Erica Montbach

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.

Progress in flexible and drapable reflective cholesteric displays

— Recent results from encapsulation work on the development of flexible and drapable cholesteric liquid-crystal displays (LCDs) on substrates such as thin plastics, fabrics, and even paper will be presented. The approaches used to create flexible displays using single- and dual-substrate methods based on printable emulsions and polymerization-induced phase-separation (PIPS) techniques will be discussed.

6.1: Invited Paper: Recent Progress in Color Flexible Reflective Cholesteric Displays

We report on highly flexible layered full color cholesteric displays built using ultra thin substrates with encapsulation through the phase separation approach. Recent progress of the state of the art of the cholesteric display technology will be presented as well.

P‐171: A Flexible Touch‐Sensitive Writing Tablet

We present a flexible touch-sensitive writing tablet utilizing a reflective bistable cholesteric liquid crystal laminated between two conductive-polymer coated polyethylene-terephthalate substrates. The device features a selective pressure response suitable for high-resolution lines to be drawn into the screen. The device is inexpensive, conformable, and laser-cut to any desired shape.

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.

New developments in flexible cholesteric liquid crystal displays

Flexible Cholesteric liquid crystal displays have been rapidly maturing into a strong contender in the flexible display market. Encapsulation of the Cholesteric liquid crystal permits the use of flexible plastic substrates and roll-to-roll production. Recent advances include ultra-thin displays, laser-cut segmented displays of variable geometry, and smart card applications. Exciting technologies such as simultaneous laser-edge sealing and singulation enable high volume production, excellent quality control and non-traditional display geometries and formats.

30.2: Single Layer Full Color Cholesteric Display

An 80ppi ¼ VGA full color, single layer, Reflex™ display with red, green and blue reflecting sub-pixels is reported. A phototunable chiral dopant is UV exposed to produce these colors, and polymer walls keep the colors separate after tuning. We will present details of this development and discuss applications.

Recent progress in flexible color reflective cholesteric displays

— Highly flexible layered full-color cholesteric displays fabricated using ultra-thin substrates with encapsulation through the phase-separation approach is reported. Recent progress of the state of the art of cholesteric display technology will be discussed as well.

Novel flexible Reflex displays

We report on unique flexible ReflexTM displays based on bistable, reflective, cholesteric liquid crystal display technology. Reflex displays are attractive for numerous applications because of the low power consumption and paper like reflective color. As the possible applications grow for flexible, reflective displays the new methods to manufacture these displays, such as web processing, also become important. We will report on several unique display types such as a pressure induced writing display and a switchable color electronic skin display. In addition, the current status of traditional Reflex displays will be discussed.