Electromagnetic input device and coil detection circuit thereof
AssigneeWaltop International Corporation
InventorCHIA-JUI YEH
Life of this patent
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Abstract
A coil detection circuit thereof for an electromagnetic input device including a plurality of first loop coils and second loop coils includes a first detection unit, a second detection unit and a selection unit. When the selection unit selects one the first loop coils to emit an electromagnetic signal for each one of the second loop coils, each one of the second loop coils forms a second closed loop for receiving the electromagnetic signal, and the second detection unit detects a second signal. When one of the second loop coils forms an open circuit or short circuit, the second detection unit detects an open-circuit signal or a short-circuit signal.
Claims12
A coil detection circuit, adapted to the electromagnetic input device comprising a plurality of first loop coils, a plurality of second loop coils, a first multiplex unit and a second multiplex unit, the first multiplex unit being coupled to the first loop coils, the second multiplex unit being coupled to the second loop coils, and the coil detection circuit comprising:
- a selection unit, coupled to the first multiplex unit and the second multiplex unit;
- a first detection unit, coupled to the first multiplex unit;
- and
- a second detection unit, coupled to the second multiplex unit;
- when the selection unit selects one of the first loop coils to emit a first electromagnetic signal to each one of the second loop coils, each one of the second loop coils forms a second closed loop for receiving the first electromagnetic signal, and the second detection unit detects a second signal;
- when one of the second loop coils does not form the second closed loop, the second detection unit detects an open-circuit signal;
- when one of the second loop coils forms a short circuit, the second detection unit detects a short-circuit signal;
- when the selection unit selects one of the second loop coils to emit a second electromagnetic signal to each one of the first loop coils, each one of the first loop coils forms a first closed loop for receiving the second electromagnetic signal, and the first detection unit detects a first signal;
- when one of the first loop coils does not form the first closed loop, the first detection unit detects the open-circuit signal;
- when one of the first loop coils forms a short circuit, the first detection unit detects the short-circuit signal.
An electromagnetic input device, comprising:
- a plurality of first loop coils;
- a plurality of second loop coils, the second loop coils and the first loop coils are in staggered arrangement;
- a first multiplex unit coupled to the first loop coils;
- a second multiplex unit, coupled to the second loop coils,
- a selection unit, coupled to the first multiplex unit and the second multiplex unit;
- a control unit, coupled to the selection unit;
- a first transmission switch unit, coupled to the first multiplex unit and the control unit;
- a first detection unit, coupled to the first transmission switch unit and the control unit, for detecting an electric property variation value of a first closed loop of each one of the first loop coils to identify a short circuit or an open circuit state;
- a second transmission switch unit, coupled to the second multiplex unit and the control unit;
- and
- a second detection unit, coupled to the second transmission switch unit and the control unit, for detecting an electric property variation value of a second closed loop of each one of the second loop coils to identify the short circuit or the open circuit state;
- when the selection unit selects one the first loop coils to emit a first electromagnetic signal to each one of the second loop coils, each one of the second loop coils forms the second closed loop for receiving the first electromagnetic signal and then the second detection unit detects a second signal;
- when one of the second loop coils does not form the second closed loop, the second detection unit detects an open-circuit signal;
- when one of the second loop coils forms a short circuit, the second detection unit detects a short-circuit signal;
- when the selection unit selects one of the second loop coils to emit a second electromagnetic signal to each one of the first loop coils, each one of the first loop coils forms the first closed loop for receiving the second electromagnetic signal and then the first detection unit detects a first signal;
- when one of the first loop coils does not form the first closed loop, the first detection unit detects the open-circuit signal;
- when one of the first loop coils forms the short circuit, the first detection unit detects the short-circuit signal.
Dependencies are inferred from the claim text.