;  US5677240-A -- EP294134-A   ALLEGHENY LUDLUM STEEL (ALLL)   DEAN D C;  JP01187983-A   ;  JP03212976-A   ;  JP60016462-A   SUWA SEIKOSHA KK (SUWA)   KATO J;  JP62286271-A   MATSUSHITA ELEC IND CO LTD (MATU)   TAKEDA Y,  KAWAGUCHI T,  MINAMINO Y,  OOKAWA N,  NAGATA S;  JP63074033-A   CANON KK (CANO)   NISHIDA N,  ENOMOTO T,  FUJIMURA F;  US4968638-A   NAT RES DEV CORP (NATR);  BRITISH TECHNOLOGY GROUP LTD (BTGB)   WRIGHT S W,  JUDGE C P,  LEE M J;  US5165075-A   SEMICONDUCTOR ENERGY LAB (SEME)   HIROKI M,  MASE A;  US5177577-A   HITACHI LTD (HITA)   TANIGUCHI H,  SHIRAHASHI K,  MATSUKAWA Y,  MATSUMARU H,  SASANO A,  SHIROHASHI K;  US5264077-A   SEMICONDUCTOR ENERGY LAB (SEME)   FUKUI T,  SAKAMOTO N,  FUKADA T;  US5414278-A   MITSUBISHI ELECTRIC CORP (MITQ)   KOBAYASHI K,  MURAI H,  HAYAMA M;  US5468987-A   SEMICONDUCTOR ENERGY LAB (SEME)   TAKAMURA Y,  YAMAZAKI S,  ZHANG H,  TAKEMURA Y;  US5808315-A -- JP01187983-A   ;  JP03212976-A   ;  JP60016462-A   SUWA SEIKOSHA KK (SUWA)   KATO J;  JP61183971-A   MATSUSHITA ELEC IND CO LTD (MATU)   FUJII K,  TAKEDA M;  JP62286271-A   MATSUSHITA ELEC IND CO LTD (MATU)   TAKEDA Y,  KAWAGUCHI T,  MINAMINO Y,  OOKAWA N,  NAGATA S;  JP63074033-A   CANON KK (CANO)   NISHIDA N,  ENOMOTO T,  FUJIMURA F;  US5177577-A   HITACHI LTD (HITA)   TANIGUCHI H,  SHIRAHASHI K,  MATSUKAWA Y,  MATSUMARU H,  SASANO A,  SHIROHASHI K;  US5264077-A   SEMICONDUCTOR ENERGY LAB (SEME)   FUKUI T,  SAKAMOTO N,  FUKADA T;  US5414278-A   MITSUBISHI ELECTRIC CORP (MITQ)   KOBAYASHI K,  MURAI H,  HAYAMA M;  US5468987-A   SEMICONDUCTOR ENERGY LAB (SEME)   TAKAMURA Y,  YAMAZAKI S,  ZHANG H,  TAKEMURA Y;  US5495353-A   SEL SEMICONDUCTOR ENERGY LAB (SEME)   YAMAZAKI S,  MASE A,  HIROKI M;  US5498573-A   GENERAL ELECTRIC CO (GENE)   WHETTEN N R;  US5500538-A   SEMICONDUCTOR ENERGY LAB (SEME)   MASE A,  YAMAZAKI S;  US5644370-A   CANON KK (CANO)   MIYAWAKI M,  SUGAWA S;  JP3202362-B2 -- JP01129234-A   ;  JP02100024-A   ;  JP02188720-A   ;  JP03166518-A   ;  JP63184210-A   SAINT-GOBAIN VITRAG (COMP);  NIPPON SHEET GLASS CO LTD (NIPG)   HIRATA M,  MISONOU M,  KAWAHARA H