光學調焦機構

Optical Refocusing Mechanism

衛星影像品質的良莠與否，焦距是光學品質的重要環節。衛星在太空中環境與地表差異極大，調焦機構可以在需要時，提供有效的焦距調整，以提升拍照影像品質。衛星影像品質關乎於微米（µm）的差異。調焦機構利用材料熱膨脹與熱傳導原理，設計出可達30µm以及維持12min穩定的焦距位移調整機構。

Focal length is an important part of optical quality. The environment of a satellite in space is very different from that on the earth. The refocus mechanism can provide effective focus adjustment to improve the image quality, commonly measured in micrometers (µm). The refocusing mechanism uses material's thermal expansion and thermal conductivity to design a focal length shift adjustment mechanism that can reach the shift of ± 30 µm and maintain its stability for 12 minutes. The body of the mechanism can support the weight of the secondary mirror (M2) and resist the effects of external forces adding to the optical mechanism during rocket launch. The important elements of the refocus mechanism are the reliability and strength of the mechanism, lightweight components, stable displacement of the optical axis, thermal insulation effect, system adjustment, heat transfer analysis of the application environment, and control logic for displacement adjustment. The refocusing mechanism is of great help to improve the quality and stability of satellite images.