I use my laptop in some non-traditional environments, such as outdoors in direct sunlight. Almost all laptops are abysmal in a scenario like this. E-Ink screens are a natural response to this requirement. Unlike traditional TFT-LCD screens, E-Ink panels are meant to be viewed with an abundance of natural light. As a human, I too enjoy natural light.
Besides my fantasies of hacking on the beach, these would be very useful to combat the raster burn that seems to be so common among regular computer users. Since TFT-LCDs act as an artificial sunlight, they can have very negative side-effects on the eyes, and indirectly on the brain. Since E-Ink screens work without a backlight they are not susceptible to these problems. This has the potential to help me reclaim some of the time that I spend without a device before bedtime for health reasons.
The limitations of E-Ink panels are well known to anybody who has used one. The refresh rate is not nearly as good, the color saturation varies between abysmal to non-existent, and the available size are much more limited than LCD panels (smaller). Despite all these reasons, the panels do have advantages. They do not give the user raster burn like other backlit panels. They are cheap, standardized, and easy to replace. They are also useable in direct sunlight. Until recently they offered competitive DPI compared to laptop panels as well.
As a computer professional many of these downsides of LCD panels concern me. I spend a large amount of my work day staring at the displays. I fear this will have a lasting effect on me and many others who do the same.
The E-Ink manufacturer offerings are surprisingly sparse, with no devices that I can find targeted towards consumers or hobbyists. Traditional LCDs are available over a USB interface, able to be used as external displays on any embedded or workstation system. Interfaces for E-Ink displays are decidedly less advanced. The panels that Amazon sources use an undocumented DTO protocol/connector. The panels that everybody else seems to use also have a specific protocol/connector, but some controllers are available.
The one panel I’ve been able to source to try to integrate into a laptop-like object is PervasiveDisplay’s 9.7″ panel with SPI controller. This would allow a computer to speak SPI to the controller board, which would then translate the calls into operations to manage drawing to the panel. Although this is useful, availability is limited to a few component wholesale sites and Digikey. Likewise it’s not exactly cheap. Although the SPI controller board is only $28, the set of controller and 9.7″ panel is $310. Similar replacement Kindle DX panels cost around $85 elsewhere on the internet.
It would be cheaper to buy an entire Kindle DX, scrap the computer and salvage the panel than to buy the PervasiveDisplays evaluation kit on Digikey. To be fair this is comparing a used consumer device to a niche evaluation kit, so of course the former device is going to be cheaper.
To their credit, they’re also trying to be active in the Open Hardware community. They’ve launched RePaper.org, which is a site advocating freeing ePaper technology from the hands of the few companies and into the hands of open hardware enthusiasts and low-run product manufacturers.
From their site:
We recognize ePaper is a new technology and we’re asking your help in making it better known. Up till now, all industry players have kept the core technologies closed. We want to change this. If the history of the Internet has proven anything, it is that open technologies lead to unbounded innovation and unprecedented value added to the entire economy.
There are some panels listed up on SparkFun and Adafruit, although those are limited to 1.44 inch to 2.0 inch displays, which are useless for my use case. Likewise, these are geared towards Arduino compatibility, while I need something that is performant through a (relatively) fast and high bandwidth interface like exists on my laptop mainboard.
Bunnie/Xobs of the Kosagi Novena open laptop project clued me in to the fact that the iMX6 SoC present in the aforementioned device contains an EPD (Electronic Paper Display) controller. Although the pins on the chip likely aren’t broken out to the board, it gives me hope. My hope is that in the future devices such as the Raspberry Pi, CubieBoard, or other single-board computers will break out the controller to a header on the main board.
I think that making this literal stockpile of panels available to open hardware enthusiasts, we can empower them to create anything from innovations in the eBook reader market to creating an entirely new class of device.