Sheet Stacking Apparatus Speed Control for Positioning Accuracy
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Solution Overview
Problem
Existing sheet stacking apparatuses face issues with accurate positioning of topmost sheets due to curled or uneven edges, leading to faulty raising and lowering operations of the stack tray, especially when sheets with inclined edges interrupt optical axes at predetermined angles, causing loop operations and erroneous positioning.
Innovation Solution
A sheet stacking apparatus with a control portion that adjusts the speed of the stack tray's movement based on detection by first and second optical axes, switching to a lower speed when the topmost sheet deviates from the predetermined position to prevent interruptions and maintain accurate positioning, thereby preventing loop operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the stack tray is moved at high speed to position the topmost sheet, then productivity is improved, but positioning precision deteriorates when sheets have curled or uneven edges
Solution Approach 1:
The control portion dynamically adjusts the moving speed of the stack tray based on real-time detection results. When the first sensor detects that the topmost sheet is at the predetermined position, the stack tray moves at high speed. When the second sensor detects that the topmost sheet deviates from the predetermined position, the stack tray switches to low speed movement, thereby adapting the system's motion characteristics to the actual sheet state.
Solution Approach 2:
The system employs dual optical sensors that continuously monitor the position of the topmost sheet and provide feedback to the control portion. The first sensor detects when the sheet reaches the predetermined position, while the second sensor detects deviations. This feedback mechanism enables the control portion to adjust the stack tray's speed accordingly, ensuring precise positioning even with curled or uneven sheets.
2Measurement precision
If dual optical sensors are used to detect sheet position, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The detection function is segmented into two distinct sensors with different detection angles. The first sensor (with first detection angle) detects when the topmost sheet reaches the predetermined position, while the second sensor (with second detection angle different from the first) detects when the topmost sheet deviates from the predetermined position. This segmentation allows each sensor to specialize in a specific detection task, improving overall measurement precision while maintaining manageable system complexity through functional division.
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 suppresses faulty raising and lowering operations by controlling the stack tray's speed in response to optical axis interruptions, ensuring the topmost sheet is consistently positioned at a predetermined height, even with curled or uneven sheets, thus preventing repeated loop operations and ensuring accurate sheet stacking.
Implementation Method 1
a first sensor (100), which detects whether or not a first optical axis L1 is interrupted by a topmost sheet, and a second sensor (200), which detects whether or not a second optical axis L2 is interrupted by the topmost sheet
Data Source
AI summary
A sheet stacking apparatus includes a movable stack portion on which sheets are to be stacked; a detection portion configured to detect whether or not a topmost sheet of sheets stacked on the stack portion is positioned at a predetermined position; and a control portion configured to position the topmost sheet at the predetermined position based on a detection result of the detection portion. In a case where the control portion moves the stack portion at a first speed so that a topmost sheet on the stack portion deviates from the predetermined position, the control portion moves the stack portion at a second speed lower than the first speed to position the topmost sheet at the predetermined position.