| 313 / | HD | ELECTRIC LAMP AND DISCHARGE DEVICES |
| 364 | DF | CATHODE RAY TUBE {11} |
| 441 | DF | .~ Ray generating or control {6} |
| 446 | DF | .~.~ Including cathode assembly {2} |
| 452 | | .~.~.~ With focus electrode adjacent cathode {2} |
| 453 | DF | .~.~.~.~> Noncircular beam type |
| 454 | DF | .~.~.~.~> Nonplanar cathode {1} |