Patent ID: 7688308

Claim:
A signal processing system for processing signals outputted from a pointing device, said signal processing system comprising: a first amplifier for amplifying a detection signal outputted by operating an operation console of the pointing device, along an x-axis direction thereof, a second amplifier for amplifying a detection signal outputted by operating the operation console, along a y-axis direction thereof, a first switching circuit for alternately switching over between respective output signals of the first and second amplifiers by the predetermined period before outputting, and a circuit for ac-grounding an output side of the first switching circuit for predetermined time upon switchover of the first switching circuit, wherein the circuit for ac-grounding the output side of the first switching circuit comprises: a first low pass filter made up of a resistor and a capacitor, connected between the output side of the first switching circuit and the ground, and a second switching circuit connected to both ends of the resistor, wherein the second switching circuit is turned on upon the switchover of the first switching circuit, and is turned off after the elapse of predetermined time from the switchover, a second low pass filter for removing low frequency noises of the output signal of the first amplifier, and a third low pass filter for removing low frequency noises of the output signal of the second amplifier, wherein an upper cut-off frequency of the first low pass filter is set lower than respective upper cut-off frequencies of the second, and third low pass filters.