JP2964503B2 - Television receiver - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver capable of switching and displaying a plurality of video sources, for example.

[Summary of the Invention]

The present invention relates to, for example, a television receiver capable of switching and displaying a plurality of video sources, in which a first image memory, a second image memory, and a video signal read from the first image memory are sequentially supplied. Display means, and memory switching means for supplying an input video signal to the first or second image memory, wherein when the input video signal is switched from the first video signal to the second video signal, A signal corresponding to the last one screen of the first video signal is written to the first image memory, and a signal corresponding to the first one screen of the second video signal after synchronization is obtained is stored in the second image signal. The first video signal and the second video signal are written on the screen of the display means while the contents of the second video memory are sequentially transferred to the first video memory. Divided into still images at the same time When the transfer of the contents of the second image memory is completed, the second video signal is supplied to the first image memory to display a moving image on the display means. By doing so, the image on the display screen of the display means is switched to the next image without being disturbed.

[Conventional technology]

When the video source is switched from a TV tuner to a video tape recorder (VTR), or when the video source is a TV tuner and the receiving channel is switched, generally, the image on the monitor display screen is temporarily disturbed. On the other hand, recently, there has been developed a television receiver in which a disturbance of an image is prevented by a so-called image mute method when a reception channel is switched. In this case, for example, when the receiving channel is switched from channel 1 (FIG. 5A) to channel 3 (FIG. 5C), as shown in FIG. 1) becomes a blanking state.

[Problems to be solved by the invention]

However, even if the disturbance of the image on the display screen (1) is eliminated, simply turning the display screen (1) into the blanking state may not be sufficient for some viewers. Furthermore, recently, with the advance of digital technology, various kinds of image processing can be performed even on a television receiver.

In view of the above, it is an object of the present invention to prevent an image on a display screen from being disturbed by a method other than image muting when a video source is switched or a receiving channel is switched.

[Means for solving the problem]

As shown in FIG. 1, for example, a television receiver according to the present invention includes a first image memory (9), a second image memory (10), and a video signal read from the first image memory (9). And a memory switching means (8) for supplying an input video signal to the first or second image memory (9). The input video signal is supplied to the first or second image memory (9). When switching from the video signal to the second video signal, a signal corresponding to the last one screen of the first video signal is transmitted to the first video signal.
And a signal corresponding to the first one screen of the second video signal after synchronization is written into the second image memory (10). While the contents of the image memory (10) are sequentially transferred to the first image memory, the first video signal and the second video signal are divided on the screen (15a) of the display means (15). The second video signal is supplied to the first image memory (9) when the transfer of the contents of the second image memory (10) is completed. In this way, a moving image is displayed on the display means (15).

[Action]

According to the present invention, when the input video signal switches from the first video signal to the second video signal, the display means (15) displays the last signal of the first video signal. Is supplied while being gradually replaced by the first signal of the second video signal. Therefore, the display means (15)
Is switched from the image of the first video signal to the image of the second video signal as in the case where the scene of a picture-story show changes.

〔Example〕

Hereinafter, an embodiment of a television receiver according to the present invention will be described with reference to FIGS.

FIG. 1 shows a television receiver of the present embodiment.
In the figure, reference numerals (2) to (4) denote input terminals, a video signal output from a TV tuner is supplied to the input terminal (2), and VTR-signals are supplied to the input terminals (3) and (4). A
And a video signal output from the VTR-B. The input terminals (2) to (4) are connected to the first to third fixed contacts of the input stage switch circuit (5), respectively, and the video signal appearing at the movable contact of the switch circuit (5) is converted into analog / digital signals. (A / D) The signal is supplied to the input terminal of the converter (6) and the input terminal of the synchronization separation circuit (7), and the output port of the A / D converter (6) is connected to the data selector (8) for memory switching. Connect to input port.

(9) is for the first video signal composed of a frame memory
RAMs (VRAM) and (10) denote second VRAMs, each of which is also comprised of a frame memory. One and the other output port of the data selector (8) are connected to a first VRAM (9) and a second VRAM, respectively.
Connect to the data input port of (10) and connect to the second VRAM (10)
Is connected to the data input port of the first VRAM (9). (11) indicates a control terminal. The control terminal (11) has a video source when the video source is switched by the input stage switch circuit (5) and a video source which is a TV.
When the receiving channel is switched in the case of a tuner, a control signal which becomes high level "1" for a predetermined period and becomes low level "0" in other periods is supplied from a control circuit (not shown). When the control signal is at a low level "0", the data selector (8) transfers the input data to the first VRAM (9).
And when the control signal is at a high level "1", the input data is supplied to the second VRAM (10).
Accordingly, the video signal for one frame is temporarily written into the second VRAM (10) only when the reception channel is switched.

Further, the synchronization separation circuit (7) supplies the separated synchronization signal to the memory controller (12), and the memory controller (12) transmits the pulse and the address signal for controlling the read / write timing to the first and second VRAM (9). ), (10), and the video signal read from the first VRAM (9) is supplied to D /
It is supplied to a cathode ray tube (15) via an A converter (13) and a video processing circuit (14) having a Y / C separation circuit and a matrix circuit. (16) is a deflection processing circuit.
Note that, for example, a Y / C separation circuit is connected to the input stage switch circuit (5) and A
It is also conceivable to arrange between the / D converter (6).

The operation of the television receiver of this example when the receiving channel is switched from the first channel to the second channel when the TV tuner is selected by the input stage switch circuit (5) will be described. In this case, after a video signal for one frame of the first channel is written to the first VRAM (9), the input circuit of the data selector (8) changes the input data of the second VRAM ( 10) The receiving channel of the TV tuner is switched to the second channel as supplied to the side. And the second
Of the second channel is synchronized.
After the video signal for the frame is written into the second VRAM (10), the control circuit transfers the image data of the second VRAM (10) partly to the first VRAM via the memory controller (12).
Transfer to (9).

The image data transfer procedure will be described in detail with reference to FIG. 2. The storage areas of the VRAMs (9) and (10) are stored in the horizontal direction (X direction) of the display screen (15a) of the cathode ray tube (15).
And the vertical direction (Y direction). First, as shown in FIG. 2A, the image data of the storage area (10a) of the second VRAM (10) corresponding to the display area of the predetermined width at the left end in the horizontal direction on the display screen (15a) is directly stored in the display area. The data is transferred to the corresponding storage area (9a) of the first VRAM (9). Since the image data of the first VRAM (9) is always read and supplied to the cathode ray tube (15), the second VRAM
The transfer of image data from (10) to the first VRAM (9) is executed at high speed during the vertical blanking period of the cathode ray tube (15).

Then, during the next vertical blanking period, as shown in FIG. 2B, the first data corresponding to the image data of the storage area (10b) adjacent to the storage area (10a) of the second VRAM (10) as it is. The data is transferred to the storage area (9b) of the VRAM (9). Similarly, as shown in FIG. 2C, the image data in the storage area (10c) of the second VRAM (10) is stored in the storage area (9) of the first VRAM (9).
Transfer to c) and repeat the transfer operation. And the second V
After all the image data of the RAM (10) is transferred to the first VRAM (9), the control circuit ensures that the input data of the data selector (8) is always supplied to the first VRAM (9). .

Therefore, the receiving channel is shifted from the first channel to the second channel.
When switching to the channel of the cathode ray tube (15)
The image on the display screen (15a) is a moving image of the first channel (FIG. 3A) → a still image of the first channel (FIG. 3B).
→ Image in which the still image of the first channel changes to a still image of the second channel in a picture-story show (FIGS. 3C and 3D) → 2nd image
Of the channel (FIG. 3E). That is, also in this example, disturbance of the image on the display screen when the reception channel is switched is prevented. Furthermore, according to the present example, unlike the case of using the conventional image muting method, the display screen (15a) does not go into a blanking state, and thus there is an advantage that the viewer has no discomfort at all.

In the above-described embodiment, the image of the first channel is gradually switched to the image of the second channel in the horizontal direction (X direction) on the display screen (15a). However, as shown in FIG. The image of the channel may be gradually switched to the image of the second channel in the vertical direction (Y direction). Also, in the case where the video source is switched from the TV tuner to the VTR-A in the above embodiment, the second VRA
By using M (10), the image of the display screen (15a) can be gradually switched to the image of the VTR-A video signal.

The present invention is not limited to the above-described embodiments, and may adopt various configurations without departing from the spirit of the present invention.

〔The invention's effect〕

According to the present invention, when the receiving channel or the video source is switched, the image on the display screen is sequentially switched to the next image without being disturbed, so that there is an advantage that the display screen does not enter a blanking state. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of an embodiment of a television receiver according to the present invention, and FIG. 2 is a VRAM (10) of the embodiment.
FIG. 3 is a diagram for explaining the means for transferring image data from the RAM to the VRAM (9), FIG. 3 is a front view showing a change in the image on the display screen at the time of input switching of one embodiment, and FIG. FIG. 5 is a front view showing a display screen of an example, and FIG. 5 is a front view showing a change of an image on the display screen at the time of input switching in a conventional example. (8) is a data selector for memory switching, (9) is a first video signal RAM (VRMA), (10) is a second video signal RAM (VRAM), (12) is a memory controller, (1)
4) is a video processing circuit, and (15) is a cathode ray tube.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 5/38-5/46 H04N 5/262-5/28

Claims (1)

(57) [Claims] A first image memory; a second image memory; display means to which video signals read out from the first image memory are sequentially supplied; and an input video signal for the first or second video memory. Memory switching means for supplying to the image memory, when the input video signal is switched from the first video signal to the second video signal, a signal corresponding to the last one screen of the first video signal The first image memory is written, and a signal corresponding to the first one screen of the second video signal after synchronization is written into the second image memory. Are sequentially transferred to the first image memory, the first video signal and the second video signal are divided on the screen of the display means, and are simultaneously displayed in a still image state. At the same time, the transfer of the contents of the second image memory is completed. When the television receiver, characterized in that said second video signal is then supplied to the first image memory so as to display the video on the display means.