Inverted Crown Counter Roller for Uniform Corona Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet image forming apparatuses face issues with wrinkles on thin and low-stiffness printing base materials when conveying speed is increased, leading to inconsistent corona discharge treatment and deteriorated image quality.
Innovation Solution
A corona treatment unit with a counter roller of inverted crown shape, where the central portion has a smaller diameter than the end portions, is used to ensure uniform corona discharge application, preventing wrinkles by maintaining a constant distance between the corona discharge electrode and the counter roller, thus stabilizing the printing base material during high-speed conveyance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the conveying speed is increased, then productivity is improved, but wrinkles occur in the printing base material and corona discharge treatment becomes inconsistent
Solution Approach 1:
The counter roller is designed with an inverted crown shape where the diameter of the central portion is smaller than the diameters of both end portions. This geometric parameter change allows the roller to apply controlled tension to the printing base material, preventing wrinkles during high-speed conveyance and ensuring uniform corona discharge treatment across the material width.
2Productivity
If the conveying speed is increased, then productivity is improved, but wrinkles occur in the printing base material
Solution Approach 1:
The inverted crown shape of the counter roller creates a tension distribution that prevents wrinkling. The smaller central diameter and larger end diameters generate appropriate tension forces on the printing base material during conveyance, maintaining material flatness even at increased conveying speeds.
3Device complexity
If a conventional counter roller with uniform diameter is used, then device complexity is reduced, but corona discharge treatment becomes inconsistent at high conveying speeds
Solution Approach 1:
The counter roller employs an inverted crown shape with the central portion diameter being smaller than the end portions. This parameter modification maintains relative structural simplicity while significantly improving corona discharge uniformity by preventing material wrinkles and ensuring consistent material-roller contact during high-speed operation.
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 inverted crown shape counter roller effectively prevents wrinkles and ensures uniform corona treatment, maintaining image quality even at high conveying speeds by stretching the printing base material, resulting in minimal density unevenness and improved ink adhesion.
Implementation Method 1
corona discharge is sometimes applied to the printing base material in order to improve adhesion between the printing base material and ink
Data Source
AI summary
An inkjet image forming apparatus include a head unit and a corona treatment unit. The head unit ejects ink on a printing base material conveyed in a predetermined conveyance direction. The corona treatment unit is disposed on an upstream side of the head unit in the conveyance direction and performs a corona discharge on the printing base material. The corona treatment unit includes a counter roller facing a corona discharge electrode. The counter roller has an inverted crown shape in which a diameter of a central portion is smaller than diameters of both end portions in a width direction crossing the conveyance direction.