Printer Edge Sensor Interpolation for Image Registration

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Solution Overview

Problem

Conventional image recording apparatuses face challenges in precisely identifying the widthwise position of a recording medium at the image recording position due to limited space for sensor placement, leading to misregistration between single-color images and reduced image quality.

Innovation Solution

The apparatus employs a configuration of edge sensors placed upstream and downstream of the recording positions, with a controller calculating relative detection values to interpolate and correct the ink ejection positions, allowing for accurate identification of the widthwise position without requiring sensors at the recording positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are placed at the recording positions to detect the widthwise position of the printing paper, then the measurement precision of the widthwise position is improved, but the device complexity increases and the ease of manufacture deteriorates due to limited space

Engineering Contradiction:
Improvewidthwise position detection accuracyVSAvoidsensor placement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary calculation process that uses detection values from sensors placed at positions other than the recording position. The controller calculates the widthwise position at the recording position by referencing detection values from upstream and downstream sensors, thereby avoiding the need to place sensors directly at the recording position where space is limited.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical approach of placing physical sensors at the recording position with a computational approach. Instead of mechanically positioning sensors in the limited space, the system uses mathematical calculation to derive the widthwise position information that would have been obtained from direct sensing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If sensors are placed at the recording positions to detect the widthwise position, then the manufacturing precision of image recording is improved, but the ease of manufacture deteriorates due to space constraints

Engineering Contradiction:
Improveimage recording precisionVSAvoidapparatus assembly ease
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent uses an intermediary calculation method where the controller computes the widthwise position at the recording position based on detection values from sensors placed at upstream and downstream positions. This intermediary calculation approach maintains image recording precision while avoiding the manufacturing difficulties of placing sensors in the constrained recording position space.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the detection position is different from the recording position, then the ease of operation is improved by allowing flexible sensor placement, but the measurement precision deteriorates due to position mismatch

Engineering Contradiction:
Improvesensor placement flexibilityVSAvoidwidthwise position detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the controller continuously monitors detection values from sensors at upstream and downstream positions and uses these values to calculate and correct the widthwise position at the recording position. This feedback loop compensates for the position mismatch between sensors and recording position, maintaining measurement precision while allowing operational flexibility.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces the mechanical alignment requirement between sensors and recording position with a computational substitution. Instead of mechanically aligning sensors with the recording position, the system uses mathematical calculations to substitute for the missing direct measurement, thereby maintaining precision while enabling flexible sensor placement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3017956B1Apparatus for and method of recording image
Publication Date: 2019.07.10 SCREEN HOLDINGS CO LTD
  • EP3017956B1 patent drawingFigure 1
  • EP3017956B1 patent drawingFigure 2~3
  • EP3017956B1 patent drawingFigure 4

AI summary

In an image recording apparatus (1) , edge sensors (30) are disposed in front of and behind a recording position (P1-P4) on a transport path of printing paper (9). The edge sensors (30) detect a widthwise position of the printing paper (9) in respective positions upstream and downstream of the recording position (P1-P4). A controller (40) in the image recording apparatus (1) calculates the widthwise position of the printing paper (9) in the recording position, based on detection results from the edge sensors (30). Thus, the widthwise position of the printing paper in the recording position is identified without the placement of an edge sensor in the recording position on the transport path.