Feed Roller Eccentricity Correction via Encoder Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet-type recording apparatuses face variations in medium feeding due to installation conditions and roller eccentricity, leading to inaccurate image dot placement, as existing solutions rely on potentially flawed test patterns for correcting feeding roller rotation.
Innovation Solution
A feed control apparatus with a sensor detecting marks on a test chart, calculating positional differences, and adjusting feeding amounts based on rotational positions to correct for errors, thereby stabilizing the feeding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a test pattern is recorded and used to detect positional displacement for controlling feeding roller rotation, then feeding amount control is improved, but accuracy deteriorates when nozzles have problems such as missing or bent nozzles
Solution Approach 1:
An encoder wheel with encoder marks is introduced as an intermediary component between the feeding roller and the detection system. The encoder wheel rotates synchronously with the feeding roller and provides reference marks that can be detected by an encoder sensor, serving as a mediator to accurately measure the rotational position of the feeding roller without being affected by nozzle conditions or test pattern quality
Solution Approach 2:
The mechanical test pattern recording method is replaced with an optical encoding system. Instead of relying on physically recorded test patterns that may be affected by nozzle problems, an optical encoder system uses light to detect the position of encoder marks on the encoder wheel, providing a more reliable and precise measurement method that is independent of the recording head's nozzle condition
2Manufacturing precision
If the feeding roller rotation is controlled based on test pattern detection, then feeding accuracy is improved, but the system complexity increases due to additional correction calculations
Solution Approach 1:
The encoder sensor continuously monitors the rotational position of the encoder wheel and provides feedback signals to the control unit. This feedback mechanism enables real-time detection of positional deviations and allows the control unit to calculate and apply correction amounts to the feeding roller rotation, achieving precise feeding control through a closed-loop system
Solution Approach 2:
The system changes the parameter being measured from test pattern image positions to encoder mark positions. By using the encoder wheel's rotational position as the measurement parameter instead of test pattern dot positions, the system simplifies the control logic while maintaining high feeding accuracy, as the encoder provides direct rotational position data without requiring complex image analysis
Data Source
AI summary
A disclosed feed control apparatus includes a feed roller; a first detection unit detecting a rotational position of the feed roller; a sensor detecting plural marks arranged on a test chart; a difference calculation unit that calculates a difference between actual and theoretical positional information of a Nth mark when the feed roller rotates one revolution; a correction feeding amount calculation unit that calculates correction feeding amounts of the marks based on the difference and actual feeding amounts of the marks; an error calculation unit that calculates errors between the correction feeding amounts and theoretical feeding amounts by matching them to the corresponding rotational positions of the feeding roller; and a feeding amount control unit that controls the feeding amount based on a relationship between the rotational positions of the feeding roller and the corresponding errors.