| Number | Date | Country | Kind |
|---|---|---|---|
| 2-75916 | Mar 1990 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3615602 | Credner et al. | Oct 1971 | |
| 4294900 | Aono | Oct 1981 | |
| 4439513 | Sato et al. | Mar 1984 | |
| 4668614 | Takada et al. | May 1987 | |
| 5064753 | Sohei et al. | Nov 1991 | |
| 5075207 | Langen et al. | Dec 1991 | |
| 5112730 | Ohkawa et al. | May 1992 |
| Number | Date | Country |
|---|---|---|
| 0173302 | Mar 1986 | EPX |
| 337370A3 | Oct 1989 | EPX |
| 3815469 | Nov 1989 | DEX |
| 221748 | Oct 1986 | JPX |
| 3304242 | Dec 1988 | JPX |
| Entry |
|---|
| Derwent Abstract of JPA 61-221748, Oct. 2, 1986. |
| European Search Report 91 10 4775, Jun. 18, 1991, S. Magrizos, The Hague. |