Capacitive sensor-based input device
First Claim
1. An input device comprising:
- an input mechanism to detect a variation of capacitances at a plurality of detection points; and
a control unit to calculate detection outputs from the plurality of detection points to determine a peak position in the variation of capacitances and to generate coordinate data from the peak position, wherein the peak position is determined using a maximum value detected at any one of the detection points, a previous value detected at at least one previous point to the detection point at which the maximum value is obtained, and a following value detected at at least one point which follows the detection point at which the maximum value is obtained, and said control unit outputs the coordinate data only when a variation of the maximum value varies from the previous value and the following value is greater than a first threshold value.
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Accused Products
Abstract
A capacitive sensor-based input device for coordinate data input includes an input unit that detects the variation of capacitances at a plurality of detection points, and a control unit that calculates detection outputs from the plurality of detection points to detect the peak position in the variation of capacitances to generate coordinate data. When the maximum value detected at any one of the detection points transitions relative to the previous and following values by less than a first threshold value, the coordinate data is cancelled. When it varies by more than the first threshold value but less than a second threshold value, a corrected value to generate the coordinate data is decreased, thereby suppressing an oscillation of a cursor on a screen while a finger rests on the input device.
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Citations
28 Claims
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1. An input device comprising:
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an input mechanism to detect a variation of capacitances at a plurality of detection points; and
a control unit to calculate detection outputs from the plurality of detection points to determine a peak position in the variation of capacitances and to generate coordinate data from the peak position, wherein the peak position is determined using a maximum value detected at any one of the detection points, a previous value detected at at least one previous point to the detection point at which the maximum value is obtained, and a following value detected at at least one point which follows the detection point at which the maximum value is obtained, and said control unit outputs the coordinate data only when a variation of the maximum value varies from the previous value and the following value is greater than a first threshold value. - View Dependent Claims (6, 7)
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2. An input device comprising:
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an input mechanism to detect the variation of capacitances at a plurality of detection points; and
a control unit to calculate detection outputs from the plurality of detection points to determine a peak position P in the variation of capacitances and to generate coordinate data at a fixed time interval from the peak position, wherein said control unit performs a first correction between the peak position, determined at a given point, and coordinate data M obtained at a previous point such that a corrected value is added to the coordinate data, the corrected value being smaller than the peak position minus the coordinate data, and said control unit;
performs the calculation using a maximum value detected at any one of the detection points, a previous value detected at at least one previous point to the detection point at which the maximum value is generated, and a following value detected at at least one point which follows the detection point at which the maximum value is generated, the first correction used when a variation of the maximum value from the previous value and the following value is less than a threshold value being smaller than when the variation is not less than the threshold value. - View Dependent Claims (3, 4, 5, 8, 9)
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10. An input device comprising:
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an input mechanism to detect a variation of capacitances at a plurality of detection points; and
a control unit to calculate detection outputs from the plurality of detection points to determine a peak position using the variation of capacitances and to generate coordinate data from the peak position, the control unit;
determining the peak position at a plurality of times that are each separated by a constant time interval and by using a maximum value detected at any one of the detection points, a previous value detected at a first point adjacent to the detection point at which the maximum value is obtained, and a following value detected at a second point adjacent to the detection point at which the maximum value is obtained, transmitting the coordinate data only when a combination of a difference between the maximum value and the previous value plus a difference between the maximum value and the following value is greater than a first threshold value, and performing a first correction to a first peak position determined at;
one time in conjunction with a second peak position determined at a succeeding time to generate coordinate data at the succeeding time, coordinate data being generated such that a first corrected value that is smaller than the second peak position minus the first peak position is added to the first peak position, the first correction being applied only when the combination is less than a second threshold value. - View Dependent Claims (11, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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12. An input device comprising:
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an input mechanism to detect a variation of capacitances at a plurality of detection points; and
a control unit to calculate detection outputs from the plurality of detection points to determine a peak position using the variation of capacitances and to generate coordinate data from the peak position, the control unit;
determining the peak position at a plurality of times that are each separated by a constant time interval and by using a maximum value detected at any one of the detection points, a previous value detected at a first point adjacent to the detection point at which the maximum value is obtained, and a following value detected at a second point adjacent to the detection point at which the maximum value is obtained, transmitting the coordinate data only when a combination of a difference between the maximum value and the previous value plus a difference between the maximum value and the following value is greater than a first threshold value, and performing a first correction and a second correction to a first peak position determined at one time in conjunction with a second peak position determined at a succeeding time to generate coordinate data at the succeeding time, coordinate data being generated such that a first corrected value and a second corrected value that are smaller than the second peak position minus the first peak position are added to the first peak position, the second corrected value dependent on whether a displacement of the peak position is within a predetermined distance.
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19. A method of decreasing oscillations of a cursor on a screen, the method comprising:
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acquiring data at constant times from variations in capacitance at different locations on an input device;
determining a maximum data value at a particular location, previous and following values detected at adjacent locations to the location of the maximum value;
calculating a present peak position of the data;
calculating a combination of a difference between the maximum value and the previous value plus a difference between the maximum value and the following value;
determining whether the combination is greater than a first threshold value;
correcting each present peak position by adding a difference between the present peak position and a function of a previously determined peak position to the previously determined peak position only when the combination is greater than the first threshold value;
determining whether the present peak position is within a predetermined distance from the previous peak position and correcting the present peak position a second time using a correction value dependent thereon;
generating coordinate data from each corrected peak position; and
transmitting the coordinate data.
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Specification