JPH0646350A - Display device - Google Patents

Abstract

PURPOSE:To obtain a device which is capable of enlarging and displaying the caption within a slave screen by moving it to the inside of a master screen when a PIP display (or a POP display) is performed. CONSTITUTION:By a slave screen caption moving circuit 36, captions are extracted from the video signal for slave screen, the sizes of the captions and the display location within a master screen are determined, processings are performed for the captions and the processed captions are supplied to a switch 38. The switch 38 inserts the captions in the video signal for master screen in accordance with the control signal from the slave screen caption moving circuit 36.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a PIP display (or P
The present invention relates to a display device capable of moving a subtitle in a child screen in the case of (OP display) to the main screen and enlarging it.

[0002]

2. Description of the Related Art In recent years, the amount of media and the amount of information are increasing very rapidly. However, when various kinds of information are obtained at a time and the information necessary for one's own is selected, the information on the display is displayed at a time. It is convenient to be able to display various information. In addition, there is an increasing demand for viewing one piece of software while viewing another piece of software and other information. Due to such a demand, the number of display devices equipped with a picture-in-picture (PIP) circuit capable of simultaneously displaying another image (child screen) in a part of the image currently viewed (in the main screen) is increasing. . Further, an increasing number of display devices are equipped with a picture-out-picture (POP) circuit that can simultaneously display another image (child screen) on a part outside the display range of the currently viewed image (parent screen).

Here, when PIP display is performed, the screen size of the child screen is 1/3 or 1/4 of the parent screen.
It is generally compressed to a certain degree. At this time, the subtitles in the child screen are naturally compressed and displayed. Therefore, if the subtitle is a subtitle that spreads over the entire sub screen, the subtitle can be read, but in the case of a subtitle that is displayed on a part of the screen, such as a movie subtitle. It will be very difficult to read this subtitle.

This state is shown in FIG. The same figure (a) is an original image, the same figure (b) is the example which carried out PIP display on the screen of aspect ratio 4: 3, and the same figure (c) is 16: aspect ratio.
This is an example of performing POP display in 9. 4 (a) to (c)
As you can see, you can easily read the subtitles on the main screen, but the subtitles on the subscreen are very difficult to read,
Or it is difficult to read.

Next, an example of the PIP circuit will be briefly described. FIG. 5 is a block configuration diagram thereof. Input terminal 1
The incoming sub-screen video signal is separated into a luminance signal Y and a color signal C by the Y / C separation circuit 7 in FIG. The separated luminance signal is passed through the vertical filter 8 and the LPF 10 to obtain A
The digital signal is converted by the / D converter 13.
On the other hand, the color signals are color difference signals RY and BY in the color demodulation circuit 9.
And are converted into digital signals in A / D converters 14 and 15 via LPFs 11 and 12, respectively. The three A / D-converted digital signals are passed through memories 16, 17, and 18, respectively, to a PIP decoder 19
To PIP after being compressed to 1/3 or 1/4
Converted to a signal. These three PIP signals are converted into analog signals by D / A converters 20, 21 and 22.
It is supplied to the switching circuit 26 via the LPFs 23, 24, 25. A switching signal is supplied from the PIP decoder 19 to the switching circuit 26 at the timing of the PIP signal, and the switching circuit 26 outputs the PIP signal in response to the switching signal. 27, 28, and 29 are output terminals of the switching circuit 26.

A horizontal sync signal (H.SYNC) input terminal 2 and a vertical sync signal (V.SYNC) input terminal 3 are connected to the PIP decoder 19. 4 is a parent screen luminance signal input terminal, 5 is a parent screen RY signal input terminal, and 6 is a parent screen B
-Y signal input terminal, which supplies a signal for the parent screen to the switching circuit 26. The LPFs 10 to 12 are provided to remove the interference of folding back,
The PFs 23 to 25 are provided for removing the clock from the output signal.

In this way, the PIP signal output from the PIP decoder is inserted by the switching circuit 26 into the signal for the parent screen coming from the input terminals 4 to 6, and the output terminal 2
It is output from 7 to 29. With the above configuration, the PIP circuit can insert the child screen into the parent screen, and the viewer can see two different video sources (for example, programs of two different channels).
Can be seen at the same time.

Even in the case of POP, there is no difference in the circuit from the PIP circuit, and only the display position of the small screen is different. Further, considering a case where a plurality of small screens are provided instead of one screen, when all the small screens are moving images, it is sufficient to have as many PIP circuits as the number of screens. Further, when used for channel search, the memory in the PIP circuit is used to store and output an image for a certain short time by the number of channels.

In the above-mentioned conventional PIP circuit, in order to make the subtitles in the small screen easy to read, the frequency characteristic of the signal of the small screen is widened and the high quality of the small screen is dealt with. On the contrary, due to the increase in the number, the aliasing noise is increased and the image quality is deteriorated. Therefore,
There is a limit to how easy it is to read subtitles by improving the image quality by widening the band, and as described above, the subtitles on the sub-screen are often very difficult to read or difficult to read.

[0010]

The problem to be solved by the present invention resides in what kind of means should be taken to make the subtitles in the sub-screen easy to read.

[0011]

In order to solve the above problems, the present invention provides a child screen display function of displaying an image-compressed child screen inside or outside a parent screen which is a normal display screen. A display device having the sub-screen subtitle moving circuit for enlarging and displaying the subtitles in the sub-screen in the main screen is provided.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention realizes an easy-to-read subtitle by enlarging and displaying the subtitle in the child screen on the main screen side. Enlarging here means displaying the subtitles by enlarging it compared to the case of displaying it in the sub screen, and you can see it from the size of the subtitle when the image displayed on the sub screen is displayed on the main screen. For example, the subtitles are reduced. (For example, if the size of the subtitle displayed in the sub-screen is 1, the size of the sub-screen in the sub-screen enlarged and displayed on the main screen side is 2 (enlarged when viewed from 1). The size (original size) of the subtitle when the original image is displayed on the main screen is 3.
(If viewed from 3, 2 is reduced)

FIG. 1 shows an essential part of one embodiment of the present invention. Three
Reference numeral 1 denotes a parent screen video signal input terminal, which inserts a child screen into a video signal coming from this terminal 31 or inserts a child screen subtitle signal. 33 is a horizontal synchronization signal (H.SYNC)
Input terminals 34 are vertical synchronization signal (V.SYNC) input terminals, which are connected to the PIP circuit 35, respectively. 32 is a sub-screen video signal input terminal, and the video signal coming from the terminal 32 is the PIP circuit 35 (or P
It is converted into a small screen signal by the OP circuit) and output.
A sub-screen subtitle moving circuit 36 has a function of enlarging and displaying subtitles in the sub-screen on the main screen side (this function will be described later). The subtitle signal of the enlarged subscreen is switched from the subscreen subtitle moving circuit 36 to the switch 3
8 is output. The display position and display size are controlled based on H.SYNC and V.SYNC coming from the terminals 33 and 34.

The switch 37 switches according to the control signal supplied from the PIP circuit 35, and inserts the compressed child screen signal output from the PIP circuit 35 into the parent screen.
The switch 38 switches according to the control signal supplied from the sub-screen subtitle moving circuit 36, and inserts the subtitle signal of the sub-screen to be enlarged and displayed into the main screen. The signal output from the switch 38 is supplied from an output terminal 39 to a video display unit (not shown) and displayed.

FIG. 3 shows an example in which the above-mentioned circuit enlarges and moves the subtitles in the child screen. The figure (a) is an example which carried out PIP display on the screen of aspect ratio 4: 3, and the figure (b) is the example which carried out POP display on the screen of aspect ratio 16: 9. The subtitles of the subscreen are also displayed in the subscreen. As can be seen from the figure, the subtitles in the sub-screen are enlarged and displayed in the main screen, which makes the subtitles easy to read.

Next, the operation of the small screen subtitle moving circuit 36 will be described. First, there is a moving method for moving the subtitles of the child screen to the parent screen side for display, but this may be done by using the method already considered in the subtitle moving circuit. An example of the subtitle moving circuit is shown in FIG. 2 and the operation will be briefly described. This circuit utilizes the fact that a caption can be distinguished from a normal video signal because the caption is normally white and the brightness level of the caption has the maximum peak value in the screen. The brightness level of the caption is detected, only the caption signal is extracted, the caption signal is written in the memory, and then read during the video display timing to move the caption.

In FIG. 2, the luminance signal of the video signal coming from the input terminal 41 is converted into a digital signal by the A / D converter 45. A pedestal detection circuit 46 performs pedestal detection of the digitized signal. Based on the pedestal level detected by the detection circuit 46 from the luminance signal, the adder 51 accurately extracts the subtitle portion and writes it in the field memory 47.
From the horizontal and vertical synchronizing signals input from the input terminals 42 and 43, the line detection circuit 49 discriminates even and odd fields, and detects the timing of writing and reading subtitles. The memory control circuit 50 includes a line detection circuit 4
The memory 47 is controlled on the basis of the timing signal from 9. The memory 47 outputs subtitles according to the read control signal from the memory control circuit 50. Next, the MIX circuit 48 (corresponding to the switch 38 in FIG. 1) inserts a caption into the video signal, and the D / A converter 52 converts the signal into an analog signal for output.

By the above operation, the subtitles can be moved. In order to move the video signal of the sub screen to the main screen side with this circuit, the luminance signal of the video signal for the sub screen is input to the input terminal 41, and the luminance signal of the video signal for the parent screen is input to the MIX circuit 48. It suffices to input the extracted subtitle signal on the sub-screen side.

Next, the operation of enlarging the size of the subtitle on the child screen will be described. The operation up to the portion for detecting the subtitle and storing it in the memory 47 is exactly the same as the operation of the above-mentioned moving circuit. Here, it can be distinguished from the subtitle of the main screen, and
If the minimum size of the subtitles that can be easily read by the viewer is about 1/2 of the size of the subtitle of the original image (size when displayed on the parent screen), the subtitle of the original signal is 1/2 You just have to compress it. The sub-screen signal is 1/3 or 1 of the original signal.
Since it is compressed to about / 4, 1/2 compression of the original signal is expanded about twice when compared with the sub-screen. This subtitle compression is, in principle, the same as the compression for creating a small screen signal, and the subtitle call stored in the field memory 47 can be halved by halving the moving operation described above. . To halve a call means, for example, that the original signal is 1
That is, it is thinned out to / 2 and written in the memory, or the original signal is written as it is and read at a timing of 1/2 of writing.

From the above, in order to increase the size of the subtitle on the sub-screen, the field memory control circuit 50 is used.
Calling the memory 47 by halves may be halved. In addition, if you want to reduce the size of the subtitle to 2/3, call 2 /
Set to 3. In this way, the size of the subtitle can be changed in two steps or several steps by making the memory call variable.

Next, variable display positions of subtitles moved from the child screen to the parent screen will be described. In the caption moving circuit described above, the H. SYNC, V.I. The position is determined by the line detection of the line detection circuit based on SYNC. Therefore, in order to make the display position of the subtitle moved to the main screen variable, the line detection of the line detection circuit 49 may be controlled from the outside by a microcomputer or the like. Therefore, the display position of the moved subtitle can be easily changed, and the subtitle can be displayed at a position where it does not disturb the original image of the main screen.

[0022]

As described above, in the display device according to the present invention, since the sub-screen subtitle moving circuit is provided, the subtitles in the sub-screen can be moved to the main screen and displayed in an enlarged manner. Screen subtitles can be provided. Further, when the display position of the sub-screen subtitle moved to the main screen is variable, the subtitle can be displayed at a position where it does not interfere with the original video on the main screen.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing a main part of an embodiment.

FIG. 2 is a block configuration diagram of a small screen subtitle moving circuit.

FIG. 3 is a diagram showing an example in which a subtitle in a child screen is enlarged and displayed in a parent screen.

FIG. 4 is a diagram showing an example of PIP display and POP display.

FIG. 5 is a block diagram of a conventional PIP circuit.

[Explanation of symbols]

 31 Parent screen video signal input terminal 32 Sub screen video signal input terminal 33 Horizontal sync signal (H.SYNC) input terminal 34 Vertical sync signal (V.SYNC) input terminal 35 PIP circuit 36 Sub screen moving circuit 37, 38 Switch 39 output terminal

Claims (1)

[Claims] 1. A display device having a child screen display function for displaying an image-compressed child screen inside or outside a parent screen which is a normal display screen, wherein subtitles within the child screen are displayed in the parent screen. A display device comprising a sub-screen caption moving circuit for enlarging and displaying on a screen.