Inventor · disambiguated record
Duane P. Littlejohn
Also filed as: LITTLEJOHN DUANE P
12 granted patents·179 citations·filing 1984–2000
91Inventor score
Files withNICOLET INSTRUMENT CORP4SIEMENS AG3SIEMENS ENERGY & AUTOMAT2APPLIED AUTOMATION INC1LEYBOLD INFICON INC1
Top patents by PatentIndex Score
12 records- 0190US6255648B1Programmed electron fluxAPPLIED AUTOMATION INC·Filed 1998·Granted Jul 3, 2001·74 cites·12 claims
- 0286US4581533AMass spectrometer and methodNICOLET INSTRUMENT CORP·Filed 1984·Granted Apr 8, 1986·32 cites·17 claims
- 0373US6498344B1Triode ion pumpSIEMENS ENERGY & AUTOMAT·Filed 2000·Granted Dec 24, 2002·10 cites·1 claims
- 0460US4739165AMass spectrometer with remote ion sourceNICOLET INSTRUMENT CORP·Filed 1986·Granted Apr 19, 1988·13 cites·21 claims
- 0557US6121609APulsed mass spectrometer leak valve with controlled energy closureSIEMENS AG·Filed 1998·Granted Sep 19, 2000·13 cites·14 claims
- 0657US5233190AFourier transform molecular spectrometerLEYBOLD INFICON INC·Filed 1991·Granted Aug 3, 1993·19 cites·14 claims
- 0744US6232599B1Ion pump relay controlSIEMENS AG·Filed 1998·Granted May 15, 2001·6 cites·6 claims
- 0840US4588888AMass spectrometer having magnetic trappingNICOLET INSTRUMENT CORP·Filed 1985·Granted May 13, 1986·8 cites·11 claims
- 0929US6608304B1Automatic background ejection (ABE)SIEMENS ENERGY & AUTOMATION·Filed 2000·Granted Aug 19, 2003·0 cites·2 claims
- 1029US6355929B1Method for forming a seat in a pulsed sampling valveSIEMENS ENERGY & AUTOMAT·Filed 1998·Granted Mar 12, 2002·3 cites·11 claims
- 1128US6225624B1Precision pressure monitorSIEMENS AG·Filed 1998·Granted May 1, 2001·0 cites·3 claims
- 1228US4668864AMass spectrometerNICOLET INSTRUMENT CORP·Filed 1984·Granted May 26, 1987·1 cites·12 claims
Join the waitlist — get patent alerts
Get an alert when Duane P. Littlejohn files or is granted a new patent.
We store only your email — no account needed. See our privacy policy.
Identity basis: PatentsView inventor disambiguation (2025Q4-odp release). How scoring works →