The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 21, 1989
Filed:
Apr. 17, 1987
Aart A van Gorkum, Tokyo, JP;
U.S. Philips Corporation, New York, NY (US);
Abstract
A cathode ray tube having an electron gun with a triode section and bi-potential focusing lens electrodes. Generally such focusing lens electrodes comprise two juxtaposed cylindrical electrodes of which the one nearer the screen (accelerating electrode) is at the screen voltage of approximately 30 kV. If it is desired to increase the diameter of the focusing lens the voltage difference between the focusing electrode and the other cylindrical electrode (accelerating electrode) must be increased. The effect of this is to make the focusing electrode voltage unacceptably low with respect to the triode section. This problem is overcome by providing the accelerating electrode 29 with a diaphragm 30 having an aperture whose area is less than half the cross-sectional area of the focusing electrode (24). The presence of the diaphragm enables the focusing electrode voltage to be increased to an acceptable level and be equal to that applied to a prefocusing lens electrode (22), enabling these electrodes (22, 24) to be interconnected electrically and/or mechanically.