Color ereader screens, like E Ink’s Advanced Color e-Paper (ACeP), Tianma’s color LCD, and ClearInk, may revolutionize ereaders in 2020 and 2021. I took a first-hand look at these technologies and analyze their potential to reach consumer ereaders, like the Amazon Kindle, in 2020 and 2021.
In short: if you’re looking for a color ereader, late 2020 is the earliest one might arrive. But why the wait?
1. ClearInk’s Color Ereaders in 2020?
New ereader screen technologies don’t come out very often. Most new products are incremental refinements that release on a three-year cycle.
Revolutionary technological leaps are rare. So rare that when they do reach devices, it’s a big deal. Sri Peruvemba, Head of Marketing at ClearInk Displays, believes 2020 (at the earliest) might be the year.
ClearInk first announced its technology in 2016 but has since picked up partners such as Lenovo and display manufacturing giant Tianma. Unlike the majority of e-paper displays, ClearInk manages to do a few things that its competitors cannot: cost-efficient color video.
ClearInk Does Color and Video for Less Money
E Ink’s Triton was the last color e-paper technology to hit ereaders but it never stood a chance of reaching Amazon’s Kindle. The Triton panel cost a fortune and suffered from a weak contrast ratio, high cost, and slow refresh rates. In other words, it didn’t look good and couldn’t play video. That’s why it didn’t last long.
ClearInk, on the other hand displays color at around 4,096 colors, or High Color. Which means it’s less vibrant compared to LCD and OLED panels. Its video refresh rate of 33Hz (equivalent to broadcast television or YouTube) allows full-motion video. Here’s an example I shot at Display Week 2019:
The video and high clarity of ClearInk comes down to the type of ink it uses. Both ClearInk and E Ink create images using electrophoresis, however, there’s a big difference between the two. E Ink uses two pigments. The additional overhead of dealing with two pigments causes slower refresh speeds and choppy video.
ClearInk differs in that it uses a single, smaller-sized pigment to create black and whites. The ink used in ClearInk, co-developed with Merck, are sharper and clearer compared to E Ink panels. According to Peruvemba:
“E Ink uses a two particle system to generate black and white. To generate white, E Ink uses a white particle to reflect light. Whereas, CLEARink only uses one particle—black—to generate [a] black state. To generate white, CLEARink uses a TIR (Total Internal Reflection) film on the front surface.”
The end result: higher contrast, lower power consumption, higher resolution, and even color video, when combined with a color layer.
While ClearInk’s video variant consumes more energy than E Ink, its power consumption relative to LCD comes in around 80 to 90 percent less. In addition, it can display motion video with a refresh rate of around 33 Hz—a little choppy, but good enough.
Problems: Ghosting, Color Accuracy, and Waveforms
ClearInk isn’t a perfect technology. On the downside, it suffers from issues with image retention, or ghosting, where portions of the display do not refresh. You can see a small amount of ghosting here:
ClearInk’s engineering team explained that the retention was an early prototype issue rather than an issue with the technology.
Additionally, ClearInk panels have the same color accuracy as the Triton 2, which, while enough for textbooks and comics, isn’t enough for enterprise-class purposes.
And finally, like E Ink, ClearInk panels require special software and hardware in order to create and draw images on its screen. In other words, the hardware-level infrastructure and software techniques used in LCD technology are not fully compatible with ClearInk panels. ClearInk screens cannot just be dropped into a computer without writing special software.
However, Peruvemba mentioned that they are working on panels that are drop-in solutions for LCD screens. Meaning, if they pull it off, manufacturers could simply swap out an LCD for a ClearInk panel without any added costs.
2. E Ink’s Color E-Paper ACeP in 2021?
E Ink Holdings Inc. announced its Advanced Color ePaper Display (ACeP) for 2021 in 2016. While ACeP offers the best range of color out of all the color ereader screens on the market, it comes with a few shortcomings that have slowed its entry into the ereader market. First, its refresh rate is extremely slow.
But its color saturation is phenomenal for a reflective panel.
Unlike E Ink and other technologies that use one or two colored oils, black or white, ACeP uses four different colors. The added complexity is what causes the slower refresh speeds.
Second, it’s likely to be extremely expensive. The digital signage products which use ACeP panels are enormously expensive. If that’s an indication of what a consumer ereader would cost, then it may remain unaffordable well past 2021. However, if any color reflective screen ever makes its way into a Kindle, it’ll likely be ACeP.
3. Color Filter Arrays for Ereaders?
Another kind of e-paper technology is the color-filter array (CFA). A CFA places a thin layer of colored liquid crystal filters over another panel, usually an electrophoretic panel, like E Ink. The multiple layers together create a full color display, although with diminished resolution compared to a standard E Ink panel.
Today’s best CFA panels have a color depth of somewhere around 4,000 colors, or High Color, and their resolution would be significantly less than Carta (as the CFA film overlaid on the Carta film will reduce its resolution).
However, CFAs are cheap to manufacture and easy to add to black-and-white reflective screens. On top of that, E Ink’s implementation of a CFA uses plastic instead of glass, making it lighter and more durable, which is perfect for an educational tablet.
If any color e-paper makes its way into a Kindle, it’s likely to be CFA-based.
4. Tianma’s Reflective Color LCD
Tianma Micro-Electronics is one of the world’s largest display manufacturers. One of their newer products is a reflective color LCD, known by its project name as Electrical Bag (almost certainly a mistranslation). Like most e-paper technologies, it doesn’t require a backlight, but is compatible with the front-lights used in most ereaders.
The panel is aimed at the educational market. The panel comes in a 10.5-inch form factor, a common size in the educational market.
Unlike E Ink, reflective LCDs can display full color and video. But the trade off is a limited color range and weak contrast ratio.
For example, Electrical Bag has a 12:1 contrast ratio and a PPI of 191. It also can only do 11% of the NTSC color range, which is about half of its competitors. However, the price is low, and they can be dropped into almost any device with little effort.
An engineer quoted a price similar to emissive LCD for a 10.5-inch panel. For the educational market, which caters to children, it’s an ideal product for reducing eyestrain.
Tianma claimed that, if any manufacturer were interested, the Electrical Bag would be available in 2020.
5. Hisense Color Ereader Phone
Hisense is a manufacturer of televisions and display panels. In Asia, it also makes smartphones and other consumer electronics. Hisense manufactured a black-and-white E Ink phone known as the Hisense A5, which cost $220 from AliExpress. This time they’re coming out with the very first smartphone with a color E Ink panel.
There’s no official word on the specific type of panel but it appears to use a CFA layer along with E Ink’s Carta technology. The dead giveaway that it uses E Ink is the slow refresh rate and ghosting, or afterimage, left behind by unrefreshed E Ink capsules. As with most E Ink products, the phone is expected to offer excellent battery life of around four days.
On the downside, like most E Ink based panels, the phone cannot display video and suffers from limited color depth, ghosting, and relatively low screen resolution.
Kindle Color in 2020 or 2021?
The big weakness of the Amazon Kindle is that it lacks color; it’s unlikely that Amazon will release a color version in 2020. Which means if you want a color ereader, the only options will use CFA panels.
In the first quarter of 2020, only two color ereaders have been announced: an unnamed Android-based device from iFlytek. Unfortunately, iFlytek is currently under sanctions from the US government for human rights’ abuses.
The iReader C6 may reach the United States through JD.com, according to a report from The Good Ereader. It will come with an undetermined version of Android, 1GB of RAM and 16GB of storage. Availability begins March 26.
While Amazon hasn’t shown interest in color e-paper since 2018, e-paper color screens may give their competitors at Kobo and Barnes & Noble a competitive edge in the education market. Both companies have shown interest in color E Ink, potentially to compete against Amazon’s educational ereaders, aimed at children