Position detecting apparatus and position pointing device including elapsed time period build up detector
First Claim
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1. A position detecting apparatus comprising:
- a sense section including a plurality of loop coils arranged parallel to each other along a position detecting direction;
electric-wave transmission means for selecting one of said plurality of loop coils in turn to transmit an electric wave;
a position pointing device having a resonance circuit composed of at least a coil and a capacitor; and
time-measuring means for measuring a time period elapsed until a signal developing in said resonance circuit reaches a predetermined level after said electric-wave transmission means starts to transmit said electric wave.
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Abstract
A position detecting apparatus is equipped with a sense section including a plurality of loop coils arranged parallel to each other along a position detecting direction. The plurality of loop coils are selected in turn by an electric-wave transmission unit to transmit an electric wave. The apparatus is further provided with a position pointing section having a resonance circuit composed of at least one coil and a capacitor. A time-measuring device measures a time period elapsed until a signal developing in the resonance circuit reaches a predetermined level after the electric-wave transmission unit starts the electric-wave transmission.
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Citations
7 Claims
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1. A position detecting apparatus comprising:
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a sense section including a plurality of loop coils arranged parallel to each other along a position detecting direction; electric-wave transmission means for selecting one of said plurality of loop coils in turn to transmit an electric wave; a position pointing device having a resonance circuit composed of at least a coil and a capacitor; and time-measuring means for measuring a time period elapsed until a signal developing in said resonance circuit reaches a predetermined level after said electric-wave transmission means starts to transmit said electric wave.
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2. A position detecting apparatus provided with a position pointing device including a resonance circuit composed of at least a coil and a capacitor to detect a coordinate position of said position pointing device by using an electromagnetic induction with a tablet, in which:
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said position pointing device comprising timing information transmission means for detecting a time that a signal developing in said resonance circuit reaches a predetermined level, and for informing the tablet side of the detected time; and said tablet comprising timing information reception means for receiving timing information transmitted from said timing information transmission means to said tablet; and time-measuring means for measuring the time period elapsed until said timing information reception means detects the time after an electric-wave transmission means starts to transmit an electric wave. - View Dependent Claims (3, 4, 5)
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6. A position pointing device comprising:
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a resonance circuit composed of at least a coil and a capacitor; timing detecting means for detecting a time that a signal developing in said resonance circuit reaches a predetermined level; and means for changing a resonance characteristic of said resonance circuit at one of the detected time or the time elapsed after a predetermined time period from the detected time. - View Dependent Claims (7)
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Specification