JP3194992B2 - Wide aspect television receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0010]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wide aspect television receiver for displaying a wide aspect television signal compatible with an NTSC signal on a wide aspect screen, and more particularly to a current aspect ratio of 4: 3 . BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wide aspect television receiver which masks a side panel portion so as not to be displayed on a screen when a video signal is displayed.

[0020]

2. Description of the Related Art There have been proposed several methods of displaying a wide aspect image having an aspect ratio of 16: 9 by adding an auxiliary signal to a video signal having an aspect ratio of 4: 3 in the current NTSC system. I have. 1 using FIG.
An example will be described. FIG. 3A shows a wide aspect video having an aspect ratio of 16: 9. This video signal is divided into a center panel at the center and side panels at both ends. Then, the side panel portion is compressed and added to both ends of the center panel portion, and the aspect ratio is 4: 4 as shown in FIG.
3 video signal. When this video signal is projected on a conventional NTSC television receiver, the side panel portion is overscanned and is not projected on the screen. When this video signal is input to a dedicated wide-aspect television receiver, the side panel section is expanded to a video signal having an original aspect ratio of 16: 9 as shown in FIG. Is projected.

[0030]

However, FIG.
As shown in FIG. 2C, when a video signal having an aspect ratio of 4: 3, which does not include a wide aspect component which is a signal of a rebroadcast, is projected by a wide aspect television receiver, as shown in FIG. As shown in (2), the video signal may be shifted into the overscan area on the side portion or a noise component may enter due to the influence of ghost or noise.
The video signal and noise shifted to this overscan area are not components related to the wide aspect, but when this signal is projected on a side panel type wide aspect television receiver, the signal of the side panel part where the signal of the overscan area is compressed As shown in FIG.
As shown in (e), the shifted video signal or noise is extended and projected at the place where the side panel should be projected, and an image having a normal aspect ratio of 4: 3 cannot be obtained. In addition, there is a problem that display quality of an image is significantly impaired.

[0040]

According to the present invention, in order to solve the above-mentioned problems, a wide aspect video signal formed by a center panel portion and side panel portions on both sides thereof compresses the side panel portion. A wide aspect television which reproduces a wide aspect television signal which is a video signal having a 4: 3 aspect ratio and is compatible with an NTSC color television signal at a wide aspect ratio. A compression / expansion means for expanding a side panel part of the video signal and compressing a center panel part, a control means for controlling the compression / expansion means based on a synchronizing signal; TV with a pilot signal superimposed on the transmitting side to identify whether it is a video signal A gate means for deriving said pilot signal from tio tone signal, a determination unit for video signals from the pilot signal extracted by the gate means is determined whether or not the video signal of the wide aspect, Wide Asupe
The video signal which is not the video signal of the
And a masking means for masking a side panel portion containing a noise component or a ghost that has been expanded .

[0050]

According to the above arrangement, it is possible to determine from a pilot signal whether or not a transmitted video signal having an aspect ratio of 4: 3 is a wide aspect video signal. If the video signal is not a wide aspect video signal,
Video signal is processed by the compression / decompression means,
Since the side panel portion including the extended noise component and the ghost is masked, the side panel portion disturbed by the noise and the ghost is not projected, and the favorable aspect ratio of the wide aspect television receiver is 4: 3. You can get the screen.

[0060]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail with reference to FIGS. First, although not shown on the transmission side, whether the video signal is a video signal having an aspect ratio of 4: 3
For example, a television signal is created by superimposing a pilot signal Ps for informing whether the image signal is a 16: 9 wide aspect image signal in a vertical blanking period of the image signal, and the television signal is transmitted.

Next, on the receiving side, when the transmitted video signal is a wide aspect video signal, the pilot signal Ps superimposed within the vertical retrace period of the video signal is detected, and this pilot signal is detected. FIG. 1 shows an embodiment of a circuit for masking the side panel portion by masking the side panel portion with Ps.

In FIG. 1, reference numeral 1 denotes a video signal input terminal;
Is an A / D conversion circuit for converting a video signal guided from the video signal input terminal 1 into a digital signal, 3 is a synchronization separation circuit for separating a synchronization signal from the video signal, and 4 is locked to a burst signal of the video signal. , Subcarrier frequency fs
This is a clock generation circuit that generates a system clock having a frequency of 4 fsc, which is four times c.

Reference numeral 5 denotes a gate circuit for extracting the pilot signal Ps superimposed in the vertical blanking period of the video signal, which is a synchronization signal from the synchronization separation circuit 3, and reference numeral 6 denotes a video signal having a wide aspect from the pilot signal Ps. Footage of
A discrimination circuit 7 for discriminating whether the signal is a signal , and a compression / expansion control circuit 7 for controlling the compression / expansion circuit 8

[0100] Reference numeral 9 denotes the discrimination circuit 6 in which the video signal is
If it is determined that the video signal is not
A mask circuit for masking the side panel portion of the video signal having an aspect ratio of 4: 3 from the expansion circuit 8, a D / A conversion circuit 10 for converting the output of the mask circuit 9 into an analog signal, and a video signal output terminal 11 It is.

Next, the operation of the embodiment of the present invention will be described.
The television signal input from the video signal input terminal 1 is supplied to an A / D conversion circuit 2, a synchronization separation circuit 3, and a clock generation circuit 4. The clock generation circuit 4 locks to the burst signal of the video signal, and has a frequency four times the subcarrier frequency fsc, 4fsc (14.3181 MH).
The clock of z) is generated and supplied to each circuit as a system clock. The synchronization separation circuit 3 separates the synchronization signal from the video signal, and supplies the synchronization signal to the gate circuit 5 and the compression / decompression control circuit 7. The compression / expansion control circuit 7 generates a control signal Co for controlling the compression / expansion circuit 8 from the synchronization signal supplied from the synchronization separation circuit 3 and supplies the control signal Co to the compression / expansion circuit 8.

The gate circuit 5 extracts the pilot signal Ps included in the vertical blanking period in the television signal from the supplied synchronization signal and supplies the pilot signal Ps to the discrimination circuit 6.
The discrimination circuit 6 determines whether the video signal transmitted from the pilot signal Ps sent from the gate circuit 5 has a wide aspect ratio.
If it is the video signal, the discrimination signal Pj is set to the "L" level, otherwise, the discrimination signal Pj is set to the "H" level and supplied to the mask circuit 9.

On the other hand, the A / D conversion circuit 2 samples the input analog video signal at a frequency of 4 fsc, digitizes it, and supplies it to the compression / decompression circuit 8. compression·
The expansion circuit 8 uses the control signal Co supplied from the compression / expansion control circuit 7 to expand the side panel portion of the video signal having an aspect ratio of 4: 3 shown in FIG.
The center portion is compressed, and a video signal having an aspect ratio of 16: 9 as shown in FIG. The mask circuit 9 determines the discrimination signal Pj supplied from the discrimination circuit 6.
Is "L" level, since the video signal as shown in FIG. 2B has an aspect ratio of 16: 9, it is supplied to the D / A conversion circuit 10 without masking, and the discrimination signal Pj
Is "H" level, the video signal has an aspect ratio of 4: 3, and the signal present in the side panel portion is an expanded noise component or ghost as shown in FIG. As shown in (f), the side panel portion is masked and supplied to the D / A conversion circuit 10.

The D / A conversion circuit 10 converts the digital signal supplied from the mask circuit 9 into an analog signal and outputs the analog signal to the video signal terminal 11. When this signal is projected on a wide aspect receiver, the transmitted video signal is
When a video signal 16: 9 video can be obtained, so
If not, a 4: 3 image in which the side panel portion is masked can be obtained.

[0150]

Since the present invention has the above configuration, it is determined whether or not a video signal transmitted with an aspect ratio of 4: 3 is a wide aspect video signal by using a pilot signal. If the video signal is not a wide aspect video signal,
The image signal is obtained by processing the image
When the image is projected by a wide aspect receiver to mask the side panel portion including the noise component and the ghost, the side panel portion disturbed by the noise component and the ghost is not projected, and a good aspect ratio of 4: 3 is obtained. Images can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a main part of the present invention.

FIG. 2 is an operation explanatory diagram of the present invention.

FIG. 3 is an explanatory diagram of a wide aspect video signal.

[Explanation of symbols]

 Reference Signs List 5 Gate circuit 6 Discrimination circuit 7 Compression / expansion control circuit 8 Compression / expansion circuit 9 Mask circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-36681 (JP, A) JP-A-63-59185 (JP, A) JP-A-63-59082 (JP, A) JP-A-1- 253378 (JP, A) JP-A-2-92082 (JP, A) JP-A-2-172387 (JP, A) JP-A-53-51922 (JP, A) JP-A-3-1781 (JP, A) JP-A-2-107080 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/46 H04N 5/44 H04N 7/01

Claims (1)

(57) [Claims] An image signal having a wide aspect formed by a center panel portion and side panel portions on both sides thereof is transmitted as a video signal having an aspect ratio of 4: 3 by compressing the side panel portion. In a wide aspect television receiver for reproducing a wide aspect television signal having a wide aspect ratio compatible with an NTSC color television signal, which is a wide aspect television signal, a side panel portion of the video signal is expanded. A compression / expansion means for compressing the center panel portion; a control means for controlling the compression / expansion means based on a synchronization signal; and a pilot signal for identifying whether or not the received video signal is a wide aspect video signal. Gate to derive the pilot signal from the television signal superimposed on the side A stage, a determination unit for video signals from the pilot signal extracted by the gate means is determined whether or not the video signal of the wide aspect, the compressed video signal is not the video signal of the wide aspect
The noise component or GO
And a masking means for masking a side panel portion including the cast .