjusted.

According to a ninth aspect of the present invention, in the first image adjusting step and the second image adjusting step, the input image signal is amplified so that the level of the horizontal synchronizing signal is substantially constant. 8. The video recording according to claim 7, wherein at least one of amplifying the color signal in the input video signal so that the level of the color burst signal is substantially constant is executed. It is a control method of the reproducing device.

According to a tenth aspect of the present invention, in the first image adjusting step and the second image adjusting step,
9. The image signal according to claim 8, wherein the input video signal is amplified so that the level of the horizontal synchronization signal is substantially constant, and the image quality information includes information on the level of the horizontal synchronization signal of the video signal. Is a control method of the video recording / reproducing device.

According to the present invention, in the first image adjusting step and the second image adjusting step,
The color signal in the input video signal is amplified so that the level of the color burst signal is substantially constant, and the image quality information includes information on the level of the color burst signal of the video signal. A control method for a video recording / reproducing apparatus according to claim 8.

The video recording / reproducing apparatus of the present invention has a video adjusting means in the conventional bypass route (second branch).
The present invention has the effect of realizing a video recording / reproducing apparatus in which the image quality hardly changes even if the first branch and the second branch are switched.

[0038]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of the present invention;

Embodiment 1 A video recording / reproducing apparatus according to Embodiment 1 of the present invention will be described below with reference to FIG. The video recording / reproducing apparatus according to the first embodiment includes a first branch 101, a second branch 102, and a switching unit 103. First branch 10
The first and second branches 102 respectively process an NTSC signal (analog signal) input from the input terminal 104 and output a processed video signal. The switching means 103 receives the output signal of the first branch 101 and the output signal of the second branch 102 and selectively outputs one of them according to the switching control signal 106.

The first branch 101 is a sink AGC 111,
Burst AGC 112, A / D converter 113, luminance signal / color signal separation means 114, demodulator 115, compression means 11
6. Recording means 117, recording medium 118, reproduction means 11
9, an expansion unit 120, a modulator 121, an adder 122, and a D / A converter 123. The second branch 102 is
It has a sink AGC 111 and a burst AGC 112. The first branch and the second branch are sink AGC 111,
The burst AGC 112 is shared.

The first branch 101 will be described. Sync AG
C111 receives an NTSC signal, and amplifies and outputs the NTSC signal so that the level (sync level) of the horizontal synchronizing signal becomes a constant value (40IRE) (the amplifier is flat in a wide frequency range from a low band to a wide band). Wide-band amplifier having a high amplification factor). The specific configuration of the sink AGC 111 will be described in detail with reference to FIG. Burst AGC
An amplifier 112 receives the output signal of the sink AGC 111 and amplifies and outputs a color signal in the NTSC signal so that the amplitude level of the burst signal (a signal of about 3.58 MHz) becomes a constant value (40 IRE). (Only the color signal having a frequency of 3 MHz to 4 MHz is amplified so that the amplitude level of the burst signal becomes a constant value.
The amplifier has no amplification factor in the following bands. ). The burst AGC 112 includes, for example, a separation circuit for a luminance signal and a chrominance signal, an automatic gain control circuit for a chrominance signal (a circuit that amplifies the burst signal so that the amplitude level of the burst signal becomes a constant value), and an amplitude level of the luminance signal and the burst signal. And an addition circuit for adding a color signal with a constant. The specific configuration of the burst AGC 112 is the same as the burst AGC 312 in FIG. The A / D converter 113 receives an analog NTSC signal and converts it into a digital signal. Luminance signal / color signal separation means 114
Separates the NTSC signal converted into a digital signal into a luminance signal and a chrominance signal. The demodulator 115 receives a color signal having a burst signal with a constant amplitude level and demodulates the color signal into two color difference signals (RY, BY). Compression means 116
Are luminance signals and color difference signals (R-
Y, BY), compress the information amount of each,
It multiplexes and outputs a multiplexed digital signal.

The recording means 117 receives the multiplexed digital signal and records the digital signal on the recording medium 118. The recording medium 118 is an HDD (hard disk). The reproducing unit 119 reproduces the multiplexed digital signal recorded on the recording medium 118 at the time of reproduction, and transmits the multiplexed digital signal to the decompression unit 120. The expansion means 120 separates the multiplexed digital signal into a luminance signal and two color difference signals (RY, BY) whose information amounts are compressed, and compresses the compressed luminance signal and color difference signal (R-Y). Y, BY) are decompressed and output. The modulator 121 receives two color difference signals, performs quadrature quadrature modulation with a subcarrier of about 3.58 MHz, and outputs a modulated color signal. The adder 122 receives and adds the luminance signal and the chrominance signal, and adds the added signal (NTS
C signal) to the D / A converter 123. The D / A converter 123 inputs an NTSC signal which is a digital signal,
NT converted to analog signal and converted to analog signal
The SC signal is transmitted to the input terminal 132 of the switching means 103.

The second branch 102 will be described. Sync AG
C111 receives the NTSC signal, amplifies and outputs the NTSC signal so that the level (sync level) of the horizontal synchronization signal becomes a constant value (40IRE).

The burst AGC 112 is provided for the sync AGC 1
11 output signal and a burst signal (about 3.58M
Amplifying and outputting the color signal in the NTSC signal so that the amplitude level of the (Hz signal) becomes a constant value (40 IRE). The output signal of the burst AGC 112 is transmitted to the output terminal 131 of the switching means 103.

If the input NTSC video signal can be copied and has a signal / noise ratio (S / N ratio) that allows digital processing such as compression, the switching means 103 operates in accordance with the switching control signal 106. , The output signal of the first branch input to the input terminal 132 is output. NTS input
If the C video signal is a signal for which copying is prohibited or a signal having an S / N ratio that is so low that digital processing such as compression cannot be performed, the switching means 103 sends the signal to the input terminal 131 in accordance with the switching control signal 106. The input output signal of the second branch is output. Since the output signal of the first branch and the output signal of the second branch have the same sync level (40 IRE) and burst level (40 IRE), the image quality of both is almost the same. Even when the switching means 103 switches the output signal, the image quality does not change on the screen.

Embodiment 2 Hereinafter, a video recording / reproducing apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. The video recording / reproducing apparatus according to the second embodiment includes a first branch 201, a second branch 202, and a switching unit 203. First branch 2
01 and the second branch 202 process the NTSC signal (analog signal) input from the input terminal 204, respectively.
Output the processed video signal. The switching means 203 includes the first
The output signal of the branch 201 and the output signal of the second branch 202 are input, and one of them is selectively output according to the switching control signal 206.

The first branch 201 includes a luminance signal / color signal separating means 211, a sink AGC 212, and an A / D converter 21.
3, 216, burst AGC 214, demodulator 215, compression means 217, recording means 218, recording medium 219, reproduction means 220, decompression means 221, D / A converter 222,
23, a modulator 224 and an adder 225. The second branch 202 includes a sink AGC 231 and a burst AGC 231.
232.

The first branch 201 will be described. Luminance signal /
The color signal separating unit 211 separates the NTSC signal input from the input terminal 204 into a luminance signal and a chrominance signal. The sync AGC 212 receives the luminance signal, and the level (sync level) of the horizontal synchronization signal of the luminance signal is constant (40IR).
E) is an amplifier (a wideband amplifier having a flat amplification factor in a wide frequency range from a low band to a high band) for amplifying and outputting a luminance signal so as to satisfy E). Sync AGC2
The specific configuration of the twelfth embodiment will be described in detail with reference to FIG.
The A / D converter 213 receives a luminance signal having a fixed sync level and converts it into a digital signal.

The burst AGC 214 receives a chrominance signal (approximately 3.
It is quadrature two-phase modulated by a 58 MHz color subcarrier. )
And an amplifier (3 MHz to 4 MHz) that amplifies and outputs the color signal so that the amplitude level of the burst signal (signal of about 3.58 MHz) of the color signal becomes a constant value (40 IRE).
This is a band amplifier that amplifies only frequencies up to MHz. ). The specific configuration of the burst AGC 214 will be described in detail with reference to FIG. The demodulator 215 receives a color signal having a burst signal having a constant amplitude level, and demodulates the color signal into two color difference signals (RY, BY). A
The / D converter 216 receives the color difference signals (RY, BY) and converts them into digital signals.

The compression means 217 receives the luminance signal and the color difference signals (RY, BY) which are digital signals, compresses and multiplexes the information amounts, and outputs the multiplexed digital signal. I do. The recording unit 218 inputs the multiplexed digital signal and records the digital signal on the recording medium 219. The recording medium 219 is an HDD (hard disk).

The reproducing means 220 reproduces the recording medium 21 during reproduction.
The multiplexed digital signal recorded in 9 is reproduced and transmitted to the decompression means 221. The decompression means 221 separates the multiplexed digital signal into a luminance signal and two color difference signals (RY, BY) whose information amounts are compressed, and compresses the compressed luminance signal and color difference signal (R-Y). Y, BY) are decompressed and output.

The D / A converter 222 receives a luminance signal, which is a digital signal, and converts it into an analog signal. The D / A converter 223 receives two color difference signals, which are digital signals, and converts them into analog signals. Modulator 224
Receives two color difference signals, performs quadrature quadrature modulation with a subcarrier of about 3.58 MHz, and outputs a modulated color signal.
The adder 225 receives the luminance signal and the chrominance signal, adds them, and outputs the added signal (NTSC signal) to the switching unit 203.
To the input terminal 234.

Next, the second branch 202 will be described. Sync AG
C231 is an amplifier that amplifies and outputs the NTSC signal input from the input terminal 204 such that the level (sync level) of the horizontal synchronization signal becomes a constant value (40IRE). The sink AGC 212 and the sink AGC 231 have the same configuration.

The burst AGC 232 is a sync AGC 2
31 output signal and a burst signal (about 3.58M
(A signal of 3 Hz) to amplify and output the color signal in the NTSC signal so that the amplitude level of the burst signal becomes a constant value (40 IRE). It is an amplifier that amplifies to a constant value and has no amplification factor in a band of 3 MHz or less.) Burst AG
C232 includes, for example, a circuit for separating a luminance signal and a chrominance signal, an automatic gain control circuit for a chrominance signal (a circuit for amplifying the burst signal so that the amplitude level of the burst signal becomes a constant value), and It is composed of an addition circuit for adding a constant color signal. Burst A
The GC 232 switches the amplified NTSC signal to the switching unit 203.
To the input terminal 233. The burst AGC 214 and the burst AGC 232 have the same configuration except for a filter that determines a frequency band.

If the input NTSC video signal can be copied and has a signal / noise ratio (S / N ratio) that allows digital processing such as compression, the switching means 203 operates in accordance with the switching control signal 206. , The output signal of the first branch input to the input terminal 334. NTS input
If the C video signal is a signal for which copying is prohibited or a signal having an S / N ratio that is so low that digital processing such as compression cannot be performed, the switching means 203 sends the signal to the input terminal 233 in accordance with the switching control signal 206. The input output signal of the second branch is output. Since the output signal of the first branch and the output signal of the second branch have the same sync level (40 IRE) and burst level (40 IRE), the image quality of both is almost the same. Even when the switching means 203 switches the output signal, the image quality does not change on the screen.

Embodiment 3 Hereinafter, a video recording / reproducing apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. The video recording / reproducing apparatus according to the third embodiment includes a first branch 301, a second branch 302, and a switching unit 303. First branch 30
The first and second branches 302 respectively process the NTSC signal (analog signal) input from the input terminal 304 and output the processed video signal. The switching unit 303 receives the output signal of the first branch 301 and the output signal of the second branch 302 and selectively outputs one of them according to the switching control signal 306.

The first branch 301 is a sink AGC 311,
Burst AGC 312, A / D converter 313, luminance / color signal separation means 314, demodulator 315, compression means 31
6, recording means 317, recording medium 318, reproduction means 31
9, decompression means 320, modulator 321 and adder 32
2 and a D / A converter 323. Sync AGC3
11 has a voltage controlled amplifier 341 and a sink level detection circuit 342. The burst AGC 312 has a voltage controlled amplifier 343 and a burst level detection circuit 344. The second branch 302 has a sink AGC 331 and a burst AGC 332. The sink AGC 331 has a voltage controlled amplifier 351. The burst AGC 332 has a voltage controlled amplifier 252.

The sink AGCs 311 and 331 will be described. The sink AGC 311 of the first branch and the sink AGC 331 of the second branch share the sync level detection circuit 342. The sync level detection circuit 342 receives the input NTS
The deviation of the level of the horizontal synchronizing signal of the C signal from the specified value is detected, and the voltage-controlled amplifiers 341 and 35 are set as error voltages.
Transmit to 1. The voltage controlled amplifiers 341 and 351 are:
An amplifier (low) that amplifies the level of the video signal of the NTSC signal based on the transmitted error voltage information so that the level (sink level) of the horizontal synchronization signal of the input NTSC signal becomes a constant value (40IRE). This is a wideband amplifier having a flat amplification factor in a wide frequency range from a high frequency range to a high frequency range.)

The burst AGCs 312 and 332 will be described. The burst AGC 312 of the first branch and the burst AGC 332 of the second branch are connected to a burst level detection circuit 34.
Share 4. The burst level detection circuit 344 detects a deviation of the input NTSC signal from a prescribed value of the burst level, and transmits it to the voltage controlled amplifiers 343 and 352 as an error voltage. Voltage controlled amplifiers 343 and 352
Is the input NTS according to the transmitted error voltage information.
An amplifier (3MH) that amplifies and outputs the level of the color signal in the NTSC signal so that the level (burst level) of the burst signal of the C signal becomes a constant value (40IRE).
Only the color signal having a frequency from z to 4 MHz is amplified so that the amplitude level of the burst signal becomes a constant value.
The amplifier does not have an amplification factor in a band of less than MHz. ). Voltage controlled amplifiers 343 and 352
Include, for example, a circuit for separating a luminance signal and a chrominance signal, an amplifier for a chrominance signal (a circuit for amplifying by controlling an error voltage so that the burst level becomes a constant value), and a constant amplitude level for the luminance signal and the burst signal And a color signal adding circuit.

The first branch 301 will be described. Sync AG
C311 is an amplifier that receives the NTSC signal and amplifies and outputs the NTSC video signal so that the amplitude level (sink level) of the horizontal synchronization signal of the NTSC signal becomes a constant value (40IRE). The burst AGC 312 has N
A TSC signal is input, and the amplitude level (burst level) of the burst signal of the NTSC signal is a constant value (40 IRE).
This is an amplifier that amplifies and outputs a color signal in an NTSC video signal such that The A / D converter 313 receives an analog NTSC signal and converts it into a digital signal. The luminance signal / color signal separating means 314 separates the digitally converted NTSC signal into a luminance signal and a chrominance signal. The demodulator 315 receives a color signal having a burst signal having a constant amplitude level and receives two color difference signals (RY, B).
-Y). The compression means 316 receives a luminance signal and color difference signals (RY, BY), which are digital signals, compresses and multiplexes the information amounts, and outputs a multiplexed digital signal.

The recording means 317 inputs the multiplexed digital signal and records the digital signal on the recording medium 318. The recording medium 318 is an HDD (hard disk). The reproducing means 319 reproduces the multiplexed digital signal recorded on the recording medium 318 during reproduction, and
20. The decompression means 320 converts the digital signal into a luminance signal whose information amount is compressed and two color difference signals (R
-Y, BY), and expands and outputs the compressed luminance signal and color difference signal (RY, BY).
The modulator 321 receives the two color difference signals and receives a signal of about 3.58.
A quadrature two-phase modulation is performed with a subcarrier of MHz, and a modulated color signal is output. The adder 322 receives the luminance signal and the chrominance signal, adds them, and adds the added signal (NTSC signal) to the D / D signal.
The signal is transmitted to the A converter 323. The D / A converter 323 receives an NTSC signal which is a digital signal, converts the signal into an analog signal, and transmits the analog-converted signal (NTSC signal) to the input terminal 334 of the switching means 303.

The second branch 302 will be described. Sync AG
C331 is an amplifier that amplifies and outputs the NTSC signal input from the input terminal 304 such that the level (sync level) of the horizontal synchronization signal becomes a constant value (40IRE). The voltage controlled amplifier 341 of the sink AGC 311 and the voltage controlled amplifier 351 of the sink AGC 331 have the same configuration.

The burst AGC 332 is a sync AGC 3
31 output signal and a burst signal (about 3.58M
An amplifier (3M) that amplifies and outputs a color signal so that the amplitude level of the
Only the color signal of a frequency from Hz to 4 MHz is amplified so that the amplitude level of the burst signal becomes a constant value,
An amplifier having no amplification factor in a band of 3 MHz or less. ). The burst AGC 332 includes, for example, a separation circuit for a luminance signal and a chrominance signal, an automatic gain control circuit for the chrominance signal (a circuit for amplifying the burst signal so that the amplitude level of the burst signal becomes a constant value), and a constant luminance signal and amplitude level. And a color signal adding circuit. The burst AGC 332 transmits the amplified NTSC signal to the input terminal 333 of the switching means 303. Voltage control type amplifier 352 of burst AGC 332 and burst A
The voltage-controlled amplifier 343 of the GC 312 has the same configuration.

If the input NTSC video signal can be copied and has a signal / noise ratio (S / N ratio) that allows digital processing such as compression, the switching means 303 operates in accordance with the switching control signal 306. , The output signal of the first branch input to the input terminal 334. NTS input
If the C video signal is a signal for which copying is prohibited or a signal having an S / N ratio that is so low that digital processing such as compression cannot be performed, the switching means 303 sends the input signal 333 to the input terminal 333 according to the switching control signal 306. The input output signal of the second branch is output. Since the output signal of the first branch and the output signal of the second branch have the same sync level (40 IRE) and burst level (40 IRE), the image quality of both is almost the same. Even when the switching means 303 switches the output signal, the image quality does not change on the screen.

Embodiment 4 A video recording / reproducing apparatus according to Embodiment 4 of the present invention will be described below with reference to FIG. The video recording / reproducing apparatus according to the fourth embodiment includes a first branch 401, a second branch 402, and a switching unit 403. First branch 40
The first and second branches 402 respectively process the NTSC signal (analog signal) input from the input terminal 404 and output the processed video signal. The switching unit 403 receives the output signal of the first branch 401 and the output signal of the second branch 402 and selectively outputs one of them according to the switching control signal 406.

The first branch 401 is a sink AGC 411,
A / D converter 412, luminance signal / color signal separation means 41
3, burst AGC 414, demodulator 415, compression means 416, recording means 417, recording medium 418, reproducing means 4
19, an expansion unit 420, a modulator 421, an adder 422, and a D / A converter 423. The second branch 402 is
It has a sink AGC 411 and a burst AGC 431. The first branch and the second branch share the sink AGC 411.

The first branch 401 will be described. Sync AG
An amplifier C411 receives an NTSC signal and amplifies and outputs the NTSC signal so that the level (sink level) of the horizontal synchronizing signal becomes a constant value (40IRE) (flat in a wide frequency range from a low frequency to a wide frequency). Wide-band amplifier having a high amplification factor). The specific configuration of the sink AGC 411 is the same as that of the sink AGC 312 in FIG. The A / D converter 412 receives an analog NTSC signal and converts it into a digital signal. The luminance signal / color signal separating means 413 separates the digitally converted NTSC signal into a luminance signal and a chrominance signal. Burst AGC414
Receives a chrominance signal (quadrature quadrature modulated with a color subcarrier of about 3.58 MHz), and the amplitude level of a burst signal of the chrominance signal (a signal of about 3.58 MHz) is a constant value (40 IRE). (Amplifies only a frequency from 3 MHz to 4 MHz so as to have a constant value). Demodulator 415
Receives a color signal having a burst signal of a constant amplitude level and demodulates the signal into two color difference signals (RY, BY). The compression means 416 receives the luminance signal and the color difference signals (RY, BY), which are digital signals, compresses and multiplexes the information amounts, and outputs the multiplexed digital signal.

The recording means 417 inputs the multiplexed digital signal and records the digital signal on the recording medium 418. The recording medium 418 is an HDD (hard disk). The reproducing unit 419 reproduces the multiplexed digital signal recorded on the recording medium 418 at the time of reproduction, and transmits the multiplexed digital signal to the decompression unit 420. The decompression means 420 separates the multiplexed digital signal into a luminance signal whose information amount is compressed and two color difference signals (RY, BY), and compresses the compressed luminance signal and color difference signal (R-Y). Y, BY) are decompressed and output. The modulator 421 receives two color difference signals, performs quadrature two-phase modulation with a subcarrier of about 3.58 MHz, and outputs a modulated color signal. The adder 422 inputs the luminance signal and the chrominance signal, adds them, and adds the added signal (NTS
C signal) to the D / A converter 423. The D / A converter 423 inputs an NTSC signal which is a digital signal,
An analog signal is converted to an analog signal (N
TSC signal) to the input terminal 433 of the switching means 403.

The second branch 402 will be described. Sync AG
C411 receives the NTSC signal, amplifies and outputs the NTSC signal so that the level (sync level) of the horizontal synchronization signal becomes a constant value (40IRE).

The burst AGC 431 is a sync AGC 4
11 output signal and a burst signal (about 3.58M
An amplifier (3M) that amplifies and outputs a color signal so that the amplitude level of the signal (Hz signal) becomes a constant value (40 IRE).
This is an amplifier that amplifies only the frequency from Hz to 4 MHz so that the amplitude level of the burst signal becomes a constant value, and has no amplification factor in a band of 3 MHz or less. ). The burst AGC 414 and the burst AGC 431 have the same configuration as the burst AGC 312 in FIG.

If the input NTSC video signal has a signal / noise ratio (S / N ratio) that can be copied and digital processing such as compression can be performed, the switching means 403 operates in accordance with the switching control signal 406. , The output signal of the first branch input to the input terminal 433. NTS input
If the C video signal is a signal whose copying is prohibited or has a signal-to-noise ratio that is so low that digital processing such as compression cannot be performed, the switching means 403 sends the input signal 432 to the input terminal 432 according to the switching control signal 406. The input output signal of the second branch is output. Since the output signal of the first branch and the output signal of the second branch have the same sync level (40 IRE) and burst level (40 IRE), the image quality of both is almost the same. Even when the switching unit 403 switches the output signal, the image quality does not change on the screen.

The video recording / reproducing apparatus according to the first to fourth embodiments uses the NTS
This was a video recording / reproducing apparatus that inputs and outputs a C signal.
With the same configuration (modulating the PAL from the NTSC modulator
It is necessary to replace it with a modulator. ), A video recording / reproducing apparatus that inputs and outputs another composite such as a PAL signal or a SECAM signal.

Embodiment 5 A video recording / reproducing apparatus according to Embodiment 5 of the present invention will be described below with reference to FIG. The video recording / reproducing apparatus according to the fifth embodiment includes a first branch 501, a second branch 502, and a switching unit 503. First branch 50
The first and second branches 502 are respectively connected to the luminance signal input terminal 50.
4 and a chrominance signal input terminal 505
, And outputs a processed video signal. The switching means 503 receives the output signal of the first branch 501 and the output signal of the second branch 502 and selectively outputs one of them according to the switching control signal 508.

The first branch 501 is a sink AGC 511,
Burst AGC 513, A / D converters 512, 514,
It has a demodulator 515, a compression unit 516, a recording unit 517, a recording medium 518, a reproduction unit 519, an expansion unit 520, a modulator 522, and D / A converters 521 and 523. The second branch 502 includes a sink AGC 531 and a burst A
It has GC532.

The first branch 501 will be described. Sync AG
An amplifier C511 receives a luminance signal from the luminance signal input terminal 504 and amplifies and outputs the luminance signal so that the level (sync level) of the horizontal synchronizing signal becomes a constant value (40IRE) (from low to wide band). Is a broadband amplifier having a flat gain over a wide frequency range. The burst AGC 513 inputs a color signal from the color signal input terminal 505, and amplifies and outputs the color signal so that the amplitude level of the burst signal (a signal of about 3.58 MHz) becomes a constant value (40IRE). (3M to 4M
Only the frequency up to Hz is amplified so that the amplitude level of the burst signal becomes a constant value. ). The A / D converter 512 receives a luminance signal having a fixed sync level and converts it into a digital signal. The A / D converter 514 is
A color signal having a constant burst level is input and converted to a digital signal. The demodulator 515 receives a color signal having a burst signal of a constant amplitude level, and demodulates the color signal into two color difference signals (RY, BY). The compression means 516
Luminance signal and color difference signal (RY, B
-Y), respectively, compresses and multiplexes the information amount, and outputs a multiplexed digital signal.

The recording means 517 inputs the multiplexed digital signal and records the digital signal on the recording medium 518. The recording medium 518 is an HDD (hard disk). The reproducing unit 519 reproduces the multiplexed digital signal recorded on the recording medium 518 at the time of reproduction, and transmits the multiplexed digital signal to the decompressing unit 520. The decompression means 520 separates the multiplexed digital signal into a luminance signal and two color difference signals (RY, BY) whose information amounts are compressed, and compresses the compressed luminance signal and color difference signal (R-Y). Y, BY) are decompressed and output. The D / A converter 521 receives a luminance signal which is a digital signal, converts the signal into an analog signal, and transmits the signal to the input terminal 536 of the switching means 503. Modulator 52
2 inputs two color difference signals, performs quadrature quadrature modulation with a subcarrier of about 3.58 MHz, and outputs a modulated color signal. The D / A converter 523 receives a color signal which is a digital signal, converts the digital signal into an analog signal, and transmits the analog-converted color signal to the input terminal 538 of the switching unit 503.

Next, the second branch 502 will be described. Sync AG
The C531 receives a luminance signal from the luminance signal input terminal 504, amplifies the luminance signal so that the level (sink level) of the horizontal synchronizing signal becomes a constant value (40IRE), and outputs the amplified signal (from low to wide band). Is a broadband amplifier having a flat gain over a wide frequency range. The sink AGC 511 and the sink AGC 531 have the same configuration.

The burst AGC 532 is connected to the color signal input terminal 5
05, a burst signal (approximately 3.5
8MHz signal) is a constant value (40IR)
E) to amplify and output the chrominance signal to become E).
Only the frequencies from MHz to 4 MHz are amplified so that the amplitude level of the burst signal becomes a constant value. ). The burst AGC 513 and the burst AGC 532 have the same configuration.

If the input NTSC video signal is copyable and has a signal / noise ratio (S / N ratio) that allows digital processing such as compression, switching means 503 operates in accordance with switching control signal 508. , Input terminals 536 and 538
, And outputs the output signal of the first branch. The input NTSC video signal is a signal for which copying is prohibited, or the S / N is so low that digital processing such as compression cannot be performed.
If the signal has a ratio, the switching unit 503 outputs the output signal of the second branch, which is input to the input terminals 535 and 537, according to the switching control signal 508. The output signal of the first branch and the output signal of the second branch have the same sync level (40IRE) and burst level (40IR).
E), the image quality of both is almost the same. Even when the switching means 503 switches the output signal, the image quality does not change on the screen.

[0080]

According to the video recording / reproducing apparatus of the present invention,
The recording route (the first route) is connected to the bypass route (the second branch route).
Image adjustment means that performs the same function as the branching path of FIG. According to the present invention, when switching between the first branch and the second branch, a sense of image quality (bright / dark, good / bad coloring, etc.) is observed when viewed. The advantage is obtained that a video recording / reproducing apparatus which hardly feels the difference of (1) can be realized.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of a video recording and reproducing apparatus according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a video recording / reproducing device according to a third embodiment of the present invention.

FIG. 4 is a block diagram of a video recording / reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a video recording / reproducing apparatus according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram of a conventional video recording / reproducing apparatus.

[Explanation of symbols]

101, 201, 301, 401, 501, 601
First branch 102, 202, 302, 402, 502, 602
Second branch 103, 203, 303, 403, 503, 603
Switching means 111, 212, 231, 311, 331, 411, 5
11, 531, 611 sink AGC 112, 214, 232, 312, 332, 414, 4
31, 513, 532, 612 Burst AGC 113, 213, 216, 313, 412, 512, 5
14, 613 A / D converter 114, 211, 314, 413, 614 Luminance signal / chrominance signal separation means 115, 215, 315, 415, 515, 515, 615
Demodulator 116, 217, 316, 416, 516, 616
Compression means 117, 218, 217, 417, 517, 617
Recording means 118, 219, 318, 418, 518, 618
Recording medium 119, 220, 319, 419, 519, 619
Reproduction means 120, 221, 320, 420, 520, 620 Decompression means 123, 222, 223, 323, 423, 521, 5
23,623 D / A converter 121,224,321,421,522,621 Modulator 122,225,322,422,622 Adder 104,204,304,404,604 NTSC
Video input terminal 105, 205, 305, 405, 605 NTSC
Video output terminal 504 Luminance signal input terminal 505 Color signal input terminal 506 Luminance signal output terminal 507 Color signal output terminal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) H04N 9/68 102 H04N 5/91 Z 5D080 F term (reference) 5C026 BA14 5C053 GB21 JA27 5C055 AA03 DA01 EA02 EA04 EA08 EA11 FA22 HA18 HA35 5C066 AA07 AA15 BA02 BA17 EA04 EA06 HA02 5D044 AB07 BC01 BC04 CC04 GK11 5D080 BA03 DA06 EA01 EA24

Claims (11)

[Claims] 1. A first video signal processing branch, a second video signal processing branch, and signal switching means, wherein the signal switching means has a first input terminal, a second input A terminal, and an output terminal for selectively outputting a video signal input to the first input terminal or a video signal input to the second input terminal in response to a switching control signal; A first video signal processing branch, an input unit for inputting a video signal, first video adjustment means for adjusting the input video signal for an arbitrary element thereof, and inputting the adjusted video signal; Compression means for compressing the information amount and outputting a compressed video signal; recording means for recording the compressed video signal on a recording medium; and reproduction means for reproducing the compressed video signal from the recording medium. Before the output by the compression means or the reproduction means. Decompressing means for decompressing the compressed video signal and transmitting the decompressed video signal to the first input terminal of the signal switching means, wherein the second video signal processing branch comprises: The input unit, the first video adjustment unit, and a transmission unit that transmits the adjusted video signal output by the first video adjustment unit to the second input terminal of the signal switching unit. A video recording / reproducing device, comprising: 2. A first video signal processing branch, a second video signal processing branch, and signal switching means, wherein the signal switching means has a first input terminal, a second input. A terminal, and an output terminal for selectively outputting a video signal input to the first input terminal or a video signal input to the second input terminal in response to a switching control signal; A first video signal processing branch, an input unit for inputting a video signal, first video adjustment means for adjusting the input video signal for an arbitrary element thereof, and inputting the adjusted video signal; Compression means for compressing the information amount and outputting a compressed video signal; recording means for recording the compressed video signal on a recording medium; and reproduction means for reproducing the compressed video signal from the recording medium. Before the output by the compression means or the reproduction means. Decompressing means for decompressing the compressed video signal and transmitting the decompressed video signal to the first input terminal of the signal switching means, wherein the second video signal processing branch comprises: The input unit; and a second video adjustment unit that adjusts the input video signal with respect to the element, and transmits the adjusted video signal to the second input terminal of the signal switching unit. A video recording / reproducing apparatus characterized by the above-mentioned. 3. The method according to claim 1, wherein the first video adjustment unit extracts image quality information from the input video signal, and the second video adjustment unit adjusts the input video signal based on the image quality information. 3. The video recording / reproducing apparatus according to claim 2, wherein 4. The first video adjustment means or the first video adjustment means and the second video adjustment means amplify the input video signal so that the level of the horizontal synchronization signal is substantially constant. And at least one of a second amplifier for amplifying a color signal in the input video signal such that the level of the color burst signal is substantially constant. The video recording / reproducing device according to claim 1 or 2. 5. The image processing apparatus according to claim 1, wherein the first video adjustment unit and the second video adjustment unit include a first amplifier that amplifies the input video signal so that a level of a horizontal synchronization signal is substantially constant. The video recording / reproducing apparatus according to claim 3, wherein the image quality information includes information on a level of a horizontal synchronization signal of the video signal. 6. A second video adjusting means for amplifying a color signal in the input video signal such that the level of the color burst signal is substantially constant. The video recording / reproducing apparatus according to claim 3, wherein the image quality information includes information on a level of a color burst signal of the video signal. 7. A control method for a video recording / reproducing apparatus which selectively executes a first video signal processing step and a second video signal processing step, wherein the first video signal processing step comprises the steps of: An input step of inputting the input video signal, a first video adjustment step of adjusting the input video signal for an arbitrary element thereof, and inputting the adjusted video signal, compressing the information amount thereof, and A compression step of outputting a video signal; a recording step of recording the compressed video signal on a recording medium; and a decompression step of decompressing the compressed video signal and outputting a decompressed video signal. The second video signal processing step includes: an input step of inputting a video signal; and a second step of adjusting the input video signal with respect to the element and outputting the adjusted video signal. Having, an image adjusting step, the control method of a video recording and reproducing apparatus, characterized in that. 8. In the first image adjusting step,
The video recording / reproducing apparatus according to claim 7, wherein image quality information is extracted from the input video signal, and the input video signal is adjusted based on the image quality information in the second video adjustment step. Control method. 9. In the first image adjustment step and the second image adjustment step, the input image signal is amplified so that the level of a horizontal synchronization signal thereof becomes substantially constant, or the input image signal is amplified. 8. The control method according to claim 7, wherein at least one of amplifying the color signal in the signal so that the level of the color burst signal is substantially constant is executed. 10. In the first image adjustment step and the second image adjustment step, the input image signal is amplified so that the level of a horizontal synchronization signal is substantially constant, and the image quality information is an image signal. The control method for a video recording / reproducing apparatus according to claim 8, further comprising information on a level of a horizontal synchronization signal of the signal. 11. In the first image adjustment step and the second image adjustment step, amplifying a color signal in the input image signal so that the level of the color burst signal becomes substantially constant, The method according to claim 8, wherein the image quality information includes information on a level of a color burst signal of the video signal.