Display Module Lens Pillar Alignment and Manufacturing

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Solution Overview

Problem

Conventional methods for manufacturing self-luminous light emitting element arrays face challenges in accurately aligning microlens arrays with light emitting elements, leading to inefficient light use and increased manufacturing complexity due to the need for glass forming molds and spacers.

Innovation Solution

A display module with a lens array configuration featuring first and second lens pillars and lens portions with curved surfaces, allowing for accurate alignment and enhanced light use efficiency, is manufactured using a simplified process involving photolithography and heat treatment of lens materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a glass forming mold is used to manufacture the microlens array, then the microlens array can be formed, but the manufacturing process becomes complex and alignment accuracy decreases

Engineering Contradiction:
Improvealignment accuracyVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent removes the glass forming mold from the manufacturing process entirely. Instead of using a mold to form the microlens array, the invention directly forms the microlens array on the light emitting element array substrate through photolithography and reflow processes. This extraction of the mold eliminates alignment errors between separate components and simplifies the manufacturing process by removing mold release and spacer requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the microlens array formation process with the light emitting element array manufacturing process. The microlens array is formed directly on the same substrate as the light emitting elements, combining what were previously separate components into a single integrated structure. This merging eliminates the need for separate mold alignment and ensures precise positional correspondence between lenses and light emitting elements.

Inventive Principle:
Principle #5Merging (Combining)

2Manufacturing precision

If spacers are added to maintain gap between microlens array and light emitting element array, then the gap can be maintained, but the number of manufacturing processes increases

Engineering Contradiction:
Improvegap controlVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent removes spacers from the manufacturing process. Instead of adding spacers to maintain the gap between the microlens array and light emitting element array, the invention directly forms the microlens array on the substrate with the light emitting elements. The gap is controlled through the photolithography pattern design and reflow process parameters, eliminating the need for separate spacer components and their associated manufacturing steps.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If lens material is removed from bonding pad regions, then the bonding pads remain accessible, but additional manufacturing steps are required

Engineering Contradiction:
Improvebonding pad accessibilityVSAvoidmanufacturing efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent performs preliminary patterning of the microlens array formation regions to exclude bonding pad areas from the outset. During the photolithography step, the microlens array is formed only in the light emitting element regions, and the bonding pad regions are inherently excluded from lens material deposition. This preliminary action ensures bonding pad accessibility without requiring separate removal steps, as the selective formation process naturally preserves bonding pad access.

Inventive Principle:
Principle #10Preliminary action

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

The solution enables accurate alignment of lenses with light emitting elements, improving light use efficiency and simplifying the manufacturing process, while allowing for arbitrary adjustment of optical axes and curvature control.

Implementation Method 1

softening the lens pillar material by heat treatment so that the lens pillar material has curved surfaces respectively on the first lens pillars

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 2

a lens array configured to focus light emitted by the light emitting elements

Methodology Applied
Scientific EffectLight focusing: Lens

Data Source

PatentEP2544233B1Display module, display device, and manufacturing method of a display device
Publication Date: 2017.03.15 OKI DATA CORP
  • EP2544233B1 patent drawingFigure 1
  • EP2544233B1 patent drawingFigure 2
  • EP2544233B1 patent drawingFigure 3

AI summary

A display module (10) includes a light emitting element array (12) and a lens array (20). The light emitting element array includes a plurality of light emitting elements (31) arranged on a substrate and driven by driving signal to emit light. A lens array is configured to focus light emitted by the respective light emitting elements. The lens array includes a plurality of first lens pillars (21) respectively provided on the light emitting elements, a plurality of second lens pillars (22) respectively provided on the first lens pillars and having curved surfaces at tops thereof, and a plurality of lens portions (23) formed so as to cover the first lens pillars and the second lens pillars, the lens portions having curved surfaces at tops thereof. A driving circuit is provided on the substrate.