Inventor · Minneapolis, MN, US

Robert D. Johnston

14Patents
6h-index
9Co-inventors
59Inventor score

Filing activity: Oct 13, 1983 → May 26, 2023

Most-cited inventions

PatentTitleAreaCited byStatus
US4747064A Approaching vehicle informing system and method Physics 33 Expired
US4577071A Echo canceller with adaptive residual center clipper controlled by echo estimate Electricity 22 Expired
US10512868B2 Filter cartridges; air cleaner assemblies; housings; features; components; and, methods Performing Operations; Transporting 20 Active
US11198083B2 Filter cartridges; air cleaner assemblies; housings; features; components; and, methods Performing Operations; Transporting 14 Active
US4782459A Adaptive recognizing device Electricity 8 Expired
US11660558B2 Filter cartridges; air cleaner assemblies; housings; features; components; and, methods Performing Operations; Transporting 7 Active
US11318405B2 Air cleaner assemblies and methods of use Performing Operations; Transporting 4 Active
US10864469B2 Air cleaner assemblies and methods of use Performing Operations; Transporting 4 Active
US6603836B1 Interactive voice response apparatus capable of distinguishing between user's incoming voice and outgoing conditioned voice prompts Electricity 3 Expired
US11951433B2 Air cleaner assemblies and methods of use Performing Operations; Transporting 0 Active
US11684882B2 Air cleaner assemblies and methods of use Performing Operations; Transporting 0 Active
US12214307B2 Air cleaner assemblies and methods of use Performing Operations; Transporting 0 Active
US12070710B2 Filter cartridges; air cleaner assemblies; housings; features; components; and, methods General 0 Revoked
USRE34205E Adaptive recognizing device General 0 Expired

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.