• Korean Journal of Optics and Photonics
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• v.18 no.2
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• pp.135-141
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• 2007

This paper describes the design technology for a third generation thermal imaging system, which is more compact than before, using a $320\times240$ mid-IR focal plane detector. The third generation non-scanning thermal imaging system was constructed as a compact thermal imaging module as a reconnaissance, surveillance and navigation sensor for helicopter and infantry vehicles in the $1980's\sim1990's$ and now, we designed a new compact infrared camera and studied a new type of non-uniformity correction lens fer this camera.

• Korean Journal of Optics and Photonics
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• v.9 no.6
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• pp.368-372
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• 1998

A 16-views 3 dimensional imaging system is designed by spatially combinding two 8-views time multiplexed image channels. Each 8-views channel composed of 3 primary color CRTs and a dichroic beam splitter which combining the three CRTs as one channel. Each CRT displays 8-view images time sequentially. These images are projected to a holographic screen of a size 1$\times$0.8 $m^2$ through a projection optics. Characteristics of the three different configurations of projection optics are examined with the optics designing program "DEMOS" to select an optimized projection optics for the system. The configulation of the optimized projection optics is found like following; images from each channel combined by two-fold mirror are projected by a projection objective through a 16-strips LCD shutter. In this configuration, the shutter should be located at the entrance pupil of the objective, and the folded edge of the two-fold mirror should contact symmetrically to the center line of the shutter.e shutter.

• Korean Journal of Optics and Photonics
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• v.7 no.1
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• pp.1-8
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• 1996

Charge-coupled device(CCD) array detectors are widely used in real time modulation transfer function(MTF) measurement systems. This paper presents the characteristics of two-dimensional CCDs used in a real time MTF measurement system for copy lenses. The MTF characteristics of a copy lens measured by this equipment show different results according to the direction of shift register, shutter speed and the amplifier gain of CCDs. An object generator is fabricated to reduce the variation of MTF values for the irradiance nonuniformity in on-axis and off-axis image plane and this MTF equipment is calibrated by using a standard lens.

• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.38-46
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• 2006

The stereoscopic camera based on the image formation principle on human eyes and the brain is designed and fabricated by using a CCD and two zoom lenses. As two zoom lenses are separated as 65 mm of the human ocular distance with the wide angle of view of $50^{\circ}$ and the variable convergence angle from $0^{\circ}$ to $16^{\circ}$, the camera can be operated by the similar binocular parallax as human eyes. In order to take the dynamic stereoscopic picture, a shutter blade for the selection of the left and right images in turns, an X-cube image combiner fur the composition of these two images through the blade, and a CCD with 60 frames per second are used.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.109-116
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• 2016

Sensing module of standing and moving human body using shutter method was developed. The module consists of Fresnel lens, pyroelectric infrared (PIR) sensor, interface circuit of the PIR, micro control unit(MCU), and alarm light emitting diode(LED). The principle for standing human body is chopping the thermal of human body using camera shutter. The human sensing signal in MCU by algorithm of interrupt function is detected. By unifying an apparatus and print circuit board(PCB), the developed module can be replaced as commercial moving human body detector. Experiment results show that sensing distance is about 7.0m and sensing angles is about $110^{\circ}$ at room temperature. In these condition, sending ratio was 100% and the power dissipation of the module was 100mW.

• Korean Journal of Optics and Photonics
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• v.15 no.6
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• pp.519-526
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• 2004

We developed a 2-D imaging system to detect ultra weak biophoton by using a high sensitive fast CCD camera. We installed an illumination apparatus to generate delayed luminescence from plant leaves. Shutters at the illumination system and detector were synchronized to each other. The lens system of the CCD camera was newly designed to accommodate the specific requirements to enhance the collection efficiency for biophoton. Based on the lens simulation, commercial lenses were chose for the lens system. All the equipment was installed in a multi-purpose dark box and the delayed luminescence of Euonymus japonica was successfully acquired.

• Korean Journal of Optics and Photonics
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• v.16 no.3
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• pp.201-208
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• 2005

In order to realize a 3-D stereoscopic display module with alternating illumination angles, several conditions required for a lenticular lens sheet were established, and then both the lens specification and the module structure were designed. Also the performance of the stereoscopic module and its tolerance characteristics were evaluated by simulating the intensity distribution on the observation plane with a finite-ray tracing technique. From the evaluation, it was known that an intersection area between two adjacent lenses should not be filled and that the lateral mismatch between a planar liquid crystal shutter and a lens sheet should be minimized.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.1
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• pp.55-61
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• 2015

When a radiation detector is applied to the measurement of the radioactivity of high-level of radioactive materials or the rapid response to the nuclear accident, several collimators with the different inner radii should be prepared according to the level of dose rate. This makes the in-situ measurement impractical, because of the heavy weight of the collimator. In this study, an IRIS collimator was developed so as to have a function of controlling the inner radius, with the same method used in optical camera, to vary the attenuation ratio of radiation. The shutter was made to have the double tungsten layers with different phase angles to prevent the radiation from penetrating owing to the mechanical tolerance. The performance evaluation through the MCNP code was conducted by calculating the attenuation ratio according to the inner radius of the collimator. The attenuation ratio was marked on the outer scale ring of the collimator. It is expected that when a radiation detector with the IRIS collimator is used for the in-situ measurement, it can change the attenuation ratio of the incident photon to the detector without replacing the collimator.

• Journal of Broadcast Engineering
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• v.19 no.5
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• pp.569-577
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• 2014

From the year 2009, 3D Stereoscopic movies and TV have been spotlighted after the huge success of a movie called "AVATAR". Moreover, most of 3D movies & contents are created by mixing real-life shots & virtual animated pictures, such as "Robocop 3", "Transformer 4" as shown in 2014. However, the stereoscopic 3D video film shooting with a traditional stereoscopic rig camera system, takes much more time to set the rig system and adjust the system setting for proper film making which necessarily resulting in bigger cost. In fact, these problems have depreciated the success of Avatar as decreasing demand for 3D stereoscopic video shooting. In this paper, inherent problems of traditional stereoscopic rig camera system are analyzed, and as a solution for the problems, a novel implementations of single-lens optical stereoscopic 3D camera system is suggested. The new system can be implemented to a technology for separating two lights when even those lights passing through in the same optical axis. The system has advantages of adjusting the setting and taking video compared with traditional stereoscopic 3D rig systems. Furthermore, this system can acquire comfortable 3D stereoscopic video because of the good characteristics of geometrical errors. This paper will be discussed the single-lens stereoscopic 3D camera system using rolling shutters, it will be tested geometrical errors of this system. Lastly, other types of single lens stereoscopic 3D camera system are discussed to develop the promising future of this system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.563-572
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• 2017

The purpose of the study is to investigate the effect of flight height, flight speed, exposure time of camera shutter and autofocusing on the visual resolution of the image in order to obtain ultra-high resolution images with a GSD less than 1cm. It is also aimed to evaluate the ease of recognition of various types of aerial targets. For this purpose, we measured the visual resolution using a 7952*5304 pixel 35mm CMOS sensor and a 55mm prime lens at 20m intervals from 20m to 120m above ground. As a result, with automatic focusing, the visual resolution is measured 1.1~1.6 times as the theoretical GSD, and without automatic focusing, 1.5~3.5 times. Next, the camera was shot at 80m above ground at a constant flight speed of 5m/s, while reducing the exposure time by 1/2 from 1/60sec to 1/2000sec. Assuming that blur is allowed within 1 pixel, the visual resolution is 1.3~1.5 times larger than the theoretical GSD when the exposure time is kept within the longest exposure time, and 1.4~3.0 times larger when it is not kept. If the aerial targets are printed on A4 paper and they are shot within 80m above ground, the encoded targets can be recognized automatically by commercial software, and various types of general targets and coded ones can be manually recognized with ease.