JP2514221B2 - Television receiver - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a television receiver, and more particularly, to a digital television receiver (IDTV) that realizes a display image with improved image quality from a received signal. It is suitable.

[Prior Art] In recent years, many television receivers to which digital signal processing is applied have been proposed in order to improve display image quality.
The luminance signal and chrome signal are separated (hereinafter referred to as Y / C separation) according to an appropriate separation method according to the image content to improve the image quality, and scanning line interpolation is performed according to the image quality content. There is a method in which the image quality is improved by performing the interpolation method.

FIG. 2 shows a conventional circuit for improving such image quality. In FIG. 2, obtained by demodulating from the RF signal,
Alternatively, the composite video signal VID directly input from the external device is converted into a digital signal through the analog / digital conversion circuit 1 and given to the Y / C separation circuit 2, where the Y / C
After being separated into the luminance signal Y and the chroma signal C in the separation circuit 2, the Y / C processing circuit 3 adjusts the contrast,
Processing such as hue adjustment, contour correction, and color demodulation is performed. The luminance signal Y thus processed and the color difference signals RY and BY obtained by demodulation are given to the scanning line interpolation circuit 4.

These signals supplied to the scanning line interpolation circuit 4 are converted into a signal in which the number of horizontal scanning lines is doubled in order to increase the vertical resolution in the scanning line interpolation circuit 4 and supplied to the time axis compression circuit 5, Is compressed to 1/2 and given to a digital / analog conversion circuit (not shown), converted into an analog signal, and then converted into three primary color signals R, G, B in a matrix circuit (not shown). It is designed to be output.

The clock generating circuit 6 forms a clock signal CK synchronized with the video signal based on the video signal VID and supplies it to each part of the video signal processing circuit.

Here, the Y / C separation circuit 2 is adapted to perform Y / C separation according to a Y / C separation method using the correlation between the video signal delayed by one frame and the original video signal via the frame memory 7. In addition, Y / C separation can be performed according to the Y / C separation method using the line correlation of the video signal, and according to the detection signal S1 from the motion detection circuit 8,
When the video signal is a moving image, Y / C separation is performed by the line correlation Y / C separation method, and when the video signal is a still image, Y / C separation is performed by the frame correlation Y / C separation method. Thus, the Y / C separation appropriate for the image content can be performed, and the image quality is improved from this point.

Further, the scanning line interpolating circuit 4 interpolates the scanning lines by utilizing the inter-field correlation between the video signal delayed by one field and the original video signal via the field memory 9, and utilizes the inter-line correlation of the video signal. When the video signal is a moving image, an interpolation method using line correlation is adopted according to the detection signal S2 from the motion detection circuit 8, and when the video signal is a still image. The interpolating method using the field correlation is adopted. Thus, the scanning line interpolation can be executed appropriately according to the image content, and the image quality is improved from this point.

The motion detection circuit 8 detects motion based on the difference between the composite video signal via the Y / C separation circuit 2 and the composite video signal via the frame memory 7.

By the way, recently, a video signal recording / reproducing device (for example, an S-VHS system video tape recorder) capable of outputting a luminance signal and a chroma signal in a separated form so as to enhance display image quality, particularly horizontal resolution, has appeared. Therefore, the television receiver can also input the luminance signal and the chroma signal in a separated form so as to be compatible with such a video signal recording / reproducing device. The luminance signal and the chroma signal thus input are converted into digital signals via the corresponding analog / digital conversion circuits 10Y and 10C, respectively, and then converted into Y / s via the switch circuits 11Y and 11C.
It is given to the C processing circuit 3 and thereafter processed in the same manner as described above. The switch circuits 11Y and 11C
Is connected to the analog / digital conversion circuits 10Y and 10C in Y / C separation input mode, and Y / C in other input modes.
It is switched so as to be connected to the separation circuit 2.

[Problem to be Solved by the Invention] However, according to the conventional circuit described above, in the Y / C separated input mode, the video signal is not input to the motion detection circuit 8, and therefore, the motion detection is not performed.
Therefore, the scanning line interpolation by the scanning line interpolation circuit 4 cannot be made adaptive according to the image content, and in this mode, the image quality deterioration in the case of a moving image is smaller than that using the field correlation. It was fixed to what was used. Therefore, the vertical resolution was reduced in the Y / C separation input mode.

In practice, even if the horizontal resolution is increased by inputting in the form of Y / C separation, it is desirable to increase the vertical resolution in the same way as the horizontal resolution is increased in consideration of the image quality of the entire image. However, as described above, scanning line interpolation cannot be adaptively performed, the vertical resolution and the horizontal resolution are poorly balanced, and the effect of improving the image quality by increasing the horizontal resolution is halved. .

The present invention has been made in consideration of the above points, and realizes a high-quality display image by increasing not only the horizontal resolution but also the vertical resolution even when the luminance signal and the chroma signal are separately input. It is intended to provide a television receiver that can be used.

[Means for Solving the Problems] In order to solve the above problems, the present invention comprises a motion detecting means for detecting a motion from a composite video signal via an analog / digital converting means, and responds to the motion detection output. In a television receiver capable of selecting the interpolation method of the scanning line interpolating means and capable of inputting and processing a luminance signal and a chroma signal provided from an external device, the television receiver is provided separately from the external device. When a mode for processing a luminance signal and a chroma signal to be selected is provided, a switching means for providing the given luminance signal to the analog / digital conversion means is provided, and the motion detection described above is performed via the switching means and the analog / digital conversion means. The luminance signal separately input to the means is given, and scanning line interpolation is performed in the processing mode based on the detected output. It is adapted to be controlled adaptively.

[Operation] In the processing mode of the composite video signal, the composite video signal via the analog / digital converting means is applied to the motion detecting means to detect the motion, and the scanning line interpolation is adaptively executed based on the detected output. I chose

Further, in the processing mode of the luminance signal and the chroma signal separated and given from the external device, the input luminance signal is given to the above-mentioned analog / digital converting means by the switching means and converted into the digital signal by this analog / digital converting means. Then, it is applied to the motion detecting means to detect the motion, and the scanning line interpolation is adaptively controlled by the output thereof.

As a result, the scan line interpolation adaptive control can be executed even in the processing mode of the separation input of the luminance signal and the chroma signal with a simple configuration without providing the analog / digital conversion means for each input, and the display image quality can be improved. it can.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to FIG. 1 in which parts corresponding to those in FIG.

In FIG. 1, the composite video signal VID is 2
It is given to one input terminal of the switch circuit 12 having an input 1 output configuration. To the other input terminal of this switch circuit 12,
A luminance signal Y given from an external video signal recording / reproducing apparatus is inputted. The switch circuit 12 selects the luminance signal in the Y / C separated input mode and supplies it to the analog / digital conversion circuit 13, and selects the composite video signal in the other input modes and supplies it to the analog / digital conversion circuit 13. .

The analog / digital conversion circuit 13 converts the incoming signal into a digital signal regardless of whether it is a luminance signal or a composite video signal, and outputs the converted output from the Y / C separation circuit 2,
And one input terminal of the switch circuit 14 having a 2-input 1-output configuration. The other input terminal of the switch circuit 14 has a Y /
The luminance signal obtained by Y / C separation by the C separation circuit 2 is given.
The switch circuit 14 switches in conjunction with the other switch circuits 10C and 12 and selects the luminance signal from the analog / digital conversion circuit 13 in the Y / C separation input mode, and switches in the other modes. The luminance signal from the Y / C separation circuit 2 is selected.

Therefore, in the Y / C separated input mode, the luminance signal given from the external video signal recording / reproducing apparatus is selected by the switch circuit 12 and converted into a digital signal through the analog / digital conversion circuit 13, It is selected by the switch circuit 14 and given to the Y / C processing circuit 3. At this time, the chroma signal C is converted into a digital signal through the analog / digital conversion circuit 10C as in the conventional case, then selected by the switch circuit 10C and given to the Y / C processing circuit 3.

 After that, processing is performed by a circuit similar to the conventional circuit.

As described above, in the Y / C separation input mode, the Y / C separation signal of the Y / C separation circuit 2 is not used for the subsequent processing. However, the luminance signal slightly delayed through the Y / C separation circuit 2 is used. That is, the Y / C separation circuit 2 is Y / C
Even if the luminance signal is separated from the processing circuit 3, the luminance signal is supplied to the frame memory 7 and the motion detection circuit 8, the motion detection circuit 8 detects the motion, and the motion detection signal S2 is supplied to the scanning line interpolation circuit 4.

Thus, the scanning line interpolation circuit 4 adopts the scanning line interpolation method using the line correlation when the video signal is a moving image based on the motion detection signal S2 obtained from the luminance signal, while
When the video signal is a still image, the scanning line interpolation method using field correlation is adopted to interpolate the scanning lines.

On the other hand, in modes other than Y / C separation input mode,
The composite video signal is selected by the switch circuit 12, converted into a digital signal through the analog / digital conversion circuit 13 and given to the Y / C separation circuit 2, Y / C separated, and then Y / C separated. The obtained luminance signal and chroma signal are selected by the switch circuits 14 and 10C and given to the Y / C processing circuit 3 to be processed. At this time, the composite video signal, which is delayed a little, is given to the frame memory 7 and the motion detection circuit 8 via the Y / C separation circuit 2. Thus, the scanning line interpolation processing similar to that of the conventional circuit is performed.

Therefore, according to the above-described embodiment, even if the luminance signal and the chroma signal are input in the separated form from the external video signal recording / reproducing apparatus, the motion detecting circuit 8 built in the television receiver is already used. Since the motion detection is executed and the scanning line is interpolated according to the detection output, the vertical resolution can be improved. Therefore, the display quality can be significantly improved in combination with the improvement of the horizontal resolution by the Y / C separation input method. Therefore, instead of separately providing a motion detection circuit, the existing motion detection circuit 8
Since it is also used in the Y / C separated input mode, it is possible to suppress the change and addition of the circuit, and the structure is not particularly complicated.

Rather, an analog / digital converter for converting a luminance signal and a composite video signal provided from an external device into a digital signal.
Since the digital conversion circuit 13 is shared, the configuration can be simplified.

Incidentally, the motion detection circuit 8 is designed to detect a motion by inputting a composite video signal. However, a black and white television signal is input so that the television receiver can ensure compatibility with the black and white television signal. Since the motion detection can be performed even if it comes, it is possible to execute the motion detection by inputting the luminance signal (which is equivalent to the monochrome television signal) as described above.

From this point of view, when the motion detection is performed using only the luminance signal component as in the Y / C separated input mode, the luminance component and the luminance component are detected as in the case of motion detection from the color television signal (composite video signal). Since the motion is not detected using both of the color components, the motion detection brightness is relatively low. However, compared with the conventional display quality in which the scanning line interpolation method is fixed, the display quality can be significantly improved even when the scanning line interpolation method is adapted using such a motion detection signal.

Note that the present invention only needs to be provided with a luminance signal and a chroma signal from an external device, and whether the external device is a video tape recorder according to the S-VHS system or the ED-β system is determined by the video tape recorder. Equipment other than
For example, it does not matter whether it is a laser disc player or not.

[Effects of the Invention] As described above, according to the present invention, even in the Y / C separated input mode, scanning is performed by detecting the motion from the luminance signal using the existing motion detection configuration while sharing the analog / digital conversion means. Since the line interpolation is adaptively performed, it is possible to obtain a television receiver that can realize a display image with improved horizontal and vertical resolution even in the Y / C separation input mode.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a television receiver according to the present invention, and FIG. 2 is a block diagram showing a conventional device. 2 ... Y / C separation circuit, 4 ... scan line interpolation circuit, 5 ... time axis compression circuit, 7 ... frame memory, 8 ... motion detection circuit, 9 ... field memory, 12,14 ... switch Circuit, 13 ... Analog / digital conversion circuit.

Claims (1)

(57) [Claims] 1. A motion detecting means for detecting a motion from a composite video signal through an analog / digital exchange means, and adaptively controlling an interpolation method of a scanning line interpolating means according to the motion detection output. And
In a television receiver capable of inputting and processing a luminance signal and a chroma signal given from an external device, the luminance given when the mode for processing the luminance signal and the chroma signal given separately from the external device is selected. Switching means for applying a signal to the analog / digital converting means is provided, and the luminance signal separately input to the motion detecting means via the switching means and the analog / digital exchanging means is applied, and based on the detection output thereof, A television receiver characterized in that scanning line interpolation is adaptively controlled even in the processing mode.