Optical Inspection Housing With Variable LED Illumination

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current optical testing devices are inadequate for quickly and reliably determining the surface topography of objects with glossy or reflective surfaces, particularly in achieving accurate and automatic inspection across a variable object spectrum.

Innovation Solution

A testing device with a hollow housing, a main camera, and multiple light sources arranged around an opening for variable illumination, combined with auxiliary cameras and an evaluation unit to record and process object images, enabling the determination of surface topography and inclination maps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If constant illumination by white light lamps is used, then the object surface can be continuously observed, but energy consumption increases and measurement precision decreases for glossy surfaces

Engineering Contradiction:
Improvecontinuous observation capabilityVSAvoidenergy consumption
Core Design Contradiction:
Duration of action of stationary objectVSUse of energy by stationary object

Solution Approach 1:

The patent employs periodic illumination using multiple LED light sources that are activated in alternating sequences rather than continuously. Different groups of LEDs are switched on and off in a periodic manner, allowing the object to be illuminated at different angles over time while consuming less energy than constant illumination would require.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The illumination system is made dynamic through the sequential activation of different LED groups. The lighting configuration changes over time, with different subsets of LEDs being activated to provide varied illumination angles, replacing the static constant illumination approach.

Inventive Principle:
Principle #15Dynamics

2Illumination intensity

If multiple light sources are arranged in a dome configuration, then illumination coverage is improved, but device complexity increases

Engineering Contradiction:
Improveillumination coverageVSAvoidlighting system complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The illumination system is segmented into multiple independent LED groups arranged around the object. Each group can be controlled separately, allowing selective activation of specific illumination zones. This segmentation provides comprehensive coverage while maintaining manageable system complexity through modular control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multiple LED groups serve multiple functions: they provide illumination from different angles, enable periodic activation patterns, and can be selectively activated based on measurement requirements. This multi-functionality achieves comprehensive illumination coverage without proportionally increasing system complexity.

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

3Measurement precision

If deflectometric inspection is performed on glossy surfaces, then surface topography can be determined, but measurement precision is reduced due to reflections

Engineering Contradiction:
Improvesurface topography determinationVSAvoidsurface reflections
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

Different groups of LEDs are activated periodically to illuminate the glossy surface from different angles. By alternating between illumination groups, the system captures surface reflections from multiple perspectives, enabling the evaluation unit to distinguish between actual surface topography features and reflection artifacts through comparative analysis.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The evaluation unit processes images captured under varying illumination conditions and uses the differences between these images to compensate for reflection effects. By analyzing how reflections change with illumination angle compared to actual surface features, the system can extract accurate topography information despite the presence of glossy surface reflections.

Inventive Principle:
Principle #23Feedback

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

Enables rapid, automatic, and reliable determination of surface topography, providing accurate measurements by combining advanced imaging and illumination techniques to handle objects with glossy or reflective surfaces effectively.

Implementation Method 1

The light sources are arranged around the opening and are designed for variable illumination of the recording plane

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3615886B1Inspection apparatus for optically inspecting an object, and object inspection arrangement
Publication Date: 2023.08.30 ROBERT BOSCH GMBH
  • EP3615886B1 patent drawingFigure 1
  • EP3615886B1 patent drawingFigure 2

AI summary

The quality of objects and workpieces of a production process is often assessed on the basis of the surface and/or form. An inspection apparatus (1) for optical inspection, in particular a deflectometric inspection, of an object (7) is proposed, said inspection apparatus having a housing (3), wherein the housing (3) is a hollow body with an opening (4), wherein the object (7) is positionable in the opening (4) for inspection purposes, having a main camera (2), wherein the main camera (2) has a recording direction and recording plane, wherein the main camera (2) is arranged with the recording direction directed at the opening (4) of the housing (3), wherein the inspection apparatus (1) comprises a plurality of light sources (6), wherein the light sources (6) are arranged around the opening (4), wherein the light sources (6) are embodied for the changeable illumination of the recording plane, wherein the main camera (2) is embodied to record a plurality of object images for the object (7) lying in the recording plane, having an evaluation unit (10), wherein the evaluation unit (10) is embodied to determine a topography of the object (7) on the basis of the object images.