PROJECTION-LENS DRIVING APPARATUS FOR USE IN A 3-BEAM PROJECTOR PROJECTION- LENS DRIVING APPARATUS FOR USE IN A 3-BEAM PROJECTOR

摘要

The projection-lens driving apparatus for a 3-beam projector includes a housing, a triplet of cylindrical projection-lens holders, a pair of cam members, each of the cam members having a triplet of guide rails, a trifurcating member, a driving means provided with a feed screw and a motor, three pairs of brackets, three pairs of feed rollers, one end of each of the brackets coupled to each of the feed rollers which, in turn, is coupled to each of the guide rails, the other end thereof being coupled to each cylindrical projection-lens holder, and a triplet of guiding means, each of the guiding means mechanically coupling each of the cylindrical projection-lens holders with the housing. The pair of cam members and the cylindrical projection-lens holders are mechanically coupled through the feed screw of the driving means to allow a synchronous movement of the components constituting the apparatus.