Abstract: An envacuated envelope has substantially flat, parallel front and back walls and spaced, parallel support walls extending between and perpendicular to the front and back walls and forming a plurality of channels. Beam guides extend along each of the channels for guiding three beams along each channel and for selectively deflecting the beams at selected points along the channel toward a phosphor screen on the front wall. Between the beam guides and the phosphor screen are deflection electrodes for deflecting the beams transversely across the channel so as to scan the portion of the phosphor screen which extends across the channel. Also between the beam guides and the phosphor screen is means forming an electron lens for converging the three beams at a point spaced from but adjacent to the screen.