Legal status (The legal status 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 status listed.)
Expired
Application number
GB753040A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Baird Television Ltd
Original Assignee
Baird Television Ltd
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.)
Filing date
Publication date
Application filed by Baird Television LtdfiledCriticalBaird Television Ltd
Priority to GB753040ApriorityCriticalpatent/GB540739A/en
Publication of GB540739ApublicationCriticalpatent/GB540739A/en
H01J40/00—Photoelectric discharge tubes not involving the ionisation of a gas
H01J40/02—Details
H01J40/04—Electrodes
H01J40/06—Photo-emissive cathodes
Abstract
540,739. Photo-electric surfaces. BAIRD TELEVISION, Ltd., and SOMMER, A. April 26, 1940, No. 7530. Addition to 532,259. [Class 39 (i)] A method of making a photo-electric surface having a spectral sensitivity approximating that of the human eye, consists in depositing on a support, which may be the glass wall of an evacuated envelope, a layer of bismuth, which is then oxidized by heating in an atmosphere of oxygen or by electric discharge in oxygen. Silver, and then an alkali metal such as caesium, are evaporated on to the bismuth oxide layer at a temperature of 150-200‹ 'C. Preferably only sufficient alkali metal is used to reduce all the bismuth oxide. The composite layer is then baked and superficially oxidized until the optimum or desired spectral sensitivity is obtained.
GB753040A1940-04-261940-04-26Improvements in or relating to photoelectrically sensitive electrodes
ExpiredGB540739A
(en)