| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a cold cathode having a low discharge voltage, and high efficiency and stability. SOLUTION: A cold cathode is prepared as follows: a raw material solution containing lanthanum nitrate La(NO3 )3 .6H2 O (S1) is prepared and applied on an electrode substrate (S2), the resulting film is subjected to preliminary reaction treatment in vacuum, at a temperature of ordinary temperature to 350 deg.C for about 30 minutes (S3), the electrode substrate is then heated in an electric furnace at a temperature of 700 deg.C to 750 deg.C so as to convert the raw solid film to an oxide crystalline film composed mainly of lanthanum oxide (S4). Then, the electrode substrate is treated in a reduction furnace to remove needless oxides therefrom (S5). The electrode substrate thus prepared is then cut and bent in a form of an electrode of the cold cathode fluorescent tube and assembled into the tube. In the cold cathode, the metal film as formed on the surface of the electrode, composed mainly of lanthanum oxide of lanthanum shows a high electron emission characteristic and sputter-resistance, so that it is useful as a cold cathode having a low discharge voltage, and a high efficiency and stability.</p> |
