Patent Application
20210088850
This application claims the benefits of the Taiwan Patent Application Serial Number 108133712, filed on Sep. 19, 2019, the subject matter of which is incorporated herein by reference.
The present disclosure relates to a light emitting diode (LED) device and a backlight module and a display device comprising the same. More specifically, the present disclosure relates to an LED device with improved color gamut and a backlight module and a display device comprising the same.
White LEDs can be applied to various fields, for example, can be used to a light source or a backlight module of a display device. It is known that the material for a light emitting layer of the white LED may be phosphors or quantum dots. Compared to the light emitting from the quantum dots, the light emitting from the phosphors have more unwanted light. Thus, the color gamut of the white LED prepared with the phosphors is not as ideal as the white LED prepared with the quantum dots. Therefore, some manufactures currently use quantum dots as the material for the light emitting layer to prepare the white LEDs to improve the backlight effect of the backlight module of the display device when the white LEDs are applied thereto.
However, the manufacture cost using the quantum dots is high. If the unwanted light emitting from the phosphors can be effectively removed to improve the color gamut of the white LEDs, the backlight effect of the backlight module of the display device can also be effectively improved even though the quantum dots are not used as the material for the light emitting layer of the white LEDs.
Therefore, it is desirable to provide a novel white LED device using phosphors to be effectively applied to the backlight module of the display device.
The present disclosure provides a light emitting diode (LED) device, wherein a yellow light absorbing material is used to improve the color gamut of the LED device.
The LED device of the present disclosure comprises: a diffusing lens comprising a diffusing body, wherein the diffusing body has a cavity and a light emitting surface; a light emitting diode (LED) disposed in the cavity; and a light absorbing material disposed on a light path that light emitting from the light emitting diode passes through the diffusing body and emits from the light emitting surface, wherein the light absorbing material is a yellow light absorbing material.
In the LED device of the present disclosure, the yellow light absorbing material is used to absorb the unwanted light (stray light) in the yellow wavelength range to reduce the intensity of the unwanted light in the yellow wavelength range, and thus the color gamut of the LED device can be improved. Hence, when the LED device of the present disclosure is applied to a backlight module of a display device, backlight with wide color gamut can be provided, and therefore the display quality of the display device can be enhanced.
In the LED device of the present disclosure, the LED can be a white light LED.
In the LED device of the present disclosure, the yellow light absorbing material is a material capable of absorbing light with wavelengths ranged from 550 nm to 610 nm. The type of the yellow light absorbing material is not particularly limited, as long as it has the property of absorbing the light with the aforesaid wavelength range. The yellow light absorbing material can be an organic dye or an inorganic pigment. Examples of the yellow light absorbing material include, but are not limited to, a triphenylmethane-based material, cobalt blue, cobalt violet or a combination thereof.
In the LED device of the present disclosure, the diffusing body of the diffusing lens may comprise a lens material. Herein, the lens material is not particularly limited, as long as it is a lens material with high transmittance. For example, the lens material may comprise, but is not limited to, polyvinyl chloride (PVC), polycarbonate (PC), poly(methyl methacrylate) (PMMA) or a combination thereof.
In one aspect of the present disclosure, the diffusing body may comprise the lens material and the light absorbing material. In other words, the diffusing body is formed by a combination of the lens material and the light absorbing material. Hence, when the light emitting from the light emitting diode penetrates through the diffusing body and emits from the light emitting surface, the light absorbing material included in the diffusing body can absorb the unwanted light in the yellow wavelength range. Herein, the feature of the lens material is described above and not repeated again.
In another aspect of the present disclosure, the light absorbing material may be disposed on the light emitting surface of the diffusing body. In other words, the light absorbing material can be formed into a thin film on the light emitting surface of the diffusing body. Hence, when the light emitting from the light emitting diode penetrates through the diffusing body and emits from the light emitting surface, the unwanted light in the yellow wavelength range which achieves the light emitting surface can be absorbed by the light absorbing material.
In further another aspect of the present disclosure, the light absorbing material may be disposed on a surface of the cavity of the diffusing body. In other words, the light absorbing material can be formed into a thin film on the surface of the cavity of the diffusing body. Herein, the surface of the cavity of the diffusing body is a light incident surface of the diffusing body. Hence, before the light emitting from the light emitting diode incidents into the diffusing body, the unwanted light in the yellow wavelength range which achieves the light incident surface can be absorbed by the light absorbing material first and then penetrate through the diffusing body and emit from the light emitting surface.
In addition, the present disclosure further provides a backlight module, comprising: a reflector; an optical film disposed on the reflector; and the aforesaid LED device disposed between the reflector and the optical film. Moreover, the present disclosure further provides a display device, comprising: the aforesaid backlight module; and a display panel disposed on the backlight module.
In the present disclosure, the backlight module can be a direct type backlight module.
In the present disclosure, the display panel can be a display panel which requires being equipped with the backlight module. For example, the display panel can be a liquid crystal display panel.
In the backlight module and display device of the present disclosure, the color gamut of the backlight module can be improved by using the aforesaid LED device. Even though phosphor powders are used in the light emitting layer of the LED in the LED device of the present disclosure, the backlight effect of the backlight module of the present disclosure is similar to that using quantum dots in the light emitting layer of the LED.
Other novel features of the disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
The following embodiments when read with the accompanying drawings are made to clearly exhibit the above-mentioned and other technical contents, features and/or effects of the present disclosure. Through the exposition by means of the specific embodiments, people would further understand the technical means and effects the present disclosure adopts to achieve the above-indicated objectives. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present disclosure should be encompassed by the appended claims.
Furthermore, the ordinals recited in the specification and the claims such as “first”, “second” and so on are intended only to describe the elements claimed and imply or represent neither that the claimed elements have any proceeding ordinals, nor that sequence between one claimed element and another claimed element or between steps of a manufacturing method. The use of these ordinals is merely to differentiate one claimed element having a certain designation from another claimed element having the same designation.
Furthermore, the terms recited in the specification and the claims such as “above”, “over”, or “on” are intended not only directly contact with the other element, but also intended indirectly contact with the other element. Similarly, the terms recited in the specification and the claims such as “below”, or “under” are intended not only directly contact with the other element but also intended indirectly contact with the other element.
Furthermore, the terms recited in the specification and the claims such as “connect” is intended not only directly connect with other element, but also intended indirectly connect and electrically connect with other element.
In addition, the features in different embodiments of the present disclosure can be mixed to form another embodiment.
As shown in
As shown in
Herein, the phosphor layer 13 is a layer formed by plural phosphor powders. The types of the phosphor layer 13 is not particularly limited, and can be selected according to the type of the LED chip 11 or the desired color of the light emitting from the phosphor powders. For example, the phosphor powders capable of emitting yellow light after excitation can be used as the phosphor powders in the phosphor layer 13; and in this case, when the phosphor layer 13 is used together with the blue light LED chip, the LED can emit white light.
As shown in FIG a protection layer 14 is formed on the phosphor layer 13. In the present embodiment, the protection layer 14 can be an optical protection layer. In addition, the method for forming the protection layer 14 is not particularly limited, and the protection layer 14 can be formed by any coating process known in the art, such as a spin coating process, a blade coating process, an inject process, a printing process, a roll coating process or a spray coating process.
After the aforesaid process, a LED of the present embodiment can be obtained, which is a white LED. As shown in
In the present embodiment, the LED chip further comprises a side surface 113 connecting to the first surface 111 and the second surface 112, and the phosphor layer 13 is further disposed on the side surface 113. More specifically, in the present embodiment, the phosphor layer 13 is disposed on all the surfaces (including the second surface 112 and the side surface 113) of the LED chip 11 except for the first surface 111.
In the present embodiment, the LED further comprises a protection layer 14, wherein the protection layer 14 is disposed on the surfaces of the phosphor layer 13 corresponding to the second surface 112 and the side surface 113. More specifically, in the present embodiment, the phosphor layer 13 is disposed on the second surface 112 and the side surface 113 of the LED chip 11, and the protection layer 14 is used to protect the phosphor layer 13. Thus, the protection layer 14 is formed on the surfaces of the phosphor layer 13 corresponding to the second surface 112 and the side surface 113.
After completing the manufacture of the LED as shown in
As shown in
In the present embodiment, as shown in
In the present embodiment, the lens material may comprise PVC, PC, PMMA or a combination thereof, but the present disclosure is not limited thereto. Any material with high transmittance without influencing the light emitting from the LED chip can be used as the lens material of the present disclosure. In addition, in the present embodiment, the light absorbing material is a yellow light absorbing material capable of absorbing light having a wavelength in a range from 550 nm to 610 nm. Examples of the yellow light absorbing material capable of absorbing light having the wavelength in the range from 550 nm to 610 nm may comprise, but are not limited to a triphenylmethane-based material, cobalt blue, cobalt violet or a combination thereof.
Thus, as shown in
In addition, as shown in
In the present embodiment, as shown in
In addition, in the present embodiment, the light absorbing material 24 is disposed on a surface 232a of the cavity 232. In other word, in the present embodiment, the light absorbing material 24 is formed into a thin film on the surface 232a of the cavity 232, and the surface 232a of the cavity 232 is the incident surface of the diffusing body 231. Herein, the method for preparing the thin film of the light absorbing material 24 is not particularly limited, and can be prepared by any coating process known in the art, such as a spin coating process, a blade coating process, an inject process, a printing process, a roll coating process or a spray coating process.
Hence, as shown in
In the present embodiment, the light absorbing material 24 is formed on the light emitting surface 233 of the diffusing body 231. In other words, in the present embodiment, the light absorbing material 24 is formed into a thin film on the light emitting surface 233 of the diffusing body 231.
Thus, as shown in
In the aforesaid embodiments of the present disclosure, the light emitting surface 233 of the diffusing lens 23 has a curved shape; but the present disclosure is not limited thereto. In other embodiments of the present disclosure, the diffusing lens 23 may have other shapes as long as the purpose of light diffusing can be achieved.
Similarly, in the aforesaid embodiments of the present disclosure, the cavity 232 of the diffusing lens 23 also has a curved shape; but the present disclosure is not limited thereto. In other embodiments of the present disclosure, the cavity 232 may have other shapes as long as the purpose of light diffusing can be achieved.
In addition, in the aforesaid embodiments of the present disclosure, one LED 1 is disposed in the cavity 232; but the present disclosure is not limited thereto. In other embodiments of the present disclosure, plural LEDs 1 may be disposed in the cavity 232.
Furthermore, the structure of the LED suitable for the present disclosure is not limited to the structure of the LED described above, and can be adjusted according to the need. For example, in other embodiments of the present disclosure, the LED can be an LED bead formed with phosphor gel.
In the present embodiment, the reflector 31 can also be used as a back plate for the backlight module. In addition, even not shown in the figure, the optical film 32 may comprise any film usually used in the backlight module, for example, a diffusing film, a prism film or a brightness enhancement film. However, the present disclosure is not limited thereto, and the component of the optical film 32 can be adjusted according to the need.
In one aspect of the present embodiment, the first substrate 41 can be a transistor substrate with transistors (not shown in the figure) disposed thereon, and the second substrate 43 can be a color filter substrate with a color filter layer (not shown in the figure) and a black matrix layer (not shown in the figure) formed thereon. In another aspect of the present embodiment, the color filter layer (not shown in the figure) may be disposed on the first substrate 41, and the first substrate 41 in this case can be a color filter on array (COA) substrate. In further another aspect of the present embodiment, the black matrix layer (not shown in the figure) may be disposed on the first substrate 41, and the first substrate 41 in this case can be a black matrix on array (BOA) substrate.
In the present text example, the LED device of Embodiment 2 (as shown in
The spectra obtained in the comparative example and the experimental example are respectively shown in
The LED device of the present disclosure can be used as a light source for the backlight module of any display device. Examples of the display device may comprise, but are not limited to, displays, mobile phones, laptops, video cameras, still cameras, music players, mobile navigators, TV sets, etc.
Although the present disclosure has been explained in relation to its embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the disclosure as hereinafter claimed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 108133712 | Sep 2019 | TW | national |
