Analyze the three stages of the evolution of the LCD panel backlight system

The liquid crystal panel itself is only glass, and it cannot emit light by itself, and a backlight is required to realize image display. The plasma display technology of the same generation as the liquid crystal is a self-illuminating mode, but it has been basically eliminated. Currently, the highly anticipated OLED panel is a self-illuminating mode that does not require backlighting.

However, from the birth to the present, LCD has always needed backlight support. The backlight system of the LCD panel has undergone changes in approximately three stages, from CCFL backlighting to LED backlighting to quantum dot backlighting, and backlight variations have also contributed to changes in display construction and display capabilities.

Analyze the three stages of the evolution of the LCD panel backlight system

CCFL backlight

Cold Cathode Fluorescent Lamp is abbreviated as CCFL. The Chinese translation is called cold cathode fluorescent tube. It has the advantages of high power and high brightness. It is widely used in display, lighting and other fields. The earliest application of the backlight of the display is this cold cathode fluorescent tube. Such a lamp is relatively large and relatively thick, resulting in a relatively thick liquid crystal panel. Therefore, the display using the backlight has a small thickness, and it is impossible to use such a light for a light and thin display. In addition, the energy consumption of such a cold cathode fluorescent tube is relatively high, so it is difficult to see such a backlight system at present.

LED backlight

The LED backlight is made of a compound containing gallium (Ga), arsenic (As), phosphorus (P), nitrogen (N), or the like. The principle is that when electrons and holes are combined, they can radiate visible light, and thus can be used to form a light-emitting diode. The typical characteristics of this type of backlight are small size, low energy consumption, long service life, and low cost. Therefore, after the LED backlight appeared, it quickly replaced the original CCFL backlight. This change has led to the current popularity of thin and light displays, and the emergence of ultra-thin mobile phones and tablets.

Quantum dot backlight upgrade

However, CCFL backlight and LED backlight have a problem, that is, the color gamut of the screen is not enough. The current backlight system, the sRGB color gamut can reach 100 very few products, mainly because the backlight purity is not enough. Therefore, in order to improve the color gamut of the screen, the panel factory began to use quantum dot backlight, which is the third stage of the development of liquid crystal backlight.

Quantum dots are actually nano-materials. Under the excitation of blue LEDs, they can emit high-purity colors. According to the size of quantum dots, a combination of three primary colors can be configured. This combination forms a thin film for lifting. The color effect of the backlight. Therefore, the essence of the quantum dot display is to improve the backlight, which is still the mode in which the blue LED excites the quantum dots, so it is not an absolute upgrade of the technology, but an upgrade of the modification.

to sum up:

The development of liquid crystal backlights has gone through three stages, the volume is getting smaller and smaller, and the energy consumption is getting lower and lower. Now our thin and light display is realized, thanks to the continuous change of backlight technology. The appearance of quantum dot backlights indicates that there is not much room for further upgrade in terms of volume and energy consumption. Therefore, improving the color gamut becomes the heart direction of backlight conversion, and it is also the reason why the new generation display technology OLED panel appears.