We have known for a long time that there are three types of matter: solid, liquid and gas.The center of mass of liquid molecules is arranged without any regularity, but if these molecules are long (or flat), their orientation may be regular.We can then subdivide the liquid state into many forms.Liquid with no regular direction is called liquid directly, while liquid with directional direction is called liquid crystal, or liquid crystal for short.Liquid crystal products are not strange to us, our common mobile phones, calculators are liquid crystal products.Liquid crystals, which were discovered in 1888 by the Austrian botanist Reinitzer, are organic compounds that have regular molecular arrangements between solids and liquids.Generally the most commonly used liquid crystal morphology of nematic liquid crystal, molecular shape for long bar, width of about 1 nm to 10 nm, under different current electric fields, the liquid crystal molecules will do arrange rules rotated 90 degrees, producing the difference of light transmittance, so the power ON/OFF under the difference between light and shade, each pixel according to the principle of control, can form the image.
The principle of liquid crystal display is a liquid crystal under the action of different voltage will be the light of the present different characteristics. LCD in physics is divided into two categories, one is Passive Passive (also known as Passive), and this kind of LCD itself does not shine, need external light source, according to the position of light source, and can be divided into reflection and transmission type two kinds. Passive LCD with low cost, but the brightness and contrast is not big, but effective Angle is small, less Passive LCD color saturation of the color, so color not bright enough. Another kind is a power source, mainly TFT (Thin FilmTransitor). Each LCD is actually a transistor may shine, so strictly speaking is not LCD. LCD screen is composed of many LCD line array, in monochrome LCD display, a liquid crystal is a pixel, whereas in the color liquid crystal display each pixel consists of red, green and blue three LCD together. At the same time can be thought of as behind every LCD a 8-bit register, register values determines the brightness of the three LCD unit respectively, but the value of the register does not directly drive the brightness of the three liquid crystal cell, but by a “palette” to visit.It is not realistic to have a physical register for each pixel. In fact, only one row of registers are equipped, which are connected to each row of pixels in turn and load the contents of that row.
Liquid crystals look and feel like a liquid, but their crystalline molecular structure behaves like a solid.Like metals in a magnetic field, when subjected to an external electric field, the molecules form a precise arrangement;If the arrangement of the molecules is properly controlled, the liquid crystal molecules will allow light to pass through;The path of light through a liquid crystal can be determined by the arrangement of the molecules that make it up, another characteristic of solids.Liquid crystals are organic compounds made up of long rod-like molecules.In nature, the long axes of these rod-like molecules are roughly parallel.Liquid Crystal Display (LCD) first features Liquid crystals that must be poured between two planes lined with slots to work properly.The slots on the two planes are perpendicular to each other (90 degrees), that is, if the molecules on one plane are aligned north-south, the molecules on the other plane are aligned east-west, and the molecules between the two planes are forced into a 90-degree twist.Because light travels in the direction of the molecules, it is also twisted by 90 degrees as it passes through the liquid crystal.But when a voltage is applied to the liquid crystal, the molecules rearrange vertically, allowing light to flow straight out without any twisting.A second feature of LCDS is that they rely on polarizing filters and the light itself. Natural light diverges randomly in all directions.These lines form a net that blocks all the light that is not parallel to these lines. The polarized filter line is perpendicular to the first one, so it completely blocks the polarized light.Only if the lines of the two filters are completely parallel, or if the light itself has been twisted to match the second polarized filter, can the light penetrate.LCDS are made up of two such vertically polarized filters, so they should normally block any light trying to penetrate.However, because the two filters are filled with twisted liquid crystals, after the light passes through the first filter, it is twisted 90 degrees by the liquid crystal molecules, and finally passes through the second filter.If, on the other hand, a voltage were applied to the liquid crystal, the molecules would rearrange themselves in such a way that the light would no longer be twisted, so it would be blocked by the second filter.Synaptics TDDI, for example, integrates touch controllers and display drives into a single chip, reducing the number of components and simplifying the design.The ClearPad 4291 supports a hybrid multipoint inline design that takes advantage of an existing layer in a liquid crystal display (LCD), eliminating the need for discrete touch sensors.ClearPad 4191 takes it a step further, utilizing existing electrodes in the LCD, thus achieving a simpler system architecture.Both solutions make touch screens thinner and displays brighter, helping to improve the overall aesthetics of smartphone and tablet designs.For the reflected TN (Twisted Nematic) liquid crystal display, its structure consists of the following layers: polarized filter, glass, two groups of mutually insulated and transparent electrodes, liquid crystal body, electrode, glass, polarized filter and reflection.