marlene henrique - Academia.edu (original) (raw)
Papers by marlene henrique
In this work a method for out-of-plane vibration measurement using structured light projection is... more In this work a method for out-of-plane vibration measurement using structured light projection is proposed. The light was generated by a Michelson interferometer with a green laser as light source. By illuminating the vibrating surface with straight and parallel interference fringes a jiggling interference pattern is obtained. In order to stabilize the fringe pattern the phase modulation was performed by using a vibrating mirror in the interferometer. We demonstrated the technique by measuring the vibration amplitudes of small objects in the millimeter and submillimeter range.
Optical Engineering, 2020
Abstract. Dioptric power measurement is an essential part of the characterization and quality con... more Abstract. Dioptric power measurement is an essential part of the characterization and quality control of lens manufacturing. In this framework, a fairly simple and potentially cost-effective method for lens characterization by interferometric fringe evaluation is reported. This technique consists of acquiring images of straight and parallel fringes projected onto a planar screen through the lens to be tested and in the regions surrounding the lens. Upon phase evaluation procedures, two apparent three-dimensional shapes of the screen are obtained, namely, the background contour and the one visualized through the test lens. The lens power is obtained as a function of the ratio between the two shapes and the parameters of the optical setup. The fringe pattern evaluation was performed by four-stepping and phase unwrapping methods. The results obtained by this technique were compared with the ones obtained by a commercial focimeter in the measurement of unifocal and progressive power lenses.
Research, Society and Development, 2020
This paper describes the conception, the development and the testing of a prototype of a simple a... more This paper describes the conception, the development and the testing of a prototype of a simple and versatile device for micro displacement measurement and thickness monitoring of paper sheets and opaque or transparent plastic films during their fabrication. The device works based on triangulation using low power red diode laser beams for the measurements and low-cost Silicon photodiodes for light detection. The system reproductibility was evaluated as well as experimental simulations for thickness variation detection on adhesive tapes were carried out. The results showed that the gauge is capable to detect and measure thickness variations smaller than 5 µm in real time and can be easily implemented in a production system.
Research, Society and Development, 2020
Three-dimensional (3D) contouring has become very important in industry and in many other product... more Three-dimensional (3D) contouring has become very important in industry and in many other production systems. The optical techniques provide many attractive properties for such measurement due to their precision, reliability, accuracy and ability to measure small and fragile objects. In this work we report the study, the development and the performance of a low-cost optical device based on interferogram projection in order to measure the sub-millimetric relief of polymeric plates containing biomimetic textures used in the automotive industry. The interferogram was generated by a Twyman-Green interferometer illuminated by a 532-nm green laser. The measurement was performed by means of phase-shifting and phase-unwrapping procedures and the results were benchmarked with the ones obtained by a commercial device.
In this work a method for out-of-plane vibration measurement using structured light projection is... more In this work a method for out-of-plane vibration measurement using structured light projection is proposed. The light was generated by a Michelson interferometer with a green laser as light source. By illuminating the vibrating surface with straight and parallel interference fringes a jiggling interference pattern is obtained. In order to stabilize the fringe pattern the phase modulation was performed by using a vibrating mirror in the interferometer. We demonstrated the technique by measuring the vibration amplitudes of small objects in the millimeter and submillimeter range.
Optical Engineering, 2020
Abstract. Dioptric power measurement is an essential part of the characterization and quality con... more Abstract. Dioptric power measurement is an essential part of the characterization and quality control of lens manufacturing. In this framework, a fairly simple and potentially cost-effective method for lens characterization by interferometric fringe evaluation is reported. This technique consists of acquiring images of straight and parallel fringes projected onto a planar screen through the lens to be tested and in the regions surrounding the lens. Upon phase evaluation procedures, two apparent three-dimensional shapes of the screen are obtained, namely, the background contour and the one visualized through the test lens. The lens power is obtained as a function of the ratio between the two shapes and the parameters of the optical setup. The fringe pattern evaluation was performed by four-stepping and phase unwrapping methods. The results obtained by this technique were compared with the ones obtained by a commercial focimeter in the measurement of unifocal and progressive power lenses.
Research, Society and Development, 2020
This paper describes the conception, the development and the testing of a prototype of a simple a... more This paper describes the conception, the development and the testing of a prototype of a simple and versatile device for micro displacement measurement and thickness monitoring of paper sheets and opaque or transparent plastic films during their fabrication. The device works based on triangulation using low power red diode laser beams for the measurements and low-cost Silicon photodiodes for light detection. The system reproductibility was evaluated as well as experimental simulations for thickness variation detection on adhesive tapes were carried out. The results showed that the gauge is capable to detect and measure thickness variations smaller than 5 µm in real time and can be easily implemented in a production system.
Research, Society and Development, 2020
Three-dimensional (3D) contouring has become very important in industry and in many other product... more Three-dimensional (3D) contouring has become very important in industry and in many other production systems. The optical techniques provide many attractive properties for such measurement due to their precision, reliability, accuracy and ability to measure small and fragile objects. In this work we report the study, the development and the performance of a low-cost optical device based on interferogram projection in order to measure the sub-millimetric relief of polymeric plates containing biomimetic textures used in the automotive industry. The interferogram was generated by a Twyman-Green interferometer illuminated by a 532-nm green laser. The measurement was performed by means of phase-shifting and phase-unwrapping procedures and the results were benchmarked with the ones obtained by a commercial device.