Number | Name | Date | Kind |
---|---|---|---|
1653683 | Whitaker | Dec 1927 | |
3517792 | Abrahamsen | Jun 1970 | |
3879722 | Knowlton | Apr 1975 | |
3892303 | Willcox | Jul 1975 | |
4208140 | Bucknam | Jun 1980 | |
4313685 | Stahl et al. | Feb 1982 |
Number | Date | Country |
---|---|---|
1080126 | Oct 1960 | DEX |
Entry |
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"Quick Changeable Keytop Indicia"; D. L. Potak; IBM Technical Disclosure Bulletin; vol. 12, No, 4, p. 662; Sep. 1969. |
"Liquid Crystal Keyboard"; Joseph Stephany et al.; Xerox Disclosure Journal; vol. 5, No. 5, p. 559, Sep./Oct. 1980. |