• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1603-1606
• /
• 2005

Eye Glass Display (EGD) with microdisplay to realize the virtual display can make the large screen, so virtual image has been developed by using microdisplay panel. This paper shows study of low cost lens design and simulation for microdisplay system with 0.6" Liquid Crystal on Silicon (LCoS) panel. Lens design optimized consider to spherical aberration, astigmatism, distortion, and chromatic aberration. Code V is used and it designed an aspheric lens about exit pupil 6mm, eye relief 20mm and 35 degree of field of view (FOV). With the application this aspheric lens to LCOS type's microdisplay, virtual image showed 50 inch at 2m. One side of the aspheric lens was constituted from diffractive optical element (DOE) for the improvement in a performance. It had less than ${\pm}2%$ of distortion value and modulation transfer function in axial had 20% of resolution with 30 lp/mm spatial frequency. The optical system is suitable for display of 0.6"-diagonal with SVGA.

• Journal of Korean Clinical Health Science
• /
• v.5 no.4
• /
• pp.1021-1025
• /
• 2017

Purpose: Changes in corneal thickness after wearing hydrogel lens and silicone-hydrogel lens with different oxygen transmission rates wew syudied. Methods: Experiments were performed on 11 subjects(22 eyes). corneal thickness was measured after wearing contact lenses for 8 hours. Corneal thickness was measured using ORB Scan II(ver. 3.14) Results: In the results of the corneal thickness measurement by direction, in the case of the hydrogel-tor lens, the center thickness was $33.63{\mu}m$, the nasal was $34.29{\mu}m$, the temporal was $27.17{\mu}m$, the inferior was $27.17{\mu}m$, the superior was $18.90{\mu}m$, and change rates were 6.28%, 5.71%, 5.40%, 4.75% and 3.09%, respectively. In the results of the corneal thickness measurement by diameter, in the case of the hydrogel-tor lens, the center was $33.63{\mu}m$, the mid-peripheral was $28.19{\mu}m$, the peripheral was $24.18{\mu}m$, and change rates were 6.28%, 4.76%, and 3.79%, respectively. Conclusions: The hydrogel lenses with relatively low oxygen transmission rates resulted in a significant increase in thickness over the entire cornea compared to silicon-hydrogel lenses with high oxygen transmission rates.

• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.12
• /
• pp.28-32
• /
• 2010

Technical demands for aspheric glass lens formed in market increases its application from simple camera lens module to fiber optics connection module in optical engineering. WC is often used as a metal core of the aspheric glass lens, but the long life time is issued because it fabricated in high temperature and high pressure environment. High hard thin film coating of lens core increases the core life time critically. Diamond Like Carbon(DLC) thin film coating shows very high hardness and low surface roughness, i.e. low friction between a glass lens and a metal core, and thus draw interests from an optical manufacturing industry. In addition, DLC thin film coating can removed by etching process and deposit the film again, which makes the core renewable. In this study, DLC films were deposited on the SiC ceramic core. The process variable in FVA(Filtered Vacuum Arc) method was the substrate bias-voltage. Deposited thin film was evaluated by raman spectroscopy, AFM and nano indenter and measured its crystal structure, surface roughness, and hardness. After applying optimum thin film condition, the life time and crystal structure transition of DLC thin film was monitored.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.05a
• /
• pp.123-126
• /
• 2005

Eye Glass Display (EGD) with microdisplay to realize the virtual display can make the large screen, so virtual image has been developed by using microdisplay panel. This paper shows study of low cost lens design and simulation for microdisplay system with 0.6"LCoS panel. Lens design optimized consider to spherical aberration, astigmatism, distortion, and chromatic aberration. Code V is used and it designed an aspheric lens about exit pupil 6mm, eye relief 20mm and 35 degree of field of view (FOV). With the application this aspheric lens to liquid crystal on silicon (LCOS) type's microdisplay, virtual image showed 50 inch at 2m. One side of the aspheric lens was constituted from diffractive optical element (DOE) for the improvement in a performance. It had less than 2.5% of distortion value and modulation transfer function in axial had 20% of resolution with 32 lp/mm spatial frequency. The optical system is suitable for display of 15.6 mm-diagonal with SVGA.

• Proceedings of the KSME Conference
• /
• 2000.11a
• /
• pp.743-746
• /
• 2000

Plastic microlenses play an important role in reducing the size, weight, and the cost of the systems in the fields of optical data storage and optical communication. In the present study, plastic microlens arrays were fabricated using micro-compression molding process. The design and fabrication procedures for mold insert were simplified by using silicon instead of metal. A simple but effective micro compression molding process, which uses polymer powder, were developed for microlens fabrication. The governing process parameters were temperature and pressure histories and the micromolding process was controlled such that the various defects developing during molding process were minimized. The radius and magnification ratio of the fabricated microlens were $125{\mu}m$ and over 3.0, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.8
• /
• pp.1242-1245
• /
• 2001

Plastic microlenses play an important role in reducing the size, weight, and the cost of the systems in the fields of optical data storage and optical communication. In the present study, plastic microlens arrays were fabricated using micro-compression molding process. The design and fabrication procedures for mold insert were simplified by using silicon instead of metal. A simple but effective micro compression molding process, which uses polymer powder, were developed for microlens fabrication. The governing process parameters were temperature and pressure histories and the micromolding process was controlled such that the various defects developing during molding process were minimized. The radius and magnification ratio of the fabricated microlens were 125$\mu\textrm{m}$ and over 3.0, respectively.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.3322-3324
• /
• 1999

This paper studies on the design and fabrication of a micro in-plane positioning actuator integrated with a microlens. Proposed in-plane actuator is a micro XY-stage which is composed of two linear comb drive actuators being orthogonal to each other. In the fabrication of actuator, the single crystalline silicon substrate anodically bonded with a #7740 glass substrate is used because of simple release and passivation. The structure of actuator is formed on the silicon facet of bonded fixture by chlorine-based deep RIE and then released by isotropic wet etching of glass (#7740) in hydrofluoric acid solution. Fabricated actuator has a large travel range up to $30({\pm}15){\mu}m$ and high resolution less than 0.01f1l1l in each direction. Experimented resonant frequency of this actuator is 630Hz. The micro-Fresnel lens is fabricated on the square-shape glass structure prepared in the center of actuator.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.9
• /
• pp.48-53
• /
• 1998

We have fabricated electrostatic lens with novel structure by mixing surface- and bulk-micromachining technology. Polysilicon was used for both the structure and sacrificial layer, and the structure layer was passivated with thermal oxide in order not to be attacked during the silicon wet etching. Compared with conventional electrostatic lens used in microcolumn, this device has the advantages in ; 1) hole alignment, throughput, reliability, damage of lens, 2) the possibility of arrayed lithography through the integration of microcolumn.

• Korean Journal of Optics and Photonics
• /
• v.12 no.6
• /
• pp.460-462
• /
• 2001

We have analyzed the characteristics of IR lens mounting with elastomer and applied the results to the mounting of a silicon lens with diameter 117 mm which is the objective of a thermal imaging system. The elastomer, the 577 primerless silicone adhesive (Dow Corning Co.) which is heat cure type, and the mount material, A16061 are used for our analysis. Theoretical analysis gives the result that the space between lens and mount is required to be more than 250 ${\mu}{\textrm}{m}$ under the operational temperature conditions of -40~+6$0^{\circ}C$.

• Journal of Information Display
• /
• v.11 no.2
• /
• pp.84-90
• /
• 2010

This paper presents the effects of a dielectric layer and an electrolyte on the driving performance of an electrowetting on dielectric (EWOD)-based liquid lens. The range of tunable focal length of the EWOD-based liquid lens was highly dependent on the conditions of the dielectric layer, which included an inorganic oxide layer and an organic hydrophobic layer. Moreover, experiments on the physical and optical durability of electrolyte by varying temperature conditions, were conducted and their results were discussed. Finally, the lens with a truncated-pyramid silicon cavity having a sidewall dielectrics and electrode was fabricated by anisotropic etching and other micro-electromechanical systems (MEMS) technologies in order to demonstrate its performance. The lens with $0.6-{\mu}m$-thick $SiO_2$ layer and 10 wt% LiCl-electrolyte exhibited brilliant focal-length tunability from infinity to 3.19 mm.