The e-reader market has lost some of its initial appeal due to the rapid rise in popularity of tablets and other similar mobile devices. However, 'tablets' with E-Ink screens continue to offer the best reading experience in terms of reducing eye strain as well as providing long battery life. E-Ink screens have not scaled well in size, with the 6" screen size being the most popular and economical choice. Products with bigger screen sizes such as the Kindle DX (9.7") have not enjoyed market success.

E-Ink - A Brief Background

We will not go into the technical details of E-Ink here, but it suffices for readers to know that E-Ink avoids the use of backlighting. Instead, it relies on reflection from ambient light for visibility. In the latter aspect, it is very close to real printed paper. The major downside is that the refresh rate of E-Ink screens is very slow and only the monochrome technology is mature enough for mass consumption in the e-reader market.

E-Ink screens have been trying to evolve in two different ways. On one hand, we have attempts being made to get some sort of color display with E-Ink characteristics. On the other hand, E-Ink is trying to bring out flexible displays as well as produce larger sized screens. While screens of up to 32" in size are available for digital signage purposes, the maximum size currently supported for direct-to-consumer sales is 13.3".

The Need for a 13.3" E-Reader

Most of our workload nowadays involves sitting in front of a computer monitor and/or staring at tablet/smartphone screens. It is common for people to experience eye fatigue due to these activities. Having used multiple tablets and phablets for content consumption, I realized that none of them fit the bill when it came to reading technical documents or annotating them for future reference. In addition, all these technical documents are typeset in either A4-sized (8.27" x 11.69") or US Letter-sized (8.5" x 11") pages. This ruled out usage of any of the large number of e-readers based on the 6" E-Ink platform. A4 and US Letter correspond to diagonals of 14.3" and 13.9" respectively. 13.3" with an aspect ratio of 4:3 is ideal for displaying documents typeset in either A4 or US Letter-sized pages.

The Sony DPT-S1 - A 13.3" E-Ink Device

Sony's Digital Paper System (DPT-S1) was launched in April 2014. It takes things to a whole new level by making use of a 13.3" E-Ink Mobius screen. It was launched with a price tag of $1100, and was quite unpalatable for the ordinary consumer. It comes with a stylus / pen for taking notes as well as PDF annotation, and business users are its main target.

Initially, my impression was that lower priced variants with the same screen would soon appear in the market and target the average e-reader. Unfortunately, we are at the end of 2015, and the Sony DPT-S1 remains the only E-Ink Mobius-based product that consumers can purchase in the market. A little bit of silver lining lies in the fact that Sony has steadily been bringing the price down (from $1100 at launch to $800 right now).

The Sony DPT-S1 comes in a nondescript box. The package consists of a quick start guide, the e-reader in a leather sleeve, the pen / stylus, three replacement tips for it along with a tool to aid in pulling out the old tips, and a 7.5W (5V @ 1.5A) USB charger with a USB to micro-USB cable. The gallery below provides high-resolution pictures of the various components.

As can be seen from the gallery above, the main reader is like a sheet of white paper surrounded by a thick bezel. The bottom bezel is slightly thicker to accommodate the navigation and context menu buttons at the center with the power button at the right corner. The power button is on a slanted panel and is not flush with the rest of the frame - this prevents accidental pressing of the power button during use.

The important aspects of any e-reader are the dimensions and the weight. While the unit as a whole comes in at 9.125" x 12.125", the viewable area / screen is 8" x 10.625" (corresponding to a diagonal size of 13.3"). Note that this needs to be compared to an A4 sheet (8.27" x 11.69") and a US Letter sheet (8.5" x 11"). The viewable area is slightly smaller than both of them, but definitely much better than the 9.7" E-Ink screensfor documents typeset with those page dimensions.

The weight of the reader alone is 355g, while the stylus/pen adds an extra 9g. Placed in the supplied sleeve, the complete package weighs in at 496g. All said, the unit is quite ergonomic to use - both in hand, as well as on a table. The screen has a pixel resolution of 1600 x 1200 and can display 16 levels of grayscale. It is likely that most use-cases for the DPT-S1 involve text-heavy documents. The DPI and color limitations are not much of a concern.

In the rest of the review, we will take a look at the hardware platform in detail and follow it up with a look at the software aspects before providing some concluding remarks.

Hardware Platform
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  • Murloc - Friday, December 18, 2015 - link

    screen diagonals, case bay dimensions, jack plug length etc. are in inches everywhere in the world because of historical reasons and because they're standard sizes (not the screen diagonals but the other things), so the number in inches could be replaced by any other name just as well, so it doesn't really matter how long it really is for consumers who have to understand if the optical drive will fit in a case. You could call them A and B instead of 5.25'' and 3.5'' but there's no point really.
  • Levish - Thursday, December 17, 2015 - link

    I'd grab one around $350 to read ebooks / manuals.
    Not sure if doable if dropping the digitizer / pen input / touch input.
    Not like there are any available alternatives in Eink.
  • Amandtec - Thursday, December 17, 2015 - link

    As someone who suffers from eyestrain something like this is a godsend. But I want it to be able to handle email, run Word and Excel, and have built in sim slot and and cover based keyboard.
  • ganeshts - Thursday, December 17, 2015 - link

    I think you are looking for an E-Ink monitor / notebook - maybe something similar to this: : I am not sure why these 13.3" E-Ink devices are not coming to the market fast enough.
  • Coup27 - Saturday, December 19, 2015 - link

    I think everybody suffers from eye strain if stare at white on a computer screen long enough. Make sure you are using the colour invert feature of Windows magnifier when spending hours in Word, Excel etc. Makes you work white on black instead of black on white and that is a godsend. High contrast for Chrome does the same thing for webpages also.

    I am a designer and use AutoCAD most the day. They realise this and work with a black background. Why Microsoft and most websites insist on as much white as possible dumbfounds me.
  • phoenix_rizzen - Tuesday, December 22, 2015 - link

    If you wear glasses, consider getting your next pair tinted yellow. A 10% yellow tint has done wonders for eye strain and dryness at work (staring at a computer screen for 7 hours). I'm tempted to try a 20% yellow tint on my next pair.

    Also really helps with driving.
  • Beany2013 - Saturday, December 26, 2015 - link

    I've noticed less eyestrain now that I'm using Redshift to auto-tune the blue out of my screen after dark. I know that's not what it's there for (it's meant to help you sleep better by pulling the blue out of the image - which means you get all melatoniny and drowsy at night) but it seems to help quite a bit.

    Redshift is the linux variant, I have Twilight on the Android phone, and I'm sure a Windows/Mac OS X variant exists, too.
  • surft - Thursday, December 17, 2015 - link

    Wioshing E-ink in color (i.e. Prism) would be made available in consumer portable products. I'd like to read my huge library of Franco-belgian comic albums on the go more often.
  • nathanddrews - Thursday, December 17, 2015 - link

    Me too, unfortunately the color e-ink available to us is lacking on saturation. Comics/magazines are just so washed out that it's just not worth the asking price. We'll get there someday.
  • AndrewJacksonZA - Friday, December 18, 2015 - link

    @surft: "my huge library of Franco-belgian comic albums"
    Billions of blue blistering barnacles!

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