JP2591064B2 - Teletext broadcast receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICABILITY The present invention reduces the display screen, for example, to about 1/4 when receiving and displaying a text multiplex broadcast, and displays a single screen or four screens simultaneously. The present invention relates to a text multiplex broadcast receiving apparatus.

2. Description of the Related Art In recent years, teletext multiplex broadcasting, which is called a new media and has been put into practical use, has come to the stage of popularization, and various additional functions are being studied in order to further expand the spread.

FIG. 6 shows a schematic block diagram of a teletext receiver (hereinafter referred to as a decoder). In the figure, reference numeral 1 denotes a central processing unit (cpu) for various processes of the decoder. 2 is a ROM storing a program for performing the processing procedure
And 3 is a work RAM of cpu1. Reference numeral 4 denotes a sampling unit that extracts a character signal from the video signal and supplies the character signal to cpu1. Reference numeral 5 denotes a system control unit that generates various signals necessary for controlling each block. Reference numeral 6 denotes a display control unit that stores, reads, and outputs the video RAM 7 in accordance with the received character signal. Reference numeral 8 denotes a kanji ROM, which stores a font (pattern) of a specified character which is encoded (coded) in a character signal, and in which cpu1 is code-coded according to a predetermined coding system (jls). Is added to the kanji ROM 8 as an address, and a pattern output corresponding to the code is read out and written on the video RAM 7, thereby displaying characters on the screen.

FIG. 7 is a block diagram of a vertical display address generator in the display controller 6 of FIG.

In the figure, reference numeral 9 denotes a counter which counts horizontal pulses H and indicates a physical position in the vertical direction. Reference numerals 10, 11, and 12 denote gate generation circuits for generating control signals shown in FIGS. 8A, 8B, and 8C based on the output of the counter 9.
7 is a register for storing the display start address.

Reference numeral 15 denotes a selector for switching the display addresses of the header section and the text section. Reference numeral 16 denotes a display address generation counter that counts horizontal pulses H.

Here, FIG. 8A is a signal indicating a vertical display width (204 lines), B is a signal for distinguishing between a header portion and a text portion,
C is a load pulse for loading the counter 16 with the display start address of the header section and the text section.

 The operation will be described below.

In the header address register 13 and the text address register 14, a memory address (display start address) at which the head data is stored is set by cpu1. These two addresses are switched by a selector 15 by a header / text switching signal B generated by the gate generation circuit 11. The display start address switched by the selector 15 is input to the display address generation counter 16. The load pulse C generated by the gate generation circuit 12 is located at the top of the header section and at the top of the text section, respectively. At this position, the display start address is loaded into the counter 16 and counts up from this value. Therefore, the header address is generated from before A to A, and the text address is generated from A to the bottom of the screen.

The operation of the decoder configured as described above will be briefly described below.

If the character signal extracted from the video signal by the character signal extracting unit 4 is subjected to cpu1 processing and the graphic information is subjected to decompression work if compression or the like is performed, the encoded character information is converted to kanji according to the code. The ROM 8 is accessed and the read pattern is input to the display control unit 6, and the display control unit 6 stores the read pattern in the video RAM 7 according to the input.

The display controller 6 simultaneously reads the display data from the video RAM 7 and outputs it as R, G, B signals.

These are normal operations. Here, as an additional function,
A so-called picture-in-picture in which a character screen is reduced and synthesized and displayed on a normal television screen has been considered. For example, a normal character screen that is 248 dots wide and 204 lines high is reduced and projected to 1/2 of 124 dots x 102 lines each of 1/4 of the normal screen. If you display the character screen in the corner of the TV screen in 1/4 size, you can see both at the same time, you can switch immediately when the screen you want to see in detail, and you can also display 4 screens at the same time More information is useful. It should be noted that the display can be reduced by using an algorithm determined by software for figures and the like, and the characters and the like can be realized by making readable reduced characters into ROM and using them.

Problems to be Solved by the Invention A reception screen of teletext broadcasting is generally composed of the above-mentioned header section and text section on a television screen. The header section has an area of 12 lines in the vertical direction and 248 dots in the horizontal direction, and displays a heading of the screen, a program number, and the like.

The text portion similarly has an area of 192 lines × 248 dots and displays the text of character / graphic information.

Normally, when selecting a program, the header is also used as a key monitor area for confirming key input from the remote controller, and the background color can be specified separately for the header raster text and the text raster color, making it an important area. ing.

When a receiving screen having such an area is to be reduced and displayed on four screens at the same time, how to handle the header becomes an issue. Also, since the coloring unit is 4 lines x 4 dots, when the header is divided vertically and horizontally and divided into four, it becomes 6 lines x 124 dots, and the vertical (vertical) coloring unit has two extra lines, and other reduced There was also the problem of affecting the header.

Means for Solving the Problems In order to solve the above problems, the text multiplex broadcast receiving apparatus of the present invention is designed to perform divided and reduced display in each area in consideration of the purpose and characteristics of a header section and a text section. Further, the problem of the coloring unit caused by dividing the inside of the header portion is characterized in that the reading start position of the memory circuit is increased by another position so that one does not affect the other.

Function The present invention, by the above-described configuration, reduces the reception screen of teletext broadcasting, when simultaneously displaying a plurality of screens, even when displaying a key monitor, without affecting the text portion,
You can see without discomfort.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A shows an example of a normal reception display screen, and FIG. 1B shows an example of simultaneous display of four screens in the present invention.

FIG. 2 is a block diagram of a vertical display address generator which is a part of a teletext receiver including a header division circuit according to an embodiment of the present invention.

9 to 16 are the same as those in FIG. 17 is a circuit for generating a gate signal for dividing the header portion,
In this example, D is generated so as to be 6 lines, which is 1/2 of the 12 lines of the header. Also, the load pulse c generated on the seventh line of the header is generated by the gate generation circuit 17 and ORed with the load pulse C by the OR gate to obtain a pulse C '. Reference numeral 18 denotes a register for storing a display start address of the second header to be divided.

Reference numeral 19 denotes a selector for switching the outputs of the header address registers 13 and 18 by a gate signal D.

The operation of the text multiplex broadcast receiving apparatus configured as described above will be described below.

When a plurality of screens are simultaneously displayed (hereinafter, multi-display) by reducing the reception screen, the header part is displayed in a multi-display manner in the header part. However, the problem of the coloring unit cannot be cleared without adding hardware. So we increased the header division position,
Further, this problem has been solved by changing the address of the memory as follows.

A gate generation circuit 17, a header address register 18, and a header address selector 19 are newly provided, and the top address of the header and the text is loaded by the load pulse C at the address switched by the selector 15 as in the past. Since the load pulse is ORed with C by the OR gate 20, a new display address is loaded into the counter 16 on the seventh line of the header, and the change point in the header portion is determined. Two are obtained, and the problem of the coloring unit is solved.

Also, the addresses stored in the header address registers 13 and 18 are close to each other as shown in FIG. Therefore, by paying attention to this, by sharing most of the first header address 13 and inverting a part of the first header address 13, by providing an address conversion means 18 'in FIG. The circuit can be simplified, and the number of gates and the trouble of creating software can be saved.

Although this embodiment has been described with respect to the vertical direction, it goes without saying that the same operation can be performed in the horizontal direction only by increasing the frequency.

According to the present invention as described above, it is possible to reduce the load on software and the number of gates of a circuit without giving a sense of incongruity to the display of a header portion when a plurality of images are reduced and simultaneously displayed.

[Brief description of the drawings]

FIG. 1 is a front view showing a screen division example b obtained by the present invention in comparison with a conventional example a, and FIG. 2 is a block diagram of a vertical display address generating circuit of a teletext broadcasting apparatus in one embodiment of the present invention. FIG. 3 is a timing chart thereof, FIG. 4 is a detailed view of a header section in the present invention, FIG. 5 is a block diagram showing another embodiment of the present invention, and FIG. FIG. 7 is a block diagram of a broadcast receiving apparatus, and FIG.
FIG. 8 is a block diagram of a vertical display address generation circuit which is a part of the display control section shown in FIG. 8, and FIG. 8 is a timing chart thereof. 9 ... line counter, 10, 11, 12, 17 ... gate generation circuit, 13, 18 ... header display start address register, 14 ...
... Text display start address register, 15, 19 ... Address data selector, 16 ... Vertical display address generation counter, 20 ... OR gate.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Toyoaki Unemura 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-company (72) Inventor Yuji Kondo 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

(57) [Claims] 1. A text multiplex broadcast receiving apparatus for receiving, storing, reading out and displaying on a display unit a character signal superimposed on a vertical blanking period of a television signal. Dividing signal generating means for generating a load pulse for loading the counter, a plurality of header address storing means for setting a head address of a memory to be displayed by dividing, and storing the plurality of header addresses by the dividing signal generating means. A header address switching means for switching the output of the means, when a screen to be received and displayed is reduced and a plurality of screens are simultaneously displayed, a header portion corresponding to a screen header is also reduced, and a plurality of headers are placed in a normal header position. A teletext broadcast receiving apparatus for displaying. 2. A method according to claim 1, wherein one header address storage means comprises:
2. The text multiplex broadcast reception according to claim 1, wherein an address conversion means is provided, and when a header address is set in the header address storage means, the second header address is uniquely determined by the address conversion means. apparatus.