Acoustic writing combination, comprising a stylus with an associated writing tablet
First Claim
1. An acoustic writing combination comprising, a writing tablet, a stylus movable about a surface of said tablet and provided with first and second ultrasonic sound sources situated on the stylus at different distances from the stylus tip, at least two microphones located at an edge of the writing tablet for receiving sound signals emitted by said first and second sound sources, and means for operating the sound sources to alternately emit pulsatory ultrasonic sound signals.
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Accused Products
Abstract
An acoustic writing combination, includes a stylus with an associated writing tablet. The stylus is provided with two ultrasonic sound sources which upon contact of the stylus with the writing tablet emit pulse-shaped sound signals which are picked up by at least two microphones which are located at the edge of the writing tablet. The two sound sources are situated at different distances from the stylus tip and are operated to alternately produce ultrasonic signals. Point-shaped or circular sound sources may be employed. The circular sound sources may then comprise piezo-electric ceramic rings.
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Citations
12 Claims
- 1. An acoustic writing combination comprising, a writing tablet, a stylus movable about a surface of said tablet and provided with first and second ultrasonic sound sources situated on the stylus at different distances from the stylus tip, at least two microphones located at an edge of the writing tablet for receiving sound signals emitted by said first and second sound sources, and means for operating the sound sources to alternately emit pulsatory ultrasonic sound signals.
- 6. An acoustic position indicator for determining the coordinate positions of a writing stylus over the surface of a writing tablet comprising, a writing tablet having first and second orthogonally extending edges and a surface data area, a stylus having a tip at one end adapted for movement adjacent to said surface of the tablet and provided with first and second ultrasonic sound sources each situated on the stylus spaced from and at a different distance from the stylus tip, first and second microphones located along said first and second edges of the tablet for receiving sound signals emitted by said first and second sound sources, and means for operating the sound sources to alternately emit pulsatory ultrasonic sound signals whereby the position of the stylus tip over the tablet data surface can be determined independent of the angle of tilt of the stylus.
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9. An acoustic position indicator as claimed in claim 9 wherein a=b so that r=2q-p.
Specification