JP2910880B2 - Television receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver for displaying a wide aspect image.

[0002]

2. Description of the Related Art An auxiliary signal is added to a video signal while maintaining compatibility with a video signal having an aspect ratio of 4: 3 in the current NTSC system to display a high-quality wide aspect video having an aspect ratio of 16: 9. Conventionally, several television systems have been proposed. One of the letterbox systems will be described with reference to FIG.

The aspect ratio shown in FIG. 6A is 16: 9.
When a wide aspect video signal is projected on a receiver having a current aspect ratio of 4: 3, the video signal is reduced to 3/4 times as shown in FIG. Auxiliary signals for projection and wide aspect are transmitted using non-image portions A and C at the top and bottom of the screen, which are indicated by oblique lines in FIG. On the other hand, as shown in FIG. 6 (c), in the wide aspect receiver, the main image B is enlarged by 4/3 times, and the image quality is enhanced by using the auxiliary signal transmitted by being superimposed on the non-image portions A and C. A wide aspect image with an aspect ratio of 16: 9 is reproduced and projected.

[0004]

However, in a wide aspect receiver having an aspect ratio of 16: 9, FIG.
As shown in (a), an image having an aspect ratio of 4: 3, which uses only a part of the cathode ray tube, is always fixed at the center E of the screen, and an image having an aspect ratio of 16: 9, which uses the entire cathode ray tube, is used. In the case where a video signal (not limited to a letterbox signal) is projected, the CRT is used more frequently in the central portion E than in the left and right sides of the screens shown in D and F of FIG. A difference in screen burn occurs between the left and right D and F and the center E. As described above, when the brightness unevenness due to the screen burn-in phenomenon occurs in the cathode ray tube, when a video signal using the entire cathode ray tube is projected, the image has uneven brightness and the image quality is degraded.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention maintains compatibility with the NTSC color television broadcasting system, adds a high-quality auxiliary signal on the transmitting side, and converts a video signal to be transmitted. In a television receiver capable of receiving a television signal on which a pilot signal for determining whether the aspect ratio is 4: 3 or a wide aspect is superimposed and displaying a high-quality wide aspect image, the pilot signal Detecting means for detecting from the television signal, and the detected pilot signal
From 4: 3 aspect ratio or wide aspect
Discriminating means for discriminating whether there is, and a signal from the discriminating means
Further , there are provided counting means for counting the projection time of a video signal having an aspect ratio of 4: 3, and display position control means for controlling the display position of an image having an aspect ratio of 4: 3 according to the projection time. With an aspect ratio of 4: 3
In the case of a video signal, an image is displayed by the display position control means.
Switch to different positions in the horizontal direction of the screen at regular intervals
Display configuration.

Further, according to the projection time of the video signal having the aspect ratio of 4: 3 counted by the counting means, when the system is turned off, the picture of the CRT generated when the image with the aspect ratio is 4: 3 is projected. Parts are fixed at regular intervals
A configuration is provided in which light emission control means for forcibly emitting light for a time is provided.

Further, a pilot signal designating a display position of a video signal having an aspect ratio of 4: 3 in a receiver is superimposed on the television signal, and the received television signal is superimposed.
A display position control means for controlling a display position of a video signal having an aspect ratio of 4: 3 according to a pilot signal extracted from the John signal by the pilot signal extraction means is provided.

[0008]

SUMMARY OF] According to the arrangement, detects a pilot signal superimposed on the video signal transmitted by the pilot signal, the aspect ratio of the video signal being transmitted
Discriminated video signal video signal being transmitted using a portion of the cathode ray tube face (aspect ratio 4: 3 video signal)
At the time, the projection time of the video signal is counted.

The display position of the projected image based on the video signal is controlled in accordance with the count value, the cathode-ray tube is caused to partially emit light when the power is turned off in accordance with the count value, and the pilot Pre-display position on signal
The information for designating the position is superimposed, and the display position of the projected image based on the video signal is controlled based on this information, thereby reducing the occurrence of uneven brightness due to the screen burn-in phenomenon of the CRT.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to FIGS. Although not shown on the transmitting side, a pilot signal Ps or an aspect ratio of 4: 3 for notifying whether a video signal to be transmitted is a current video signal having an aspect ratio of 4: 3 or a video signal of a letterbox system. For example, a television signal in which a pilot signal Pa for selecting a display position of the video signal is superimposed in a vertical blanking period is transmitted. First, a first embodiment of the present invention will be described with reference to FIGS.
An example will be described.

FIG. 1 is a block diagram of a first embodiment for reducing the brightness unevenness of a cathode ray tube when the television signal is received and an image is displayed on a part of the cathode ray tube. In the wide aspect receiver, the television signal input from the video input terminal 1 is supplied to an A / D conversion circuit 2, a synchronization separation circuit 3, and a clock generation circuit 4. The clock generation circuit 4 locks to the burst signal of the video signal, and has a frequency four times the subcarrier frequency fsc, 4fsc (14.318 MHz).
The clock of z) is generated and supplied to each circuit as a system clock.

The synchronization separation circuit 3 separates a synchronization signal from a video signal and supplies the synchronization signal to a gate circuit 5. The gate circuit 5 uses the synchronization signal to generate a synchronization signal within a vertical blanking period of a television signal. The superimposed pilot signal Ps is supplied to the sampling determination circuit 6. The discriminating circuit 6 determines that the aspect ratio of the transmitted video signal is 16: 9 based on the pilot signal Ps sent from the gate circuit 5.
In the case of the letter box system, for example, the discrimination signal Pj is set to L level, and when the current aspect ratio is 4: 3, the discrimination signal Pj is set to H level, and the wide aspect processing circuit 7, It is supplied to the counter circuit 8 and the display position control circuit 10.

The counter circuit 8 does not count when the discrimination signal Pj supplied from the discrimination circuit 6 is at the L level.
Counting is performed at the H level, and when a certain count value (for example, 24 hours) is reached, a counter pulse Cu is supplied to the display position control signal generation circuit 9. The display position control signal generating circuit 9 detects the counter pulse Cu and holds the state. The display position control signal generation circuit 9 controls the V supplied from the power-off detection signal input terminal 12 so that the image display position does not change during image projection.
When the O signal becomes L level, the control signal DS for controlling the control signal DS by the detected counter pulse Cu so that, for example, the position of the display image is on the left side of the screen as shown in FIG. 4B. And supplies it to the display position control circuit 10.

[0014] The control signal DS is similarly
From the control signal DC for controlling the display position of the display image to be, for example, sequentially in the center of the screen as shown in FIG. 4A, the display image is shifted to the right side of the screen as shown in FIG. Is switched again to the control signal DL through a control signal DR for controlling the control signal DL.

The display position control signal generating circuit 9 supplies a reset signal RE for resetting the count of the counter circuit 8 to the counter circuit 8 when the switching of the control signal DS is completed. The counter circuit 8 resets the count value by the reset signal RE. The counter circuit 8 keeps the above-mentioned count value even when the power of the system is not supplied.

On the other hand, the A / D conversion circuit 2 samples the input analog video signal at 4 fsc, digitizes it, and supplies it to the wide aspect processing circuit 7. When the discrimination signal Pj supplied from the discrimination circuit 6 is at the L level indicating that it is a wide aspect video signal, the wide aspect processing circuit 7 enlarges the main screen by 4/3 as shown in FIG. The image is enlarged and the image quality is enhanced by using the auxiliary signal multiplexed in the non-image portion, and is supplied to the display position control circuit 10. When the discrimination signal Pj is at the H level, the video signal is a video signal having the current aspect ratio of 4: 3, and is compressed to 3/4 times in the horizontal direction and supplied to the display position control circuit 10.

The display position control circuit 10 has an aspect ratio of 4: 3 when the display position control signal DS supplied from the display position control signal generation circuit 9 is a control signal DL for displaying a screen on the left side.
4B is shifted to the left as shown in FIG. 4B, and when the control signal DC causes the screen to be displayed at the center, the screen is displayed at the center as shown in FIG. Is the control signal DR to be displayed on
As shown in FIG. 4C, a video signal whose screen is displayed on the right side is output.

When the discrimination signal Pj supplied from the discrimination circuit 6 is at the L level, since the video signal is a letter box type wide aspect video signal, regardless of the state of the display position control signal DS, FIG. As shown in c), it is supplied to the D / A conversion circuit 11 of the next stage as a normal wide aspect video signal displayed on the entire screen.
The D / A conversion circuit 11 includes a display position control circuit 10
The supplied digital signal is converted into an analog signal and output from a video signal output terminal 13. When the video signal has a wide aspect, it is used as a video of the entire screen, and when the video signal has an aspect ratio of 4: 3, an image is displayed. Are displayed at the center of the left and right at regular intervals. Therefore, it is possible to reduce a partial difference in screen burn of the CRT.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. In FIG. 2, portions corresponding to those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. FIG. 2 is a block diagram of a second embodiment of the present invention. The discrimination signal Pj from the discrimination circuit 6 is supplied to the wide aspect processing circuit 7 and the counter circuit 8, and the counter circuit 8 outputs the discrimination signal Pj supplied from the discrimination circuit 6.
When the signal is at the L level, counting is not performed, and when the signal is at the H level, counting is performed.
6

The flash signal generation circuit 16 holds that the counter pulse Cu has been supplied, and sets the signal VO input from the power-off detection signal input terminal 12 to L.
When the level is reached, that is, when the power is turned off,
A flash signal as shown in FIG. 5B is generated for a fixed time (for example, one second) and supplied to the selector circuit 17. However, at this time, if the power of the system is turned off, for example, by detecting a switch or the like, and the power supply voltage of the system is turned off after a certain period of time, the system is kept constant even after VO becomes L level. Works for hours.

The flash signal generated by the flash signal generating circuit 16 is represented by a hatched area shown in FIG. 5A which is generated when a video signal having an aspect ratio of 4: 3 is projected by a wide aspect receiver. This is a video signal shown in FIG. 5B that causes only the image portions D and F to emit light. Therefore, the screen burn is forcibly caused only in the non-image portions D and F indicated by diagonal lines in FIG.
The image is burned to the same degree as the image display portion E.

The flash signal generation circuit 16 generates a reset pulse RE for resetting the count value of the counter circuit 8 after generating the flash signal.
, The count value of the counter circuit 8 is reset. It should be noted that the count value of the counter circuit 8 is held even when the power of the system is not supplied.

On the other hand, the A / D conversion circuit 2 samples the input analog video signal at 4 fsc, digitizes it, and supplies it to the wide aspect processing circuit 7. When the discrimination signal Pj supplied from the discrimination circuit 6 is at the L level, the wide aspect processing circuit 7 expands the main screen by a factor of 4/3 as shown in FIG. The auxiliary signal is used to enhance the image quality and supply it to the selector circuit 17. When the discrimination signal Pj is at the H level, the video signal is the current video signal having the aspect ratio of 4: 3, so that 3 / The data is compressed four times and supplied to the selector circuit 17.

The selector circuit 17 selects the wide aspect processing circuit 7 when the signal VO input from the power-off detection signal input terminal 12 is at the H level, and switches the input to the flash signal generation circuit 16 when the signal VO is at the L level. Side, the flash signal is output when the power is turned off.
It is supplied to the A conversion circuit 11. The D / A conversion circuit 11 converts the digital signal supplied from the selector circuit 17 into an analog signal and outputs the analog signal to the video signal output terminal 13, thereby forcibly turning off the side of the cathode ray tube for a certain period of time and for a certain time when the power is off. The portion can emit light, and the difference in screen burn between the central portion and the side portion of the cathode ray tube can be reduced.

Next, a third embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. In FIG. 3, portions corresponding to the first and second embodiments shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. FIG. 3 is a block diagram of a third embodiment of the present invention. The gate circuit 5 uses the synchronization signal supplied from the synchronization separation circuit 3 to have an aspect ratio of 4: 4 superimposed during the vertical blanking period of the television signal.
The pilot signal Pa having the display position information of the image No. 3 is extracted and supplied to the display position control signal generation circuit 14. The display position control signal generation circuit 14 determines a display position of an image having an aspect ratio of 4: 3 based on the value of the pilot signal Pa supplied from the gate circuit 5.

That is, the pilot signal Pa is previously set to, for example, 2
"00" is a letterbox signal, "01" is a signal for displaying an image having an aspect ratio of 4: 3 at the center, and "10" is an image having an aspect ratio of 4: 3. The signal to be displayed, "11", may be defined as a signal for displaying an image having an aspect ratio of 4: 3 to the right. In this way, when the pilot signal Pa is "00", the display position control signal generating circuit 14 causes the control signal DS to display a wide aspect image on the entire display screen as shown in FIG. 6C. When the control signal DW is "01", the control signal DC is a control signal DC for displaying an image having an aspect ratio of 4: 3 in the center of the display screen as shown in FIG. 4A, and is "10" or "11". In the case of "", FIG.
(B) or a control signal DL to be displayed on the left or right side of the display screen as shown in FIG.
Alternatively, it is supplied to the wide aspect processing circuit 7 and the display position control circuit 15 as DR.

On the other hand, the A / D conversion circuit 2 samples the input analog video signal at 4 fsc, digitizes it, and supplies it to the wide aspect processing circuit 7. When the control signal DS supplied from the display position control signal generating circuit 14 is the control signal DL, DC, or DR, the wide aspect processing circuit 7 is a video signal having an aspect ratio of 4: 3, so that the horizontal direction is 3/4. Control signal DC and the control signal D
In the case of W, the main screen is expanded to 4/3 times as shown in FIG. 6C, the image quality is enhanced using the auxiliary signal multiplexed in the non-image portion, and the image is supplied to the display position control circuit 15. .

When the control signal DS supplied from the display position control signal generating circuit 14 is the control signal DL, the display position control circuit 15
As shown in FIG. 4B, the screen having an aspect ratio of 4: 3 is shifted to the left. When the control signal is DC, the screen is centered as shown in FIG.
As shown in FIG. 6C, the video signal is shifted to the right, and when the control signal DS is the control signal DW, it is a wide aspect signal, so that the video signal having an aspect ratio of 16: 9 as shown in FIG. D / A at the next stage
It is supplied to the conversion circuit 11. The D / A conversion circuit 11 converts a digital signal into an analog signal, outputs a video signal whose display position is controlled from an output terminal 13, and sorts and displays an image having an aspect ratio of 4: 3 at the left and right centers. Therefore,
Partial differences in screen burn of the CRT can be reduced.

Since the present invention has the above configuration, the first aspect of the present invention is as follows.
According to or claim 3 configuration, the aspect ratio in wide aspect receiver is 4: Rukoto changing the display position of the image non-picture portion occurs when allowed out movies the third video, also
According to the configuration of the second aspect, by causing the non-image portion to forcibly and temporarily emit light, it is possible to reduce the occurrence of uneven brightness due to screen burning.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of another embodiment of the present invention.

FIG. 3 is a block diagram of still another embodiment of the present invention.

FIG. 4 is an operation explanatory diagram of FIGS. 1 and 3;

FIG. 5 is an operation explanatory diagram of FIG. 3;

FIG. 6 is an operation explanatory diagram of FIGS. 1, 2, and 3;

[Explanation of symbols]

 5 Gate 6 Discrimination circuit 8 Counter 9 Display position control circuit 16 Flash signal generation circuit 17 Selector

Claims (3)

(57) [Claims] 1. An image processing apparatus according to claim 1, further comprising: adding an auxiliary signal for enhancing image quality on a transmission side while maintaining compatibility with an NTSC color television broadcasting system; and determining whether an aspect ratio of a transmitted video signal is 4: 3 or a wide aspect. In a television receiver capable of receiving a television signal on which a pilot signal to be discriminated is superimposed and displaying a high-quality wide-aspect image, detecting the pilot signal from the television signal
And the aspect ratio from the detected pilot signal
Judgment for judging 4: 3 or wide aspect
Another means, counting means for counting the projection time of a video signal having an aspect ratio of 4: 3 based on a signal from the determination means, and an aspect ratio of 4: 3 according to the projection time.
Display position control means for controlling the display position of the image of the image is provided. When the aspect ratio is a video signal of 4: 3,
The display position control means causes the image to be displayed
A television receiver characterized in that the image is switched and displayed at predetermined positions at predetermined intervals . 2. Compatibility with the NTSC color television broadcasting system, adding a high-quality auxiliary signal on the transmitting side, and determining whether the aspect ratio of the transmitted video signal is 4: 3 or wide aspect. In a television receiver capable of receiving a television signal on which a pilot signal to be discriminated is superimposed and displaying a high-quality wide-aspect image, detecting the pilot signal from the television signal
And the aspect ratio from the detected pilot signal
Judgment for judging 4: 3 or wide aspect
Another means, counting means for counting the projection time of a video signal having an aspect ratio of 4: 3 based on a signal from the determination means, and an aspect ratio of 4: 3 when the system is turned off according to the projection time. of movies and emission control means for temporarily emitted the non-image portion of the cathode ray tube caused provided at output image, every predetermined time when the power is turned off, a fixed time forcibly bra
By illuminating the non-picture part of the
Forcibly burn the screen only in the non-image part of the CRT
A television receiver characterized by reducing uneven brightness caused by a screen burn-in phenomenon of a cathode ray tube. 3. A compatibility with the NTSC color television broadcasting system, a high-quality auxiliary signal is added on the transmitting side, and a display position of a video signal having a 4: 3 aspect ratio on a CRT is transmitted. Information to specify
Receiving a television signal superimposed as a pilot signal on a television receiver capable of displaying a high-quality wide-aspect image, wherein the pilot signal extracting means for extracting the pilot signal from the television signal; and aspect ratio is 4 in accordance with: a television receiver, characterized in that a display position control means for controlling the display position of the third video signal.