Number | Name | Date | Kind |
---|---|---|---|
2405960 | Land | Aug 1946 | |
3576357 | Levy | Apr 1971 | |
3884548 | Linder | May 1975 | |
4136926 | Sigler | Jan 1979 |
Number | Date | Country |
---|---|---|
119260 | Sep 1979 | JPX |
Entry |
---|
Optical Engineering, Jul./Aug. 1974, vol. 13, No. 4. |
Xerox Disclosure Journal, vol. 6, No. 5, Sep.--Oct., 1981. |