Apple(US:AAPL) 3 6 Ke·2026-01-04 09:23Core Viewpoint - The competition in resolution among digital devices continues, with mobile manufacturers still pushing for higher resolutions, while television manufacturers may not need to follow suit as closely due to viewing distance considerations [1][9]. Group 1: Resolution and Human Perception - The concept of "retina display" was introduced by Apple with the iPhone 4, featuring a pixel density of 326 pixels per inch (ppi), which exceeds the human eye's limit of 300 ppi at a distance of 10 to 12 inches [2][5]. - The critical measure for human visual clarity is pixels per degree (ppd), which considers viewing distance; the previously accepted limit was 60 ppd, forming the basis for the 300 ppi standard [4][5]. - Recent research indicates that the human eye can discern higher resolutions than previously thought, with limits reaching 94 ppd for black and white patterns and 89 ppd for red-green patterns [6][8]. Group 2: Implications for Device Manufacturers - The study suggests that not all devices require continuous resolution increases; for instance, 8K televisions only show advantages at viewing distances less than 1.3 times the screen height, making them less necessary for typical viewing scenarios [9]. - In contrast, mobile devices still have room for improvement in resolution, as the effective resolution of upcoming devices like the 13-inch iPad Pro is still below the human eye's limits at common viewing distances [9][10]. - The concept of "eccentric rendering" is proposed, where high resolution is maintained in the center of the screen while reducing it at the edges, which can optimize processing load and bandwidth consumption [11].