JP2781386B2 - Video display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a case where an image is displayed on a display device having an aspect ratio different from that of a video image to be displayed. The present invention relates to a video display device suitable for displaying television images.

[Prior Art] An ordinary television receiver has an aspect ratio (horizontal: vertical) of a screen of 4: 3, and a fluorescent screen having a size ratio substantially equal to that of the screen is used. In contrast, in HDTV, a high-definition television system called high-definition television, this ratio is 5: 3
Alternatively, a proposal of 16: 9 has been proposed. Naturally, a television receiver having such a landscape screen is required as a receiver, but in this case, the image to be received is not only an HDTV image but also a conventional television image (aspect ratio 4). : 3) It is necessary to perform the display. For example, when an image having this ratio of 4: 3 is displayed on the phosphor screen of a receiver having a width-to-length ratio of 16: 9, the image is displayed on both ends or one side of the screen as shown in FIGS. A blank portion is not displayed. If used for a long time in such a state, the phosphor of the image display part will be degraded, or the brightness will deteriorate due to the browning phenomenon of the panel glass, and if the entire phosphor screen is used to display the HDTV screen, This results in uneven brightness. In particular, this uneven brightness is very noticeable because a step is formed on the boundary between the 4: 3 screen edge and the margin,
When an HDTV image is displayed on the entire screen, the image quality is significantly degraded.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned conventional problems, and a video display in which a difference in brightness is not conspicuous at an image end even when used for displaying a plurality of types of images having different aspect ratios. It is intended to provide a device.

[Means for Solving the Problems] In the present invention, in order to solve the above problems, when displaying an image having an aspect ratio different from the aspect ratio of the display surface of the device on the display surface of the device, A pattern that changes with time or moves within the blank portion in a blank portion where no image is displayed is displayed in a color having a brightness similar to the average brightness of the image and a low saturation.

[Operation] When a normal display device is used, not limited to the cathode ray tube, it is inevitable that a deterioration in members related to image display causes a decrease in luminance or a change in display color at a place where the device is used for a long time. . In the present invention, as described above, the entire display surface of the display device is used as uniformly as possible, and occurs at the boundary between image display units having different aspect ratios due to the difference in display time.
Brightness and color differences that are unavoidable are eliminated.

When illuminating a portion that does not display an image that is the original observation target, that is, a blank portion, from the basic idea of the present invention, it is possible to illuminate uniformly at the same brightness as the average luminance of the main screen, that is, glow in gray. Although preferable, it is acceptable to add a little color or to display a pattern having a relatively low contrast. If a color close to the primary color is displayed, the degree of luminance degradation differs for each phosphor, which also causes a kind of burning phenomenon. Therefore, when a color other than gray is used, a color with low saturation is preferable. . When displaying a pattern, it is desirable to change the pattern with time or to move the pattern on the screen so that the pattern is not burned.

[Embodiment] In order to specifically perform gray display or other image display in a blank portion, it is necessary to interpolate a signal in the blank portion in addition to the received raster signal. This interpolation can be performed by preparing a line memory or a frame memory. For example, an EDTV or an HDTV usually has a built-in frame memory, so that it can be used as it is. The basic technology of image interpolation is exactly the same as the one that is currently in practical use, such as displaying a sub-screen of another channel in the main screen or displaying a channel on a normal screen, etc. Technology can be applied.

As the image to be displayed in the margin according to the present invention, as described above, channel display and other information display,
Alternatively, a small screen of a television can be displayed. However, it is not preferable to display a specific image for a long time from the viewpoint of screen burning as described above. Therefore, for example, a channel display is not always displayed, but is displayed only when necessary. Consideration such as returning to gray display is necessary.

The above description has been made mainly on the case of displaying a 16: 9 screen and a 4: 3 screen on a television receiver, but the aspect ratio may be any other one, and the application is also for a television. It is needless to say that the present invention can be applied to various purposes such as general display, industrial use, monitoring use, and the like, without being limited thereto.

[Effects of the Invention] As described above, according to the present invention, an image having an aspect ratio different from that of the display surface of a device is displayed for a long time, and then an image having the same aspect ratio as the display surface of the device is displayed. In this case, the difference in luminance and color at the boundary of the previous image display portion does not occur, and a high-quality image can be observed.

[Brief description of the drawings]

 1 to 3 are explanatory diagrams of a blank portion.

Claims (1)

(57) [Claims] When displaying an image having an aspect ratio different from the aspect ratio of a display surface of an apparatus on the display surface, the image is temporally changed to a blank portion where no image is displayed on the display surface. Alternatively, the video display device is characterized in that a pattern moving in the margin is displayed in a color having a luminance substantially equal to the average luminance of the image and a low saturation.