| 摘要 |
PURPOSE:To reduce scattering of results of inspection by a method, in which the other electrodes except a focusing electrode are impressed by the fixed voltage for putting them into an operating state, while the focusing electrode is impressed by the positive and negative voltage as against the fixed voltage in order to discern the quality from the luminous condition of the static spot light on a phosphor film. CONSTITUTION:A luminous film 2 is made to luminesce by generating an electron beam only at the time of output of the pulse power source 21 while putting an electron gun into the operating state. In this state, the power source 25a for vertical deflection and the power source 25b for horizontal deflection of the power source 25 are regulated to shift an electron beam to an optional position of the face part in order to be fixed. Next, when the power source 23 is made to change while increasing or decreasing as against the rating value, the diameter of a spot light on the phosphor film 2 changes. When said quantity of light is detected by a spot meter 26, its output becomes the minimum in the vicinity of the rating voltage as shown in the curve A, while the spot light enlarges while increasing the quantity of light with being distant from the rating voltage. Accordingly, the quality of resolution can be known by detecting the quantity of light in the rating value of the focusing voltage and the quantity of light when shifted positively and genatively by the fixed voltage from the focusing voltage. |
