JPH025072B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video control device for a television receiver that displays images of other programs as part of the television image being received.

Conventional configurations and their problems Recently, television receivers have been announced that display one image with another image inserted into it. The idea behind this method is shown below.

FIG. 1 is a conceptual diagram of an inset display type television receiver, where A is the television receiver and B is the television receiver.
C is a parent image portion, and C is a child image portion into which another TV image is reduced and inserted.

Hereinafter, a conventional video control device will be described with reference to the drawings.

FIG. 2 is a block diagram of a conventional video control circuit.

In the figure, the video signal for the parent image () is provided by a signal processing circuit () 11 and a video control circuit () 12.
and is processed by the D/A conversion circuit ( ) 13 and supplied to the insertion circuit 31. Further, the video signal for the child image () is processed by the signal processing circuit () 21, the D/A conversion circuit () 23, and the video control circuit () 22, and is supplied to the insertion circuit 31, where the parent image signal and is supplied to the cathode ray tube 31. The part surrounded by the dotted line in the figure is the circuit for the child image signal.

Here, the video control circuits 12 and 22 are independently controlled by a digital control signal () and a DC voltage control signal (), respectively. For this reason, for example,
If the video of the parent image and child image is set to the maximum by the user adjustment, and the video of the parent and child images is equivalent, when the video of the parent image is changed to the smaller setting, the video control will be independent for the parent and child. Because we are
Compared to the parent image, only the child image shines brightly, making it difficult to see. In such a case, there is a drawback that the image of the child image must be reset to an appropriate location to match the parent image. Here, video control means control of signal amplitude or brightness.

OBJECT OF THE INVENTION The present invention solves the above-mentioned drawbacks, and is capable of independently controlling the desired video for both parent and child images, and automatically controlling the video of the child image appropriate for the video control of the parent image. The purpose of this invention is to provide a video control circuit that can perform the following functions.

Configuration of the Invention A video control device according to the present invention includes a first video control circuit that controls a first video signal, a D/A conversion circuit that converts the controlled signal into a D/A, and a D/A conversion circuit that performs D/A conversion of the controlled signal. An insertion circuit that inserts a second video signal controlled by a second video control circuit into the first video signal is provided, and the first control signal of the first video control circuit is D/A converted, and this signal is is provided with a D/A conversion superimposition circuit that superimposes the signal on the second control signal of the second video control circuit, and the first and second video signals are independently used as the first and second control signals, and The first control signal can simultaneously control the first and second video signals.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a block diagram of a video control device according to an embodiment of the present invention. In FIG. 3, components having the same names and numbers as those in FIG. 2 perform the same operations, so their explanations will be omitted.

41 is a D/A conversion superimposition circuit, which is a feature of this device. The control signal () (for parent image) that controls the video control circuit 12 is also supplied to this D/A conversion superimposition circuit 41, and the control signal () is converted into a D/A
It is converted and superimposed on the control signal () for the child image at a certain ratio. This superimposed control signal is supplied to the video control circuit ( ) 22 to control the video signal ( ) for the child image.

In the video control circuit configured as described above, the video signals for the parent image and the child image can be controlled independently by the control signals () and (), and in conjunction with the control signal (), It is also possible to control the video signal ( ) of the small screen image at a certain ratio.

FIG. 4 shows a specific circuit example of one embodiment of the D/A conversion/superimposition circuit 41 shown in FIG. 3. In the figure, components having the same names and numbers as in FIG. 4 perform the same operations, and their explanations will be omitted. D/A converting the control signal () from digital data using a pulse width modulation output type D/A converter 51;
Furthermore, the pulse width is modulated, and the output is supplied to the intersection of resistors 64 and 65 using a pull-up resistor 61, an integrating resistor 62, and a capacitor 63, and the control signal ()
are superimposed at a certain ratio.

The control signal ( ) is a voltage obtained by resistively dividing Vcc by resistors 64 and 65 and a variable resistor 66 , and the voltage obtained by superimposing this voltage and the control signal ( ) above is applied to 22 Controls the video control circuit ().

Effects of the Invention As described above, according to the present invention, by D/A converting the control signal for the parent image () and superimposing it on the control signal for the child image, the amplitude or brightness of the signal for the parent and child screens can be adjusted. , can be set independently to the desired state, and can control the appropriate amplitude or brightness of the child screen in conjunction with the settings of the parent screen, eliminating the troublesome settings of parent and child screens. Furthermore, as is clear from the configuration shown in FIG. The video control of the child image is performed by superimposing it on the analog control signal of the child image, so that the child image is automatically controlled only when the main parent image is controlled, and the parent image is not controlled when the child image is controlled. By simply setting the desired child image to match the parent image, a child image that follows the control of the main parent image can always be obtained.

[Brief explanation of drawings]

FIG. 1 is a front view showing the concept of a built-in display type television receiver, FIG. 2 is a block diagram of a conventional video control device, and FIG. 3 is a block diagram of a video control device according to an embodiment of the present invention. FIG. 4 is a circuit diagram showing a specific circuit example of the D/A conversion and superimposition circuit used in the same embodiment. 12... Video control circuit (), 13... D/A conversion circuit, 31... Insertion circuit, 22... Video control circuit (), 41... D/A conversion superimposition circuit.

Claims (1)

[Scope of Claims] 1. A first video control circuit that controls a first video signal forming a parent image, and a D/
A D/A conversion circuit that performs A conversion, and a second video signal that is controlled by a second video control circuit for the first video signal that has been D/A converted.
an insertion circuit for inserting the video signal of the first image as a child image, and a first video signal of the first video control circuit.
D/A converts the control signal of the
D/ to be superimposed on the second control signal of the video control circuit of
1. A video control device, comprising: an A conversion superimposition circuit, and configured to simultaneously control the first and second video signals using the first control signal. 2. The video control device according to claim 1, wherein the D/A conversion superimposition circuit comprises a pulse width modulation output type D/A converter and an integrating circuit that integrates the output thereof.