Pen input device using electrostatic coupling

Details Pen input device using electrostatic coupling Pen input device using electrostatic coupling

1999-01-07

2001-08-28

Saras, Steven (Department: 2775)

Computer graphics processing and selective visual display system

Display peripheral interface input device

Stylus

C345S173000, C345S179000, C178S018010, C178S018060

Reexamination Certificate

active

06281888

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to handwriting data entry, and more particularly to methods and systems for facilitating data entry using a pen input device.
2. Description of the Related Art
Pen input devices have been provided in which the movement of a stylus across a detector is sensed by the detector and converted into alpha-numeric characters by handwriting recognition algorithms. Signals representing the alpha-numeric characters are then electronically stored in a computer document or database. In previous devices, the stylus contains either an active transmitter with associated battery, or a passive transmitter that includes a coil which is inductively coupled to remote transmitting circuitry. U.S. Pat. No. 5,608,390 is representative of the former genre of pen input devices, and U.S. Pat. No. 5,619,431 is representative of the latter genre of pen input devices.
It will be appreciated that in either type of existing pen input device, a special purpose stylus is required. This not only increases the cost of the devices, but the special purpose stylli are large and/or heavy compared to ordinary writing instruments. Consequently, the special purpose stylli typically are cumbersome. Further, special purpose stylli are not commonly available, making rapid replacement difficult.
A system incorporating electrostatic coupling of signals through a human body as a medium for short range communication, referred to as Personal Area Network (PAN), is discussed in U.S. Pat. No. 5,796,827, owned by the same assignee as the present invention and incorporated herein by reference. As disclosed in the above-mentioned patent, using the principles of PAN a small, lightweight transmitter automatically communicates information to a PAN receiver via an electrostatic field with which the person conducts. Owing to the principles underlying PAN communications, the PAN receivers are small, low power, low latency, low cost receivers that can be easily disposed on a variety of devices. The receivers sense signals that are sent by the transmitter and that are coupled to the person's body.
We have recognized that the principles of PAN electrostatic communication can be used to provide a pen input device that overcomes the above-noted drawbacks of existing pen input systems by permitting the use of an ordinary, off-the-shelf writing instrument. Thus, the present invention recognizes that it is possible to overcome the above-noted problems efficiently and effectively.
SUMMARY OF THE INVENTION
A pen input device is disclosed for sensing the position of a tip of a writing instrument regardless of whether the writing instrument includes electrical components. In other words, the writing instrument can be a conventional writing instrument containing no electrical components, but only ink, pencil graphite, a conductive body, or other conductive element. The device of the present invention includes an array of receiver electrodes, each of which generates a received signal characterized by a signal strength. Also, a transmitter is associated with the array for coupling transmitted electric signals into a person's hand. Specifically, a person can use the writing instrument to write on a substrate positioned on the array, and the transmitter is arranged such that the transmitted signals are coupled to the person's hand when the person writes on the substrate. A processor is connected to the receiver array to receive at least some of the received signals and to determine a position of the tip based at least in part on the signal strengths.
In a preferred embodiment, the transmitter is positioned adjacent the receiver array. In an alternate embodiment, at least one of the receiver electrodes is controlled by the processor through a multiplexer to establish the transmitter.
As disclosed in detail below, contact logic means are associated with the processor for determining when the tip contacts the substrate. Moreover, position logic means determine a position of the tip by determining a ratio of the sum of plural signal strengths multiplied by one or more corresponding electrode coordinates to the sum of plural signal strengths. A handwriting recognition engine is also disclosed that receives the positions from the processor for correlating the positions to alpha-numeric characters.
In another aspect, in a pen input device including an array of electrodes and one or more electrostatic transmitters juxtaposed with the electrodes, a logic device is disclosed which includes position logic means for determining a position of an ordinary writing instrument relative to the array based on signals from the array. Thus, the invention can include a general purpose computer programmed according to the inventive steps herein. The invention can also be embodied as an article of manufacture—a machine component—that is used by a digital processing apparatus and which tangibly embodies a program of instructions that are executable by the digital processing apparatus to undertake the present invention. This invention is realized in a critical machine component that causes a digital processing apparatus to perform the inventive method steps herein.
In still another aspect, a device for outputting a signal representative of the position of a general purpose writing instrument on a paper substrate includes a base positionable under the paper substrate and plural receivers on the base. At least one transmitter is also supported on the base. In accordance with the present invention, the transmitter is 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 propagate 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.
In another aspect, a method is disclosed for generating position signals representative of positions of a writing instrument on a substrate for use of the position signals by a handwriting recognition engine. The method includes providing a writing instrument that contains no electrical components, but that does inherently contain a conductive element, such as a conductive body, conductive ink or pencil graphite. Most inks contained in commonly available pens are naturally conductive due to the presence on ions in the ink solution. Signals are coupled into a hand of a person manipulating the writing instrument against the substrate, and the signals propagate through the hand and writing instrument. Then, signals are received from the writing instrument and based thereon, the position signals are output to the handwriting recognition engine.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:


REFERENCES:
patent: 4281323 (1981-07-01), Burnett et al.
patent: 4293734 (1981-10-01), Pepper, Jr.
patent: 4550221 (1985-10-01), Mabusth
patent: 5343537 (1994-08-01), Bellagarda et al.
patent: 5606346 (1997-02-01), Kai et al.
patent: 5652412 (1997-07-01), Lazzouni et al.
patent: 5747748 (1998-05-01), Zigler
patent: 5764218 (1998-06-01), Della Bona et al.
patent: 5912662 (1999-06-01), Bunn et al.
patent: 5914701 (1999-06-01), Gersheneld et al.
patent: 6124848 (2000-09-01), Ballare et al.
patent: 6211799 (2001-04-01), Post et al.

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