• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.233-236
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• 1997

In modem industry, the accuracy and the surface-finish requirements for machined parts have been becoming ever more stringent. Optical method in measurements is playing an important role in vibration measurement, crack and defect detection and surface topography with the advent of opto-mechatronics. In this study, the principle of the general confocal microscope is introduced for surface measurement, and the advanced confocal microscope that has better measuring speed than the traditional confocal microscope is developed. A study on improving the resolution of the advanced confocal microscope is followed. Finally, Software for data acquisition and analysis of various parameters in surface geometrical features has been developed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.163.2-163
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• 2001

Confocal scanning microscopy (CSM) has been reported as an excellent method using the optical probe in scanning probe microscopy (SPM). Transmission or reflection confocal scanning microscopy (TCSM, RCSM) has been used in the three-dimensional reconstruction of specimen or the non-destructive measurement in vivo. The axial movement of the primary focal point having the information of specimen gives a good measurement performance with the great sensitivity. Application of the confocal theory and astigmatism to displacement measurement sensor uses the aperture as the pinhole or slit after collecting lens relating to confocal response in non-contact measurement; and astigmatic lens using four-segments detector as short-range sensor, long-range one combining the grating and rotary one hating the rotary directional grating. The aperture type can play an ...

• Current Optics and Photonics
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• v.4 no.1
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• pp.44-49
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• 2020

In this paper, a new method is presented to measure the refractive index of single plain glass or multilayered materials, based on a laser frequency-shifted confocal feedback microscope. Combining the laser frequency-shifted feedback technique and the confocal effect, the method can attain high axial-positioning accuracy, stability and sensitivity. Measurements of different samples are given, including N-BK7 glass, Silica plain glass, and a microfluidic chip with four layers. The results for N-BK7 glass and Silica plain glass show that the measurement uncertainty in the refractive index is better than 0.001. Meanwhile, the feasibility of this method for multilayered materials is tested. Compared to conventional methods, this system is more compact and has less difficulty in sample processing, and thus is promising for applications in the area of refractive-index measurement.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.51-54
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• 2000

The traditional surface measuring method using confocal principle requires much time to measure an object surface since it is a scanning tool. In this paper, the upgraded confocal microscope is introduced. It is also a scanning tool but it requires 2D-scanning while the traditional one requires 3D-scanning. It means the time for measuring is considerably reduced. In addition, the measuring system is configured to increase the efficiency of beam. He-Ne laser whose frequency is 632.8nm is used for the laser source. An example of measuring result through the upgraded confocal microscope is showed.

• Journal of the Semiconductor & Display Technology
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• v.7 no.1
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• pp.11-16
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• 2008

Confocal scanning microscopy is a widely used technique for three dimensional measurements because it is characterized by high resolution, high SNR and depth discrimination. Generally an image is generated by moving one optical probe that satisfies the confocal condition on the specimen. Measurement speed is limited by movement speed of the optical probe; scanning speed. To improve measurement speed we increase the number of optical probes. Specimen region to scan is divided by optical probes. Multi-point information each optical probe points to can be obtained simultaneously. Therefore image acquisition speed is increased in proportion to the number of optical probes. And multiple optical probes from red, green and blue laser sources can be used for color imaging and image quality, i.e., contrast, is improved by adding color information by this way. To conclude, this technique contributes to the improvement of measurement speed and image quality.

• Applied Microscopy
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• v.44 no.2
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• pp.61-67
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• 2014

Layered structures of fiber cell wall of Korean red pine (Pinus densiflora) were investigated by confocal reflection microscopy (CRM). CRM micrographs revealed detailed structures of the fiber cell wall such as S1, S2, and S3 layers as well as transition layers (S12 and S23 layers), which are present between the S1, S2, and S3 layers. Microfibril angle (MFA) measurement was possible for the S2 and S3 layer in the cell wall. The experimental results suggest that CRM is a versatile microscopic method for investigation of layered structures and MFA measurement in individual sub layer of the tracheid cell wall.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.279-285
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• 2015

Hyperpigmentation on face is a highly anxiety-producing symptom, especially for women from the aspect of beauty. Pigmentation of the skin is related to the amount of melanin that provides protection against UV radiation. In vivo reflectance confocal microscopy is a non-invasive imaging tool allowing visualization of the skin without tissue alteration, by placing a microscopy directly on the living skin. The aim of this study was to develop the new evaluation method of whitening effects using in vivo reflectance confocal microscopy and to validate other instruments for measuring skin colors, and UV-induced hyperpigmentation was elicited on the inside skin of the forearm. It suggested that the new method for whitening effects using the confocal microscopy was useful to evaluate the de-pigmentation products and to easy for understanding to customers.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.52-57
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• 2008

We demonstrate the operation of an apparatus that we call the laser scanning confocal microscopy. It is valuable tool of the investigations for imaging process. We measured the thin metal structure through the SCM manufacture. Confocal microscopy offers several advantages including shallow depth of field, elimination of out-of-focus glare, and the ability to collect serial optical sections from thick specimens than conventional optical microscope. This research is manufactured of scanning confocal microscopy and after measured of metal materials structure.

• Journal of the Optical Society of Korea
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• v.15 no.1
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• pp.9-14
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• 2011

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.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.12
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• pp.1130-1135
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• 2015

The bond pull test is the most widely used technique for the evaluation and control of wire bond quality. The wire being tested is pulled upward until the wire or bond to the die or substrate breaks. The inspector test strength of wire by manually and it takes around 3 minutes to perform the test. In this paper, we develop a 3D vision system to measure 3D position of wire. It gives 3D position data of wire to move a hook into wires. The 3D measurement method to use here is a confocal imaging system. The conventional confocal imaging system is a spot scanning method which has a high resolution and good illumination efficiency. However, a conventional confocal systems has a disadvantage to perform XY axis scanning in order to achieve 3D data in given FOV (Field of View) through spot scanning. We propose a method to improve a parallel mode confocal system using a micro-lens and pin-hole array to remove XY scan. 2D imaging system can detect 2D location of wire and it can reduce time to measure 3D position of wire. In the experimental results, the proposed system can measure 3D position of wire with reasonable accuracy.