Paper Feed Tray Movable Lever Mechanism for Accurate Size Detection
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Solution Overview
Problem
Conventional image forming apparatuses lack accurate detection of paper size in both feed direction and width direction, leading to paper jams, increased cost due to multiple sensors, and reduced productivity due to inaccurate paper transfer.
Innovation Solution
A paper size detecting mechanism using a tray with sliding regulating members and movable levers with convex members that engage with switches to accurately detect paper size, ensuring precise alignment and minimizing errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple paper size detecting sensors are provided to detect paper size in both feed direction and width direction, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines the functions of multiple sensors into a single integrated sensor unit. The sensor detects paper size by measuring the position of the lever arm, which is influenced by the gravitational force acting on the lever. This single sensor can determine both paper width and feed direction dimensions by analyzing the lever's angular position, thereby reducing the number of sensors needed while maintaining measurement precision.
Solution Approach 2:
The lever-based sensor system serves multiple functions: it detects both paper width and feed direction dimensions, and can identify various paper sizes (A4, A3, A2, etc.) using a single sensing mechanism. The lever's rotational movement encodes information about both spatial dimensions, allowing one sensor to perform what would traditionally require multiple specialized sensors.
2Ease of operation
If the lever engages with the regulating member at the back side for convenience, then ease of operation is improved, but measurement precision deteriorates due to shaking and precision accumulation errors
Solution Approach 1:
The patent introduces a reference mark and reference position mechanism that is set up in advance before the lever engages with the regulating member. The reference mark is positioned at a known location on the lever arm, and the system pre-calculates the expected position based on the lever's engagement point. This preliminary setup allows the system to compensate for potential shaking and accumulation errors by comparing actual measurements against the pre-established reference, thereby maintaining measurement precision even when the lever engages at the back side for operational convenience.
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 enables accurate detection of paper size, reduces errors, and allows for a single tray to accommodate various paper sizes, enhancing productivity and reducing costs by eliminating the need for multiple sensors.
Implementation Method 1
a first movable member that engages with the first regulating member, rotates around a pivot in conjunction with the first regulating member
Implementation Method 2
a plurality of switches that are selectively pressed by a combination of the first convex members and the second convex members when the tray is attached to the device
Data Source
AI summary
A detector detects a size of a recording medium stored in a tray of a device. The tray includes a first regulating member that can slide in a width direction of the recording medium, and a second regulating member that can slide in a feed direction of the recording medium. A first movable member engages with the first regulating member, and a second movable member, overlapped by the first movable member, engages with the second regulating member. Both the first and second movable members rotate around a common pivot and include convex members on peripheral edges thereof. Switches are selectively pressed by the convex members when the tray is attached to the device.