| Number | Date | Country | Kind |
|---|---|---|---|
| 2-90980 | Apr 1990 | JPX | |
| 3-64939 | Mar 1991 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4060848 | Hyatt | Nov 1977 | |
| 4118871 | Kirkham | Oct 1978 | |
| 4228495 | Bernhard et al. | Oct 1980 | |
| 4291375 | Wolf | Sep 1981 | |
| 4511979 | Amirante | Apr 1985 | |
| 4536646 | Adams et al. | Aug 1985 | |
| 4816654 | Anderl et al. | Mar 1989 | |
| 4878176 | Teranishi et al. | Oct 1989 | |
| 4956765 | Iwagaya | Sep 1990 | |
| 4964065 | Hicks et al. | Oct 1990 | |
| 5046014 | Anjo | Sep 1991 |
| Number | Date | Country |
|---|---|---|
| 0107291 | Aug 1983 | EPX |
| 0236506 | Sep 1986 | EPX |
| 0227113 | Dec 1986 | EPX |
| Entry |
|---|
| Patent Abstracts of Japan, vol. 13, No. 217 (M828), May 22, 1989, and JP-A-1-034-776 (Tokyo Electric Co. Ltd.), Feb. 1989, Abstract. |