TWI886491B - Reflector and direct-type backlight module with the reflector - Google Patents

Abstract

A reflector and a direct-type backlight module with the reflector are provided. The reflector includes a plurality of reflective cups. Each reflective cup includes a bottom opening and a reflecting side face surrounding and connected to the bottom opening. The reflecting side face has a top opening away from the bottom opening. An anti-reflective structure is positioned along the edges of the top opening of the reflecting side face. The reflectivity of the surface of the anti-reflective structure is lower than that of the reflecting side face. The invention utilizes the anti-reflection structure to reduce the light reflection near the top opening of the reflective cup so that the diffuse reflection caused by the structural end of the reflective cup is greatly improved. In this way, the optical effect of the reflector can be improved.

Description

Reflection cover and direct-type backlight module having the same

The invention relates to the field of liquid crystal display technology, and in particular to a reflective cover and a direct-type backlight module having the reflective cover.

Since LCDs are not self-luminous, they require a backlight module to provide a light source of sufficient brightness to display the image. With the development of semiconductor manufacturing processes, the size of light-emitting diodes (LEDs) has also shrunk to hundreds of micrometers, which is the so-called sub-millimeter light-emitting diode (Mini LED). When using Mini LED as a backlight source, due to its small size, its light mixing distance is much smaller than that of traditional LEDs. Direct backlight technology can be used to arrange thousands, tens of thousands, or even more Mini LEDs in a matrix array at the bottom of the LCD to obtain better brightness and brightness uniformity. In order to increase the efficiency of reflected light, a reflector structure can be further configured on the light source of the direct-lit backlight module, which can improve the brightness of the entire backlight module, reduce the halo effect, and reduce the thickness (reduce the light density value).

Mini LED direct backlight technology has the advantage of local dimming zones. The Mini LED matrix can be divided into multiple local dimming zones. Each dimming zone can accurately adjust the brightness according to the display content of the LCD, thereby achieving a high contrast of the LCD. As shown in Figure 1, the reflector 1 in the backlight module is composed of multiple reflective cups 2. The reflective cup 2 has one or more openings 3 so that it can accommodate one or more Mini LED light sources when connected to the backplane. However, when the Mini LED direct-type backlight module is driven for local dimming, as shown in FIG. 2 , the reflector cup 2 is prone to diffuse reflection around the end of the structure, causing the local light source 4 to leak to the adjacent area, affecting the edge dark area, thereby generating a halo phenomenon, resulting in the problem that the dark band is still visible, affecting the display effect.

Therefore, the current industry urgently needs to seek a reflector that can improve the diffuse reflection problem at the end of the reflector cup structure and its application in a direct-lit backlight module, so that the various difficulties and deficiencies encountered in the above-mentioned prior art can be solved.

In view of this, the main purpose of the present invention is to provide a reflector and a direct-type backlight module having the reflector, which utilizes an anti-reflection structure to reduce light reflection near the top opening of the reflector cup, thereby greatly improving the diffuse reflection phenomenon caused by the structural end of the reflector cup and avoiding affecting the optical effect.

To achieve the above-mentioned purpose, the present invention provides a reflective cover, which includes a plurality of reflective cups, each of which includes a bottom opening and a reflective side surface surrounding and connected to the bottom opening, the reflective side surface is provided with a top opening away from the bottom opening, and an anti-reflective structure is provided along the edge of the top opening of the reflective side surface, and the reflectivity of the anti-reflective structure surface is lower than that of the reflective side surface.

According to an embodiment of the present invention, the aforementioned anti-reflection structure comprises a low-reflection material or a light-absorbing material.

According to an embodiment of the present invention, the reflectivity of the surface of the anti-reflection structure is 1 to 90%.

According to an embodiment of the present invention, the aforementioned anti-reflection structure is configured as a strip pattern, and the strip pattern extends in the length direction to be continuously or discontinuously distributed along the edge of the top opening.

According to an embodiment of the present invention, the aforementioned strip pattern has a width of at least 0.1 mm.

According to an embodiment of the present invention, the aforementioned anti-reflection structure is configured as a plurality of strip patterns, and the distance between these strip patterns is less than 0.1 mm.

According to an embodiment of the present invention, the thickness of the anti-reflection structure is greater than 9 microns.

According to an embodiment of the present invention, the aforementioned anti-reflection structure is a flat surface structure, a rough surface structure or an arc curved surface structure.

According to an embodiment of the present invention, the aforementioned anti-reflection structure is formed by stacking and arranging a plurality of ink resin composite particles.

According to an embodiment of the present invention, the reflectivity of the anti-reflection structure increases from the top opening to the bottom opening.

According to an embodiment of the present invention, the aforementioned anti-reflection structure is an ink layer, and the color of the ink layer gradually becomes lighter from the top opening to the bottom opening.

According to an embodiment of the present invention, the aforementioned anti-reflection structure is formed by arranging a plurality of inkjet particles, and the sizes of these inkjet particles decrease in sequence from the top opening to the bottom opening.

According to an embodiment of the present invention, the aforementioned anti-reflection structure is formed by arranging a plurality of inkjet particles, and the density of these inkjet particles decreases from the top opening to the bottom opening.

According to an embodiment of the present invention, the aforementioned anti-reflection structure is formed by a multi-layer adhesive tape, and the color of the multi-layer adhesive tape gradually becomes darker from the inner layer attached to the reflective side to the outer layer.

In addition, the present invention also provides a direct-type backlight module, including a back plate, a plurality of LED light sources, a light guide plate and an optical film arranged in sequence, and at the same time, also including any of the above-mentioned reflective covers, the reflective cover is arranged between the back plate and the light guide plate, and at least one LED light source is arranged in the bottom opening.

Compared with the prior art, the present invention has the following advantages: (1) The reflector provided by the present invention can reduce the diffuse reflection phenomenon around the end of the reflector cup by setting an anti-reflection structure near the top opening of the reflector cup, so as to avoid the reflector cup affecting the optical effect. (2) The direct-type backlight module provided by the present invention uses an anti-reflection structure in the reflector cup that can avoid diffuse reflection around the end of the reflector cup to enhance the optical effect of the reflector in the direct-type backlight module, thereby achieving more precise backlight and screen brightness control.

The following detailed description is based on specific embodiments to make it easier to understand the purpose, technical content, features and effects of the present invention.

The embodiments of the present invention will be further explained below in conjunction with the relevant drawings. As much as possible, the same reference numerals in the drawings and the specification represent the same or similar components. In the drawings, the shapes and thicknesses may be exaggerated for the sake of simplicity and convenience. It is understood that the components not specifically shown in the drawings or described in the specification are the forms known to those with ordinary knowledge in the relevant technical field. Those with ordinary knowledge in the field can make various changes and modifications based on the content of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, and back) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

As described in the previous technology, the known reflector at the end of the reflector cup is prone to diffuse reflection, which will affect the edge dark area and thus produce a halo phenomenon, causing the display screen to have the problem of whether it is dark or not. In order to solve the above technical problems, the basic idea of the present invention is to provide a reflector and a direct-type backlight module with the reflector, and use an anti-reflection structure to reduce the light reflection near the top opening of the reflector cup, thereby improving the problem of poor display effect caused by diffuse reflection.

Please refer to Figures 3 to 5. Figure 3 is a top view of the reflector of the first embodiment of the present invention; Figure 4 is a partial cross-sectional view of the reflector in Figure 3, showing three reflector cups; and Figure 5 is a schematic structural view of a reflector cup in Figure 4. In the first embodiment, the reflector 10 is composed of a plurality of reflector cups 11 distributed in a matrix, each reflector cup 11 includes a bottom opening 14 and a reflective side surface 13 surrounding and connected to the bottom opening 14, wherein the bottom opening 14 is used to accommodate an LED light source 40, and the reflective side surface 13 is provided with a top opening 15 away from the bottom opening 14, the top opening 15 and the bottom opening 14 are arranged concentrically, and an anti-reflection structure 16 is arranged along the edge of the top opening 15 of the reflective side surface 13, and the reflectivity of the surface of the anti-reflection structure 16 is lower than the reflectivity of the reflective side surface 13. The anti-reflection structure 16 can reduce the surface reflectivity. As shown in FIG. 4 , the light from the LED light source 40 incident on the top opening 15 of the reflective cup 11 will be absorbed or attenuated by the anti-reflection structure 16, thereby reducing the diffusion phenomenon.

The anti-reflection structure 16 of the present invention is used to reduce the light reflection near the top opening 15 of the reflective cup 11. The anti-reflection structure 16 can be a stacked structure of a single layer or multiple layers of materials, and can be formed on the edge area of the top opening 15 of the reflective cup 11 by a low-reflection material or a light-absorbing material by coating, spraying, and transfer printing. Alternatively, the anti-reflection structure 16 and the reflective side surface 13 can be bonded together by an adhesive layer (not shown in the figure) by gluing. Specifically, the material of the low-reflection material can be selected from black resin materials, blackened metals (such as metal oxides, metal nitrides, metal nitride oxides), brown organic materials, etc. The material of the light-absorbing material can be, for example, black gel or dye molecules, but is not limited thereto. It is particularly noted that the reflectivity of the anti-reflection structure 16 of the present invention is, for example, the reflectivity of the above-mentioned low-reflection material or light-absorbing material, but is not limited thereto. In other embodiments, the reflectivity of the anti-reflection structure 16 may also be lower than the reflectivity of its own material, that is, the surface of the anti-reflection structure 16 may be provided with an anti-reflection optical microstructure so that its overall reflectivity is lower than the reflectivity of its own material. Preferably, the reflectivity of the surface of the anti-reflection structure 16 of the present invention is between 1 and 90%.

The anti-reflection structure 16 of the present invention is preferably disposed around the top opening 15 of each reflector cup 11. As shown in FIG. 5, the anti-reflection structure 16 of the first embodiment is configured as a strip pattern on the four sides of the top opening 15 of each reflector cup 11. The strip pattern extends in the length direction to be continuously distributed along the edge of the top opening 15. Preferably, the strip pattern has a width D of at least 0.1 mm, and the thickness t of the anti-reflection structure 16 is greater than 9 microns (see FIG. 4). In addition, the strip pattern formed by the anti-reflection structure 16 of the present invention can also be distributed discontinuously along the edge of the top opening 15 of the reflector cup 11. As shown in FIG. 6 , the strip pattern of the anti-reflection structure 16 has a breakpoint on each side of the top opening 15 of the reflective cup 11 . As shown in FIG. 7 , the strip pattern of the anti-reflection structure 16 is distributed in a dotted pattern along the edge of the top opening 15 of the reflective cup 11 .

The anti-reflection structure 16 of the present invention can be configured as a single strip-shaped pattern as proposed in the first embodiment above, and can also be configured as a plurality of strip-shaped patterns in actual application, please refer to the second embodiment. As shown in Figures 8 and 9, the anti-reflection structure 16 of the second embodiment is two strip-shaped patterns. Of course, the number of strip-shaped patterns of the anti-reflection structure 16 can also be three or more. In the anti-reflection structure 16 of the present invention having a plurality of strip-shaped patterns, the spacing d between these strip-shaped patterns is preferably less than 0.1 mm.

The anti-reflection structure 16 of the present invention can be a flat surface structure, a rough surface structure or an arc surface structure. The anti-reflection structure 16 of the first and second embodiments can be a flat surface structure. As shown in FIG. 10, the anti-reflection structure 16 of the third embodiment is formed by stacking and arranging a plurality of ink-resin composite particles 18. The ink-resin composite particles 18 are composite material particles with round or irregular shapes formed by mixing resin in ink and forming a rough surface structure. As shown in FIG. 11, the anti-reflection structure 16 of the fourth embodiment is configured as a convex arc surface structure. In practical applications, the surface morphology of the anti-reflection structure 16 can be designed according to requirements.

The anti-reflection structure 16 of the present invention can also be configured to have a reflectivity distribution that increases from the top opening 15 of the reflective side surface 13 to the bottom opening 14, so as to enhance the optical effect of the reflector 10. As shown in FIG. 12, the anti-reflection structure 16 of the fifth embodiment is an ink layer 21, and the color of the ink layer 21 gradually becomes lighter from the top opening to the bottom opening (from top to bottom in the figure), that is, the color near the top opening (the top) is dark (for example, 100% pure black), and then gradually becomes lighter (for example, 5% black) toward the bottom opening (towards the bottom). To further illustrate, the ink layer 21 in FIG. 12 is divided into four color blocks of different shades, and the area occupied by each color block can be sequentially smaller or larger from dark to light, or each color block can be the same area. In addition, as shown in FIG. 13, the anti-reflection structure 16 of the sixth embodiment is formed by arranging a plurality of inkjet particles 22, and the sizes of these inkjet particles 22 decrease in sequence from the top opening to the bottom opening (from top to bottom in the figure), that is, the largest particles are near the top opening (the top), and then gradually become smaller particles toward the bottom opening (towards the bottom); further, the inkjet particles 22 of different sizes can have the same spacing, or they can have different spacings. As shown in FIG. 14 , the anti-reflection structure 16 of the seventh embodiment is also formed by arranging a plurality of inkjet particles 22, but the density of these inkjet particles 22 decreases from the top opening to the bottom opening (from top to bottom in the figure), that is, the density is highest near the top opening (topmost), and then gradually becomes the lowest density toward the bottom opening (downward); further explained, the inkjet particles 22 in FIG. 14 have the same size and are divided into four blocks with different densities, each block occupies the same area, the density is highest near the top opening (topmost), that is, it has the most inkjet particles 22, and the density is lowest near the bottom opening (bottommost), that is, it has the least inkjet particles 22; in actual application, it is not limited to this, and the area occupied by each block can be adjusted according to needs.

In addition, the anti-reflection structure 16 of the present invention can be formed by using a multi-layer adhesive tape, with the inner layer of the multi-layer adhesive bag attached to the reflective side surface 13, and the outer layer facing outward, and the color of the multi-layer adhesive tape gradually becomes darker from the inner layer to the outer layer. As shown in FIG. 15, the anti-reflection structure 16 of the eighth embodiment is a double-layer adhesive tape, and the structure of the double-layer adhesive tape can be, for example, the inner layer 24 attached to the reflective side surface 13 is a white adhesive tape, and the outer layer 25 is a black adhesive tape. Of course, the actual application is not limited to this. For example, when three layers of tape are used, the inner layer is a light-colored tape, the middle layer is a medium-colored tape, and the outer layer is a dark-colored tape. Other such examples will not be elaborated on.

The reflective covers proposed in the above-mentioned embodiments can all be applied to direct-type backlight modules. Please refer to FIG. 16, which shows an exploded view of the direct-type backlight module of the ninth embodiment provided by the present invention. In the ninth embodiment, the direct-type backlight module includes a back plate 30, a plurality of LED light sources 40, a light guide plate 50, and an optical film 60 arranged in sequence, and also includes a reflective cover 10 of any of the above-mentioned embodiments, the reflective cover 10 is arranged between the back plate 30 and the light guide plate 50, and at least one LED light source 40 is arranged in the bottom opening 14 of the reflective cup 11. The present invention sets an anti-reflection structure 16 at the edge of the top opening 15 of the reflective cup 11 of the reflective cover 10, so that the light of the LED light source 40 incident on the top opening 15 near the reflective cup 11 will be absorbed or attenuated by the anti-reflection structure 16, thereby reducing the diffusion phenomenon. The LED light source 40 is particularly suitable for a Mini LED light source. The reflector 10 with the anti-reflection structure 16 of the present invention helps the Mini LED direct-type backlight module to achieve accurate regional dimming, thereby increasing the contrast between the bright and dark parts of the image, thereby improving the display effect.

Specifically, the optical film 60 of the direct-type backlight module may include an upper diffusion film 61, an upper brightness enhancement film 62, a lower brightness enhancement film 63 and a lower diffusion film 64, which are connected in sequence, and the lower diffusion film 64 is connected to the light guide plate 50. The actual application is not limited thereto, and the optical film 60 may be a reflective film, an anti-reflection film, a filter, a polarizing film, a compensation film, an alignment film, a diffusion film, a brightness enhancement film, a light shielding film, etc., according to its purpose, characteristics and application.

In summary, according to the reflector cover and the direct-type backlight module having the reflector cover provided by the present invention, the anti-reflection structure is used to reduce the light reflection near the top opening of the reflector cup, so that the diffuse reflection phenomenon caused by the structural end of the reflector cup is greatly improved, and the optical effect of the reflector cover in the direct-type backlight module can be enhanced, thereby achieving more precise backlight and picture brightness control.

However, the above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Therefore, all equivalent changes or modifications based on the features and spirit described in the scope of the present invention should be included in the scope of the patent application of the present invention.

1: Reflector 2: Reflector cup 3: Opening 4: Light source 10: Reflector 11: Reflector cup 13: Reflective side 14: Bottom opening 15: Top opening 16: Anti-reflection structure 18: Ink resin composite particles 21: Ink layer 22: Inkjet particles 24: Inner layer 25: Outer layer 30: Backplane 40: LED light source 50: Light guide plate 60: Optical film 61: Upper diffusion film 62: Upper brightness enhancement film 63: Lower brightness enhancement film 64: Lower diffusion film D: Width d: Spacing t: Thickness

FIG. 1 is a top view of a reflector cover of the prior art. FIG. 2 is a cross-sectional view of a reflector cup along the section line _x1 - _x1 in FIG. 1, where diffuse reflection occurs at the end of the structure. FIG. 3 is a top view of a reflector cover of the first embodiment provided by the present invention. FIG. 4 is a partial cross-sectional view of the reflector cover along the section line _x2 - _x2 in FIG. 3, where three reflector cups are shown. FIG. 5 is a schematic diagram of the structure of a reflector cup in FIG. 4. FIG. 6 and FIG. 7 are schematic diagrams of the partial distribution of the anti-reflection structure of the first embodiment provided by the present invention. FIG. 8 is a schematic diagram of the structure of a reflector cup of the second embodiment provided by the present invention. FIG. 9 is a cross-sectional view of a reflector cup along the section line _x3 - _x3 in FIG. 8. FIG. 10 is a cross-sectional view of a reflector cup of the third embodiment provided by the present invention. Figure 11 is a cross-sectional view of the reflective cup of the fourth embodiment provided by the present invention. Figure 12 is a schematic diagram of the color gradient of the ink layer of the anti-reflective structure of the fifth embodiment provided by the present invention. Figure 13 is a schematic diagram of the inkjet particle distribution of the anti-reflective structure of the sixth embodiment provided by the present invention. Figure 14 is a schematic diagram of the inkjet particle distribution of the anti-reflective structure of the seventh embodiment provided by the present invention. Figure 15 is a cross-sectional view of the reflective cup of the eighth embodiment provided by the present invention. Figure 16 is an exploded view of the direct-type backlight module of the ninth embodiment provided by the present invention.

11: Reflection cup

13: Reflective side

15: Top opening

16: Anti-reflection structure

40:LED light source

t: thickness

Claims (15)

A reflector, comprising a plurality of reflector cups, each of which comprises a bottom opening and a reflective side surface surrounding and connected to the bottom opening, the reflective side surface being provided with a top opening away from the bottom opening, wherein: the reflector further comprises an anti-reflection structure, the anti-reflection structure being provided only along the edge of the top opening of the reflective side surface, and the reflectivity of the surface of the anti-reflection structure being lower than that of the reflective side surface. A reflective cover as described in claim 1, wherein the anti-reflective structure comprises a low-reflective material or a light-absorbing material. A reflector as described in claim 1, wherein the reflectivity of the anti-reflection structure surface is 1 to 90%. A reflector as described in claim 1, wherein the anti-reflection structure is configured as a strip pattern, and the strip pattern extends in the length direction to be distributed continuously or discontinuously along the edge of the top opening. A reflector as described in claim 4, wherein the strip pattern has a width of at least 0.1 mm. A reflector as described in claim 4, wherein the anti-reflection structure is configured as a plurality of strip patterns, and the spacing between the strip patterns is less than 0.1 mm. A reflector as described in claim 1, wherein the thickness of the anti-reflection structure is greater than 9 microns. A reflector as described in claim 1, wherein the anti-reflection structure is a flat surface structure, a rough surface structure or an arc curved surface structure. A reflective cover as described in claim 1, wherein the anti-reflective structure is formed by stacking and arranging a plurality of ink resin composite particles. A reflective cover as described in claim 1, wherein the reflectivity of the anti-reflective structure increases sequentially from the top opening to the bottom opening. A reflective cover as described in claim 1, wherein the anti-reflective structure is an ink layer, and the color of the ink layer gradually becomes lighter from the top opening to the bottom opening. A reflective cover as described in claim 1, wherein the anti-reflective structure is formed by arranging a plurality of inkjet particles, and the sizes of the inkjet particles decrease in sequence from the top opening to the bottom opening. A reflective cover as described in claim 1, wherein the anti-reflective structure is formed by arranging a plurality of inkjet particles, and the density of the inkjet particles decreases in sequence from the top opening to the bottom opening. A reflector as described in claim 1, wherein the anti-reflection structure is formed by a multi-layer adhesive tape, and the color of the multi-layer adhesive tape gradually becomes darker from the inner layer attached to the reflective side to the outer layer. A direct-type backlight module comprises a back plate, a plurality of LED light sources, a light guide plate and an optical film arranged in sequence, characterized in that: The direct-type backlight module further comprises a reflector as described in any one of claims 1-14, the reflector is arranged between the back plate and the light guide plate, and at least one of the LED light sources is arranged in the bottom opening.

Images