JPH05103279A - Master screen display video device - Google Patents

Abstract

PURPOSE:To obtain a most satisfactory display without any video signal of a master and slave screen by operating the inversion of the master and slave screen, or a PinP (both master and slave screen display function) ON/OFF control by the detection of the video signal of the master and slave screen. CONSTITUTION:When only the input signal (a) of the master screen is present, and only the periodic signal is detected, a PinP ON/OFF control circuit 13 is controlled by a master and slave screen control circuit 12, the PinP is turned OFF, the switching of the input signal is not operated by an input switching control circuit 14, and only the input signal (a) of the master screen is guided to a PinP output switching circuit 5, and outputted as it is. Also, when only the input signal (b) of the slave screen is present, and only the periodic signal is detected, the input switching control circuit 14 is switched by the master and slave screen control circuit 12, and the input signals (a) and (b) are inverted. Thus, the input signal (b) is turned to the signal of the master screen, and outputted while only the master screen is present. Afterwards, the PinP of the PinP ON/OFF control circuit 13 is turned OFF by the input switching control circuit 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parent-child screen display image device in which a child screen is displayed in a parent screen, and more particularly to a television receiver or a VTR having a parent-child screen display function. The present invention relates to a parent-child screen display video device.

[0002]

2. Description of the Related Art In recent years, as television receivers have become larger and more sophisticated, video equipment with a parent-child dual-screen display function (hereinafter referred to as "PinP") for displaying a sub-screen within the main screen has been developed. ing. FIG. 3 shows the configuration of the conventional video equipment. In FIG. 3, reference numeral 1 is an analog processing unit, and the analog processing unit 1 is a changeover switch circuit 2 for switching between input signals a and b which are video signals of a parent and child screen, a chroma / synchronization processing circuit 3 of a child screen, and a parent screen. Synchronous processing circuit 4
And a PinP output switching circuit 5 for deriving a PinP output by switching the video signal of the parent-child screen at a timing.

First, the input signal a and the input signal b are input to the changeover switch circuit 2, one input signal a as a parent screen signal to the PinP output switching circuit 5 and the parent screen synchronization processing circuit 4, and the other input signal b. Is switched and input as a small screen signal to the small screen chroma / synchronization processing circuit 3. In the parent screen synchronization processing circuit 4, the vertical synchronization signal MVD and the horizontal synchronization signal MHD of the parent screen are extracted and led to the digital processing unit 6 in the next stage.

Further, in the chroma / synchronization processing circuit 3 for the sub-screen, the chroma demodulation and the sync separation of the sub-screen are performed, and the luminance signal (Y) and the color difference signal (BY) of the sub-screen are sent to the digital processing section 6.
・ RY), vertical sync signal SVD and horizontal sync signal SH
D is input. In the digital processing unit 6, the image information Y, BY, RY of the small screen is converted into a digital signal by the A / D conversion circuit 7, and the PinP control circuit 8 temporarily outputs VR.
It is written in AM10 and read by the PinP control circuit 8 at the output timing of the small screen.
The sync signals for both parent and child screens, which are input to the nP control circuit 8, are used to create the timing of writing and reading.

The picture signal of the sub-picture stored in the V-RAM 10 is guided to the D / A conversion circuit 9 by the PinP control circuit 8 and converted into an analog signal again, and then to the PinP output switching circuit 5 of the analog processing section 1. Then, it is combined with the input signal a of the main screen at a timing, and Pin
It is derived as P output.

[0006]

In the above-mentioned conventional apparatus, when the video signal of the main screen or the sub-screen disappears, the video of that part on the screen is interrupted unless the user manually performs the switching operation. Then, the two-screen display state without the parent screen or the child screen continues, which is not preferable.

[0007]

In order to solve the above problems, the present invention provides a parent-child screen display video device in which a parent screen and a child screen are displayed on the same screen, and the presence or absence of video signals of both parent and child screens. In the case where the video signal detecting means for detecting the video signal and the detection signal from the video signal detecting means are signals that detect only the parent screen, the display function of both the parent and child screens is canceled by the signal, and only the child screen is detected. If it is a signal,
After the parent screen and the child screen are reversed by the signal, the parent-child both-screen display function is canceled and the signal detects both the parent-child screen at the same time or both the parent-child screen cannot be detected at the same time. Is configured to include parent-child screen control means for controlling the display function of the parent-child screen so that the display functions of both the parent-child screen are maintained as they are.

[0008]

With the above configuration, the PinP display function is canceled when only the video signal of the parent screen is displayed, and the video of the parent screen is displayed on the entire screen, and when only the video signal of the child screen is displayed, the parent screen and the child screen are displayed. After reversing, the PinP display function is released and the image of the pre-reversal sub-screen is displayed on the entire screen, and the video signals of both the parent and child screens are detected, or the video signals of both the parent and child screens are not detected Then, the display function of both parent and child screens is kept as it is, and all of them are automatically controlled.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an embodiment of the present invention. Parts corresponding to those of the conventional example shown in FIG. In FIG. 1, reference numeral 10 is a sync signal detection circuit for detecting a sync signal of an input signal a, which is a main screen,
Reference numeral 11 is a sync signal detection circuit for detecting a sync signal of the input signal b which is a child screen, 12 is a parent-child screen control circuit for controlling switching of parent-child screens, 13 is a PinPON ON / OFF control circuit, and 14 is input for both parent-child screens. The input switching control circuit switches between the signals a and b.

Therefore, the vertical synchronizing signal of the parent screen (hereinafter referred to as "M") extracted by the synchronizing processing circuit 4 for the input signal a which is the parent screen.
A VD ") and a horizontal synchronizing signal (hereinafter referred to as" MHD ") are input to the parent screen synchronizing signal detection circuit 10. In addition, the vertical synchronization signal of the child screen (hereinafter referred to as "SV
"D") and a horizontal sync signal (hereinafter referred to as "SHD")
Is input to the synchronization signal detection circuit 11. In the sync signal detection circuits 10 and 11, the MVD, MHD and S
Presence or absence of VD and SHD is detected, and the information is input to the parent-child screen control circuit 12.

The parent-child screen control circuit 12 receives the detection signal of the synchronization signal from the synchronization signal detection circuits 10 and 11 and the Pin according to the flowchart shown in FIG.
PON / OFF control circuit 13 and input switching control circuit 14
To control.

That is, when both the parent-child screen input signals a and b are present and their synchronizing signals are detected, the parent-child screen control circuit 1
The PinPON ON / OFF control circuit 13 is controlled by 2 so that the PinP maintains the ON state and the input switching control circuit 1
The input signal is not switched by 4 and the V-RAM1
The image signal of the child screen stored in 0 is read out, converted again into an analog signal by the D / A conversion circuit 9 and guided to the PinP output switching circuit 5, where it is combined with the parent screen at a proper timing to produce a PinP output. Derived.

Further, when there is only the input signal a of the parent screen and only the synchronizing signal thereof is detected, the parent-child screen control circuit 12 controls the PinPON / OFF control circuit 13 to set Pi.
The nP is turned off, the input switching control circuit 14 does not switch the input signal, and only the input signal a of the parent screen is guided to the PinP output switching circuit 5 and output as it is.

When there is only the input signal b of the child screen and only the synchronizing signal thereof is detected, the parent / child screen control circuit 12 first switches the input switching control circuit 14 to invert the input signals a and b. As a result, the input signal b becomes the main screen signal, and only the main screen exists, and the input signal b is output. After that, the input switching control circuit 14 causes the Pin
PON / OFF control circuit is controlled to turn off PinP
To the state of.

[0015]

Since the present invention is constructed as described above,
Even when both parent and child screens are displayed, even if there is no video signal on either screen, all can automatically be set to the best screen display state, and there is no need to bother the user to improve operability. You can

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the present invention.

FIG. 3 is a configuration diagram of a conventional example.

[Explanation of symbols]

 2 Changeover switch circuit 3 Chroma / synchronization processing circuit for child screen 4 Synchronization processing circuit for parent screen 5 PinP output switching circuit 10 Synchronization signal detection circuit for parent screen 11 Synchronization signal detection circuit for child screen 12 Parent-child screen control circuit 13 PinPON / OFF Control circuit 14 Input switching control circuit

Claims (1)

[Claims] 1. In a parent-child screen display video device in which a parent screen and a child screen are displayed on the same screen, a video signal detection means for detecting the presence or absence of video signals of both the parent and child screens, and the video signal detection means. When the detection signal of is a signal that detects only the parent screen, the signal cancels the display function of both the parent and child screens, and when the signal detects only the child screen, the signal causes the parent screen and the child screen to be separated. After reversing, the display function of both parent and child screens is released, and if both parent and child screens are detected at the same time or if both parent and child screens cannot be detected at the same time, both parent and child screens display function A parent-child screen display video device, which is provided with a parent-child screen control means for controlling the display function of the parent-child screen so as to keep the same as it is.