Switchable Privacy Displays: Applications, Optical Measurements, and Evaluation With Focus on Automotive

ABSTRACT Data security is in high demand, for example, for personal data on mobile devices in public places or at ATMs. Today, the solution to avoid “spying” or “shoulder surfing” is “fixed privacy” with louvered films, but this is rarely used for mobile devices as it is mostly inconvenient. Switchable privacy displays (SPDs) can electronically change between multiple viewers (public) and a single on‐axis (private) user. This technology gained worldwide attention by the introduction of the first smartphone equipped with an SPD in March 2026. Applications of SPDs are introduced with a focus on automotive codriver displays, as these are the most demanding use case in terms of driver distraction (safety) and high image quality for the codriver. The associated optical measurements to judge on the performance of SPDs (most important are the horizontal viewing angle characteristics) can easily be transferred to other applications with respect to their geometric and ambient light conditions. The evaluation of switchable privacy for codriver displays was performed with 20 participants. Additionally, an efficient proposal for standardization of switchable privacy mode displays is presented on the basis of easy‐to‐measure luminance values.