Slit Diaphragm for Wide-Angle Light Field Capture

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Solution Overview

Problem

Existing image recording units in automatic inspection systems, particularly for holograms and light field determination, face limitations in capturing a large angular range of object views, leading to incomplete light field analysis.

Innovation Solution

Incorporating a slit diaphragm in the beam path between the object plane and the surface sensor, with its slit parallel to the sensor's rows, allows for a compact and versatile image recording unit that captures a broader light field by assigning beams at large angular distances, enabling movement of objects to be viewed from various directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional aperture diaphragm is used to image objects onto the area sensor, then the optical configuration is simple, but the angular range of the light field that can be captured is limited

Engineering Contradiction:
Improveangular range of light field captureVSAvoidoptical configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The aperture diaphragm is segmented into multiple independently movable segments that can be positioned at different radial distances from the optical axis. This segmentation allows each segment to capture light rays from different angular ranges, and by combining multiple segments, the system achieves a broader overall angular range without requiring a completely different optical configuration.

Inventive Principle:
Principle #1Segmentation

2Volume of stationary object

If the aperture diaphragm is positioned close to the area sensor for compact design, then the device size is reduced, but the angular distribution of visual rays is degraded

Engineering Contradiction:
Improvedevice sizeVSAvoidangular distribution of visual rays
Core Design Contradiction:
Volume of stationary objectVSManufacturing precision

Solution Approach 1:

Different segments of the aperture diaphragm are assigned different radial positions relative to the optical axis, creating local variations in the optical path. Segments closer to the optical axis capture rays at smaller angles, while segments farther from the axis capture rays at larger angles. This local differentiation allows the system to maintain compact dimensions while preserving good angular distribution characteristics through the combined effect of all segments.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If multiple aperture diaphragms are used to expand the angular range, then the light field capture capability is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveangular range coverageVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The aperture diaphragm is designed as a universal component with multiple segments that can function both as individual aperture elements and as a combined multi-angle capture system. Each segment can be independently positioned and adjusted, allowing the same basic component structure to serve multiple functions: maintaining optical precision, enabling compact design, and expanding angular range coverage without requiring entirely separate optical systems for each function.

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 enables the recording of a larger light field with improved imaging quality and compactness, facilitating simple light field recordings and automated testing of multiple objects.

Implementation Method 1

an optical unit arranged in front of the area sensor, preferably a lens or a lens system, wherein the optical unit images objects located on an object plane within its recording area onto the area sensor

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3062090B1Image recording unit
Publication Date: 2020.02.05 AIT AUSTRIAN INSTITUTE OF TECNOLOGY GMBH
  • EP3062090B1 patent drawingFigure 1
  • EP3062090B1 patent drawingFigure 2
  • EP3062090B1 patent drawingFigure 3

AI summary

The invention relates to an image acquisition unit (1) comprising an area sensor (11) with sensor pixels (113) arranged in a raster pattern in rows and columns and an optical unit (12), preferably a lens (120) or a lens system (121), arranged in front of the area sensor (11). The optical unit (12) images objects (2) located on an object plane (13) within its acquisition area (131) onto the area sensor (11) through an aperture diaphragm (100). The invention provides that a slit diaphragm (14) is provided in the beam path between the object plane (13) and the area sensor (11), the slit (141) of the slit diaphragm (14) being parallel to a row (111) of the area sensor (11). This makes it possible to capture the light field of objects over a wider angular range, while maintaining the optical configuration and thus making the image acquisition unit (1) more compact and versatile.Furthermore, by using an additional slit aperture (17) that runs perpendicular to the first slit aperture (14), it is possible to further optimize the image quality of the device.