FLUORESCENT DISPLAY TUBE

PROBLEM TO BE SOLVED: To form a half mirror in a simple way having a similar function as a neutral-density filter on the surface of a receptacle of a fluorescent display tube and further form a pattern of no hindrance to a display on the face plate due to the half mirror. SOLUTION: A half mirror having a opening 101 and a non-opening 102 is formed on the surface of a fluorescent display tube, and a pseudo-half mirror is formed from the opening 101 and the non-opening 102. As an example of a pattern, the opening 101 and the non-opening 102 are formed in a frame shape, and a new pattern not hindrance to a light-emitting display of the fluorescent display tube is formed on a face plate by combination of frame shapes. Transmittance of the pseudo-half mirror is decided by area ratio of the opening 101 and the non-opening 102. That is, by changing the area ratio of the opening 101 and the non-opening 102, transmittance of the pseudo-half mirror can be set at will to form a pattern not hampering the light-emitting display.