Indexing control for microfiche reader - has guide plate with raster grooves and locating slider with pegs to follow grooves

摘要

A simple, robust indexing control for the microfiche reader has a grooved plate (3) alongside the viewing position, with the grooves corresponding to the frame matrix. The microfiche holder (6) is fitted with a guide block which runs over the grooved plate on a series of pegs sets at the spacing of the grooves. The user presses the block to follow the grooves and so has an accurate indexing control to select any part of the microfiche. No moving parts are required for the indexing control.