Touch pad for handheld device

Abstract

A touch pad system is disclosed. The system includes mapping the touch pad into native sensor coordinates. The system also includes producing native values of the native sensor coordinates when events occur on the touch pad. The system further includes filtering the native values of the native sensor coordinates based on the type of events that occur on the touch pad. The system additionally includes generating a control signal based on the native values of the native sensor coordinates when a desired event occurs on the touch pad.

1 - 36 . (canceled) 
     
     
         37 . A method comprising:
 sending information identifying an initial object location on a touch pad to a host device when a signal state is changed from a first state to a second state,   determining a difference between a current object location and a prior object location, and   generating a message for the host device when the difference is greater than a threshold value,   wherein the message comprises the current object location.   
     
     
         38 . The method of  claim 37 , wherein the message is sent to the host device when the signal state is in the second state. 
     
     
         39 . The method of  claim 38 , comprising filtering messages sent to the host device if the signal state is in the first state. 
     
     
         40 . The method of  claim 39 , comprising filtering messages sent to the host device when the signal state is changed from the second state to the first state. 
     
     
         41 . The method of  claim 37 , wherein the difference between the current object location and the prior object location corresponds to an amount of movement of the object relative to the touch pad. 
     
     
         42 . The method of  claim 41 , comprising determining whether the amount of movement is associated with an undesired event or a desired event,
 filtering the undesired event, and   sending the desired event to the host device when the signal state is in the second state.   
     
     
         43 . The method of  claim 37 , comprising converting the current location into a logical device unit when the difference in object location is greater than the threshold value,
 wherein the logical device unit corresponds to a button function.   
     
     
         44 . The method of  claim 43 , wherein the message comprises the button function. 
     
     
         45 . The method of  claim 44 , wherein the message is sent to the host device only when the signal state is in the second state. 
     
     
         46 . A touch pad assembly, comprising:
 a touch pad comprising one or more sensors configured to detect a current object location and a prior object location,   a controller configured to filter an output of the current object location when a difference between the current object location and a prior object location is equal to or less than a threshold value, and   a user modifiable signal state that can be set to filter the output of the current object location even when the difference in object location is greater than the threshold value.   
     
     
         47 . A method comprising:
 receiving a current object location on a touch pad having a surface and one or more sensors configured to map the surface into native sensor coordinates,   generating a message comprising a changed object location when a difference between the current object location and a prior object location exceeds a threshold value that corresponds to a number of sensor levels in the touch pad, and   filtering the message from a host device when a user modifiable signal state is in an inactive state.   
     
     
         48 . The method of  claim 47 , wherein the current object location is sent to the host device when the signal state is changed from an inactive state to an active state, even when the difference in object location does not exceed the threshold value. 
     
     
         49 . The method of  claim 48 , wherein the message is sent to the host device if the signal state is in an active state. 
     
     
         50 . The method of  claim 49 , comprising filtering messages received by the host device when the signal state is changed from the active state to the inactive state. 
     
     
         51 . The method of  claim 47 , wherein the threshold value corresponds to a number of sensors in the touchpad. 
     
     
         52 . The method of  claim 47 , comprising converting the changed object location into a logical device unit when a difference between the current object location and the past object location exceeds a threshold value that corresponds to a number of sensor levels in the touch pad. 
     
     
         53 . The method of  claim 52 , wherein the logical device unit corresponds to a button function. 
     
     
         54 . The method of  claim 53 , wherein the message comprises the button function. 
     
     
         55 . The method of  claim 54 , comprising filtering messages received by the host device if the signal state is in an inactive state.