JPH02231876A - Television receiver - Google Patents

Abstract

PURPOSE:To move a video to an arbitrary position in a vertical direction on a screen by delaying a video signal or a vertical synchronizing signal only for an arbitrary time in a receiver, for which the aspect radio of the screen is made larger than 4:3 and deviating the phases of the video signal or the vertical synchronizing signal. CONSTITUTION:A monostable multivibrator 61 detects the rise of a vertical synchronizing signal VSO and makes an output VS2 rise after the lapse of a time gamma1. The above-mentioned vibrator 62 detects the rise of the VS2 and stops an output VS1 after the lapse of a time gamma2. The time constant of the vibrator 62 is adjusted so that the time gamma2 can be the width of a vertical synchronizing pulse. When the video is deviated upward on the screen, namely, even when the video signal is advanced by a time gamma to the vertical synchronizing signal, the vertical synchronizing signal is delayed for the time gamma1=(a/60sec+gamma). Thus, the desired video can be adjusted by a variable delay circuit 6 so as to be between optical pathes 81 and 85.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a television receiver, and in particular, the screen aspect ratio, which is suitable for playing back horizontally long images such as cinemascope-sized video software, is changed from the conventional one. It concerns a television receiver that is larger than the original.

[Conventional technology]

While the aspect ratio of the screen of current television receivers is 4:3 (=1.33:1), the aspect ratio of CinemaScope movies is 2.
The aspect ratio of VistaVision is 1.35:1.
85:1 is 9, and the aspect ratio of high-definition is 16:9 (=1.67=1).

There are two methods to convert these horizontally long screens into images for current televisions with an aspect ratio of 4:3.

(Manpo 1) As shown in Figure 2 (a), match the vertical size of the original video and the television screen, and cut the right and left parts of the original video.

(Manpo 2) As shown in Figure 2 (b), match the horizontal size of the original video and the television screen.

On the screen, a horizontally long image is projected in the center, and areas without images are displayed above and below. If necessary, subtitles may be added below the video.

This method (method 2) has the advantage of being able to transfer the original video to the television screen without cutting it, but it is also possible to convert a CinemaScope size movie to a videotape or video disc for general television. In so-called cinemascope-sized video software, the areas with no images at the top and bottom account for about 40% of the entire television screen.

As a countermeasure to this problem, as shown in FIG. 2 (Q), the screen can be used effectively by increasing the aspect ratio of the television screen and preventing portions without images from being displayed on the screen. Particularly in projection televisions in which images projected on a cathode ray tube are enlarged and projected onto a screen, the aspect ratio of the screen can be easily increased by changing the screen.

FIG. 6 shows an example of the external shape of a television receiver with a large screen aspect ratio. In Figure 3, (a),
(a') is a direct-view television, which is a system in which you can view the screen directly on a cathode ray tube; (b) . (b') is a rear projection television in which the image on the cathode ray tube is enlarged with a lens and projected from the back of the screen, and (c) is a front projection television in which the image is similarly projected from the front of the screen. This is an example of increasing the aspect ratio.

A device related to the above-mentioned television receiver is described in Japanese Patent Publication No. 62-2752. In this previously proposed example, the screen of a projection television is made horizontally elongated by displaying an overscan image in the horizontal direction and blanking in the vertical direction.

[Problem to be solved by the invention]

By adjusting the aspect ratio of the screen of the television receiver as described above, the following effects can be obtained.

([Effect 1]) By increasing the aspect ratio of the screen of a television receiver, when displaying horizontally long images such as cinemascope-sized video software, it is possible to reduce the proportion of the non-image area that is reflected on the screen. , the screen can be used effectively. In particular, projection television
By changing the screen, you can freely choose the aspect ratio of the screen.

(Effect 2) By setting the aspect ratio of the screen of the television receiver to 16:9, it is possible to convert the no-vision video to a general television video using a down converter or the like.

However, in realizing these, two problems arise. Below, we will discuss the problems with a rear projection television as an example.

(1) The first problem will be explained with reference to FIG.

Cinemascope size video software is originally intended to be displayed on a screen with an aspect ratio of 4:3.
The vertical position of the video part varies depending on the video software. Therefore, if an attempt is made to display the image on a screen with a large aspect ratio, the image may not be displayed on the screen as shown in FIG.

(2) The second problem will be explained with reference to FIG.

FIG. 5 is a diagram showing a general television image displayed on a screen with a large aspect ratio. 51 to 54 in the figure indicate the original path of light emitted in brown color. Since the aspect ratio of the image to be displayed is smaller than the aspect ratio of the screen on which it is displayed, light from the image also shines outside the screen. Of these, the light between 52 and 56 is projected onto the screen, but the light between 51 and 52 and the light between 53 and 54 is unnecessary light that is not projected onto the screen and is diffusely reflected inside the cabinet. and deteriorate the contrast of the screen. Furthermore, when displaying an image with a small aspect ratio in a front projection television, contrast deterioration similarly occurs. Furthermore, when displaying images with a small aspect ratio on a direct-view television,
Cathode rays are also irradiated to areas of the cathode ray tube that are not coated with phosphor, raising the temperature of those areas, which may eventually lead to damage to the cathode ray tube.

An object of the present invention is to solve the above two problems and achieve the two effects described above in a television with a large screen aspect ratio.

[Means to solve the problem]

Means for solving the above two problems will be described below.

(1) A means for solving the first problem will be explained with reference to FIG. FIG. 6(a) is an example of a timing chart of a video signal after synchronization separation and a vertical synchronization signal of cinema scope size video software.

Here, ■ is a vertical retrace period, ■ is a video portion, ■ is a subtitle portion, and ■ and V are portions without video. Hereinafter, two cases will be described: a case where the video portion and subtitle portion of the video software shown in FIG. 6(a) are transferred to a 16:9 screen, and a case where only the video portion is transferred.

When displaying the video portion and the subtitle portion on the screen, the phases of the video signal and the vertical synchronization signal are shifted as shown in FIG. 6(b).

In reality, this can be achieved by using a monostable multivibrator or the like and delaying the vertical synchronization signal by [lL3msθC. When only the video portion is displayed on the screen, the phases of the video signal and the vertical synchronization signal are shifted as shown in FIG. 6(a), and the subtitle portion is blanked. The blanking method will be described later. To shift the phase as shown in FIG. 6(C), the video signal is shifted by 0. It is sufficient to delay the video signal by 2 msec, but the circuit for delaying the video signal is expensive. To implement this at low cost, the video signal should be set to 0. Instead of delaying by 2 msec, the vertical synchronization signal (1760 sec -
0.2 msec), a roughly equivalent effect can be obtained. 1/60sθC is the time for one field. Delaying the vertical synchronization signal can be easily achieved using a monostable multiviprator, but in NTSC signals, the odd and even fields are shifted by half a horizontal period, which can cause the screen to flicker up and down. To prevent this, the vertical synchronization signal may be delayed by generating a clock pulse of 1/2 horizontal period and using a counter to count the clock pulse.

As mentioned above, the first problem can be solved by delaying the vertical synchronization signal, but this delay time differs depending on the video software and also differs depending on whether subtitles are displayed or not. It is necessary to be able to change it to .

(2) Means for solving the second problem will be explained with reference to FIG. FIG. 7(a) is an example of a timing chart of a general video signal with an aspect ratio of 4:3 and a vertical synchronization signal. If this is displayed on a screen with an aspect ratio of 16:9, the portions marked ■ and ■ will protrude from the screen, resulting in deterioration of contrast in projection televisions and damage to the cathode ray tube in direct view televisions.

In order to prevent this, a blanking pulse is generated so that no light is emitted in the portions marked with ■ and ■, as shown in FIG. 7(b). Blanking is performed by applying this blanking signal to the cathode ray tube, or by multiplying the bride video signal and the blanking signal (as in factor 7 (b)). Note that the blanking width can be made variable in case the screen size is changed or if subtitles are not displayed as mentioned above.

[Effect]

By using the above two means 9, the following effects can be obtained.

(1) The vertical position where the image is displayed is determined by the current value of the vertical deflection current, and since the vertical deflection current is synchronized with the vertical synchronization signal, the first method, vertical synchronization By providing a function to shift the phase of the signal and video signal, the video can be moved up and down.

(2) The second method is to adjust the pulse width of the vertical blanking pulse according to the screen size.
By setting the video signal of the part not displayed on the screen to a black level, it is possible to prevent the generation of unnecessary sources that are not projected on the screen or the irradiation of cathode rays to the part where the phosphor of the cathode ray tube is not coated.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

81J (a) is a front view showing the external shape of a television receiver as an embodiment of the present invention, and FIG. 8(b) is a sectional view taken along the line A-A' in FIG. 8Ca).

The television receiver shown in FIG. 8 is a projection type television, and its screen aspect ratio is 16:9.
This makes it possible to make effective use of the screen when transmitting software that converts high-definition video to regular TV video or cinemascope-sized video software that has a wide subtitle area. 81 and 82 in FIG. 8(b) indicate the optical paths of light emitted from the cathode ray tube, and the light between the optical paths 81 and 82 is projected onto the screen.

11N(a) is a block diagram showing the main parts of a television receiver as an embodiment of the present invention, FIG. 1(b) is a waveform diagram showing the waveforms of the main part signals of FIG. 1(.), It is.

In FIG. 1(a), 6 is a variable delay circuit, and 7 is a blanking pulse generation circuit. In addition, vSO is the video signal before correction, VSO is the vertical synchronization signal before correction, VI1
is a corrected video signal, and VS1 is a corrected vertical synchronization signal.

First, the operation of variable delay circuit B will be explained.

In cinemascope-sized video software, the center of the image part is often shifted upwards from the center of the screen, so by delaying the phase of the video signal with respect to the vertical synchronization signal, the image is moved downwards on the screen.

The variable delay circuit 6 is a circuit that delays the vertical synchronization signal.

Here, the time delayed by the variable delay circuit 6 is defined as time τ1. For example, delay by one field. That is, when τ, = 1760 sec, the phase relationship between the video signal and the vertical synchronization signal hardly changes.

Also, if you delay the time a little shorter than the time for one field, that is, if the time τ is set to 0 - τ (1/120 seo, τ, = (1/60 sec - τ)), the phase of the vertical synchronization signal will be different from the video signal. The variable delay circuit 6 converts the vertical synchronizing signal to τ, = (1 76 0 sec
By delaying the video signal by a time τ, an effect equivalent to delaying the video signal by a time τ with respect to the vertical synchronization signal can be obtained.

The detailed configuration and operation will be described below.

61 is a monostable multiviprator with variable time constant;
62 is a monostable multivibrator.

The monostable multivibrator 61 detects the rising edge of the vertical synchronizing signal VSO, and causes the output VS2 to rise after a time τ. Moreover, the monostable multiviprator 62 is VS
The rising edge 9 of 2 is detected, and the K output VS1 is caused to fall after a time τ2. Note that here, the time constant of the κ multivibrator 620 is adjusted so that the time τ2 becomes the width of the vertical synchronization pulse.

This allows the vertical synchronization signal vSO to change over time (1/60 se
c-τ) A delayed signal VS1 can be generated.

When shifting the image upwards on the screen, that is, when advancing the video signal by a time τ relative to the vertical synchronization signal, the vertical synchronization signal can be delayed by a time τ, = (176 0 sec + τ), or simply delayed by a time τ. It can be realized easily. Note that, since the optimum value of the amount by which the image is moved differs depending on the video software, the time constant τ of the monostable multiviprator 610 can be varied by using a polymer or the like.

In the manner described above, the variable delay circuit 6 can adjust the desired image so that it is located between the original paths 81 and 82 shown in FIG. 8(b).

Next, the operation of the blanking pulse generation circuit 7 will be explained.

The blanking pulse generation circuit 7 is a circuit that generates blanking pulses matched to the vertical size of the screen before and after the vertical synchronization signal, and is composed of monostable multivibrators 71 and 72 with variable time constants.

The monostable multivibrator 71 detects the rising edge 9 of the corrected vertical synchronization signal vsi, and outputs BL2 after time T.
'i stand down. This falling point 9 is the end of the blanking pulse. The monostable multiviprator 72 is B
The falling of L2 is detected, and the output BL3 is caused to fall after a rising time τ4. This fall is 9
is the beginning of the blanking pulse (9). The time T is the Plankink width. By multiplying the blanking pulse BL3 thus created with the video signal VIO, a blanked video signal VI1 is generated. Note that in order to change the pulse width in accordance with the screen size, the time constant τ3 of the monostable multivibrator 71 and the time constant τ4 of the monostable multivibrator 72 are made variable by adjusting the volume or the like. As described above, the blanking pulse generation circuit 7 can prevent light from being emitted outside the original paths 81 and 82.

The above embodiments can be realized with a simple circuit at low cost, but lack stability.

Next, another embodiment of the present invention will be described using FIG. 9.

FIG. 9(a) is a block diagram showing the main parts of a television receiver as another embodiment of the present invention, and FIG. 9(b) is a waveform showing the waveform of the main part signal of FIG. 9(a). Figure.

In FIG. 9(a), 8 is a variable delay circuit, and 9 is a blanking pulse generation circuit. Also, 81, 82.
91. 92 is a counter, and clock pulse PA1
count. FAI has a period that is half the horizontal period. 86 and 93 are flip-flops.

First, the operation of the variable delay circuit 8 will be explained.

Here, the explanation will be given assuming that the image is moved upward by n horizontal scanning lines. In this case, the vertical synchronization signal may be advanced by n horizontal periods with respect to the video signal.

Here, the vertical synchronization signal vso
'(525-
By delaying the signal by 2×n), an effect equivalent to advancing the vertical synchronizing signal by n times with respect to the video signal can be obtained.

The detailed operation will be described below.

The counter 81 detects the rising edge of the vertical synchronizing signal vSO, then counts (525-2×n) pulses PA1, and then raises the output VSA.

The counter 82 detects the rising edge 9 of VS3, then counts m pulses FAI, and then raises the output vS4. The flip-flop 83 inputs vS6 and VS4, detects the rise of VS3 and raises the output VS1, and detects the rise of VS4 and lowers the output vsi. By adjusting m so that the m/2 horizontal period is equal to the pulse width of the vertical synchronizing signal, the vertical synchronizing signal v
It is possible to create a signal vS1 that is advanced by 1,000 cycles of sot-n water. It is assumed that the counter amount of the counter 81 is variable so that the amount of image shift can be adjusted using video software.

Next, the blanking pulse generation circuit 9 will be explained.

The blanking pulse generation circuit 9 operates in the same manner as the variable delay circuit 8, so that the output rises after t/2 horizontal periods of the input signal vS1, and further falls after k/2 1,000 periods of the rising 9. Make BL3. Note that by making the count amounts t and k variable and adjusting them, it is possible to obtain the blanking pulse BL3 that corresponds to the screen size.

In this embodiment, by using pulses with a 1/2 horizontal period, stable operation can be achieved in both odd and even fields.

Next, another embodiment of the present invention will be described using FIG. 10.

FIG. 10(a) is a block diagram showing the main parts of a television receiver as another embodiment of the present invention, FIG. 10(b)
is a waveform factor indicating the waveform of the main signal in FIG. 10(a).

In FIG. 10(a), 10 is a variable delay circuit consisting of an image memory.

The video signal VIO is input to the variable delay circuit 10 and output with a delay of n horizontal periods. This allows the image to be moved downward by n horizontal scanning lines.

The above description has been made using a projection television as an example, but it goes without saying that the same implementation can be applied to a direct-view television.

〔Effect of the invention〕

According to the present invention, by moving the image in the vertical direction of the screen,
Since it can be set at the optimal position, the video can be displayed on the screen no matter what cinemascope size video software is played back.

Furthermore, according to the present invention, images that protrude from the screen can be blanked using blanking pulses, thereby preventing contrast deterioration in projection televisions and damage to the cathode ray tube in direct-view televisions. can do.

As described above, even if the aspect ratio of the screen is increased, no problem occurs, and therefore, the screen can be used effectively.

[Brief explanation of the drawing]

FIG. 1(a) is a block diagram showing the main parts of a television receiver as an embodiment of the present invention, and the first factor (b) is the first factor.
Waveform diagram showing the waveforms of the main signals in Figure (a), Figure 2 (a)
- (Q) are explanatory diagrams showing display examples when images by video software are displayed on the screen of a television receiver, respectively;
FIG. 3(a) is a front view showing the external shape of a direct-view television with a large screen aspect ratio, FIG. b) is a front view showing the external shape of a rear projection television with a large screen aspect ratio, FIG. 3(b') is a cross-sectional view in the B-B' direction of FIG. ) is a perspective view showing the external shape of a front projection television with a large screen aspect ratio, FIGS. 4(a) and (b) are explanatory diagrams for explaining the first problem in the conventional method, and FIG. 5 is an explanatory diagram for explaining the second problem in the conventional method, and FIG.
) to (Q) and FIGS. 7(a) and (b) are explanatory diagrams for explaining the operating principle of the present invention, and FIG. 8(a), respectively.
8(b) is a front view showing the external shape of a television receiver as an embodiment of the present invention, and FIG. 8(b) is A- in FIG. 8(a).
A sectional view in the direction A', FIG. 9(a) is a block diagram showing the main parts of a television receiver as another embodiment of the present invention,
FIG. 9(b) is a waveform diagram showing the waveform of the main part signal of FIG. 9(a), and FIG. 10(a) is a block diagram showing the main part of a television receiver as another embodiment of the present invention. 10(b) is a waveform diagram showing the waveforms of the main signals in FIG. 10(a). Explanation of symbols 6, 7.10...Variable delay circuit, 7, 9...
...Blanking pulse generation circuit. mmi heart N ~. i-Nura 4 Mori Utsu Engineering Procedure Amendment (Relationship with the case of the person making the amendment) Patent applicant Name (510) Co., Ltd. 1 Hitachi Manufactured by Shiroi Meijin 100 Marunouchi, Chiyoda-ku, Tokyo 5-1 Hitachi, Ltd. Telephone: East 1.2 + 2-1111 (main representative) (6850) ``Physical Engineer Ogawa''
Date of Katsuo amendment order: May 30, 1999
Date (shipment date) Subject of amendment Column 1 for brief explanation of drawings in the specification. From page 20, line 17 to page 21, line 5 of the specification
[Figure 3(a) is a front view showing the external shape of a direct-view television with a large screen aspect ratio, and Figure 6(a') is a view taken along the line AA' in Figure 3(a). 6(b) is a front view showing the external shape of a rear projection television with a large aspect ratio of the image αI, and FIG. 6(b') is a cross-sectional view taken along line BB' in FIG. 3(C) is a perspective view showing the external shape of a front projection television with a large screen aspect ratio." is corrected as follows. [Figure 6 (a) is a front view showing the external form of a direct-view television with a large screen aspect ratio, Figure 3 (a2) is a Figure 6 (b1) is a front view showing the external shape of a rear projection television with a large screen aspect ratio, and Figure 3 (b2) is
), B-B' Manko Danjizu, Figure 6 (C) is a perspective view showing the external appearance of a front projection television with a thicker screen aspect ratio. to correct. (In order to delete the dasochy symbols in Figure 3 (α) and Figure 3 (薯′), Figure 6 (α) is changed to Figure 3 (α1), Figure 3 (tL') is changed to Figure 3 ( α2), Figure 3 (season is Figure 6 (wa), Figure 3 ('') is Figure 3 (薯2), Figure 6 (C
) are not corrected. ) More than that (α1冫(α?) A-A'hoshunl!IT Menyun〈b1) (b2)

Claims (1)

[Claims] 1. A television receiver in which the horizontal-to-vertical ratio of the screen is greater than 4:3, and a video obtained by the video signal is displayed on the screen based on a vertical synchronization signal separated from the video signal. In the machine, by providing a variable delay means capable of delaying the video signal or the vertical synchronization signal by an arbitrary amount of time, and shifting the phase of the video signal and the vertical synchronization signal,
A television receiver characterized in that a video obtained by the video signal can be moved to any vertical position on the screen. 2. The television receiver according to claim 1, wherein the variable delay means includes a first means for generating clock pulses having a horizontal period of 1/2 in synchronization with the video signal, and a first means for counting the clock pulses. A television receiver comprising at least a second means for delaying the vertical synchronization signal by an arbitrary amount of time. 3. The television receiver according to claim 1 or 2, further comprising blanking signal generating means for generating a vertical blanking signal of a vertical period having an arbitrary blanking period based on the vertical synchronization signal, By multiplying the video signal by a vertical blanking signal or by driving a display means by the vertical blanking signal, only a desired portion of the video obtained by the video signal is displayed on the screen. A television receiver featuring: 4. The television receiver according to claim 3, wherein the blanking signal generating means includes means for generating clock pulses having a horizontal period of 1/2 in synchronization with the video signal, and means for counting the clock pulses. What is claimed is: 1. A television receiver comprising at least the following: a vertical period pulse signal having an arbitrary pulse width indicating a blanking period is generated from the vertical synchronization signal as the vertical blanking signal.