Force invariant touch screen
First Claim
1. A load control device for controlling the amount of power delivered to an electrical load from an AC power source, the load control device comprising:
- a 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 actuator having a touch sensitive front surface responsive to a point actuation characterized by a position and a force, the touch sensitive actuator having an output operatively coupled to the controller for providing a control signal to the controller; and
a stabilizing circuit coupled to the output of the touch sensitive actuator;
wherein the control signal is substantially responsive only to the position of the point actuation.
2 Assignments
0 Petitions
Accused Products
Abstract
A touch dimmer has a three-wire touch sensitive screen that produces an output voltage signal representative of a position of a manual pressure touch along a longitudinal axis of the touch screen. To reduce the occurrence of erroneous position indications due to low-pressure touches of the touch screen, a filter circuit is coupled to the output of the touch screen to prevent the detection of transient touches, and to prevent the detection of low-pressure touches having less than a certain actuation force. As a result, a controller may accurately determine the position of the manual pressure touch. In a preferred embodiment, two filters are coupled to the output of the touch screen. The first filter conditions the output voltage signal to allow the controller to accurately determine whether a manual pressure touch actuation has occurred. The second filter conditions the output voltage signal to allow the controller to accurately determine the position of the manual pressure touch along a longitudinal axis of the touch screen. An alternative embodiment of the touch dimmer uses a four-wire touch sensitive screen that produces a second output voltage signal representative of a position of a manual pressure touch along a transverse axis of the touch screen. The first filter is coupled to receive the second output signal to permit accurate detection of a manual pressure touch actuation.
62 Citations
37 Claims
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1. A load control device for controlling the amount of power delivered to an electrical load from an AC power source, the load control device comprising:
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a 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 actuator having a touch sensitive front surface responsive to a point actuation characterized by a position and a force, the touch sensitive actuator having an output operatively coupled to the controller for providing a control signal to the controller; and a stabilizing circuit coupled to the output of the touch sensitive actuator; wherein the control signal is substantially responsive only to the position of the point actuation. - View Dependent Claims (2, 3, 4, 5)
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6. A user interface for a lighting control, the user interface comprising:
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a touch sensitive actuator having a touch sensitive front surface responsive to a point actuation characterized by a force and a position along a longitudinal axis of the touch sensitive actuator, the touch sensitive actuator having an output for providing a control signal representative of the position; and a stabilizing circuit coupled to the output of the touch sensitive actuator; wherein the control signal is responsive only to the position of the point actuation.
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7. A load control device for controlling the amount of power delivered to an electrical load from an AC power source, the load control device comprising:
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a 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 actuator having a touch sensitive front surface responsive to a point actuation characterized by a position and a force, the touch sensitive actuator having an output for providing a control signal; a usage detection circuit operatively coupled between the output of the touch sensitive actuator and the controller for determining whether the point actuation is presently occurring; and a stabilizing circuit operatively coupled between the output of the touch sensitive actuator and the controller for stabilizing the control signal from the output of the touch sensitive actuator; wherein the controller is responsive to the control signal when the usage detection circuit has determined that the point actuation is presently occurring. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A user interface for a lighting control, the user interface comprising:
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a touch sensitive actuator having a touch sensitive front surface responsive to a point actuation characterized by a position and a force, the touch sensitive actuator having an output for providing a control signal; a usage detection circuit operatively coupled to the output of the touch sensitive actuator for determining whether the point actuation is presently occurring; a stabilizing circuit operatively coupled to the output of the touch sensitive actuator and comprising an output, the stabilizing circuit operable to stabilize the control signal from the output of the touch sensitive actuator; and a controller coupled to the usage detection circuit and the output of the stabilizing circuit, the controller responsive to the control signal when the usage detection circuit has determined that the point actuation is presently occurring.
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- 15. In a control circuit for operating an electrical load in response to an output signal from a touch pad, said touch pad comprising an elongated manually touchable resistive area which produces an output signal at an output terminal, said signal representative of the location at which the touch pad is manually touched, said control circuit including a microprocessor having an input connected to said output signal and producing an output for controlling said load in response to the manual input to said touch pad, the improvement comprising a filter capacitor connected between said output terminal and a ground terminal to define a resistive-capacitive circuit with the resistance of said touch pad, said resistive-capacitive circuit characterized by a time constant and being adapted to prevent large transient voltage changes due to low pressure touches of said touch pad.
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28. In a manually operable control structure for producing an electrical signal dependent on the location at which a touch screen is touched;
- said control structure comprising a resistive touch screen having a control voltage connected to terminals at its opposite ends and an output terminal which is connected to said touch screen at the location of a local manual pressure applied to said screen by a user;
a microprocessor having an input connected to said output terminal and producing an output related to the position at which said screen receives said local manual pressure;
the improvement which comprises a filter capacitor connected between said output terminal and a ground terminal and defining an R/C circuit with the resistance of said touch screen between said position at which said screen receives local manual pressure and one of its said terminals. - View Dependent Claims (29, 30, 31, 32, 33, 34)
- said control structure comprising a resistive touch screen having a control voltage connected to terminals at its opposite ends and an output terminal which is connected to said touch screen at the location of a local manual pressure applied to said screen by a user;
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35. A process for generating an operating signal from a resistive touch screen in which an output voltage on a output terminal is related to both the location on the screen area which is touched by a users finger and to the pressure of the touch;
- said process comprising the production of an x signal in response to the touching of said screen at any location on its surface and the production of a y signal in response to the location at which the screen is touched, and applying said x and y signals to a microprocessor;
said microprocessor producing an output signal to a circuit to be controlled only when an x output signal is present and a y output signal is also present at the end of a predetermined sample interval. - View Dependent Claims (36, 37)
- said process comprising the production of an x signal in response to the touching of said screen at any location on its surface and the production of a y signal in response to the location at which the screen is touched, and applying said x and y signals to a microprocessor;
Specification