| Number | Name | Date | Kind |
|---|---|---|---|
| 3556796 | Van den Eynde | Jan 1971 | |
| 4208210 | Sakai et al. | Jun 1980 | |
| 4725530 | Kobayashi et al. | Feb 1988 | |
| 4833069 | Hamada et al. | May 1989 | |
| 4857442 | Fujita et al. | Aug 1989 | |
| 4883746 | Shimada et al. | Nov 1989 | |
| 4957853 | Kobayashi et al. | Sep 1990 | |
| 4983503 | Ishikawa et al. | Jan 1991 |
| Number | Date | Country |
|---|---|---|
| 250201 | Jun 1987 | EPX |
| 48-057961 | May 1973 | JPX |
| 48-059838 | Oct 1973 | JPX |
| 63-187239 | Jul 1988 | JPX |
| 01185630 | Mar 1989 | JPX |
| Entry |
|---|
| Research Disclosure 29015, Jun. 1988, Disclosed Anonymously. |