Editing Electronic paper (section)

==Technologies==

===Gyricon===
{{main|Gyricon}}
Electronic paper was first developed in the 1970s by Nick Sheridon at [[Xerox]]'s [[Xerox PARC|Palo Alto Research Center]].<ref>{{cite web|last1=Genuth|first1=Iddo|title=The Future of Electronic Paper|url=https://thefutureofthings.com/3081-the-future-of-electronic-paper/|publisher=The Future Of Things|access-date=2 March 2015|ref=tfot|date=2007-10-15|archive-date=2020-08-17|archive-url=https://web.archive.org/web/20200817181702/https://thefutureofthings.com/3081-the-future-of-electronic-paper/|url-status=live}}</ref> The first electronic paper, called '''Gyricon''', consisted of polyethylene spheres between 75 and 106 micrometers across. Each sphere is a [[Janus particle]] composed of negatively charged black plastic on one side and positively charged white plastic on the other (each bead is thus a [[dipole]]).<ref name="gyroid_dipole">{{cite journal |last1=Crowley |first1=Joseph M. |last2=Sheridon |first2=Nicholas K. |last3=Romano |first3=Linda |title=Dipole moments of gyricon balls |journal=Journal of Electrostatics |volume=55 |issue=3–4 |pages=247–259 |doi=10.1016/S0304-3886(01)00208-X|year=2002}}</ref> The spheres are embedded in a transparent silicone sheet, with each sphere suspended in a bubble of oil so that it can rotate freely. The polarity of the voltage applied to each pair of electrodes then determines whether the white or black side is face-up, thus giving the pixel a white or black appearance.<ref name="newscientist_1">{{citation |last=Daviss |first=Bennett |title=Paper goes electric |date=15 May 1999 |magazine=New Scientist |publisher=Reed Business Information |url=https://www.newscientist.com/article/mg16221864.700-paper-goes-electric.html |access-date=20 November 2011 |archive-date=7 August 2012 |archive-url=https://web.archive.org/web/20120807002203/http://www.newscientist.com/article/mg16221864.700-paper-goes-electric.html |url-status=live }}</ref>
A benefit of this type of e-paper is that the contents are retained even after the voltage have been stopped. At the FPD 2008 exhibition, Japanese company Soken demonstrated a wall with electronic wall-paper using this technology.<ref name="Soken">Techon [https://tech.nikkeibp.co.jp/dm/english/NEWS_EN/20081104/160670/ Soken electronic wall-paper] {{Webarchive|url=https://web.archive.org/web/20190327223517/https://tech.nikkeibp.co.jp/dm/english/NEWS_EN/20081104/160670/ |date=2019-03-27 }}</ref> In 2007, the Estonian company Visitret Displays was developing this kind of display using [[polyvinylidene fluoride]] (PVDF) as the material for the spheres, dramatically improving the video speed and decreasing the control voltage needed.<ref name="Liiv">J. Liiv. [https://web.archive.org/web/20160611190750/https://www.scholars-press.com/catalog/details/store/us/book/978-3-639-51567-1/pvdf-as-material-for-active-element-of-twisting-ball-displays?search=liiv PVDF as material for active element of twisting-ball displays]</ref>

===Electrophoretic===
[[File:E-ink.svg|thumb|500px|Appearance of pixels]]
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{{cn|date=January 2025}}. A dark-colored dye is also added to the oil, along with [[surfactant]]s and charging agents that cause the particles to take on an electric charge. This mixture is placed between two parallel, conductive plates separated by a gap of 10 to 100 [[micrometre]]s. When a voltage is applied across the two plates, the particles migrate [[electrophoresis|electrophoretically]] to the plate that bears the opposite charge from that on the particles. When the particles are located at the front (viewing) side of the display, it appears white, because the light is scattered back to the viewer by the high-index{{clarify|date=December 2019}} titania particles. When the particles are located at the rear side of the display, it appears dark, because the light is absorbed by the colored dye. If the rear electrode is divided into a number of small picture elements ([[pixel]]s), then an image can be formed by applying the appropriate voltage to each region of the display to create a pattern of reflecting and absorbing regions.

EPDs are typically addressed using [[MOSFET]]-based [[thin-film transistor]] (TFT) technology. TFTs are often used to form a high-density image in an EPD.<ref>{{cite journal | last1=Srikanth | first1=G | last2=Kariyappa | first2=B | title=Parametric analysis of amorphous silicon thin film transistors | url=https://ieeexplore.ieee.org/abstract/document/7808111/metrics#metrics | date=2016 | journal=IEEE International  | pages=1642–1646 | doi=10.1109/RTEICT.2016.7808111 | isbn=978-1-5090-0774-5 }}</ref>
A common application for TFT-based EPDs are e-readers.<ref>{{cite book |last1=Brotherton |first1=S. D. |title=Introduction to Thin Film Transistors: Physics and Technology of TFTs |date=2013 |publisher=[[Springer Science & Business Media]] |isbn=9783319000022 |url=https://books.google.com/books?id=E0x0Zghk7okC}}</ref> Electrophoretic displays are considered{{by whom|date=December 2019}} prime examples of the electronic paper category, because of their paper-like appearance and low power consumption.{{citation needed|date=December 2019}} Examples of commercial electrophoretic displays include the high-resolution [[active matrix]] displays used in the [[Amazon Kindle]], [[Barnes & Noble Nook]], [[Sony Reader]], [[Kobo eReader]], and [[iRex iLiad]] e-readers. These displays are constructed from an electrophoretic imaging film manufactured by [[E Ink Corporation]]. A mobile phone that used the technology is the [[Motorola Fone]].<ref>{{Cite web |last=Willings |first=Adrian |date=2022-02-03 |title=Motorola phones through the years: The best and the worst, in pictures |url=https://www.pocket-lint.com/phones/news/131575-motorola-phones-since-1983-the-best-and-the-worst-in-pictures/ |access-date=2023-11-09 |website=Pocket-lint |language=en}}</ref>

Electrophoretic Display technology has also been developed by SiPix and [[Bridgestone]]/Delta. SiPix is now part of E Ink Corporation. The SiPix design uses a flexible 0.15&nbsp;mm Microcup architecture, instead of E Ink's 0.04&nbsp;mm diameter microcapsules.<ref>{{cite web|url=https://www.e-ink-info.com/introduction|title=E-Paper (E Ink) introduction and basic e-paper information|access-date=2019-03-27|archive-date=2019-03-27|archive-url=https://web.archive.org/web/20190327223528/https://www.e-ink-info.com/introduction|url-status=live}}</ref><ref>{{cite web|url=http://www.epapercentral.com/epaper-technologies-guide |title=Epaper technologies guide |publisher=epapercentral |url-status=dead |archive-url=https://web.archive.org/web/20120919211056/https://www.epapercentral.com/epaper-technologies-guide |archive-date=2012-09-19 }}</ref> [[Bridgestone]] Corp.'s Advanced Materials Division cooperated with Delta Optoelectronics Inc. in developing Quick Response Liquid Powder Display technology.<ref>{{cite web|url=http://www2.bridgestone-dp.jp/global/adv-materials/QR-LPD/|title=製品情報（タイヤ/化工品/スポーツ用品/自転車） - 株式会社ブリヂストン|access-date=2009-11-11|archive-url=https://web.archive.org/web/20090716125733/http://www2.bridgestone-dp.jp/global/adv-materials/QR-LPD/|archive-date=2009-07-16|url-status=dead}}</ref><ref>{{cite web|url=http://thecoolgadgets.com/bridgestone-flexible-epaper-quick-response-liquid-powder-technology/|title=BridgeStone Flexible ePaper – Quick Response Liquid Powder Technology - The Cool Gadgets - Quest for The Coolest Gadgets|date=2009-10-29|access-date=2009-11-11|archive-date=2010-11-19|archive-url=https://web.archive.org/web/20101119175344/http://thecoolgadgets.com/bridgestone-flexible-epaper-quick-response-liquid-powder-technology/|url-status=live}}</ref>

Electrophoretic displays can be manufactured using the [[EPLaR|Electronics on Plastic by Laser Release (EPLaR)]] process, developed by [[Philips|Philips Research]], to enable existing [[AM-LCD]] manufacturing plants to create flexible plastic displays.<ref>{{cite web
| url = http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=DTPSDS000038000001001599000001&idtype=cvips&gifs=yes
| title = 53.4: Ultra-Thin Flexible OLED Device
| work = SID Symposium Digest of Technical Papers -- May 2007 -- Volume 38, Issue 1, pp. 1599-1602
| access-date = 2007-12-03
}}</ref>

====Microencapsulated electrophoretic display====
[[File:How It Works, Black & White Capsules.pdf|thumb|275px|right|Scheme of an electrophoretic display]]
[[File:Epd color.svg|thumb|275px|right|Scheme of an electrophoretic display using color filters]]
[[File:Kindle 3 texture (crop).jpg|thumb|Macro photograph of Kindle 3 screen; microcapsules are evident at [//upload.wikimedia.org/wikipedia/commons/5/54/Kindle_3_texture_%28crop%29.jpg full size.]]]

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<ref>{{cite news|title= A New Printing Technology Sets Off a High-Stakes Race|url= https://www.wsj.com/articles/SB946939872703897050|newspaper= Wall Street Journal|access-date= 2015-11-27|issn= 0099-9660|first= Alec Klein Staff Reporter of The Wall Street|last= Journal|archive-date= 2015-12-08|archive-url= https://web.archive.org/web/20151208050730/http://www.wsj.com/articles/SB946939872703897050|url-status= live}}</ref> as described in their Nature paper.<ref name="e_ink_nature"/> J.D. Albert, [[Barrett Comiskey]], Joseph Jacobson, Jeremy Rubin and Russ Wilcox co-founded [[E Ink Corporation]] in 1997 to commercialize the technology. E Ink subsequently formed a partnership with [[Philips|Philips Components]] two years later to develop and market the technology. In 2005, Philips sold the electronic paper business as well as its related patents to [[Prime View International]]. <blockquote>"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. In this context, microparticle-based displays have long intrigued researchers. Switchable contrast in such displays is achieved by the electromigration of highly scattering or absorbing microparticles (in the size range 0.1–5 μm), quite distinct from the molecular-scale properties that govern the behavior of the more familiar liquid-crystal displays. Micro-particle-based displays possess intrinsic bistability, exhibit extremely low power d.c. field addressing and have demonstrated high contrast and reflectivity. These features, combined with a near-[[Lambertian reflectance|lambertian]] viewing characteristic, result in an 'ink on paper' look. But such displays have to date suffered from short lifetimes and difficulty in manufacture. 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 issues and permits the fabrication of a bistable electronic display solely by means of printing. This system may satisfy the practical requirements of electronic paper."<ref>{{cite journal|title= An electrophoretic ink for all-printed reflective electronic displays|journal= Nature|date= 1998-07-16|issn= 0028-0836|pages= 253–255|volume= 394|issue= 6690|doi= 10.1038/28349|first1= Barrett|last1= Comiskey|first2= J. D.|last2= Albert|first3= Hidekazu|last3= Yoshizawa|first4= Joseph|last4= Jacobson|bibcode= 1998Natur.394..253C|s2cid= 204998708}}</ref></blockquote>

This used tiny microcapsules filled with electrically charged white [[molecule|particles]] suspended in a colored [[mineral oil|oil]].<ref name="e_ink_nature">{{cite journal |last1= Comiskey |first1= B. |last2= Albert |first2= J. D. |last3= Yoshizawa |first3= H. |last4= Jacobson |first4= J. |year= 1998 |title= An electrophoretic ink for all-printed reflective electronic displays |doi= 10.1038/28349 |journal= Nature |volume= 394 |issue= 6690 |pages= 253–255|bibcode= 1998Natur.394..253C |s2cid= 204998708 }}</ref> In early versions, the underlying [[circuitry]] controlled whether the white particles were at the top of the capsule (so it looked white to the viewer) or at the bottom of the capsule (so the viewer saw the color of the oil). This was essentially a reintroduction of the well-known [[electrophoresis|electrophoretic]] display technology, but microcapsules meant the display could be made on flexible plastic sheets instead of glass.
One early version of the electronic paper consists of a sheet of very small transparent capsules, each about 40 [[micrometre|micrometer]]s across. Each capsule contains an oily solution containing black dye (the electronic ink), with numerous white [[titanium dioxide]] particles suspended within. The particles are slightly negatively [[electric charge|charged]], and each one is naturally white.<ref name="newscientist_1"/>
The screen holds microcapsules in a layer of [[liquid]] [[polymer]], sandwiched between two arrays of electrodes, the upper of which is transparent. The two arrays are aligned to divide the sheet into pixels, and each pixel corresponds to a pair of electrodes situated on either side of the sheet. The sheet is laminated with transparent plastic for protection, resulting in an overall thickness of 80 micrometers, or twice that of ordinary paper.
The network of electrodes connects to display circuitry, which turns the electronic ink 'on' and 'off' at specific pixels by applying a voltage to specific electrode pairs. A negative charge to the surface electrode repels the particles to the bottom of local capsules, forcing the black dye to the surface and turning the pixel black. Reversing the voltage has the opposite effect. It forces the particles to the surface, turning the pixel white. A more recent implementation of this concept requires only one layer of electrodes beneath the microcapsules.<ref>{{cite news |last=Sample |first=Ian |newspaper=New Scientist |title=Roll The Presses |date=24 April 2001 |url=https://www.newscientist.com/article/dn659-roll-the-presses.html |access-date=20 November 2011 |archive-date=9 March 2011 |archive-url=https://web.archive.org/web/20110309061210/http://www.newscientist.com/article/dn659-roll-the-presses.html |url-status=live }}</ref><ref>{{cite journal |first1=John A |last1=Rogers |first2=Zhenan |last2=Bao |first3=Kirk |last3=Baldwin |first4=Ananth |last4=Dodabalapur |first5=Brian |last5=Crone |first6=V R |last6=Raju |first7=Valerie |last7=Kuck |first8=Howard |last8=Katz |first9=Karl |last9=Amundson |first10=Jay |last10=Ewing |first11=Paul |last11=Drzaic |title=Paper-like electronic displays: Large-area rubber-stamped plastic sheets of electronics and microencapsulated electrophoretic inks |date=24 April 2001 |journal=PNAS |volume=98 |issue=9 |pages=4835–4840 |doi=10.1073/pnas.091588098 |pmid=11320233 |pmc=33123|doi-access=free }}</ref> These are commercially referred to as Active Matrix Electrophoretic Displays (AMEPD).

===Reflective LCD===
{{Main|Liquid-crystal display}}
This technology is similar to common [[LCD]] while the [[backlight]] panel is substituted by a reflective surface.<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/lcd|title=Definition of LCD|website=Merriam-Webster.com|access-date=February 15, 2015|archive-date=February 25, 2021|archive-url=https://web.archive.org/web/20210225191614/https://www.merriam-webster.com/dictionary/LCD|url-status=live}}</ref>
A comparable technology is also obtainable in backlight LCDs by software or hardware deactivating the backlight control.

===Electrowetting===
{{Main|Electrowetting}}
'''Electrowetting display''' ('''EWD''') is based on controlling the shape of a confined water/oil interface by an applied voltage. With no voltage applied, the (colored) oil forms a flat film between the water and a hydrophobic (water-repellent) insulating coating of an electrode, resulting in a colored pixel. When a voltage is applied between the electrode and the water, the interfacial tension between the water and the coating changes. As a result, the stacked state is no longer stable, causing the water to move the oil aside. This makes a partly transparent pixel, or, if a reflective white surface is under the switchable element, a white pixel. Because of the small pixel size, the user only experiences the average reflection, which provides a high-brightness, high-contrast switchable element.

Displays based on [[electrowetting]] provide several attractive features. The switching between white and colored reflection is fast enough to display video content.<ref>{{citation |last=Zyga |first=Lisa |date=26 July 2010 |title=Oil-based color pixels could let you watch videos on e-paper |url=https://phys.org/news/2010-07-oil-based-pixels-videos-e-paper.html |newspaper=PhysOrg |access-date=20 November 2011 |archive-date=15 October 2015 |archive-url=https://web.archive.org/web/20151015221450/http://phys.org/news/2010-07-oil-based-pixels-videos-e-paper.html |url-status=live }}</ref> It is a low-power, low-voltage technology, and displays based on the effect can be made flat and thin. The reflectivity and contrast are better than or equal to other reflective display types and approach the visual qualities of paper. In addition, the technology offers a unique path toward high-brightness full-color displays, leading to displays that are four times brighter than reflective LCDs and twice as bright as other emerging technologies.<ref>LiquaVista electrowetting display technologies http://www.liquavista.com {{Webarchive|url=https://web.archive.org/web/20191102144309/https://www.liquavista.com/ |date=2019-11-02 }}</ref> Instead of using red, green, and blue (RGB) filters or alternating segments of the three primary colors, which effectively result in only one-third of the display reflecting light in the desired color, electrowetting allows for a system in which one sub-pixel can switch two different colors independently.

This results in the availability of two-thirds of the display area to reflect light in any desired color. This is achieved by building up a pixel with a stack of two independently controllable colored oil films plus a color filter.

The colors are [[CMYK color model|cyan, magenta, and yellow]], which is a subtractive system, comparable to the principle used in inkjet printing. Compared to LCD, brightness is gained because no polarisers are required.<ref>{{cite web |url=http://www.hinduonnet.com/seta/2003/10/02/stories/2003100200060200.htm |date=October 2, 2003 |title=The Hindu: Technology for reflective full-color display |access-date=2018-11-30 |archive-url=https://web.archive.org/web/20110309052402/http://www.hinduonnet.com/seta/2003/10/02/stories/2003100200060200.htm |archive-date=2011-03-09 |url-status=usurped }}</ref>

====Electrofluidic====
'''Electrofluidic display''' is a variation of an electrowetting display that place an aqueous pigment dispersion inside a tiny reservoir. The reservoir comprises less than 5-10% of the viewable pixel area and therefore the pigment is substantially hidden from view.<ref>{{cite web|title=Gamma Dynamic Technology|url=http://gammadynamics.net/technology/|publisher=Gamma Dynamics|access-date=1 April 2012|archive-url=https://web.archive.org/web/20120303154148/http://gammadynamics.net/technology/|archive-date=3 March 2012|url-status=dead|df=dmy-all}}</ref> Voltage is used to electromechanically pull the pigment out of the reservoir and spread it as a film directly behind the viewing substrate. As a result, the display takes on color and brightness similar to that of conventional pigments printed on paper. When voltage is removed liquid surface tension causes the pigment dispersion to rapidly recoil into the reservoir. The technology can potentially provide greater than 85% white state reflectance for electronic paper.<ref>{{cite journal| title = May 2009 issue of Nature Photonics| journal = Nature Photonics| date = May 2009| volume = 3| issue = 5| pages = 304| doi = 10.1038/nphoton.2009.66| last1 = Graydon| first1 = Oliver| doi-access = free}}</ref>

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.<ref>{{Cite web|url=http://www.gammadynamics.net/|title=gammadynamics.net|website=www.gammadynamics.net|access-date=2009-04-22|archive-date=2009-05-02|archive-url=https://web.archive.org/web/20090502144448/http://www.gammadynamics.net/|url-status=live}}</ref><ref>{{cite web |url=https://www.usnews.com/articles/science/2009/05/04/make-brighter-full-color-electronic-readers--brilliant.html |title=Make Brighter, Full-Color Electronic Readers? — Brilliant! |date=2009-05-09 |work=US News }}</ref>

It has a wide margin in critical aspects such as [[brightness]], [[color saturation]] and [[Response time (technology)#Display technologies|response time]].
Because the optically active layer can be less than 15 micrometres thick, there is strong potential for [[rollable display]]s.

===Interferometric modulator (Mirasol)===
{{Main|Interferometric modulator display}}

The technology used in [[electronic visual display]]s that can create various colors via [[interference (wave propagation)|interference]] of reflected light. The color is selected with an electrically switched light [[modulator]] comprising a [[micromachinery|microscopic cavity]] that is switched on and off using [[driver circuit|driver]] [[integrated circuit]]s similar to those used to address [[liquid-crystal display]]s (LCD).

===Plasmonic electronic display===
[[Plasmonic]] nanostructures with conductive polymers have also been suggested as one kind of electronic paper.<ref>Xiong, Kunli; Emilsson, Gustav; Maziz, Ali. "[https://onlinelibrary.wiley.com/doi/full/10.1002/adma.201603358 Plasmonic Metasurfaces with Conjugated Polymers for Flexible Electronic Paper in Color] {{Webarchive|url=https://web.archive.org/web/20190327223518/https://onlinelibrary.wiley.com/doi/full/10.1002/adma.201603358 |date=2019-03-27 }}"Advanced Materials: sid. n/a–n/a. [http://onlinelibrary.wiley.com/doi/10.1002/adma.201603358/full doi:10.1002/adma.201603358] {{Webarchive|url=https://web.archive.org/web/20161030080629/http://onlinelibrary.wiley.com/doi/10.1002/adma.201603358/full |date=2016-10-30 }}. ISSN 1521-4095. 28 October 2016.</ref> The material has two parts. The first part is a highly reflective metasurface made by metal-insulator-metal films tens of nanometers in thickness including nanoscale holes. The metasurfaces can reflect different colors depending on the thickness of the insulator. The standard RGB color schema can be used as pixels for full-color displays. The second part is a polymer with optical absorption controllable by an electrochemical potential. After growing the polymer on the plasmonic metasurfaces, the reflection of the metasurfaces can be modulated by the applied voltage. 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. In addition, it has ultralow power consumption (< 0.5&nbsp;mW/cm2) and potential for high resolution (>10000 dpi). Since the ultrathin metasurfaces are flexible and the polymer is soft, the whole system can be bent. Desired future improvements for this technology include bistability, cheaper materials and implementation with TFT arrays.

===Other technologies===
Other research efforts into e-paper have involved using [[OFET|organic transistors]] embedded into [[flexible substrate]]s,<ref name="organic_transistors">{{cite journal |last1= Huitema |first1= H. E. A. |last2= Gelinck |first2= G. H. |last3= van der Putten |first3= J. B. P. H. |last4= Kuijk |first4= K. E. |last5= Hart |first5= C. M. |last6= Cantatore |first6= E. |last7= Herwig |first7= P. T. |last8= van Breemen |first8= A. J. J. M. |last9= de Leeuw |first9= D. M. |year= 2001 |title= Plastic transistors in active-matrix displays |doi= 10.1038/414599a |pmid= 11740546 |journal= Nature |volume= 414 |issue= 6864 |page= 599|bibcode= 2001Natur.414..599H |s2cid= 4420748 |doi-access= free }}</ref><ref name="org_nat_mater">{{cite journal |last1= Gelinck |first1= G. H. |display-authors= etal |year= 2004 |title= Flexible active-matrix displays and shift registers based on solution-processed organic transistors |doi= 10.1038/nmat1061 |journal= Nature Materials |volume= 3 |issue= 2 |pages= 106–110 |pmid=14743215|bibcode= 2004NatMa...3..106G |s2cid= 7679602 }}</ref> including attempts to build them into conventional paper.<ref name="org_on_paper">{{cite journal |last1= Andersson |first1= P. |last2= Nilsson |first2= D. |last3= Svensson |first3= P. O. |last4= Chen |first4= M. |last5= Malmström |first5= A. |last6= Remonen |first6= T. |last7= Kugler |first7= T. |last8= Berggren |first8= M. |year= 2002 |title= Active Matrix Displays Based on All-Organic Electrochemical Smart Pixels Printed on Paper |journal= Adv Mater |volume= 14 |issue= 20 |pages= 1460–1464 |doi=10.1002/1521-4095(20021016)14:20<1460::aid-adma1460>3.0.co;2-s|doi-access= free |bibcode= 2002AdM....14.1460A }}</ref>
Simple color e-paper<ref>{{cite news |work=New Scientist |url=https://www.newscientist.com/article/dn837.html |title=Read all about it |date=June 6, 2001 |author=Duncan Graham-Rowe |archive-url=https://web.archive.org/web/20070930041117/http://www.newscientist.com/article/dn837.html |archive-date= 2007-09-30}}</ref> consists of a thin colored optical filter added to the monochrome technology described above. The array of pixels is divided into [[triad (monitors)|triad]]s, typically consisting of the standard cyan, magenta and yellow, in the same way as [[CRT monitor]]s (although using subtractive primary colors as opposed to additive primary colors). The display is then controlled like any other electronic color display.