CN103217835A - Flexible liquid crystal display panel based on normal-temperature light orientation technology and manufacturing method thereof - Google Patents

Abstract

The invention belongs to the technical field of liquid crystal display devices, in particular to a flexible liquid crystal display panel based on normal temperature photo-alignment technology and a manufacturing method thereof. The method of the present invention includes coating the photo-alignment material at room temperature on the surface of two flexible substrates to form an alignment layer, applying UV polarized light to the alignment layer to cause a cross-linking reaction to occur in the alignment layer to form anisotropy to induce liquid crystal molecular alignment, and then combining the two layers of substrates A sandwich structure is formed to make a flexible liquid crystal display panel. The panel is thin and bendable. This method avoids the problem of deformation of the flexible substrate caused by high-temperature baking.

Description

Flexible liquid crystal display panel based on room temperature photo-alignment technology and its manufacturing method

technical field

The invention belongs to the technical field of liquid crystal display devices, and in particular relates to a flexible liquid crystal display panel based on normal temperature photo-alignment technology and a manufacturing method thereof.

technical background

An important direction for the development of displays is the thinning and lightening of the external dimensions. With the emergence of diversified applications, the demand for portability is becoming more and more intense, and the emergence of flat panel display technology has well filled this demand. The development of display devices has gone through from CRT to PDP to LCD and OLED. While the display quality can be maintained or even further improved, the size of the display becomes thinner and thinner. The applications on portable devices are also becoming more and more abundant, such as mobile phones, notebook computers, tablet computers, e-books and so on. In the process of thinning and lightening, the ultimate development goal is flexible display.

However, flexible liquid crystal display devices have new requirements for substrate characteristics. Traditional glass substrates are no longer applicable in terms of thinness and flexibility, and flexible substrates, especially plastic substrates, cannot withstand the harshness of traditional liquid crystal production and orientation processes. High temperature processing link, which greatly hinders the development of flexible liquid crystal display.

At the same time, the development of flexible display devices will introduce a new production process, especially the Roll-to-Roll-based assembly line process. These new processes will greatly improve the production efficiency of display devices and reduce production costs. The traditional liquid crystal alignment layer manufacturing process requires high-temperature curing, drying and other film-forming processes, which cannot meet the requirements of the Roll-to-Roll open production process. Photo-alignment at room temperature solves this process problem, enabling the substrate alignment layer to be formed at room temperature or low temperature, making continuous manufacturing of flexible display devices possible.

Contents of the invention

The object of the present invention is to provide a flexible liquid crystal display panel with simple manufacturing process, low production cost and good device performance and its manufacturing method. the

The flexible liquid crystal display panel provided by the present invention is based on photo-alignment technology, and is a sandwich structure formed by combining two layers of flexible substrates. The surfaces of the two layers of flexible substrates are coated with alignment materials to form an alignment layer. Polarized light causes the alignment layer to undergo a cross-linking reaction to form anisotropy and induce alignment of liquid crystal molecules. The flexible liquid crystal display panel has the characteristics of being light, thin and bendable. The invention avoids the deformation problem of the flexible substrate caused by high-temperature baking.

The manufacturing method of the flexible liquid crystal display panel provided by the present invention includes the processing of the alignment layer:

Spin-coat an alignment material on the surface of the flexible substrate, the alignment material includes a chain polymer and a photosensitive group on the side chain;

UV polarized light of a certain wavelength is used to irradiate the alignment layer with a certain intensity, so that the chain polymer is cross-linked in the direction of the polarization plane to form anisotropy of the alignment layer, and induce the alignment of liquid crystal molecules. The wavelength range of UV polarized light is 254-365nm, and the light energy range is 1-5000mJ.

The manufacturing method of the flexible liquid crystal display panel that the present invention provides, concrete steps are:

Spin-coating an alignment material on the surface of the first flexible substrate to form a phase-taking layer;

performing light orientation treatment on the first flexible substrate;

Spin-coating an alignment material on the surface of the second flexible substrate to form a phase-taking layer;

performing light orientation treatment on the second flexible substrate;

making spacers on the surface of the second flexible substrate;

Wherein at least one of the phase-taking layer materials on the surface of the first and second flexible substrates includes a chain polymer and a photosensitive group on the side chain;

Lay the above-mentioned first and second flexible substrates together to form a flexible liquid crystal panel box; and apply UV polarized light irradiation with a certain wavelength and a certain intensity to the phase-taking layer including the chain polymer and the photosensitive group on the side chain , making the chain polymer cross-link in the direction of the polarization plane to form the anisotropy of the alignment layer, and induce the alignment of liquid crystal molecules; the wavelength range of UV polarized light is 254-365nm, and the light energy range is 1-5000mJ;

Liquid crystal is poured into the bonded flexible liquid crystal panel box to obtain a complete flexible liquid crystal display panel.

Further, one vertical UV polarized light irradiation and one or more oblique UV polarized light irradiations are applied to the alignment layer, or one or more oblique UV polarized light irradiations are applied separately to obtain the liquid crystal alignment pretilt angle related to the oblique irradiation angle.

Further, in the present invention, the poured liquid crystal is a nematic liquid crystal to form a transmissive flexible liquid crystal display panel; or the poured liquid crystal is a cholesteric liquid crystal to form a reflective flexible liquid crystal display panel.

Further, for a transmissive flexible liquid crystal display panel, the display mode can be a mode in which at least one of the two substrates such as TN, STN, and IPS involves parallel alignment of liquid crystals; for a reflective flexible liquid crystal display panel, the orientation directions of the two substrates involve 0-360° different The orientation and direction match.

Description of drawings

Figure 1. Schematic diagram of the structure of a flexible liquid crystal display panel based on room temperature photo-alignment technology.

Figure 2. Implementation method of room temperature photo-alignment technology.

Figure 3. The relationship between UV polarization direction and liquid crystal molecular orientation.

Detailed ways

The invention comprises a method for forming an alignment layer on the surface of a flexible plastic substrate by using a light alignment process at normal temperature, and assembling and processing the flexible plastic substrate with the alignment layer into a flexible liquid crystal display panel. Its specific implementation is as follows:

Dissolve the high molecular polymer used for orientation in an organic solvent to make an orientation material solution with a certain concentration, and apply it to the first flexible plastic (made of PET, PS, PE, PI, or PVC) substrate 1, 9, 11, one layer of high molecular polymer alignment layer 2, 8, 11 is made on the surface. The polymer is a chain polymer, and the side chain is connected with coumarin or other photosensitive groups with a certain length of carbon segment on the side chain. The first substrate coated with the alignment layer is placed in a dry environment at normal temperature for a certain period of time to evaporate the solvent to form a polymer alignment layer with a thickness of 60-80 nm.

Use a high-pressure xenon lamp to obtain UV polarized light 7 of a certain intensity at the sensitive wavelength of the photosensitive group through a filter and a polarizer (Glan prism, etc.), and direct the UV polarized light to the surface of the first substrate with an alignment layer vertically, and irradiate After a certain period of time, the photosensitive group will undergo cross-linking reaction in the polarization direction of UV light, forming anisotropy of the alignment layer.

The second flexible plastic substrates 4 , 9 , 11 are treated the same as the first flexible substrates to obtain second substrates with anisotropic alignment layers 5 , 8 , 11 . And fabricate a layer of spacers 3 evenly distributed on the surface of the second substrate by spin coating or spraying.

The first flexible substrate with an alignment layer and the second flexible substrate with an alignment layer and uniformly distributed spacers are relatively attached to form a flexible display panel box that is not filled with liquid crystal.

On the basis of the above-mentioned embodiments, the first embodiment of the present invention is a glass substrate with a photo-alignment layer and a flexible substrate with a photo-alignment layer to make a display panel box, and the orientation direction of the two substrates adopts the TN mode. And pour nematic liquid crystals 6 and 10 into the panel box to obtain a complete transmissive liquid crystal display panel. Liquid crystal molecular orientation and UV polarization direction.

On the basis of the above embodiments, the second embodiment of the present invention is to make a display panel box from two flexible substrates with photo-alignment layers, the alignment directions of the two substrates are parallel to each other, and pour cholesteric liquid crystals into the panel box 6 , 10, obtaining a complete reflective flexible liquid crystal display panel.

On the basis of the above embodiments, the third embodiment of the present invention is a non-transparent substrate with a photo-alignment layer and a flexible substrate with a photo-alignment layer to make a display panel box, and pour the nematic phase into the panel box Liquid crystals 6 and 10 to obtain a complete reflective liquid crystal display panel.

Claims (5)

1. based on the flexible liquid crystal panel of normal temperature light orientation technology, it is characterized in that sandwich structure for the formation of two sheets of flexible substrate in combination, described two sheets of flexible substrate surface applies the oriented layer that oriented material forms, cross-linking reaction takes place through applying the UV polarizing light irradiation in this oriented layer, forms anisotropy and induces liquid crystal molecular orientation.

2. the manufacture method of the flexible liquid crystal panel based on normal temperature light orientation technology as claimed in claim 1 is characterized in that concrete steps are:

At first flexible base, board surface spin coating oriented material, form and get layer mutually;

This first flexible base, board is carried out the illumination orientation process;

At second flexible base, board surface spin coating oriented material, form and get layer mutually;

This second flexible base, board is carried out the illumination orientation process;

Make introns on second flexible base, board surface;

Wherein the phase layer material of getting on the first and second flexible base, board surfaces has a photosensitive group that comprises on chain type high molecular polymer and the side chain at least;

Above-mentioned first and second flexible base, boards are fitted each other, form flexible liquid crystal panel box; And get mutually to what comprise photosensitive group on chain type high molecular polymer and the side chain that layer applies the UV polarizing light irradiation, make the chain polymerization thing be cross-linked to form the anisotropy of oriented layer, induce liquid crystal molecular orientation in the plane of polarization direction; Described UV polarized light wavelength is 254-365nm, and the illumination energy is 1-5000mJ;

Pour into liquid crystal in the flexible liquid crystal panel box after fitting, obtain complete flexible liquid crystal panel.

3. manufacture method according to claim 2, it is characterized in that oriented layer is imposed once vertical UV polarizing light irradiation and one or many inclination UV polarizing light irradiation, or impose one or many inclination UV polarizing light irradiation separately, obtain the liquid crystal aligning tilt angle relevant with the oblique illumination angle.

4. manufacture method according to claim 2 is characterized in that, the liquid crystal of perfusion is a nematic liquid crystal, forms transmission-type flexible liquid crystal panel; Or the perfusion liquid crystal be cholesteryl liquid crystal, form reflective flexible liquid crystal panel.

5. manufacture method according to claim 4 is characterized in that for transmission-type flexible liquid crystal panel, display mode is TN, STN or IPS, has at least one to be the parallel-oriented pattern of liquid crystal in two flexible base, boards; For reflective flexible liquid crystal panel, the two substrates direction of orientation has 0-360 ° of different direction of orientation collocation.

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