Why R.E.A.D Uses E-Paper and Not a Conventional LCD Screen?
E-Paper (also often referred to as E-Ink Displays) are the displays you find on E-Readers, such as Kindles and beginning to turn up in other places like tags and badges. But what makes them more suitable for this project than traditional LCD screens? In this blog post we’ll take a look at our reasoning and the benefits E-Paper screens have as alternative displays in museums.
Ease of Reading in Daylight or Variable Light Conditions
E-Paper is extremely well adapted to reading because it doesn’t rely on a light source to display the image. Did you have one of these toys when you were small?
These work by having black metallic particles sitting under a thick white liquid membrane. When you put the magnet on the top the black particles are pulled through and sit on top of the white. To reset, you run a second magnet on a slider underneath the image and they are pulled back underneath. This is same principle in e-paper displays, with the exception that the magnet is provided by running a small electric charge to the specific areas of the screen, allowing for a higher resolution that the “Fisher Price Magna-Doodle” was capable of. All this means the display is much easier on the eye and more like traditional print. It also means that it only uses power when updating leading to point 2…
Low Power Usage
LCD displays rely on an internal light generation that is constantly drawing power, even if the display isn’t changing. This means that in a similar use case, e-paper uses just 0.008% of the power. Obviously this is a big deal in terms of dealing with the climate crisis and rising energy costs but in our example, where the display is effectively replacing a label and so will be on 100% of the time, this is an absolute crucial factor.
It Looks Like Paper and Not Like A Screen
Screens are everywhere! We carry them around, we stare at them all day and they are crucial to our day-to-day life (I’m looking at one now). However, there is definitely a feeling on screen fatigue and when visiting a museum, we don’t want an in-person experience substituted for looking at an electronic display. R.E.A.D is attempting as much as possible to replace, like for like, traditional museum labels so it’s important that they don’t feel obtrusive or difficult to use for casual visitors.
So Why Not Replace All Screens With E-Paper?
There are several limits that means e-paper is not suitable for all projects where a screen is needed. Firstly, it’s limited to just grayscale or displays with only several colours available, so anything that needs a full colour display won’t be displayed correctly. The other limiting factor is the speed in refreshing a display- e-paper can take a few seconds to refresh, so can’t provide moving images or things that need frequent updates. There is also a limit to the available sizes- at the moment large scale e-paper screens are very expensive.
Hopefully that’s given a little background to the our thinking around the usuage of e-paper and why we chose to use it in this project. Next time we’ll be going deep and looking at the specific hardware we are using and why we have chosen these.
Head of Digital Innovation
St Ives Museum and Cornwall Museums Partnership is part of the DOORS – Digital Incubator of Museums network. DOORS has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101036071.