JPH05211649A - Video tape recorder - Google Patents

Abstract

PURPOSE:To prevent an internal composite signal from being superimposed on a video by a superimpose signal from a de-scrambler. CONSTITUTION:A switching circuit 42 which selects the internal composite signal from a recording and reproduction processing part 38 or a through composite signal from the de-scrambler 12 is interlocked with a switching circuit 44 which seals a blanking signal to permit superimposition from the de-scrambler 12. When the switching circuit 42 selects the internal composite signal, the switching circuit 44 prohibits the superimposition from the de-scrambler 12 by sealing the blanking signal, and when the switching circuit 42 selects the through composite signal from the de-scrambler 12, the switch circuit 44 permits the superimposition from the de-scrambler 12 by sending out the blanking signal.

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, and more particularly to a video tape recorder to which a descrambler for descrambling is connected.

[0002]

2. Description of the Related Art For example, there is a service that requires a paid descrambler to receive a broadcast, such as Canal Plus broadcast in France. In order to cope with this, video tape recorders destined for the same country are often provided with dedicated input terminals for descrambler connection. A video tape recorder adopting that format usually has a switch for selecting an output signal of its own recording / reprocessing system and an output signal from which the input from the descrambler connection terminal is sent as it is. It has the function of viewing and recording by freely switching between broadcasting that requires descrambling.

In this case, an RGB superimpose signal may be generated from the descrambler for the purpose of superimposing on the image sent from the descrambler. This RGB superimpose signal does not make sense unless it is combined with the composite signal from the descrambler. Therefore, in the conventional technique, as in the video tape recorder 1 shown in FIG. 3, the superimpose is prohibited by sealing the blanking signal by the switch circuit 2 during reproduction, and the reproduced image is reproduced by the RGB superimpose signal. I was avoiding being superposed by.

[0004]

In this conventional video tape recorder 1, since superimposing is unconditionally prohibited during tape reproduction, the switch circuit 3 is switched as shown by the dotted line in FIG. Even when the composite signal from the descrambler is viewed using the through function, superimposing cannot be executed unless playback is stopped.

Further, since the blanking signal is unconditionally output, that is, superimpose is allowed, except when the switch circuit 2 is switched as shown by the dotted line in FIG. 3, that is, during tape reproduction. Switch circuit 3
3 is switched as shown by the solid line in FIG. 3 and the general broadcast is being viewed by the tuner built in the video tape recorder 1, the RGB signal can be output from the descrambler.
If the superimpose signal is transmitted, the superimpose that is not related to the viewed video will be executed.

For example, even when a general broadcast (here, a baseball broadcast) as shown in FIG. 4 is being watched by the built-in tuner 4 of the video tape recorder 1, the descrambler displays the dialogue as shown in FIG. When a drama with a superimpose is sent, the dialogue of the drama is superimposed on the video of the baseball broadcast as shown in FIG. Moreover, since the superimpose is not combined with the composite signal from the descrambler, its position is not fixed, and the superimpose appears shifted in the vertical direction or flows in the horizontal direction.

Further, at this time, even when a general broadcast by the built-in tuner 4 is recorded and the signal being recorded is viewed on the monitor, the RGB superimpose signal from the descrambler superimposes the signal as described above. Is done. Although this superimpose is not recorded on the tape, it appears on the monitor screen, giving the illusion that it was recorded.

Further, assuming that a device for generating an RGB superimposing signal such as a teletext decoder is built in the video tape recorder itself, the RGB superimposing signal from the descrambler and the teletext decoder can be used. It is necessary to determine the selection and transmission of the RGB superimpose signal, but the conventional video tape recorder 1 cannot handle this.

Therefore, a main object of the present invention is to provide a video tape recorder which can be correctly superimposed depending on the source of a composite signal.

[0010]

According to the present invention, there is provided a through circuit for directly outputting a first composite signal from a descrambler, a processing circuit for outputting a second composite signal, a first composite signal and a second composite signal. First selecting means for selecting one of the signals, and first
Allows the superimposing from the descrambler when the first selecting means selects the first composite signal, and the superimposing from the descrambler when the first selecting means selects the second composite signal. It is a video tape recorder provided with a 2nd selection means to prohibit.

[0011]

When the first selecting means selects the output of the through circuit, that is, the composite signal from the descrambler,
In conjunction with the first selecting means, the second selecting means selects the blanking signal from the descrambler and sends it to the monitor. At this time, the RGB superimposing signal from the descrambler is given to the monitor as it is. Therefore, the blanking signal and the RGB superimposing signal from the descrambler are given to the monitor, and the image by the composite signal from the descrambler is also superimposed by the RGB superimposing signal from the descrambler. ..
When the first selecting unit selects the second composite signal from the processing circuit, the second selecting unit interlocks with the first selecting unit and seals the blanking signal from the descrambler. .. Therefore, R from the descrambler
Even if the GB superimpose signal is given to the monitor as it is, superimposition by it is prohibited.

[0012]

According to the present invention, the superimpose from the descrambler is allowed only when the video by the composite signal from the descrambler is displayed, so that the superimpose having no context with the video can be displayed. It can be prevented from being executed.

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the detailed description of the following embodiments made with reference to the drawings.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a video tape recorder 10 of this embodiment includes a descrambler connection terminal 14 to which a descrambler 12 is connected. The descrambler connection terminal 14 includes a descrambler input terminal 16 for inputting a demodulated composite signal, a blanking input terminal 18 for inputting a blanking signal, an RGB input terminal 20 for inputting an RGB superimpose signal, and a scramble before demodulation. It has a descrambler output terminal 22 for outputting a signal to the descrambler 12.

The video tape recorder 10 also includes a television set connection terminal 26 for connecting the television set 24. The television set connection terminal 26 is a line input terminal 28 for receiving a reception signal from a tuner (not shown) built in the television set 24, and an RGB superimposing signal for outputting an RGB superimpose signal from the RGB input terminal 20 to the television set 24. Blanking signals from the output terminal 30 and blanking input terminal 18 are supplied to the television set 2
4 and a composite output terminal 34 for outputting a composite signal to the television set 24.

Further, the video tape recorder 10 has a built-in tuner 36 and a recording / reproducing processing section 38 therein, and the recording / reproducing section 38 outputs a composite signal. The composite signal from the descrambler 12 input from the descrambler input terminal 16 passes through the through circuit 40 and one input 42 of the switch circuit 42.
Input to a. The output of the switch circuit 42 is connected to the composite output terminal 34 of the television set connection terminal 26, which allows the composite signal from the descrambler to be looped through. Then, the blanking signal input from the blanking input terminal 18 is input to one input 44a of the switch circuit 44. The output of the switch circuit 44 is the TV set connection terminal 2
6 is connected to the blanking output terminal 32. Also, the RGB input terminal 20 of the descrambler connection terminal 14
From the RGB output terminal 30 of the TV set connection terminal 26 to the TV set 24.

The composite signal of the descrambler 12 from the descrambler input terminal 16 of the descrambler connection terminal 14 is applied to one input 46a of the switch circuit 46 in addition to the through circuit 40. Switch circuit 4
The output from the built-in tuner 36 is given to the other input 46b of the reference numeral 6. The switch circuit 46 is switched so as to send one of these inputs to the recording / playback processing unit 38.
The output from the switch 46 is the switch circuit 48.
One input 48a is input. The composite signal from the line input terminal 28 of the television set connection terminal 26 is input to the other input 48b of the switch circuit 48. Therefore, the switch circuit 48 has the built-in tuner 36.
Recording / playback processing unit 3 by selecting either the composite signal from the TV set 24 or the composite signal from the descrambler 12 and the composite signal from the TV set 24.
Send to 8.

The output of the recording / playback processing unit 38, that is, the composite signal created inside the video tape recorder 10 is input to the other input 42b of the switch circuit 42. The composite signal from the television set 24 is input to the one input 50a of the switch circuit 50. Then, the composite signal from the built-in tuner 36 is input to the other input end 50b of the switch circuit 50. Also,
The composite signal from the output terminal of the switch circuit 50 is input to the descrambler via the composite output terminal 22 of the descrambler connection terminal 14. Therefore, the switch circuit 50 selectively gives the composite signal from the built-in tuner 36 or the composite signal from the television set 24 as the composite signal input to the descrambler.

In operation, for example, when the power supply of the video tape recorder 10 is turned off, or when the composite signal from the built-in tuner 36 is internally processed in the recording / playback processing unit 38, or tape playback is performed. If the switch circuit 50 is tilted to the one input 50a side, the descrambler 12
The scrambled signal before demodulation from the television set 24 is input to. In this case, even if there is a composite signal output from the recording / playback processing unit 38, the composite circuit signal from the descrambler is sent to the television set 24 through the through circuit 40 by tilting the switch circuit 42 to the one input 42a side. The video received by the television set 24 and demodulated by the descrambler can be displayed on the monitor of the television set 24.
At this time, since the switch circuit 44 interlocks with the switch circuit 42 and falls to the one input 44a side, the descrambler 1
The blanking signal from 2 is sent to the television set 24. Therefore, descrambler 12 to TV set 2
By the RGB superimpose signal sent to 4,
The loop-through function superimposes the image according to the composite signal from the descrambler 12 sent to the television set 24.

On the other hand, when the composite signal from the built-in tuner 36 is recorded and displayed on the monitor of the television set 24, or during tape reproduction, the switch circuit 42 is tilted to the other input 42b side. Then, in conjunction with the switch circuit 42, the switch circuit 44 is connected to the other end 44b.
Since the blanking signal from the descrambler is sealed, the superimposing by the RGB superimposing signal from the descrambler 12 is prohibited. As a result, it is possible to prevent superimposing from the descrambler 12 which has no context in the image by the internal processing of the video tape recorder 10. Therefore, even when a composite signal other than the composite signal from the descrambler 12 is recorded and the video being recorded is displayed on the monitor of the television set 24,
There is no possibility of giving the viewer an error that superimposing is performed by the RGB superimposing signal from the descrambler 12 and it is recorded.

Incidentally, such a video tape recorder 1
At 0, when the switch circuit 46 is tilted to the one input 46a side, the descrambler 12
The composite signal from is sent. In this case, the switch circuit 42 collapses to the other input 42b side, and the composite signal output of the recording / reproducing processing unit 38 is sent to the television set 24 to display the image. At this time, the RGB superimpose signal from the descrambler 12 is not superimposed on the image, but the RGB superimpose signal from the descrambler 12 can be viewed only in real time and is not recorded on the tape.
There is no problem if it is not superimposed.
At that time, if it is desired to see the contents of the superimpose, the switch circuit 42 may be switched so as to select the composite signal from the descrambler 12.

Next, referring to FIG. 2, a video tape recorder 10 of another embodiment has a teletext decoder 52 for receiving, for example, teletext, added to the video tape recorder 10 of the embodiment of FIG. It is a thing. In this case, the teletext decoder 52 is inserted between the switch circuit 48 and the recording / playback processing unit 38. Along with this, the teletext decoder 52 outputs an RGB superimposing signal and a blanking signal for teletext superimposing. In order to deal with this, the switch circuit 44 of FIG.
Replace with. The blanking signal from the descrambler 12 is input to one input 54a of the switch circuit 54, and the blanking signal from the teletext decoder 52 is input to the other input 54b. Further, the switch circuit 56 is provided on the line connecting the RGB input terminal 20 of the descrambler connection terminal 14 and the RGB output terminal 30 of the television set connection terminal 26. The RGB superimpose signal from the descrambler 12 is input to one input 56a of the switch circuit 56, and the other input 5
The RGB superimpose signal from the teletext decoder 52 is input to 6b.

The switch circuits 54 and 56 are switched in conjunction with the switch circuit 42. That is, when the switch circuit 42 selects the through circuit 40 side to loop through the composite signal from the descrambler 12, that is, when the switch circuit 42 falls to the one input 42a side, the switch circuit 54 causes the blanking from the descrambler 12 to occur. In order to select a signal, the one-sided input 54a side is collapsed, and in order to select the RGB superimpose signal from the descrambler 12, the switch circuit 56 is collapsed to the one-sided input 56a side.

When the switch circuit 42 selects the internal processing signal of the video tape recorder 10, that is, when it falls to the other input 42b side, the switch circuit 54 selects the blanking signal from the teletext decoder 52. To the other input 54b side and switch circuit 5
6 falls to the other input 56b side in order to select the RGB superimpose signal from the teletext decoder 52.

Therefore, the superimposing by the descrambler 12 or the teletext decoder 52 can be properly controlled in accordance with the composite signal sent to the television set 24.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing another embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional technique.

FIG. 4 is an illustrative view showing a transmission source from a built-in tuner in a specific state of FIG.

5 is an illustrative view showing a transmission source from a descrambler in the specific state of FIG. 3. FIG.

6 is an illustrative view showing an example in which a transmission source from the built-in tuner of FIG. 3 is superimposed by an RGB superimpose signal from the descrambler of FIG. 5 having no context.

[Explanation of symbols]

 10 ... video tape recorder 12 ... descrambler 14 ... descrambler connection terminal 24 ... TV set 26 ... TV set connection terminal 36 ... built-in tuner 38 ... recording / playback processing unit 40 ... through circuit 42, 44, 54, 56 ... switch circuit 52 ... Teletext decoder

Claims (1)

[Claims] 1. A through circuit for directly outputting a first composite signal from a descrambler, a processing circuit for outputting a second composite signal, and selecting one of the first composite signal and the second composite signal. And a first selecting unit that allows superimposing from the descrambler when the first selecting unit selects the first composite signal, and the first selecting unit includes the second selecting unit. A video tape recorder, comprising second selecting means for prohibiting superimposing from the descrambler when a composite signal is selected.