JPH0670264A - Television receiver - Google Patents

Abstract

PURPOSE:To reduce the operating time of a part or the whole of a digital circuit constructing a TV signal processing circuit and to reduce the power consumption together with improvement of reliability for a TV receiver which contains the TV signal processing circuit constituted with the digital circuit. CONSTITUTION:A horizontal synchronizing signal is not inputted to a counter 25 as a reset signal for a prescribed period, that is, no TV signal is not inputted for a prescribed period. Under such conditions, the counter 25 continuously output the overflow signals until the horizontal synchronizing signal is supplied, in other words, until the input of the TV signal is restarted. Thus a relay 27 is kept off. In such a constitution, the supply of the power voltage VCC is cut to TV signal processing circuit 6 and this circuit is turned off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver having a television signal processing circuit composed of a digital circuit.

[0002]

2. Description of the Related Art Since its birth, television receivers have evolved as vacuum tubes, transistors, and ICs as their main components, and have progressed toward higher brightness and higher resolution in cathode ray tubes, and have developed into highly reliable home appliances. From a digital technology perspective, this can be divided into four generations, so-called 0th generation to 3rd generation.

Most of the 0th generation television receivers except the digital circuit for sampling the space-time in the process of scanning and the digital circuit for separating and reproducing the synchronizing signal. Was composed of analog circuits.

In first-generation television receivers, digitalization of control systems such as channel selection control has progressed, wireless remote controllers have become widespread, and most circuits of the television signal control system have been replaced by digital circuits. .

In the second-generation television receiver, by utilizing the characteristics of digital technology, functions which cannot be realized by analog technology, for example, functions such as two-screen display, still image display, multi-screen display and time-lapse display are achieved. Was done.

[0006] The third-generation television receiver attempts to maximize the image quality of the current television by making full use of a large-capacity frame memory and field memory, and most circuits of the television signal processing system. Has been replaced by a digital circuit, and the development of this third generation television receiver is currently in progress.

[0007]

In the case where the television signal processing circuit is composed of a digital circuit, it has a multi-function.
Although it is possible to achieve high image quality, in order to achieve high functionality and high image quality, the number of gates in a digital circuit increases and high-speed signal processing is required.

Therefore, since the power consumption becomes too large, it is necessary to reduce the power consumption by some method in order to eliminate the waste of the power consumption and to suppress the heat generation as much as possible.

[0009] In general, when heat is generated in a circuit, it is consumed, its life is shortened, and reliability is lowered. Therefore, it is necessary to suppress heat generation by reducing power consumption in order to improve the reliability of the digital circuit included in the television signal processing circuit.

In view of the above points, the present invention reduces the operating time of all or part of the digital circuit which constitutes the television signal processing circuit, reduces power consumption, and reliability of the digital circuit which constitutes the television signal processing circuit. It is an object of the present invention to provide a television receiver capable of improving the performance.

[0011]

FIG. 1 is a diagram for explaining the principle of the present invention. A television receiver according to the present invention detects the presence / absence of a television signal input, and if there is no television signal input, the television It is configured to include a television signal presence / absence detection circuit 2 that puts all or part of the digital circuit 1 forming the signal processing circuit into an operation stop state, so-called off state.

Reference numeral 3 is a monitor for displaying an image, and 4 is a circuit other than a television signal processing circuit, for example, a control circuit or a circuit for making the screen of the monitor 3 a "blue screen" when there is no television signal input. Is.

[0013]

In the present invention, when there is no television signal input, for example, when the power of the tuner is not turned on, or when the tuner is set to a channel without broadcasting, a digital circuit which constitutes a television signal processing circuit. All or part of 1 is controlled to be in an off state by the television signal presence / absence detection circuit 2.

Therefore, according to the present invention, the operating time of all or a part of the digital circuit 1 constituting the television signal processing circuit is reduced, the power consumption is reduced, and the digital circuit 1 constituting the television signal processing circuit is reduced. It is possible to improve reliability.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described below with reference to FIGS.
The present invention is applied to the IDTV (impr.
oved definition television).

First Embodiment FIG. 2 FIG. 1 is a block diagram showing an essential part of the first embodiment of the present invention, in which 5 is a television signal input terminal to which a television signal (NTSC signal) is input. , 6 is a television signal processing circuit, 7 is a circuit other than the television signal processing circuit, and 8 is a monitor.

The circuit 7 other than the television signal processing circuit
Is directly connected to the monitor 8 and has the main function of relaying the RGB signal output from the television signal processing circuit 6 and outputting the RGB signal to the monitor 8; Generate a signal and monitor it
If there is no additional function of outputting to
It has an additional function of displaying an uncomfortable screen such as a “black screen” or a “blue screen” on the monitor 8 under the control of an overflow signal described later.

Reference numeral 9 is a television signal presence / absence detection circuit for detecting the presence / absence of input of a television signal, and 10 is a power supply voltage cutoff circuit for cutting off the supply of the power supply voltage to the television signal processing circuit 6.

Here, in the television signal processing circuit 6,
Reference numeral 11 is an A / D converter to which a sampling clock (4f _SC ) synchronized in phase with the color burst signal (f _SC ) is supplied, 12 is a motion adaptive YC separation circuit, and 13 is a frame memory.

Further, 14 is a motion detection circuit, 15 and 16 are field memories, 17 and 18 are color demodulation circuits, 19 and 2
Reference numeral 0 is a matrix circuit, 21 is a motion adaptive scanning line interpolation circuit, 22 is a double speed circuit, and 23 is a D / A converter.

Further, in the television signal presence / absence detection circuit 9, 24 is a horizontal synchronization separation circuit for separating the horizontal synchronization signal from the television signal, and 25 is a self-propelled counter which uses the horizontal synchronization signal as a reset signal.

Unless the horizontal synchronizing signal is input as the reset signal, the counter 25 is self-propelled and repeats counting up, and when the count value becomes a predetermined value or more, that is, the television signal is input for a predetermined period. If the horizontal sync signal is not input as the reset signal for a predetermined period, counting up is prohibited, and thereafter, the overflow signal is continuously output until the horizontal sync signal is input and reset. ing.

Further, in the power cutoff circuit 10, 26 is a VCC power supply line for supplying a power supply voltage VCC to the television signal processing circuit 6, 27 is a relay (relay), which is in an ON state when an overflow signal is not output, It is turned off while the overflow signal is output.

In the present embodiment having such a configuration, if the horizontal synchronizing signal is not input to the counter 25 for a predetermined period, that is, if the television signal is not input for a predetermined period, the counter 25 causes the horizontal synchronization thereafter. Until the signal is supplied, that is, until the television signal is input again, the overflow signal is continuously output, the relay 27 is turned off, and the television signal processing circuit 6
The supply of the power supply voltage VCC to the circuit is cut off, and the television signal processing circuit 6 is controlled to the off state.

As described above, when the television signal processing circuit 6 is turned off, the circuits 7 other than the television signal processing circuit receive the control of the overflow signal and the monitor 8 displays a "black screen", a "blue screen", or the like. Operates to display a comfortable screen.

After that, when the input of the television signal is restarted, the horizontal synchronizing signal is separated by the horizontal synchronizing separating circuit 24, which is supplied to the counter 25 as a reset signal, the counter 25 is reset, and the overflow signal is not output. Therefore, the relay 27 is turned on, the supply of the power supply voltage VCC to the television signal processing circuit 6 is restarted, and the television signal processing circuit 6 restarts its operation.

As described above, according to the first embodiment,
When no TV signal is input, the TV signal processing circuit 6 is turned off. Therefore, the operating time of the TV signal processing circuit 6 is reduced to reduce power consumption and reliability of the TV signal processing circuit 6. Can be improved.

In the first embodiment, the horizontal synchronizing signal is separated and used as the reset signal for the counter 25. Instead, however, the vertical synchronizing signal is separated and used as the reset signal for the counter 25. You can do it,
In the case of the MUSE transmission system, the frame pulse can be separated and used as a reset signal for the counter 25.

Second Embodiment FIG. 3 FIG. 3 is a block diagram showing an essential part of the second embodiment of the present invention. In this second embodiment, instead of the power cutoff circuit 10 shown in FIG. , A gate circuit 28 is provided,
Others are the same as those in the first embodiment.

Here, in the gate circuit 28, the system clock to be supplied to the television signal processing circuit 6 is input to one input terminal, and the overflow signal output from the counter 25 is input to the other input terminal of the system clock. When there is no television signal input as the passage prohibition signal, the supply of the system clock to the television signal processing circuit 6 is cut off to control the television signal processing circuit 6 in the off state.

Also in the second embodiment, as in the first embodiment, when the television signal is not input, the television signal processing circuit 6 is turned off, so that the operating time of the television signal processing circuit 6 is increased. Can be reduced to reduce power consumption and improve the reliability of the television signal processing circuit 6.

In the second embodiment, the television signal processing circuit 6 is composed of a circuit, such as a CMOS circuit, which consumes almost no power unless a current flows in a steady state and a switching operation is not performed. This is especially effective in the case.

Third Embodiment ... FIG. 4 and FIG. 5 FIG. 4 is a block diagram showing the essential parts of a third embodiment of the present invention. The parts corresponding to those in FIG. 2 are designated by the same reference numerals. .
Therefore, duplicate description will be omitted.

In the television receiver of the third embodiment, when the television signal is not input, one of the television signal processing circuits 6 is
It is intended to cut off the supply of the power supply voltage VCC to the television signal processing circuit 29 except for the A / D converter 11.

In the figure, 30 is a phase locked loop circuit (hereinafter referred to as PLL circuit) for generating a sampling clock to be supplied to the A / D converter 11, 31 is a circuit configuration with the television signal presence / absence detection circuit 9 shown in FIG. Of different TV signal presence detection circuits.

In the PLL circuit 30, reference numeral 32 is a horizontal sync separation / timing signal generation circuit for separating the horizontal sync signal from the television signal and generating a timing signal in timing with the color burst signal.

Further, 33 reads the digital information sampled in the color burst period on the basis of the timing signal output from the horizontal sync separation / timing signal generation circuit 32 to detect the phase error between the color burst signal and the sampling clock. It is a phase error detection circuit for detecting.

Further, 34 is a low-pass filter (LF) for averaging the detected phase errors in order to avoid erroneous detection of the phase error, and 35 is a sampling of a frequency controlled by the voltage output from the low-pass filter 34. A voltage controlled oscillator (VCO) that outputs a clock.

FIG. 5 is a waveform diagram showing a color burst signal. The color burst signal is a sine wave with a fixed frequency and is transmitted during the color burst period in the television signal. However, when the sampling clock and the color burst signal are in phase, the sampling timing is at time A. Therefore, the phase error value output from the phase error detection circuit 33 becomes “0”.

However, when the sampling timing is too early, for example, when the time point X is the sampling timing, the phase error value output from the phase error detection circuit 33 becomes negative.

On the other hand, when the sampling timing is late, such as when the time point Y is the sampling timing, the phase error value output from the phase error detection circuit 33 becomes positive.

Here, when the phase error value is negative,
The output of the voltage controlled oscillator 35, that is, the frequency of the sampling clock is controlled to be high, and when the phase error value is positive, the frequency of the sampling clock is controlled to be low, and finally the sampling Is A
At this time, the PLL circuit 30 is locked.

Therefore, in the third embodiment, the television signal presence / absence detection circuit 31 detects the presence / absence of the television signal input by averaging the phase error values output from the phase error detection circuit 33 several times. However, when it is determined that the TV signal is not input, the operation prohibition signal is output.

That is, this television signal presence / absence detection circuit 31
When the input of the television signal is stopped, the PLL circuit 30 is unlocked and is in the unlocked state, and the phase error value output from the phase error detection circuit 33 becomes a value other than “0”. The phase error value output from the error detection circuit 33 is averaged several times, and when it exceeds a predetermined value, it is determined that the television signal is not input. The reason why the phase error values are averaged several times is to avoid erroneous detection due to noise.

Therefore, in the third embodiment, when the operation prohibition signal is output from the television signal presence / absence detection circuit 31, the relay 27 is turned off and the television signal processing of the portion excluding the A / D converter 11 is performed. The supply of the power supply voltage VCC to the circuit 29 is cut off, and the A / D converter 1
The television signal processing circuit 29 except for 1 is turned on.

On the other hand, the television signal presence / absence detection circuit 3
When the operation prohibition signal is not output from 1, the relay 27 maintains the ON state, supplies the power supply voltage VCC to the TV signal processing circuit 29 in the part excluding the A / D converter 11, and excludes the A / D converter 11. A part of the television signal processing circuit 29 is turned on.

In the third embodiment, when there is no television signal, the circuits 7 other than the television signal processing circuit are
Instead of the overflow signal in the case of the first embodiment, under the control of the operation prohibition signal, an operation of displaying a screen such as a "black screen" or a "blue screen" without a feeling of strangeness on the monitor 8 is performed. ing.

In the third embodiment thus constructed, when the average value of the phase error values output from the phase error detection circuit 33 becomes equal to or more than a predetermined value, that is, the input of the television signal. When the signal disappears, the television signal presence / absence detection circuit 3
1, the operation prohibition signal is output, the relay 27 is turned off, the supply of the power supply voltage VCC to the television signal processing circuit 29 of the portion excluding the A / D converter 11 is cut off, and the portion of the portion excluding the A / D converter 11 is shut off. The television signal processing circuit 29 is turned off.

In this way, when the television signal processing circuit 29 of the portion excluding the A / D converter 11 is turned off, the circuits 7 other than the television signal processing circuit are controlled by the operation prohibition signal and the monitor 8 displays "black". It operates so as to display a screen that does not look uncomfortable, such as "screen" or "blue screen".

After that, when the input of the television signal is restarted, the phase error value of the phase error detection circuit 33 becomes "0" and the operation prohibition signal is not output from the television signal presence / absence detection circuit 31, so the relay 27 is turned on. State, A
TV signal processing circuit 2 of the portion excluding the / D converter 11
The supply of the power supply voltage VCC to 9 is restarted, and the television signal processing circuit 29 of the part excluding the A / D converter 11 restarts its operation.

As described above, according to the third embodiment,
If there is no TV signal input, A / D converter 1
Since the television signal processing circuit 29 of the portion other than 1 is turned off, the operating time of the television signal processing circuit 29 of the portion other than the A / D converter 11 is reduced to reduce the power consumption and the television signal processing circuit. 6 can be improved in reliability.

Fourth Embodiment FIG. 6 FIG. 6 is a block diagram showing an essential part of a fourth embodiment of the present invention. In this fourth embodiment, instead of the power cutoff circuit 10 shown in FIG. , A gate circuit 28 is provided,
Others are the same as those in the third embodiment.

Here, in the gate circuit 28, the system clock to be supplied to the television signal processing circuit 29 of the portion excluding the A / D converter 11 is input to one input terminal,
When the operation prohibition signal output from the television signal presence / absence detection circuit 31 is input to the other input terminal as the passage prohibition signal of the system clock and there is no television signal, the television signal processing circuit 29 of the portion excluding the A / D converter 11 By cutting off the system clock supply to
TV signal processing circuit 2 of the portion excluding the / D converter 11
9 is controlled to an off state.

Also in the fourth embodiment, as in the third embodiment, when no television signal is input, the television signal processing circuit 29 except the A / D converter 11 is turned off. , The operation time of the television signal processing circuit 29 other than the A / D converter 11 can be reduced to reduce the power consumption and improve the reliability of the television signal processing circuit 6.

[0055]

As described above, according to the present invention, when no television signal is input, all or part of the digital circuits forming the television signal processing circuit is turned off.
The operating time of all or part of a digital circuit included in the television signal processing circuit can be reduced, power consumption can be reduced, and reliability of the digital circuit included in the television signal processing circuit can be improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a block diagram showing a first embodiment of the present invention.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a block diagram showing a third embodiment of the present invention.

FIG. 5 is a waveform diagram showing a color burst signal.

FIG. 6 is a block diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

 1 Digital circuit that composes TV signal processing circuit 2 TV signal presence / absence detection circuit 3 Monitor 4 Circuit other than TV signal processing circuit

Claims (5)

[Claims] 1. A television signal for detecting the presence or absence of a television signal input, and controlling the whole or a part of a digital circuit (1) constituting a television signal processing circuit to an off state when the television signal is not input. A television receiver comprising a presence detection circuit (2). 2. The television signal presence / absence detection circuit (2) is configured to detect the presence / absence of an input of a television signal by detecting a synchronization signal included in the television signal. The television receiver according to claim 1. 3. The television signal presence / absence detection circuit (2) detects a lock / unlock state of a phase locked loop circuit for generating a sampling clock for sampling a television signal, thereby detecting the input of the television signal. The television receiver according to claim 1, wherein the television receiver is configured to detect the presence or absence. 4. The television signal presence / absence detection circuit (2) controls all or part of a digital circuit (1) constituting the television signal processing circuit to an off state by cutting off the supply of power supply voltage. The television receiver according to claim 1, 2 or 3, characterized in that. 5. The television signal presence / absence detection circuit (2) controls all or part of a digital circuit (1) constituting the television signal processing circuit to an off state by cutting off supply of a system clock. The television receiver according to claim 1, 2 or 3, characterized in that.