• Journal of the Optical Society of Korea
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• v.19 no.4
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• pp.421-426
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• 2015

This paper presents a hybrid single optical system for an LED surgical light that combines the advantages of both lens- and reflector-type single optical systems. The proposed hybrid single optical system includes a lens in the center and the LED light originating from the lens is redirected using a reflector to achieve a high beam spread. Iterative optical software simulations are used to provide data for the design of the lens and reflector for a single optical system, and for a complex optical system for the LED light assembly. The resulting data is also used to fabricate a prototype system. Experiments using the prototype of the hybrid single optical system and a mock-up LED surgical light confirm the system's shadow dilution performance and its applicability to surgical operations.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.143-147
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• 2003

Despite of outstanding optical performance of glass lens, glass lens have not been widely used because of poor productivity and high cost due to manufacturing process i.e. grinding, polishing. However, press-forming method of glass lens overcomes this disadvantage because of mass production. When glass lens is produced by press-forming method using closed die, it is needed that the volume of glass lens preform precisely measured in order to prevent incomplete products and to increase in life of die. The present paper shows the shortcoming of forming process with closed die, and performs FEM simulation of forming process with open die in order to overcome this shortcoming. The design parameter of open die is selected in standard of assembly with optical module and maintenance of optical performance. FEM simulation is carried out with selected parameter of open die and two basic preform. According to distribution of effective strain in glass lens, optical property of glass lens formed at each set of die and preform is compared.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.629-637
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• 2015

Compact system cameras (CSCs) are commonly used nowadays and feature enhanced video functions and thin yet light interchangeable lenses. They differ from digital single-lens reflex (DSLR) cameras in their lack of mirror boxes. CSCs, however, have autofocus (AF) speeds lower than those of conventional DSLRs, requiring weight reduction of their AF groups. To ensure the marketability of large telephoto zoom lenses with fixed f/2.8 regardless of field angle variation, in particular, light weight AF groups are essential. In this paper, we introduce a paraxial optical design method and present a new, large, telephoto zoom lens with f/2.8 regardless of the field angle variation, plus a lightweight AF group consisting of only one lens. Using the basic paraxial optical design and optimization methods, we fabricated a new and lighter zoom lens system, including a single-lens, lightweight AF group with almost the same performance.

• 연구논문집
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• s.32
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• pp.23-34
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• 2002

Up to now, collimators have teen generally produced by handwork and only a few companies have produced by semi-automatic system. Under this situation, automatic system for assembly of optical collimators has risen as a mast essential technique in the development of optical communication components. In this study, it was constructed to develop optical collimators with high functionality and we manufactured optical collimators with a GRIN rod lens and spherical lens using automatic system. Therefore, we worked a performance test through a comparison of collimators made by automatic system and handwork with angle augment, bean size. Also we selected a optimum assembly condition of GRIN rod lens and spherical lens. As a result, it brought a reduction of the tact time and an improvement of an efficiency and a productivity of optical collimators, therefore it was found that automatic system was indispensable for materialization of optical collimators with high functionality.

• Korean Journal of Optics and Photonics
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• v.25 no.1
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• pp.14-20
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• 2014

The equivalent of a thick lens is a lens which has the same power of refraction and paraxial imaging characteristics for a reference ray, but with a different axial thickness. In this study, thick lenses of an optical system were converted to their equivalent lenses referenced to pupil imaging. Aberration changes due to the lens conversion were compared to the general equivalent lens conversion referenced to object imaging.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.38-49
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• 1998

The 3rd generation optical pick-up used popularly in resent years is composed of many optical and electronic components such as laser diode, photo diode, beam splitter, objective lens, grating lens, concave lens, collimator lens etc. Therefore, the design of its optical system and its main base which the said optical and electronic components are set on, is complicated and needs high precision. Its assembly and adjustment in the production line is also difficult. This complication and the demand of high precision get its production cost to be high and its reliability to be low. In this paper, the 4th generation optical pick-up is designed and developed, with the hologram device which laser diode. photo diode, beam splitter. and grating lens are integrated in. This optical pick-up reduces the number of points of adjustment by 3, compared with the 3rd generation optical pick-up of which the number of points of adjustment is 6. This optical pickup also decreases by 4 the number of points of W bonding to have bad influence on environmental reliability, decreases by about 10 the number of parts, and establishes about 20% cost-down of material cost, compared with the 3rd generation optical pick-up.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.19-19
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• 2009

Recently, Light Emitting Diode(LED) has many advantages in comparison with conventional light sources; low power consumption, long lifetime, and less environmental pollution. Therefore, the use of LED is multiplying and increasing rapidly. In general, however, spherical lens is used in LED-lighting which cause many problems induces by optical aberration of spherical lens; low illumination, a yellow belt, unpleasant feeling in human eye. As a potential solution of this problem, aspherical lens can be employed. This study reports the improvement of LED-lighting performance by adopting aspherical lens. From the commercial program, $LightTools^{TM}$, the optical problem were ensured. And then, to improve this problem, optimum aspheric form was designed using Code $V^{TM}$.

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.739-744
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• 2016

We have designed a new TIR(Total Internal Reflection) structure for generating an LED lens which can produce a rectangular beam with small divergence angle in two perpendicular directions for an optical guidance system. The lens can control the divergence angle in the horizontal direction to be a small value of about $8^{\circ}$ with a $1mm{\times}1mm$ LED source, also in the vertical direction it can be about $7^{\circ}$, with optical collection efficiency higher than 0.83. After the lens is manufactured, the work demonstrates that the lens is suitable for an optical guidance system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.964-967
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• 2001

Aspherical lens with the higher numerical aperture has been needed in the optical storage device to increase the recording density on the disk. However, high numerical aperture means the large slope angle at the clear aperture of the lens. Therefore, the measurement and manufacturing technique including the lens molding process for the slope angle should be developed. In this paper, the evaluation technique was described for the optical performance of the aspherical lens. Aspherical form error brings about the wavefront error and the side lobe of the beam intensity profile. A schematic diagram of the aspherical lens manufacturing was drawn to explain the aspherical form error compensation. Finally, form error of the aspherical lens was defined and plotted using the raw data of the Formtalysurf.

• Transactions of Materials Processing
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• v.12 no.4
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• pp.296-301
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• 2003

Though a glass tens has outstanding optical performance, it has not been widely used because manufacturing process shows poor productivity and high cost. However, press-forming method of glass lens overcomes these disadvantages with mass production. When glass lens is produced by press-forming method using closed die, it is needed that the volume of glass lens preform is precisely measured in order to prevent incomplete products and to increase in life of die. The present. paper shows the shortcoming of forming process with closed die, and performs FEM simulation of forming process with open die in order to overcome this shortcoming. The design parameters of open die are selected on the basis of assembly with optical module and maintenance of optical performance. FEM simulation is carried out with selected parameter of open die and two basic preform. According to distribution of effective strain in glass lens, optical property of glass lens formed at each set of die and preform is compared.