Detecting Lever Sheet Floating Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image recording apparatuses, when a detecting lever is positioned upstream of the recording head, it can cause the sheet to float up from the platen, leading to soiling or jamming due to the actuator pushing the sheet downward.
Innovation Solution
The apparatus includes a roller pair, a recording head with nozzles, a platen, first and second guide members, and a detecting lever with a sensor to detect the sheet's position, ensuring the sheet remains in contact with the platen by corrugating it with contact portions and preventing it from floating up.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the actuator is provided in an upper portion of the conveyance path like the recording head, then the sheet position can be detected, but the sheet may be pushed downward by the actuator, causing a portion of the sheet to float up from the platen
Solution Approach 1:
The detecting lever is divided into multiple contact portions (first contact portion and second contact portion) that are spaced apart in the widthwise direction. Each contact portion independently contacts the sheet at different positions, distributing the pushing force and preventing the sheet from floating up while maintaining detection capability
Solution Approach 2:
The contact portions are positioned at specific locations in the widthwise direction to correspond with the sheet's position during conveyance. This local positioning ensures that the detecting lever contacts the sheet at the correct location without causing harmful floating, while maintaining detection precision
2Measurement precision
If the detecting lever is disposed in a head-side portion of the conveying path, then sheet detection is enabled, but the sheet may be soiled or jammed due to contact with the recording head
Solution Approach 1:
The detecting lever acts as an intermediary component between the sheet and the recording head. It contacts the sheet upstream of the recording head to detect position, while the multiple contact portions prevent the sheet from reaching the recording head in a manner that would cause soiling or jamming
Solution Approach 2:
The detecting lever performs the sheet position detection action before the sheet reaches the recording head. By detecting the sheet's position in advance using the contact portions, the system can prevent the sheet from contacting the recording head in a harmful manner
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
This configuration effectively prevents the sheet from floating up from the platen, even with a detecting lever positioned near the recording head, maintaining proper sheet alignment and preventing jams or soiling.
Implementation Method 1
a detecting lever provided rotatably and including an arm protruding from the first guide member toward the second guide member into the conveyance path
Implementation Method 2
a roller pair configured to nip and convey a sheet in a conveying direction along a conveyance path
Implementation Method 3
a recording head including a plurality of nozzles and configured to eject liquid from the plurality of nozzles
Data Source
AI summary
An image recording apparatus includes: a roller pair for conveying a sheet in a conveying direction along a conveyance path; a head for ejecting liquid; a platen opposite the head; contact portions, spaced apart from each other in a widthwise direction and opposite the platen, for contacting the sheet between the roller pair and nozzles of the head; first and second guide members disposed upstream of the roller pair in the conveying direction and disposed in the conveyance path nearer to the head and the platen, respectively; a rotatable lever including an arm protruding from the first guide member toward the second guide member into the conveyance path; and a sensor for detecting rotation of the lever. The arm in the widthwise direction overlaps at least one of the contact portions.