CN111025744A - Mixed light optical film, backlight module and display device - Google Patents

Abstract

The invention relates to a light mixing optical film, a backlight module and a display device, wherein the light mixing optical film comprises an optical base film layer and a light mixing structure layer, the light mixing structure layer comprises at least two layers of light mixing structure layers, the at least two layers of light mixing structure layers are arranged on the surface and/or inside the optical base film layer, and the projections of the at least two layers of light mixing structure layers on the lower surface of the optical base film are partially overlapped, so that the total thicknesses of the light mixing structure layers in different regions are different. When the illumination intensity of the Mini LED in each area is different, the total thickness of the light mixing structure layer of each area with the different illumination intensity is set to be different, so that the light transmittance of each area with the different illumination intensity is different, and the brightness of the light passing through each area is basically similar, so that the bright spots and the dark spots on the backlight module provided with the light mixing optical film are eliminated, the thickness of the backlight module is not increased, and the problem that the backlight uniformity and the light efficiency of the Mini backlight module are contradictory is solved.

Description

Mixed light optical film, backlight module and display device

Technical Field

The invention relates to the technical field of display, in particular to a light-mixing optical film, a backlight module and a display device.

Background

The MiniLED, also known as a submillimeter LED, is a surface-mount LED consisting of a large number of individual LED chips of 100 to 300 microns in size, and the MiniLED technology is a transition technology between the conventional LED technology and the micro LED (micro LED) technology.

Most of the existing MiniLED backlight modules adopt a bottom light emitting mode, and a light mixing structure is adopted to realize uniform light mixing in order to realize a better light mixing effect. The light mixing structure is usually realized by printing, coating, spraying, spot coating or a mold, the mold cannot be matched with the design of a plurality of differentiated MiniLED light sources due to cost, and the light mixing structures generated by other modes are parallel structures, namely, the thicknesses of the light mixing structures generated by the modes are consistent no matter the light mixing structures are dots or patterns or other types, and the differences of the transmittances cannot be generated. However, because the MiniLED has different luminous intensities in each region, the backlight module using the MiniLED as a light source is prone to have bright spots or dark spots, and other film materials need to be added to eliminate the bright spots or the dark spots.

Disclosure of Invention

The invention aims to provide a light-mixing optical film, a backlight module and a display device, and aims to solve the technical problems that in the prior art, if bright spots or dark spots on the backlight module using a MiniLED as a light source are eliminated, only a film can be increased, and the thickness of the backlight module can be increased.

The invention is realized in such a way that the light-mixing optical film comprises an optical base film layer and a light-mixing structure layer, wherein the light-mixing structure layer comprises at least two light-mixing sub-structure layers, and a light-homogenizing layer for enhancing light reflection and scattering is arranged in each light-mixing sub-structure layer;

the at least two mixed photon structure layers are arranged on the surface and/or inside the optical base film layer, and projections of the at least two mixed photon structure layers on the lower surface of the optical base film layer are partially overlapped, so that the total thicknesses of the mixed photon structure layers in different regions are different.

Further, the optical base film layer is an optical base film with an optical function, the surface of the optical base film includes an upper surface and a lower surface which are oppositely arranged, and the mixed photon structure layer in the mixed light structure layer is arranged on at least one of the upper surface and the lower surface of the optical base film.

And further, the mixed photon structure layers are arranged on the same surface of the optical base film, have different areas and are sequentially stacked on the surface of the optical base film.

Further, the mixed photon structure layers are arranged on different surfaces of the optical base film, and the projection of the mixed photon structure layer with a small area on the lower surface of the optical base film is contained in the projection of the mixed photon structure layer with a large area on the lower surface of the optical base film.

Further, the optical base film layer is a composite optical film, and the mixed photon structure layer in the mixed light structure layer is arranged inside the composite optical film.

Further, the optical base film layer is a composite optical film, the surface of the composite optical film comprises an upper surface and a lower surface, and the mixed photon structure layer in the mixed light structure layer is arranged on at least one of the upper surface and the lower surface of the composite optical film.

Further, the optical base film layer is a composite optical film, the surface of the composite optical film comprises an upper surface and a lower surface, the mixed optical sub-structure layer in the mixed optical structure layer is arranged in the composite optical film, and at least one of the upper surface and the lower surface of the composite optical film is arranged.

Furthermore, a light homogenizing layer for enhancing light reflection and scattering is arranged in the mixed photon structure layer;

the light homogenizing layer is a reflecting layer formed by a plurality of light homogenizing elements in a layout mode;

the light homogenizing element is formed by at least one structure or pattern of a mesh point, a concave-convex structure, filling and a stripe and is used for reflecting polychromatic light or monochromatic light.

Compared with the prior art, the light-mixing optical film provided by the invention has the following beneficial effects: the light mixing optical film comprises an optical base film layer and a light mixing structure layer, wherein the light mixing structure layer comprises at least two layers of mixed photon structure layers, the at least two layers of mixed photon structure layers are arranged on the surface and/or inside the optical base film layer, the projection of the at least two layers of mixed photon structure layers on the lower surface of the optical base film layer is partially overlapped, the total thickness of the mixed light structure layers in different regions is different, and the light transmittance of the mixed light optical film in different regions is different. When the illumination intensity of the MiniLED in each area is different, the total thickness of the light mixing structure layer of each area with the different illumination intensity is set to be different thicknesses, so that the light transmittance of each area with the different illumination intensity is different, and the brightness of light passing through each area is basically similar, so that the bright spots and the dark spots on the backlight module provided with the light mixing optical film are eliminated, the thickness of the backlight module is not increased, and the problem that the backlight uniformity and the light efficiency of a common backlight module are contradictory is solved.

The invention also provides a backlight module which comprises a light source for emitting light, a circuit board and the light mixing optical film, wherein the light mixing optical film is arranged right above the light source, and a reflecting layer capable of generating reflection is arranged on the surface of the circuit board.

Compared with the prior art, the backlight module provided by the invention has the following beneficial effects: the backlight module adopts the light mixing optical film, so that bright spots and dark spots on the backlight module provided with the light mixing optical film are eliminated, the thickness of the backlight module is not increased, and the problem that the backlight uniformity and the light efficiency of a common backlight module are contradictory is solved. Meanwhile, the ultra-thin design of the backlight module is facilitated, and the production cost of the backlight module is greatly reduced.

The invention also provides a display device which comprises the light mixing optical film or the backlight module. The light mixing effect is better, the ultra-thin design is easier to realize, the production cost is reduced, and the market competitiveness of the product is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic cross-sectional view of a first embodiment of a light-mixing optical film according to the present invention;

FIG. 2 is a schematic cross-sectional view of a second embodiment of a light-mixing optical film according to the present invention;

FIG. 3 is a schematic cross-sectional view of a second embodiment of a light-mixing optical film according to the present invention;

FIG. 4 is a schematic cross-sectional view of a second embodiment of a light-mixing optical film according to the present invention;

FIG. 5 is a schematic cross-sectional view of a second embodiment of a light-mixing optical film according to the present invention;

FIG. 6 is a schematic cross-sectional view of a first embodiment of a light-mixing optical film according to the present invention;

FIG. 7 is a schematic cross-sectional view of a second embodiment of a light-mixing optical film according to the present invention;

FIG. 8 is a schematic cross-sectional view of a third embodiment of a light-mixing optical film according to the present invention;

FIG. 9 is a schematic cross-sectional view of a light-mixing optical film according to a fourth embodiment of the present invention;

FIG. 10 is a schematic cross-sectional view of a second embodiment of a light-mixing optical film according to the present invention;

FIG. 11 is a schematic cross-sectional view of a third optical film according to a fourth embodiment of the present disclosure;

FIG. 12 is a schematic cross-sectional view of a fourth embodiment of a light-mixing optical film according to the present invention;

FIG. 13 is a schematic cross-sectional view of a fourth embodiment of a light-mixing optical film according to the present invention;

FIG. 14 is a schematic cross-sectional view of a sixth embodiment of a light-mixing optical film according to the present invention.

Reference numerals referred to in the above figures are detailed below: 1. an optical base film; 2. a composite optical film; 3. a light mixing structure layer; 31. a first mixed photon structure layer; 32. a second mixed photon structure layer; 33. and a third mixed photon structure layer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly or indirectly secured to the other element. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element. The terms "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positions based on the orientations or positions shown in the drawings, and are for convenience of description only and not to be construed as limiting the technical solution. The terms "first", "second" and "first" are used merely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "plurality" is two or more unless specifically limited otherwise.

In order to explain the technical solution of the present invention, the following detailed description is made with reference to the specific drawings and examples.

The light-mixing optical film provided by the invention is described in detail below with reference to fig. 1 to 14.

It should be noted that the light-mixing optical film can be used in the field of liquid crystal display, and is mainly used in a MiniLED direct type backlight structure, such as liquid crystal display products of mobile phones, tablet computers, vehicle-mounted displays, VR, televisions, and the like. Of course, other suitable fields or structures or products may actually be used.

In general, the light mixing optical film provided by the embodiment of the present invention includes an optical base film layer and a lightmixing structure layer 3, where the lightmixing structure layer 3 includes at least two layers of light mixing structure layers, the at least two layers of light mixing structure layers are disposed on the surface and/or inside of the optical base film layer, and projections of the at least two layers of light mixing structure layers on the lower surface of the optical base film are partially overlapped, so that the total thicknesses of the lightmixing structure layers 3 in different regions are different, and further, the light transmittances of the light mixing optical film in different regions are different. When the illumination intensity of the MiniLED in each area is different, the total thickness of the light mixing structure layer in each area with the different illumination intensity is set to be different, so that the light transmittance of each area with the different illumination intensity is different, and the brightness of light passing through each area is basically similar, so that the bright spots and the dark spots on the light mixing structure layer are eliminated, the thickness of the backlight module is not increased, and the problem that the backlight uniformity and the light efficiency of the common light mixing structure layer are inconsistent is solved. For example, when the illumination intensity of the MiniLED in the first region is greater than the illumination intensity of the MiniLED in the second region, the total thickness of the light mixing structure layer in the first region may be set to be thicker than the total thickness of the light mixing structure layer in the second region, so that the light transmittance of the first region will be smaller than the light transmittance of the second region, so that when the light emitted by the MiniLED exits through the first region and the second region, the brightness is substantially similar, and the bright spots and the dark spots on the light mixing structure layer are eliminated. Wherein, the total thickness of the light mixing structure layer is the sum of the thicknesses of the light mixing sub-structure layers in the region. It should be noted that, the thickness difference of the total thickness of the mixed light structure layers in each region is generally greater than or equal to 5 μm, the stacking position of each mixed light sub-structure layer in the mixed light structure layer is relatively fixed, and the tolerance is less than 0.1 mm. The total thickness of the light-mixing optical film in the embodiment is 50-300 μm.

The mixed photon structure layer is internally provided with a light homogenizing layer for enhancing light reflection and scattering, the reflectivity of the light homogenizing layer is 50% -100%, and the transmissivity of the light homogenizing layer is 0-50%, so that most of light can be reflected and scattered after being irradiated on the light homogenizing layer, namely, the mixed photon structure layer realizes light homogenization mainly through light reflection and scattering on the premise of ensuring the light utilization rate, the light homogenizing effect is obviously improved, and the realization of mixed light with an ultra-short distance is facilitated. Obviously, compare conventional leaded light piece, even membrane materials such as slide, this mixed photon structural layer belongs to a new functional layer that has even light function, simple structure, and the design can be diversified, is convenient for use in different structures, and the very big ultra-thin design of being convenient for does benefit to and extensively uses the popularization.

The light-mixing optical film comprises an optical base film layer and a light-mixingstructural layer 3, wherein the light-mixingstructural layer 3 comprises at least two mixed photon structural layers. In order to improve the light mixing effect of the light mixing optical film, the light mixing sub-structure layer in the lightmixing structure layer 3 is disposed on the surface and/or inside the optical base film layer. It can be understood that the mixed photon structure layer has a dodging function. Thus, when the optical base film layer has other optical functions, the light-mixing optical film has multiple optical functions, not only the dodging function. Therefore, in practical application, some optical films can be omitted by adopting the light-mixing optical film, and the ultra-thin structure is convenient to realize. In addition, as shown in fig. 1 to 14, at least two layers should be disposed on the mixed photon structure layer, and the specific number of the disposed layers should be determined according to actual needs.

In addition, in order to ensure that the mixed photon structure layer has the light uniformizing function, the mixed photon structure layer is provided with a light uniformizing layer. Wherein, the reflectivity of the even light layer is 50-100%, the transmissivity is 0-50%, and the even light layer is mainly used for enhancing the reflection and scattering of light. It can be understood that the light-mixing optical film mainly achieves the purpose of light homogenization by reflecting and scattering incident light, thereby realizing light mixing in an ultra-short distance. It should be noted that the dodging layer may be a highly reflective mirror surface or a highly reflective scattering surface. Further, the mixed photonic structure layer is also mixed with optical particles, which may include but are not limited to: inorganic white particles, organic white particles, colored particles, fluorescent particles, inorganic liquid which is dissolved with the mixed photon structure layer, organic liquid which is dissolved with the mixed photon structure layer, and the like, and the optical particles are used for improving the chromaticity uniformity and the brightness uniformity of the backlight product.

Referring to fig. 1 and fig. 2, a light-mixing optical film according to a first embodiment of the present invention is shown. In this embodiment, the optical base film layer is theoptical base film 1 having an optical function, and the mixed photonic structure layer in the mixedoptical structure layer 3 includes a first mixedphotonic structure layer 31 and a second mixedphotonic structure layer 32, wherein projections of the first mixedphotonic structure layer 31 and the second mixedphotonic structure layer 32 on the lower surface of the optical base film are partially overlapped, so that the total thicknesses of the mixedoptical structure layer 3 in different regions are different. The surface of theoptical base film 1 includes an upper surface and a lower surface which are oppositely arranged, and it should be noted that, in general, the lower surface of theoptical base film 1 may be an incident surface or an emergent surface of light. Correspondingly, the upper surface of theoptical base film 1 may be an exit surface or an entrance surface of light. The mixed photon structure layer in the mixedlight structure layer 3 is disposed on at least one of the upper surface and the lower surface of theoptical base film 1.

Further, the mixed photon structure layers arranged on the same surface of theoptical base film 1 are sequentially stacked on the surface of theoptical base film 1. The mixed photon structure layers are arranged on different surfaces of the optical base film, and the projection of the mixed photon structure layer with a small area on the lower surface of the optical base film is contained in the projection of the mixed photon structure layer with a large area on the lower surface of the optical base film.

Specifically, as shown in fig. 1, a first specific implementation is provided for this embodiment. In this embodiment, the first mixedphoton structure layer 31 and the second mixedphoton structure layer 32 are sequentially stacked on the upper surface of theoptical base film 1. Thus, when the light-mixing optical film is placed right above the MiniLED light source, the light emitted by the MiniLED light source can be incident on the first light-mixingsubstructure layer 31 and the second light-mixingsubstructure layer 32 of the light-mixing optical film, and is reflected and scattered onto the circuit board by the first light-mixingsubstructure layer 31 and the second light-mixingsubstructure layer 32, and then is reflected onto the first light-mixingsubstructure layer 31 and the second light-mixingsubstructure layer 32, so that the light is fully homogenized. Correspondingly, as shown in fig. 2, a second specific embodiment is provided for this embodiment. In this embodiment, the first mixedphotonic structure layer 31 is disposed on the upper surface of theoptical base film 1, the second mixedphotonic structure layer 32 is disposed on the lower surface of theoptical base film 1, and the first mixedphotonic structure layer 31 and the second mixedphotonic structure layer 32 are corresponding in position.

Further, in the present embodiment, as shown in fig. 1 and 2, theoptical base film 1 may be classified as any one of film materials such as a Polyethylene terephthalate (PET) film, an acrylic plastic (acrylics) film, and a Polycarbonate (PC) film; the functional classification may be any one of film materials such as a diffusion film, a brightness enhancement film, a light conversion film, a light selection film, a spectroscopic film, a light diffusion film, an absorption film, and a fluorescent film. Of course, theoptical base film 1 may also be other suitable optical films, and is not limited herein.

It is understood that, taking theoptical base film 1 as a diffusion film as an example, the light-mixing optical film has not only a light-homogenizing function but also a light-diffusing function. Therefore, in practical application, theoptical base film 1 with different functions can be selected according to actual needs to design the light-mixing optical film, so that the material saving and ultrathin design can be realized.

Further, in this embodiment, the dodging layer is a reflective layer laid out by a plurality of dodging elements. Wherein the light homogenizing element is formed by at least one structure or pattern of lattice points, concave-convex structures, fillings or stripes, and specifically, the light homogenizing element is an opaque thin layer with white color or other colors (such as red, orange, yellow, green, cyan, blue or purple, etc.). It will be appreciated that the light homogenizing element is primarily configured to reflect polychromatic or monochromatic light, such as white or other colored light. Taking one of the dodging elements as a dot as an example, the dodging layer may be formed by arranging all the dot structures, may be formed by arranging all the dot patterns, may be formed by arranging a part of the dot structures and another part of the dot patterns in a mixed manner, and may be formed by arranging a part of the dot structures, a part of the concave-convex structures, a part of the stripe patterns in a mixed manner. Of course, in practice, the light homogenizing element can also be other suitable structures or patterns that function as light homogenizing elements. In addition, in order to achieve a better light mixing effect, all the light homogenizing elements are generally uniformly arranged.

Further, in this embodiment, in order to improve the light uniformizing effect, the light mixing sub-structure layer is usually located right above the MiniLED light source, and the arrangement density of the light uniformizing elements is inversely related to the distance between the light uniformizing elements and the MiniLED light source. In other words, the closer to the position of the MiniLED light source, the more densely the arrangement of the light uniformizing elements is, whereas the farther from the position of the MiniLED light source, the more sparsely the arrangement of the light uniformizing elements is.

Referring to fig. 3 to 5, a light-mixing optical film according to a second embodiment of the present invention is shown. The main technical features of this embodiment are substantially the same as those of the first embodiment, and are not described herein again, and the main differences from the first embodiment are as follows:

in the embodiment, the mixed optical sub-structure layer in the mixedoptical structure layer 3 includes a first mixedoptical sub-structure layer 31, a second mixedoptical sub-structure layer 32 and a third mixedoptical sub-structure layer 33, wherein the first mixedoptical sub-structure layer 31, the second mixedoptical sub-structure layer 32 and the third mixedoptical sub-structure layer 33 have different areas and corresponding positions, so that the total thickness of the mixedoptical structure layer 3 in different regions is different.

Specifically, as shown in fig. 3, a first specific implementation is provided for this embodiment. In this embodiment, the first mixedphotonic structure layer 31, the second mixedphotonic structure layer 32 and the third mixedphotonic structure layer 33 are sequentially stacked on the upper surface of theoptical base film 1. As shown in fig. 4, a second embodiment is provided for this embodiment. In this embodiment, the first mixedphotonic structure layer 31 and the second mixedphotonic structure layer 32 are sequentially stacked on the upper surface of theoptical base film 1, the third mixedphotonic structure layer 33 is disposed on the lower surface of theoptical base film 1, and the first mixedphotonic structure layer 31 and the second mixedphotonic structure layer 32 correspond to the third mixedphotonic structure layer 33. As shown in fig. 5, a third embodiment is provided for this example. In this embodiment, the first mixedphotonic structure layer 31 is disposed on the upper surface of theoptical base film 1, the second mixedphotonic structure layer 32 and the third mixedphotonic structure layer 33 are sequentially stacked on the lower surface of theoptical base film 1, and the first mixedphotonic structure layer 31 corresponds to the second mixedphotonic structure layer 32 and the third mixedphotonic structure layer 33.

Referring to fig. 6 to 8, a light-mixing optical film according to a third embodiment of the present invention is shown. The main technical features of this embodiment are substantially the same as those of the first embodiment, and are not described herein again, and the main differences from the first embodiment are as follows:

in the embodiment, the optical base film layer is a composite optical film 2, and the composite optical film 2 can be formed by compoundingoptical base films 1 with the same optical function; or the optical base film can be compounded by at least twooptical base films 1 with different optical functions; or a base film, and the base film is processed by printing, coating, spraying, spot coating or die, etc. to form an optical film with multiple optical functions, wherein the optical film has at least two of the functions of diffusion, light enhancement, light conversion, light selection, light splitting, light scattering, absorption, etc. Specifically, in the present embodiment, the composite optical film 2 is formed by combining twooptical base films 1. It can be understood that, in this embodiment, the light-mixing optical film not only has the light-homogenizing function, but also has a plurality of optical functions, so that some film materials with the same function can be omitted by using the light-mixing optical film, and the purpose of saving cost is achieved.

It is understood that in the present embodiment, the composite optical film 2 may be formed by combining a PET film and a diffusion film, so that the PET film and/or the diffusion film in the optical structure may be omitted; the composite optical film 2 may be formed by compounding a diffusion film and a fluorescent film, and the composite optical film 2 may be formed by compounding a PET film, a diffusion film and a fluorescent film.

Specifically, as shown in fig. 6, a first specific embodiment is provided for this embodiment. In this embodiment, the first mixedphotonic structure layer 31 and the second mixedphotonic structure layer 32 are sequentially stacked between twooptical base films 1. In the present embodiment, the first mixedphotonic structure layer 31 and the second mixedphotonic structure layer 32 are disposed between two types ofoptical base films 1, and the mixed photonic structure layer is not disposed on the surface of the composite optical film 2, that is, the mixed photonic structure layer is only disposed inside the composite optical film 2.

Further, as shown in fig. 7 to 8, in addition to the mixed photon structure layer provided between the two kinds ofoptical base films 1, a mixed photon structure layer is provided on at least one of the upper surface and the lower surface of the composite optical film 2. Fig. 7 shows a second specific embodiment of this embodiment. In this embodiment, the first mixedphotonic structure layer 31 is disposed on the upper surface of the composite optical film 2, and the second mixedphotonic structure layer 32 is disposed between twooptical base films 1 of the composite optical film 2. Fig. 8 shows a third embodiment of the present embodiment. In this embodiment, the first mixedphotonic structure layer 31 is disposed between twooptical base films 1 of the composite optical film 2, and the second mixedphotonic structure layer 32 is disposed on the lower surface of the composite optical film 2. Of course, in another specific embodiment provided in this embodiment, the mixed photon structure layer may be disposed only on at least one of the upper surface and the lower surface of the composite optical film 2, and not disposed inside thereof.

Obviously, compared with the first embodiment, the structure in the present embodiment is more complex, but the optical function that can be realized is more, and the light mixing effect is better.

Please refer to fig. 9 to 14, which illustrate a light-mixing optical film according to a fourth embodiment of the present invention. The main technical features of this embodiment are substantially the same as those of the first embodiment, and are not described herein again, and the main differences from the first embodiment are as follows:

in the embodiment, the mixed optical sub-structure layer in the mixedoptical structure layer 3 includes a first mixedoptical sub-structure layer 31, a second mixedoptical sub-structure layer 32 and a third mixedoptical sub-structure layer 33, wherein the first mixedoptical sub-structure layer 31, the second mixedoptical sub-structure layer 32 and the third mixedoptical sub-structure layer 33 have different areas and corresponding positions, so that the total thickness of the mixedoptical structure layer 3 in different regions is different. The optical base film layer is a composite optical film 2, and the composite optical film 2 can be formed by compoundingoptical base films 1 with the same optical function; or the optical base film can be compounded by at least twooptical base films 1 with different optical functions; or a base film, and the base film is processed by printing, coating, spraying, spot coating or die, etc. to form an optical film with multiple optical functions, wherein the optical film has at least two of the functions of diffusion, light enhancement, light conversion, light selection, light splitting, light scattering, absorption, etc. Specifically, in the present embodiment, the composite optical film 2 is formed by combining twooptical base films 1. It can be understood that, in this embodiment, the light-mixing optical film not only has the light-homogenizing function, but also has a plurality of optical functions, so that some film materials with the same function can be omitted by using the light-mixing optical film, and the purpose of saving cost is achieved.

Specifically, as shown in fig. 9, a first specific embodiment is provided for this embodiment. In this embodiment, the first mixedphotonic structure layer 31, the second mixedphotonic structure layer 32 and the third mixedphotonic structure layer 33 are sequentially stacked between twooptical base films 1. As shown in fig. 10, a second embodiment is provided for this example. In this embodiment, the first mixedphotonic structure layer 31 and the second mixedphotonic structure layer 32 are sequentially stacked between twooptical base films 1, and the third mixedphotonic structure layer 33 is disposed on the upper surface of the composite optical film 2. As shown in fig. 11, a third embodiment is provided for this embodiment. In this embodiment, the first mixedphotonic structure layer 31 and the second mixedphotonic structure layer 32 are sequentially stacked between twooptical base films 1, and the third mixedphotonic structure layer 33 is disposed on the lower surface of the composite optical film 2. As shown in fig. 12, a fourth embodiment is provided for this example. In this embodiment, the first mixedphotonic structure layer 31 is disposed between twooptical base films 1, and the second mixedphotonic structure layer 32 and the third mixedphotonic structure layer 33 are sequentially stacked on the upper surface of the composite optical film 2. As shown in fig. 13, a fifth embodiment is provided for this embodiment. In this embodiment, the first mixedphotonic structure layer 31 is disposed between twooptical base films 1, and the second mixedphotonic structure layer 32 and the third mixedphotonic structure layer 33 are sequentially stacked on the upper surface of the composite optical film 2. As shown in fig. 14, a sixth embodiment is provided for this embodiment. In this embodiment, the first mixedphotonic structure layer 31 is disposed on the upper surface of the composite optical film 2, the second mixedphotonic structure layer 32 is disposed between the twooptical base films 1, and the third mixedphotonic structure layer 33 is disposed on the lower surface of the composite optical film 2. Of course, in another specific embodiment provided in this embodiment, the mixed photon structure layer may be disposed only on at least one of the upper surface and the lower surface of the composite optical film 2, and not disposed inside thereof.

The embodiment of the invention also provides a backlight module which comprises a light source for emitting light and the light mixing optical film. The light mixing optical film is arranged right above the light source.

It should be noted that, in the backlight module, the light source is usually formed by arranging a plurality of MiniLED light emitting units in an array. It is understood that the dodging element in the mixed light sub-structure layer of the mixed light structure layer is usually located right above the light emitting unit.

Therefore, the backlight module can conveniently increase the distance between the light emitting units, namely, can ensure the uniform light mixing among the light emitting units with larger distances, is favorable for saving the number of light source components, further greatly saves the production cost, and is favorable for realizing the ultrathin design of the direct type backlight module on the premise of ensuring the light utilization rate and the better light mixing effect.

Furthermore, the backlight module also comprises a circuit board. Typically, the circuit board may be a rigid printed circuit board, a flexible circuit board or other suitable circuit board. In order to enhance the light mixing effect of the backlight module, a reflecting layer is arranged on the surface of the circuit board. Wherein the reflective layer is reflective, typically predominantly diffuse, to ensure that the reflectivity of the reflective layer is greater than or equal to 80%. Specifically, in this embodiment, the circuit board is a flexible circuit board; the reflective layer is a white oil reflective layer, although in practice other suitable reflective layers may be used.

It can be understood that, in general, the light mixing distance of the light mixing optical film is the distance from the surface of the reflecting layer to the light homogenizing layer of the light mixing optical film close to the reflecting layer. In this embodiment, the light mixing distance can be less than 0.3 mm. In practical applications, the light mixing distance may vary according to the display device.

The embodiment of the invention also provides a display device which comprises the light mixing optical film or the backlight module. The display device can be products or components with any display function, such as a mobile phone, a tablet personal computer, a vehicle-mounted display, a liquid crystal television, a liquid crystal display, a notebook computer, a computer display, a digital photo frame, a navigator and the like.

The invention is not to be considered as limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.

Claims (10)

1. The light-mixing optical film is characterized by comprising an optical base film layer and a light-mixing structural layer, wherein the light-mixing structural layer comprises at least two light-mixing sub-structural layers, and a light-homogenizing layer for enhancing light reflection and scattering is arranged in the light-mixing sub-structural layer;

the at least two mixed photon structure layers are arranged on the surface and/or inside the optical base film layer, and projections of the at least two mixed photon structure layers on the lower surface of the optical base film layer are partially overlapped, so that the total thicknesses of the mixed photon structure layers in different regions are different.

2. The light-mixing optical film of claim 1, wherein the optical base film layer is an optical base film having an optical function, the surface of the optical base film includes an upper surface and a lower surface that are opposite to each other, and the mixed photonic structure layer of the mixed light structure layer is disposed on at least one of the upper surface and the lower surface of the optical base film.

3. The light-mixing optical film of claim 2, wherein the light-mixing sub-structure layers are disposed on the same surface of the optical base film, and each of the light-mixing sub-structure layers has different areas and is sequentially stacked on the surface of the optical base film.

4. The light-mixing optical film of claim 2, wherein the projection of the small-area mixed photon structure layer on the lower surface of the optical base film is included in the projection of the large-area mixed photon structure layer on the lower surface of the optical base film.

5. The light-mixing optical film of claim 1, wherein the optical base film layer is a composite optical film, and the mixed photon structure layer in the mixed light structure layer is disposed inside the composite optical film.

6. The light-mixing optical film of claim 1, wherein the optical base film layer is a composite optical film, the surface of the composite optical film comprises an upper surface and a lower surface, and the mixed optical sub-structure layer in the mixed optical structure layer is disposed on at least one of the upper surface and the lower surface of the composite optical film.

7. The light-mixing optical film according to claim 1, wherein the optical base film layer is a composite optical film, the surface of the composite optical film comprises an upper surface and a lower surface, the mixed light substructure layer in the mixed light structure layer is disposed inside the composite optical film, and at least one of the upper surface and the lower surface of the composite optical film.

8. The light-mixing optical film of claim 1, wherein a light-homogenizing layer is disposed in the light-mixing photonic structure layer to enhance light reflection and scattering;

the light homogenizing layer is a reflecting layer formed by a plurality of light homogenizing elements in a layout mode;

the light homogenizing element is formed by at least one structure or pattern of a mesh point, a concave-convex structure, filling and a stripe and is used for reflecting polychromatic light or monochromatic light.

9. A backlight module, comprising a light source for emitting light, a circuit board, and the optical film according to any one of claims 1 to 8, wherein the optical film is disposed directly above the light source, and a reflective layer is disposed on the surface of the circuit board for generating reflection.

10. A display device, characterized in that the display device comprises the light-mixing optical film according to any one of claims 1 to 8 or comprises the backlight module according to claim 9.

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