TWI432851B - Patterned retarder film and method for manufacturing the same - Google Patents

Description

Patterned phase retardation film and method of manufacturing same

The present invention relates to a patterned phase retardation film and a method of fabricating the same, and more particularly to a patterned phase retardation film fabricated by imprinting.

The patterned phase retardation film has been applied to a three-dimensional stereoscopic display, and after wearing the polarized glasses, the viewer can view the three-dimensional stereoscopic image on a liquid crystal display having a patterned phase retardation film. There are a number of methods for fabricating patterned phase retardation films in the related art. For example, U.S. Patent No. 6,624,863 discloses a method of making a patterned phase retardation film, and U.S. Patent No. 6,498,679 discloses the use of a monolithic phase retardation film. Microstructure retardation film. The present invention provides a novel method of fabricating a patterned retardation film, particularly by using an imprint method to fabricate a patterned phase retardation film.

The present invention relates to a patterned phase retardation film and a method of fabricating a patterned phase retardation film by imprinting.

According to one aspect of the invention, a method of fabricating a patterned phase retardation film having a microstructure is provided. The patterned phase retardation film has a plurality of first phase retardation regions and a plurality of second phase retardation regions, and the manufacturing method thereof comprises the steps of: providing a substrate; forming an alignment layer on the first surface of the substrate; Coating a polymerizable liquid crystal material on the alignment layer to form a liquid crystal layer; aligning the liquid crystal layer with the alignment layer; printing the liquid crystal layer as a predetermined pattern to form a plurality of first phase retardation regions and a plurality of second phase retardation regions The first phase delay region and the second phase delay region have a grid-like stripe structure and are parallel to each other, and the second phase delay region has a groove-like structure with respect to the first phase delay region and is first The phase retardation regions are interlaced with each other; the patterned liquid crystal layer is cured; wherein a difference between phase retardation values of the first phase retardation region and the second phase retardation region is 180 degrees.

According to another aspect of the present invention, a patterned phase retardation film having a plurality of first phase retardation regions and a plurality of second phase retardation regions is provided. The patterned phase retardation film comprises a substrate; an alignment layer on the first surface of the substrate; a liquid crystal layer formed by coating a polymerizable liquid crystal material on the alignment layer; a plurality of first phase delays a region and a second phase retardation region formed by printing a liquid crystal laminate as a predetermined pattern, wherein the first phase retardation region and the second phase retardation region have a grid-like stripe structure and the two are parallel to each other, The second phase retardation region is a groove-like structure with respect to the first phase retardation region and interlaced with the first phase retardation region; curing the patterned liquid crystal layer; wherein the first phase retardation region and the second phase retardation region The difference between the phase delay values is 180 degrees.

In accordance with yet another aspect of the present invention, a method of fabricating a patterned phase retarder film having a microstructure is provided. The patterned phase retardation film can be attached to at least one functional optical film, such as a polarizing film, a hard-coating film, a low reflective film, an anti-reflective film (anti -reflective film), anti-glaring film.

According to still another aspect of the present invention, a patterned phase retardation film is proposed. The patterned phase retardation film can be applied to a display to provide a three dimensional image of the viewer.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

First embodiment

Please refer to Figure 1. 1 is a cross-sectional view showing a patterned phase retardation film 100 in accordance with a preferred embodiment of the present invention. The patterned phase retardation film 100 includes a substrate 110, an alignment layer 120, and a patterned liquid crystal layer 130. The patterned liquid crystal layer 130 has a plurality of first phase retardation regions 131 and a plurality of second phase retardation regions 132. A release film 140 is attached over the cured liquid crystal layer 130. When a functional optical film such as a polarizing film is attached to the liquid crystal layer 130, the release film 140 can be removed.

Please refer to FIG. 2, FIG. 3A, FIG. 3B, FIG. 3C, and FIG. 3D simultaneously. 2 is a schematic view showing a preferred embodiment of a method of manufacturing a patterned phase retardation film of the present invention. 3A through 3D illustrate the various stages of the preferred embodiment of the method of fabricating the patterned phase retardation film. In step S201, a substrate 210 is provided. The substrate 210 has a phase retardation value of less than 90 degrees, preferably a phase retardation value of substantially 0 degrees. The substrate 210 is selected from the group consisting of polyethylene terephthalate (PET), polycarbonate (PC), triacetyl cellulose (TAC), and polymethyl methacrylate (poly methyl methacrylate). Methacrylate, PMMA) and a group of cyclo-olefin polymers (COP). Wherein, the thickness of the substrate 210 is between 30 micrometers (μm) and 300 micrometers (μm).

In step S202, the alignment layer 220 is formed on the substrate 210. The formation of alignment layer 220 on substrate 210 is by methods well known to those of ordinary skill in the art, such as micro-scratch alignment treatment, rubbing treatment, light. Photo-alignment, SiO ₂ evaporation and ion-beam alignment.

Referring to FIG. 3A, in step S203, a liquid crystal material 1201 is coated on the alignment layer 220. The liquid crystal material 1201 used in the method for producing a patterned phase retardation film of the present invention is a polymerizable liquid crystal. The liquid crystal used in one embodiment of the present invention is BASF LC242 (Polymerized Liquid Crystal Diacrylate, BASF, Germany). The liquid crystal used in still another embodiment of the present invention is RMS 10-021 (photopolymerizable active liquid crystal cell solution, Merck Optoelectronics Technology Co., Ltd., Taiwan). After the liquid crystal is mixed with the solvent, it is applied onto the alignment layer 220. The solid content of the liquid crystal solution ranges from 10% to 50%. In a preferred embodiment of the invention, the liquid crystal solution has a solids content of 20%. The solvents used in the present invention are well known to those of ordinary skill in the art, such as propylene glycol monomethyl ether acetate (PGMEA). The solvent in the liquid crystal solution is removed before the liquid crystal layer 230 is imprinted as a predetermined pattern.

Referring to step S204 in FIG. 2, the liquid crystal material 1201 is heated to remove the solvent therein, and at the same time, the liquid crystal layer 230 is aligned with the alignment layer 220. The temperature at which the heat treatment is carried out is between 20 ° C and 100 ° C, preferably between 50 ° C and 100 ° C. In a preferred embodiment of the invention, the temperature at which the heat treatment is carried out is 70 °C. Controlling the heating temperature can affect the alignment effect of the liquid crystal material 1201 and the alignment layer 220. The heat treated liquid crystal material 1201 has a thickness of between 0.1 micrometers (μm) and 9.9 micrometers (μm) depending on the use of different liquid crystal materials and the different phase retardation values to be provided. The thickness of the liquid crystal material 1201 is preferably between 1 micrometer (μm) and 3 micrometers (μm). In an embodiment of the invention, the polymerizable liquid crystal material 1201 is BASF LC242, and the liquid crystal material 1201 has a coating thickness of 1.78 micrometers (μm). In another embodiment of the present invention, the polymerizable liquid crystal material 1201 is Merck RMS 10-021, and the liquid crystal material 1201 has a coating thickness of 2.1 micrometers (μm).

Referring to step S205 in FIG. 2, the liquid crystal material 1201 is subjected to heat treatment and then imprinted. In step S205, the liquid crystal material 1201 is imprinted into a liquid crystal layer 230 having a predetermined pattern, the liquid crystal layer including a plurality of first phase retardation regions (for example, the relief structure 231) and a plurality of second phase retardation regions (eg, grooves) Shaped structure 232), as depicted in Figure 3B. The imprint process is imprinted by an imprinting device having a predetermined pattern on the surface or a roller. As shown in FIG. 4, in an embodiment of the present invention, the embossing process uses a grooved roller 630. The surface of the roller 630 is a mold having an embossed grid-like stripe structure 631, and the relief structures are parallel to each other. The set of relief structures 631 extend on the roller 630 in the rolling direction. In another embodiment of the present invention, the set of relief structures 631 extend in a direction perpendicular to the direction of rotation of the roller 630 (not shown).

When the imprint process step S205 is performed, the liquid crystal layer 230 forms a set of groove structures 232 and a set of relief structures 231 due to the imprint of the groove rollers 630. The relief structures 231 and the groove structures 232 are grid-like stripe structures that are staggered in parallel with each other. The difference between the phase delay values of the relief structures 231 and the recess structures 232 is 180 degrees.

The height of the relief structures 231 is between 0.1 micrometers (μm) and 9.9 micrometers (μm), preferably between 1 micrometer (μm) and 3 micrometers (μm). The height of the relief structures 231 varies depending on the polymerizable liquid crystal used and the phase delay value provided. The height of the relief structures 231 is such that the difference between the phase retardation values of the groove structure 232 and the relief structure 231 is 180 degrees. In an embodiment of the invention, the liquid crystal material 1201 used is BASF LC242, and the thickness of the coated liquid crystal layer is 1.78 micrometers (μm). In another embodiment of the invention, the liquid crystal material 1201 used is Merck RMS 10-021 and the thickness of the coated liquid crystal layer is 2.1 micrometers (μm). Therefore, the size of the display with the patterned phase retardation film, the resolution of the display, and the viewing distance will determine the spacing between the two relief structures 231. Generally, the spacing of the two relief structures 231 is between 10 micrometers (μm) and 900 micrometers (μm). For example, when a 24 inch liquid crystal monitor is used, the distance between the two relief structures 231 is about 250 micrometers (μm).

In step S206, the patterned liquid crystal layer 230 is subjected to a curing process. The method of curing treatment is a method well known to those skilled in the art, such as ultraviolet curing or thermal curing. Figure 4 is a schematic illustration of a system for continuous production, such as roll-to-roll production, used in one embodiment of the present invention.

After the patterned liquid crystal layer 230 is cured, at least one additional optical film may be pasted on the patterned liquid crystal layer 230, as shown in step S207. In an embodiment of the invention, the other film attached to the liquid crystal layer 230 is a release film 240. When the patterned phase retardation film is attached to the display or the polarizing film, the release film can be peeled off. 240. In another preferred embodiment of the present invention, the attached optical film is a polarizing film and the polarizing film is directly attached to the patterned liquid crystal layer 230.

The method of fabricating the patterned phase retardation film of the present invention can be carried out by batch production or continuous production. System 400 is used to fabricate the patterned phase retardation film of the present invention. The substrate 411 is unwound from the first roller 410 and forms an alignment layer (not shown) via the alignment device 420. Next, a layer of the polymerizable liquid crystal 421 is applied onto the alignment layer by a coating device 430. The solvent in the liquid crystal coating layer 421 is removed by the heating device 440, and the liquid crystal coating layer 421 is simultaneously aligned with the alignment layer, wherein the heating temperature of the coating liquid crystal layer is between 20 ° C and 100 ° C. Preferably, it is between 50 ° C and 100 ° C, more preferably 70 ° C. Then, the aligned liquid crystal coating layer 421 is embossed by the groove roller 630 to form a plurality of relief structures and a plurality of groove structures. The plurality of relief structures and recess structures are cured by a curing device 450. The curing device can be an ultraviolet curing device or a thermal curing device. After the curing process, the difference between the phase delay values of the relief structures and the groove structures is 180 degrees. The patterned phase retardation film 451 is then unwound from the second roller 460. In another embodiment of the present invention, the patterned phase retardation film 451 may be laminated with a release film 471 unwound from the third roller 470. The direction of the release film 471 faces the patterned phase retardation film 451. The release film 471 and the patterned phase retardation film 451 are passed through a laminating device 480, and then unwound from the roller 490, as shown in FIG.

In an embodiment of the invention, the patterned phase retardation film can be attached to at least one functional optical film to further provide additional desired optical properties. For example, a polarizing film, a hard-coating film, a low reflective film, an anti-reflective film, an anti-glaring film. The functional optical films are located on the substrate to form the other side of the alignment layer.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100, 451. . . Patterned phase difference retardation film

110, 210, 411. . . Substrate

120, 220. . . Alignment layer

130, 230. . . Liquid crystal layer

131, 231. . . First delay zone

132, 232. . . Second delay zone

140, 240, 471. . . Release film

1201. . . Liquid crystal material

400. . . system

410. . . First wheel

420. . . Orientation device

421. . . Liquid crystal coating

430. . . Coating device

440. . . heating equipment

450. . . Curing device

460. . . Second wheel

470. . . Third wheel

480. . . Laminating device

490. . . Wheel

630. . . Trough roller

631. . . Relief structure

632. . . Groove structure

S201, S202, S203, S204, S205, S206, S207. . . step

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view showing a patterned phase retardation film according to an embodiment of the present invention.

2 is a flow chart showing a method of manufacturing a patterned phase retardation film according to an embodiment of the present invention.

3A to 3D are schematic views showing the manufacturing steps of an embodiment of the present invention.

4 is a schematic diagram of a device for fabricating a phase retardation film manufacturing system according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a device for fabricating a phase retardation film manufacturing system according to still another embodiment of the present invention.

100. . . Patterned phase retardation film

110. . . Substrate

120. . . Alignment layer

130. . . Liquid crystal layer

131. . . First phase delay zone

132. . . Second phase delay zone

140. . . Release film

Claims (20)

A method of fabricating a patterned phase retardation film having a first phase retardation region and a second phase retardation region, comprising: providing a substrate; forming an alignment layer on the first surface of the substrate; and coating a liquid crystal material Forming a liquid crystal layer; aligning the liquid crystal layer with the alignment layer; printing the liquid crystal layer as a predetermined pattern to form a plurality of first phase retardation regions and a plurality of second phase retardation regions; the first phase retardation region And the second phase retardation region has a grid-like stripe structure and is parallel to each other, the second phase retardation region is a groove structure with respect to the first phase retardation region and is interlaced with the first phase retardation region; and curing the pattern And a liquid crystal layer; wherein a difference between phase delay values of the first phase delay region and the second phase delay region is 180 degrees. The method of producing a patterned phase retardation film according to claim 1, wherein the substrate has a phase retardation value of substantially 0 degrees. The method for producing a patterned phase retardation film according to claim 1, wherein the substrate is selected from the group consisting of polyethylene terephthalate (PET), polycarbonate (PC), A group consisting of triacetyl cellulose (TAC), polymethyl methacrylate (PMMA) and cyclo-olefin polymer (COP). The method of producing a patterned phase retardation film according to claim 1, wherein the substrate has a thickness of between 30 micrometers (μm) and 300 micrometers (μm). The method for producing a patterned phase retardation film according to claim 1, wherein the method of forming the alignment layer on the substrate is selected from the group consisting of micro-scratch alignment treatment, brush-grinding alignment Rubbing treatment, photo-alignment, a group consisting of SiO ₂ evaporation and ion-beam alignment. The method of producing a patterned phase retardation film according to claim 1, wherein the cured patterned liquid crystal layer has a thickness of between 1 micrometer (μm) and 3 micrometers (μm). The method of producing a patterned phase retardation film according to claim 1, wherein a temperature at which the liquid crystal layer is aligned with the alignment layer is between 50 ° C and 100 ° C. The method of producing a patterned phase retardation film according to claim 7, wherein the temperature at which the liquid crystal layer is aligned with the alignment layer is 70 °C. The method of producing a patterned phase retardation film according to claim 1, wherein the curing method of curing the patterned liquid crystal layer is an ultraviolet curing treatment or a thermal curing treatment. The method of manufacturing a patterned phase retardation film according to claim 1, further comprising coating a polarizing film on the cured liquid crystal layer. The method of manufacturing a patterned phase retardation film according to claim 1, further comprising: coating at least one functional optical film on the second surface of the substrate, the second surface being located on an opposite side of the first surface; Wherein, the functional optical film is selected from the group consisting of a polarizing film, a hard-coating film, a low reflective film, an anti-reflective film, and an anti-glare film. (anti-glaring film) group or combination of the above. A patterned phase retardation film comprising: a substrate; an alignment layer on the first surface of the substrate; a liquid crystal layer formed by coating a liquid crystal material on the alignment layer; and a plurality of first phase retardation regions And a plurality of second phase retardation regions; the liquid crystal layer is printed as a predetermined pattern to form the phase retardation regions; the first phase retardation region and the second phase retardation region have a grid-like stripe structure and the two are parallel to each other The second phase delay region is a groove structure with respect to the first phase delay region and is interleaved with the first phase delay region; wherein a phase delay value of the first phase delay region and the second phase delay region The difference is 180 degrees. The patterned phase retardation film of claim 12, wherein the substrate has a phase retardation value of less than 90 degrees. The patterned phase retardation film of claim 12, wherein the substrate has a phase retardation value of substantially 0 degrees. The patterned phase retardation film of claim 12, wherein the substrate is selected from the group consisting of polyethylene terephthalate (PET), polycarbonate (PC), and triacetate. A group of triacetyl cellulose (TAC), polymethyl methacrylate (PMMA) and cyclo-olefin polymer (COP). The patterned phase retardation film of claim 12, wherein the substrate has a thickness of between 30 micrometers (μm) and 300 micrometers (μm). The patterned phase retardation film of claim 12, wherein the alignment layer forming method on the substrate is selected from the group consisting of micro-scratch alignment treatment, rubbing alignment method (rubbing) Treatment), photo-alignment, a group consisting of SiO ₂ evaporation and ion-beam alignment. The patterned phase retardation film of claim 12, wherein the cured patterned liquid crystal layer has a thickness of between 1 micrometer (μm) and 3 micrometers (μm). The patterned phase retardation film of claim 12, further comprising a polarizing film attached to the cured liquid crystal layer. The patterned phase retardation film of claim 12, further comprising at least one functional optical film attached to the second surface of the substrate, the second surface being located on the first surface The opposite side; wherein the functional optical film is selected from the group consisting of a polarizing film, a hard-coating film, a low reflective film, an anti-reflective film, A group consisting of an anti-glaring film or a combination of the above.