| 摘要 |
PURPOSE:To prolong the life which is concerned with the electron emission rate of the cold electron emitting material of an image pickup tube, by arranging the cold electron emitting material on the inside of a deflecting coil and a focusing coil. CONSTITUTION:Being affracted by the second electrode 13, the third electrode 14 and a mesh electrode 15, an electron emitted from the surface 101 of a cold electron emitting material 10 collides with a photoconductive layer 16, and scans two- dimensionally the surface of the photoconductive layer 16 horizontally and vertically by an alternating magentic field cxcited by a deflecting coil 22. In this device, the cold electron emitting material 10 is in the magnetic field of the deflecting coil 22. Accordingly, as positive ion generated in a image pickup tube scarcely collides with the surface of the cold electron emitting material 10, the electron emission rate of the cold electron emitting material 10 may not be deteriorated. |
