Digitizer tablet with coarse and fine position determination
First Claim
1. A method for determining at least one coordinate position of a stylus relative to a plurality of substantially parallel electrical conductors comprising the steps of:
- (a) grouping said conductors into two interleaved sets, the conductors of each of said sets being substantially equally spaced from and parallel to each other, to form a series of conductor pairs containing juxtaposed conductors of each of said sets, said first set being divided into subsets each containing a predetermined plurality of juxtaposed conductors of that subset, said second set being divided into subsets each containing a plurality of conductors equal to the number of subsets in said first set, where the ith subset of the second set contains the conductor pair mates to the conductors in the ith position in each subset of the first set, where i=1, 2, 3 . . . m and m equals said predetermined plurality;
(b) sequentially energizing at least one of the subsets of the first set, each subset being energized by a single driver connected to all of the conductors in said subset;
(c) detecting the electric or magnetic field produced at said stylus by said energized conductors to generate a coarse position signal representative of the coarse position of said stylus;
(d) sequentially energizing at least one of the subsets of the second set, each subset being energized by a single driver connected to all of the conductors in said subset;
(e) detecting the electric or magnetic field produced at said stylus by said energized conductors to generate a fine position signal representative of the fine position of said stylus;
(f) combining said first and second signals to determine the position of said stylus.
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Accused Products
Abstract
A grid of electrical conductors for locating the position of a stylus utilizes a reduced number of line drivers. The grid utilizes twice as many conductors as required by conventional grids for a given resolution. The conductors are divided into coarse and fine sets which are interleaved and coextensive in the long dimension of the conductors. The coarse set is divided into subsets which consist of a predetermined number of conductors in close proximity to each other, adjacent coarse conductors being separated by only one fine conductor. The fine set is divided into a number of subsets equal to the number of conductors in each coarse subset. The number of conductors in each fine subset equals the number of coarse subsets. Each of the conductors of the fine subsets is spaced one from the other by a number of fine conductors equal to the number of coarse subsets. The conductors of each subset are connected to each other and to the output of a single driver. The position of the stylus is located by scanning the coarse conductors to determine a coarse position and by scanning the fine conductors to determine a fine position. The coarse and fine positions are combined to produce the location of the stylus.
68 Citations
20 Claims
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1. A method for determining at least one coordinate position of a stylus relative to a plurality of substantially parallel electrical conductors comprising the steps of:
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(a) grouping said conductors into two interleaved sets, the conductors of each of said sets being substantially equally spaced from and parallel to each other, to form a series of conductor pairs containing juxtaposed conductors of each of said sets, said first set being divided into subsets each containing a predetermined plurality of juxtaposed conductors of that subset, said second set being divided into subsets each containing a plurality of conductors equal to the number of subsets in said first set, where the ith subset of the second set contains the conductor pair mates to the conductors in the ith position in each subset of the first set, where i=1, 2, 3 . . . m and m equals said predetermined plurality; (b) sequentially energizing at least one of the subsets of the first set, each subset being energized by a single driver connected to all of the conductors in said subset; (c) detecting the electric or magnetic field produced at said stylus by said energized conductors to generate a coarse position signal representative of the coarse position of said stylus; (d) sequentially energizing at least one of the subsets of the second set, each subset being energized by a single driver connected to all of the conductors in said subset; (e) detecting the electric or magnetic field produced at said stylus by said energized conductors to generate a fine position signal representative of the fine position of said stylus; (f) combining said first and second signals to determine the position of said stylus. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An electographic system for determining at least one coordinate position of a stylus relative to a grid of electrical conductors comprising:
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(a) a first plurality of substantially parallel electrical conductors lying in a plane, each of said conductors being spaced one from the other by a predetermined distance; (b) a second plurality of substantially parallel conductors being interleaved with and substantially coplanar with said first plurality, each of said conductors in said second plurality being spaced one from another by said predetermined distance to form a series of conductor pairs containing juxtaposed conductors of each of said pluralities; (c) a plurality of first driver means, each being connected to a predetermined nunber of juxtaposed ones of said first plurality of conductors; (d) a plurality of second driver means, equal in number to said predetermined number, each being connected to a group of said second plurality of conductors, the conductors in said group being spaced one from the other by a number of conductors in said second plurality equal to the number of said first driver means; means for sequentially activating each of said plurality of first driver means to sequentially energize the conductors connected thereto; (f) means for sequentially activating each of said plurality of second driver means to sequentially energize the conductors connected thereto; (g) means for detecting the electric or magnetic field produced at said stylus by said energized conductors to generate a coarse position signal representative of the coarse position of said stylus when said first plurality of drivers is activated and a fine position signal representative of the fine position of said stylus when said second plurality of drivers is activated; (h) means for combining said coarse and fine signals to generate a signal representative of the position of the stylus. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A grid of electrical conductors for use in an electrographics system for determining at least one coordinate position of a stylus relative to said grid comprising:
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(a) a first plurality of substantially parallel electrical conductors lying in a plane, each of said conductors being spaced one from another by a predetermined distance, the conductors of said first plurality being divided into groups each comprising a predetermined number of juxtaposed conductors, all of the conductors of each group being connected together; (b) a second plurality of substantially parallel conductors being interleaved with, and substantially coplanar with said first plurality, each of said conductors of said second plurality being spaced one from another by said predetermined distance to form a series of conductor pairs containing juxtaposed conductors of each of said pluralities;
the conductors of said second plurality being divided into groups each comprising a predetermined number of conductors, each of the conductors of the group being spaced one from the other by the number of groups of conductors in said first plurality, all of the conductors of each group being connected together;each of the groups of both said first and second pluralities being adapted to be connected to separate drivers whereby the number of drivers required is equal to substantially twice the square root of the number of conductor pairs. - View Dependent Claims (19, 20)
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Specification