JPH0824372B2 - Color video signal display device - Google Patents

Description

The present invention relates to a color television receiver for receiving and displaying a high quality color video signal sent from a color video signal transmitter such as a video tape recorder or a video disc. The present invention relates to a color video signal display device.

2. Description of the Related Art In the field of conventional consumer video tape recorders (abbreviated as VTR), the transmission of color video signals between a VTR and a color television (abbreviated as CTV) may be either the base band or the broadcast wave band. Even in the (RF band), a composite video signal (composite video signal) in which a luminance signal and a carrier color signal are frequency-multiplexed is used. For example, broadcast technical magazines,
As stated in the August 1983 issue, pages 59-71
For the transmission of color video signals between the VTR and the so-called AV system TV, the baseband signal of the NTSC composite video signal is transmitted from the video (video) output terminal of the VTR and received by the video input terminal of the AV system TV. It is in the form of transmission. The baseband transmission of the composite video signal between the VTR and the CTV is an excellent transmission method compared to the transmission in the broadcast wave band, because the composite video signal is less deteriorated as much as the RF converter and the filter are not passed. .

However, although the luminance signal and the color signal are recorded separately in the standards such as the VHS standard and the β standard for the consumer VCR of the NTSC system or the 8 mm VTR and the VHD video disc (that is, the luminance signal and the color signal are recorded separately). Is treated as a component signal and recorded separately) As the output signal from the VTR, a composite video signal in which the luminance signal and the carrier color signal are frequency-multiplexed is output, transmitted to the CTV, and a comb filter, etc. is set in the CTV. Extra operations such as frequency multiplexing and frequency separation, in which the luminance signal and the carrier color signal are frequency-separated again by using them, are performed. That is, the amplitude and phase information of the transmission signal is impaired due to the imperfections of the filter and the amplifier in the frequency multiplexing and the frequency separation of the luminance signal and the carrier color signal, and further the circuit noise is added to deteriorate the quality of the transmission signal. Have a point

The operation of the conventional color video signal display device, for example, CTV, in transmitting the color video signal as the composite video signal between the conventional VTR and CTV will be described below with reference to the drawings.

FIG. 3 is a block diagram of a main part of an example of a conventional color video signal transmission system between a VTR and a CTV. In FIG. 3, a luminance signal and a color signal recorded or reproduced in the VTR are output to the output terminals 2, 3 and 4 of the VTR color video signal processing circuit 1, respectively. In FIG. 3, a luminance signal (Y signal, Y signal in FIG. 2A) is output from the output terminal 2, and color signals (I signal, Q signal, I in FIG. 2B) are output from the output terminals 3 and 4. , Q signal) is output. These Y, I and Q signals reach the low-pass filter 1 (abbreviated as LPF1), LPF3 and LPF5, respectively, and their outputs are as shown by Y ₁ , I ₁ and Q ₁ in FIGS. 2 (c) and 2 (d). Bandwidth limited. Y in the NTSC standard system,
Bandwidth limits for I and Q signals are 4.2MHz and 1.5M respectively
Hz and 0.5 MHz. The output signals of LPF3 and LPF5, the I ₁ and Q ₁ signals, reach the quadrature two-phase modulator 11 and are 3.579545MH.
Carrier suppression quadrature two-phase amplitude modulation is performed by the sub-carrier of z to become the K signal in FIG. 2 (g), which is frequency multiplexed with the Y ₁ signal in FIG. 2 (c), which is the output signal of LPF1 in the Y / C mixing circuit 13. The composite video signal shown in FIG. 2 (h) is obtained. When the transmission of the composite video signal from the VTR to the CTV is in the base band, the output of the Y / C mixing circuit is output from the output terminal 15 of the VTR and CT
It is input from the V input terminal 19 and reaches the Y / C separation circuit 24 in the CTV. Also, when the composite video signal transmission from the VTR to the CTV is in the broadcast wave band, the output of the Y / C mixing circuit is modulated in the broadcast wave band by the RF modulator 14 and the output terminal 16 of the VTR to the input terminal of the CTV. At 20, the RF demodulator 23 demodulates the composite video signal in the base band again and reaches the Y / C separation circuit in the CTV. In the Y / C separation circuit, the composite video signal shown in FIG. 2 (h) is converted into a luminance signal (eg, Y _{1 in} FIG. 2 (c)) and a carrier color signal (eg, K in FIG. 2 (g)). Frequency separated
Input to the input terminals 33 and 34 of the TV color video signal processing circuit 35.

Problems to be Solved by the Invention Transmission of a color video signal between a conventional VTR and a CTV is performed in the form of an NTSC composite video signal which is a standard television signal in which a luminance signal and a carrier color signal are frequency-multiplexed as described above. Since it is transmitted, the amplitude and phase information of the transmission signal is damaged due to the incompleteness of the filter and the amplifier in the frequency multiplexing of the luminance signal and the carrier color signal on the VTR side or the frequency separation on the TV side, causing waveform distortion, Since the circuit noise is added, the quality of the transmission signal deteriorates, and as a result, the display quality of the video signal display device deteriorates, which is a serious problem.

In addition, for example, in the NTSC system, the luminance signal and the carrier color signal are frequency-multiplexed due to the frequency interleaving relationship, and cross color and cross luminance due to mutual interference between the luminance signal and the color signal give noise to the image quality. There is a problem that the adverse effect is great.

Furthermore, in the NTSC system, the bandwidth of the luminance signal is 4.2MH
Since the bandwidths of z and chrominance signals are determined to be 1.5MHz and 0.5MHz for I and Q signals respectively, it is natural to transmit luminance signals and chrominance signals in a wider bandwidth than that determined by the NTSC standard. No, it cannot display video signals with different aspect ratios such as EDTV and HDTV. When the NTSC signal is used for broadcast radio waves, its composition as a composite video signal is effective, but when used in a scene other than broadcast radio waves, it is often restricted as a composite video signal. Is a drawback.

In view of the above problems, the present invention has a wider band such as EDTV or HDTV than a case of handling an NTSC standard signal by a simple addition change of an output circuit system of a VTR handling an NTSC signal and an input circuit system of a CTV. It provides a video signal display device that displays a high-quality video signal by easily transmitting a high-quality luminance signal and carrier color signal with a highly realistic aspect ratio between the VTR and TV. is there.

Means for Solving the Problems In order to solve the above problems, the color video signal display device of the present invention has a band wider than the bands of two color difference signals forming a composite video signal which is a standard television signal. Further, two color difference signals having different numbers of scanning lines, different effective scanning lines and different aspect ratio are quadrature-phase modulated with a color subcarrier having the same frequency as the frequency of the color subcarriers forming the composite video signal. It has a wider band than the band of the obtained carrier color signal and the luminance signal constituting the composite video signal which is the standard television signal, and has the same number of scanning lines, the same number of effective scanning lines and the aspect ratio as those of the two color difference signals. First and second component video signal input terminals for separately inputting the luminance signal and
The carrier color signal and the luminance signal input from the first and second component video signal input terminals are separated from the composite video signal which is a standard television signal input from the composite video signal input terminal. A switcher circuit for switching and outputting the carrier color signal and the luminance signal is provided.

Effect In the present invention, by the method described above, it is a VTR and a CTV that handle a conventional NTSC composite video signal, but there is no mutual interference such as cross color and cross luminance in a wider band than that determined by the standard of NTSC system. In addition, it is possible to receive and display a high-quality color video signal with less additional noise in the circuit system. In particular, it is also effective for component transmission and display of high quality video signals such as EDTV and HDTV which have a more realistic aspect ratio.

Embodiment An embodiment of the color video signal display device of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a main part of a color video signal transmission system according to an embodiment of the present invention. In FIG. 1, a luminance signal and a color signal recorded or reproduced in the VTR are output to output terminals 2, 3 and 4 of a VTR color video signal processing circuit 1 in the VTR. In FIG. 1, a luminance signal (Y signal in FIG. 2A) is output from the output terminal 2, and color signals (I signal and Q signal in FIG. 2B) are output from the output terminals 3 and 4, respectively. It The Y signal output from the output terminal 2 is branched into two systems, one is input to the LPF1 that limits the bandwidth of NTSC 4.2MHz, and the other is input to the LPF2 having a 20MHz pass band wider than the LPF1. . The I signal output from the output terminal 3 is branched into two systems, one is input to the LPF3 that limits the band of the NTSC system, and the other is input to the LPF4 having a pass band of 3 MHz wider than the LPF3. . The Q signal output from the output terminal 4 is branched into two systems, one of which is NT
Input to LPF5 that performs SC band limitation, and the other input to LPF6 that has a pass band of 3MHz wider than LPF5. As a result, the outputs of LPF1, LPF3, and LPF5 become the Y ₁ signal in FIG. 2 (c), the I ₁ signal in FIG. 2 (d), and the Q ₁ signal, respectively. The outputs of LPF2, LPF4 and LPF6 are the Y ₂ signal in FIG. 2 (e), the I ₂ signal and the Q ₂ signal in FIG. 2 (f), respectively. The I ₁ signal that is the output of LPF3 and the Q ₁ signal that is the output of LPF5 are subjected to carrier suppression quadrature two-phase amplitude modulation by the subcarrier in the NTSC system in the quadrature two-phase modulator 11, and become the K signal in FIG. 2 (g). Converted, Y / C mixing circuit 13
Frequency-multiplexed with the Y ₁ signal which is the output of LPF _{1 at}
The composite video signal shown in FIG. When the transmission of the composite video signal from the VTR to the CTV is in the base band, the output of the Y / C mixing circuit is output from the output terminal 15 of the VTR and the input terminal 19 of the CTV, and the Y / C separation circuit in the CTV. Up to 24. Also
When the transmission of the composite video signal from the VTR to the CTV is in the broadcast wave band, the output of the Y / C mixing circuit is modulated in the broadcast wave band by the RF modulator 14 and is output from the VTR output terminal 16 to the CTV input terminal 20. Then, the RF demodulator 23 demodulates the composite video signal in the base band again and reaches the Y / C separation circuit 24 in the CTV. In the Y / C separation circuit, the composite video signal shown in FIG. 2 (h) is converted into the luminance signal shown by Y ₁ signal in FIG. 2 (c) and K in FIG. 2 (g).
The signals are frequency-separated into carrier color signals represented by signals and input to the input terminal 26 of the switch 25 and the input terminal 30 of the switch 29, respectively. By the way, I ₂ signal which is the output signal of LPF 4
Q ₂ signal is LPF6 output signal of the quadrature two-phase modulator 12, the sub-carriers are quadrature two-phase amplitude modulation in the NTSC system, the output terminal 1 of the VTR becomes K ₂ signal in FIG. 2 (i)
It is output from 8 and reaches the input terminal 22 of the CTV and the switch 2 in the CTV
9 to the input terminal 31. The Y ₂ signal, which is the output signal of LPF ₂ , is output from the output terminal 17 of the VTR, reaches the input terminal 21 of the CTV, and reaches the input terminal 27 of the switch 25 in the CTV. Switch 25
When outputting the Y ₁ signal to the output terminal 28, the input terminal 26 and the output terminal 28 are conducted, and when outputting the Y ₂ signal, the input terminal 27 and the output terminal 28 are conducted. When the K signal is output to the output terminal 32 of the switch 29, the input terminal 30 and the output terminal 32 are electrically connected, and when the K ₂ signal is output, the input terminal 31 is connected.
And the output terminal 32 are electrically connected. The two output terminals 28 and 32 of the switch 25 and the switch 29 are connected to the input terminals 33 and 34 of the TV color video signal processing circuit 35, respectively. That is, the switches 25 and 29 can switch between the luminance signal and the carrier color signal input to the TV color video signal processing circuit. That is, it is possible to input a luminance signal and a carrier color signal having a wider band than that of the NTSC standard signal to the TV color image processing circuit. Since the broadband carrier color signal input from the input terminal 34 of the TV color image processing circuit 35 is also modulated by the NTSC subcarrier, the broadband I ₂ signal and Q ₂ signal or R- Y signal and B
-It is easy to demodulate into a Y signal or the like. By controlling the pass band of the filter of the carrier chrominance signal demodulation circuit with I ₁ signal, Q ₁ signal, I ₂ signal and Q ₂ signal, etc., a good color difference signal of signal to noise can be obtained, resulting in high quality in a wide band. Na
RGB signal is obtained.

As described above in detail, by changing the CTV reception method, it is possible to easily transmit high-quality luminance and color signals in a wider band than the NTSC standard when transmitting color video signals between the NTSC VTR and CTV. The signal display device can easily receive and display a high-quality video signal.

In the embodiments, the VTR is used as the transmission source of the broadband luminance signal and the chrominance signal, and the CTV is used as the receiver, but the transmission source is any media such as a video disc or a laser disc, CATV or a new type. It can be applied to all transmission systems such as broadcasting systems. Further, as a receiver, that is, a video signal display device, it can be applied not only to a CRT CTV but also to any color video signal display device such as a flat panel display using a liquid crystal or a projection TV. Further, in the embodiment, the case of handling the Y, I and Q signals has been described, but the Y, RY and BY signals and R ₁ , G and B signals.
Even in the case of handling a signal or the like, since there is a one-to-one correspondence between these color video signals, the present invention can be applied to the case of handling any color video signal.

Further, although the case of the NTSC system has been described in the embodiment, the present invention may be applied to the reception and display of a color video signal that handles all composite video signals including internationally standardized systems such as the PAL system and the SECAM system. Is possible.

Effect of the Invention Conventional color video signal transmission between a consumer VTR and a CTV is
As described above, for example, it is performed in the form of the composite video signal of the NTSC system, the band of the luminance signal and the chrominance signal is limited by the NTSC standard, and the interference due to the mutual interference and the Y / C separation filter etc. The quality of the transmitted color video signal deteriorates due to waveform distortion and additional noise of the circuit system.

According to the present invention, there is a great effect that a VTR or CTV of the NTSC standard can be used to receive and display a high quality luminance signal or color signal in a wider band than the luminance signal or color signal of the NTSC standard. Especially, color video signal output such as VTR is broadcast by NTS
In the case of a luminance signal or a color signal that does not pass through the NTSC system in a video camera or the like, which is not a recorded / reproduced C type color video signal, the luminance signal and the color signal are always treated as separate component signals. Therefore, the effect of improving the image quality according to the present invention is very large. Further, according to the present invention, a single device can receive a composite color video signal of the NTSC standard, and a high-quality luminance having a wider aspect ratio than the luminance signal and the color signal determined by the NTSC standard. It is also possible to receive and display signals and color signals such as EDTV video signals and high-definition video signals. Further, according to the present invention, a reproduction output such as a VTR in which a luminance signal and a chrominance signal having a band wider than the band of the conventional standard television signal are separately recorded, is temporarily recorded by the NTS.
C It is possible to directly input the separated component signals to the television receiver as they are without converting them to the C composite video signal, which is extremely effective.

[Brief description of drawings]

FIG. 1 is a block diagram of an essential part of an embodiment of the present invention, and FIGS. 2 (a) to (i) are diagrams for explaining a relationship between a luminance signal and a color signal in a frequency band in the embodiment of the present invention and a conventional example. And FIG. 3 is a block diagram of a main part in the conventional example. 1 ... VTR color video signal processing circuit, 5 ... LPF1, 6 ...
… LPF2,7 …… LPF3,8 …… LPF4,9 …… LPF5,10 ……
LPF6, 11 ... Quadrature two-phase modulator, 12 ... Quadrature two-phase modulator,
13 …… Y / C mixing circuit, 14 …… RF modulator, 23 …… RF demodulator, 24 …… Y / C separation circuit, 25 and 29 …… Switch, 35
...... TV color video signal processing circuit.

Front page continuation (72) Inventor Akihiro Takeuchi 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Yoshitomi Nagaoka 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial (72) Invention Noriaki Gentsu, 1006 Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. (72) Inventor Sakon Nagasaki, 1006, Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. (56) References (JP, Y1) Actual public Sho 57-58854 (JP, Y2) Actual public Sho 58-29669 (JP, Y2)

Claims (1)

[Claims] 1. Two color differences having a wider band than the bands of two color difference signals constituting a composite video signal which is a standard television signal, and having different number of scanning lines, different number of effective scanning lines and different aspect ratio. A carrier chrominance signal obtained by quadrature two-phase modulation of the signal with a color subcarrier having the same frequency as the frequency of the color subcarrier forming the composite video signal, and a luminance signal forming the composite video signal which is a standard television signal. First and second two component video signals having a band wider than the band and separately inputting the two color difference signals and the luminance signal having the same number of scanning lines, the same number of effective scanning lines and the same aspect ratio. Input terminal,
The carrier color signal and the luminance signal input from the first and second component video signal input terminals are separated from the composite video signal which is a standard television signal input from the composite video signal input terminal. A color video signal display device comprising a switcher circuit for switching and outputting a carrier color signal and a luminance signal.