| 摘要 |
PURPOSE:To prevent insulation failure from occurring between tip parts of cathodes and prolong the useful life of a plasma optical head, by providing a first dielectric film for covering the opposed tip portions of the cathodes, and second dielectric films for covering the cathodes, exclusive of exposed parts for forming discharge regions of plasma light-emitting parts. CONSTITUTION:A first dielectric film 30 is disposed to extend in a band form, for example, in the array direction of cathodes 28 to cover tip parts of the cathodes 28 on one side and tip parts of the cathodes 28 on the other side. Similarly, second dielectric films 32 are disposed on the cathodes 28 on both sides to extend in a band form, for example, in the array direction of the cathodes 28. The first dielectric film 30 and each of the second dielectric films 32 are disposed separately from each other so that an exposed part Q is provided therebetween. Thus, the tip parts of the cathodes 28 on both sides are covered by the first dielectric film 30, whereby deposition between the tip parts of the cathodes 28 due to sputtering is prevented from occurring, and insulation failure between the tip parts of the cathodes 28 can be obviated. |
