TWI385416B - Brightness enhancement film - Google Patents

Description

Optical brightness enhancement film

This invention relates to an optical film, and more particularly to an integrated optical brightness enhancing film.

Optical brightening film is one of the main components of the backlight module structure of the display. Due to the rapid development of the display industry in recent years, the technology of optical brightness enhancement film has become the development focus of many manufacturers.

The conventional optical brightness enhancement film, as shown in the Patent No. M330483 of the Republic of China, is provided with an upper surface and a lower surface; the upper surface is provided with a plurality of parallel parallel microstructures; the microstructure is provided with a top surface, and the microstructure The periphery of the top surface is adjacent to the diffraction area; the diffraction area is multi-stepped in a curved surface; each step is arranged at an equal height or an unequal height, and the step is from the apex of the top surface along the center line to the curve The endpoints of the two ends are equally divided into equal parts. Thereby, the conventional optical brightness enhancement film can transmit the multi-step structure, so that the incident light will spread to the periphery and generate a diffraction phenomenon on the surface of the conventional optical brightness enhancement film.

However, the above-mentioned conventional optical brightness enhancement film has the following disadvantages, for example, since the microstructure of the conventional optical brightness enhancement film is parallel in parallel and structurally formed, the uniformity of concentration of the conventional optical brightness enhancement film is achieved. In order to overcome this disadvantage, the two optical brightening films are superposed on each other, and the microstructures of the two brightness enhancing films are vertically staggered, thereby improving the overall uniformity of light collection; Moreover, the optical diffusing film of the conventional optical brightening film has poor optical diffusivity, so it is necessary to stack a diffusion film after the two conventional optical brightening films are vertically stacked alternately to achieve the desired expansion. Dispersion, this not only causes an increase in the cost of use, but also causes the disadvantage of an increase in the overall thickness; in addition, the adjacent portion between the two adjacent microstructures of the conventional optical brightness enhancement film [gap] is prone to light leakage. , and the brightness may be affected.

Another conventional optical brightness enhancement film, as disclosed in the Chinese Patent Publication No. 200643459, the conventional optical brightness enhancement film has an incident surface, an exit surface and a plurality of convex portions for receiving a light source. a diverging light beam; the exit surface is away from the light source and the light is emitted; the plurality of raised portions are arranged on the exit surface in a two-dimensional array structure, and the raised portion is a hemispherical structure.

The above-mentioned other conventional optical brightness enhancement film has the following disadvantages, for example, since the periphery of each convex portion of the conventional optical brightness enhancement film is surrounded by four large flat surfaces, the flat surface is prone to generate a large amount of light leakage, thereby causing light. In addition, the conventional optical brightening film has poor condensing property, and usually needs to be combined with an optical brightening film or a kind of lens which is better in condensing, which will also cause the disadvantages of increased thickness and increased cost. For the above reasons, it is indeed necessary to further improve the above optical brightness enhancement film.

The main object of the present invention is to provide an optical brightness enhancement film for enhancing the light collecting effect, condensing uniformity, diffusion effect, reducing light leakage, reducing thickness, and reducing cost.

In order to achieve the above object, the technical means of the present invention is to arrange a plurality of concentrating units in an array arrangement on one surface of a substrate, and each of the concentrating units is provided with a plurality of steps, and is not Concentrating unit A plurality of microlenses are disposed on the plurality of uncovered surfaces, so that the array arrangement can be used to improve the uniformity of the light collection, the structure of the plurality of steps is used to enhance the light collecting effect, and the plurality of lenses are used to improve the diffusion effect. Reduce light leakage.

The optical brightness enhancement film according to the present invention comprises: a substrate, a plurality of concentrating units, and a plurality of microlenses. The substrate comprises an incident surface and an exit surface; the plurality of light collecting units are arranged in an array on the exit surface of the substrate, and each of the light collecting units comprises a top surface and a plurality of step portions, the plurality of steps a portion is disposed on a circumferential surface of the concentrating unit, and the circumferential surface is located between the top surface and the exit surface; the plurality of microlens systems are disposed on the exit surface and are located in the gap of the array arrangement The plurality of concentrating units and the plurality of microlenses are arranged in a staggered arrangement.

The above and other objects, features and advantages of the present invention will become more <RTIgt; It is to be noted that the optical brightness enhancement film 1 of the first embodiment of the present invention can be selected from optical materials such as resin, plastic or optical glass. The optical brightness enhancement film comprises a substrate 1, a plurality of concentrating units 2 and a plurality of microlenses 3, and the plurality of concentrating units 2 are arranged in an array on one surface of the substrate 1. The lens 3 is interposed between the plurality of concentrating units 2, and the plurality of concentrating units 2 and the microlenses 3 are alternately arranged. The substrate 1, the concentrating unit 2 and the microlens 3 are all available for a light to pass through.

Referring to FIGS. 1 and 2, the substrate 1 of the first embodiment of the present invention includes an incident surface 11 and an exit surface 12, and the light is incident on the substrate 1 from the incident surface 11 and is formed by the exit surface. 12 shots.

Referring to FIGS. 1 and 2, the concentrating unit 2 of the first embodiment of the present invention is arranged in an array on the exit surface 12 of the substrate 1. Therefore, the concentrating unit 2 on the exit surface 12 There are a plurality of uncovered surfaces 121 that are not covered by the concentrating unit 2, that is, gaps in the array arrangement. The concentrating unit 2 can be connected to a three-dimensional surface such as a semi-spherical surface, a parabolic curved surface or a tapered surface (including a cone or a pyramid). In this embodiment, the concentrating unit 2 is selected to be a half sphere or a parabola. The surfaces are connected.

Each of the concentrating units 2 includes a top surface 21 and a plurality of step portions 22. The surface 21 can be selected as a plane or a curved surface, and the curved surface can be selected as a parabolic curved surface, a semi-spherical spherical surface or a tapered surface. For example, the top surface 21 of the embodiment is selected as a parabolic curved surface, so that the top surface 21 is selected. The diffusion effect of the light can be further increased; the plurality of step portions 22 are formed on the circumferential surface of the concentrating unit 2, and the circumferential surface is interposed between the top surface 21 and the exit surface 12, so that the concentrating unit 2, forming a multi-level structure, in this embodiment, the end edge 221 of the step portion 22 of the concentrating unit 2 is selected to be in contact with a semi-spherical surface or a parabolic curved surface, in other words, through the axial center of the concentrating unit 2 In the longitudinal section of the line L, the end edge 221 of the step portion 22 is located on an arc C, and the arc C can be selected as a half circle or a parabola. As shown in FIG. 2, the steps of the embodiment are The end edge 221 of the portion 22 is located on the arc C of the half circle; or as shown in Fig. 3, the end edge 221 of each step portion 22 is located on a parabola.

Since the edge 221 of the step portion 22 of the concentrating unit 2 is selected to be in contact with a semi-spherical surface or a parabolic curved surface, the peripheral shape of each layer is circular, and the lateral dimension of the concentrating unit 2 is also from the top. The surface 21 is incrementally directed toward the exit surface 12, and the step portion 22 is symmetrically formed with the center line L of the axial direction of the concentrating unit 2 as an axis of symmetry to cause the light to be diffracted when the light passes therethrough. The plurality of step portions 22 can reduce the loss of the light, thereby effectively improving the light concentration, the condensing property, and the overall brightness. In the embodiment, the heights of the step portions 22 are the same. Of course, the step portions 22 are The height can also optionally be set to a different height to adjust the height of each step 22 for different concentrating requirements.

Referring to FIGS. 1 and 2 again, the plurality of microlenses 3 of the first embodiment of the present invention may be selected as a semi-spherical or non-semi-spherical lens, and the surface of the non-semi-spherical lens is parabolic. a curved surface, the plurality of microlenses 3 are respectively disposed on the plurality of uncovered surfaces 121, such that the concentrating unit 2 and the microlens 3 are alternately arranged, and each of the microlenses 3 is adjacent to the concentrating unit 2 abuts to reduce the area of the uncovered surface 121, thereby reducing light leakage. The diameter of the microlens 3 is preferably smaller than the diameter of the outermost circumference of the concentrating unit 2 to reduce the area of the uncovered surface 121. Since the microlens 3 has a diffusion effect, the optical brightness enhancement film of the present invention can have the diffusion effect of the diffusion film, and the arrangement of the diffusion film can be omitted when the whole backlight module is disposed, thereby reducing the overall thickness and saving. cost.

Referring to Figures 4 and 5, which are the second embodiment of the optical brightness enhancing film of the present invention, the optical brightness enhancing film of the present embodiment comprises a substrate 4, a number The concentrating unit 5 and the plurality of microlenses 6 are also provided with an incident surface 41 and an exit surface 42.

Referring to FIGS. 4 and 5 again, the concentrating unit 5 of the second embodiment of the present invention is arranged in an array on the exit surface 42 of the substrate 4, and the exit surface 42 is provided with a plurality of concentrating units. 5 covered uncovered surface 421. The concentrating unit 5 of this embodiment is selected to be in contact with a tapered surface. Each of the concentrating units 5 includes a top surface 51 and a plurality of step portions 52. In this embodiment, the top surface 51 is selected as a plane; the plurality of step portions 52 are formed on the circumferential surface of the concentrating unit 5, and the circumferential surface is located on the top surface 51 and the exit surface 42. The concentrating unit 5 is formed into a multi-layer structure, and since the end edge 521 of the step portion 52 of the concentrating unit 5 is selectively connected to a tapered surface, the peripheral shape of each layer may be selected as a circle. The rectangle or the square is selected as a square in this embodiment. In this embodiment, the height of each of the step portions 52 is selected to be set to a different height. Thus, the plurality of step portions 52 can reduce the loss of light, thereby effectively improving the light concentration, the condensing property, and the overall brightness.

Referring to the fourth and fifth embodiments, the plurality of microlenses 6 of the second embodiment of the present invention are respectively disposed on the plurality of uncovered surfaces 421, so that the concentrating unit 5 and the microlens 6 are alternately arranged. And each of the microlenses 6 is adjacent to the adjacent concentrating unit 5 to reduce the area of the uncovered surface 421, thereby reducing light leakage. The diameter of the microlens 6 is equal to the side length of the outermost square of the concentrating unit 5. Since the microlens 6 has a diffusion effect, the optical brightness enhancement film of the present invention can have the diffusion effect of the diffusion film, and the arrangement of the diffusion film can be omitted, thereby reducing the overall thickness. And save on the cost of use.

As described above, the optical brightness enhancement film of the present invention is formed by arraying the plurality of concentrating units 2, 5 on the substrate 1 and 4 to effectively enhance the uniformity of condensing; further, each concentrating unit The circumferential surface of the 2, 5 is formed with a plurality of step portions 22, 52 to effectively enhance the concentrating effect of the optical brightness enhancing film; further, the plurality of uncovered surfaces 121 of the concentrating unit 2, 5 are not covered. The microlenses 3 and 6 are respectively disposed on the 421, so that the optical brightness enhancement film of the present invention has the effects of diffusing light and reducing light leakage at the same time.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

1‧‧‧Substrate

11‧‧‧ incident surface

12‧‧‧ exit surface

121‧‧‧Uncovered surface

2‧‧‧concentrating unit

21‧‧‧ top surface

22‧‧‧Steps

221‧‧‧ edge

3‧‧‧Microlens

4‧‧‧Substrate

41‧‧‧ incident surface

42‧‧‧ exit surface

421‧‧‧Uncovered surface

5‧‧‧ concentrating unit

51‧‧‧ top surface

52‧‧‧Steps

6‧‧‧Microlens

C‧‧‧ Curve

L‧‧‧ center line

Fig. 1 is a top view of an optical brightness enhancing film of a first embodiment of the present invention.

Fig. 2 is a cross-sectional view showing an optical brightness enhancing film of a first embodiment of the present invention.

Figure 3 is a cross-sectional view showing an optical brightness enhancing film of a first embodiment of the present invention.

Figure 4: Top view of the optical brightness enhancing film of the second embodiment of the present invention.

Figure 5 is a cross-sectional view showing an optical brightness enhancing film of a second embodiment of the present invention.

1‧‧‧Substrate

11‧‧‧ incident surface

12‧‧‧ exit surface

2‧‧‧concentrating unit

21‧‧‧ top surface

22‧‧‧Steps

221‧‧‧ edge

3‧‧‧Microlens

C‧‧‧ arc

L‧‧‧ center line

Claims (15)

An optical brightness enhancement film comprising: a substrate comprising an incident surface and an exit surface; a plurality of concentrating units arranged in an array on the exit surface of the substrate, each of the concentrating units comprising a top surface and a plurality of stepped portions disposed on a peripheral surface of the concentrating unit, wherein the peripheral surface is located between the top surface and the exit surface; and a plurality of microlenses disposed on the exit surface And located in the gap of the array arrangement, such that the plurality of concentrating units and the plurality of microlenses form a staggered arrangement. The optical brightness enhancement film of claim 1, wherein the microlens is adjacent to an adjacent concentrating unit. The optical brightness enhancement film according to claim 1, wherein the concentrating unit has a center line, and the plurality of step portions are symmetric with respect to the center line as an axis of symmetry. The optical brightness enhancing film according to claim 3, wherein an end edge of each of the step portions is located on an arc through a longitudinal section of the center line, and the arc may be a parabola or a semicircle. The optical brightness enhancement film according to claim 1, wherein the plurality of steps form the concentrating unit to form a multi-layer structure, the concentrating unit is connected to a tapered surface, and the peripheral shape of each layer is It is one of a circle, a rectangle, and a square. The optical brightness enhancement film according to claim 5, wherein the peripheral shape of the layers is a square, and the diameter of the microlens is equal to the maximum The side of the outer square is long. The optical brightness enhancement film according to claim 1, wherein the plurality of steps form the concentrating unit to form a multi-layer structure, the concentrating unit is connected to the semi-spherical surface, and the outer shape of each layer is a circle And the diameter of the microlens is smaller than the diameter of the outermost circumference of the concentrating unit. The optical brightness enhancement film according to claim 1, wherein the top surface of the concentrating unit is a plane or a curved surface. The optical brightness enhancing film according to claim 8, wherein the curved surface is a hemispherical surface, a parabolic curved surface or a tapered surface. The optical brightness enhancing film of claim 1, wherein each of the step portions has the same height. The optical brightness enhancement film of claim 1, wherein each of the step portions has a different height. The optical brightness enhancement film of claim 1, wherein the microlens is a hemispherical lens. The optical brightness enhancing film according to claim 1, wherein the microlens is a non-hemispherical lens, and the non-hemispherical surface is a parabolic curved surface. The optical brightness enhancement film according to claim 1 is made of a material of one of a resin, a plastic and an optical glass. The optical brightness enhancement film of claim 1, wherein the lateral dimension of each of the concentrating units is increased from the top surface toward the exit surface.