Which of the two technologies is the mainstream route, MIP or COB?

Recently, around Micro LED display patent disputes, new technologies related to pixel engines and virtual pixels have attracted the attention of people in the industry. For a long time, the two technical routes of MIP and COB have been engaged in a fierce tug-of-war for the packaging process used for Micro LED chips. In 2023, virtual pixels will join the competition of MIP and COB technologies. If LED large-screen companies want to achieve unique virtual pixel technology design, they must master new arrangement techniques and processes at the subpixel level. At the same time, the industry is still worried about one issue: logical pixel definition is always weaker than physical pixel definition, which tests the actual market performance capabilities of virtual pixel technology, which makes the appearance and growth of virtual pixel +COB combination in 2024 more popular. Market expectations.

Wen| Xiaoxin

edit| Chen Xinnuo

Technology of the new era--virtual pixels

The cause of the patent dispute was that an LED display company officially announced that the company had initiated patent infringement lawsuits against a number of companies under Zhaochi in December 2023. Zhaochi had obtained two new display patents in China and overseas without authorization. Infringement was committed on the two new display patents, mainly involving Zhaochi COB product series virtual pixel displays, which infringed on the patent rights of a company'spixel engine display technology.

Subsequently, the official Weibo of Zhaochi Co., Ltd. issued a solemn statement. In response to recent reports, the infringement cases mentioned are currently in the pre-litigation joint investigation stage and have not yet been formally filed, and the court has not yet conducted a trial or ruling. Therefore, the report refers to the company's infringement. Related remarks lack legal basis. The company has always respected the intellectual property rights and legitimate rights and interests of others, strictly abided by national laws and regulations, and resolutely opposed any form of infringement. It hereby solemnly declares that the company has never engaged in any infringement of the intellectual property rights of others.

The two sides exchanged statements, each holding its own word. Behind the patent litigation, what is involved is the increasing game of COB technology. One party has a patented technology layout and holds a patent pool in hand, and the other party is the manufacturer with the largest direct display COB production capacity. As the COB market game becomes increasingly fierce, related technologies in this field are bound to cause disputes.

In this patent dispute, the pixel engine mentioned by both parties belongs to virtual pixel technology, which means that specific hardware layout and software algorithms are used to increase the resolution and display details of the display screen, so that the number of physical pixels on the display screen and the actual displayed pixel points achieve a 1: N (N= 2,4) relationship, and it can display 2 or 4 times more image pixels than the actual pixels of the display screen. Simply put, by changing the chip arrangement method, and then taking advantage of the illusion of delayed human visual response to accelerate the lighting of the chip, so that the original 2K/4k display can achieve a 4K/8K display effect.

In fact, real pixels and virtual pixels are widely used in daily life. For example, smartphones, tablets, TVs and other devices mainly display real-pixel displays. For the details and colors of high-definition pictures and videos, the physical pixels on the display screen and the actual displayed pixels show a 1:1 relationship. As many physical pixels as there are on the display screen, the number of pixel information is displayed.

Virtual pixels usually play an important role in some specific situations. For example, by applying virtual pixel display technology to VR technology for creating virtual scenes, it is easy for the experimenter to be immersed in a virtual world with real texture. Of course, in real life, virtual pixels are also used in some relatively high-end display devices, such as large LED displays, which use virtual pixel technology to combine multiple physical pixels into one virtual pixel, thereby improving the display. Clarity and resolution.

"Strong entry of COB+ virtual pixels

Unlike real pixels, the luminous point of virtual pixels is between the tubes. With the help of virtual pixel technology, the pixel spacing of LED displays can be reduced by half under the same display area and the same number of lamps. In theory, the resolution can be increased by up to four times, and the cost of the entire screen is lower.

In the field of LED display, virtual pixel technology is closely related to COB technology. COB directly solidifies LED chips on a PCB substrate, and then covers and connects them with packaging materials to achieve high-density integrated packaging. Compared with traditional SMD packaging technology, COB technology can achieve higher packaging density, reduce the distance between devices (dot spacing), and enable the display to achieve a smaller pixel spacing, thereby achieving a higher definition display effect.

Due to the high technical difficulty of COB, there is a large gap between COB and SMD in terms of yield, inspection and repair, and manufacturing costs. Therefore, the cost is high and it has not been possible to produce large-scale mass production in the market. Pixel engine display technology is a further optimization and upgrade of display performance based on COB technology.

Especially in the field of Micro LEDs, by designing specific pixel arrangements on COB packaged LED substrates and adopting advanced display algorithms, pixel engine technology can effectively utilize limited LED chip resources, drive hardware work through software algorithms, and simulate more display pixels than actual physical pixels, thereby improving the overall display resolution and detail, while controlling and reducing production costs.

Due to the high price, the market scale and popularization of small-pitch LED products have been slowly increasing. Although small-pitch technology has produced extreme technologies such as p0.4 and p0.3, it is difficult for the market to see a large number of similar products being used. The problem is in terms of price, because the cost of LED direct display is almost geometrically related to pixel density. The emergence of virtual pixel technology has opened up a new path for COB to reduce costs, and is expected to promote COB displays/TVs to truly sink into the commercial display and consumer markets. The decline in price and cost will accelerate the comprehensive expansion of the LED small-pitch market and help the industry upgrade with high quality.

A hundred flowers bloom and promote innovation and upgrading of the industrial chain

It is foreseeable that the application prospects of virtual pixels in small-pitch displays are very broad. At the just-past ISLE 2024 exhibition, many industry leading companies exhibited related COB products using virtual pixels.

Lianjian Optoelectronics exhibited dynamic pixel technology COB0.9 products, which can reduce process costs and achieve higher resolution. It also adopts Vmicro micro-pitch display technology independently developed by Lianjian Optoelectronics and is fully flip-chip COB packaged to present higher contrast. Skyworth Commercial exhibited COB boxes at this exhibition. The product specifications include virtual pixel P0.6, P0.7, P0.9, and P1.25.

In addition to the multiple efforts of screen companies, in the field of LED display peripheral equipment, Carlett brought virtual pixel solutions at the exhibition. Carlett used an average display algorithm to solve the problem of reducing the smoothness of virtual pixel pictures. Dynamic peak brightness and dynamic contrast improve the edge definition of virtual pixels. In addition, there are functions such as virtual pixel correction and one-click real/virtual switching. At the same time, Carlett's 5G transmission and 8K Media Processing Service technology easily achieves large tape loads, allowing 2K/4K to achieve 4K/8K display effect, helping to promote and apply micro-spaced products.