The pulley on the LCIT lift motor [A] at the back of the paper feed tray winds up the wires that lift the bottom plate [B]. The mechanism consists of 2 wires of different lengths at the front and rear of the tray, which work together to keep the bottom plate level as they lift it. The short wire lifts the front of the bottom plate, while the long wire lifts the rear.
The motor lifts the bottom plate until the paper upper limit sensors [C] detect the surface of the paper, turning the motor off and stopping the movement of the plate. There are two paper upper limit sensors and which sensor is used to detect the paper is determined at the timing of a job start.
Paper upper limit sensor 2 on the lower side detects the paper by default. When receiving the start job of the paper feeding, it is switched to the sensor that is suitable to the paper thickness by the acquisition of the paper information.
If the surface of the paper drops during printing, it turns the top sensor off, which turns the LCIT lift motor and lifts the paper. When the paper feed tray is pulled out, the bottom plate drops down by its own weight.
If the paper feed belt unit [D] (located at the ceiling of the bottom plate) is lifted up too much, the tray upper limit sensor [E] detects it and generates SC503-015/504-015 “bottom plate over lift”, and stops the bottom plate at the limit. (If more than two of the units are docked, SC505-115/506-015, SC507-015/508-015)
If this happens, pull out the paper feed tray to release it.