TWI863254B - Light guiding member and front light module - Google Patents

Abstract

A light guiding member and a front light module is provided by the present invention, wherein the light guiding member has a light guiding region and a light mixing region disposed at a side of the light guiding region. The light guiding member includes a base film and an optical film disposed on the base film. The optical film and the base film include different materials, wherein the optical film includes an upper surface and a lower surface opposite to each other, the lower surface directly contacts the base film, the upper surface has a light controlling microstructure, and the light controlling microstructure includes optical directivity patterns. The thickness of the portion of the optical film in the light guiding region is not greater than the thickness of the base film.

Description

Light guide components and front light modules

The present invention relates to a light guide component and a front light module, and in particular to a light guide component and a front light module having a surface microstructure.

The front light module can be applied to a non-self-luminous display panel to provide a display light source. Specifically, the front light module can be arranged on one side of the display surface of the display panel (such as a reflective display panel or a micro-transmission display panel) and provide light, wherein the light can be emitted to the surface of the display panel and displayed after being reflected by the display panel. The front light module may include a light-emitting element and a light-guiding component, wherein the light-guiding component can make the light emitted by the light-emitting element uniform and guide it into the display panel. However, the existing front light module may have a problem of uneven light intensity due to the poor light uniformity effect of the light-guiding component, or the thickness of the front light module may be too thick, making the overall thickness of the display device larger. Therefore, how to improve the design of the light-guiding component to improve the light-emitting effect of the front light module or reduce the thickness of the front light module is one of the important issues.

The main purpose of the present invention is to provide a light guide assembly that can improve the uniform light characteristics and reliability and a front light module including the light guide assembly, wherein the front light module can achieve a thinning effect.

An embodiment of the present invention provides a light guide assembly, wherein the light guide assembly has a light guide area and a light mixing area disposed on one side of the light guide area. The light guide assembly includes a base film and an optical film disposed on the base film. The optical film and the base film include different materials, wherein the optical film includes an upper surface and a lower surface opposite to each other, the lower surface is in direct contact with the base film, and the upper surface has a light control microstructure, and the light control microstructure includes an optical directivity pattern. The thickness of the optical film in the light guide area is not greater than the thickness of the base film.

Another embodiment of the present invention provides a front light module, which may include the above-mentioned light guide assembly and at least one light-emitting element. The light-emitting element is arranged adjacent to the light mixing area, wherein the light emitted by the light-emitting element enters the light guide assembly from the light mixing area.

BF: Basement membrane

C1, A1, B1, D1: thickness

DD: Display device

DP: Display Panel

FM: front light module

GR: Light-guiding area

L1,L2,L3: Light

LG: Light guide components

LT: Length

LU: Light-emitting element

LU1: First light emitter

MR: Mixed light area

MS, MSR, MSG, MSR’, MSG’: light-controlling microstructures

OF:Optical film

PP: protruding part

S1: Second surface

S3: Lower surface

S2,TS1,TS2,TS3: upper surface

S4: First surface

SL1,SL2,SL3: Side

SW: Sidewall

X,Y,Z: Direction

Figure 1 is a schematic diagram of the appearance structure of the front light module of the first embodiment of the present invention.

Figure 2 is a cross-sectional schematic diagram of the front light module of the first embodiment of the present invention.

Figure 3 is a schematic diagram of the appearance structure of the front light module of the second embodiment of the present invention.

Figure 4 is a cross-sectional schematic diagram of the front light module of the second embodiment of the present invention.

Figure 5 is a schematic diagram of the appearance structure of the front light module of the third embodiment of the present invention.

Figure 6 is a top view schematic diagram of the front light module of the third embodiment of the present invention.

Figure 7 is a schematic cross-sectional view of a display device including the front light module of the present invention.

The present invention can be understood by referring to the following detailed description and combining it with the drawings. It should be noted that in order to make it easier for readers to understand and the drawings are concise, the multiple drawings in the present invention only depict a part of the front light module or a display device including the front light module, and the specific components in the drawings are not drawn according to the actual scale. In addition, the number and size of each component in the figure are only for illustration and are not used to limit the scope of the present invention.

Certain terms are used throughout the specification and patent application of this invention to refer to specific components. Those skilled in the art should understand that manufacturers may refer to the same component by different names. This document does not intend to distinguish between components that have the same function but different names. In the following specification and patent application, the words "including" and "comprising" are open-ended words, so they should be interpreted as "including but not limited to...".

It should be understood that when an element or a layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or directly connected to the other element or layer, or there can be an intervening element or layer between the two. Conversely, when an element is referred to as being "directly" on or "directly connected to" another element or layer, there can be no intervening element or layer between the two.

It should be noted that the following embodiments can replace, reorganize, and mix the technical features in several different embodiments to complete other embodiments without departing from the spirit of the present invention.

Please refer to Figures 1 and 2. Figure 1 is a schematic diagram of the appearance structure of the front light module of the first embodiment of the present invention, and Figure 2 is a schematic cross-sectional diagram of the front light module of the first embodiment of the present invention. The front light module of the present invention can be applied to a non-self-luminous display device as a light source in the display device. The non-self-luminous display device may include, for example, a reflective display panel or a micro-transmission display panel, but is not limited thereto. At the same time, the front light module of the present invention can be applied to any suitable display device. For example, it includes a laptop, a public display, a spliced display, a car display, a touch display, a television, a monitor, a smart phone, a tablet computer, an electronic reader, a lighting device, or an electronic device applied to the above products, etc.

According to the present embodiment, the front light module FM includes a light guide component LG and a light emitting element LU, but is not limited to the above. The light emitting element LU can emit light (such as light L1 and light L2 shown in FIG. 2) to the light guide component LG. When the front light module FM is applied to a display device, the light guide component LG can make the light emitted by the light emitting element LU have a light uniformity effect and guide the light to the display panel in the display device as a display light source. Specifically, the light guide component LG can have a light guide area GR and a light mixing area MR. The light mixing area MR can be set on one side of the light guide area GR, and the light emitting element LU is set adjacent to the light mixing area MR of the light guide component LG. In other words, the light emitted by the light emitting element LU can enter the light guide component LG from the light mixing area MR. In the light mixing region MR, light can be refracted, reflected, diffused or the light path can be changed in other ways through the structure of the light guide component LG, thereby achieving a light mixing effect. Then, the mixed light can enter the light guide region GR from the light mixing region MR, and emit from the light output area of the front light module FM in the light guide region GR to serve as a display light source for the display panel. The light output area of the front light module FM can roughly overlap with the light guide region GR, so the light guide region GR can roughly overlap with the display area of the display device. The light emitted by the light-emitting element LU of the present embodiment can be a point light source or a line light source, and when the light enters the light mixing region MR of the light guide component LG, the light can be mixed in the light mixing region MR, so that the light output of the front light module FM is more uniform and can be converted into a surface light source, thereby improving the light output effect of the front light module FM. In this embodiment, the light emitting element LU may include, for example, a light bar on which a plurality of light emitting diodes are disposed, but is not limited thereto. In some embodiments, the light emitting element LU may include any suitable light emitting diode. The light emitting diode may include, for example, a sub-millimeter light emitting diode (mini LED), a micro light emitting diode (micro LED), or other types of light emitting diodes, but is not limited thereto.

According to the present embodiment, the light guide component LG includes a base film BF and an optical film OF disposed on the base film BF. In other words, the light guide component LG of the front light module FM is formed by stacking the base film BF and the optical film OF in sequence. According to the present embodiment, the base film BF and the optical film OF include different materials, that is, they are formed by different materials, so the light guide component LG of the present embodiment may include at least two materials, or may be formed by stacking at least two materials. In some embodiments, the optical film OF and the base film BF may be formed by different processes, and the optical film OF may be disposed on the base film BF in any suitable manner to form the light guide component. The structure and other features of each film layer of the light guide component LG of the present embodiment will be described in detail below.

According to the present embodiment, the base film BF may include any suitable light-guiding material, such as polymethyl methacrylate (PMMA), but not limited thereto. The base film BF has a high transmittance or a low light absorption rate, so that light can advance in the base film BF. In some embodiments, the transmittance of the base film BF may be not less than 89%, but not limited thereto. As shown in FIG. 1 and FIG. 2 , the base film BF has a first surface S4 and a second surface S1, wherein the first surface S4 and the second surface S1 may be respectively regarded as the upper surface and the lower surface of the base film BF, the first surface S4 is the surface of the base film BF facing the optical film OF, and the second surface S1 is the surface of the base film BF away from the optical film OF. According to the present embodiment, the light emitted by the light-emitting element LU may leave the light-guiding component LG from the second surface S1 of the base film BF, that is, the second surface S1 of the base film BF may be the light-emitting surface of the front light module FM. The base film BF of this embodiment has a substantially uniform thickness, that is, the base film BF is substantially a flat film layer. In other words, the thickness of the base film BF in the light guiding region GR and the thickness of the base film BF in the light mixing region MR can be substantially the same, for example, the thickness C1 of the base film BF shown in FIG. 2 .

The optical film OF is disposed on the base film BF, wherein in the top-view direction of the front light module FM (for example, parallel to the direction Z), the two sides of the optical film OF may be respectively aligned with the two sides of the base film BF. In other words, the optical film OF may not protrude from the base film BF. The optical film OF includes an upper surface S2 and a lower surface S3 opposite to each other, wherein the lower surface S3 is in direct contact with the base film BF, that is, no other film layer is included between the optical film OF and the base film BF. According to this embodiment, the optical film OF may have high transmittance, low haze value, and low light absorption rate. Specifically, the transmittance of the optical film OF may be not less than 89%. In some embodiments, the transmittance of the optical film OF may be greater than 89%. In some embodiments, the transmittance of the optical film OF may be greater than 89%. In some embodiments, the transmittance of the optical film OF may be greater than 89% or less than 95%. In some embodiments, the haze value of the optical film OF may be less than 0.5. In some embodiments, the haze value of the optical film OF may be between 0.5 and 0.3. Specifically, the light absorptivity of the optical film OF may be less than 0.07%. In some embodiments, the light absorptivity of the optical film OF may be between 0.07% and 0.03%. In some embodiments, the light absorptivity of the optical film OF may be less than 0.03%. The refractive index of the optical film OF may be between 1.3 and 1.7, and the refractive index of the base film BF may be greater than 1.7, but not limited thereto. Furthermore, in this embodiment, a material having a hardness greater than that of the base film BF may be selected as the material of the optical film OF, that is, the hardness of the optical film OF may be greater than that of the base film BF, for example, the hardness of the optical film OF may range from 1H to 4H, but not limited thereto.

Accordingly, in this embodiment, a material that meets the above characteristics can be selected as the material of the optical film OF. In detail, the optical film OF may include a first material, wherein the first material may be selected from any suitable material having high light transmittance, low haze value, and low light absorption rate. In some embodiments, the first material may also be selected from a material whose refractive index may be between 1.3 and 1.7. In some embodiments, the first material may also be selected from a material whose hardness is greater than the hardness of the base film BF, that is, the hardness of the first material may be greater than the hardness of the base film BF. For example, the optical film OF may include, for example, a transparent polymer material, but is not limited thereto. The transparent polymer material may include, for example, ultraviolet (UV) optical glue, resin (such as polycarbonate, polyethylene terephthalate, but not limited thereto), artificial fiber, other suitable materials, or a combination of the above materials. It should be noted that the above-mentioned examples of the first material are only exemplary, and the optical film OF may include any suitable material that meets the above-mentioned characteristics, and the present invention is not limited thereto. In some embodiments, the first material included in the optical film OF may be a single material. In some embodiments, the first material may be a composite material, wherein the composite material is formed by two or more materials that meet the above-mentioned characteristics. Through the first material, the optical film OF can have high light transmittance, low haze value, and low light absorption rate, thereby making the optical film OF have good optical properties. In other words, light can more easily advance in the optical film OF without being absorbed and/or blocked. In addition, by including the first material with higher hardness, the surface of the optical film OF can have good scratch resistance and corrosion resistance. When the optical film OF is set on the base film BF, the optical film OF can provide the protection effect of the base film BF, thereby improving the reliability of the light guide component LG.

A1/C1

2)，而厚度B1對厚度C1的比值範圍從0.001到0.99(即， 0.001

B1/C1

0.99)。在另一些實施例中，厚度B1可與厚度C1相同。換句話說，厚度A1、厚度B1與厚度C1三個值中至少有兩個值不相等。據此，可改善基底膜BF對於光學膜OF的支撐效果，進而改善導光組件LG的可靠性。 Please refer to Figure 2. The portion of the optical film OF in the light guiding region GR of the light guiding component LG and the portion of the optical film OF in the light mixing region MR of the light guiding component LG may have different thicknesses. In detail, as shown in Figure 2, the portion of the optical film OF in the light mixing region MR may have a thickness A1, and the portion of the optical film OF in the light guiding region GR may have a thickness B1, wherein the thickness A1 and the thickness B1 may be different. The thickness A1 may, for example, be defined as the maximum thickness of the portion of the optical film OF in the light mixing region MR, and the thickness B1 may, for example, be defined as the maximum thickness of the portion of the optical film OF in the light guiding region GR. The thickness B1 of the portion of the optical film OF in the light guiding region GR is not greater than the thickness C1 of the base film BF. In the present embodiment, the thickness B1 is less than the thickness C1, for example, the ratio of the thickness A1 to the thickness C1 ranges from 0.1 to 2 (i.e., 0.1

A1/C1

2), and the ratio of thickness B1 to thickness C1 ranges from 0.001 to 0.99 (i.e., 0.001

B1/C1

0.99). In other embodiments, the thickness B1 may be the same as the thickness C1. In other words, at least two of the three values of thickness A1, thickness B1 and thickness C1 are not equal. Accordingly, the supporting effect of the base film BF on the optical film OF can be improved, thereby improving the reliability of the light guide assembly LG.

In addition, in the embodiment shown in FIG. 2 , the thickness A1 of the portion of the optical film OF in the light mixing region MR is greater than the thickness B1 of the portion of the optical film OF in the light guiding region GR, that is, the optical film OF in the light mixing region MR is thicker. Therefore, in the cross-sectional view of the light guiding assembly LG, the portion of the optical film OF in the light mixing region MR includes a protruding portion PP that protrudes from the portion of the optical film OF in the light guiding region GR. The protruding portion PP may include any suitable shape and is not limited to that shown in FIG. 2 . Taking FIG. 2 as an example, the protruding portion PP of the present embodiment has a rectangular shape in the cross-sectional view of the light guiding assembly LG, wherein the protruding portion PP includes a side wall SW and an upper surface TS1, but is not limited thereto. The side wall SW of the protruding portion PP may be a side wall of the optical film OF, and is located at the junction of the light guiding region GR and the light mixing region MR. The upper surface TS1 of the protruding portion PP may be the portion of the upper surface S2 of the optical film OF located in the light mixing region MR. In the present embodiment, the portion of the upper surface S2 of the optical film OF located in the light mixing region MR (i.e., the upper surface TS1) may be parallel to the portion of the upper surface S2 of the optical film OF located in the light guiding region GR, or in other words, may be parallel to the first surface S4 of the base film BF. According to the present embodiment, since the thickness A1 of the portion of the optical film OF in the light mixing region MR is greater than the thickness B1 of the portion of the optical film OF in the light guiding region GR, the protruding portion PP may be included, and the light emitted by the light-emitting element LU may be reflected by the side wall SW of the protruding portion PP when advancing in the light mixing region MR, thereby improving the light mixing effect of the light mixing region MR. In addition, by reducing the thickness B1 of the optical film OF in the light guide area GR, the light guide component LG can be thinned, and when the front light module FM is applied to the display device, the overall thickness of the display device can be reduced.

In addition, in this embodiment, the thickness A1 of the optical film OF in the light mixing region MR may be greater than the thickness C1 of the base film BF. In some embodiments, the thickness A1 may be the same as the thickness C1. By making the thickness A1 of the optical film OF in the light mixing region MR greater than the thickness C1 of the base film BF, the proportion of the optical film OF in the light mixing region MR in the light guide assembly LG can be increased, thereby improving the light mixing effect of the light mixing region MR.

D1，因此光學膜OF的上表面S2位於混光區MR的部分(即上表面TS1)可不突出於發光元件LU的上表面TS2。 The maximum thickness of the light guide assembly LG is the sum of the thickness A1 of the portion of the optical film OF in the light mixing region MR and the thickness C1 of the base film BF. According to the present embodiment, since the light emitting element LU is disposed adjacent to the light mixing region MR of the light guide assembly LG, the maximum thickness of the light guide assembly LG (i.e., the sum of the thickness A1 and the thickness C1) can be designed according to the thickness of the light emitting element LU. As shown in FIG. 2 , the light emitting element LU (e.g., but not limited to, a light strip including a light emitting diode) can have a thickness D1 in the top view direction of the light guide assembly LG (i.e., parallel to the direction Z), and the maximum thickness of the light guide assembly LG can be less than or equal to the thickness D1 of the light emitting element LU, i.e., A1+C1.

D1, so the portion of the upper surface S2 of the optical film OF located in the light mixing region MR (ie, the upper surface TS1) may not protrude from the upper surface TS2 of the light emitting element LU.

According to the present embodiment, as shown in FIG. 1 and FIG. 2 , the upper surface S2 of the optical film OF has a light-controlling microstructure MS, wherein the light-controlling microstructure MS includes an optical directivity pattern. The optical directivity pattern may include any pattern that can change the path of light. For example, the light-controlling microstructure MS of the present embodiment may include (but is not limited to) a prismatic structure. The "prismatic structure" herein is defined as any suitable structure including a prismatic portion, wherein the prismatic portion refers to a portion formed by two surfaces connected in a vertical cross-sectional view of the structure. For example, as shown in FIG. 1 , the light-controlling microstructure MS may have a pyramid shape, and as shown in FIG. 2 , the light-controlling microstructure MS includes a prismatic portion formed by two inclined surfaces connected in a cross-sectional view, that is, the light-controlling microstructure MS forms a prismatic groove on the upper surface S2 of the optical film OF. It should be noted that the above description of the structural shape of the light-controlling microstructure MS is only exemplary, and the present invention is not limited to the above or Figures 1 and 2. In some embodiments, the light-controlling microstructure MS can have any suitable shape according to the design of the light-guiding component LG. In addition, the arrangement of the light-controlling microstructure MS shown in Figure 2 is only exemplary, and the present invention is not limited thereto. According to this embodiment, the light-controlling microstructure MS can be formed on the upper surface S2 of the light-guiding component LG through any suitable patterning process. In some embodiments, the light-controlling microstructure MS can be, for example, a prismatic groove formed by removing part of the optical film OF on the upper surface S2, but is not limited thereto.

According to the present invention, the light-controlling microstructure MS can be distributed in the light-guiding region GR and the light-mixing region MR, and can be used to change the optical path of light in the light-guiding component LG. As shown in FIG. 1 and FIG. 2 , the portion of the light-controlling microstructure MS distributed in the light-guiding region GR is the light-controlling microstructure MSG, and the portion distributed in the light-mixing region MR is the light-controlling microstructure MSR. In addition, the light-controlling microstructure MSR can also be disposed on the side wall SW surface of the protruding portion PP of the optical film OF. When light travels in the light-guiding component LG and contacts the light-controlling microstructure MS, the light-controlling microstructure MS can cause the light to generate total internal reflection. In detail, when light (e.g., light L1, represented by a solid line) contacts the light-controlling microstructure MSG in the light-guiding region GR, the light-controlling microstructure MS can cause the light L1 to generate total internal reflection, so that the light L1 can move downward, or move in a direction away from the upper surface S2 of the optical film OF, thereby improving the light output brightness of the front light module FM. On the other hand, when light (e.g., light L2, represented by a dotted line) contacts the light-controlling microstructure MSR in the light-mixing region MR, the light-controlling microstructure MSR can cause the light L2 to generate total internal reflection or refraction, thereby increasing the time and/or path length of the light L2 in the light-mixing region MR, and improving the light-mixing effect of the light-mixing region MR.

As shown in the cross-sectional view of FIG2 , in the present embodiment, the portion of the light-controlling microstructure MS located in the light-mixing region MR (i.e., the light-controlling microstructure MSR) may have an asymmetric pattern in the vertical cross-sectional direction, but is not limited thereto. In other words, the light-controlling microstructure MSG located in the light-guiding region GR and the light-controlling microstructure MSR located in the light-mixing region MR may have different shape designs. Here, “the light-controlling microstructure MS has an asymmetric shape” may refer to a situation in which the slopes of the inclined surfaces on both sides of the prismatic portion of the light-controlling microstructure MS are different in the vertical cross-sectional direction of the light-controlling microstructure MS. For example, as shown in FIG2 , the inclined surfaces on both sides of the prismatic portion of the light-controlling microstructure MSR located in the light-mixing region MR may have different slopes, that is, different degrees of inclination. By making the light-controlling microstructure MSR have an asymmetric pattern, the light mixing effect of the light-mixing region MR can be further improved or adjusted, thereby improving the uniform light effect of the light-guiding component LG. It should be noted that the shape of the light-controlling microstructure MS of this embodiment is not limited to that shown in FIG. 2. In some embodiments, the light-controlling microstructure MSG located in the light-guiding region GR can have an asymmetric pattern as needed. In some embodiments, the light-controlling microstructure MSG located in the light-guiding region GR and the light-controlling microstructure MSR located in the light-mixing region MR can have a symmetric pattern.

As described above, by setting a light-controlling microstructure MS on the upper surface S2 of the optical film OF, the uniform light effect and light output brightness of the front light module FM can be improved. The slopes of the two side slopes of the prismatic part of the light-controlling microstructure MS of the present invention can be determined according to the thickness of the front light module FM (such as the maximum thickness of the light guide component LG, but not limited to this) and/or the length of the light mixing area MR (such as the length LT), and are not limited to that shown in FIG. 2, thereby adjusting the optical path of the light to achieve the above-mentioned effect of improving the uniform light effect and/or light output brightness. It should be noted that the components and/or film layers included in the front light module FM of the present invention are not limited to the above-mentioned structures, but may include other suitable components and/or film layers.

More embodiments of the present invention will be described below. To simplify the description, the same film layers or components in the following embodiments will use the same labels, and their features will not be repeated, and the differences between the embodiments will be described in detail below.

Please refer to Figures 3 and 4, Figure 3 is a schematic diagram of the appearance structure of the front light module of the second embodiment of the present invention, and Figure 4 is a schematic cross-sectional diagram of the front light module of the second embodiment of the present invention. In this embodiment, the portion of the optical film OF located in the light mixing region MR may include a protruding portion PP, wherein the protruding portion PP may protrude from the portion of the optical film OF located in the light guiding region GR. Compared with the above-mentioned first embodiment, the portion of the optical film OF in the light mixing region MR of this embodiment may have different shapes, that is, the protruding portion PP may have different shapes. In detail, the protruding portion PP of the optical film OF of this embodiment has, for example, a wedge shape, and may have an upper surface TS3, wherein the upper surface TS3 is an inclined surface, and is connected to the portion of the upper surface S2 of the optical film OF located in the light guiding region GR at the junction of the light guiding region GR and the light mixing region MR. The upper surface TS3 of the protruding portion PP of the optical film OF can be defined as the portion of the upper surface S2 of the optical film OF in the light mixing region MR. Since the protruding portion PP of the present embodiment has a wedge shape, the portion of the upper surface S2 of the optical film OF in the light mixing region MR (i.e., the upper surface TS3) and the first surface S4 of the base film BF contacting the lower surface S3 of the optical film OF can intersect on the extension line, that is, the upper surface TS3 is not parallel to the first surface S4 of the base film BF. In addition, since the thickness of the optical film OF in the light mixing region MR of the present embodiment is not uniform, the thickness A1 of the optical film OF in the light mixing region MR can be the maximum thickness of the optical film OF in the light mixing region MR, that is, the thickness A1 can be the thickness of the portion of the optical film OF contacting the light emitting element LU. It should be noted that the structure of the optical film OF of the light guide assembly LG of the present invention is not limited to that shown in Figures 3 and 4.

As shown in FIG. 3 and FIG. 4 , in this embodiment, the light-controlling microstructure MS can be distributed in the light-guiding region GR and the light-mixing region MR, wherein the light-controlling microstructure MS distributed in the light-guiding region GR is the light-controlling microstructure MSG’, and the light-controlling microstructure MS distributed in the light-mixing region MR is the light-controlling microstructure MSR’, wherein the light-controlling microstructure MSR’ can be disposed on the upper surface TS3. The structural features of the light-controlling microstructure MS can refer to the contents of the first embodiment above, so it will not be repeated. By setting a light-controlling microstructure MSR' on the upper surface TS3 located in the light-mixing region MR, when light (e.g., light L3) advances in the light-mixing region MR and contacts the light-controlling microstructure MSR', the light-controlling microstructure MSR' can cause the light L3 to generate total internal reflection, thereby increasing the time and/or path length of the light L3 in the light-mixing region MR, thereby improving the light-mixing effect of the light-mixing region MR. In addition, when the light L3 advances in the light-mixing region MR and contacts the inclined upper surface TS3, the light L3 can be reflected by the upper surface TS3, thereby improving the light-mixing effect of the light-mixing region MR.

Please refer to Figures 1 to 4 again. As described above, the light-emitting element LU of the front light module FM is arranged adjacent to the light mixing area MR of the light guide component LG, so that the light emitted by the light-emitting element LU can enter the light guide component LG from the light mixing area MR, and then the light can be uniformed in the light mixing area MR and then travel to the light guide area GR, and then emit light from the light guide area GR, thereby achieving a uniform light effect. According to the present invention, the light-emitting element LU can be arranged at any suitable position in the front light module FM. For example, as shown in Figures 1 to 4, the light-emitting element LU is arranged near a side SL3 of the light mixing area MR opposite to the light guide area GR, wherein the side SL3 is located on the side of the light mixing area MR opposite to the light guide area GR, so the light mixing area MR is located between the light-emitting element LU and the light guide area GR. The following describes other arrangements of the light-emitting element LU of the front light module FM of the present invention.

Please refer to Figures 5 and 6. Figure 5 is a schematic diagram of the structure and appearance of the front light module of the third embodiment of the present invention, and Figure 6 is a schematic diagram of the top view of the front light module of the third embodiment of the present invention. In order to simplify the diagram, Figure 6 does not show the light control microstructure arranged on the upper surface S2 of the optical film OF, and its characteristics can refer to the description of the above embodiments. According to this embodiment, the light-emitting element LU includes at least one first light-emitting body LU1, and the first light-emitting body LU1 can be respectively arranged on the opposite sides of the light mixing region MR of the light guide component LG (for example, a light-emitting diode is arranged on each side), so that the light emitted by the first light-emitting body LU1 can enter the light guide component LG from both sides of the light mixing region MR. Among them, the first light-emitting body LU1 can, for example, include a light source group formed by arranging a plurality of light-emitting diodes, but is not limited thereto. In the top view shown in FIG6 , the light mixing region MR includes a side SL1 and a side SL2 opposite to each other, and two first light emitting bodies LU1 are respectively disposed adjacent to the side SL1 and the side SL2 of the light mixing region MR, so that the light mixing region MR can be located between the two first light emitting bodies LU1 in the arrangement direction perpendicular to the light guiding region GR and the light mixing region MR (i.e., direction Y). It should be noted that the structure of the light emitting element LU of this embodiment is not limited to that shown in FIG5 and FIG6 . In some embodiments, the first light emitting body LU1 can be disposed adjacent to only one of the side SL1 and the side SL2. In some embodiments, the light emitting element LU can also include more first light emitting bodies LU1, disposed at any suitable position, for example (but not limited to) disposed near the side SL1, the side SL2 and the side SL3 at the same time. In addition, the arrangement of the first light emitting body LU1 shown in FIG. 5 and FIG. 6 can be applied to the light guide assembly LG shown in FIG. 1 and FIG. 2. According to this embodiment, since the light emitting element LU can be arranged adjacent to the side SL1 and/or side SL2 of the light mixing region MR, the length of the light mixing region MR can be shortened (for example, the length LT shown in FIG. 2), and the length of the front light module FM along the arrangement direction of the light guide region GR and the light mixing region MR (i.e., direction X) can be reduced, thereby reducing the size of the front light module FM.

Please refer to Figure 7, which is a cross-sectional schematic diagram of a display device including the frontlight module of the present invention. In order to simplify the diagram, Figure 7 simply shows the stacking relationship between the frontlight module FM and the display panel DP in the display device DD, and the frontlight module FM and the display panel DP are respectively represented by a single layer. The detailed structure of the frontlight module FM can refer to the contents of the above-mentioned embodiments, so it is not repeated here. The display panel DP may, for example, include a reflective or micro-transmitting liquid crystal display panel, which includes two substrates and a circuit layer, a display medium layer and/or other components or film layers arranged between the two substrates, but is not limited thereto. According to this embodiment, the display device DD may include the frontlight module FM and the display panel DP in any of the above-mentioned embodiments, wherein the frontlight module FM may be arranged on the display panel DP and provide a display light source. Specifically, the light emitting element LU of the front light module FM can emit light, and the light can be guided by the front light module FM and move downward, so that the light is emitted from the bottom of the front light module FM and moves toward the display panel DP. Therefore, the light provides a light source for the display panel DP and can be reflected by the display panel DP to display an image. It should be noted that the application of the front light module FM of the present invention is not limited to the above content, but can be applied to any suitable electronic device.

In summary, the present invention provides a light guide assembly, a front light module including the light guide assembly, and a display device including the front light module. The light guide assembly can be formed by stacking a base film and an optical film having different materials, wherein the optical film can be selected from materials having high transmittance, low haze value, and low light absorption rate. In addition, the upper surface of the optical film can have a light control microstructure, and the portion of the optical film in the light mixing area can protrude from the portion of the optical film in the light guide area. Thereby, the uniform light effect and light output effect of the light guide assembly can be improved. In addition, the hardness of the optical film can be greater than the hardness of the base film, so as to provide a protective effect for the light guide assembly and improve the reliability of the light guide assembly.

The above is only the preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

BF: Basement membrane

FM: front light module

GR: Light-guiding area

LG: Light guide components

LU: Light-emitting element

MR: Mixed light area

MS, MSR, MSG: light-controlling microstructures

OF:Optical film

S1: Second surface

S3: Lower surface

S2,TS1: upper surface

S4: First surface

SL3: Side

X,Y,Z: Direction

Claims (9)

A front light module comprises: a light guide assembly having a light guide area and a light mixing area arranged on one side of the light guide area, the light guide assembly comprising: a base film; and an optical film arranged on the base film, the optical film and the base film comprising different materials, the optical film having an upper surface and a lower surface, the upper surface and the lower surface facing each other, and the lower surface directly contacting the base film, wherein the upper surface has a light control microstructure, and the light control microstructure comprises an optical directivity pattern; and at least one light emitting element arranged adjacent to the light mixing area, wherein the light emitted by the at least one light emitting element enters the light guide assembly from the light mixing area; wherein the thickness of the portion of the optical film located in the light guide area is not greater than the thickness of the base film. According to the front light module described in claim 1, the base film includes polymethyl methacrylate (PMMA), the optical film includes a first material, the light transmittance of the first material is not less than 89% and the haze value is less than 0.5, and the hardness of the first material is greater than the hardness of the base film. According to the front light module described in claim 1, the refractive index of the optical film is less than the refractive index of the base film. According to the front light module described in claim 1, the maximum thickness of the portion of the optical film located in the light mixing area is A1, the thickness of the portion of the optical film located in the light guiding area is B1, and the thickness of the base film is C1, wherein at least two of the thickness A1, the thickness B1 and the thickness C1 are not equal. According to the front light module described in claim 1, the base film has a first surface in contact with the lower surface of the optical film, and the portion of the upper surface of the optical film located in the light mixing area is parallel to the first surface of the base film. According to the front light module described in claim 1, the base film has a first surface in contact with the lower surface of the optical film, and the portion of the upper surface of the optical film located in the light mixing area intersects with the first surface of the base film on an extension line. According to the front light module described in claim 1, the portion of the light-controlling microstructure located in the light-mixing area has an asymmetric pattern in the vertical cross-sectional direction. According to the front light module described in claim 1, the at least one light-emitting element is arranged on the side of the light mixing area opposite to the light guiding area. According to the front light module described in claim 1, the at least one light-emitting element includes a plurality of first light-emitting bodies, and the light mixing area is arranged between two of the plurality of first light-emitting bodies.

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