| 摘要 |
PURPOSE:To obtain a color cathode-ray tube, which provides a screen having appropriate color and can be easily seen, without deteriorating the contrast increasing effect by making a material for a filter plate to be added with Nd2O3 and a small amount of at least one of Cr2O3 and Pr2O3. CONSTITUTION:A curve (B) in the figure indicates the spectral transmittance of glass which has a thickness of 3X and contains 3.0wt% of Nd2O3. Here, when 0.003wt% to the above Nd2O3 of Cr2O3 is added to the above glass, the transmittance of the glass changes mainly in the red and the blue regions, and shows a curve (C) indicated by a broken line. As the result, in the wavelength range of 575-585nm, the difference between the light transmittances of a part of the above glass which highly absorbs light and the other part of the above glass is decreased. Therefore, the color of the above glass is not changed into raddish purple, and the color change to external light of the above glass is reduced. In addition, since the blending of Pr2O3 increases the absorbency of only the blue light component, the color of the filter plate can be adjusted close to neutral. It is preferred that the blending ratio of Pr2O3 to the above Nd2O3 is in the range of 0.1-0.5wt%. |
