| 摘要 |
PURPOSE:To display an excellent picture free of the influence of mechanical vibration by switching linear cathodes alternately and driving them with pulses, and adjusting heating currents to the linear cathodes, cathode by cathode. CONSTITUTION:This describes an example of a circuit used for optional one of linear cathodes 2a-2o. Transistors (TR) 47a-47o turn on in low-level periods of vertical driving pulses, i.e. in heating periods, and the linear cathodes 2a-2o are heated by a current I1 from a power source +B1 to hold the linear cathodes 2a-2o at positive potentials, so no electron beam is emitted. When the pulses (a-o) are at high levels, a negative power source -B2 is applied to the linear cathodes 2a-2o through TRs 48a-48o to turn of diodes 50a-50o. Consequently, the linear cathodes 2a-2o are held at low potentials to emit electrons with a uniform distribution, and heating currents to the linear cathodes 2a-2o are adjusted individually by variable resistors 57a-57o. |
