Pixel arrangement structure for organic light emitting display device

What is this patent about?

’803 is related to the field of organic light emitting diode (OLED) displays, specifically focusing on the geometric layout and spatial distribution of pixels. In high-resolution OLED manufacturing, the proximity of neighboring pixels creates a tension between achieving a high aperture ratio and maintaining deposition reliability when using fine metal masks. Traditional layouts often struggle to balance these factors, leading to manufacturing defects or reduced display brightness and longevity.

The underlying idea behind ’803 is to optimize the pixel geometry and spacing by utilizing a virtual square grid where different colored pixels are offset from one another in a specific diagonal relationship. By placing a smaller pixel at the center of a virtual square and larger, differently sized pixels at the vertices, the design maximizes the physical gap between emission layers of the same color. This spatial staggering allows for larger individual pixel areas—and thus better brightness and lifespan—without increasing the risk of color contamination during the evaporation process.

The claims of ’803 focus on a specific tri-color pixel arrangement where a first pixel, designated for green light, is positioned at the center of a virtual square. A second pixel and a third pixel are located at neighboring vertices of this square, with the second pixel specifically required to have a larger surface area than the third pixel. Furthermore, the claims define a linear progression where a second pixel is sandwiched between two green pixels along a diagonal line, establishing a repeating pattern across the display panel.

In practice, this arrangement typically assigns the largest area to blue pixels to compensate for their naturally shorter functional lifespan, while the green pixels remain the smallest and most centrally located. The pixels are shaped as polygons, such as octagons or quadrilaterals, which allows them to nestle closer together at their corners while maintaining a consistent inter-pixel gap. This geometry ensures that the fine metal mask used during production has sufficient structural integrity between its apertures, reducing the likelihood of shadow effects or material overlap.

This approach differs from prior solutions by breaking the symmetry of the sub-pixel sizes and utilizing a diagonal staggered layout rather than a standard side-by-side stripe pattern. By varying the areas of the second and third pixels (typically blue and red) and centering the green pixel, the invention achieves a higher effective resolution and aperture ratio. The increased distance between identical sub-pixels across the grid significantly improves manufacturing yields for high-density displays while simultaneously extending the operational life of the panel.