Dental x-ray monitoring system

Claim 1

An x-ray system comprising a. an x-ray tube exhibiting a characteristic emission current upon application of filament and plate voltages thereto for generating x-rays, b. means connected to said tube for supplying said plate voltage thereto, c. means connected to said tube for supplying said filament voltage thereto, d. means for stabilizing said emission current, e. emission current monitoring means for generating a signal X indicative of said emission current, f. inverting means receiving said signal X and generating a signal X equal to the inverse of X, g. plate voltage monitoring means for generating a signal P indicative of plate voltage at said X-ray tube, h. timer means for generating a signal T indicative of elaped time within a preselectable exposure time period, i. logic means for combining said signals X, X, P and T so as to generate a signal M indicative of a signal equivalent to the expression P.T.X + (P+T) X, and j. control means for initiating and terminating the generation of x-rays upon command from a human operator and for prohibiting the generation of x-rays in the absence of said signals M and X which are supplied to said control means only during proper operation of said system.