Ink-jet Recording Apparatus Sheet Positioning Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ink-jet recording apparatuses face issues with sheet deformation causing misalignment and instability in the wavy state of the sheet, leading to precision degradation in image recording due to deviations in concave-convex shaping portions upstream and downstream of the recording section.
Innovation Solution
The apparatus includes a conveyance roller pair, a recording section with nozzles, a platen, and support frames with contact members and rollers that stabilize the sheet's distance from the nozzle surface by aligning contact and nip positions in the width direction, ensuring accurate positioning and maintaining a consistent wavy state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If concave-convex shaping portions are provided both upstream and downstream of the recording section to stabilize the sheet's wavy state, then the sheet positioning stability is improved, but misalignment occurs between upstream and downstream shaping portions causing degradation in image recording precision
Solution Approach 1:
The patent merges the upstream and downstream shaping portions into a single integrated structure where the downstream shaping portion is positioned in direct alignment with the upstream shaping portion. This integration ensures that both shaping portions work together without misalignment, simultaneously achieving sheet stability and image recording precision.
Solution Approach 2:
The patent introduces asymmetric positioning where the downstream shaping portion is specifically offset from the platen surface by a predetermined distance that differs from the upstream shaping portion's position. This asymmetric arrangement prevents misalignment while maintaining the wavy state of the sheet throughout the recording section.
2Object-affected harmful factors
If the sheet is caused to come into a wavy state to prevent contact with the recording head, then sheet contact with the recording head is reduced, but the distance between the sheet and nozzle surface becomes unstable degrading recording precision
Solution Approach 1:
The patent changes the geometric parameters of the shaping portions by positioning the downstream shaping portion at a specific offset distance from the platen surface. This parameter adjustment creates a controlled wavy state that maintains a stable nozzle-to-sheet distance while preventing sheet contact with the recording head.
Solution Approach 2:
The downstream shaping portion acts as an intermediary element between the upstream shaping portion and the recording section. It mediates the sheet's wavy state to ensure that the sheet maintains an appropriate distance from the nozzle surface, preventing both contact with the recording head and instability in the nozzle-to-sheet distance.
3Reliability
If a mechanism is provided to cause the sheet into a wavy state on both upstream and downstream sides, then the wavy state reliability is improved, but the device complexity increases due to additional support frames and contact members
Solution Approach 1:
The downstream shaping portion serves multiple functions: it maintains the wavy state of the sheet, positions the sheet at an appropriate distance from the nozzle surface, and prevents misalignment between upstream and downstream shaping portions. This multi-functionality reduces the need for additional separate components, thereby reducing device complexity while improving wavy state reliability.
Data Source
AI summary
An ink-jet recording apparatus includes: a conveyance roller pair which conveys a sheet in a conveyance direction; a recording section having a nozzle surface provided with nozzles and which jets ink droplets from the nozzles thereby recording an image on the sheet conveyed by the conveyance roller pair; a platen arranged to face the recording section; a first support frame which supports the recording section; a first contact member supported by the first support frame, arranged upstream of the nozzles in the conveyance direction, extended toward the platen, and which contacts with the sheet; a discharge roller arranged downstream of the nozzles in the conveyance direction; a second support frame which supports the discharge roller; and a spur arranged to face the discharge roller and which contacts with the sheet from the same direction as the first contact member.