JPH01115291A - Rgb multi-terminal input type sequential scanning conversion television receiver - Google Patents

Abstract

PURPOSE:To facilitate an optimum designing for a video signal and RGB signals by providing individual sequential scanning conversion circuits for RGB signals inputted from an RGB multisignals, and executing a digital processing. CONSTITUTION:An NTSC composite video signal is inputted to a sequential scanning conversion circuit 6 via a clamping circuit 3, and A/D converter 4, and an YC signal processing circuit 5, and digitized, then, the signal is supplied to an RGB interface 16 via a D/A converter 7. RGB signals YM, YS signals are inputted to a sequential scanning conversion circuit 14 through a clamping circuit 19 and an A/D converter 13, and digitized, thereafter, they are supplied to the interface 16 through a D/A converter 15. The system clocks of both signal processing systems are outputted from a burst synchronizing clock generating circuit 9 and a horizontal synchronizing clock generating circuit 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-definition television receiver that converts an incremental scan video signal to a sequential scan video signal on the receiver side, and particularly relates to a high-definition television receiver that converts an incremental scan video signal to a progressive scan video signal, and particularly relates to The present invention relates to a television receiver that can also handle RGB signals.

[Conventional technology]

Current ink-lace scanning has ink-lace disturbances such as interline flicker and line crawling.
This causes image quality deterioration. Therefore, a progressive scan conversion television receiver is now in practical use, in which the image receiver side converts increment scan to progressive scan to improve image quality.

[Problem that the invention seeks to solve]

The above image quality improvement is achieved by converting the NTSC signal into a digital signal and using a large capacity memory to perform Y/C separation and scanning line interpolation. The system clock for digital processing is 4', c clock (fs
cC color subcarrier frequency) and 8 fsc clock. In a broadcasting NTSC signal, the color subcarrier is synchronized with the burst signal, so digital processing is performed in synchronization with the burst signal frequency.

By the way, the above-mentioned high-definition digital television receiver usually uses its high image quality to connect to a personal computer (
It is equipped with an RGB multi-terminal so that it can be used for image display from a personal computer (hereinafter abbreviated as a personal computer) or teletext broadcasting, and can also process these signals.

Input from such an RGB multi terminal (RG
B multi-signal (abbreviated as "B multi-signal") compatible scan conversion television receivers are equipped with R multi-signal demodulated video signals before progressive scan conversion.
The method is to combine the GB signal and the RG and B multi signals. When inputting a video signal to a progressive scan conversion television receiver and achieving high image quality, motion adaptive Y/C separation amount interpolation is performed on the child signal/C signal, but RGB
In order to use the multi-signal, the R, G, and B signals must be processed separately, so three field memories, for example, are required, increasing the circuit scale. On the other hand, since the RGB multi-signal is mainly a two-character multiplex broadcast/PC input, it is a still image and does not require motion interpolation, and it is sufficient to write sequential scan conversion twice.
It is true that processing of the three signals R2O and B is necessary, but the characteristics of the video signal processing circuit are excessive.

As mentioned above, the optimal signal processing conditions are different for the video signal and the RGB multi-signal, and there is a problem in performing the processing using the same circuit.

The purpose of the present invention is to reasonably solve the above problems and to
An object of the present invention is to provide a progressive scan conversion television receiver that can support B multi-signals.

[Means for solving problems]

The progressive scan conversion television receiver of the present invention inputs an NTSC composite video signal as a television receiver, and
/D conversion After conversion, C demodulation circuit and subsequent scanning conversion circuit performs digital processing, D/A conversion, and outputs Y, R-Y, B-child signals. RGB.

A signal processing system is provided which converts the YM+Ys signal into a progressive scanning signal using a dedicated progressive scanning conversion circuit. Above 2
The outputs of the two signal processing systems are combined by an interface circuit,
It is output as a composite RGB signal.

The system clocks of both signal processing systems generate a clock phase-locked to the burst signal and a clock phase-locked to the horizontal synchronization signal, and are switched in accordance with the input NTSC composite video signal and RGB multi-terminal signal. It is supplied to each signal processing system as a system clock. Furthermore, since the phases of the two signal processing systems differ, a means is provided to adjust and match the phases before combining the interface circuits.

[Effect]

Since the RGB multi-signal may not have a burst signal, a clock synchronized with the horizontal synchronization signal is used as the system clock. In the case of an RGB multi-signal, the clock generation circuit is switched by an AV] control signal from the RGB multi-terminal, and the signal is supplied to each processing system as a system clock. When inputting an NTSC composite video signal, no AV control signal is input, the system clock becomes a clock phase-locked to the burst signal, and the composite video signal is processed by the system clock phase-locked to the burst signal in the NTSC signal processing system. Ru.

Depending on the mode, the video input terminal of the RGB multi terminal inputs a video video signal when a character multiplexing adapter is connected and superimposed display is being performed, and a composite synchronization signal when inputting to a computer. different.

In the case of RGB multi-signal, the video input terminal signal (
The video signal input (hereinafter referred to as the video signal input) is input to the NTSC signal processing system, and the RGB, Y, Ys signals are input to separate signal processing systems, but the signal is processed using the same system clock that is phase-locked to the horizontal synchronization signal. be done. Here Ys is RG
The B signal switching signal and Y14 are shadow switching signals.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of an embodiment of the present invention. A composite video signal from the tuner is input from terminal 1, and RGB
Video signal input from multi-terminal 20 21. An AV control input 22 and RGB, Yn, Ys signals 23 are input. The upper part of Figure 1 is the NTSC signal processing system, and the lower part is the Y system.

This is an RGB signal processing system including Y and Y signals. 9 is a burst synchronous clock generation circuit, and 10 is a horizontal synchronous clock generation circuit. The outputs of the clock generation circuits 9 and 10 are selected by the changeover switch 11, and are selected from the NTSC signal processing system, RGB
Supplied as a system clock to the signal processing system. A.V.
The changeover switches 2 and 11 are switched by the control input 22. In addition to the AV control input 22, a control signal is applied to the changeover switch 11 via an OR circuit 12 so that the changeover can be performed by a changeover signal 17 (described later) indicated by a dotted line.

First, the NTSC signal processing system will be explained. When the AV control manual input 22 is not input, the selector switch 2 directly inputs the NTSC composite signal from the tuner, and this NT
The SC composite signal is clamped by a clamp circuit 3 and converted into a digital signal by an A/D converter 4. At the same time, it is input to the synchronization separation circuit 8 and outputs horizontal and vertical synchronization signals. Further, the burst synchronous clock generation circuit 9 described above generates a clock synchronized with the burst signal. At this time, 4f, c, 8f, c and other clocks are generated as system clocks and supplied to each section of the signal processing system.

In the figure, to avoid complexity, the signal is supplied as tia only to the progressive scan conversion circuit 6.14, but it is supplied to the entire system.

The output of the A/D converter 4 is processed as a Y signal by a YC signal processing circuit 5.
After demodulating into R-Y signal and B-Y signal, progressive scanning conversion circuit 6
The D/A converter group 7 converts each signal into an analog signal. Note that the YC signal processing circuit 5. The progressive scan conversion circuit 6 is a well-known motion adaptive circuit, and the YC signal processing circuit 5 processes the Y signal and C signal, and the demodulated signal is also time-multiplexed with the Y signal, the R-Y signal, and the B signal. -Y signal, which is subjected to color division after scan conversion in the progressive scan conversion circuit 6. The output of the progressive scanning conversion circuit 6 is inputted to the RGB interface circuit 16 as an analog signal by a D/A converter group 7.

Next, the RGB signal processing system will be explained. From the RGB multi-terminal 20, a video signal is input 21. The AV control human power 22 inputs the input, the changeover switch 2 is changed by the AV control human power 22, and the video signal human power 21 is changed to the above-mentioned N.
Input to TSC signal processing system. The video signal input 21 at this time differs depending on the mode. Further, the clock output of the horizontal synchronization clock generation circuit 10 becomes the system clock of each processing system by the changeover switch 11. This clock output is 910F, 1820fH synchronized with the horizontal synchronization signal. Here fH is the horizontal signal frequency. The RGB signal from the RGB multi-terminal 20 is clamped by the clamp circuit 19, and then YM again.

The signals Y and Y are converted into digital signals as they are by the A/D converter group 13, and are converted from incremental signals to progressive scanning signals by the progressive scanning conversion circuit J4.

Since the progressive scan conversion circuit 14 does not need to perform motion correction on the input signal, it simply writes twice without performing any interpolation operation. The outputs of the sequential scan conversion circuit 14 are converted into analog signals by a D/A converter group 15, respectively.
It is input to the RGB interface circuit 16. The RGB interface circuit 16 inputs and synthesizes the output Y, R-Y, B-Y signals of the D/A converter group 17 of the NTSC signal system and the 15 output RGB signals of the RGB signal system, and generates a composite R'. G
Outputs 'B' signal. In addition, synchronization signal 1 to the deflection circuit
8 from the Y signal output of the D/A converter 7 and outputs it.

When inputting RGB multi-signals, the synchronizing signal passes through the NTSC signal processing system, while the RGB signal passes through the RGB signal processing system, so there is a considerable phase difference, so it is necessary to match the phases.

When reading the memory (not shown) in the progressive scan conversion circuits 6 and 14, a reset signal 6a is generated.

Phase matching is performed by setting signals 14a to be the same.

〔Effect of the invention〕

As explained above, the present invention is a progressive scan conversion television receiver compatible with RGB multi-signals, in which a separate progressive scan conversion circuit is provided to perform digital processing on the RGB signals inputted from the RGB multi-signal. This is what I did. RGB signals do not require motion-adaptive processing, and the progressive scan conversion circuit can be easily configured by simply writing to the memory twice and reading out at double speed. For NTSC signals, it is possible to design high image quality using conventional technology, which is related to RGB multi-signals.

Therefore, optimization design becomes easier than in the conventional case where the video signal from the tuner and the RGB multi-signal are switched at the analog input stage and processed by one signal processing system.

In addition, as an NTSC composite signal, non-standard N
When a TSC signal is input, an error occurs in the NTSC signal processing system due to jitter. At this time, the YC signal processing circuit 5 detects that the signal is a non-standard NTSC signal, outputs a detection signal 17 shown by a dotted line, passes through the OR circuit 12, switches the changeover switch 11, and horizontally synchronizes the clock generator 1.
The output clock of 0 is used as the system clock.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention. 1 - (NTSC composite signal input) terminal, 2.11 - changeover switch, 5 - VC signal processing circuit, 6 - (NTSC signal processing system) sequential scan conversion circuit,
9-Burst synchronous clock generation circuit, 10-Horizontal synchronous clock generation circuit, 14-.(RGB multi-signal signal system next scan conversion circuit, 16.--RGB interface circuit, 20.--.-.
RGB multi terminal, 21--video signal input, 22--AV control input, 23--RGB, YM, Y3 signal.

Claims (1)

[Claims] In a progressive scan conversion television receiver that inputs an NTSC composite video signal and demodulates the luminance signal and color signal using a signal processing system that includes progressive scan conversion, the RGB, Y_M, and Y_S signals input from the RGB multi terminal are exclusively used. a signal processing system that converts the progressive scanning signal into a progressive scanning signal using the progressive scanning conversion circuit;
An interface circuit inputs the outputs of each of the two processing systems and outputs a composite RGB signal, and generates a clock phase-locked to the burst signal and a clock phase-locked to the horizontal synchronization signal, and receives an input NTSC composite video signal. ,
means for switching adaptively to the RGB multi-terminal signal and supplying each of the signal processing systems as a system clock;
A progressive scan conversion television receiver compatible with RGB multi-terminal input, comprising means for adjusting and matching the phases of two processing systems.