| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a negative electrode base having sufficient ion impact resistance, satisfactory electron-emitting characteristic and furthermore satisfactory low-temperature operating characteristic even under high-voltage and high- frequency conditions. SOLUTION: A porous tungsten base is formed through sintering, and the electron emitting material is fused for impregnation in a vacant hole of the porous tungsten base. A scandium oxide thin film and a tungsten thin film are formed in this order on the porous negative electrode base by spattering. An impregnated negative electrode structure 1 provided with the porous negative electrode base 4 is assembled in a cathode-ray tube, and subjected to an activation process at 1,200-1,300 deg.C for 1 to 2 hours. The porous negative electrode base 4 has tungsten, scandium and oxygen in the electron-emitting surface side thereof as well as a scandium thin film. The scandium thin film has a positive density gradient of the scandium atom density in the depth direction from the surface of the electron-emitting surface side.</p> |
