USPC Class Details – HistoricIP

Description: 257 active solid-state devices (e.g., transistors, solid-state diodes) / 257 active solid-state devices (e.g., transistors, solid-state diodes)/(1) bulk effect device (6) intervalley transfer (e.g., gunn effect)

Hierarchy/Derived subclasses

257 / 1	-> 6	-> 7
		-> 8

uspto searches

Patent Apps in 257/6

Granted Patents in 257/6

Use the links above or do an advanced search in ppubs for:
(257/6.ccls. or 257/7.ccls. or 257/8.ccls.)

This will show what classes derive from the input. Ex: entering 43/42.24 shows the derived classes and the search that can be used to find patents or patent applications in those subclasses.