JPS61208981A - High definition television receiver with two picture display function - Google Patents

Abstract

PURPOSE:To change over from an normal picture to still and moving pictures of high picture quality at a TV receiver by combining a field memory and a line buffer line memory and performing reading at a horizontal frequency twice that at the time of writing. CONSTITUTION:The same video signals repeatedly read from a field memory 602 is selectively written in one of line buffer memories 604, 605. The video information is read from the other at the rate of clocks four times of that at the time of writing and the TV picture with double horizontal frequency is compressed horizontally to 1/2. Then, when a picture changeover switch 617 is changed over from the normal picture to two pictures, line memories 608-610 write at the normal speed and read at twice the writing speed and this is repeated alternately for outputting 611 two series signals to supply to a signal multiplexer 613 the averaged 612 high quality signals averaged so that moving and still pictures are outputted 614. The multiplexed color difference signals are outputted after color difference separation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a television receiver that can simultaneously display moving images and still images on one screen.

[Background of the invention]

In recent years, in order to make effective use of the cathode ray tube screen in television receivers, so-called small screen insertion (small screen insertion), in which other television programs are displayed in a reduced size on a part of the original television screen, has been introduced.
PinP) TV has been announced (Unexamined Japanese Patent Publication [54-98
(See Publication No. 116).

The concept of this PinP (Picture in O Picture) will be briefly explained below with reference to FIGS. 6 to 9.

FIG. 6 is a conceptual diagram of a PinP screen, in which 101 is a television receiver, 102 is a cathode ray tube, 103 is a main screen section, 104 is a small screen section into which other program screens have been reduced and inserted; Each small screen can be tuned independently.

Figure #I7 shows an example of a method for inserting a small screen. ■ is the small screen before reduction, and ■ is the parent screen into which the small screen is inserted. If the screen reduction rate is (scanning cycle after reduction)/(scanning cycle of original signal), then if the screen reduction rate of the small screen is 1/3 vertically and horizontally, one out of three scanning lines from the screen of small screen I The image is extracted, the horizontal period is time-compressed to 1/3, synchronized with the parent screen, and then inserted into the parent screen. Scanning lines 1 to 2 show part of the scanning lines before and after reduction.

Figure Wg8 shows the state of small screen insertion on a time axis. ■ is the video signal before the reduction of the small screen, and ■ is the video signal of the main screen into which the small screen has been inserted. As shown in Figure 7, from the video signal I of the small screen, one out of every three scanning lines is extracted and written into an analog or digital field memory mK, and the small screen insertion position of the video signal ■ of the main screen (thick line By reading the signal using a triple clock in the section), it is possible to obtain a 2# screen television signal. At this time, field memory (2) is required for Ae B 2 fields. That is, when reading memory A, the next field is written to memory BK, and when reading memory B, the next field is written to memory A.

@Figure 9 K shows the configuration of a conventional example of P in P television.

In the figure, 401 is an antenna, 402 is a small screen insertion circuit, 403 is a video processing circuit, 404 is a cathode ray tube, and 402 is a small screen insertion circuit.
05 is a main screen tuner, 406 is an IF/video detection circuit, 407 is a synchronization separation circuit, 408 is a small screen tuner,
409 is an IF/video detection circuit, 410 is a synchronous separation circuit,
411 and 412 are field memories A and B, 413 is a write clock generation circuit, and 414 is a read clock generation circuit.

Tuner 408. The small screen video signal obtained by the IP/video detection circuit 409 is written into, for example, the A field memory 411 by a write clock generation circuit 413 whose timing is determined by a synchronization separation circuit 410. During this time, the video signal of the previous field written in the B field memory 412 is inserted into the four-track generation circuit 414 for reading, whose insertion timing is determined according to the synchronization signal separated from the video signal of the main screen by the synchronization separation circuit 407. The small screen insertion circuit 402 inserts the video signal into the main screen video signal. If writing to the field memory for the child screen is stopped at this point, a still image can be obtained.

By the way, the small screen on the conventional PinP TV explained above has a small number of scanning lines, for example 1/3, and a small number of horizontal period samples, for example 100, so the image quality is rough and it is impossible to read fine text. In addition, there was a problem in that there was little practical need to tune in and watch programs from other channels at the same time, or in other words, there was little demand to watch them, so the practical significance of their existence was questionable.

[Purpose of the invention]

The present invention has been made in view of the conventional technical circumstances as described above, and therefore, an object of the present invention is to provide a high-quality image regardless of whether it is a parent screen or a child screen. Above, to provide a high-definition television receiver with a dual-screen display function that allows viewing the screen of the same program as a moving image and a still image on PinP, rather than viewing programs on other channels at the same time. There is K.

[Summary of the invention]

In order to achieve this objective, the present invention makes the sizes of moving images and still images the same, performs scanning line interpolation using a line memory for moving images, and performs still 1i! The iIK is characterized in that it is composed of one field memory, the number of samples in the horizontal period is approximately 300, and scanning is performed using all the scanning lines, and that high-quality images can be obtained by scanning every millimeter.

Another feature of the present invention is that two color difference signals are multiplexed into one signal and processed by utilizing the fact that the frequency band of the color difference signal is narrower than that of the luminance signal.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure is a block diagram showing the functions of the television receiver according to the present invention, in which 501 is a scanning line conversion circuit;
502 is a deflection circuit, and the same parts as in FIG. 9 are given the same reference numerals.

Next, the operation of the embodiment of the present invention will be explained.

antenna 401. The video signal processed by the tuner 405 and the IF/video detection circuit 406 is separated into a synchronization signal by the synchronization separation circuit 407, and further generates a horizontal synchronization signal having twice the repetition frequency.

Based on the double frequency horizontal synchronization signal, vertical synchronization signal, and K, the deflection circuit 502 converts the video signal converted by the 0 scan line conversion circuit 501 that drives the scanning system into the video processing circuit 403.
After various controls (for example, contrast, hue, saturation, 9 image quality, etc.) are applied to the CRT 404,
will be displayed.

Next, a detailed block diagram of the scanning line conversion circuit 501 is shown in FIG. 2A, and its operation will be explained.

In the ta2A diagram, 601 is a luminance signal input terminal, 602
is a field memory, 603 is a switch (S1), 60
4.605 is line buffer memory, 606 is switch (82), 607 is switch (S3), 608.609
, 610 is a line memory, 611 is a switch (S4),
612 is an averager, 613 is a signal multiplexer, 614 is a luminance signal output terminal, 615 is a synchronization signal input terminal, 616 is a control circuit, and 617 is a screen changeover switch (S5).

First, we will explain the luminance signal.O First, the input terminal 60
When a luminance signal is input to field memory 602, field memory 602 stores one field's worth of video.

Since a new screen is written for each field in the stored screen, the current image and the image stored in the field memory are always shifted by one field. When the screen changeover switch 617 is switched to the 21ii side, the control circuit 616
The field memory 602
is controlled, writing is stopped and only reading is possible. In the same state, still image information is output from the field memory 602.

This image information is written into one of the line buffer memos 9604 and 605 selected by the switch (81) 603. One line buffer memory (e.g. 6
04) is in the write state, the other line buffer memory (for example, 605) is in the read state, and the switch (82) is in the read state.
) 606 to output image information. This line buffer & - + bulk → λ2L magazine's 4 coffin's Hiroku's 〃 lock is used to read out the image profit inertia, so if the horizontal frequency is twice that of normal television, the 5 images will be 1/1/2 in the horizontal direction. Compressed into 2.

Next, the operation of the line memory, which is the other signal flow, will be explained.

When a brightness signal is input from the input terminal 601, the switch (
83) 607 switches every horizontal period and connects the signal to any one of the next stage line memories. Line memory! As shown in FIG. 3, writing (W) is performed at normal speed, and reading (R) is performed one after another at twice the writing speed. When the three line memories repeat this alternately at the timing shown in FIG. 3, continuous double-speed video signals can be obtained. The switch (84) 611 switches the video signal output from the line memory as shown in FIG. 3A and H, and outputs two continuous video signals.

Note that the 9th incoming column and the B signal string are always delayed by 1/2 horizontal period with respect to the 9th incoming column and the B signal string.

If this human signal sequence and B signal sequence are averaged by an averager 612, a new scanning line obtained by averaging the upper and lower scanning lines is interpolated between the upper and lower scanning lines as shown in FIG. 3C, resulting in a high quality image. A good signal can be obtained. Furthermore, if the averager 612 extracts only either the A signal train or the B signal train, a high-quality signal in which the scanning line is repeated twice can be obtained.

Here, the screen changeover switch (Ss>617
When switching to the two-screen side, the three line memories 608, 609,
610 halves the amount of video information when writing, and reads at twice the speed of writing.

The situation will be explained with reference to FIG. 4. A rectangle in the same figure represents one line memory, and one section in the rectangle represents a square in which one sample is placed. FIG. 4(a) shows the operation of a normal line memory, in which video information is sequentially written starting from 1. (
b) shows the state of the line memory in the case of two screens, in which video information is sent sequentially starting from 1, but the amount of information is halved by writing every other piece of video information during writing.

By reading out from the KH at twice the speed as usual, video information compressed to 1/2 in the horizontal direction can be obtained as an output. By performing an operation to project a moving image on the left side of the screen and a still image on the right side in the middle of the screen, a still image of the desired image as shown in the same figure can be viewed at the same time as the moving image. If you switch the screen changeover switch <85) 617 to the normal screen,
The screen is lli! You can watch normal videos on page 1.

Next, the color difference signal will be explained.0 Fig. 2B is a block diagram showing the processing of the color difference signal by the scanning line conversion circuit 501 in Fig. 623 is a color difference signal separator, and 624 and 625 are color difference signal output terminals. In addition, the same parts as those in FIG. 2A are given the same reference numerals, and the operation is the same as in the case of the luminance signal, so the explanation is omitted. ◎ The color difference signals (几-Y, B-Y) are connected to the color difference signal input terminal 620.
．． 621 respectively as shown in @2cIgJa and 4, the color difference signal multiplexer 622 outputs #! As shown in Fig. 2C, two color difference numbers 4m1 are multiplexed dot-sequentially.

Here, the information content of the chrominance signal is half that of the luminance signal, but since the frequency band of the chrominance signal is narrower than that of the luminance signal, there is no visual problem. Similarly processed color difference signal separator 62
The O color difference signal separator 623 inputted to 3 performs the opposite operation to the color difference signal multiplexer 622, that is, it outputs color difference signals by alternately taking out the color difference signals multiplexed point-sequentially into two output systems. Separated color difference signals (Y, B-Y) are obtained at terminals 624 and 625.

Also, when displaying a still image as a black and white screen, the second
Field memory 602 in Figure B) Switch (81) 60
3. Line buffer 604.605, switch (82)
This can be achieved by simply removing 606.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a high-quality image with twice the number of scanning lines using line memory and a simple fee, and for two screens, a high-quality image with twice the number of scanning lines can be obtained for a moving image. Yes, still images have twice the number of scanning lines, allowing you to view the desired image still. Furthermore, since the field memory only requires a small capacity, it has the effect of realizing a two-screen television receiver more economically.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2A is a block diagram showing a specific example of a scanning line conversion circuit for luminance signals, and FIG. 2B is a specific example of a scanning line conversion circuit for color difference signals. FIG. 2C is a schematic diagram illustrating the color difference signal multiplexing method, FIG. 3 is a timing diagram illustrating the operation of the line memory, and FIG. 4 is a schematic diagram illustrating the operation of the line memory in the 21i11 screen. , FIG. 5 is a conceptual diagram of the two-screen television screen according to the present invention, and FIG.
FIGS. 7 and 8 are explanatory diagrams for explaining the small screen insertion method, respectively, and FIG. 9 is a block diagram showing a conventional small screen insertion television. Code explanation 401...Antenna, 403...Video processing circuit, 404...Cathode ray tube, 405...
...Tuner, 406...IF-video detection circuit, 407...Synchronization separation circuit, 501...
...Scanning line conversion circuit, 502...Deflection circuit,
601... Brightness signal input terminal, 602...
...Field memory, 603...Switch (
S1), 604.605...line buffer,
606... Switch (S2), 607...
...Switch (S3), 608°609.610...
... Line memory, 611 ... Switch (S
4), 612... Averager, 613...
Signal multiplexer, 614... Luminance signal output terminal, 6
15... Synchronization signal input terminal, 616...
・Control circuit, 617... Screen changeover switch (8
5), 620, 621... color difference signal input terminal,
622...Color difference signal multiplexer, 623...
・Color difference signal separator, 624, 625... Color difference signal output terminal agent Patent attorney Akio Namiki Figure 3 H [1 (b) 7 J 5 7 9 1113151
719---IIIS Figure 11176! ! I Small Five Sides I 11j, ll. Figure 8

Claims (1)

[Scope of Claims] 1) A plurality of line memories capable of storing video signals for one line in the horizontal direction are provided, and line interpolation signals are generated by controlling writing and reading of input video signals to and from these line memories. a television signal converting means for converting a television signal according to a 2:1 interlace scanning system as the input video signal into a television signal according to a 1:1 non-interlace scanning system and outputting the television signal (
A television receiver that has a TV signal conversion means (hereinafter abbreviated as TV signal conversion means) and that enables high-quality display screens includes a field memory that can store one field of video signals and multiple line buffer memories. By controlling the writing and reading of the same video signal repeatedly read out from the field memory to and from the line buffer memory, the still image is displayed on a dimensionally reduced screen when displayed on the screen. Still image signal creation means for creating and outputting a signal; Screen switching means; When the screen switching means is switched from the normal screen side to the dual screen side, the TV signal conversion means outputs the signal. converts the TV signal displayed on the screen into a TV signal that is displayed on a dimensionally reduced screen, and displays the same screen as two screens of a moving image and a still image together with the still image signal output from the still image signal generating means. A high-definition television receiver with a two-screen display function. 2) In the television receiver according to claim 1, the two color difference signals obtained by YC separation of the input television signal are multiplexed point-sequentially and then transmitted to the television receiver. A television receiver characterized in that signal processing is performed in the signal conversion means and the still image signal creation means.