Abstract: A color cathode ray tube in which beam landing errors caused by non-uniform thermal expansion of a shadow mask are corrected is provided such that color purity is improved. The color cathode ray tube in accordance with the present invention comprises a panel having a phosphor screen formed on an inner surface thereof, a shadow mask having a faceplate portion and a peripheral skirt portion bent back from the faceplate portion and a frame joined to the skirt portion, wherein a height of the skirt portion is less than or equal to 12 mm for substantially the entire skirt portion, and a plurality of holes are perforated at the skirt portion.

Abstract: An electron gun for a cathode ray tube is disclosed, which has a simple structure and can prevent the spot on a screen from being degraded. In the electron gun for a cathode ray tube including a cathode that emits electron beams, a first electrode that controls the electron beams emitted from the cathode, a second electrode that accelerates the electron beams emitted from the first electrode, and third to fifth electrodes sequentially arranged in a screen direction to act as pre-focus lenses, the electron gun is characterized in that the third to fifth electrodes have different sized electron beam through holes.

Abstract: The color cathode-ray tube includes a panel having a fluorescent screen formed on the inner surface thereof, a funnel coupled to the panel, an electron gun mounted into the neck portion of the funnel for emitting electron beams toward the fluorescent screen, and a shadow mask mounted on the fluorescent screen formed on the inner surface of the panel and having a predetermined distance from the fluorescent screen for carrying out color selection. The shadow mask is in a rectangular shape having a longer axis and a shorter axis and including a plurality of beam through apertures. The vertical pitch of the beam through apertures is between 0.15 mm and 0.35 mm. The vertical pitch of the beam through apertures increases as it goes from the central portion to the end portion of the shorter axis of the shadow mask.

Abstract: A color image display device has an auxiliary means for compensating brightness simply and inexpensively by using an electron gun of a cathode ray tube. Brightness uniformity is improved in the image display device having a flat-type color cathode ray tube with a glass panel having a high wedge ratio and a low transmissibility. The color image display includes a panel housing a screen on an inner face thereof, a funnel engaged with the panel; an electron gun engaged with a neck portion of the funnel for emitting electron beams toward the screen, a deflection device for displaying an image by deflecting the electron beams emitted from the electron gun in horizontal and vertical directions with respect to the screen, and a cathode ray tube including a shadow mask aligned from the screen at a predetermined distance.

Abstract: An electron gun for a CRT having a cathode for discharging electron beams, a first electrode for controlling the electron beams discharged from the cathode, and a second electrode for accelerating the electron beams having passed the first electrode, third, fourth and fifth electrodes sequentially installed in the direction of a screen and serving as a pre-focus lens, in which an electron beam passing hole of the third electrode, an electron beam passing hole of the fourth electrode and an electron beam passing hole of the fifth electrode have different sizes By controlling the size of the electron beam passing hole of the third the fourth and the fifth electrodes, the divergence angle and the electron beam size are reduced and the spherical aberration is also reduced Accordingly, a degradation of the spot focussed on the screen can be effectively prevented.