Earticle

This paper presents a method of measuring the 6 DOF　motion of a micro object using images taken of interference fringes projected onto the object. Information from the fringe patterns allows for extracting the 6 DOF motion of the object in one image, allowing for real time measurement of the object's pose. This measurement technique is applied to a visual servo control scheme where the object's 6 DOF　motion is controled. Experimental results of the developed system are presented.

Non-contacting optical microscopes are increasingly used in recent industrial applications of probes for coordinate measuring machines. They have been found more efficient than conventional touch trigger porbes with ball tips especially in inspecting small-sized objects. There are two major factors affecting measuring accuracy: (1) geometric relations between coordinate systems, (2) magnification ratios of a microscope. In order to determine the magnification ratios exactly, optical imaging of edge was theroretically analyzed and practically adopted to image processing for edge detection. In addition, this paper proposes a geometric calibration method to obtain exact coordinates of measured points from the relations between the machine coordinate system and the image. In the method, the error according to the squareness between the machine axises was also removed. The method was practically adopted to a real coordinate measuring machine. An ultraprecision measurement of 0.2 um uncertainty can be practically achieved.

산업사회가 발전하면서 초정밀 분야의 측정기술 또한 시대적 요구에 걸맞게 발전을 거듭하고 있다. 광을 이용한 측정기술에 있어서 보다 작은광 스팟의 구현은 높은 분해능을 위해서 필수 불가결한 조건이며, 광 기록분야에 있어서는 높은 기록밀도를 위해 핵심적인 기술이다. 하지만 스팟의 직경은 광의 회절한계(diffraction limit)에 의한 최소치를 갖는다. 예로서, 측정을 위한 광학 현미경 중 현재 일반적으로 널리 쓰이는 고배율 광학 현미경(high resolution optical microscope)은 측정 대상 표면에 물리적 손상을 주지 않으며, 측정 범위가 크고, 값이 싼 장점이 있다.(중략)

We developed a line standards measurement system using an optical microscope and measured two kinds of line standards. It consists of three main parts: an optical microscope module including a CCD camera, a stage system with a linear encoder, and a measurement program for a microscopic image processing. The magnification of microscope part was calibrated using one-dimensional gratings and the angular motion of stage was measured to estimate the Abbe error. The threshold level in line width measurement was determined by comparing with certified values of a line width reference specimen, and its validity was proved through the measurement of another line width specimen. The expanded uncertainty (k=2) was about 100 nm in the measurements of $1{\mu}m{\sim}10{\mu}m$ line width. In the comparison results of line spacing measurement, two kinds of values were coincide within the expanded uncertainty, which were obtained by the one-dimensional measuring machine in KRISS and the line standards measurement system. The expanded uncertainty (k=2) in the line spacing measurement was estimated as $\sqrt{(0.098{\mu}m)^2+(1.8{\times}10^{-4}{\times}L)^2}$. Therefore, it will be applied effectively to the calibration of line standards, such as line width and line spacing, with the expanded uncertainty of several hundreds nanometer.

This paper describes a three dimensional profile measurement method for sheet metal products which have flexible and porous sculptured surfaces. Shadow masks are used as measuring objects for practical implementation or this study. The shadow masks are located inside the fluorescent glasses of monitors for televisions or computers and used to prevent electron guns from interfering between pixels. Three dimen- sional surface profiles are measured by adopting a software autofocusing technique to capture focused images. The experimental results show that the method is very effecive and suitable for sheet meal prod- ucts with flexible and porous surfaces.

Measurement of surface roughness is an important metrology procedure widely used in the industry during the final phases of the manufacturing process for quality control. This paper presents a measurement system that uses an optical microscope equipped with a vision sensor to measure the surface roughness of bearings. Shape from Focus / Defocus method is applied to measure the 3D surface coordinates of the object surface from which roughness calculations can be undertaken.

IT산업의 핵심인 디지털 카메라나 스마트폰 카메 라 등은 광학기술의 발전과 함께 창의적인 디자인의 제품이 개발되고 있다. 스마트폰의 발전으로 인해 mp3, 카메라, 다이어리, 녹음기, 디지털기기 등 다양 한 시장과 제품들이 스마트폰에 의해 흡수되고 있다. 본 연구개발 목표는 차별화된 디자인을 통한 스마 트폰 광학바이오현미경의 제품디자인이다. ‘나인’기업 이 보유한 320배율 광학바이오현미경 기술을 기반으 로 창의적인 스마트폰현미경 제품디자인 개발을 통해 기술과 디자인의 융합개발을 시도하였다. 디자인의 중요성을 인식하며, 개발된 제품디자인의 차별화를 통해, 일반 광학 loupe나 USB 현미경을 대체할 수 있는 제품으로서 고부가가치의 시장을 확보하고자 한 다. 본 연구의 제품디자인 개발을 위해 스마트폰 제품 디자인 시장을 분석하고 디자인 특성요소와 PPP 평 가방법을 도입하여, ‘나인’과 소비자의 관점에서 제품 의 우수성을 인정하고, 제조와 공급이 용이할 수 있 도록 제품의 문제점이나 개선점을 도출하였다. 돌출 된 20가지의 기준을 적용하여 사용의 편리성, 유연성, 조작직관성, 공간효율성, 사용다양성 내구성, 경제성, 심미성 등을 갖춘 ‘Z’ 복합형 스마트폰 광학바이오현 미경 제품디자인을 개발하였다. 본 연구는 기술력과 제품디자인의 융합개발을 통해 기존 현미경제품과 차별성을 주어 거치와 휴대가 가능한 복합형 광학바이오현미경으로 가정용 의료기 기의 역할, 교육용, 미용, 실험실 전문가용 등 다양한 분야에서 사용 가능하기에 충분한 독창성을 가진다.

According to development of optical technology, products of digital camera and smart phone with excellent functions are being developed, which are the core of IT industry. Due to development of smart phone, various markets and products such as mp3, camera, diary, recorder, and digital devices are absorbed into smart phone. Objective of this study is to develop product design of smart phone optical bio-microscope through differentiated design development. It attempted fusion of optical bio-microscope technology and design field through development of differentiated product design based on 1,000 magnification optical bio-microscope technology owned by‘NINE’It intends to secure high value markets through products which can replace ordinary optical loupe or USB microscope through differentiation of developed product design. In order to develop such product design, it analyzed smart phone product design market, introduced design characteristic elements and PPP evaluation method, and drew product problems and improvements to recognize products excellence from the standpoint of‘NINE’and consumers and then, to facilitate manufacture and supply of products. It developed product design of ‘Z’ combined smart phone optical bio-microscope considering convenience, flexibility, intuitive operation, space efficiency, diversified usage, durability, economic feasibility, and aesthetics by application of projected 20 criteria. This study has differentiation from existing microscope products through technology and fusion development of product design and so, it retains sufficient creativity for a combined optical bio-microscope to be used in many fields with potable and stand function.

We developed a new scheme for the highly sensitive near-field scanning optical microscope (NSOM) by using a dithering sample stage rather than a dithering probe. In the proposed scheme, the sample is directly loaded on one prong surface of a dithering bare tuning fork. Gap control between probe and sample is performed by detecting the shear force between an immobile fiber probe and the dithering sample. In a conventional NSOM, the Q factor drastically decreases from 7783 to 1000 or even to 100 by attaching a probe to the tuning fork. In our proposed NSOM, on the contrary, the Q factor does not change significantly, 7783 to 7480, when the sample is loaded directly to the tuning fork instead of attaching a probe. Consequently, the graphene sheets that cannot be observed by a conventional NSOM were clearly observed by the proposed method with sub-nanometer vertical resolution due to the extremely high Q factor.

근접장광학계 (Near-Field Scanning Optical Microscope :NSOM)의 표본과 팁의 거리 유지를 위해 소리굽쇠모양의 수정발진자 (tuning forktype quartz crystal unit)의 한쪽 다리에 광섬유를 고정시키고 광섬유 팁을 수정발진자와 같이 진동하게 만들어 사용하였다. 수정 진동자는 광섬유 팁이 시료에 얼마나 가까이 갔느냐에 따라 진폭이 바뀌게 되고 이 변화를 일반적인 방법인 레이저 빛에 의하여 읽어내는 것이 아니라 바로 수정 발진자의 임피던스 변화에 따른 전압 변화를 측정하여 알아냈다. 팁이 표면에 접근함에 따라 수정발진자 진동폭의 변화와 팁을 통해 들어오는 빛의 세기 변화 등을 측정하여 계의 감도를 조사하였다.

We attached a fiber tip on the branch of a quartz crystal oscillator in order to make a feedback control system for near field optical microscope. The electrical impedance of the quartz crystal oscillator depends on the distance between the surface of the sample and the tip caused by the surface damping. Using this method, we can directly monitor the distance between the sample and the tip without inserting extra beam which might give extra optical noise. We characterize the XY scanning resolution and the amplitude of the vibrating tip and the Z-dependent decay of the evanescent wave.

A magneto-optical microscope magnetometer (MOMM) has been developed to simultaneously measure 2-dimensional array hysteresis loops of each local area of $320\times320-nm^2$ spots on ferromagnetic films, in addition to grabbing time-resolved domain evolution patterns. Using the system, spatial distribution of local coercivity can be quantitatively generated and then, compared directly with domain patterns grabbed at precisely the same position of a sample. It is clearly demonstrated that local coercivity distribution governs domain reversal behavior via a thermally activated relaxation process.

In coherent anti-Stokes Raman scattering (CARS) microscopy reported until now, conventional microscope objectives are used, so that they are limited for introduction into a living body. Gradient-index (GRIN) rod lenses might be a solution for miniaturized microscope objectives for in-vivo CARS microscopy. However, due to the inherent large amount of chromatic aberration, GRIN rod lenses cannot be utilized for this purpose. CARS imaging catheter, composed of miniaturized microscope objective and fiber bundle, can be introduced into a living body for minimally invasive diagnosis. In order to design the catheter, we have to first investigate design requirements. And then, the optical design is processed with design strategies and intensive computing power to achieve the design requirements. We report the miniaturized objective lens system with diffraction-limited performance and completely corrected chromatic aberrations for an in-vivo CARS imaging catheter.

A stack of gradient-index (GRIN) rod lenses cannot be used for coherent anti-Stokes Raman scattering (CARS) microendoscopy for insertion to internal organs through a surgical keyhole with minimal invasiveness. That's because GRIN lens has large amount of inherent chromatic aberrations in spite of absolutely requiring a common focus for pump and Stokes beam with each frequency of ${\omega}_p$ and ${\omega}_S$. For this endoscopic purpose, we need to develop a long slender probe-type objective, namely probe-type microscope objective (PMO). In this paper, we introduce the structure, the working principle, and the design techniques of PMO which is composed of a probe-type lens module (PLM) and an adaptor lens module (ALM). PLM is first designed for a long slender type and ALM is successively designed by using several design parameters from PLM for eliminating optical discords between scanning unit and PLM. A combined module is optimized again to eliminate some coupling disparities between PLM and ALM for the best PMO. As a result, we can obtain a long slender PMO with perfectly diffraction-limited performance for pump beam of 817 nm and Stokes beam of 1064 nm.

In this study, the internal structure of an optical waveguide embedded in a flexible optical circuit board is observed with a confocal microscope. In order to increase the light reflection from an internal material interface with a very small index difference, and thus enhance the signal contrast, a theta microscopy scheme has been integrated into a conventional confocal microscope, and a high NA oil-immersion lens has been used. The interface reflectivity is increased from roughly 0.0015% to 0.025% by the proposed method, and the internal structure can thus be successfully measured.

In this paper, a method is proposed for simultaneously measuring the front and back surface profiles of transparent micro-optical components. The proposed method combines a dual-wavelength digital holographic microscope with liquids to record holograms at different wavelengths, and then numerically reconstructs the three-dimensional phase information to image the front and back sides of the sample. A theoretical model is proposed to determine the surface information, and imaging of an achromatic lens is demonstrated experimentally. Unlike conventional interferometry, our proposed method supports nondestructive measurement and direct observation of both front and back profiles of micro-optical elements.

NSOM(Near-field Scanning Optical Microscopy) 조화 진동자(Tuning fork)와 광섬유 탐침을 결속시켜 미소신호를 검출하여 증폭과 잡음을 제거하기 위한 Pre-amplifier의 설계 및 제작과 더불어 시료-탐침간 거리를 파장보다 짧게 유지시키는 Shear force 검출, 효율적인 시료-탐침 거리유지 알고리즘 구연 및 탐침을 시료 표면에서 일정한 거리를 안정적으로 유지하도록 제어 및 시료의 높이 정보를 얻어내는 시스템을 설계 및 제작하였다. 또한 ����$CO_2Laser$를 이용한 Heat Pulling 장치개발을 통해 탐침을 제작, LabVIEW를 통해 개별적인 시스템을 하나로 통합하여 AFM 테스트 시료인 SiO 샘플의 표면 형상을 측정하였다.

Light Field Rendering 을 이용하여 성능이 떨어지는 Low resolution 카메라 장비로 얻는 영상의 한계를 극복하고, Image Processing 기술로 직접 조정해야 해결할 수 있는 수차 및 성능 문제 해결한다. 저가형 장비, 렌즈를 사용하여도 컴퓨터기반 처리를 이용하여 물리적인 한계를 극복한 간이 광학현미경을 만들고자 함. 3D print 를 이용한 뼈대구조를 만들고, 저렴한 raspberry pi 임베디드 플랫폼을 이용하여 설계도만 있다면, 누구나 쉽게 만들 수 있기에 많은 사람들이 이 분야에 더 쉽게 다가설 수 있게 한다.

세포단위에서 혈관 생성과정 관찰 시 사용되는 광학현미경 영상은 광원의 특성으로 인해 부분적으로 영상이 밝거나 혹은 어둡게 나타난다. 이러한 현상은 혈관 영상에서의 혈관 분석을 어렵게 하므로 본 논문에서는 신 혈관 생성 영상에서 명도 불균형 문제를 해결하는 혈관 추출 및 정량화 기법을 제안한다. 불균형 명도 문제를 해결하기 위해 지역적 문턱치화 방법을 사용하고, 잡음 및 혈관 내 틈새 문제를 해결하기 위해 형태학적 연산 처리를 하였다. 그 결과 명도가 어두운 지역에서 배경 잡음이 없고, 영역이 끊어지지 않고 하나로 연결된 혈관을 추출할 수 있었다. 추출된 혈관 영역에서 골격화와 혈관 세그먼트에 기반하여 두께, 길이, 넓이를 정량화함으로써 혈관 분석 시 현미경에 탑재되어 있어 가장 널리 사용되고 있는 메타 모르프보다 정확한 정량화 결과를 얻었다.