Printer Tray Barrier Mechanism for Sheet Media Stability
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Solution Overview
Problem
Existing printer systems lack an effective barrier system to prevent the stack of sheets from sliding out when the input tray is removed and to ensure proper sheet alignment during printing, as the lift plate mechanism does not adequately block the stack when lowered or allow the top sheet to be picked when raised.
Innovation Solution
A movable barrier system integrated with the lift plate, actuated by a mechanism that moves between closed and open positions based on the lift plate's position, ensuring the stack is blocked when the tray is not in use and unblocked when printing, using a lever, pinion, and rack configuration to automatically adjust with the lift plate's movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a barrier is used to block the downstream end of the stack when the lift plate is lowered, then the stack is prevented from sliding out of the tray, but the barrier blocks the top sheet from being picked when the lift plate is raised to the pick position
Solution Approach 1:
The barrier is made movable between a closed position (blocking the downstream end) and an open position (allowing sheet picking). The barrier dynamically adjusts its position based on the lift plate position, being closed when the lift plate is lowered and open when the lift plate is raised to the pick position, thus resolving the contradiction between stack stability and sheet picking ease
Solution Approach 2:
The system uses the lift plate position as feedback to control the barrier position. When the lift plate is raised to the pick position, the barrier automatically opens; when the lift plate is lowered, the barrier automatically closes. This feedback mechanism ensures the barrier state is appropriate for the current operational phase
2Reliability
If the barrier remains in the closed position to prevent sheets from sliding out, then stack stability is maintained, but the top sheet cannot be picked for printing
Solution Approach 1:
The barrier dynamically transitions between closed and open states based on operational requirements. During normal operation when the lift plate is raised, the barrier opens to allow productive sheet picking. During non-operational states when the lift plate is lowered, the barrier closes to maintain stack containment, thus balancing reliability and productivity
3Ease of operation
If a removable input tray is used to allow easy media changes, then ease of operation is improved, but the stack may slide out of the tray when the tray is removed
Solution Approach 1:
The barrier provides dynamic protection for the stack during tray removal. When the tray is removed from the printer, the barrier remains in the closed position to prevent the stack from sliding out, thus maintaining stack retention reliability while preserving the ease of operation benefit of removable trays
Solution Approach 2:
The barrier is positioned and configured to preemptively prevent the harmful effect of stack sliding out during tray removal. By having the barrier in place before tray removal occurs, the system pre-counteracts the potential instability, ensuring reliable stack retention during media changes
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 barrier system effectively prevents the stack from sliding out when the tray is removed and ensures the top sheet can be picked for printing by blocking the stack when the lift plate is lowered and unblocking it when raised, maintaining proper alignment and preventing sheet displacement.
Implementation Method 1
The barrier is actuated by a mechanism that moves between closed and open positions based on the lift plate's position, ensuring the stack is blocked when the tray is not in use and unblocked when printing, using a lever, pinion, and rack configuration
Data Source
AI summary
In one example, a tray to hold sheet media for printing includes: a movable support to support a downstream part of a stack of media sheets in the tray; a barrier near a downstream end of the support, the barrier movable between a closed position in which, when a stack of media sheets is on the support, the barrier blocks a downstream end of the stack and an open position in which, when a stack of media sheets is on the support, the barrier does not block a downstream end of at least part of the stack; and an actuator configured to move the barrier from the closed position to the open position.