JP2703330B2 - Teletext receiver - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a teletext receiver for receiving teletext teletext broadcasting.

[Conventional technology]

Conventionally, television teletext broadcasting is performed during one or a plurality of horizontal scanning periods within a vertical blanking period of the television signal.
It is performed by multiplexing teletext data.

Further, a teletext receiver for receiving teletext broadcasts, as described in the specification and drawings of Japanese Patent Application No. 62-283617, 284691, for example, digitally converts received teletext data. Demodulates and switches the video signal between television broadcast and teletext according to the display mode of teletext and CR
Supply to T etc.

At this time, in order to reduce the so-called waiting time, the data of the teletext is stored in a large-capacity memory called a buffer RAM in a cyclic manner in a plurality of pages in the order of reception.

The buffer RAM also stores and holds program data such as the number data of the selected reserved program.

When a program or page is selected while viewing a text broadcast screen such as a CRT, the data of the selected program or page is immediately read from the buffer RAM, and the desired program or page is displayed on the screen without waiting time.

[Problems to be solved by the invention]

In the case of the conventional teletext receiver, when the receiving channel is switched, the buffer RAM stores the stored contents in order to prevent the teletext data of the channel before switching and the teletext data of the channel after switching from being mixed. Is initialized by resetting such as erasing or writing, and reading pointer.

Therefore, the receiving channel is switched from the channel of the teletext broadcasting to the other channel of the television broadcasting,
After watching this channel television broadcast, even if the receiving channel is restored and the original teletext is to be watched again, the user must wait until the desired program or page is received, resulting in poor usability. There is.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a teletext receiver in which initialization of the buffer RAM based on switching of a receiving channel is prohibited by a switch operation to improve usability.

[Means for solving the problem]

To achieve the above object, a teletext receiver according to the present invention stores and holds teletext data of a reception channel,
A memory which is initialized at the time of channel switching, an operation switch for setting the inhibition of the initialization, and a channel switching after the setting of the inhibition of the switch; Data storage means for prohibiting until returning to the channel.

(Operation)

In the case of the teletext receiver of the present invention configured as described above, if the initialization is set to be prohibited by the operation switch, the data storage means returns the reception channel to the original channel at the time of the inhibition setting. The initialization based on the switching of the reception channel of the memory as the buffer RAM and the reception and demodulation of the teletext are prohibited.

Therefore, the original data is saved in the memory, the initialization channel is set to prohibit, the receiving channel is switched, and then the channel is returned to the original channel again. Is displayed.

〔Example〕

One embodiment will be described below with reference to FIGS. 1 to 3.

In FIG. 1, (1) is an input terminal for a received signal of teletext broadcasting, (2) is a synchronization separation circuit, (3) is waveform equalization,
A character signal separation circuit for performing signal separation, (4) is an error correction circuit, and (5) is a microprocessor (hereinafter referred to as CPU).

(6) is a program ROM storing a processing program (method) for demodulation, display, etc., and (7) is a work RA for executing the processing.
M, (8) is a large-capacity buffer RAM, (9) is a character generator, (10) is a keyboard for operating the receiver main body, and (11) is a keyboard interface.

(12) is a remote control transmitter (hereinafter referred to as a remote controller) for wireless operation, and (13) is a remote controller interface for receiving and inputting an operation signal of the remote controller (12).

(14) a display clock generator for generating a reference clock for display control, (15) a display and bus control circuit for controlling display and data transfer, and (16) a display memory for demodulated screen display. The color code data is written.

A color code decoding circuit (17) decodes the color code data of the display memory (16) by matrix processing and decodes the digital signals of the three primary colors (R, G, B) of the teletext and Ys, Form the Ym signal. (18) is a D / A conversion circuit for converting digital signals of three primary colors into analog signals.

(19) is an additional sound interface for transferring additional sound data of teletext to an audio decoder (20), and (21) is an output switching circuit, which comprises three primary color signals of television broadcast and teletext, and an audio signal (S ) And output.

The buffer RAM (8) comprises a cyclic memory for storing and storing received text broadcast data and a reserved program memory for storing and storing program data such as a reserved program. , Each time the receiving channel is switched.

The remote control (12) is provided with various operation keys as shown in FIG.

The operation modes of the receiver are selection keys (23), (24), (2) for video input, television broadcasting, and text broadcasting.
It can be switched by the operation of 5).

Selection of a channel for television broadcasting and the like are performed by operating a television broadcasting control key unit (26), and selection of a text broadcast program and page are performed by operating a text multiplexing control key unit (27).

In addition, the character lock key (28) is used for buffer RAM (8).
When an operation switch is set for prohibiting the setting of the initialization, and the initialization is prohibited by the operation of this key (28), the CPU (5) forming the data storage means is used when the reception channel is switched. The initialization of the buffer RAM (8) and the reception and demodulation of teletext are prohibited.

And the operation control of the receiver is usually performed by remote control (12)
After the power is turned on by the power key (22), when a channel for teletext broadcasting is selected by the control key section (26), the received signal of this channel is input to the input terminal ( The signal is input to the sync separation circuit (2) and the character signal separation circuit (3) via 1).

At this time, based on the synchronization signal of the synchronization separation circuit (2), the display clock generator (14) displays and the bus control circuit (15)
Supplies a reference clock for display control.

The character signal separating circuit (3) separates and extracts teletext data from the waveform-equalized received signal, and the data is processed by the error correction circuit (4).

On the other hand, based on the teletext processing program in the program ROM (6), the CPU (5) executes the reception and display processing of FIG.

That is, when the power is turned on, each part of FIG. 1 is initialized by step (F1), and the character lock mode flag is reset by step (F2).

In addition, the character lock key (28)
The presence or absence of the above operation is determined, and it is detected whether or not the initialization of the buffer RAM (8) is prohibited.

If the initialization is not prohibited, the process shifts to the text broadcasting process of step (F4).

By receiving and storing the teletext processing, teletext data of the program selected by the control unit (27) and the reserved program are sequentially stored in the buffer RAM (8).

Also, by decoding and displaying teletext processing, buffer RA
The data read from M (8) is separated into character, graphic color code, and voice data.

The color codes of characters and figures are stored in the display memory (1
6) is decoded by the color code decoding circuit (17) via
The three primary color signals of the teletext and the three primary color signals of the television broadcast formed by this decoding are supplied to a CRT or the like via an output switching circuit (20), and the selected teletext is displayed on the screen.

The additional sound data is decoded by an audio decoder (20), and an output switching circuit (2) converts the audio signal of the additional sound of the teletext and the audio signal of the television broadcast formed by the decoding.
It is supplied to the speaker etc. via 1).

If the character lock key (28) is not depressed, the flow shifts from step (F4) to (F6) via (F5), and the presence or absence of switching of the receiving channel is detected by this step (F6).

When the receiving channel is switched, the process proceeds to (F9) via steps (F7) and (F8), and the buffer RAM is switched.
After (8) is initialized, the flow returns to step (F4) to receive the text broadcast of the channel.

On the other hand, during the teletext processing, the text lock key (28) is pressed to set the text lock mode, and the buffer RAM (8) is set.
When the setting of the initialization is prohibited, the character lock mode flag is set by the step (F10) based on the judgment of the step (F5), and the number of the current receiving channel is set by the step (F11). It is stored in the work RAM (7) as a number.

Further, based on the setting notification processing in step (F12), the program ROM (6) uses the setting character notification “character lock in progress” from the program ROM (6).
Is transferred to the display memory (16), and the above-mentioned notification character of "character locked" is superimposed on the display screen of a CRT or the like.

Then, the presence or absence of the switching of the receiving channel is detected by the step (F6), and when the receiving channel is switched, the teletext data is not transferred to the display memory (16) by the step (F7), and the display of the teletext is displayed. Will be erased.

In addition, switching from teletext processing to television broadcasting processing,
The three primary color signals output from the output switching circuit (21) are held as television primary broadcast three primary color signals in which the notification character is superimposed.

Therefore, when the receiving channel is switched in the character lock mode, the screen display of the character broadcasting is prohibited, the television broadcast of the switched receiving channel (hereinafter, referred to as a new channel) is displayed on the screen, and the switching based on the data in the buffer RAM (8) is performed. Erroneous display of the teletext of the previous channel (hereinafter referred to as the old channel) is prevented.

Furthermore, from step (F7) through (F8) (F13)
Then, based on the comparison of the channel numbers in this step (F13), it is determined whether or not the receiving channel has returned to the old channel at the time of locking.

At this time, if the receiving channel has returned to the channel at the time of the lock, the process proceeds to step (F14), the character lock mode flag is reset, the lock mode is released, and the setting notification process is stopped at step (F15). After the screen display of the notification character is deleted, the process returns to step (F4), and the text broadcasting process is restarted.

On the other hand, if the receiving channel is not the channel at the time of the lock, the process proceeds from step (F13) to (F16), and after the same detection as in step (F6) is performed, the process proceeds to step (F17).
In step (F5), the same determination as in step (F5) is performed. The detection of step (F16) and the determination of step (F17) are repeated until the character lock mode is released. When the character lock mode is released, step (F5) is performed. By F18), the current reception channel (hereinafter referred to as the current channel) is compared with the channel at the time of locking.

Based on this comparison, if the current channel is the lock channel, the process returns to step (F4) via steps (F14) and (F15). If the current channel is other than the lock channel, the process returns to step (F19). Buffer RAM by
After (8) is initialized, the process returns to step (F4) via steps (F14) and (F15), and the text broadcasting process is performed.

If the receiving channel is switched at the time of detecting the step (F16), the same processing as the step (F7) is performed by the step (F20), and then the step (F13)
Move to

Further, when comparing the step (F13), if the new channel is other than the channel at the time of the lock, the process returns to the step (F16).

Therefore, when the character lock key (28) is not pressed and used without setting the character lock mode, the operation is the same as that of the conventional receiver as described below.

That is, after the power is turned on, the steps (F3) to (F6) are repeated until the receiving channel is switched, and based on the teletext processing, the teletext data of the channel is stored in the buffer RAM (8) and The broadcast screen is displayed.

When the receiving channel is switched, the process returns to step (F4) through steps (F7) to (F9) based on the judgment of step (F6), the buffer RAM (8) is initialized, and the data of the old channel is restored. After the data is deleted, the teletext data of the new channel is buffered based on the teletext processing.
While being stored in the RAM (8), the screen display of the text broadcast of this channel is performed.

Next, when the character lock key (28) is pressed during reception and display of the text multiplex broadcast, and the reception channel is switched in the state of the text lock mode, the operation will be described as follows.

That is, if the character lock key (28) is pressed while the steps (F3) to (F6) are repeated, the process shifts from the step (F5) to the steps (F10) to (F12), and enters the character lock mode. The notification character is set and displayed on the screen.

When the receiving channel is switched in this state, the process moves from step (F6) to (F13) via (F7) and (F8),
Until the receiving channel returns to the lock channel, the loop processing of step (F16) and (F17) or the step (F1)
3), (F16) and (F20) loop processes are performed.

At this time, the initialization of the buffer RAM (8) and the text broadcast processing are not performed, the data of the channel at the time of locking is stored as it is, and the television broadcast of the reception channel in which the notification character is superimposed is displayed on the screen. Erroneous display of teletext is prevented.

When the receiving channel returns to the locked channel, the process proceeds from step (F13) to (F4) via (F14) and (F15), the character lock mode is automatically released, and the notification character is erased. The teletext processing is restarted.

At this time, a text program is immediately displayed on the screen based on the data stored in the buffer RAM (8).

Therefore, when the character lock key (28) is pressed to switch the receiving channel from the character multiplex broadcasting A channel to the television broadcasting B channel, and then returning from the B channel to the A channel again, the character broadcasting of the A channel is displayed without waiting time. Is displayed.

Also, when the character lock key (28) is pressed to switch the receiving channel from the A channel to the B channel, the C channel, and so on and return to the A channel, the text broadcasting of the A channel is displayed on the screen without waiting time.

Therefore, when teletext is not performed in private broadcasting such as early morning or late at night, for example, it is possible to watch the necessary teletext broadcasting of NHK only for unnecessary time, such as commercial broadcasting of commercial television broadcasting. You can also watch commercial broadcasts between the teletexts.

By the way, the character lock key (2
Press 8) to go from step (F17) to (F18), (F19),
Transfer to (F4) via (F14), (F15), buffer RA
M (8) is initialized, the lock mode is released, the teletext processing is resumed, and the reception and display of the teletext of an arbitrary channel are started.

Also, after the receiving channel returns to the channel at the time of locking and the lock mode is released, if the receiving channel is switched to another channel and returned again, initialization is performed in step (F9) and the old buffer RAM (8) is used. The data is deleted, and the teletext screen display starts from the latest program.

Next, a case will be described in which the character lock key (28) is pressed twice without switching the reception channel in order to cancel the erroneously set character lock mode.

In this case, based on the first operation, the process shifts from step (F5) to (F3) via (F10) to (F12) and (F6), and after the character lock mode is set, the steps (F16), (F16) F
The loop processing of 17) is repeated.

Further, based on the second operation, the process proceeds from step (F17) to (F4) via (F18), (F19), (F14), and (F15), the character lock mode is released, and the character of the original channel is released. Broadcast processing continues.

〔The invention's effect〕

Since the present invention is configured as described above,
The following effects are obtained.

If initialization is prohibited by the operation switch,
Until the receiving channel returns to the original channel at the time of the prohibition setting, the data storage means inhibits the initialization based on the switching of the receiving channel of the memory as the buffer RAM and the reception and demodulation of the teletext.

Therefore, the original data is saved in the memory, the initialization channel is set to prohibit, the receiving channel is switched, and then the channel is returned to the original channel again. Based on the data saved in the memory, the text broadcast is displayed without waiting time. Can be displayed,
Usability is significantly improved.

[Brief description of the drawings]

The drawing shows an embodiment of the teletext receiver of the present invention,
FIG. 2 is a block diagram, FIG. 2 is a front view of the remote control transmitter, and FIG. 3 is a flowchart for explaining the operation. (5) ... CPU, (8) ... Buffer RAM, (28) ... Character lock key.

Claims (1)

(57) [Claims] 1. A memory for storing and holding teletext data of a reception channel and initialized at the time of channel switching, an operation switch for setting the inhibition of the initialization, and a channel switching after the setting of the switch is inhibited. A data storage means for prohibiting initialization and reception and demodulation of teletext until the receiving channel returns to the channel at the time of prohibition setting.