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US 10,095,326 B2Granted
Method for continuously detecting a state of contact or non-contact between a tip of an instrument and a writing medium having a variable thickness, and related system
AssigneeIskn
InventorsRabeb Aloui, Tristan Hautson
Life of this patent
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Abstract
A method is provided for continuously detecting a state of contact or non-contact between a tip of an instrument and a writing surface of a writing medium of variable thickness positioned on a bearing surface of a tracking device.
Claims8
A method for continuously detecting a state of contact or non-contact between a tip of an instrument and a writing surface of a writing medium of variable thickness positioned on a bearing surface of a tracking device;
- said method comprising the steps consisting in:
- determining, at a current instant in time, the position of the tip of the instrument with respect to the bearing surface;
- determining, at the current instant in time, a distance between the bearing surface and the tip, on the basis of said position of the tip;
- updating the current value of a minimum distance between the bearing surface and the writing surface with the distance between the bearing surface and the tip at the current instant in time, when said distance is shorter than the current value of the minimum distance;
- determining, at the current instant in time, a movement parameter of the tip, representative of a ratio of the movement tangential to the writing surface to the movement normal to the writing surface between the current instant in time and the preceding instant in time;
- determining, at the current instant in time, an amplitude parameter representative of the amplitude of the movement of the tip between the current instant in time and the preceding instant in time;
- determining a state of contact between the tip and the writing surface, at the current instant in time, when:
- the distance is shorter than or equal to the sum of a minimum current distance and a tolerance, said tolerance being representative of an uncertainty regarding the distance between the writing surface and the bearing surface;
- the movement parameter is representative of a movement that is essentially tangential to the writing surface, i.e. its value is lower than or equal to a tangential movement threshold;
- and
- a norm of the amplitude parameter is higher than or equal to a minimum amplitude threshold;
- otherwise determining a state of non-contact between the tip and the writing surface, at the current instant in time.
9 more elements
A system for continuously detecting a state of contact or non-contact between a tip of an instrument and a writing surface of a writing medium of variable thickness positioned on a bearing surface of a tracking device;
- said system comprising a computer capable of:
- determining, at a current instant in time, the position of the tip of the instrument with respect to the bearing surface;
- determining, at the current instant in time , a distance between the bearing surface and the tip, on the basis of said position of the tip;
- updating the current value of a minimum distance between the bearing surface and the writing surface with the distance between the bearing surface and the tip at the current instant in time, when said distance is shorter than the current value of the minimum distance;
- determining, at the current instant in time, a movement parameter of the tip, representative of a ratio of the movement tangential to the writing surface to the movement normal to the writing surface between the current instant in time and the preceding instant in time;
- determining, at the current instant in time, an amplitude parameter representative of the amplitude of the movement of the tip between the current instant in time and the preceding instant in time;
- determining a state of contact between the tip and the writing surface, at the current instant in time, when:
- the distance is shorter than or equal to the sum of a minimum current distance and a tolerance, said tolerance being representative of an uncertainty regarding the distance between the writing surface and the bearing surface;
- the movement parameter is representative of a movement that is essentially tangential to the writing surface, i.e. its value is lower than or equal to a tangential movement threshold;
- and
- a norm of the amplitude parameter is higher than or equal to a minimum amplitude threshold;
- otherwise determining a state of non-contact between the tip and the writing surface, at the current instant in time.
9 more elements
Dependencies are inferred from the claim text.