摘要 |
553,181. Electron beam apparatus. PHILIPS LAMPS, Ltd. (Naamlooze Vennootschap Philips' Gloeilampenfabrieken). Nov. 12, 1941, No. 14595. Drawings to Specification. [Class 39 (i)] The subject-matter of this Specification is identical with that of Specification 600,429, [Group XL (a)]. |