Coordinate input device used for inputting characters and drawings into a personal computer/word processor
First Claim
1. A coordinate input device, comprising:
- a panel having a coordinate input area;
indicating means for indicating a point on said panel;
coordinate sensing means for sending coordinates of the point indicated by said indicating means;
switch means disposed in said indicating means and switched;
when provided with an operational power supply, depending on whether or not said indicating means is pressed against said panel;
switch condition sensing means for providing said switch means with said operational power supply, and for sensing whether said switch means is in an `ON` state or in an `OFF` state; and
switch control means, connected to said switch condition sensing means, for controlling said switch condition sensing means, so that said switch condition sensing means senses whether said switch means is in the `ON` state or in the `OFF` state, by providing the operational power supply to said switch means only during the switch sensing period that is irrelevant to the accuracy in sensing by said coordinate sensing means.
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Accused Products
Abstract
A coordinate input device includes (1) a pen switch sensing circuit for providing a power supply to a pen switch in a position sensing pen, and for sensing that the pen switch is turned on and off and (2) a pen switch control circuit for controlling a timing of the power supply. The power supply is provided to the pen switch only when coordinate sensing operations are not affected. The power supply is stopped in order to avoid a voltage change happening to the pen switch when the coordinate sensing operation is affected. Therefore, the pen switch is neither turned on nor turned off during a coordinate sensing period. Consequently, it is possible to avoid a wrong sensing of a coordinate indicated with the position sensing pen.
50 Citations
15 Claims
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1. A coordinate input device, comprising:
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a panel having a coordinate input area; indicating means for indicating a point on said panel; coordinate sensing means for sending coordinates of the point indicated by said indicating means; switch means disposed in said indicating means and switched;
when provided with an operational power supply, depending on whether or not said indicating means is pressed against said panel;switch condition sensing means for providing said switch means with said operational power supply, and for sensing whether said switch means is in an `ON` state or in an `OFF` state; and switch control means, connected to said switch condition sensing means, for controlling said switch condition sensing means, so that said switch condition sensing means senses whether said switch means is in the `ON` state or in the `OFF` state, by providing the operational power supply to said switch means only during the switch sensing period that is irrelevant to the accuracy in sensing by said coordinate sensing means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15)
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8. A coordinate input device, comprising:
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a panel having a coordinate input area; indicating means for indicating a point on said panel; coordinate sensing means for sensing coordinates of the point indicated by said indicating means; switch means, disposed in said indicating means and which is switched, when provided with an operational power supply, depending on whether or not said indicating means is pressed against said panel; switch condition sensing means for providing said switch means with said operational power supply, and for sensing whether said switch means is in an `ON` state or in an `OFF` state; and switch control means, connected to said coordinate sensing means and said switch condition sensing means, for controlling a coordinate sensing period during which said coordinate sensing means senses the coordinates, and for controlling said switch condition sensing means so that said switch condition sensing means senses whether said switch means is in the `ON` state or in the `OFF` state, by providing the operational power supply to said switch means only during the switch sensing period that is irrelevant to the accuracy in sensing by said coordinate sensing means. - View Dependent Claims (9)
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Specification