Glass bulb for a cathode ray tube and cathode ray tube
AssigneeAsahi Glass Company, Limited
InventorsTsunehiko Sugawara, Toshihide Murakami, Mikio Ueki
Life of this patent
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Abstract
There is provided a glass funnel for a cathode ray tube, which has a deflection angle of 120 deg or more, which has a concave portion in a funnel body portion around a yoke portion so as to have a depth of 10 mm or more, wherein a compressive stress layer is formed in a position where a tensile stress, which is generated on an outer surface of the funnel body portion, takes a maximum value σVTmax, the compressive stress layer has a compressive stress value σC of 80 to 350 MPa, the compressive stress layer has a thickness of 60 μm or more, and the maximum value σVTmax is 10 to 100 MPa.
Claims5
A glass funnel for a cathode ray tube, which comprises an open seal edge portion formed in a substantially rectangular shape, a cylindrical neck portion, a yoke portion for mounting a deflection yoke and a funnel body portion extending between the yoke portion and the seal edge portion, which forms a glass bulb for a cathode ray tube along with a glass panel, and which has a deflection angle of 120 deg or more;
- the funnel body portion having a concave portion formed around the yoke portion, the concave portion having a depth of 10 mm or more, the depth of the concave portion being a distance in a direction of a bulb axis between a point on an outer surface of the funnel body portion closest to the neck portion in the direction of the bulb axis and a point on an outer surface of the concave portion farthest from the neck portion in the direction of the bulb axis in a first funnel section, which is a cross-section containing the bulb axis and a point PS1 lying closest to the bulb axis and on the outer periphery of the seal edge portion;
- wherein a compressive stress layer is formed in a position where a tensile stress, which is generated on the outer surface of the funnel body portion when evacuating an inner space of the glass bulb for production of a cathode ray tube, takes a maximum value σVTmax, the compressive stress layer has a compressive stress value σC of 80 to 350 MPa, the compressive stress layer has a thickness of 60 μm or more, and the maximum value σVTmax is 10 to 100 MPa.
Dependencies are inferred from the claim text.