16‐cm Large Neck Projection CRT for HDTV Display

A 16-cm, large neck (36.5mm neck diameter) projection CRT having a Hi-UPF electron gun has been developed. The deflection sensitivity, dynamic focus voltage and velocity modulation coil sensitivity, which were drawbacks of previous large neck designs, were made nearly equal to 29.1mm neck CRT. The large neck allowed increasing the effective focusing lens diameter of the electron gun to 21mm. This resulted in a 5% beam spot size of 0.18mm and 0.28mm at a cathode current of 2.0mA and 6.0mA, respectively. This CRT will provide the enhanced image quality required for HDTV projection displays.