Pen input device using electrostatic coupling
First Claim
1. A pen input device for sensing the position of a tip of a writing instrument regardless of whether the writing instrument includes electrical components, comprising:
- an array of electrodes, at least some electrodes being receive electrodes generating a respective received signal characterized by a signal strength, at least one of the electrodes being selectable in a cycle as a transmitting electrode for coupling transmitted signals into a person'"'"'s hand; and
a processor connected at least to the array, whereby a person can use the writing instrument to write on a substrate positioned on the array, the transmitting electrode being selected by the processor such that the transmitted signals are coupled to the person'"'"'s hand when the person writes on a substrate, the processor receiving at least some of the received signals and determining a position of the tip based at least in part on the signal strengths, the processor discriminating signals from the array generated by hand contact from signals generated by writing instrument contact and selecting a transmitting electrode at least partially based thereon.
3 Assignments
0 Petitions
Accused Products
Abstract
A pen input device includes an array of receiver electrodes and a transmitter juxtaposed with the array for coupling electric signals from the transmitter to a person'"'"'s hand. A person can use an ordinary writing instrument to write on a paper or other substrate that rests on the array, and the signal from the transmitter is coupled through the person'"'"'s hand and writing instrument back to the array. The received signal strength is sent to a microprocessor for determining the position of the tip of the writing instrument, and the position can then be sent to a handwriting recognition algorithm to correlate pen strokes across the substrate to alpha-numeric characters. The transmitter can be separate from the receiver electrode array, or the receiver electrodes can be multiplexed such that one of the electrodes is selected to function as the transmitter.
67 Citations
21 Claims
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1. A pen input device for sensing the position of a tip of a writing instrument regardless of whether the writing instrument includes electrical components, comprising:
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an array of electrodes, at least some electrodes being receive electrodes generating a respective received signal characterized by a signal strength, at least one of the electrodes being selectable in a cycle as a transmitting electrode for coupling transmitted signals into a person'"'"'s hand; and
a processor connected at least to the array, whereby a person can use the writing instrument to write on a substrate positioned on the array, the transmitting electrode being selected by the processor such that the transmitted signals are coupled to the person'"'"'s hand when the person writes on a substrate, the processor receiving at least some of the received signals and determining a position of the tip based at least in part on the signal strengths, the processor discriminating signals from the array generated by hand contact from signals generated by writing instrument contact and selecting a transmitting electrode at least partially based thereon. - View Dependent Claims (2, 3, 4, 5, 6)
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7. In an electrostatic pen input device including a general purpose writing instrument, an array of electrodes and one or more transmitters juxtaposed with the electrodes, a logic device, comprising:
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position logic means for determining a position of said writing instrument relative to the array based on signals from the array; and
contact logic means for determining when the writing instrument contacts a surface at least partially based on a velocity of the writing instrument relative to the surface. - View Dependent Claims (8, 9)
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10. A device for outputting a signal representative of the position of a general purpose writing instrument on a paper substrate, comprising:
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a base positionable under the paper substrate;
plural receivers on the base; and
at least one transmitter on the base, the transmitter being arranged on the base such that signals from the transmitter are coupled into a hand of a person when the paper substrate is supported on the base and the person manipulates the general purpose writing instrument to write on the paper substrate, the signals propagating through the general purpose writing instrument for detection of the signals by the receivers when the person manipulates the general purpose writing instrument to write on the paper substrate. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A method for generating position signals representative of positions of a writing instrument on a substrate, comprising:
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providing a writing instrument containing no electrical components;
coupling signals into a hand of a person manipulating the writing instrument against the substrate, the signals propagating through the hand and writing instrument as the writing instrument deposits ink or graphite on the substrate;
receiving signals from the writing instrument, and based thereon;
outputting the position signals. - View Dependent Claims (18, 19, 20, 21)
providing an array of electrodes, each electrode defining one or more electrode coordinates; and
determining a ratio of a sum of plural signal strengths multiplied by one or more corresponding electrode coordinates to a sum of plural signal strengths.
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20. The method of claim 17, wherein the coupling and receiving steps are respectively undertaken by one or more transmitters and one or more receivers.
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21. The method of claim 17, further comprising correlating the position signals to alpha-numeric characters.
Specification