Head Mount Display Luminance Control for Eye Fatigue

The patent implements dynamic luminance adjustment by transitioning from a fixed initial luminance to a variable watching luminance that adapts over time. The luminance controller dynamically modifies the image luminance based on elapsed time since device activation, creating a time-dependent luminance profile that reduces eye fatigue while maintaining manageable system complexity through controlled variation rather than full adaptability

The patent changes the luminance parameter over time according to a specific equation (L2 = L1 × (1 - e^(-t/τ))). This parameter change approach allows the system to maintain simplicity by using a mathematical model with fixed constants (initial luminance L1, time constant τ) rather than complex adaptive algorithms, while still achieving the benefit of reduced eye fatigue through gradual luminance adjustment

The patent applies beforehand cushioning by implementing a gradual luminance transition instead of abrupt changes. The time constant τ in the luminance equation controls the rate of change, cushioning the visual system against sudden luminance shifts that would cause discomfort. This preparatory gradual adjustment allows the user's eyes to adapt smoothly to environmental changes without experiencing the harmful effects of rapid luminance variation

The patent implements periodic action through the time-based luminance adjustment mechanism. The luminance changes continuously over time according to the exponential decay model, creating a controlled periodic adaptation process. This time-dependent approach allows the system to achieve environmental adaptability while regulating the rate of change to prevent eye fatigue, effectively using time as the controlling parameter for smooth adaptation

The patent uses a simple mathematical model with fixed parameters (initial luminance L1, time constant τ, ambient luminance La) that can be pre-calculated and stored. Rather than implementing complex real-time adaptive algorithms, the system uses a straightforward exponential decay equation that is computationally inexpensive and easy to implement. This approach achieves effective eye fatigue reduction through a simple, almost disposable calculation method rather than complex persistent algorithms

The patent replaces complex mechanical or algorithmic luminance adjustment systems with a mathematical model-based approach. Instead of using multiple sensors, actuators, and complex control algorithms, the system substitutes a simple luminance calculation based on time and ambient light measurements. This substitution of complex mechanical/control systems with a mathematical relationship achieves the same eye fatigue reduction effect with minimal device complexity