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:
Nov. 11, 1997
Filed:
Sep. 14, 1995
Katsuhiko Nishikawa, Aichi, JP;
Hiroya Ikeda, Aichi, JP;
Sony Corporation, Tokyo, JP;
Abstract
A cathode current detecting method wherein both a highlight detection pulse used to detect a white component and a cutoff detection pulse used to detect a black component are input to a signal input unit, and a cathode current flowing through a cathode is detected which corresponds to one of the highlight detection pulse and the cutoff detection pulse, includes the steps of: outputting a leak current detection pulse having the same magnitude as that of the cutoff detection pulse at a preselected timing; prohibiting an electron beam emitted from the cathode from flowing through an anode at the preselected timing; and detecting the leak current flowing through the cathode in response to the leak current detection pulse at the preselected timing to clamp a voltage corresponding to the leak current to a predetermined reference potential. A cathode current detecting circuit is provided wherein both a highlight detection pulse used to detect a white component and a cutoff detection pulse used to detect a black component are inputted to a signal input unit, and a cathode current corresponding to an electron beam flowing from a cathode to an anode based upon one of the highlight detection pulse and the cutoff detection pulse, of: includes a signal output circuit for outputting a leak current detection pulse having the same magnitude pulse as that of the cutoff detection pulse at a preselected timing; A current for prohibiting the electron beam emitted from the cathode from flowing at the preselected timing; a prohibit signal circuit for outputting a signal used to cause the prohibiting circuit to perform a prohibit operation in response to the output from the signal output circuit at the preselected timing; and a clamping circuit for detecting a leak current flowing through the cathode in response to the leak current detection pulse at the preselected timing to clamp a voltage corresponding to the leak current to a predetermined reference potential.