Anti-thread-looseness structure for removing play in a pairing of threads positions symmetrically rotational optical elements like lenses in a projector's chassis

摘要

Set zigzag at 120[deg] to each other and molded near an external male screw thread (4) on a cylindrical holder (1) and/or near an internal female screw thread on a projector's chassis, three non-threaded fixed links (5) are shaped into an increasing wedge towards a screw-in direction.