Abstract: A control device including a signal emitter, a signal receiver, and a processing unit is disclosed. The signal emitter emits an output signal including a first output component and a second output component. The signal receiver receives an input signal. The input signal includes a reflected component when the first output component is reflected by an object. The input signal includes an emitted component when the second output component is received by the signal receiver. The processing unit compares a first threshold value with the amplitude of the input signal and compares a second threshold value with the amplitude of the input signal when the input signal simultaneously includes the reflected component and the emitted component. The processing unit differentiates the reflected component and the emitted component and invalidates the emitted component according to the compared results.

Abstract: A system for power management and safety protection and a method thereof are presented. The system and method are applicable to a computer device having a sensor. The sensor detects position information of a user relative to the computer device so as to determine whether to enter a sleep mode or a recognition mode. The sensor also detects motion information of a particular motion of the user so as to return to an operating mode.