Photoelectric reader unit for optically scanned patterns - has luminous diode and circular photocell

摘要

The luminous diode (5) is placed in the inner opening of the circular photocell (4) and both are designed as semiconductor bodies on the same sublayer. Between the luminous diode and the photocell there is a circular shield (6) which is so dimensioned that light from the luminous diode cannot reach the photocell directly. The unit can have a common terminal for the luminous diode and the photocell and two other terminals (9, 10) for the diode and the photocell. The photocell can be thicker than the luminous diode. This prevents light from the diode from reaching the photocell directly.