Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Publication of BE539818ApublicationCriticalpatent/BE539818A/xx
H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
H01J37/02—Details
H01J37/21—Means for adjusting the focus
Landscapes
Chemical & Material Sciences
(AREA)
Analytical Chemistry
(AREA)
Length-Measuring Devices Using Wave Or Particle Radiation
(AREA)
Photometry And Measurement Of Optical Pulse Characteristics
(AREA)