Inventor · Marlborough, MA, US

Robert P. Ryan

91Patents
36h-index
77Co-inventors
91Inventor score

Filing activity: Jul 22, 1981 → Aug 4, 2023

Most-cited inventions

PatentTitleAreaCited byStatus
US7203021B1 Self-heating disk drive Physics 174 Expired
US6795268B1 Disk drive employing seek time vcm ir voltage calibration for velocity control of an actuator arm Physics 142 Expired
US8370683B1 System and method to reduce write splice failures Physics 134 Active
US6104153A Disk drive employing method of spinning down its spindle motor to reduce the time required for spinning it down and subsequently spinning it up Physics 133 Expired
US6476996B1 Disk drive comprising an actuator driver circuit for retracting a head independent of a servo microprocessor when a spindle speed fault mode is detected Physics 133 Expired
US7907364B2 Disk drive including a delay circuit to provide a delayed reset signal Physics 132 Active
US6198590A Disk drive employing method of spinning down its spindle motor to reduce the time required for subsequently spinning it up Physics 130 Expired
US6538839B1 Disk drive employing adaptive feed-forward vibration compensation to enhance a retry operation Physics 130 Expired
US6690536B1 Disk drive employing VCM demand current to calibrate VCM IR voltage for velocity control of an actuator arm Physics 129 Expired
US6577465B1 Disk drive comprising spin down circuitry having a programmable signal generator for enhancing power and braking control Physics 127 Expired
US6574062B1 Disk drive comprising a demand limit circuit for enhancing power management during spin down Physics 125 Expired
US6970319B1 Disk drive comprising a pulse width modulated demand limit circuit for enhancing power management during spin-down Physics 125 Expired
US6549359B1 Disk drive comprising spin down circuitry having a current limit circuit for enhancing power and braking control Physics 125 Expired
US6549361B1 Disk drive comprising spin down circuitry having a power clamp circuit for enhancing power and braking control Physics 123 Expired
US6934135B1 Disk drive monitoring a supply current to protect motor driver circuits Physics 120 Expired
US7548392B1 Disk drive controlling a voice coil motor during an emergency unload Physics 119 Active
US8179626B1 Adaptive shock detection Physics 118 Active
US6967458B1 Decreasing spin up time in a disk drive by adjusting a duty cycle of a spindle motor PWM signal to maintain constant average input current Physics 117 Expired
US6867944B1 Disk drive comprising VCM stall detector for velocity control of an actuator arm Physics 117 Expired
US6900959B1 Disk drive comprising an offset-nulling amplifier for detecting a back EMF voltage of a voice coil motor Physics 115 Expired
US7158329B1 Disk drive employing active braking using inductive sense Electricity 115 Expired
US7852588B1 Disk drive adjusting gain of shock detector relative to resonant frequency amplitude Physics 114 Active
US7095579B1 Disk drive employing momentum based unload during power failure Physics 113 Expired
US6560056B1 Disk drive comprising a motor driver IC employing a serial interface for initiating the transmission of real-time status data to a controller IC Physics 113 Expired
US6788483B1 Disk drive comprising a programmable inverting voltage regulator configured relative to the disk drive's mode of operation Physics 112 Expired

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.