E Ink (electronic ink) is an electronic paper (e-paper) display technology marketed by E Ink Corporation, co-founded in 1997 by MIT students JD Albert and Barrett Comiskey, MIT Media Lab professor Joseph Jacobson, Jerome Rubin, and Russ Wilcox.
It is available in grayscale and color and is used in mobile devices such as e-readers, digital signage, smartwatches, cell phones, electronic shelf labels and architectural panels.
History
Background
The idea of a low-power, paper-like display had existed since the 1970s and was originally developed by researchers at Xerox PARC but never realized. While a postdoctoral researcher at Stanford University, physicist Joseph Jacobson envisioned a multi-page book whose contents could be changed at the touch of a button and which required little power.
Neil Gershenfeld recruited Jacobson to the MIT Media Lab in 1995 after hearing Jacobson’s ideas for an electronic book. Jacobson, in turn, recruited MIT students Barrett Comiskey (mathematics major) and J.D. Albert (mechanical engineering major) to develop the display technology needed to realize his vision.
Product development
The original approach was to develop tiny spheres that were half white and half black and rotated to show the white or black side on the display, depending on the electrical charge. Albert and Comiskey were told by most experienced chemists and materials scientists that this approach was impossible, and they had difficulty making these perfectly half-white and half-black spheres; during his experiments, Albert accidentally created some all-white spheres.
Comiskey experimented with charging and encapsulating these all-white particles in microcapsules mixed with a dark dye. The result was a system of microcapsules that could be applied to a surface and then charged independently to produce black-and-white images. A first patent was filed by MIT in October 1996 for the microencapsulated electrophoretic display.
The scientific paper was published on the cover of Nature, which is extremely unusual for an undergraduate paper. The advantages of the microencapsulated electrophoretic display and its potential to meet the practical needs of electronic paper were summarized in the abstract of the Nature article:
For many years, the goal of researchers in the field of display media has been to create a flexible, low-cost system that is the electronic analog of paper … the viewing characteristics lead to an “ink on paper” look. But such displays have so far suffered from short lifetimes and difficulties in fabrication. Here we report the synthesis of an electrophoretic ink based on the microencapsulation of an electrophoretic dispersion. The use of a microencapsulated electrophoretic medium solves the lifetime problems and enables the fabrication of a bistable electronic display by printing alone. This system can meet the practical requirements of electronic paper.
A second patent was filed by MIT for the microencapsulated electrophoretic display in March 1997.
As a result, Albert, Comiskey and Jacobson, along with Russ Wilcox and Jerome Rubin, formed E Ink Corporation in 1997, two months before Albert and Comiskey graduated from MIT.
History of the Company
E Ink Corporation (or simply “E Ink”) is a subsidiary of E Ink Holdings (EIH), a Taiwanese holding company (8069.TWO). It is a manufacturer and distributor of electrophoretic displays, a type of electronic paper, which it markets under the name E Ink. E Ink Corporation is headquartered in Billerica, Massachusetts. The company was founded in 1997 by two students, J.D. Albert and Barrett Comiskey, along with Joseph Jacobson (professor at the MIT Media Lab), Jerome Rubin (co-founder of LexisNexis) and Russ Wilcox. Two years later, E Ink partnered with Philips to develop and commercialize the technology. Jacobson and Comiskey are listed as inventors on the original patent filed in 1996. Albert, Comiskey and Jacobsen were inducted into the National Inventors Hall of Fame in May 2016. In 2005, Philips sold its electronic paper business and related patents to one of its major business partners, Prime View International (PVI), a manufacturer based in Hsinchu, Taiwan.
At E Ink Corporation, Comiskey led development efforts for E Ink’s first generation electronic ink, while Albert developed manufacturing methods for high-volume production of electronic ink displays. Wilcox held a number of business roles and served as CEO from 2004 to 2009.
Acquisition
On June 1, 2008, E Ink Corp. announced it was to be acquired by PVI for $215 million, an amount that eventually reached $450 million after negotiations. E Ink was officially acquired on December 24, 2009. The purchase by PVI increased the scale of production for E Ink’s e-paper display, as Prime View also owns BOE Hydis Technology Co. and has a strategic partnership with Chi Mei Optoelectronics Corp. (now Chimei InnoLux Corporation, part of the Hon Hai-Foxconn group). Foxconn is the sole ODM partner for Prime View’s Netronix Inc. and supplier of e-ink panel e-readers, but the final products appear in various forms, e.g., as Bookeen, COOL-ER, PocketBook, etc.
PVI renamed itself E Ink Holdings Inc. after the purchase. In December 2012, E Ink acquired SiPix, a competing electrophoretic display company.
Applications
E Ink is processed into a film and then integrated into electronic displays, enabling novel applications in phones, watches, magazines, wearables and e-readers, etc.
The Motorola F3 was the first cell phone to use E Ink technology in its display to take advantage of the material’s ultra-low power consumption. The Samsung Alias 2 also uses this technology in its keypad to allow for different reader orientations.
The October 2008 limited edition North American issue of Esquire was the first magazine cover to integrate E Ink. This cover featured flashing text. It was manufactured in Shanghai and shipped refrigerated to the United States for binding. The E Ink was powered by an integrated battery with a runtime of 90 days.
In July 2015, the New South Wales Roads and Maritime Authority installed E Ink traffic signs in Sydney, Australia. The installed e-paper traffic signs are the first use of E Ink in traffic signage. Transport for London tested E Ink displays at bus stops to provide real-time schedules, route maps and travel information. Some Whole Foods 365 stores have deployed E Ink-powered electronic shelf labels that can be customized and updated remotely to include additional information, such as whether a product is gluten-free. Announced at International CES in January 2015, E Ink Prism is the internal name for E Ink’s bistable ink technology in a film that can dynamically change colors, patterns and designs on architectural products. E Ink displays can also be flexibly designed, just like LCDs, OLEDs and microLEDs.
Commercial display products
E Ink has now partnered with several companies, including Sony, Motorola and Amazon. E Ink’s “Vizplex” technology is used by Sony Reader, MOTOFONE F3, Barnes & Noble Nook, Kindle, txtr Beagle and Kobo eReader. E Ink’s “Pearl” technology is said to offer a 50% better contrast ratio. It is used by the 2011-2012 Kindle models, Barnes & Noble Nook Simple Touch, Kobo Touch, and Sony PRS-T1. E Ink’s “Carta” technology is used by Kindle Paperwhite (2nd and 3rd generation), Kindle Voyage, Kobo Glo HD, Kobo Aura H2O, and Kindle Oasis.
Versions or models of E Ink
E Ink Vizplex is the first generation of E Ink displays. Vizplex was announced in May 2007.
Close-up of Kindle screen, focused just below the surface; microcapsules are shown in full size.
E Ink Pearl, announced in July 2010, is the second generation of E Ink displays. The updated Amazon Kindle DX was the first device announced with this screen, and the Kindle Keyboard, Kindle 4, and Kindle Touch also feature the Pearl display. Amazon continues to use this display technology in all of its Kindle generations (excluding the Paperwhite, Voyage, and Oasis). Sony has also incorporated this technology into its latest version of the Sony Reader Touch. This display is also used in the Nook Simple Touch, Kobo eReader Touch, Kobo Glo, Onyx Boox M90, X61S, and Pocketbook Touch.
E Ink Mobius is an E Ink display with a flexible plastic back that can withstand small bumps and some flexing. Products using this include Sony Digital Paper DPT-S1, Pocketbook CAD Reader Flex, Dasung Paperlike HD and Onyx Boox MAX 3.
The E Ink Triton, announced in November 2010, is a color display that is easy to read in bright light. The Triton can display 16 shades of gray and 4,096 colors. E Ink Triton is used in commercially available products such as the Hanvon color e-reader, ectaco’s JetBook Color, and PocketBook’s PocketBook Color Lux.
E Ink Triton 2
The latest generation of E Ink Triton color displays. E-readers equipped with it appeared in 2013, including Ectaco Jetbook Color 2 and Pocketbook Color Lux.
E Ink Carta
Announced at International CES in January 2013, offers 768 x 1024 resolution on 6-inch displays with a pixel density of 212 ppi. Called Carta, the display is used in the first (2012) and second (2013) generation Kindle Paperwhite, Pocketbook Touch Lux 3 (2015) and Kobo Nia (2020).
E Ink Carta HD
This one offers 1080 x 1440 resolution on a 6-inch, 300 ppi screen. It is used in many eReaders, including the Kindle Voyage (2014), Tolino Vision 2 (2014), 3rd and 4th generation Kindle Paperwhite (2015 and 2018), Kobo Glo HD (2015), Nook Glowlight Plus (2015), Cybook Muse Frontlight, Kindle Oasis (2016), PocketBook Touch HD (2016), PocketBook Touch HD 2 (2017), and Kobo Clara HD (2018).
E Ink Carta and Carta HD
These displays support shelf waveform technology, which reduces the need for page refreshes.
E Ink Spectra
A three-pigment display. The display uses microcups, each containing three pigments. It is available for retail and electronic shelf label applications. It is currently manufactured with black, white and red or black, white and yellow pigments.
Advanced Color ePaper (ACeP)
This one was announced at SID Display Week in May 2016. The display contains four pigments in each microcapsule or microcup, eliminating the need for a color filter overlay. The pigments used are cyan, magenta, yellow and white, enabling the display of a full color gamut and up to 32,000 colors. Originally intended for the store signage market, the 20-inch displays, with a resolution of 1600 x 2500 pixels at 150 ppi and a refresh rate of two seconds, began shipping in late 2018 for signage purposes, but are still years away from being available for e-readers.
E Ink Kaleido
Originally announced as “Print Color” in December 2019, is the first of a new generation of color displays based on E Ink’s grayscale display with a color filter layer. E Ink Kaleido uses a plastic color filter layer, as opposed to the glass filter layer used in the E Ink Triton family of displays.
E Ink Kaleido Plus (New Kaleido)
In early 2021, E Ink released a new generation of the Kaleido family called E Ink Kaleido Plus. In this new version, adjustments were made to the printed CFA to provide better color balance and print texture, and the CFA was moved closer to the ink to reduce light scatter. New image rendering algorithms allow for sharper text. In addition, adjustments have been made to the light guides to better optimize the LED color spectrum to minimize color bleeding. This e-ink is used in the Pocket Book 741 InkPad Color (2021), ONYX BOOX NOVA 3 Color.