SYSTEM AND METHOD FOR SENSING THE POSITION OF A POINTING OBJECT
First Claim
1. A system for sensing the position of a pointer with respect to a reference frame comprising:
- a sensing device capable of measuring an electric field around the pointer when it is in proximity to the reference frame;
said sensing device also capable of taking measurements of the electric field from a first and second sensing location;
a processing device capable of receiving signals regarding the measured electric field;
wherein said processing device designates the measurement of the electric field from the second sensing location as a reference value when the measurements of the electric field from the first and second sensing locations meet predetermined qualifications; and
wherein said processing device calculates the position of the pointer on a first axis in the reference frame based on measurements of the electric field from the first and second sensing locations and said reference value.
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Abstract
A system for sensing the position of a pointer with respect to a reference frame is described wherein the system has a sensing device capable of measuring an electric field around the pointer when it is in proximity to the reference frame and a processing device capable of receiving signals regarding the measured electric field. The sensing device is also capable of taking measurements of the electric field from at least a first and second sensing location. The processing device designates the measurement of the electric field from the second sensing location as a reference value when the measurements of the electric field from the first and second sensing locations meet predetermined qualifications and calculates the position of the pointer on a first axis in the reference frame based on measurements of the electric field from the first and second sensing locations and said reference value.
71 Citations
13 Claims
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1. A system for sensing the position of a pointer with respect to a reference frame comprising:
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a sensing device capable of measuring an electric field around the pointer when it is in proximity to the reference frame;
said sensing device also capable of taking measurements of the electric field from a first and second sensing location;
a processing device capable of receiving signals regarding the measured electric field;
wherein said processing device designates the measurement of the electric field from the second sensing location as a reference value when the measurements of the electric field from the first and second sensing locations meet predetermined qualifications; and
wherein said processing device calculates the position of the pointer on a first axis in the reference frame based on measurements of the electric field from the first and second sensing locations and said reference value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for sensing the position of a pointer with respect to a reference frame comprising the steps of:
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measuring the electric field around a pointer from first and second sensing locations when said pointer is in proximity to the reference frame;
designating the measurement of the electric field from the second sensing location as a reference value when the processing device determines that the measurements of the electric field meet certain predetermined qualifications; and
calculating the position of the pointer in a first axis in the reference frame based on measurements of the electric field from the first and second sensing locations and said reference value.
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13. A system for sensing and automatically calibrating the three-dimensional position of a pointer, the system comprising:
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a three-dimensional sensing device operable to output first, second and third signals representing measurements of the electric field around said pointer from three different sensing locations;
a processor coupled to the three dimensional sensor;
a memory coupled to the processor;
an autocalibration program stored in memory and executable by the processor, wherein the processor executing the program;
continuously monitors the first, second and third signals;
determines if the first, second and third signals meet a predetermined criteria;
stores the first signal if the first, second and third signals do meet the predetermined criteria; and
calculates the position of the pointer based on the measurements of the monitored first, second and third signals and the stored first signal.
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Specification