The disclosure provides a reading device (2, 20) adapted to read-out infrared readable data (D, D10) provided by a covered part (1.1.1.2, 10.1.1.2) of a movable component (1.1, 10.1) of a drug delivery device (1, 10), wherein the reading device (2, 20) comprises - at least one electromagnetic radiation source (2.2, 20.2) configured to emit infrared radiation and adapted to illuminate the infrared readable data (D, D10) on the covered part (1.1.1.2, 10.1.1.2), - at least one optical sensor unit (2.3, 20.3) configured to detect infrared radiation reflected from the covered part (1.1.1.2, 10.1.1.2) of the movable component (1.1, 10.1) and - at least one processing unit (2.4, 20.4) configured to determine a data value of the infrared readable data (D, D10) as a function of the detected reflected infrared radiation. The disclosure further provides a drug delivery device (1, 10) and a drug delivery device (1, 10) in combination with the reading device (2, 20).
