Lighting Control for Optical Measuring Devices

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Solution Overview

Problem

Existing coordinate measuring machines with optical sensors face challenges in accurately marking the image detection area during measurement, leading to increased setup times and potential temperature influences due to unnecessary lighting, which can interfere with the measurement process.

Innovation Solution

Implementing a lighting control method that switches on only the necessary lighting arrangements during image acquisition, using a control signal to manage measurement lighting and employing additional lighting arrangements like bright field incident light illumination or lasers outside of image recording periods to mark the image capture area without interfering with measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous lighting arrangements are used to mark the image detection area, then the marking function is always available, but heat input increases and temperature influences interfere with measurement accuracy

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidheat input from lighting
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The lighting arrangements are switched on and off periodically in synchronization with the image acquisition cycles. The control device activates the lighting only during image recording periods and keeps it off during non-recording periods, creating a periodic on-off pattern that eliminates continuous heat generation while maintaining marking functionality when needed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The marking of the image detection area is performed in advance during non-image acquisition periods. By preparing the visual marking before the measurement cycle begins, the system ensures the marking function is available when needed without interfering with the actual measurement process.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If lighting arrangements are switched on continuously, then the image detection area is always marked, but setup time increases due to unnecessary lighting during non-measurement periods

Engineering Contradiction:
Improvesetup timeVSAvoidtime wasted with unnecessary lighting
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The lighting arrangements operate in periodic cycles synchronized with image acquisition. During non-measurement periods, the lighting remains off, eliminating unnecessary setup time and allowing faster transitions between measurement tasks while maintaining the marking capability when actually needed.

Inventive Principle:
Principle #19Periodic action

3Illumination intensity

If multiple lighting arrangements operate simultaneously, then comprehensive illumination is achieved, but temperature influences and interference with measurements increase

Engineering Contradiction:
Improvecomprehensive illuminationVSAvoidtemperature influences on workpiece
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

Multiple lighting arrangements are activated periodically during image acquisition periods rather than continuously. This timing synchronization ensures comprehensive illumination is provided only when the optical sensor is actively recording, eliminating thermal interference with the workpiece while maintaining complete illumination coverage when needed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system provides sufficient illumination intensity during the brief image acquisition windows by activating all necessary lighting arrangements simultaneously during these short periods, achieving comprehensive illumination without the cumulative thermal effect of continuous operation.

Inventive Principle:
Principle #16Partial or excessive 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

This approach reduces heat input, minimizes temperature influences, and allows for efficient marking of the image detection area without affecting measurement accuracy or results, thereby streamlining the measurement process.

Implementation Method 1

optical sensors that enable the non-contact detection of a workpiece's coordinates

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

The laser beam can be emitted, for instance, from a light source attached to the object being measured

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 3

incident light illumination can be provided, which may be configured as brightfield/darkfield illumination

Methodology Applied
Scientific EffectIncident light illumination: Light

Data Source

PatentEP3303990B1Lighting control when using optical measuring devices
Publication Date: 2021.03.03 CARL ZEISS INDUSTRIELLE MESSTECHNIKE GMBH
  • EP3303990B1 patent drawingFigure 1
  • EP3303990B1 patent drawingFigure 2
  • EP3303990B1 patent drawingFigure 3

AI summary

The invention relates to a measuring device (10), in particular a coordinate measuring device, comprising at least one optical sensor (34) for capturing images in an image detection region (80) during an image capturing time period (86), a control signal transmitter (89) which provides a control signal that represents the image capturing time period (86), a measurement lighting arrangement (96) for lighting the image detection region (80), and a controller (19). The controller (19) is designed to activate the measurement lighting arrangement (96) during the image capturing time period (86) depending on the control signal, and the controller (19) is additionally designed to activate at least one additional lighting arrangement (97, 98, 100, 102) outside of the image capturing time period (86) depending on the control signal. The invention further relates to a measuring system and to a lighting control method.