Number | Name | Date | Kind |
---|---|---|---|
3640496 | Duncan | Feb 1972 | |
4923158 | Saisho | May 1990 | |
5007607 | Kim | Apr 1991 | |
5088669 | Zinnbauer | Feb 1992 | |
5312078 | Marsh | May 1994 | |
5568708 | Kassardjian et al. | Oct 1996 | |
5697669 | Yemini | Dec 1997 |
Entry |
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PI, Inc. Advertisement; Undated, admitted prior art. |