JP3491958B2 - 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 an image having an aspect ratio different from that of a display screen,
In particular, the present invention relates to a television receiver that displays letterbox format video software called Vista size or Sinesco size.

[0002]

2. Description of the Related Art In a television receiver having a wide aspect ratio (16: 9) (hereinafter referred to as a wide aspect television receiver), a normal NTSC image (4:
Aspect ratio of 3) can be displayed, but as it is an image that extends in the horizontal direction as it is, the image displayed on the screen can be compressed in the horizontal direction or in the vertical direction by processing the image signal. It is also possible to stretch and display.

In recent years, letterbox format video software called Vista size or cinemasco size is often used in broadcasting and package software. This letterbox format video is also displayed on the full screen by using the above-mentioned function. You can do it. In this letterbox format,
A non-image part is created above and below an image with an aspect ratio of 4: 3, and a horizontally long image is inserted only in the center. Therefore, the aspect ratio of the horizontally long part is close to 16: 9. It is possible to project the full screen.

When a subtitle is superimposed on the non-picture portion, it is usually detected that a white level appears in the non-picture portion, that is, an all-black portion, and this position is automatically optimized by the subtitle moving function. Subtitles are also moved to the position and displayed, which is reflected.

FIG. 7 shows the configuration of a conventional wide aspect television receiver having a subtitle display function, and an image processing method for letterbox format signals will be described.

The composite video signal is supplied to the video signal processing circuit 1, where Y / C separation and color demodulation are performed to generate RG.
While the B signal is output, it is determined whether or not the image signal is a letterbox format signal, and the determination signal is output. Here, after the luminance signal and the chrominance signal in the composite video signal are separated, a letter box format video signal is detected by, for example, a method of detecting a non-image, that is, a black level signal in the upper and lower parts of the screen from the luminance signal. Is determined.

The signal of this judgment is supplied to the control means (for example, a microcomputer) 2 and the control means 2 detects that it is a letterbox signal. Using this signal, from the microcomputer 2 via the IIC bus,
It is transmitted to the vertical deflection control circuit 3A that the image is in the letterbox format. It is well known that the IIC bus is composed of a two-wire system including a clock signal and a data line.

Upon receiving this determination, the vertical deflection control circuit 31 supplies a control signal in the expansion mode or the normal mode to the vertical deflection circuit 3B. Based on this control signal, the vertical deflection circuit 3B extends the amplitude of the sawtooth wave for vertical deflection based on this control signal, and drives the vertical deflection coil (not shown) in the display means 4.

As a result, the screen in the vertical direction is enlarged and a letterbox format image is displayed on the entire screen.

Further, when a subtitle is detected, in addition to the above-mentioned enlargement mode and normal mode, another enlargement mode different from the above-mentioned enlargement mode is provided, and a control signal obtained by detecting this mode is set. It is used to expand the projection range, including the subtitle part, to project the full screen.

These plural enlargement modes respectively correspond to the above-mentioned video contents, that is, only the image in the letterbox format and the video in which the subtitles and the image in the letterbox format are added. Here, the two are distinguished. Therefore, the former is described as a letterbox mode and the latter is described as a subtitle only mode.

Further, in this subtitle only mode, when the subtitles extend over a plurality of lines, the subtitles are detected line by line, and the range including the detected subtitles is expanded every time the following lines are added. Therefore, the subtitles will be described as the first subtitle-only mode and the second subtitle-only mode in correspondence with the small and large number of subtitle lines. .

However, in the above-described apparatus, when the letterbox format is detected, the apparatus immediately shifts to the enlarged letterbox mode. For this reason, when the letterbox mode and the normal mode are frequently switched, not only is there a problem that the screen switches in a short time and the screen is very difficult to see, but the normal mode is momentarily seen in the letterbox mode. It is expected that the upper and lower images will be missing.

This state is shown in FIG. Note that FIG. 8 is a front view of the screen of the picture tube in the display means 4. In FIG. 8, (a) is a display example of the letterbox format in the normal mode, and it is possible to shift to the enlargement mode as shown in (b) by detecting the letterbox. When a normal video signal is input in this state, the mode shifts to the normal mode as shown in (c). Therefore, the states of (b) and (c) may frequently switch depending on the contents of the screen.

On the other hand, when there is a subtitle, the subtitle-only mode is entered at the same time as the subtitle is detected, and the subtitle-only mode is switched to the normal mode at the same time as the subtitle is lost. Similarly, there is a problem that not only the screen is very difficult to see but also subtitles are missing.

Furthermore, when the number of lines of subtitles exceeds a plurality of times, the first subtitle only mode and the second subtitle only mode are switched each time the subtitle range changes, so that the screen is difficult to see as in the above case. However, there were problems such as missing subtitles.

[0017]

As described above, in the conventional device, when the normal mode, the letterbox mode, and the subtitle only mode are frequently switched, the screen size is frequently switched at the same time as the mode is switched. Was very difficult to see, and there were problems such as lack of video information.

The present invention has been made in view of such a problem, and even if the normal mode, the letterbox mode, and the subtitle only mode are frequently switched, the screen instantly responds to the conversion of this mode. It is an object of the present invention to provide a television receiver that can smoothly switch between screens without causing any loss of video information due to screen switching.

[0019]

A television receiver according to the present invention as defined in claim 1 is a letterbox type video signal having a non-image portion adjacent to an effective image portion, or an ordinary second video signal. When inputting the first video signal, a television receiver capable of enlarging and displaying an image processes an input terminal to which the video signal is supplied and a video signal from the input terminal. A video signal processing means for supplying an output video signal to the display means, and whether the video signal supplied to the input terminal is the first video signal. Letterbox detection means for outputting a first discrimination signal when it is continuously detected for a predetermined period of time, and horizontal / vertical scanning of the display means are performed, and the image amplitude displayed on the display means is enlarged. Mode and normal mode A deflection means which can switch on, the deflection means controlled by an output from said letterbox detecting means, when said first video signal is input,
The first discrimination signal in response to a <br/> enlargement mode after the elapse of the predetermined time period, when the second video signal is input in this mode state, the control for switching immediately to the normal mode Means and means are provided.

The television receiver according to claim 2 is
The first image signal in the letterbox format or the normal second image signal having the non-image part adjacent to the effective image part and the subtitle information inserted in the non-image part is processed, and the first image signal is processed. At the time of inputting the video signal of, a television receiver capable of enlarging and displaying an image, and an input terminal to which the video signal is supplied,
Video signal processing means for processing a video signal from the input terminal to supply an output video signal to the display means, and when the video signal supplied to the input terminal is a first video signal,
Based on the output of the first discriminating unit that discriminates whether or not there is subtitle information in the non-image part and outputs a first discriminating signal, the subtitle information is stored for a predetermined period. Horizontal / vertical scanning is performed on the second discriminating means for outputting the second discriminating signal upon detecting that the detection is not continued, and the image amplitude displayed on the display means is enlarged. And a deflection means capable of switching between a first mode in which the effective image portion and the subtitle information portion are displayed and a normal second mode, and the deflection means is controlled by the outputs of the first and second discrimination means. However, when the first video signal is input, the mode is immediately switched to the first mode in response to the first determination signal, and when the second video signal is input in this mode state, In response to the second determination signal, the predetermined period
And a control means for switching to the second mode after a lapse of time .

A television receiver according to claim 3 is
The first image signal in the letterbox format or the normal second image signal having the non-image part adjacent to the effective image part and the subtitle information inserted in the non-image part is processed, and the first image signal is processed. At the time of inputting the video signal of, a television receiver capable of enlarging and displaying an image, and an input terminal to which the video signal is supplied,
Video signal processing means for processing a video signal from the input terminal to supply an output video signal to the display means, and when the video signal supplied to the input terminal is a first video signal,
It is determined whether or not there is subtitle information in the non-image part, a first discriminating unit that outputs a first discrimination signal, and a change in the number of lines of the subtitle information are detected, and the state of the same number of lines is predetermined. The second discriminating means for outputting the second discriminating signal when continuously detected and the horizontal / vertical scanning of the display means are performed, and
The deflection means is capable of switching between a first mode in which the image amplitude displayed on the display means is enlarged to display the effective image portion and the subtitle information portion, and a normal second mode, and the deflection means is the first mode. 1, controlled by the output of the second discriminating means,
When the first video signal is input , the first mode is immediately set in response to the first determination signal, and when the second video signal is input, the mode is switched to the second mode.
Further, the number of lines of the subtitle information changes in the first mode
In the case of the above, in response to the second determination signal, the predetermined
And a control means for switching the image amplitude after the lapse of the period .

[0022]

In the present invention according to claim 1, after it is confirmed by the letterbox detecting means that continuous letterbox format video signals are obtained for a predetermined time,
A signal for enlarging the image amplitude is supplied from the control means to the deflection means, and the display means displays a letterbox format video signal on the full screen and the letterbox format video signal disappears, and at the same time the control is performed. A control signal is supplied from the means to the deflection means to instantly switch to the normal display screen.

In the present invention as defined in claim 2, at the same time when the letter signal of the letterbox format is detected by the first discriminating means, at the same time, a control signal is supplied to the deflecting means so as to enlarge the image amplitude, and the display is performed. And displaying the subtitles inserted in the effective image part and the non-image part in the letterbox format together on the entire screen as a video by using the means.
After it is confirmed that the subtitle information is not detected for a predetermined period after the subtitle information is no longer detected by the discriminating means, the control signal is supplied from the control means to the deflection means to switch to the normal display screen.

In the present invention according to claim 3, at the same time that the first discriminating means detects a subtitle signal or an increase in the subtitle scanning width,
A control signal for expanding the image amplitude is supplied from the control means to the deflection means, and the display means is used to display the entire screen together with the subtitles inserted in the effective image part and the non-image part in the letterbox format. Is displayed as the second
After detecting that the vertical scanning width of the subtitle has been reduced by the determining means, after confirming that the reduced scanning width is maintained for a predetermined period, the control means supplies a control signal to the deflection means. Switch to a display screen that reduces the number of subtitle lines.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of a vertical deflection circuit according to the present invention. In FIG. 1, the same components as those in FIG. 7 are designated by the same reference numerals for description. FIG. 1 is a diagram showing a configuration of a television receiver according to the present invention.

In FIG. 1, a composite video signal is supplied to a video signal processing circuit 10 where Y / C separation and color demodulation are performed to output an RGB signal, while it is determined whether the video signal is a letterbox format. It discriminates and outputs a discrimination signal.

Here, after the luminance signal and the chrominance signal in the composite video signal are separated, a letter box format is used by, for example, detecting a non-image or black level signal in the upper and lower parts of the screen from the luminance signal. Is determined. On the other hand, control means (for example, a microcomputer) 20
Includes a letterbox detector 21, and recognizes that the video content is in a letterbox format from the discrimination signal supplied from the video signal processing circuit 10.

In the discrimination signal supplied from the video signal processing circuit 10 to the control means 20, for example, a portion corresponding to a non-image or black level signal is associated with a low level and a portion corresponding to an image portion is associated with a high level. Yes, it informs the control means 20 that it is a binarized video signal which has been binarized. This binarized signal is hereinafter referred to as a letterbox signal. The letterbox signal is formed for each vertical period (hereinafter referred to as 1V) and is continuously supplied to the control means 20.

When the video signal processing circuit 10 determines that there is no letterbox format video, a signal whose amplitude is fixed to either a high level signal or a low level signal is supplied to the control means 20. It

On the other hand, the control means 20 is provided with a letterbox detector 21, and detects from the letterbox signal that the video content is in the letterbox format. The detection unit 21 is connected to the signal processing unit 25 at the next stage,
The signal processing unit 25 calculates the relative positional relationship of the video portion with respect to 1V. Further, the video content (contents in the normal mode or the letterbox mode) is constantly monitored from the detection signal, and the vertical deflection means 30 of the next stage is provided via the IIC bus.
Is notified of these detected contents.

Further, the letterbox detecting section 21 is provided with a counter circuit (not shown) in the detecting section 21, and can count the letterbox signals supplied from the video signal processing circuit 10. ing. When the count value of the counter circuit reaches a certain count or more, that is, after confirming that the letterbox signal is continuously supplied for a predetermined time, the vertical deflection means 30 in the next stage is notified of the video content.

On the other hand, the vertical deflection means 30 comprises a vertical deflection control circuit 31 and a vertical deflection circuit 32, and the vertical deflection control circuit 31 and the control means 20 are connected to a bus such as IIC.
It is connected by bus. An address is assigned in advance to the vertical deflection control circuit 31, and data transfer to the vertical deflection control circuit 31 is performed via the IIC bus. It is well known that the IIC bus is composed of a two-wire system including a clock signal and a data line.

First, the address is put on the bus, and then the data is put on the bus and transferred from the control means 20 to the vertical deflection control circuit 31. As a result, it is transmitted from the control means 20 to the vertical deflection control circuit 31 that the video signal at this point of time is a letterbox format video signal.

Then, a control signal for controlling the amplitude, phase or inclination of the sawtooth wave is supplied from the vertical deflection control circuit 31 to the vertical deflection circuit 32 on the basis of the information on the image content.

The vertical deflection circuit 3 supplied with this control signal
2 generates a sawtooth wave corresponding to the normal mode and the letterbox mode according to the image content. When letterboxed, the vertical amplitude of the sawtooth wave is stretched. The sawtooth wave is supplied from the vertical deflection circuit 32 to the display means 40, for example, a picture tube (not shown), and the display means 40 is displayed.
Displays the video signal based on the sawtooth wave.
Output from.

Needless to say, when the letterbox detection section 21 does not detect the letterbox signal, the control means informs the vertical deflection means 30 via the IIC bus that the video signal has a normal video content (normal mode). To that effect.

As a result, when the letterbox signal is detected for a predetermined time, the vertical screen is enlarged,
When the letterbox format image is displayed on the entire screen of the display means 40 and the letterbox signal is no longer detected, the normal mode image is immediately displayed.

The operation of FIG. 1 will be described with reference to FIG. Figure 2
Shows an image displayed on a screen 41 in the display means 40, FIG. 2 (a) is a diagram for explaining a transition state of the letterbox screen from the normal mode to the enlarged screen, and FIG. 2 (b) is
It is a figure explaining the transition state from the expansion mode of the letterbox screen to the normal mode.

In the figure, when a letterbox type video signal is displayed in the normal mode, a portion corresponding to the horizontally long image portion is designated by reference numeral 42, and a portion corresponding to the non-image portion is designated by reference numeral 43. There is.

First, a description will be added for the case where a letterbox format image is detected and the mode is changed from the normal mode to the letterbox mode.

In this embodiment, after the letterbox signal is detected, the screen shown on the left side of FIG. 2A shifts to the screen shown on the right side of FIG. 2A after a predetermined time.

As a result, the effective image portion 42 is displayed on the entire screen 41.

The above-mentioned transition is based on the detection unit 2 in the control means 20.
In No. 1, it is performed by detecting that the letterbox signal supplied for each V is continuously supplied for a predetermined time.

That is, it is confirmed here that the image is surely in the letterbox format.

It should be noted that the determination here may be performed by using, for example, 1 V as a basic unit and using NV (N: a positive number) as a determination reference value.

In the conventional television receiver, when the letterbox signal is detected, the switching to the enlargement mode is immediately performed, which causes the input video signal to be a signal similar to the letterbox signal. There was a problem of viewing the image in the normal mode, which was (the signal in which the upper and lower portions of the screen are at the black level) in the letterbox mode, but in the present embodiment, the control means 20 displays the image in the letterbox format for a predetermined period. Since switching is performed after confirming that there is such a situation, it is possible to avoid displaying a normal image in the letterbox mode.

Further, as shown in FIG. 2B, when the image in the letterbox format is changed to the image in the normal mode, the switching is performed immediately as in the conventional case, so that the image information on the screen is changed. An easy-to-see image can be displayed on the screen without damaging it.

With such a configuration, even if the letterbox mode screen and the normal mode screen are frequently switched, the normal mode screen will not be seen on the letterbox mode screen.

FIG. 3 shows another embodiment according to the present invention. The same components as those in FIG. 1 are designated by the same reference numerals and will be described. 1 is the same as that of FIG. 1 except that a caption detection function is added to the embodiment of FIG.

As in the case of FIG. 1, after the letter-box format is discriminated by the video signal processing circuit 10A, the letter-box signal which is the discrimination signal is supplied to the control means 20.
Further, in the video signal processing circuit 10A of the present embodiment, after the caption is further discriminated, the discrimination signal is supplied to the control means 20 as the caption signal.

Similar to the embodiment of FIG. 1, after the luminance signal and the chrominance signal in the composite video signal are separated, for example, a non-image, that is, a black level signal in the upper and lower parts of the screen is detected from the luminance signal. In addition to the determination of the letterbox format, the subtitles are detected by a method of detecting a white signal in a black signal of a non-image part.

Here, the caption signal supplied from the video signal processing circuit 10A to the control means 20 is, for example, a portion corresponding to the black level signal in the upper and lower non-picture portions, that is, a low level portion, and a portion corresponding to the picture portion. Is set to a low level, and this part is made to correspond to a high level only during a period when a white signal (caption) is detected in a non-image part. In this way, the subtitle signal notifies the control means 20 that the video signal is a letterbox format in which subtitles are inserted in the non-picture portion. This caption signal is generated for each 1V and is continuously supplied to the control means 20, like the letterbox signal.

When the video signal processing circuit determines that there is no letterbox format video, a signal whose amplitude is fixed to either a high level signal or a low level signal is supplied to the control means 20, Similarly, when no caption is detected, the caption signal is supplied with a signal fixed at either level.

On the other hand, the control means 20 is provided with a letterbox detecting section 21 and a subtitle detecting section 22, and the letterbox signal indicates that the video content is in the letterbox format, and the subtitle signal indicates the letterbox format. It detects that subtitles are inserted in the non-image part of. These detection units are connected to the signal processing unit 25 at the next stage, and the signal processing unit 25 calculates the relative positional relationship of the video signal with respect to 1V. Also, the video contents are constantly monitored from the respective detection signals, and the detected contents are notified to the vertical deflection means 30 in the next stage via the IIC bus.

In addition, the signal processing unit 25 detects the position from the scanning width of the non-image part and the detection signal of the caption signal, for example, and the lines are divided into a plurality of lines based on the relationship with a plurality of scanning lines corresponding to one line. It is determined whether there is a subtitle signal that extends.

Further, the caption detection section 22 is provided with, for example, a counter circuit or a timer circuit, and detects that the caption signal is not supplied for a predetermined period. With such a configuration, it can be detected that the caption signal is not supplied within a predetermined period.

This can also be realized by, for example, a method of generating a gate signal such as a multivibrator (single shot) for a certain period and detecting the presence or absence of a caption signal during this gate period. Also, using a re-trigger type multivibrator, the trigger signal is re-triggered.
It is also possible to adopt a configuration in which it is detected that the supply to the type trigger terminal is stopped.

Here, after confirming that the caption signal is not supplied to the control means 20 for a predetermined period, that is, after a fixed time after the caption signal is no longer detected, control for switching from the caption-only mode to the normal mode is performed. A signal is supplied to the vertical deflection control circuit 31 via the IIC bus.

That is, the signal processing circuit 25 can supply a control signal to the vertical deflection means at the next stage by providing a time difference of a predetermined period after the caption signal disappears.

The vertical deflection means 30 comprises a vertical deflection control circuit 3
1 and a vertical deflection circuit 32, and the control means 20 and the vertical deflection control circuit are connected by an IIC bus.

Therefore, the signals corresponding to the video contents are transmitted from the control means 20 to the vertical deflection control circuit 31 designated by a predetermined address via the IIC bus.

It is well known that the IIC bus is composed of a two-line system of a clock signal and a data line.

The vertical deflection control circuit 31 receives the discrimination signal and supplies the vertical deflection circuit with a control signal in the letterbox mode, the normal mode or the subtitle only mode. The vertical deflection circuit is capable of generating a sawtooth wave corresponding to each mode (that is, a sawtooth wave having a vertical amplitude corresponding to each mode), and a predetermined signal is generated based on a switching signal from the vertical deflection control circuit 31. The sawtooth wave of is selected.

Based on this signal, the vertical deflection circuit 32 selects a sawtooth wave corresponding to the subtitle-dedicated mode, letterbox mode or normal mode among the above sawtooth waves and outputs it to the display means.

As a result, the screen in the vertical direction is enlarged corresponding to each letterbox mode, and in the subtitle only mode, the subtitle and the letterbox format image are displayed together on the entire screen of the display unit 40 .

It is assumed that the letterbox signal is continuously detected by the letterbox detection section 21 for a predetermined period, or the letterbox signal and the caption signal are switched to the caption only mode when both are detected.

The operation of FIG. 3 will be described with reference to FIG. Figure 4
FIG. 4A is a diagram illustrating a transition state from the normal mode to the subtitle-only mode, and FIG. 4B is a diagram illustrating a transition state from the subtitle-only mode to the normal mode.

In the figure, when a letterbox format video signal is displayed in the normal mode, the portion corresponding to the horizontally long image portion is denoted by reference numeral 42, the portion corresponding to the non-image portion is denoted by reference numeral 43, and Reference numeral 44 is attached to the subtitle portion.

First, a description will be added for the case where both the letterbox format video signal and the subtitles inserted in the non-picture part of the video signal are detected and the normal mode is switched to the subtitle only mode.

In this embodiment, when a signal in which a subtitle is inserted in the non-picture portion is input and a letterbox format image is detected, the normal mode screen shown on the left side of FIG. 4A is immediately displayed. To the screen in the subtitle-only mode shown on the right side of FIG.

When the subtitles are no longer detected by the subtitle detection section 22, the subtitle only mode screen shown on the left side of FIG. 4B is shifted to the normal mode screen after a predetermined period.

As a result, the effective image portion 42 and the subtitles 44
The screen that was also displayed is switched to the normal screen.

The period required for the transition is within the control means 20.
In subtitle signal detecting section 22, the caption signal supplied to every 1V is detected once, from no longer being subsequently detected,
This is done by making sure that no caption signal is detected for a predetermined period.

That is, after surely confirming that the video content has no subtitles, the mode is shifted to another mode.

It should be noted that the determination here may be performed by using, for example, 1 V as a basic unit and using NV (N: a positive number) as a determination reference value.

In the conventional television receiver, this switching is performed immediately. Therefore, when a screen with subtitles and a screen without subtitles frequently appear, the switching operation cannot be followed, and the subtitle dedicated screen is not displayed. Although there are problems such as missing subtitles and viewing letterbox screens with missing subtitles, in the present embodiment, this problem is avoided by delaying this switching for a predetermined period by the control signal processing means 20. .

Further, in the case of shifting from the normal mode to the subtitle only mode, as in the conventional case, the switching is performed immediately, so that an easily viewable image can be displayed on the screen without damaging the image information on the screen. .

The transition from the subtitle only mode to the letterbox mode is similarly performed. With such a configuration, even if the subtitle-only mode and the normal mode or the letterbox mode and the subtitle-only mode are frequently switched, the subtitle is not lost.

FIG. 5 shows another embodiment according to the present invention. The same components as those in FIG. 1 are designated by the same reference numerals and will be described. Similar to the embodiment of FIG. 3, the video signal processing means generates a letterbox signal and a caption signal for each 1V and continuously supplies them to the control means 20.

On the other hand, the control means 20 comprises a letterbox detecting section 21 and a caption detecting section 23, and recognizes the video content from these signals supplied from the video signal processing circuit 10A.

On the other hand, the control means 20 is provided with a letterbox detecting section 21 and a subtitle detecting section 23. The letterbox detecting section 21 confirms that the video content is in the letterbox format from the letterbox signal. The caption detection unit 23 detects that the caption is inserted from the caption signal into the non-picture part of the letterbox format video signal. Also,
The control means 20 is provided with a signal processing unit 25 at the latter stage of these detection units 21 and 23, and uses the signals of the preceding detection units 21 and 23 to cause the signal processing unit 25 to use the relative position of the video signal with respect to 1V. Relationships and the like are calculated. Further, the video contents (normal mode, letterbox mode, first and second subtitle only mode) are constantly monitored from the respective detection signals, and these are sent to the vertical deflection means 30 of the next stage via the IIC bus. Notification of the detected content. In addition, this signal processing unit 2
In No. 5, for example, the position is detected from the number of scanning lines in the non-image part and the white signal detection signal, and it is determined whether there is a caption signal extending over a plurality of lines from the relationship with a plurality of scanning lines corresponding to one line. To be determined.

Further, the above-mentioned subtitle detecting section 23 is provided with, for example, a counter circuit, etc., and once a plurality of subtitle signals are supplied, the number of lines of subtitles changes and the number of lines decreases, that is
A pulse in which the high period is shorter than the V period is detected for a predetermined period. Here, the decrease change is not detected, but a reliable switching from the second subtitle-only mode to the first subtitle-only mode is performed by the detection while the pulse width is maintained for a predetermined period after the reduction. It is detected by the unit 23. As described above, unlike the caption detection unit 22 of the embodiment of FIG. 3, the caption information can be supplied according to the change in the number of lines of captions.

This is done by, for example, detecting the difference between the pulse immediately before and the pulse supplied next, and detecting that the difference is not detected for a predetermined period after the change is detected. Composed.

After such processing is performed, a control signal for shifting from the second subtitle-only mode to the first subtitle-only mode is supplied to the vertical deflection means via the IIC bus.

The vertical deflection means 30 comprises a vertical deflection control circuit 31 and a vertical deflection circuit 32.
0 and the vertical deflection control circuit 31 are connected by an IIC bus.

Therefore, the signals corresponding to the video contents are transmitted from the control means to the vertical deflection control circuit designated by a predetermined address via the IIC bus.

It is well known that the IIC bus is composed of a two-line system of a clock signal and a data line, and addresses and data are transferred in a start-stop synchronization system.

As described above, the vertical deflection control circuit 31 receives the command from the control means 20 and supplies the vertical deflection circuit with a control signal for converting the letterbox mode, the normal mode, or the first and second subtitle-only modes. To do.

Further, the vertical deflection circuit can generate a sawtooth wave corresponding to each mode. Based on a signal from the vertical deflection control circuit, the first and second sawtooth waves are selected. The sawtooth wave corresponding to the subtitle only mode, letterbox mode or normal mode is selected and output to the display means.

As a result, the screen in the vertical direction is enlarged corresponding to the letterbox mode, and in the first and second subtitle only modes, the subtitle and the letterbox format image are combined on the entire screen of the display unit 40 . It is projected.

The operation of FIG. 5 will be described with reference to FIG. Figure 6
Shifts from the normal mode to the second subtitle-only mode (from the left side of FIG. 6 to the center), and further from the second subtitle-only mode to the first subtitle-only mode (from the center of FIG. 6 to the right side). ).

In FIG. 6, when a letterbox format video signal is displayed in the normal mode, the portion corresponding to the horizontally long image portion is denoted by reference numeral 42, and the portion corresponding to the non-image portion is denoted by reference numeral 43. Further, the reference numeral 44 is attached to the subtitle portion in the first line, and the reference numeral 45 is attached to the subtitle portion extending over a plurality of lines.

First, in the case where both the letterbox format video signal and the subtitle signal extending over a plurality of lines inserted in the non-picture part of the video signal are detected and the normal mode is switched to the second subtitle only mode, , Add explanation.

In the present embodiment, when the letterbox signal is detected, the screen in the normal mode shown on the left side of FIG. 6 immediately shifts to the screen in the second subtitle only mode shown in the center of FIG. Here, the video of the portion including the subtitles 44 and 45 and the effective image portion 42 is displayed on the entire screen.

Also, the decrease in the number of lines of subtitles 44 and 45 is the second
After being detected for a predetermined period by the subtitle detection means 23, the screen shifts from the second subtitle dedicated mode shown in the center of FIG. 6 to the first subtitle dedicated mode shown in the right side of FIG.

Here, only the combined portion of the first-line caption 44 and the effective image portion 42 is displayed on the entire screen.

This is because in the second caption signal detection unit 23 in the control means 20, caption signals with a small number of lines supplied for each 1V, that is, caption signals of which the high period is shortened are continuous. For a certain period of time,
After detection, it is done.

That is, after confirming that the video content with a small number of subtitle lines has been reliably switched, in other words, the second subtitle dedicated mode has been reliably switched to the first dedicated mode, the mode is switched to another mode. is doing.

It is to be noted that the determination here may be performed by using, for example, 1 V as a basic unit and using NV (N: positive number) as a determination reference value.

In the conventional television receiver, this switching is performed immediately. Therefore, when the number of subtitle lines is frequently switched, the switching operation cannot be followed,
There were problems such as missing subtitles on the subtitles-only screen and viewing letterbox screens with missing subtitles, but in the present embodiment, this problem is avoided by providing a time difference in the signal processing unit 25.

Further, in the case of shifting from the normal mode to the first subtitle-only mode or from the first subtitle-only mode to the second subtitle-only mode, the switching is performed immediately as in the conventional case, and therefore the screen image is displayed. Without damaging the information
Easy-to-view images can be displayed on the screen.

With such a configuration, even if the first subtitle only mode and the second subtitle only mode are frequently switched, the subtitles will not be lost.

Further, in the case of shifting from the normal mode to the subtitle only mode, as in the conventional case, the switching is performed immediately, so that an easily viewable image can be displayed on the screen without damaging the image information on the screen. .

[0104] With such a configuration, the normal mode Oh Rui also switched to frequent the first subtitle-only mode and the second subtitle-only mode, it will not be subtitles lacking.

In the present embodiment described above, the binarized signal is supplied to the control means 20 for detection.
The present invention is not limited to this, the control means 20 is provided with an analog input terminal, the analog signal from the video signal processing means 10 is supplied, and this signal is separated in the control means 20 to form a letterbox signal. It is also possible to generate a subtitle signal.

[0106]

As described above, according to the present invention as set forth in claim 1, even when an image corresponding to each mode frequently appears, a predetermined image is switched for switching from a normal image to a letterbox image. Since the time and time are set, it is possible to provide a screen that is always easy to see without missing video information.

According to the second aspect of the present invention, even if the video corresponding to each mode frequently appears, a predetermined time and a grace period are provided for switching the screen from the video with subtitles to the normal video. Therefore, there is an effect that it is possible to provide a screen that is always easy to see without missing subtitles.

According to the third aspect of the present invention, even if a video corresponding to each mode frequently appears, a screen from a video with subtitles extending over a plurality of lines to a video with subtitles with a small number of lines is displayed. There is a grace period for switching, so
There is an effect that can provide always easy to see the screen without even multiple lines eyes of subtitles are missing.

[Brief description of drawings]

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

FIG. 2 is a front view of a screen displayed on a picture tube of the display unit shown in FIG.

FIG. 3 is a block diagram showing another embodiment of the television receiver according to the present invention.

4 is a front view of a screen displayed on a picture tube of the display unit of FIG.

FIG. 5 is a block diagram showing another embodiment of the television receiver according to the present invention.

6 is a front view of a screen displayed on a picture tube of the display unit shown in FIG.

FIG. 7 is a block diagram showing another embodiment of a conventional television receiver.

FIG. 8 is a front view of a screen displayed on a picture tube of the display unit shown in FIG.

[Explanation of symbols]

Video signal processing circuit (video signal processing means) 20 ... Control means 21 ... Letterbox detector (first discriminating means) 22, 23 ... Subtitle detection unit (second determination means) 25 ... Signal processing unit 30 ... Vertical deflection means 40 ... Display means

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Claims (3)

(57) [Claims] 1. A first video signal of a letterbox format having a non-image part adjacent to an effective image part or a normal second video signal is processed, and at the time of inputting the first video signal, A television receiver capable of enlarging and displaying an image, comprising: an input terminal to which a video signal is supplied; and a video signal processing for processing a video signal from the input terminal and supplying an output video signal to a display means. Means for determining whether the video signal supplied to the input terminal is the first video signal, and detecting that the video signal is the first video signal continuously for a predetermined period A letter box detecting means for outputting a discrimination signal; a deflecting means for performing horizontal / vertical scanning of the display means and for switching the image amplitude displayed on the display means between a magnifying mode and a normal mode; Means the letter Controlled by the output from the box detecting means, the first when the video signal is inputted, the lapse of the predetermined period in response to said first determination signal
The expansion mode is set later, and in this mode state, the second
And a control means for instantly switching to the normal mode when the video signal is input. 2. A letterbox format first video signal or a normal second video signal having a non-picture part adjacent to the effective picture part and subtitle information inserted in the non-picture part. Then
When the first video signal is input, the television receiver is capable of enlarging and displaying an image, and an input terminal to which the video signal is supplied and a video signal from the input terminal are processed and displayed on a display unit. A video signal processing means for supplying an output video signal; and when the video signal supplied to the input terminal is the first video signal, it is determined whether or not there is caption information in the non-image part, and the first Based on the output of the first discriminating unit, the second discriminating signal is output by detecting that the caption information is not detected continuously for a predetermined period. And a first mode for performing horizontal / vertical scanning of the display unit and enlarging the image amplitude displayed on the display unit to display the effective image portion and the subtitle information portion. Deflecting means switchable to the second mode of Wherein the serial deflecting means first, and controlled by the output of the second determining means, when said first video signal is input, switching to the first mode immediately in response to said first determination signal , When the second video signal is input in this mode state, in response to the second determination signal, after the predetermined period has elapsed
And a control means for switching to the second mode. 3. A letterbox format first video signal or a normal second video signal having a non-picture part adjacent to the effective picture part and subtitle information inserted in the non-picture part. Then
When the first video signal is input, the television receiver is capable of enlarging and displaying an image, and an input terminal to which the video signal is supplied and a video signal from the input terminal are processed and displayed on a display unit. A video signal processing means for supplying an output video signal; and when the video signal supplied to the input terminal is the first video signal, it is determined whether or not there is caption information in the non-image part, and the first And a second discriminator which outputs a second discriminating signal when a change in the number of lines of the caption information is detected and the state of the same number of lines is continuously detected for a predetermined period. The first mode in which the discrimination unit and the display unit perform horizontal / vertical scanning and the image amplitude displayed in the display unit is enlarged to display the effective image portion and the subtitle information portion, and the normal second mode A deflection means capable of switching to a mode, and the deflection means The first, and controlled by the output of the second determining means, when said first video signal is input, the first mode immediately in response to the first determination signal,
When the second video signal is input, the mode is switched to the second mode, and in the first mode , the subtitle information
When the number of rows has changed, it responds to the second discrimination signal.
And a control means for switching the image amplitude after the lapse of the predetermined period .