CN111965737B

CN111965737B - Optical film and display device

Info

Publication number: CN111965737B
Application number: CN202010939563.2A
Authority: CN
Inventors: 董冠佑; 刘耿瑜
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2020-02-20
Filing date: 2020-09-09
Publication date: 2022-03-01
Anticipated expiration: 2040-09-09
Also published as: TW202132819A; TWI718007B; CN111965737A

Abstract

An optical film and a display device are provided, the optical film includes a transparent substrate, a plurality of particles and a transparent layer. The first surface of the transparent substrate is provided with a plurality of convex structures. The particles are arranged above the first surface, and the orthographic projection of the geometric center of each particle on the light-transmitting base material is not overlapped with the highest point of each convex structure. The transparent layer is configured on the first surface and covers the convex structures and the particles.

Description

Optical film and display device

Technical Field

The present disclosure relates to optical films and display devices, and particularly to an optical film and a display device with an anti-glare function.

Background

With the development of flat panel display technology, various electronic products with display functions, such as flat panel televisions, notebook computers, tablet computers, smart phones, and the like, have been popularized in the consumer market for a long time. In order to prevent Glare from being generated after ambient light is reflected by the display surface of these products and to reduce the quality of viewing in a high-brightness environment, Anti-Glare (AG) treatment is generally performed on the display surface.

Specifically, the anti-glare treatment is to form a concave-convex microstructure on the optical film on the display interface to increase the haze of the optical film, so that the degree of glare generated after ambient light is reflected at the optical film is reduced. However, the irregular distribution of the rugged microstructures may form many surrounding structures, and the portion of the smudges attached to the optical film is limited in the surrounding structures and is difficult to be removed.

Disclosure of Invention

The invention provides an optical film, which is easy to remove dirt on the surface.

The invention provides a display device, wherein dirt on the surface of an optical film is easy to remove.

The optical film of the invention comprises a light-transmitting substrate, a plurality of particles and a light-transmitting layer. The first surface of the transparent substrate is provided with a plurality of convex structures. The particles are arranged above the first surface, and the orthographic projection of the geometric center of each particle on the light-transmitting base material is not overlapped with the highest point of each convex structure. The transparent layer is configured on the first surface and covers the convex structures and the particles.

In an embodiment of the invention, a refractive index of the light-transmitting layer, a refractive index of the light-transmitting substrate, and a refractive index of the particles are between 1.3 and 1.9.

In an embodiment of the invention, a refractive index of the transparent layer is not equal to a refractive index of the transparent substrate or is not equal to a refractive index of the particles.

In an embodiment of the invention, the transparent layer has a second surface and a third surface opposite to each other, the second surface is bonded to the first surface and the convex structures, and the third surface is undulated relative to the first surface along with the distribution of the particles.

In an embodiment of the invention, a minimum distance between the third surface and the first surface is H1, a maximum distance between the third surface and the first surface is H2, and a difference between H2 and H1 is greater than or equal to 2.4 micrometers.

In an embodiment of the invention, a maximum height of the convex structures relative to the first surface is Hg, a minimum distance between the convex structures and the third surface is Ha, and an average particle size of the particles is D, (Ha + Hg)/D is greater than or equal to 0.5.

In an embodiment of the invention, the average pitch of the convex structures is P, the average particle diameter of the particles is D, and P is greater than D.

In an embodiment of the invention, the average pitch of the convex structures is P, the average particle size of the particles is D, and D/P is greater than or equal to 0.33 and less than or equal to 0.4138.

In an embodiment of the invention, a volume concentration of the particles in the transparent layer is greater than or equal to 20%.

In an embodiment of the present invention, the convex structures do not intersect with each other.

In an embodiment of the invention, the convex structures are parallel to each other.

In an embodiment of the invention, each of the convex structures is a straight bar structure.

In an embodiment of the invention, the convex structures are arranged at intervals along a first direction.

In an embodiment of the invention, the at least one convex structure has a plurality of breaking portions, and the breaking portions divide the at least one convex structure into a plurality of sections, and the sections are arranged at intervals along a second direction perpendicular to the first direction.

In an embodiment of the invention, a width of each of the breaking portions along the second direction is W1, an average particle size of the particles is D, and W1 is less than 0.25 × D.

In an embodiment of the invention, the light-transmitting substrate has a plurality of microstructures on the first surface, a maximum width of each microstructure is Wm, an average particle diameter of the particles is D, and Wm is smaller than D.

In an embodiment of the invention, the convex structures are arranged equidistantly.

In an embodiment of the invention, the convex structures are not arranged equidistantly.

In an embodiment of the invention, the at least one convex structure has a concave portion, and the at least one particle is located above the concave portion.

The display device comprises a display device main body and an optical film. The display device main body is provided with a display interface. The optical film is disposed on the display interface and includes a transparent substrate, a plurality of particles, and a transparent layer. The first surface of the transparent substrate is provided with a plurality of convex structures. The particles are arranged above the first surface, and the orthographic projection of the geometric center of each particle on the light-transmitting base material is not overlapped with the highest point of each convex structure. The transparent layer is configured on the first surface and covers the convex structures and the particles.

Based on the above, in the optical film of the present invention, the geometric centers of the particles are offset from the highest points of the convex structures on the transparent substrate, that is, the transparent substrate separates the particles by the convex structures, so that the particles are not distributed completely randomly but are distributed regularly to some extent. Therefore, the probability that the particles and the light-transmitting layer covering the particles form the surrounding structure can be reduced, and the problem that part of dirt on the optical film is difficult to remove because the dirt is limited in the surrounding structure is avoided.

Drawings

Fig. 1 is a schematic diagram of a display device according to an embodiment of the invention.

Fig. 2 is a partial cross-sectional view of the optical film of fig. 1.

Fig. 3 is a partial structural perspective view of the optical film of fig. 2.

Fig. 4 is a cross-sectional view of a part of the optical film according to another embodiment of the present invention.

Fig. 5 is a cross-sectional view of a portion of an optical film according to another embodiment of the present invention.

Fig. 6 is a perspective view of a partial structure of an optical film according to another embodiment of the present invention.

The reference numbers are as follows:

10 display device

12 display device main body

12a display interface

100 optical film

110 transparent base material

110a first surface

112 convex structure

1121 breaking part

1122 section

112a concave part

114 microstructure

120 particles

130 transparent layer

130a second surface

130b third surface

A is the highest point

C geometric center

D, particle diameter

D1 first direction

D2 second direction

H1, H2, Ha distance

Height of Hg

P, P' spacing

W1, Wm width

Detailed Description

Fig. 1 is a schematic diagram of a display device according to an embodiment of the invention. Referring to fig. 1, a display device 10 of the present embodiment includes a display device main body 12 and an optical film 100. The display device main body 12 may be various electronic products with display function, such as a flat panel television, a notebook computer, a tablet computer, a smart phone, and the like, which is not limited in the present invention. The optical film 100 is disposed on a display interface 12a of the display device main body 12, and the display interface 12a is, for example, a surface of a display panel of the display device main body 12.

Fig. 2 is a partial cross-sectional view of the optical film of fig. 1. Fig. 3 is a partial structural perspective view of the optical film of fig. 2. Referring to fig. 2 and fig. 3, the optical film 100 of the present embodiment includes a transparent substrate 110, a plurality of particles 120, and a transparent layer 130. The material of the transparent substrate 110 is, for example, resin or other suitable material with light transmittance, and a first surface 110a of the transparent substrate 110 has a plurality of convex structures 112. The particles are made of, for example, resin, silicon dioxide, aluminum oxide, or other suitable materials, and are disposed above the first surface 110a of the transparent substrate 110. The transparent layer 130 is made of, for example, resin or other suitable material with light transmittance, and is disposed on the first surface 110a of the transparent substrate 110 to cover the convex structures 112 and the particles 120.

Specifically, the transparent layer 130 has a second surface 130a and a third surface 130b opposite to each other. The second surface 130a of the transparent layer 130 is bonded to the first surface 110a of the transparent substrate 110 and the convex structures 112, and the third surface 130b of the transparent layer 130 undulates relative to the first surface 110a of the transparent substrate 110 along with the distribution of the particles 120. By the arrangement of the convex structures 112 and the particles 120, the inner haze of the optical film 100 is increased, and the outer haze of the optical film 100 is increased by the undulation of the light-transmitting layer 130, so that the degree of glare generated by ambient light after being reflected at the optical film 100 is reduced. In the present embodiment, the refractive index of the transparent layer 130, the refractive index of the transparent substrate 110, and the refractive index of the particles 120 are, for example, between 1.3 and 1.9, and the refractive index of the transparent layer 130 is, for example, not equal to the refractive index of the transparent substrate 110 or not equal to the refractive index of the particles 120. The invention does not limit the refractive index of the transparent layer 130, the transparent substrate 110 and the particles 120.

As shown in fig. 2, in the present embodiment, an orthographic projection of the geometric center C of each particle 120 on the transparent substrate 110 does not overlap with the highest point a of each convex structure 112. The highest point a means a point on the convex structure 112 that is farthest from the first surface 110 a. That is, the light-transmitting substrate 110 separates the particles 120 by the convex structures 112, so that the particles 120 are not completely randomly distributed, but are distributed regularly to some extent. Therefore, the probability of the surrounding structure formed by the particles 120 and the transparent layer 130 covering the particles can be reduced, and the problem that part of the dirt on the optical film 100 is difficult to be removed because the dirt is confined in the surrounding structure can be avoided.

In detail, the convex structures 112 of the present embodiment are straight bar structures arranged at intervals along a first direction D1, as shown in fig. 3, and are parallel to each other and do not intersect with each other. That is, each of the convex structures 112 extends in a one-dimensional manner on the first surface 110a of the transparent substrate 110. In the process of manufacturing the optical film 100, for example, the particles 120 are firstly poured onto the first surface 110a of the transparent substrate 110, the particles 120 are concentrated at the lower positions between the convex structures 112 due to the gravity and the guidance of the convex structures 112, so that the orthographic projection of the geometric center C of each particle 120 on the transparent substrate 110 does not overlap the highest point a of each convex structure 112 as described above. Next, a solvent (a glue material for curing the light-transmitting layer 130) is poured onto the first surface 110a of the light-transmitting substrate 110, so that the solvent covers the convex structures 112 and the particles 120, and the solvent becomes the light-transmitting layer 130 after curing.

The optical film 100 manufactured in this way has an undulating distribution of the outer surface (i.e., the third surface 130b shown in fig. 2) substantially corresponding to the distribution of the particles 120, and is substantially distributed in a one-dimensional manner by the separation of the convex structures 112, so that the probability of forming the surrounding structure can be reduced as described above. Thus, when a user wipes the outer surface (i.e., the third surface 130b shown in fig. 2) of the optical film 100, the structure on the outer surface does not contact or block the dirt in a second direction D2 (labeled in fig. 3) perpendicular to the first direction D1, and the wiping cloth and the dirt are more likely to contact the dirt in the second direction D2, thereby reducing the adhesion of the dirt to the outer surface and increasing the adhesion of the dirt to the wiping cloth.

Referring to fig. 2, in the embodiment, a minimum distance between the third surface 130b of the light-transmitting layer 130 and the first surface 110a of the light-transmitting substrate 110 is H1, and a maximum distance between the third surface 130b of the light-transmitting layer 130 and the first surface 110a of the light-transmitting substrate 110 is H2. The difference Δ H between H2 and H1 is, for example, greater than or equal to 2.4 micrometers, such that the third surface 130b of the light-transmitting layer 130 has a sufficient degree of undulation to provide sufficient external haze for the optical film 100.

In the present embodiment, the maximum height of the convex structures 112 relative to the first surface 110a of the light-transmitting substrate 110 is Hg, the minimum distance between the convex structures 112 and the third surface is Ha, and the average particle diameter of the particles 120 is D. In the process of manufacturing the optical film 100, the particles 120 can be prevented from falling off due to too small amount of solvent by providing appropriate amount of solvent (the glue material for curing the light-transmitting layer 130) so that (Ha + Hg)/D is greater than or equal to 0.5.

In the present embodiment, the average pitch of the convex structures 112 is P. P is larger than the average particle diameter D of the particles 120 so that the particles 120 can be smoothly concentrated at the lower portion between the convex structures 112. In addition, the average particle diameter D and the number of the particles 120 are related to whether they can provide sufficient haze. For example, D/P is, for example, equal to or greater than 0.33 and equal to or less than 0.4138, and the volume concentration of the particles 120 in the light-transmitting layer 130 is, for example, equal to or greater than 20% to provide sufficient haze for the optical film 100.

As shown in fig. 2, the transparent substrate 110 may further have a plurality of microstructures 114 on the first surface 110a to further increase the internal haze of the optical film 100. The maximum width of each microstructure 114 is Wm, which is, for example, smaller than the average particle diameter D of the particles. In other embodiments, the transparent substrate 110 may not have the microstructures 114 on the first surface 110a, and the invention is not limited thereto.

In the embodiment shown in fig. 2 and 3, the convex structures 112 are arranged equidistantly, but the invention is not limited thereto. This is illustrated below by the figures. Fig. 4 is a cross-sectional view of a part of the optical film according to another embodiment of the present invention. The embodiment shown in fig. 4 differs from the embodiment shown in fig. 2 in that a pitch P' of the convex structures 112 is different from the other pitches P of the convex structures 112, that is, the convex structures 112 are arranged unequally.

Fig. 5 is a cross-sectional view of a portion of an optical film according to another embodiment of the present invention. The embodiment shown in fig. 5 is different from the embodiment shown in fig. 4 in that two adjacent convex structures 112 in fig. 5 are closer to each other and can be collectively regarded as a convex structure, and the top of the convex structure has a concave portion 112a, and a part of the particles 120 can be located above the concave portion 112 a.

Fig. 6 is a perspective view of a partial structure of an optical film according to another embodiment of the present invention. The difference between the embodiment shown in fig. 6 and the previous embodiments is that the convex structure 112 of fig. 6 has a plurality of breaking portions 1121, the breaking portions 1121 divide the convex structure 112 into a plurality of segments 1122, and the segments 1122 are arranged at intervals along a second direction D2 perpendicular to the first direction D1. Further, the width of each of the cut-off portions 1121 along the second direction D2 is W1, the average particle size of the particles is D (as indicated in fig. 2), and W1 is, for example, less than 0.25 × D. In other embodiments, the transparent substrate 110 may have other types of convex structures formed thereon, which is not limited in the present invention.

In summary, in the optical film of the present invention, the geometric centers of the particles are offset from the highest points of the convex structures on the transparent substrate, that is, the transparent substrate separates the particles by the convex structures, so that the particles are not distributed completely randomly, but are distributed regularly to some extent. For example, the particles may be divided into a distribution in a substantially one-dimensional manner by a convex structure extending in a one-dimensional manner. Therefore, the probability that the particles and the light-transmitting layer covering the particles form the surrounding structure can be reduced, and the problem that part of dirt on the optical film is difficult to remove because the dirt is limited in the surrounding structure is avoided.

Claims

1. An optical film, comprising:

a transparent substrate, wherein a first surface of the transparent substrate is provided with a plurality of convex structures;

a plurality of particles disposed above the first surface, wherein an orthographic projection of a geometric center of each particle on the light-transmitting substrate does not overlap a highest point of each convex structure; and

a transparent layer disposed on the first surface and covering the plurality of convex structures and the plurality of particles;

the light-transmitting substrate is provided with a plurality of microstructures on the first surface, the maximum width of each microstructure is Wm, the average particle diameter of a plurality of particles is D, and Wm is smaller than D.

2. The optical film as claimed in claim 1, wherein the refractive index of the light-transmissive layer, the refractive index of the light-transmissive substrate and the refractive index of the plurality of particles are between 1.3 and 1.9.

3. The optical film as claimed in claim 1, wherein the refractive index of the light-transmissive layer is not equal to the refractive index of the light-transmissive substrate or to the refractive index of the plurality of particles.

4. The optical film according to claim 1, wherein the light-transmitting layer has a second surface and a third surface opposite to each other, the second surface is bonded to the first surface and the plurality of convex structures, and the third surface is undulated with respect to the first surface according to the distribution of the plurality of particles.

5. The optical film of claim 4, wherein the minimum distance between the third surface and the first surface is H1, the maximum distance between the third surface and the first surface is H2, and the difference between H2 and H1 is greater than or equal to 2.4 microns.

6. The optical film as claimed in claim 4, wherein a maximum height of the plurality of convex structures with respect to the first surface is Hg, a minimum distance between the plurality of convex structures and the third surface is Ha, and an average particle diameter of the plurality of particles is D, (Ha + Hg)/D is 0.5 or more.

7. The optical film as claimed in claim 1, wherein the average pitch of the plurality of convex structures is P, the average particle diameter of the plurality of particles is D, and P is greater than D.

8. The optical film as claimed in claim 1, wherein the average pitch of the plurality of convex structures is P, the average particle diameter of the plurality of particles is D, and D/P is 0.33 or more and 0.4138 or less.

9. The optical film as claimed in claim 1, wherein the volume concentration of the plurality of particles in the light-transmitting layer is 20% or more.

10. The optical film as recited in claim 1, wherein a plurality of the convex structures do not intersect each other.

11. The optical film as recited in claim 1, wherein a plurality of the convex structures are parallel to each other.

12. The optical film as claimed in claim 1, wherein each of the convex structures is a straight bar structure.

13. The optical film as claimed in claim 1, wherein a plurality of the convex structures are arranged at intervals along a first direction.

14. The optical film as claimed in claim 13, wherein the at least one convex structure has a plurality of breaks dividing the at least one convex structure into a plurality of segments, the plurality of segments being arranged at intervals along a second direction perpendicular to the first direction.

15. The optical film of claim 14, wherein each of the discontinuities has a width W1 along the second direction, a plurality of the particles have an average particle size D, and W1 is less than 0.25 x D.

16. The optical film as defined by claim 1 wherein a plurality of the convex structures are arranged equidistantly.

17. The optical film as defined by claim 1 wherein a plurality of the convex structures are arranged unequally.

18. The optical film according to claim 1, wherein at least one of the convex structures has a concave portion, and at least one of the particles is located above the concave portion.

19. A display device, comprising:

a display device main body having a display interface; and

the optical film according to claim 1, disposed on the display interface.