• Journal of the Semiconductor & Display Technology
• /
• v.20 no.4
• /
• pp.114-118
• /
• 2021

In this research, the dimensional error of the measured specimen according to the measurement method was analyzed for the length, angle, radius of curvature and diameter using a projector which is used in industry. One-way analysis was performed on each data tested 30 times using a statistical technique. Through the experiment, it was found that an error occurred in each data when measuring the length and radius of curvature according to the measurement method, and the null hypothesis that no error occurred when measuring the angle and length was established. Based on this experimental data, the automatic measurement when measuring the projector causes less measurement error, so automatic measurement is recommended when measuring a small product. Also, an optimal measuring method is suggested for securing reliability on formulations of measurement automation.

• Advances in robotics research
• /
• v.2 no.1
• /
• pp.45-57
• /
• 2018

Even though the popularity of projection mapping continues to increase and it is being implemented in more and more settings, most current projection mapping systems are limited to special purposes, such as outdoor events, live theater and musical performances. This lack of versatility arises from the large number of projectors needed and their proper calibration. Furthermore, we cannot change the positions and poses of projectors, or their projection targets, after the projectors have been calibrated. To overcome these problems, we propose a projection mapping method using a projector robot that can perform projection mapping in more general or ubiquitous situations, such as shopping malls. We can estimate a projector's position and pose with the robot's self-localization sensors, but the accuracy of this approach remains inadequate for projection mapping. Consequently, the proposed method solves this problem by combining self-localization by robot sensors with position and pose estimation of projection targets based on a 3D model. We first obtain the projection target's 3D model and then use it to accurately estimate the target's position and pose and thus achieve accurate projection mapping with a projector robot. In addition, our proposed method performs accurate projection mapping even after a projection target has been moved, which often occur in shopping malls. In this paper, we employ Ubiquitous Display (UD), which we are researching as a projector robot, to experimentally evaluate the effectiveness of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.149-150
• /
• 2009

• The Journal of the Korea Contents Association
• /
• v.13 no.4
• /
• pp.469-480
• /
• 2013

The purpose of this study is to investigate young children's user experience on three types of dramatic activity: traditional dramatic activities, dramatic activities relying on robot projector based augmented reality and creative dramatic activities relying on robot projector based augmented reality. Participants were 20 five-year-old children attending D kindergarten, in Seoul, Korea. They read 3 picture books, then did 3 types of dramatic activities in order. Participants were divided into 3 groups in each activity then they took a role as actors and audiences in order. After all dramatic activities had been done, participants had been interviewed regarding to user experience. The findings of this study are as follows; First, the most interesting dramatic activity for young children was creative dramatic activities relying on robot projector based augmented reality. On the other hand, the least interesting activity was traditional dramatic activities. Second, They answered it the easiest one for them the dramatic activities relying on robot projector based augmented reality, whereas the hardest one was the creative dramatic activities relying on robot projector based augmented reality. Thirdly, all the participants answered that it was not hard for them to use the technology embedded in dramatic activities relying on robot projector based augmented reality. They acknowledged the effects of augmented reality technology and the role of robot as well. The result of this study would suggest the feasibility of new technology promoting young children's digital literacy.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.11
• /
• pp.1168-1172
• /
• 2011

Beam projector is popularly used for presentation. In order to pay attention to local area of the beam projector display, a laser pointer is used together with a pointing device(Mouse). Simple wireless presenter has limited functions of a pointing device such as "go to next slide" or "back to previous slide" in a specific application(Microsoft PowerPoint) through wireless channel; thus, there is inconvenience to do other tasks e.g., program execution, maximize/minimize window etc. provided by clicking mouse buttons. The main objective of this paper is to implement a multi-functional laser-pointer mouse that has the same functions of a computer mouse. In order to get position of laser spot in the projector display, an image processing to extract the laser spot in the camera image is required. In addition, we propose a transformation of the spot position into computer display coordinates to execute mouse functions on computer display.

• Korean Journal of Optics and Photonics
• /
• v.13 no.3
• /
• pp.173-181
• /
• 2002

The principle of an illumination system including fly-eyes lenses for a liquid crystal display (LCD) projector with 3-panels was presented and its optical system was designed by using the OSLO (premium edition 6.1) optical system design program. Two panels of the illumination system are well aligned for so that the illumination path length is the same, and the third panel has a longer pass length than the others. The two illumination types with the same or different illumination path lengths were derived by using the paraxial ray design method. Refraction powers and positions of each lens were analytically determined by the method, and the damped least square method was utilized to obtain the optimized uniform illumination system.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.1167-1171
• /
• 2008

The flow and thermal performance of the skiving and louver fin type heat sinks for the cooling system of the small LED projector were experimentally evaluated. A small fan tester based on AMCA standards was used to control and measure the air flow rate into the heat sink. Three heat blocks were used to simulate the heat and light sources(red, green and blue) of the small LED projector. We measured the pressure drop, temperatures and input power at the specific air flow rate and discussed those results. As a result, it is found that the louver fin type heat sink has higher pressure drop and lower thermal resistance than the skiving type. From the comparison of the temperature of the heat block between skiving and louver fin type, the louver fin type heat sink was found to be more suitable for cooling the high power heat source than skiving type. The thermal performance of the fan-sink(louver fin type) system was discussed with the picture taken by a thermal video.

• International Journal of Precision Engineering and Manufacturing
• /
• v.1 no.1
• /
• pp.98-105
• /
• 2000

The projectors using liquid crystal display(LCD) have faults such as low optical efficiency, low brightness and even heat generation. To solve these problems reflective-type spatial light modulators based on MEMS (Microelectromechanical Systems) technology have emerged. Digital Micromirror DeviceTM(DMDTM), which was already developed by Texas Instruments Inc., and Thin-film Micromirror ArrayTM(TMATM), which has been recently developed by Daewoo Electronics Co., are the representative examples. The display using TMATM has particularly much higher optical efficiency than other projectors. But the micromirrors manufactured by semiconductor processes have inevitable distortion because of the limitations of the manufacturing processes, so that the distortions of their surfaces have great influence on the optical efficiency of the projector. This study investigated the effects of mirror flatness on the optical performance, including the optical efficiency, of the TMATM projector. That is to say, as a part of the efforts to enhance the performance of the TMATM projector, how much influence the form errors of a micromirror surface exert on the optical efficiency and the modulation of gray scale of the projector were analyzed through a pertinent modeling and simulations.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.44 no.4 s.316
• /
• pp.35-43
• /
• 2007

With the current trend of digital convergence in mobile phone, imaging devices such as cameras, displays and beam-projectors have been made smaller and become into mobile phones. Especially, built-in beam-projectors (we call it mobile beam-projector hereafter) have been developed to overcome small screen size of mobile display and to provide the realistic image while watching movies or broadcasting. However, mobile beam-projector can project an original image on various colored-screen, different from general data projector with white screen, thereby degrading the image quality of projected images. Therefore, this paper proposed a method of correcting projected images on colored-screens by adapting color constancy theory that has been mainly used for illumination estimation.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.6
• /
• pp.436-444
• /
• 2016

Uniformity in transducer performance is a must-have to ensure the reliable acoustic performance of a tile projector, used for active echo reduction. However, practical limitations imposed by variations in material properties and fabrication errors lead to performance variations among unit transducers, which could degrade the radiation characteristics (transmitting voltage response and directivity) of the tile projector and ultimately the echo reduction performance. In this paper we present a method to minimize these adverse effects via an appropriate placement of unit transducers within the tile projector. To this end, we perform a series of coupled acoustic-piezoelectric simulations, assuming a group of 36 unit transducers having 6 dB variations in transmitting voltage response, to analyze and compare the radiation characteristics of tile projectors under different transducer placement schemes.