What is the market space for COB panels?

1. Incremental: Consumer-grade applications open up upward space

Consumer-grade applications: Overseas brands will test the waters first, and may enter the 100,000-level price range in 2024. With the gradual maturity of Mini RGB technology and the continuous cost reduction of various core components in the upstream, Samsung launched a new The Wall series in December 2020, which further lowered the The Wall series originally positioned in the commercial display field to the home C-end market. The first product has a screen size of 110 inches, equipped with 4K UHD resolution and 120% color gamut, supports HDR10+, and has a maximum brightness of 2000 nits. In April and November 2023, Samsung further released 89-inch and 101-inch versions, both of which were first launched and exhibited in China. In addition to Samsung, other TV brands such as Sony, LG, Hisense, Konka, and MLED direct display industry brands such as Leman Optoelectronics and Li Yade have also followed up and released a number of MLED direct display TVs from 2021 to 2022. It is expected that with the rapid cost reduction and price reduction of COB technology in 2023, MLED direct display TVs are expected to usher in a year of product explosion and technology sinking in 2024, and prices will continue to penetrate into the 100,000-level price range.

Mini/Micro RGB direct display is different from MiniLED backlight. Direct display uses RGB LED lamp beads directly as display pixels to provide the basic unit of imaging. The principle of self-luminescence is consistent with OLED. In terms of display effect, Mini/Micro RGB has the advantages of self-luminescence, very thin, wide color gamut, high contrast, long life, and reliability. Compared with LCD: Mini/Micro RGB products have the advantages of high contrast, wide color gamut, high resolution, fast response speed, low power consumption and long life. At the same time, since the screen is mainly installed by splicing, it does not have the common household installation problems of LCD products when installed in consumer-level scenarios. Compared with OLED: Mini/Micro RGB products do not need to use LCD screens, and they also use the principle of self-luminescence, with advantages such as higher brightness and longer life.

According to statistics from TrendForce, from the perspective of the consumer market, the annual sales volume of all-in-one machines in the display market is about 3 million units, while the annual sales volume in the TV market is about 200 million units. Assuming that 10% of all-in-one machines and 1.5-2% of the TV market can be replaced by LED direct display, compared with the current demand for about 100,000 4K screens in the entire display market, there is a potential for several times the growth in market size.

2. Boost: Virtual pixel technology boosts the implementation of C-end applications

What is virtual pixel technology? Virtual pixel technology is to split pixels into independent LED units, and reproduce the corresponding primary color information of several adjacent pixels by time-division multiplexing each LED unit. COB integrated packaging technology can support arbitrary arrangement of RGB LED chips. Under the same display area, the resolution doubling effect can be achieved with the help of pixel engine algorithm (Nova Nebula/Colorite). However, due to the thickness limit of the bracket, the SMD process is relatively difficult to achieve the equidistant arrangement between each chip, so it is difficult to realize the application of virtual pixel technology at this stage.

Virtual pixel technology is the most mature solution that can effectively achieve rapid cost reduction in the current environment. Taking the four-lamp solution as an example, the number of pixels can be increased to four times the original on the basis of only doubling the green light chip and a small amount of driver IC and software costs, and the product with native pixels of 2K can present 4K, or the product with native pixels of 4K can present 8K display effect, which greatly optimizes the cost performance while abandoning some effects. The application of most technologies is often a trade-off between several parameters, and virtual pixels are no exception. Due to the change in the arrangement sequence between pixels, problems such as unevenness are prone to occur on the straight line display, and because virtual pixels reuse LED light sources, the contrast of the product will be partially affected. However, the problem of straight line display is weakened in home scenes dominated by pictures. At the same time, due to the limitations of human eye resolution, the problem of straight line display unevenness caused by virtual pixels is further weakened at a reasonable viewing distance. The large-scale promotion of virtual pixels is expected to help MiniRGB products better build a product matrix and quickly extend to a lower price band, in commercial display all-in-one machines, home theaters, high-end TVs, etc. Considering the relatively high price sensitivity of the consumer market, it has become an important driving force for rapid promotion in the consumer market.

3. Calculation: Home theaters and ultra-large-size TVs or home scene product cuts

New technologies always face a trade-off between performance and cost-effectiveness when entering the consumer market. On the one hand, they must have sufficient performance to attract the first batch of users with fresh needs, and on the other hand, they must reduce the price band as much as possible to expand the target customer base. The same is true for MLED direct display TVs. On the one hand, higher resolution and larger size can bring users a more perfect viewing experience, but on the other hand, the increase in resolution also brings about an exponential increase in the number of core components such as lamp beads and driver ICs, which poses new challenges to manufacturing processes and costs. So is the rapidly developing COB technology sufficient to support the needs of the consumer market? To answer this question, we first need to see what size and what dot pitch products are ideal for entering the consumer market, so as to achieve a balance between performance and cost performance. Generally speaking, a smaller dot pitch can bring higher resolution on a TV of the same size, thereby bringing more delicate picture performance, but due to the physical structure of the human eye, most users find it difficult to distinguish two pixels that are too close. According to the research of American scholars such as Levine in "Edler's Ophthalmology Physiology", the minimum distance between two points that an average person can see under normal vision forms a visual angle of 1 arc minute (i.e. 1/60 angle), also known as the visual resolution limit (Visual Threshold). Therefore, in theory, the relationship between the user's naked eye's discernible limit dot pitch and viewing distance is shown in Table 1. Although a smaller dot pitch can bring more delicate picture quality at a closer distance, it is only technically redundant for most users at the recommended distance, and the cost-effectiveness is sharply reduced under the condition of limited viewing experience improvement.

LED display screens are mainly installed by box splicing, and the overall size is no longer limited by the elevator space. At the same time, since the manufacturing difficulty of large-pitch products is relatively lower, in order to achieve an immersive viewing experience, the overall size is usually 60° horizontally and 55° vertically, considering the limited space of the living room/home theater scene: 1) Considering the limited overall area of the living room in the home scene, the user's viewing distance is usually within the range of 2~4 meters, and the naked eye has a limited viewing angle. According to the research in the 11th edition of "Human Anatomy & Phsiology", the field of vision that the human eye can focus on is usually 60° horizontally and 55° vertically. 2) Floor/wall height restrictions (the wall height in a general home environment is 2.5~3 meters, 2.5 meters is taken here), and considering that the home screen is usually 16:9, the overall size is also affected; 3) Considering that the viewing center is preferably at the user's eye level under the comfortable viewing angle of the viewer, the overall size is also affected by the height of the user's eyes when sitting (according to the research of Ma Guangtao, Ding Juan, etc. in "Study on the Static Dimensions of Human Body in the Design of Sitting and Lying Furniture", the average eye height of adult males in a sitting state is about 1.3 meters); In summary, we calculated that in a home environment, in a living room scene with a viewing distance of 2 meters or more, the maximum size of the display screen is 104~201 inches.

Through comprehensive consideration of the maximum resolvable distance and the corresponding display screen size at different viewing distances, we can draw the following inferences: Inference 1: In a home environment, 4K real pixels or 2K+ virtual pixels can basically meet the requirements of the maximum naked eye resolution; Inference 2: In a home environment, P0.6 products can already meet the needs of 4K real pixels or 8K virtual pixels in a home environment, so COB technology can basically meet the needs of C-end TVs or home theater products; Inference 3: Unlike the cost curve of OLED and LCD (including traditional backlit LCD and MiniLED backlit TV), the cost per square meter of MiniLED direct display TV decreases rapidly as the size increases. Taking a 4K real pixel direct display screen as an example, the current cost of a 156-inch P0.9 screen is about 203,000 yuan (about 30,000 yuan per square meter), while the cost of a 209-inch P1.2 screen is only 133,000 yuan (about 133,000 yuan per square meter). 12,000 yuan),