JPH0666923B2 - Video controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a digital television receiver having a multi-screen display function capable of simultaneously displaying a plurality of different channel images on one screen. The present invention relates to a video control device used in.

<Outline of the Invention> The present invention, in a video control device for controlling a multi-screen display function of a digital television receiver or the like, maintains this multi-screen state during multi-screen channel selection operation when switching from a multi-screen to a normal screen. However, after the tuning operation is completed, the multi-screen is switched to the normal screen.

<Prior Art> Conventionally, there has been disclosed a device which can simultaneously display a plurality of images on one screen by using a single tuner.
-16683, etc.

FIG. 3 shows a schematic configuration of these conventional video control devices.

1 is a system control circuit for controlling the entire system, 2 is a tuning circuit equipped with a tuner and a video signal processing section, 3 is a tuning control circuit for controlling the tuning circuit to select an arbitrary channel, and 4 is A / D converter 5, field memory 6, D /
A field memory circuit including the A converter 7 and an electronic switch 8 for selectively switching the tuner video signal output from the channel selection circuit 2 and the multi-video signal output from the field memory circuit 4.

Next, the operation will be described. The system control circuit 1 causes the channel selection control circuit 3 to perform channel selection operation by a channel selection control signal, and the tuner image signal is sequentially embedded in the divided portion of the multi-screen as a multi-image signal in the field memory circuit 4.
If the multi-screen is released during this operation, the system control circuit 1 outputs a multi-screen release signal and the electronic switch 8
To the curve video signal side, and a tuner video signal is output as a video output signal. Therefore, if you cancel the multi screen and switch to the tuner screen during the tuning operation of the multi screen, the tuner screen during the tuning operation is sent to the video output signal, and then the specified tuner screen is switched. . Therefore, if you cancel the multi-screen during tuning operation,
The tuning operation screen is displayed on the normal screen (screen that is not divided).

<Problems to be Solved by the Invention> In the above conventional technique, if the tuning operation is not completed when the multi-screen is switched to the tuner screen during the tuning operation, the screen during the tuning operation is monitored. There is a problem in that an image displayed on the screen and not specified by the user appears for a moment, which gives the user discomfort.

<Means for Solving Problems> In order to solve the above-mentioned conventional problems, a video control device of the present invention includes a video signal directly output from a channel selection circuit and a multi-video signal output from a field memory circuit. An electronic switch that selectively switches between and to produce a video output signal, and an image switching circuit that controls the electronic switch and holds the electronic switch in the multi-video signal during the multi-channel selection operation. It will be.

<Operation> The video control device configured as described above operates as follows.

That is, when the multi-screen is switched to the tuner screen while the tuning control circuit is performing the tuning operation, the video switching circuit operates the electronic switch until the tuning end signal is output from the multi-video signal. When the tuning end signal is output, a video switching signal is output and the electronic switch is switched to the tuner video signal side to switch from the multi screen to the tuner screen.

<Examples> Examples of the present invention will be described below with reference to the drawings. The same parts as in the conventional case are designated by the same reference numerals.

In FIG. 1, 1 is a system control circuit for controlling the entire system, 2 is a tuning circuit equipped with a tuner and a video signal processing section, 3 is a tuning control for controlling the tuning circuit to select an arbitrary channel. Reference numeral 4 denotes a field memory circuit including an A / D converter 5, a field memory 6, and a D / A converter 7, and 8 denotes a tuner video signal output from the channel selection circuit 2 and a multi-channel output from the field memory circuit 4. An electronic switch for selectively switching a video signal to a video output signal, and a video switching circuit 9 for controlling switching of the electronic switch.

Next, the operation of the video control device having the above configuration will be described. The video signal selected by the tuning circuit 4 is quantized by the A / D converter 5. It is stored in the field memory 6 as a part of the malech screen obtained by dividing the monitor screen. The data is D / A converted by the D / A converter 7, and the converted multi-video signal is displayed as a video signal on the monitor screen. These operations are sequentially applied to the divided parts of the multi-screen by the system control circuit 1 using the tuning control signal to the tuning control circuit 3. For example, 1ch → 3ch → 4ch → 6ch → 8ch → 1
Input 0ch → 12ch → ... to the field memory circuit 4 as a multi-screen. By the way, its operation process is 6ch → 8
When canceling multi during channel selection operation and the user specifies a channel different from the currently selected channel such as 12ch, the video output signal is 8ch video signal when switching from multi screen to tuner screen immediately. And then 1
Since the video signal is switched to the 2ch video signal, in the present invention, the electronic switch 8 is left on the multi-video signal side in the video switching circuit 9 during these switching periods. In other words, when the multi-screen is released, during the tuning operation with the station designation control signal d = "H" in the sections of FIGS. Even if the release signal a = "H", the video switching signal b = "L" is kept until the tuning end signal c = "H", the electronic switch 8 is on the multi-video signal side, and the video output signal is It becomes a video signal, and shifts to the section while maintaining the multi screen. The multi-screen is held in the section, the tuner video signal is no signal, and even if 8ch is output, it is not output to the video output signal sent to the monitor. When the channel selection control circuit 3 finishes the channel selection operation of 12ch, the station designation control signal d becomes "L", and the video switching circuit 9
The tuning end signal c = “H” to be transmitted to Thereafter, the video switching circuit 9 sets the video switching signal b to "H" to switch the electronic switch 8 to the tuner video signal side and select the tuner video signal as the video output signal (section).

<Effects of the Invention> As described above, according to the present invention, when the multi-screen is switched to the tuner screen during the channel selection operation, the screen may be disturbed when there is no vertical sync signal, or a channel that appears against the intention for a moment may appear. It is possible to significantly improve the visual sensation and the unnatural movement.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 (a) is a timing chart of each signal in the embodiment, and FIG. 2 (b) is a view showing a display state of a monitor in the embodiment. FIG. 3 is a block diagram showing a conventional example. 1 ... System control circuit, 2 ... Channel selection circuit, 3 ... Channel selection control circuit, 4 ... Field memory circuit, 8 ... Electronic switch, 9 ... Video switching circuit.

Claims (1)

[Claims] 1. A video control apparatus for switching channels at a constant cycle by a single tuner to store video signals of each channel and sequentially reading out the stored video signals to display images of a plurality of channels in one screen. A tuning circuit including the tuner, a tuning control circuit that controls the tuning circuit to perform a tuning operation, and a multi-video signal that quantizes and stores a video signal output from the tuning circuit. An electronic switch for selectively switching between a video signal output directly from the channel selection circuit and a multi-video signal output from the field memory circuit as a video output signal; and the electronic switch. A video switching circuit for controlling and holding the electronic switch on the multi-video signal side while the tuning control circuit is in the multi-tuning operation; A system control circuit for controlling the state and outputting a switching control signal between the multi-screen and the normal screen to the video switching circuit is provided, and even if a command for switching from the multi-screen to the normal screen is input to the system control circuit. A video control device, wherein a multi-screen display state is maintained until the tuning control circuit ends the multi-tuning operation.