JPH05236383A - Television receiver - Google Patents

Abstract

PURPOSE:To provide the television receiver of simple constitution which displays no blanking part at the right and left parts on a screen by incorporating a high-vision/NTSC converting means which converts a high-vision signal into an NTSC signal. CONSTITUTION:The television receiver is equipped with vertical and horizontal deflecting circuits 18 and 19 wherein the deflection widths of vertical deflection and horizontal deflection can be varied and set and when the output of a MUSE /NTSC converter 5 is projected on a CRT 15, a microcomputer 7 sends control signals for increasing the deflection widths of the vertical deflection and horizontal deflection by specific ratios respectively to the vertical and horizontal deflecting circuits 18 and 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts a high-definition signal such as a MUSE signal into an NTSC signal for CRT.
The present invention relates to a television receiver capable of displaying on.

[0002]

2. Description of the Related Art In recent years, high-definition broadcasting using broadcasting satellites has been put into practical use, and a special receiver that constitutes one screen by approximately twice the number of scanning lines of a conventional television receiver provides high-definition screens with high-definition. It is possible to watch the broadcast. As a video transmission method of high-definition broadcasting using a broadcasting satellite, MUSE (Multiple Sub-Nyqu
ist Sampling Encode) method has been developed.

In such a situation, the MUSE signal is changed to the NTSC signal in response to the demand to watch the high-definition broadcast by using the current television receiver which has already been popularized in general households, regardless of the special receiver for the high-definition television. A MUSE / NTSC converter for converting into a video signal has been developed (for example, magazine "TV Technology", October 1989, pages 40 to 45). 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 broadcast programs, but also high-definition broadcast programs 1
Can be viewed on a single receiver.

By the way, in the television receiver of the NTSC system, the aspect ratio of the screen is 4: 3, whereas in the MUSE system, it is 16: 9. Also, NTS
In the C method, there are 525 scanning lines per screen, whereas in the MUSE method, there are 1125 scanning lines. Therefore, MU
Assuming that the entire screen with an aspect ratio of 16: 9 by SE broadcasting is not displayed on the screen of a CRT with an aspect ratio of 4: 3, if the widths of both screens are the same, the vertical portion of the entire screen area with an aspect ratio of 4: 3 is displayed. A width of 75% in the direction becomes an effective display area, and band-shaped blanking portions are displayed above and below the screen of the CRT (15) as shown in FIG.

In this case, of the 525 scanning lines forming the screen of the NTSC system, 75% of the 394 scanning lines are effective. Therefore, in the MUSE / NTSC converter, 1125 scanning lines of MUSE broadcasting are 394 scanning lines. A conversion that reduces to scan lines is required. The scanning line ratio at this time is 2.8.
It is 55 to 1, which is not an integer ratio.

Therefore, in order to convert the scanning lines by a simple process, a conversion system is adopted in which the 1125 scanning lines of MUSE broadcasting are reduced to 375 at a ratio of 3: 1. In this method, the number of scanning lines, which should be reduced to 394 originally, is reduced to 375, so that the vertical width of the screen is 3
It is compressed to a ratio of 75/394, or about 95%. Therefore, as shown in FIGS. 4 (a) and 4 (b), the video signal V between the horizontal synchronizing signals H is time-compressed in the horizontal direction, and the horizontal width of the screen is also compressed at the same ratio. The whole screen is displayed on the screen without distortion.
It is displayed on the RT.

[0007]

However, by compressing the width of the screen to about 95% as described above, the blanking portion is displayed on the left and right of the screen of the CRT (15) as shown in FIG. Becomes Generally, in the NTSC system, about 8% overscan is performed in consideration of the influence of the earth's magnetism etc. However, even in this case, the overscan margin is almost eliminated by the above 95% compression. If the mutual phase of the synchronizing signal and the video signal is slightly deviated from each other, it is inevitable that blanking parts are displayed on the left and right sides of the screen. If the blanking portions are displayed not only on the upper and lower sides of the screen but also on the left and right sides, not only the screen becomes difficult to see, but also a problem of giving a viewer anxiety that there is a misalignment occurs.

An object of the present invention is to provide a television receiver having a simple structure in which blanking portions are not displayed on the left and right sides of the screen.

[0009]

A television receiver according to the present invention has a built-in high-definition / NTSC conversion means for converting a high-definition signal into an NTSC signal, and a first mode for displaying an NTSC broadcast on a CRT (15). And the second mode in which the video signal from the high-definition / NTSC conversion means is displayed on the CRT (15) can be switched and set.

Further, the vertical and horizontal deflection circuits (18) and (19) capable of variably setting the deflection widths of the vertical deflection and horizontal deflection, and the vertical and horizontal deflection circuits (18) (18) when the second mode is set. 19)
On the other hand, the control means for sending the control signals for increasing the deflection widths of the vertical deflection and the horizontal deflection respectively by a predetermined ratio as compared with the deflection widths in the first mode is provided.

[0011]

In the second mode, vertical and horizontal deflection circuits
(18) Since the deflection deflection width of (19) increases and the horizontal width and vertical width of the image displayed on the screen are expanded at the same ratio, the horizontal width of the screen is about 95 by the high-definition / NTSC conversion means.
Even when compressed to%, if the enlargement ratio is set to, for example, about 10%, the blanking parts are not displayed on the left and right of the screen. In this case, if the enlargement ratios of the deflection widths of vertical deflection and horizontal deflection are set to the same value, no distortion will occur in the image.

[0012]

The television receiver according to the present invention has a simple structure in which the swing width of the vertical and horizontal deflection circuits is simply expanded without changing the conversion method by the high-definition / NTSC conversion means. The blanking display on the left and right of the screen can be prevented.

[0013]

The examples are for the purpose of illustrating the present invention and should not be construed as limiting the invention or limiting the scope of the invention.

FIG. 1 shows the configuration of a television receiver embodying the present invention. The television signal selected by the UV tuner (1) is detected by the detection circuit (2) and output as a composite video signal. The composite video signal is sent to the video circuit (8) and the sync separation circuit (9) via the change-over switch (6), and the video circuit
Converted to RGB signal by (8), and 60Hz vertical sync signal and 15.75K by sync separation circuit (9).
The Hz horizontal sync signal is separated. The output of the video circuit (8) is sent to the CRT (15) via the drive circuit (10).

The vertical synchronization signal and the horizontal synchronization signal are sent to the vertical oscillation circuit (11) and the horizontal oscillation circuit (13), respectively.
The sawtooth voltage thus created is amplified and waveform-shaped by the vertical output circuit (12) and the horizontal output circuit (14), and then applied to the CRT (15).

On the other hand, the M selected by the BS tuner (3)
The USE signal is supplied to the MUSE / NTSC converter (5) via the detection circuit (4) and converted into an NTSC signal.
The MUSE / NTSC converter (5) performs the above-mentioned scanning line conversion and time compression in the horizontal scanning direction, and its specific configuration is the same as the conventional one. MUSE /
The NTSC signal from the NTSC converter (5) passes through the changeover switch (6) and the video circuit (8) and the sync separation circuit (9).
Be led to.

The mode switching and channel selection operation by the viewer are performed, for example, by key operation of a remote controller, and the operation signal is supplied to the microcomputer (7). Also, M
At the same time as inputting the MUSE signal, the USE / NTSC converter (5) supplies a MUSE / NTSC determination signal representing the input to the microcomputer (7).

The microcomputer (7), based on the operation signal and the MUSE / NTSC determination signal, outputs the B signal.
S tuner (3), changeover switch (6), vertical output circuit (1
2), which controls the horizontal output circuit (14) and the like.

FIG. 2 shows a configuration example of the vertical deflection circuit (18) including the vertical oscillation circuit (11), which is connected in parallel to the first resistor R ₁ by closing the switch (16). It comprises a second resistance R ₂ to be applied. By opening and closing the switch (16) by the switching signal from the microcomputer (7), the amplitude of the vertical sawtooth wave voltage can be increased or decreased by 2
The type can be switched, and when the MUSE signal input determination signal is sent from the MUSE / NTSC converter (5), the amplitude of the vertical sawtooth voltage is increased by about 7 to 8%.

On the other hand, FIG. 3 shows an example of the configuration of the horizontal deflection circuit (19) including the horizontal output circuit (14). By closing the switch (17), it is connected in parallel with the third resistor R ₃ . A fourth resistor R ₄ to be connected to. In response to a switching signal from the microcomputer (7), the switch (1
The amplitude of the horizontal sawtooth voltage can be switched between large and small by opening and closing 7). MUSE / NTSC
When the determination signal of the MUSE signal input is sent from the converter (5), the amplitude of the horizontal sawtooth voltage is increased at the same rate as the amplitude of the vertical sawtooth voltage.

According to the above television receiver, the MUS
When E-broadcast is converted to NTSC format and displayed on the screen,
Vertical deflection circuit (18) without changing the horizontally compressed MUSE / NTSC converter output as shown in (b).
Also, the deflection deflection width of the horizontal deflection circuit (19) can be enlarged from the chain line to the broken line in FIG. 5 to prevent blanking display on the left and right sides of the screen. In addition, as a configuration for that, a switch and a resistor capable of controlling opening and closing are added to the conventional vertical deflection circuit (18) and horizontal deflection circuit (19), and software of the microcomputer (7) is slightly added. All you have to do is modify it. It should be noted that since the vertical width and the horizontal width of the screen are both enlarged at the same rate, the roundness of the image does not decrease.

By the way, in the case of on-screen display of the functions and features related to the satellite broadcasting of the television receiver by the normal NTSC system, in order to simulate the satellite broadcasting, the screen of the CRT (15) is displayed as shown in FIG. The band-shaped blanking portions are displayed above and below. In this case, in the conventional television receiver, the microcomputer for channel selection counts the horizontal synchronizing signal from the time when the vertical synchronizing signal is generated, and based on the count value, the blanking display section at the top and bottom of the screen is displayed. Since the start and end positions are determined, the start and end positions of the blanking display section are discrete corresponding to one cycle of the counting operation. As a result, as shown in FIG. 9, there is a problem that a blanking portion is not formed at the top and bottom of the screen.

Against this problem, if the vertical width and the horizontal width of the screen are enlarged by a certain ratio as in the present invention, a normal simulated demonstration screen as shown in FIG. 8 can be generated without damaging the background screen. Can be done.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or limiting the scope. The configuration of each part of the present invention is not limited to the above embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a television receiver embodying the present invention.

FIG. 2 is a circuit diagram showing a configuration example of a vertical deflection circuit.

FIG. 3 is a circuit diagram showing a configuration example of a horizontal deflection circuit.

FIG. 4 is a time chart explaining a video signal compression operation by a MUSE / NTSC converter.

FIG. 5 is an explanatory diagram showing how the vertical and horizontal deflection deflection widths are enlarged.

FIG. 6 is a diagram showing an example in which an entire screen of a video signal converted by a MUSE / NTSC converter is displayed on the screen with an aspect ratio of 4: 3.

FIG. 7 is a diagram showing an example in which an entire screen of a video signal obtained by compressing the output of the MUSE / NTSC converter is displayed on the screen with an aspect ratio of 4: 3.

FIG. 8 is a diagram showing an example of a screen of a simulated demonstration of satellite broadcasting.

FIG. 9 is a diagram illustrating a problem when the screen of FIG. 8 is displayed.

[Explanation of symbols]

 (5) MUSE / NTSC converter (18) Vertical deflection circuit (19) Horizontal deflection circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H04N 11/20 7337-5C

Claims (1)

[Claims] 1. A high-definition / NTSC conversion means for converting a high-definition signal into an NTSC signal is built in, and the NTS
A television receiver capable of switching between a first mode for displaying C broadcast on a CRT (15) and a second mode for displaying a video signal from the high-definition / NTSC conversion means on a CRT (15). The vertical and horizontal deflection circuits (18) and (19) in which the deflection width of the vertical deflection and the horizontal deflection can be variably set, and when the second mode is set, the vertical and horizontal deflection circuits (1
8) With respect to (19), the deflection width of vertical deflection and horizontal deflection is
A television receiver, comprising: a control means for transmitting a control signal for increasing each of the shake widths in the mode by a predetermined ratio.