Jetstack Plate Alignment via Bottom Lighting Contrast

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Solution Overview

Problem

Current ink jet printer jet stack plate alignment processes are inefficient due to poor contrast between shiny stainless steel plates and automated video systems, leading to erroneous measurements and increased manual alignment time, often resulting in skipped quality control steps.

Innovation Solution

Implementing a cone or array alignment feature with smaller diameter holes at specific positions on each plate, utilizing bottom lighting to enhance contrast and precision for automated vision system alignment, allowing for accurate and rapid plate alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If automated video system with top lighting is used for hole alignment measurement, then measurement automation is achieved, but measurement precision deteriorates due to poor contrast and reflections on shiny stainless steel plates

Engineering Contradiction:

Improvemeasurement automationVSAvoidhole alignment measurement precision

Core Design Contradiction:

Extent of automationVSMeasurement precision

Solution Approach 1:

The patent inverts the lighting direction from top lighting to bottom lighting. By positioning the light source below the plates and directing it upward through the holes, the system achieves better contrast between the holes and the plate surface, eliminating the reflection problems that occurred with top lighting. This inversion of the lighting approach allows the automated vision system to accurately detect hole positions on shiny stainless steel plates.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent employs optical contrast enhancement by changing the lighting condition to create favorable optical properties. Bottom lighting creates a dark background with bright hole edges, effectively changing the optical contrast characteristics to enable accurate automated detection, similar to how color changes can improve visibility and measurement precision.

Inventive Principle:

Principle #32Color changes

2Measurement precision

If manual re-measuring and alignment is performed to correct erroneous measurements, then measurement precision is improved, but productivity deteriorates due to increased time consumption

Engineering Contradiction:

Improvehole alignment measurement precisionVSAvoidalignment process efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical manual measurement and alignment process with an optimized optical measurement system. By implementing bottom lighting to improve contrast, the automated vision system can reliably detect hole positions without erroneous measurements, eliminating the need for manual re-measuring and alignment operations, thus maintaining both precision and productivity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Quantity of substance

If hole diameter increases from aperture plate to diaphragm plate, then ink flow capability is improved, but alignment difficulty increases due to larger size variations and poorer contrast

Engineering Contradiction:

Improveink flow capabilityVSAvoidhole alignment detection difficulty

Core Design Contradiction:

Quantity of substanceVSDifficulty of detecting and measuring

Solution Approach 1:

The patent inverts the lighting approach to bottom lighting, which provides consistent contrast enhancement across holes of different sizes. This allows the vision system to accurately detect and measure alignment for larger diameter holes in downstream plates without the contrast problems that affect smaller holes, thus maintaining measurement precision throughout the entire jet stack assembly.

Inventive Principle:

Principle #13The other way round (Inversion)

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 method significantly reduces alignment time by half, ensuring precise plate alignment with reduced manual intervention and improved process efficiency, while maintaining high accuracy.

Implementation Method 1

The plates are shiny, stainless steel and the hole and surface quality vary. The automated video system uses top lighting and it becomes difficult for the system to sort out reflections and locate the hole edges

Methodology Applied

Scientific EffectLight: Light

Data Source

PatentUS7669985B2Jetstack plate to plate alignment

Publication Date: 2010.03.02 XEROX CORP

AI summary

An apparatus has a first plate having a first array of holes, with a first plate alignment hole having a smaller size than the other holes in the array, a second plate having a second array of holes to be alignable to the first array of holes, a second plate alignment hole having a smaller size than the other holes in the array, and the first plate alignment hole and the second plate alignment hole having different positions. A method of aligning plates provides a first plate having a top and bottom and first array of holes including a first plate alignment hole having a size smaller than the other holes in the first array, places a second plate having a second array of holes on the top of the first plate such that the first array of holes and the second array of holes align, directs light at the bottom of the first plate, locates a profile of the first plate alignment hole in the second array of holes to verify alignment.