| Project/Area Number |
17560321
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electron device/Electronic equipment
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| Research Institution | Kanazawa Institute of Technology |
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Principal Investigator |
FUKUDA Ichiro Kanazawa Institute of Technology, College of Engineering, Professor, 工学部, 教授 (10064445)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAMOTO Yasutada Kanazawa Institute of Technology, College of Engineering, Professor, 工学部, 教授 (50148152)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | LCD / Transflective / Homogeneous-mode / Retardation film / Achromatic-LCD / Low power consumption / Wide viewing angle |
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| Research Abstract |
High-quality color liquid-crystal displays (LCDs) that are light weight and low in power consumption are important devices in highly functional information terminals. Transflective LCDs are the general preference for mobile applications because the combination of backlighting and reflection of ambient light creates high visibility under any intensity of ambient illumination. Low power consumption without recharging the battery is a key requirement for extended use of mobile devices. Therefore, it is advantageous to reduce the TFT-LCD's power consumption in the panel while maintaining its superior image quality.
To confirm the possibility of reducing power consumption of a transflective homogeneous-cell with two retardation films, we numerically analyzed the relationship between device parameters, including the birefringence dispersion of the retardation film, Δn_R(λ), and the electro-optical properties of the LCD.
We found that the optimized LCD produces an achromatic high-quality image with wide viewing angles, even when the on-voltage is reduced to 2.0V. The power consumption in the panel can thus be decreased to about one-fourth that of a current transflective TFT-LCD operating at 4.0V in the on-state. In addition, we studied the feasibility of enhancing the performance of the LCD using previous calculations. We further reduced the power consumption of the LCD by raising the off-state voltage from 0V to 0.5V, which did not affect the display characteristics. We also realized considerable improvement in the optical properties of the viewing angle by incorporating a two-domain structure. In addition, we found that we could easily produce the LCD using present technology. We confirmed by calculation that the electro-optical properties of the LCD were not affected, even if the cell-gap changed to ±2% from the designed value.
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