Electronic paper display

E Ink technology

The purpose of this page is to educate anyone interested in learning more about E Ink technology and the ways it can be applied to innovative products.

The technology which imitates the look of ink on paper.

Electronic paper is also known as e-paper, e-ink or electronic ink. However, it is most commonly referred to as E Ink, after the company who brought the product to market. The content displayed on an E Ink screen is as clear and readable as if you had written it with a pen onto a piece of paper. Sometimes electronic paper displays are also known as EPD or electrophorectic displays. EPDs are one of the e-paper technologies mainly used by E Ink. [1]

Thanks to its remarkable adaptability, e-paper is used in a variety of innovative ways. The range of usages is extensive, some examples include but are not limited to accessories, phone displays, digital signs and other devices. Unlike traditional paper, it cannot be folded into origami shapes but it is still flexible in that its capabilities are still being explored.

’’E-paper’s amazing characteristics such as excellent visibility, paper-like readability and extremely low energy consumption make it perfect for all sorts of incredible products.’’ [2]

PRIMOZIC, U., ’’ELECTRONIC PAPER EXPLAINED: WHAT IS IT AND HOW DOES IT WORK’’

How does it work?

Electronic paper works thanks to millions of tiny ink capsules.

These ink capsules are filled with a transparent fluid. The fluid within each capsule contains miniscule particles, approximately as wide as a human hair. E Ink displays consist of millions of these capsules in a thin film, with differing electrical charges and colors.

Color particles inside capsules are moved by electric charge.

Above and below the capsules film electrodes are placed. When a positive or negative electric field is applied to an individual electrode, the color particles with the corresponding charge will move either to the top or bottom of the capsule.

Differently colored particles.

The particles inside an e-ink capsule in the simplest version of an e-paper display will be white or black. The ink particles which carry a positive charge are white and the ink particles which carry a negative charge are black.

EPD gets colored by the capsules.

Capsules filled with negatively and positively charged particles color the surface of an EPD when an electric charge is applied. When a negative electric charge is applied, the particles which are black (and negative) are forced to the top of the capsule. In the areas where the black particles are, the surface of the display appears black in colour.

Why did we choose an EInk screen over an LCD screen?

1. Longer battery life

No power is needed to hold an image.

Bistable displays are a kind of E Ink screen that has the potential to hold on to an image, even without a power source. Using E Ink technology means that the display doesn’t consume power unless the display changes. It is still visible, without requiring a battery, or power source of any kind. In order to change the content displayed on the E Ink screen, the device will need to be charged.

Bistability lessens the amount of energy consumed.

This is just one of the reasons people choose this kind of display for devices such as eReaders, as power is only required when you want to turn to the next page but by reading the page, no power is consumed. Longer battery life also means these types of displays are more environmentally friendly.

2. Analog feel

E Ink has an analog feel. It looks like real printed paper from all angles and in all lighting conditions.

The use of a frontlight means that it’s readable in both sunlight and at night, without glare. This also means that when it comes to your health, an E Ink screen is going to cause less eye strain.

’’By reducing the need for paper, E Ink technology is saving trees and lessening the environmental effects of papermaking and printing process. Compared to PDAs, laptops, and tablets, eBooks require a fraction of the energy to display information. A single battery charge can give you up to a month of reading. Using a sustainable technology like E Ink is easy on the eyes and environment.’’ [3]

WWW.EINKCORP.CO

3. No blue light exposure

Blue light can affect your sleep quality

After an hour and a half of technology usage in the evening, the sleep hormone melatonin is suppressed. This is due to the blue ‘backlit’ light emitted from the LCD screens built into phones, computers, televisions and other screen based devices. We have not yet adapted biologically to technology and our bodies still associate bright light with daylight.

E Ink displays are a type of reflective display and LCD displays are a type of emissive display. LCD displays work so that anything being displayed can be seen using a backlight, the content is visible because the light is projected through the display. LCDs become virtually unreadable in bright sunlight because the backlight, designed to make the image in the liquid crystal visible, can’t compete with the brightness of the sun.

E Ink displays work differently than LCD ones. There is no backlight.

The outdoor performance on an E Ink screen is that the display remains perfectly usable in the day or the night. Light from the environment, or ambient light, is reflected from the surface of the display so that the content is visible. The dark areas absorb the sunlight and the light areas reflect it, thereby creating a visible image.

’’As with any reflective surface, the more ambient light, the brighter the display looks. This attribute mimics traditional ink and paper, and users of E Ink displays have said that they do not have the same eye fatigue as with LCDs when reading for long periods of time.’’[4]

www.eink.com

4. Frontlight

Content on the display is visible at night without exposure to the back light.

As opposed to LCD screens, E Ink screens can use a frontlight thanks to their transparency. Viewing the screen is based on reflected light only.

In Mudita products, the frontlight panel illuminates the display, so that the light is uniform. It can be used both day and night, without glare. A filter is used, which makes the light warmer. This is not common in every frontlight. For our frontlight we’ve chosen FLEx technology. This technology inserts light into plastic films thinner than a piece of paper. It then radiates out precisely to where the film guides it. Our LED light guide technology uses off-the-shelf LEDs.’ [5]

Why is E Ink better for your wellbeing?

We decided on an E Ink screen as we felt that this option was the most considerate to human health.

We decided on an E Ink screen as we felt that this option was the most considerate to human health.

This kind of display is significantly better for your eyes, it consumes less energy (thanks to its bistability, when energy is only needed to change the display content), there’s more of an analog feel to it, a higher pixel density and it’s easier to read from in the daylight than a regular LCD screen. Studies have shown that using a device which emits blue light, especially at night, can interrupt sleep cycles and contribute to a host of ailments such as heart palpitations, muscle pain and weakness, and daytime irritability. [5]

Blue light emitting devices are usually backlit such as smartphone or computer LCD screens which use LEDs. A recent study from the Lighting Research Center indicates you need to log off and shut down your devices 2 hours before you go to sleep. [6]

A study, entitled ‘The potential influence of LED lighting on mental illness’ shows that there may be a correlation between negative mental health effects and the restriction of melatonin. [7]Bauer, M. et al. (2017) The potential influence of LED lighting on mental illness [Online] Melatonin is the hormone which signals the brain that it’s time to go to sleep, so when it’s delayed or suppressed by too much light exposure from our devices, sleep will be disturbed. Researchers are also investigating the connection between skin damage and screen-emitted visible light. [8]

Our products are supposed to be both neutral and simple, not attention grabbing, not needlessly interfering with life.

All of the aforementioned reasons have in some way aided us in the decision making process with regards to our products.

If you think our decision to opt for an E Ink display was the right one, let us know!

If you’re interested in sharing your experiences with us, send us an email via hello@mudita.com or join the discussion on our Forum! Please feel free to get in touch. You can find us on Facebook, Twitter and Instagram - let’s connect! To learn more about Mudita, take a look at our website and the Mudita Blog.

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