Haptic electromagnetic actuator

Abstract

A haptic electromagnetic actuator for track pad is provided. The actuator includes an array of electromagnets with alternating South and North poles on a first end, each magnet comprising a metal core and an electrical wire around the metal core. The array of magnets is coupled to a base plate on a second end opposite to the first end. The actuator also includes an attraction plate at a distance from the first end of the array of the magnets such that the attraction plate moves toward the magnets when an electrical current flows through the electrical wire around the metal core and moves away from the magnets when the current becomes zero. The array of magnets is configured to form a uniform gap from the attraction plate.

What is claimed is: 
     
         1 . A haptic electromagnetic actuator for trackpad, the actuator comprising:
 an array of electromagnets with alternating poles at a first end, each magnet comprising a metal core and an electrical wire around the metal core; and   an attraction plate at a distance from the first end of the array of the magnets such that the attraction plate moves toward the magnets when an electrical current flows through the electrical wire around the metal core and moves away from the magnets when the current becomes zero, the array of magnets being configured to form a uniform gap from the attraction plate.   
     
     
         2 . The actuator of  claim 1 , wherein the array of the electromagnets comprises four magnets. 
     
     
         3 . The actuator of  claim 1 , wherein each of the electromagnets is coupled to a base plate at a first end. 
     
     
         4 . The actuator of  claim 3 , wherein each of the electromagnets defines a pointed end opposite the first end. 
     
     
         5 . The actuator of  claim 4 , wherein the attraction plate defines a sawtooth shape, the sawtooth shape comprising a plurality of projections. 
     
     
         6 . The actuator of  claim 5 , wherein each of the plurality of projections is received between at least two electromagnets. 
     
     
         7 . The actuator of  claim 1 , wherein each adjacent electromagnetic actuator cooperates to form an electromagnetic field. 
     
     
         8 . The actuator of  claim 7 , wherein the array of electromagnets define a non-uniform field. 
     
     
         9 . The actuator of  claim 1 , wherein the array of electromagnets are non-uniform in at least one dimension. 
     
     
         10 . A method for forming an electromagnetic actuator, comprising:
 stamping a metal sheet to form an array of metal cores;   annealing the array of metal cores;   winding one of a plurality of wires about each of the array of metal cores; and   affixing each end of the plurality to a power source.   
     
     
         11 . The method of  claim 10 , wherein each of the plurality of wires is wound about a bobbin prior to being wound about each of the array of metal cores. 
     
     
         12 . An input device, comprising:
 a plate;   an actuator operatively connected to the plate;   a force sensor operatively connected to the plate;   a touch sensor operatively connected to the plate; and   a controller operatively connected to at least one of the touch sensor, actuator, and force sensor; wherein   the controller actuates the actuator, causing the plate to move to provide a haptic feedback in response to the an input to the force sensor.   
     
     
         13 . The input device of  claim 12 , further comprising:
 a position sensor operatively connected to the plate; wherein   the position sensor is operative to detect a motion of the plate.   
     
     
         14 . The input device of  claim 13 , wherein the controller operative to actuate the plate to provide the haptic feedback in response to a signal from the controller. 
     
     
         15 . The input device of  claim 14 , wherein the position sensor is operative to detect a motion of the plate relative to the actuator. 
     
     
         16 . The input device of  claim 12 , wherein the plate is a track pad plate. 
     
     
         17 . The input device of  claim 13 , wherein the position sensor comprises an accelerometer. 
     
     
         18 . The input device of  claim 12 , further comprising a force sensor operative to determine an approximate force exerted on the plate. 
     
     
         19 . The input device of  claim 18 , further comprising a touch sensor operative to determine a location at which a touch is present on the plate. 
     
     
         20 . The input device of  claim 19 , wherein the controller is operative to correlate the approximate force with the location. 
     
     
         21 . The input device of  claim 12 , wherein the plate moves in-plane when moved by the actuator. 
     
     
         22 . The input device of  claim 21 , wherein the plate moves laterally with respect to the actuator.