Differential Sensing in an Active Stylus
Granted: May 2, 2013
Application Number:
20130106798
In one embodiment, a stylus receives a first signal from a first electrode of the stylus, the stylus being operable to communicate wirelessly with a device through a touch sensor of the device; receives a second signal from a second electrode of the stylus, the second signal being a reference signal and the second electrode being a reference electrode; and compares the first signal with the second signal.
Active Stylus with Capacitive Buttons and Sliders
Granted: May 2, 2013
Application Number:
20130106796
In one embodiment, a device includes a form factor of a stylus. The form factor includes a surface area. The device also includes one or more substrates disposed along one or more portions of the surface area; and one or more touch sensors disposed on one or more of the substrates. At least one of the touch sensors includes a distinct touch-sensitive area that includes a touch-sensitive button, a touch-sensitive wheel, or a touch-sensitive slider. The device also includes a…
Dynamic Adjustment of Received Signal Threshold in an Active Stylus
Granted: May 2, 2013
Application Number:
20130106795
In one embodiment, a method includes receiving a signal at a stylus. The stylus is operable to wirelessly transmit signals to and receive signals from a device. The stylus includes a plurality of electrodes disposed in a tip of the stylus. The method includes determining a characteristic of the signal, and based at least in part on the characteristics of the signal, a threshold for determining whether to process signals received wirelessly from the device is dynamically adjusted.
Capacitive Force Sensor
Granted: May 2, 2013
Application Number:
20130106794
In one embodiment, a method includes detecting movement of a spring structure of a force sensor coupled to a center shaft of an active stylus; measuring a change of capacitance between electrodes of the force sensor; and determining an amount of force applied to the center shaft based on the change of capacitance.
Active-Stylus Nib with Rolling-Ball Tip
Granted: May 2, 2013
Application Number:
20130106771
In one embodiment, an apparatus includes a stylus nib of a stylus. The stylus nib comprising a tapered end. The apparatus also includes a rolling-ball tip. At least a portion of the rolling-ball tip is housed within the tapered end of the stylus nib, and the rolling-ball tip includes an electrode configured to transmit a signal wirelessly to a device through a touch-sensor of the device.
Active Stylus with Energy Harvesting
Granted: May 2, 2013
Application Number:
20130106770
In one embodiment, a stylus includes one or more electrodes and one or more computer-readable non-transitory storage media embodying logic for transmitting signals wirelessly from the stylus to a device through a touch sensor of the device. The stylus has one or more sensors for kinetic, thermal, solar or electric energy harvesting from an environment of the stylus or from the stylus itself.
Capacitive and Inductive Sensing
Granted: May 2, 2013
Application Number:
20130106769
In one embodiment, a method includes in an inductive-sensing mode, by a controller, applying an alternating-current (AC) signal on a first electrode of a capacitive touch sensor. The capacitive touch sensor is configured to operate in the inductive-sensing mode and a capacitive-sensing mode. The method also includes sensing a signal indicative of a magnetic field on the first electrode. The signal is due at least in part to a magnetic field generated by the object and the magnetic field…
Modulating Drive Signal for Communication Between Active Stylus and Touch-Sensor Device
Granted: May 2, 2013
Application Number:
20130106767
In one embodiment, an apparatus comprises a sense unit and a drive unit. The sense unit is operable to sense a first signal from drive lines of a touch sensor. The touch sensor comprises the drive lines and sense lines arranged relative to the drive lines such that intersections of the drive lines and the sense lines form one or more capacitive nodes. The drive unit is operable to transmit a second signal based on the first signal to the sense lines such that transmission of the second…
Active Stylus with Configurable Touch Sensor
Granted: May 2, 2013
Application Number:
20130106766
In one embodiment, a device includes a form factor of a stylus. The form factor includes a surface area. The device also includes one or more substrates disposed along one or more portions of the surface area; one or more touch sensors disposed on one or more of the substrates; and a computer-readable non-transitory storage medium coupled to one or more of the touch sensors and embodying logic configured to control one or more of the touch sensors.
Single-Layer Touch Sensor
Granted: April 25, 2013
Application Number:
20130100038
In one embodiment, a touch sensor includes multiple first electrode lines along a first direction. Each of the first electrode lines includes multiple first electrodes. The touch sensor also includes multiple second electrode lines along a second direction substantially perpendicular to the first direction. Each of the second electrode lines includes one second electrode. The second electrode of each of the second electrode lines is interdigitated with one of the first electrodes of each…
Multi-Channel Driver Equalizer
Granted: April 25, 2013
Application Number:
20130099697
The disclosed multi-channel driver equalizer circuit matches currents in multiple strings of illumination devices at low current levels by using an analog equalizer to sequentially couple the output of a reference amplifier in series with each current source amplifier in a current limit loop of the driver equalizer circuit to correct the offsets of the current source amplifiers, resulting in the matching of string currents on average.
HIGH ACCURACY RC OSCILLATOR
Granted: April 18, 2013
Application Number:
20130093522
A device includes an RC oscillator circuit and incorporates various features that individually and in combination can help improve the stability or accuracy of the oscillator output frequency. The oscillator circuit is operable to provide a tunable output frequency and includes a bias circuit switchable between first and second modes of operation. One of the modes has less drift in oscillator bias current relative to the other mode. The device also includes drift compensation circuitry…
DRIVING CIRCUITS FOR LIGHT EMITTING ELEMENTS
Granted: April 18, 2013
Application Number:
20130093339
A circuit for driving light emitting elements, such as LEDs, includes .a first transistor having a source coupled to ground through a first resistive element, and a second transistor having a gate electrically coupled to a gate of the first transistor, a source electrically coupled to ground, and a drain for electrical connection to a first group of light emitting elements. The circuit also includes circuitry to provide a predetermined voltage at the source of the first transistor,…
DRIVING CIRCUITS FOR LIGHT EMITTING ELEMENTS
Granted: April 18, 2013
Application Number:
20130093338
A circuit for driving light emitting elements, such as LEDs, includes a first transistor having a source coupled to ground through a first resistive element, and a second transistor having a gate electrically coupled to a gate of the first transistor, a source electrically coupled to ground, and a drain for electrical connection to a first group of light emitting elements. The circuit also includes circuitry to provide a predetermined voltage at the source of the first transistor,…
PRIMARY SIDE PFC DRIVER WITH DIMMING CAPABILITY
Granted: April 4, 2013
Application Number:
20130083578
A primary side PFC driver circuit is disclosed that includes a switch control circuit for commanding a switch to allow an inductor coupled to an output load (e.g., LEDs) to transfer energy provided by an input voltage source. The switch control circuit provides two signals for commanding the switch. A first signal having a first frequency, with a duty cycle in proportion to the input voltage amplitude, commands the switch to allow the average input current to be proportional to the input…
PRIMARY SIDE PFC DRIVER WITH DIMMING CAPABILITY
Granted: April 4, 2013
Application Number:
20130082621
A primary side PFC driver circuit is disclosed that includes a switch control circuit for commanding a switch to allow an inductor coupled to an output load (e.g., LEDs) to transfer energy provided by an input voltage source. The switch control circuit provides two signals for commanding the switch. A first signal having a first frequency, with a duty cycle in proportion to the input voltage amplitude, commands the switch to allow the average input current to be proportional to the input…
LOW POWER CAPACITIVE TOUCH DETECTOR
Granted: March 21, 2013
Application Number:
20130069672
A low power capacitive detector is disclosed. The detector includes a mechanism to measure and detect touch on capacitive sensors. The detector uses signal processing to suppress noise and increase sensitivity. The detector does not require dedicated analog circuitry, making it easy to adopt in a microcontroller system. The detector can be scaled to a larger number of capacitive sensors without noticeable increase in silicon cost.
LOW POWER CAPACITIVE TOUCH DETECTOR
Granted: March 21, 2013
Application Number:
20130069671
A low power capacitive detector is disclosed. The detector includes a mechanism to measure and detect touch on capacitive sensors. The detector uses signal processing to suppress noise and increase sensitivity. The detector does not require dedicated analog circuitry, making it easy to adopt in a microcontroller system. The detector can be scaled to a larger number of capacitive sensors without noticeable increase in silicon cost.
SENSORLESS BLDC MOTOR CONTROL BY COMPARING INSTANTANEOUS & AVERAGE BEMF VOLTAGES
Granted: February 7, 2013
Application Number:
20130033212
Sensorless driving of a brushless DC (BLDC) motor includes detecting a zero crossing time from back electromotive force (BEMF) voltage of the BLDC motor. An instantaneous BEMF voltage and an average BEMF voltage are compared to detect the crossover time, which can be used to change the commutation switching sequence. Since the average BEMF voltage differs for odd and even steps of the commutation switching sequence, average BEMF voltages are calculated separately for odd and even…
MICROCONTROLLER SYSTEM BUS SCHEDULING FOR MULTIPORT SLAVE MODULES
Granted: February 7, 2013
Application Number:
20130036246
A system includes master modules, at least one multiport slave module, and a scheduler connected by a system bus. The scheduler is configured to provide scheduling information to the multiport slave module. The scheduling information includes master categorization information and anticipated burst information. The anticipated burst information is based on a scheduler determination for an anticipated bus access by an anticipated master module. The master categorization information…
