• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1013-1017
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• 1997

This study is on the precision of the optical scanner which is suitable for shape modeling and non-contact equipment, comparing with a razer scanner. The optical scanner not only has all merits that non-contact methods have but also improve a veil phenomenon which is a razer scanner's demerits. However, the optical scanner has not been used extensively because the measurements are not very precise and there are not the definite methods of measurements, Hence, this study is to find out how parameters such as camera's hight, angle, luminous intensity, distance to object, and so on have an influence on measuring using the optical scanner and to establish the methods of measuring precision.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.70-75
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• 2003

It is very important to inspect the color of printed texture in the textile process. The standard colorimetric system used for the recognition of the color in the textile industry. It uses XYZ color system defined by CIE (Commission Internationale de 1Eclairage), but is too expensive. Therefore, in this paper, we propose a color inspection system of the printed texture using a color scanner. Because the scanner uses RGB value for color, it is necessary the mapping from RGB to XYZ. However, the mapping is not simple, and the scanner has even positional deviation because of the geometric characteristics. To transform from RGB to XYZ, we used a NN (neural network) model and also compensated the positional deviation. In real experiments, we could get fairly exact XYZ value from the proposed color inspection system in spite of using a color scanner with large measuring area.

• Journal of Biomedical Engineering Research
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• v.39 no.4
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• pp.153-160
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• 2018

3D ultrasound bladder scanners are getting popular in hospitals for the patients with bladder dysfunction. A current bladder scanner adopts a mechanical scan to acquire 3D images and requires two motors and complicated mechanical devices. In this paper, we propose a new ultrasound bladder scanner using hand-motion scan. Instead of two motors and mechanical devices, it has a motion sensor to record transducer positions during hand-motion scan. The experiments with a bladder phantom and volunteers showed similar measurement accuracy to a conventional 3D ultrasound bladder scanner. We expect that the proposed method will reduce the cost and size of the bladder scanner.

• Journal of Korean society of Dental Hygiene
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• v.19 no.1
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• pp.33-44
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• 2019

Objectives: To investigate how dental hygienists who have never used a digital oral scanner perceive the impression acquisition and evidence needed for prosthesis planning by using a digital oral scanner. Methods: From July 1, 2017 to December 31, 2017, subjects from Daegu, Gyeongsangbuk-do, Korea, were selected. The purpose of the study was described to dental hygienists who had never used a digital intraoral scanner. Questionnaires were distributed to the students selected. Of the 137 questionnaires distributed, 93 were used in the analysis after excluding 44 completed questionnaires that had errors or missing answers. Results: Of the respondents, 33.7% (36/93) were aged ${\geq}30$ years, 68.8% graduated from a 3-year vocational college course, 33.5% were aged ${\geq}33$ years, and 61.3%. At present, our center has the largest number of clinics (92.5%). The difficulty of impression taking using the digital oral scanner significantly differed (p<0.05) according to age and current occupation (p<0.05). Impression taking using a digital oral scanner significantly affected the present workflow of dental hygienists and their interest in sharing information about future use of digital oral scanner (p<0.01). Conclusions: If more routes are available to access digital intraoral scanners and more systems are developed for clinical use, the digital intraoral scanner could become digitized in the dental system; thereby, the existing impressions could be replaced with digitized impressions. With digital intraoral scanners, the expansion of the business of dental hygiene can be expected.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.1
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• pp.1-8
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• 2006

Effective three dimensional modeling becomes essential in a wide range of drawings, such as construction, machinery and design. In particular, it has been developed as the tool enabling reverse design. Three dimensional modeling requires rapidity, accuracy and tangibility. Data acquisition methods for modeling including contact type coordinate measurement machine, LASER scanner, pattern scanner and digital photogrammetry. In this study, we try to analyze modeling techniques as well as introduce three dimensional modeling using pattern scanner. In addition, this study conducts three dimensional modeling using OPTO-Top pattern scanner with distinguished accuracy and rapidity, and then compare efficiency with digital photogrammetry. And, this study attempts to form environment that enables to turn around models on web in three dimensional ways.

• Broadcasting and Media Magazine
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• v.6 no.2
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• pp.84-101
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• 2001

In this paper, we present a primitive system design of a super multi-view(SMV) 3-D display system based on a focused light array(FLA) concept using reflective vibrating scanner array(ViSA). The parallel beam scanning using a vibrating scanner array is performed by moving left and right an array of curvature-compensated mirrors or diamond-ruled reflective grating attached to a vibrating membrane. The parallel laser beam scanner array can replace the polygon mirror scanner which has been used in the SMV 3-D display system based on the focused light array(FLA) concept proposed by Kajiki at TAO(Telecommunications) Advancement Organization). The proposed system has great advantages in the sense that it requires neither huge imaging optics nor mechanical scanning pals. Some mathematical analyses and fundamental limitations of the proposed system are presented. The proposed vibrating scanner array, after some modifications and refinements, may replace polygon mirror-based scanners in the near future.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.863-868
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• 2008

This paper investigates the abnormal noise of polygon mirror scanner motor due to the mechanical contact. In the high speed polygon mirror scanner motor the vibration of polygon mirror scanner motor is one of the main sources of abnormal noise, because structure-borne noise due to the vibration is bigger than aerodynamic noise, especially when the rotating part contacts the stationary parts. This research determines the main harmonics of structure-borne noise by using sound quality evaluation. It also develops an experimental set-up to measure the mechanical contact and vibration of polygon mirror scanner motor simultaneously. This paper also show that mechanical contact between rotating shaft and stationary sleeve is one of the dominant vibration sources of structure-borne noise which cause the abnormal noise of the high speed polygon mirror scanner motor by using the developed experimental set-up.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.845-846
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• 2006

In this paper, we describe a capacitive position sensing and motion control scheme of a MEMS scanner used for laser display application. The laser displays can be made by scanning laser beams much the same way a CRT scans electron beams. So the accuracy of the scanner motion determines the quality of the displayed image. The MEMS scanner under consideration is composed of electrostatic comb electrodes with initial gap and requires large driving voltage. Due to the under-damping and nonlinear driving characteristics, the scanner motion is subject to be an unwanted oscillation. For the linear scanner motion, we devise a differential charge amplifier and phase compensator. The experimental results show that the implemented feedback control system provides sufficient electrical damping and improves the dynamic performance of the scanner.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.11 s.104
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• pp.1295-1302
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• 2005

This paper shows experimental evaluation results of the nano-positioning planar scanner used in the scanning probe microscope. The planar scanner is composed of flexure guides, piezoelectric actuators and feedback sensors as like explained in detail in Ref. (5). First, the fabrication methods were explained. Second, as the static Properties of the Planar scanner. we evaluated the maximum travel range & crosstalk. Also, we presented the correcting method for crosstalk using electric circuits finally. as the dynamic properties of the planar scanner, we evaluated the first resonant frequency. Also, we presented the actual AFM(atomic force microscope) imaging results with up to 2Hz imaging scan rate. Experimental results show that properties of the proposed planar scanner are well enough to be used in SPM applications like AFM.

• Tribology and Lubricants
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• v.15 no.1
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• pp.108-115
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• 1999

The electrical and frictional properties of oil-impregnated sintered-metal bearing (OSB) and herringbone-grooved fluid bearing (HFB) with varying loads and speeds were measured. OSB shows very good performance up to 20,000 rpm and 0.05 N, and HFB successfully works up to 35,000 rpm and 0.05 N. From the endurance tests on start-stop and continuous operation, it was confirmed that those bearings could be mass-produced fur use on scanner motor in a laser scanner unit.