Touch screen with sensory feedback

Abstract

A load control device for controlling the amount of power delivered to an electrical load from an AC power source provides improved sensory feedback to a user of the load control device. The load control device comprises a touch screen actuator having a touch sensitive front surface responsive to a plurality of point actuations, each characterized by a position and a force. The touch screen actuator has an output operatively coupled to a controller for providing a control signal representative of the position of the point actuation. The load control device further comprises a visual display and an audible sound generator, both responsive to the controller. The controller is operable to cause the visual display to illuminate and the audible sound generator to generate an audible sound in response to the control signal of the touch screen actuator.

1 . A load control device for controlling an amount of power delivered from an AC power source to an electrical load, the load control device comprising:
 a bidirectional semiconductor switch operable to be coupled in series electrical connection between the source and the load, the semiconductor switch having a control input for controlling the semiconductor switch between a non-conductive state and a conductive state;   a controller operatively coupled to the control input of the semiconductor switch for controlling the semiconductor switch between the non-conductive state and the conductive state;   a touch sensitive front surface adapted to be pressed;   a touch sensitive device responsive to the touch sensitive front surface being pressed, the touch sensitive device having an output operatively coupled to the controller for providing a control signal representative of a position at which the touch sensitive front surface is pressed; and   an audible sound generator responsive to the controller;   wherein the controller is operable to cause the visual display to illuminate and the audible sound generator to generate a first audible sound in response to the control signal of the touch sensitive device when the touch sensitive front surface is pressed, and to generate a second audible sound in response to the control signal when the touch sensitive front surface is released.   
     
     
         2 . The load control device of  claim 1 , wherein the touch sensitive front surface comprises a toggle portion and an intensity portion;
 wherein the controller is operable to control the electrical load between an on state and an off state in response to an actuation of the toggle portion of the front surface, and to control the amount of power delivered to the electrical load in response to an actuation of the intensity portion of the front surface.   
     
     
         3 . The load control device of  claim 2 , wherein the touch sensitive front surface further comprises a keepout region between the toggle portion and the intensity portion;
 wherein the controller is operable to maintain the amount of power delivered to the electrical load constant in response to an actuation of the keepout region of the front surface.   
     
     
         4 . The load control device of  claim 3 , further comprising:
 a status indicator responsive to the controller for illuminating the toggle portion of the front surface.   
     
     
         5 . The load control device of  claim 4 , wherein the status indicator is illuminated to a first color when the electrical load is in the on state and to a second color when the electrical load is in the off state. 
     
     
         6 . The load control device of  claim 1 , further comprising:
 a visual display responsive to the controller.   
     
     
         7 . The load control device of  claim 6 , wherein the visual display comprises a linear array of status indicators provided on the front surface, the status indicators illuminated to display a representation of the amount of power delivered to the electrical load. 
     
     
         8 . The load control device of  claim 1 , wherein the first and second audible sounds simulate the sound made when a tactile switch is actuated. 
     
     
         9 . The load control device of  claim 1 , wherein the first audible sound is different than the second audible sound. 
     
     
         10 . The load control device of  claim 1 , wherein the audible sound generator comprises an audio power amplifier coupled to the controller and a speaker coupled to the audio power amplifier, the audio power amplifier operable to receive a sound wave signal from the controller and to provide an amplified sound wave signal to the speaker for generating the audible sound. 
     
     
         11 . A user interface for a lighting control, the user interface comprising:
 a touch sensitive front surface adapted to have an operating pressure applied thereto;   a touch sensitive device responsive to the touch sensitive front surface being pressed, the touch sensitive device having an output operatively coupled to the controller for providing a control signal representative of a position at which the touch sensitive front surface is pressed; and   an audible sound generator operable to generate a first audible sound in response to the control signal of the touch sensitive device when the touch sensitive front surface is pressed, and to generate a second audible sound in response to the control signal when the touch sensitive front surface is released.   
     
     
         12 . The user interface of  claim 11 , wherein the first and second audible sounds simulate the sound made when a tactile switch is actuated. 
     
     
         13 . The user interface of  claim 11 , wherein the first audible sound is different than the second audible sound. 
     
     
         14 . A load control device for controlling the amount of power delivered from an AC power source to an electrical load, the load control device comprising:
 a bidirectional semiconductor switch operable to be coupled in series electrical connection between the source and the load, the semiconductor switch having a control input for controlling the semiconductor switch between a non-conductive state and a conductive state;   a controller operatively coupled to the control input of the semiconductor switch for controlling the semiconductor switch between the non-conductive state and the conductive state;   a touch sensitive front surface;   a touch sensitive device responsive to a plurality of point actuations at the touch sensitive front surface, each of the point actuations characterized by a position and a force, the touch sensitive device having an output operatively coupled to the controller for providing a first control signal in response to a first point actuation and a second control signal in response to a second point actuation; and   an audible sound generator responsive to the controller;   wherein the controller is operable to control the amount of power delivered to the electrical load to a first amount of power and to cause the audible sound generator to generate a first audible sound in response to the first control signal, the controller further operable to control the amount of power delivered to the electrical load to a second amount of power and cause the audible sound generate to generate a second audible sound different than the first sound in response to the second control signal.   
     
     
         15 . The load control device of  claim 14 , wherein the first audible sound is generated in response to a toggle event and the second audible sound is generated in response to a change intensity event. 
     
     
         16 . The load control device of  claim 14 , wherein the audible sound generator comprises an audio power amplifier coupled to the controller and a speaker coupled to the audio power amplifier, the audio power amplifier operable to receive a sound wave signal from the controller and to provide an amplified sound wave signal to the speaker for generating the audible sound. 
     
     
         17 . A user interface for a lighting control, the user interface comprising:
 a touch sensitive front surface;   a touch sensitive device responsive to a plurality of point actuations at the touch sensitive front surface, each of the point actuations characterized by a position and a force, the touch sensitive device operable to begin providing a control signal when the magnitude of the force of each of the point actuations exceeds a minimum magnitude and to cease providing the control signal when the magnitude of the force subsequently decreases below the minimum magnitude; and   an audible sound generator operable to generate a first audible sound in response to the control signal when the magnitude of the force of each of the point actuations exceeds the minimum magnitude, and to generate a second audible sound in response to the control signal when the magnitude of the force subsequently decreases below the minimum magnitude.   
     
     
         18 . The user interface of  claim 17 , wherein the first and second audible sounds simulate the sound made when a tactile switch is actuated. 
     
     
         19 . The user interface of  claim 17 , wherein the first audible sound is different than the second audible sound. 
     
     
         20 . A method of providing audible feedback in a load control device, the method comprising the steps of:
 applying an operating pressure to a touch sensitive front surface of the load control device;   transmitting the operating pressure to a touch sensitive device of the load control device;   generating a control signal representative of a position of the operating pressure on the touch sensitive front surface;   generating a first audible sound in response to the step of applying an operating pressure;   ceasing to apply the operating pressure to the touch sensitive front surface; and   generating a second audible sound in response to the step of ceasing to apply the operating pressure.   
     
     
         21 . The method of  claim 20 , wherein the first and second audible sounds simulate the sound made when a tactile switch is actuated. 
     
     
         22 . The method of  claim 21 , wherein the first audible sound is different than the second audible sound.