Patent ID: 8289278

Claim:
A pointing device comprising: a base; an operator supported on said base and movable relative to an original position in a horizontal direction; a magnetic element mounted on said operator and movable with said operator; at least one magneto-electric transducer disposed adjacent to said magnetic element for detecting a variation in magnetic field of said magnetic element due to movement of said operator and for generating a voltage signal based on a detection result made thereby; a sampling unit coupled to said magneto-electric transducer for receiving the voltage signal therefrom, and sampling the voltage signal so as to generate a sampling voltage; a storage unit for storing therein reference information corresponding to a voltage range from a lower limit value to an upper limit value; and a processing unit coupled to said sampling unit and said storage unit, receiving the sampling voltage from said sampling unit, operable to determine, based on the reference information stored in said storage unit and the sampling voltage received thereby, whether the sampling voltage is within the voltage range and whether a displacement of said operator from the original position is greater than a predetermined distance, and to generate a control signal corresponding to the movement of said operator upon detecting one of that the sampling voltage is not within the voltage range and that the sampling voltage is within the voltage range while the displacement of said operator is greater than the predetermined distance, wherein said storage unit further stores therein reference voltage data that includes at least one reference voltage, and a reference control signal; when the sampling voltage is not within the voltage range, said processing unit generates the control signal based on the sampling voltage received thereby and the reference voltage of the reference voltage data stored in said storage unit such that the control signal is equal to a result obtained by subtracting the reference voltage from the sampling voltage; and said processing unit is further operable to update the reference control signal stored in said storage unit with the control signal generated thereby.