JPS6055776A - Television receiver - Google Patents

Abstract

PURPOSE:To obtain smoothly and simultaneously the picture information on other channels through a single CRT and by means of a tuner selection circuit and a VIF video wave detecting circuit, by clamping the level of a video signal obtained before switching. CONSTITUTION:A signal (c) subjected to the video processing is supplied to a memory 20 and processed by clocks (a) and (b) to be supplied to a slave screen inserting circuit 18. While the output of a master screen video signal processing circuit 14 is divided into two parts. One of these two divided outputs is supplied to a switching circuit 23: while the other is supplied to the circuit 23 via a blanking signal inserting circuit 21 and a clamping circuit 22. Then the output of the circuit 23 is supplied to an inserting circuit 18, and the output of the circuit 18 is supplied to a CRT19. In such a constitution, the picture information on other channels can be obtained smoothly and simultaneously through a single CRT and by means of a tuner selection circuit 12 and a VIF video wave detecting circuit 13.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a television receiver that displays images of other programs as part of the television receiver image being received.
The so-called Picture in Picture
It is called ``PinP''.

Conventional configuration and its problems In recent years, P+nP televisions have been announced.

The idea behind this method is shown below.

FIG. 1 is a conceptual diagram of PinP, in which (a) is a television receiver, (b) is a main screen area, and (/→ is a child screen area inserted by subtracting another television screen by 1+i).

Figure 2 is a circuit block diagram of the main parts of a conventional television receiver, where (υ is an antenna, (2a) and (2b) are tuner and channel selection circuits for the parent screen and child screen, respectively, and (3a)
) (3b) are video detection circuits for the main screen and child 03II, respectively, (4a) and (4b) are video signal processing circuits for the main screen and child screen, respectively, (5a)
(5b) is a synchronization separation circuit for the main screen and child screen, respectively, (6) is a readout clock generation circuit, and (7)
1i>J, is the clock generation circuit for inclusion, (8) is memo I
J, (9) is the small side insertion circuit, and the name is the Plaquen tube. The signal for the child screen is stored in the memory (8) by the clock obtained by the write clock generation circuit (7) using the synchronization signal obtained by the synchronization separation circuit (5b). Furthermore, the readout clock generated by the readout clock generation circuit (6) reads the child screen signal from the memory (8), and the child screen insertion circuit (9) inserts it into the main screen No. 1U, and outputs the plackon signal tζ. .

However, in such a television receiver, a tuner/MPA circuit (2b) for sub-screen standby and a VIP
- Requires a video detection circuit (3b), which is expensive and rare.

Therefore, one chi 1. A method has been devised in which a PinP circuit is configured with a channel selection circuit and a VIF video detection circuit to check programs on other channels while checking the programs on that channel. As an example, two addresses are provided in the channel menu that stores the selected channel, and the currently selected channel (main screen) and the previously selected channel are stored. There is a method of displaying a still image of the channel that was previously selected on the sub screen. To explain this operation specifically, gf 1 time A
It is assumed that the user was watching CH and is currently viewing B cb (main screen). When the PinP other screen switch key is pressed, channel selection is performed as Bch -" Ach - + Bch. The principle of this operation over time is shown in Figure 3. In other words, when the PinP other screen switch key is pressed, The station voltage changes from vB to VA, and the main screen changes from Bch to Ach.
Switch to . At this time, the child screen is Ach still + 1Ij (
From state 1), after the signal becomes completely Ach, it becomes Ach.
h video mode. Then, from the final state of the video [2], by making the main screen switch to still image mode while Ach, the child screen changes from Ach still image [1] to Ach.
The image changes to a still image [2], and it becomes possible to view 2C11 on one screen using the same tuner/channel selection circuit and VIP/video detection circuit.

However, this case has the following drawbacks. As a practical matter, the channel selection cannot respond to sudden changes as shown in Figure 3, and in the case of UHF low channels and no channels, the large cycle of VB → vA → vB is 0.15 ~ 0
．． It usually takes 3 seconds. Others, VIP
- It takes time due to AGC response speed, etc. The human eye can sufficiently see the contrast even if the change is less than 0.2 m, so when you are looking at the Bch main screen as shown in Figure 3, if you press the P inP other screen switch key, the Ach The screen of ``Bch-) Ach 18ch-'' is also visible to the human eye during the transition period of Bch, resulting in an unsightly image.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional technology.When the PinP other screen switch key is pressed to display the video signal of the Iya channel on the sub screen in a static state, the 1+! Il
SUMMARY OF THE INVENTION In order to achieve the above object, the television receiver of the present invention includes an electronic tuner and an electronic tuner. a control means for controlling an electronic tuner; a projection means for projecting a television signal selectively received by the electronic tuner onto a cathode ray tube; insertion means for inserting a television signal received by the same channel selection system into a part of the image projected on the tube using memory means; This configuration includes a 9J switching means for switching to a signal with a voltage corresponding to the average voltage level of the video signal.

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

FIG. 4 is a circuit block diagram of the main parts of a television receiver according to an embodiment of the present invention, αυ is an antenna, (6) is a tuner/channel selection circuit, the head is a VIP/video detection circuit, and u4 is a tuner/channel selection circuit.
105 is a video signal processing circuit, a QfH synchronization separation circuit, (
17) is a read/write tarlock generation circuit, a barrel is a small screen insertion circuit, cII is a cathode ray tube, 翺 is a memory, nari is a blanking signal insertion circuit, (e) is a clamp circuit, and rut is a switching circuit. The video signal processing field tc) for the child screen is transferred from the video signal processing circuit αQ to the memory (
A) is input to the read/write tarlock generation circuit α
After being processed by the read clock (at) and the write clock (bl) from η, it is input to the secondary Okinawa circuit (G), and its output is output to the 1st electrode ray tube (11).Current screen The output of the video signal processing circuit (14) is inputted to the terminal (23b) of the switching circuit for switching the other side through the blanking signal insertion circuit υ and the clamp circuit, and the remaining part is input to the terminal (23b) of the switching circuit for switching the other side. It is input to the terminal (23a) of the switching circuit for plane switching (23a) of the C switching circuit (23a).
) is manually input to the child curved surface insertion circuit 08). A switching signal from the tuner/channel selection circuit α'4 is added to the switching circuit for switching other parts.

In FIG. 3, when the main screen is BcbO, the switching circuit (c) shown in FIG. 4 is switched to the terminal (23a) side and sends a normal signal to the cathode ray tube 0.

Next, when the other side changeover switch key is pressed, a signal to control the switching circuit (2) is applied from the tuner/tuning circuit (2), and the switching circuit is connected to the terminal (23b).
Switch to the side. In Fig. 3, when the current screen is Bch, the Plankingey signal insertion circuit Qυ is switched to the terminal (21a) side and becomes f, I, and the output of the video signal processing circuit Q is a clamp. Through the circuit 4, the other 11 is inputted to the terminal (23b) of the switching circuit for switching. When the blanking signal insertion circuit eυ enters the Ach state in FIG. 3, VJ is switched to the terminal (21b) side, and the output of the clamp circuit (2) is output from the switching circuit. This clamp circuit (2) may be any circuit that stores the Bch signal level that has been displayed up until now, such as a circuit that can store an average voltage for a certain period of time using a capacitor or the like.

In this way, when the main screen switches to another channel for a certain period of time, the average voltage level of the video signal on the main screen before QJ switching or the video signal with a voltage corresponding to that voltage level, so the TV receiver There is no sense of harmony for those watching. Also, other channels or unnecessary modes will not be displayed.

Thus, by using one tuner/channel selection circuit and one positive/video detection circuit, it is possible to simultaneously obtain image information of other channels through one cathode ray tube U without any sense of incongruity. Also, by repeatedly pressing this PinP other screen switch key (generating pulses) at the cycle of rotation, it is also possible to advance frames of other channels.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, according to the present invention, 11 image information of other channels can be simultaneously transmitted through one cathode ray tube using one tuner/channel selection circuit and one VIF/video detection circuit. Obtainable.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram showing the image state of a television receiver that projects other incense groups in a part of the television image being received, and Figure 2 is the main part of a conventional television receiver. FIG. 3 is an explanatory diagram of the operation of the television receiver, and FIG. 4 is a circuit block diagram of essential parts of the television receiver according to an embodiment of the present invention. o'4...di, -s/tuning circuit, u:1...VIF
・Video detection circuit, (1410~...Video signal processing circuit, Message...Synchronization separation circuit, αη...Read/write black 7 generation circuit, αι...Small screen insertion circuit, 01...
・Cathode ray tube, 4...memory, &I)...blanking signal insertion circuit, (2)...clamp circuit, wire...
Switching circuit Figure 1 43b Figure 3 B! tPJ Figure 4

Claims (1)

[Claims] 1, a slave tuner, a control means for controlling the electronic tuner, a projection means for projecting a television signal selectively received by the electronic tuner onto a cathode ray tube, and one channel selection system including the electronic tuner; insertion means for inserting, using memory means, a television signal received by the same channel selection system into a part of the image selectively received and projected on the cathode ray tube; and a signal supplied to the cathode ray tube. and switching means for switching over a predetermined period of time to a signal with a voltage corresponding to the average voltage level of the previous video signal.