Patent · US Expired

Semi-active focus and thermal compensation of a centrally-obscured reflective telescope

US6404547B1 · kind B1 · utility

15Cited by
4References
19Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 1, 2000
Grant dateJun 11, 2002
Priority date
Expiry dateMar 1, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B23/16
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A centrally-obscured reflective telescope having a semi-active focus and thermal compensation system. The telescope has a housing having an input window, a primary mirror, a secondary mirror suspended between the input window and the primary mirror by support struts, an optional tertiary mirror, and an optional fold mirror. The system includes one or more heating elements respectively disposed on each of the support struts. A first temperature sensor (disposed on the primary mirror) generates a reference temperature, a second temperature sensor is disposed on the secondary mirror, and one or more third temperature sensors are disposed on each of the support struts. A temperature compensation controller is coupled to the heating elements and temperature sensors and controls the heat output of the plurality of heating elements to heat the support struts and control the position of the secondary mirror relative to the primary mirror.

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