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
Comments Locked


View All Comments

  • Samus - Thursday, December 17, 2015 - link

    Yeah, GREAT review. This is why I love Anandtech. Engadget and the like would never touch something like this.
  • ganeshts - Thursday, December 17, 2015 - link

    I think it is light enough. Any lighter, and I think it would get very flimsy. Hopefully, these types of large screen E-Ink devices come to market soon. Competition will definitely help drive down the price of the DPT-S1 further.
  • Murloc - Friday, December 18, 2015 - link

    yes I have a small one and it's totally fine to read pdf with small pages or slide stacks, but if the documents are A4 you'd have to zoom in and shift around which is simply not possible with the long refresh time unless you want to kill your eyes.

    My sony reader which is much older than this actually features the automatic cutting out of the white space, so I'm surprised it isn't included in this one.
  • Raniz - Thursday, December 17, 2015 - link

    Dimensions in inches and weight in grams? Pick one system (metric)!
  • Kepe - Thursday, December 17, 2015 - link

    Display sizes are reported in inches everywhere. I've never seen a TV, laptop, tablet, phone or a computer display size being reported or advertised in millimeters or centimeters, and I live in Europe.
    BUT this is only true for the diagonal size of a display. When reporting how tall/wide a screen is, for me it would still be more informative if metric numbers were used.
  • ddriver - Thursday, December 17, 2015 - link

    Oddly enough, the only 3 countries in the world still using imperial units are the US... Burma... and... Liberia. Still cherishing the good old days of colonialism I guess. Gotta use imperial, even long after the empire died and went for metric.
  • name99 - Thursday, December 17, 2015 - link

    Myanmar (Burma) does not exactly use imperial units. It uses traditional Burmese units (consequence of being detached from the rest of the world for two generations) but is on the way to SI (metric). The legal formalities have been performed, and I expect that over the next few years as infrastructure is added and replaced, all signage will be in metric.
  • Tams80 - Sunday, December 20, 2015 - link

    The UK uses a mix, and I'm sure there are plenty of other countries (particularly past colonies) that do. In the UK, some of these are very deeply embedded as well; such as miles.
  • Beany2013 - Saturday, December 26, 2015 - link

    In the UK, the generation born in the 60s and 70s are pretty entrenched in imperial, anyone born after that is generally pretty au-fait with both. 1 x 1.6 for km-miles, etc.

    I still get confused with gallons and litres, but as the only time I see it as at the petrol pumps, I'm more concerned with how light my wallet is getting, and how lighter I should really be pushing the right-hand pedal in the car.

    I do use kilos for everything, except my weight, because weighing myself is such a wholly disappointing experience that I've stopped doing it, and that's the only time I used to use stones.

    Actually, let me rephrase that - those of us born in the 80s are mathematical freaks.
  • phoenix_rizzen - Tuesday, December 22, 2015 - link

    To really screw things up, though, different countries measure screen size differently.

    Canada measures viewable sizes (from the inside of the bezel) while the US measures actual screen size (including any parts of the screen hidden underneath the bezel).

    This probably isn't that big of a deal any more with LCD panels, but it was a huge deal back in the CRT days. A 27" TV imported from the US could actually have less viewable area than a 24" TV in Canada.

    Aren't "standards" wonderful? :)

Log in

Don't have an account? Sign up now