• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.129-135
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• 2016

There are many visual enhancement devices for people with low vision. However, almost conventional devices have been simple magnifying and high cost. The symptoms of people with low vision are very variety. It needs to control of image magnifying, brightness, and contrast to improve the visuality. We developed a portable microdisplay driver and device for visual enhancement. This device based on our suggested four methods such as image magnifying, specific color control, BLU brightness control, and visual axis control using a prism. The basic clinical experiments of the proposed Head Mounted Visual Enhancement Device (HMVED) have been performed. The results show beneficiary effects compared with conventional devices, and improve the life quality on people with low vision on account of low weight, low cost, and easy portability.

• Journal of Information Display
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• v.3 no.2
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• pp.1-5
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• 2002

A CMOS driving circuit for active matrix type polymer electroluminescent displays was designed to develop an on-chip microdisplay on the single crystal silicon wafer substrate. The driving circuit is a conventional structure that is composed of the row, column and pixel driving parts. 256 gray scales were implemented using pulse amplitude modulation method. The 2-transistor driving scheme was adopted for the pixel driving part. The layout was carried out considering the compatibility with the standard CMOS process. Judging from the layout of the driving circuit, it turns that it is possible to implement a high-resolution display about 400 ppi resolution. Through the HSPICE simulation, it was verified that this circuit is capable of driving a VGA signal mode display and implementing 256 gray levels.

• Journal of the Semiconductor & Display Technology
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• v.8 no.2
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• pp.59-62
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• 2009

In order to check the validation of LC simulation, 0.7 inch LCOS panel in full-HD resolution was fabricated and used for the electro-optical measurement. Compared the measured data with the calculated data, the averaged difference was 1.72% under 0 ~ +6 V bias on pixel electrode. To improve the optical characteristics of full-HD LCOS panel, the planar structure and trench structures (0.1 um, 0.2 um and 0.3 um-in-depth) between adjacent pixels were investigated with LC simulation. The planar structure showed the higher reflectance and faster reflectance-voltage response time than the trench structure. The optical fill factor and contrast ratio of planar structure were also higher than those of trench structures. As compared 1 um-in-depth trench structure resembled to the real structure with the planar structure, the optical fill factor was improved by 1.15% and the contrast ratio was improved by 5.26%. In order to minimize the loss of luminance and contrast ratio, the planar structure need to be applied between adjacent pixels.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.8
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• pp.6-11
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• 2009

The electro-optical characteristics of the Liquid Crystal on Silicon (hereinafter "LCOS") micro-display on vertically alignment (VA) mode were studied with 3-dimensional LC code. 5 different cell gaps, such as 1.4 ${\mu}m$, 1.8 ${\mu}m$, 2.1 ${\mu}m$, 2.4 ${\mu}m$ and 2.8 ${\mu}m$, were selected. The reflectance-voltage (R-V) characteristics, distribution of reflected light, reflectance, optical fill factor and contrast ratio were calculated and investigated depending on various cell gaps. Due to the surface anchoring effect, higher cell gap showed higher reflectance. However, considering the optical fill factor and contrast ratio, middle-height 2.1 ${\mu}m$ showed the best electro-optical characteristic. 0.7 inch Full-HD LCOS panels having same geometry and material property were fabricated. The reflected light intensity and contrast ratio were measured and the measured results were well-matched to the calculated results.