US5515040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of self-calibration for a key-type mouse
Assignee: Sejin Electron Inc
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Filing: 1993-09-28
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Granted: 1996-05-07
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Expires: 2013-09-28
Abstract
Abstract This invention relates to methods of self-calibration for computer display cursor positioning devices imbedded within a computer keyboard key (sometimes referred to herein as a "key-type mouse") or other pointing device. A plurality of Force Sensitive Resistor grids ("FSRs") or other pressure sensitive sensors are used to detect relative pressure applied in various directions to a predetermined key of a computer keyboard. An RC circuit is used to indirectly read the values of the FSRs. A predetermined delay period is associated with each sensor followed by a measurement period. The resistance of the FSR is related to the measurement period taken to reach a given voltage value after the predetermined delay period. A positive or negative offset to the predetermined delay period adjusts the time necessary for the RC circuit to reach a predetermined bias voltage value. By breaking the charging time into a delay period and a measurement period the amount of time that the keyboard controller or microprocessor must spend devoted to watching the voltage across the RC circuit for the moment when it reaches V CC is reduced, improving the operation of the keyboard.
Inventors
- 👤 Hyung J. Lee
- 👤 Byung T. Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:04
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/033; G06F3/038; G06F3/0383; G01; G01L; G01L25/00; G06F3/0338
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
244 words
A method of self-calibration for an FSR-type force detecting sensor associated with a typing key in a computer keyboard including the steps of: charging an RC circuit comprising a fixed capacitor and the FSR-type force detecting sensor from a first voltage value to a second voltage value over a period of time comprising a first period and a second period to obtain a present calibration state of the FSR-type force detecting sensor; charging the RC circuit during said first period having a predetermined delay time to increase the first voltage value; charging the RC circuit during said second period having a variable delay time which begins at the end of said predetermined delay time and ends when said RC circuit has reached said second voltage value; generating a numerical value associated with said variable delay time; detecting whether or not the typing key was depressed either just prior or just subsequent to said periods of time and continuing with the self-calibration for the FSR-type force detecting sensor only if the typing key was not so depressed; and if said numerical value is out of range of a predetermined bias value plus or minus a predetermined tolerance value, adjusting the length of said predetermined delay time in response to the magnitude of the difference between said bias value and said numerical value multiplied by a predetermined calibration rate to set a new value for said predetermined delay time which calibrates the FSR-type force detecting sensor.
Claim 2
Independent Claim
244 words
A method of self-calibration for an FSR-type force detecting sensor associated with a typing key in a computer keyboard including the steps of: charging an RC circuit comprising a fixed capacitor and the FSR-type force detecting sensor from a first voltage value to a second voltage value over a period of time comprising a first period and a second period to obtain a present calibration state of the FSR-type force detecting sensor; charging the RC circuit during said first period having a predetermined delay time to increase the first voltage value; charging the RC circuit during said second period having a variable delay time which begins at the end of said predetermined delay time and ends when said RC circuit has reached said second voltage value; generating a numerical value associated with said variable delay time; detecting whether or not the typing key was depressed either just prior or just subsequent to said periods of time and continuing with the self-calibration for the FSR-type force detecting sensor only if the typing key was not so depressed; and if said numerical value is out of range of a predetermined bias value plus or minus a predetermined tolerance value, adjusting the length of said predetermined delay time in response to the magnitude of the difference between said bias value and said numerical value multiplied by a predetermined calibration rate to set a new value for said predetermined delay time which calibrates the FSR-type force detecting sensor.
Claim 3
Independent Claim
241 words
A method of self-calibration for an FSR-type force detecting sensor associated with a pointing device including the steps of: charging an RC circuit comprising a fixed capacitor and the FSR-type force detecting sensor from a first voltage value to a second voltage value over a period of time comprising a first period and a second period to obtain a present calibration state of the FSR-type force detecting sensor; charging the RC circuit during said first period having a predetermined delay time to increase the first voltage value; charging the RC circuit during said second period having a variable delay time which begins at the end of said predetermined delay time and ends when said RC circuit has reached said second voltage value; generating a numerical value associated with said variable delay time; detecting whether or not the pointing device was in use either just prior or just subsequent to said periods of time and continuing with the self-calibration for the FSR-type force detecting sensor only if the pointing device was not in use; and if said numerical value is out of range of a predetermined bias value plus or minus a predetermined tolerance value, adjusting the length of said predetermined delay time in response to the magnitude of the difference between said bias value and said numerical value multiplied by a predetermined calibration rate to set a new value for said predetermined delay time which calibrates the FSR-type force detecting sensor.
Claim 4
Independent Claim
241 words
A method of self-calibration for an FSR-type force detecting sensor associated with a pointing device including the steps of: charging an RC circuit comprising a fixed capacitor and the FSR-type force detecting sensor from a first voltage value to a second voltage value over a period of time comprising a first period and a second period to obtain a present calibration state of the FSR-type force detecting sensor; charging the RC circuit during said first period having a predetermined delay time to increase the first voltage value; charging the RC circuit during said second period having a variable delay time which begins at the end of said predetermined delay time and ends when said RC circuit has reached said second voltage value; generating a numerical value associated with said variable delay time; detecting whether or not the pointing device was in use either just prior or just subsequent to said periods of time and continuing with the self-calibration for the FSR-type force detecting sensor only if the pointing device was not in use; and if said numerical value is out of range of a predetermined bias value plus or minus a predetermined tolerance value, adjusting the length of said predetermined delay time in response to the magnitude of the difference between said bias value and said numerical value multiplied by a predetermined calibration rate to set a new value for said predetermined delay time which calibrates the FSR-type force detecting sensor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-07 | 1999-11-06 | 2000-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-07 | 2003-11-06 | 2004-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-07 | 2007-11-06 | 2008-05-07 | $7700.00 | Window Closed / Lapsed |