JPH01162083A - Character broadcasting signal fetching circuit - Google Patents

Abstract

PURPOSE:To simultaneously execute the memory of the program data of plural channels by providing the plural couples of a tuner and a signal sampling circuit, coupling a buffer memory to respectively temporarily execute the memory of a character broadcasting signal independently in each couple and coupling the buffer memory to a main memory. CONSTITUTION:The character broadcasting signal of a channel to be selected by a first tuner 1 is sampled by a first signal sampling circuit 2 from a vertical retrace line period and temporarily stored through a first error correcting circuit 3 to a first RAM4. The data of this RAM4 are transferred to a first main memory 13 in a processable block which is interval until the next vertical retrace line period. Next, during a time the data of the first memory 13 are displayed in a display part 12, a signal to be received by a second tuner 7 and to be sampled by a second signal sampling circuit 8 is successively shifted in a short time and stored in a second memory 14. Thus, the data to be stored in the first and second memories 13 and 14 are wholly displayed in the display part 12 immediately by a command from a microcomputer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a teletext signal acquisition circuit that is capable of simultaneously storing teletext data of different channels in memory.

``Prior Art'' A conventional teletext signal acquisition circuit includes a TV broadcast tuner and a teletext signal extracting circuit, and uses this tuner to select and display a certain program on a certain channel, even if it is within the same channel. It was possible to store all different programs in memory.

``Problems to be Solved by the Invention'' However, with such conventional circuits, even if you want to select and display a certain channel and simultaneously select and memorize another channel, you cannot memorize it. After the program data of a certain channel has been stored, it is necessary to switch to another desired channel and store the data.

Therefore, it takes time to memorize one screen's worth of data after switching to another channel, and
Simultaneous broadcasts of counter programs had problems such as data being unable to be stored in memory if the timing was off.

An object of the present invention is to provide a device that can simultaneously store program data of two channels by providing two or more sets of tuners.

The present invention has been made to achieve the above-mentioned object, and it extracts teletext signals received by a tuner using a signal sampling circuit according to instructions from a controller, and stores them in a main memory. At the same time, in the circuit for displaying a target program on the display section, a plurality of sets of the tuner and the signal sampling circuit are provided, and a buffer memory for temporarily storing the teletext signal independently for each set. and these buffer memories are coupled to the main memory via a bus switching circuit within the controller.

"Operation" When a character signal of a certain channel is being received by one tuner, the character signal data of that channel is temporarily stored in the buffer memory, then stored in the main memory and displayed on the display section. In this state, if the other tuner receives a character signal from another channel, -
After being stored in the buffer memory, the data is instantly moved and stored in the main memory. Therefore, when the channel is switched to another channel, the data in the main memory is immediately displayed on the display.

"Example" Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, (1) is a first tuner, and this first tuner (1) is connected to a buffer memory via a first signal extraction circuit (2) and a first error correction circuit (3). 1 RAM (4) and a microcomputer (6) in the controller (5). Similarly, the second tuner (
7) is connected to the second RA as a buffer memory via the second signal sampling circuit (8) and the second error correction circuit (9).
M (10) and the microcomputer (
6). The first and second RAM (
4) (10) is coupled to the microcomputer (6) via a bus switching circuit (11). This microcomputer (6) includes a display section (12), first and second main memories (13) (1
4) are combined.

The operation of the above configuration will be explained.

The teletext signal of a certain channel selected by the first tuner (1) is transmitted to the first signal sampling circuit (2) from the vertical blanking period.
) and is temporarily stored in the first RAM (4) via the first error correction circuit (3).

The data in this first RAM (4) is stored in the first main memory (13) in a processable period up to the next vertical retrace period.
will be forwarded to. In this way, teletext data of a certain program on a certain channel is stored in the main memory (13).

Here, when the data in the first main memory (13) is called to the display section (12) by a command from the microcomputer (6), the data already stored in the memory is immediately displayed on the display section (12).

Next, during the time when the data in the first memory (13) is displayed on the display section (12), the second tuner (7) receives data from another channel different from the first tuner (1). In order to receive and store it in memory, the teletext signal extracted by the second signal extraction circuit (8) is transferred to the second RAM
(10) - Temporarily memorize. This second RAM
After the correction operation period, the data stored in (10) is sent as an interrupt signal from the microcomputer (6) to the second RAM (10) via the bus switching circuit (11). Second RAM (10) and microcomputer (
6) and the second RAM
The data (10) is transferred to the second memory (14) and stored therein. Similarly, signals received by the second tuner (7) and extracted by the second signal extraction circuit (8) are sequentially transferred in a short time and stored in the second memory (14). In this way, the first and second memories (13)
All data stored in (14) are immediately displayed on the display section (12) according to instructions from the microcomputer (6).

"Effects of the Invention" Since the present invention is configured as described above, when one tuner is performing regular reception, the teletext signal of the back channel can be memorized in the other tuner within the same time, so that the teletext signal of the back channel can be stored in the memory of the two channels. Teletext broadcasts of programs can be displayed at the same time as changing channels.

In addition, since there is only one display section, it can be provided at a much lower cost than when two devices are provided.

[Brief explanation of the drawing]

The figure is a block diagram of a teletext signal acquisition circuit according to the present invention. (1)(7)...Tuner, (2)(8)...Signal extraction circuit, (3)(9)...Error correction circuit, (
4)(10)...RAM, (5)...Controller, (6)...Microcomputer, (11)...Bus switching circuit, (12)...Display section, (13)(14) )...Main memory. Applicant Fujitsu General Ltd.

Claims (2)

[Claims] (1) In a circuit that extracts a teletext signal received by a tuner by a signal sampling circuit according to a command from a controller, stores it in the main memory, and displays the desired program on a display section, the tuner and the signal sampling circuit are connected to each other. A plurality of sets are provided, and buffer memories for temporarily storing teletext signals independently for each set are coupled, and these buffer memories are coupled to the main memory via a bus switching circuit in the controller. A teletext signal acquisition circuit characterized by: (2) The teletext signal acquisition circuit according to claim 1, which comprises two sets of tuners and signal extraction circuits.