Nook GlowLight teardown reveals secrets behind integrated light and lower weight

Bill Detwiler cracks open the Nook Simple Touch with Glowlight and shows you how Barnes and Noble reduced the e-reader's weight and gave it an integrated light.

Not only did Barnes and Noble make the 2012 Nook lighter and give it an antiglare screen protector, they added a killer feature for nighttime reading--an integrated light. In this week's Cracking Open, I show you what's inside the new Nook Simple Touch and reveal the secret behind its GlowLight.

The Nook Simple Touch with GlowLight has an 800 MHz Texas Instruments OMAP3621 applications processor, 256MB of RAM, 2GB of storage, a 6-inch Pearl e-ink screen with Neonode zForce touchscreen, and 802.11 b/g/n WLAN support. It measures measures 6.5" (H) x 5" (W) x 0.5" (D) and weighs 6.9 ounces. It weighs half an ounce less than the standard Nook Simple Touch.

Full teardown gallery: Cracking Open the Nook Simple Touch with GlowLight

Cracking Open observations

  • Replaceable battery is same as standard Nook Simple Touch: The 1,530 mAh battery has the same model number (MLP305787) as the one on the standard Nook. This makes the batteries interchangeable, but it also means a single charge won't last as long when running the reader's light.
  • Same base hardware as Nook Simple Touch: As with the outer shell and battery, the circuit board is nearly identical to the one on the standard Nook. There's an 800 MHz TI OMAP processor, a 256MB mobile DRAM chip, a 2GB storage chip, a Jorjin Wi-Fi module, and Neonode's . Besides a few extra really small ICs and components, the only big difference, is a connector used for the GlowLight's LEDs.
  • Lighter, magnesium display mounting plate: Looking at the display assembly, one difference between the GlowLight and standard Nook jumps out immediately. The screens' mounting plates are made from different materials. The standard Nook's screen has what appears to be an aluminum plate. The GlowLight's plate however, is made from a die cast magnesium alloy (AZ91D). The new material may be necessary for the GlowLight system, but it also makes the plate about about half an ounce lighter.
  • GlowLight contains eight LEDs: According to CNET's David Carnoy, GlowLight uses a form of LED front-lighting, instead of the traditional backlights found on everything from tablets to TVs. Barnes and Noble developed GlowLight in house and has filed for a patent. As my teardown shows, the light from GlowLight comes from eight LEDs mounted just above the actual e-ink display.

Bottom Line

I really enjoyed dissecting the Nook Simple Touch with GlowLight. It was a cinch to take apart, has a beautifully simple internal design, and I discovered how Barnes and Noble made it weigh less and light up.

Read David Carnoy's CNET review of the Nook Simple Touch with GlowLight for more information on the e-reader's performance and his impressions of the integrated light.

Internal hardware

Our Nook Simple Touch with GlowLight test unit has the following hardware:

  • 3.7V, 1,530mAh Li-ion battery (model: MLP305787)
  • 6-inch Pearl e-ink screen with Neonode zForce touchscreen
  • 800MHz Texas Instruments OMAP3621 applications processor
  • Samsung K4X2G323PC-8GD8 256MB mobile DDR SDRAM
  • Samsung  KLM2G1HE3F-B001 2GB eMMC NAND flash storage module
  • Lattice Semiconductor ispMACH 4032ZE CPLD
  • Texas Instruments CD74HC4067 High Speed CMOS 16-Channel Analog Multiplexer/Demultiplexer
  • Texas Instruments TPS65921B Integrated Power Management IC with USB HS Transceiver
  • Texas Instruments TPS65181 Power Management IC for E Ink Vizplex Enabled Electronic Paper Display
  • Jorjin Technologies WG7310-2A 802.11b/g/n Wi-Fi SiP module
  • CKP TI A3T9
  • Texas Instruments BQ27520 System-Side Impedance Track Fuel Gauge
  • Texas Instruments 2624I
  • Texas Instruments MSP430F2272 16-bit Ultra-Low-Power Microcontroller
  • Texas Instruments YE04 18K G4 A919
  • Texas Instruments HP4067 1AK G4 D024


Bill Detwiler is Managing Editor of TechRepublic and Tech Pro Research and the host of Cracking Open, CNET and TechRepublic's popular online show. Prior to joining TechRepublic in 2000, Bill was an IT manager, database administrator, and desktop supp...

rocket ride
rocket ride

I wonder what would be patentable about the device. The idea of using a thin waveguide to front-illuminate a page is not new in and of itself. Look up a device called a "Light Wedge" that works on the same principle, and has been in production for years. The principle is that LEDs shine into the thick end of a narrow tapered piece of transparent material called a waveguide. Most of the photons that get very far into the waveguide therefore moving at shallow angles through it. Because of these shallow angles, a phenomenon called total internal reflection* (TIR) causes most of the light to bounce back and forth between its front and back surfaces with relatively small losses. The light that does escape either does so from the front surface and mostly at a shallow angles so that it doesn't put much glare into the reader's eyes or from the rear surface-- this is the light which illuminates the display. This light is reflected (or not, depending on the pixel value where it hits the display surface) from the display at much steeper angles and therefore passes more-or-less straight out through the waveguide (no TIR involved) to be seen by the reader. What I suspect might be patentable are tweaks that would be useful in building such a device between a display panel and a touch sensor system, or, more likely, fabricating the touch sensor directly on the front surface of the waveguide. The thin films involved in the touch sensor could possibly do interesting things to the optical characteristics of that front surface which may need to be accounted for. There also could be something like microtexturing on the back surface to locally enhance light loss through that surface. . . * Look it up on Wikipedia.


I've got a question. My wife and I read a lot, really, a lot (we don't watch TV) and have between us 2 Generic Android tablets with the kindle app, a working Kindle 3 and 4 Kindle 3's with broken screens (they're rather fragile it seems as my 14 pound cat put her paw on them when II left them on the bed). TThe Kindles re in good working order, except for the screens. I have searched for replacement screens everywhere and they are rather expensive, at about $70 wholesale in lots of 5 or more, so repair isn't a viable option. Does anyone have an idea as to what I can do with these units? A hack would be appreciated.

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