The basic study on new high picture quality reflective-type color liquid crystal display

高质量、轻量、反射、低功耗的彩色lcd是高功能、便携信息终端的重要器件。虽然已经提出了各种反射式lcd，但目前实际应用的只有采用单偏振片TN-LCD和STN-LCD的反射式彩色lcd。然而，反射式液晶显示器的质量必须得到提高。为此，我们提出了如下几种新型反射式液晶，并对其电光特性进行了数值分析。单偏振DSTN-LCD和带四分之一波板的FDSTN-LCD 2。带有四分之一波板的单偏振DTN-LCD和FSTN-LCD。我们发现显示模式(1)在理论上具有无穷大的高对比度和48%的高光反射率，与占空比无关；显示模式(2)和(3)通过器件参数的优化设计，显示模式(2)和(3)具有很高的对比度和50%的高光反射率。另外，反射色TN-LCD的耗电量是反射色STN-LCD的数倍。因此，希望在保持高图像质量的同时降低TN-LCD的功耗。为了确认降低功耗的可能性，我们分析了如下几种新型反射式lcd的电光特性与tft - lcd的导通电压之间的关系。带有四分之一波板的单偏振DTN-LCD和FSTN-LCD。带有延迟膜的单偏振DTN-LCD和FSTN-LCD。我们发现，即使导通电压降至2V， lcd也能显示出约50%的高反射率和非常高的对比度的消色差图像。因此，功耗可以降低到电流反射5V TFT-LCD在导通状态下的1/6到1/7。

High-quality, lightweight, reflective color LCDs with low power consumption are important devices for highly functional and portable information terminals. Though various reflective LCDs have been proposed, only reflective color LCDs using a single-polarizer TN-LCD and STN-LCD are presently being used in practical applications. However, the quality of the reflective LCDs must be improved. To achieve this, we proposed some new reflective LCDs like the following and numerically analyzed the electro-optical properties of the LCDs.1. Single-polarizer DSTN-LCD and FDSTN-LCD with a quarter-wave plate2. Single-polarizer DTN-LCD and FSTN-LCD with a quarter-wave plate3. Single-polarizer MDTN-LCD with a retardation filmWe found that the display mode (1) exhibits a high contrast ratio of infinity in theory and high luminous reflectance of 48 %, independent of the duty ratio, and display modes (2) and (3) exhibit a very high contrast ratio and a high luminous reflectance of 50 % through optimum deign of the device parameters. In addition, the consumption of the reflective color TN-LCD is several times larger than that of the reflective color STN-LCD. It is thus desirable to reduce the TN-LCD's power consumption while maintaining its high image quality. In order to confirm the possibility to reduce power consumption, we analyzed the relationship between the electro-optical properties of some new reflective LCDs like the following and the on-voltage of a TFT-LCD.1. Single-polarizer DTN-LCD and FSTN-LCD with a quarter-wave plate2. Single-polarizer DTN-LCD and FSTN-LCD with a retardation film3. Single-polarizer TN-LCD with retardation film of the two sheetsWe found that the LCDs exhibit an achromatic image of high luminous reflectance of about 50 % and a very high contrast ratio, even if the on- voltage is reduced to 2V. The power consumption can thus be decreased to about 1/6 to 1/7 that ofa current reflective 5V TFT-LCD in the on- state.