Angular optical characteristics of a standard twist indicator with a phase compensator

Background and Objectives: One of the disadvantages of a liquid crystal display device for information on the twist effect is its relatively narrow viewing angle. In this regard, an urgent task is to find ways to increase the viewing angle of such a device. Materials and Methods: Based on the computer simulation method, an original and simple design of a liquid crystal twist indicator with a phase compensator, which has improved angular optical characteristics, is proposed. Results: The design has a sandwich structure and consists of an input polarizer, a classic liquid crystal twist cell, a phase compensator and an output polarizer arranged in series one after another. The phase compensator consists of two identical uniaxial anisotropic films, the optical axes of which form an angle of 90$^\circ$. Computer modeling made it possible to find the optimal design of this device, which, unlike other designs, has a wider viewing angle. It has been found that for each LC material there is an optimal set of design parameters of the device (orientation angle and phase compensator thickness) and there is a linear relationship between the thickness of the LC liquid crystal layer and the thickness of the phase compensator, at which the total viewing angle is maximum. In addition, a relationship has been found between the control voltage and the total viewing angle of the device. Conclusion: The proposed original design of a liquid crystal information display device based on the twist effect with a phase compensator can serve as the basis for the production of simple and technological liquid crystal displays with a wide viewing angle.