| 摘要 |
PURPOSE:To extend development time in accordance with the degree of deterioration of a developer by measuring the magnitude of a transmission light by irradiating a recovered circulating developer with a light beam, and deciding the degree of deterioration of the developer from the transparency of the developer. CONSTITUTION:The transparency of a developer can always be measured by a light source 19 and a detector 20 shown in a part 18. An electric signal from the detector 20 is sent to a controller 21, and in the controller 21, a control signal for lowering the feed speed of a carrying roll 17, or a control signal for prolonging temporary stop time on the carrying roll of a substrate in a developer 1 is generated to a carrying mechanism so that the development time is prolonged as the transparency of the developer falls. In such a manner, the degree of deterioration of the developing capacity of the developer can be decided by detecting the transparency of the developer, and in accordance with the transparency of this developer, the development time can be controlled automatically. |
