LCD Display Working Principle

- Aug 24, 2017 -

Liquid crystal display, for the flat ultra-thin display device, which consists of a certain number of color or black and white pixels, placed in front of the light source or reflector. LCD power consumption is very low, so much favored by engineers, suitable for the use of battery electronic equipment. Its main principle is to stimulate the liquid crystal molecules to produce points, lines, surface with the back of the lamp composition of the screen.

The working principle of liquid crystal display: liquid crystal is a kind of solid and liquid between the special substances, it is an organic compound, under normal liquid, but its molecular arrangement and solid crystals are very regular, so named LCD Another characteristic of its existence is that if an electric field is applied to the liquid crystal, it changes its molecular arrangement, and if it is given a polarizer, it has the effect of preventing the passage of light (when no electric field is applied, Smooth through), if coupled with the color filter, change the size of the LCD voltage added to change the amount of light can be a certain amount of light, you can also say that the image changes at both ends of the LCD voltage can change its transparency (But in practice this must be with the polarizer).

Liquid crystal is such an organic compound, at room temperature, showing the flow of both liquid, and optical anisotropy of the crystal, which is called "liquid crystal." In the electric field, magnetic field, temperature, stress and other external conditions Under the influence of its molecules prone to re-arrangement, so that the various optical properties of liquid crystal changes, such as the anisotropy of liquid crystal and its molecular arrangement vulnerable to external electric field, magnetic field control is the use of this liquid crystal physical basis , That is, the "electro-optical effect" of the liquid crystal, the light is modulated by the electrical signal, so as to make the liquid crystal display device.Under different current electric field, the liquid crystal molecules will do regular rotation 90 degree arrangement, In the power ON / OFF to produce the difference between light and shade, according to the principle of control of each pixel, can constitute the required image.

The physical characteristics of the liquid crystal is: when the power conduction, arranged in order to make the light easy to pass; no power when the arrangement of chaos, to prevent light through. Let the liquid crystal, such as the gate to block or let the light penetrate. Technically, the LCD panel contains two very fine no sodium glass material, called Substrates, the middle sandwiched a layer of liquid crystal. When the light beam through this layer of liquid crystal, the liquid crystal itself will be arranged to stand or twisted irregularly, so the barrier or the smooth passage of light. Most of the liquid crystal belongs to the organic complex, composed of long rods. In the natural state, the long axes of these rodlike molecules are substantially parallel. The liquid crystal into a well-machined slotted plane, liquid crystal molecules will be arranged along the slot, so if those slots are very parallel, the molecules are completely parallel.

working principle

Liquid crystal display composition and working principle: from the LCD display structure, whether it is a laptop screen or desktop LCD display, the use of liquid crystal display screen is composed of different parts of the layered structure. The liquid crystal display is composed of two plates, about 1mm thick, which is separated by a 5um even interval containing liquid crystal material. Since the liquid crystal material itself does not emit light, so in the display below are provided as a light source of the lamp, and in the LCD screen on the back of a backlit board (or light plate) and reflective film, the backlight is composed of fluorescent material, Can emit light, its role is to provide a uniform backlight. [1] 

The light emitted by the backlight plate enters the liquid crystal layer containing thousands of liquid crystal droplets after passing through the first layer of the polarizing filter layer. [1] 

The droplets in the liquid crystal layer are contained in a small cell structure, and one or more cells constitute a pixel on the screen. Between the glass plate and the liquid crystal material is a transparent electrode, the electrode is divided into rows and columns, at the intersection of rows and columns, by changing the voltage to change the liquid crystal rotation state, the role of liquid crystal material similar to a small light valve The


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