Patent · US Expired

Tracking auto focus system

US7301133B2 · kind B2 · utility

12Cited by
5References
27Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 20, 2005
Grant dateNov 27, 2007
Priority date
Expiry dateDec 20, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/285
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A tracking auto-focus system maintains a microscope pointed at a TFT array continuously in focus so as to eliminate the auto-focusing time that would otherwise be required. The tracking auto-focus system includes, in part, a microscope Z actuator, an auto-focus sensor, an analog-to-digital converter (ADC), a signal conditioner, a digital proportional integrating and differentiating (PID) controller, and a digital-to-analog converter. The actuator adjusts the distance between the microscope's objective lens and the target and includes, in part, an amplifier, a linear motor, and a linear encoder which provides positional feedback. The auto-focus sensor together with the ADC and signal conditioner continuously monitor and detect the distance between the microscope's objective lens and the target and supply the measured distance to the amplifier. The PID controller together with the DAC stabilizes the distance separating the microscope's objective lens and the target to maintain the best focus.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.