Mark Lightfoot

Thin flexible photosensitive cholesteric displays

— A novel optically addressable, flexible bistable cholesteric liquid-crystal display (ChLCD) is presented. These displays utilizeazo-binaphthalene photosensitive chiral dopants that undergo photo-isomerization upon exposure to light. The isomerization results in a change in the pitch of the cholesteric liquid crystal (ChLC), which enables the creation of inherently high-resolution light-weight displays that are optically written. The displays can be photo-addressed without patterned electrodes or complex addressing schemes. Capitalizing on the dynamic pitch and the bistability of photosensitive ChLCDs, the display is switched with a single pulse at a specific single voltage to drive the region of the display with a shorter pitch to the focal-conic texture and the region of the display with a longer pitch to the planar texture. Once in the different textures, the display can hold an image indefinitely regardless of ambient lighting. As such, these displays are a natural fit for badges, shelf-labels, and point-of-sale cards. In this paper, the photosensitive properties of an encapsulated display system in comparison to an unencapsulated display system is discussed. Properties such a photosensitivity, thermal relaxation, and electro-optical response are studied and reported. In addition, a flexible optically addressable ChLCD is developed and demonstrated.

56.3: Flexible Ink Jet Printed Conductive Polymer Electrode Cholesteric Display

We report on the first flexible cholesteric display made with ink jet printed conducting polymers as top and bottom electrodes on thin plastic substrates. Ink jet printed conductive polymer electrodes provide ease of patterning as well as enable highly flexible displays. This paper focuses on deposition techniques and trade-offs and benefits of printed flexible electrodes.

4.2: Flexible Electronic Skin Display

Reflex™ electronic skin displays can be conformed to cover the case of electronic consumer devices allowing the consumer to instantaneously switch the case color electronically. These displays have inherent reflective color and an ultra thin and flexible form factor. The optical performance, environmental ruggedness, and conformability of these displays are presented.

73.3: Flexible Smart Card Displays

Reflex displays are bistable, lightweight, and flexible making them an ideal choice for lamination into smart cards. Reflex displays are amenable to both direct drive, icon displays as well as multiplexed, graphical displays. The optical performance, power consumption, and mechanical ruggedness of these displays are presented.