Sensor Casing Design for Sheet Jam Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image recording apparatuses face issues with sheet snagging and jamming due to exposed sensors, and dust accumulation affecting optical sensor accuracy.
Innovation Solution
A conveying device with a sensor casing and movable member that guides the sheet, ensuring the sensor is protected and accurately sensing the sheet's position, reducing the risk of snagging and dust interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the optical sensor is exposed to the conveyance path for sheet sensing, then the sheet position can be detected, but the sensor becomes vulnerable to dust accumulation and external light interference
Solution Approach 1:
The optical sensor is nested within a sensor casing that has a window facing the conveyance path. This allows the sensor to be protected from dust and external light while still enabling it to detect sheet position through the window, resolving the contradiction between exposure for sensing and protection from interference.
2Measurement precision
If the sensor face is exposed to the sheet conveying path, then sheet position sensing is enabled, but the sheet may get snagged on the sensor causing skew or jam
Solution Approach 1:
The sensor is nested within a casing that extends along the conveyance path, with the sensor face positioned through a window in the casing. This protects the sensor from direct contact with the sheet while maintaining sensing capability, preventing sheet snagging.
Solution Approach 2:
The sensor casing acts as an intermediary between the sheet and the optical sensor. The window in the casing allows optical signals to pass through while physically separating the sheet from the sensor, preventing direct contact and potential snagging.
3Object-affected harmful factors
If the sensor is protected from dust and external light, then sensor accuracy is maintained, but the sensor may not be able to sense the sheet reliably
Solution Approach 1:
The sensor casing is designed with specific local properties: it is opaque to protect from dust and external light, but includes a specific window area that is transparent to allow optical sensing. This local differentiation enables both protection and sensing functionality simultaneously.
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
Ensures reliable sheet sensing and smooth conveyance by protecting the sensor from dust and external light, preventing sheet jams and maintaining optical sensor accuracy.
Implementation Method 1
a sensed portion which is located in the sensor casing and moved from a first position to a second position by movement of the sheet that is conveyed on the second conveying surface while contacting the contact portion
Data Source
AI summary
A conveying device includes: a conveyor for conveying a sheet; a path defining member having a first conveying surface that guides the sheet; and a sensor device for sensing the sheet. The sensor device includes: a sensor casing provided on the path defining member and including a second conveying surface that guides the sheet and a main wall whose outer surface is exposed from the path defining member and contiguous to the first conveying surface; a movable member including (i) a contact portion projecting to a second-conveying-surface side of the main wall through an opening formed in the main wall and (ii) a sensed portion located in the sensor casing and moved by the sheet conveyed on the second conveying surface while contacting the contact portion; and a signal output device, provided in the sensor casing, for sensing the sensed portion to output a signal related to its position.