Patent Application
20180341154
This application claims the priority of Chinese patent application CN 201611217557.6, entitled “Light Irradiation Device, Liquid Crystal Alignment Method, and Apparatus” and filed on Dec. 26, 2016, the entirety of which is incorporated herein by reference.
The present disclosure relates to the technical field of liquid crystal display, and in particular, to a light irradiation device, a liquid crystal alignment method, and an apparatus.
In a liquid crystal display device, liquid crystals cover an entire panel of the display device in the form of a thin layer. In this case, liquid crystal molecules need to be neatly arranged in a certain direction (called “alignment”). When light falls on the display device, it depends on alignment of the liquid crystal molecules whether the light is transmitted or the light is obscured. Therefore, it is necessary for all liquid crystal molecules to be arranged in a same direction constantly. At present, commonly used nematic liquid crystals are rod-like molecules. These rod-like molecules per se can be naturally arranged in a certain direction within a certain range of angles, but if not controlled, this arrangement is often of a certain degree of dispersion. In order to meet the requirements for use of the display device, liquid crystal molecules need to be arranged in an orderly manner. However, the natural force among the molecules merely is not enough, and therefore artificial control is necessary.
At present, a widely used liquid crystal alignment technology is PS-VA (Polymer Stabilized Vertical Alignment). In a PS-VA cell process, liquid crystals contain reactive monomers, and there is a liquid crystal alignment process. The reactive monomers in the liquid crystals are caused to react by irradiating a substrate with UV light so that the liquid crystal forms a pretilt angle, which is called ultraviolet light alignment.
In an ultraviolet light alignment process, an ultraviolet light source is needed. Main light-emitting members of ultraviolet light sources used in the prior art are metal halide lamps or fluorescent lamps, which have low light emitting efficiency and short service life, generally several thousand hours. Moreover, these light-emitting members are easily broken and contain harmful substances (such as mercury). They emit light with a broad range of wavelengths, including useless light and even light with wavelengths harmful to production.
Furthermore, a light-emitting member of the prior art is generally provided in the form of a lamp tube, and requires a high voltage to excite light emission, which is energy intensive. Moreover, when a machine base is too large, in order to match the size of the machine base, the lamp tube needs to be made so long that a drive voltage is required to be higher. Thus, energy consumption is further increased. Besides, illumination uniformity of a long lamp tube is not high.
In order to solve the problem in the prior art that a liquid crystal alignment light source is low in efficiency, high in cost and high in energy consumption, the present disclosure provides a light irradiation device, and provides a liquid crystal alignment method and an apparatus at the same time.
The light irradiation device provided by the present disclosure comprises one or a plurality of light boxes each provided with a plurality of light-emitting members and configured to emit light from inside to outside thereof through the light-emitting members. Light-emitting surfaces of the light boxes are in a same plane.
The light irradiation device is composed of arranged light boxes, and therefore, in the liquid crystal alignment process, the number of light boxes can be selected according to a size of a liquid crystal cell so that energy consumption and costs can be reduced.
As a further improvement to the present disclosure, the light is ultraviolet light. The light irradiation device emitting ultraviolet light can directly provide ultraviolet light used for liquid crystal alignment, and no auxiliary device is needed to block out unnecessary light. Thus, costs can be further reduced. In addition, the ultraviolet light does not damage a liquid crystal structure and thus a quality of a LCD panel can be improved.
As a further improvement to the present disclosure, the light-emitting members are light emitting diodes (LEDs). A wavelength range of a light-emitting diode is relatively concentrated. Through selection of semiconductor materials and change of material doping methods, the ultraviolet light required for liquid crystal alignment can be obtained directly. Meanwhile, a LED light source contains no mercury and other harmful substances, and has high luminous efficiency, low energy consumption, and a service life up to tens of thousands to hundreds of thousands of hours. Thus, frequent replacement of light boxes can be avoided, thereby reducing operating costs and improving productivity. At the same time, because a LED has a small size, they can be arranged in the light boxes in an intended manner to further improve the production flexibility.
In particular, when a wavelength of ultraviolet light is in a range of from 280 nm to 400 nm, liquid crystal alignment can be fully realized. Also, because light with other wavelengths is not present, a liquid crystal structure would not be damaged and no heat would be caused. As a result, not only quality of a product is improved, but also an auxiliary device is no longer needed for cooling treatment, thereby further reducing production costs.
When the light intensity of the light emitting diodes is adjusted by adjusting a voltage at both ends of each light emitting diode, in order to match the manufacture process, the light intensity of the light irradiation device can be controlled according to the needs of the manufacture process, further reducing the energy consumption and improving the product quality.
As a further improvement to the light irradiation device, the light emitting surfaces of the light boxes are circular or polygonal in shape. Light boxes with such shapes are easy to manufacture. When the plurality of the light boxes are arranged in a matrix, to meet a requirement of a regular square-shaped liquid crystal panel, the number of rows and columns of the light boxes can be set according to a size of the liquid crystal panel. When the plurality of the light boxes are arranged concentrically, to meet a requirement of a circle-shaped liquid crystal panel, the number and spacing of concentric circles can be set according to a diameter of the liquid crystal panel. Thus, excess light boxes are voided so as to realize energy conservation.
The present disclosure further provides a liquid crystal alignment method, characterized in that a substrate is irradiated with a light irradiation device provided by the present disclosure so that a liquid crystal forms a pretilt angle to complete the liquid crystal alignment.
The present disclosure further provides an apparatus, characterized in that the apparatus comprises a machine base and a light irradiation device from bottom to top; a liquid crystal cell is placed on the machine base; and light emitted from the light irradiation device irradiates the liquid crystal cell to complete the liquid crystal alignment.
In summary, the light irradiation device according to the present disclosure can directly provide ultraviolet light used for liquid crystal alignment in the liquid crystal alignment process, and an auxiliary device is no longer needed to block out unnecessary light, so that costs can be further reduced. In addition, the ultraviolet light may not cause damage to a liquid crystal structure, thus improving quality of a liquid crystal panel. Light-emitting diodes are used for emitting ultraviolet light so as to further reduce energy consumption and to avoid frequent replacement of lamp tubes, thereby improving productivity.
The present disclosure will be described in a more detailed way below based on embodiments and with reference to the accompanying drawings, in which:
In the accompanying drawings, same components use same reference signs. The accompanying drawings are not drawn according to actual proportions.
The present disclosure will be explained in details below with reference to the embodiments. Terms such as “upper”, “lower”, “left”, and “right” below are referred to with respect to positions in the figures, and should not be construed as limiting the present disclosure.
According to the present embodiment, the plurality of light boxes 11 are arranged in matrix. As shown in
According to the present embodiment, the plurality of light boxes 11 are arranged in a circular manner concentrically with an outer circumference of the lamp body 22. As shown in
Similarly, the light box 21 may be provided therein with more light-emitting members according to actual needs, and the light-emitting members are preferably light emitting diodes.
The light intensity of the light-emitting diodes can be adjusted by adjusting a voltage at both ends thereof to achieve the light intensity adjustment of the light irradiation device so as to meet requirements for liquid crystal alignment in different stages.
In manufacture of a liquid crystal cell, in the liquid crystal alignment process, the light irradiation device of the present disclosure can be used to irradiate a substrate with ultraviolet light, so that a liquid crystal forms a pretilt angle to complete the liquid crystal alignment.
It should be noted herein that the above embodiments are described only for explaining, rather than restricting the technical solutions of the present disclosure. While the present disclosure is explained in details with reference to the preferred embodiments, it should be understood by any person skilled in the art that the technical solutions of the present disclosure may be amended or equivalently replaced without departing from the spirit and scope of the present disclosure. The protection scope of the present disclosure shall be determined by the scope as defined in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201611217557.6 | Dec 2016 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2017/071238 | 1/16/2017 | WO | 00 |
