Document Feeder Tray Height Control for Discharge Stack Clearance

The patent applies the dynamics principle by making the lower limit position of the document feeding tray variable rather than fixed. The tray's lower limit position is dynamically adjusted based on the detected amount of documents on the discharge tray. When few documents are present, the tray can be lowered to its maximum capacity position. When many documents are present, the tray's lower limit position is automatically raised to prevent contact. This dynamic adjustment resolves the contradiction between maximizing tray capacity and ensuring reliable document feeding operations.

The system dynamically adjusts the lower limit position of the document feeding tray based on real-time detection of document quantity on the discharge tray. A document sensor detects whether documents are present on the discharge tray and sends signals to the control unit, which then appropriately adjusts the tray position. This eliminates the need for a fixed conservative position and allows the system to maintain reliability while maximizing capacity when conditions permit.

The system implements self-service through automatic detection and adjustment mechanisms. A document sensor automatically detects the presence and quantity of documents on the discharge tray, and the control unit automatically adjusts the lower limit position of the feeding tray based on this detection. This eliminates the need for manual intervention or complex manual control systems while providing adaptive behavior. The system serves itself by autonomously optimizing its configuration based on operating conditions.