E-Ink Ereaders

Black and white (sometimes called monochrome or greyscale) E-ink readers leaped on to the market a few years ago rapidly gained huge popularity. They provide a paper-like display using technology that mimics the appearance of ink on a traditional printed book page, and gives the feeling of reading a normal paper printed book or a newspaper. E-Ink displays are excellent for lengthy reading sessions, something which many book readers perform when they're engrossed in a great novel.

E-Ink displays work using electrophoretic technology in a similar way to most current ereaders on the market. In technical terms, black and white charged particles float in a dielectric fluid, while enclosed in a minute micro capsule. When an electric field is applied to them, these particles gravitate towards an electrode making the surface look black or white at that point on the screen.

They support very high resolutions, giving sharp, crisp, easily readable writing on a thin, lightweight device. 

An E-Ink reader uses a reflective display, which means there must be an external source of light to be able to read text. The more light, the better you can read on it. You cannot read an E-ink reader in dark conditions unless you have another light source,  unlike an LCD display.

One great advantage of E-ink is that it has a longer battery life giving anywhere up to several weeks use before the battery runs out. The battery life is enhanced because it has no backlighting, a slow refresh rate,  and of course no other color except from black and white. E-Ink displays are known as bistable, which means that power is used only to form a new image. That means the device only draws power  when you turn a new page.

You can read more about how E-Ink works at HowStuffWorks.com

LCD Ereaders

The arrival of the colour ereader has seen the use of LCD displays which can display the necessary colours in a more vibrant way, and handle other entertainment mediums such as video too. LCD technology is what's used in our laptop screens, flat screen computer monitors and televisions, and it works by twisting "liquid" crystals to create all colors in the spectrum.

The twisting crystals give no light and just relying on a backlighting source, either supplied by CFL florescent or LED technology. LCD type colour e-readers are backlit so they provide rich and vibrant colors in all lighting conditions except in direct sunlight. Their fast refresh rates resulting in nicely moving graphics and sharp focus on images and text. An overall experience you cannot get with E-ink ereader.

One of the big advantages of LCD colour e-readers is that they allow night reading and fast page turn. However, there are some drawbacks. Notably in the areas of higher levels of eyestrain over long reading sessions and consumption of battery power at a greater rate than with E-ink readers. The battery of an LCD colour e-reader typically last for 8 hours up to a day while e-ink readers’ battery can last for up to a month. When in comes to pricing, LCD colour e-readers are much more expensive than e-ink display e-readers.

Electrowetting Technology

The latter capability is possible with the Dutch-made Liquavista, which utilizes electrowetting technology.

Unlike LCDs, this works without any back light, making it more energy efficient. Electrowetting uses colored oil instead of black and white beads. This works to combine the best of the two other technologies. There is color capability and at the same time energy efficiency and good readability under varied conditions of lighting.

In addition, electrowetting technology is greener. If applied to computer and laptop screens it can significantly lower power consumption and give increased battery life.

If Electrowetting diplays can be perfected they do have significant potential to rival E-Ink and LCD. All the evidence so far suggests they can be viewed in all lighting conditions, offer strong color performance, have lower manufacturing costs, and significantly lower power consumption.

That sounds good. And it must have sounded good to Samsung too, because the manufacturing giant acquired Dutch company Liquidvista - the pioneer of the technology - in early 2011. That gives Samsung a potent weapon to go into battle with, either by creating their own model or selling the technology to other manufacturers.

16.7 million colours is not to be sniffed at. Nor is a refresh rate that's around 70 times faster than on an E-Ink. Liquidvista claim that they've got a solution that works using 10 percent of the power of current LCD colour ereaders.

Once it's perfected,  we may well see electrowetting used in next generation tablet PCs as well as color ereaders.

What Does The Future Hold? Where Is Colour Ereader Technology Heading?

As we look to the future, improvements in display technologies are clearly going to have a major impact. Particularly with colour ereader technology.

Another company known as Bridgestone are reportedly developing a liquid powder solution. This is powder that behaves like a liquid, giving high fluidity in motion. The particles move in air and can move with great speed when influenced by electric fields.

A company known as Pixel Qi have developed a hybrid type of ereader display that runs in two modes, combining an LCD which gives full depth of colours and handles video, and a reflective ereader screen that saves power.

These types of hybrid ereaders hold some promise for the future, but they may be challenged by two other solutions which hold the promise of the jewel in the crown - a great, colour rich display with low power requirements.

Mirasol Color Ereader Display Technology

The first we've already mentioned - the Liquidvista solution. The second is known as the Mirasol display. This works similarly to E-Ink by reflecting light so that wavelengths within it clash with each other to create colours. This gives Mirasol displays the potential to show irridescent colours.

Mirasol color displays will be readable in sunlight and rival the energy consumption of E-Ink, possibly even surpassing it. Mirasol ereader technology works by using minute membranes positioned over a mirrored surface. These membrane are electrically charged to give reflective properties. Refracted light is reflected back out through these membranes that clashing wavelengths create colours.

They need no backlighting or illumination from other light sources which renders them highly energy efficient, the light which makes them work is similar to that found in nature.

Mirasol does have other advantages over both LCD and E-Ink. The fast response time coupled with high quality colour display ability allows playing of games and videos - both without any significant impact on battery life. 

And this non reliance on any form of backlighting means that Mirasol colour ereader displays can be manufactured so that they're even thinner and lighter than LCD models. The technology isn't just limited to ereaders either - it's likely we'll see Mirasol in cameras, mobiles, game devices, TVs, and other electronic products and gadgets in future.

The day may not be far off when we see flexible ereaders that can be rolled up like a newspaper.

Colour Ereader Technology - How Colour Ereaders Work
Colour Ereader Technology - A Brief Introduction

If you're totally new to ereaders you're going to first want a brief summary of what an ereader is. So here goes....

An ereader is a lightweight, portable electronic gadget that was initially designed for reading electronic books. It does this by using electronic paper technology to show content to the reader on a specially designed electronic screen. It's easy to see from this that the most important aspects of colour ereader technology are in the displays themselves.

There are currently two main types of display used in colour ereaders - LCD and E-Ink. New technologies such as Mirasol are under development.

Most colour ereaders already available use traditional LCD displays that are similar to the ones you get in laptops and tablets, but if they want to enjoy a successful future we'll need to see development of coloured screens using either E-Ink or another more advanced technology.

It's E-Ink technology that's contributed to the success of the well known black and white readers. Reading text on an E-Ink display prevents eye strain by replicating the experience of reading on paper, which is in contrast to the occasional negative effects of reading on backlit tablet and computer screens in bright conditions.

Here we'll take a look at the currently used display types and examine the potential of more advanced second generation technologies.