Liquid Ejecting Device Three-Sensor Space Detection

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Solution Overview

Problem

Existing liquid ejecting devices face challenges in accurately detecting and adjusting the space between the recording head and the medium, which affects image formation accuracy, as they often rely on single sensors to determine if the space is too wide or too narrow, leading to inefficiencies in image formation.

Innovation Solution

The implementation of a third sensor positioned between the first and second sensors in the ejection direction, along with a control unit that adjusts the space and ejection timing based on detection results, ensures high-accuracy detection and automatic adjustment of the space between the ejecting unit and the medium, preventing errors in image formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two detectors are used to detect whether the space is too wide or too narrow, then the detection capability is improved, but the measurement precision is insufficient for high-accuracy image formation

Engineering Contradiction:
Improvedetection capabilityVSAvoidspace detection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The detection function is segmented into three independent sensors positioned at different locations in the ejection direction. Each sensor detects a specific region (too narrow, appropriate, or too wide), and the control unit integrates these segmented detection results to determine the overall space condition, achieving both comprehensive coverage and high precision

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detection system transitions from a two-point detection approach to a three-point detection approach by adding sensors at different positions along the ejection direction. This dimensional expansion in the detection layout enables more precise measurement of the space between the ejecting unit and medium

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If manual space adjustment is performed, then the device complexity is low, but the productivity and image formation accuracy are reduced

Engineering Contradiction:
Improvesystem structureVSAvoidimage formation efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The control unit receives detection results from the three sensors and automatically adjusts the space between the ejecting unit and medium based on this feedback. The system continuously monitors the space condition and makes real-time adjustments without manual intervention, improving productivity while maintaining simple operation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment of the ejection space based on sensor feedback. The control unit automatically determines whether the space is appropriate, too narrow, or too wide and adjusts accordingly, enabling the device to service itself without requiring operator intervention for space calibration

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the space is not accurately controlled, then the device operation is simple, but the image formation accuracy deteriorates

Engineering Contradiction:
Improveoperation simplicityVSAvoidimage formation accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The manual mechanical adjustment of space is replaced with an automated control system that uses sensor detection and electronic control to adjust the ejection space. This substitution maintains ease of operation while achieving high precision through automated feedback control

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

Data Source

PatentEP3702163B1Liquid ejecting device and space detection method
Publication Date: 2023.05.03 SEIKO EPSON CORP
  • EP3702163B1 patent drawingFigure 1
  • EP3702163B1 patent drawingFigure 2
  • EP3702163B1 patent drawingFigure 3

AI summary

Provided is a liquid ejecting device (1) including a support portion (3) configured to support a medium, an ejecting unit (7) configured to eject liquid, a detector (11) including a plurality of sensors, and a control unit configured to determine, based on a detection result from the detector, a first space being a space between the ejecting unit and the medium. The plurality of sensors includes a first sensor, a second sensor provided downstream of the first sensor in an ejection direction, and a third sensor provided at a position between the first sensor and the second sensor in the ejection direction. The control unit determines that the first space is in an error state when the first sensor detects the medium, and determines the first space based on a detection result of the medium when the first sensor does not detect the medium but at least one of the second sensor and the third sensor detects the medium.