Viewing angle limitations

A numerical evaluation of the maximum number of lines that can be multiplexed with such a single-frequency scheme requires specification of the acceptable viewing angle, temperature dependence of the various parameters, and so on see Kahn and Birecki (1980). The present upper limit appears to be about 25 lines for a direct view, temperature-compensated TN LCD and 91 for a transmission display, but further progress in LC chemistry will increase this number in the future. 

The number of addressable lines in a multiplexed LCD with acceptable contrast and viewing angle dependency is limited, although to a much lesser extent than using direct addressing. The maximum number of addressable lines (AO is given by (see Figure 2.15) ... 

The noise came a in, and then Jemy saw a man emerge from the darkness. From her angle, cbse to the floor, her view was limited. There was a glimpse of jeans and what looked like an am jacket before he moved in front of the li. His silhouette ve an inpressbn of size and bulk as he busied himself at the workbench. Then he was coining towards her. 

The baseline detector system is a high pressure imaging proportional counter placed behind a coded mask placed at 4 meters from the detector window. The instrument view angle is limited by a square passive collimator with a FOV of 6 degrees FWHM. 

Table 9.2. Viewing angle range and gray scale inversion range (in degrees) of various LC / foil configurations as measured on active matrix test displays (MD = monodomain, DD = dual domain). The angular range accesible for measurements was limited to angles between —70 and 70 degrees.

The information rate to be displayed by liquid crystals is limited by the multiplexing capability of the liquid crystal display. Therefore electrooptic effects with a strong nonlinearity of the electrooptic characteristics and short duty cycle response for a wide range of viewing angles are required. 

In the preceding sections, we learned that the ultimate multiplexing limit for direct view FSM TN-LCDs with reasonably broad viewing angles is going to be less than 25 rows. Assuming less than 200 columns, the maximum information content to be expected for FSM TN-LCDs will be 10 picture elements (pels) even with column leads coming from both sides of the display. Thus,... 

We have shown in this paper that single frequency fast scan multiplexed TN-LCDs with moderate viewing angles will be limited to less than about 25 multiplexed lines and about 10 pixels. The principal improvements required to obtain N 25 multiplexing were... 

Multiplexed twisted nematic liquid crystal devices (TN-LCDs) are the mainstay of low power, medium information content displays. At present, the voltage threshold and the nonlinearity of the electrooptic response intrinsic to the twisted nematic structure are used to achieve multiplexing. The multiplexing level achievable using this technology is limited by the sharpness of the electrooptic response and by the variations of this response with viewing angle. ... 

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