Electronic paper

[2][needs update] An ideal e-paper display can be read in direct sunlight without the image appearing to fade.

[9] An electrophoretic display (EPD) forms images by rearranging charged pigment particles with an applied electric field.

In the simplest implementation of an EPD, titanium dioxide (titania) particles approximately one micrometer in diameter are dispersed in a hydrocarbon oil[citation needed].

When the particles are located at the rear side of the display, it appears dark, because the light is absorbed by the colored dye.

[13][14] Bridgestone Corp.'s Advanced Materials Division cooperated with Delta Optoelectronics Inc. in developing Quick Response Liquid Powder Display technology.

In the 1990s another type of electronic ink based on a microencapsulated electrophoretic display was conceived and prototyped by a team of undergraduates at MIT[18] as described in their Nature paper.

Albert, Barrett Comiskey, Joseph Jacobson, Jeremy Rubin and Russ Wilcox co-founded E Ink Corporation in 1997 to commercialize the technology.

"It has for many years been an ambition of researchers in display media to create a flexible low-cost system that is the electronic analog of paper.

Micro-particle-based displays possess intrinsic bistability, exhibit extremely low power d.c. field addressing and have demonstrated high contrast and reflectivity.

The use of a microencapsulated electrophoretic medium solves the lifetime issues and permits the fabrication of a bistable electronic display solely by means of printing.

Each capsule contains an oily solution containing black dye (the electronic ink), with numerous white titanium dioxide particles suspended within.

Because of the small pixel size, the user only experiences the average reflection, which provides a high-brightness, high-contrast switchable element.

When voltage is removed liquid surface tension causes the pigment dispersion to rapidly recoil into the reservoir.

[28] The core technology was invented at the Novel Devices Laboratory at the University of Cincinnati and there are working prototypes developed by collaboration with Sun Chemical, Polymer Vision and Gamma Dynamics.

The first part is a highly reflective metasurface made by metal-insulator-metal films tens of nanometers in thickness including nanoscale holes.

This technology presents broad range colors, high polarization-independent reflection (>50 %), strong contrast (>30 %), the fast response time (hundreds of ms), and long-term stability.

Other research efforts into e-paper have involved using organic transistors embedded into flexible substrates,[32][33] including attempts to build them into conventional paper.

In September 2012, Amazon announced the fifth generation of the Kindle called the Paperwhite, which incorporates a LED frontlight and a higher contrast display.

[49] It differs from other e-readers in having a replaceable battery, and a separate touch-screen color LCD below the main electronic paper reading screen.

[50] In 2020, Onyx released the first frontlit 13.3 inch electronic paper Android tablet, the Boox Max Lumi.

The French daily Les Échos announced the official launch of an electronic version of the paper on a subscription basis in September 2007.

The offer included either a light (176g) reading device (adapted for Les Echos by Ganaxa) or the iRex iLiad.

Flexible display cards enable financial payment cardholders to generate a one-time password to reduce online banking and transaction fraud.

Electronic paper offers a flat and thin alternative to existing key fob tokens for data security.

Some devices, like USB flash drives, have used electronic paper to display status information, such as available storage space.

[51] Once the image on the electronic paper has been set, it requires no power to maintain, so the readout can be seen even when the flash drive is not plugged in.

E-paper based electronic shelf labels (ESL) are used to digitally display the prices of goods at retail stores.

Some variants use ZBD (zenithal bistable display) which is more similar to LCD but does not need power to retain an image.

Compared to LED or liquid-crystal displays (LCDs), they consume lower energy and the text or graphics stays visible during a power failure.

Typically, e-paper electronic tags integrate e-ink technology with wireless interfaces like NFC or UHF.

Many e-readers , devices meant to replace traditional books, utilize electronic paper for their displays in order to further resemble paper books; one such example is the Kindle series by Amazon.
Appearance of pixels
Scheme of an electrophoretic display
Scheme of an electrophoretic display using color filters
Macro photograph of Kindle 3 screen; microcapsules are evident at full size.
An e-paper display on a watch refreshes to remove ghosts.
The Motorola F3 uses an e-paper display instead of an LCD.
iLiad e-book reader equipped with an e-paper display visible in the sunlight
USB flash drive with E Ink-implemented capacity meter of available flash memory
Tram timetables on e-paper. Prague, prototype from May 2019.