what is LCD (LCD)? What are the characteristics?
what is LCD (LCD)? What are the characteristics?
The composition of liquid crystal is an organic compound,which is composed of carbon.At room temperature,the liquid crystal is a kind of substance between solid and liquid,that is,the dual characteristics of solid and liquid substances.The LCD produced by the effect of liquid crystal is LCD.It is widely used in various fields as terminal display devices.
The liquid crystal display (LCD) makes up and down two pieces of glass with transparent electrodes and seals them around with glue frames,forming a very thin box.TN liquid crystal material is injected into the box.Through a specific process,the rod like molecules of the TN type liquid are arranged in parallel between the upper and the lower electrodes.Figure shows the basic structure of the TN liquid crystal display.
Different electrodes can be made according to needs,and different contents can be displayed.At ordinary times,the LCD displays a bright background.After the voltage is added to the electrode,black characters or graphics are displayed,which is called positive display.If the lower polarizer in Figure is converted to the same polarization direction of the upper polarizer,it is on the contrary,the background is black,and the character part is bright after adding voltage,which is called negative display.The latter is suitable for the color display of the backlight.
The main features of the LCD display are as follows.
Low voltage and low power consumption.With very low working voltage,as long as 2~3V, the working current is only a few micro amps,that is,the power consumption is only 1~ 10 W/CM.
flat plate structure.The basic structure of LCD is two conductive glass,with thin liquid crystal box in the middle.The advantage of this structure is that the opening rate is high and the most advantageous for the display window;the display area is easy to be large and small;it is easy to automate mass production,the production cost is low;the device is very thin,only a few millimeters thick.
passive display type.The liquid crystal itself does not light up,by adjusting the external light to achieve the display purpose,that is to rely on the different reflection and transmission of the external light to form different contrast to achieve the purpose of display.
the amount of information is large.In LCD,there is no isolation between pixels,so the same display window area can accommodate more pixels.
It is easy to color.General liquid crystal display is colorless,so color filter can easily be used to achieve color images.
long life.Because of its low voltage and small working current,the liquid crystal itself is hardly deteriorated and has a long life.No radiation,no pollution.CRT shows X - ray radiation,but liquid crystal does not have such problems.The shortcomings of LCD display are:the display angle is small,most liquid crystal displays use the liquid crystal molecules to form the image to the opposite sex.The reflectivity of the people in different directions is different,and the angle of view is small,only 30 ~ 40%.With the increasing of the angle of view,the contrast is rapidly deteriorating;the response speed is slow,the liquid crystal display is mostly depended on the dependence.Under the effect of external electric field,the arrangement of liquid crystal molecules changes,so the response speed is greatly influenced by the viscosity of the material,which is generally 100~200ms,so the quality of the liquid crystal display in the display of fast moving is generally not too good.