Until recently, it has been thought that for LCD fabrication it was necessary to coat an LC alignment film, such as a polyimide (PI) film, on the substrate before filling the LC material. Generally, plastic substrates for flexible displays are incompatible with the thermal processes for curing a PI layer after the coating process on the substrate. Recently, LC alignment techniques that do not require a PI layer have been proposed. In this chapter, the slit coater method as a PI-free LC alignment technique is introduced.

Chapter Contents:

• 8.1 Introduction
• 8.2 Shear flow alignment
• 8.2.1 LC alignment in flow
• 8.2.2 Flow-coating method
• 8.3 LC alignment without using polyimide
• 8.3.1 Function of polyimide alignment film
• 8.3.2 Reactive mesogen
• 8.3.3 PI-less alignment technique
• 8.4 Slit coater method
• 8.4.1 Basic concept
• 8.4.2 Mechanism of slit coater method
• 8.4.3 LC alignment and electrooptical properties
• 8.5 Future applications
• References

Inspec keywords: liquid crystal displays; nematic liquid crystals; electro-optical effects; liquid mixtures

Other keywords: LC alignment film; plastic substrates; LC material; thermal processes; polyimide film; PI-free LC alignment technique; LCD fabrication

Subjects: Display technology; Liquid crystal devices