Cathode, electron gun, and cathode-ray tube having a heating element for use during cold electron emisson
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorYasuo Iwasaki
Life of this patent
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Abstract
A cathode, an electron gun, and a cathode-ray tube, having a configuration wherein a heat source for heating an electron emission portion in which an electric field is applied to the tip so that electrons are pulled out is disposed, whereby instability and reduction in amount of emitted electron rays which are due to an effect of adsorbed gas molecules can be prevented from occurring.
Claims15
A cathode which emits electrons toward a fluorescent layer functioning as an anode, comprising:
- an electron emission portion having a projection, a tip of said projection being sharpened;
- an electron pulling electrode which is disposed in the vicinity of said tip and which pulls out electrons from said tip;
- and
- a heat source which heats said electron emission portion during electron emission, thereby preventing said tip from adsorbing gas molecules.
An electron gun which accelerates and focuses electrons emitted from a cathode toward a fluorescent layer functioning as an anode, comprising:
- an electron emission portion having a projection, a tip of said projection being sharpened;
- an electron pulling electrode which is disposed in the vicinity of said tip of said electron emission portion and which pulls out electrons from said tip;
- a heat source which heats said electron emission portion during electron emission, thereby preventing said tip from adsorbing gas molecules;
- an acceleration electrode which is disposed in a side of said fluorescent layer of said electron pulling electrode and which accelerates electrons pulled out by said electron pulling electrode;
- and
- a focusing electrode which is disposed in a side of said fluorescent layer of said electron pulling electrode and which focuses electrons pulled out by said electron pulling electrode.
A cathode-ray tube in which electrons emitted from a cathode are accelerated and focused to impinge on a fluorescent layer functioning as an anode, comprising:
- an electron emission portion having a projection, a tip of said projection being sharpened;
- an electron pulling electrode which is disposed in the vicinity of said tip of said electron emission portion and which pulls out electrons from said tip;
- a heat source which heats said electron emission portion during electron emission, thereby preventing said tip from adsorbing gas molecules;
- an acceleration electrode which is disposed in a side of said fluorescent layer of said electron pulling electrode and which accelerates electrons pulled out by said electron pulling electrode;
- a focusing electrode which is disposed in a side of said fluorescent layer of said electron pulling electrode and which focuses electrons pulled out by said electron pulling electrode;
- and
- a fluorescent screen having a fluorescent layer and a metal film on which electrons focused by said focusing electrode impinge.
Dependencies are inferred from the claim text.