Display device with different element densities and direct-type backlight thereof

A display device and a direct-type backlight thereof are provided. The direct-type backlight includes a central area and a peripheral area. The central area is configured with a plurality of central area light-emitting elements to provide light to a liquid crystal display (LCD) panel. The density of these central area light-emitting elements in the central area is a first density. The peripheral area is configured with a plurality of peripheral area light-emitting elements to provide light to the LCD panel. The density of the peripheral area light-emitting elements in the peripheral area is a second density. Wherein, the second density is less than the first density.

BACKGROUND

Technical Field

The invention relates to a liquid crystal display device. More particularly, the invention relates to a head-mounted display device and a direct-type backlight.

Description of Related Art

Liquid crystal display (LCD) device include a LCD panel and a backlight panel. Backlight modules may provide surface light sources to LCD panels, as such, users may conveniently view the images shown by the LCD panels. Generally, the backlight modules may be divided into the direct-type backlight and the side-type backlight. Comparing to the side-type backlight, the direct-type backlight is capable of providing a surface light source of greater brightness. Therefore, when a backlight source is required to provide greater brightness, a direct-type backlight module is adopted most of the time.

SUMMARY

The invention provides a display device and a direct-type backlight thereof for effectively enhancing a contrast of a central area and/or reducing a number of peripheral area light-emitting elements. The display device of the invention may be used in a head-mounted display (HMD) device, and the head-mounted display device may be worn by a user to allow the user to be exposed to a virtual reality environment or an augmented reality environment.

In an embodiment of the invention, a direct-type backlight is provided. The direct-type backlight includes a central area and a peripheral area. A plurality of central area light-emitting elements are disposed in the central area to provide light to a liquid crystal display (LCD) panel. A density of the central area light-emitting elements in the central area is a first density. A plurality of peripheral area light-emitting elements are disposed in the peripheral area to provide light to the LCD panel. A density of the peripheral area light-emitting elements in the peripheral area is a second density, wherein the second density is less than the first density.

In an embodiment of the invention, a display device is provided. The display device includes a LCD panel and a direct-type backlight. The direct-type backlight includes a central area and a peripheral area. A plurality of central area light-emitting elements are disposed in the central area to provide light to the LCD panel. A density of the central area light-emitting elements in the central area is a first density. A plurality of peripheral area light-emitting elements are disposed in the peripheral area to provide light to the LCD panel. A density of the peripheral area light-emitting elements in the peripheral area is a second density, wherein the second density is less than the first density.

In the direct-type backlight provided by the embodiments of the invention, element densities of the light-emitting elements in different areas are different. The element density of the light-emitting elements in the central area that the user is interested in is greater. Hence, a contrast and image performance of the central area may be effectively enhanced in the direct-type backlight provided by the embodiments, and problems such as image sticking in a dynamic image may be improved. The element density of the light-emitting elements in the peripheral area of the direct-type backlight is lower. For instance, the number of the peripheral area light-emitting elements may be reduced in the direct-type backlight provided by the embodiments, so as to lower costs of a direct-type backlight module.

DESCRIPTION OF THE EMBODIMENTS

The term “coupled to (or connected to)” used in the entire disclosure (including claims) refers to any direct or indirect connecting means. For example, if the disclosure describes a first device is coupled to (or connected to) a second device, the description should be explained as the first device that is connected directly to the second device, or the first device, through connecting other device or using certain connecting means, is connected indirectly to the second device. Moreover, elements/components/steps having same reference numerals represent same or similar parts in drawings and embodiments where possible. Elements/components/steps having same reference numerals or same terms are used as cross reference in different embodiments.

FIG. 1is a schematic diagram illustrating an application scenario of a display device100according to an embodiment of the invention. In the embodiment shown inFIG. 1, the display device100may be used in a head-mounted display (HMD) device. That is, the display device100may be worn on the head of a user10, as such, the user10may conveniently view an image shown by the display device100.

The display device100includes a liquid crystal display (LCD) panel110and a direct-type backlight panel120. The direct-type backlight panel120may provide a surface light source to the LCD panel110, as such, the user10may conveniently view an image shown by the LCD panel110. Generally, when the user10wears a head-mounted display device including the display device100of the invention, the user10is exposed to a virtual reality environment or an augmented reality environment. At this moment, a main field of view (FOV)11of the user10falls on a central area101of the LCD panel110(a direct-type backlight panel120). That is, the central area101is an area that the user10is interested in. Comparing to an image shown in the central area101, an image shown in a peripheral area102of the LCD panel110(the direct-type backlight panel120) is relatively less important.

FIG. 2is a schematic three-dimensional view illustrating the LCD panel110and the direct-type backlight panel120ofFIG. 1according to an embodiment of the invention. In the direct-type backlight panel120shown inFIG. 2, each dot (small circle) represents one light-emitting element. The light-emitting element may be a light-emitting diode (LED) or other light-emitting element based on design requirement. In the embodiment shown inFIG. 2, the direct-type backlight panel120includes the central area101and the peripheral area102. The central area101may be defined by the main field of view (FOV)11of the user10. For instance (but is not limited thereto), a range covered by20main FOV11may be defined as the central area101.

A plurality of central area light-emitting elements are disposed in the central area101of the direct-type backlight panel120. In the embodiment shown inFIG. 2, the central area101of the direct-type backlight panel120has 6*6 central area light-emitting elements. The central area light-emitting elements of the central area101may provide light to a central area of the LCD panel110.

A plurality of peripheral area light-emitting elements are disposed in the peripheral area102of the direct-type backlight panel120. In the embodiment shown inFIG. 2, the peripheral area102of the direct-type backlight panel120has 6*4-2*2 peripheral area light-emitting elements. The peripheral area light-emitting elements of the peripheral area102may provide light to a peripheral area of the LCD panel110.

A density of the central area light-emitting elements in the central area101is a first density, and a density of the peripheral area light-emitting elements in the peripheral area is a second density, wherein the second density is less than the first density. In other words, element densities of the light-emitting elements in different areas of the direct-type backlight panel120are different. The element density of the light-emitting elements in the peripheral area102of the direct-type backlight panel120is lower. For instance, a number of the peripheral area light-emitting elements may be reduced, so as to lower costs of the direct-type backlight panel120. The element density of the light-emitting elements in the central area101that the user10is interested in is greater. Hence, a contrast and image performance of the central area101may be effectively enhanced in the direct-type backlight panel120, and problems such as image sticking in a dynamic image may be improved.

FIG. 3is a schematic three-dimensional view illustrating the LCD panel110and the direct-type backlight panel120ofFIG. 1according to another embodiment of the invention. In the direct-type backlight panel120shown inFIG. 3, each dot (small circle) represents one light-emitting element. The light-emitting element may be a LED or other types of light-emitting element based on design requirement. In the embodiment shown inFIG. 3, the direct-type backlight panel120includes the central area101and the peripheral area102. Since the descriptions of the central area101and the peripheral area102illustrated inFIG. 3may be deduced from the descriptions ofFIG. 2, no further explanation is provided hereinafter.

The direct-type backlight panel120further includes a or a plurality of first areas103. The first areas103are disposed between the central area101and the peripheral area102. A plurality of first area light-emitting elements are disposed in each of the first areas103. In the embodiment of shown inFIG. 3, the direct-type backlight panel120further includes two first areas103. 2*4 first area light-emitting elements are disposed in each of the first areas103.

The first area light-emitting elements may provide light to a corresponding area of the LCD panel110. A density of the first area light-emitting elements in each of the first areas103is a third density, wherein the third density is between the first density and the second density.