JPH02152380A - Television receiver - Google Patents

Abstract

PURPOSE:To prevent baking due to a pattern by projecting the picture of the prescribed pattern and scrolling the picture in a margin part, which is generated when the picture of a present standard broadcast is projected, in a TV receiver, whose aspect ratio is 16:9. CONSTITUTION:A high grade TV signal VHD is supplied to an input edge 1 and a standard TV signal VNT is supplied to an input edge 2. A time axis transforming circuit 5 compresses a picture period TV1 in the horizontal direction of the sign VNT to a picture period TV2 and idle periods T1 and T2 are provided in the both edges of a horizontal period. Then, a switch control signal SW is outputted. A design pattern generating circuit 7 generates the design pattern so as to be scrolled in a prescribed direction. By the signal SW, a switch circuit 6 is changed over to an (a) side during the picture period TV2 and the circuit 6 is changed over to a (b) side during the idle periods T1 and T2, in which the design pattern is added. The output of the circuit 6 is supplied through the (b) side of a switch circuit 4 to a receiver 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a television receiver capable of receiving images of both the current standard television system and high-definition television system.

[Summary of the invention]

This invention projects a predetermined pattern in the blank space that occurs when images of current standard broadcasting are projected on the screen in a television receiver having a screen with an aspect ratio of (16:9). By scrolling this pattern, uneven brightness of the screen due to changes over time can be prevented, and the pattern can be projected using the margin.

[Conventional technology]

High-definition television (HDTV), which is capable of reproducing high-resolution images with a sense of realism, is being developed. In high-definition television, the aspect ratio is (16:9),
The number of horizontal scanning lines is 1125. On the other hand, in the current NTSC system, the aspect ratio is (4:3).
The number of horizontal scanning lines is 525.

In this way, high-definition televisions have a large aspect ratio and a large number of horizontal scanning lines, making it possible to reproduce high-resolution images with a sense of realism. And MUSE(n+ultiple 5ub
-Nyquist sampling encodein
It is planned to perform high-definition television broadcasting on a satellite broadcast channel using a band compression method called g) method.

[Problem to be solved by the invention]

In preparation for the start of such high-definition television broadcasts, development of television receivers that can receive both current television broadcasts and high-definition television broadcasts is underway.

In television receivers that can receive both high-definition television broadcasting and current television broadcasting, the aspect ratio of the high-definition television screen is (161), while the aspect ratio of the current NTSC television screen is (161). Since the ratio is (4:3), when an NTSC screen is displayed on the receiving screen of a high-definition television, a blank area will appear on the screen.

If such margins are set to a black level, the screen will look unnatural. Therefore, Japanese Unexamined Patent Publication No. 63-26173 proposes a method in which a monochromatic pattern is added to such margins to create a natural-looking screen.

However, when a monochromatic pattern is added to the margin, the brightness of the margin is constant, but the brightness of the image part changes depending on the pattern, so the electron beam irradiation is different between the image part and the margin, and the brightness changes over time. This causes uneven brightness and color on the screen.

It has also been proposed to add various designed patterns using the blank space. However, when a fixed pattern is added, this pattern causes screen burn-in.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a television receiver that can prevent uneven brightness of the screen due to changes over time, project a pattern in the margin, and prevent the screen from being burned by the pattern. .

[Means to solve the problem]

This invention projects a predetermined pattern of video in the blank space that occurs when images of current standard broadcasting are projected on the screen in a television receiver having a screen with an aspect ratio of (16:9). This is also a television receiver that scrolls this pattern.

[Effect]

A pattern is added to the blank space that occurs when an NTSC screen with an aspect ratio of (4:3) is displayed on a high-definition television screen with an aspect ratio of (16:9). This pattern is scrolled. Since the pattern is scrolled in this way, the pattern does not burn in.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

In FIG. 1, input terminal 1 has an aspect ratio of (1
6:9), a high-definition television signal with 1125 horizontal scanning lines■. is supplied. A high-quality television signal VHII from this input terminal 1 is supplied to an input terminal a of a switch circuit 4.

The input terminal 2 is supplied with a standard television signal VNT (for example, a demodulated signal of the NTSC system) having an aspect ratio of (4:3) and a number of horizontal scanning lines of 525. A standard television signal V version from the input terminal 2 is supplied to the time axis conversion circuit 5.

The time axis conversion circuit 5 is supplied with a synchronization signal 5YCsy of a standard television signal from the input terminal 3.

The time axis conversion circuit 5 converts the horizontal time axis of the standard television signal VNT from the input terminal 2 to an aspect ratio of (
4:3) standard television screen with an aspect ratio of (1)
6:9) so that it can be displayed on a high-definition television picture tube 10.

That is, the video period TvI of the standard television signal ■1 from the input terminal 2 shown in FIG. 2A is time-compressed into the video period Tv□ as shown in FIG. 2B. Then, at both ends of the horizontal period, there are blank periods T and T! will be provided. Corresponding to the margin periods T and Tt, the time axis conversion circuit 5
A switch control signal SW as shown in FIG. 2C is output from the switch control signal SW.

A standard television signal time-compressed by the time base conversion circuit 5 is supplied to an input terminal a of the switch circuit 6.

The pattern generation circuit 7 is supplied with the synchronization signal SY(, +y) of the standard television signal from the input terminal 3.The pattern generation circuit 7 outputs a pattern.This pattern is displayed on the screen. is scrolled in a predetermined direction.

The pattern pattern output from the pattern generation circuit 7 is supplied to the input terminal of the switch circuit 6.

The switch circuit 6 is supplied with a switch control signal SW (FIG. 2C) from the time axis conversion circuit 5.

By this switch control signal SW, the switch circuit 6 is switched to the a side during the video period Tv□, and the switch circuit 6 is switched to the b side during the margin periods Tt and T2. As a result, the switch circuit 6 outputs a standard television signal with a pattern added to the blank period T and T2, as shown in the second diagram. The output of this switch circuit 6 is supplied to the b-side input terminal of the switch circuit 4.

When receiving high-definition television, the switch circuit 4 is switched to the a side. When the switch circuit 4 is switched to the a side, the high-quality television signal VNtl from the input terminal 1 is supplied to the picture tube 10 via the switch circuit 4 and the driver 9.

Then, a screen of the high-quality television signal VND from the input terminal 1 is displayed on the picture tube 10.

Since the aspect ratio of the picture tube 10 is (16:9),
When receiving high-definition television, the high-definition television screen is displayed on the entire screen of the picture tube IO.

When receiving standard television, the switch circuit 4 is switched to the b side. When the switch circuit 4 is switched to the b side, the pattern output from the switch circuit 6 is a standard television signal (second
D) is supplied to the picture tube 10 via the driver 9.

Therefore, as shown in FIGS. 3A to 3F, when receiving standard television, the standard television broadcast screen is projected on the screen 20, and the margins 21A are generated on both sides of the screen.
and 21B, a scrolling pattern is displayed.

FIG. 3A is an example in which the pattern displayed in the margins 21A and 21B is scrolled downward. FIG. 3B is an example in which the pattern displayed in the margins 21A and 21B is scrolled upward. Third
FIG. C is an example in which the pattern displayed in the margins 21A and 21B is divided and scrolled in both the upper and lower directions.

If the pattern projected on the margins 21A and 21B is scrolled in this way, the brightness of the margins will constantly change, so that the pattern will not be burned.

Note that any design may be used for the pattern of the margin portions 21A and 21B.

By devising the design of this pattern, it is possible to improve the texture of the video screen.

The pattern generation circuit 7 that adds the scrolling pattern to the margins 21A and 21B as described above is configured as shown in FIG. 4, for example.

In FIG. 4, 41 is a pattern generation ROM. The pattern generation ROM 41 stores character data corresponding to the pattern patterns of the margins 21A and 21B (FIG. 3A to FIG. 3C).

The address generation circuit 40 is supplied with a horizontal synchronization signal HD, a vertical synchronization signal VD, and a clock CK.

The address generation circuit 10 generates a pattern pattern generation circuit R from the horizontal synchronization signal HD, vertical synchronization signal VD, and clock GK.
A read address for OM 41 is formed. The start position of this read address is shifted for each screen at a predetermined period so that the pattern scrolls.

The output of the address generation circuit 40 is a pattern generation ROM.
41. By the read address supplied from this address generation circuit 40, pattern generation RO
Character data is read from M41.

The output of the pattern generation ROM 41 is supplied to the D/A converter 42. A D/A converter 42 converts the character data read from the pattern generation ROM 41 into an analog signal. By the output of the D/A converter 42, a scrolling pattern is added to the margin areas 2LA and 21B.

In this way, the pattern pattern generation circuit ROM 41 in which character data is stored is prepared, and the start position of the read address for this pattern pattern generation circuit ROM 41 is shifted for each screen at a predetermined period, thereby scrolling to the margin areas 21A and 21B. It is possible to project a pattern of patterns.

〔Effect of the invention〕

This invention allows NTSC to be used on high-definition television screens.
Patterns can be projected in the margins that appear when the system screen is projected. Since this pattern pattern is scrolled, there is no burn-in caused by the pattern pattern, and since the scrolling pattern pattern is projected in the margin area, the changes over time between the margin area and the projected area of the screen are approximately equal. , the occurrence of uneven brightness and color can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the invention, and FIG. 2 is a waveform diagram used to explain the embodiment of the invention. 3A to 3C are route diagrams used to explain an embodiment of the present invention, and FIG. 4 is a block diagram of an example of a pattern generation circuit in an embodiment of the present invention. Explanation of main symbols in the drawings: Input terminal for high-definition television signals. 2: Standard television signal input terminal. 5: Time axis conversion circuit, 7: Pattern generation circuit. 21A, 21B: Margin area. /gov1sk0-ruqirrl Figure 3C 1 time, Y & Figure 4

Claims (1)

[Claims] In a television receiver having a screen with an aspect ratio of (16:9), a predetermined pattern of video is projected in the margin that occurs when the current standard broadcasting image is projected on the screen, and the above pattern is A television receiver that allows scrolling.