• Journal of the Optical Society of Korea
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• 제20권3호
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• pp.427-430
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• 2016

The effect of the liquid density difference on interface shape of a double-liquid lens is analyzed in detail. The expressions of interface shape of two liquids with liquid density difference are analyzed and fitted with “even asphere”. The imaging analysis of the aspheric interface shape of a double-liquid lens is presented. The results show that the density difference of two liquids can cause the interface to be an aspheric surface, which can improve the image quality of a double-liquid lens. The result provides a new selection for the related further research and a wider application field for liquid lenses.

• 전자공학회논문지A
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• 제30A권2호
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• pp.22-28
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• 1993

In this paper, the ultrasonic transducer with a spherical liquid lens is designed and an efficient method to calculate the acoustic field radiated from the transducer is presented. A prototype ultrasonic transducer with a spherical liquid lens is constructed and tested. The experimental results are compared with those of the computer simulations and good agreements are achieved. The dynamic control of the geometric focus is obtained by adjusting the radius of curvature of the lens membrane with the volumetric control of the liquid in the lens.

• Journal of the Optical Society of Korea
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• 제16권1호
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• pp.22-28
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• 2012

We report a focal-length tunable liquid lens based on thermopneumatically driven fluidic pressure. The fluidic pressure is generated by deformation of an elastomeric diaphragm induced by thermopneumaticity from a laterally integrated microheater sealed within an air chamber. The pressure is transmitted by a confined liquid to a lens diaphragm through an internal fluid channel. The liquid filling under the lens diaphragm functions as a liquid lens for dynamic focusing with properties depending on the curvature of the deformed diaphragm. The diaphragm area of the air chamber is designed five times larger than that of the lens cavity to yield high focal-length tunability by amplified deflection of the lens diaphragm. With our method, we achieved excellent focal-length tunability from infinity (without an input current) to 4 mm (with an input current of 12 mA) with a lens aperture diameter of 2 mm.

• 한국가시화정보학회지
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• 제8권3호
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• pp.22-28
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• 2010

In the present study, we performed the velocity field measurement in a microchannel using a focal length variable micro liquid lens. The liquid lens is used as a beam expander in a micro-PIV system to acquire the scatter image of the seeded particle. A thin film-type micro liquid lens was made of PDMS material and it was attached on top of the 700-micron-wide working fluid supply channel trench. As a result, the focal length and contact angle of the liquid lens changed with variations in applied pressure.

• Journal of the Optical Society of Korea
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• 제19권1호
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• pp.88-94
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• 2015

This paper reports the fabrication of a lenticular liquid crystal (LC) lens array with thermally tunable focus and with the function of a convertible lens type, using the surface structure of a UV-curable polymer and a twisted-nematic (TN) LC cell. The TN LC cell makes the LC lenticular lens function as a converging or diverging lens by controlling electrically the polarization of input light. Therefore, the focal lengths for both the converging and diverging lenses, which can be switched from the TN cell, can be tuned by changing the effective refractive index of the LC by Joule heating of the transparent electrode. As a result, the focal length of the lens with the E7 LC was changed continuously from 8.7 to 31.2 mm for the converging lens type and from -9.8 to -14.2 mm for the diverging lens when the temperature was increased from 25 to $56^{\circ}C$.

• Current Optics and Photonics
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• 제3권2호
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• pp.177-180
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• 2019

Based on liquid-lens technology and our previous findings on the optical model of the Chinese eye, the liquid lens is applied in the research of the crystalline-lens optical model. Theoretical models of three-layer liquid lenses are built with COMSOL software, and the effect of voltage on the shape of the interface between two liquids is analyzed. By polynomial fitting, different equations describing the interface shape are set up under different voltages. Finally, the optical system of the human eye with a three-layer liquid lens is built and analyzed with Zemax optical design software, and moreover the optical system models of emmetropia, myopia, and hyperopia are presented. This method to build a model of the human eye with a variable-focus liquid lens can provide a novel idea for more practical human-eye models for clinical regulation and control in the future.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.731-735
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• 2008

The fluid ensemble in the liquid lens, which is composed of electrolyte and silicone oil, is the key material system to vary the focal length processing of the electrochemical desorption. In order to characterize the capability of the liquid lens according to response time and optical range, we prepared a fluid ensemble comprising the electrolyte and oil. To elucidate the physical mechanism of the effective response time, we examined the viscosity dependency while satisfying the requirements for the density and refractive index of the electrolyte and oil, respectively. The characterization results indicated that the response time (up and down) is influenced by the viscosity of the electrolyte and oil. On this basis, we prepared a fluid ensemble capable of reversibly adjusting for the focal length of the liquid lens, as well as the response time. The ensemble is applicable to various systems such as micro-lens and optical sensors.

• 한국전기전자재료학회논문지
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• 제29권8호
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• pp.494-498
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• 2016

In this paper, we proposed the 3-dimenstional (3D) analysis for calculating the optical characteristics of an autostereoscopic display with electric field driven liquid crystal (ELC) lens. From 3D analysis considering the slanting of lens, we calculate the cross-talk of each images and the distortion of viewing zone. Using geometric opics and extended Jones matrix method (EJMM), phase retardation of ELC lens according to position is calcuated and then optical path difference in 3D space considering tilt and azimuth angle of incident light is gotten. Then, intensity distribution is presented in the space. Through camparing the intensity distribution using ideal lens with the ELC lens, we identify the noise and image distortion of ELC lens. As a result, this analysis is expected to provide optimum design conditions for realistic and rigorous 3D display with ELC lens.

• 대한기계학회논문집A
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• 제34권5호
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• pp.557-560
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• 2010

본 논문에서는 4 비트 디지털구동기를 가변초점 유체렌즈에 적용하였다. 4 비트 디지털구동기는 총 16 단계로 렌즈곡면을 조절하여 렌즈의 초점을 변화시킨다. 본 가변초점 유체렌즈는 별도의 정밀 압력 및 유체량 제어기 없이 디지털구동기의 On/Off 제어만으로 렌즈곡면을 ${\pm}200nm$ 의 정밀도로 제어하여 초점거리를 3.63mm에서 38.6mm 까지 조절할 수 있다.

• Journal of Information Display
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• 제11권2호
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• pp.84-90
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• 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.