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AssigneesHitachi, Ltd., Hitachi Electronic Devices Co., Ltd.
InventorsTakeshi Mera, Masato Miura, Yoshiaki Takahashi
Estimating the term…
In an electron gun for a cathode ray tube in which a focus electrode group includes a single platelike electrode having three apertures arrayed in one plane and a thickness equal to a depth of each of the three apertures, a tapered surface is formed on the entrance side and/or exit side of each of the three apertures, the tapered surface having a diameter larger than the aperture diameter and having a linear or curved shape in cross section, and a step which extends in the direction of the depth is formed around an aperture periphery of the tapered surface. With this constitution, the concentricity between each of the tapered surfaces and a respective one of the apertures can be measured with high precision on the basis of the boundary between each of the tapered surfaces and the corresponding one of the steps, thereby improving the precision of measurement of the concentricity between each of the apertures formed in the platelike electrode and the tapered surface formed around the aperture periphery.
An electron gun for a cathode ray tube, comprising a single platelike electrode having an aperture, wherein a circumferential surface is formed around at least one of an entrance side and an exit side of said aperture, said circumferential surface having a diameter larger than a diameter of said aperture and having a linear or curved shape in cross section, and a step which extends in a direction of a depth of said aperture is formed around said circumferential surface.
An electron gun for a cathode ray tube comprising a single platelike electrode having three apertures arranged in one plane including a central aperture and two side apertures, wherein a circumferential surface is formed around at least one of an entrance side and an exit side of each of said three apertures, said circumferential surface having a dimension larger than a corresponding dimension of said aperture taken along any direction perpendicular to a depth direction of each of said three apertures and having a linear or curved shape in cross section, and a step which extends in the depth direction is formed around said circumferential surface.
An electron gun for a cathode ray tube comprising a single platelike electrode having there apertures arrayed in one plane including a central aperture and two side apertures, wherein both the entrance side and exit side of each of said three apertures are tapered and have dimensions larger than the corresponding dimensions of said apertures, each of the two side apertures has a non-circular shape having a longer axis in a direction in which said three apertures are arrayed, and an inside surface of each of said three apertures having either one of an even surface and a recessed surface extending along said inside surface.
A method of manufacturing an electron gun electrode for a cathode ray tube, which includes a single platelike electrode having three apertures arrayed in one plane, comprising the steps of:
Dependencies are inferred from the claim text.