US 6,583,547 B1Granted

Cathode ray tube with UPF type electron gun having particular electrode structure and spacing

AssigneesHitachi, Ltd., Hitachi Electronic Devices Co., Ltd.

InventorsToshio Nakayama, Yasuo Tanaka, Nobuyuki Suzuki, Shoichi Wakita, Shoji Shirai

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Abstract

A lens structure of a pre-focus part of an Hi-UPF electron gun to be used for a cathode ray tube has a cathode, a control electrode, an acceleration electrode, a first anode, a focus electrode and a second anode arranged in this order. The first anode and the second anode are to be commonly supplied with an anode voltage, and the focus electrode is to be supplied with a focus electrode. In a cathode ray tube of this construction, in the pre-focus part, the control electrode has an electrode beam passage hole of 0.57 mm or smaller and the distance in the vicinity of the electron beam passage hole between the acceleration electrode and the first anode is 1.9 mm or smaller.

Claims29

Dependent claims

In a cathode ray tube having an envelope comprising a panel part having a fluorescent screen, a neck part incorporating an electron gun, and a funnel part joining said panel part and said neck part, the cathode ray tube being characterized in that:

said electron gun has a cathode, a control electrode, an acceleration electrode, a first anode, a focus electrode and a second anode arranged in this order in a direction toward said fluorescent screen;
said first anode and said second anode to be commonly supplied with an anode voltage;
said focus electrode to be supplied with a focus voltage, a length of said focus electrode in a tube axis direction being larger than a length of said first anode in the tube axis direction;
said control electrode and said first anode in their portions facing said acceleration electrode and said acceleration electrode having electron beam passage holes;
the electron beam passage hole of said control electrode having a diameter which is equal to or smaller than 0.57 mm;
and said acceleration electrode and said first anode in the vicinity of the outer periphery of their electron beam passage holes being spaced by a distance of 1.9 mm or less.

3 more elements

Dependencies are inferred from the claim text.