Flat type color cathode ray tube
AssigneeLG. Philips Displays Korea Co., Ltd.
InventorHoon Jeong
Life of this patent
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Abstract
In a flat type color cathode ray tube, in using of a tint or a dark tint panel capable of improving contrast characteristics of a screen and reducing production processes, namely, having the conventional coating process reduction advantage, by optimizing a horizontal pitch and a transmissivity of a shadow mask and a transmissivity of a screen in order to solve a brightness balance deterioration problem at the circumference portion of the screen due to a glass transmissivity difference, it is possible to maintain inner impact resistance and howling characteristics of the shadow mask, in addition, by improving a circumference portion transmissivity of the shadow mask and a screen transmissivity, it is possible to improve a brightness balance at the circumference portion and a quality of the screen.
Claims14
In a flat type color cathode ray tube including a rectangular panel having an almost flat outer surface and an inner surface having a certain radius of curvature, a funnel installed to the rear of the panel, a fluorescent surface coated onto the internal surface of the panel and performing a certain fluorescence function, an electron gun discharging electron beams radiating the fluorescent surface, a shadow mask for making the electron beams from the electron gun land on a certain portion of the fluorescent surface, a frame for fixing/supporting the shadow mask, a spring and a stud pin for combining the frame assembly with the panel, an inner shield combined with the certain side of the frame from the panel side to the funnel side in order to protect the cathode ray tube against a terrestrial magnetism, an electron gun placed inside a neck portion of the funnel and generating the electron beams, a deflection yoke installed to the outer surface of the neck portion of the funnel in order to deflect the electron beams from the electron gun in a certain direction, a CPM (convergence & purity magnet) for precisely adjusting the deflected direction of the electron beams and a reinforcing band installed to the outer circumference of the portion at which the panel and the funnel are combined in order to protect the panel and the funnel against an air pressure and external impacts, wherein a flat type color cathode ray tube satisfies
- 1.2≦PhH/PhC≦1.6, 1.2<PhD/PhC≦1.6
- when a central portion glass transmissivity of the panel is about 45%˜75%, a radius of curvature in the diagonal direction (RpD) of the panel has a range of 3.5 R≦RpD≦8.0 R (R is calculated by multiplying 1.767 by an effective surface diagonal axis length of the panel), a horizontal pitch of an electron beam passage hole at the central portion of the shadow mask is PhC, a horizontal pitch of the outmost electron beam passage hole in the long axis direction is PhH, a horizontal pitch of the outmost electron beam passage hole in the short axis direction is PhV and a horizontal pitch of the outmost electron beam passage hole in the diagonal axis direction is PhD.
In a flat type color cathode ray tube including a rectangular panel having an almost flat outer surface and an inner surface of a certain radius of curvature, a funnel installed to the rear of the panel, a fluorescent surface coated onto the internal surface of the panel and performing a certain fluorescence function, an electron gun discharging electron beams radiating the fluorescent surface, a shadow mask for making the electron beams from the electron gun land on a certain portion of the fluorescent surface, a frame for fixing/supporting the shadow mask, a spring and stud pin for combining the frame assembly with the panel, an inner shield combined with the certain side of the frame from the panel side to the funnel side in order to protect the cathode ray tube against a terrestrial magnetim, an electron gun placed inside a neck portion of the funnel and generating the electron beams, a deflection yoke installed to the outer surface of the neck portion of the funnel in order to deflect the electron beams from the electron gun in a certain direction, a CPM (convergence & purity magnet) for precisely adjusting the deflected direction of the electron beams and a reinforcing band installed to the outer circumference of the portion at which the panel and the funnel are combined in order to protect the panel and the funnel against an air pressure and external impacts, wherein a flat type color cathode ray tube satisfies
- 0.80≦TsD/TsC≦1.20
- when a central portion glass transmissivity of the panel is about 45%˜75%, a radius of curvature in the diagonal direction (RpD) of the panel is within a range of 3.5 R≦RpD≦8.0 R (R is calculated by multiplying 1.767 by an effective surface diagonal axis length of the panel), a circumference portion screen transimissivity is TsD and a central portion screen transmissivity of the effective surface of the panel is TsC.
Dependencies are inferred from the claim text.