JP3282768B2 - Television display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Table of Contents] The present invention will be described in the following order. Industrial application field Conventional technology (FIG. 17) Problems to be solved by the invention (FIGS. 17 to 23) Means for solving the problems (FIG. 10) Action (FIG. 10) Working example (FIGS. 1 to 16) (1) Screen display of wide television (FIGS. 1 to 6) (2) Configuration of television receiver (FIGS. 7 to 15) (3) Other embodiments (FIG. 16)

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television display method, and is particularly applicable to a case where a video signal in a so-called letterbox format with subtitles is displayed on a display screen having an aspect ratio of 16: 9.

[0003]

2. Description of the Related Art Conventionally, as a television receiver having a landscape screen with an aspect ratio of 16: 9, a wide television apparatus and a high vision television have been proposed. When a 4: 3 aspect ratio image is enlarged and displayed on a television receiver having a screen with an aspect ratio of 16: 9, that is, a so-called wide television set, 4: 3
The upper or lower part of the image having the aspect ratio is cut.

[0004] As a normal video having an aspect ratio of 4: 3, there is a video signal in a letter box format called a Vista size or a Sinesco size, which is used as broadcasting or package software. In the video signal of the letter box format, as shown in FIG. 17, non-picture parts are formed above and below the 4: 3 picture, and a horizontally long picture part is inserted only in the center. This allows the user to watch the movie software by trimming without cutting left and right. Therefore, the aspect ratio of the video portion of the video signal of the letter box format is close to 16: 9, and in a wide-screen television, a so-called zoom mode for enlarging the video signal vertically, horizontally, and so on is required to display such movie software on the entire screen. Can be.

[0005]

However, there is a video signal of the letter box format in which subtitles are arranged in a non-picture portion. In this case, as described above, an attempt is made to display the video signal in a full screen in the zoom mode. Then, as shown in FIG. 18, there is a problem that the caption of the non-image portion comes out of the effective screen.

As a method of solving such a problem, there is a method of scrolling the screen upward or moving subtitles by superimposing. In the subtitle display method of scrolling the screen upward, the video section is moved upward until the subtitle appears in the effective screen, as shown in FIG. However, when the video section is moved upward in this way, there is a problem that the upper portion of the screen is cut off by the amount of the subtitles.

As shown in FIG. 20, a subtitle display method for moving a subtitle is to extract information exceeding a certain luminance level from a subtitle area set by a user at a lower portion of the screen, and display the information on the original screen. Move and superimpose. However, user settings generally need to be performed according to the following procedure, which is not easy. That is, first, when the subtitle movement setting mode is entered, the screen shown in FIG.
A line AB appears as shown in FIG. 5 and moves up and down to set a range for extracting subtitles. Next, as shown in FIG. 22, by moving the line CD on the screen up and down, the upper end for superimposing the extracted subtitle area is set.

Further, as shown in FIG. 23, there is a case where the first line of the subtitle is included in the video. At this time, if the upper limit of the subtitle is set by the line EF as described above, the high-luminance portion of the video signal is extracted in addition to the subtitle, and when superimposed, the original image is hidden and the image is difficult to see. In addition, the border between the character and the background is not clear, and in each case, it is still insufficient for practical use.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points. When displaying a video signal in the letter box format with subtitles on a display screen having an aspect ratio of 16: 9, the subtitles are simply and optimally displayed. It proposes a possible television display method.

[0010]

According to the present invention, in order to solve the above-mentioned problems, a non-picture part is arranged above and / or below a picture having an aspect ratio of 4: 3, and a horizontally long picture is formed in a central part. A video signal in a letter box format, in which a video signal in a letter box format in which a portion is arranged and subtitles are arranged in a non-picture portion or a video portion is displayed on a display screen having an aspect ratio of 16: 9. Is expanded vertically and horizontally, and the non-image part is arranged outside the effective screen of the display screen, and the image part is displayed as the parent screen so as to fill the effective screen of the display screen. By setting the AC component in the video signal including at least subtitles in the letter box format to be displayed on the child screen to 0,
The sub-screen is displayed in black and white with white subtitles and a black background image, and when the luminance level in the video signal of the letter box format is less than a predetermined level, the background image luminance level in the background image of the sub-screen is set to 0, and the luminance level is set to a predetermined level. At this time, the background image luminance level is linearly controlled according to the luminance level in the video signal of the letter box format.

[0011]

[Function] By setting the AC component in a video signal including at least subtitles in the letter box format displayed on a sub-screen arranged at an arbitrary position in the main screen to 0, the sub-screen is rendered black and white with white subtitles and a black background image. After displaying, when the luminance level in the video signal of the letter box format is lower than a predetermined level, the background image luminance level in the background image of the child screen is set to 0, and when the luminance level is higher than the predetermined level, the background image luminance level is lettered. By performing linear control according to the luminance level in the video signal of the box format, it is possible to control the luminance level of the background image in the background image of the child screen according to the change in the luminance level in the video signal of the main screen. Therefore, it is possible to display a child screen having a background image that is optimal and has no uncomfortable feeling according to the luminance level of the parent screen.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

(1) Screen display of wide television The screen display of wide television in this embodiment is as follows.
The present invention is applied to an NTSC television receiver using a cathode ray tube (CRT) having an aspect ratio of 16: 9. However, the same applies to the case of displaying an NTSC video signal on a television receiver using a CRT having an aspect ratio of 16: 9 for high vision. In general, three display modes of the wide television set are a normal mode, a full mode (wide mode), and a zoom mode.
There is one.

In practice, when a video signal displayed as shown in FIG. 1 is displayed in each mode on a 4: 3 CRT, first, in the normal mode, the right and left sides of the 16: 9 CRT are reduced as shown in FIG. And an image similar to that of a 4: 3 CRT is displayed at the center. Further, in the full mode (wide mode), as shown in FIG. 3, since all of the video signals are displayed on the 16: 9 CRT, the image becomes horizontally long compared to the image of FIG. Further, in the zoom mode, as shown in FIG. 4, the upper and lower portions of the video signal are cut and displayed on a 16: 9 CRT. At this time, the aspect ratio of the image is 4: 3 as in the case of FIG.

In the screen display of this wide television,
In addition to the three display modes described above, as a picture-in-picture function (PinP), as shown in FIG. 5, a child screen can be displayed while the main screen is being displayed. Make the video different from the screen smaller and insert it in the main screen. Further, as shown in FIG. 6, the child screen can move the four corners of the main screen or change its size.

In the screen display of the wide-screen television of this embodiment, a video signal in the letter box format with subtitles as described above with reference to FIG. 17 is displayed in the zoom mode described above with reference to FIG. The subtitle part is displayed in the effective screen of the CRT, and at the same time, the same picture as the parent screen is displayed on the child screen and the size is changed, so that the subtitle part in the letter box format is displayed in the child screen.

(2) Configuration of Television Receiver As shown in FIG. 7, in the television receiver 1 that realizes the picture-in-picture function, the video signal for the main screen and the video for the child screen are displayed. Each signal is processed separately. For example, a television broadcast wave received by an antenna 2 is selected by a terrestrial tuner 3, and a video signal obtained as a result is input to an input switching circuit 4. Similarly, the satellite television broadcast wave or communication wave received by the parabolic antenna 5 is selected by the BS / CS tuner 6, and the resulting video signal is input to the input switching circuit 4.

The switching circuit 4 includes a terrestrial tuner 3 and B
In addition to the video signal input from the S / CS tuner 6,
For example, three external inputs 7 are input. The switching circuit 4 has two switching switches SW1 and SW2 for separately selecting the video signals of the total of five systems described above in accordance with the specification of the system control 19, and the main screen is switched through the switching switches SW1 and SW2. And a video signal for the child screen are output.

Of these, the video signal for the main screen is input to the Y / C separation circuit 8, and the resulting luminance signal Y and chroma signal C are respectively converted to Y / C-Y / chroma / deflection processing circuit 9. The signals are input to the processing circuit 10 and the chroma processing circuit 11. The Y processing circuit 10 performs processing such as aspect conversion on the input luminance signal Y as a screen display specific to the wide television described above with reference to FIGS. The luminance signal Y obtained as a result is transmitted to the matrix circuit 13 from the output terminal thereof through the first input terminal of the switching circuit 12A, which is controlled by the switching signal BLK for sub-picture insertion.

The chroma processing circuit 11 obtains color difference signals RY and BY from the input chroma signal C. In addition, in the chroma processing circuit 11, the color difference signals RY, B
For -Y, processing such as aspect conversion is performed as in the Y processing circuit 10. The resulting color difference signals RY, B-
Y is transmitted to the matrix circuit 13 from the output terminal thereof through the first input terminals of the switching circuits 12B and 12C which are controlled to be switched by the switching signal BLK for inserting the small screen.
The matrix circuit 13 generates three color signals R, G, B from the input luminance signal Y and color difference signals RY, BY, and outputs these color signals R, G, B through the CRT drive circuit 14. Send to CRT15.

The luminance signal Y sent from the Y / C separation circuit 8 is also input to the deflection processing circuit 16 in the main screen / Y-chroma / deflection processing circuit 9. Deflection processing circuit 16
Separates a synchronizing signal from the luminance signal Y, and based on the synchronizing signal, a vertical pulse V _P corresponding to processing such as aspect conversion.
Is sent to the small screen processing circuit 17, and the vertical drive signal V _DR and the horizontal drive signal _HDR are input to the deflection output circuit 18. Vertical drive signal V _DR deflection output circuit 18 is inputted, drives the CRT15 vertical yoke VDY and horizontal yoke HDY in response to the horizontal drive signal H _DR, a horizontal pulse H _P according to the actual driving, respectively the deflection It is sent to the processing circuit 16 and the small screen processing circuit 17.

Further, the switching circuits 12A, 12B and 12C of the main screen / Y-chroma / deflection processing circuit 9 are switched.
To the second input terminals of A, 12B, and 12C, the luminance signal Y _O and the color difference signals R-Y _O and B-Y _O for the small screen output from the small screen processing circuit 17 are respectively input. Switching is controlled in accordance with a switching signal BLK for sub-screen insertion sent from the screen processing circuit 17.

Here, the small-screen processing circuit 17 is configured as shown in FIG. 8, and a video signal for a small screen is input to the Y-chroma decoder 20. Y-chroma decoder 20
Are the luminance signal Y and the color difference signal R from the input video signal.
-Y, and generates a B-Y, sends out the analog-to-digital (A / D) converter 21, respectively, withdrawn vertical pulse V _PS for the child screen, the horizontal pulses H _PS, and sends it to the controller 22.

The analog-to-digital converter 21 the luminance signal Y and color difference signals R-Y, converts the B-Y for example, 6 bits in digital data, the resulting luminance data Y ₀ to Y _5, color difference data R-Y ₀ ~ RY ₅ , BY
_{0 to} BY ₅ are read in the memory 24 through the filter 23. The luminance data Y ₀ read into the memory 24
To Y _5, color difference data _{R-Y 0 ~R-Y 5} , B-Y 0 ~B
-Y _5, the conversion of the screen shaft is subjected during the due connexion read control of the controller 22, digital-to-analog (D
/ A) The signals are converted into analog signals by the converter 25 and output to the above-described switching circuits 12A, 12B and 12C as luminance signals Y _O , color difference signals R-Y _O and B-Y _O for the small screen.

The analog digital converter 21, the filter 23 and the memory 24 store the vertical pulse V _{P of the main} screen,
Is Yotsute controlled on the child screen size and position of the basis of the horizontal pulse H _P. Further, the controller 22 generates a switching signal BLK for inserting a child screen into the main screen. The luminance signal Y of the main screen, the chrominance signals RY and BY, and the luminance signal Y of the child screen are provided at predetermined timing by the switching signal BLK.
_O , the color difference signals R-Y _O and B-Y _O are switched and inserted so that a child screen can be displayed in the main screen.

Here, the television receiver 1 of this embodiment
In, the video signal of the letter box format with subtitles is displayed on the main screen in the zoom mode so that the video part of the letter box format is fully displayed within the effective screen of the CRT, and the child screen processing circuit 17 Input and display the same video signal. At this time, change the size of the sub screen,
Displays only the subtitles in letterbox format. The setting of this size is realized by lowering the upper limit of the range in which the switching signal BLK for inserting a small picture is at the H level, that is, the range in which the small picture is inserted.

When a normal sub-picture is displayed at the lower right position, as shown in FIG. 9, the switching signal BLK becomes H level within the range surrounded by the lines A0, B0, C0, D0, and A subscreen is inserted. In the subtitle mode, as shown in FIG. 10, the user moves the line A1-B1 up and down,
A range in which the switching signal BLK becomes H level is set. Actually, the sub-screen processing circuit 17 sends out the switching signal BLK output from the controller 22 in FIG. 8 through the BLK control circuit, and can change and control the line from which the switching signal BLK starts to be output according to an instruction from the system controller. Has been made.

That is, the BLK control circuit shown in FIG. 11 is a digital circuit, and the NAND gates G9 and G10 constitute a set-up flip-flop (SRFF). The counter 30 counts the input switching signal BLK _IN . The counter 30 and excisional reset Prefectural Pufu Rotsu flops G9 and G10 are Yotsute reset the vertical pulse V _P. The digital values A _{0 to} A ₅ are set and input by the system controller as the number of lines for cutting the upper part of the small screen display.

Digital value A₀~ A_FiveAnd count output value
B₀~ B_FiveExclusive OR game
The outputs of G1 to G6 are all at L level. Therefore input
Switching signal BLK_INIs at H level and digital
Value A₀~ A_FiveAnd count output value B₀~ B_FiveMatches
Output of the OR gate G7 becomes L level,
Set flip-flops G9 and G10 are set and
The output of the gate G10 goes high. Therefore and
By the gate G8, the subsequent switching signal BLK _INIs valid
And the switching signal BLK_OUTIs output as

In this BLK control circuit, since the digital value input from the system controller is composed of 6 bits, it is possible to control 64 lines. In this manner, the range in which the switching signal BLK for sub-picture insertion becomes H level, that is, the upper limit of the range in which the sub-picture is inserted is lowered by operating the system controller, thereby changing the size of the sub-picture and changing the letter. Only the box format subtitles can be displayed on the small screen.

In the small-screen processing circuit 17 of this embodiment, the AC components of the color difference signals RY and BY output from the Y-chroma decoder 20 are forcibly set to 0 as necessary. Have been made to gain. As a result, the child screen in the parent screen is selected to be displayed in black and white, and the child screen suitable for the subtitle portion can be displayed.

In addition to this, in the small screen processing circuit 17 of this embodiment, the input / output characteristics of the luminance signal Y when the subtitle portion is displayed in black and white as described above, and the input / output characteristics of the digital data as shown in FIG. Non-linearly controlled to bend at 50 [%]. As a result, even when the subtitle portion is included in the video portion, the dark portion of the background image is further darkened, so that the distinction from the subtitle can be made clear, and a sub-screen display more suitable for the subtitle portion can be performed. I do.

In practice, in order to realize this non-linear input / output characteristic, for example, in the small screen processing circuit 17, the luminance data Y _{0 to} Y ₅ read from the memory 24 are converted into the data shown in FIG.
Is input to the digital-to-analog converter 25 through an input / output control circuit as shown in FIG. In the output control circuit, bit Y ₅ is luminance data MSB (most SIGNi
ficant bits), which are output as they are and input to the OR gate G16. The lower 5 bits Y ₀ to Y ₄ of the luminance data is output through the AND gate G11～G15.

[0034] Thus, in the control signal A2 is H level input to the OR gate G16, and the luminance data Y ₀ to Y ₅
When the MSB of H is at H level, the lower bits Y _{0 to} Y
₄ becomes effective. MSB of the slave connexion luminance data Y ₀ to Y ₅
Is at the L level (in the section of the straight line A3 C3 in FIG. 12),
The output maintains the black level, while the MSB of the luminance data is H
When the signal is at the level (in the section of the straight line C3 D3 in FIG. 12), the output becomes linear. Note the control signal A2 is of the switching signal to the nonlinear made on whether polygonal line to the input-output characteristics linear, when the control signal A2 is L-level, the luminance data Y ₀ ~
Y ₅ is output as it is. The input / output characteristics can be bent at a value other than 50% depending on the combination of gates.

Further, in the small-screen processing circuit 17 of this embodiment, when displaying a video signal in the Subtitles format with subtitles on the small screen, it is determined that there is a pixel in the displayed small screen whose luminance exceeds a certain level. It detects the presence and absence of subtitles in the frame and turns on and off the sub-screen instantly,
Thus, only when there is a subtitle, the subtitle can be displayed in the child screen.

In this case, referring to FIG.
The switching signal BLK output from the control circuit is further controlled. The switching signal BLK _OUT of the BLK control circuit is input to the AND gate G21 together with the subtitle detection signal as the input switching signal BLK _IN . Here, as the caption detection signal, for example, using the MSB of the luminance data Y ₀ to Y ₅ read from the memory 24, is made as the luminance signal Y can detect that there is a subtitle when 50 [%] or higher I have.

Here, the inner gates G22 and G23 constitute a set-up flip-flop (SRFF).
D flip-flops 31 holds the state of the input A4 at the rise of the vertical pulse V _P by delivering as output B4. Excisional reset Prefectural Pufu Rotsu flops G22 and G23 are Yotsute reset the vertical pulse V _P. When the input switching signal BLK _IN becomes H level and the subtitle detection signal becomes H level, that is, when there is a subtitle in the sub-screen display, the reset flip-flops G22 and G23 are set and the D flip-flop is set. The input A4 of H.31 goes to H level.

[0038] If no subtitles Matako screen display, input A4 is output at the L level B4 of the D flip flop 31 when the rise of the vertical pulse V _P becomes L level, the switching signal output from a result the AND gate G24 BLK
_{OUT is} also at the L level, and no child screen is inserted. Input A4 of D flip-flop 31 when there is a subtitle in the child screen display conversely the output B4 of the D flip-flop 31 at the rise of the vertical pulse V _P becomes H level to the H level, the switching signal is outputted from the AND gate G24 BLK _OUT Displays a valid child screen. Although the D flip-flop 31 is used in this subtitle control circuit, an appropriate time constant of the vertical period may be provided by the peak hold of the analog circuit.

In the case of this embodiment, as shown in FIG. 15, in the case of an image in which a part of the subtitle is included in the video portion of the main screen, it corresponds to the area extracted as the subtitle in the sub-screen display. It is possible to enjoy only the video by erasing the portion to be played from the video portion of the main screen. For example, in subtitle mode, when the upper side of the original sub-screen is displayed with m lines removed, and the size of the sub-screen is 1 / n of the parent screen,
Main picture n × m lines after across vertical pulse V _P of and allowed to the switching signal BLK in H level. At this time,
The luminance signals Y _O , R-Y _O , and B-Y _O for the small-screen display are
Set to a predetermined DC level.

According to the above configuration, the video signal of the letter box format is enlarged vertically and horizontally, the non-image portion is arranged outside the effective screen in the display screen, and the image portion is displayed to fill the effective screen of the display screen. In addition, a subtitle is displayed by projecting a video signal in the letter box format on a child screen movably displayed at an arbitrary position on the display screen, so that the subtitle can be displayed simply and optimally.

Further, according to the above configuration, when a subtitle is included in a video, a sub-screen in the subtitle mode is displayed in black and white, so that subtitle display in which the subtitle can be easily distinguished can be realized. Also, by making use of the fact that the brightness of the subtitles is high and leaving the subtitles black in the darker part of the background, it is possible to realize subtitle display in which the distinction becomes clearer.

Further, according to the above arrangement, when no subtitle is displayed even in a video with a subtitle with subtitles, the display of the subtitle is not necessary, and the insertion into the main screen can be minimized. Also, when a part of the subtitles enters the screen of the video, only the video can be enjoyed by erasing the portion corresponding to the area extracted in the sub-screen from the main screen, thereby improving the usability of the user. .

(3) Other Embodiments In the above embodiment, the luminance signal Y and the color difference signals RY and BY of the parent screen and the luminance signal Y and the color difference signals RY and B- Y and a switching signal BL for inserting a small screen
Although the case where the picture-in-picture function is realized by switching at the timing of K has been described, the present invention is not limited to this, and even if the RGB signal of the main screen and the RGB signal of the sub-screen are switched, The same effect as that of the embodiment can be realized. In this case, a switch circuit for switching the main screen and the sub-screen may be inserted after the matrix circuit.

In the above-described embodiment, the case where the BLK control circuit for controlling the range of the sub-picture to be inserted is realized by a digital circuit has been described. However, a preset counter may be used. Alternatively, it may be realized by an analog circuit. In this case, FIG.
As shown, in the BLK control circuit, the switching signal BLK in the transistor Q ₀ is input.

The transistor Q ₁ and the capacitor C ₁ are a peak hold circuit for the switching signal BLK, and take out a range where the switching signal BLK exists in the vertical cycle with an arbitrary time constant determined by the capacitor C ₁ and the resistor R _1. . Transistors Q ₂ and Q ₃ , resistors R ₂ , R ₃ , R ₄ , capacitor C
₂ is a sawtooth wave generation circuit, and the transistor Q ₂ is
To reset the sawtooth wave for discharge of the capacitor C _2.

The transistors Q ₄ and Q ₅ are comparators. When the voltage at the base of the transistor Q ₄ becomes higher than the analog output voltage set and input from the system controller given to the base of the transistor Q ₅ , the transistor Q ₆ is turned on. Turn off. When the switching signal BLK at the base of the transistor Q ₀ starts to enter, the switching signal BLK is picked up by the capacitor C ₁ and the transistor Q 0
_The reset is released by ₂ .

[0047] and the ramp waveform is generated in the capacitor C _2. When the voltage of the capacitor C ₂ exceeds the voltage from the system controller, the transistor Q ₆ switching signal BLK to emitter of the transistor Q ₇ is turned off is effective as Do connexion output. Thus, by controlling the voltage from the system controller, the first line on which the switching signal BLK is valid can be determined.

In the above-described embodiment, the case where the AC component of the color difference signal output from the Y-chroma decoder is set to 0 and the child screen is displayed in black and white is replaced with the digital data of the color difference signal. A gate may be inserted in the line to forcibly set the center value. In this case, the gate may be inserted either after the A / D converter or before the D / A converter.
The same effects as in the above embodiment can be realized.

In the above embodiment, the MSB of the luminance data Y _{0 to} Y ₅ is used to detect the presence or absence of a subtitle, and it is detected that the subtitle is present when the luminance signal Y is at least 50%. Although the case has been described, it is also possible to determine that there is a caption when the luminance signal Y is not less than 50% and is equal to or higher than a predetermined level. In this case as well, the combination of the AND gate and the analog converted luminance signal may be detected by the comparator. it can.

[0050]

As described above, according to the present invention, the AC component in a video signal including at least subtitles in the letterbox format to be displayed on a child screen arranged at an arbitrary position in the parent screen is set to zero. When the luminance level of the video signal of the letter box format is less than a predetermined level, the background image luminance level of the background image of the child screen is set to 0, and the luminance level is set to 0. Is greater than or equal to a predetermined level, the background image luminance level is linearly controlled according to the luminance level in the video signal of the letterbox format, so that the child screen of the child screen is changed in accordance with the change in the luminance level in the video signal of the main screen. Since the background image brightness level in the background image can be controlled, a child screen having an optimum and comfortable background image according to the brightness level of the parent screen It can be displayed, thus possible to realize a television display method capable of displaying high visibility subtitles through the main screen and sub-screen with no discomfort.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a 4: 3 display screen as a premise of a display screen of a wide television set according to the present invention.

FIG. 2 shows a wide-screen television in a normal mode.
It is an approximate line figure showing the display screen of 16: 9.

Figure 3: 16 in full mode as a widescreen television:
9 is a schematic diagram illustrating a display screen of No. 9;

[Fig. 4] 1 in zoom mode as a wide-screen television
It is an approximate line figure showing the display screen of 6: 9.

FIG. 5 is a schematic diagram illustrating a display screen of a picture-in-picture function (PinP).

FIG. 6 is a schematic diagram illustrating movement of a child screen in a display screen of a picture-in-picture function (PinP).

FIG. 7 is a block diagram showing a television receiver for implementing the television display method according to the present invention.

FIG. 8 is a block diagram showing a small picture processing circuit in the television receiver.

FIG. 9 is a schematic diagram for explaining the setting of the size of the child screen.

FIG. 10 is a schematic diagram illustrating caption display in a television display method according to an embodiment of the present invention.

FIG. 11 is a connection diagram showing an embodiment in which a BLK control circuit for setting the size of a small screen is constituted by a digital circuit.

FIG. 12 is a characteristic curve diagram showing input / output characteristics for lowering luminance around a subtitle portion.

FIG. 13 is a connection diagram showing a configuration of an embodiment of an input / output control circuit for realizing the input / output characteristics.

FIG. 14 is a connection diagram illustrating a configuration of an embodiment of a caption control circuit that detects the presence or absence of a caption and selects whether to display a caption in a main screen.

FIG. 15 is a schematic diagram illustrating caption display in a television display method according to an embodiment of the present invention.

FIG. 16 is a connection diagram showing an embodiment in which a BLK control circuit for setting the size of a child screen is constituted by an analog circuit.

FIG. 17 is a schematic diagram for explaining a video and a subtitle in the 4: 3 letter box format.

FIG. 18 is a schematic diagram for explaining a conventional method of displaying subtitles in a video signal of a letterbox format.

FIG. 19 is a schematic diagram for explaining a conventional method of displaying subtitles in a video signal of the letter box format.

FIG. 20 is a schematic diagram for explaining a conventional method of displaying subtitles in a video signal of a letterbox format.

FIG. 21 is a schematic diagram for explaining a conventional method of displaying subtitles in a video signal of a letterbox format.

FIG. 22 is a schematic diagram for explaining a conventional method of displaying subtitles in a video signal of a letterbox format.

FIG. 23 is a schematic diagram for explaining a conventional method of displaying subtitles in a video signal of a letterbox format.

[Explanation of symbols]

1 television receiver, 2 antenna, 3 terrestrial tuner, 4 input switching circuit, 5 parabolic antenna, 6 BS / CS tuner, 7 external input,
8 ... Y / C separation circuit, 9 ... Main screen / Y-chroma / deflection processing circuit, 10 ... Y processing circuit, 11 ... Chroma processing circuit, 12A, 12B, 12C ... switching circuit, 13 ...
Matrix circuit, 14 ... CRT drive circuit, 15 ...
... CRT, 16 deflection processing circuit, 17 small screen processing circuit, 18 deflection output circuit, 19 system control, 20 Y-chroma decoder, 21 analog digital converter, 22 controller , 23
…… Filter, 24 …… Memory, 25 …… Digital analog converter.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-6-54271 (JP, A) JP-A-5-30641 (JP, A) JP-A-5-236350 (JP, A) JP-A-5-236350 336446 (JP, A) JP-A-6-46350 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/44-5/46 H04N 3/16-3/40 H04N 5/262-5/28

Claims (4)

(57) [Claims] An image having an aspect ratio of 4: 3.
And a non-image area below, and a horizontal
An image part is arranged, and subtitles are arranged in the non-image part or the image part.
16: 9 A
Television table to be displayed on a display screen having a spectral ratio
In the display method, the video signal of the letter box format is expanded vertically and horizontally.
To move the blank area out of the effective screen in the display screen.Distribute
Along withFill the image area with the effective screen of the display screen
ToAs parent screendisplayAnd  the aboveMain screenAnywhere insideArrangedOn the sub screenindicate
Including at least the above subtitles in the above letterbox format
Video signalBy setting the AC component at to 0,
The above sub screen is displayed in black and white with white subtitles and black background, Luminance level in the video signal of the above letter box format
Is less than the predetermined level, the background
The scene brightness level is set to 0, and the brightness level is set to a predetermined level.
When the level is equal to or higher than the
Linear according to the luminance level of the video signal
Control  A television display method, characterized in that: Wherein in response to user operation, constituting the said child screen
To by upper and or move down the frame upper portion or line corresponding to the frame lower part of the frame, the said child screen according to claim 1, characterized in that set to a size suitable for the display of the caption Television display method. (3)The brightness of the pixels in the above sub-screen is
The above sub-screen is determined by judging whether or not
Within the white subtitles described above,
On / off control of the above sub-screen  The television display method according to claim 1, wherein:
Law. 4. The television display method according to claim 1, wherein when the white subtitle is displayed on the sub-screen, an area displayed in a frame forming the sub-screen is deleted from the main screen.