JPH0548987A - Multi-screen television receiver - Google Patents

Abstract

PURPOSE:To use a PIP system displaying slave screens at conventional four corners when a video image in 4:3 is displayed on a 16:9 wide aspect display device and the slave screens are displayed in a vacant area. CONSTITUTION:This device consists of a phase correction circuit 20 for a vertical synchronization signal which variably changes the display positions in the vertical direction of respective slave screens, a circuit switching the phase of the vertical synchronization signal of the phase correction circuit 20 with respect to the phase of a horizontal synchronization signal corresponding to an odd/even field of a master screen displaying the slave screens, and a circuit fixing the phase regardless of the odd/even field of the master screen. Thus, the device can be used as the PIP for the wide aspect TV.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a multi-screen television receiver.

[0002]

2. Description of the Related Art Presently available multi-screen televisions have a sub-screen inserted in a part of the main screen (hereinafter referred to as PIP:
In Picture In Picture), 1 is a lot of plane images, and the display positions thereof are displayed at the four corners of the parent screen as shown in FIG.
That is, many PIP systems used have a function of displaying only four corners.

Next, a method of displaying the child screen will be briefly described. The image signal of the small screen is A / D converted and stored in the image memory at a compression rate according to the size of the small screen. Normally, the odd / even fields are stored respectively. And the stored data is an odd number of the parent screen that displays the child screen /
In accordance with the even field (when the parent screen is an odd field, the odd field data of the child screen is called, etc.), the digital data of the child screen is read from the memory, D / A converted, and converted back to an analog video signal. Is superposed on and the inset screen is displayed.

In order to read the child screen data from the memory, the odd / even fields of the parent screen to be displayed are determined by detecting the phases of the vertical synchronizing signal and the horizontal synchronizing signal as shown in FIG.

By the way, recently, a cathode ray tube having an aspect ratio of 16: 9 has been developed, and a wide aspect TV is attracting attention. When a normal television screen with an aspect ratio of 4: 3 is displayed on this wide aspect TV, blanks are created on the left and right sides of the television screen.
A wide aspect TV multi-screen as shown in FIG. 6 for displaying the screen becomes possible. However, the display position of this PIP is different from that of the conventional PIP as shown in FIG.
This cannot be realized by using three Ps, and a dedicated PIP system is required. The development of this dedicated PIP system requires a considerable amount of cost and time, which delays the commercialization of the TV.

Now, let us consider whether or not a PIP system capable of displaying only four corners can be displayed at the positions shown in FIG.

First, as the horizontal position, as shown in FIG. 7 (a), the clock is counted from the rising / falling edge of the horizontal synchronizing signal and displayed, and the display position is determined by this counter value. Left / right is determined. Therefore, in order to display as shown in FIG. 6, it can be seen that the original PIP is displayed at the upper right / lower right and the phase of the horizontal synchronizing signal is shifted as shown in FIG. 7B. Further, since this phase correction is extremely small, it does not particularly affect the determination of the odd / even field of the parent screen shown in FIG.

Next, the movement in the vertical direction will be described. As for the position in the vertical direction, as shown in FIG. 8A, a method of counting and displaying the horizontal synchronizing signal from the rising / falling of the vertical synchronizing signal is used. The bottom is decided. Therefore, in order to display as shown in FIG. 6, it is sufficient to shift the phase of the vertical synchronizing signal as shown in FIG. 8B. However, the phase of the vertical synchronizing signal and the horizontal synchronizing signal shifted at this time is displayed on the parent screen. Vertical jitter occurs in the sub-screen if it is not displayed by being matched with the odd / even field of.

[0009]

A system in which a 16: 9 wide aspect TV displays a normal television screen with an aspect ratio of 4: 3 and PIP is displayed in the margin has only four corner display positions. The present invention solves the problem of vertical jitter that occurs when a PIP system is applied.

[0010]

To this end, according to the present invention, a second or a plurality of TV screens are fixed on a part of a screen of a first television receiver (hereinafter abbreviated as TV) which is a main screen. In a multi-screen TV that is compressed and displayed as a sub-picture and is inserted as a sub-picture, (1) a vertical synchronization signal phase correction circuit for varying the vertical display position of each sub-picture, and (2) each A circuit for switching the phase of the vertical synchronizing signal of the phase correction circuit with respect to the phase of the horizontal synchronizing signal in accordance with the odd / even field of the parent screen displaying the child screen. Further, the multi-screen TV of the present invention has a circuit for fixing the phase regardless of the odd / even field of the parent screen.

[0011]

[Function] To make it possible to use a PIP system having only the four-corner display function as a PIP for a wide aspect TV with a simple application, it is possible to save the labor of developing a new dedicated PIP system and shorten the set development period. Is possible.

[0012]

FIG. 1 shows an embodiment of the present invention, and FIGS.
This will be explained using the timing chart of. From the input HSYNC (a), the IC (8) produces an odd / even determination pulse (b) with a 50% duty. The input VSYNC (c) and (f) are inverted by IC (1) and I
The pulse (b) is input to C (2) as a latch clock and the pulse (b) is latched, and the IC (2) outputs a latch output (H in the odd field, L in the even field) (i). Thus, ICs (1), (2), (3),
(8) constitutes a timing generation circuit (19).

The input HSYNC (j) is IC
From (9), (10), (11), L to H of VSYNC
Is reset to and the rising edge of HSYNC (j) is counted. That is, the number of scanning lines on the television screen is counted. The IC (12) is pre-loaded with SW (1
If it matches with the value set in 7) (the value corresponding to the vertical position of the small screen), the match detection pulse (K) is output.
If this is latched by the IC (13) at the rising edge of HSYNC (j), the latch output (l) becomes the original form of the vertical synchronizing signal that varies the vertical display position of the sub-screen. If a phase correction for the odd / even fields of the parent screen is added to this, a complete vertical sync signal is obtained. Thus IC (9), (1
0), (11), (12) and (13) form a phase correction circuit (20).

Next, a timing pulse for making a phase correction for the odd / even fields is generated by the IC (14) by triggering at the rising edge of the latch output (l). That is, IC
The one-shot pulse (m) of (14) is an odd number /
Transistor (18) with even field pulse (i)
Is turned on / off to switch the external time constant of the IC (14) to generate a pulse as shown in (m), and the falling edge of the pulse is used as a trigger for the VSYNC pulse (n) having a constant width,
Make (p). If the pulse is inverted by the IC (16), the vertical synchronizing signal V for varying the vertical display of the complete child screen is obtained.
SYNC '(o), (g). In this way, IC
(14), (15), (16) and transistor (18)
Constitutes a phase switching circuit (21).

What has been described above is the movement of the sub-picture within the same field in FIG. 9, and the movement to the next field can be done by reversing the phases of the odd / even fields (i) of the output. IC (3) may be added so that the phases are reversed. However, this method simply inverts the phase of the vertical synchronizing signal for the sub-screen from that of the previous field, so that when a non-interlaced signal such as a still image of a VCR (whether the odd / even fields are repeated). (When performed), the phase of the vertical synchronization signal is reversed, so that signals that do not interlace can be handled by adjusting the phases by setting SW (6): OFF and SW (7) ON / OFF. In this way, IC (4), (5) and SW
(6) and (7) form a circuit (22) that fixes the phase.

[0016]

According to the present invention, a PIP system having only four corner display position functions can be used as a PIP for a wide aspect TV without changing the system.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention.

FIG. 2 is a timing chart for explaining FIG.

FIG. 3 is a timing chart for explaining FIG. 1.

FIG. 4 is a view showing display positions of four corners of a conventional PIP child screen.

FIG. 5 is a diagram for explaining an odd / even field determination method.

FIG. 6 is a view showing a PIP child screen display position of a 16: 9 wide aspect TV.

FIG. 7 is a diagram for explaining how to determine a horizontal display position.

FIG. 8 is a drawing for explaining how to determine a vertical display position.

FIG. 9 is a diagram for explaining conversion from a four-corner display PIP to a wide aspect TV.

[Explanation of symbols]

 Reference numeral 19 ... Timing generation circuit 20 ... Phase correction circuit 21 ... Phase switching circuit 22 ... Phase fixing circuit

Claims (2)

[Claims] 1. A second or a plurality of TV screens are compressed at a constant rate and are inserted as child screens in a part of a screen of a first television receiver (hereinafter abbreviated as TV) which is a main screen. In a multi-screen TV that displays like this, (1) a vertical sync signal phase correction circuit for varying the vertical display position of each sub-screen, and (2) an odd / even number of the parent screen displaying each sub-screen. A multi-screen television receiver comprising a circuit for switching the phase of the vertical synchronizing signal of the phase correcting circuit to the phase of the horizontal synchronizing signal according to the field. 2. The multi-screen television receiver according to claim 1, further comprising a circuit for fixing the phase thereof regardless of the odd / even field of the main screen.