TWI416173B - Optical film - Google Patents

Abstract

An optical film includes a hard coat layer and an antiglare layer formed on the hard coat layer. The hard coat layer serves as a base layer for the antiglare layer, and is used to protect a display panel from physical damage.

Description

Optical film

This invention relates to an optical film, and more particularly to an optical film for use in display elements.

With the user's requirements for display quality, convenience, and friendliness of the display, a touch panel is provided on the display panel, and the touch panel replaces a conventional input device such as a button or a mouse. Provides a way for users to perform interactive input operations using a finger or a stylus. In the development of various touch panel technologies such as resistive, capacitive, electromagnetic, surface acoustic wave and infrared, capacitive touch panels are multi-touch and durable. High strength, long life and other advantages have sprung up.

However, whether using a cathode ray tube (CRT) display, a flat panel display, or a touch display with a touch panel, the surface of the screen or panel is usually covered with a multilayer optical film to protect the panel, Improve image quality and increase user comfort when watching. Please refer to FIG. 1. FIG. 1 is a schematic cross-sectional view of a conventional optical clear adhesive (OCA) structure. As shown in FIG. 1 , the optical adhesive structure 100 has a main optical adhesive layer 102 for providing adhesion between different panels or layers. The two surfaces of the optical adhesive layer 102 are respectively provided with a release layer 104 and 106. To avoid sticking before the optical adhesive structure 100 is attached. Generally, the thickness of the optical adhesive layer is about 0.025 to 0.175 mm (millimeter, hereinafter referred to as mm).

Please refer to FIG. 2. FIG. 2 is a schematic cross-sectional view of a conventional anti-reflection film. The conventional anti-reflective film 200 comprises a substrate layer 202 and a substrate disposed on the substrate. A layer of triacetyl cellulose (hereinafter referred to as TAC) 204 having anti-glare and anti-reflection ability on the layer 202. On the TAC layer 204, the optical adhesive layer 102 is used to provide the adhesion function of the anti-reflection film 200; of course, an unseparated release layer 104 is disposed on the optical adhesive layer 102 that has been attached to the surface of the TAC layer 204. /106, to avoid sticking before the anti-reflection film 200 is attached. In general, the thickness of the substrate layer is about 0.005 mm, the thickness of the optical adhesive layer 102 is about 0.025 to 0.175 mm as previously described, and the thickness of the TAC layer 204 is about 0.08 mm. Therefore, the thickness of the anti-reflection film 200 is approximately between 0.11 and 0.26 mm. The TAC layer 204 itself has an anti-glare function and is therefore commonly used in anti-reflective film technology to avoid reflection of light rays back and forth between interfaces and glare problems caused by them. By the arrangement of the anti-reflection film 200, the reflection phenomenon on various types of displays is reduced, so that the transmittance of the entire optical system is increased, thereby improving the image quality of the display.

Please refer to FIG. 3 , which is a schematic structural diagram of a conventional capacitive touch panel. As shown in FIG. 3 , the conventional capacitive touch display 300 includes a thin display panel such as a liquid crystal display (LCD) panel 310 and a capacitive touch panel 320 . An anti-reflection film 200 is disposed on the surface of the capacitive touch panel 320 opposite to the LCD panel 310. The anti-reflection film 200 is adhered to the capacitive touch panel 320 by using the optical adhesive layer 102 by removing the release layer 104/106. The surface of the LCD panel 310 is opposite. On the surface of the anti-reflection film 200 with respect to the LCD panel 310, the capacitive touch panel 320 having the anti-reflection film 200 and the LCD panel 310 are adhered by an optical adhesive layer 102 having a thickness of about 0.175 mm. It can be seen that at least two to three film layers are added on the surface of the capacitive touch panel 320 opposite to the LCD panel 310, and the total thickness is increased by at least 0.29 mm. On the surface of the capacitive touch panel 320 opposite to the LCD panel 310, a protective film 330 is adhered to the surface by an optical adhesive layer 102 having a thickness ranging from about 0.025 to 0.175 mm for protecting the capacitor. The transparent conductive layer (not shown) of the touch panel 320 prevents physical damage to the finger or the stylus and improves durability.

According to the above-mentioned prior art, the capacitive touch display 300 generally requires at least three different functional film layers: the optical adhesive layer 102, the anti-reflection film 200 and the protective film 330, and two to three layers of the optical adhesive layer 102 are repeatedly used as Different film layers and panels, such as the medium between the anti-reflection film 200 and the LCD panel 310, between the capacitive touch panel 320 and the anti-reflection film 200, and between the capacitive touch panel 320 and the protective film 330. More importantly, the adhesion of the above-mentioned film layer is at least four or five bonding processes, and each additional bonding process increases the manufacturing cost of a large amount of manpower and equipment, and also increases the product defect rate; let alone the capacitive touch. The overall thickness of the display 200 is increased and the transmittance is reduced. Therefore, how to reduce the manufacturing cost, reduce the number of layers required for the touch display and the total thickness of the film layer, and not jeopardize other properties of the touch display such as durability, anti-glare and light transmittance. It is a topic of constant concern to the industry.

In view of the above, it is an object of the present invention to provide an optical film which can reduce the number of layers of a film layer and the overall thickness of a film layer while achieving the requirements for durability, anti-glare, and the like of the display.

The present invention discloses an optical film. In a preferred embodiment, the optical film includes a hard coat layer and an anti-glare layer disposed on the hardened protective layer.

According to the optical film provided by the present invention, the hardened protective layer is used as the substrate layer of the anti-glare layer, and the hardened protective layer still retains the original protective function, thereby protecting the display panel from physical damage. Therefore, the optical film system provided by the present invention combines protection The layer and the glare layer effectively reduce the number of layers and the overall thickness of the film without compromising the durability and anti-glare of the display.

Please refer to FIG. 4. FIG. 4 is a schematic diagram of a preferred embodiment of the optical film provided by the present invention. As shown in FIG. 4, the optical film 400 of the present invention comprises a hard coat layer 410 having a first surface 412 and an opposite second surface 414. The material constituting the hardened protective layer 410 further includes a polyester resin such as polyethylene terephthalate (hereinafter abbreviated as PET) or a polyacrylate resin such as polymethacrylic acid. Polymethyl methacrylate (PMMA), or polycarbonate (PC), etc., of which PET is preferred. In the preferred embodiment, the hardened protective layer 410 is PET and has a thickness of 0.03 to 0.05 mm.

Please continue to see Figure 4. The optical film 400 provided by the present invention further includes an anti-glare layer 420 disposed on the first surface 412 of the hardened protective layer 410. The material constituting the anti-glare layer 420 further includes, but is not limited to, triacetyl cellulose (TAC). In addition, those skilled in the art should be aware that since TAC itself has anti-glare properties, it is commonly used as a main film layer for anti-glare and anti-reflection. The thickness of the anti-glare layer 420 is not more than 0.08 mm; in the preferred embodiment, the thickness of the anti-glare layer 420 is 0.08 mm.

The optical film 400 further includes a first adhesive layer 430 disposed on the anti-glare layer 420; and a second adhesive layer 440 disposed on the second surface 414 of the hardened protective layer 410. The first adhesive layer 430 and the second adhesive layer 440 are optical adhesives having high light transmittance and high adhesion, and include an acrylic resin or the like. First adhesive layer 430 The thickness of the second adhesive layer 440 is between 0.04 and 0.05 mm; in the preferred embodiment, the thickness of the first adhesive layer 430 and the second adhesive layer 440 is 0.05 mm. However, depending on different product requirements, the first adhesive layer 430 and the second adhesive layer 440 may have the same thickness as shown in the preferred embodiment, and are not limited to have different thicknesses. In addition, the optical film 400 of the present invention further includes a first release layer 450 disposed on the other surface of the first adhesive layer 430 opposite to the anti-glare layer 420; and a second release pattern. The layer 460 is disposed on the other surface of the second adhesive layer 440 with respect to the hardened protective layer 410. The first release layer 450 and the second release layer 460 are used to avoid sticking of the optical film 400 to the target panel or the target film layer. According to the optical film 400 provided by the present invention, the total thickness of the film layer is about 0.19 to 0.23 mm.

Next, please refer to FIG. 5. FIG. 5 is a schematic diagram of a touch display having the optical film provided by the present invention. It should be noted that those skilled in the art will disclose the embodiment of the optical film 400 provided by the present invention by taking a touch display as an example, but the optical film 400 is not limited to use in a touch display application, but can be Product requirements apply to any suitable display component. As shown in FIG. 5 , the touch display 500 includes a display panel 510 such as an LCD panel and a capacitive touch panel 520 . The capacitive touch panel 520 is a double-sided indium tin oxide (DITO) substrate; it is bonded to the display panel 510 by a conventional optical adhesive 530. On the other surface of the capacitive touch panel 520 with respect to the display panel 510, the optical film 400 provided by the present invention is attached. The optical film 400 adheres the second adhesive layer 440 to the other surface of the capacitive touch panel 520 relative to the display panel 510 by removing the second release layer 460.

According to the optical film 400 provided by the present invention, the hardened protective layer 410 as the substrate layer of the optical film 400 comprises PET, and the hardness thereof can be greater than the pencil hardness of 3H, and has high light transmittance, so that it can simultaneously function as a capacitive touch panel. 520 protective film. Hardening protection The anti-glare layer 420 on the layer 410 provides an anti-glare effect, ensuring that the optical requirements of the capacitive touch panel 520 are not affected. In addition, the first adhesive layer 430 of the optical film 400 can be exposed for the optical film 400 to adhere to other film layers by removing the first release layer 450 according to different product requirements.

Compared with the prior art, in the past, three different single function membrane layers were needed: optical glue, anti-reflection film, protective film, and it is necessary to repeatedly use optical glue and multiple bonding processes to bond different film layers and panels to achieve panel assembly. The function of protecting the surface of the touch panel and improving the light transmittance. The optical film provided by the present invention utilizes a hardened protective layer as a base layer of the anti-glare layer, and the hardened protective layer still retains the original protective function, thereby simultaneously protecting the display panel from physical damage and improving light transmittance. the goal of. Moreover, since the optical film has an adhesive layer on both sides, the optical film can be bonded to other film layers or panels according to different product requirements. Therefore, the optical film provided by the invention retains the optical adhesive double-sided. The function of bonding. It can be seen from the above description that the total thickness of the optical film provided by the present invention is smaller than the total thickness of the conventional film in which a single film layer having different functions of optical glue is repeatedly used, so that the touch display can be further reduced. Thickness, improve product competitiveness. In addition, compared with the prior art, the optical film provided by the invention can reduce the bonding process of one to two film layers, thereby saving manufacturing cost and increasing product yield.

In summary, the optical film provided by the present invention at least combines the protective layer and the glare layer, effectively reducing the number of layers and the overall thickness of the film layer while simplifying the durability and anti-glare of the display, and simplifying The process can improve product competitiveness and yield.

While the present invention has been described above in terms of the preferred embodiments thereof, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of patent protection of the invention is subject to this statement. The scope of the patent application attached to the attached book shall prevail.

100‧‧‧Optical adhesive structure

102‧‧‧Optical adhesive layer

104, 106‧‧‧ release layer

200‧‧‧Anti-reflective film

202‧‧‧Substrate layer

204‧‧‧ triacetate layer

310‧‧‧LCD panel

320‧‧‧Capacitive touch panel

330‧‧‧Protective film

400‧‧‧Optical film

410‧‧‧ hardened protective layer

412‧‧‧ first surface

414‧‧‧ second surface

420‧‧‧Anti-glare layer

430‧‧‧First adhesive layer

440‧‧‧Second adhesive layer

450‧‧‧First release layer

460‧‧‧Second release layer

500‧‧‧ touch display

510‧‧‧ display panel

520‧‧‧Capacitive touch panel

1 is a schematic cross-sectional view of a conventional optical adhesive structure; and FIG. 2 is a schematic cross-sectional view of a conventional anti-reflective film.

FIG. 3 is a schematic structural diagram of a conventional capacitive touch panel.

4 is a schematic view of a preferred embodiment of an optical film provided by the present invention; and FIG. 5 is a schematic view of a touch display having the optical film provided by the present invention.

400‧‧‧Optical film

410‧‧‧ hardened protective layer

412‧‧‧ first surface

414‧‧‧ second surface

420‧‧‧Anti-glare layer

430‧‧‧First adhesive layer

440‧‧‧Second adhesive layer

450‧‧‧First release layer

460‧‧‧Second release layer

Claims (9)

An optical film comprising: a hardened protective layer having a thickness of 0.03 to 0.05 mm; and an anti-glare layer disposed on the hardened protective layer. The optical film of claim 1, wherein the hardened protective layer further comprises polyethylene terephthalate, polymethyl methacrylate, or polycarbonate. The optical film of claim 1, wherein the anti-glare layer further comprises cellulose triacetate. The optical film of claim 1, wherein the optical film further comprises a first adhesive layer, and the first adhesive layer is disposed on the anti-glare layer. The optical film of claim 4, wherein the optical film further comprises a first release layer, the first release layer being disposed on the first adhesive layer. The optical film of claim 4, wherein the optical film further comprises a second adhesive layer, the second adhesive layer being disposed under the hardened protective layer. The optical film of claim 6, wherein the optical film further comprises a second release layer, the second release layer being disposed under the second adhesive layer. The optical film of claim 6, wherein the first adhesive layer and the second adhesive layer further comprise acrylic acid. The optical film of claim 6, wherein the first adhesive layer and the second adhesive layer have a thickness of 0.04 to 0.05 mm.