| Number | Date | Country | Kind |
|---|---|---|---|
| 7033/77 | Jun 1977 | CHX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 39296 | Livermore | Jul 1863 | |
| 2922993 | Sack | Jan 1960 | |
| 3142039 | Irland | Jul 1964 | |
| 3495232 | Wagner | Feb 1970 | |
| 3704343 | Howard | Nov 1972 | |
| 3803834 | Reese | Apr 1974 | |
| 3823545 | Vittoz et al. | Jul 1974 | |
| 3909785 | Howells | Sep 1975 | |
| 3980823 | Howard | Sep 1976 | |
| 4005400 | Engdahl | Jan 1977 | |
| 4047010 | Perotto et al. | Sep 1977 |
| Entry |
|---|
| IBM Technical Disclosure Bulletin, vol. 14, No. 3, Aug., 1971, Wolfe, R. N., "Keyboard for Electronic Tablet or Digitizer". |