TWI490263B - Image display device employing a liquid crystal module and method for fabricating the liquid crystal module - Google Patents

Description

Image display device with liquid crystal display module and manufacturing method of liquid crystal display module

The present invention relates to an image display device, and more particularly to an image display device having a liquid crystal display module.

The liquid crystal display device is used in a wide range of fields by utilizing the advantages of thinness, light weight, and low power consumption. The liquid crystal display device may include a pair of substrates, and an electrode is provided on the substrate, and a liquid crystal layer is provided between the substrates. When a voltage is appropriately applied to the electrodes provided on the substrate, the rotation direction of the liquid crystal molecules contained in the liquid crystal layer can be controlled. The liquid crystal display device usually has a liquid crystal alignment film provided on the surface of the liquid crystal layer side of the substrate to control the alignment direction of the liquid crystal molecules.

The liquid crystal alignment film is mainly made of a polymeric material. The liquid crystal alignment film acts as a director for guiding the liquid crystal molecules. When the liquid crystal molecules are moved by the influence of the electric field to present an image, the liquid crystal alignment film orients the molecules in a predetermined direction. In general, it is necessary to uniformly align liquid crystal molecules in order to provide uniform brightness and high contrast ratio to the liquid crystal device.

Conventional methods for aligning liquid crystals include coating a polymer film such as polyimide on a glass substrate, and rubbing the surface of the substrate in a certain direction with a polyester such as nylon or polyester. . However, the rubbing method causes serious problems in dust or electrostatic discharge (ESD) generated when the fiber is rubbed against the polymer film.

In order to solve the problems caused by the rubbing method, the optical radiation alignment method (referred to as photoalignment) has recently been studied in the industry, and the anisotropy of the polymer film is induced by irradiating light on the film to align the liquid crystal molecules. A photoalignment method has been proposed which utilizes a polymer having a photofunctional group as an alignment film material. These polymers are anisotropically photoisomerized, photocrosslinked, or photolyzed by irradiation with polarized light to provide anisotropy to the surface, thereby enabling it to induce alignment of the liquid crystal molecules in a certain direction.

The material used for the liquid crystal alignment film should have optical stability and thermal stability so as to be suitable for use in a liquid crystal display device. However, in this regard, the alignment film formed by the conventional light alignment material has poor optical stability and thermal stability, resulting in unstable alignment force and failure to pass the reliability test. In addition, in general, the alignment film formed by the photo-alignment processing method has an anchoring energy smaller than that of the alignment film formed by the rubbing method, which may cause a decrease in response speed or cause image retention (image) Sticking).

Based on the above, there is a need in the industry for a novel photo-alignment method to form an alignment film having high stability and anchoring effect to solve the problems posed by the prior art.

In view of the above, the present invention provides an image display device having a liquid crystal display module, which has an improved photo-cleaving alignment layer, which has higher alignment effect and optical stability than the conventional photo-cleavage alignment method. The impurities generated when the photocleaving alignment layer is formed are isolated. In addition, the present invention also provides a method for manufacturing an image display device, which can reduce the illumination time of the photo-disintegration compound layer, increase the stability and anchoring effect of the alignment film, and achieve the purpose of reducing cost and increasing productivity.

The image display device of the present invention includes a liquid crystal display module, and the liquid crystal display module includes: a first substrate and a second substrate, wherein the first substrate and the second substrate are disposed in parallel with each other; a photo-cleaving alignment layer is disposed on an upper surface of the first substrate, and a second photo-disintegration alignment layer is disposed on a lower surface of the second substrate, wherein the first photo-cleaving alignment layer and the second light Cracking the surface of the alignment layer and having a plurality of protrusions, and the protrusions are formed by polymerization of a non-polar monomer having the following structure:

Wherein R is a methyl group or an ethyl group; and an In-Plane Switching liquid crystal layer is disposed between the first photo-cleaving alignment layer and the second photo-cleaving alignment layer.

The present invention also provides a method for manufacturing a liquid crystal display module, comprising: providing a first substrate and a second substrate, wherein the first substrate and the second substrate are disposed in parallel with each other; and coating the surface of the first substrate a first photo-cleaving compound layer, and a second photo-cracking compound layer coated on the lower surface of the second substrate; applying a first energy to the first photo-lysing compound layer and the second photo-lysing compound layer, Forming a first photo-cleaving alignment layer and a second photo-cleaving alignment layer respectively; injecting a liquid crystal composition between the first photo-cleaving alignment layer and the second photo-cleaving alignment layer, wherein the liquid crystal combination The material comprises a transverse electric field switching (In-Plane Switching) liquid crystal and a non-polar monomer, and the non-polar monomer has the following structure:

Wherein R is a methyl group or an ethyl group; and applying a second energy to the liquid crystal composition to form a plurality of surfaces on the surface of the first photo-cleaving alignment layer and the second photo-cleaving alignment layer a protrusion, wherein the protrusion is formed by polymerization of the non-polar monomer.

In order to make the above objects and features of the present invention more comprehensible, the following detailed description of the preferred embodiments and the accompanying drawings

Referring to FIG. 1 , a liquid crystal display module 100 according to an embodiment of the present invention includes a first substrate 12 and a second substrate 14 , wherein the second substrate 14 and the The first substrates 12 are disposed in parallel with each other. The first substrate 12 and the second substrate 14 may be a transparent substrate, such as a glass substrate. A first photo-disintegration alignment layer 16 is disposed on the upper surface 11 of the first substrate 12, and a second photo-disintegration alignment layer 18 is disposed on the lower surface 13 of the second substrate 14. The first photo-cleaving alignment layer 16 and the second photo-cleaving alignment layer 18 are formed by applying a first energy to a photo-cleavable compound, wherein the photo-cleavable compound may have a ring. A compound of a butane dianhydride group. For example, the photocleavable compound can have the following repeating units: Wherein Ar is an aromatic group (for example, Phenyl, Naphthyl, Diphenyl, Anthryl, Pyrenyl, Phenanthryl, and A group consisting of a dibenzopentacyclic (Fluorene), and other forms of a polyphenyl ring substituent biphenyl. According to an embodiment of the invention, the photocleavable compound has the following repeating units: . It should be noted that, referring to FIG. 2, it is a partially enlarged schematic view of the region 2 shown in FIG. 1, the upper surface 15 of the first photo-cleaving alignment layer 16 (and the second photo-cleaving alignment layer 18). The lower surface 17) has a plurality of protrusions 22 which may have a height of no more than 20 nm and a width of not more than 200 nm. Wherein, the protrusion 22 is formed by a polymerization reaction by applying a second energy to a non-polar monomer, wherein the non-polar monomer has 2 or 3 acrylate functional groups. For example, the non-polar monomer can have the following structure: ,or Wherein R is a methyl group or an ethyl group. The plurality of protrusions 22 can exert an anchoring effect, stabilize and enhance the alignment force of the first photo-cleaving alignment layer 16 and the second photo-cleaving alignment layer 18, and can isolate the impurities generated when the photo-cleaving alignment layer is formed. . In addition, the upper surface 11 of the first substrate 12 may further be provided with a lateral electric field switching electrode layer 30, that is, the transverse electric field switching electrode layer 30 may be disposed between the first photo-disintegration alignment layer 16 and the first substrate 12. . According to another embodiment of the present invention, the lateral electric field switching electrode layer 30 may also be disposed between the second photo-disintegration alignment layer 18 and the second substrate 14.

Still referring to FIG. 1 , an In-Plane Switching liquid crystal layer 20 is disposed between the first photo-cleaving alignment layer 16 and the second photo-disintegration alignment layer 18 . According to an embodiment of the invention, the liquid crystal display module is a horizontal electric field switching liquid crystal display module.

Please refer to FIG. 3 , which is a flowchart of a process of the liquid crystal display module 100 shown in FIG. 1 . The method for manufacturing the liquid crystal display module may include the following steps: First, providing a first substrate and a first And a second substrate, wherein the first substrate and the second substrate are disposed in parallel with each other (step 101). Next, a first photo-dissolving compound layer is coated on the upper surface of the first substrate, and a second photo-cleaving compound layer is coated on the lower surface of the second substrate (step 102). The photocleavable compound may be an azo polymer such as an aromatic azo polymer. For example, the photocleavable compound can have the following repeating units: Wherein Ar is an aromatic group (for example, Phenyl, Naphthyl, Diphenyl, Anthryl, Pyrenyl, Phenanthryl, and a group of dibenzopentacene (Fluorene) and other forms of polyphenyl ring substituent biphenyl). According to an embodiment of the invention, the photocleavable compound has the following repeating unit: . Next, after the coating of the photo-cleaving compound layer is completed, a first energy is applied to the first photo-cleaving compound layer and the second photo-lysing compound layer to form a first photo-cleaving alignment layer and a The second photocleaving alignment layer (step 103). It should be noted that the first energy may be ultraviolet light having a wavelength of 240-280 nm (for example, ultraviolet light having a wavelength of 254 nm, which may be general UV light or linear polarized light), and the first photo-cleaving compound layer and the second The photolysis compound layer may apply the first energy for 1 to 100 seconds, the illuminance may be 10 to 80 mW, and the total irradiation amount may be 0.1 to 3 J. After forming the first photo-cleaving alignment layer and a second photo-cleaving alignment layer, a liquid crystal composition may be injected between the first photo-cleaving alignment layer and the second photo-cleaving alignment layer (step 104) Wherein the liquid crystal composition may comprise a transverse electric field switching (In-Plane Switching) liquid crystal and a non-polar monomer, and the non-polar monomer has 2 or 3 acrylic functional groups. For example, the non-polar monomer can have the following structure:

Wherein R is a methyl group or an ethyl group. In the liquid crystal composition, the non-polar monomer has a weight percentage of 0.05 to 3 wt%, for example, 0.3 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, or 3 wt% (the weight percentage is The total weight of the liquid crystal composition is based on the basis). When the weight percentage of the non-polar monomer is less than 0.05% by weight, the problem of insufficient photo-alignment ability may be caused; and when the weight percentage of the non-polar monomer is more than 3% by weight, excessive non-polar monomers may cause alignment of the liquid crystal molecules. Disorder. In addition, the liquid crystal composition can be injected into a One Drop Filling (ODF) or a conventional liquid crystal injection process. Finally, after injecting the liquid crystal composition, the liquid crystal composition is subjected to a second energy (step 105) to polymerize the non-polar monomer in the liquid crystal composition and adhere to the first photo-cracking reaction. The alignment layer and the second photo-cleaving alignment layer form a plurality of protrusions on the surface of the first photo-disintegration alignment layer and the second photo-disintegration alignment layer to obtain the liquid crystal display module. The second energy may be ultraviolet light having a wavelength of 310-380 nm (which may be general UV light or linear polarized light), and the second energy may be applied to the liquid crystal composition for 50 seconds to 5 hours, and the illumination may be introduced. At 1~100mW, the total exposure can be 0.5J~100J.

The above and other objects, features and advantages of the present invention will become more apparent and understood.

First, two transparent glass substrates are respectively coated thereon with a photo-cleaving compound layer and the two substrates are disposed in parallel so that the surfaces of the two substrates coated with the photo-cleaving compound layer face each other. Wherein the photocleaving compound layer has the following repeating unit The compound is composed of a thickness of 400 to 800 mm. Next, the photo-cleaving compound layer is irradiated with ultraviolet rays having a wavelength of 240 to 280 nm, the irradiation time is 1-100 seconds, the illuminance is 10 to 80 mW, and the total irradiation amount is 0.1 to 3 J, and the upper and lower layers of the photo-cleavage alignment layer are obtained. Next, a liquid crystal composition (sold by IPS liquid crystal (sold by Merck) and a non-polar monomer (having the following structure: Mixing, wherein the non-polar monomer has a weight percentage of 0.1-1% by weight based on the total weight of the liquid crystal composition) and is injected into the two substrates by a One Drop Filling (ODF) process to cause the liquid crystal composition to The upper and lower photocleavage alignment layers are in contact. Finally, the liquid crystal composition is irradiated with ultraviolet light having a wavelength of 310-380 nm at a wavelength to polymerize the non-polar monomer in the liquid crystal composition, and is attached to an upper and lower photo-cleaving alignment layer to form a plurality of Protrusion. The irradiation time of the 310-400 nm ultraviolet light is 50 seconds to 5 hours, the illuminance is 1 to 100 mW, and the total irradiation amount is 0.5 to 100 J.

Based on the above, the liquid crystal display module and the method of manufacturing the same according to the present invention, in addition to using a photo-cleavable alignment layer, further use a liquid crystal composition having a non-polar monomer to contact the photo-cleaving alignment layer and apply an energy The non-polar monomer is polymerized on the surface of the photocleaving alignment layer. Since the plurality of protrusions formed after the polymerization of the non-polar monomer can exert an anchoring effect, enhance the alignment force and stability, the time for applying ultraviolet rays to the photo-cleaving compound layer in the step of forming the photo-cleaving alignment film can be further reduced.

FIG. 4 is a block diagram showing an image display device 200 including a liquid crystal display module 100 according to an embodiment of the invention. The image display device 200 can be coupled to the liquid crystal display module 100 by a control unit 50. The control unit 50 includes a microprocessor for inputting signals to the liquid crystal display module 100 and displaying the images after processing. The image display device 200 includes, for example, a personal digital device (PDA), a mobile phone, a notebook computer, a laptop computer, or other portable electronic device.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope is based on the definition of the scope of the patent application attached.

2. . . region

11. . . Upper surface of the first substrate

12. . . First substrate

13. . . Lower surface of the second substrate

14. . . Second substrate

15. . . First photocleaving alignment layer upper surface

16. . . First photolysis aligning layer

17. . . Second photocleaving of the lower surface of the alignment layer

18. . . Second photolysis aligning layer

20. . . Liquid crystal layer

twenty two. . . Protrusion

30. . . Transverse electric field switching electrode layer

50. . . control unit

100. . . Liquid crystal display module

101-105. . . step

200. . . Image display device

FIG. 1 is a cross-sectional view showing a liquid crystal display module according to an embodiment of the invention.

Fig. 2 is a partially enlarged schematic view showing a region 2 of Fig. 1.

FIG. 3 is a flow chart showing the steps of a method for fabricating a liquid crystal display module according to an embodiment of the invention.

4 is a block diagram showing an image display device according to an embodiment of the invention.

2. . . region

11. . . Upper surface of the first substrate

12. . . First substrate

13. . . Lower surface of the second substrate

14. . . Second substrate

15. . . First photocleaving alignment layer upper surface

16. . . First photolysis aligning layer

17. . . Second photocleaving of the lower surface of the alignment layer

18. . . Second photolysis aligning layer

20. . . Liquid crystal layer

30. . . Transverse electric field switching electrode layer

100. . . Liquid crystal display module

Claims (20)

An image display device having a liquid crystal display module, comprising: a liquid crystal display module, comprising: a first substrate and a second substrate, wherein the first substrate and a second substrate are disposed in parallel with each other; a first light Disposing a splitting alignment layer on an upper surface of the first substrate, a second photo-cleaving alignment layer disposed on a lower surface of the second substrate, wherein the surface of the first photo-cleaving alignment layer and the second light The surface of the cracked alignment layer has a plurality of protrusions, and the protrusions are formed by polymerization of a non-polar monomer having the following structure: ,or Wherein R is a methyl group or an ethyl group; and a transverse electric field switching liquid crystal layer is disposed between the first photo-cleaving alignment layer and the second photo-cleaving alignment layer. The image display device with a liquid crystal display module according to claim 1, wherein the first photo-cleaving alignment layer and the second photo-cleaving alignment layer apply a first energy to a photo-cleavable compound. Formed afterwards. Liquid crystal display module as described in claim 2 An image display device wherein the photocleavable compound is a compound having a cyclobutane dianhydride group. An image display device having a liquid crystal display module according to claim 2, wherein the photocleavable compound has the following repeating unit: , wherein the Ar system is an aromatic group. An image display device having a liquid crystal display module according to claim 2, wherein the photocleavable compound has the following repeating unit: An image display device having a liquid crystal display module according to claim 1, wherein the protrusion is formed by applying a second energy to the non-polar monomer. The image display device with a liquid crystal display module according to claim 1, wherein the liquid crystal display module is a horizontal electric field switching liquid crystal display module. The liquid crystal display module as described in claim 1 The image display device further includes a lateral electric field switching electrode layer on the upper surface of the first substrate. The image display device with a liquid crystal display module according to claim 1, wherein the lower surface of the second substrate further comprises a transverse electric field switching electrode layer. A method for manufacturing a liquid crystal display module includes: providing a first substrate and a second substrate, wherein the first substrate and the second substrate are disposed in parallel with each other; and coating a first light on a surface of the first substrate Cracking the compound layer, and coating a second photo-dissolving compound layer on the lower surface of the second substrate; applying a first energy to the first photo-cleaving compound layer and the second photo-lysing compound layer to form a first a photo-cleaving alignment layer and a second photo-cleaving alignment layer; injecting a liquid crystal composition between the first photo-cleaving alignment layer and the second photo-cleaving alignment layer, wherein the liquid crystal composition comprises a lateral direction In-Plane Switching liquid crystal and a non-polar monomer, and the non-polar monomer has the following structure: ,or Wherein R is a methyl group or an ethyl group; and applying a second energy to the liquid crystal composition to form a plurality of protrusions on the surface of the first photo-cleaving alignment layer and the second photo-cleaving alignment layer Wherein the protrusion is formed by polymerization of the non-polar monomer. The method of manufacturing a liquid crystal display module according to claim 10, wherein the first photo-cleaving compound layer and the second photo-cleaving compound layer comprise a photo-cleavable compound. The method for producing a liquid crystal display module according to claim 11, wherein the photocleavable compound is a compound having a cyclobutane dianhydride group. The method of manufacturing a liquid crystal display module according to claim 11, wherein the photocleavable compound has the following repeating unit: , wherein the Ar system is an aromatic group. The method of manufacturing a liquid crystal display module according to claim 11, wherein the photocleavable compound has the following repeating unit: For example, the liquid crystal display module described in claim 10 The method of manufacturing, wherein the non-polar monomer has a weight percentage of from 0.05 to 3% by weight based on the total weight of the liquid crystal composition. The method of manufacturing a liquid crystal display module according to claim 10, wherein the first energy system is ultraviolet light having a wavelength of 240 to 280 nm. The method of manufacturing a liquid crystal display module according to claim 10, wherein the time for applying the first energy is 1-100 seconds. The method of manufacturing a liquid crystal display module according to claim 10, wherein the second energy system is ultraviolet light having a wavelength of 310 to 380 nm. The method of manufacturing a liquid crystal display module according to claim 10, wherein the time for applying the second energy is 50 seconds to 5 hours. The method of manufacturing a liquid crystal display module according to claim 10, wherein the protrusion has a height of less than or equal to 20 nm and a width of less than or equal to 200 nm.