Pen
AssigneeWacom Co., Ltd.
InventorTakeshi Koike
Life of this patent
Estimating the term…
Abstract
A pen includes: an electrode; a power supply circuit which, in operation, supplies a first voltage; a low voltage integrated circuit (LVIC) coupled to the power supply circuit, wherein the LVIC, in operation, outputs a transmission signal at the first voltage; a high voltage integrated circuit (HVIC) including a level shifter which, in operation, outputs the transmission signal at a second voltage that is higher than the first voltage; an inter-IC wire which, in operation, supplies the transmission signal having the first voltage from the LVIC to the HVIC; an electrode wire which, in operation, supplies the transmission signal having the second voltage from the HVIC to the electrode; and a step-up circuit coupled to the power supply circuit, wherein the HVIC in operation, supplies the second voltage to the level shifter.
Claims15
A pen comprising:
- an electrode;
- a power supply circuit which, in operation, supplies a first voltage;
- a first integrated circuit coupled to the power supply circuit, wherein the first integrated circuit, in operation, outputs a transmission signal at the first voltage;
- a second integrated circuit including a level shifter which, in operation, outputs the transmission signal at a second voltage that is higher than the first voltage;
- an inter-integrated circuit wire which, in operation, supplies the transmission signal having the first voltage from the first integrated circuit to the second integrated circuit;
- an electrode wire which, in operation, supplies the transmission signal having the second voltage from the second integrated circuit to the electrode;
- and
- a step-up circuit coupled to the power supply circuit, wherein the step-up circuit, in operation, supplies the second voltage to the level shifter,
- wherein the second integrated circuit further includes:
- an Rx terminal which, in operation, outputs a reception signal received by the electrode;
- a Tx terminal which, in operation, receives the transmission signal;
- and
- a switch which, in operation, switches a destination to which the electrode wire is coupled between the Rx terminal and the Tx terminal,
- wherein the high voltage switch includes an Rx guard circuit which, in operation, prevents the transmission signal from flowing into the Rx terminal,
- wherein the Rx guard circuit, in operation, sets a potential of a wire coupled to the Rx terminal to a predetermined potential.
Dependencies are inferred from the claim text.