Duplex Sheet Registration Using In-Line Skew Correction
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Solution Overview
Problem
Existing technologies fail to accurately align and print on the technical problem of the technical problem of existing technologies fail to effectively address the technical problem of existing technologies have not effectively address the alignment and alignment of images on the technical problem of existing technologies have not effectively address the technical problem of existing technologies have not effectively solve the technical problem of existing technologies have not effectively solve the technical problem of existing technologies fail to accurately align images on both surfaces of a sheet due to variations in sheet shape and environmental factors, leading to misalignment of images on the front and rear surfaces.
Innovation Solution
The inkjet recording apparatus employs a registration unit and in-line scanner unit to detect and correct the inclination and position of sheets, using motors and sensors to adjust the skew and alignment of sheets in both directions, and a reversing module to switch the orientation of the sheet to ensure precise alignment of the sheet to ensure precise alignment of the sheet to ensure precise alignment of the sheet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If one reference side of the sheet is set to form images on both front and rear surfaces, then the image formation process is simplified, but accurate alignment of images on both surfaces cannot be achieved due to sheet shape variations
Solution Approach 1:
Instead of using a fixed reference side approach, the patent inverts the problem by detecting the actual sheet shape and calculating corrected target positions that account for shape variations. The system determines the inclination of each sheet edge and adjusts the target position accordingly, effectively reversing the conventional approach of assuming a fixed reference frame.
Solution Approach 2:
The patent changes the parameter of target position based on detected sheet shape parameters. By measuring the inclination of sheet edges and calculating corrected target positions that compensate for shape variations, the system dynamically adjusts formation positions to maintain accurate alignment despite sheet shape differences.
2Device complexity
If sheet shape variations due to manufacturing errors and environmental factors are not compensated, then the control system is simpler, but image alignment between front and rear surfaces deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the sheet shape is detected by measuring the inclination of sheet edges, and this detection information is used to calculate corrected target positions. The system continuously monitors sheet shape variations and adjusts formation positions based on the detected deviations, creating a closed-loop control system that compensates for shape variations.
Solution Approach 2:
The patent performs preliminary detection of sheet shape before image formation, calculating the inclination of sheet edges and determining corrected target positions in advance. This preliminary action allows the system to pre-compensate for shape variations before the actual image formation process begins.
3Ease of operation
If conventional reference side control is used, then the control method is simpler, but relative position control of images on front and rear surfaces becomes inaccurate
Solution Approach 1:
The patent changes the control parameter from a fixed reference side to dynamic target positions that are calculated based on detected sheet shape. By determining corrected target positions that account for edge inclinations and shape variations, the system maintains ease of operation while achieving accurate relative position control of images on both surfaces.
Data Source
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AI summary
An image forming apparatus that forms images on both surfaces of a sheet includes registration sensors that detect the sheet conveyed by a conveyance roller pair, a registration unit that controls an orientation of the sheet, an in-line scanner unit that reads the sheet, another conveyance roller pair that conveys the sheet switched back by a reversing unit, to the conveyance roller pair, and a controller that controls duplex printing. When an image is formed on a second surface of the sheet after an image is formed on a first surface of the sheet, the controller controls the orientation of the sheet on which an image is to be formed on the second surface, based on an inclination of a leading and a trailing edge of the sheet detected by the in-line scanner unit, and an inclination of the leading edge of the sheet detected by the registration sensors.