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:
Jun. 30, 1987
Filed:
Jun. 19, 1985
Hans-Detlef Brust, Dudweiler, DE;
Johann Otto, Bad Toelz, DE;
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Abstract
A circuit for preventing burn-in spots on the picture screen 23 of a visual display 2 comprising an electron beam 19 that is intensity modulated and positioned controlled by way of a deflection system 21, 22 as, for example, for a scanning electron microscope. The protection to prevent burn-in spots utilizes a circuit wherein the signal input 24 of at least one deflection system 21 is electrically connected to a differentiator which produces an output that is connected to the first input of a comparator which also receives a reference voltage and the comparator output is switched to the input of a retriggable trigger circuit so as to control the intensity of the electron beam 19 and thus prevent burn-in on the picture screen.