| 摘要 |
<p>PURPOSE:To save the wasted quantity of light by forming a grid electrode to be arranged between the array arrangement of a dot array fluorescent tube changing-over an information signal to optical information and a cathode filament so as to have the slit-shaped opening part. CONSTITUTION:A cathode filament 12, phosphors 14-1-14-i, a grid electrode 16 and a transparent electrode 13 are arranged in a rectangular vacuum chamber composed of a substrate glass 10 and a face glass 11 for forming a dot array fluorescent tube for writing optical information. Thereby, the grid electrode 16 is made to have the slit-shaped opening part corresponding to the array arrangement of the phosphor 14-i while forming the other part except the opening part as a hexagon mesh construction. And the filament 12 is heated for emitting light selectively by impressing voltage on the prescribed phosphor 14. Accordingly, the optical information is not intercepted by the grid electrode 16 so as to be able to prevent generation of waste and unevenness of the quantity of light.</p> |
