IP Library Granted Patent US 4,521,909
Granted Patent Utility
US 4,521,909 · App. 06/538,858

Dual level pattern recognition system

Inventor: Patrick Wang
Patented Case View Patent ↗
Granted: Jun 4, 1985 Filed: Oct 4, 1983
Inventor
Patrick Wang
Assignee (at issue)
Wang Laboratories, Inc.

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.

Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 4,521,909
App. No.
06/538,858
Filed
1983-10-04
Granted
1985-06-04
Kind
A