The pixel arrangement of a color film display module is a key factor in determining its display quality. Different arrangements directly impact key performance indicators such as color reproduction, clarity, and contrast by influencing subpixel distribution, sharing mechanisms, and optical properties. The traditional standard RGB arrangement uses red, green, and blue subpixels to form a complete pixel. Each subpixel emits light independently, without relying on neighboring pixels to share light. This results in smooth color transitions, sharp text edges, and precise detail reproduction, particularly when displaying high-resolution content. This arrangement has become the mainstream solution for LCD screens. However, this arrangement requires high material utilization. Increasing pixel density requires simultaneously reducing subpixel size, significantly increasing process complexity and cost.
The Pentile arrangement balances lifespan and cost by optimizing subpixel sharing. Because OLED subpixels emit light independently and blue materials have a short lifespan, the Pentile arrangement increases the area of the blue subpixel and reduces its number. At the same time, the green subpixel is used as the center, and the red and blue subpixels are shared with neighboring pixels, forming an "RG-BG" alternating structure. This design extends the lifespan of blue subpixels and reduces power consumption, but at the expense of some clarity. When displaying fine-grained content, subpixel sharing necessitates algorithmic interpolation to fill in edge pixels, which can easily result in color fringing, jagged edges, and graininess, especially noticeable at low resolutions. For example, when displaying the edges of white text, the alternating red and blue subpixels can create a colored halo, disrupting the reading experience.
The Diamond array is Samsung's improved Pentile array, focusing on enhancing display detail through optimized subpixel shape and layout. Diamond subpixels are designed as diamonds and utilize a "RGGB" (roughly 4-pixel) arrangement, resulting in a higher density of green subpixels than red and blue subpixels, more closely matching the human eye's high sensitivity to green. This layout reduces the spacing between subpixels, improving equivalent resolution and resulting in smoother edges and significantly reduced graininess when displaying diagonal or curved lines. Although still a shared subpixel solution, the Diamond array, through precise pixel arrangement and algorithmic compensation, achieves clarity approaching that of a standard RGB array while maintaining low power consumption, making it a leading technology for high-end OLED screens.
The Zhou Dongyu arrangement, a domestically developed solution from BOE, features a split green sub-pixel into two independent sections, alternating with red and blue sub-pixels. This design was initially intended to improve sub-pixel distribution uniformity, but in practice, the split green sub-pixel results in a reduction in equivalent resolution. Edge blurring is particularly noticeable when displaying fine text or lines, compared to the diamond arrangement. However, by optimizing sub-pixel shape and spacing, the Zhou Dongyu arrangement mitigates the color fringing issue of the Pentile arrangement to some extent, while also being more cost-effective and suitable for the mid-range market.
The Delta arrangement reduces manufacturing complexity by altering the sub-pixel arrangement. It arranges sub-pixels in a triangular pattern, with each pixel composed of portions of three adjacent sub-pixels. This reduces the number of mask openings and improves vapor deposition efficiency. However, this arrangement results in lower vertical pixel density, making it more prone to blurring or streaking when displaying vertical lines. Overall clarity is inferior to the standard RGB arrangement, making it primarily used in cost-sensitive entry-level products.
Furthermore, the pixel arrangement also affects the power consumption and lifespan of color film display modules. Shared sub-pixel solutions like Pentile and Diamond extend the lifespan of OLED screens by reducing the number of sub-pixels and lowering driving current. Standard RGB arrangements, on the other hand, use independent pixels, resulting in relatively high power consumption but more stable color performance. Furthermore, the arrangement is closely related to the color film substrate design. For example, BOE's latest patent utilizes a double-layer black matrix to block the openings around the display area, optimizing edge light distribution, reducing light leakage and color cast, and further enhancing the actual display quality of the pixel arrangement.
Pixel arrangement is a key performance trade-off for color film display modules，the standard RGB arrangement pursues extreme clarity, while Pentile and Diamond arrangements balance lifespan and cost. Zhou Dongyu's Delta arrangement explores domestically produced alternatives. In the future, with advances in vapor deposition processes and algorithmic compensation technologies, pixel arrangements will prioritize the coordinated optimization of sub-pixel utilization and optical efficiency, driving displays towards higher resolution, lower power consumption, and more natural colors.
