Atmel Corporation

Wacom Co., Ltd.

Eivind Holsen

Vemund Kval Bakken

Andreas Onsum

Kishore Sundara-Rajan

Trond Jarle Pedersen

James D Lyle

Arne Aas

Odd Magne Reitan

Odd Jostein Svendsli

Sharooz Shahparnia

Shahrooz Shahparnia

Lloyd Clark

In one embodiment, a stylus includes one or more electrodes included in a tip, and a computer-readable non-transitory storage medium embodying logic that is configured when executed to receive, by the one or more electrodes and an analog front end, signals transmitted from a touch sensor coupled to a touch-sensor controller, and convert the signals into sequences of digital signals. The logic is further configured when executed to feed the sequences of digital signals received in different periods into a memory; correlate each of the sequences of digital signals with a digital data defined by a wide-band code to generate multiple correlations; and transmit a transmission signal to the touch-sensor controller according to a synchronization timing determined based at least in part on one or more of the multiple correlations.

Timing synchronization of active stylus and touch sensor

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.

Electronic device with fractional clock-cycle timing

In one embodiment, an active stylus includes a receiver and a transmitter configured to receive and transmit signals from and to a device via a touch sensor of the device, wherein the transmitter is integrated with or comprises an adaptive voltage generation circuit including: a boost voltage controller; a comparator; a switch control; and a bleeder circuit. The active stylus further includes a stylus controller configured to: (a) in a first operation state, control the adaptive voltage generation circuit and the transmitter to transmit signals at a second transmit voltage, and (b) in a second operation state different from the first operation state, control the adaptive voltage generation circuit and the transmitter to transmit signals at a first transmit voltage lower than the second transmit voltage.

Adaptive transmit voltage in active stylus

In one embodiment, a computer-readable non-transitory storage medium embodies logic that is configured when executed to determine a first correlation between first consecutive edges of a synchronization signal and a pre-determined coefficient vector. The logic is further configured when executed to determine a second correlation between second consecutive edges of the synchronization signal and the pre-determined coefficient vector and synchronize one or more timings for communication between a stylus and a device based at least in part on the first and second correlations.

In one embodiment, an active stylus includes a transmitter configured to transmit electrical signals to a device through a touch sensor of the device. The active stylus also includes a receiver configured to receive electrical signals from the device through the touch sensor of the device. Furthermore, the active stylus includes a controller configured to determine a strength of an electrical signal received by the receiver from the touch sensor of the device and instruct the transmitter to transmit electrical signals to the device at a voltage based at least on the determined strength of the electrical signal received by the receiver.

Active stylus with fractional clock-cycle timing

In one embodiment, a stylus includes a controller, a delay line, a coefficient line and a computer-readable non-transitory storage medium. The controller is operable to receive a synchronization signal that is transmitted from a computing device and received by the stylus. The delay line is operable to store a first consecutive edges of the synchronization signal. The coefficient line includes a pre-determined coefficient vector. The computer-readable non-transitory storage medium embodies logic that is configured when executed to: determine a first correlation between the first consecutive edges of the synchronization signal and the pre-determined coefficient vector of the coefficient line; remove oldest signal period of edges of the first consecutive edges from the delay line; store next signal period of new consecutive edges of the synchronization signal to the delay line, the new consecutive edges composing a second consecutive edges of the synchronization signal; determine a second correlation between the second consecutive edges of the synchronization signal and the pro-determined coefficient vector; and synchronize one or more timings for communication between the stylus and the computing device based at least in part on the first and second correlations.

In certain embodiments, a method includes wirelessly receiving, by an electrode of a stylus, a signal sent from a touch sensor of a computing device. The received signal includes a data bit and is based on a predefined code sequence. The method also includes producing, by the electrode of the stylus, a derivative signal from the received signal, the derivative signal corresponding to a derivative with respect to time of the received signal. The method further includes performing, by the stylus, a cross-correlation of the derivative signal and an expected-signal pattern, the expected-signal pattern based on a derivative with respect to time of the predefined code sequence, where the cross-correlation produces a cross-correlation signal including one or more cross-correlation pulses. The method also includes determining, by the stylus, based on the cross-correlation signal, that the received signal is associated with the predefined code sequence.

Communication between active stylus and touch sensor

In one embodiment, a stylus includes a controller, a delay line, a coefficient line and a computer-readable non-transitory storage medium. The controller is operable to receive a synchronization signal that is transmitted from a computing device and received by the stylus. The delay line is operable to store a first consecutive edges of the synchronization signal. The coefficient line includes a pre-determined coefficient vector. The computer-readable non-transitory storage medium embodies logic that is configured when executed to: determine a first correlation between the first consecutive edges of the synchronization signal and the pre-determined coefficient vector of the coefficient line; remove oldest signal period of edges of the first consecutive edges from the delay line; store next signal period of new consecutive edges of the synchronization signal to the delay line, the new consecutive edges composing a second consecutive edges of the synchronization signal; determine a second correlation between the second consecutive edges of the synchronization signal and the pre-determined coefficient vector; and synchronize one or more timings for communication between the stylus and the computing device based at least in part on the first and second correlations.

In one embodiment, a stylus includes a receiver for receiving signals wirelessly transmitted by a device. The stylus can alternate, during a first period of time, power supplied to the receiver between a first power for a first duration and a second power for a second duration. The first power is greater than the second power. The stylus can determine how many events exceeding an event criteria occurred the each first duration, and if the events exceed a threshold, the stylus can initiate wakeup components in the stylus for communicating with the device by initiating a provision of third power to those components. The third power is greater than the first power. When the first period of time expires, the stylus can provide low power to the receiver for a second period of time.

Growing community of inventors

Trondheim, Norway

Eivind Holsen