LED vs. LCD vs. OLED

It is no wonder that the display screen has been called one of the greatest inventions of the 20th century, and our lives have been greatly graced by its appearance. With the development of science and technology, the display screen is no longer limited to the application of TV screens, large-size commercial display began to break into our lives, shopping malls, cinemas, indoor sports venues and other places can see its figure, and at this time LCD, LED, OLED and other professional terms also linger in our ears, although there are many people talk about them, But most people know little about them, what is the difference between the “long” and similar ones?

LCD, LED and OLED

1. LCD

LCD is short for Liquid Crystal Display, which refers to liquid crystal display. The main types are TFT, UFB, TFD, STN and so on. The structure includes a plastic ball, a glass ball, a frame glue, a glass substrate, an upper polarizer, a directional layer, a liquid crystal, a conductive ITO pattern, a conduction point, an IPO electrode and a lower polarizer.

LCD basic structure

It uses the most well-known TFT-LCD is a thin film transistor liquid crystal display. The basic structure is to place a liquid crystal box in two parallel glass substrates, the film transistor (that is, TFT) is set on the lower substrate glass, and the color filter is set on the upper substrate glass, and the rotation direction of the liquid crystal molecules is controlled by the signal and voltage change on the thin film transistor, so as to control the polarized light emitted by each pixel and achieve the purpose of display.

TFT structure

The principle of liquid crystal display is that liquid crystal will show different light characteristics under the action of different voltages. Liquid crystal display is composed of many liquid crystal array, in the monochrome liquid crystal display, a liquid crystal is a pixel (the smallest unit that can be displayed on the computer screen), and in the color liquid crystal display, each pixel is composed of red, green and blue three liquid crystals. At the same time, it can be considered that there is an 8-bit register behind each liquid crystal, and the value of the register determines the respective brightness of the three liquid crystal units, but the value of the register does not directly drive the brightness of the three liquid crystal units, but is accessed through a “palette”. It is not practical to have a physical register for each pixel, in fact there are only one line of registers, which in turn connect to each pixel line and load the contents of that row, driving all the pixel lines once to display a complete picture.

2. LED

LED is short for Light Emitting Diode, that is, light-emitting diode. It is a type of semiconductor diode that converts electrical energy into light. When electrons are combined with holes, visible light is emitted and can be used to make light-emitting diodes. Light-emitting diodes, like ordinary diodes, are composed of a PN junction and also have one-way conductivity.

When the forward voltage is added to the LED, the holes injected from the P region into the N region and the electrons injected from the N region into the P region are combined with the electrons in the N region and the holes in the P region within a few microns near the PN junction, respectively, to produce spontaneous radiation fluorescence. The energy states of electrons and holes in different semiconductor materials are different. When electrons and holes combine, the amount of energy released varies, and the more energy released, the shorter the wavelength of the light emitted. Diodes that emit red, green, or yellow light are commonly used.

LED is known as the fourth generation light source, with energy-saving, environmental protection, safety, long life, low power consumption, low heat, high brightness, waterproof, micro, shockproof, easy dimming, beam concentration, easy maintenance and other characteristics, can be widely used in a variety of indicators, display, decoration, backlight, general lighting and other fields. Such as LED display, traffic lights, LED Neon Flex, car lights, LCD screen backlight, household lighting and other lighting sources.

3. OLED

OLED is short for Organic Light-Emitting Diode. Also known as organic laser display, organic light-emitting semiconductor. The diode was discovered in a laboratory in 1979 by Chinese-American professor Deng Qingyun.

OLED consists of an external OLED display unit and a light-emitting material sandwiched within it, including a cathode, emission layer, conductive layer, anode and base. Each OLED display unit can be controlled to produce three different colors of light.

OLED display technology has the characteristics of self-luminescence, using a very thin coating of organic materials and glass substrate, when there is a current through, these organic materials will light up, and OLED display screen viewing Angle is large, and can save power consumption. Since 2003, this display technology has been used in MP3 music players.

Today, a prominent representative of the use of OLED is the mobile phone screen, OLED screen can show the perfect picture contrast, the display screen will be more vivid and real. LCD screens do not support bending due to the characteristics of liquid crystal, compared to this, OLED can be made into curved screens.

Difference Between the Three

1.On the gamut

OLED LCD screen can display endless colors, but also not affected by the backlight, pixels in the display of all black screen is very advantageous, LCD LCD screen color gamut is currently between 72 percent to 92 percent, while led LCD screen color gamut is more than 118 percent.

2.In price

The same size LED LCD screen is more than 1 times more expensive than the LCD screen, and the OLE LCD screen is more expensive.

3.Mature technology

Because the LCD LCD screen is a traditional display, it is much better than the OLED LCD screen and LED LCD screen in terms of technology maturity, such as display reaction speed, OLED LCD screen and LED LCD screen are far less than LCD LCD screen.

4.Display Angle

The OLED LCD screen is much better than the LED LCD screen and the LCD screen, which is reflected in the fact that the viewing Angle of the LCD screen is very small, while the LED LCD screen is not satisfactory in the sense of hierarchy and dynamic performance, and the depth of the LED LCD screen is not good enough.

It can be seen that whether OLED or LCD or LED, it is not perfect, and which technology is better to choose? It depends on personal preference. After all, all three have their advantages and disadvantages.

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