公开(公告)号：US10551215B2

公开(公告)日：2020-02-04

申请号：US14737403

申请日：2015-06-11

Applicant: ANALOG DEVICES GLOBAL UNLIMITED COMPANY

Inventor： Eoin E. English ,  Javier Calpe Maravilla ,  Robert Guyol ,  Alan J. O'Donnell ,  Maria Jose Martinez ,  Jan Kubik ,  Krystian Balicki

IPC: G01D5/20

Abstract: An embodiment of a position sensing system includes a signal generation circuit to generate an excitation signal according to a selected characteristic signal, a drive circuit to drive an excitation source with the excitation signal, an input circuit to receive a sensor output while driving the excitation source, a signal detection circuit to identify a component of the sensor output corresponding to the characteristic signal, and a control circuit to determine the position of the movable object as a function of the identified component of the sensor output. The positioning system may be included an electronic camera, where the movable object may be a lens. The excitation source may be a conductive coil, the excitation a magnetic field, and the sensor a magneto resistive sensor. Alternatively, the excitation source may be an optical excitation source, the excitation an optical excitation, and the sensor an optical sensor.

公开(公告)号：US10824050B2

公开(公告)日：2020-11-03

申请号：US14821395

申请日：2015-08-07

Applicant: ANALOG DEVICES GLOBAL UNLIMITED COMPANY

Inventor： Javier Calpe Maravilla ,  Eoin E. English ,  Rafael Mahiques ,  Jose Carlos Canada ,  Maria Jose Martinez

IPC: G03B3/10

Abstract: Actuators are used to move a variety of objects to desired positions. It is generally desirable that they can do this quickly without exhibiting overshoot or ringing. Some actuators are required to respond very quickly and examples of these are voice coil drivers used to move lenses in autofocus cameras provided in everyday devices such as smart phones and tablets. A rapid two step controller scheme had already been disclosed by Analog Devices Inc. While the scheme works well, it can only be used reliably if the resonant frequency of the actuator is known to within 2 or 3%. The inventors have discovered that the resonant frequency of an actuator unexpectedly changes as a function of position. This disclosure provides ways of modifying the control scheme to cope with changes in resonant frequency.