Parasitic reflection elimination using binary pattern in phase measuring deflectometry

Wang, Ruiyang; Li, Dahai; Xu, Kun; Zhang, Xinwei; Luo, Peng

doi:10.1016/j.optcom.2019.06.009

Cited by 11 publications

(5 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As mentioned before, scanning techniques can be suitable to avoid superposition of signals, either as a single line or, if the object is sufficiently uniform, with the densest possible array of bright or (to enable phase measurements) sinusoidally modulated lines (Gühring, 2000;Faber et al, 2009;Wang et al, 2019).…”

Section: Handling Multiple Reflectionsmentioning

confidence: 99%

Deflectometry for specular surfaces: an overview

et al. 2023

View full text Add to dashboard Cite

Deflectometry as a technique to assess reflective surfaces has now existed for some 40 years. Its different aspects and variations have been studied in multiple theses and research articles; reviews are available for certain subtopics. Still a field of active development with many unsolved problems, deflectometry now encompasses a large variety of application domains, hardware setup types, and processing workflows for different purposes, and spans a range from qualitative defect inspection of large vehicles to precision measurements of microscopic optics. Over these years, many exciting developments have accumulated in the underlying theory, in the systems design, and in the implementation specifics. This diversity of topics is difficult to grasp for experts and non-experts alike and may present an obstacle to a wider acceptance of deflectometry as a useful tool for research and industrial applications. This paper presents an attempt to summarize the status of deflectometry and to map relations between its notable branches. Its aim is to provide a communication basis for experienced practitioners and also to offer a convenient entry point for those interested in learning about the method. The list of references introduces some prominent trends and established research groups in order to facilitate further self-directed exploration.

show abstract

Section: Handling Multiple Reflectionsmentioning

confidence: 99%

Deflectometry for specular surfaces: an overview

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Known intensity differences between front and rear side reflection can be accounted for by intensity thresholding [181,412]. As mentioned before, scanning techniques can be suitable to avoid superposition of signals, either as a single line or, if the object is sufficiently uniform, with the densest possible array of bright or (to enable phase measurements) sinusoidally modulated lines [399,516,517].…”

Section: Handling Multiple Reflectionsmentioning

confidence: 99%

Deflectometry for specular surfaces: an overview

Burke¹,

Pak²,

Höfer³

et al. 2022

Preprint

View full text Add to dashboard Cite

Deflectometry as a technical approach to assessing reflective surfaces has now existed for almost 40 years. Different aspects and variations of the method have been studied in multiple theses and research articles, and reviews are also becoming available for certain subtopics. Still a field of active development with many unsolved problems, deflectometry now encompasses a large variety of application domains, hardware setup types, and processing workflows designed for different purposes, and spans a range from qualitative defect inspection of large vehicles to precision measurements of microscopic optics. Over these years, many exciting developments have accumulated in the underlying theory, in the systems design, and in the implementation specifics. This diversity of topics is difficult to grasp for experts and nonexperts alike and may present an obstacle to a wider acceptance of deflectometry as a useful tool in other research fields and in the industry.This paper presents an attempt to summarize the status of deflectometry, and to map relations between its notable "spin-off" branches. The intention of the paper is to provide a common communication basis for practitioners and at the same time to offer a convenient entry point for those interested in learning and using the method. The list of references is extensive but definitely not exhaustive, introducing some prominent trends and established research groups in order to facilitate further selfdirected exploration by the reader.

show abstract

“…In principle, the reflections from the top and bottom surfaces can be separated spatially. A class of methods is to directly avoid forming the superposed fringes, in which a binary pattern or gray code is used to separate the overlapping signals [ 11 , 12 ]. The former needs to set a suitable size of Zone-M to cover the measurement area [ 11 ].…”

Section: Introductionmentioning

confidence: 99%

“…A class of methods is to directly avoid forming the superposed fringes, in which a binary pattern or gray code is used to separate the overlapping signals [ 11 , 12 ]. The former needs to set a suitable size of Zone-M to cover the measurement area [ 11 ]. The latter needs to know the phase-shift caused by the thickness difference between the upper and lower surfaces [ 12 ].…”

Section: Introductionmentioning

confidence: 99%

Parasitic Reflection Eliminating for Planar Elements Based on Multi-Frequency Phase-Shifting in Phase Measuring Deflectometry

Huang,

Liu,

2024

Sensors

View full text Add to dashboard Cite

Phase measuring deflectometry (PMD) stands as an extremely important technique for specular surface measurement. However, the parasitic reflection from the rear surface poses a challenge for PMD. To solve this problem, this paper proposes an effective method based on multi-frequency and phase-shifting to search for the correct phase. Firstly, the relationship between the phase error and fringe frequency is adequately investigated. Subsequently, an auxiliary function is established to find the special frequency at which the phase error is zero theoretically and the unwrapped phase is the phase of the top surface exactly. Then, the shape of the top surface can be reconstructed correctly. A standard plane element with a thickness of 40 mm and a flat glass with 19 mm were measured. The experimental results verify the feasibility of the proposed method. Considering the result of the interferometer as a reference, the RMSE of the error map is up to 20 nm for the standard plane element. The experimental results demonstrate that the proposed method can successfully untangle the superposed reflections and reliably reconstruct the top surface of the object under test.

show abstract

Parasitic reflection elimination using binary pattern in phase measuring deflectometry

Cited by 11 publications

References 16 publications

Deflectometry for specular surfaces: an overview

Deflectometry for specular surfaces: an overview

Deflectometry for specular surfaces: an overview

Parasitic Reflection Eliminating for Planar Elements Based on Multi-Frequency Phase-Shifting in Phase Measuring Deflectometry

Contact Info

Product

Resources

About