JPH04318779A - Video display device - Google Patents

Abstract

PURPOSE:To receive a video image efficiently even when the aspect ratio of the video image to be displayed is changed. CONSTITUTION:Let the maximum aspect ratio among plural kinds of video images to be displayed be A:B and the minimum aspect ratio among plural kinds of video images to be displayed be C:D, then the substantial ratio of the size of a video display area in the horizontal direction to the size of the video display area in the vertical direction is selected to be (root of the product between the A and C):(root of the product between the B and D). Thus, a usual TV broadcast whose aspect ratio is 4:3 and a DHTV broadcast whose aspect ratio is 16:9 are received efficiently by a single receiver in a way that both the broadcast images are impartially watched.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a television (TV) or the like that selectively projects a plurality of types of images with different aspect ratios on an image display area such as a picture tube, a liquid crystal display panel, or a projection screen. The present invention relates to a video display device.

0002

2. Description of the Related Art Conventionally, the standard aspect ratio (horizontal size to vertical size) of images on TV has been 4:3. In addition, as the quality of playback images improves, demands for larger and wider screens are increasing, and the next generation of high-definition TVs (HDTVs) are now using an aspect ratio of 16.
:9 is the unified standard. In the field of movies, screens with various aspect ratios are used, but screens with an aspect ratio of 16:9 have become mainstream.

[0003] In order to receive a plurality of types of images having different aspect ratios, various types of image receiving apparatuses having image display areas with aspect ratios suitable for each type of image are required. but,
From the viewpoint of use and economy, it is desirable to realize a video display device that can selectively display a plurality of types of video images with different aspect ratios on a single video display area.

[0004] In the technical field of TV, the aspect ratio is 4:3.
Various systems are being considered on the premise of coexistence of the 16:9 aspect ratio and the 16:9 aspect ratio. For this reason,
The current reality for TV broadcasting is to display a movie screen with an aspect ratio of 16:9 with the left and right sides cut off, or with blank spaces left at the top and bottom.

The one shown in FIG. 5 has an aspect ratio of 16:9.
In this example, image 2 with an aspect ratio of 4:3 is displayed in image display area 1, and there are large blank spaces on the left and right sides of image 2. What is shown in FIG. 6 is an example in which a video 2 with an aspect ratio of 16:9 is displayed in a video display area 1 with an aspect ratio of 4:3, and there are large blank spaces above and below the video 2.

[0006]

[Problem to be Solved by the Invention] However, if the left and right sides of the movie screen are cut or the left and right margins are left on the top and bottom, the reproducibility of the image will not only be significantly impaired;
When displaying in a layout such as that shown in FIG.

Therefore, an object of the present invention is to provide an image display device that can selectively display a plurality of types of images having different aspect ratios on a single image display area with good reproducibility and balance. do.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention selects a plurality of types of images having different aspect ratios between the horizontal size and the vertical size in a substantially rectangular image display area. In a video display device that displays images, when the maximum aspect ratio of the plurality of types of images is A to B and the minimum aspect ratio is C to D, the horizontal size to vertical size of the video display area. (H:
Let the actual value of V) be expressed by the following formula.

[0009]

[Math 2]

0010

[Operation] With this configuration, the aspect ratio of the image display screen takes a compromise value in terms of area with respect to the aspect ratio of multiple types of images to be displayed, so each type of image can be displayed as a single image. It is possible to selectively display the image on the area efficiently and with good reproducibility.

[0011]

[Example] In the following explanation, four types of images with different aspect ratios (horizontal size to vertical size) are
They will be referred to as a video, a second video, a third video, and a fourth video, respectively, and the horizontal size versus vertical size of a rectangular video display area in which these videos are selectively displayed is expressed as H:V. However, the aspect ratio of the first video = a:b = 2:1 The aspect ratio of the second video = c:d = 16:9 The aspect ratio of the third video = e:f = 4:3 The aspect ratio of the fourth video =g:h=1:1 Here, the maximum aspect ratio is 2:1 of the first image, and the minimum aspect ratio is 1:1 of the fourth image.

In the present invention, when the maximum aspect ratio is A to B and the minimum aspect ratio is C to D among a plurality of types of images to be displayed, the horizontal size to vertical size ( The actual value of H:V)

0013
]

[Math 3]

[0014] Therefore,

[0015]

[Math 4]

[0016] The margin area ratio for each video is 1-(H/V) x (b/a)≒ for the first video.
0.2929 Regarding the second image, 1-(H/V)×(d/c)≒
0.2045 Regarding the third video: 1-(V/H)×(e/f)≒
0.0572 Regarding the 4th image: 1-(V/H)×(g/h)≒
0.2929, and its maximum value can be reduced.

The required aspect ratios for current TVs are 4:3 (=16:12=12:9) and 16:9.
It is a kind. The aspect ratio of the highly efficient video display area shared by both is determined by the above-mentioned reason.

0018
]

[Math 5]

[0019] Figures 1 and 2 show this example, and the margin area ratio for 4:3 and 16:9 images is

[0020]

[Math 6]

[0021] This is the ratio of each margin area when the aspect ratio (H:V) of the video display area is 16:9 and 4:3: 1 - (9 x 12) / (9 x 16) = 0 .251-(9×
16)/(12×16)=0.25, which is approximately 1/2.

Considering that general TV receivers normally perform overscanning of about 10%, the margin area ratio has an even smaller value, as shown in FIGS. 3 and 4.

[0023]

[Math 7]

##EQU1## Therefore, the margin area is almost negligible. The image display area of the currently most popular 29-inch color picture tube has a minimum effective display area of 540.8 x 405.6 square mm. The size of the video display surface that has the same area as this display area and can be shared by video with an aspect ratio of 16:9 and video with an aspect ratio of 4:3 is as follows: h is the long side and v is the short side.

00
25]

[Math. 8]

The size in the diagonal direction determined from this is 693 mm. This value corresponds to the diagonal size of 676 mm in a conventional 29-inch color picture tube.
It is 17mm (approximately 2.5%) larger than the .

[0027]

As described above, the video display device according to the present invention can selectively and efficiently project a plurality of types of videos with different aspect ratios onto a single video display area. Since there are no cuts on the left and right sides or large blank spaces on the top and bottom, image reproducibility is good and visual balance is improved. In particular, for two aspect ratios, 4:3 and 16:9, it is possible to make each screen the same size without placing too much emphasis on either aspect ratio, and by allowing some overscan, the image display can be improved. The area can be fully utilized.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the relationship between a video display area and a video of a video display device embodying the present invention.

FIG. 2 is a plan view showing the relationship between the video display area and the video of the video display device embodying the present invention.

[Fig. 3] A plan view showing the relationship between the video display area and the video when overscan is allowed in the device shown in Fig. 1.

[Figure 4
] A plan view showing the relationship between the video display area and the video when overscan is allowed in the device shown in FIG. 2.

[Figure 5] An aspect ratio of 4:3 is displayed in a video display area with an aspect ratio of 16:9.
Plan view when projecting an image of

[Fig. 6] Plan view when an image with an aspect ratio of 16:9 is projected on an image display area with an aspect ratio of 4:3.

[Explanation of symbols]

1 Video display area 2 Video

Claims (1)

[Claims] 1. A video display device for selectively displaying a plurality of types of images having different aspect ratios, i.e., a ratio of a horizontal size to a vertical size, in a substantially rectangular video display area, wherein the plurality of types of images have different aspect ratios. The maximum aspect ratio of
When the minimum aspect ratio is C to D, the horizontal size to vertical size of the video display area (H:V
) is expressed by the following formula. [Math 1]