Design of a large aperture focal plane curtain shutter

Subject of study. A large aperture focal plane curtain shutter was designed, the aperture focal plane was up to 506 mm. Purpose of the work. According to the task requirements of theWide- Field Survey Telescope, the shutter should have the characteristics of a large aperture focal plane, compact structure, fast response time, and high exposure accuracy and uniformity. Method. The shutter used ball screws and rollers to drive and wind (or unwind) the curtain, respectively, ensuring that the curtain driving speed is similar to the winding (or unwinding) speed through the transmission system, and a torsion spring was set to provide tension for the curtain and compensate for the slight difference between the driving speed and winding (or unwinding) speed. In order to select the best curtain material, six kinds of curtain materials were selected, and each material was evaluated by life, wrinkling, and pollutants. Polyvinyl chloride fabric was selected as the shutter curtain material. Main results. Compared with the traditional roller-driven curtain shutter, the shutter of theWide-Field Survey Telescope had higher exposure accuracy and uniformity; the curtain does not need to open, and the shutter exposure width can be larger and more reliable. The experimental results showed that the exposure accuracy of the shutter of the Wide-Field Survey Telescope was 0.48%, and the exposure uniformity was 0.28%. Practical significance. It meets the technical requirements of the Wide-Field Survey Telescope and is also suitable for other large aperture ground-based telescopes. (c) 2023 Optica Publishing Group