• Journal of the Optical Society of Korea
• /
• v.10 no.1
• /
• pp.48-54
• /
• 2006

White-light scanning interferometry (WLI) and phase shifting interferometry (PSI) are increasingly used for surface topography measurements, particularly for areal measurements. In this paper, we compare surface profiling results obtained from above two optical methods with those obtained from stylus instruments. For moderately rough surfaces ($Ra{\approx}500\;nm$), roughness measurements obtained with WLI and the stylus method seem to provide close agreement on the same roughness samples. For surface roughness measurements in the 50 nm to 300 nm range of Ra, discrepancies between WLI and the stylus method are observed. In some cases the discrepancy is as large as 109% of the value obtained with the stylus method. By contrast, the PSI results are in good agreement with those of the stylus technique.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.04a
• /
• pp.613-617
• /
• 2000

This paper descries the effect of the stylus tip size on the measuring error in surface topography measurement. To analyze the distortional effect of an actual surface geometry originating from the finite stylus size, the surface is modeled as a sinusoid and the stylus tip as a circle. the measuring error is defined as the ratio of the standard deviation of a tracing profile and an original profile. It is shown that this measuring error depends on the amplitude and wavelength of an original profile. In this paper, the spectrum analysis is applied to investigate the distortional effect due to the mechanical filtering of the stylus in the frequency domain. and, the cumulative power spectrum is applied to determinate the minimum wavelength limits to be measured with the various stylus tip radius from these results, a new method to select proper stylus tip radius is proposed.

• Journal of the Korean Society for Precision Engineering
• /
• v.8 no.3
• /
• pp.105-113
• /
• 1991

The practicability of Ion-Sputter machining renders it possible to make diamond stylus for surface roughness measurement with micro stylus tip radius less than 2${\mu}mR$, and to measure surface roughness of fine-machined surface. In this study, we researched the wear or Ion-Sputtered stylus with 0.1${\mu}mR$ and 0.5${\mu}mR$ for micro-figure measurement and polished stylus with 0.5${\mu}mR$ according to measurement distance. As a result, we know that the case of Ion-Sputtered stylus is worn down easilier the case of polished stylus. And we know that in the evaluation of stylus wear, it is more useful method that examine the wear by measuring the variation of stylus tip radius than by evaluating the variation of Ra values.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.12
• /
• pp.174-181
• /
• 1999

This paper describes the effect of the stylus tip size on the shape error in surface topography measurement. To analyze the distortional effect of an actual surface geometry origination from the finite stylus size, the surface is modeled as a sinusoid and the stylus tip as a circle. The magnitude of this distortion is defined as the ration of standard deviation, and this is expressed as an analytic function of the stylus tip radius and the geometrical parameter of a sinusoid. In this paper, the spectrum analysis of the profile is applied to investigate the distortional effect due to the mechanical filtering of the stylus in the frequency domain. and, the cumulative power spectrum is proposed to assess the shape error of measured data according to the various stylus tip sizes. From these results, a new method to select proper stylus tip radius is proposed.

• Journal of the Korean Society for Precision Engineering
• /
• v.3 no.1
• /
• pp.69-76
• /
• 1986

The measuring Method by stylus, which measures surface roughness, has been widely used since G. Schmaltz developed the first equipment of that type. Withe the resent development of the measuring method by stylus, surface foughness testing instruments of the very high magnification ratio, hundreds of thousands, are manu- factured. However, as the techniques of the high precision roughness measurement are being required, the response problems due to the tip shapes and the plastic deformations of measured surface of mild material are to be serious factors. In this study, diamond stylus of tip radius $0.5\mu\textrm{m}$, $2\mu\textrm{m}$, $5\mu\textrm{m}$ and $10\mu\textrm{m}$ were used under the measuring force of 0.01gf, 0.02gf, 0.07gf, 0.4gf and 1.6gf, and from the experimental data, maximum measured value devrements between $2\mu\textrm{mR}$ stylus and $5\mu\textrm{mR}$ stylus, $2\mu\textrm{mR}$ stylus and $10\mu\textrm{mR}$ stylus are 22% and 31%, respectively when the measured value of $2\mu\textrm{mR}$ stylus goes to $0.01\mu\textrm{m Ra}$, $\lambda$ c2.5mm. And it is shown that plastic deformations on the plastic deformations on the measured surface are proportional to W/R(W;measured force, R;stylus tip radius).

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.8 no.1
• /
• pp.126-134
• /
• 1999

In this paper, a new error compensating technique for form-error compensation of rough-surface profile obtained by contact stylus profilometer is proposed. By the method, the real contact points of rough-surface and diamond stylus can be estimated and the measured profile data corrected. To verify the compensation effect, the properties(Ra, RMS, Kurtosis, Skewness) of measured profile data and compensated data were compared. And, the cumulative RMS slope was proposed to assess the compensated effect of upper area of profile. The results show that the measuring error could be compensated very well in amplitude parameters and in proposed cumulative RMS slope by the developed form-error compensating technique.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.5 no.4
• /
• pp.108-120
• /
• 1996

A new technique and theory are proposed which correct orientation of a cylinder to perform a reliable measurement of the surface profile. We analyze characteristics of machined surfaces, e.g., ground, lapped and turned surfaces. Based upon the results. the optimum correction technique is derived by the statistical method. To verify the techinques, measurements are carried out by using the contact stylus profilometer on a controllable table. The measurement shows that surface information of cylinders can be acquired with high accuracy.

• Journal of the Korean Society for Precision Engineering
• /
• v.3 no.1
• /
• pp.60-68
• /
• 1986

Measurement of surface roughness has been done by two dimensional method until now. In recent, three dimensuional method is introduced for the precise measurement of surface roughness. But the study about stylus type three dimensional measurement method is a little. Therefore, in this study, arbitrary machined surface is selected and same part is measured by two dimensional and three dimensional method. The result is that the ratio of tow dimensional to three dimensional value is 0.9-1.1 in Ra. But two dimensional measurement method is underestimated because the ratio is 0.5-0.9 in Rz, Rmax. And it is suitable that the number of measuring line is 100 and y pitch is 5 um by three dimensional surface roughness measuring method.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.3
• /
• pp.120-130
• /
• 1998

In this study, we implemented a scanning capacitance decimicron micorscope(SCdM) which scans a surface of the object mechanically in two or two point five dimensions with a stylus of size 0.2.mu.m. X-Y stage and stylus driving method are used as the scanning method, and VHD disk plate and IC chip are used as the object. Experimenal resutl of these object show that SCdM obtain 0.1.mu.m resolution power which exceeds that of optical microscope, and this microscope will be used as a powerful tool for inspecting ULSI pattern or biological data as a decimicron mcirocope which zoom a function of optical microscope and guide STM. The experimental system is composed of a VHD video disk method which captures the capacitance changes of the video disk suface and converts it into video signal.

• Journal of the Korea Society of Computer and Information
• /
• v.20 no.10
• /
• pp.15-21
• /
• 2015

In this paper, we propose a stable automatic signature verification algorithm applicable to various smart devices. The proposed algorithm uses real and forgery data all together, which can improve the verification rate dramatically. As a tool for signature acquisition in a smart device, two applications, one using touch with a finger and the other using a pressure-sensing-stylus pen, are developed. The verification core is based on SVM and some modifications are made to include the characteristics of signatures. As shown in experimental results, the minimum error rate was 1.84% in the SVM based method, which can easily defeat 4.38% error rate with the previous parametric approach. Even more, 2.43% error rate was achieved with the features excluding pressure-related features, better than the previous approach including pressure-related features and only about 0.6% more error than the best result, which means that the proposed algorithm can be applied to a smart device with or without pressure-sensing-stylus pens and used for security purposes.