LCD panel backlight technology

LCD panel backlight technology

    At present, the LCD panel backlight technology on the market is still quite a lot, but in fact, the backlight used in the mainstream common display products is not so much, and the ordinary consumers can often have access to so many:  WLED, RGB-LED, GB-r LED, QLED (quantum dot), Mini LED, and old CCFL (lamp, non-LED).

     WLED

     WLED is white LED lamp beads, low cost and high output, so it has become the most common type on the market. It emits light by placing a white backlight layer on the back of the liquid crystal matrix (high technical content, thick product) or on the side (low technical difficulty, quickly replacing CCFL), so that the color can be displayed.

     Although WLED has many advantages such as low cost, low heat, durability, and rich manufacturing experience, the WLED backlight layer has fatal disadvantages - the amount of blue light is large, and the damage to the eyes is large (the wavelength is between 400nm-480nm with relatively high energy light. Blue light in this wavelength will increase the amount of toxins in the macular area of the eye, threatening our eye health, and will feel dry and tired eyes after watching the monitor for a long time).

     Of course, some users insist on using CCFL backlit displays, so as to avoid blue light damage to the eyes, but the sale of CCFL backlit displays is less and less, but also really difficult to buy; At the same time, the CCFL backlight tube has a low life and low brightness, which also makes everyone abandon the CCFL backlight display.

     RGB-LED

     RGB-LED, which can be known by its name, uses the "three colors" of LED (red, green and blue) to produce a broad spectrum of white light, and does not require a filter to screen out different wavelengths of light, so in theory its color will be more standard.

      Although this backlight technology has the advantages of large brightness, high contrast, and extremely wide color gamut, due to cost, size, weight, different degradation of leds (resulting in color imbalance throughout the screen over time) and relatively poor energy consumption, it has gradually withdrawn from the field of view, but some professional displays still use this backlight scheme.

     GB-r LED

     GB-r leds currently benefit from ultra-high color gamut, which is the backlight used by most ultra-wide color gamut displays on the market.

Although the disadvantages of RGB-LED are obvious, but because it can restore a more true color, a wider gamut, there are still many people on its favor, some display manufacturers are also improved for it, save a little cost but still can retain most of the advantages of RGB LED backlighting, that is, GB-r LED.

Instead of using a blue LED (WLED) coated with a yellow phosphor, the backlight combines a blue and green LED with a red phosphor. This causes blue, green and red light to produce distinct spectral peaks, thus achieving an effect close to RGB-LED.

     QLED (Quantum Dots)

     Although the ultimate form of QLED is self-luminescence technology (AMQLED), but currently can not reach such technology, QLED is often used in blue light-emitting layer (WLED) with quantum dot film to achieve, the practice is to add a layer of quantum dot strengthening film in front of the WLED light source, and then through WLED to provide energy to the quantum dots on the film. Give them a reddish green color. The blue backlight layer ensures the purity of blue light and better color gamut display.

     Current QLED displays are often not so "beautiful" in terms of price, but the wide color gamut, high color depth and excellent color accuracy performance also make them one of the cards of high-end displays. The spectrum generated after optimization can be comparable to RGB-LED, especially in the Adobe RGB gamut display capability, QLED has a high advantage.

     Mini LED

     The recent fire of Mini LED can be said to be a new hot spot in the current hardware circle, the principle is to split the original LED backlight board into thousands of individual LED light beads to form a LED backlight matrix, the advantage is that these LED light beads can be turned into hundreds of control areas, to a common 27-inch Mini LED display on the market as an example, It is basically 2304 lamp beads; 576 controlled partition backlit areas.

      The biggest advantage of Mini LED is that it has ultra-high contrast and local brightness, because when displaying the black area, the lamp beads in the area are in the off state, so in theory its contrast is equal to the OLED display, and there is no OLED display for a long time will burn the risk, is a new direction for the development of LCD displays.

      Another big advantage of Mini LED is that its independent regional lamp beads can stimulate a large brightness in a short time, and some excellent Mini LED can achieve the highest brightness of 2000 nits in the local area, and common Mini LED can basically pass the HDR1000 certification. That is, the average maximum brightness can be maintained at about 1000 nits, which makes the Mini LED very friendly to HDR content, and the display effect of a good Mini LED screen is almost the same as that of some OLeds.

      At the same time, there will be no OLED screen due to long-term high brightness display caused by overheating, life reduction, is currently used to play HDR games, watch HDR movies and TV ideal choice.

     Brief summary

     At present, the mainstream display on the market is the use of WLED backlight technology, while GB-r LED appears in some high-end positioning color monitor, video monitoring monitor, to play its high color gamut characteristics, QLED as a new material, is currently positioned in the high-end game display. The Mini LED still has some way to go on the road to popularity.