Touch panel, and touch-type input apparatus and control method therefor
First Claim
Patent Images
1. A touch panel comprising:
- a piezoelectric sheet of poly-L-lactic acid having a stretching axis oriented in a predetermined direction and having first and second opposed surfaces;
a plurality of first electrodes distributed discretely in plural positions on the first surface of said piezoelectric sheet; and
a plurality of second electrodes distributed discretely in plural positions on the second surface of said piezoelectric sheet and respectively opposing the plurality of first electrodes so as to form a plurality of sets of opposed electrodes.
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Abstract
A touch panel capable of detecting a pen and a finger, capable of corresponding to multi-touch, capable of detecting pressing force, and capable of reducing the use amount of a transparent electrode as much as possible. The touch panel has a piezoelectric sheet of poly-L-lactic acid having a predetermined stretching axial direction, electrodes that are opposed to each other and formed on the piezoelectric sheet do not cover the entire surface of the piezoelectric sheet and are formed so that they are discretely distributed in plural positions. The piezoelectric sheet is brought into the condition that tension is imparted in directions not coincident with the stretching axial direction.
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Citations
20 Claims
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1. A touch panel comprising:
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a piezoelectric sheet of poly-L-lactic acid having a stretching axis oriented in a predetermined direction and having first and second opposed surfaces; a plurality of first electrodes distributed discretely in plural positions on the first surface of said piezoelectric sheet; and a plurality of second electrodes distributed discretely in plural positions on the second surface of said piezoelectric sheet and respectively opposing the plurality of first electrodes so as to form a plurality of sets of opposed electrodes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for controlling a touch-type input apparatus comprising a piezoelectric sheet of poly-L-lactic acid having a stretching axis oriented in a predetermined direction and having first and second opposed surfaces, a plurality of first electrodes distributed discretely in plural positions on the first surface of said piezoelectric sheet, and a plurality of second electrodes distributed discretely in plural positions on the second surface of said piezoelectric sheet and respectively opposing the plurality of first electrodes so as to form a plurality of sets of opposed electrodes, and a processor configured to calculate a pressing position where a pressing operation is made and a pressing force of the pressing operation by comparing voltages generated in each set of said plurality of sets of opposed electrodes when the pressing operation is made on said touch panel, the method comprising:
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setting grid matrix coordinates on an operation surface of said touch panel; measuring said voltages generated in each set of said plurality of sets of opposed electrodes in association with the pressing operation by predetermined weight application on each grid point of said grid matrix coordinates; and storing said voltages in a memory as base voltages in said respective grid points; determining an actual measured voltage generated in each set of said plurality of sets of opposed electrodes in association with an actual pressing operation made on said operation surface of said touch panel; calculating a ratio of said actual measured voltage relative to said base voltage for each set of said plurality of sets of opposed electrodes for each of said grid points; determining an average of said ratio for each set of said plurality of sets of opposed electrodes for each of said grid points; determining a standard deviation of said ratio for each of said grid points; ranking said grid points in ascending order of said standard deviation; selecting predetermined top n grid points in said ranked grid points; determining a coordinate (X, Y) of an actual pressing position at which the actual pressing operation is made as
X=Σ
(Xk/Sk)/Σ
(1/Sk),Y=Σ
(Yk/Sk)/Σ
(1/Sk)when the coordinate of said selected grid point is represented by (Xk, Yk) (k=1, 2, . . . , n), and said standard deviation is represented by Sk (k=1, 2, . . . , n); and determining an actual pressing force of the actual pressing operation by multiplying said applied weight by said average of said ratio of the top grid point in the ranking. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification