| 摘要 |
PURPOSE:To enable to adjust focusing condition without giving influence to deflecting condition by making variable a constant current of the fourth and fifth constant current circuits in accordance with a focusing control signal. CONSTITUTION:A current, which is equal to resistors Rc and Rd connected to the first and second deflecting signal input terminals Tc and Te by changing a constant current ib of the fourth and second constant current circuits IKb1 and IKb2, flows and equal direct current voltage occurs at both ends. Thus, an overlapped signal of a focusing control signal of a value equal to a differential output deflecting signal can be obtained at the first and second deflecting signal output terminals Td and Tf. Therefore, focusing condition can be adjusted without giving influence to deflecting condition. |
