Apple Inc.

Seagate Technology Incorporated

Iolon, Inc.

International Business Machines Corporation

Stephen J Hrinya

Karl Arnold Belser

Parin Patel

Jerry E Hurst, Jr

John F Heanue

Yehonatan Perez

Alan A Fennema

Alexander Tselikov

Rajarshi Paul

Eugene Lvovich Shoykhet

Jill D Berger

Glen Alan Jaquette

David A King

Jeffrey P Wilde

Yonglin Huang

Douglas W Anthon

Man Cheung

Anthony Juliana

David E Call

Di Zhao

Olga Gorbounova

Fedor A Ilkov

Max T Artusy

Howard S Lee

Subrata K Dutta

Heather L Tavernier

A switching power converter circuit may include output voltage overshoot mitigation circuitry that can modify operation of the converter responsive to an overvoltage condition by switching from a pulse width modulation (PWM) mode to a pulse frequency modulation (PFM) mode. A clamp may be provided to clamp a control voltage or a compensating capacitor voltage of the main output voltage control loop (e.g., a PWM control loop) to a control voltage of the PFM loop. An output pull down circuit may be provided to temporarily apply a load to the converter output.

Peak voltage overshoot control for switch mode power converters

An electronic device may include a conductor sensing assembly for sensing movement of a conductor, for example, in order to provide an input assembly that may be operative to detect a user's manipulation of a distance between the conductor and a portion of the conductor sensing assembly for controlling a functionality of the device. The conductor sensing assembly may include an oscillator that may produce oscillations that decay at different rates dependent upon a variable distance between a component of the conductor sensing assembly and a conductor of the input assembly. As the decay rate may be dependent on or otherwise correlate with the magnitude of a distance between the oscillator and a conductor, detection of the decay rate of the oscillator may enable determination of a state of a button input assembly that includes a conductor operative to be movable by a user with respect to the oscillator.

Conductor sensing assemblies

Systems and methods for in-band communication across a wireless power interface from a load device to a source device. The load device selectively modifies the timing of switches within a voltage rectifier coupled to an output of a receive coil within the load device that receives power from a transmit coil within the source device. The source device detects changes in the power transfer (or in the relative timing of a voltage or a current) as digital information received from the load device.

In-band signaling within wireless power transfer systems

A host electronic device may be coupled to an accessory electronic device. During normal operation, the host device may supply the accessory device with power over a power supply line. Back-powering events in which the accessory device delivers power to the host device may be prevented by interposing a protection transistor in the power supply line. A current mirror may be formed using the protection transistor and an additional transistor that produces a sense current proportional to the amount of current that is flowing through the power supply line. A current-to-voltage amplifier may produce a sense voltage that is proportional to the sense current. A bias circuit may be used to bias the sense current through the current mirror. A control circuit may compare the sense voltage to one or more reference voltages and turn off the protection transistor when appropriate to prevent back-powering of the host device.

Electronic device power protection circuitry

An asymmetric multiphase boost that provides flash functionality for display backlights. A backlight power management module for a display backlight may implement and control an asymmetric multiphase boost that includes two boost phases: a primary boost phase for typical display backlighting, and a secondary or flash boost phase that provides flash functionality via the display backlight when needed. The primary boost phase may be sized to provide high low-load efficiency, high inductance, and low switching frequency for normal display backlight operations. The flash boost phase may be sized for high current and peak power, low inductance, and high switching frequency for pulsed current applications. Via the asymmetric multiphase boost, the backlight power management module may, for example, be used to provide a camera flash function for front facing cameras.

Asymmetric multiphase boost for display backlights

An apparatus and method for controlling the phase of a tunable laser is provided. Stabilization of the mode of a laser beam is provided as the laser is tuned to a target frequency. For one embodiment, a laser generates a reference beam and an output beam. The power of each of beam is measured by optical detectors, and a ratio thereof is utilized to detect when a mode hop occurs as the laser is coarsely tuned. The average of the pre and post mode hop ratios is utilized as a control setpoint while finely tuning the laser to the target frequency. Wavelength lockers, optical power dividers and optical detectors are utilized to determine power levels of the reference and output beams while also monitoring frequency characteristics thereof. A control unit utilizes the outputs from the wavelength locker to control the operation of the extended cavity laser during and after tuning.

Apparatus and method for phase control of tunable external cavity lasers

An apparatus comprising a first reference element having an output power that varies monotonically with input frequency over an operating frequency range and receiving at least a portion of an output beam of light from an optical source. A second reference element having an output power that is frequency dependent receives at least a portion of the output beam of light. A first optical detector measures the power of a first reference beam of light from the first reference element. A second optical detector measures the power of a second reference beam of light from the second reference element. Electronic circuitry is coupled to the first and second optical detectors for receiving first and second reference signals therefrom and producing a coarse error signal for permitting coarse adjustment and a fine error signal for permitting fine adjustment of the frequency of the output beam of light.

Apparatus for frequency tuning and locking and method for operating same

A patterned recording media is comprised of a combination of raised features and depressed features in or on the surface of the recording disk. A depressed feature is known as a pit, while a raised feature is known as an island. The islands form areas where one or more data bits can be written. The recording head is synchronized to the discrete bit pattern by determining the correct clock cycle (phase) and clock count within the clock cycle.

Method for synchronizing the write current for magnetic recording with the bit islands on discrete bit patterned media

A system and method is disclosed for correcting gain and offset errors in a signal amplifier for a position sensitive detector. The present invention eliminates the need to perform division for normalization by holding constant a signal proportional to the sum of the two signals generated by the position sensitive detector. First the two signals generated by the position sensitive detector are pulse-width modulated with a common variable duty cycle clock, and then the resulting modulated signals are low-pass filtered to extract the DC component. The duty cycle is varied so that the sum of the two DC components is held constant. In the preferred embodiment, the means for varying the duty cycle are closed-loop feedback and open-loop feed forward. The closed-loop feedback gives long term accuracy and the open-loop feed forward gives rapid settling time. Once the sum of the DC components of the modulated signals is held constant, the individual DC components of the modulated signals are normalized and may be used for servo or other applications.

System and method of correcting gain and offset error in a signal amplifier for a position sensitive detector

In a magneto-optical storage device, a digitally adjustable preamplifier stage balances polarization signal levels through use of a digital compensation value. A separate digital compensation value is stored for the signals corresponding to each detector head. Each time a different detector head is activated, the digital compensation value for the polarization signals corresponding to that head is accessed. The accessed digital compensation value is input to a digital to analog converter (DAC), which produces a voltage for setting the gain of the adjustable amplifier.

Magneto-optical preamplifier

An actuator assembly directs a first beam of light towards an optical assembly. A particular angular displacement of the beam of light relative to the optical assembly by the actuator assembly directs the beam of light to exit the optical assembly at a particular output port.

Fiber bundle switch

Optical switching of light is effected between an input and an output utilizing a low-bandwidth actuator and a hi-bandwidth actuator.

Optical switch with coarse and fine deflectors

Curvilinear servo sector patterns are produced on a master media by determining a series of offsets between a radially aligned reference and the desired curvilinear servo sector and expressing each offset as a delay that can be expressed in settings for controlling a master writer. Incorporation of the delay into the master writer allows a curvilinear servo sector pattern to be produced using data mapping that is ordinarily used for the radially aligned servo sector pattern. Thus, curvilinear servo sector patterns with a desired resolution are produced without increasing computational overhead or memory requirements, or decreasing throughput. The delay can be converted into control settings such as sector delay, clock cycle delay and residual fractional delay settings that each represent a portion of the delay. In certain embodiments, a piece-wise linear approximation of the curvilinear shape can be implemented to reduce the amount of required control data, and a master writer controller that generates pulses for multiple lasers can be implemented.

Controlling a media master writing machine to produce curvilinear servo sector patterns

An optical disk recorder employs laser drive signals having diverse current or power levels. A scaling digital-analog-converter (DAC) supplies a scaled reference signal to a plurality of scaled DACs. The scaled DACs supply the diverse laser drive signals. Calibrating the scaling DAC calibrates the scaled DACs. A base array of DACs include not only the scaling DAC but a plurality of base array DACs. Such base array DACs control reading operations as well as supplying a threshold current. The threshold current is that laser drive signal current level below which laser 25 does not emit a laser beam. During writing, the CUT current is added to the laser drive currents supplied by the scaled DACs. A desired CUT current is determined by calculating a slope of the laser drive current to emission of radiation. Then the slope is extrapolated to a zero emission point below which no coherent emission of radiation occurs.

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San Jose, CA, United States of America

Stephen J Hrinya