JPH0817482B2 - Television signal processor - Google Patents

Description

Description: TECHNICAL FIELD The present invention is capable of transmitting and reproducing a video signal having an aspect ratio different from that of a current television system while maintaining compatibility in the same transmission band as that of the current television system. The present invention relates to a possible television signal processing device.

Conventional Technology Japan's current NTSC (National Television System Committee)
mittee)] method for color television broadcasting in Showa 35
More than 25 years have passed since it started in the year. Meanwhile, various new television systems have been proposed in response to the demand for high-definition screens and the improvement in performance of television receivers. In addition, the contents of the programs to be provided themselves are changing from simple studio programs and relay programs to programs with higher image quality and more realistic images, such as cinema-sized movie broadcasts.

Against this background, the Japan Broadcasting Corporation (NHK) has proposed a high-definition television system. (For example, literature special issue on high-definition television (Journal of the Television Society, Vol. 36, Vol.
No. 10, 1982, see)) The content is 1125 scanning lines,
2: 1 interlace scanning, luminance signal horizontal bandwidth of 20MHz, and high definition, while the aspect ratio (ratio of horizontal to vertical of screen) is set to 5: 3 from the viewpoint of visual engineering such as presence. is there.
This system has been almost completed in the closed system, and the MUSE system that transmits high-definition television in the band of one satellite channel with the start of satellite broadcasting (reference, Yuichi Ninomiya et al., Satellite 1-channel transmission system (MUSE) for high-definition television (IEICE Technical Report IE84-72, 1984)),
Experiments are in progress.

On the other hand, the current broadcasting has various specifications such as 525 scanning lines, 2: 1 interlaced scanning, luminance signal horizontal bandwidth 4.2MHz, and aspect ratio 4: 3. (For example, bibliographic broadcasting technology, bibliography, color television, edited by the Japan Broadcasting Corporation, Japan Broadcast Publishing Association, 1961
If you want to serve a movie as the above program, cut the screen size so that the aspect ratio of the current TV receiver is 4: 3, or set an invalid screen at the top and bottom of the screen. The aspect ratio of the effective screen is emitted to the value of the movie.

Problems to be Solved by the Invention As described above, when releasing or servicing a movie program or a realistic screen in the current broadcast, the screen may be partially cut or the screen area may be reduced. There was a problem that the intention of was not fully communicated. Also, simply
If a signal with an aspect ratio larger than 4: 3 is simply transmitted, a normal receiver cannot receive it. When the number of scanning lines and the frame frequency are the same as those of the current broadcasting, in order to obtain the same horizontal resolution, the aspect ratio m: 3 (m is a real number of 4 or more) requires a video band that is m / 4 times the current video band. However, from the viewpoint of effective use of radio resources, it is impossible to extend the transmission band.

Therefore, an apparatus has been invented that transmits an image having an aspect ratio of 4: 3 or more, that is, an image having a wide aspect ratio within the band of the current television broadcasting. This will be explained below. Generally, in order to obtain the same horizontal resolution when the number of scanning lines and the frame frequency are the same, the aspect ratio is 5:
In the 3 system, the bandwidth required for transmission is 1.25 times that of the 4: 3 aspect ratio. Therefore, the increased bandwidth is accumulated in the first and third quadrants on the "time-vertical" two-dimensional frequency, or by a method such as being piled up in the high range of the color signal, while maintaining the horizontal resolution while maintaining the bandwidth of the current television system. It is intended to transmit video with a wide aspect ratio inside. (See Japanese Patent Laid-Open No. 60-213185) However, if an image with an aspect ratio of 5: 3 is transmitted as it is by such a conventional technique, it will be converted into a vertically long image when received by a current television receiver. However, there is a drawback that compatibility with the current television receiver cannot be maintained. In the case of a moving image, the increased bandwidth cannot be multiplexed in the first and third quadrants on the "time-vertical" two-dimensional frequency due to the crosstalk, so that the horizontal resolution is lowered.

The present invention has been made in view of the above points, and an object of the present invention is to provide a television signal processing device that is compatible with the current television system and that reproduces a television signal having a horizontally long aspect ratio. To do.

Means for Solving the Problems In order to solve the above problems, the television signal synthesizing device of the present invention has an aspect ratio of an electrical signal obtained by capturing an original image having an aspect ratio of 4: 3 or more 4: 4. The part corresponding to 3 is time-axis expanding means for expanding the time axis, composite video signal generating means for generating a composite video signal, and a signal obtained from the remaining part of the electric signal is used as a high frequency component and a low frequency component of the frequency. A frequency axis multiplexing means for time-axis expanding and frequency-axis multiplexing the high-frequency component of the frequency, and a time-axis multiplexing means for time-axis compressing the low-frequency component of the frequency and time-axis multiplexing. A frequency axis multiplex signal separating means for receiving the television signal and separating the frequency axis multiplex signal, a time axis multiplex signal separating means for separating the time axis multiplex signal, and the composite video signal A time axis compression means for time axis compression of the obtained luminance signal and chrominance signal is provided.

Effect The present invention generates a television signal that enables multiplex transmission of other information within the band of the current television broadcasting standard by the above-described device, so that a dedicated receiver can display the image of the conventional television broadcasting. Not only can the multiplexed information be obtained. That is, an image having a wide aspect ratio can be obtained, and even a current television receiver can receive it as an image of a conventional television broadcast with almost no trouble.

Embodiment A television signal processing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 3 (a)
Shows an example of a display screen of a current television, and FIG. 3 (b) shows a composite video signal in one scanning line period near the center of the screen. Since the aspect ratio is 4: 3, part of the left and right circles among the three circles may be cut off as in the display example of FIG. FIG. 4 (a) shows a case where the aspect ratio is made larger than the current one, for example,
An example of the display screen in the case of 5: 3 is shown in FIG. 4 (b), which is a video signal in one scanning line period near the center of the screen, and FIG. 4B shows a composite video signal obtained by rewriting the video signal of FIG. 4B so as to be equal to that of FIG. 4B and adding a synchronizing signal and a color burst signal. The aspect ratio is not limited to 5: 3.
If the aspect ratio is increased as shown in FIG. 4 (a), more video information can be obtained as compared with the screen shown in FIG. 3 (a). Here, in the current television receiver, even when receiving the video signal of the aspect ratio 5: 3, it is possible to receive the image without trouble as compared with the conventional one, that is, in order to maintain compatibility, the current television receiver The time-axis expansion is applied to the television signal in the period displayed on the screen. This can be seen by comparing FIG. 3 (b) and FIG. 4 (c), and when the current television receiver receives the signal of FIG. 4 (c), the original image is a circle. Nevertheless, since it becomes a vertically long ellipse, it is necessary to extend the signal of FIG. 4 (c) on the time axis. That is, when the original image is captured with a horizontally long aspect ratio m: 3 (m is a real number of 4 or more), the image capture signal corresponding to the portion displayed on the screen of the current television receiver 4: 3 is m / 4 times time axis extension is sufficient. Further, in order to obtain screen information with an aspect ratio of m: 3, the remaining signal portion is sent by time-axis multiplexing the low frequency portion and frequency-multiplexing the high frequency component. In a CCD camera or the like that does not require a horizontal blanking period as much as the image pickup tube, it is not always necessary to extend the image pickup signal corresponding to the portion displayed on the screen of the current television receiver on the time axis. That is, because the horizontal blanking period becomes shorter, there is a margin in the time axis direction.

FIG. 5 is a spectrum diagram showing a frequency multiplexing processing method of the television signal processing device on the transmitting side according to an embodiment of the present invention. FIG. 5 (a) is a spectrum diagram of a television signal that has been subjected to vestigial sideband amplitude modulation in the current television system. Here, the case where the lower sideband of the image carrier P ₁ is the vestigial sideband is shown. In FIG. 5 (b) another multiplexed signal from the television signal shown in FIG. 5 (a), the picture carrier P ₁ and the same frequency at and phase 90 ° different carrier P _2, the carrier P ₂ The vestigial sideband is amplitude-modulated so as to be removed. If the carrier wave P ₂ is removed only in part or all of the blanking period and the carrier wave P ₂ is not removed in the video signal period, the DC component can be multiplexed and transmitted. The signal of FIG. 5 (b) is shown in FIG. 5 (a).
FIG. 5 (c) shows a television signal synthesized by the present invention, which is multiplexed with the television signal of FIG.

Next, a television signal processing method on the receiving side will be described. In the following, the case of terrestrial broadcasting will be taken as an example. FIG. 6 (a) is a block diagram of a current television receiver performing video synchronous detection. 41 is an antenna, 42 is a tuner, 43 is a video intermediate frequency filter, 44 is a video detector,
Reference numeral 45 is a carrier wave reproducing circuit, and 46 is a video baseband signal output terminal. The signal transmitted from the transmission side is received by the antenna 41, frequency-converted into an intermediate frequency band by the tuner 42,
The band is limited by the video intermediate frequency filter 43. The band-limited signal is supplied to the video detector 44 and the carrier wave reproducing circuit 45. The carrier recovery circuit 45 to recover the carrier I ₁ for synchronous detection. The band-limited signal is detected by the video detector 44 with the carrier I ₁ and becomes a video baseband signal.
Here, the frequency characteristics of the video intermediate frequency filter 43 will be described. The frequency characteristic is shown in FIG. 6 (b). That amplitude is 6dB attenuation at the picture carrier I _1, and has a Nyquist filter characteristic having a substantially odd symmetrical amplitude characteristic with respect to the picture carrier I _1. On the other hand, as shown in FIG. 5 (d), if the multiplexed signal is band-limited by a filter having a characteristic opposite to the frequency characteristic of the video intermediate frequency filter of the receiver, the shaded area in FIG. 6 (b) is obtained. The multiple signal component of is almost a double sideband. When this is displayed as a vector, it becomes as shown in FIG. 6 (c). Where I ₁ is the video carrier of the video baseband signal, I ₂ is the carrier of the multiplexed signal, I ₁
The carrier wave has the same frequency as and a phase difference of 90 degrees. Since the video baseband signal is a vestigial sideband when considering the carrier I ₁ as the center, the upper and lower sidebands become the vector a _u and the vector a _L , and when decomposed into orthogonal vectors, they become the vector a ₁ and the vector a _2. . Also, since the multiplexed signal has almost double sidebands, if the upper and lower sidebands are the vector b _u and the vector b _L , the combined vector thereof is b ₂ , and only the component orthogonal to the vector I ₁ . That is, when the carrier wave I ₁ is synchronously detected, the orthogonal distortion due to the vector a ₂ and the vector b ₂ components does not occur, and the interference by the multiple signal to the current television receiver performing the image synchronous detection does not occur in principle.

FIG. 1 is a block diagram of a television signal processing device on the transmitting side according to an embodiment of the present invention. In FIG. 1, 1 is an input terminal of a luminance signal Y obtained from a signal captured by a camera having a larger aspect ratio than the current aspect ratio, 4 is an input terminal of a wide band color difference signal I obtained from the signal, and 7 is obtained from the signal. Input terminal for narrowband color difference signal Q, 2,
5, 8 are signal distributors, 3, 6, 9, 14 are time axis expansion circuits, 11, 13, 22, 29 are adders, 10 and 12 are balanced modulation circuits,
15 is a signal generation circuit, 16 is an amplitude modulator, 17 is a first filter, 18 is an oscillator, 19 is a phase shifter, 20 is a modulator, 21 is a second filter, 23 is a composite television signal output terminal, and 24 is LPF
(Low-pass filter), 25 is a subtractor, 26 is a time axis compression circuit, 27 is a time axis adjustment circuit, and 28 is a reference signal generation circuit. A signal corresponding to a portion displayed on the screen of a current television receiver is an original signal, and a signal corresponding to other portions, for example, both sides of the screen is a multiplexed signal. A luminance signal Y obtained from a signal imaged by a camera having a larger aspect ratio than the current aspect ratio through a well-known matrix circuit and the like enters a signal distributor 2 and is distributed to a time axis expansion circuit 3 and an adder 13. Similarly, the wideband color difference signal I and the narrowband color difference signal Q
Enter the signal distributors 5 and 8, respectively, and are distributed to the time axis expansion circuits 6 and 9 and the balanced modulation circuit 12. The time axis expansion can be performed, for example, by writing to the memory and changing the read clock. Conventionally, when an original image is captured with a horizontally long aspect ratio m: 3 (m is a real number of 4 or more), the original signal corresponding to the part displayed on the screen of the current television receiver is displayed, for example, in FIG. As shown in, the time axis expansion circuits 3, 6 and 9 perform m / 4 times time axis expansion.
As described above, in a CCD camera or the like that does not require the horizontal blanking period as much as the image pickup tube, the signal corresponding to the portion displayed on the screen of the current television receiver does not necessarily have to be expanded in the time axis. Next, the signal distributors 5 and 8
Of the color difference signals distributed by
The remaining chrominance signal components other than the chrominance signal expanded by are modulated by the balance modulation circuit 12 and added by the adder 13 with the remaining brightness components other than the brightness signal expanded by the time axis expansion circuit 3 in the brightness signal. It This luminance signal has a waveform as shown in FIG. 8 (a) as an example on the time axis, and as a characteristic of a general image signal on the frequency axis, as shown in FIG. 9 (a). Shows the spectrum distribution with low high frequency energy. The output of the adder 13 by the LPF 24 and the subtractor 25 is
High energy low frequency component (waveform of FIG. 8 (b), frequency spectrum of FIG. 9 (b)) and high frequency component of relatively low energy (waveform of FIG. 8 (d), FIG. 9 (d))
Of the frequency spectrum) and are supplied to the time axis compression circuit 26 and the time axis expansion circuit 14, respectively. In the time-axis compression circuit 26, the low-frequency component shown in FIG. 8 (b) is time-axis compressed into a frequency spectrum within a band that can be transmitted by the NTSC system, as shown in FIG. 8 (c).
It is supplied to the time axis adjustment circuit 27. In the time axis adjusting circuit 27, as shown in FIG. 7, the time axis compressed signals are time axis multiplexed during a part of the front porch of the electron beam overscan period and the horizontal retrace line period of the receiver. To adjust the time. Generally, a receiver overscans the electron beam by about 8% of the effective screen. Therefore, for example, if the time is adjusted so that the time-axis-compressed signals are time-axis-multiplexed in a period corresponding to 2% of them and the effective screen of the front porch 2%, the time-axis is reproduced in a general receiver. The multiplexed signal does not interfere. The time axis adjustment may be performed by delaying the signal with a memory or the like. In the time-axis expansion circuit 14, the high-frequency component shown in FIG. 8 (d) is expanded in the time-axis so that the band becomes equal to or less than the band in which the frequency-axis multiplexing can be performed. The signal band-compressed by the time axis expansion circuit 14 is applied to the reference signal generation circuit 28.
Is added to the reference signal from the adder 29 and input to the modulator 20. The reference signal generating circuit 28 generates a reference signal in a part of the vertical blanking period as shown in FIG. 10, for example. The reference signal is a reference reference signal that allows the receiving side to correct, for example, the white signal level, the black signal level, the amplitude and phase of the color signal. The output signals of the time axis expansion circuits 6 and 9 are balanced modulation circuits.
The signal is modulated by 10, and its output is an identification signal for identifying the output signal of the time axis expansion circuit 3 and the synchronization signal from the signal generation circuit 15, the burst signal, the composite television signal and the television signal of the current broadcast. The adder 11 adds the reference signal generated in the same manner as the reference signal generating circuit 28. The identification signal is, for example, superimposed in the vertical blanking period, but the reference signal may be used instead. It is also the low frequency component of the multiplexed signal
The output of the LPF 24 is time-axis compressed below the transmission band by the time-axis compression circuit 26, and its output is input to the time-axis adjustment circuit 27. The time axis adjusting circuit 27 arranges the input signal at a predetermined time position. This can be done, for example, by using a memory or the like. The output of the time-axis adjusting circuit 27 is added to the above-mentioned signal by the adder 11, that is, time-axis multiplexed. The output of the adder 11 is a video baseband signal, and the output of the adder 29 is a multiplexed signal. An amplitude modulator 16 amplitude-modulates a carrier P ₁ obtained from an oscillator 18 with a video baseband signal output from the adder 11. The obtained amplitude-modulated wave is band-limited by the first filter 17 to form the residual sideband, and then added to the adder 22. Oscillator
The carrier P ₁ obtained from 18 is phase-shifted by the phase shifter 19 by 90 ° and is referred to as carrier P ₂ . The carrier wave P ₂ is subjected to double sideband amplitude modulation by the multiplexed signal output from the adder 29. The carrier P ₂ is removed during part or all of the blanking period. In addition,
The phase shift direction of the phase shifter 19 may be fixed, but for example, if the phase shift direction is changed at least every one horizontal scanning period, every one field, every one frame, the interference given to the current television receiver is further increased. Less. Modulator 20
The output of is subjected to band limitation by the second filter 21 and then added to the adder 22. The output of the adder 22 becomes a composite television signal. That is, the multiplexed signal is superimposed on the video baseband signal to form a composite television signal. The second filter 21
The frequency characteristic of is assumed to have a characteristic as shown in FIG. In the above explanation, the original signal corresponding to the part displayed on the screen of the current television receiver was expanded in the time axis and then converted into the composite signal. Good.

FIG. 11 is a block diagram showing an example of the internal configuration of the signal generation circuit 15 of FIG. 101 is a synchronizing signal generation circuit, 102
Is a burst signal generation circuit, 103 is an identification signal generation circuit, and 104
Is a reference signal generation circuit, 105 is an adder, and 106 is an output terminal of the signal generation circuit. The sync signal generation circuit 101 and the burst signal generation circuit 102 are assumed to generate the same signals as in the current broadcasting system, for example. The identification signal generation circuit 103 may generate a signal for identifying whether or not a video with a wide aspect ratio is being transmitted, and may, for example, multiplex a pilot signal or the like in the blanking period. Reference signal generation circuit 104
Is a circuit for generating a reference signal for correcting the signal to the reference value on the receiving side, similar to the reference signal generating circuit 28 in FIG. The output of the signal generating circuit 15 is the sum of the outputs of the above four generating circuits.

Next, a processing method of the television signal processing device on the receiving side in the embodiment of the present invention will be described. The signal in the video intermediate frequency band, which is the output of the tuner, is band-limited by a filter that removes orthogonal distortion as shown in FIG. A vector display of this is as shown in FIG. 12 (b). Since the video baseband signal has almost double-sidebands due to the filter, if the upper and lower sidebands are vector a _u and vector a _L , their combined vector is a ₁ , and only the component orthogonal to vector I ₂ is obtained. Also, since the multiplexed signal is a vestigial sideband when the carrier I ₂ is considered as the center, the upper and lower sidebands become vectors b _u and b _L , and when decomposed into orthogonal vectors, they become vectors b ₁ and b ₂ . That is, when the coherent detection is performed on the carrier I ₂ , orthogonal distortion due to the vector a ₁ and vector b ₁ components does not occur, and only the multiple signal component can be demodulated.

FIG. 2 is a block diagram of a television signal processing device on the receiving side according to an embodiment of the present invention. In FIG. 2, 61 is an antenna, 62 is a tuner, 63 is a video intermediate frequency filter, 64 is a video detector, 65 is a carrier recovery circuit, 66 is a filter, 67 is a phase shifter, 68 is a multiple signal detector, 70, Reference numeral 77 is a YC separation circuit, 72, 73, 74 and 76 are time axis compression circuits corresponding to time axis expansion on the sending side, 71 and 78 are I and Q demodulation circuits, 75 is a signal switching circuit, and 69 is a signal separation circuit. , 79 is a matrix circuit,
80 is an R, G, B signal output terminal, 81 is a reference signal extracting circuit,
Reference numerals 82 and 84 are luminance / chromaticity adjustment circuits, 83 is a time axis expansion circuit corresponding to time axis compression on the sending side, and 85 is a time axis adjustment circuit. The signal sent from the transmitting side is received by the antenna 61, frequency converted to an intermediate frequency band by the tuner 62, and band-limited by the video intermediate frequency filter 63. Although the antenna is illustrated, the transmission path is not limited to the wireless system, and may be a wired system.
The band-limited signal is sent to the video detector 64 and carrier recovery circuit.
Supplied to 65. The carrier recovery circuit 65 reproduces the carrier I ₁ for synchronous detection. The band-limited signal is the carrier I ₁
Then, the video detector 64 performs synchronous detection. Video detector 64
Is used as the video baseband signal. Tuner 62
The output of is band-limited by the filter 66 as shown in FIG. The carrier wave I ₁ obtained from the carrier wave recovery circuit 65 is transferred to the phase shifter 67.
With the carrier wave I ₂ whose phase is shifted by 90 °, the band-limited signal is synchronously detected by the multiple signal detector 68. The phase shift direction of the carrier wave I ₂ is the same as that of the sending side. The detection output becomes a multiplexed signal. The video baseband signal is separated into a Y signal and a C signal by the YC separation circuit 70. The signal separation circuit 69 separates the sync signal, the color burst signal, the identification signal for distinguishing the wide television signal from the television signal of the current broadcast and the reference signal from the video baseband signal. The reference signal is a reference reference signal that allows the receiving side to correct, for example, the white signal level, the black signal level, the amplitude and phase of the color signal. An example is shown in FIG. The correction is performed by the brightness / chromaticity adjustment circuit 84. The Y signal output from the luminance / chromaticity adjustment circuit 84 is time-axis compressed by the time-axis compression circuit 72 to become a Y ₁ signal. Further, the C signal which is the output of the luminance / chromaticity adjusting circuit 84 is separated into the I signal and the Q signal by the I and Q demodulation circuit 71. The I signal is time-axis compressed by the time-axis compression circuit 73 to become an I ₁ signal. The Q signal is time-axis compressed by the time-axis compression circuit 74 and becomes a Q ₁ signal. The multiplexed signal is time-axis compressed by the time-axis compression circuit 76 and its output is input to the YC separation circuit 77. The signal separated into the Y signal and the C signal by the YC separation circuit 77 is input to the luminance / chromaticity adjustment circuit 82. On the other hand, of the multiple signals output from the multiple signal detector 68, the reference signal sampling circuit 81 extracts the reference signal that is previously superimposed on the transmitting side. The reference signal is a reference reference signal that can correct the white signal level, the black signal level, the amplitude, the phase, etc. of the color signal on the receiving side as described above, and matches the video baseband signal and the multiplexed signal. It is for making it. The luminance / chromaticity adjusting circuit 82 corrects the multiple signals. The Y ₃ signal that is the output of the luminance / chromaticity adjustment circuit 82 is input to the time axis adjustment circuit 85. Further, the C signal which is the output of the luminance / chromaticity adjusting circuit 82 is separated into the I ₃ signal and the Q ₃ signal by the I and Q demodulating circuit 78 and is input to the time axis adjusting circuit 85. The time-axis adjusting circuit 85 performs the reverse process of the time-axis adjustment on the transmitting side, and the transmission and reception are integrated so that the regular time relationship is maintained. Of the video baseband signal output from the video detector 64,
As shown in FIG. 7, the signal time-axis compressed on the transmitting side is
The time axis expansion circuit 83 expands the time axis. The time-axis expansion can be performed by changing the write and read clocks to the memory, as in the time-axis compression. The output of the time axis expansion circuit 83 is Y _{3 in the} time axis adjustment circuit 85.
It is added to the signal. The output of the time axis adjustment circuit 85 is the Y ₂ signal.
It is input to the signal switching circuit 75 as an I ₂ signal / Q ₂ signal. Wherein _{Y 1, I 1 Q 1,} Y 2, I 2, Q 2 signal, the signal switching circuit 75, first, an aspect ratio of 4: For the portion corresponding to the third current television receiver screen, Y ₁ , select I ₁ Q ₁ signal. Since these are time-axis compressed, for the remaining period of one horizontal scanning period, a blanking signal or the like is generated and selected inside the signal switching circuit 75 for the current broadcast. When receiving the wide television signal, Y ₂ , I ₂ , and Q ₂ signals are selected. The signal switching control is performed by an identification signal from the signal separation circuit 69 for identifying the wide television signal and the television signal of the current broadcast. Signal switching circuit
The output of 75 becomes R, G, B signals by the matrix circuit 79. The time-axis compression circuits 72, 73, 74, and 76 are provided so that the current television broadcasting can be received without any trouble, and by compressing the time-axis expanded portion of the television signal having a horizontally long aspect ratio, It is for restoring a television signal. That is, as shown in FIG. 3 (b) and FIG. 4 (c), the current television signal can be received without changing the aspect ratio of the current broadcast image. It needs to be compressed. The compression ratio is determined by the aspect ratio. However, it is not always necessary to compress the time axis for a display such as a liquid crystal display that does not require a blanking period as much as a CRT. When receiving a current television signal, a screen with an aspect ratio of 4: 3 is displayed near the center, and the remaining area of the receiver screen with a landscape aspect ratio is darkened by blanking or the like. It suffices to perform processing such as. The identification signal may be superimposed on the vertical blanking period, for example, and may be substituted with the reference signal.

FIG. 13 shows a signal switching circuit 75 according to an embodiment of the present invention.
It is a block diagram of. 51 and 52 are selectors, 53 is a blanking signal generation circuit, and 54 is an identification signal input terminal. If the identification signal determines that the image does not have a wide aspect ratio, the selectors 51 and 52 select the Y ₁ , I ₁ , and Q ₁ signals during the period corresponding to the screen with the aspect ratio of 4: 3, and select the blur signal in other periods. The blanking signal from the ranking signal generating circuit 53 is selected. If it is determined by the identification signal that the image has a wide aspect ratio, the selectors 51 and 52 select Y ₂ ,
The I ₂ and Q ₂ signals should be selected.

A signal expanded on the time axis on the transmission side expands the band by time axis compression on the reception side. Therefore, even if the aspect ratio is increased, the resolution does not decrease. Of the multiplex signals corresponding to the information on both sides that do not fit in the screen with the aspect ratio of 4: 3, the frequency-multiplexed signal is
In the current receiver, since it is almost canceled by the synchronous detection with the image carrier, the interference due to the frequency multiplexed signal hardly occurs. Also, in the receiver for multiple signal demodulation, the video baseband signal can be taken out without quadrature distortion like the current receiver, and the aspect ratio of 4: can be obtained by synchronous detection with the filtered and phase-controlled video carrier. The frequency-multiplexed signal corresponding to the information on both sides that does not fit in the screen of 3 can also be extracted without orthogonal distortion. Further, the time-multiplexed signal can also be reproduced by processing such as time-axis expansion. That is, it is possible to reproduce the original image having an aspect ratio of 4: 3 or more captured by the transmitting side.

EFFECTS OF THE INVENTION As is clear from the above description, by generating a television signal that enables multiplex transmission of other information within the band of the current television broadcasting standard, a dedicated receiver can perform conventional television broadcasting. It is possible to obtain not only the video but also the multiplexed information. That is, it is possible to reproduce an image having a wide aspect ratio. In addition, there is almost no interference when received by the current television receiver, and compatibility with the current television receiver is secured.
That is, since different information can be multiplex-transmitted within the band defined by the standard, it is very effective from the viewpoint of effective use of radio wave resources.

[Brief description of drawings]

FIG. 1 is a block diagram of a television signal processing device on the transmitting side in one embodiment of the present invention, and FIG. 2 is a block diagram of a television signal processing device on the receiving side in one embodiment of the present invention. FIG. 3A is an explanatory view showing an example of a display screen of a current television, FIG. 3B is an explanatory view showing a composite video signal in one scanning line period near the center of the screen, and FIG. FIG. 4A is an explanatory diagram of an example of a display screen when the aspect ratio is set to 5: 3, and FIG. 4B is an explanatory diagram showing a video signal in one scanning line period near the center of the screen. FIG. 6C shows a composite video signal in which the sync signal and the color burst signal are added by rewriting the video signal shown in FIG. 4B so that the time axis scale becomes equal to that of FIG. 3B. FIG. 5 (a) is an explanatory diagram showing the residual sideband amplitude in the current television system. FIG. 5 (b) is a spectrum diagram of a tuned television signal, and FIG. 5 (b) is a spectrum diagram in which a signal different from the signal shown in FIG. 5 (a) in one embodiment of the present invention is modulated and band-limited. FIG. 5 (c) is a spectrum diagram in which the signal shown in FIG. 5 (b) is multiplexed with the signal of FIG. 5 (a),
FIG. 6 (a) is a block diagram of a current television receiver performing video synchronous detection, and FIGS. 6 (b) and 6 (c) are spectra at the time of synchronous detection of the current television receiver. FIG. 7 is a diagram and a vector diagram, FIG. 7 is an explanatory diagram showing time axis compression, time axis expansion and time axis multiplex positions, and FIG. 8 is a signal waveform diagram showing a signal processing process of time axis compression and time axis expansion. 8 is a spectrum diagram of the signal waveform of FIG. 8, FIG. 10 is a waveform diagram showing the reference signal, FIG. 11 is a circuit configuration diagram of an example of the signal generating circuit 15 in FIG. 1, FIG. 12 (a), 12th
FIG. 13B is a spectrum diagram and a vector diagram at the time of demodulating a multiple signal (side signal), and FIG. 13 is a circuit configuration diagram of an example of the signal switching circuit 75 in FIG. 3,6,9,14,83 …… Time axis expansion circuit, 26,72,73,74,76 ……
Time axis compression circuit, 10, 12 …… Balanced modulation circuit, 27, 85 …… Time axis adjustment circuit, 28, 104 …… Reference signal generation circuit, 19, 67…
… Phase shifter, 24 …… LPF, 25 …… Subtractor, 17 …… First filter, 21 …… Second filter, 63 …… Video intermediate frequency filter, 66 …… Filter, 82,84 …… Luminance ・Chromaticity adjustment circuit, 8
1 …… Reference signal sampling circuit, 75 …… Signal switching circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideshi Inoue 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Hideyo Kamihata, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A time axis extending means for extending the time axis of a portion corresponding to an aspect ratio of 4: 3 of an electric signal obtained by capturing an original image having an aspect ratio larger than 4: 3, and a composite video signal. A composite video signal generating means for generating, a means for separating a signal obtained from the remaining part of the electric signal into a high frequency component and a low frequency component of the frequency, and a high frequency component of the high frequency component for time axis expansion and frequency axis multiplexing. Frequency axis multiplexing means and
A television signal synthesizing device comprising a time-axis multiplexing means for time-axis-compressing and time-axis-multiplexing the low-frequency component of the frequency;
Frequency axis multiplex signal separating means for receiving the television signal and separating the frequency axis multiplex signal, time axis multiplex signal separating means for separating the time axis multiplex signal, and luminance obtained from the composite video signal A television signal processing device comprising a television signal decoding device comprising a time axis compression means for time axis compression of signals and color signals. 2. The frequency axis multiplexing means includes a carrier wave generating means,
A first amplitude modulating means for amplitude-modulating the carrier wave output from the carrier wave generating means by the composite video signal, a phase shift means for phase-shifting the carrier wave by 90 °, and a high frequency component for the frequency axis on a time axis. Second amplitude modulation means for amplitude-modulating the output carrier of the phase shift means with the expanded signal in a part of the blanking period for removing the carrier, and the output of the second amplitude modulation means for the residual sideband signal. And an inverse Nyquist filter having a Nyquist characteristic that
The television signal processing device according to the item. 3. The time axis multiplexing means comprises means for multiplexing a signal obtained by time axis compression of the low frequency component of the frequency in a part of a video signal period and a blanking period. The television signal processing device according to item (1). 4. A frequency-axis multiplex signal separating means, a filter for removing quadrature distortion, a means for synchronously detecting a carrier having the same frequency as the image carrier and a phase difference of 90 °, and time-axis compression of the synchronously detected signal. The television signal processing device according to claim 1, further comprising: 5. The television signal processing apparatus according to claim 1, wherein the time axis multiplex signal separating means comprises a time axis expanding means and a time axis adjusting means.