JPH0139023Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a teletext receiver that notifies the update of the program content of the received teletext signal, and when the program content is updated, the program content of which program has been updated. It is an object of the present invention to provide a teletext broadcasting receiver that broadcasts the following information.

Conventionally, television teletext broadcasting repeatedly transmits several types of programs, and the program content of each program is not frequently updated.

Incidentally, each program is transmitted in a format in which digital signals in units of data packets according to the display mode of each program are multiplexed onto television broadcast waves, that is, in the format of data packets, and each data packet is transmitted in the form of a first packet consisting of synchronization data and control data. to 6th byte header part, and 7th to 31st bytes consisting of control data and display pattern data.
It consists of a byte information data section.

Furthermore, the program number code of a program in a display mode such as full-screen fixed display mode is written to the 7th and 8th bytes of the page control packet (hereinafter referred to as PCP), and the erase and update codes are written to the 11th byte. , the program number code of the program in the one-line horizontal scroll display mode is written in the seventh and eighth bytes of the horizontal scroll data packet (hereinafter referred to as HDP), and the erase code and update code are written in the ninth byte.

And when the program is updated, the PCP
The second bit of the 11th byte becomes logic 1 (hereinafter referred to as "1"), and the second bit of the 9th byte of HDP becomes "1".

Therefore, conventional teletext receivers are constructed as shown in FIGS. 1 to 3, respectively.
In the diagram, a received digital signal in data packet format, that is, a teletext signal, is input to an update code detection circuit 1, and when an update code of "1" is detected, the detection circuit 1 outputs, for example, a buzzer drive circuit 2. A detection signal of "1" is output to the buzzer 3 via the buzzer, and the update of the program content is notified by the buzzer sound.

However, when the buzzer sounds based on a received teletext signal, the program of the teletext signal is not always displayed on the receiver, and the receiver may display other teletext programs based on the user's selection. In some cases, a signal program or a television broadcast program is displayed, and the receiver shown in FIG. 1 is inconvenient to use because it is unclear which program has been updated.

On the other hand, in the case shown in FIG. 2, the teletext signal is input to the update code detection circuit 4, and the mode detection circuit 4' detects whether or not the program of the teletext signal is being displayed. When the update code is detected and a teletext signal program is being displayed, the detection signals of "1" from both circuits 4 and 4' are input to the AND gate 5.
outputs a gate signal of "1" to the buzzer drive circuit 2 to make the buzzer 3 sound.

However, even with the receiver shown in FIG. 2, it is unclear which program has been updated, and there are disadvantages in that program updates are notified only when a teletext signal program is being displayed.

Furthermore, in the one shown in FIG. 3, the teletext signal is input to the program number code and update code detection circuit 6, and the program number code of the currently displayed program output from the program number buffer 7 is input to the detection circuit 1. , detects an update code only when the program number code in the 7th and 8th bytes of PCP and HDP match the program number code of buffer 7, and sounds buzzer 3 when an update code of "1" is detected. .

The receiver shown in FIG. 3 has the disadvantage that only updates of programs that are being displayed are notified, and updates of programs that are not being displayed are not notified.

This invention was made with the above points in mind, and includes an update code detection section that detects a program update code from a teletext signal, and a number code detection section that detects a program number code from the teletext signal. and a notification means for notifying a program number based on the program number code by inputting the update code and the program number code when the program is updated.

Therefore, it is possible to easily know which program's program content has been updated, and the update can be notified not only while displaying teletext signal programs but also while displaying television broadcast signal programs, improving usability. It can be significantly improved.

Next, an embodiment of the teletext broadcasting receiver of this invention will be described with reference to FIG. 4 and the following drawings.

First, one embodiment will be described with reference to FIG.

The received teletext signal is input to the clock run-in extraction circuit 8, which extracts the clock run-in code written in the header section of each data packet, and the extracted clock run-in code is input to the clock generation circuit 9. is input to the clock generation circuit 9.
A clock pulse having a phase-locked frequency of (8/5)·fsc, that is, 5.7272 MHz, is output from the clock.

Further, the teletext signal and the clock pulse are input to the framing code detection circuit 10, and the framing code written in the header portion of each data packet, that is, the code for determining the byte period, is detected, and the detection pulse of the detection circuit 10 is input to the framing code detection circuit 10. After being output to the generation circuit 9 and inputting the detection pulse of the detection circuit 10, the clock generation circuit 9 outputs 64 clock pulses.

Furthermore, the clock pulses from the clock generating circuit 9 are input to the load pulse generating shift register circuit 11, and one load pulse is output from the shift register circuit 11 every time eight clock pulses are input.

On the other hand, the teletext signal and clock pulse are 8
The teletext signal is input to the shift register circuit 12 for bit serial/parallel conversion, and the teletext signal is output in 8-bit units, that is, byte units, from the shift register circuit 12 to the decoder circuit 13 for Hamming code correction. The upper four bits of each byte, ie, information bits, are output to the holding shift register circuit 14. Note that the shift register circuit 14 has the first to 32nd output terminals 1 to 32.
32 are provided.

In addition, the shift register circuit 14 receives a clock pulse frequency-divided by the 1/2 frequency divider circuit 15, and
A load pulse of the shift register circuit 11 is input.

Then, while 64 clock pulses are generated and 8 load pulses are generated, the upper 4 bits of the 4th to 11th bytes of each data packet are sequentially transferred to the shift register circuit 14.
is input.

By the way, a service identification and an interrupt code indicating whether or not it is a teletext signal and the transmission mode are written in the fourth byte of each PCP and HDP, and when it is a teletext signal, both the first and second bits of the fourth byte are written. It is set to logic 0 (hereinafter referred to as "0"). Also, PCP and
A data identification code for data packet identification is written in the 5th and 6th bytes of each HDP,
For PCP, the upper 4 bits of both bytes are all “1”, and for HDP, the 6th
Only the second bit of the byte becomes "0".

Therefore, when all the upper 4 bits of the 4th to 11th bytes of the data packet are input to the shift register circuit 14, the 32nd bit of the shift register circuit 14 is inputted according to the first and second bits of the fourth byte.
The outputs of the 31st output terminals 32 and 31 both become "0", and a teletext detection signal of "1" is output from the NOR gate circuit 16 to which the outputs of both the output terminals 32 and 31 are input.

Also, according to the first to fourth bits of the fifth and sixth bytes, the 28th, 27th, ..., 23rd, 22nd, etc. of the shift register 14 at the time of PCP, respectively.
21st output terminal 28, 27,..., 23, 22, 21
All outputs become "1", and only the 23rd output terminal 23 becomes "0" in HDP mode.

The outputs of the 28th to 21st output terminals 28 to 21 are input to the PCP gate circuit 17 and the HDP gate circuit 18, respectively, and when PCP, a PCP detection signal of "1" is output from the gate circuit 17,
HDP “1” from gate circuit 18 when HDP
A detection signal is output.

Also, the first to fourth bytes of the seventh and eighth bytes are
Shift register circuit 14 according to each bit
20th, 19th, ..., 14th, 13th output terminals 20, 1 of
The program number code is output from 9,..., 14, 13 to the LED display 20 via the data latch circuit 19, and at the time of PCP, the 11th
According to the second bit of the byte, an update code of "1" is output from the third output terminal 3 of the shift register circuit 14, and in HDP, the update code of "1" is output from the third output terminal 3 of the shift register circuit 14 according to the second bit of the ninth byte. 11 An update code of "1" is output from the output terminal 11.

Then, the PCP detection signal of the gate circuit 17 and the third
When the update code of the output terminal 3 is input to the PCP AND gate circuit 21, the gate circuit 21 outputs a PCP update detection signal of "1", and the HDP detection signal of the gate circuit 18 and the 11th output terminal 11 are input. When the update code is input to the HDP AND gate circuit 22, the HDP of “1” is output from the gate circuit 22.
An update detection signal is output.

Furthermore, both update detection signals are output to the OR gate circuit 23.
is input to one input terminal of the update command AND gate circuit 24 via the gate circuit 1.
The teletext detection signal 6 is input to the other input terminal of the AND gate circuit 24, and the update command signal ``1'' is input from the gate circuit 24 to the update command latch circuit 25.

On the other hand, the load pulse of the shift register 11 is input to the latch gate circuit 26, and when the last load pulse, that is, the eighth load pulse, is input, the gate circuit 26 outputs the latch circuit 25.
A latch pulse of "1" is output to one input terminal of the inhibit gate circuit 27, and the output signal of the gate circuit 24 is input to the latch circuit 25 by the latch pulse. If the command signal is a signal, the monostable multivibrator 28 operates for a predetermined period of time, for example, 2 seconds, and the pulse of the multivibrator 28 for a predetermined period drives the buzzer 29 to generate a buzzer sound. Pulse is displayed on display 20 and gate circuit 2
7 for the predetermined period,
A two-digit program number is displayed on the display 20, and input to the gate circuit 27 is prohibited.

Note that the extraction circuit 8 or the gate circuit 18
and AND gate circuit 21 to gate circuit 26
The update code detection section is configured by the sampling circuit 8 or the 1/2 frequency divider circuit 15 and the latch circuit 1.
9 and gate circuits 26 and 27 constitute a number code detection section, and furthermore, an LED display 20, a multivibrator circuit 28, and a buzzer 29 constitute a notification means. Also, PCP
And the detection part of HDP is extracted circuit 8 or 1/2
It is formed by a frequency dividing circuit 15 and gate circuits 17 and 18. Furthermore, if the buzzer sound is unpleasant to the ears, the buzzer 29 does not need to sound.

Next, FIG. 5 showing another embodiment will be explained.

In FIG. 5, the same symbols as in FIG. At the same time, the clock pulse of the display clock generation circuit 31 is input to the generator 30,
A character display signal corresponding to the program number code is output from the generator 30 to the display AND gate circuit 32, and the multivibrator circuit 28
The output of is input to the AND gate circuit 32, and the fourth
Based on the update command signal from the gate circuit 24 shown in the figure, only when the multivibrator circuit 28 operates, the AND gate circuit 32 sends the adder circuit 33 to the adder circuit 33.
At the same time, the character display signal is output to the adder circuit 33, and the character display signal is added to the video signal of the program display signal processing circuit 34, and the video signal to which the character display signal has been added is sent from the adder circuit 33 to the display tube 35. is output, and when the teletext program is updated, the program number of the updated teletext program is displayed on the display tube 35 together with the television broadcast program based on the video signal and the teletext program.

According to this invention, the program number of the text program is displayed not only when the text program is being displayed as described above, but also when updating other text programs, while displaying the text program, and even while the TV program is being displayed. It is possible to provide a teletext receiver that is very convenient for viewers.

[Brief explanation of the drawing]

1 to 3 are block diagrams of a part of a conventional teletext receiver, respectively, FIGS. 4 and 5 show an embodiment of the teletext receiver of this invention, and FIG. FIG. 5 is a block diagram of main parts of the embodiment, and FIG. 5 is a block diagram of a part of another embodiment. 8...Clock line extraction circuit, 9,3
1...Clock generation circuit, 10...Fleming code detection circuit, 11, 12, 14...Shift register circuit, 13...Decoder circuit, 15...1/2
Frequency dividing circuit, 16-18, 21-24, 26-28
...Gate circuit, 19,25...Latch circuit, 2
0...LED display, 28...monostable multivibrator circuit, 29...buzzer, 30...character generator, 33...addition circuit, 34...
Program display signal processing circuit, 35...Display tube.

Claims (1)

[Scope of utility model registration request] In a teletext receiver that receives a teletext signal configured such that a program number code of a character program and an update code indicating whether or not the program has been updated form a data packet together with the character data of the program, the character A program number code detection circuit that detects a program number code in a broadcast signal, a latch circuit that latches the program number code each time it is detected, and a text program that is updated by obtaining an update code in the teletext signal. and a display circuit that displays the program number corresponding to the program number code latched by the latch circuit when the output of the update code detection circuit is obtained. Broadcast receiver.