# US 10,768,723 B2 · Electronic pen and electronic pen main body > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,768,723 B2 - Document ID: US10768723B2 - Status: Granted - Kind: B2 - Application number: 15/697,070 - Filed: 2017-09-06 - Published: 2018-01-11 - Granted: 2020-09-08 - Earliest claimed: 2015-03-31 - Assignees: Wacom Co., Ltd. - Applicants: Wacom Co., Ltd. - Inventors: Yuji Katsurahira; Toru Eguchi - Web page: https://patentgrep.com/patent/US10768723B2 ## CPC - G06F 3/0446: {using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes} - G06F 3/03: Arrangements for converting the position or the displacement of a member into a coded form - G06F 3/03545: {Pens or stylus} - G06F 3/0383: {Signal control means within the pointing device} - G06F 3/041: Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means - G06F 3/044: by capacitive means - G06F 3/0442: {using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser} - G06F 3/046: by electromagnetic means - G06F 2203/04105: Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position - G06F 2203/04107: Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An electronic pen includes a magnetic core that has a through-hole and around which a coil is wound in a direction along this through-hole, a core body that is inserted in the through-hole of this magnetic core and has electrical conductivity, a capacitor that forms a resonant circuit with the coil, a signal generation circuit that generates a signal that enables a position of the electronic pen to be detected, which is transmitted through the core body, an electricity storage device, and a charge circuit that charges the electricity storage device by an induced current generated in the coil according to an external magnetic field. While the resonant circuit operates, the signal generated by the signal generation circuit is concurrently transmitted through the core body. ## Claims ### Claim 1 An electronic pen comprising: a magnetic core that has a through-hole and around which a coil is wound in a direction along the through-hole; a core body that is inserted in the through-hole of the magnetic core and has electrical conductivity; a capacitor that forms a resonant circuit with the coil; a signal generation circuit which, in operation, generates a signal that enables a position of the electronic pen to be detected, the signal being transmitted through the core body; a switch electrically coupled between the signal generation circuit and the core body; an electricity storage device; and a charge circuit which, in operation, charges the electricity storage device by an induced current generated in the coil according to an external magnetic field, wherein, while the resonant circuit operates, the signal generated by the signal generation circuit is concurrently transmitted through the core body, wherein, in a state in which the electronic pen is used with a first sensor of an electromagnetic induction system, the switch is in a state in which the signal does not flow from the signal generation circuit to the core body, and the electronic pen, in operation, receives electromagnetic energy from the first sensor and returns the received electromagnetic energy to the first sensor by the resonant circuit, charges the electricity storage device by the induced current generated in the coil, and transmits a signal that indicates a position of the electronic pen from the resonance circuit to the first sensor of the electromagnetic induction system, and wherein, in a state in which the electronic pen is used with a second sensor of a capacitive coupling system, the switch is in a state in which the signal flows from the signal generation circuit to the core body, and the electronic pen, in operation, transmits the signal generated by the signal generation circuit to the second sensor through the core body. ### Claim 2 (depends on 1) The electronic pen according to claim 1, wherein, in the state in which the electronic pen is used with the sensor of the capacitive coupling system, the electronic pen, in operation, charges the electricity storage device by the induced current generated in the coil if the external magnetic field is received by the electronic pen. ### Claim 3 (depends on 1) The electronic pen according to claim 1, wherein the electronic pen, in operation, charges the electricity storage device by the induced current generated in the coil if the external magnetic field is received by the electronic pen. ### Claim 4 (depends on 1) The electronic pen according to claim 1, further comprising: a writing pressure detection circuit, wherein one end of the core body inserted in the through-hole of the magnetic core is protruded from the through-hole of the magnetic core and is used as a pen tip, and an end of the core body opposite to the one end that is protruded from the through-hole of the magnetic core is coupled to the writing pressure detection circuit. ### Claim 5 (depends on 4) The electronic pen according to claim 4, wherein the core body is coupled to the writing pressure detection circuit insertably and removably and is replaceable. ### Claim 6 (depends on 4) The electronic pen according to claim 4, wherein the writing pressure detection circuit, in operation, varies a resonance frequency of the resonant circuit according to an applied writing pressure, and is connected to the resonant circuit. ### Claim 7 (depends on 6) The electronic pen according to claim 6, wherein the signal generation circuit includes an oscillation circuit, and the resonant circuit, in operation, varies a frequency of an oscillation signal generated by the oscillation circuit. ### Claim 8 (depends on 1) The electronic pen according to claim 1, further comprising: a switch which, in operation, is switched between a state in which the capacitor is connected to the coil and a state in which the capacitor is disconnected from the coil. ### Claim 9 (depends on 1) The electronic pen according to claim 1, further comprising: a switch which, in operation, is switched between a state in which the electricity storage device is charged by the induced current generated in the coil according to the external magnetic field and a state in which a charge to the electricity storage device is stopped. ### Claim 10 (depends on 1) The electronic pen according to claim 1, further comprising: a determination circuit which, in operation, determines whether the electronic pen is in a used state or in an unused state based on an operation state of an operation part that is operable by a user, wherein the switch, in operation, is switched to the state in which the signal does not flow from the signal generation circuit to the core body when the determination circuit determines that the electronic pen is in the unused state. ### Claim 11 (depends on 1) The electronic pen according to claim 1, further comprising: a determination circuit which, in operation, determines whether the electronic pen is in a used state or in an unused state based on an operation state of an operation part that is operable by a user; and a second switch which, in operation, is switched between a state in which the capacitor is connected to the coil and a state in which the capacitor is disconnected from the coil, wherein the switch, in operation, is switched to the state in which the signal does not flow from the signal generation circuit to the core body and the second switch is switched to the state in which the capacitor is disconnected from the coil when the determining circuit determines that the electronic pen is in the unused state. ### Claim 12 An electronic pen comprising: a tubular chassis in which an opening is made on one end in an axial center direction serving as a pen tip side and another end is closed; and an electronic pen main body housed in the tubular chassis, wherein the electronic pen main body includes: a magnetic core that has a through-hole and around which a coil is wound in a direction along the through-hole, a core body that is inserted in the through-hole of the magnetic core and has electrical conductivity, a capacitor that forms a resonant circuit with the coil, a signal generation circuit which, in operation, generates a signal that enables a position of the electronic pen main body to be detected, the signal being transmitted through the core body, a switch electrically coupled between the signal generation circuit and the core body; an electricity storage device, and a charge circuit which, in operation, charges the electricity storage device by an induced current generated in the coil according to an external magnetic field, wherein, while the resonant circuit operates, the signal generated by the signal generation circuit is concurrently transmitted through the core body, wherein, in a state in which the electronic pen is used with a first sensor of an electromagnetic induction system, the switch is in a state in which the signal does not flow from the signal generation circuit to the core body, and the electronic pen, in operation, receives electromagnetic energy from the first sensor and returns the received electromagnetic energy to the first sensor by the resonant circuit, charges the electricity storage device by the induced current generated in the coil, and transmits a signal that indicates a position of the electronic pen from the resonance circuit to the first sensor of the electromagnetic induction system, and wherein, in a state in which the electronic pen is used with a second sensor of a capacitive coupling system, the switch is in a state in which the signal flows from the signal generation circuit to the core body, and the electronic pen, in operation, transmits the signal generated by the signal generation circuit to the second sensor through the core body. ### Claim 13 (depends on 12) The electronic pen according to claim 12, further comprising: a knock mechanism of a knock-type ballpoint pen coupled to the electronic pen main body in the chassis. ### Claim 14 (depends on 13) The electronic pen according to claim 13, further comprising: a detection circuit which, in operation, detects whether the electronic pen is set to a used state in which part of the core body protrudes externally from the chassis through the opening by operation of the knock mechanism or is set to an unused state in which all of the core body is located inside the chassis, and a second switch which, in operation, is switched between a state in which the capacitor is connected to the coil and a state in which the capacitor is disconnected from the coil, wherein, in operation, the switch is switched to the state in which the signal does not flow from the signal generation circuit to the core body and the second switch is switched to the state in which the capacitor is disconnected from the coil when the detection circuit detects that the electronic pen is set to the unused state in which all of the core body is located inside the chassis. ### Claim 15 An electronic pen main body having at least a pen tip housed in a tubular chassis of an electronic pen, the pen tip being protrudable from an opening on one side of the tubular chassis in an axial center direction, the electronic pen main body comprising: a magnetic core that has a through-hole and around which a coil is wound in a direction along the through-hole; a core body that is inserted in the through-hole of the magnetic core and has electrical conductivity; a capacitor that forms a resonant circuit with the coil; a signal generation circuit which, in operation, generates a signal that enables a position of the electronic pen main body to be detected, the signal being transmitted through the core body; a switch electrically coupled between the signal generation circuit and the core body; an electricity storage device; and a charge circuit which, in operation, charges the electricity storage device by an induced current generated in the coil according to an external magnetic field, wherein, while the resonant circuit operates, the signal generated by the signal generation circuit is concurrently transmitted through the core body, wherein, in a state in which the electronic pen is used with a first sensor of an electromagnetic induction system, the switch is in a state in which the signal does not flow from the signal generation circuit to the core body, and the electronic pen, in operation, receives electromagnetic energy from the first sensor and returns the received electromagnetic energy to the first sensor by the resonant circuit, charges the electricity storage device by the induced current generated in the coil, and transmits a signal that indicates a position of the electronic pen from the resonance circuit to the first sensor of the electromagnetic induction system, and wherein, in a state in which the electronic pen is used with a second sensor of a capacitive coupling system, the switch is in a state in which the signal flows from the signal generation circuit to the core body, and the electronic pen main body, in operation, transmits the signal generated by the signal generation circuit to the second sensor through the core body.