Abstract: A cathode-ray display tube for color printers has a phosphor screen comprises a blue-emitting phosphor having a maximum ability of color emission in the range of wavelengths of 480 m.mu. and below with a radiant energy in the range of wavelengths of about 480 m.mu. and higher being 10% or less of the overall radiant energy; a green-emitting phosphor having a maximum ability of color emission in the range of wavelengths of 520 through 570 m.mu. with a radiant energy in the range of wavelengths of about 500 m.mu. and less and of about 630 m.mu. and higher being 5% or less of the overall radiant energy; and a red-emitting phosphor having a maximum ability of color emission in the range of wavelengths of 630 through 750 m.mu. with a radiant energy in the range of wavelengths of about 590 m.mu. and less being about 10% or less of the overall radiant energy.Phosphor dots located beyond the area of normal raster are sensed to provide timing signals for controlling beam deflection.