cholesteric lcd display factory

A cholesteric liquid crystal display (ChLCD) is a display containing a liquid crystal with a helical structure and which is therefore chiral. Cholesteric liquid crystals are also known as chiral nematic liquid crystals.

KDI has world class manufacturing expertise in roll to roll manufacturing of liquid crystal films, face shield lenses, and other functional flexible materials in including the award winning flexible Boogie Board eWriter LCD films.

The eWriter works on the principle of anisotropic flow, a unique feature of cholesteric liquid crystals, in which crystals flow at different rates, depending on the direction of pressure being applied.

The cholesteric (or chiral nematic) liquid crystal phase is typically composed of nematic mesogenic molecules containing a chiral center which produces intermolecular forces that favor alignment between molecules at a slight angle to one another. This leads to the formation of a structure which can be visualized as a stack of very thin 2-D nematic-like layers with the director in each layer twisted with respect to those above and below. In this structure, the directors actually form in a continuous helical pattern about the layer normal. The black arrow in the animation represents director orientation in the succession of layers along the stack.

An important characteristic of the cholesteric mesophase is the pitch. The pitch, p, is defined as the distance it takes for the director to rotate one full turn in the helix as illustrated in the above animation. A byproduct of the helical structure of the chiral nematic phase, is its ability to selectively reflect light of wavelengths equal to the pitch length, so that a color will be reflected when the pitch is equal to the corresponding wavelength of light in the visible spectrum. The effect is based on the temperature dependence of the gradual change in director orientation between successive layers, which modifies the pitch length resulting in an alteration of the wavelength of reflected light according to the temperature. The angle at which the director changes can be made larger, and thus tighten the pitch, by increasing the temperature of the molecules, hence giving them more thermal energy. Similarly, decreasing the temperature of the molecules increases the pitch length of the chiral nematic liquid crystal. This makes it possible to build a liquid crystal thermometer that displays the temperature of its environment by the reflected color. Mixtures of various types of these liquid crystals are often used to create sensors with a wide variety of responses to temperature change. Such sensors are used for thermometers often in the form of heat sensitive films to detect flaws in circuit board connections, fluid flow patterns, condition of batteries, the presence of radiation, or in novelties such as "mood" rings.

The wavelength of the reflected light can also be controlled by adjusting the chemical composition, since cholesterics can either consist of exclusively chiral molecules or of nematic molecules with a chiral dopant dispersed throughout. In this case, the dopant concentration is used to adjust the chirality and thus the pitch.

Recognizing Cholesteric Liquid Crystal Displays (ChLCD) key attribute of “No Power” to maintain an image, Ebulent Technologies has been a supplier of this unique display technology from the beginning. No other company has more ChLCD design wins or manufacturing experience than us. No other company has shipped more segmented and graphic ChLCD modules than Ebulent Technologies Corp.

Fundamental purpose of the present invention, the inboard that is lower glass substrate is coated with the photoresistance that one deck has color, to form the background color layer, and make the controllable film thickness system of background color layer even, phenomenon that can coloured inequality, and can improve disappearances such as pin hole, foreign matter and scratch, the background color uniformity coefficient is good when allowing display element light, and has preferable display effect.

Cholesteric liquid crystal display element through method for making of the present invention is made because the background color layer of infrabasal plate is to be shaped with the solid bake mode of photoresistance, therefore can not produce the disappearance that pin hole or foreign matter adhere to.In addition, be formed with protective seam on this background color layer, this background color layer can be subjected to the protection of this protective seam, in assembling process, is difficult for producing scratch.Moreover this background color layer is to be shaped with blue photoresistance rotary coating, so the controllable film thickness system of this background color layer is even, and can not produce the phenomenon of look inequality, and when display element was lighted, the background color homogeneity was good, can produce preferable display effect.Also have, infrabasal plate one side is pasted with reflector plate, can increase the effect of reflection background color layer color.

Fundamental purpose of the present invention, the inboard that is lower glass substrate is coated with the photoresistance that one deck has color, to form the background color layer, and make the controllable film thickness system of background color layer even, phenomenon that can coloured inequality, and can improve disappearances such as pin hole, foreign matter and scratch, the background color uniformity coefficient is good when allowing display element light, and has preferable display effect.

Cholesteric liquid crystal display element through method for making of the present invention is made because the background color layer of infrabasal plate is to be shaped with the solid bake mode of photoresistance, therefore can not produce the disappearance that pin hole or foreign matter adhere to.In addition, be formed with protective seam on this background color layer, this background color layer can be subjected to the protection of this protective seam, in assembling process, is difficult for producing scratch.Moreover this background color layer is to be shaped with blue photoresistance rotary coating, so the controllable film thickness system of this background color layer is even, and can not produce the phenomenon of look inequality, and when display element was lighted, the background color homogeneity was good, can produce preferable display effect.Also have, infrabasal plate one side is pasted with reflector plate, can increase the effect of reflection background color layer color.

A blue phase mode LCD is a liquid crystal display (LCD) technology that uses highly twisted cholesteric phases in a blue phase. It was first proposed in 2007 to obtain a better display of moving images with, for example, frame rates of 100–120 Hz to improve the temporal response of LCDs.anisotropic alignment layers (e.g., rubbed polyimide) and thus theoretically simplifies the LCD manufacturing process.

For almost 100 years, scientists assumed that the most stable cholesteric helical structure could be described by a single helical axis about which the director rotates. It turned out that in the new structure the director rotates in a helical fashion about any axis perpendicular to a line as illustrated in fig. 1. Although an unlimited number of helical axes are actually present, this structure was named double twist structure.

In May, 2008 Samsung Electronics announced that it has developed the world"s first Blue Phase LCD panel which can be operated at an unprecedented refresh rate of 240 Hz. Samsung unveiled a 15 inch prototype model of its Blue Phase LCD panel at the SID (Society for Information Display) 2008 international Symposium, Seminar and Exhibition, which was held in Los Angeles from May 18 to 23, 2008.

Developed with a look at cost-efficiency, Samsung"s Blue Phase mode does not require liquid crystal alignment layers, unlike today"s most widely used TFT LCD modes such as Twisted Nematic (TN), In-Plane Switching (IPS) or Vertical Alignment (VA). The Blue Phase mode can make its own alignment layers, eliminating the need for any mechanical alignment and rubbing processes. This reduces the number of required manufacturing steps, resulting in savings on production costs. Additionally it has been claimed that Blue Phase panels would reduce the sensitivity of the liquid crystal layer to mechanical pressure which could impair the lateral uniformity of display (e.g. luminance, chromaticity).

In a blue phase based LC-display for TV applications it is not the selective reflection of light according to the lattice pitch (Bragg reflection) that is used for display of visual information, but an external electric field induces a birefringence in the liquid crystal via the Kerr effect.Blue Phase Mode LC layer is placed between crossed polarizers.

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Lavrentovich, O. D.; Kleman, M. (2001). "Cholesteric Liquid Crystals: Defects and Topology". Chirality in Liquid Crystals. New York: Springer-Verlag. pp. 115–158. doi:10.1007/0-387-21642-1_5. ISBN 0-387-98679-0.

Haseba, Yasuhiro; Kikuchi, Hirotsugu (2006). "Electro-optic effects of the optically isotropic state induced by the incorporative effects of a polymer network and the chirality of liquid crystal". Journal of the Society for Information Display. Wiley. 14 (6): 551–556. doi:10.1889/1.2210806. ISSN 1071-0922.

Ge, Zhibing; Gauza, Sebastian; Jiao, Meizi; Xianyu, Haiqing; Wu, Shin-Tson (2009-03-09). "Electro-optics of polymer-stabilized blue phase liquid crystal displays". Applied Physics Letters. AIP Publishing. 94 (10): 101104. doi:10.1063/1.3097355. ISSN 0003-6951. Archived from the original on 2012-07-13. Retrieved 2019-12-05.

Ge, Zhibing; Rao, Linghui; Gauza, Sebastian; Wu, Shin-Tson (2009). "Modeling of Blue Phase Liquid Crystal Displays". Journal of Display Technology. Institute of Electrical and Electronics Engineers (IEEE). 5 (7): 250–256. doi:10.1109/jdt.2009.2022849. ISSN 1551-319X.

Rao, Linghui; Ge, Zhibing; Wu, Shin-Tson; Lee, Seung Hee (2009-12-07). "Low voltage blue-phase liquid crystal displays". Applied Physics Letters. AIP Publishing. 95 (23): 231101. doi:10.1063/1.3271771. ISSN 0003-6951.

O.D. Lavrentovich, M. Kleman: Defects and Topology of Cholesteric Liquid Crystals" in "Chirality in Liquid Crystals, 5", Springer Verlag: New York (2001), excerpt available here.