• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1018-1021
• /
• 2009

Define a designated eye position (DEP) for the 3D displays is a critical issue. It shows the system performance without content issue. We use luminance meter to capture these optical characteristic and discuss between one point measurement, two points measurement and three points measurement situation.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.49-52
• /
• 2001

Moire topography method is a well-known non-contacting 3-D measurement method. Recently, the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using projection moire topogrphy is very attractive because of it s high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection moire topography tested to measuring object with the $2\pi$-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the $2\pi$-ambiguity problem can be effectively overcome so as to treat large step discontinuities in measured objects.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.935-938
• /
• 2008

Three-dimensional (3D) display systems based on wavefront reconstruction are presented. To obtain the wavefront of 3D objects, we present holographic recording using temporally or spatially phase-shifting interferometer. In the 3D display systems, phase-only reconstruction using a spatial light modulator and an approach to increase the reconstructed power are presented.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.23 no.5
• /
• pp.428-434
• /
• 2014

Measurement of the absolute displacement of the moving machinery components in three-dimensions (3D) is of critical functional importance. This paper describes the system that measures motion associated with six degrees-of-freedom in 3D. Wire-sensors are used to estimate the positions of an object in a 3D Cartesian coordinate system, based on the values of their initial position and the measured values. For inducing the transfer function, which represents the motion of an object, the number of the minimum measurement points is determined. Also, the experimental measuring device is configured to visualize the behavior of a rectangular object in real-time. The software for measuring the six types of motions is directly programmed using a commercial software.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.2054-2059
• /
• 2003

3D-PTV measurement was conducted on the wake of a goldfish in order to understand its swimming motions. The measurement system consisted of three CCD cameras, an image grabber, an Ar-Ion laser and a host computer. The flow properties of the wake of the goldfish were measured under three different velocities of the currents. Unsteady flow structures around the goldfish were quantitatively clarified using the time-consecutive instantaneous three-dimensional vectors obtained by the constructed 3D-PTV system.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1748-1753
• /
• 2003

3D-PTV measurement was conducted on the wake of a sphere. The Reynolds number is 1130 with the diameter(d=30mm). The measurement system consisted of three CCD cameras, an image grabber, an Ar-Ion laser and a host computer. An eigenvalue analysis was introduced for the analysis on the wake. Statistical turbulent properties were quantitatively clarified using the time-consecutive instantaneous three-dimensional vectors obtained by the 3D-PTV system. The spatial distributions of the sphere wake showed strong relations with spiral motions of the vortcies shedded from the surface of the sphere.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.8
• /
• pp.65-72
• /
• 2004

For the burrs formed in machining are irregular and very sharp in shape, it is usually very difficult to measure burr accurately. It was proved that micro burr geometry can be measured imprecision by the Conoprobe sensor using conoscopic holography method. We developed 3D burr measurement system using this sensor. The system is composed of Conoprobe sensor, XY table, controller and 3D measurement program. Some measurements using the developed system are conducted for the burrs formed in micro drilling and piercing. Specific software fur burr measurement includes several function, calculation of burr volume, average burr height. Burs formed on a curved surface were compensated and measured successfully using the basic surface compensation function.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.951-954
• /
• 2003

Generally, for the burrs formed in machining are irregular and very sharp in shape, it is usually very difficult to measure burr accurately. But, it is proved that precision measurement for micro burr using the conoprobe sensor by conoscopic holography method is possible. We developed 3D burr measurement system using this sensor. The system is composed of Conoscopic laser Sensor, X-Y table, controller and 3D measurement program. Some measurements using the developed system are applied to burrs formed in micro drilling and piercing.

• Proceedings of the KIEE Conference
• /
• 2001.07d
• /
• pp.2628-2630
• /
• 2001

This paper developed a 3D inspection system. The system consists of two parts : one includes hardwares such as actuators, linear scales and a probe, etc. the other involves softwares for management and control of the system. Compared with existing 3D measurement systems, this system achieved automatically the inspection. This automatic inspection makes the system have some advantages to reduce a measurement time and to be easily used by operators.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.389-392
• /
• 2016

As technologies evolve, 3D measurement techniques using cameras have been developed continuously. In 3D measurement, high accuracy, fast speed, and easy implementation are very important factors. Recently, 3D measurement using multi-frequency fringes has been widely used. This method is generally a method of measuring the height of a image obtained by projecting a sine wave through the projector. The sine wave is produced by software. However, this sine wave is not a perfect sine wave by gamma of projector. This is given a bad influence on the height measurement, and can not measure the correct height. In this paper, we propose a method for correcting the phase of the sine wave to avoid being affected gamma. Through this method it will be able to make more accurate height measurement.