From the second half of 2016, the concept of the Micro LED has been booming. At the end of the CES2018, Samsung's 146-inch modular Micro LED TVs are again in the limelight, with the traditional LCD Compared with TV, there has been a considerable improvement in brightness, contrast and color saturation. Apple also paid a lot of money to buy Micro LED research and development company LuxVue as early as 2014, and has technical reserves, patents and R&D. Capability. Although there are currently no consumer electronics products using this technology, Apple still hopes to find a breakthrough in it. Every move is also very eye-catching.
So what is the Micro LED? In the future, will Micro LEDs replace it? OLED / LCD becomes mainstream Display technology What?
What exactly is a Micro-LED?
Micro LED is also called μLED or micro LED. It is somewhat similar to LCD or OLED. It was first invented in 2000 by Prof. Hung Hing of Kansas State University and Professor Jingyu Lin of Texas Tech University. Micro LED is the same as OLED. Diode composition, is a television technology, with content on the screen display Effect related.
Micro LED refers to an array of high-density, tiny-size LEDs integrated on a single chip, such as LED display Each pixel can be addressed, individually driven to light, can be seen as outdoor LED display A miniature version of the screen that reduces pixel distances from millimeters to micrometers.
Like OLEDs, Micro LEDs also consist of light emitting diodes. Each red, green, and blue sub-pixel emits its own light, unlike LCD screens that require a dedicated backlight. Therefore, Micro LEDs monitor Can provide the same OLED and the same contrast and color performance, can also be kept light and thin in production. The difference lies in the composition of the LED material. O in the OLED represents organic (Organic), refers to the light emitting part of the pixel stack Organic materials are used. However, Micro LED is not the same. This technology uses inorganic gallium nitride (GaN) materials in the light emitting part.
How does MicroLED work?
Before explaining the operation principle of the Micro LED, we first need to look at what kind of TV has appeared so that we can understand exactly why it is a very advanced technology.
The most mainstream TV technology now is LED. It is actually installing an LCD panel, but it will LED backlight Placed behind a panel. All major manufacturers use LED technology. The TV you are watching most likely is a LED TV. Because LCD screens cannot light themselves, white LED backlights let light pass through layers one after another, and these layers are filtered by color. With polarizers, then you can use light to depict the image, let's see.
In the past few years, backlighting technology has continued to advance, but it is still difficult to show deep blacks because backlighting is inaccurate. If there are bright elements next to dark elements, the contrast will be affected. How to solve it? Solved by OLED, it is composed of pixels that can emit light alone. That means a single pixel can be completely turned off, displaying perfect black, and the colors are more dazzling, and the viewing angle is wider. However, the OLED screen is not as bright as the LCD screen, and Is manufactured with organic compounds, life is bound to be shorter than the LCD.
The seemingly sudden emergence of the Micro LED combines the advantages of the two panel technologies and discards the weaknesses. From the first name, the Micro LED uses a large number of tiny LEDs. These LEDs are decomposed into red, blue, and green sub-pixels (most commercial OLEDs). Use only white light to form the individual pixel elements of the picture.
At the same time, due to the use of inorganic materials, Micro LED will not have the problem of short lifetime on the OLED screen. Micro LED also reduces the need for polarization and encapsulation layer, can make the panel become thinner. The structure is composed of a large number of micro LED arrays. Therefore, in addition to achieving high brightness, ultra-high resolution and color saturation, each pixel can be independently driven, as well as having the advantages of power saving, fast response, etc. In terms of power consumption, it is 90% lower than LCD and 50 times lower than OLED. %.
Micro LED advantages
- thinner than OLED
One of the advantages of OLED displays over conventional LCDs is that they are thinner. However, Micro LED is an advantage over OELD in this respect.
Micro LEDs are similar to OLEDs, but they use gallium nitride inorganic materials (similar to traditional color LEDs). In fact, they are very similar to ordinary color LEDs, but they are much smaller in size. Because the sub-pixels have luminosity (they They can self-emit as OLEDs, so they don't need a backlight or a liquid crystal layer. However, Micro LEDs don't need polarizers, and they only have a thin layer of glass on top. They are thinner than OLEDs and are much thinner than ordinary LCDs.
- More efficient
Ultra-small LEDs in Micro LED displays are more efficient in converting electricity into photons. Basically, they can generate more 'luminance per watt' than traditional LCD or OLED displays. Micro LEDs are still not yet fully commercial New products, but industry insiders estimate that Micro LED can generate the same brightness with half the energy consumption of OLED. Other industry insiders think that the energy efficiency of Micro LED will be higher.
This is good news for any device, because the display is one of the biggest enduring killers of today. Not only that, this is even more beneficial for devices such as VR all-in-one devices. With the help of Micro LED, the VR all-in-one can be thinner and lighter, while having Longer endurance.
- Higher resolution
LCD and OLED displays have little difference in the maximum resolution. The Sony Z5 Premium compresses the full 4K resolution onto a 5.5-inch display at a staggering 806 pixels per inch. Although not yet in the official product, Google and LG have developed a VR display with an area of 4. 3 inches and a pixel count of 180,000. In other words, up to 1443 pixels per inch.
No commercial Micro LED products have yet been released, but individual red, green, and blue LEDs can be explored from a microscopic perspective. LEDs smaller than 100 micrometers. It has several times more resolution than conventional LCDs or OLEDs. The first Micro LED displays should not be able to achieve such high resolution, but this technology can obviously reach this standard, and even more.
- More resistant to 'burning'
You may have heard of the OELD screen 'burn'. Basically, when the monitor displays the same image in the same position for a long time, it will begin to leave its own 'image', so you can always see it. This happens on a variety of screens, such as the LCD screen on a car dashboard. There may be fading but non-disappearing interface elements.
The LED in the Micro LED display is far more resistant than the organic compounds in the OLED or the liquid crystal layer in the conventional LCD. The 'burning' will not be a problem for most Micro LED products.
- Ultra-fast switching time, very suitable for VR
The best LCDs can completely switch colors in milliseconds (thousandths of a second). OLED displays switch in microseconds (millionths of a second). That's why they are used for VR heads. One of the reasons is that the switching speed of LCD monitors is not fast enough to achieve a good VR experience.
The switching speed of the Micro LED sounds more like a microchip, not a display. Its unit of measure is in nanoseconds (billionths of a second). It can achieve ultra-high resolution at ultra-small size while being ultra-fast. The switching speed, Micro LED became the perfect choice for VR and AR head display.
- Excellent color tone, contrast and brightness
Again, there is no consumer product yet to test, but the Micro LED should be able to produce a brighter display with near-infinite contrast (because black pixels disappear completely), making it an excellent choice for HDR. Higher The maximum brightness will further improve the readability of the Micro LED in sunlight, which is very suitable for AR.
The Micro LED is said to have a wider color range, which means a wider color gamut, and we can control the Micro LED more precisely for better color accuracy.
Micro LED disadvantages
If there is any weakness in the Micro LED, it must be a cost. The LED is produced in a nearly silicon chip and then transferred to the backplane filled with the pin grid. It is like transferring part of a computer chip to another computer chip. This is done again and again in batches, and errors may occur at each step. Therefore, before the actual expansion of production capacity, the price of the Micro LED will be very expensive.
Micro LED Applications
Micro LED has its unique advantages, its low operating voltage, high efficiency, high brightness, simple optical structure, wide operating range, etc. It has been recognized as an ideal next-generation display technology with a large probability, and its application fields are very broad. Large/medium size outdoor/indoor large screen, desktop/laptop monitor, mobile products such as mobile/digital camera/portable Projector Screens and watches/bracelets and other wearable products.
Micro LED market size
The vastness of the application field determines the huge market size. However, the current production cost of Micro LED due to the quantitative transfer technology is too high, which is the biggest reason for the current mass production. If the Micro LED can break through the production technology difficulties and drastically reduce the cost, it will Its unique high resolution, low loss and high definition are bound to create a new era of LED.
But it is very important that the transition from LCD/OLED to Micro LED will not be like that year Plasma Screens are as difficult to fight as LCD screens. The reason is that they all use FTF backplanes. A large part of the resources can be shared. Therefore, the transition of manufacturers is less difficult. LCD The scale of the components of the device to estimate, including backlight modules, LCD, polarizer, etc., Micro LED future potential market size of about 300-400 billion US dollars.
About the future
Whether it is OLEDs, quantum dots, or Micro LEDs, you can see that self-emissions are necessarily the trend of display. Although Micro LED is a cool new technology, its maturity and cost are still quite large compared to OLEDs. About the future, we quote a quote from Li Yunli, the founder of Taiwan's Xinchuang company.
The key to the success of 'Micro LED' is twofold: First, the needs of Apple, Samsung and these brand factories; Second, wafer handling technology, handling millions of ultra-small LED chips at a time, there are thresholds to overcome.
