• The Korean Journal of Vision Science
• /
• v.20 no.4
• /
• pp.413-420
• /
• 2018

Purpose : We present a novel method for the analysis of blue light applied by the analysis method of David L. with optical experiment and blue light by measuring the transmittance by dividing it by the refractive power in the spectacle lens made by MR8. Methods : The lenses of -8.00D, -7.00D, -6.00D, -5.00D, -4.00D, -3.00D, and 0.00D manufactured by MR8 being sold in the market, were selected. The transmittance was measured at the intervals of 5 nm from 200 to 1000 nm with UV-VIS Spectrophotometers (SolidSpec 3700), and they were in range of the blue light (380 to 500 nm) analyzed by a David L.'s analysis method. Results : All of the MR8 lenses selected for this study almost completely blocked at the UV range. A lens of -8.00D was measured as the lowest transmittance of 59.56% in the blue light area and low values were measured at the blue areas 1 and 2 according to the analysis of David L.In the infrared ray area, the transmittance of all lenses gradually decreased. The average value of the luminous transmittance was 23.67% ~ 26.33% and then gradually decreased from -4.00D. Conclusion : Applying the analysis of David L., a minimum of 41.28% and a maximum of 46.60% were measured at the blue light 1 area and a minimum of 87.30% and a maximum of 97.55% were measured at the blue light 2 area. A minimum of 86.83% and a maximum of 96.55% were measured at the blue light 3 area, and the average was 94%. The luminous transmittance of the -3.00D lens was 26.33%, which was the highest, and that -8.00D was 23.67%, which was the lowest.

• Korea-Australia Rheology Journal
• /
• v.19 no.3
• /
• pp.171-176
• /
• 2007

LCD-BLU (Liquid Crystal Display-Back Light Unit) of medium size is usually manufactured by forming numerous dots with $50{\sim}300\;{\mu}m$ in diameter by etching process and V-grove shape with $50\;{\mu}m$ in height by mechanical cutting process. However, the surface of the etched dots is very rough due to the characteristics of the etching process and V-cutting needs rather high cost. Instead of existing optical pattern made by etching and mechanical cutting, 3-dimensional continuous micro-lens of $200\;{\mu}m$ in diameter was applied in the present study. The continuous micro-lens pattern fabricated by modified LIGA with thermal reflow process was tested to this new optical design of LGP. The manufacturing process using LIGA-reflow is made up of three stages as follows: (i) the stage of lithography, (ii) the stage of thermal reflow process and (iii) the stage of electroplating. The continuous micro-lens patterned LGP was fabricated with injection molding and its test results showed the possibility of commercial use in the future.

• Journal of Korean Ophthalmic Optics Society
• /
• v.19 no.2
• /
• pp.135-143
• /
• 2014

Purpose: To evaluate the blue-light blocking ratio and luminous transmittance of blue-light blocking lenses using the blue-light hazard function as specified in international standard. Methods: In order to calculate the blue-light blocking ratio and luminous transmittance for a total of 41 blue-light blocking lenses from 8 manufacturers, UV-Vis spectrophotometer was used for measuring the spectral transmittance of wavelengths from 380 to 780 nm. Blue-light blocking ratio was calculated using blue-light hazard function as specified in ANSI Z80.3:2010 and ISO 13666(or Korean Standard KS B ISO 13666:2004). Results: The range of the blue-light blocking ratio was from 9.3 to 96.8%, the range of the transmittance from 53.5 to 92.7%, and the range of the luminous transmittance from 58.0% to 98.1%. In general the blue-light blocking lens prepared by coating tended to have a higher luminous transmittance, while those prepared by tinting a higher blue-light blocking ratio. Conclusions: The behavior of the spectral distribution of lenses showed the possibility of the performance improvement in the blue-light blocking lenses. Manufactures need to acquire their own technology that can evaluate the performance of blue-light blocking lens based in international standard.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.3 s.258
• /
• pp.395-402
• /
• 2007

This paper considers about the tilt measurement of lens module with multiple lenses. The tilt between lenses in lens module and barrel or between image sensor and barrel can be measured precisely with the proposed algorithm. The magnitude and direction of the tilt vector of lens and image sensor can be measured from the best focal surface. The selecting and setting of image sensor, test chart, image sensor centering to lens module, axis align, focus measure method are also explained to get highly precise tilt results. The proposed algorithm is verified with the lens module inspection system we developed, and the experimental results show that the tilt measure proposed in this paper is robust and precise. With the proposed tilt measurement algorithm, the tilt of an image sensor and any other lens which intermediates light can be measured.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.05a
• /
• pp.241-244
• /
• 2004

Microlens patterned micro-mold fabrication method for Light Guiding Plate(LGP), kernel part of LCD-BLU(Back Light Unit), was presented. Instead of erosion dot pattern for LCP optical design, microlens pattern, fabricated by LIGA-reflow process, was applied. Optical pattern design method was also developed not only for negative pattern LGP, but also positive pattern LGP. In order to achieve flow balance during the micro-injection molding process and dimensional accuracy, two LGP pattern was made in one micro-mold.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.2
• /
• pp.133-139
• /
• 2011

We have performed optical design of light guide plates (LGPs) for a photobioreactor by using an illumination design tool. An LGP having light emitting diodes (LEDs) as a light source on the four sides was designed by optimizing the distribution of LGP patterns and design of another LGP, on top of which sunlight was focused by a Fresnel lens, was executed. Finally, a hybrid-solar-and-LED-lighting scheme was described. Detailed design process and optical performances of the designed LGPs are presented.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.1
• /
• pp.157-164
• /
• 2017

In this research, the overlapped illumination model was used for designing a freeform LED lens with a uniform illuminance distribution on its illuminating plane, and their performances and tolerances were compared. And, the illuminations on a illumination plane was measures for change with average illuminance and illuminance uniformity. As a result of the tolerance analysis about z-axis direction change, thickness change in lens and tilt change of light emission and characteristic change in LED source, overlapped model and divergent illumination model are similar to the performance about Z-axis direction change of light emission in LED source. but the uniformity illumination value in this overlapped model is more remarkably value than it in divergent illumination model about thickness change in LED lens. Also, even though the lens based on a divergent illumination model showed good performance compare to the lens based on an overlapped illumination model, the latter was less the deviation to variation of LED beam radiation ability.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2196-2198
• /
• 2005

The luminous intensity distribution of a 1W high-power LED with a wide view angle should be concentrated to be used as a light source for an automotive reading lamp. In this paper, an optical lens made of PMMA is simulated by using an optical design software for that purpose. As the result, with the help of the devised lens, the reading light gives over 80 lx at the center of a target surface of radius of 0.2m located below 0.5m from the lamp, and a minimum of 20 lx at the perimeter of the target surface. Thus, a 1W high-power LED with an appropriate lens would suffice for an automotive reading lamp.

• Journal of the Korea Convergence Society
• /
• v.6 no.1
• /
• pp.43-48
• /
• 2015

We studied on the injection molding conditions of defect-free PMMA lens for surgical light. When the heat temperature of mold is low, more imperfect molding or weldlines and flow marks have showed. A defective lens depends on low fluidity of the PMMA resin and its temperature is high, a flexural strain has occurred. The longer cooling time of specimens, the more cracks have occurred due to resin crystallization. In this study, optimal molding conditions for defect-free PMMA lens is as follows. The heat temperature of core mold was 110 [$^{\circ}C$] and also the cooling time was 25 [sec]. PMMA materials can realized low expense to produce plastic optical lens and applications.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.2019-2023
• /
• 2005

A aspheric lens is one a key point optical element in the optical industry. The feature of a aspheric lens is not to have the spherical aberration. A aspheric lens is also essential element for high-precision and light-weight in the optical machine. Generally it have been used in a tailor progression an aspheric lens modelling much. In this study we applied a lay back-tracer using a index of refraction to draw a creative aspheric lens. And we executed a comparison experiment for refraction situation of shape and straightness experiment to inspect the drawn aspheric lens in this study