JP2809322B2 - Small screen display circuit for MUSE signal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-screen display circuit for a MUSE signal, and more particularly to a circuit for displaying a MUSE signal by utilizing the characteristics of the MUSE signal.
The present invention relates to a circuit for generating a small-screen display signal from a MUSE signal. At present, experimental broadcasting is being conducted with respect to high-definition broadcasting, and the development of image receiving devices for receiving these broadcasts is underway. Instead, it is desirable that other high-definition software signals be input and reproduced. Also, considering the case where the high-definition broadcasting is going to be multi-channel in the future, it is convenient to make it possible to display a small screen on the main screen so that signals from two sources can be received simultaneously.

[0002]

2. Description of the Related Art A conventional small-screen display circuit using a MUSE decoder employs a circuit as shown in FIG. 6, in which a high-definition signal for displaying a main screen is transmitted to an MUSE decoder 2 via an input terminal 1. The MUSE decoder 2 demodulates the HDTV signal and the like, and outputs the RG for displaying the main screen.
The MUSE decoder 10 converts the MUSE signal into a B image signal and outputs the MUSE signal to the synthesizing circuit 3. The MUSE signal for displaying a small screen is input to the MUSE decoder 10 via the input terminal 4. The signal is demodulated, converted into an RGB video signal and output, input to a filter circuit 11, and output from the MUSE decoder 10 by the filter circuit 11.
Each of the B video signals is thinned out and output with a reduced pixel data density, input to the buffer memory 12, and each of the RGB video signals is written to the memory in the buffer memory 12, and the clock pulse used for the writing is written. By reading and outputting with a higher-speed clock pulse, the horizontal and vertical directions of the video signal are compressed and output as RGB video signals for small-screen display and input to the synthesizing circuit 3. Then, the RGB signal for displaying the main screen is combined with the RGB signal for displaying the main screen and output as a video signal output, so that the sub-screen of the main screen can be displayed on the display based on the video signal output.

[0003]

Therefore, the conventional MUS
The small-screen display method using two E-decoders has a problem that the circuit scale becomes large. The present invention relates to MUS
By using a small screen display circuit that takes advantage of the characteristics of the E signal, the circuit size is small and the cost is low.
It is an object of the present invention to provide a signal small-screen display circuit.

[0004]

FIG. 1 is an electric circuit block diagram of a small-screen display circuit of a MUSE signal showing an embodiment of the present invention. As shown in FIG. 1, a luminance signal of a MUSE signal is thinned out. Signal processing circuit 7 for lowering the pixel data density, and time for compressing the output from the luminance signal processing circuit 7 to about 1/4 in the horizontal direction and thinning out to about 1/4 in the vertical direction for output. An axis compression circuit 8, a color signal processing circuit 5 for synthesizing the RY and BY signals line-sequentially multiplexed with the MUSE signal, further reducing the output to about 1/2, and A sub-screen creation circuit comprising an output of a compression circuit 8 and a matrix circuit 6 for converting an output of the color signal processing circuit 5 into a primary color signal and outputting the signal. For example, a video signal obtained by demodulating a Hi-Vision signal by the MUSE decoder 2 Main screen signal The synthesizing circuit 3 synthesizes the signal from the sub-screen creation circuit with the same main screen signal to display a sub-screen having a display size of about 1/4 in both the horizontal and vertical directions with respect to the main screen. It was made.

[0005]

According to the present invention, the MUS is displayed on the main screen by the above configuration.
The E signal is demodulated to display a sub-screen. FIG. 2 is an explanatory diagram showing the signal format of the MUSE signal.
The SE signal has 1125 scanning lines in the vertical direction, one line is sampled at 480 points in the horizontal direction, and a predetermined signal is transmitted as a sample value. The vertical direction in the figure indicates the line number, The horizontal direction indicates the sample number. As shown in the figure, the chrominance signal is time-division multiplexed with the luminance signal,
In the horizontal direction, luminance signals are assigned to sample numbers 107 to 480, whereas color signals are assigned to sample numbers 13 to 480.
To 106, and about 1 for the luminance signal.
/ 4. In the vertical direction, color signals, RY, and BY signals are line-sequentially multiplexed from line numbers 43 to 558, and each of the RY and BY signals is one.
The chrominance signal synthesized from the book is compressed to half the luminance signal having 516 lines.

[0006] The small picture forming circuit has a circuit configuration for matching a luminance signal to a color signal, and a vertical one-pitch is used to reproduce a high-definition signal.
Assuming that the MUSE signal is to be displayed in a small screen with a size of ４ and a width of 横, the horizontal direction and the vertical direction of the luminance signal are compressed to about 1/4 by the time axis compression circuit 8 and about 129 lines in the vertical direction And the horizontal direction is adjusted to the time length of the color signal. The 516 color signals, RY, and BY signals line-sequentially multiplexed with the luminance signal of the MUSE signal are: It is sufficient to combine them into 258 lines, further perform a process such as thinning out and convert them to about し て to obtain about 129 color signals. Since the color signals have already been compressed with respect to the luminance signal, It is possible to partially omit the compression circuit of the small screen creation circuit, and to reduce the circuit scale. In addition, the sub-screen has a small display space, does not have a sense of incongruity even if the resolution is lower than that of the main screen, and the transmission limit of the MUSE signal is about 20 MHz.
Because of the bandwidth of z, the quality of image quality displayed as a sub-screen is sufficient if a bandwidth of about 4 MHz is sufficient, and the MUSE signal is output to the luminance signal processing circuit 7 by using a filter circuit having a bandwidth of about 4 MHz. Is thinned to reduce the pixel data density. If the bandwidth of the luminance signal processing circuit 7 is set to about 4 MHz, since the aliasing component due to the band compression of the MUSE signal is not included, the interpolation processing of the pixel data becomes unnecessary. Can be omitted, circuit processing such as motion detection is not required, and field interpolation processing can be omitted to simplify the small-screen creation circuit.

[0007]

FIG. 1 is an electric circuit block diagram of a sub-screen display circuit for a MUSE signal showing an embodiment of the present invention. Reference numeral 4 denotes an input terminal. And input to the luminance signal processing circuit 7 and the chrominance signal processing circuit 5. As the luminance signal processing circuit 7, a filter having a pass band of about 4 MHz is used, and the luminance signal of the input MUSE signal is reduced to about 1/4.
Since the pixel data density is reduced and output is performed, high resolution is not required for the child screen, so that processing of a still area such as frame interpolation can be omitted, and therefore, such as motion detection and the like can be omitted. Circuit processing is not required, and the field interpolation processing is omitted, so that the circuit configuration can be simplified.

The output from the luminance signal processing circuit 7 is input to a time axis compression circuit 8, and FIG. 4 is an explanatory diagram showing horizontal processing of a luminance signal according to the present invention. As shown in FIG. The axis is compressed by about 1/4 in the horizontal direction by the axis compression circuit 8 so that the color signal and the time in the horizontal direction are matched.
FIG. 5 is an explanatory diagram showing the processing in the vertical direction of the color signal and the luminance signal according to the present invention. As shown in FIG. / 4
And outputs as about 129 luminance signal scanning lines.
In the color signal processing circuit 5, the color signals, R-Y and B, which are line-sequentially multiplexed with the luminance signal of the input MUSE signal.
The Y signal is synthesized into 258 color signals. Further, as shown in FIG.
Output as about 129 color signals. Time axis compression circuit 8
And an output from the color signal processing circuit 5 are input to a matrix circuit 6, which converts the signals into RGB primary color signals and outputs the signals as child screen creation signals.

For example, a high-definition software signal is input to the MUSE decoder 2 via the input terminal 1 using high-definition software as a main screen signal, and the MUSE decoder 2 demodulates the high-definition soft signal to convert the RGB primary color signals into the master signal. Output as a screen signal, input to the synthesis circuit 3,
The synthesizing circuit 3 synthesizes and outputs the parent screen signal and the child screen creation signal, and as shown in FIG. 3, which is a composite diagram of the child screen and the parent screen according to an embodiment of the present invention. The screen is displayed with a display size of about 1/4 in both the horizontal and vertical directions with respect to the main screen. As the main screen signal, a HDTV signal interlaced with 1125 scanning lines or an EDTV signal non-interlaced with 525 scanning lines may be used. A small screen can be displayed with a display size of 1/4.

[0010]

As described above, according to the present invention,
By processing the luminance signal in accordance with the color signal compressed and transmitted in the MUSE signal, it is possible to partially omit the compression circuit of the small screen creation circuit, and high resolution is not required for the small screen. By eliminating the still image processing of the luminance signal, the circuit scale can be made smaller than before, and a low-cost and economical MUSE signal small-screen display circuit can be provided.

[Brief description of the drawings]

FIG. 1 is an electric circuit block diagram of a small screen display circuit for a MUSE signal, showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a signal format of a MUSE signal.

FIG. 3 is a composite diagram of a child screen and a parent screen according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing horizontal processing of a luminance signal according to the present invention.

FIG. 5 is an explanatory diagram showing vertical processing of a color signal and a luminance signal according to the present invention.

FIG. 6 is an electric circuit block diagram of a small-screen display circuit showing a conventional example.

[Explanation of symbols]

 Reference Signs List 1 input terminal 2 MUSE decoder 3 synthesis circuit 4 input terminal 5 color signal processing circuit 6 matrix circuit 7 luminance signal processing circuit 8 time axis compression circuit 10 MUSE decoder 11 filter 12 buffer memory

Claims (2)

(57) [Claims] 1. An M-converted and extracted digital signal
A luminance signal processing circuit for reducing the pixel data density by thinning out the luminance signal of the USE signal, and time-axis-compressing the output from the luminance signal processing circuit to about 1/4 in the horizontal direction and to about 1/4 in the vertical direction A time axis compression circuit for thinning out and outputting, and an MU
RY and BY multiplexed line-sequentially on the SE signal
A color signal processing circuit for synthesizing the signals, further thinning out about 1/2, and outputting the same; a matrix circuit for converting the output of the time axis compression circuit and the output of the color signal processing circuit into a primary color signal for output; Consisting of a sub-screen creation circuit consisting of: synthesizing the signal from the sub-screen creation circuit with the main screen signal;
A small screen display circuit for a MUSE signal, wherein the small screen is displayed on the main screen in a display size of about 1/4 in both the horizontal and vertical directions. 2. A small screen display circuit for a MUSE signal, wherein the luminance signal processing circuit comprises a filter circuit having a pass band of about 4 MHz.