JPH05199473A - Television signal receivers of different aspect ratios - Google Patents

Abstract

PURPOSE:To prevent the ringing occurring on a CRT display screen by turning off the scanning speed modulation of an electronic beam at a boundary part of the received images. CONSTITUTION:In regard to the high-definition TV signals sent from a signal converting circuit 12, the horizontal synchronizing scanning time is compressed by an image converting means 13 in a rate of (4/3)/(16/9) and the converted video signal containing the black level images equivalent to the compression time before and after its position is inputted to a high-definition TV receiver 14 through an output terminal 13a. Meanwhile the luminance signal is inputted to a speed modulation switch circuit 18 through a luminance signal output terminal 13b. In the circuit 18, a control signal is outputted to a terminal 13c from the means 13. Thus the circuit 18 is controlled. The control signal turns off the circuit 18 at the parts near the right-left both end boundary parts 102e and 103e of a compressed image where the luminance signal has a large changing degree. Therefore the ringing never occurs at the parts 102e and 103e. As a result, the hard-to-see images due to the ringing can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television signal receiver having a different aspect ratio for displaying a standard television signal or the like on a horizontally long standard television receiver or a high definition television receiver.

[0002]

2. Description of the Related Art High-definition television system (aspect ratio 16 /
9) In the high-definition television receiver that receives the signal of the current standard television system (aspect ratio 4/3) different in aspect ratio from 9), the signal of the standard television system is the high-definition television CR.
The signal was converted into a high-definition television system based on the vertical length of the T screen and displayed on the CRT screen in the state shown in FIG.
Here, 100 is a CRT screen having an aspect ratio larger than 4/3 as in a high definition television system, and 101 is a standard television C.
A screen area corresponding to RT, 102 and 103 are areas which are not displayed without a converted standard television image signal, 102e,
103e is a boundary line part of the above-mentioned areas. on the other hand,
In the case of a horizontally long standard television receiver, the television system signal conversion is not necessary, but it was displayed on the screen in the state shown in FIG.

[0003]

As described above, when a current standard television signal is displayed on a high-definition television receiver or a horizontally long standard television receiver, the following are displayed on the left and right boundary parts 102e and 103e of the screen 101. There was a problem as shown. That is, in order to increase the sharpness of the image, a horizontal magnetic field proportional to the change amount (differential amount) of the luminance signal is superimposed on the horizontal deflection magnetic field at each time in each horizontal scanning period, and the portion before and after the change in luminance is superimposed. In the case of using a so-called speed modulation circuit for changing the horizontal scanning speed to a speed higher or lower than the reference speed.

FIG. 3 shows a conventional example in which a speed modulation circuit is used in a high definition television receiver. Here, 11 is a standard television signal input terminal, 12 is a signal conversion circuit for converting into a high-definition television signal, 12a is a luminance signal output terminal, 14 is a high-definition television receiver, 14a is a video signal processing circuit, and 14b is a CR.
T, 14c is a cathode, 14d is a grid electrode, 14
e and 14f are horizontal / vertical deflection coils, 16 is a velocity modulation circuit, and 17 is a velocity modulation coil.

The output of the luminance signal generated in the signal conversion circuit 12 or the video signal processing circuit 14a is used as the speed modulation circuit 1
6 and sends a current output to the speed modulation coil 17 so as to change the horizontal scanning speed to a higher speed and a lower speed than the reference in the front and rear portions where the brightness changes. This improved the sharpness of the image.

However, the boundary line portion 102 shown in FIG.
In e and 103e, the velocity modulation circuit 16 receives a large change amount of the luminance signal, and the boundary line portions 102e and 1e of the CRT screen are changed.
Ringing occurred in 03e, resulting in a glaring and unsightly image.

An object of the present invention is to eliminate the above-mentioned problems. When a standard television signal having a smaller aspect ratio is received by a high-definition television receiver or a landscape standard television receiver, the speed modulation is performed. It is an object of the present invention to provide a television receiver having a speed modulation circuit effect which does not cause a glaring and unsightly image due to ringing on the screens of those CRT display devices even if the circuit is provided.

[0008]

In order to solve the above problems, a television signal receiver of a different aspect ratio according to the present invention has an aspect ratio different from the aspect ratio peculiar to the receiver on the screen of the television receiver. In a television signal receiver that generates dark color level images at both ends of the screen when playing back a received image, speed modulation of the electron beam scanning speed is turned off at the boundary between the received image of the television signal and the dark color level image. It is characterized by doing. Further, in the television receiver, each horizontal cycle scanning time of the input television signal is compressed in inverse proportion to the increasing ratio of the aspect ratio of the CRT screen of the receiver, and the dark color level video signal corresponding to the compressed time is compressed. While outputting the converted video signal added before and after the compressed video signal, the generation of the luminance signal of the converted video signal and the time obtained by adding a predetermined time from the compressed video signal start time in each horizontal scanning period An image conversion means for generating a control signal until a time obtained by subtracting a predetermined time from the end time of the compressed video signal, a speed modulation circuit and a speed modulation coil for generating a CRT electron beam scanning horizontal magnetic field for improving the sharpness of the video. A speed at which the luminance signal generated by the image conversion means is passed through the speed modulation circuit for the time during which the control signal from the same means is generated A tone switch circuit, and when the input television signal system and the television signal system of the television receiver are different, the input television signal is converted to the television signal system of the television receiver, and then the image conversion means is provided. It is characterized by inputting.

[0009]

When the television receiver such as the landscape standard television receiver receives the television signal having the same aspect ratio as the input television signal system and the aspect ratio is small, the aspect ratio of the television signal is greatly increased by the image conversion means. The image signal is sent to the video processing circuit by a conversion in which the horizontal cycle scanning time is compressed in inverse proportion to the above and the black level signal video signal corresponding to the compression time is added to the front and back. On the other hand, the luminance signal generated by the image conversion means is sent to the velocity modulation circuit, and a current is passed through the velocity modulation coil. Since the speed modulation circuit is activated by the control signal generated simultaneously by the image conversion means, the speed modulation circuit should be prevented from operating in a large portion of the change in the luminance signal near the left and right boundary lines of the compressed image. Become.

When a television receiver such as a high-definition television receiver receives a television signal having a small aspect ratio unlike the input television signal, first the input television signal is converted into the television signal system of the television receiver. To the image conversion means.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram of one embodiment. Here, 11, 12, 14, 14a to 14f, 16 and 17 are shown in FIG.
Is the same as. Reference numeral 13 is an image converting means, 13a is a converted video signal output terminal, 13b is a luminance signal output terminal, and 13c is a control signal output terminal. Reference numeral 18 is a speed modulation switch circuit.

The operation is as follows. The standard television signal is converted by the signal conversion circuit 12 into a high definition television signal. Next, the image conversion means 13 compresses each horizontal cycle scanning time at a ratio of (4/3) / (16/9), and a converted video signal in which black level (dark color level) video corresponding to the compressed time is added before and after. Is input to the high-definition television receiver 14 from the output terminal 13a. On the other hand, the brightness signal subjected to the image conversion from the brightness signal output terminal 13b of the image conversion means 13 is input to the speed modulation switch circuit 18. A control signal is output to the output terminal 13c of the speed modulation switch circuit 18 by the image conversion means to control the operation of the speed modulation switch circuit 18. The control signal causes the speed modulation switch circuit 18 to be in the OFF state in a portion where the amount of change in the luminance signal near the left and right boundary portions 102e and 103e of the compressed image is large, so that the ringing at the boundary line portions 102e and 103e. Will never happen. FIG. 2 shows the relationship between the luminance signal a, the control signal b, and the screen c of the television receiver. ΔT ₁ in scanning time,
A control signal that is shorter than the time compressed by ΔT ₂ is generated. Further, in FIG. 2, instead of the control signal b, the output current of the speed modulation circuit may be increased / decreased in proportion to the analog amount like the control signal d.

In the embodiment shown in FIG. 1, the input TV signal is different from the TV signal system of the TV receiver.
In the same case, the signal conversion circuit 12 of FIG. 1 is not necessary. The same applies when the input is a standard television signal and the television receiver is a horizontally long standard television receiver.

[0014]

When a standard television signal having a smaller aspect ratio is received by a high-definition television receiver or a horizontally long standard television receiver, even if a speed modulation circuit is provided, a CR
This makes it possible to eliminate the unsightly image due to ringing on the screen of the T display device and to provide a television receiver having a speed modulation circuit effect.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of control signals to the speed modulation switch circuit of the present invention.

FIG. 3 is a block diagram of a conventional example.

FIG. 4 is an explanatory diagram showing a state in which a video signal is not displayed on both ends of a screen.

[Explanation of symbols]

 11 standard television input terminal 12 signal conversion circuit 13 image conversion means 13a converted video signal output terminal 13b luminance signal output terminal 13c control signal output terminal 14 high-definition television receiver 16 speed modulation circuit 17 speed modulation coil 18 speed modulation switch circuit

Claims (2)

[Claims] 1. A television signal receiver for generating a dark color level image on both ends of a screen when a received image having an aspect ratio different from an aspect ratio peculiar to the receiver is reproduced on the screen of the television receiver, A television signal receiver having a different aspect ratio, characterized in that velocity modulation of an electron beam scanning velocity is turned off at a boundary portion between the received image of the television signal and the dark color level image. 2. A television receiver, wherein each horizontal cycle scanning time of an input television signal is compressed in inverse proportion to a ratio in which an aspect ratio of a CRT screen of the receiver is increased, and a dark color corresponding to the compressed time is compressed. While outputting a converted video signal in which level video signals are added before and after the compressed video signal, a luminance signal of the converted video signal is generated and a predetermined time is added from the compressed video signal start time of each horizontal scanning period. Image conversion means for generating a control signal from the time when the predetermined time is subtracted from the end time of the compressed video signal, and a speed modulation circuit and speed for generating a CRT electron beam scanning horizontal magnetic field for improving the sharpness of the video. The modulation coil and the luminance signal generated from the image conversion means are passed through the speed modulation circuit for the time during which the control signal from the same means is generated. When the input TV signal system and the TV signal system of the TV receiver are different, the input TV signal is converted to the TV signal system of the TV receiver, and then the image conversion is performed. A television signal receiver having a different aspect ratio, characterized by inputting means.