JPH07307902A - Television receiver - Google Patents

Abstract

PURPOSE:To set the omitted part of an input video signal to be displayed on a screen corresponding to the character superimpose on the input video signal. CONSTITUTION:When the result of a comparator circuit 17 shows that an almost fixed waveform is continued for prescribed time, a microcomputer 18 for control judges the character superimpose, prepares control signals k1 and m1 so that a line provided with this character superimpose can not get extended out of the screen of a picture tube, and respectively supplies those signals to a vertical amplitude control circuit 20 and a vertical picture moving circuit 21. Thus, the character superimposed part on the input video signal can be prevented from being omitted.

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 an input video signal on a screen having a second aspect ratio whose aspect ratio is horizontally larger than that of the input video signal having the first aspect ratio. In particular, the present invention relates to a television receiver capable of setting a missing portion of a video signal displayed on a screen depending on the presence or absence of a character superimpose.

[0002]

2. Description of the Related Art In recent years, in the field of broadcasting systems, research and development of a high-definition system (aspect ratio 16: 9) has been carried out in parallel with the conventional NTSC system (aspect ratio 12: 9 = 4: 3). The experimental broadcast of has also started. In response to this, on the side of the television receiver, N
A model capable of receiving both TSC television broadcasting and high-definition broadcasting has been developed. Such a television receiver has a screen aspect ratio of 16: 9.
And the aspect ratio of the screen is 4: 3.

When displaying an NTSC television broadcast, a television receiver having a screen aspect ratio of 16: 9 enlarges the image vertically and horizontally by using a zoom function to display the 4: 3 image vertically. A method of displaying the image on the screen of the picture tube by dropping it and a method of enlarging the image left and right by using the full mode function are used.

The method using the zoom function is very inefficient because the images on the original screen are vertically lost by 1/4.

In the method using the full mode function, the image is stretched to the left and right by 4/3 times, which makes it very unsightly for images of people and the like.

Corresponding to this, the aspect ratio of 4: 3
Television using a method of reducing the vertical amplitudes of the upper and lower parts of the remaining image by reducing the number of missing parts on the upper and lower sides of the image of 1 to less than 1/4 of the image. A receiver is being developed.

FIG. 6 shows a case where an image signal of an NTSC television broadcast having a character superimpose on the upper and lower sides of an image is displayed on such a conventional television receiver for displaying a high-definition broadcast. FIG.

In FIG. 6, first, a video signal of an NTSC television broadcast having a character superimpose on the upper side and the lower side of the image has an aspect ratio of 4: 3.
When it is displayed on the screen 101 of an SC type picture tube, the character superimpose on the upper left of the image 102 (8:32)
103 and the lower right character superimpose (morning news) 104 are displayed without any partial omission.

When such a video signal of an NTSC television broadcast is displayed on the screen 105 of a picture tube for displaying a high-definition broadcast having an aspect ratio of 16: 9,
The upper part 107 and the lower part 108 of the image 106 are compressed into a horizontally long image, and the character superimposition (8:32) 10 of the time information shown in the upper left of the image 106 is displayed.
9 and the character superimpose (morning news) 110 shown in the lower right of the program content are about half missing.

FIG. 7 is an explanatory view showing a case where an image signal of an NTSC television broadcast having a character superimpose on the upper side of an image is displayed on a conventional television receiver for displaying a high-definition broadcast.

In FIG. 7, first, when an image signal of an NTSC television broadcast having a character superimpose on the upper side of the image is displayed on a screen 101 of an NTSC picture tube having an aspect ratio of 4: 3. , Video 112
The character superimpose (Seibu 1-Daiei 3) 113 of the program content shown at the upper left of is displayed without partial omission.

When such an NTSC television broadcast video signal is displayed on a picture tube screen 105 for displaying a high-definition broadcast having an aspect ratio of 16: 9,
The upper side 117 and the lower side 118 of the image 116 are compressed to form a horizontally long image, and the character superimpose (Seibu 1-Daiei 3) 117 at the upper left of the image 116 is missing about half.

In such a conventional display method by the television receiver for displaying the high-definition broadcast, when the NTSC television broadcast having the character superimpose on the upper and lower sides of the image is displayed, the character superimpose is displayed. There is a problem that some poses are missing and unreadable.

Corresponding to this, if the upper and lower missing parts of the image are made smaller, the upper and lower parts of the remaining image must be compressed more, resulting in an input video signal. If there is no text superimpose, the user is uncomfortable.

[0015]

In such a conventional television receiver, when the upper and lower missing portions of the image are reduced to prevent the character superimpose from being lost, the remaining image of the remaining image is not displayed. The upper part and the lower part must be compressed more, and if the input video signal does not have the character superimpose, the user is uncomfortable.

Therefore, an object of the present invention is to provide a television receiver capable of setting a missing portion of the input video signal displayed on the screen in accordance with the presence or absence of character superimposition in the input video signal.

[0017]

A television receiver according to a first aspect of the present invention has a screen having a second aspect ratio, the aspect ratio of which is larger in the horizontal direction than the input video signal having the first aspect ratio. A picture tube for displaying the input video signal on the screen, a vertical amplitude adjusting circuit for adjusting vertical amplitudes of upper and lower parts of the input video signal displayed on the screen of the picture tube, and A vertical screen position adjusting circuit for adjusting the vertical position of the input video signal, and whether or not a character superimpose is present in at least one of the upper predetermined position and the lower predetermined position of the image by the input video signal. If the character superimpose detection circuit for detecting whether or not the character superimpose detection circuit detects that the character superimpose has occurred, the character superimpose detection circuit Wherein the chromatography's are equipped with a control circuit for controlling at least one of said vertical amplitude adjustment circuit and the vertical screen position adjustment circuit to be displayed on the screen of the picture tube.

A television receiver according to a second aspect of the present invention has a screen having a second aspect ratio whose aspect ratio is horizontally larger than that of the input video signal having the first aspect ratio. On the screen, a vertical screen position adjusting circuit for adjusting the vertical position of the input video signal displayed on the screen of the picture tube, and a character superindicator at a predetermined position above the video by the input video signal. A character superimpose detection circuit for detecting whether or not a pause is present, and for detecting whether or not a character superimpose is present at a predetermined position below the image by the input video signal, and a character superimpose detection circuit. When the pause detection circuit detects that the character superimpose appears only at a predetermined position above the image by the input image signal, the vertical movement is performed. The adjustment circuit is controlled to move the vertical position of the input video signal to the lower side, and the character superimpose detection circuit displays the character superimpose only at a predetermined position below the image by the input video signal. And a control circuit for controlling the vertical amplitude adjusting circuit to move the vertical position of the input video signal to the upper side when the above is detected.

A television receiver according to a third aspect of the present invention has a screen having a second aspect ratio whose aspect ratio is horizontally larger than that of the input video signal having the first aspect ratio. On the screen, a vertical amplitude adjusting circuit for adjusting the vertical amplitude of the upper and lower parts of the input video signal displayed on the screen of the picture tube, and a predetermined position above and below the video by the input video signal. A character superimpose detection circuit that detects whether or not a character superimpose is present in at least one of the predetermined positions on the side, and this character superimpose detection circuit detects that a character superimpose is present. And a control circuit for controlling the vertical amplitude adjusting circuit so that the superimposed character is displayed on the screen of the picture tube. And butterflies.

[0020]

According to the structure of the present invention, the character superimpose detection circuit causes the character superimpose to appear in at least one of the upper predetermined position and the lower predetermined position of the image by the input video signal. If the character superimpose detection circuit detects that there is a character superimpose, the control circuit displays the character superimpose on the screen of the picture tube. In addition, since at least one of the vertical amplitude adjusting circuit and the vertical screen position adjusting circuit is controlled, it is possible to prevent the character superimposing portion from being missing in the input video signal.

According to the second aspect of the present invention, the character superimpose detection circuit detects whether or not the character superimpose appears at a predetermined position above the image by the input video signal, and the input video signal is detected. The character superimpose detection circuit detects whether or not a character superimpose appears at a predetermined position on the lower side of the image by this, and the character superimpose detection circuit outputs the character superimpose only at a predetermined position on the upper side of the image by the input video signal. Is detected, the control circuit controls the vertical amplitude adjustment circuit to move the vertical position of the input video signal downward, and the character superimpose detection circuit causes When it is detected that the character superimpose appears only at a predetermined position on the side, the control circuit controls the vertical amplitude adjusting circuit to input. Since moving the vertical position of the image signal to the upper, it is possible to prevent missing of a character superimposing portion in the input video signal.

According to the third aspect of the present invention, the character superimpose detection circuit outputs the character superimpose to at least one of a predetermined position on the upper side and a predetermined position on the lower side of the image by the input image signal. If the character superimpose detection circuit detects that there is a character superimpose, the control circuit displays the character superimpose on the screen of the picture tube. Since the vertical amplitude adjusting circuit is controlled, it is possible to prevent the missing of the character superimposed portion in the input video signal.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given below with reference to the drawings.

FIG. 1 is a block diagram showing a circuit system for displaying an NTSC composite video signal of a television receiver according to the present invention.

In FIG. 1, reference numeral 11 denotes a composite video signal (input video signal having a first aspect ratio) a1 of NTSC aspect ratio 4: 3 from the video amplifier circuit or an external video signal input terminal. The composite video signal a1 guided to the input terminal 11 is the horizontal and vertical sync signal detection circuit 12 and the changeover switch 13.
To the first input terminal A1 and the video output circuit 31.

The horizontal and vertical sync signal detection circuit 12 receives the horizontal and vertical sync signals b from the supplied composite video signal a1.
1H and b1V are detected, and the detected horizontal and vertical synchronizing signals b1H and b1V are detected by the horizontal and vertical counter gate circuits 14
And to the horizontal and vertical deflection circuits 32.

The horizontal and vertical counter gate circuits 14 are
The supplied horizontal and vertical synchronization signals b1H and b1V are counted, and a gate pulse signal c1 for extracting the upper and lower parts of the image of the composite video signal a1 is created based on the count result, and the changeover switch 13 is operated. Lead to the switching signal input terminal. Gate pulse signal c1 in this case
Is a high-level period (gate pulse period) in the period for extracting the upper and lower parts of the image, and is a low-level period in other cases.

The changeover switch 13 has the other input terminal A2.
Is connected to the reference potential point. The common terminal C of the changeover switch 13 is connected to the input terminal of the white peak detection / white area detection circuit 15. The changeover switch 13 selects the first input terminal A1 when the gate pulse signal c1 from the horizontal and vertical counter gate circuits 14 is in a high level period (gate pulse period) and selects the common terminal C1.
When the gate pulse signal c1 is in the low level period (period other than the gate pulse), the second input terminal A2 is selected and connected to the common terminal C. As a result, the composite video signal d1 of the upper and lower parts of the image where the character superimpose may be displayed is supplied to the white peak detection and white area detection circuit 15.

The white peak detection and white area detection circuit 15 is
It is detected whether or not the level of the white peak is exceeded with respect to the supplied composite video signal d1, the area of the white peak is detected from this detection result, and the white area detection signal e1 of this detection result is detected.
Is supplied to the character superimpose existence determination circuit 16.

Character superimpose presence / absence determining circuit 16
Indicates that the white area detection signal e1 from the white peak detection and white area detection circuit 15 indicates that the white peak portion of the composite video signal d1 is intermittent (white peaks of a predetermined area or less at predetermined intervals or less). After a predetermined number of times), it is determined that this portion is the character superimpose, and the white area detection signal e1 of the line determined to be the character superimpose is supplied to the comparison circuit 17 as the white area detection signal f1. . The comparison circuit 17 supplies a data signal g1 indicating the state to the control micro computer 18, and is controlled by the control signal h1 from the control micro computer 18.

When the data signal g1 indicates the supply of the white area detection signal f1, the control micro computer 18 causes the comparison circuit 17 to store the white area detection signal f1 in the memory 19 as the white area detection signal i1. Control. Further, when the data signal g1 indicates the supply of the white area detection signal f1 in a plurality of fields in succession, the control micro computer 18 changes the white area detection signal f1 to the white area detection signal i.
The control signal h1 stored in the memory 19 as 1 is supplied to the comparison circuit 17, and the read control signal j1 is supplied to the memory 19 to store the white area detection signal i1 of the same line stored in the memory 19 as the white area detection signal i2. As the white area detection signal i from the memory 19
2 is compared with the white area detection signal f1 from the character superimpose existence determination circuit 16. Further, in the control micro computer 18, the comparison result of the comparison circuit 17 is
When it is shown that a substantially constant waveform continues for a predetermined time, it is determined that the character superimpose is present, and the line having the character superimpose is a picture tube 33 described later.
The video lacking portion is set so as not to protrude from the screen, and control signals k1 and m1 are created and supplied to the vertical amplitude adjusting circuit 20 and the vertical screen moving circuit 21, respectively.
When the comparison result of the comparison circuit 17 does not indicate that the substantially constant waveform is continued for a predetermined time, the control micro computer 18 determines that the character is not superimposed and is displayed on the picture tube 33. A control signal k1 for vertically compressing the upper and lower parts of the image at a compression ratio (first compression ratio described later) that does not make the viewer feel unnatural is created and supplied to the vertical amplitude adjustment circuit 20. To do.

The vertical amplitude adjustment circuit 20 generates a vertical amplitude adjustment control signal n1 for adjusting the vertical amplitudes of the upper side and the lower side of the video signal q1 displayed on the picture tube 33, which will be described later, based on the control signal k1. Supply to the horizontal and vertical deflection circuits 32.

The vertical screen position adjusting circuit 21 controls the control signal m.
Image signal q displayed on a picture tube 33, which will be described later, based on 1.
Vertical position adjustment control signal p for adjusting the vertical position of 1
1 is supplied to the horizontal and vertical deflection circuits 32.

As a result, the horizontal and vertical synchronizing signal detecting circuit 12, the changeover switch 13, the horizontal and vertical counter gate circuit 14, the white peak detecting and white area detecting circuit 15,
Character superimpose presence / absence determination circuit 16 and comparison circuit 1
The memory 7 and the memory 19 constitute a character superimpose detection circuit for detecting whether or not a character superimpose is present in at least one of a predetermined position on the upper side and a predetermined position on the lower side of the image by the composite video signal a1. When the character superimpose detection circuit detects that the character superimpose has appeared, the control micro computer 18 adjusts the vertical amplitude so that the character superimpose is displayed on the screen. A control circuit that controls at least one of the circuit 20 and the vertical screen position adjustment circuit 21 is configured.

The horizontal and vertical deflection circuits 32 include a picture tube 33.
A vertical deflection adjustment control signal n1 and a vertical position adjustment control signal are supplied to the deflection yoke 34, and a vertical deflection current I1V for vertical deflection of the picture tube 33 is supplied to the deflection yoke 34. It is supplied to the deflection yoke 34 after being adjusted by p1.

The video output circuit 31 performs video signal processing such as blanking and amplification on the composite video signal a1 from the input terminal 11 to create a video signal q1 for display, and a picture tube 33.
Supply to the cathode.

The deflection yoke 34 is used for the horizontal and vertical deflection circuits 3
Horizontal deflection and vertical deflection of the electron beam emitted from the cathode of the picture tube 33 are performed by the horizontal deflection current I1H and the vertical deflection current I1V from 2.

The picture tube 33 has a first aspect ratio (4:
3) having a screen having a second aspect ratio (16: 9) whose aspect ratio is larger in the horizontal direction than that of the composite video signal a1 having the third aspect, the display video signal q1 is horizontally and vertically deflected by the deflection yoke 34. Displayed on the screen.

Although not shown, this television receiver is also provided with a circuit system for displaying a composite video signal having a screen of the second aspect ratio (16: 9) on the picture tube 33.

The operation of this embodiment will be described below with reference to FIGS.

FIG. 2 is a timing chart for explaining the operation of detecting the character superimposition in such an embodiment. FIG. 2 (a) shows the composite video signal d1 and FIG. 2 (b).
Indicates the white area detection signal e1.

In this case, it is assumed that a character superimpose appears on the upper left of the image by the composite image signal a1 guided to the input terminal 11 and a relatively large white image appears on the upper right of the image.

The composite video signal a1 guided to the input terminal 11 is supplied to the white peak detection and white area detection circuit 15 as the composite video signal d1 on the upper side and the lower side of the image of one field by the changeover switch 13. As a result, as shown in FIG. 2A, the composite video signal d1 on the upper side of the video of one field in which the character superimposition is generated has a white peak of a predetermined area or less on the left side of the video at a predetermined interval of 4 or less. This is a state in which the white peak having a predetermined area or more appears once on the right side of the image. The white peak detection and white area detection circuit 15 detects the white peak level of the composite video signal d1 shown in FIG. 2A (8 in the case of this embodiment).
0 IRE) is exceeded, the area of the white peak is detected from this detection result, and the white area detection signal e1 of this detection result is used as the character superimposition presence / absence determination circuit 16
Supply to. The white area detection signal e1 in this case is as shown in FIG.
As shown in (b), a low level (L) state is used as a reference level, and a high level (H) pulse for a predetermined period or less continues 4 times at a predetermined interval or less on the left side of the image, and the right side of the image is displayed. In, the high level (H) pulse for a predetermined period or more appears once.

Character superimposing presence / absence determining circuit 16
Indicates that the white peak portion of the composite video signal d1 is intermittent on the left side of the white area detection signal e1 as described above. Therefore, it is determined that this portion is the character superimpose and it is determined. Line white area detection signal e1
Is supplied to the comparison circuit 17 as a white area detection signal f1.

Here, the white area detection signal e1 is as shown in FIG.
Since a high level (H) pulse equal to or less than a predetermined period continues four times at a predetermined interval or less for a continuous field, the control micro-computer 18 causes the comparison circuit 17 to output the white area detection signal i2 from the memory 19 to the comparison circuit 17. And the white area detection signal f1 from the character superimpose existence determination circuit 16 are compared. In this case, since the comparison result of the comparison circuit 17 indicates that the substantially constant waveform is continued for the predetermined time, the control micro computer 18 determines that it is the character superimpose and has the character superimpose. The control signals k1 and m1 are created and supplied to the vertical amplitude adjusting circuit 20 and the vertical screen moving circuit 21, respectively, so that the lines do not protrude from the screen of the picture tube 33 described later.

FIG. 3 is an explanatory diagram showing an operation when the composite video signal a1 having no character superimposed is displayed on the upper and lower sides of the image on the television receiver of FIG.

When the composite video signal a1 of an NTSC television broadcast having no character superimposition on the upper and lower sides of the image is displayed on the screen 41 of an NTSC picture tube having an aspect ratio of 4: 3. , The horizontal and vertical balance of the image 42 becomes normal.

When the composite video signal a1 is in such a state, the control micro computer 18 vertically compresses the upper and lower parts of the image displayed on the picture tube 33 at the first compression rate. The control signal k1 is created and supplied to the vertical amplitude adjusting circuit 20.

As a result, on the screen 45 of the picture tube 33 for displaying a high-definition broadcast having an aspect ratio of 16: 9, the upper portion 47 and the lower portion 48 of the image 46 are compressed at the first compression ratio and the horizontally long image is obtained. And the upper part 4 of the image 46
The intermediate part 51 between the lower part 7 and the lower part 48 is not compressed in the vertical direction and becomes a normal image.

FIG. 4 is an explanatory diagram showing the operation in the case of displaying the composite video signal a1 having the character superimpose on the upper and lower parts of the image on the television receiver of FIG.

In FIG. 4, first, a composite video signal a1 of an NTSC television broadcast having a character superimpose on the upper and lower sides of the video has an aspect ratio of 4 :.
When displayed on the screen 41 of the NTSC picture tube of No. 3, the character superimpose (8: 3
2) 63 and the lower right character superimpose (morning news) 64 are displayed without partial omission.

When the composite video signal a1 is in such a state, the control micro-computer 18 lacks a video so that the line having the character superimpose does not protrude from the screen of the picture tube 33 described later. A part is set, and the upper and lower parts of the image displayed on the picture tube 33 are vertically compressed at the second compression rate, and the upper and lower parts of the image displayed on the picture tube 33 are compressed. A control signal k1 for compressing the intermediate portion in the vertical direction in the vertical direction at a third compression rate lower than the second compression rate is created and supplied to the vertical amplitude adjustment circuit 20.

As a result, on the screen 45 of the picture tube 33 for displaying a high-definition broadcast having an aspect ratio of 16: 9, the upper portion 67 and the lower portion 68 of the image 66 are compressed at the second compression ratio to produce a horizontally long image. And the text information superimposed on the time information shown in the upper left of the image 66 (8:32)
69 and the character superimposition (morning news) 70 shown in the lower right of the program content are displayed without any partial omission. Also, the upper side 67 and the lower side 6 of the image 66
The intermediate portion 71 between 8 is compressed at a third compression rate lower than the second compression rate to form a slightly horizontally long image. In this case, since the intermediate portion 71 is also compressed in the vertical direction, the upper portion 67 and the lower portion 68 of the image 66 do not become a horizontally long image.

FIG. 5 is an explanatory diagram showing the operation when the composite video signal a1 having the character superimposition is displayed only on the upper part of the video on the television receiver of FIG.

In FIG. 5, first, the composite video signal a1 of the NTSC television broadcast having the character superimpose on the upper side of the video is NT with the aspect ratio of 4: 3.
When displayed on the screen 41 of the SC type picture tube, the character superimpose (Seibu 1-Daiei 3) 83 of the program content shown in the upper left of the video 82 is displayed without being partially omitted.

When the composite video signal a1 is in such a state, the control micro computer 18 loses the video so that the line having the character superimpose does not protrude from the screen of the picture tube 33 described later. The control signal k1 for setting the portion and vertically compressing the upper and lower parts of the image displayed on the picture tube 33 at the first compression rate is supplied to the vertical amplitude adjusting circuit 20 and to the picture tube 33. A control signal m1 for moving the vertical position of the displayed image downward is created and supplied to the vertical screen moving circuit 21.

As a result, on the screen 45 of the picture tube 33 for displaying a high-definition broadcast having an aspect ratio of 16: 9, the upper side portion 87 and the lower side portion 88 of the image 86 are compressed at the first compression ratio and the horizontally long image is displayed. At the same time, the vertical position of the image 86 is moved downward and the upper left character superimpose (Seibu 1-Daiei 3) 89 of the image 86 is displayed without being partially omitted. Further, the intermediate portion 91 between the upper side portion 87 and the lower side portion 88 of the image 86 is not compressed in the vertical direction and becomes a normal image.

Although not shown, when the composite video signal a1 having the character superimpose is displayed only on the lower part of the image, the control micro-computer 18 has a line having the character superimpose described later. When the upper and lower parts of the image displayed on the picture tube 33 are vertically compressed at the first compression ratio so as not to overflow from the screen of the picture tube 33, the control signal k1 is changed to the vertical amplitude adjusting circuit 20.
And a control signal m1 for moving the vertical position of the image displayed on the picture tube 33 to the upper side, and supplying the control signal m1 to the vertical screen moving circuit 21.

As a result, the character superimpose is displayed on the screen of the picture tube 33 for displaying the high-definition broadcast without being partially lost.

According to such an embodiment, the missing portion of the video signal q1 displayed on the screen can be set according to the presence or absence of the character superimposition in the composite video signal a1. If there is a character superimpose on the screen, the character superimpose can be displayed so as not to protrude from the screen of the picture tube 33, and if there is no character superimpose on the composite video signal a1, the character superimpose is displayed on the screen. By taking a large amount of loss of the displayed image, it is possible to prevent the upper and lower parts of the remaining image from being compressed in the vertical direction so much that the user is uncomfortable.

In the embodiment of FIG. 1, both the vertical amplitude adjusting circuit 20 and the vertical direction screen moving circuit 21 are provided and controlled by the control micro computer 18, but only the vertical amplitude adjusting circuit 20 is provided. It may be configured to adjust only the vertical amplitude when the video signal q1 is displayed on the screen when the character superimpose is displayed. When the character superimpose is displayed only by providing the vertical screen movement circuit 21. Alternatively, only the vertical amplitude when the video signal q1 is displayed on the screen may be adjusted. With this configuration, the manufacturing cost can be reduced as compared with the embodiment shown in FIG. In the embodiment of FIG. 1, the first aspect ratio is set to 4: 3, an NTSC composite video signal is used as the input video signal having the first aspect ratio, and the aspect ratio is higher than the first aspect ratio. The second aspect ratio, which is large in the horizontal direction, is set to 16: 9, but other combinations such as the first aspect ratio may be used as the combination of the first aspect ratio, the input video signal, and the second aspect ratio. 16: 9, a high-definition composite video signal is used as the input video signal having the first aspect ratio, and the second aspect ratio is 2.35: the cinemascope size.
A combination of 1 may be used. Further, in the embodiment of FIG. 1, as the character superimpose detection circuit, the horizontal and vertical sync signal detection circuit 12, the changeover switch 13,
The horizontal and vertical counter gate circuits 14, the white peak detection and white area detection circuit 15, the character superimposition presence / absence determination circuit 16, the comparison circuit 17, and the memory 19 are used.
Other circuit configurations, for example, analog / digital conversion of a predetermined position on the upper side and a predetermined position on the lower side of the composite video signal a1 to create digital data of the video signal, and various data stored in advance in the digital data It is also possible to use a circuit for detecting whether or not the character superimpose appears at least at one of the upper predetermined position and the lower predetermined position of the image by the composite video signal a1 by performing a comparative analysis.

[0062]

As described above, according to the present invention, it is possible to set the missing portion of the input video signal displayed on the screen according to the presence or absence of the character superimpose in the input video signal. If the video signal has a character superimpose, the character superimpose can be displayed so that it does not overflow from the image receiving screen.
If the input video signal does not have a character superimpose, the loss of the video displayed on the screen is set to a large amount to prevent the upper and lower parts of the remaining video from being compressed in the vertical direction too much, which causes user discomfort. Can be prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a television receiver according to the present invention.

FIG. 2 is a timing chart showing the operation of the embodiment of FIG.

3 is an explanatory diagram showing an operation when a composite video signal having no character superimpose on the upper side and the lower side of the image is displayed on the television receiver of the embodiment of FIG. 1. FIG.

FIG. 4 is an explanatory diagram showing an operation when a composite video signal having a character superimpose on the upper and lower sides of a video is displayed on the television receiver of the embodiment of FIG.

5 is an explanatory diagram showing an operation when displaying a composite video signal having a character superimpose only on an upper side of an image on the television receiver of the embodiment of FIG. 1. FIG.

FIG. 6 is an explanatory diagram showing an operation when displaying an NTSC television broadcast having a character superimpose on the upper and lower sides of an image on a conventional television receiver.

FIG. 7 is an explanatory diagram showing an operation when displaying an NTSC television broadcast having a character superimpose only on an upper side of an image on a conventional television receiver.

[Explanation of symbols]

 12 horizontal and vertical sync signal detection circuit 13 changeover switch 14 horizontal and vertical counter gate circuit 15 white peak detection and white area detection circuit 16 character superimpose presence / absence determination circuit 17 comparison circuit 18 control micro computer 19 memory 20 vertical amplitude adjustment circuit 21 vertical screen moving circuit 31 video signal processing circuit 32 horizontal and vertical deflection circuit 33 picture tube 34 deflection yoke

[Procedure amendment]

[Submission date] September 14, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

Claims (3)

[Claims] 1. A picture tube having a screen having a second aspect ratio, the aspect ratio of which is larger in the horizontal direction than that of an input video signal having a first aspect ratio, and a picture tube which displays the input video signal on the screen. A vertical amplitude adjusting circuit for adjusting the vertical amplitude of the upper and lower parts of the input video signal displayed on the screen of the picture tube; and a vertical screen position adjusting circuit for adjusting the vertical position of the input video signal displayed on the screen of the picture tube. A character superimpose detection circuit for detecting whether or not a character superimpose is present in at least one of a predetermined position on the upper side and a predetermined position on the lower side of the image by the input video signal; When the detection circuit detects that the character superimpose is generated, the vertical amplitude adjustment is performed so that the character superimpose is displayed on the screen of the picture tube. Television receiver, characterized by comprising a control circuit for controlling at least one of the circuit and the vertical screen position adjustment circuit. 2. A picture tube having a screen having a second aspect ratio, the aspect ratio of which is larger in the horizontal direction than that of the input video signal having the first aspect ratio, and a picture tube which displays the input video signal on the screen. A vertical screen position adjusting circuit for adjusting the vertical position of the input video signal displayed on the screen of the picture tube, and detecting whether or not a character superimpose appears at a predetermined position on the upper side of the video by the input video signal. A character superimpose detection circuit for detecting whether or not a character superimpose appears at a predetermined position on the lower side of the image based on the input video signal; When it is detected that the character superimpose appears only at the upper predetermined position, the vertical amplitude adjustment circuit is controlled to change the vertical position of the input video signal. The vertical amplitude adjusting circuit is controlled when the character superimpose detection circuit is moved to the lower side and the character superimpose detection circuit detects that the character superimpose appears only at a predetermined position on the lower side of the image by the input video signal. And a control circuit for moving the vertical position of the input video signal to the upper side. 3. A picture tube having a screen having a second aspect ratio whose aspect ratio is horizontally larger than that of the input video signal having the first aspect ratio, and a picture tube for displaying the input video signal on the screen. A vertical amplitude adjusting circuit for adjusting the vertical amplitude of the upper and lower portions of the input video signal displayed on the screen of the picture tube, and a character on at least one of the upper predetermined position and the lower predetermined position of the image by the input video signal. A character superimpose detection circuit for detecting whether or not the superimpose is present, and when the character superimpose detection circuit detects that the character superimpose is present, the character superimpose is detected as described above. A television receiver comprising a control circuit for controlling the vertical amplitude adjusting circuit so that the vertical amplitude adjusting circuit is displayed on the screen of the picture tube.