JPH05153637A - Television signal transmission system and reproducing device therefor - Google Patents

Abstract

PURPOSE:To identify the broadcast system without giving effect on another signal by applying frequency modulation to an identification control signal with a carrier in the relation conjugate to a chrominance subcarrier at a time- vertical-two-dimension frequency area and multiplexing the result onto a vertical overscan section. CONSTITUTION:A broadcast system identification control signal CO generated by a signal generating circuit 1 is shifted by using a carrier U 3.58MHz in conjugation relation with a chrominance subcarrier at a time-vertical-two- dimension frequency region by a frequency converter 2 and the result is fed to a BPF 3, a prescribed band limit is applied and the result is sent to a gate circuit 4. Then a synchronizing signal is used to open a gate only at a vertical overscan section, an identification signal is fed to an adder 5, in which the result is added to a video signal and the sum is outputted. Thus, while keeping the compatibility with the NTSC system without eliminating a teletext and a GCR superimposed on the vertical blanking part or the like, the identification control is multiplexed to avoid visual disturbance in a receiver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television signal transmission system, and more particularly to an auxiliary signal for improving image quality while maintaining compatibility with the current NTSC color television broadcasting of EDTV which is compatible with the current television system. The present invention relates to a television signal transmission system for additionally obtaining a high-quality wide aspect image.

[0002]

2. Description of the Related Art Several broadcasting systems have been proposed in which an auxiliary signal is added to a video signal to display a high-quality wide aspect image while maintaining compatibility with the current NTSC video signal. When the broadcast system is received by a wide aspect receiver, it is necessary to determine whether it is the current NTSC or a high quality wide aspect video signal. For this reason, it has been proposed to superimpose the identification control signal on the vertical blanking portion of the television signal on the transmission side.

[0003]

In the case of multiplexing the above-mentioned identification control signal with a television signal, the conventional proposal is to multiplex with the vertical blanking portion of the television signal. However, the vertical blanking parts 10H to 13H are reserved for teletext and the like, and 14H to 16H.
H and 21H are used for teletext. 17H is multiplexed with VITS (VERTICAL INTERVAL TEST SIGNAL) for testing, 18H and 281H are multiplexed with GCR (ghost elimination reference signal), and 19H and 20H are multiplexed with net cue signal which is an operation control signal of a commercial television station. There is.

For this reason, when the identification control signal is multiplexed, it is being studied whether it is shared with an existing signal or reserved 10H to 13H or the like is used.

[0005]

In order to solve the above-mentioned problems, in the first invention, the identification control signal on the transmitting side has a conjugate relationship with the color subcarrier in the "time-vertical" two-dimensional frequency domain. It has means for frequency conversion by the carrier wave u and means for multiplexing in the vertical overscan unit.

In the second invention, the receiving side has means for extracting the identification control signal multiplexed in the vertical overscan section, means for frequency conversion by the carrier wave u, and means for reproducing the identification control signal.

Further, in the third invention, means for identifying NTSC and EDTV as the identification control signal, and a first generation E
It has means for identifying DTV and second generation EDTV, means for identifying the presence or absence of high definition information, means for identifying the presence or absence of digital audio, and means for identifying 30 Hz motion information of the entire screen.

[0008]

According to the present invention, as a first operation, the identification control signal is frequency-converted by the carrier wave u having a conjugate relationship with the color subcarrier in the "time-vertical" two-dimensional frequency domain, and the vertical overscan unit is operated. Since it is multiplexed into the vertical blanking section, the identification control signal can be transmitted without using the teletext signal or GCR signal currently multiplexed in the vertical blanking section.

As a second effect, since the identification control signal is multiplexed in the "time-vertical" two-dimensional frequency domain of the vertical overscan section in a region conjugate with the color subcarrier, it interferes with the current receiver. Does not appear.

As a third action, since 30 Hz motion information of the entire screen which cannot be detected in principle on the receiving side is multiplexed as an identification control signal on the transmitting side, the receiving side can easily detect the motion information.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a television signal transmission system and a reproducing apparatus thereof according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a part of a transmission unit according to the first embodiment of the present invention.

In FIG. 1, the video signal input and the sync signal input are respectively supplied with a 16: 9 video signal and the sync signal accompanying it. The identification control signal generation circuit 1 generates an identification control signal CO and supplies it to the frequency conversion circuit 2. The frequency conversion circuit 2 sends the identification control signal CO to the carrier wave u.
Frequency shift by (3.58MHz), BPF
It is supplied to the filter (bandpass filter) 3. Here, the carrier wave u performs phase inversion for each horizontal scanning line frame,
As shown in FIG. 3A, the color subcarrier fsc is a carrier having a conjugate relationship in the "time-vertical" two-dimensional frequency domain. Therefore, the frequency domain of the identification control signal CO is shown in FIG.
When the frequency is 0 to 0.5 MHz as shown in the area a of
When this region is frequency-shifted by the above-mentioned carrier wave u, it is shifted to the shaded region b in the figure and multiplexed as the identification control signal CO ′.

Next, the BPF filter 3 shown in FIG.
As shown in, the band is limited to 3.08 MHz to 4.08 MHz. The band-limited identification control signal CO ′ is supplied to the gate circuit 4. The gate circuit 4 uses the synchronizing signal to detect, for example, 23H and 28 of the vertical overscan portion.
Only when 6H, the gate is opened and the discrimination control signal CO ′ is supplied to the adder circuit 5. The adder circuit 5 and the video signal 23
The identification control signal CO ′ multiplexed with H and 286H is added and a video signal is output.

It should be noted that 23H and 286H are preliminarily set to 23H and 286H so that the spectrum of the video signal applied to the adding circuit 5 does not overlap with the frequency-shifted identification control signal CO '.
Bandwidth is limited to the area excluding the diagonal lines shown in (a).

Next, FIG. 2 shows a part of the receiving side according to the second embodiment of the present invention.

The video signal input to the video input terminal is supplied to the sync separation circuit 21 and the BPF filter (bandpass filter) 22. The sync separation circuit 21 performs sync separation from the video signal and supplies it to the gate circuit 23. The gate circuit 23 uses the synchronization signal to generate 23H, 286H
Only when, the gate is opened and the identification control signal CO ′ whose band is limited by the BPF filter 22 is supplied to the frequency conversion circuit 24. The frequency conversion circuit 24 shifts the frequency of the identification control signal CO ′ multiplexed in the shaded area of FIG. 4A by the carrier wave u as shown in FIG.
Supply to 5. In the LPF filter 25, the band is limited to 0 to 0.5 MHz as shown in FIG. 4C, and only the region a in FIG. 4A is allowed to pass. That is, the original identification control signal C
Only O is taken out and the identification control signal is reproduced.

The structure of the identification control signal according to the third embodiment of the present invention is shown in FIGS.

The CR, FC, information, and inspection shown in FIG. 5A are formed as shown in FIGS. 5B to 5E, respectively.
CR in FIG. 5B represents a clock line for bit synchronization, and FC in FIG. 5C represents a frame code for frame synchronization. The information bits in FIG. 5 (d) are, for example, b0 for NTSC / EDTV switching, b1 for first generation EDTV / second generation EDTV switching, b2 for high definition information presence, b3 for digital audio presence, and b4 to Let b7 be information when the entire screen moves at 30 Hz, and information about how many pixels have moved per frame.

The motion information of 30 Hz cannot be detected in principle because the motion detection circuit using the difference between frames on the receiving side can detect only the shaded area in FIG. 3B.
Therefore, it is necessary to transmit 30 Hz motion information on the transmitting side. The check bit h is an error correction code or the like and detects an error in the information bit and corrects it.

The vertical overscan multiplexing region, the frequency of the frequency conversion carrier wave, and the band of the identification control control signal shown in the above embodiment are examples, and the present invention is not limited thereto.

[0022]

Since the present invention has the above-mentioned structure,
The identification control signal can be multiplexed while maintaining compatibility with the NTSC system and without deleting the character broadcast, GCR, etc. multiplexed in the vertical blanking section. In addition, since the identification control signal is transmitted while being superimposed on the vertical overscan unit, no visual disturbance appears on the existing receiver. Furthermore, since 30 Hz motion information of the entire screen, which cannot be detected on the receiving side, is multiplexed on the transmitting side as an identification control signal, the receiving side can easily detect the motion information.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a transmitting side of the present invention.

FIG. 2 is a block diagram showing an embodiment of the receiving side of the present invention.

FIG. 3 is an explanatory diagram of a carrier wave for frequency multiplexing of the present invention.

FIG. 4 is an explanatory diagram of amplitude characteristics of a frequency shift filter according to the present invention.

FIG. 5 is an explanatory diagram of a configuration of an identification control signal according to the present invention.

[Explanation of symbols]

 1 Identification control signal generation circuit 2 Frequency conversion circuit 3 BPF filter 4 Gate circuit 5 Addition circuit 21 Sync separation circuit 22 BPF filter 23 Gate circuit 24 Frequency conversion circuit 25 LPF filter fsc Color subcarrier u Carrier wave

Claims (3)

[Claims] 1. A television signal transmission system for obtaining a high-quality wide aspect image by adding an auxiliary signal for high image quality while maintaining compatibility with the current NTSC color television broadcasting, at the transmitting side. Means for frequency-converting an identification control signal for identifying a broadcasting system by a carrier having a conjugate relationship with a color subcarrier in a "time-vertical" two-dimensional frequency domain; and a vertical overscan for the frequency-converted identification control signal. A television signal transmission system, characterized in that it has means for multiplexing in a part of the section. 2. A reproducing apparatus applied to the television signal transmission system according to claim 1, further comprising means for extracting an identification control signal multiplexed in a vertical overscan section.
A television signal reproducing apparatus comprising means for converting the frequency again by a carrier wave and means for reproducing the identification control signal. 3. An identification control signal in a television signal transmission system for obtaining a high quality wide aspect image by adding an auxiliary signal for high image quality while maintaining compatibility with the current NTSC color television broadcasting. Means for discriminating between the current NTSC color television broadcasting system and a high-definition television broadcasting system including one or more high-definition signals, and the first-generation EDT based on the high-definition signals.
V, means for identifying a plurality of high-definition television broadcasting systems such as second generation EDTV, means for identifying the presence or absence of high definition information, and means for identifying the presence or absence of digital audio, A television signal transmission system having means for identifying motion information corresponding to a field frequency.