Richard H. Johnson

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Lemont, IL, US

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Patents Grantslast 30 patents

Information Patent Grant
Verification method using pressure and heat-sensitive chromogenic s...
- Patent number 5,595,955
- Issue date Jan 21, 1997
- Wallace Computer Services, Inc.
- John C. H. Chang
- G07 - CHECKING-DEVICES
Information Patent Grant
Document with heat and pressure sensitive chromogentic composition...
- Patent number 5,401,060
- Issue date Mar 28, 1995
- Wallace Computer Services, Inc.
- John C. H. Chang
- G07 - CHECKING-DEVICES