JPS627278A - Television signal responding equipment - Google Patents

Abstract

PURPOSE:To permit responses after automatically judging times of receiving TV signals through a standard system and through a high definition TV broadcasting by utilizing synchronous/asynchronous state signals which are taken out of phase lock loop circuits. CONSTITUTION:Video signal V1 which are input through an input part 11 are fed to a high definition video signal processing part 12 as well as the phase lock loop PLL circuits 120 which are included in the above part 12 and also are fed to a standard system video signal processing part 16. The PLL circuits 120 reproduces a system lock as well as horizontal and vertical synchronous signals at an inside of a receiver and outputs the synchronous/asynchronous state signal S1. The signal S1 together with a video signal V11 from the processing part 12 is input in a signal changeover part 13. And scanning lines of the signal fed to the processing part 16 are converted and a video signal V21 is input in the signal changeover part 13. Responding to the signal S1, the changeover part 13 selects either one of the signals V11 and V21. Thus, two TV signals in standard and high definition systems are decided automatically, the response can be done accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a television signal response device used in a digital television receiver or the like.

[Technical background of the invention and its problems] As a television broadcasting system, the number of scanning lines in one frame is greater than the current 525 (NTSC) or 625 (PAL), and the frequency bandwidth is approximately 4.2 MHz f. Various devices have been developed that exceed this frequency, and even exceed 20 MHz. In Japan, a system has been developed in which the number of scanning lines in one frame is 1125, which is about twice the current 525. Below is an example of a high-quality video signal with 112 scanning lines.
The five signals are referred to as high-quality video signals, and the video signal based on the current system is referred to as a standard video signal.

Transmitting high-definition video signals as broadcast signals requires a baseband transmission band of more than 20 MEIz.
As a transmission method for broadcasting such broadband signals in high quality and on a nationwide scale, a method of transmitting FM signals by relaying them by satellite is considered to be a promising method. However, the frequency allocation for Japanese broadcasting satellites is that one channel band is 27M.
Hz, band compression is essential for transmitting a wideband signal such as a high-definition television signal over a single channel. In this way, NHK (
Muse (Muse) was developed by Japan Broadcasting Corporation and published in a paper.
There is a USE ) method. [Ninomiya, Inuzuka, et al., “High Definition Television Satellite Single Channel Transmission System (MUSE)”, Technical Report of the Television Society, November 1984. High definition television broadcasting using the MULE system as described above was carried out via a broadcasting satellite. Just as in the early days of color television broadcasting, when black-and-white television broadcasts and color television broadcasts were broadcast on the same channel in a time-sharing manner, standard format broadcasting and MUSE format broadcasting will now be performed on a time-sharing basis. It is assumed that

1 for standard broadcasting and MUSE broadcasting as described above.
At present, a television receiver that can be used on a stand-alone basis has not been realized.

If we consider a television receiver that can receive both standard broadcasting and MUSE broadcasting and display images,
Naturally, all switches are required to switch between reception mode and signal processing mode.

In other words, a switch is required to select between standard broadcast reception and MUSE universal broadcast reception.

When such a reception state changeover switch is provided, if it is configured to be operated manually, operation of the switch is cumbersome. This is because, as mentioned above, the standard method and the MUSE method are performed on one channel in a time-sharing manner, so it is necessary to judge at what point the method has been switched while looking at the screen. Also, when there is a temporary broadcast interruption, users may mistakenly believe that the system has been switched even though the system has not been switched. Furthermore, due to the user's erroneous judgment, it may be mistakenly recognized that the television receiver has malfunctioned.

[Purpose of the invention]

This invention was made to deal with the above-mentioned circumstances, and provides a television signal that automatically determines whether a standard television signal is being received or a high-definition television broadcasting television signal and responds accordingly. The purpose is to realize a response device with a relatively simple configuration.

[Summary of the invention]

The present invention achieves all of the above objects by extracting the synchronous/asynchronous state signal S1 from the phase long loop circuit 120 and utilizing it, as shown in FIG. 1, for example.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which an input section 11 is supplied with a video signal v1 received by a tuner and subjected to detection processing. This video signal v is processed by the high-quality video signal processing unit 12 and a phase-locked loop (hereinafter referred to as P) included therein.
(referred to as LL) circuit 120. Further, the video signal v1 is also supplied to the standard video signal processing section 16.

The PLL circuit 120 operates as a system clock (
Its main functions are reproducing the horizontal synchronizing signal (H8) and vertical synchronizing signal (VS).

A PLL circuit is also used inside current standard television receivers in order to perform 1-1 synchronization separation. However, the PLL circuit inside a standard television receiver does not operate accurately if the S/N ratio of the input signal deteriorates. To give a numerical example, at an S/N of 20 dB, malfunctions of the PLL circuit inside a standard television receiver become noticeable.

On the other hand, in the MUSE system, a synchronization format called positive desotal synchronization is adopted, and as shown in FIG. 5, a strictly defined frame pulse and horizontal synchronization waveform (HD) are used as synchronization signals.

FIG. 5 shows the HD waveform (enlarged) of the frame pulses inserted in the 605th and 606th lines.

The PLL circuit of a MUSE television receiver that employs such a synchronization system can achieve extremely accurate phase locking and is resistant to noise. Therefore, the input signal S
A stable phase-locked state can be obtained even when the C is 20 dB.

In the high-quality video signal processing section 12, video signal processing (for example, data interpolation, etc.) transmitted by the MUSE method is performed, and the output video number is supplied to the signal switching section 13.

On the other hand, the standard video signal processing section 16 performs processing similar to the video signal processing of current broadcasting, and its output is supplied to the scanning line converter 17. The reason why this is necessary is that while the standard video signal has 525 scanning lines and an aspect ratio of 4:3, the high-definition video signal has 1125 scanning lines. Display 1
This is because the aspect ratio of 4:4 is 5:3, so even if the output of the standard video signal processing section 16 is directly input to a high-definition display, a normal image cannot be obtained. Therefore, the scanning line converter 17 converts 525 scanning lines into 1125 scanning lines by interpolation processing, and also converts the aspect ratio from 4:3 to 5:3. Transducers of this type are - for example, "Izumi, Kokubu et al."
This is disclosed in "Standard Adapter for SE System Reception", "Television Society Technical Report, September 1984".

Here, the signal switching unit 13 as a response means selects either the video signal Vll from the high-quality video signal processing unit 12 or the video signal V21 from the scanning line converter 17,
The selection is made in response to the synchronous/asynchronous status signal S1 of circuit 12. The synchronous/asynchronous state signal S1 becomes, for example, a high level "H#" in a synchronous state, and becomes a low level "L" in an asynchronous state. A means is provided which constitutes a phase-locked circuit and detects a synchronous/asynchronous state signal based on the phase relationship between a synchronous signal generated by itself and an input synchronous signal.Furthermore, the synchronous/asynchronous state signal S is It is also supplied to an indicator 15 as a response means.The indicator 15 receives the synchronous/asynchronous status signal S1.
When is at high level "H" (during MUSE system broadcasting), the power supply terminal 151, the light emitting element 152, and the inverter 153
A current flows and the light turns on. In addition, when the synchronous/asynchronous state signal S1 is at a low level "L", this indicator 1
5 is in an off state. Therefore, the signal switching section 13
When the display 15 is on, the video signal Vll is selected and supplied to the high quality display 14, and the display 1
5 is off, the video signal V21 is selected and supplied to the high quality display 14.

Therefore, according to the television receiver of the present invention described above,
It is possible to automatically determine whether standard format broadcasting or high definition television broadcasting is being performed, display which format it is on display 15, and automatically select the video signal to be supplied to display 14. Become.

FIG. 2 shows another embodiment of the invention. This example is
This is a case where the standard display 20 is used as the display. The difference from the previous embodiment shown in FIG. 1 is as follows.
Number of scanning lines of the output video signal of the high-quality video signal processing unit 12 @
Convert from 1125 lines to 525 lines and aspect ratio 5:3
A scanning line converter 21 for converting from 4:3 to 4:3 is provided between the high-quality video signal processing section 12 and the signal switching section 13, and the output video signal of the standard video signal processing section 16 is directly connected to the signal switching section. 13.

In the above embodiment, the synchronous/asynchronous state signal S obtained by the PLL circuit 120 is used as the control signal for the signal switching unit 130, but in order to obtain more reliable and stable operation, the following configuration is used. It may be.

The embodiment shown in FIGS. 1 and 2 is used directly as a control signal for the synchronous/asynchronous state signal Slf signal switching section 13 of the PLL circuit 120. Normally, when the signal input to the receiver is good, the PLL circuit 120 operates stably and always outputs a level "H#" indicating a synchronized state. However, when the input signal is very poor, Then, PLL circuit 12
There is a risk that a zero lock state may be established or broken. In other words, the synchronous state and the asynchronous state are irregularly repeated, and as a result, the selection state of the signal switching section 13 is frequently switched. However, in this case, C/N
Even if it is bad, the PLL circuit 120 requires a certain lock state (when receiving a high-definition television signal including a digital synchronization signal, for example, a MUSE system signal), and the signal switching unit 13 also requires a certain lock state. The high-quality video signal processing section 12 should be selected. If the signal switching section 13 makes an incorrect selection due to poor quality, the displayed image will fail.

Therefore, when the signal switching unit 13 is in poor condition, it is necessary to take measures to stabilize the selection state of the signal switching unit 13.

FIG. 3 shows an embodiment that solves the above-mentioned problems. That is,
The same parts as those in the embodiment shown in FIG. 1 will be described with the same reference numerals.
In the case of this embodiment, the synchronous/asynchronous state signal 81f from the PLL circuit 120 is once supplied to the judgment circuit 30, and the judgment circuit 30 generates the switching open side signal S2 which is not easily affected even if the situation is bad. I have to.

FIG. 4 shows an example of the determination circuit 30.

A synchronous/asynchronous state signal S1 from the PLL circuit 120 is supplied to the input terminal 31. This terminal 31 is connected to an up/down switching terminal of an up/down counter 32. Furthermore, fixed initial data, for example rABcD=0001J, is given to the initial data set terminals (A, B, C, D) of this up/down counter 32. Also, when a load pulse is applied to the load terminal of this up/down counter 32, the initial data rABcD
=0001J is the output terminal r OA , OB , QC
.

Hail to ODJ.

Now, as mentioned above, in the up/down counter 32 that has started, assume that the terminal 31 is at a high level, that is, a signal indicating a synchronized state is input.
2 counts up to clock (CK) 1. Then, when rOA~0D==1111J, the all "1" detector 33 detects this, and the detection 1? The signal is supplied to the J input terminal of the flip-flop circuit 35.

Therefore, the Q output of the flip-flop circuit 35 becomes high level "H", and the signal at the output terminal 36 indicates that the MUSE system is being received.

Conversely, when the up/down counter 32 starts,
When the terminal 31 is at a low level, that is, when a signal indicating an asynchronous state is input, the initial data rA-D=0001
A countdown operation of J is obtained. And the output r
When OA to ODJ become all MO'', the all-0 detector 34 also obtains a detection pulse, which is supplied to the input terminal of the flip-flop circuit 35. Therefore, the Q output of the flip-flop circuit 35 is at a low level. The signal at the output terminal 36 becomes "L", indicating that the standard format is being received.

The OR circuits 3B and 39 and the inverter 40 operate as follows. That is, when the detection pulse DP2 is obtained or when the detection pulse DP2 is obtained, the up/down counter 32 is returned to the initial state and the initial data is preset. However, at this time, even though the up/down counter 32 is preset, the current state of the flip-flop circuit 35 does not change. Further, as signals for setting the amplifier down counter 32 to the initial state, there are an initial signal when the system power supply supplied from the terminal 41 is turned on, and a channel switching pulse obtained when the channel channel supplied from the terminal 42 is switched. .

Therefore, according to this determination circuit 3o, even if the synchronous/asynchronous state signal S1 applied to the terminal 31 is frequently switched due to the aforementioned bad reason, the clock (CK
), the period in which the initial data rA-DJ finishes counting becomes a dead zone period. As a result, the selection operation of the signal switching section 13 becomes stable and reliable even in the case of bad conditions.

In the above embodiments, the present invention has been described as a multiple television receiver capable of supporting high-definition television broadcasting and standard format broadcasting. However, it is needless to say that the invention is not limited to this, and can also be applied to compatible video tape recorders and video disc systems. In other words, by employing the present invention in the signal recording system and reproduction system, it is possible to obtain video processing that has a wide range of use and is highly reliable.

Furthermore, the present invention is effective in obtaining savings in the power supplied to the system, and also provides accurate switching information.

In other words, if the PLL circuit 120 and its signal supply stage are operating, it is possible to determine whether the receiving state is the MUSE method or the standard method. Therefore, when using a combination of television receivers, video tape recorders, video disk systems, etc., the output of the above-mentioned synchronous/asynchronous status signal or judgment circuit may be used with an unused circuit Glock or device. It can be used as power on/off information for circuit blocks or equipment. Furthermore, a video tape recorder exclusively for the Δ'ILTSE system,
When obtaining continuous recording of the MUSE system signal and the standard system signal using a video tape dedicated to the standard system, it is possible to use the determination signal according to the present invention as information for automatically obtaining equipment selection and power on/off. can.

There is a broadcasting system that is intermediate between standard broadcasting and high-definition television broadcasting in terms of resolution, and in which synchronization signals contain digital data all around, and luminance signals and color signals are time-division multiplexed. For example, MAC (Multipl)
Exed Analog Components) method is available. Since digital data is used as a synchronization signal in the MAC method, stable synchronization can be obtained and the gist of the present invention can be achieved.

That is, it can be easily inferred that the present invention can be implemented in a case where standard format broadcasting and MAC format broadcasting coexist.

In the present invention, synchronous and asynchronous state signals are created from a high-quality video signal that is stable and has nine synchronous signals, but conversely, even from a standard format video signal, the performance of the standard format phase-locked loop circuit is improved compared to the current one. It can be easily inferred that by strengthening it, it is possible to create synchronous and asynchronous state signals and implement the present invention with performance similar to the present invention.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a detection signal that can identify television signals of different formats with a relatively simple configuration.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of this invention, FIGS. 2 and 3 are circuit diagrams showing other embodiments of this invention, and FIG. 4 is a specific example of the determination circuit shown in FIG. 3. The circuit diagram shown in FIG. 5 is an explanatory diagram of synchronization pulses of a high-definition television signal. 12... High quality video signal processing section, 13... Signal switching section, 14... Display, 15... Display device, 1
6... Standard video signal processing unit, 17... Scanning line converter, 120... Phase locked loop circuit. Original agent Patent attorney Takehiko Suzue Line No. n
+I HD Figure 5

Claims (7)

[Claims] (1) a standard video signal processing section that processes a standard television signal to obtain a standard video signal; a high definition video signal processing section that processes a high definition television signal to obtain a high definition video signal; In the high-definition video signal processing section, a phase-locked loop circuit that reproduces a horizontal synchronization signal, a vertical synchronization signal, and a system clock in synchronization with the synchronization signal of the high-definition television signal, and synchronization of the phase-locked loop circuit. a detection means for detecting a state and an asynchronous state, and a response form is switched between when the phase-locked loop circuit is in a synchronous state and when the phase-locked loop circuit is in an asynchronous state in response to an output of the detection means. 1. A television signal response device comprising: response means. (2) The television according to claim 1, wherein the response means is a display device to which the output of the detection means is supplied and whose light emitting state is switched between the synchronous state and the asynchronous state. Signal response device. (3) The response means is configured such that the output of the detection means is supplied to a control terminal, and in the synchronous state, the output of the high-quality video signal processing section is introduced into the display, and in the asynchronous state, the output of the standard video signal is supplied to the control terminal. 2. The television signal response device according to claim 1, further comprising means for introducing the output of the processing section to the display. (4) The display is a high-definition display, and the means for introducing the output of the standard video signal processing unit to the display includes a first scanning line converter, and the means for introducing the output of the standard video signal processing unit to the display is 4. The television signal response device according to claim 3, wherein the television signal response device is installed in a television signal response device. (5) The display is a standard format display, and the means for introducing the output of the high-definition video signal processing unit to the display includes a second scanning line converter, and the means for introducing the output of the high-definition video signal processing unit to the display includes a second scanning line converter, and 4. The television signal response device according to claim 3, wherein the television signal response device is installed in a television signal response device. (6) The response means replaces a period in which the output of the detection means indicates the synchronous state and a period in which the output indicates the asynchronous state with count data, and selects the one with the larger count data within a certain cycle as the state determination result. A television signal response device according to claim 1, characterized in that it comprises circuit means obtained as follows. (7) The response means is means for turning off the power of the standard video signal processing section when the output of the detection means indicates the synchronized state. television signal response equipment.