Chunghwa Picture Tubes, Ltd.

Chung Picture Tubes, Ltd.

Kuo-Chu Wang

Chun-Min Hu

Hua-Sou Tong

Yu-Chung Yu

Ming-Yu Hsu

For use in a color cathode ray tube (CRT) having a display screen with a flat outer surface and a curved inner surface, a 2-layer antistatic and antireflective coating for the display screen's flat outer surface compensates for the variation in screen thickness to provide uniform light transmission through the screen and coating combination, a high degree of video image contrast, effective electrostatic shielding and discharge, and reduced light reflectivity. The coating includes a first inner electrically conductive layer disposed on the CRT display screen's flat outer surface containing carbon black particles for a high level of video image contrast and improved electrical conductivity for electrostatic shielding and discharge. The extent of light transmission through the inner conductive layer may be adjusted in accordance with the display screen's thickness by varying the amount of carbon black particles in the coating solution.

Antistatic/antireflective coating for video display screen with adjustable light transmission

A two-layer coating for the outer surface of the display screen of a color cathode ray tube (CRT) includes an inner carbon black-based layer and an outer silica-based layer. The inner layer is antistatic, while the outer layer is antireflective. To compensate for the increased absorption of blue light by the carbon black particles, which results in a color video image having a yellowish tint, a blue additive, such as a pigment or dye, is added to the coating to adjust its light absorbance characteristics and provide uniform light absorbance over the entire visible spectrum of 400-700 nm for improved color video image presentation.

Carbon black coating for CRT display screen with uniform light absorption

A two-layer coating for the outer surface of a glass display screen of a video display device such as a cathode ray tube (CRT) includes an inner antistatic layer and an outer antireflective layer. The outer antireflective layer contains silica and has a refractive index in the range of 1.4-1.5. The inner layer contains carbon black powder particles which provide high electrical conductivity to dissipate electrostatic charge on the glass display screen. The inner layer further includes a surface activation agent, such as glycol, for dispersing the carbon black particles in the antistatic solution. To increase the refractive index of the inner layer to a value greater than its typical value, which is in the range of 1.5-2.0, for the purpose of reducing light reflection from the glass display screen while maintaining high conductivity, ZrO , ZnO, ZnS or TiO , or a combination thereof, is added to the inner antistatic layer to provide a stable solution with optically and electrically desirable characteristics.

Antistatic/antireflective coating for video display screen with improved refractivity

For use in a self-emitting color display device such as a cathode ray tube (CRT) having a display screen with a phosphor coating on its inner surface, a surface coating disposed on the display screen's outer surface affords improved color purity, or contrast, by reducing overlap in the color spectrum between two adjacent primary colors, i.e., between red and green and/or between green and blue. An organic dye is added to either an inner antistatic layer or an outer antireflective layer of an antireflective/antistatic outer coating on the display screen, where both of the aforementioned layers contain silane. The dye functions as a color filter absorbing only light within the frequency range between adjacent primary colors, such as between the red and green color phosphors, i.e., in the range of 460-500 nm, and/or between the green and blue color phosphors, i.e., in the range of 560-600 nm. A silane coupling agent is also added to serve as a binding agent bridging the organic dye and silane together. In this manner, the organic dye is bonded to the silane in either the antistatic layer or the antireflective layer to prevent separation and escape of the organic dye filter from either of these layers of the outer coating on the display screen.

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Taipei, Taiwan

Kuo-Chu Wang