An improved disc feeder/conveyor (2) with optical sensor (200) and return chute (10) for multiple industrial, commercial or agricultural applications. The conveyor (2) comprises a pair of co-rotating (or counter-rotating) roller shafts (11A, 11B) driven by a belt (104) drive. The rollers (11A, 11B) are non-parallel, slightly angled, and the rotation of the shafts frictionally engages, the sample caps or other elements being advanced away from the production line causing the items seated thereon advance. Sensors (200, 202) detect the presence/absence of items on the rollers for gating. Another pair of co- or counter-rotating roller shafts (15A, 15B) may act as a return chute (10).