Inkjet Image Forming Control for Duplex Sheet Curl Suppression

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing image forming apparatuses using inkjet methods face issues with sheet curling during duplex printing due to ink adherence, leading to potential sheet contact with the ejection portion during back surface image formation, and existing solutions fail to adequately address curls at the center portion of the sheet.

Innovation Solution

The apparatus acquires adherence amount information for specific areas on the sheet surface, including the center and end portions, and sets a stop time based on this information to temporarily halt sheet conveyance, thereby suppressing curl generation and unnecessary stop time prolongation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If conveyance is stopped for a stop time based on the amount of ink that adheres onto the end portion of the front surface, then unnecessary prolongation of the stop time is suppressed, but curl generation at the center portion of the sheet is not adequately addressed

Engineering Contradiction:

Improvestop timeVSAvoidcurl suppression

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The image forming area on the front surface is divided into multiple specific areas (first area, second area, third area, fourth area) along the conveying direction. The adherence amount is calculated separately for each area, and the stop time is determined based on the maximum adherence amount among all areas. This segmentation ensures that curl generation at any position, including the center portion, is adequately addressed while avoiding unnecessary stop time prolongation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the sheet are treated differently by calculating adherence amounts for each specific area. The system identifies which area has the maximum adherence amount and uses that to determine the stop time. This local quality approach ensures that the stop time is precisely tailored to the actual curl risk at each position, rather than using a uniform approach for the entire sheet.

Inventive Principle:

Principle #3Local quality

2Reliability

If conveyance is stopped for a stop time based on the amount of ink that adheres onto the front surface, then curl generation is suppressed, but unnecessary prolongation of the stop time occurs

Engineering Contradiction:

Improvecurl suppressionVSAvoidstop time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The front surface is divided into multiple specific areas along the conveying direction. By calculating the adherence amount for each area and using the maximum value to determine the stop time, the system avoids unnecessarily prolonging the stop time for areas with low adherence, while still ensuring adequate curl suppression for areas with high adherence.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of using the total adherence amount for the entire front surface, the system focuses on the partial areas with the maximum adherence amount. This partial action approach ensures that the stop time is sufficient to suppress curls where they are most likely to occur, without adding unnecessary stop time for areas with minimal adherence.

Inventive Principle:

Principle #16Partial or excessive action

3Productivity

If duplex image forming processing is executed without stopping conveyance, then productivity is maintained, but sheet contact with the ejection portion occurs due to curl generation

Engineering Contradiction:

Improveduplex printing continuityVSAvoidsheet contact with ejection portion

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary calculation of the adherence amount for each specific area on the front surface before the back surface image formation begins. Based on this preliminary information, the stop time is determined in advance, and conveyance is stopped at the appropriate moment to prevent sheet contact with the ejection portion during the critical back surface printing phase.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the adherence amount calculation to dynamically determine the stop time. By monitoring the ink adherence characteristics and using that information to control the conveyance stop, the system prevents sheet contact with the ejection portion while maintaining productivity through optimized timing.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20250296368A1Image forming apparatus capable of suppressing generation of curls in sheets, and image forming method

Publication Date: 2025.09.25 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

An image forming apparatus includes an acquisition processing portion and a stop processing portion. The acquisition processing portion acquires, when duplex image forming processing is executed, adherence amount information related to an adherence amount of ink by image formation for each of a plurality of specific areas preset in an image forming area on a first surface of a sheet. The stop processing portion temporarily stops, based on a stop time set based on a plurality of pieces of the adherence amount information, conveyance of the sheet after the image formation on the first surface of the sheet and before the image formation on the second surface of the sheet during the execution of the duplex image forming processing.