JPS63121384A - Magnetic recording and reproducing device for color video signal - Google Patents

Abstract

PURPOSE:To transmit a color video signal higher in quality than a transmission through an NTSC system by converting the color video signal output of a VTR into an RGB three primary colors signal, and transmitting it to a CTV. CONSTITUTION:An input carrier chrominance signal C is demodulated into a signal I and the signal Q by a color demodulation circuit 5, and they are converted by a YIQ/RGB conversion together with an input Y signal, and transmitted as each of three primary colors signal. Each of the three primary colors signal through a transmission line is inputted to the CTV and supplied to a switcher 21. Then, one of two pairs of the input of the RGB tree primary colors signal is selected and outputted to terminals 28, 29 and 30. Namely, the RGB tree primary colors signal, outputted from the terminals 28, 29 and 30, can be switched to either the RGB three primary colors signal inputted from the input terminals 22, 23 and 24 of the switcher 21, or the RGB three primary colors signal inputted from the input terminals 25, 26 and 27.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a color video signal magnetic recording and reproducing device such as a video tape recorder capable of transmitting high quality color video signals to a color video signal display device such as a color television. It is.

2. Description of the Related Art In the field of conventional consumer video reader (abbreviated as VTR), VTR and color television receiver (CT)
A composite video signal obtained by frequency-multiplexing a luminance signal and a carrier chrominance signal is used to transmit a color video signal between the baseband and the broadcast wave band (RF band).

For example, Broadcasting Technology Magazine, August 1983 issue, 59-71.
As described on the page, to transmit color video signals between a VTR and a so-called AV system TV, the baseband signal of the NTSC composite video signal is transmitted from the video output terminal of the VTR, and the baseband signal of the NTSC composite video signal is transmitted from the video output terminal of the VTR, and the It takes the form of baseband transmission in which the signal is received by the input terminal. This baseband transmission of composite video signals between a VTR and CTV can be said to be an excellent transmission method that causes less deterioration of the composite video signal than transmission in the broadcast wave band because it does not pass through an RF converter or filter. .

However, for example, in the VH3 standard, β standard, or 8-Ryu VTR standard of a consumer VTR using the NTSC system, although the luminance signal and the color signal are recorded separately, the output signal from the VTR is the brightness signal and the carrier color signal. outputs a composite video signal frequency-multiplexed with CTV
1 again using a comb filter etc. within the CTV.
Extra operations of frequency multiplexing and frequency separation are performed in which the signals are separated into variable signals and carrier color signals. In other words, imperfections in filters and amplifiers in frequency multiplexing and frequency separation of luminance signals and carrier chrominance signals impair the amplitude and phase sensitivity of the transmitted signal, and furthermore, circuit noise is added, degrading the quality of the transmitted signal. I have a problem.

Hereinafter, the conventional VTR and CT described above with reference to the drawings will be explained.
An example of a method for transmitting a color video signal as a composite video signal between Vs will be described. Figure 2 shows conventional VTR and CTV
FIG. 2 is a block diagram of main parts of an example of a color video signal transmission system between the two.

In FIG. 2, it is assumed that a luminance signal and a color signal to be recorded or reproduced in a VTR are input to terminals 1 and 2, respectively. However, here, the color signal is a carrier color signal subjected to quadrature two-phase modulation using a subcarrier. For example, the case of the NTSC system in which the frequency of the subcarrier is 3.579545 MHz will be described below. Now, the luminance signal input from terminal 1 and the carrier color signal input from terminal 2 reach the Y/C mixing circuit 3, where they are frequency multiplexed and converted to NTSC.
It becomes a composite video signal and is output from the Y/C mixing circuit to terminal 8.
The signal is output as a baseband NTSC signal and reaches the input terminal 13 of the CTV via a transmission line. Furthermore, the baseband NTSC composite video signal, which is the output of the Y/C mixing circuit, reaches the RF modulator 4, is modulated into a broadcast wave band signal, is output from the output terminal 7 of the VTR, and is sent to the input terminal 1 of the CTV via the transmission line.
2.

NT of the broadcast wave band input from the input terminal 12 of the CTV
SC? 3 [The color-determined image signal is demodulated into a baseband NTSC composite video signal in the RF demodulator 17 and then sent to the Y/C separation circuit 1
It reaches 8. Further, the baseband NTSC composite video signal inputted from the input terminal 13 of the CTV also reaches the Y/C separation circuit 18. Although omitted in Fig. 2, Y/C separation circuit 1
As for the input signal to 8, either the signal from terminal 13 or the signal from RF demodulator 17 is selected by a switcher. In the Y/C separation circuit 1, the baseband NTSC composite video signal is frequency-separated into a luminance signal (Y signal) and a carrier color signal (C signal) and output, respectively.The carrier color signal is sent to the color demodulation circuit 19. At this point, the color signal is further demodulated into two color signals, a (2) signal and a C signal. Then, the Y signal output of the Y/C separation circuit 18 and the ■ and C signal outputs of the color demodulation circuit 19 are input to the YIQ/ROB conversion circuit 20, where they are converted into RGB three primary color signals, and the R signal, C signal, and B signal are sent to respective terminals. It is output from 31, 32 and 33 and reaches the cathode ray tube drive circuit of the CTV.

Problems to be Solved by the Invention As mentioned above, in the conventional transmission of color video signals between a VTR and a CTV, the luminance signal and the carrier color signal are transmitted in the form of a composite video signal that is frequency-multiplexed. During frequency multiplexing of the luminance signal and carrier chrominance signal and frequency separation on the TV side, imperfections in filters and amplifiers can cause the amplitude and phase information of the transmitted signal to be lost, causing waveform distortion and adding circuit noise. This has a major problem in that the quality of the transmitted signal deteriorates.

In addition, for example, in the NTSC system, the luminance signal and the carrier chrominance signal are frequency multiplexed in a frequency interleaved relationship, and cross interference due to mutual interference between the luminance signal and the chrominance signal occurs.
There is a problem in that color and cross luminance become noise and have a large negative impact on image quality.

Furthermore, in the NTSC system, the luminance signal band is 4.
Since the bands of the 2M)lz and chrominance signals are determined to be 1, 5Mllz and 0.5MHz for the summer signal and C signal, respectively, it is natural that the luminance signal has a wider band than that specified by the NTSC standard. and color signals cannot be transmitted.

In view of the above problems, the present invention provides a VTR that handles NTSC signals.
Converts the color video signal output to ROB three primary color signals and performs CT
The present invention provides a magnetic recording and reproducing device that can transmit a color video signal of higher quality than when transmitting in the form of an NTSC standard signal by transmitting it in the form of an NTSC standard signal.

Means for Solving the Problems In order to solve the above problems, in the present invention, the NTS
The VTR is equipped with a new circuit that converts the luminance signal and color signal in a band wider than the band limited by the C standard into RGB three primary color signals.
and outputs the RGB three primary color signals directly from the VTR.
, B Transmit to a CTV with input terminals for three primary color signals.

Operation In the present invention, by the method described above, the conventional NTSC
Although VTRs and CTVs handle composite video signals,
It is possible to transmit high-quality color video signals with a wider band than that determined by the NTSC standard, free from mutual interference such as cross color and cross luminance, and with less additional noise in the circuit system.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of main parts in one embodiment of the present invention. In FIG. 1, it is assumed that a luminance signal (Y signal) and a carrier color signal (C signal) to be recorded or reproduced in the VTR are manually input to terminals 1 and 2 in the VTR, respectively. The luminance signal input from terminal 1 and the carrier color signal input from terminal 2 reach Y/C mixing circuit 3, where they are frequency multiplexed to become an NTSC composite video signal, which is output from the Y/C mixing circuit and sent to CTV via a transmission line. to the input terminal 13 of. Further, the output of the Y/C mixing circuit reaches the RF modulator 4, is modulated into a broadcast wave band signal, is outputted from the output terminal 7 of the VTR, and reaches the input terminal 12 of the CTV via a transmission line. CT
NTSC of the broadcast wave band input from input terminal 12 of V
The composite video signal is converted to baseband NT in the RF demodulator 17.
It is demodulated into an SC composite video signal and reaches the Y/C separation circuit 18. Further, the baseband NTSC composite video signal inputted from the input terminal 13 of the CTV also reaches the Y/C separation circuit 18. Although omitted in FIG. 1 as it is not essential for explaining the present invention, the input signal to the Y/C separation circuit 18 is input to the terminal 13 by the switcher or to the RF demodulator 1.
Either one of the signals from 7 and 7 is selected.

In the Y/C separation circuit 18, the baseband NTSC composite video signal is frequency-separated into a luminance signal and a carrier chrominance signal and outputted, respectively.The carrier chrominance signal reaches the color demodulation circuit 19, where it is further divided into two chrominance signals. The color is demodulated into an I signal and a C signal.

Then, the Y signal output of the Y/C separation circuit 18 and the color demodulation circuit 1
The I and C signal outputs of No. 9 are input to the YIQ/ROB converter 20 and converted into RGB three primary color signals, and the R (No. 3, C signal and B signal are input to input terminals 22, 23 and 24 of the switcher 21, respectively). The operation of 0 or more is the same as in the conventional example, but in the present invention, the input terminal 2 in FIG.
The manually generated carrier color signal C reaches the color demodulation circuit 5, where it is demodulated into two color signals, the ■ signal and the C signal.
YIQ/RGB along with the Y signal input from input terminal 1
The signal reaches the conversion circuit 6 and is converted into RGB three primary color signals, and the R signal, C signal and B signal are sent to the VTR output terminals 9 and 1, respectively.
0 and 11.

VTR output terminal9. The R signal, C signal, and B signal output to IO and 11 reach input terminals 14, 15, and 16 of the CTV via a transmission path.

Recently, consumer CTVs and peripheral equipment have been receiving R signals.

Standards for connections using G and B signals were established by the Electronics Industries Association of Japan (EIAJ) and defined in the EIAJ technical file TTC-008, "Interconnection of Television Receivers and Peripheral Devices." With the establishment of this standard, general connection connectors (so-called analog RGB multi-connectors) are also installed on consumer CTVs, and analog RGB signal output from personal computers, etc. is directly displayed on consumer CTVs via this analog RGB multi-connector. It became possible. However, in the field of VTRs, there is no EIAJ general connection connector that transmits consumer c''rv and RGB signals.
It is also possible to use this EIAJ analog RGB multi-connector.

By the way, the RGB three primary color signals inputted from terminals 14, 15 and 16 in FIG. 1 reach input terminals 25, 26 and 27 of switcher 21.

During switch -21, select one of the two sets of RGB three primary color signal inputs and connect terminals 28, 29 and 3.
Output to 0. That is, the RGB 3 primary color signals outputted from the terminals 28, 29 and 30 are the RGB 3 primary color signals inputted from the input terminals 22, 23 and 24 of the switcher 21, or the ROB 3 primary color signals inputted from the input terminals 25, 26 and 27. It can be switched to either.

As detailed above, by newly installing a circuit in the VTR that converts the luminance signal and color signal into RGB three primary color signals, signal processing in the transmission of color video signals between the VTR and CTV, that is, the luminance signal and the carrier color. Since a series of signal processing such as signal mixing, frequency separation, and even RF modulation/demodulation can be omitted, it is possible to avoid deterioration of the amplitude and phase information of the transmitted signal caused by imperfections in filters and amplifiers during these signal processing, as well as new problems. There is no added circuit noise, and high quality color video signals can be transmitted to CTV rather than VTR.
can be transmitted to.

In the embodiment, V is used as an example of a color video signal reproducing device.
Although the case of TR has been described, it can be applied to any package type color video signal reproducing device such as a video disc or a laser disc. Furthermore, in the embodiment, the case where Y, ■ and Q signals were handled was described, but <Y, R-
Even when handling Y and B-Y signals, there is a one-to-one correspondence between these color video signals, so the present invention can be applied to cases where all color video signals are handled.

Furthermore, although the embodiments have been described using the NTSC system, the present invention can be applied to color video signal reproducing devices that handle all composite video signals, including internationally standardized systems such as the PAL system and the SECAM system. It is.

Effects of the Invention Conventionally, color video signals are transmitted between a consumer VTR and a CTV in the form of a composite video signal of the NTSC system, for example, as described above, and the bands of luminance signals and color signals are limited by the NTSC standard. In addition, the quality of the transmitted color video signal is degraded by interference due to mutual interference, waveform distortion due to Y/C separation filters, and additional noise from the circuit system.

According to the present invention, the brightness signal and the color signal are newly added to the VTR.
By providing a circuit that converts to GB3 primary color signals,
This has the great effect of allowing the use of an NTSC standard VTR or CTV to transmit brightness signals and color signals of higher quality over a wider band than the brightness signals and color signals of the NTSC standard. Especially VTR
The image quality improvement according to the present invention can be applied when the color video signal output is not a recording and reproduction of an NTSC color video signal such as a broadcast wave, but a luminance signal or color signal that does not pass through the NTSC system in a video camera or the like. The effect is huge.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of main parts of an embodiment of the present invention, and FIG. 2 is a block diagram of main parts of a conventional example.

Claims (5)

[Claims] (1) A color video signal magnetic recording and reproducing device composed of a luminance signal and a color signal, comprising a matrix circuit for converting the luminance signal and color signal into three primary color signals of red, green, and blue. playback device. (2) The color video signal magnetic recording and reproducing device records and reproduces a luminance signal and a chrominance signal as a frequency-separated one-channel signal, as set forth in claim (1). Device. (3) A color video signal magnetic recording and reproducing device according to claim 1, wherein the color video signal magnetic recording and reproducing device records and reproduces two-channel component signals of a luminance signal and a color signal. (4) The color signal is a color signal obtained by orthogonal two-phase modulation of two color difference signals using a subcarrier, and the color signal input to the matrix circuit is the two color difference signals. A color video signal magnetic recording and reproducing device according to scope (1). (5) The matrix circuit converts the coordinate axes into three primary color signals of red, green, and blue that have the desired brightness, hue, and color saturation by adding and subtracting the luminance signal and two color difference signals that make up the color video signal at a desired ratio. A color video signal magnetic recording and reproducing apparatus according to claim (1).