Schema of an Electrophoretic Display
Schema of an Electrophoretic Display
[edit] Electrophoretic
Schema of an Electrophoretic Display
Schema of an Electrophoretic Display Using Color FiltersAn electrophoretic display is an information display that forms visible images by rearranging charged pigment particles using an applied electric field.
In the simplest implementation of an electrophoretic display, titanium dioxide particles approximately one micrometre in diameter are dispersed in a hydrocarbon oil. A dark-colored dye is also added to the oil, along with surfactants 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 micrometres. When a voltage is applied across the two plates, the particles will migrate electrophoretically to the plate bearing 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 light is scattered back to the viewer by the high-index titania particles. When the particles are located at the rear side of the display, it appears dark, because the incident light is absorbed by the colored dye. If the rear electrode is divided into a number of small picture elements (pixels), 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.
Electrophoretic displays are considered prime examples of the electronic paper category, because of their paper-like appearance and low power consumption.
Examples of commercial electrophoretic displays include the high-resolution active matrix displays used in the Amazon Kindle, Sony Librie, Sony Reader, and iRex iLiad e-readers. These displays are constructed from an electrophoretic imaging film manufactured by E Ink Corporation. The Motorola Motofone is the first mobile phone which uses the technology to help eliminate glare from direct sunlight during outdoor use[6].
Another producer of electrophoretic displays is the California based company SiPix[7]. Sipix, along with manufacturing partner SmartDisplayer, received a 1996 Society for Information Display Gold Award for an IC smart card with an integrated electrophoretic display[8].
Electrophoretic displays can be manufactured using the Electronics on Plastic by Laser Release (EPLaR) process developed by Philips Reasarch to enable existing AM-LCD manufacturing plants to create flexible plastic displays.
In the 1990s another type of electronic paper was invented by Joseph Jacobson, who later co-founded the E Ink Corporation which formed a partnership with 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. This used tiny microcapsules filled with electrically charged white particles suspended in a colored oil.[9] In early versions, the underlying circuitry controls whether the white particles were at the top of the capsule (so it looked white