Flat-Field Lens Assembly for Gap-Free Expanded Scan Fields

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Solution Overview

Problem

Energy beam systems with multiple telecentric lenses suffer from gaps in the aggregate scan field due to the space occupied by their housings, limiting the effective area that can be irradiated in additive manufacturing and other applications.

Innovation Solution

Incorporating flat-field lenses, such as telecentric, f-theta, or f-tan-theta lenses, with scan field expansion assemblies that include field-expanding optical elements to create overlapping scan fields, thereby closing gaps and increasing the irradiated area without requiring large lens geometries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple telecentric lenses are used to expand the scan field, then the irradiated area increases, but gaps appear between scan fields due to housing space occupation

Engineering Contradiction:
Improveirradiated areaVSAvoidscan field continuity
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent places the scan field expansion assembly inside the housing of the telecentric lens, nesting one optical system within another. This allows the expansion optics to be housed within the existing lens structure, eliminating gaps between separate components while maintaining continuous scan field coverage across multiple lenses.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent combines the telecentric lens and scan field expansion assembly into a single integrated optical unit. By merging these previously separate components, the system eliminates the housing space that caused gaps between scan fields, while the expansion assembly still achieves its field-expanding function through integrated optical elements.

Inventive Principle:
Principle #5Merging (Combining)

2Manufacturing precision

If the housing space for telecentric lenses is reduced to eliminate gaps, then scan field continuity improves, but the complexity of optical assembly increases

Engineering Contradiction:
Improvescan field continuityVSAvoidoptical assembly complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the optical system into distinct functional modules: the telecentric lens unit and the scan field expansion assembly. Each module can be designed, tested, and adjusted independently, then integrated together. This segmentation manages complexity by breaking down the integrated system into manageable components with defined interfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The scan field expansion assembly is designed to work with multiple telecentric lenses using the same interface and mounting configuration. This universal design reduces overall system complexity by using standardized components rather than custom solutions for each lens, allowing the same expansion assembly to serve multiple functions across different lens positions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 allows for larger areas to be irradiated efficiently, maintaining telecentricity and reducing gaps between scan fields, enhancing the capabilities of energy beam systems in additive manufacturing and other applications.

Implementation Method 1

The first scan field expansion assembly may include one or more first field-expanding optical elements configured to provide a first expanded scan field coinciding with the first flat focal plane

Methodology Applied
Scientific EffectOptical field expansion: Lens

Data Source

PatentEP4001993A1Energy beam generation systems and optical systems with expanded scan fields
Publication Date: 2022.05.25 CONCEPT LASER
  • EP4001993A1 patent drawingFigure 1
  • EP4001993A1 patent drawingFigure 2A~2B
  • EP4001993A1 patent drawingFigure 3A

AI summary

An optical system may include a first optical assembly and a first scan field expansion assembly. The first optical assembly may include or may be configured as a first flat-field lens. The first flat-field lens may have a first nominal scan field with a first flat focal plane. The first scan field expansion assembly may include one or more first field-expanding optical elements configured to provide a first expanded scan field coinciding with the first flat focal plane. The first expanded scan field may have a cross-sectional width and/or area that exceeds a corresponding cross-sectional width and/or area of the first nominal scan field. A method of additively manufacturing a three-dimensional object may include directing a first energy beam through the first optical assembly, and directing the first energy beam through the first scan field expansion assembly.