 
                 Patent Grant
 Patent Grant
                     5457019
 5457019
                    | Number | Date | Country | Kind | 
|---|---|---|---|
| 5-026031 | Jan 1993 | JPX | 
| Number | Name | Date | Kind | 
|---|---|---|---|
| 5132202 | Nishijima et al. | Jul 1992 | |
| 5212055 | Morigaki et al. | May 1993 | 
| Entry | 
|---|
| Reseach Disclosure, vol. 308, Item 308119, Dec., 1989. |