TW201443858A - Multimedia display having increased contrast and reduced power consumption of backlight - Google Patents

Abstract

A multimedia display is provided with including a display panel and a direct-lit backlight module having individually controllable light-emitting elements. When an image having black bars is displayed on the display panel, the multimedia display may control at least one of the light-emitting elements corresponding to the black bars to turn off or reduce brightness, and therefore may increase image contrast and reduce power consumption of the direct-lit backlight module.

Description

Multimedia display that improves contrast and reduces backlight power consumption

The present invention relates to a multimedia display, and more particularly to a multimedia display using a direct-lit backlight module.

Please refer to FIG. 1, which is a schematic diagram of several pictures with black borders. When the original image is different from the aspect ratio of the display screen, if the original image with the original aspect ratio is displayed on the screen, black bars will appear on the screen. Or, when the original image has a different aspect ratio from the converted target image, if the original image with the original aspect ratio is included in the target image, black edges will be generated in the converted target image.

The first case, as shown in (a) of Figure 1, occurs, for example, when the aspect ratio of the original image (e.g., 16:9 ≒ 1.78) is greater than the aspect ratio of the screen (e.g., 4:3 ≒ 1.33). At this time, the screen 11 displayed on the screen displays an image corresponding to the original image, and the undisplayed area 11b is displayed on the upper and lower sides of the normal display area 11a, because the undisplayed area 11b is black (here The network cable indicates black), so it is called black bars. The case where the black border appears on the top and bottom of the screen is called Letterboxing, and the screen with the upper and lower black borders is called the Letterboxed screen.

The second case, as shown in (b) of Figure 1, occurs, for example, when the aspect ratio of the original image (e.g., 3:4 = 0.75) is less than the aspect ratio of the screen (e.g., 4:3 ≒ 1.33). At this time, the screen 12 displayed on the screen displays the black image of the undisplayed area 12b on the left and right sides of the normal display area 12a except that the normal display area 12a displays an image corresponding to the original image. The situation where black borders appear on the left and right sides of the screen is called Pillarboxing, and the screen with left and right black borders is called Pillarboxed.

In the third case, as shown in (c) of FIG. 1, for example, an original image having an aspect ratio of 4:3 is processed into a 16:9 aspect ratio image by the Pillarbox method, and then processed into a width and height by a Letterbox method. When compared to 4:3 images. At this time, the screen 13 displayed on the screen displays the black image of the undisplayed area 13b on the upper, lower, left, and right sides of the normal display area 13a except that the normal display area 13a displays an image corresponding to the original image. A black border on the top and bottom of the screen or a black frame on the screen is called Windowboxing, and a screen with black bars on the top, bottom, left, and right sides or a frame with a black frame is called a Windowboxed screen or a black frame.

Please refer to FIG. 2 , which is a schematic diagram of a conventional multimedia display using a direct type backlight module. The multimedia display includes a display panel 1 and a direct type backlight module 2, wherein the display panel 1 is used for displaying an image screen, and the direct type backlight module 2 is disposed behind the display panel 1 for providing a display screen of the display panel 1. Backlighting. The direct-lit backlight module 2 includes a plurality of light-emitting diodes (LED) lightbars 20, and each of the LED strips 20 is provided with a plurality of LEDs (not shown) coupled in series. . These LED strips 20 are driven in parallel to provide the same operating current to each other to provide the same brightness to provide a uniform brightness backlight.

The multimedia display controls the LED strips 20 to be illuminated together when the display panel 1 displays a screen to provide the desired backlight, and controls the LED strips 20 to be turned off and not illuminated when the screen is not displayed. Therefore, whether the display panel 1 is a full-screen display image or a screen 11 with a black border, the LEDs in the direct-lit backlight module 2 are displayed as shown in FIG. The light bar 20 is illuminated and illuminated, so the direct type backlight module 2 has no influence on the contrast between different screens, and the power consumption of the direct type backlight module 2 is the same.

In view of this, the object of the present invention is to provide a multimedia display using a direct type backlight module, which can improve the picture contrast and reduce the power consumption of the direct type backlight module when displaying a picture with a black border.

To achieve the above and other objects, the present invention provides a multimedia display including a display panel and a direct type backlight module, wherein the direct type backlight module includes a plurality of independently controlled light emitting elements. When the display panel displays a picture with a black border, the multimedia display can control at least one of the light-emitting elements corresponding to the black edge in the direct-lit backlight module to not emit light or reduce the brightness of the light.

In an embodiment, when the display panel displays a screen with a black border, the multimedia display can control that all of the light-emitting elements corresponding to the black border in the direct-lit backlight module do not emit light.

In an embodiment, when the display panel displays a screen with a black border, the multimedia display can control all of the light-emitting elements corresponding to the black border in the direct-lit backlight module to reduce the brightness of the light.

In an embodiment, when the display panel displays a screen with a black border, the display panel can control at least one of the light-emitting elements corresponding to the black border in the direct-lit backlight module to emit no light and at least one of the light-emitting elements is lowered. Luminous brightness.

In an embodiment, the multimedia display can be a liquid crystal display. The light-emitting elements in the direct-lit backlight module can be LED strips or cold cathode fluorescent lamps (CCFLs).

The invention controls at least one of the illuminating elements corresponding to the black rim in the direct type backlight module to display no light or reduce the illuminating brightness when the screen with the black border is displayed, thereby improving the screen contrast and reducing the direct type backlight. The power consumption of the module.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

1. . . Display panel

11, 12, 13. . . Picture with black border

11a, 12a, 13a. . . Normal display area

11b, 12b, 13b. . . Area not shown

2, 3. . . Direct type backlight module

20, 30. . . LED strip

Figure 1 is a schematic diagram of several pictures with black borders.
2 is a schematic diagram of a conventional multimedia display using a direct type backlight module.
3 is a schematic diagram of a multimedia display using a direct type backlight module according to an embodiment of the invention.
4 is a schematic diagram of a plurality of direct type backlight module control modes of the multimedia display shown in FIG. 3 when displaying a screen with upper and lower black edges.
FIG. 5 is a schematic diagram of a plurality of direct type backlight module control modes when the multimedia display shown in FIG. 3 displays a screen with left and right black edges.
6 is a schematic diagram of a plurality of direct type backlight module control modes of the multimedia display shown in FIG. 3 when displaying a screen with upper, lower, left, and right black edges or with a black frame.

Please refer to FIG. 3 , which is a schematic diagram of a multimedia display using a direct type backlight module according to an embodiment of the invention. The multimedia display of the present invention is, for example, a liquid crystal display, which includes a display panel 1 and a direct type backlight module 3, wherein the display panel 1 is used for displaying an image screen, and the direct type backlight module 3 is disposed behind the display panel 1 for providing The backlight required for the display panel 1 to display the screen. The direct-lit backlight module 3 includes a plurality of independently controlled light-emitting elements 30. In the present embodiment, the light-emitting elements 30 are LED strips, and each of the LED strips 30 is provided with a plurality of LEDs coupled in series. (not shown). However, the present embodiment is not intended to limit the present invention. For example, these light-emitting elements may also be CCFLs. When the display panel 1 displays the screen 11, 12 or 13 with a black border as shown in FIG. 1, it can control at least one LED strip in the LED strip corresponding to the black edge in the direct type backlight module 3 Illuminating or reducing the brightness of the light, so that the original image displayed in the normal display area 11a, 12a or 13a of the picture is not disturbed by the non-use light source corresponding to the undisplayed area 11b, 12b or 13b, thereby improving the contrast of the picture, in addition The power consumption of the direct type backlight module 3 can be reduced.

Please refer to FIG. 4 , which is a schematic diagram of the control mode of several direct type backlight modules 3 when the multimedia display shown in FIG. 3 displays the screen 11 with the upper and lower black edges as shown in FIG. 1 . As shown in FIG. 4( a ), when the screen 11 with the upper and lower black edges as shown in FIG. 1 is displayed, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 (ie, All of the LED strips 30) corresponding to the undisplayed area 11b of the screen 11 do not emit light, and the LED strips that are filled with the internal line are indicated here as LED strips that do not emit light. In addition, the remaining LED strips 30 in the direct type backlight module 3 (ie, all the LED strips 30 corresponding to the normal display area 11a of the screen 11) are of course normal illumination, and here the internal blank LED strips A LED strip that indicates normal illumination.

As shown in FIG. 4(b), when the screen 11 with the upper and lower black edges as shown in FIG. 1 is displayed, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 (ie, All of the LED strips 30) corresponding to the undisplayed area 11b of the screen 11 reduce the luminance of the light, and the LED strips which are internally filled with dots represent the LED strips which reduce the luminance. In addition, the remaining LED strips 30 (i.e., all of the LED strips 30 corresponding to the normal display area 11a of the screen 11) in the direct type backlight module 3 are of course normal illumination.

As shown in (c) and (d) of FIG. 4, when the screen 11 with the upper and lower black edges as shown in FIG. 1 is displayed, the multimedia display can control the LED strip corresponding to the black border in the direct type backlight module 3. Of the 30 (i.e., all of the LED strips 30 corresponding to the undisplayed area 11b of the screen 11), part of the LED strips 30 do not emit light, and the remaining LED strips 30 still emit light normally. In addition, the remaining LED strips 30 (i.e., all of the LED strips 30 corresponding to the normal display area 11a of the screen 11) in the direct type backlight module 3 are of course normal illumination.

As shown in FIG. 4(e), when the screen 11 with the upper and lower black edges as shown in FIG. 1 is displayed, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 (ie, Of all the LED strips 30) corresponding to the undisplayed area 11b of the screen 11, some of the LED strips 30 do not emit light, and the remaining LED strips 30 reduce the luminance. In addition, the remaining LED strips 30 (i.e., all of the LED strips 30 corresponding to the normal display area 11a of the screen 11) in the direct type backlight module 3 are of course normal illumination.

As shown in FIG. 4(f), when the screen 11 with the upper and lower black edges as shown in FIG. 1 is displayed, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 (ie, Among all the LED strips 30) corresponding to the undisplayed area 11b of the screen 11, some of the LED strips 30 do not emit light, and some of the LED strips 30 reduce the luminance, and the remaining LED strips 30 still emit light normally. In addition, the remaining LED strips 30 (i.e., all of the LED strips 30 corresponding to the normal display area 11a of the screen 11) in the direct type backlight module 3 are of course normal illumination.

Please refer to FIG. 5 , which is a schematic diagram of the control mode of several direct type backlight modules 3 when the multimedia display shown in FIG. 3 displays the screen 12 with left and right black edges as shown in FIG. 1 . When the screen 12 with left and right black edges as shown in FIG. 1 is displayed, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 as shown in FIG. 5(a) (ie, All of the LED strips 30) corresponding to the undisplayed area 12b of the screen 12 do not emit light. Alternatively, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 (ie, all the LED light bars 30 corresponding to the undisplayed area 12b of the screen 12) as shown in FIG. 5(b). In the middle, part of the LED light bar 30 does not emit light, and the remaining LED light bar 30 still emits light normally. Alternatively, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 (ie, all the LED light bars 30 corresponding to the undisplayed area 12b of the screen 12) as shown in FIG. 5(c). In the middle, part of the LED strips 30 do not emit light, and some of the LED strips 30 reduce the brightness of the light, and the remaining LED strips 30 still emit light normally. In addition, the remaining LED strips 30 in the direct type backlight module 3 (i.e., all of the LED strips 30 corresponding to the normal display area 12a of the screen 12) are of course normal illumination.

Please refer to FIG. 6 , which is a schematic diagram of the control mode of the plurality of direct type backlight modules 3 when the multimedia display shown in FIG. 3 displays the screen 13 with the upper, lower, left and right black edges or the black frame as shown in FIG. 1 . When the screen 13 with a black frame as shown in FIG. 1 is displayed, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 as shown in FIG. 6(a) (ie, with the screen). All of the LED strips 30) corresponding to the undisplayed area 13b of 13 are not illuminated. Alternatively, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 (ie, all the LED light bars 30 corresponding to the undisplayed area 13b of the screen 13) as shown in FIG. 6(b). In the middle, part of the LED light bar 30 does not emit light, and the remaining LED light bar 30 still emits light normally. Alternatively, the multimedia display can control the LED light bar 30 corresponding to the black edge in the direct type backlight module 3 (ie, all the LED light bars 30 corresponding to the undisplayed area 13b of the screen 13 as shown in FIG. 6(c). In the middle, part of the LED strips 30 do not emit light, and some of the LED strips 30 reduce the brightness of the light, and the remaining LED strips 30 still emit light normally. In addition, the remaining LED strips 30 (i.e., all of the LED strips 30 corresponding to the normal display area 13a of the screen 13) in the direct type backlight module 3 are of course normal illumination.

In summary, the present invention controls at least one of the light-emitting elements corresponding to the black side in the direct-lit backlight module to display no light or reduce the light-emitting brightness when displaying the image with the black border, thereby improving the screen contrast. And reduce the power consumption of the direct type backlight module.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

12a. . . Normal display area

12b. . . Area not shown

3. . . Direct type backlight module

30. . . LED strip

Claims (7)

A multimedia display includes a display panel and a direct-lit backlight module. The direct-lit backlight module includes a plurality of independently controlled light-emitting elements. The multimedia display controls the display panel when displaying a black-edged screen. In the direct type backlight module, at least one of the light emitting elements corresponding to the black side does not emit light or reduces the light emitting brightness. The multimedia display of claim 1, wherein the multimedia display controls all of the light-emitting elements corresponding to the black border in the direct-type backlight module when the display panel displays the black-edged screen Glowing. The multimedia display of claim 1, wherein the multimedia display controls the light-emitting elements corresponding to the black edges in the direct-type backlight module to be reduced when the display panel displays the black-edged screen. Luminous brightness. The multimedia display of claim 1, wherein the multimedia display controls at least one of the light-emitting elements corresponding to the black edge in the direct-type backlight module when the display panel displays the black-edged screen A light-emitting element does not emit light and at least one light-emitting element reduces light-emitting brightness The multimedia display of claim 1, wherein the multimedia display is a liquid crystal display. The multimedia display of claim 1, wherein the light-emitting elements are light-emitting diode light strips. The multimedia display of claim 1, wherein the light emitting elements are cold cathode fluorescent tubes.