JPH0662343A - Aspect ratio converter - Google Patents

Abstract

PURPOSE:To make the screen size of both modes fixed by only increasing/ decreasing the amplitudes of a vertical deflection and a horizontal deflection and the set quantity of a vertical deflection position and the horizontal deflection position. CONSTITUTION:An operator performs mode change over and channel selection by the key operation of a remote control transmitter 2, for example, and an operation signal is supplied to CPU 7 (microcomputer). By respectively detecting operated keys, CPU 7 controls a UV tuner 1, a BS tuner 3, a MUSE/NTSC converter 5, a change-over switch 6, a scanning line interpolation filter circuit 24, a vertical output circuit 12 and a horizontal output circuit 14 base on an operation signal and a MUSE/NTSC judging signal. In this case, vertical and horizontal deflection means are controlled by a control means so as to set an aspect ratio (complete roundness rate) of a picture to almost 1 without differing respective aspect ratios and the amplitudes of the vertical/horizontal deflections are changed.

Description

Detailed Description of the Invention

[0001]

This invention relates to MUSE (Multiple S
Converting high-definition signals such as ub-Nyquist Sampling Encoding) signals to NTSC signals, CRT (CRT)
The present invention relates to an aspect conversion device that can be projected on. In particular, it relates to a television receiver.

[0002]

2. Description of the Related Art In recent years, high-definition broadcasting has been put to practical use by satellite broadcasting, and a high-definition screen can be viewed by a special receiver that constitutes one screen with more scanning lines than a conventional television receiver. Has become. As a video transmission system for this high-definition broadcasting, the MUSE system has been developed.

Regardless of the special receiver for high definition,
In response to the demand to watch high-definition broadcasts using the current television receivers that are already popular in ordinary homes, MUSE / converts MUSE signals to NTSC signals.
NTSC converters have been developed. This MUSE /
The NTSC converter is shown on pages 31 to 45 of the magazine "TV Technology October 1989" published by Electronic Technology Publishing Co., Ltd.

According to the MUSE / NTSC converter, the high-definition signal received by the BS tuner is converted into an NTSC signal, and the NTSC signal is supplied to the video input terminal of the television receiver.
Not only broadcasting but also high-definition broadcasting programs can be viewed on one receiver.

By the way, in an NTSC television receiver, the aspect ratio of the screen is 4: 3, whereas in the MUSE method it is 16: 9. Also, NT
The SC system has 525 scanning lines per screen, while the MUSE system has 1125 scanning lines.

Accordingly, the entire screen having an aspect ratio of 16: 9 by MUSE broadcasting is displayed on a CRT having an aspect ratio of 4: 3.
If the horizontal widths of both screens are made to match each other in order to display on the screen, the vertical 3/4 of the total screen area with an aspect ratio of 4: 3 is displayed.
(That is, the aspect ratio is 4: 3 = 16: 12, so 9/12
3/4) becomes the effective display area.
As described above, band-shaped non-image area portions are displayed above and below the screen of the CRT.

In this case, of the 525 scanning lines that make up the screen of the NTSC system, 394 of 3/4 become effective, so that in the MUSE / NTSC converter, MUSE
It would be necessary to reduce the broadcast 1125 scan lines to 394 scan lines. The ratio of the number of scanning lines at this time is 2.85.
The ratio is 7: 1, which is not an integer ratio. As a result, when the scanning line conversion is performed, the circularity (ratio between the vertical direction and the horizontal direction of the circle) becomes poor.

Therefore, in order to perform the scan line conversion by a simple process, a conversion system is adopted in which 1125 lines of MUSE broadcasting are reduced to 375 scan lines at a ratio of 3: 1.

In this method, since the number of scanning lines that should be reduced to 394 is reduced to 375, the width in the vertical direction of the screen is compressed to a ratio of 375/394, that is, approximately 95%.

Therefore, in order to maintain the roundness, the width in the lateral direction needs to be compressed by about 95%.

Generally, in the NTSC system, an overscan of about 8% is performed in consideration of the influence of the geomagnetism and the like. However, such a 95% compression almost eliminates the margin for overscan. Therefore, if the horizontal sync signal and the video signal are slightly out of phase,
It is inevitable that the non-image areas are displayed on the left and right sides of the screen.

When the non-image areas are displayed not only on the top and bottom of the screen but also on the left and right as shown in FIG. 4, not only does the screen become difficult to see, but the operator also feels that there is a misalignment. Gives rise to the problem.

Therefore, the applicant of the present application has previously filed Japanese Patent Application No. 3-16.
No. 4351 proposes a method for solving the above problems.

FIG. 2 shows the configuration of a conventional television receiver. U receiving VHF and UHF bands
The television signal selected by the V tuner 1 is detected by the detection circuit 2 and output as a video signal. This video signal is input to one end of the changeover switch 6, and passes through the changeover switch 6 and then the video circuit 8 and the sync separation circuit 9
Sent to. Then, the video signal is converted into an RGB signal by the video circuit 8 and, by the sync separation circuit 9, 60
The vertical sync signal of Hz and the horizontal sync signal of 15.75 KHz are separated.

The output signal of the video circuit 8 is the drive circuit 1
It is sent to CRT15 via 0.

Further, the vertical synchronizing signal and the horizontal synchronizing signal are sent to the vertical oscillating circuit 11 and the horizontal oscillating circuit 13, respectively, and the sawtooth wave voltage generated thereby is sent to the vertical output circuit 12 and the horizontal output circuit 14. After being amplified and waveform-shaped, it is applied to the CRT 15.

On the other hand, the MUSE signal selected by the BS tuner 3 which receives the BS broadcast from the broadcasting satellite is supplied to the MUSE / NTSC converter 5 through the detection circuit 4 and converted into the NTSC signal. In addition, MUSE / NTS
The C converter 5 performs scanning line number conversion and time compression in the horizontal operation direction, and has the same configuration as the conventional one.

N from the MUSE / NTSC converter 5
The TSC signal is input to the other end of the changeover switch 6 and passes through the changeover switch 6 to the video circuit 8 and the sync separation circuit 9
Sent to. After that, the same processing as in the case of the UV tuner is performed.

Although not shown, mode switching and channel selection operations by the operator are performed by key operations such as external control means (remote control transmitter), and operation signals are supplied to a microcomputer (hereinafter referred to as CPU) 7.

The MUSE / NTSC converter 5 receives the MUSE signal at the same time when the MUSE signal is input.
The NTSC discrimination signal is supplied to the CPU 7.

The CPU 7 controls the operation signal and MUSE / N.
The BS tuner 3, the changeover switch 6, the vertical output circuit 12, the horizontal output circuit 14 and the like are controlled based on the TSC discrimination signal.

According to the above television receiver, the MUS
When converting the E method to the NTSC method and displaying it on the screen,
The amplitude of the deflection of the vertical deflection circuit 18 and the horizontal deflection circuit 19 can be enlarged without changing the output of the horizontally compressed MUSE / NTSC converter to prevent the display of the left and right non-image areas of the screen.

Further, since both the vertical width and the horizontal width of the screen are enlarged at the same rate, the roundness of the image does not decrease.

Next, when viewing a high-definition broadcast on a television receiver with a built-in scanning line interpolation filter in which the number of scanning lines of the NTSC system is increased from 525 to 735, there are two methods described below.

First, one of them is the number of scanning lines of the effective screen of the high-definition broadcast, that is, the effective scanning line number from 1032 to 1 by the high-definition / NTSC conversion means
344 lines thinned to 3/3 are generated, and the scan line interpolation filter (from 525 lines to 735 lines is increased). Therefore, 7 scan lines are generated from 5 scan lines, that is, 7/5 times. By the filter converting the scan line to
This is a method of multiplying 344 lines by 7/5 to interpolate to 481.6 lines (hereinafter referred to as wide mode).

On the other hand, a high-definition / NTSC conversion means is used for the upper part 33 of the effective scanning line number 1032.
, 966, which is the lower 33 (66 in total)
This is a method of thinning out / 2 to generate 483 lines and incorporating 483 lines into 735 lines by the scanning line interpolation filter (hereinafter referred to as squeeze wide mode).

By the way, as described above, in general, NTSC
In the case of the television receiver of the system, the number of effective scanning lines is 4
About 85% of the 85 lines are overscanned. Therefore, when the above scanning line interpolation filter also performs 8% overscan in the horizontal and vertical directions, the number of scanning lines displayed on the CRT is (485 × 7/5 × 92%) = 6.
It will be 24.68.

On the other hand, the aspect ratio is 4: 3 (16: 1).
Since the signal of 16: 9 is put on the CRT which is 2), (624.68 lines × 9/12/92%) = 50
Roundness (vertical length /
The horizontal length) is 1.

In the squeeze wide mode, the above 1
Aspect ratio is 16: 9 instead of 16: 9 because the upper 33 and the lower 33 (total 66) of 032 lines are cut off.
This is 8.42. Therefore, (624.68 lines × 8.
42/12/92%) = 476.43 lines, the roundness becomes 1. However, since the number of effective scanning lines in the squeeze wide mode is 483, 483/47
The roundness is 6.43 = 1.02.

In the wide mode, since the number of effective scanning lines is 481.6, it is 481.6 / 509.25.
The circularity is 0.95.

As described above, the roundness of the wide mode is slightly worse than that of the squeeze wide mode.

By the way, recording of a VTR (video tape recorder) has a structure in which a magnetic tape is obliquely scanned in a 1/2 vertical period, and a switching noise of a magnetic head is generated at the bottom of the screen every 1/2 vertical period. . In normal playback,
This noise generated at the bottom of the screen is overscanned, so it cannot be seen by the operator.

However, VT in squeeze wide mode etc.
As described above, the recording signal to the R puts the effective screen of the high-definition broadcast on the 483 scanning lines. This is NTS
It covers almost the entire area of 485 lines that can carry video signals in the C format. When the VTR reproduction signal is viewed on the above television receiver, 483 of this effective screen is displayed.
Since the scanning lines of the book are all displayed on the screen, the noise is visible to the operator.

Therefore, in the squeeze wide mode, 483 effective screens are generated by the scanning line interpolation filter.
The process of cutting off 0 is performed. Therefore, the aspect ratio of 16: 8.42 was 16: 8.
As compared with the wide mode, the screen displayed on the CRT has a difference of 0.75 in aspect ratio. In a 33-inch CRT with an aspect ratio of 4: 3, the difference is about 3.1 cm, which is the difference in the area of the non-image portion as it is, which gives the operator a feeling of strangeness.

In the squeeze wide mode, about 20 lines at the bottom of the screen are cut off, so that the difference in the area of the non-image area becomes larger at the bottom of the screen.

In order to improve the roundness, it is possible to increase the vertical deflection and horizontal deflection amplitudes by a predetermined amount in the specific mode to make the roundness almost 1 in the above-mentioned conventional example. The area difference of the image part is not solved.

[0037]

SUMMARY OF THE INVENTION The present invention solves the above problems by making the circularity approximately 1 and making the areas of the upper and lower non-image areas substantially equal.

[0038]

According to the present invention, an input first television signal of a first system is converted into a second television signal of a second system or a third television signal of a third system having different aspect ratios. In the changing aspect ratio conversion device, a scanning line interpolating means for converting the number of scanning lines of a CRT displaying an image from the number of scanning lines of the first method into the number of scanning lines of the second and third methods, and the scanning line interpolating means. The vertical deflection means and the horizontal deflection means for deflecting the CRT in the vertical direction and the horizontal direction according to the vertical and horizontal synchronizing signals separated from the output signal, the scanning line interpolating means, the vertical deflection means and the horizontal deflection means are external. The aspect ratio of the second television signal and the aspect ratio of the third television signal are different from each other. In addition, the vertical and horizontal deflection means are controlled by the control means so that the vertical to horizontal ratio (roundness) of the image is approximately 1, and the amplitude of the vertical and horizontal deflection is changed. An aspect ratio conversion device is provided.

Also, the aspect ratio converting apparatus is characterized in that the control means controls so that the image of the second television signal or the third television signal is positioned substantially at the center of the CRT. It is a thing.

[0040]

According to the present invention, the width and the starting position of the horizontal and vertical deflections are switched depending on the set mode in the television receiver which performs the scanning line interpolation.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of a television receiver embodying the present invention. In the circuit of FIG. 1, the same parts as those of the conventional example of FIG.

Reference numeral 24 denotes a scanning line interpolation filter circuit which creates seven scanning lines from five scanning lines when scanning line interpolation is performed by a switching signal (wide mode / squeeze wide mode switching signal) from the CPU 7. , One end is connected to the fixed end of the changeover switch 6, and the other end is connected to the video circuit 8 and the sync separation circuit 9.

The sync separation circuit 9 has a vertical sync signal of 60 Hz and 22.05 KHz (current broadcasting is 15.75 KHz, and the scanning line is 7/5 times in the squeeze wide mode, so the frequency is also 7/5 times). To obtain a horizontal sync signal of 22.05 KHz).

The mode switching and channel selection operation by the operator are performed, for example, by key operation of the remote control transmitter 23, and this operation signal is supplied to the CPU 7. Then, each of the operated keys is detected, and the CPU 7 detects the operation signal and the MUS.
UV tuner 1, BS based on E / NTSC judgment signal
The tuner 3, the MUSE / NTSC converter 5, the changeover switch 6, the scanning line interpolation filter circuit 24, the vertical output circuit 12, the horizontal output circuit 14 and the like are controlled.

In addition, the MUSE / NTSC converter 5
At the same time as the input of the MUSE signal,
The SE / NTSC determination signal is supplied to the CPU 7.

Next, considering the deflection width and deflection position, the vertical deflection amplitude is controlled by changing the amplitude of the vertical sawtooth wave voltage, and the horizontal deflection amplitude is controlled by the horizontal sawtooth wave voltage. Is controlled by changing. This is described in the above-mentioned Japanese Patent Application No. 3-164351, and its explanation is omitted.

The vertical deflection position is controlled by changing the DC level of the vertical sawtooth wave voltage. The horizontal deflection position is controlled by changing the phase of the FBP (flyback pulse) and the video signal or changing the DC level of the horizontal sawtooth wave voltage.

Now, assume that the wide mode is selected by the operator. At this time, the CPU 7 causes the vertical output circuit 12 to output about 10 of the amplitude of vertical deflection in the current broadcast.
It is assumed that the control signal for obtaining the vertical deflection amplitude of 5% (actually, the circularity of 95% as described above is 1 / 0.95 times this reciprocal). With this control signal, the roundness in the wide mode can be set to 1. That is, the number of scanning lines 509.2 described above.
The roundness becomes 1 when the number is 5. The aspect ratio of the screen at this time is 16: 9.78.

Further, it is assumed that the operator selects the squeeze wide mode. Since the roundness of the squeeze wide mode is as good as 1.02, the roundness is kept as it is.

Then, in order to make the screen the same size as the wide mode, the aspect ratio is 16: 9.78.
To Therefore, the amplitude of vertical and horizontal deflection is increased as follows.

That is, assuming that the number of scanning lines is x when the aspect ratio is 16: 9.78,

[0052]

[Equation 1]

It becomes

The scanning line obtained by the equation 1 has the following ratio as compared with the scanning line of the conventional squeeze wide mode.

[0055]

[Equation 2]

Therefore, the CPU 7 sends to the vertical output circuit 12 a control signal for increasing the vertical deflection amount by about 14% with respect to the vertical deflection amount in the current mode. Moreover,
This CPU 7 is approximately 14 times the horizontal deflection amount in the current mode.
A control signal for increasing the horizontal deflection amount of% is transmitted. Further, the control signal for changing the vertical position is sent so that the areas of the non-image area in the squeeze wide mode become equal in the vertical direction. With this control signal, the area difference between the squeeze wide mode and the wide mode in the non-image area portion can be improved.

It is also possible to set the amplitudes of vertical deflection and horizontal deflection in the wide mode and the squeeze wide mode, and the correction amounts of the vertical position and the horizontal position by operating the keys of the remote control transmitter. Amplitudes of vertical deflection and horizontal deflection in the mode and squeeze wide mode and correction amounts of vertical position and horizontal position are stored in the non-volatile memory 22, and the CPU 7 reads the correction amount from the non-volatile memory 22 when the power is turned on again. However, it is also possible to perform the above operation.

[0058]

According to the present invention, the amplitudes of vertical deflection and horizontal deflection, and the vertical deflection position and the horizontal deflection position are simply set without changing the aspect ratio converter which can select the wide mode and the squeeze wide mode. The screen size in both modes can be made constant with a simple configuration simply by increasing or decreasing the amount.

Further, even when the amplitude of one of the horizontal and vertical deflections changes, the amplitude of the other deflection can be easily adjusted so as to maintain the perfect circularity.

[Brief description of drawings]

FIG. 1 is a block diagram of one embodiment according to the present invention.

FIG. 2 is a block diagram of a conventional example.

FIG. 3 is a diagram showing a display state of a CRT.

FIG. 4 is a diagram showing left and right non-image area portions displayed on a CRT.

[Explanation of symbols]

 1 UV Tuner 2, 4 Detection Circuit 3 BS Tuner 5 MUSE / NTSC Converter 6 Changeover Switch 7 CPU 8 Video Circuit 9 Sync Separation Circuit 10 Drive Circuit 11 Vertical Oscillation Circuit 12 Vertical Output Circuit 13 Horizontal Oscillation Circuit 14 Output Output Circuit 15 CRT 16 Vertical amplitude switching signal 17 Vertical position switching signal 18 Horizontal amplitude switching signal 19 Horizontal position switching signal 20 Vertical deflection circuit 21 Horizontal deflection circuit 22 Nonvolatile memory 23 Remote control transmitter 24 Scan line interpolation filter circuit

Claims (2)

[Claims] 1. An aspect ratio conversion device for converting an input first television signal of a first system into a second television signal of a second system or a third television signal of a third system having different aspect ratios, Scanning line interpolating means for converting the number of scanning lines of the CRT for displaying an image from the number of scanning lines of the first system to the number of scanning lines of the second system and the third system, and a vertical line separated from the output signal of the scanning line interpolating means A vertical deflection means and a horizontal deflection means for deflecting the CRT in the vertical and horizontal directions by a horizontal synchronization signal, and the scanning line interpolation means, the vertical deflection means and the horizontal deflection means are controlled by an external control means or an internal storage means. The aspect ratio of the second television signal and the aspect ratio of the third television signal do not differ from each other, and the vertical and horizontal directions of the image are different from each other. The ratio controls the vertical and horizontal deflection means by said control means so as to substantially 1 (roundness), the aspect ratio conversion apparatus characterized by varying the amplitude of the vertical and horizontal deflection. 2. The aspect ratio conversion according to claim 1, wherein the control means controls the image of the second television signal or the third television signal so that the image is located substantially in the center of the CRT. apparatus.