Lens drive device and lens drive method
US10564387B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 16, 2017 |
| Grant date | Feb 18, 2020 |
| Priority date | — |
| Expiry date | Jul 29, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2205/0069
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A controller within a lens drive device, the controller comprising an open loop control section that performs open loop control of the stepping motor using a given excitation position change and a given drive voltage, and a closed loop control section that, at the time of rotating the stepping motor, calculates tracking lag for change in rotational position for change in excitation position, and performs closed loop control of drive speed and drive voltage of the stepping motor in accordance with a control error, which is a difference between target tracking lag and tracking lag, wherein the closed loop control section performs at least open loop control of drive voltage during an acceleration operation of the stepping motor, as well as closed loop control of drive voltage and drive speed in accordance with control error by transitioning to closed loop control of drive voltage when an acceleration operation is completed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.