JPS61269469A - Television receiver - Google Patents

Abstract

PURPOSE:To make it possible to project pictures in multimode in a picture by switching a tuner at a fixed period by a channel selection controlling section, making video signals of each broadcasting channel outputted successively, and storing video signals for 1 picture outputted successively in a buffer memory. CONSTITUTION:Signals for 1 picture is stored in a buffer memory 24. When storing of the picture data in the buffer memory 24 is completed, A central controlling section 28 operation of which is controlled by a program ROM 29 and a work RAM 30 transfers picture data from the buffer memory 24 to a display memory 26 in vertical flyback time. When transfer for data of one picture is completed, a tuner 2 is changed and set to display of video signals from the next television broadcasting station. When storing and transfer of picture data from eight television broadcasting station is completed, individual contact b1 of an input change-over switch 14 is changed to a contact c1, and video signals from an external video equipment introduced through an external input terminal 31 are inputted to a sub-video amplifier 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a television receiver, and particularly to a television receiver that can receive television images from a plurality of television broadcast stations and images from external video equipment such as a video tape recorder. This invention relates to a television receiver having a plurality of small screens, each of which is displayed on one television screen.

(Prior art) In current television broadcasting, the number of television broadcasting stations that can be received in one area is approximately nine, but programs from each of these television broadcasting stations are broadcast on one television screen. If it were possible to display all television programs simultaneously in the area, that is, in multi-mode, it would be convenient for viewers to be able to see all the television programs broadcast in that area and instantly select the program they would like to watch.

However, in order to display multiple television images in multi-mode on a single television screen using a conventional television receiver, it is necessary to install an additional tuner to accommodate the number of television images, which increases the number of television images. It is difficult to adopt this method because the manufacturing cost of the receiver is high.

(Object of the Invention) The present invention has been made in view of the above circumstances, and it is possible to display a plurality of television images on one television screen without increasing the manufacturing cost of the television receiver. The purpose is to be able to display images at the same time.

The present invention further provides that by utilizing a configuration for displaying a plurality of television images on one television screen, images from an external video device such as a video tape recorder (VTR) or a video disc playback device can also be displayed on the television screen. The purpose is to make the television multi-functional by allowing the television image to be displayed on both sides at the same time and having the function as a monitor for external video equipment.

(Structure of the Invention) In order to achieve the above object, the present invention includes a main circuit section that processes normal television images and a special image processing circuit section that performs special image processing such as multi-mode. , the main body circuit portion includes a tuner, a tuning control section, a video amplification section that amplifies and outputs a video signal selected by the tuning control section and output from the tuner, and a CR.
and a video output circuit to this CRT. An input selector switch that selectively introduces video signals, a buffer memory that stores one image of the video signal from the video amplification section or an external input terminal, and a display memory that stores one screen of the video signal of each of the images. a buffer memory control unit that controls writing of a video signal to the buffer memory; and a display memory control unit that controls writing from the buffer memory to the display memory and reading from the display memory; When displaying a television screen in multi-mode, the tuner is switched at regular intervals by the channel selection control section, and the video amplification section sequentially outputs the video signal of each broadcast channel from the tuner, and the video signal is sequentially output. 1 each of the video signal of the video amplification unit that comes and the video signal of the external video equipment
The image portion is stored in the buffer memory, the video signal stored in the buffer memory is transferred to the display memory, and the video signal is read from the display memory and sent to the CR'I' via the video output circuit. It is designed to be output.

(Example) The present invention will now be described in detail based on an example shown in the drawings. FIG. 1 is a circuit block diagram of the entire television receiver according to an embodiment of the present invention.

This television receiver is mainly divided into a main circuit section A that performs image processing so that a television image is displayed on a CRT in a normal state on one television screen, and a main circuit section A that processes a television image so that it is displayed on a CRT in a normal state on one television screen. In addition to image processing so that TV programs from each television broadcasting station and images from external video equipment can be displayed simultaneously on the screen, in other words, multi-mode, it also processes images for other strobe modes and two-screen mode. It is comprised of a special image processing circuit part B that is made to be able to perform the following functions.

In the main circuit section A, 1 is a television antenna, 2 is a tuner, 3 is a channel selection control section, 4 is a video amplification circuit, 5 is an audio signal processing section, 6 is a video signal processing section, 7 is a synchronization signal processing section, 8 9 is an audio output section, 9 is a video output section, IO is a deflection output section, 11 is a speaker, 12 is a deflection coil, and 13 is a CRT. Since such a configuration is a normal television receiver, only the names will be listed and a description of its operation will be omitted.

In this embodiment, the case where multiple small screens are simultaneously displayed on one television screen based on television signals from multiple television broadcasting stations and video signals from external video equipment is referred to as multi-mode. , a normal-sized television image (so-called main program) and a small-screen television image (
Dual-screen mode refers to the case where multiple television images are displayed frame-by-frame on a single television screen based on television signals from multiple television broadcasting stations. Let's call it strobe mode. In this embodiment, in addition to the multi-mode display, various other display modes can also be displayed on the television screen.

In the special image processing circuit portion B, the first. A second manual changeover switch 14,15 and a video cuff changeover switch 16 are provided.

The first manual changeover switch 14 has three individual contacts as
, bl, and cl, and in the multi-screen mode, two of these individual contacts bl and cl are selectively closed, and in the two-screen mode, the other individual contact a1 is closed.

The second manual changeover switch 15 has two individual contacts a2
, b2 and a movable contact C2. The movable contact C2 of the second manual changeover switch I5 is configured to switch to the individual contact b2 side in the multi-mode mode, and to switch to the individual contact a2 side in the two-screen mode.

The video output changeover switch 16 similarly consists of two individual contacts a3 and b3 and a movable contact c3, and this movable contact C3 switches between the two individual contacts a3 and b3, but in the case of normal television images. is its movable contact C
3 is switched to the individual contact a3 side, and switched to the individual contact b3 side in multi mode, dual screen mode, and strobe mode.

(Δ) Multi-mode Next, the configuration of the main part of the present invention will be described in the case where a multi-mode television image is displayed on a CRT+3.

In the first input changeover switch 14, first, the individual contact bl
, one b1 of cl is closed, and the second manual changeover switch! The movable contact C2 of No. 5 is switched to the individual contact h2 side, and the movable contact C3 of the video output changeover switch 16 is switched to the individual contact b3 side. The sub video processing section 20 is supplied with a video signal from the video amplification circuit 4 of the main circuit section A via the individual contact b1 of the first manual changeover switch 14.

By the way, in multi mode, the tuner 2 is controlled by the tuning control section 3.
Since the tuner 2 operates to switch one after another at a constant cycle, synchronization disturbance occurs when the tuner 2 is switched. In order to prevent this synchronization disturbance from occurring, a composite synchronization signal generation circuit 19 is provided. This composite synchronization signal generation circuit 1
The composite synchronization signal from 9 is sent to the second manual changeover switch 1.
The signal is applied to the synchronizing signal processing unit 7 via the individual contact b2 of 5 and the movable contact c2. The synchronization signal processing section 7 processes this composite synchronization signal and outputs it to the deflection output section 10, thereby preventing synchronization disturbance.

The sub-image processing unit 20 processes the applied image signal and extracts a luminance signal (Y) and a color difference signal (R-) from this image signal.
Y, B-Y) and a write synchronization signal. The synchronization signal from the sub video processing section 20 is a horizontal synchronization signal S
I-1 and the vertical synchronization signal SV to the buffer memory control unit 21. The buffer memory control section 21 outputs a switching signal that controls the operation timing of each circuit section based on the applied synchronization signal.

The luminance signal (Y) and color difference signal (Y) from the Zabu video processing unit 20
R-Y, B-Y) are provided to the multiplexer 22. The switching output from the multiplexer 22 is A/D converted by the A/D conversion circuit 23 and then temporarily stored (written) in the buffer memory 24 .

In such a case, the buffer memory control unit 2I controls the multiplexer 2 within one horizontal scanning line period (write line) once every three horizontal scanning line periods, as shown in FIG.
A write clock is output so that the switching output from 2 is written into the buffer memory 24. Also, as shown in FIG. 3, during the one horizontal scanning period which is this write line, the multiplexer 22 converts each image data of the luminance signal and the color difference signal into Yl, R1-Y, Y2J31-Y, Y
3. R2-Y, . . . are sequentially switched and output.

In this case, in order to display nine images on one television screen, the amount of image data in the vertical direction is set to 173, and in the horizontal direction, the read clock is three times as large as the write clock.

In this way, one image is stored in the buffer memory 24. When the storage of this image data in the buffer memory 24 is completed, the program ROM 29 and the work r(A
The central control unit 28, whose operation is defined by M30, transfers the image data from the buffer memory 24 to the display memory 26 during the vertical retrace period.

In this way, when the transfer of data for one image is completed, the corner 2 is switched and set to display the video signal from the next television broadcasting station. This setting is repeated eight times, and when the storage and transfer of each image data from the eight television broadcasting stations is completed, the individual contacts of the input selector switch 14 change from contact b1 to contact cl.
Then, a video signal from an external video device introduced through the external input terminal 31 is input to the sub video amplifying section 20. Regarding the video signal from this external video equipment, as well as the television signal from the television broadcasting station,
Each image is digitized and stored in the buffer memory 24, and then transferred to the display memory 26.

In this way, each image data transferred to and stored in the display memory 26 is then read out by the display memory control section 25, and then D/A converted by the D/A conversion circuit section 27, and outputted as a video image. It is output to the video output section 9 via the changeover switch I6 and displayed on the television screen -1- of (4T+3).

Now, on the television screen, as shown in FIG. 7(a), there are television images A, B, C2..., H from eight television broadcasting stations, and images from external video equipment. is displayed.

(B) Strobe mode In the strobe mode, the individual contact b1 of the first manual changeover switch 14 is closed, and the movable contact C2 of the second manual changeover switch 15 is switched to the individual contact b2 side. In addition, the movable contact C3 of the video output changeover switch 16 is an individual contact B.
Can be switched to side 3. In this strobe mode, the image data of one broadcast channel is stored in the buffer memory 24 at regular intervals without switching the tuner 2 as in (A) above. In this way, if you set it to one television broadcast station and repeat the multi-mode operation described in 1-1, multiple television images will be displayed on one television screen at the same time, like frame-by-frame, with a certain time lag. It will be done.

(C) Two-screen mode In this case, the individual contact a1 of the first manual changeover switch I4 is closed, and the movable contact C2 of the second manual changeover switch 15 is switched to the individual contact R2 side. The movable contact c3 is switched to the individual contact b3 side when displaying a small screen, and to the individual contact R3 side when displaying a normal size television image.

4'', small screen tuner 32 and video amplification circuit 33
The video signal processed by
4 to the sub-video processing section 20. In addition, the video signal for normal television images is transmitted to the video amplification circuit 4.
is output to the main body circuit portion A side via the individual contact a2 and the movable contact c2 of the second manual changeover switch 15.

The video signal given to the sub video processing section 20 is
), a luminance signal, a color difference signal, and a synchronization signal are created from the video signal, the synchronization signal is output to the buffer memory control section 21, and the luminance signal and color difference signal are output to the multiplexer 22. 22, as shown in FIG. 3, each image data of a luminance signal and a color difference signal is
During the horizontal scanning line period, Yl, rtl-Y, Y2 . Bl-Y
, Y3. R2-Y, . . . are sequentially switched and output.

The switching output from the multiplexer 22 is A/D converted by the A/D conversion circuit section 23 and then sent to the buffer memory 24.
The data is stored in a part (the shaded part) as shown in FIG. Writing to this buffer memory 24 is performed as described in (A) above.
It is similar to Further, each image data is transferred from the buffer memory 24 to the display memory 25, but this transfer is performed within the next horizontal scanning period of the write line as shown in FIG. It is applied to a part of the area (the shaded area). This transfer is controlled by the buffer memory control section 21. In this way, each image data transferred to this display memory 25 is read out by the display memory control section 25.

This readout is performed by reading A or reading L as shown in FIG.
It is read during the high level period of B.

Also, while read A or B is at a high level, =1
5- The movable contact c3 of the video output changeover switch 16 is switched to the individual contact b3 side, and during the period when the movable contact c3 is at a low level, the movable contact c3 is switched to the individual contact R3 side. Further, the position where each readout A or B becomes high level corresponds to the position on the television screen of the small screen moving image shown by the solid line or broken line in FIG. 7(b). In this case, readout ■-1 is the horizontal synchronization signal SH
It corresponds to Therefore, the position of this small screen moving image can be changed by controlling the high level position of readout A or B. In this way, each small screen moving image data output from the display memory 26 is transferred to the D/A
After being subjected to D/A conversion in the conversion circuit section 27, it is applied to the video output section 9 via the video output changeover switch 16, whereby the small screen moving image is displayed on the television screen on the CRT 13.

(Effects of the Invention) As described in Part 2, according to the present invention, when displaying multiple images in multi-mode, the tuner is switched at a constant cycle by the control unit, and the video amplifying unit switches the tuner to the tuner. The video signals of each broadcasting channel are sequentially output, one image of the sequentially output video signals is stored in a buffer memory, the video signal stored in the buffer memory is transferred to a display memory, and the video signal is transferred from the display memory. Since the video signal is read out and outputted to the CRT via the video output circuit, only one tuner is required, thus reducing the manufacturing cost of the television receiver and allowing multi-mode display on one television screen. It became possible to display television images.

Moreover, in the present invention, when displaying multiple images in multi-mode, the configuration for displaying multiple images is used to
Images from external video equipment such as a VTR can be displayed on a small screen, which is convenient for selecting the image you want to see.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of the entire television receiver according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the write-in and image data transfer, and FIG. 3 is for explaining the operation of the multiplexer. 4 is a diagram for explaining the multi-mode, FIG. 5 is a diagram for explaining the structure of the buffer memory, FIG. 6 is a diagram for explaining the structure of the display memory, and FIGS. 7(a)(b) ) are diagrams for explaining the multi-mode and two-screen mode, respectively, and FIG. 8 is a diagram for explaining the readout timing of each image data from the display memory. A is a main body circuit part, B is a special image processing circuit part, 14 is a second manual switching switch, 15 is a second manual switching switch, 16 is a video output switching switch, 21 is a buffer memory control unit, 24 is a buffer memory, 25 26 is a display memory, and 31 is an external input terminal. Patent attorney Oka, agent of Sharp Co., Ltd. 1) To Hidee Kazu

Claims (3)

[Claims] (1) The main circuit includes a main circuit section that processes normal television images and a special image processing circuit section that performs special image processing such as multi-mode, and the main circuit section includes a tuner, a channel selection control section, The special image processing circuit section includes a video amplifying section that amplifies and outputs a video signal selected by the tuning control section and output from the tuner, a CRT, and a video output circuit to the CRT. includes an input changeover switch for selectively introducing the video signal output from the video amplification section or the video signal from an external video device inputted through the external input terminal, and one of the video signals from the video amplification section or the external input terminal. A buffer memory that stores images,
a display memory that stores video signals for one screen of each image; a buffer memory control unit that controls writing of video signals to the buffer memory; and a display memory control section that controls readout, and the tuner is switched at a constant cycle by the channel selection control section when displaying a television screen in multi-mode, and the video amplification section is switched from the tuner to the display memory control section. sequentially outputs the video signals of each broadcasting channel, and stores one image each of the video signal of the video amplifying section and the video signal of the external video equipment, which are sequentially output, in the buffer memory; A television receiver that transfers a video signal to the display memory, reads the video signal from the display memory, and outputs the video signal to the CRT via the video output circuit. (2) When displaying a television screen in strobe mode, one image of a video signal on one broadcast channel is stored in the buffer memory at a constant cycle without switching the broadcast channel. The television receiver described in . (3) When displaying a television screen in two-screen mode, image data of one broadcast channel is stored in a buffer memory in units of one display horizontal scan, and the storage contents of the buffer memory are transferred to the buffer memory in the next horizontal scan period. The storage and transfer are repeated during the display scanning period, and the small screen moving image is read out from the display memory during the display period of the synchronization signal to display the small screen moving image in the normal television image. The television receiver according to scope 1 or 2.