TN type liquid crystal display principle

Liquid crystal display technology of TN type is the most basic liquid crystal display, and liquid crystal display other types in the type of TN is to be improved. Similarly, its principle of operation is a simple technique to. Represented in the diagram is a simple graph TN type liquid crystal display device, including a polarizing plate, the vertical and horizontal direction, with fine groove alignment film, liquid crystal materials and conducting glass substrates. (1) without the electric field under the condition of the incident light through the polarizer, the liquid crystal layer, polarizing molecular torsional arrangement of the liquid crystal layer is rotated 90 degrees, away from the liquid crystal layer, the polarization direction and the other is polarizing plate in the same direction, so the light can pass through the electrode surface is bright. (2) when the electric field of the optical axis of the liquid crystal molecules, each turn is consistent with the direction of the electric field, the liquid crystal layer is therefore lost rotation ability, results from the polarized incident polarizing film, polarizing direction of the polarized direction of polarizer and a vertical relationship, and not through the electrode surface, thus showing a dark state. The imaging principle of the liquid crystal material in two attached to the vertical axis of polarizing plate transparent conductive glass, liquid crystal molecules will depend on the alignment film grooves arranged according to the direction of rotation, if the electric field is not formed, the light will pass through the polarizer shoots, in accordance with the rotation direction of liquid crystal molecules, and the other from the injection side. If the electricity in two pieces of glass, will cause the electric field between two pieces of glass, and in the arrangement of liquid crystal molecules, the molecular rods were reversed, light cannot penetrate, and block the light. The resulting light dark contrast phenomenon, called the twisted nematic field effect, referred to as TNFE (twisted nematic field effect). Liquid crystal display used in electronic products, almost all use of twisted nematic field effect principle made.

STN the principle of liquid crystal display

STN display principle is similar to TN, different TN twist nematic liquid crystal molecular field effect of the incident light is rotated 90 degrees, while the STN super twisted nematic field effect is the incident light rotation degree 180~270.

Here it is, TN liquid crystal display simple itself only and two cases (or black and white), and there is no way to change color. STN liquid crystal display it involves the relationship between liquid crystal materials, and light interference, so that the tone is given priority to with light green and orange. But if in the traditional STN monochrome liquid crystal display with a color filter (color filter), and a pixel monochrome display matrix (pixel) is divided into three sub pixels (sub-pixel), respectively, through the color filter display red, green, blue three primary colors, and then through the proportion of harmonic, also can show the color of color. In addition, TN type LCD display screen as if more, the screen contrast is poor, but the improvement of STN technology, it can make up for the shortage of contrast.

TFT the principle of liquid crystal display

A liquid crystal display TFT type is more complex, mainly composed of, fluorescent tubes, light guide plate, polarizing plate, filter plate, glass substrate, alignment film, liquid crystal materials, thin mode transistor and so on. The first liquid crystal display must first use of back light source, is fluorescent tube light source projected, the light will go through a polarizer and then through the LCD, then the liquid crystal molecular arrangement and change the angle of light through the lcd. Then the light coming through the front filter must be in color and another piece of polarizer. Therefore, as long as we change the value of voltage stimulation can control liquid crystal light intensity and color finally appeared, and then be able to change the LCD panel with different shades of color combinations.