| Number | Date | Country | Kind |
|---|---|---|---|
| 56-117082[U] | Aug 1981 | JPX | |
| 56-117083[U] | Aug 1981 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2593337 | O'Brien | Apr 1952 | |
| 3222467 | Meyer | Dec 1965 | |
| 3254163 | Wanlass | May 1966 | |
| 3288947 | Wanlass et al. | Nov 1966 | |
| 4065650 | Lou | Dec 1977 |
| Entry |
|---|
| Xerox Disclosure Bulletin, Kowalski, D.C., Semi-Captive Keyboard, vol. 1, No. 2, Feb. 1976, p. 85. |