INSPECTION DEVICE FOR CATHODE-RAY TUBE

PURPOSE:To improve the reliability of inspection by conducting the inspection using a light source of the illuminance of 2000lux or greater from behind a cathode-ray tube with its phosphor surface formed with a metal back layer. CONSTITUTION:The forming condition of a metal back layer on a panel 1 of a cathode-ray tube is inspected from the front of the panel 1 by opening a shutter 4 by the operation of a switch 5 to illuminate the panel from behind. As a light source 3, a light source for exposure ordinarily used for forming phosphor surface is suited. This light source is a high pressure mercury-vapor lamp of 2000lux or greater, about 1kW, 3000lux for example, having sufficient capacity to satisfy the purpose. The illuminance of 2000lux or greater is preferable because the forming condition of the metal back layer is hard to observe in detail under the condition of a shadow mask installed, if the illuminance of the light source is below 2000lux.