JPS6114707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television receiver capable of simultaneously displaying images of a plurality of channels on one screen.

Traditionally, this type of television receiver has been capable of simultaneously projecting images from two channels, the main and sub channels, on one screen, as in the case of Japanese Patent Application No. 47-39273 (Japanese Unexamined Patent Publication No. 49-2419). have already been proposed and some have been put into practical use.

First, the basic operation of a conventional television receiver capable of simultaneously displaying images of two channels, the main channel and the sub channel, will be explained with reference to FIG.

In Fig. 1, there is an antenna, 2 a tuner for receiving the main channel, 3 an intermediate frequency amplification circuit, 4 a video detection circuit, 5 a video amplification circuit, 6 an audio detection circuit, and 7 an audio amplification circuit. , 8 is a speaker, 9 is a tuner for sub-channel reception, 10 is the same intermediate frequency amplification circuit, 11 is the same video detection circuit, 1
2 is the video amplification circuit, 13 is the synchronous separation circuit, 14
15 is a vertical deflection circuit, 15 is a horizontal deflection circuit, 16 is a signal switching circuit, 17 is a video output circuit, 18 is a picture tube, 19 is a synchronization separation circuit for sub-channels, 20 is a storage device, and 21 is a control signal generation circuit. , and 22 are main channel selection switches SW ₁ , SW ₂ ,
...SW ₉ and secondary channel selection switch
A channel selection operation unit having SW ₁ ′, SW ₂ ′...SW ₉ ′, 23
are switching transistors TR ₁ , TR ₂ , ...
TR ₉ Variable resistor for main channel setting VR ₁ , VR ₂ ,…
...VR ₉ and a main channel selection circuit having diodes D ₁ , D ₂ , ...D ₉ , 24 is a switching transistor TR ₁ ′, TR ₂ ′, ... TR ₉ ′, and a variable resistor VR ₁ for setting the sub channel. ′, VR ₂ ′, . . . VR ₉ ′, and diodes D ₁ ′, D ₂ ′, . . . D ₉ ′.

If any one of the main channel selection switches SW ₁ to _{SW 9} of the channel selection operation unit 22 is turned on, the switching transistors TR ₁ to TR are connected to the channel selection circuit 23 corresponding to that switch. TR ₉ no 1
is turned on, and the tuning voltage preset by variable resistors VR ₁ to VR ₉ is applied to the diode D _{1 .}
~ _D9 to the main channel reception tuner 2, and the channels corresponding to the channel selection switches _SW1 ~ _SW9 are received. That is, at this time, the main channel television signal received and processed by the tuner 2 for main channel reception, the intermediate frequency amplification circuit 3, the video detection circuit 4, and the video amplification circuit 5 is transmitted via the signal switching circuit 16 and the video output circuit 17. Picture tube 18
The main channel image is projected onto the main part of the picture tube 18. Also, at this time, the audio intermediate frequency signal of the main channel obtained from the video amplification circuit 5 is audio detected, and the audio signal after detection is amplified by the warm voice amplification circuit 7 and supplied to the speaker 8.
The audio of the main channel is emitted from the speaker 8.

On the other hand, if one of the sub channel selection switches SW ₁ ′ to _{SW 9} ′ of the selection operation section 22 is turned on at the same time, the variable resistors VR _{1 ′} to SW 9 ′ are turned on in the same way as in the above case.
The tuning voltage preset by VR ₉ ' is supplied to the tuner 9 for receiving sub-channels via the diodes _D1 ' to _D9 ', and the channels corresponding to the channel selection switches _SW1 ' to _SW9 ' are received. be done. That is, at this time,
The television signal of the width channel received and processed by the tuner 9 for sub-channel reception, the intermediate frequency amplification circuit 10, the video detection circuit 11, and the video amplification circuit 12 is supplied to the storage device 20, where it is sent to the control signal generation circuit. Based on the control signal from 21, the television signals of each scanning line of the reduced number of scanning lines, for example, one out of every three scanning lines, are sequentially written into the storage device 20, and the signals once written in this way are It is read out intermittently and sequentially at three times the writing speed, and as a result, the time axis is read out from the storage device 20.
A sub-channel television signal compressed to 1/3 is derived. When this compressed sub-channel television signal is supplied to the signal switching circuit 16, it is switched based on the control signal of the control signal generating circuit 21 and is replaced with the main channel television signal obtained from the video amplifier circuit 5. Picture tube 18
As a result, a sub-channel image of 1/3 the size is simultaneously displayed on a part of the main channel screen of the picture tube 18. Here, the size of the sub-channel image is determined by the rate at which the sub-channel television signal is time-base compressed in the storage device 20. Further, the position of the image on the sub-channel is determined by a control signal from the control signal generation circuit 21.

As described above, the images of the sub-channel are simultaneously displayed on a portion of the main-channel television screen.

However, with the above-mentioned television receiver, only two images, the main and sub images, can be displayed on one screen at the same time, and if you want to display more images at the same time, you will have to use the same number of channels as the number of images. Must be expanded.

Currently, in Japan, the number of broadcast stations that can be received in one area is nine at most, and if nine images are displayed simultaneously on one screen, it is possible to check all broadcast channels in that area at the same time. In this case there are usually 9 chunas and 9 BBDs.
Alternatively, a memory element such as RAM is required.

The present invention effectively utilizes two tuners in a television receiver that can simultaneously display images of two channels, a main channel and a sub channel, and displays images of a plurality of channels, for example, two channels, on the same screen when desired. To provide a television receiver capable of simultaneously displaying images.

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 2 shows one embodiment of the present invention in a block diagram, in which the same parts as in FIG. 1 are given the same reference numerals. Here, the television receiver shown in FIG. 1 is further equipped with a clock pulse generator 25, electronic switching circuits 26, 28, 32, an octal ring counter 30, a signal switching circuit 31, a control signal generation circuit 33, storage devices 27, 34, In addition to adding an address counter 35, the channel selection operation section 22 is provided with a multi-screen switch SW ₁₀ .

Here, the operation when the main channel selection switches SW ₁ to _{SW 9} and the sub channel selection switches SW ₁ ′ to SW ₉ ′ of the selection operation section 22 are in the on state is shown in FIG. 1 described above. It is exactly the same, and at this time, images of two channels, the main channel and the sub channel, are projected on the screen of the picture tube 18.

However, if the multi-screen switch SW ₁₀ of the channel selection operation unit 22 is turned on at the desired time in this state, the main channel selection switches SW ₁ to
Leave SW ₉ as it is and use it as the sub channel selection switch.
SW ₁ ′ to SW ₉ ′ are all turned off, and the switching circuits 26 and 28 are turned on.

Therefore, at this time, the main channel video signal obtained from the main channel receiving video amplification circuit 5 is supplied to the storage device 27 via the switching circuit 26, where it is extracted at a ratio of one for every three scanning lines. It is written and read intermittently at three times the writing speed, and thus the storage device 27
A video signal of the main channel whose time axis is compressed is derived at predetermined intervals controlled by the control signal of the control signal generation circuit 33, and this is sent to the picture tube via the signal switching circuit 31 and the video output circuit 17. 18. As a result, the television image of the main channel is displayed in a reduced size on the screen of the picture tube 18, for example, in the lower right corner shown in FIG.

On the other hand, at this time, the clock pulse generated by the clock pulse generator 25 is applied to the switching circuit 28.
is supplied to the octal ring counter 30 via the octal ring counter 30.
Here, in the clock pulse generator 25, for example,
Since a 200msec clock pulse is generated, the octal ring counter 30 has a clock pulse of 200msec →
→→・・・→→, 1.6
It completes one cycle every second.

Therefore _, in the channel selection circuit 24, the switching transistors TR ₁ ′, TR _{2 ′ ,} TR _{3 ′} .
The tuning voltage set to VR ₈ ' is sequentially switched and supplied to the tuner 9 for receiving the sub-channel. As a result, the video amplification circuit 1 for receiving the sub-channel
The video signals of the respective channels received in this way are sequentially derived from 2, and are supplied to the storage device 34 via the switching circuit 32. The switching circuit 32 is turned on every time a clock pulse is supplied from the clock pulse generator 25, that is, every 200 msec. Therefore, at this time, the tuning circuit 2
Four variable resistors VR ₁ ′, VR _{2 ′} , .

The storage device 34 is composed of a group of storage elements such as BBD elements, has a storage capacity for eight screens, and an address counter 35 specifies the writing and reading positions thereof. In the storage device 34, the video signal of each channel is extracted at a rate of one for every three scanning lines based on the control signal from the control signal generation circuit 33, and one video signal is extracted from the storage element of each designated address.
Each frame (one screen) is written. Note that since the address counter 35 is driven by the clock pulse of the clock pulse generator 25 and is therefore synchronized with the operation of the ring counter 30, the video signals of each channel cannot be individually written to the same memory element. become. In other words, the video signals of each channel written in each memory element are intermittently rewritten with new signals every 1.6 seconds.

Meanwhile, in the storage device 34, the video signal of each channel from each storage element is designated by the address counter 34 at a higher speed than the writing speed (in this case, three times the writing speed) based on the control signal from the control signal generation circuit 33. The data are sequentially and repeatedly read out in the same order.

The video signals of each channel read out from the storage device 34 are supplied to the picture tube 18 via the signal switching circuit 31 and the video output circuit 17, and as a result, the screen of the picture tube 18 is displayed as 8 as shown in FIG.
Images of three channels are displayed simultaneously at positions A, B, C...H. In this case, each image is 1.6
The image is switched to a new image every second, and the image remains static for 1.6 seconds during this period.The inventors have experimentally found that with a static image of this level, the broadcast contents of each channel can be easily adjusted, although the movement may be a bit strobe-like. I made sure that I knew enough. Of course, the clock pulse period of the clock pulse generator 16 is
It goes without saying that the shorter the clock pulse period is to 150 msec or 100 msec, the closer the image will be to a natural image, but in order to obtain stable operation of the tuner 9, etc., it is impossible to shorten the clock pulse period too much.

In this way, in this embodiment, the multi-screen switch
When SW ₁₀ is turned on, part of the picture tube screen displays the image of the main channel that was being received.
The images are reduced to 1/9 and displayed, and the images of eight channels are also displayed simultaneously, allowing viewers to easily know the broadcast contents of each channel without having to turn on the channel selection switches SW ₁ to _{SW 9} in sequence. be able to.

In this case, the image of the main channel that had been received up to that point will be reduced but will continue to be displayed continuously on a part of the screen, and the audio of this main channel will be emitted from the speaker 8, which may be particularly inconvenient. There isn't.

After turning on the multi-screen switch SW ₁₀ and viewing the broadcast contents of each channel as described above, turn off the multi-screen switch SW ₁₀ and turn on the channel selection switches SW ₁ to _{SW 9} of the desired channel. At this time, the switching circuits 26, 28
is turned off, and the signal switching circuit 31 is switched back to its original state. At this time, the desired channel is continuously received and the received image is displayed on the picture tube screen.

In the above embodiment, the storage devices 27 and 34
An example of using an analog storage element such as a BBD element has been described, but of course it is also possible to convert the video signal into digital video information and store it using a digital storage element such as RAM and an AD converter and a DA converter. Good too.

According to the present invention, in a television receiver having two tuners and displaying images of two channels, the main channel and the sub channel, as described above, a specific channel selected by one of the tuners can be displayed at a desired time. The video signal is once written to the first storage device, and at this time, the other tuner sequentially selects a plurality of channels at a fixed period, and the video signals of the plurality of channels obtained in this way are individually written to a predetermined location in the second storage device. Write intermittently to the address of
Since the video signals of each channel are read out at high speed from the second storage device in a predetermined order corresponding to the screen position and supplied to the picture tube, the picture of a specific channel is reduced and displayed continuously on the picture tube screen. In addition to the images of multiple channels, for example eight, being displayed simultaneously in a strobe-like manner, viewers can instantly know the broadcast contents of each channel without having to repeatedly select channels, which is very convenient. It is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional television receiver, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is an explanatory diagram of a television screen displayed in the same embodiment. 2... Tuner for main channel reception, 9... Tuner for sub channel reception, 22... Tuning operation section, 23... Tuning circuit for main channel, 24...
Sub channel selection circuit, 25...Clock pulse generator, 27...Storage device, 30...Octal ring counter, 31...Signal switching circuit, 33...Control signal generation circuit, 34...Storage device, 35 ...address counter.

Claims (1)

[Claims] 1. In a television receiver having two tuners and displaying images of two channels, main and sub, at the same time, the television signal of a specific channel selected by one of the tuners is temporarily written and stored at a desired time. At the same time, the other tuner repeatedly selects a plurality of channels in sequence at a constant cycle, and the television signal of each channel obtained by the channel selection means is individually sent to a predetermined address. a second storage means for intermittently writing and storing; and a readout control means for reading out the television signals of each channel from the first and second storage means in a predetermined order corresponding to the screen position at a higher speed than when they were written. A television, characterized in that it is capable of continuously displaying a reduced image of a specific channel at a predetermined position on one screen when desired, and further displaying strobe-like images of a plurality of channels at the same time. receiver.