JP2669546B2 - Television receiver - Google Patents

Description

The present invention relates to signal processing of video signals in a television (TV) receiver, and is particularly suitable for displaying an image having a current aspect ratio in a receiver having a wide aspect ratio. TV receiver.

[Conventional technology]

Conventionally, television signals having an aspect ratio of 4: 3 have been employed. However, recently, there has been increasing interest in television receivers having a wide aspect ratio capable of displaying a more realistic image. For example,
HDTVs, which are being developed as the next generation of TVs, use 16: 9 aspect ratios.

[Problems to be solved by the invention]

A wide aspect ratio television receiver does not consider compatibility with the current television system, and when the current television signal is received by this receiver, the reproduced image is distorted.

It is an object of the present invention to provide a television receiver having a wide aspect ratio, which can reproduce an image of a current television signal without distortion.

[Means for solving the problem]

In order to achieve the above object, the conventional 4: 3 aspect ratio, such as the current television signal, is converted to a signal that has been subjected to time axis compression processing and displayed, so that the reproduced image can be reproduced. The above distortion is removed.

In addition, by inserting a specific signal at a position where a video signal does not exist by the time axis compression process, the viewer does not feel discomfort.

Furthermore, with respect to a signal that has been artificially widened by omitting the top and bottom of the screen in the current television signal, interpolation processing of the screen signal is performed so that the wide aspect can be displayed as it is. It is the one.

Furthermore, for television receivers with a wide aspect ratio that differs from the current system in the number of scanning lines, when the signal is converted to a signal that has been subjected to time-axis compression in both the horizontal and vertical directions, or the frequency of the horizontal synchronization signal Is changed and displayed.

[Action]

FIG. 2 is a diagram showing the principle of operation when the present invention is applied to a television receiver having a wide aspect ratio, for example, 16: 9, in which the number of scanning lines matches that of the current television.

Figure (a) shows the aspect ratio of the current system (4: 3).
3 shows an image when the television signal is reproduced as it is by a receiver having a wide aspect ratio. In this case, an image with an aspect ratio of 4: 3 is displayed with an aspect ratio of 16: 9, so the image that should be displayed as a solid line in the figure is also stretched in the horizontal direction as indicated by the dotted line in the figure. It will be displayed as an image. That is, the image is distorted.

On the other hand, FIG. 2B shows a case where the current television signal is displayed after being subjected to time axis compression processing in the horizontal direction. In this case, the image can be displayed in the hatched area in the same figure in the normal state where the aspect ratio 4: 3 is preserved. Therefore, no distortion occurs in the displayed image. In this case, since there is no information in the areas at both ends of the screen, it is possible to display a visually preferable image signal by displaying the image in place of a specific signal, for example, a black level signal.

On the other hand, as shown in FIG. 3C, the image obtained by widening the screen by cutting the top and bottom of the screen within the frame of the current aspect ratio is subjected to the time axis compression processing as shown in FIG. The image is displayed in the area. Therefore, in such a case, an image enlargement operation can be further performed by an interpolation process or the like to display the image on the entire screen.

Next, FIG. 3 shows an operation principle diagram when the present invention is applied to a television receiver having a wide aspect ratio in which the number of scanning lines is different from that of the current television. In this example, the number of scanning lines is larger than that of the current television, and the aspect ratio is 16: 9.

In the figure (a), an image with an aspect ratio of 4: 3 is displayed within the range of the current number of scanning lines by horizontal and vertical time axis compression processing, and the image with the current aspect ratio is displayed in the hatched area. it can. Since there is no information to be displayed outside the hatch area, it is desirable to perform masking with a specific signal such as a signal corresponding to a black level, as described above.

FIG. 3C shows a signal of the form shown in FIG.
Further, an image enlargement operation is performed by interpolation processing or the like.
Image display is performed using up and down frames.

On the other hand, FIG. 2B shows a case where the horizontal synchronization system is changed to a specially changed display form having the same number of scanning lines as the current system.
The signal which is horizontally compressed on the time axis by the changed synchronous system is displayed. In this case, the present invention can be applied when the synchronization system of the receiver is within the pull-in range.

As described above, according to the present invention, it is possible to display an image of a current television signal without distortion in a receiver having a wide aspect ratio different from the aspect ratio of the current television system.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG. This is an embodiment in the case where the number of scanning lines is the same as that of the current television and the aspect ratio is, for example, 16: 9. Also, the description will be made assuming that the television signal is a signal in a baseband region.

The television signal is subjected to a predetermined demodulation operation by a wide aspect signal decoder circuit 1 and a current television signal decoder circuit 2, respectively, and is demodulated into, for example, three primary color signals R, G and B.

On the other hand, the control signal invention circuit 9 generates various control signals such as a clock signal and a synchronization signal necessary for the operation of each section. Further, the mode identification circuit 10 identifies and determines the mode of the wide aspect signal or the current television signal based on, for example, an identification signal.

Now, the signal of the current television signal decoder circuit 2 is subjected to a predetermined time axis compression process in the horizontal time axis compression circuit 3 so as to be a signal corresponding to an area as shown in FIG. . Since the time axis compression circuit can be easily realized by using a memory or the like, a description of a specific configuration and the like will be omitted.

Next, the specific signal insertion circuit 4 converts an image signal portion corresponding to a portion other than the region displayed at the current aspect ratio into:
For example, processing is performed when a specific signal such as a black level signal is used.

Further, as shown in FIG. 2C, the image enlargement processing circuit 5 generates an image signal corresponding to an enlarged image by interpolation processing or the like.

The selection circuit 6 selects either the signal sequence A 'corresponding to the display mode of FIG. 2 (b) or the signal sequence B' corresponding to the display mode of FIG. 2 (c). This selection is made by the mode selection signal. Normally, the series A'is selected, but the viewer can select the series B'signal.

Then, in the selection circuit 7, the signal of the series A corresponding to the wide aspect ratio and the signal of the series B corresponding to the current aspect ratio are output.
Is selected by the display mode control signal from the mode identification circuit. The image is displayed on the three primary color picture tube 8.

FIG. 4 shows another embodiment of the present invention. This example is
As shown in FIG. 3, there is shown a case where an image is displayed in the form of FIG. 3 (a) or (c) in a television receiver having different scanning lines. This embodiment is the same except that the horizontal time axis compression circuit 4 of FIG. 1 is replaced by a horizontal and vertical time axis compression circuit 11. The horizontal and vertical time axis compression circuit 11 operates in the same manner as in FIG. 1 except that the time axis compression processing is performed not only in the horizontal direction but also in the vertical direction. Is omitted.

FIG. 5 shows another embodiment of the present invention. This is a case where an image signal corresponding to FIG. 3 (b) is generated. In this case, the control signal generating circuit 12 differs from the conventional aspect signal in that it generates different types of horizontal synchronizing signal sequences for the wide aspect signal and the current television signal, but the other operations are the same. , Detailed description is omitted.

As described above, in the present embodiment, the output signal of the current television signal decoder circuit has been described as an example of the R, G, B3 primary color signal. However, the present invention is not particularly limited thereto. For example, a luminance signal, two color difference signals It is apparent that the present invention can be applied to such a form.

〔The invention's effect〕

According to the present invention, in a television receiver having a wide aspect ratio different from the aspect ratio of the current system, an image can be displayed without distortion in both the wide aspect signal and the current television signal. Can receive a plurality of different types of television signals.

It should be noted that the signal processing of the present invention includes analog, digital,
Alternatively, it can be realized in any form in which both are mixed.

In the picture tube, a progressive scanning type may be used in order to reduce interference such as flickering. In this case, the current television signal decoder circuit 2
For example, it is desirable to realize such a configuration as a signal such as an IDTV in which a signal subjected to signal processing such as scanning line doubling interpolation is used as an output signal.

Moreover, although the aspect ratio of 16: 9 has been described as an example in this embodiment, it is obvious that the aspect ratio is not limited to this and can be appropriately applied to any wide aspect ratio.

[Brief description of the drawings]

1, 4 and 5 are circuit block diagrams of a television receiver according to one embodiment of the present invention, and FIGS. 2 and 3 are explanatory diagrams of the operation principle of the present invention. 1 ... Wide aspect signal decoder circuit, 2 ... Current television signal decoder circuit, 3 ... Horizontal time axis compression circuit, 4 ... Specific signal insertion circuit, 5 ... Image enlargement processing circuit, 6, 7 ... Selection Circuit, 8 ... 3 primary color picture tube, 9,12 ...
Control signal generating circuit, 10 Mode discriminating circuit, 11 Horizontal and vertical time axis compression circuit.

Claims (1)

(57) [Claims] 1. A television receiver capable of displaying a wide aspect ratio television signal or a television signal of a current television signal and having a wide aspect ratio different from that of a current system, wherein the wide aspect ratio television signal is used. First demodulating means for demodulating the current television signal, second demodulating means for demodulating the current television signal, and performing horizontal time axis compression on the signal output from the second demodulating means. A time axis compression unit for performing processing; an image enlargement processing unit for performing horizontal and vertical image enlargement operations by interpolating an image signal on a signal output from the time axis compression unit; Means for displaying an output signal of one of the time axis compression means and the image enlargement processing means. Revision receiver.