JPS60236377A - Secondary screen inserting device of television receiver - Google Patents

Abstract

PURPOSE:To simplify the structure of the titled inserting device together with reduction of the cost by reading out a recording medium storing the information on a secondary screen at a speed N times as high as a normal case. CONSTITUTION:The TV signal received by an antenna 11 is sent to an adder circuit 23 as well as to a synchronizing circuit 13 to undergo the synchronizing separation. Thus the 1st horizontal and vertical synchronizing signals are obtained. These signals are used as the timing signals to obtain the 2nd video signal for secondary screen and also as the control signals for insertion of screen. When signals are read out of a magnetic disk 14, the rotational frequency is kept to three times that of a recording mode owing to the servo control applied based on the 1st synchronizing signal. Thus the video signal for secondary screen which is picked up by a magnetic head 17 is used as the 2nd video signal with 1/3 reduction. Therefore, various types of still pictures can be inserted as the secondary screen by synthesizing main screen signals.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sub-screen insertion device for inserting a still image into a part of the screen of a television receiver.

[Prior art]

A conventional device of this type is shown in FIG.

In the figure, 1 is an antenna, 2 is a television receiver, 3 is a tuner that obtains a signal for the sub-screen, 4 is a video/chroma signal processing circuit for the signal for the sub-screen, and 5 is a TV receiver 8!2 and synchronization from the tuner 3. a synchronous circuit that generates various timing signals based on signals; 6 a control circuit that provides various control signals to each block to be described later using signals from the synchronous circuit 5;
7 is a control circuit D converter for the output of the video/chroma signal processing circuit 4; 8 is a memory for sequentially storing the digital signal from the A/D converter 7 according to the signal from the control circuit 6; 9 is a digital converter stored in the memory 8; A D/A converter reads the signal according to the signal from the control circuit 6 and converts it into an analog signal, and 10 is a main screen video signal from the TV receiver 8!2 and a sub screen video output from the D/A converter 9. The signal is switched by the signal from the control circuit 6.
This is a video switch circuit with a built-in matrix circuit for obtaining color difference signals, and these constitute a sub-screen insertion device.

Next, the operation will be explained. The operation of the sub-screen insertion device can be roughly divided into a first mode in which a television broadcast signal to be inserted into the television receiver 2 as a sub-screen is written into the memory 8;
There is a second mode in which the signal written in the memory 8 is read out to the television receiver 2 as a sub-screen signal.

First, the first mode will be explained. A television broadcast signal obtained by an antenna 1 is selected by a television receiver 2 and a tuner 3, and a single-station television signal is output. This output is input to the synchronization circuit 5, where it is synchronously separated and shaped into a stabilized synchronization signal. This synchronization circuit 5 has an identification circuit for odd and even fields, and generates an identification signal by detecting coincidence between a vertical synchronization signal and a horizontal synchronization signal in the odd field. The TV signal from the tuner 3 is also input to the video/chroma signal processing circuit 4, and the Y signal and R signal are
Signal processing is performed to demodulate the -Y and B-Y color difference signals.

In the write mode, the control circuit 6 operates mainly based on the synchronization signal from the tuner 3, and the A/D converter 7 and the memory 8 are controlled by the timing signal necessary for writing output from the control circuit 6. For example, if the area ratio between the inserted screen and the main screen is 1:9 (scale 1/3 (integer)), 128 scanning lines and 96 horizontal pixels on the inserted screen are necessary to obtain general image quality. Since it is the number of pixels, the high frequency of the video signal is 1/3 of the conventional video signal, that is, it is sufficient to reproduce the frequency of approximately I Ml (Z). Therefore, the sampling to the A/D converter 7 necessary for writing The clock frequency is 2.3 MHz.

This is the first signal output from the control circuit 6. Further, the second signal output from the control circuit 6 is an address control signal, the third signal is a timing signal for holding input data to the memory 8 for a required period, and the fourth signal is a timing signal. The fifth signals include a memory chip control signal and a field identification signal, respectively.

Y, R-Y, B- from the video/chroma signal processing circuit 4
Each Y signal is sent to the control circuit 6 in the A/D converter 7.
The signal is sampled by the sampling clock signal from the 6-bit digital signal, and is input to the memory 8. Memory 8 uses static RAM, and Y
, RY, and BY signals for one field each. When one system is performing a write operation, the other system is performing a read operation. As mentioned above,
In the write mode, the memory 8 operates with a 2.3 MHz clock, and one system selected by the field identification signal is digitally programmed by the address control signal, latch timing signal, and memory chip/knob control signal output from the control circuit 6. The encoded video signal is written.

Next, the operation in the second mode (read mode) will be explained. The reference timing signal in this mode is the synchronization signal from the television receiver, and the clock frequency is 6.9 MH2- synchronized with the television receiver. In addition to the above-mentioned signals, control signals necessary for the read mode include a read selection signal to be applied to the memory 8 and a video switch drive signal to control the video switch circuit 10, and these signals are outputted from the control circuit 6 to each section.

The second system, which has finished writing the video signal, counts the scanning lines from the vertical synchronization signal of the main screen video signal, and uses a start signal (included in the readout selection signal) that instructs the desired vertical screen insertion position. clock (i,
Readout begins at 9 MHz.

The signal read out by the clock is sent to the D/A converter 9.
The signal then becomes an analog video signal again and reaches the video switch circuit 10. Video switching is done at the video signal drive stage, so the signal is Y.

In addition to R-Y and B-Y, G-Y signals are also required, and the video switch circuit IO uses a built-in matrix circuit to
The G-Y signal is obtained from the -Y and B-Y signals. Video switching is performed by a video switch drive signal from the control circuit 6.

Through the above operations, a second television broadcasting screen with an area ratio of 1/9 can be obtained on the receiving screen of the television receiver 2.
If the control circuit 6 gives a signal to the memory 8 to stop the write operation and repeat the read operation, it is also possible to insert one frame worth of still images as a sub-screen into the television reception fi2.

Since the conventional sub-screen insertion device for a television receiver is configured as described above, it requires a semiconductor digital memory for one frame and is expensive, so that it has not been widely put into practical use. There is also a system in which a small CRT is provided separately from the main screen CRT and images of another channel are displayed on this, but in this case, it is a mere two-screen television and has the disadvantage that still images cannot be obtained on the sub-screen.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and the video signal for the sub-screen is recorded on a recording medium, and the signal is multiplied by N times the recording time based on the main screen synchronization signal. By reading the sub-screen signal at a speed of The purpose of the present invention is to provide an inexpensive sub-screen insertion device for a television receiver.

[Embodiments of the invention]

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

In FIG. 2, 11 is an antenna, 12 is a first video signal processing circuit including a main screen TV tuner, and 13 is a first synchronization circuit for extracting a first synchronization signal from the output video signal of the video signal processing circuit 12. It is a circuit. Also, 14 is 1
A magnetic disk (rotating recording medium) on which video signals for three fields per circumference are concentrically recorded (recorded at a rotation speed of 1200 rpm in the case of NTSC); 15 is a motor that rotates the magnetic disk 14; 16 is a control described later. This is a motor drive circuit that drives the motor 15 at 3600 rpm based on a signal. Further, 17 is a magnetic head that pinks up the information recorded on the magnetic disk 14, 18 is a second video signal processing circuit that processes the second video signal from the magnetic head 17, and 19 is the output of the signal processing circuit 18. This is a second synchronization circuit that extracts a second synchronization signal from the video signal. Reference numeral 20 denotes a first control circuit (20) which provides a control signal to the drive circuit 16 so that the frequency of the second synchronization signal is exactly tripled with respect to the first synchronization signal, and the phase can be arbitrarily changed. phase control circuit).

Further, 40 is a television signal combining means for inserting a video signal for the sub-screen into a part of the video signal for the main screen and combining both video signals. In the combining means 40, 21 is a second
a sampling circuit that removes the synchronization signal from the video signal and outputs a third video signal; 22 is a second control circuit that generates various timing signals based on the first and second synchronization signals;
23, the first control circuit 23 receives a control signal from the second control circuit 22.
This is an addition circuit that removes a part of the third video signal, synthesizes the determined part of the third video signal with this removal part, and outputs the result as a fourth video signal. The above-mentioned circuits constitute a sub-screen insertion device.

Next, the operation will be explained in detail. This device inserts a still image previously recorded on a magnetic disk 14 at an arbitrary position on the main screen at an area ratio of 1/9.

The television signal received by the antenna 11 is sent to the adder circuit 23 via the video signal processing circuit 12 as a video signal that is the basis of the output signal of this device.

Further, this video signal is subjected to synchronization separation by a synchronization circuit 13, and first horizontal and vertical synchronization signals are obtained as the output of the synchronization circuit 13. This first synchronization signal is used as a timing signal when obtaining a second video signal for the sub-screen, and is also used to create a control signal for screen insertion.

The second video signal for the sub screen is recorded on the magnetic disk 14, and in the case of an NTSC signal, the second video signal is recorded on the magnetic disk 14.
The zero rotation speed is recorded at 120 rpm (3 fields per lap). If this second video signal is to be inserted into the main screen with an area ratio of 1/9, it is necessary to obtain a video signal compressed to 1/3 of the time axis of the main screen signal. .

Therefore, the rotation speed when reading signals from the magnetic disk 14 is the same as that of the magnetic head 17. Second video signal processing circuit 18.
Second synchronous circuit 19. First control circuit 20. Drive port FI
li16. Motor 15. A servo is applied in the closed circuit of the magnetic disk 14 based on the first synchronization signal,
The speed is maintained at three times the speed during recording, that is, 3600 rpm. The sub-screen video signal thus big-amplified by the magnetic head 17 passes through the second video signal processing circuit 18 to the second video signal processing circuit 18.
However, since the insertion scale of the second video signal is 1/3, in order to obtain the same level of image quality as the main screen, it is necessary to use approximately 1/3 of the pink-amplified original signal. Any signal having a signal band may be used. This second video signal is input to a second synchronization circuit 19, where a second horizontal and vertical synchronization signal having a frequency three times that of the first synchronization signal is obtained, and the synchronization signal is connected to the first and second synchronization signals. 2 control circuit 20.22.

Further, the synchronizing signal is removed from the second video signal by a sampling circuit 21, and a third video signal consisting only of a video signal is obtained.

The second control circuit 22 generates a control signal for removing a predetermined section of the first video signal and a third video signal from the first and second synchronization signals and the sub-screen insertion position designation signal pre-sensed within the control circuit 22. A control signal 9 for extracting a specific field of the signal (one field out of three fields), a composite control signal, etc. are generated, and these are supplied to the adder circuit 23 for control. As a result, the adder circuit 23 combines the first and third video signals to obtain a fourth video signal with a sub-screen inserted therein.

In this way, in this embodiment, a magnetic disk that can record concentrically with narrow trunk intervals was used as the recording medium.
Many still images can be saved at the same time, and many types of still images can be inserted as sub-screens.

In addition, in this embodiment, all video signals are processed in analog quantities, so there is no need for expensive A/D, D/A converters, or semiconductor digital frame memories.
This has the effect of making the device cheaper.

In addition, in the above embodiment, the scale of the sub-screen was set to 1/3, but
By setting the number of rotations of the magnetic disk during playback to N times the number of rotations of the magnetic disk during recording and synchronizing with the main screen signal, it is possible to easily obtain a video signal in which a sub-screen with a scale of 1/N is inserted. . Furthermore, by adding a function of recording the main screen signal onto a magnetic disk and a function of varying the number of rotations of the magnetic disk to the device of the above embodiment, it is possible to create a television receiver with a TV still image insertion function as a single closed system. .

〔Effect of the invention〕

As described above, according to the sub-screen insertion device for a television receiver according to the present invention, the recording medium on which sub-screen information is recorded is read out at N times the speed based on the main screen synchronization signal, and 1/
Since the time-axis compressed sub-screen signal is obtained in N and is combined with the main-screen signal, it is possible to easily and inexpensively obtain a device that can insert many types of still images as sub-screens.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional sub-screen insertion device, and FIG. 2 is a professional diagram showing a sub-screen insertion bag for a television receiver according to an embodiment of the present invention. In the figure, 2 is a television receiver, 5 is a synchronization circuit, 6 is a control circuit, 7 is an A/D converter, 8 is a memory, and 9 is a D/D/D converter.
A converter, 12 is a first video signal processing circuit, 13
17 is a magnetic head; 18 is a second video signal processing circuit; 19 is a second synchronous circuit (second synchronous metal separation means); 20 is a first synchronous circuit; control circuit (
40 is a television signal synthesis means, 21 is a sampling circuit, 22 is a second control circuit, and 23 is an addition circuit. Agent Masuo Oiwa

Claims (1)

[Claims] (1) A first video signal processing means that receives a television broadcast signal and outputs a first composite television signal for the main screen, and a first synchronization separation means that separates a synchronization signal from the first composite television signal. a recording ring on which a second composite television signal for the sub-screen is recorded; and a second video signal processor that processes the reproduction signal from the recording medium and outputs the second composite television signal for the sub-screen. a second synchronization separating means for separating a synchronization signal from the second composite television signal; a motor drive circuit for driving the recording medium; Phase control that uses the output of the second synchronization separation means as input and applies a control signal to the motor drive circuit for making the pulse interval of the synchronization signal for the sub-screen one-Nth of the pulse interval of the synchronization signal for the main screen. A sub-screen of a television receiver, comprising: a circuit; and television signal synthesis means for inserting the second composite television signal into a part of the first composite television signal and synthesizing the two television signals. Insertion device.