A knock-type electronic pen including a tubular casing, a first position indicator such as a written input indicator, a second position indicator such as an eraser, a knock cam mechanism, and a holding mechanism. The knock cam mechanism includes a knock portion including a part protruding outward from an opening at a second end of the tubular casing, and is configured to cause a tip of the first position indicator to protrude from, or be housed within, an opening at a first end of the tubular casing. The holding mechanism, in the state in which the tip of the first position indicator protrudes from the opening at the first end, returns the knock portion pushed into the tubular casing to a state of protruding from the opening at the second end such that at least a tip of the second position indicator protrudes outward.

An electronic pen includes a cylindrical housing including an opening on one end of the housing in an axial direction of the housing, a core body attached inside of the housing such that an end of the core body protrudes from the opening on the one end of the housing, and a signal generation circuit which, in operation, generates a signal that is transmitted from the core body. The core body includes a core rod that is conductive and a protection member. The core rod includes a front portion that protrudes from the opening on the one end of the housing, a back portion, and an intermediate portion between the front portion and the back portion. The intermediate portion has a tapered shape narrowing from the front portion toward the back portion. The core rod receives the signal from the signal generation circuit. The protection member covers a side surface of the intermediate portion of the core rod.

An active stylus, including a housing, a pen core, a first circuit board, and a touch sensing module, is provided. The pen core, the first circuit board, and the touch sensing module are disposed in the housing. The touch sensing module includes a touch sensing element and a second circuit board. The touch sensing element is disposed on and electrically connected to the second circuit board. The second circuit board is electrically connected to the first circuit board and is abutted to a lateral surface of the first circuit board. The second circuit board is perpendicular to the first circuit board. The pen core is abutted to the touch sensing element.

An input device such as a stylus for providing input to a touch-sensitive surface with reduced sensitivity to leakage current variations over temperature is disclosed. A passive stylus may include one or more diodes in parallel with one or more bleed resistors. The non-linear load of the diode and resistor network can be operative to provide a stylus electric field in response to a stimulation signal from an electronic device that can be capacitively coupled to, and sensed by, the electronic device. The signal sensed by the electronic device can be a function of the total leakage current, which can vary greatly as a function of temperature and frequency. In order to improve performance, the diode and resistor network, including the bleed resistor(s) and diodes within that network, can be selected and/or designed to provide a reduced variation in the leakage current and more accurate stylus detection.

Provided is a processing device for controlling input by an electronic pen. The electronic pen includes a side switch disposed on a side surface of the electronic pen and a device that obtains contact information indicating whether or not a pen tip of the electronic pen is in contact with a panel. The processing device includes a processor and a memory storing instructions which, when executed by the processor, cause the processing device to: obtain switch information indicating a depression state of the side switch, determine whether or not the pen tip is in contact with the panel based on the contact information, output the switch information when the pen tip is not determined to be in contact with the panel, and disable a value of the switch information when the pen tip is determined to be in contact with the panel.

According to certain embodiments, a foldable electronic device comprises: a flexible display; a first housing in which a first region of the flexible display is positioned; a second housing in which a second region of the flexible display is positioned; a hinge structure interposed between the first housing and the second housing and forming a folding axis; a sensor panel interposed between the flexible display and each of the first housing and the second housing, the sensor panel configured to identify input information of a stylus pen, and including a plurality of first vertical channels interposed the first housing and the first region of the flexible display and a plurality of second vertical channels disposed between the second housing and the second region of the flexible display; and a processor configured to control the sensor panel, wherein the processor is configured to: detect whether the foldable electronic device is folded; when the foldable electronic device is folded, transmit a deviation detection signal to at least one of the plurality of first vertical channels and receive the deviation detection signal through at least one of the plurality of second vertical channels; and correct the input information of the stylus pen using a compensation value corresponding to the received deviation detection signal.

In one embodiment, a method performed by an active stylus includes wirelessly receiving a synchronization signal from a touch controller. The method also includes determining a synchronization parameter of the synchronization signal, the synchronization parameter including an integer part and a fractional part, the integer part representing a positive integer multiple of an active-stylus clock period and the fractional part representing a fractional portion of the active-stylus clock period. The method further includes wirelessly transmitting information for reception by the touch controller, where the information includes a series of data portions, a successive data portion in the series being separated from a preceding data portion by a time interval. The time interval is based at least in part on the active-stylus clock period, the integer part of the synchronization parameter, and an updated fractional error value.

Embodiments described herein is able to provide a touch display device, an active pen, a touch system, a touch circuit, and a pen recognition method capable of efficiently providing a display function, a touch-sensing function, and a pen-touch-sensing function.

A position indicator includes a housing and a first electrode and a second electrode disposed on a side of one end of the housing and a signal generating circuit which, in operation, generates a signal supplied to at least the first electrode. A capacitive interaction between the first electrode and a sensor of a position detecting device formed through supply of the signal to the first electrode. The second electrode surrounds the first electrode and the first electrode is partially exposed from the second electrode in an axial direction of the housing. The position indicator includes a signal transmission control circuit that is coupled to the second electrode and that, in operation, controls the second electrode to change the capacitive interaction between the first electrode and the sensor formed through supply of the signal from the signal generating circuit to the first electrode.

A computing device including a wireless communication device, an electrostatic interface, and a processor. The processor may be configured to, via the electrostatic interface, detect a peripheral device proximate the surface. In response to detecting the peripheral device, the processor may be further configured to establish wireless pairing with the peripheral device at least in part by performing an identifier exchange via the electrostatic interface. Subsequently to performing the identifier exchange, establishing wireless pairing may further include generating a temporary key and transmitting the temporary key to the peripheral device via the electrostatic interface. Subsequently to transmitting the temporary key, establishing wireless pairing may further include receiving a first wireless pairing signal from the peripheral device via the wireless communication device. Subsequently to receiving the first wireless pairing signal, establishing wireless pairing may further include transmitting a second wireless pairing signal to the peripheral device via the wireless communication device.