This part is a kind of semiconductor called PS2016.

Function of this product has (PS20xxx) NPN-OUTPUT DC-INPUT OPTOCOUPLER.

Manufacturers : NEC

Image and pinout :

Some of the text within the PDF file :

w w a D . w S a t e e h U 4 t m o .c w w .D w t a S a e h U 4 t e .c m o w w w .D a S a t e e h U 4 t m o .c [ ... ]

PS2016 PDF Datasheet Download