| 摘要 |
In a laser printer, a test patch is generated on the photoreceptor by inserting a transmission filter momentarily into the path of the laser beam. The filter has a controlled density and results in the latent image of a grey test patch being generated on the photoreceptor. The patch is subsequently developed and the toner density of the developed patch is measured to determine whether or not any adjustment is required in the toner concentration in the developer apparatus of the machine. To ensure that the filter is moved rapidly into and out of the path of the laser beam, a solenoid is used to move the filter into the beam and a spring is provided to cause the return movement. |
