This part is a kind of semiconductor called SMJ40.

Function of this product has Stepping Motor.

Manufacturers : FDK

Image and pinout :

Some of the text within the PDF file :

SM-SME001-0504 Stepping Motor Applications Mobile equipment Digital cameras, Mobile equipments, PDA, etc. Office automation equipment Printers, facsimiles, Typewriters, Photocopiers, FDD head drives, CD-ROM pickup drives, Scanners, etc. Audio-visual equipment Video cameras, Digital cameras, etc. Measuring instruments Automotive odometers, Various integrating meters and counters Game equipment Pachinko machines, etc. Structure and operation Stepper motors convert electric pulses into incremental mechanical motions. FDK's stepper motors have a claw-pole yoke structure with a cylindrical permanent magnet rotor, as illustrated below. These motors rotate when a rotating magnetic field is generated and when the rotor magnet is synchronized with the rotating magnetic field. [ ... ]

SMJ40 PDF Datasheet Download