JPH0482494A - Television signal converter - Google Patents

Abstract

PURPOSE:To unnecessitate the changeover of a Y/C separation input signal into a composite video input signal by an outside monitor by adding both a circuit which separates an NTSC signal into a luminance component and a chrominance component, and a decision part which decides the presence or absence of the Y/C separation signal input. CONSTITUTION:The NTSC signal inputted from the outside through a terminal B is inputted also to a Y/C separation circuit 4, separated into the luminance component and the chrominance component, and outputted to a selector 5. At that time, the presence or absence of the Y/C separated NTSC signal inputted from the outside through a terminal C is decided by a signal decision part 6, and the output signal of a selector 5 is switched by the decided result. When the Y/C separation input signal is present, the Y/C separation signal from the outside is selected, and when the Y/C separation input signal is absent, the output of the Y/C separation circuit 4 is selected, and outputted to a selector 3. Therefore, it is not necessary that the changeover of the Y/C separation input into the composite video input is operated by the outside monitor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to high-definition television signals such as MUSE (M
uitipul 5ub-Nyquist Sample
ing) signal and converts it to the current standard television signal, NTSC (National Televisio).
The present invention relates to a television conversion device having a function of converting the video signal into a video signal in which a luminance signal and a color signal are separated (hereinafter referred to as Y/C separation).

Conventional technology In recent years, television signals with a transmission method different from the conventional television signal, NTSC signal, such as the MUSE signal, which transmits 4-field sampling of one image as a high-definition television transmission method, have been developed and used. It started to be done.

Accordingly, it has become necessary to convert MUSE signals to NTSC signals and reproduce them on conventional television receivers.

Figure 2 shows a schematic diagram of a conventional television signal converter.
It shows 7ri. In Figure 2, 1 is the external B
S (Broadcasting 5atellit
e) A signal processing circuit for converting a MUSE signal inputted from a tuner (not shown) through terminal A into an NTSC signal; 2 is an NTSC signal inputted from the outside through terminal B;
A selector 3 switches and outputs the C signal and the output signal from the signal processing circuit 1, and the selector 3 selects and outputs the Y/C separated NTSC signal input through the terminal C and the output signal from the signal processing circuit 1. A selector for switching, terminal E is a terminal for connecting the output signal of selector 2 to an external monitor (not shown), and terminal E is a terminal for connecting the output signal of selector 3 to a monitor equipped with an external Y/C separation input terminal. (not shown).

Next, the operation of the conventional television signal converter configured as described above will be explained. In Figure 2,
MU manually powered from an external BS tuner (not shown)
The SE signal is input from the input terminal A, converted into an NTSC signal by the signal processing circuit 1, and output to the selector 2 as well as to the selector 3 as a Y/C separated NTSC signal. The selector 2 switches between the NTSC signal input from the outside through the terminal B and the output signal of the signal processing circuit 1 using a control signal from the signal processing circuit 1, and outputs the signal to an external monitor through the terminal. Similarly to the selector 2, the selector 3 also inputs a Y/C separated NTSC signal input from the outside through the terminal C and a Y/C separated NTSC signal from the signal processing circuit l to the signal processing circuit 1. It is switched by a control signal from the input terminal E and outputs to an external monitor equipped with a separate Y/C input terminal.

Problems to be Solved by the Invention However, in the conventional television signal converter described above, when outputting the output signal of the television signal converter as a video output (hereinafter referred to as projection) on a monitor having a Y/C separate input terminal, If the Y/C separated input signal is not input to the television signal converter, there is a problem in that the Y/C separated input signal and the composite video input signal must be switched using the external monitor.

The present invention solves the above-mentioned conventional problems, and provides a television with a simple configuration that has the function of inputting a MUSE signal, converting it to an NTSC signal, and outputting the NTSC signal as a Y/C separated video signal. The object of the present invention is to provide a signal converting device.

Means for Solving the Problems In order to achieve the above object, the television signal conversion device of the present invention includes a signal processing circuit that converts a MUSE signal into an NTSC signal, an NTSC signal input from the outside, and the signal processing circuit. Y to separate the luminance component and color component of the NTSC signal along with a selector for switching between the output signals of the
A /C separation circuit and a signal determination section for determining the presence or absence of a Y/C separation signal input are provided.

Operation Therefore, according to the television signal conversion device of the present invention, the Y/C signal that separates the luminance component and color component of an NTSC signal is used.
By providing a separation circuit and a signal determination section for determining the presence or absence of a Y/C separation signal input, a MUSE signal is input and converted into an NTSC signal, and an NTSC signal is converted into a Y/C signal.
/C Can be output as a separated video signal, Y
When displaying the output of a television signal converter on a monitor with a /C separate input terminal, even if the Y/C separate input signal is not input to the television signal converter, the Y/C
This eliminates the need for switching between the C-separated input signal and the composite video input signal using an external monitor.

Embodiment FIG. 1 is a block diagram showing the configuration of a television signal converter according to an embodiment of the present invention.

In FIG. 1, parts common to those of the conventional example shown in FIG. 2 are given the same reference numerals and detailed explanations will be omitted.

In the figure, 4 is a Y/C separation circuit for separating the luminance component and color component of the NTSC signal input from the outside through terminal B, and 5 is the Y/C separation circuit for separating the output signal of the Y/C separation circuit 4 and the signal input from the outside through terminal C. 6 is a selector for switching the Y/C separated input signal, and 6 is a Y input signal input from the outside through terminal C.
This is a signal determination unit for determining the presence or absence of a /C separated input signal. Note that the selector 3 switches and outputs the output signal of the signal processing circuit 1 and the output signal of the selector 5.

Next, the operation of the above embodiment will be explained. external BS
A MUSE signal input from a tuner (not shown) is input from input terminal A, converted to an NTSC signal by the signal processing circuit, and output to selector 2, as well as output to selector 3 as a Y/C separated NTSC signal. be done. In selector 2, N is manually input from the outside through terminal B.
Switching between the TSC signal and the output signal of the signal processing circuit 1,
It is switched by a control signal from the signal processing circuit 1 and output to an external monitor through a terminal.

The NTSC signal input from the outside through terminal B is Y/
The NTSC signal is also input to the C separation circuit 4, which separates the NTSC signal into a luminance component and a color component, and outputs it to the selector 5. Also selector 5
A Y/C-separated NTSC signal input from the outside through terminal C is input to the other input terminal. At this time, the signal determination unit 6 determines whether or not there is a Y/C separated NTSC signal input from the outside through the terminal C.
The output signal of the selector 5 is switched depending on the judgment result, and when there is a Y/C separated input signal, the Y/C input signal from the outside is switched.
When there is no separation signal or Y/C separation input signal input, the output of the Y/C separation circuit 4 is selected and output to the selector 3. In the selector 3, the Y/C separated NTSC signal inputted from the selector 5 and the Y/C separated NTSC signal from the signal processing circuit 1 are switched by the control signal from the signal processing circuit 1 and passed through the terminal E. External Y/
The image will be displayed on a monitor equipped with a C-separated input terminal, and even if the Y/C-separated input from terminal C is not input, switching between the Y/C-separated input and the composite video input will be done on the external monitor. There is no need to do so, and it is possible to always perform projection using the Y/C separated signal.

Effects of the Invention As is clear from the above embodiments, the present invention includes a Y/C branch circuit Y/C separating the luminance component and color component of an NTSC signal.
By adding a signal determination section to determine the presence or absence of a C-separated input signal, when displaying the output of the television signal converter on a monitor with Y/C separate inputs, the television signal converter has a Y/C separate input signal. C Even if there is no separate input,
This has the effect of realizing a television signal conversion device that eliminates the need for switching between YC separated input and composite video input using an external monitor.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of a television signal converter according to an embodiment of the present invention, and FIG. 2 is a schematic block diagram of a conventional television signal converter. 1... Signal processing circuit, 2.3.5...
Selector, 4... Y/C separation circuit, 6...
...Signal judger.

Claims (1)

[Claims] a signal processing circuit for inputting a high-definition television signal and converting it into a current standard television signal; a selector for switching between a current standard television signal input from an external source and an output signal of the signal processing circuit; Equipped with a Y/C separation circuit that separates the luminance component and color component of a television signal, and a signal determination section that determines whether or not a Y/C separation signal is input, high-definition television signals can be converted into current standard television signals. A television signal converter having a function of outputting a converted signal and a current standard television signal input from the outside as a Y/C separated video signal.