Sony Digital Paper System DPT-S1 Review

Hardware Platform

In the previous section, we had a brief description of the external hardware aspects of the Sony DPT-S1. A few aspects not noted over there include the presence of a microSD slot on the back as well as a micro-USB charging / data transfer port just beneath the navigation / context menu buttons at the bottom. The microSD slot can accommodate microSDHC cards up to 32GB in size. The back panel also includes a reset hole that can be activated with a pin while booting up to restore the device to factory conditions.

Thanks to a forum member over at mobileread, we have some insight into the internals of the system. The pictures linked in the forum are reproduced in the gallery below.

The board shots reveal the following components:

1. Freescale i.MX508 application processor (single core Cortex-A8 at up to 1GHz)
2. Samsung LPDDR2 K4P8G304EQ x32 8Gb (1GB) DRAM
3. SanDisk 4GB eMMC 4.51 19nm flash (SDIN7DP2-4G)
4. Wacom digitizer
5. Neonode zForce NN1001 optical touch controller

In addition, the FCC ID printed in the back (VPYLBWN572) indicates the presence of a Murata WLAN module which internally uses a Atheros AR6003G 1x1 802.11b/g/n 2.4GHz radio-on-chip WLAN controller.

The stylus / pen supplied as part of the DPT-S1 is passive. It doesn't need any batteries. No recharging is necessary. The Wacom digitizer is also passive in nature. According to a forum post on mobileread, it is possible to use non-Sony digitizer pens with the DPT-S1. This indicates that Wacom's EMR (Electro-Magnetic Resonance) technology is in use. The power requirements for EMR are satisfied by the display side. The digitizer generates a magnetic field that allows energy inducement in the pen's resonator. This can, in turn, be detected by the digitzer to determine the coordinates of the pen's position and its orientation.

The DPT-S1 has a touchscreen with multi-touch support. The teardown reveals an optical touch controller. The DPT-S1 integrates a set of light emitters and detectors along the edges of the screen and an optical light guide to the neonode touch controller IC. The IC controls the light sent out and also monitors the detectors. Changes in lighting conditions can indicate the presence of a touch object. The coordinates can also be calculated by the IC once calibration is in-place.

The device contains a rechargeable Li-ion battery rated at 3.7 V DC, 1270mAh. With the supplied 5V @ 1.5A USB charger, Sony indicates that full charging can take up to 2.5 hours.

Coming back to the general characteristics of the hardware, we find that the rear side of the device is a fingerprint magnet despite not being glossy. The front screen itself, thankfully, is not that bad. The navigation and context menu buttons make an audible click when pressed. While this is good feedback, there appears to be a lack of consistency across the three buttons in terms of the force required for activation. The placement of the power button in a slanted panel works perfect, but some users might prefer the power button elsewhere. The placement of the micro-USB port is unfortunate in the sense that the device has to be taken out of the sleeve for charging purposes. All these are minor aspects in the overall scheme of things.

The physical characteristics of the E-Ink Mobius screen (8" x 10.625" with a 13.3" diagonal, 1600 x 1200 resolution and 16 levels of grayscale support) have already been discussed. Readers might be wondering if a 13.3" tablet would be a good alternative if the backlighting / eye strain issue is not a big problem.

The above photograph shows the same graphics-heavy PDF page displayed on a Sony DPT-S1 and a Dell Inspiron 13 7000 series in tablet mode (13.3" 1920x1080 touchscreen). Despite the absence of color capabilities, it is obvious that the aspect ratio of the DPT-S1 leads to a better experience with the perusal of the content.