Patent ID: 7221355

Claim:
In a system included in a pointing device, the system having an inactive state and an on state, apparatus including: a set of at least one sensor associated with the pointing device, each sensor being one of a proximity sensor, a touch sensor operative to detect whether the pointing device is touching an active area, or a button sensor operative to detect whether a button is pressed by a user; an on-off circuit coupled to the set of sensors and responsive to a triggering event involving any of those sensors; a regulator coupled to the on-off circuit, responsive to a signal from the on-off circuit, and capable of being turned on or off in response to that signal; and an operational circuit coupled to the set of at least one sensor and to the regulator, the operational circuit being responsive to whether the regulator is on or off, wherein the operational circuit can determine which one or more of the set of sensors is involved in any such triggering event; wherein each sensor of the set of at least one sensor includes a passive switch coupled to a corresponding resistor and a power source, such that for each particular sensor, no power is consumed by the particular sensor and its corresponding resistor unless there is a triggering event for the particular sensor, and such that as a result of a triggering event for the particular sensor, there is a current flowing through the corresponding resistor, wherein for each particular sensor, a sensor signal indicative of a voltage drop across the resistor corresponding to the particular sensor coupled to the operational circuit operative to indicate that there has been a triggering event, and wherein the system consumes substantially no power in its inactive state and operates normally in its on state.