Nippon Electric Glass Co., Ltd.

Other

Masaya Kyono

Hiroshi Kakigi

Hiroshi Sakurai

Hiromi Wakasono

Hajime Makio

Shigeyoshi Ito

Koji Kuwahara

Upper end edges () of positioning reference portions () to be formed on outer walls of a funnel () for cathode ray tube are formed at distances (downwardly) toward a narrow open end () of the funnel from a maximum profile line () formed in the vicinity of a wide open end () by mold matching of forming mold at the time of press molding, thereby suppressing molding defects such as deficiency and wrinkle resulting from that glass is not completely filled, which are likely to occur in reference surfaces () of the positioning reference portions, and eliminating occurrences of small cracks caused by concentration of heat stress, which are likely to occur in the upper end edges () of the reference portions, to improve the productivity of the funnel.

CRT funnel with positioning reference portions

A body portion of the funnel has a first region of dimension h, the dimension h being measured from the seal edge surface in a direction parallel to a tube axis, and a second region excluding the first region. The second region has a thickness relatively smaller than the thickness of the first region, so that a boundary portion between the two regions forms a stepped portion on the external surface of the body portion.

Glass funnel and glass bulb for cathode ray tube

A body portion of the funnel, within a range excluding corners, has a first region of predetermined dimension, the predetermined dimension being measured from the seal edge surface in a direction parallel to a tube axis, and a second region excluding the first region. The second region has a thickness relatively smaller than the thickness of the first region, so that a boundary portion between the two regions forms a stepped portion on the external surface of the body portion.

Glass funnel for cathode-ray tube and glass bulb for cathode-ray tube

With respect to a highly flat glass bulb for cathode ray tube having an effective screen diameter along a diagonal axis of a glass panelof more than or equal to 500 mm, and an average radius of curvature of an outer surface of a face portion of more than or equal to 10,000 mm, a ratio between a length h of a skirt portionof the glass panel and a distance H in the tube axis direction from an edge surface portion where a funnel is sealed with the glass panel to a reference line is defined so as to fall within a predetermined range in relation to a deflection angle &#x3b8; of the funnel representing substantial degree of divergence in the tube axis direction of the funnel, thereby achieving reduction of weight of the glass bulb while maintaining a certain mechanical strength, as well as suppressing breakage during frit seal heating process.

Glass bulb for cathode ray tube

In a disclosed glass bulb for a cathode-ray tube (CRT), a funnel unit have a less depth than a conventional one. The glass bulb for the CRT includes a panel unit having a panel screen, a neck unit holding an electron gun, and a funnel unit having a funnel-like shape, and the panel unit and the neck unit are bridged by the funnel unit. In the glass bulb, the funnel unit is formed from a plurality of glass members and a maximum-to-minimum thickness ratio of each of the plurality of glass members is designed to be within a range suitable for producing the glass members using pressing.

Glass bulb for a cathode-ray tube and a cathode-ray tube device

With respect to a highly flat glass bulb for cathode ray tube having an effective screen diameter along a diagonal axis of a glass panel of more than or equal to 500 mm, and an average radius of curvature of an outer surface of a face portion of more than or equal to 10,000 mm, a ratio between a length h of a skirt portion of the glass panel and a distance H in the tube axis direction from an edge surface portion where a funnel is sealed with the glass panel to a reference line is defined so as to fall within a predetermined range in relation to a deflection angle &thgr; of the funnel representing substantial degree of divergence in the tube axis direction of the funnel, thereby achieving reduction of weight of the glass bulb while maintaining a certain mechanical strength, as well as suppressing breakage during frit seal heating process.

Glass bulb for cathode-ray tube

In a glass panel for cathode ray tube of which effective screen diameter D along the diagonal axis of the glass panel is more than or equal to 500 mm, and average radius of curvature of an outer surface of a face portion is more than or equal to 10,000 mm, when a distance h along a tube axis from a contact between an effective screen end of an inner surface of the glass panel and a blend R portion to a seal edge surface is defined as a length of a skirt portion , and a glass wall thickness of the seal edge surface of the skirt portion is defined as t, ranges of h and t are specified by ratios with respect to the effective screen diameter D, and a product of h and t is also specified to satisfy a predetermined range in relation to the effective screen diameter D. In this way, deformation of the skirt portion due to inclination is suppressed, reduction in mechanical strength due to shortening of the skirt portion is compensated by the glass wall thickness of the seal edge surface, and thus weight reduction of the glass panel is accomplished while retaining the predetermined mechanical strength.

Growing community of inventors

Nagahama, Japan

Masaya Kyono