Supplementary band in optical binary coded angle transmitter - has flanks between opaque and transparent areas in different position to those on main band representing lowest decimal value

摘要

The binary coded angle transmitter comprises a coded field with a number of parallel strips each with opaque and transparent/white areas, and representing a binary number in a series. The field is attached via a movable part in the angle transmitter, and a probe - comprising l.e.d.s and photo-transistors - is fixed in a housing in which the movable part is rotatably located. Parallel to the bands is a further one with the same division between opaque and transparent/white areas as that with the lowest decimal value or a tighter division than it. The extra band's flanks between the opaque and transparent/white areas differ in position from those corresponding in the lowest decimal value band. The field is read by probing the supplementary band's flank. (Provisional Basic advised week K14).