Sheet Feeding Device Near-End Detection Control
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Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately detecting the near-end state of sheet stacks, leading to potential feeding failures such as paper jams and multi-feeds, due to false detections by height sensors when the stack height is low.
Innovation Solution
A feeding device with a lifting mechanism, sheet detector, sheet count detector, and near-end detector is implemented, where the lifting mechanism is controlled based on detection results from both the sheet detector and sheet count detector to maintain the optimal height and count of sheets, preventing false detections and ensuring consistent sheet feeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a height sensor is used to detect the near-end state of sheet stacks, then the detection range can be extended, but false detections occur when the stack height is low
Solution Approach 1:
The detection function is segmented into two independent detectors: a height sensor for general height monitoring and a sheet count detector for accurate near-end detection. By dividing the detection task into separate functional components, each detector operates in its optimal range without interfering with the other, eliminating false detections that occurred when a single height sensor attempted to perform both functions.
Solution Approach 2:
The sheet count detector acts as an intermediary mechanism that provides accurate sheet quantity information to the control unit. This intermediary detection method bridges the gap between physical sheet height (which becomes unreliable at low stacks) and logical sheet count (which remains accurate), allowing the system to maintain reliable near-end detection throughout the entire sheet consumption cycle.
2Stability of the object's composition
If the loading portion is continuously lifted to maintain sheet height, then sheet feeding consistency is improved, but the system complexity increases
Solution Approach 1:
The control unit implements a feedback control system that continuously monitors sheet height via the height sensor and adjusts the loading portion elevation accordingly. When the sheet stack height decreases, the feedback signal triggers the lifting mechanism to raise the loading portion, maintaining consistent sheet presentation to the conveying unit. This closed-loop feedback ensures feeding stability without requiring complex mechanical adjustments.
Solution Approach 2:
The loading portion is designed with dynamic elevation capability, allowing it to adjust its height position based on sheet stack levels. This dynamic adjustment mechanism transforms a static structure into an adaptive component that automatically responds to changing sheet quantities, maintaining optimal sheet feeding conditions throughout operation without manual intervention.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents feeding failures by accurately detecting the near-end state and adjusting the lifting mechanism, ensuring reliable sheet feeding even when the stack height is low, thereby enhancing the operational reliability of the image forming apparatus.
Implementation Method 1
air is blown from a blower device toward a bundle of sheets loaded on a loading portion
Implementation Method 2
the uppermost sheet blown by the blower device is lifted and attracted by a suction device
Data Source
AI summary
A feeding device includes a loading portion, a lifting mechanism, a conveying unit, a sheet detector, a near-end detector, and process circuitry. The loading portion stacks a plurality of sheets. The lifting mechanism lifts the loading portion. The conveying unit conveys the sheets on the loading portion. The sheet detector detects presence or absence of the sheets on the loading portion at a specified height position. The sheet count detector detects a number of sheets conveyed by the conveying unit. The near-end detector detects a near-end state in which a stack height of the sheets on the loading portion is a specified value or less. The process circuitry controls the lifting mechanism based on a detection result of the sheet detector before the near-end state is detected, and controls the lifting mechanism based on a detection result of the sheet count detector after the near-end state is detected.