CN111722433A

CN111722433A - Light source module and display device

Info

Publication number: CN111722433A
Application number: CN201910220073.4A
Authority: CN
Inventors: 杨文勋; 黄于铵
Original assignee: Coretronic Corp
Current assignee: Coretronic Corp
Priority date: 2019-03-22
Filing date: 2019-03-22
Publication date: 2020-09-29
Also published as: TW202036058A

Abstract

A light source module comprises a reflector plate, a light-transmitting substrate, a plurality of light-emitting light sources and an encapsulation layer. The light-transmitting substrate is provided with a first surface and a second surface which are opposite, and the first surface faces the reflector plate. The light-emitting light sources are arranged on the first surface or the second surface of the light-transmitting substrate. The packaging layer has light transmittance and covers the light-emitting sources and the first surface or the second surface on which the light-emitting sources are arranged. The invention also provides a display device. The display device of the invention has good display quality because of comprising the light source module with uniform surface light source.

Description

Light source module and display device

Technical Field

The present invention relates to a light source module and a display device, and more particularly, to a direct-type light source module and a display device having the same.

Background

The liquid crystal display mainly comprises a backlight module, a display panel, an outer frame and other components. The backlight module can be divided into an edge-type backlight module and a direct-type backlight module according to different light source directions. Currently, a large-medium-sized liquid crystal display (lcd) with Light Emitting Diodes (LEDs) as a backlight module light source is often used to have a direct type backlight module with local dimming (local dimming) function for displaying High Dynamic Range (HDR) and high contrast requirement. The direct type backlight module is structurally designed to convert light rays of the light emitting diodes into a uniform surface light source and then irradiate the uniform surface light source to the display panel.

The backlight module of the liquid crystal display is provided with a backlight chamber. The light emitting diodes may be located at the bottom of the backlight cavity, and a diffuser plate may be disposed above the backlight cavity. If the thickness of the backlight module is reduced to reduce the thickness of the backlight cavity, more leds must be disposed at the bottom of the backlight cavity to reduce the distance between the leds and improve the uniformity of the surface light source, but the cost is also increased.

In addition to more leds disposed in the backlight cavity, another method for reducing the thickness of the backlight cavity and maintaining or even improving the uniform light diffusion effect is to diffuse the light of the leds in the backlight cavity first. A layer of encapsulation colloid can be covered on the substrate provided with the light-emitting diode, and the light emitted by the light-emitting diode can be totally reflected in the encapsulation colloid so as to achieve the effect of light diffusion.

However, a reflective layer is usually disposed on the substrate for disposing the light emitting diode, so that part of the light emitted from the light emitting diode can be transmitted farther in the encapsulant to form a uniform surface light source. The reflective layer is usually a metal layer, and the encapsulant needs to cover the substrate at a high temperature, which easily causes the reflective layer to deteriorate, so that the reflectivity of the reflective layer is reduced, and the uniformity of the surface light source is affected, thereby reducing the display quality of the liquid crystal display.

The background section is provided to facilitate an understanding of the present disclosure, and thus the disclosure in the background section may include other art that is not known to those of skill in the art. Furthermore, the statements contained in the "background" section do not represent a representation of the claimed subject matter or the problems associated with one or more embodiments of the present disclosure, nor are they intended to be known or appreciated by those skilled in the art prior to the present disclosure.

Disclosure of Invention

The invention provides a light source module with a uniform surface light source.

The invention provides a display device with good display quality.

Other objects and advantages of the present invention will be further understood from the technical features disclosed in the present invention.

In order to achieve one or a part of or all of the above or other objects, the light source module provided by the present invention includes a reflective sheet, a transparent substrate, a plurality of light emitting sources, and an encapsulation layer. The light-transmitting substrate is provided with a first surface and a second surface which are opposite, and the first surface faces the reflector plate. The light-emitting light sources are arranged on the first surface or the second surface of the light-transmitting substrate. The packaging layer has light transmittance and covers the light-emitting sources and the first surface or the second surface on which the light-emitting sources are arranged.

To achieve one or a part of or all of the above or other objects, the present invention provides a display device including the light source module and a display panel disposed opposite to the light source module.

The reflector plate in the embodiment of the invention does not participate in the high-temperature process of combining the packaging layer with the substrate, so that the deterioration is avoided, the reflector plate can keep the original reflectivity to reflect the light of the light-emitting source, and the light source module has a uniform surface light source. The display device of the embodiment of the invention has good display quality because of comprising the light source module with the uniform surface light source.

In order to make the aforementioned and other objects, features and advantages of the invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic cross-sectional view of a light source module according to an embodiment of the invention.

Fig. 2 is a schematic cross-sectional view of a light source module according to another embodiment of the invention.

Fig. 3 is a schematic cross-sectional view of a light source module according to another embodiment of the invention.

Fig. 4 is a schematic cross-sectional view of a light source module according to another embodiment of the invention.

Fig. 5A is a schematic cross-sectional view of a light source module according to another embodiment of the invention.

Fig. 5B is an enlarged schematic view of the region a in fig. 5A.

Fig. 6 is a partial cross-sectional view of a light source module according to another embodiment of the invention.

Fig. 7 is a partial cross-sectional view of a light source module according to another embodiment of the invention.

Fig. 8 is a schematic cross-sectional view of a display device according to an embodiment of the invention.

Detailed Description

The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. Directional terms as referred to in the following examples, for example: up, down, left, right, front or rear, etc., are simply directions with reference to the drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting.

Fig. 1 is a schematic cross-sectional view of a light source module according to an embodiment of the invention. Referring to fig. 1, a light source module 100 of the present embodiment includes a reflective sheet 110, a transparent substrate 120, a plurality of light emitting sources 130, and an encapsulation layer 140. The transparent substrate 120 has a first surface 121 and a second surface 122 opposite to each other, and the first surface 121 faces the reflective sheet 110. The light sources 130 are disposed on the first surface 121 of the transparent substrate 120. The encapsulation layer 140 is transparent and covers the light sources 130 and the first surface 121 on which the light sources 130 are disposed.

In the present embodiment, the transparent substrate 120 has light transmittance, and the material may include Polyimide (PI) or glass. The transparent substrate 120 may be a transparent circuit board, and a plurality of circuits (not shown) are disposed on the first surface 121 to electrically connect the plurality of light-emitting sources 130, and the material of the circuits may include conductive ink of conductive polymer material (PEDOT) or a structure having both transparency and conductivity such as Indium Tin Oxide (ITO), or the material of the circuits may also include metal, such as silver. The transparent substrate 120 and the encapsulation layer 140 may have the same refractive index, or the absolute value of the difference between the refractive indexes of the transparent substrate 120 and the encapsulation layer 140 is between 0 and 0.5.

In the present embodiment, the light source 130 can be an unpackaged led die directly cut from a wafer, specifically, a die-level nitride led die that emits blue light at a dominant wavelength, for example. The plurality of light emitting sources 130 may be arranged in an array on the first surface 121.

In the present embodiment, the reflective sheet 110 is disposed opposite to the encapsulation layer 140 with a gap G1. The encapsulation layer 140 may be a silicon gel or a resin, and is suitable for covering the first surface 121 of the transparent substrate 120 in a high temperature working environment. The reflective sheet 110 is separated from the package layer 140 and the transparent substrate 120, and thus does not participate in the high temperature packaging process. The reflective sheet 110 may be a white paint reflective sheet having a diffuse reflection characteristic or a silver paint reflective sheet having a specular reflection characteristic.

In the present embodiment, the package layer 140 has a light emitting surface 141 far away from the transparent substrate, and the light emitting surface 141 may include a plurality of microstructures 142 thereon. The microstructures 142 may be formed by pressing a mold (not shown) corresponding to the package layer 140, or by etching. Since the transparent substrate 120 and the package layer 140 have light transmittance and have refractive indexes equal to or similar to each other, the light L1 emitted from the light sources 130 is totally reflected between the light-emitting surface 141 and the second surface 122, and at this time, the microstructures 142 on the light-emitting surface 141 can disperse the light L1 into light beams with multiple angles, a portion of the light beams is continuously reflected between the light-emitting surface 141 and the second surface 122, and a portion of the light beams passes through the light-emitting surface 141 and is reflected by the reflective sheet 110. However, in other embodiments, according to the design requirement of the surface light source of the light source module 100, the second surface 122 of the transparent substrate 120 may also be directly provided with a microstructure (not shown), which has substantially the same function as the microstructure 142 fabricated on the light-emitting surface 141, and therefore, the description thereof is omitted.

The light source module 100 of the present embodiment may further include an optical film 150 disposed opposite to the transparent substrate 120 and the encapsulation layer 140, and the transparent substrate 120 and the encapsulation layer 140 are located between the optical film 150 and the reflective sheet 110. In the present embodiment, the optical film 150 is disposed toward the second surface 122 of the transparent substrate 120, but is not limited thereto. The optical film 150 may include a diffusion film, a brightness enhancement film, a wavelength conversion film, or other films, and the present embodiment shows a single optical film 150 as an illustration, but is not limited thereto and may further include other optical films.

The reflective sheet 110 in this embodiment is separated from the package layer 140 and the transparent substrate 120, so that the reflective sheet does not deteriorate due to the high temperature process of the package layer, and the reflective sheet can keep the original reflectivity to reflect the light of the light source 130, thereby enabling the light source module 100 to have a uniform surface light source.

Fig. 2 is a schematic cross-sectional view of a light source module according to another embodiment of the invention. Referring to fig. 2, a light source module 100a of the present embodiment is substantially the same as the light source module 100 of fig. 1, except that the light sources 130 of the present embodiment are disposed on the second surface 122 of the transparent substrate 120, the encapsulation layer 140 covers the light sources 130 and the second surface 122 on which the light sources 130 are disposed, and the reflective sheet 110 and the first surface 121 are disposed opposite to each other at an interval G1. In this embodiment, the first surface 121 of the transparent substrate 120 may include a plurality of microstructures 123, but is not limited thereto, and in other embodiments, the microstructures 123 may also be disposed on the light emitting surface 141 of the package layer 120 as shown in fig. 1.

Fig. 3 is a schematic cross-sectional view of a light source module according to another embodiment of the invention. Referring to fig. 3, a light source module 100b of the present embodiment is substantially the same as the light source module 100 of fig. 1 or the light source module 100a of fig. 2, except that a plurality of microstructures 144 are included between the encapsulation layer 140 and the transparent substrate 120. The package layer 140 may include a connection surface 143 opposite to the light emitting surface 141 and connected to the transparent substrate 120, and in this embodiment, the connection surface 143 may include the microstructures 144, but is not limited thereto. The transparent substrate 120 may also include the microstructures 144, for example, when the connection surface 143 is connected to the first surface 121 of the transparent substrate 120, the first surface 121 may include the microstructures 144, but is not limited thereto, and in other embodiments, the connection surface 143 and the first surface 121 may also include the microstructures 144, respectively. The present embodiment can also be applied to the embodiment of fig. 2, in which the connection surface 143 in fig. 2 is connected to the second surface 122, and at least one of the connection surface 143 and the second surface 122 can also include the microstructure 144.

Fig. 4 is a schematic cross-sectional view of a light source module according to another embodiment of the invention. Referring to fig. 4, a light source module 100c of the present embodiment is substantially the same as the light source module 100 of fig. 1, the light source module 100a of fig. 2, or the light source module 100b of fig. 3, except that the reflective sheet 110c of the present embodiment is connected to the encapsulation layer 140 or the transparent substrate 120. After the high-temperature packaging process of the package layer 140 and the transparent substrate 120 is completed and the temperature is reduced, the reflective sheet 110c may be connected to the light-emitting surface 141 of the package layer 140 (as the reflective sheet 110c shown as a solid line) or connected to the transparent substrate 120 (as the reflective sheet 110c shown as a dotted line) according to the stacking position of the reflective sheet in the light source module 100 c. Note that the solid-line reflection sheet 110c and the broken-line reflection sheet 110c shown in fig. 4 are not present at the same time, but are merely used to indicate positions where the reflection sheets 110c are present in different designs. Although the light-emitting source 130 of fig. 4 is illustrated as being disposed on the first surface 121 of the transparent substrate 120 such that the reflective sheet 110c is connected to the second surface 122 of the transparent substrate 120, in other embodiments, when the light-emitting source 130 is disposed on the second surface 122, the reflective sheet 110c is connected to the first surface 121 of the transparent substrate 120.

Similar to all the aforementioned embodiments, the light emitting surface 141, the connection surface, the first surface 121, and the second surface 122 of the light-transmitting substrate 120 of the present embodiment may include microstructures (not shown).

Fig. 5A is a schematic cross-sectional view of a light source module according to another embodiment of the invention, and fig. 5B is an enlarged schematic view of a region a in fig. 5A. Referring to fig. 5A and 5B, the light source module 100d of the present embodiment can be applied to all the embodiments described above, and the light emitting surface 141d of the package layer 140d of the present embodiment can include a plurality of reflective grooves 145 respectively disposed opposite to the plurality of light emitting sources 130, and a reflective pattern 160 disposed in each reflective groove 145.

In the present embodiment, each of the reflective troughs 145 has an opening 146 on the light-emitting surface 141d, and the light-emitting sources 130 respectively have a light-emitting surface 131 facing the opening 146, and the area of the opening 146 is larger than that of the light-emitting surface 131. Each reflective groove 145 has a bottom surface 1451 and a surrounding side surface 1452 surrounding and connected to an edge of the bottom surface 1451 at the bottom, and the area of the opening 146 is larger than that of the bottom surface 1451. The surrounding side surface 1452 is inclined with respect to the light emitting surface 141d, and the bottom surface 1451 may be a curved surface (as shown by the dotted line in fig. 5B) or a flat surface (as shown by the solid line in fig. 5B). In a cross-sectional view perpendicular to the light emitting surface 141D through the centers of the corresponding pair of light emitting sources 130 and the reflection groove 145, the distance between the two ends of the opening 146 is D, the distance between the two ends of the light emitting surface 131 is L, and the light emitting surface 131A distance Dl from the first surface 121 on which the light emitting source 130 is disposed, a distance De from the first surface 121 to the light emitting surface 141d, a depth H of the reflective groove 145, H < De-Dl, a refractive index Nm of the encapsulation layer 140d, a refractive index Na of air, and a critical angle θ of total reflection of the light L1 emitted from one end of the light emitting surface 131 toward the light emitting surface 141d, Sin^-1(Na/Nm) and the width D of the opening satisfies the relation D ≧ 2 × [ (De-Dl) × tan (Sin)^-1(Na/Nm))+L/2]。

With the above relationship, most of the light L1 emitted by each light-emitting source 130 is emitted toward the surrounding side surface 1452 and the bottom surface 1451 of the corresponding reflective groove 145 and is reflected to the transparent substrate 120 or the light-emitting surface 141a at various angles, and the light L1 with various angles is totally reflected between the light-emitting surface 141d and the second surface 122 and is emitted from the package layer 140d at various angles. In the embodiment, the optical film 150 is disposed toward the transparent substrate 120, and the reflective sheet 110 is disposed toward the light-emitting surface 141d of the package layer 140d, under the action of the reflective groove 145, a large amount of light L1 is emitted toward the transparent substrate 120, and the reflective sheet 110 is matched to reflect the light L1 passing through the light-emitting surface 141d, so that the light L1 can be converted into a uniform light L2 emitted from the second surface 122 of the transparent substrate 120. And the optical film 150 can further convert the light L2 into a surface light source. However, in another embodiment not shown, the light emitting source 130 may also be disposed on the second surface 122, and the light L2 may exit from the light exit surface 141d to the optical film 150.

Fig. 6 is a partial cross-sectional view of a light source module according to another embodiment of the invention. Referring to fig. 6, a light source module 100e of the present embodiment is substantially the same as the light source module 100d of fig. 5A, except that: the reflection pattern 160e of the present embodiment includes a light diffusion layer 161 covering the bottom of the reflection groove 145 and a reflection layer 162 covering the light diffusion layer 161, wherein the refractive index of the light diffusion layer 161 is lower than the refractive index of the encapsulation layer 140 d. In the present embodiment, the material of the reflective layer 162 may be white paint having a diffuse reflection characteristic or silver paint having a specular reflection characteristic. Since the refractive index of the light diffusion layer 161 is lower than that of the encapsulation layer 140d, the light L1 emitted from the light source 130 is deflected when entering the light diffusion layer 161 from the encapsulation layer 140d, thereby promoting the diffusion of the light L1.

Fig. 7 is a partial cross-sectional view of a light source module according to another embodiment of the invention. Referring to fig. 7, a light source module 100f of the present embodiment is substantially the same as the light source module 100d of fig. 5A, except that: the reflective pattern 160f of the present embodiment includes a wavelength conversion layer 163 covering the bottom of the reflective cavity 145 and a reflective layer 162 covering the wavelength conversion layer 163. The wavelength converting layer 163 may include wavelength converting layer particles 164. The material of the wavelength converting particles 164 may include Quantum dots (Quantum dots) or phosphors. When the wavelength conversion layer 163 is disposed in the reflective trench 145, the optical film 150 in fig. 5A may not need to have a wavelength conversion function.

Fig. 8 is a schematic cross-sectional view of a display device according to an embodiment of the invention. Referring to fig. 8 and fig. 1, the display device 10 of the present embodiment includes a display panel 11 and a light source module 100 disposed opposite to the display panel 11, and the transparent substrate 120 and the encapsulation layer 140 are disposed between the display panel 11 and the reflective sheet 110. The light source module 100 included in the display device 10 of the present embodiment is only for illustration and is not limited thereto. The display device 10 of the present embodiment may also include the light source modules of all the embodiments. The display device 10 of the present embodiment has a good display quality because it includes a light source module having a uniform surface light source.

It should be understood that the above-mentioned embodiments are only preferred embodiments of the present invention, and that the scope of the present invention should not be limited thereby, and all the simple equivalent changes and modifications made by the claims and the summary of the invention should be included in the scope of the present invention. Moreover, it is not necessary for any embodiment or claim of the invention to address all of the objects, advantages, or features disclosed herein. In addition, the abstract and the title of the invention are provided for assisting the search of patent documents and are not intended to limit the scope of the invention. Furthermore, the terms "first," "second," and the like in the description and in the claims are used for naming elements (elements) or distinguishing between different embodiments or ranges, and are not intended to limit the upper or lower limit on the number of elements.

Description of reference numerals:

10: display device

100. 100a, 100b, 100c, 100d, 100e, 100 f: light source module

11: display panel

110. 110 c: reflector plate

120: light-transmitting substrate

121: first surface

122: second surface

130: luminous light source

131: luminous surface

140. 140 d: encapsulation layer

141. 141 d: light emitting surface

123. 142, 144: microstructure

143: connecting surface

145: reflection groove

1451: bottom surface

1452: surrounding side surface

150: optical film

160. 160e, 160 f: reflective pattern

161: light diffusion layer

162: reflective layer

163: wavelength conversion layer

164: wavelength converting particles

D: width of

D1: thickness of

De: distance between two adjacent plates

G1: spacer

H: depth of field

L1, L2: light ray

θ: critical angle for total reflection.

Claims

1. A light source module, wherein the light source module comprises a reflective sheet, a transparent substrate, a plurality of light emitting sources and an encapsulation layer, wherein:

the light-transmitting substrate is provided with a first surface and a second surface which are opposite, and the first surface faces the reflector plate;

the plurality of light-emitting light sources are arranged on the first surface or the second surface of the light-transmitting substrate; and

the encapsulation layer has light transmittance and covers the plurality of light-emitting sources and the first surface or the second surface on which the plurality of light-emitting sources are disposed.

2. The light source module of claim 1, wherein the plurality of light emitting sources are disposed on the first surface, and the reflective sheet is connected to the encapsulation layer or disposed opposite to the encapsulation layer at an interval.

3. The light source module of claim 1, wherein the plurality of light emitting sources are disposed on the second surface, and the reflector plate is connected to the first surface or disposed opposite to the first surface at an interval.

4. The light source module of claim 1, wherein the encapsulation layer has an opposite light emitting surface and a connecting surface connected to the first surface or the second surface, and at least one of the light emitting surface and the connecting surface has a plurality of microstructures.

5. The light source module of claim 1, wherein at least one of the first surface and the second surface has a plurality of microstructures.

6. The light source module of claim 1, wherein the light-transmissive substrate is a light-transmissive circuit board.

7. The light source module of claim 1, wherein an absolute value of a difference between a refractive index of the encapsulation layer and a refractive index of the light-transmissive substrate is between 0 and 0.5.

8. The light source module of claim 1, wherein the encapsulation layer has a light-emitting surface away from the transparent substrate, the light-emitting surface has a plurality of reflective grooves, the reflective grooves are disposed opposite to the light-emitting sources, the reflective grooves have surrounding sides inclined with respect to the light-emitting surface, and the light source module further includes a plurality of reflective patterns disposed in the reflective grooves.

9. The light source module of claim 8, wherein each of the plurality of reflective troughs has an opening at the light emitting surface, and the plurality of light emitting sources respectively have a light emitting surface facing the opening, and the area of the opening is larger than the area of the light emitting surface.

10. The light source module of claim 9, wherein in a cross-sectional view passing through a corresponding pair of the light emitting source center and the reflective groove center and perpendicular to the light emitting surface, a distance between two ends of the opening is D, a distance between two ends of the light emitting surface is L, a distance between the light emitting surface and the first surface or the second surface is Dl, a distance between the first surface or the second surface and the light emitting surface is De, a depth of the reflective groove is H, and H < De-Dl, a refractive index of the encapsulation layer is Nm, a refractive index of air is Na, and a critical angle of total reflection θ ═ Sin of a light ray emitted from one end of the light emitting surface toward the light emitting surface^-1(Na/Nm), and the width D of the opening satisfies the relation D ≧ 2 × [ (De-Dl) × tan (Sin)^-1(Na/Nm))+L/2]。

11. The light source module of claim 9, wherein each of the reflective cavities has a bottom surface, a bottom of the surrounding side surface is connected to an edge of the bottom surface, and the opening has an area larger than that of the bottom surface.

12. The light source module of claim 11, wherein the bottom surface comprises a curved surface or a flat surface.

13. The light source module of claim 8, wherein each of the reflective patterns comprises:

a light diffusion layer covering the bottom of the reflection groove, and having a refractive index lower than that of the encapsulation layer; and

a reflective layer covering the light diffusion layer.

14. The light source module of claim 8, wherein each of the reflective patterns comprises:

a wavelength conversion layer covering the bottom of the reflective trench; and

a reflective layer covering the wavelength conversion layer.

15. The light source module of claim 1, further comprising an optical film, wherein the light-transmissive substrate and the encapsulation layer are positioned between the optical film and the reflective sheet.

16. A display device, comprising a display panel and a light source module, wherein the light source module is disposed opposite to the display panel and comprises a reflective sheet, a light-transmitting substrate, a plurality of light-emitting sources, and an encapsulation layer, wherein:

the encapsulation layer has light transmittance and covers the plurality of light-emitting sources and the first surface or the second surface on which the plurality of light-emitting sources are disposed,

the transparent substrate and the packaging layer are positioned between the display panel and the reflector plate.