| 摘要 |
PURPOSE:To substantially form a main electron lens of large aperture, by using an electrode main body, shielding members and composite members. CONSTITUTION:An electrode structural body 31 is formed as a whole in a flat saucer-shape where a plane part 32 is provided with an electron beam through-hole part 33 in its center and electron beam through-hole parts 34, 35 at its both sides while the end edge part of said plane part 32 is connected to a flange part 37 through a side wall part 36 and supporting tips 38 are provided in said flange part 37. Then shielding members 46 are arranged in connection regions 43, 44 to form three mutually independent electron beam through-hole parts 33, 34, 35. |
