Image display apparatus.

摘要

The video image display apparatus of flat tube type comprises:
a phosphor screen having a phosphor layer for emitting light at impingement by electron beam,
an electron beam source comprising a predetermined number (15) of line cathodes for in-turn emitting said predetermined number of horizontal rows of electron beams, each row having a second predetermined number (320) of rod shaped electron beams for together producing one horizontal line of image on said phosphor screen,
a vertical deflection means for vertical deflections of the electron beams of the horizontal rows in a manner that electron beams of a horizontal row impinging the phosphor screen at one vertically divided segment corresponding to one of said horizontal row is driven vertically, thereby vertically moving one of the horizontal line in the vertically divided segment.
the vertical deflection signal is a step wave having saw-tooth wave envelope, and the envelope is adjusted so as to be expanded or compressed or level changed, thereby undesirably black horizontal band or white horizontal band on the screen can be eliminated and a uniform raster is obtainable.