Abstract: A method for touchless gesture recognition is provided. The method includes transmitting ultrasonic signals via a speaker. The method includes generating ultrasonic signals. The method includes receiving the reflected ultrasonic signals from an object via two or more microphones. The method includes computing a frequency shift according to the reflected ultrasonic signals. The method includes identifying a gesture that corresponds to a movement of the object according to the frequency shift. The method includes performing a function that corresponds to the gesture.

Abstract: A method for touchless gesture recognition is provided. The method includes transmitting ultrasonic signals via a speaker. The method includes generating ultrasonic signals. The method includes receiving the reflected ultrasonic signals from an object via two or more microphones. The method includes computing a frequency shift according to the reflected ultrasonic signals. The method includes identifying a gesture that corresponds to a movement of the object according to the frequency shift. The method includes performing a function that corresponds to the gesture.

Abstract: A front light module includes a reflective display device, a front light guide, and a light emitting unit plate. The front light guide plate includes a micro-structure. The micro-structure has a first angle between a surface thereof close to the light emitting unit and an upper surface of the front light guide plate. The micro-structure has a second angle between a surface thereof away from the light emitting unit and the upper surface of the front light guide plate. The micro-structure has a third angle between the surface thereof close to the light emitting unit and the surface thereof away from the light emitting unit. The first angle is within a range between 30 degrees and 60 degrees, the second angle is within a range between 30 degrees and 59 degrees, and the third angle is greater than 90 degrees.

Abstract: A burst mode resonant power converter with high conversion efficiency has a rectifier, a power factor correction circuit, a resonant circuit, a controller, and a burst mode triggering unit. The maximum frequency switching end of the controller is connected to a maximum frequency variable circuit. When the load is medium or heavy, the maximum frequency variable circuit increases the maximum switch frequency of the controller. When the load is in the no-load or the light conditions, it reduces the maximum switch frequency thereof. Therefore, the controller reduces the number of times that the resonant circuit switches the bridge switch circuit. The conduction cycle of the 50% pulse signal output to the bridge switch circuit becomes longer. Larger energy can be transmitted at a time to the secondary coil of the transformer. This increases the overall efficiency.

Abstract: A burst mode resonant power converter with high conversion efficiency has a rectifier, a power factor correction circuit, a resonant circuit, a controller, and a burst mode triggering unit. The maximum frequency switching end of the controller is connected to a maximum frequency variable circuit. When the load is medium or heavy, the maximum frequency variable circuit increases the maximum switch frequency of the controller. When the load is in the no-load or the light conditions, it reduces the maximum switch frequency thereof. Therefore, the controller reduces the number of times that the resonant circuit switches the bridge switch circuit. The conduction cycle of the 50% pulse signal output to the bridge switch circuit becomes longer. Larger energy can be transmitted at a time to the secondary coil of the transformer. This increases the overall efficiency.