• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.1-6
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• 2008

Purpose: Plastic optical monomer materials having ultra high refractive index have an income of the whole quantity from advanced nations to domestic companies which are related to plastic optical lens. It is necessary to develop novel plastic optical lens materials in order to overcome a FTA provision and revitalize a stagnating optical lens industry in the interior optical lens industries. The new plastic optical lens materials against the substitution effect of income should be gradually demanded. This work will be synthesized novel super high refractive monomer resin materials of urethane lens series and studied the properties of optical lens using it. Methods: ETS-4 (2-(2-mercaptoethylthio)-3-{2-[3-mercapto-2-(2-mercaptoethylthio)propyl thio]ethylthio}propane -1-thiol), which is optical lens monomer resin having super high refractive index, was synthesized and identified its structure and property by elemental analysis, EI-MS, TGA, FT-IR spectroscopy, $^1H$ and $^{13}C$ NMR spectroscopies. After mixing evenly from mixed monomer resin and diisocyanate series, it was casting in glass mold. After thermal curing, the obtained optical lenses were measured and compared with the refractive index and Abbe number for studies of their optical properties. Results: We have synthesized the novel ultra high refractive index monomer resin, ETS-4, and have identified its structure and property by elemental analysis, EI-MS, TGA, FT-IR spectroscopy, $^1H$ and $^{13}C$ NMR spectroscopies. The existence of three isomers for EST-4 was identified by $^{13}C$ NMR spectroscopy. The refractive index ($N_d$ at $25^{\circ}C$) of monomer resin in liquid state obtained from the Abbe refractometer was 1.647. The refractive indexes of raw plastic optical lenses prepared from the mixed ETS-4 monomer and diisocyanate series were in the range of 1.656~1.680. Conclusions: Novel super high refractive index plastic optical lens monomer was synthesized and analysed, the optical lenses prepared using it were colorless transparency and excellent properties. It is of utility for the industrialization.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.204-204
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• 2009

적외선 광투과 칼코게나이드 유리를 성형온도, 단위공정시간, 서냉 시 가압력등 성형조건을 변화시키면서 고온압축성형하였다. 성형된 칼코게나이드 유리렌즈의 특성평가를 위해 성형조건에 따른 렌즈깨짐 현상, 성형렌즈의 결정성 및 투과도를 측정하였다. 성형과정에서의 내부응력과 소재 자체의 낮은 경도로 인해 성형조건에 따른 렌즈깨짐 현상이 발생하였으며, 고온압축성형시 성형온도 범위 ($330{\sim}340^{\circ}C$)와 단위공정시간(100초~200초) 조건 변화에 따른 성형 렌즈의 광투과도 및 결정성 차이는 나타나지 않았다. 본 연구를 통해 칼코게나이드 유리 소재의 고온압축 성형성을 확인하여 적외선 광학계 렌즈로써의 적용 가능성을 확인 할 수 있었다.

• Korean Journal of Optics and Photonics
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• v.19 no.5
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• pp.349-359
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• 2008

For an inner-focusing 3-groups zoom lens system, this study suggests a new initial design method which applies the process that changes thin lenses into thick ones effectively and quickly, using the hybrid lens system(thin lens+thick lens). In other words, the hybrid lens system is the semi-automatic design process that makes the thin lens of one group change into a thick one while the other groups are composed of thin lenses. Keeping the total power of the system fixed, the power of each group and the distance between principal planes can be fixed. Of course, the other groups composed of thin lenses could be changed into thick lenses sequentially by this process. This design conception results in the 1/4" 5 M inner-focusing 3-groups 2x zoom lens system satisfying the specifications and performances of zoom lens for phone cameras. Also aspherization on lens elements of glass and plastic material enhanced the resolution and reduced the lens size. As a result, we have an ultra-compact inner-focusing 3-groups 2x zoom lens system for a phone camera, with a slim size with TTL of 9.8 mm.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.45-50
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• 2008

Purpose: A soft contact lens was manufactured by adding naringin known as natural anti-bacterial material to resin solution. With solution eluted from manufactured contact lens, we examined its optical properties, physical and chemical states of naringin in the polymer, and elution properties. Methods: The soft contact lens with naringin was synthesized by bulk polymerization method. IR spectrum and HPLC were used to define the bonding type of naringin itself in the soft contact lens contained naringin, elution process of naringin to the saline solution, and the amount of naringin solution eluted from the lens with elapsed time. Results: Naringin was continuously eluted with constant concentration from the soft contact lens for about a month and the structure ofnaringin which is eluted was as same as before it was added to resin solution. Any change in optical properties such as transmittance couldn't be found. Bonding state and the structure of naringin in contact lens were explained with IR spectrum and HPLC results. Conclusions: In the contact lens with naringin, naringin remained in the contact lens bonding with weak hydrogen bonding and/or van der Waals force between naringin and polymer. Naringin was continuously eluted from the contact lens contained naringin during about 1 month. Even after 1 month, it showed that the concentration of the naringin eluted was approximately 10 ppm in a day. From the results, adding naringin to the soft contact lens resin is very effective method for manufacturing the soft contact lens which has anti-bacterial function for a period of time.

• Korean Journal of Optics and Photonics
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• v.7 no.1
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• pp.51-59
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• 1996

In this paper, we propose a new type of a planar waveguide lens, a meniscus lens instead of a plano-convex lens used widely for the optical integrated circuits such as optical numerical processors. A plano-convex lens has a spherical aberration caused by the linear boundary. In the proposed meniscus lens, this linear boundary is replaced by a circular-boundary, and the spherical aberration is removed. To test the performance of the proposed lens, a meniscus lens is designed using Fermat principle and fabricated on the Y-cut $LiNbO_3$ substrate. First a $Ti:LiNbO_3$ planar waveguide is fabricated on the $LiNbO_3$ substrate by Ti indiffusion. Then a meniscus lens is fabricated on the planar waveguide by TIPE(Ti indiffued proton-exchange) method. A plano-convex lens is also fabricated on the same substrate to compare the spot size at the focal point. The measured spot size of the meniscus lens is reduced to 59% that of the plano-convex lens. This result shows that the proposed meniscus lens is more effective for optical integrated circuits than the plano-convex lens.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1635-1641
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• 2009

In this study, we have prepared plastic lenses with both photochromic and hard properties by hard coating, and evaluated their optical properties and surface characteristics. Photochromic effects could be observed on the UV spectra of the closed forms and the visible spectra of the open forms. Visible light transmittance of photochromic lenses was from 83.44% for graphite(GP) to 85.15% for blue(BL) in colourless state and from 71.10% for red(RE) to 79.98% for yellow(YE) in colour state. Red photochromic lens was higher in optical density(${\Delta}$OD) and color difference(${\Delta}$$E^{\ast}_\;{ab}$) than the others. Photochromic lenses applied by hard coating showed good adhesion, hot water resistance, chemical resistance and surface appearance. Also, compared to the uncoated lens, hardness and abrasion resistance were increased. Consequently, this coating system could impart functional properties such as photochromic and hard coating property onto ophthalmic lenses.

• Korean Journal of Optics and Photonics
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• v.15 no.2
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• pp.130-136
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• 2004

We investigate characteristics of viewing resolution improvement in three-dimensional integral imaging, when a dynamic lens array method is adopted. We show that the viewing resolution changes for different moving directions and distances of the lens array through computer-synthesized integral imaging. From this study, optimal moving conditions of the lens array for efficient viewing resolution improvement can be determined.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.145-148
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• 2001

SiC composites were developed by incorporating glass phase into SiC, in the light of improving mechanical properties of material for spectacle lens cutting. Specimens for spectacle lens cutting with glass phase as sintering additives have been fabricated by hot-pressing at $1810^{\circ}C$ for 2 hr under a pressure of 25 MPa. The fracture toughness and hardness of hot-pressed specimens were characterized and compared with previous works. Typical hardness and fracture toughness of materials for spectacle lens cutting were 12 GPa and $5.1MPa{\cdot}m^{1/2}$ respectively.

• Journal of the Korean Chemical Society
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• v.65 no.5
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• pp.320-326
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• 2021

This study investigated the effect of the structure of the crosslinking agent used in contact lens polymerization on the physical properties and drug dissolution of contact lenses.es Contact lenses were manufactured using 0.3% and 3% of 4 types of crosslinking agents, respectively, and ofloxacin was used as the drug. Contact lenses using hydrophilic crosslinking agents improved water contents and wettability, and the more hydrophilic functional groups, the greater the effect. Contact lenses with a high concentration of crosslinking agent had a low concentration of eluted drug and a longer release time. The cross-linking agent structure of contact lenses had an effect on improving the performance of contact lenses and controlling drug release.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.447-451
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• 2019

This study were to investigate the scratches and replacement cycles of eyeglasses according to personal characteristics in daily life. The subjects were 58 people who voluntarily participated in this study. The replacement cycle of eyeglasses according to the contact of eyelashes with eyeglasses, type and the number of eyeglasses wiped on a day were analyzed. The statistical analysis were performed by X² test and Fisher's exact test. The average replacement cycle of the eyeglasses were longer females than males. The eyeglasses replacement cycle were significantly shorter when the eyelashes contacted the eyeglasses and when the eyeglasses were wiped using a tissue or clothes other than the eyeglasses towel. The coating film of the eyeglasses may be damaged by the convergence effect such as eyelashes or minor carelessness in daily life, and this study will continue to follow up on this result.