This part is a kind of semiconductor called 961N51.

Function of this product has OPB961.

Manufacturers : Optek Technology

Image and pinout :

Some of the text within the PDF file :

Product Bulletin OPB960 February 1998 Types OPB960, OPB970 Series Photologic™ Slotted Optical Switches Features • Choice of mounting configuration • Choice of aperture • Choice of output configuration • Choice of opaque or IR transmissive shell material Absolute Maximum Ratings (TA = 25oC unless otherwise noted) Supply Voltage, VCC (Not to exceed 3 sec.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10V Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to +85oC Operating Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to +70oC Lead Soldering Temperature [1/16 inch (1.6mm) from case for 5 sec. with soldering iron] . . . . . . . . . . . . . . . . . . . . . . . . . [ ... ]

961N51 PDF Datasheet Download