| Number | Name | Date | Kind |
|---|---|---|---|
| 4160879 | Sullivan et al. | Jul 1979 | |
| 4425627 | Eibner | Jan 1984 | |
| 4431870 | May et al. | Feb 1984 | |
| 4443664 | Grange | Apr 1984 | |
| 4475013 | Lee et al. | Oct 1984 | |
| 4531186 | Knapman | Jul 1985 | |
| 4660166 | Hopfield | Apr 1987 | |
| 4680729 | Steinhart | Jul 1987 | |
| 4689737 | Grant | Aug 1987 | |
| 4744050 | Hirosawa et al. | May 1988 |
| Entry |
|---|
| "Touchphone: A New Generation in Telephone Design", Telesis, Two; Bloeden, R. et al.; 1985, pp. 20-25. |
| "An Interactive Touch Phone for Office Automation", IEEE Communications Magazine, vol. 23, No. 2; Hsing, R. et al., 1985, pp. 21-26. |