Pointing device with hand detection

Abstract

An input device having a housing and electronic circuitry for detecting user inputs, and transmitting signals corresponding to those inputs to an electronic device, such as a computer. A sleep mode is provided for the electronic circuitry to conserve power. A hand detection circuit is provided for detecting the proximity of a user's hand to the housing and producing a hand detect signal in response. The hand detect signal will awaken the input device from its sleep mode.

1 . An input device comprising: 
 a housing;    electronic circuitry for detecting user inputs and transmitting signals corresponding to said inputs to an electronic device;    a sleep-mode circuit, coupled to said electronic circuitry, for activating a reduced power operation of said electronic circuitry;    a capacitive hand detection circuit for detecting the proximity of a user's hand to said housing and producing a hand detect signal; and    said sleep mode circuit being responsive to said hand detect signal to awaken said electronic circuitry from said reduced power operation.    
   
   
       2 . The device of  claim 1  wherein said input device is a pointing device and said electronic device is a computer.  
   
   
       3 . The device of  claim 1  wherein said hand detection circuit detects the touch of a hand.  
   
   
       4 . The device of  claim 1  wherein said hand detection circuit is mounted inside a top of said housing, such that a portion of said housing insulates said user's hand from said capacitive hand detection circuit.  
   
   
       5 . The device of  claim 4  wherein said capacitive detection circuit comprises: 
 first and second electrodes on said housing for capacitive connection with a user's hand;    a first circuit, coupled to said first electrode, for determining an amount of time for charging of a capacitance connected to said first circuit; and    a second circuit, coupled to said second electrode, for determining an amount of time for discharging of a capacitance connected to said second circuit;    such that an internal virtual ground is produced between said first and second electrodes.    
   
   
       6 . The device of  claim 4  wherein said hand detection circuit includes first and second electrodes covering more than 25 percent of the underside surface of a top surface of said housing.  
   
   
       7 . The device of  claim 4  wherein said electrodes are mounted on first and second opposed sides of said housing where they can be directly contacted simultaneously by the grasping of said user's hand.  
   
   
       8 . The device of  claim 1  wherein said sleep mode circuit includes an interrupt input, and said hand detection circuit periodically activates, and provides an interrupt signal to said interrupt input when said user's hand is detected.  
   
   
       9 . The device of  claim 1  wherein said input device is a mouse, and said electronic circuitry is an optical module for reflecting light off a surface and detecting movement of said mouse relative to said surface.  
   
   
       10 . A mouse comprising: 
 a housing;    electronic circuitry for detecting user inputs and transmitting said inputs to an electronic device, said electronic circuitry including an optical module for reflecting light off a surface and detecting movement of said mouse relative to said surface;    a sleep-mode circuit, coupled to said electronic circuitry, for activating a reduced power operation of said electronic circuitry, said sleep mode circuit being responsive to a wake-up signal to awaken said electronic circuitry from said reduced power operation; and    a capacitive hand detection circuit for detecting the proximity of a user's hand to said housing and mounted inside a top of said housing, such that a portion of said housing insulates said user's hand from said capacitive hand detection circuit, said hand detection circuit producing said wake up signal, said hand detection circuit comprising    first and second electrodes on said housing for capacitive connection with a user's hand,    a first circuit, coupled to said first electrode, for determining an amount of time for charging of a capacitance connected to said first circuit, and    a second circuit, coupled to said second electrode, for determining an amount of time for discharging of a capacitance connected to said second circuit;    such that an internal virtual ground is produced between said first and second electrodes.    
   
   
       11 . A method for operating an input device comprising: 
 detecting user inputs and transmitting said inputs to an electronic device external to said input device;    activating a reduced power mode of said input device in the absence of user inputs for a period of time;    capacitively detecting the proximity of a user's hand to said input device and producing a hand detect signal; and    awakening said input device from said reduced power mode in response to said hand detect signal.    
   
   
       12 . The method of  claim 11  wherein said detecting the proximity of a user's hand detects a change in capacitance inside a housing of said input device due to said proximity of a user's hand outside said housing of said input device.  
   
   
       13 . The method of  claim 12  wherein said change in capacitance is determined using the simultaneous charging and a discharging of a capacitances coupled to two electrodes.