Electronics Production | December 07, 2009
ECO Friendly Display – E Paper is Coming
Environmental degradation has made more and more people go for ECO friendly things and activities. This is the reason why E Paper (Electronic Paper) has caught so much attention recently. The success of Amazon Kindle brings a rapid demand growth in the e-paper market.
The reason why E-paper displays are taking off with consumers is because of their low power consumption and ease of use: for reading (they are especially sunlight readable). To compare with conventional display, E paper does not need to be refreshed constantly; the wider viewing angle makes the reading very easy for users. In addition, e-paper displays are 'green', because they reduce paper consumption. Electronic labels also can save time and labour costs by enabling dynamic pricing in stores. E-Paper: Category There are several different technologies to build E paper that already exist in market; such as electrophoretic, electrochromic & electrowetting displays, cholesteric LCDs and other bi-stable technologies – with electrophoretic displays and cholesteric LCD being the most popular. Electronic paper is a display technology designed to mimic the appearance of ordinary ink on paper. Unlike conventional flat panel displays, E paper doesn't require a backlight to illuminate its pixels. E Paper reflects light like ordinary paper and is capable of holding text and images indefinitely without drawing electricity, while allowing the image to be changed later. E-Paper: Technical Theory E Paper is composed of charged particle. If a charged particle is floating on the surface, the colour will be white. However, is the particle dragged to the bottom, its colour will change to black. This movement is controlled by a conductor and a transparent conductor with an electrode. (See the diagram below; Sipix) The e-paper driving pin includes three parts: Common (a transparent conductor of e-paper film), Background (background colour of e-paper, which is a big ICON (Segment); the signal driving method is same as for the segment.) and Segment (for the display E-Paper ICON). To display the ICON black or white, there must be a potential difference in Common and Segment. The waveform can be example as below: If the user would like to display a white character, the common can be 0V and the segment set value of 30V. To make the e-paper work is simple, just input different a voltage to show what you would like to display. E-Paper: Control and Block Diagram Below is the control diagram and functional block diagram of e-paper as a reference. E-Paper: Modules Production Process It will be easy to create different products function, so that manufactures adopt e-paper modules for their applications. That is to say that manufactures might better purchase different module types from display manufactures – and not just e-paper film. Making e-paper modules requires three important production processes – cut the e-paper film, laminate the backplane and than add the driver IC. E Paper: Modules Key Features E-paper has to be regarded as a ‘green’ display technology, as it comes with several advantages (which are listed below). And that may also be the prominent reason, why the e-paper technology has led the rapid growth in demand within the display device market. • Flexible and Durable • Impact resistant • Long lifetime: It can be updated up to 1 million times • Max size: the film size is 6 inch (diagonal size) • Image retain without power • Extremely thin • High contrast • Wide view angle: almost 180 degree E Paper: Main Application The above mentioned advantages also lead to several applications – apart from the all too well know e-book: • Smart Card (Computer Security System, Credit Card, Password card, etc.) • Pricing Labels • Purchase Signs • Point–of-purchase (POP) • Clocks / Watches • Indicators & Logos ----- Source: Winstar