JP2002271713A - Television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a television receiver that makes on-screen display stable for indication on which a character signal is superimposed even in the absence of a video signal. SOLUTION: The television receiver is provided with a changeover circuit 26 that selects any of a plurality of received video signals, a digital storage device 21 that reproduces a recording medium storing digital signals and outputs an analog video signal, and a signal detection circuit 25 that uses a tuner 1 of the television receiver to detect a video signal absence state. The television receiver uses the changeover 26 to select the analog video signal when detecting the video signal absence state and generates a screen display signal synchronously with a synchronizing signal of the analog video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device (hereinafter referred to as a DVD drive or a hard disk drive) capable of recording and reproducing digital signals in a television receiver.
The present invention relates to a television receiver (hereinafter, referred to as a TV receiver) having a built-in digital storage device. In particular, in an on-screen display in which characters are superimposed on an input video signal and displayed, no video signal state or electric field strength is present. It is characterized by on-screen character display at the time of inputting a video signal having jitter such as a tuner signal and a video reproduction signal in a low state.

[0002]

2. Description of the Related Art Conventionally, some TV receivers have an on-screen display function of superimposing a character signal on a received video and displaying the video signal. As an example of this type of video processing apparatus, there is a registered utility model publication. No. 3,055,796 is known.

FIG. 5 shows a block diagram of this video processing apparatus. In FIG. 5, reference numeral 12 denotes a TV signal processing circuit. The video signal output from the tuner 1 is switched by a switching circuit 2 and supplied to a horizontal synchronization separation circuit 4 and a vertical synchronization separation circuit 5 through a synchronization separation circuit 3.

The horizontal synchronization signal separated by the horizontal synchronization separation circuit 4 is input to a horizontal oscillation AFC circuit 6 to generate a predetermined AFC control signal. The horizontal synchronization signal and the horizontal oscillation output circuit 7 are output by the AFC control signal. A horizontal oscillation signal is synchronized with the horizontal oscillation signal, and the horizontal oscillation signal is used as a trigger, and the horizontal drive circuit 10
(Hereinafter referred to as FBT) and drive the CRT 20
Is performed in the horizontal direction. The vertical synchronization signal separated by the vertical synchronization separation circuit 5 is input to the vertical oscillation output circuit 8 and oscillates a vertical oscillation signal synchronized with the vertical synchronization signal. The circuit 9 scans the cathode ray tube 20 in the vertical direction.

[0005] The horizontal synchronizing signal obtained from the FBT 11 and the vertical synchronizing signal from the vertical oscillation output circuit 8 are input to an on-screen character generating circuit 19 of a microprocessor 18 so that an on-screen character synchronized with an input video signal is obtained. A signal can be created and displayed, and the horizontal position of the character to be displayed is determined by the horizontal synchronization signal.

The video signal switched by the switching circuit 2 is converted into a component signal Y by a chroma processing circuit 13, a demodulation circuit 14, and a Y (luminance) processing circuit 15.
Signal, a color difference signal of a BY signal / RY signal,
After being converted into R, G, and B signals by the matrix circuit 16, the signals are switched to on-screen character signals by the output switching circuit 17, and displayed on the surface of the cathode ray tube 20, which is a display medium.

Here, when a channel is selected by the tuner 1 and there is no video signal or a weak electric field, the sync separation circuit 3
Incorrect AFC because noise and jitter are input to the
A control signal is generated. Therefore, the synchronization of the horizontal oscillation signal output from the horizontal oscillation output circuit 7 with the input video signal becomes unstable, the display of the on-screen character becomes unstable, and the character screen is disturbed. For this reason, when performing full-screen on-screen display, grounding the input side of the switching circuit 2 eliminates noise and jitter input to the synchronization separation circuit 3 and the horizontal oscillation output circuit 7 and the vertical oscillation output circuit 8 A self-propelled horizontal oscillation signal and a vertical oscillation signal are obtained from these signals. By displaying based on these signals, it is possible to display a character without jitter.

[0008]

However, the conventional circuit configuration has the following problems. Sync separation circuit 3, A
The FC circuit and the oscillation circuit are generally built in the TV signal processing circuit 12 (comprising an integrated circuit IC), but depending on the type of the TV signal processing circuit 12,
The self-running horizontal frequency and vertical frequency are set to a predetermined frequency (NTS
In the case of a C television signal, the vertical frequency (59.9)
4 Hz) = horizontal frequency (15.734 KHz) / 26
2.5) In some cases, the characters of the displayed characters may become smaller due to the horizontal scanning, or may not move stably without interlacing and may not be stable because they may not be interlaced or may not be properly interlaced. is there.

[0009]

In order to solve the above-mentioned problems, a TV receiver according to the present invention comprises: a switching circuit for selecting a plurality of input video signals; A digital storage device that outputs a video signal; a signal detection unit that detects a video signal non-signal state; and when the signal detection unit detects a video signal non-signal state, the analog video signal is switched and selected by the switching circuit. And an on-screen display signal generating means for generating a screen display signal synchronized with the synchronizing signal of the analog video signal.

According to the present invention, in a TV receiver having an on-screen display function of superimposing and displaying a character signal, a TV receiver capable of performing stable on-screen display even when no input video signal is present is provided. Is what you do.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A TV receiver according to the present invention comprises: a switching circuit for selecting a plurality of input video signals; a digital storage device for reproducing a digitally recorded recording medium and outputting an analog video signal; A signal detecting means for detecting a video signal no-signal state in a tuner of a television receiver, and when the signal detecting means detects a video signal no-signal state, the analog video signal is switched and selected by the switching circuit, An on-screen display signal generating means for generating a full-screen display signal synchronized with the synchronizing signal of the analog video signal is provided.

In the above-described embodiment, in the absence of a video signal, a full-screen on-screen display signal synchronized with a synchronization signal of an analog video signal from a digital storage device is created. The screen display signal can be displayed on the TV receiver. Further, since a character signal is generated in synchronization with the analog video signal, a stable on-screen character signal free from noise and jitter can be displayed.

In addition, even when the tuner of the TV receiver is automatically selected, the FM radio broadcast is received, and the main screen video signal at the time of PINP display is a video signal no signal state, the analog video signal from the digital storage device is not transmitted. Creates a full-screen on-screen display signal synchronized with the sync signal,
A stable on-screen display signal without noise and jitter can be displayed on the TV receiver. Further, since the character signal is generated in synchronization with the analog video signal, a stable on-screen character signal free from noise and jitter can be displayed.

An embodiment of a TV receiver according to the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) A first embodiment of the present invention will be described with reference to FIGS. Note that portions having the same configuration and operation as those of the conventional technique are denoted by the same reference numerals as those in FIG. 5 and detailed description thereof will be omitted.

FIG. 1 shows a block diagram of a TV receiver incorporating a digital storage device of the present invention.

FIG. 1 differs from FIG. 5 in that a digital storage device 21 built in the TV receiver is added, and a signal detection circuit 25 is built in the tuner 1 as means for detecting a video signal no-signal state. Another difference is that the number of video signals input to the switching circuit 26 for selecting a plurality of video signals, such as video signals from the digital storage device 21 and VHS playback video signals, has increased. The digital storage device 21 is a DVD drive device, an HDD drive device, or the like, and is usually an MPE that demodulates compressed moving image data.
Although the G decoder 22 is built-in, when the TV receiver detects a video signal non-signal state, an analog video signal having a predetermined horizontal synchronization signal and a vertical synchronization signal is output to the input video signal switching circuit 26. I do. The tuner 1 is for analog / digital terrestrial TV broadcasting, BS / CS
Satellite signals, FM radio broadcasts and the like are received, and a switching signal from the VTR of the VHS reproduction video signal is also input to the switching circuit 26 as an external video signal.

The tuner 1 transmits a signal received by an antenna (not shown) through an RF circuit 23 to an IF (intermediate frequency).
VI for converting to a signal and processing the video intermediate frequency signal
The tuner video signal obtained by performing the video detection processing by the F circuit 24 is output to the switching circuit 26. The switching circuit 26 has a signal detection circuit 25 therein. Output.

The switching circuit 26 converts the tuner video signal, a LINE video signal input from an external video device, and a digital device video signal demodulated by the MPEG decoder 22 in the digital storage device 21 and encoded into an analog video signal. Switching is selected and supplied to the TV signal processing circuit 12. The selected video signal is converted into a Y signal, a BY signal, and an RY signal through a chroma processing circuit 13 and a demodulation circuit 14, and processed by a matrix circuit 16 together with the Y signal passed through a Y processing circuit 15. Then, it is supplied to the cathode of the cathode ray tube 20 via the output switching circuit 17 as R, G, B signals of the video signal, and the video is displayed.

On the other hand, the input video signal selected and switched is supplied to the sync separation circuit 3 and the horizontal sync separation circuit 4
To output a horizontal signal synchronized with the horizontal synchronization signal of the input video signal through a horizontal oscillation AFC circuit 6 and a horizontal oscillation output circuit 7.
The FBT 11 is driven to perform horizontal scanning and generate an anode voltage of the cathode ray tube 20. The vertical oscillation signal output from the vertical oscillation output circuit 8 is operated by the vertical drive circuit 9 to operate the cathode ray tube 20 vertically.

Here, the case in which the signal detection circuit 25 in the tuner 1 detects the absence of a video signal means that the channel selected by the tuner 1 (hereinafter referred to as CH).
Is a TVCH without broadcasting, or a case where an FM radio broadcast is received, a case where all channels are automatically selected, and the like, and a detection result of a video signal no signal state is sent to the microprocessor 18. When supplied, the MPEG decoder 22 generates a predetermined black screen signal according to a command from the microprocessor 18, and switches the switching circuit 26 to a video signal from the digital storage device 21.
After that, the output switching circuit 1 demodulates the on-screen character signal and the black screen signal generated by the on-screen character generation circuit 19 into R / G / B signals.
At 7, switching is made to the R / G / B signal of the video signal up to now. The synchronization separation circuit 3 includes a digital storage device 21
Since a video signal from a digital device is input to the apparatus, a normal horizontal synchronizing signal and a vertical synchronizing signal can be obtained by the horizontal synchronizing / separating circuit 4 and the vertical synchronizing / separating circuit 5. An on-screen character with characters superimposed on the screen display can be displayed.

Of course, in order to display a digital device video signal on a screen of any color other than a black screen, the phase of the burst signal of the digital device video signal from the digital storage device 21 and the video signal level are changed. This is possible.

FIG. 2 shows an on-screen display when a non-broadcasting channel is received. FIG. 2A shows a conventional TV receiver in which a character signal is superimposed on a video signal in a noise state, and FIG. Is a circuit in which the switching circuit 26 according to the present invention selects a digital device video signal, switches to a black screen signal, and superimposes and displays a character signal.

As described above, when the video signal is absent, the FM radio is received, the tuner is automatically selected, the VHS reproduction signal having a jitter in the synchronizing signal is selected, and the switching circuit 26 controls the digital device video. By selectively switching the signals, stable characters without jitter or noise and without interlace errors can be displayed on-screen.

In the present embodiment, it goes without saying that the video signal non-signal state includes a weak electric field state in which a normal synchronization signal cannot be obtained.

(Embodiment 2) Next, claim 4 of the present invention
3 and 4 according to the second embodiment of the invention described in FIG.
This will be described with reference to FIG.

FIG. 3 shows a block configuration of a main part of a TV receiver in the case of a picture-in-picture (hereinafter referred to as PINP), that is, a parent-child screen display, and the portions having the same configuration and operation as the first embodiment are as follows. The same reference numerals as those in FIG. 1 denote the same parts, and a detailed description thereof will be omitted.

The difference from FIG. 1 is that a plurality of tuners are provided, and switching circuits 27 and 28 are provided for selectively switching video signals for a main screen and a sub-screen. Further, a PINP signal processing circuit 29 is provided. It is an added point.

In FIG. 3, the tuners 1 and 100 are for simultaneously receiving different TVCHs. The tuner video signals obtained by the tuners 1 and 100 and the digital storage output from the MPEG decoder 22 of the digital storage device 21 are output. The device video signal, the external LINE video signal, and the VHS playback video signal from the VTR are all input to the main screen video signal switching circuit 27 and the small screen video signal switching circuit 28, and are selectively switched by the microprocessor 18 to PINP. The signal is supplied to the signal processing circuit 29.

The PINP signal processing circuit 29 converts the parent screen video signal and the child screen video signal selected by the switching circuits 27 and 28 into a parent screen video signal Y / C separation circuit 30 and a child screen video signal Y / C Separation circuit 31 separates luminance signal Y and chrominance signal C. The Y / C separated small-screen video signal is
The data is converted into digital data by an A / D signal processing circuit 32, and is converted into a BY signal and a RY signal, which are digital color difference signals, by a video signal demodulation circuit (demod shown) 33. The digital data of the Y, BY, and RY signals are rearranged by an illustrated) 34 and written into the field memory 35. The digital data written in the field memory 35 is called by a clock of a predetermined frequency synchronized with the synchronization signal and the subcarrier signal of the main screen, and the signals of Y, BY and RY are passed through a demultiplexer (shown as DEMPX) 36. Rearrange it. The BY and RY signal data of the color signal are
An NTSC encoder (shown as ENCODE) 37 modulates with a subcarrier of the main picture, and a chroma signal D / A circuit (shown as D / A) 40 creates a small picture chroma signal. On the other hand, the luminance signal Y is delayed by a luminance signal delay circuit (illustrated as DL) 38 in order to take timing with the chroma signal C, and the luminance signal D / A circuit (D /
A (illustrated as A) 39 creates a small-screen luminance signal.

The created child screen luminance signal and child screen chroma signal are sent to a parent / child luminance signal switching circuit (shown as YSW) 4
1 and parent-child chroma signal switching circuit (illustrated as CSW) 4
2, the TV signal processing circuit 12 shown in FIG.
Supplied to That is, the output from the YSW 41 is T
Y processing circuit 15 of V signal processing circuit 12 and synchronization separation circuit 3
Is input to each of them and predetermined signal processing is performed.
The output from W42 is input to the chroma processing circuit 13 of the TV signal processing circuit 12, where the signal is processed.

If the tuner 1 selects a video signal no-signal channel as the main screen signal, the video signal detection circuit 25 detects that there is no signal.
The detection signal is transmitted to the microprocessor 18.

Based on this information, the microprocessor 18 commands the MPEG decoder 22 of the digital storage device 21, and the digital storage device 21
By generating a black screen video signal having a subcarrier, a horizontal synchronization signal, and a vertical synchronization signal compliant with the SC and switching and controlling the switching circuit 27 of the main screen video signal to the digital storage side, the PINP signal processing circuit 2
9 outputs a parent screen video signal having a stable horizontal synchronizing signal and a vertical synchronizing signal, and is supplied to the synchronizing separation circuit 3 in the TV signal processing circuit 12, so that a child screen having no abnormality can be displayed. .

When a signal reproduced by the digital storage device 21 is displayed on the child screen and a video non-signal CH is selected on the main screen, the main screen video signal switching circuit 27 is controlled to control the child screen. While the same signal as the screen is processed as the main screen signal, the microprocessor 18 controls the on-screen character generation circuit 19 so that the on-screen R, G, and B signals are black during periods other than the child screen. The output switching circuit 17 of FIG.
By switching, the parent screen is a black screen and a stable child screen is obtained.

FIG. 4 shows an example of a display screen when a signal with a broadcast is received on the main screen and an example of a display screen when a signal without a broadcast is received. FIG. 4C shows a main screen in a conventional TV receiver. A display screen with and without a video signal, and (d) shows a display screen with and without a main screen video signal in the TV receiver of the present invention. When the signal CH is selected, the FM radio broadcast is received, and the VHS reproduction including the noise from the VTR is reproduced, the child screen of the parent-child display is normally displayed on the video display medium.

[0036]

As described above, according to the TV receiver having the digital storage device of the present invention, when a non-broadcasting channel is received, when an FM radio broadcast is received, VHS reproduction from a VTR has a large amount of jitter. Even when a reproduced video signal is input, it is possible to perform on-screen display in which stable characters are superimposed.

Further, it becomes possible to provide a system which can normally display a child screen even when the parent screen is in a state of no video signal by the PINP operation.

Although the present invention has been described with respect to a system using a cathode ray tube as a display element medium, the present invention can be similarly realized by using various video display media such as a liquid crystal display, a plasma display, and an EL display. Of course.

[Brief description of the drawings]

FIG. 1 is a block diagram of a TV receiver according to Embodiment 1 of the present invention.

FIG. 2A shows a display screen of a TV receiver in a conventional configuration. FIG. 2B shows a display screen of the TV receiver in the configuration of the first embodiment of the present invention.

FIG. 3 is a block diagram of a TV receiver according to Embodiment 2 of the present invention.

FIG. 4 (c) PIN of TV receiver in conventional configuration
Diagram showing P screen display (d) Diagram showing PINP screen display of TV receiver in the configuration of Embodiment 2 of the present invention

FIG. 5 is a block diagram of a TV receiver having a conventional configuration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 100 Tuner 2, 26, 27, 28 Switching circuit 3 Synchronization separation circuit 4 Horizontal synchronization separation circuit 5 Vertical synchronization separation circuit 12 TV signal processing circuit 13 Chroma signal processing circuit 14 Demodulation processing circuit 15 Luminance signal processing circuit 16 Matrix circuit 17 Output switching circuit 18 Microprocessor 19 On-screen character generation circuit 21 Digital storage device 22 MPEG decoder 25, 250 Signal detection circuit 29 PINP signal processing circuit 41 Parent-child luminance signal switching circuit 42 Parent-child chroma signal switching circuit

Claims (5)

[Claims] 1. A switching circuit for selecting a plurality of input video signals, a digital storage device for reproducing a digitally recorded recording medium and outputting an analog video signal, and detecting a video signal non-signal state by a tuner. A signal detecting means for detecting the video signal non-signal state by the signal detecting means, selecting and switching the analog video signal by the switching circuit, and creating a screen display signal synchronized with a synchronizing signal of the analog video signal. A television receiver provided with an on-screen display signal creating means. A switching circuit for selecting a plurality of input video signals; a digital storage device for reproducing a digitally recorded recording medium to output an analog video signal; A television receiver, comprising: an on-screen display signal generation unit that selects a video signal by the switching circuit and generates a screen display signal synchronized with a synchronization signal of the analog video signal. 3. A switching circuit for selecting a plurality of input video signals, a digital storage device for reproducing a digitally recorded recording medium and outputting an analog video signal, and a tuner for receiving an FM radio broadcast. A television receiver comprising an on-screen display signal creating means for switching and selecting an analog video signal by the switching circuit and creating a screen display signal synchronized with a synchronization signal of the analog video signal. 4. A switching circuit for selecting a plurality of input video signals, a digital storage device for reproducing a digitally recorded recording medium and outputting an analog video signal, and a television receiver having a picture-in-picture function When detecting the signal absence state of the video signal for the main screen, the analog video signal is switched and selected by the switching circuit, and an on-screen that generates a main screen display signal synchronized with the synchronization signal of the analog video signal. A television receiver provided with a display signal creation unit. 5. The television receiver according to claim 1, wherein a character signal is generated by an on-screen character generator in synchronization with a synchronization signal of the analog log video signal.