Printer Cap Positioning for Ink Scattering Control

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Solution Overview

Problem

The existing printing apparatuses face a decrease in throughput when using a cap for both preliminary discharge and cleaning, as the cap arrangement either increases cleaning time or compromises ink scattering during wiping, necessitating a solution to optimize the cap and wiper positioning for efficient operation.

Innovation Solution

The printing apparatus employs a maintenance unit with a cap and wiper positioned at distinct locations, allowing preliminary discharge at a position closer to the printing region and cleaning at a separate position further away, reducing the printhead's moving distance and minimizing ink scattering, thereby maintaining throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the cap is arranged closer to the printing region to improve throughput, then preliminary discharge efficiency is improved, but ink scattering during cleaning increases

Engineering Contradiction:
ImprovethroughputVSAvoidink scattering
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the cap's functions into two separate operational positions: one for preliminary discharge (closer to printing region) and another for cleaning (farther from printing region). This spatial segmentation allows the cap to optimize its position for each specific function, reducing ink scattering during cleaning while maintaining high throughput during preliminary discharge.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the cap and wiper are placed at the same position to reduce parts, then device complexity is reduced, but cleaning time increases due to printhead movement requirements

Engineering Contradiction:
Improvenumber of partsVSAvoidcleaning time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent employs a movable cap structure that can dynamically change its position along the main scanning direction. The cap moves between a first position (closer to printing region) for preliminary discharge and a second position (farther from printing region) for cleaning. This dynamic positioning enables the single cap to perform both functions efficiently without increasing device complexity, while reducing cleaning time by eliminating unnecessary printhead movements.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enables efficient preliminary discharge while reducing the impact of ink scattering during cleaning, maintaining throughput and shortening cleaning time by allowing the cap and wiper to perform their functions without interfering with the printing process.

Implementation Method 1

preliminary discharge or printhead cleaning is known. As the printhead cleaning, for example, negative pressure suction by a cap

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

negative pressure suction by a cap

Methodology Applied
Scientific EffectNegative pressure suction: Suction

Implementation Method 3

wiping by a wiper is known

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3278991B1Printing apparatus and performance maintaining method
Publication Date: 2020.12.30 CANON KK
  • EP3278991B1 patent drawingFigure 1A~1B
  • EP3278991B1 patent drawingFigure 2A~2B
  • EP3278991B1 patent drawingFigure 3

AI summary

A printing apparatus (1) includes: a printhead (12); a carriage (11), on which the printhead is mounted, configured to move in a first direction such that the printhead moves across a printing region (R1) where a printing operation by the printhead is performed and a standby region (R2) adjacent to the printing region; a cap (51) arranged in the standby region and configured to suck the ink from the printhead; and a wiper (52) configured to perform wiping for the printhead. The cap can be displaced to a first position (P2') and a second position (P1') farther from the printing region in the first direction than the first position. At the second position, the cap can be displaced to an upper position to cap the printhead and a lower position to be separated from the printhead allowing the wiper to wipe the printhead.