A High-gm and Low Emittance Cathode with Convex Surface

Because of the availability of the internet and digital cameras, the opportunities to enjoy dynamic images and photographs on PC monitors have increased. A cathode with a convex surface has been studied for large screen (i.e. 22in.) high brightness (i.e. 300cd/m2) PC-CRTs. The dimensions of the convex surface were optimized using computer simulations. We obtained an emission current of 1, 300μA, required for 300cd/m2 luminance 22-in. CRTs, with less than a 50-V drive voltage and improved the emittance. We verified significant improvements in the drive and focus characteristics have been verified by prototype CRTs.