| 摘要 |
<p>PURPOSE:To remove decrease of brilliance due to a charge up phenomenon by a method wherein a grid voltage supply means, and a voltage additioning means which adds specific voltage to specific grid voltage during a write pause period by being controlled by a synchronizing signal discriminating an image write period from the write pause period, are established. CONSTITUTION:Since a synchronizing signal/FSYNC comes to be of a low level while a recording head 101 writes, a transistor Tr1 becomes nonconducting, and its emitter voltage v1 becomes O (v). Voltage VG applied to an input terminal 15 is applied as it is to an operational amplifier OP1, and output voltage VG is taken out as v0 VG to be impressed to a grid electrode 5. Then, when a write pause period comes, the synchronizing signal/FSYNC comes to be of a high level, and the transistor Tr1 conducts. Voltage of a power source terminal 16 appears at the emitter of the transistor Tr1 to become v1. The voltage v1 is added to the voltage VG to be inputted to the operational amplifier OP1. Consequently grid voltage is altered to v0 VG+v1. A transistor Tr2 supplies a current amplified by the voltage v0 to a grid electrode 5.</p> |
