| 摘要 |
PURPOSE:To improve shading characteristics and resolution characteristics by allowing an electron beam to enter vertically to a photosensitive layer. CONSTITUTION:A deflection control unit 20 is constituted with two pairs of electromagnetic deflection scanning units, i.e., electromagnetic deflection coils 21, 22, and both coils are installed on the tube axis apart from each other so that the center separation (1) between them is about one half of a loop length of an electron beam formed by electromagnetic focusing. According to such a camera tube device, an electron beam is applied with a deflection force F1 and deflected by the deflection magnetic field from the first deflection coil 21 on the electron gun side then is applied with a deflection force F2 by the second deflection coil. The deflection force F2 by the second deflection coil 22 on the photosensitive layer side acts in the direction to offset the former deflection force F1 because the separation (1) between both coils corresponds to one half of a loop length of the electron beam, thus changing the beam to a direction parallel to the tube axis. Thereby, the angle of incidence of the electron beam to the photosensitive layer can be made zero, thus allowing vertical incidence. |
