Review: Progress in liquid crystal displays by new developments in functional polymers

Abstract

Functional polymers have become essential in the functioning and performance of many products for information and communication technologies. Special polymers have been constructed with an accurate control over their morphology to a size down to the wavelength of light. These polymers improve liquid crystal displays on eye-catching properties like brightness and viewing angle. The improved energy efficiency is crucial for the mobile communication equipment in today's information society.

Multiple-Color Reflectors Using Bichiral Liquid Crystal Polymer Films and Their Applications in Liquid Crystal Displays

“…The parameters of the BLCPFs that are used in Figure 6 b and those used in Figure 6 a are identical. The unpolarized light (denoted by 0 in Figure 6 b) from the LED light-source unit, which consists of a diffuser, edge-lit LED (whose emission bands are shown in Figure 6 a), a waveguide, a prism array, and others [ 29 , 30 , 31 , 32 , 37 , 38 , 39 , 40 , 41 ], propagates toward the BLCPFs (whose reflection bands are marked by black color in Figure 6 a). A reflector is placed on the backside of the light-source unit.…”

“…If CLC#A and CLC#B are right-handed, then left-handed circularly polarized light (CPL) (denoted by 1 in Figure 6 b) passes through the BLCPFs, and right-handed CPL (denoted by 2 in Figure 6 b) is reflected. Thereafter, the reflected circularly polarized light is reflected by the reflector with depolarization in order to become unpolarized light (denoted by 3 in Figure 6 b), and only the left-handed CPL passes through the BLCPFs and the right-handed CPL is reflected [ 32 , 40 ]. The left-handed CPL (denoted by 1 and 4 in Figure 6 b) transforms into linearly polarized light (denoted by 5 in Figure 6 b) after passing through a broadband WP.…”

“…The BLCPFs select the right polarization (left-handed CPL) to let it pass and the wrong polarization (right-handed CPL) to be reflected by repeating the process. Notably, the configuration still works if the reflector shown in Figure 6 b has the function of polarization conversion [ 40 ]. The CPLs are used to elucidate the operation that is shown in Figure 6 b; the actual polarization of light exiting the BLCPFs is not exactly a CPL, which will be discussed later.…”

An overview of LC polyazomethines with aliphatic–aromatic moieties: Thermal, optical, electrical and photovoltaic properties

“…Conversely, one of the main disadvantages of LC polymers is the fact that they do not exhibit obvious and easily detected mesophases as in the case of small organic LC compounds. Presently, LC polymers are mainly tested as (i) NLO materials, (ii) membranes with penetrability created by an electrical field, (iii) temperature detectors or (iv) materials for nanoelectronics [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Among the various types of LC polymers, two main groups of thermotropic polymers are indicated: 1) polymers with mesogenic groups in the main chain, e.g., polyesters or polyamides (Kevlar) and 2) polymers with mesogenic groups in the side chain, e.g., polyolefins or polysiloxanes.…”

Visual Stimuli in Daily Life

“…Because of their small size and, generally, a low information content, such displays can do with a rather low spatial resolution (number of pixels ≤10,000). For this type of application, mainly the liquid crystal display (LCD) technology is used (6,7). LCDs exist in reflective mode (in which the light output is generated by modulating the reflected environmental light), in transmissive mode (in which the light output is generated by modulating the light from a backlight) or in transflective mode (which is a combination of both) (7).…”