Reflective displays transflective

For outdoor applications, the displayed images of a transmissive LCD could be washed out by sunlight A reflective LCD would be a better choice. However, such a reflective display is unreadable in dark ambient conditions. Transflective LCDs integrate the features... 

A director patterned retarder can be used in a transflective LCD to boost the optical performance and to lower the power consumption. A transflective display is the combination between a reflective and a transmissive display. 

Figure 9.21 shows a simplified cross section of a transflective LCD. It consists of two ITO covered glass plates, with the LC molecules in between, that act as the optical valve. In order to distinguish between the on- and off-state, two polarisers are required. A full colour display is created by addition of a colour filter. The reflective mode is enabled by a mirror on top of the bottom... 

This effect has been successfully implemented in seven-segment and similar fixed format displays and in simple dot-matrix displays. Such displays may be employed in a reflective mode, backlit, or in a transflective combination of both these modes. Although not outstandingly attractive in appearance, the TN LCD has proved to be versatile, relatively cheap to manufacture and drive, and reliable. Its most obvious limitations are speed (the turnoff time can be tens or hundreds of milliseconds), and the difficulty that it experiences in showing complex information. 

In an attempt to overcome the above drawbacks and take advantage of both reflective and transmissive LCDs, transflective LCDs have been developed to use the ambient light when available and the backlight only when necessary [5]. A transflective LCD can display images in both transmissive mode (T-mode) and reflective mode (R-mode) simultaneously or independently. Since LC material itself does not emit hght, the transflective LCD must rely on... 

Polymer-dispersed LC (PDLC) [30], polymer-stabilized cholesteric texture (PSCT) [31], and LC gels [32] all exhibit optical scattering characteristics and have wide applications in displays and optical devices. The LC gel-based reflective LCD can also be extended to transflective... 

Unless identical display modes are adopted in both T- and R-modes, otherwise there are always some discrepancies between their voltage dependent transmittance and reflectance curves. This is the reason that none of the abovementioned transflective mixed-mode LCDs has perfectly matched voltage dependent transmittance and reflectance curves. Different from the mixed display modes employed between transmission and reflection regions as described above. Sharp Corp. also introduced the dual-cell-gap concept for transflective LCDs [57]. 

J. Ouderkirk, S. Cobb Jr., B. D. Cull, M. F. Weber, D. L. Wortman, Transflective displays with reflective... 

It is more useful to pattern the polarizer in pixelated form. For example, it may be possible to make transflective displays with subpixels having different polarizer orientations, with one subpixel being in the transmissive mode and the other one being in the reflective mode. We shall discuss such a possibility in Section 5.3. 

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