Physical properties (LCD)
When the electric conduction, arranged orderly, make the light easy through;Without power arrangement chaos, prevent light through.Let LCD as gate blocking or let light through.Technically, in a nutshell, the LCD panel contains two quite delicate without sodium glass material, known as the Substrates, with a layer of liquid crystal in the middle.When the beam through the layer of liquid crystal, liquid crystal itself can stand in rows or reverse the irregular shape and thus cut off or make light beam pass.Most LCD belong to organic compounds, made up of long rod molecules.Under the natural state, the parallel to the long axis roughly rod-shaped molecules.To pass through the fine processing of liquid crystal pour into a slotted plane, the liquid crystal molecules will line up along the trough, so if the slot is parallel, each molecule is completely parallel.


Liquid crystal display
Liquid Crystal Display, or LCD (Liquid Crystal Display), for the plane ultrathin Display device, it is composed of a certain number of color or black and white pixels, placed Yu Guangyuan or front side.LCD power consumption is very low, so the engineer, is suitable for the battery-operated electronic devices.
Each picture element consists of the following several parts: suspended in between two transparent electrode (indium tin oxide) a list of liquid crystal molecules, two polarization direction perpendicular polarization filter, if there are no electrodes of liquid crystal, light passing through one of the filter is bound to be another barrier, through a light polarization direction of the filter by liquid crystal rotation, so that they can through the other.
Liquid crystal molecules themselves with charge, will add a small amount of charge to each pixels or sub pixels transparent electrode, the liquid crystal molecules will rotate by electrostatic force, through light, were also rotate and change an Angle, so that they can pass the polarization filter.
Before the charge to the transparent electrode, the liquid crystal molecules in unconstrained condition, the charge on the molecule makes the molecules of the spiral, or circular (crystalline), in some of the LCD, the electrode surface of the chemicals can be used as seed crystal, so the molecular crystal according to the need of Angle, through a filter of light through the liquid chip polarization line before and after the rotation, so that the light can through another polaroid enough, a small portion of the light is absorbed by the polaroid, but the rest of the equipment is transparent.
After the charge to the transparent electrode, the liquid crystal molecules will be arranged along the direction of the electric field, thus limiting the light through the rotation of the polarization direction, if the liquid crystal molecules are completely break up, by the light of its polarization direction and the second polaroid completely vertical, so be completely blocked out the light, the pixels are not shine, by controlling the direction of rotation of each pixels in the liquid crystal, we can control the light to illuminate pixels, may be less than.
Many LCD under the action of alternating current (ac) black, alternating current (ac) destroys the spiral effect of liquid crystal, and close the current, the LCD will brighten or transparent.
In order to save electricity, LCD display with the method of reuse, the reuse model, the end of the electrode grouped together, each set of the electrode is connected to a power source, the other end of the electrode and grouping connection, each group is connected to the power supply At the other end, grouping design ensure each pixels by an independent power control, electronic devices or drive software of the electronic equipment by controlling the power on/off sequence, to control the display of the pixels.
Inspection of LCD monitor indexes including the following important aspects: according to the size, the reaction time (synchronous speed), array type (active and passive), Angle of view, supported by the color, brightness and contrast, resolution and aspect ratio, screen and input interface (such as visual interface and video display array).


Principle of LCD display
Using the basic properties of liquid crystal display.Natural light after a polaroid "filter" for the linear polarized light, due to the liquid crystal molecules in a box in the twisted pitch than visible light waves grow up much, so when the orientation of the membrane on the surface of the liquid crystal molecules are arranged in the same direction or orthogonal linear polarized light after the incident, the polarization direction after the liquid crystal layer can distort 90 ° from the other side, the orthogonal partial vibration pervious to light effect;If a certain value of voltage applied on the liquid crystal box, long axis of the liquid crystal started along the electric field direction, when the voltage of about 2 times after the threshold voltage, in addition to the liquid crystal molecules on the surface of the electrode, all the liquid crystal box The liquid crystal molecules between the two electrodes is along the direction of the electric field to rearrange, then 90 ° rotation function disappear, lost between orthogonal vibration pills optical effect, make the device can not pervious to light.If you use a parallel polaroid, on the other hand.
It is used for liquid crystal box electricity or to power to change its light through - obscure state, so as to realize display.Up and down the polaroid in orthogonal or parallel direction display performance is often white or black often mode.


Transmission and reflection
LCD can be displayed transmission, but also the reflection shows, is determined by its light to put where.Transmission type LCD from behind a screen of light to illuminate, while watching the screen on the other side (front).This type of multi-purpose in need high brightness LCD display applications, such as computer monitors, PDA and mobile phones.Used to illuminate the LCD lighting power consumption is often higher than the LCD itself.
Reflective LCD, common in electronic watch and computer, (sometimes) by the back of the scattering of the reflecting surface is reflected light of external light screen.This type of LCD with high contrast, because the light passes through liquid crystal twice, so be cut twice.Do not use lighting significantly reduces the power consumption, so using battery equipment use longer.Because of the small reflective LCD power consumption is very low, so that the cell is sufficient To give it power supply, so they can be used for pocket calculator.
Half through reflective LCD can be used as a transmission type, also can be used as a reflective.When the external light is enough, the LCD according to the reflective work, and when the external insufficient light, it can be used as a transmission type.
Color display
Color LCD, each picture element is divided into three units, or pixels, the additional filter respectively marked red, green and blue.Three child pixels can be controlled independently, the corresponding pixels, the tens of thousands or even millions of different colors.Old-fashioned CRT display colors use the same method.According to the need, the color components according to the different painting element geometry principle.