JP2506336Y2 - Y / C separation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a three-dimensional Y / C separation device for separating a luminance signal (Y signal) and a color signal (C signal) in a color video signal. The present invention relates to improvement of a Y / C separation device used in a digital television receiver or a video tape recorder (VTR).

[Prior Art] As a conventional digital three-dimensional Y / C separation device, there is one that separates and outputs a Y signal and a C signal from a digitally converted inter-frame video signal.

For example, an NTSC video signal tuned by a tuner circuit of a television receiver is subjected to three-dimensional Y / C separation processing to output a Y signal and a C signal, while a YTR and a C signal previously separated from a VTR or the like are output. As for signals, Y signals and C signals are output as they are without being separated, or Y signals and C signals are mixed and then three-dimensional Y / C signals are used like normal NTSC video signals.
There is known a configuration in which a Y signal and a C signal are output after being separated.

[Problems to be Solved by the Invention] However, in the above-described Y / C separation device, in the configuration in which the Y signal and the C signal separated in advance are output as they are, the input Y signal and C signal are completely separated. The image quality of the image display device in the subsequent stage is inferior depending on whether or not the image signal is present.
The configuration in which the dimension Y / C separation processing is performed and output has the following problems.

That is, if the input Y signal and C signal are in a so-called standard signal state in which there is an interleave frequency relationship between frames, even if the Y signal and C signal with sufficient separation are input, the three-dimensional Y / C separation processing is performed. It is possible to separate and output the Y signal and the C signal almost completely.

However, when the input Y signal and C signal are non-standard signals that do not have an interleaved frequency relationship, the Y signal and C signal cannot be well separated even if the three-dimensional Y / C separation process is performed, resulting in dot interference or cross color. And the like, and image deterioration easily occurs.

The present invention has been made to solve such a problem, and Y / C is obtained by mixing Y signals and C signals separated in advance.
In the separation configuration, even if the Y signal and the C signal having a non-standard signal relationship are input, the image quality is not deteriorated, and the best Y / C separation can be performed according to the input Y signal and C signal. C
The purpose is to provide a separation device.

[Means for Solving the Problems] In order to solve such problems, the present invention provides a mixing means for mixing a Y signal and a C signal to create a video signal, and a separation means for separating the Y signal and the C signal from the video signal. 3D Y / C
Separation means, non-standard signal detection means for detecting whether or not the video signal is a non-standard signal, and three-dimensional Y when the non-standard signal detection means detects the video signal as a non-standard signal. Instead of the Y signal and the C signal from the / C separating means, there is provided a selecting means for selectively selecting and outputting the Y signal and the C signal before mixing.

[Operation] In the present invention equipped with such means, the non-standard signal detection means detects whether the input Y signal and C signal have a standard signal relationship or a non-standard relationship after being converted into a video signal. In the case of a standard signal relationship, a Y signal and a C signal are created into a video signal by a mixing means, then separated into a Y signal and a C signal by a three-dimensional Y / C separation means, and output through a selection means. To do.

On the other hand, when the Y signal and the C signal are in a non-standard signal relationship, the non-standard signal detection means switches and controls the selection means, and outputs the Y signal and C signal before mixing as they are through the selection means.

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

FIG. 1 is a block diagram showing an embodiment of a Y / C separation device according to the present invention.

The analog video signal in which the Y signal and the C signal are already mixed is input to the input end P1, and the analog Y signal and the C signal which are separated in advance are input to the input ends P2 and P3, respectively. P1 and P2 are fixed contacts a and b of the selection circuit S1.
The input terminal P3 is connected to the A / D conversion circuit 1.

The video signal includes an NTSC video signal from a tuner circuit of a television receiver, and the separated Y signal and C signal include a signal from a VTR or the like which reproduces a recorded soft tape.

The selection circuit S1 selectively switches the video signal and the Y signal, and the movable contact c is connected to the A / D conversion circuit 3.

The A / D conversion circuits 1 and 3 are for A / D converting the video signal, the Y signal and the C signal into digital signals, respectively. The A / D conversion circuit 3 is provided to the mixing circuit 5 and the A / D conversion circuit 1 is provided. Is connected to the fixed contact b of the selection circuit S2.

The selection circuit S2 is interlocked with the selection circuit S1, and when the Y signal from the input terminal P2 is selected, it opens and closes the circuit so that the digitally converted C signal is output to the mixing circuit 5. The contact c is connected to the mixing circuit 5.

The mixing circuit 5 is an adder that mixes the digital Y signal and the C signal from the A / D conversion circuits 1 and 3 to create a video signal, and is a three-dimensional Y / C separation circuit 7 and a non-standard signal detection circuit 9.
It is connected to the.

The mixing circuit 5 outputs the video signal from the input terminal P1 as it is.

The three-dimensional Y / C separation circuit 7 has a conventionally known configuration including a motion adaptive comb filter that delays a video signal between frames, adds and subtracts it, and separates a Y signal and a C signal.

Moreover, the 3D Y / C separation circuit 7 is preferably a 3D Y / C.
Not only the separation function, but also the two-dimensional Y / C separation function that separates the Y signal and the C signal from the inter-line video signal, and the mere bandpass filter function that separates the Y signal and the C signal. It is preferable that the switching control is performed by the non-standard signal detection circuit 9, for example, according to the state.

The non-standard signal detection circuit 9 detects whether the signal form of the video signal formed by the mixing circuit 5 has an interleave frequency relationship between frames, that is, a standard signal form, and if it is a non-standard signal form, a selection described later is made. It has a function of switching and controlling the circuits S3 and S4.

As the configuration of the non-standard signal detection circuit 9, for example, one field is counted by a clock phase-locked to a burst signal in a video signal, reset for each field and compared with a reference number. A configuration is used in which the video signal is detected as a standard signal, and if there is a deviation from the reference number, it is detected as a non-standard signal form.

The Y signal output from the three-dimensional Y / C separation circuit 7 is the selection circuit S3.
Is connected to one fixed contact a, and the C signal output is a selection circuit
The non-standard signal detection circuit 9 is connected to one fixed contact a of S4 and is configured to output a control signal for switching to the selection circuits S3 and S4 via the fixed contact b and the movable contact c of the selection circuit S5. ing.

The selection circuit S5 works in conjunction with the selection circuits S1 and S2,
When the Y signal of P2 is selected, close control is performed.

The non-standard signal detection circuit 9 is also connected to the three-dimensional Y / C separation circuit 7 so that the signal form of the video signal is three-dimensional according to the degree of interleave frequency relation between frames.
It has a function of switching the Y / C separation function of the Y / C separation circuit 7.

For example, if the video signal is a standard signal, it is possible to switch to a three-dimensional Y / C separation function or a two-dimensional Y / C separation operation, and a bandpass filter function operation for a slight deviation.

The fixed contacts b of the selection circuits S3 and S4 are the A / D conversion circuits 3 and 1, respectively.
Are connected via the delay circuits 11 and 13, the movable contact c normally selects the fixed contact a, and the movable contact a is controlled by the control signal from the non-standard signal detection circuit 9.
Is switched to the fixed contact b and selected.

The movable contact c of each selection circuit S4, S5 is a D / A conversion circuit 1
It is connected to the output terminals P4 and P5 via 5 and 17.

The delay circuits 11 and 13 are generated when the Y signal and the C signal from the three-dimensional Y / C separation circuit 7 are switched to the direct Y signal and the C signal from the A / D conversion circuits 1 and 3 and output as described later. Compensates for image delay, D / A conversion circuit 1
Reference numerals 5 and 17 are for converting the digital Y signal and C signal into an analog signal.

A sync separation circuit 19 is connected to the movable contact c of the selection circuit S1.

The selection circuits S1, S2, S5 described above are controlled to be switched manually by a switch means (not shown) or automatically in association with the Y signal and C signal input to the input terminals P2, P3.

Next, the operation of the Y / C separation device of the present invention thus constructed will be described.

First, a case where an NTSC video signal which is a standard signal is input to the input terminal P1 will be described.

The analog video signal input to the input terminal P1 is converted into a digital signal by the A / D conversion circuit 3 and added to the mixing circuit 5.

Since the C signal from the A / D conversion circuit 1 is not input to the mixing circuit 5, it is directly added to the three-dimensional Y / C separation circuit 7.

The three-dimensional Y / C separation circuit 7 separates the Y signal and the C signal and adds them to the D / A conversion circuits 15 and 17 through the selection circuits S3 and S4, and the D / A conversion circuits 15 and 17 convert the analog signals The converted data is output from the output terminals P4 and P5 and output to a display device (not shown) in the subsequent stage.

The sync separation circuit 19 separates the sync signal included in the video signal and outputs it to a display device or the like (the same applies hereinafter).

Next, a case will be described in which the previously separated Y signal and C signal having a standard signal relationship are input.

The movable contacts c of the selection circuits S1, S2, S5 switch and select the fixed contacts b, and the Y and C signals applied to the input terminals P2, P3 are converted into digital signals by the A / D conversion circuits 3, 1. It is converted and added to the mixing circuit 5, and mixed in the mixing circuit 5 to create a video signal.

Then, while the three-dimensional Y / C separation circuit 7 separates the Y signal and the C signal, the video signal input to the three-dimensional Y / C separation circuit 7 is a standard signal. The Y signals and the C signals separated from each other are not switched to the selection circuits S3 and S4 and are added to the D / A conversion circuits 15 and 17 via the selection circuits S3 and S4. It is converted into a signal and output from the output terminals P4 and P5.

Further, the case where the Y signal and the C signal having a nonstandard signal relationship are input will be described.

In this case, the Y signal and C applied to the input terminals P2 and P3
The signals are converted into digital signals by the A / D conversion circuits 3 and 1 and added to the mixing circuit 5, and mixed by the mixing circuit 5 to create a video signal.

However, since the nonstandard signal detection circuit 9 detects the nonstandard signal, the selection circuits S3 and S4 are switched and controlled, and the digital Y signal and C signal from the A / D conversion circuits 3 and 1 are delayed by the delay circuits 11 and 13. It is added to the fixed contacts b of the selection circuits S3 and S4 with a delay time, and the movable contacts c from the D / A conversion circuits 15 and 17 are added.
Is converted into an analog signal and output from the output terminals P4 and P5.

As described above, in the Y / C separation device of the present invention, when the Y signal and the C signal have a non-standard signal relationship, the Y signal and the C signal are not mixed and Y / C separated, but output as a Y signal before mixing. Since the signal and the C signal are output as they are, the Y signal and the C signal, which have a non-standard signal relationship, are mixed again, and the three-dimensional Y /
Image deterioration is less than in the case of C separation processing, and it is possible to suppress dot interference and cross color.

Note that the three-dimensional Y / C separation circuit 7 is not limited to the above-described configuration, and the Y signal and the C signal are separated from the video signal between different fields.
The object of the present invention can be achieved with a three-dimensional structure in which signals are separated.

[Effects of the Invention] As described above, the present invention provides a mixing means for mixing a Y signal and a C signal to create a video signal, and a three-dimensional Y / C separation for separating the video signal into a Y signal and a C signal. Means, non-standard signal detection means for detecting whether or not the video signal is a non-standard signal, and selection means for selectively selecting and outputting the Y signal and C signal before mixing when the non-standard signal is detected. Therefore, when the input Y signal and C signal have a standard signal relationship, a Y signal and a C signal are separated and output after forming a video signal, while the Y signal and the C signal are nonstandard signals. When there is a relationship, the video signal is not mixed with the video signal and is output as it is by the selection means.

Therefore, even if a Y signal and a C signal having a non-standard signal relationship are input, they can be output without forcibly mixing and separating them, and the best signal according to the input Y signal and C signal can be obtained.
Y / C separation is possible, and the image quality of the display device is not degraded.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a Y / C separation device according to the present invention. 1, 3 ... A / D conversion circuit, 5 ... Mixing means (mixing circuit), 7 ... 3D Y / C separation means (motion adaptive 3D Y / C)
Separation circuit), 9 ... Non-standard signal detection means (non-standard signal detection circuit), 11, 13 ... Delay circuit, 15, 17 ... D / A conversion circuit, 19 ... Synchronous separation circuit, P1 to P3 ... … Input end, P4, P5…
… Output terminal, S1, S2, S5 …… Selection circuit, S3, S4 …… Selection means (selection circuit).

Claims (1)

(57) [Scope of utility model registration request] 1. Mixing means for mixing a Y signal and a C signal to create a video signal, and a three-dimensional Y / C for separating the Y signal and the C signal from the video signal.
C separation means, non-standard signal detection means for detecting whether or not the video signal is a non-standard signal, and the three-dimensional when the non-standard signal detection means detects the video signal as a non-standard signal Y from Y / C separation means
A Y / C separation device comprising: selection means for switching and selecting the Y signal and C signal before mixing instead of the signal and C signal.