Optical Design Perspectives on OLED Screens in VR Devices

I. Design Trends and Screen Selection for VR Devices

Next-generation VR devices are evolving toward smaller size and lighter weight, making high-resolution OLED screens the inevitable choice. The screen shape is intricately linked to VR optical design: take the current mainstream 1.03-inch screen as an example, its square shape (18.5mm side length, 26.2mm diagonal) poses challenges for VR optical systems—the optical system must perform aberration correction based on the diagonal length as the reference image height, imposing strict requirements on lens design parameters and driving up manufacturing costs. More crucially, a large area outside the screen remains unused within the lens imaging region: measurements show that the square display area accounts for only 63.7% of the lens aberration correction circle area.

When users watch 16:9 ratio videos (resolution 2560×1440), the effective screen size is only 0.85 inches, resulting in insufficient cost-performance advantages. This phenomenon mirrors the logic behind many current VR products using octagonal Fast-LCD screens: the 16:9 display area occupies only 56.2% of the square screen.

II. Contradiction Between Wafer Cutting Efficiency and Screen Shape

From the perspective of wafer cutting efficiency, a 12-inch wafer can yield 120 pieces of 1.03-inch square screens, maximizing production capacity. However, the optical utilization rate of square screens remains unoptimizable.

The industry's pursuit of wider field of view (FOV) in VR has driven R&D into larger screens, with current focus on 1.3-inch square screens—achieving a resolution of 3230×3230 at the same pixel density. Yet a 12-inch wafer can only produce 82 such pieces, accompanied by three key pain points: high difficulty in aberration correction, low utilization rate for 16:9 video format (display area accounts for 56.2%), and insufficient cost-performance due to wasted imaging area.

III. Regular Hexagon Screens: An Optimized Solution for Optics and Cost

We propose changing the screen shape from square to regular hexagon, with core advantages as follows:

1. Simplified optical design: When the horizontal pixel count remains 3230, the diagonal of a 1.3-inch square screen is 33mm, while the longest vertex distance of a regular hexagon is only 27mm, significantly reducing aberration correction difficulty. This enables a FOV of 105°–115° (excellent image quality + low distortion), or 135°–140° with moderate distortion allowed.

2. Improved display area utilization: The regular hexagon display area accounts for 82.4% of the lens aberration correction circle area, and 65.2% for 16:9 video format—9% higher than square screens.

3. Optimized wafer cutting efficiency: A 12-inch wafer can yield at least 91 regular hexagon screens with a horizontal size of 23.35mm—9 more pieces than square screens—creating significant cost advantages.

IV. Technical Implementation Challenges

It should be noted that the feasibility of regular hexagon screen cutting processes still requires professional evaluation from screen manufacturers. While the scheme has been verified through optical design simulation, actual mass production needs to break through the engineering bottlenecks of cutting processes.

Keywords: VR optical design; OLED screens; regular hexagon; aberration correction; field of view (FOV); wafer cutting efficiency