JP3054465B2 - Video tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video tape recorder (VTR) capable of receiving a teletext broadcast and recording a teletext screen.

[0002]

2. Description of the Related Art In West Germany, for example, as shown in FIG.
When connecting to a V (television receiver), a so-called 21-pin terminal is used to connect the corresponding terminals of the VTR and the TV, whereby an RGB signal line, a composite (COMP.) Signal line, AV signal line and B
LANK signal lines are connected to each other, AV signal and BLA
The mode of the TV is switched as shown in FIG. 4 by switching the NK signal between active and inactive.

That is, as shown in FIG. 4, an AV signal and a BLANK
If the signals are both active, the TV will output R from the VTR.
An RGB mode for receiving a GB signal and displaying it on a screen is set. If the AV signal is active and the BLANK signal is inactive, the RGB signal from the VTR is not accepted, and the mode is switched to the line display mode in which the composite signal from the VTR is received and displayed. Also, A
If both the V signal and the BLANK signal are inactive, the mode is switched to the TV tuner mode for outputting the signal received by the TV tuner to the TV screen.

Meanwhile, in a conventional VTR capable of recording a teletext screen and outputting an RGB signal, displaying a teletext screen on a TV is more difficult than displaying in a line display mode in an RGB mode. Display is better in terms of image quality.
The signal is forcibly set to active. Similarly, when recording a teletext screen, BLANK
The RGB mode is set with the signal and the AV signal active.

[0005]

However, at the time of recording a teletext screen, the TV is forcibly set to the RGB mode as described above.
There has been a problem that a TV program received by a TV tuner, that is, a counter program cannot be viewed. The purpose of the present invention is
When recording the teletext screen, the AV signal and BLAN
An object of the present invention is to provide a video tape recorder in which both K signals are set to inactive and a signal received by a TV tuner can be output to a TV screen.

[0006]

Video tape recorder according to the present invention SUMMARY OF] includes means for detecting that in addition to the above configuration, the teletext screen recording mode is set, the recording
When the mode is set, the AV signal and BLANK signal
It has means to set the number to inactive.

[0007]

[Operation and Effect] When displaying a teletext screen on a TV, the TV is set to a mode for displaying an RGB signal on a screen (RGB mode), and a teletext broadcast received by a VTR is output to the TV as an RGB signal and displayed. Is done. Therefore, the teletext screen can be viewed with good image quality. Further, when the recording mode of the teletext screen is set, this mode is detected and the mode switching signal is
A mode in which a signal received by a tuner of a television receiver is displayed on a screen from a mode (RGB mode) in which an RGB signal is displayed on a screen by being sent from a TR to a TV.
(TV tuner mode). Therefore, a TV program (counter program) can be viewed while recording the teletext screen.

[0008]

The examples are illustrative of the present invention and should not be construed as limiting the invention described in the claims or reducing the scope thereof. FIG. 1 shows the configuration of a VTR embodying the present invention. The broadcast signal captured by the antenna (1) is selected by the tuner (2) after reception.
It is supplied to a display / recording signal switching circuit (5) through a video intermediate frequency and detection circuit IF / DET (3) and a video signal processing circuit (4).

The display / recording signal switching circuit (5) is a teletext controller (6) composed of a microcomputer.
A video signal b from a video signal processing circuit (4), a character signal from a teletext decoder (7), or a composite signal c of a character signal and a video signal, and outputs the selected signal. It is.

Output i from display / recording signal switching circuit (5)
Are supplied to a 21-pin terminal (18) for display and to a recording circuit (15) for recording.

On the other hand, the teletext signal multiplexed in the vertical blanking period among the video signals obtained from the IF DET (3) is extracted by a teletext signal extracting circuit (8).
It is supplied to a teletext decoder (7).

The teletext decoder (7) extracts only the data of the page number specified by the teletext control unit (6) and supplies it to the screen memory (9). by this,
Screen data of a specific page number selected by the teletext decoder (7) is written in the screen memory (9) in accordance with a control signal from the teletext control unit (6). The data written in the screen memory (9) is read out according to a control signal from the teletext control unit (6), and is converted into a character signal by a teletext decoder (7).

The RG from the teletext decoder (7)
The B output g is subjected to level matching and impedance conversion in the buffer 17, and the output h of the buffer 17 is supplied to the 21 pin terminal 18.

The teletext control unit (6) comprises a teletext decoder (7) and a display / recording signal switching circuit (5) as described above.
In addition to controlling the display of the television screen and the teletext screen by sending a command to the screen memory, any character can be displayed by directly writing data to the screen memory (9).

The teletext control unit (6) directly transmits an AV signal d for switching the TV to an external input to a pin 21 (1).
Supply to pin 8 of 8). The level of the BLANK signal e for switching the TV to the RGB input is adjusted in the buffer 16, and the output f of the buffer 16 is supplied to the 16th pin of the 21-pin terminal 18. You.

[0016] Remote control transmitter (10) and VT
A signal input by operating a keyboard (11) provided on the R body is converted into a common code signal by an input control unit (12), and then input to a VTR control unit (13). VTR
The control unit (13) controls the tuning circuit (14) to perform a tuning operation according to the content of the code signal from the input control unit (12),
Alternatively, various operations of the VTR, that is, recording is executed by controlling the recording circuit (15), operations such as reproduction, fast forward, rewind, and stop, and program recording reservation are performed. It is supplied to the control unit (6).

Next, referring to FIG. 2, the operation of the teletext control unit (6) in signal switching between the normal teletext screen display and the teletext screen recording will be described.
The teletext control unit (6) transmits the VT from the VTR control unit (13).
Waiting for a change in the mode of R, that is, a change in the state of the VTR from stop to playback, pause to recording, etc. (step S1)
When the mode change information is received from the VTR control unit (13), the process proceeds to step S2. In step S2, it is checked whether or not the current state of the display screen is the teletext screen display. If the display state is the teletext screen display, the process proceeds to step S3. In step S3, it is checked whether or not the changed VTR mode is video recording. If it is video recording, the process proceeds to step S4. Step S4
Then, the AV signal d and the BLANK signal e of the 21-pin terminal (18) are made inactive, and the process returns to step S1.

If it is determined in step S3 that the changed VTR mode is not recording, the process proceeds to step S5. In step S5, it is checked whether the mode is reproduction, and if it is reproduction, the process proceeds to step S6. In step S6, the teletext screen is canceled, and the process returns to step S1.

If it is determined in step S5 that the changed VTR mode is not recording / reproduction, the process proceeds to step S7. Step S
7, the AV signal d of the 21-pin terminal (18) and BLANK
Check if signal e is inactive,
If active, the process returns to step S1, and if inactive, the process proceeds to step S8. In step S8, the AV signal d and the BLANK signal e of the 21-pin terminal (18) are activated, and the process returns to step S1.

According to the above series of procedures, in a normal teletext screen viewing state, RGB signals are output to the TV, and the teletext screen can be viewed with good image quality. Also, when in the teletext screen recording state, 21
BLANK signal (pin 16) and AV signal (8
(Pin No.) to inactive,
Since the TV does not enter the RGB mode of external input, it is possible to view a TV program (counter program) during recording on the teletext screen.

The description of the above embodiments is for the purpose of illustrating the present invention and should not be construed as limiting the invention described in the appended claims or reducing the scope thereof. Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a video tape recorder embodying the present invention.

FIG. 2 is a flowchart showing a mode switching procedure.

FIG. 3 is a block diagram illustrating a connection mode between a TV and a VTR using 21-pin terminals.

FIG. 4 is a table illustrating mode switching by an AV signal and a BLANK signal.

[Explanation of symbols]

 (6) Teletext controller (18) 21-pin terminal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/93 H04N 5/44 H04N 7/025 H04N 7/03 H04N 7/035

Claims (1)

(57) [Claims] 1. A tuner for receiving a teletext broadcast.
With the provision of (2), it is possible to record a teletext screen and connect to a television receiver having a tuner.
The active or active of the AV signal and the BLANK signal, respectively.
AV signal line and BLANK signal for transmitting inactivity
AV signal and BLANK signal are both activated.
To display the external input signal on the television receiver
Set to RGB mode, AV signal and BLANK signal
Both inactive TV receivers
In a video tape recorder which allows the display of the received image with toner, means for detecting that the teletext screen recording mode is set, when the該録picture mode is set, AV signal and BLA
A video tape recorder comprising means for setting an NK signal to inactive .