JPS6117433B2 - - Google Patents

Description

[Detailed Description of the Invention] Recently, various types of TV multiplex broadcasting have been considered in order to effectively utilize broadcast radio waves, and one of them is weather forecasts, stock market conditions, and road information consisting of text or graphics in ordinary households. Teletext multiplex teletext broadcasting is being considered, which allows recipients to view information programs such as price information and the like on the screen of their television receivers whenever they wish.

As an example of this teletext system, one horizontal section within the vertical retrace period of each field of a television video signal, for example, the 20th horizontal section (hereinafter referred to as 20H) and the 283rd horizontal section (hereinafter referred to as 20H) of each frame, is used. (hereinafter referred to as 283H), a digital character pattern signal is inserted, and multiple programs are transmitted in a time-sharing manner in units of 200 field periods per program, and for example, information transmitted during the 200 field periods, There is one screen that consists of 200 horizontal sections of information.

In this method, one screen has a maximum of 15 characters/8 characters, for example.
It can now be composed of lines.

Furthermore, the character information signal of this method is configured as follows. That is, FIG. 1 shows 20H or 283H on which a character information signal is superimposed, and FIG. FIG. 1B shows a pattern packet that is inserted into the horizontal section following the horizontal section of the row control packet. In this figure 1, S
_H is a horizontal synchronizing pulse, S _B is a color burst signal, and the character information signal L _D is inserted in a period after the color burst signal S _B.

The character information signal L _D has a total of 296 bits, for example, and the 16 bits after the color burst signal S _B are the write clock synchronization code _SC , and the next 8 bits are the frame synchronization code that also serves as a signal that the writing starts from here. The next 8 bits are the framing code _SF to be used, and the screen display method of the teletext program is
C to display a fixed image on the entire screen
Which is the S method, which displays two fixed lines at the bottom of the screen, the T method, which scrolls one line horizontally at the bottom of the screen, or the X method, which scrolls the entire screen vertically? The service identification code S _ID that determines the
For example, the bit and the next 8 bits are 256
The program codes S _P1 and S _P2 identify the respective teletext program channels. These are common to row control packets and pattern packets.

In the case of a line control packet, the next 8 bits of the program code S _P2 are the line code S _L that specifies the line number on the screen, and the remaining 240 bits that follow are Color code S _A that specifies the color of characters (or figures) in that line
It is said that

In the case of a pattern packet, the 248 bits following the program code S _P2 are a data code S _S for displaying characters or figures divided into horizontal line units.

In this case, the first four bits of the framing code S _F , service identification code S _ID , program codes S _P1 , S _P2 , and line code S _L are used as information bits, and the last four bits are used as redundant bits for error correction. There is.

Note that the basic clock frequency of the above code signal is selected to be 8/5 f _sc (f _sc is the color subcarrier frequency).

The selection of teletext programs is performed as follows.

That is, FIG. 2 shows an example of a conventional teletext receiving device, in which 1 is a receiving antenna, 2 is a receiving antenna,
3 is an electronic tuning tuner, 3 is a video intermediate frequency amplification circuit, and 4 is a video detection circuit.

Reference numeral 5 designates a television channel selection section, which includes a clock oscillator 51, a counter 52, a decoder 53, a channel selection signal generation circuit 54, and a display circuit 55. The channel selection signal generation circuit 54 is connected to a channel selection button switch SA. ₁ , SA ₂ ...... SA _o , preset volume VA ₁ , VA ₂ ...... VA _o , and transistor
TA ₁ , TA ₂ ......TA _o , and display circuit 5
5 has indicator lamps LA ₁ , LA ₂ . . . LA _o . Note that 56 and 57 are terminals from which a positive DC voltage can be obtained, respectively.

6 is a teletext program selection section, and a clock oscillator 6
1, a counter 62, a decoder 63, a selection switch circuit 64, and a display circuit 65. The selection switch circuit 64 is a program selection button switch.
SB ₁ , SB ₂ ...... SB _n and transistors TB ₁ , TB ₂
...... TB _n , and the display circuit 65 is a display lamp.
LB ₁ , LB ₂ ...... has LB _n . In addition, 66
and 67 are terminals from which positive DC voltage can be obtained.

Then, in the TV channel selection section 5, a selection button switch for selecting, for example, one TV channel is pressed.
When SA ₁ is turned on, the DC voltage obtained at terminal 56 is applied to clock oscillator 51 via volume VA ₁ and switch SA ₁ , which oscillates.
A clock pulse is obtained from this. Then, this clock pulse is supplied to the counter 52 and increments, and the output of this counter 52 is supplied to the decoder 53, and when only the output DA ₁ of the n outputs of this decoder 53 becomes "1", This turns on transistor _TA1 . Then, since the collector potential of the transistor TA ₁ becomes almost zero, the oscillation of the oscillator 51 stops, the output DA ₁ maintains the state of "1", and the state in which the transistor TA ₁ is turned on is maintained. Therefore, even if the tuning button switch _SA1 is released and turned off after that, this state will be maintained. In this state, the television channel selection section 5 obtains the voltage EA 1 as the channel selection signal for selecting one channel set in the volume VA ₁ , and this is the voltage EA ₁ that is used by the tuner 2. The TV broadcast waves of one channel are selectively received by being supplied to a variable capacitance diode provided in a local oscillation circuit or the like.

At this time, the lamp LA ₁ lights up to indicate that channel 1 is selected.

Then, a signal converted to a video intermediate frequency is obtained from the tuner 2, and this signal is supplied to the video detection circuit 4 through the video intermediate frequency amplification circuit 3 and detected.

The video detection output from the video detection circuit 4 is supplied through a buffer amplifier 7 to a mixing circuit 8 for a television program and a text broadcast program, and also to a extraction circuit 9 for a text information signal L _D.
On the other hand, the output of the video detection circuit 4 is supplied to a synchronization signal separation circuit 10, from which a horizontal synchronization signal S _H and a vertical synchronization signal S _V are extracted, and these signals S _H and S _V are supplied to a counter 11. The sampling pulses of the 20th horizontal section and the 283rd horizontal section are obtained from this counter 11, and are supplied to the sampling circuit 9, whereby a character information signal L _D is obtained. The character information signal L _D extracted in this way is supplied to a buffer memory 13 via a serial/parallel converter 12 and temporarily stored therein, and the output of this buffer memory 13 is supplied to a transfer gate circuit 14.

Also, the character information signal L _D from the extraction circuit 9
is supplied to the program code extraction circuit 15,
As a result, program codes S _P1 and S _P2 are obtained, which are supplied to the comparison circuit 16 and compared with the program designation code S _P from the teletext program selection section 6.

In the teletext program selection section 6, the selection operation is performed in almost the same way as in the TV channel selection section 5, and there is a button switch for specifying a certain teletext program.
When SB ₁ is turned on, the voltage available at terminal 66 is applied to clock oscillator 61, which starts oscillating and provides clock pulses. This clock pulse is then supplied to a counter 62, which is incremented, and the output of this counter 62 is supplied to a decoder 63.

Then, when only DB ₁ of the m outputs of this decoder 63 becomes "1", the transistor TB ₁ is turned on, the oscillation of the oscillator 61 is stopped, and the transistor TB ₁ is kept in the on state. .
Therefore, this state is maintained thereafter even if the button switch _SB1 returns and is turned off.

At this time, the output state of the counter 62 is equal to the program code of the teletext program designated by the button switch _SB1 , and this is supplied to the comparison circuit 16 as the program designation code _SSP .

When this program designation code S _P matches the program codes S _P1 and S _P2 of the teletext signal received from the extraction circuit 15, a matching signal is obtained from the comparison circuit 16, and this is sent to the transfer gate circuit 14. The character information signal L _D stored in the buffer memory 13 is supplied to the main memory 17 and stored therein. Since the character information signal of one program lasts for 200 field periods as mentioned above, the above operation is repeated during these 200 field periods, and the character information signals L _D of 20H and 283H are stored in the main memory 17.
The images are sequentially written and stored, and one screen is completed. The information stored in the main memory 17 is then supplied to the mixing circuit 8 via the parallel-serial converter 18, and the buffer amplifier 7
This signal is mixed with the TV broadcast reception signal from the TV broadcasting station, and is supplied to the video display circuit including the cathode ray tube, and the screen of the cathode ray tube is switched with the TV broadcast program.
Alternatively, a teletext program is displayed superimposed on this.

And at this time, in addition to lamp LA ₁ , the lamp
LB ₁ lights up, indicating that the teletext program corresponding to button switch SB ₁ is selected on channel 1 of the TV.

In this way, the desired teletext program is selected and displayed on the cathode ray tube screen.

By the way, in the above example, when selecting a teletext program, operate one of the TV channel selection buttons SA ₁ , SA ₂ ...SA _o ,
After selecting a desired television channel, at least two operations were required: operating one of the teletext program selection buttons SB ₁ , SB ₂ . . . SB _o .

However, teletext programs such as weather forecasts and news programs are unrelated to television programs, and it is desirable to be able to select them with a single operation from the viewpoint of simplicity and speed of selection operation.

In view of this point, this invention, in one operation,
The aim is to provide a user with the ability to select desired teletext programs.

Hereinafter, an example of the teletext receiving apparatus according to the present invention will be described with reference to FIG. 3, taking as an example a case in which three of the teletext programs can be selected with a single touch.

In Figure 3, 20 is a non-volatile memory, 21
is a memory address designation circuit, and this memory address designation circuit 21 has three switches SC ₁ , SC ₂ and SC ₃ .

The output of the stored program designation circuit 21 is supplied to the code conversion circuit 22, and when any one of the switches SC ₁ , SC ₂ , and SC ₃ is turned on,
A code corresponding to the switch turned on is obtained from the code conversion circuit 22, and is supplied to the address memory 23 and stored therein. A storage address in the nonvolatile memory 20 is designated by the output of the address memory 23.

24 is a write switch, and when this switch is turned on, the signal being supplied to the input terminal of the memory 20 at that time is written to the memory address specified by the output of the address memory 23.

On the other hand, the outputs of the counters 52 and 62 are supplied to the input terminal of the nonvolatile memory 20.

In this nonvolatile memory 20, counters 52 and 6 are stored at each memory address designated by switches SC ₁ , SC ₂ , and SC ₃ as will be described later.
Predetermined television channel designation codes and teletext program designation codes from 2 are written and stored.

Further, in this invention, between the counter 52 and the decoder 53 and between the counter 62 and the decoder 6,
3 and the comparison circuit 16.
The output of the counter 52, that is, the television channel designation code C _T , and the output of the counter 62, that is, the teletext program designation code C _L , are respectively supplied to one input terminal of this switching circuit 25, and read out from the memory 20. The television channel designation code M _T and the teletext program designation code M _L are respectively supplied to the other input terminal of the switching circuit 25 . The output obtained at one output terminal of this switching circuit 25 is supplied to the decoder 53, and the output obtained at the other output terminal is supplied to the decoder 63 and the comparator circuit 1.
6.

The switching circuit 25 is switched as follows by the output of the flip-flop circuit 26. That is, the flip-flop circuit 26 is set by a signal obtained when one of the switches SC ₁ , SC ₂ and SC ₃ is turned on in the memory address designating circuit 21, and its output is set to "1".
On the other hand, the TV channel selection section 5 selection button switch
SA ₁ , SA ₂ ...... A signal that rises to "1" when any one of SA _o is turned on and one of the button switches SB ₁ , SB ₂ ...... SB _n of the teletext program selection section 6 is turned on. The signal that rises to "1" when the
It is supplied to the reset terminal of 6, which is reset and its output is set to ``0''. When the output of the flip-flop circuit 26 is "0", the switching circuit 25 is in the state shown in the figure, and the output is "1".
When , the state is switched to the opposite state from the state shown in the figure.

By the way, as described above, predetermined television channel designation codes and teletext program designation codes are stored in advance in the memory 20 in the following manner.

That is, for example, the television channel selection section 5
Then, when the tuning button switch SA ₁ is turned on, the switching circuit 25 is switched to the state shown in the figure, so the counter 52 reads "1" in the same manner as described above.
A state is reached in which a designation code C _T for selecting a channel can be obtained. Next, in this state, if the button switch SB ₁ is turned on in the teletext program selection unit 6, the counter 62 selects the teletext program specified by the button switch SB ₁ in the same manner as described above. Code C _L is obtained.

In such a state, for example, if the switch SC ₁ of the memory address designation circuit 21 is turned on, the address "1" of the memory 20 is designated by the output of the address memory 23. Next, when the write switch 24 is turned on, the designation code for one television channel and the designation code for the teletext program designated by the switch _SB1 are written and stored at address "1".

Thereafter, when switch _SC1 is turned on, the specified code stored at address "1" is read out as codes M _T and M _L.

Thereafter, in the same manner, the designation code of the desired teletext program of the desired TV channel is written and stored at addresses "2" and "3" designated by switches SC ₂ and SC ₃ , and thereafter, switch
If SC ₂ and SC ₃ are turned on, that is what is read.

When the switches SC ₁ , SC ₂ and SC ₃ are turned on, the flip-flop circuit 26 is set and the switching circuit 25 is switched to the state opposite to the state shown in the figure. Instead of the outputs C _T and C _L of
Each specified code M read from the memory 20
_T and M _L are obtained and supplied to the decoder 53 as well as to the comparison circuit 16, whereby channel selection and program selection are performed.

Therefore, if the weather forecast, stock market information, and news programs of the teletext programs are selected by the designated codes stored in the memory addresses designated by switches _SC1 , _SC2 , and _SC3 , then , these teletext programs are selected by switches SC ₁ , SC ₂ and
Selective reception can be performed by simply turning on the desired _SC3 .

[Brief explanation of the drawing]

FIG. 1 is a waveform diagram for explaining a teletext information signal, FIG. 2 is a system diagram of an example of a conventional teletext receiver, and FIG. 3 is a system diagram of an example of a teletext receiver according to the present invention. . 2 is an electronic tuning tuner, 5 is a television channel selection section, 6 is a teletext program selection section, 9 is a text information signal extraction circuit, 15 is a program code extraction circuit, 16 is a comparison circuit, 17 is a main memory, and 20 is a non-volatile 21 is a storage address designation circuit, SC ₁ , SC ₂ and SC ₃ are address designation switches, 24 is a write switch, and 25 is a switching circuit.

Claims (1)

[Claims] 1. A television tuner, a television channel selection section that obtains a television channel selection signal to be supplied to this television tuner, a teletext program selection section that obtains a designation code for a teletext program, a non-volatile memory, and a storage address for this memory. The memory includes a signal for obtaining a TV channel selection signal for a specific TV channel and a designation code for a specific teletext program at the address specified by the address designation switch. When the address designation switch is operated, the specific television channel selection signal and the specific teletext program designation code stored at the designated address are read out from the memory, and the specified code is read out from the memory. The TV channel selection signal is supplied to the TV tuner instead of the channel selection signal from the TV channel selection section to select the specific TV channel, and the specific designation code is sent to the teletext program selection section. The teletext receiving device is configured to select the specific teletext program by comparing it with a program channel code of a received teletext signal instead of a specified code.