Kindle Review – Kindle Fire Review, Kindle 4 Review

While Qualcomm’s Mirasol Color eReader displays stole the show at CES 2010 and Qualcomm have everyone’s rapt attention with the promise of a color eReader in the second half of 2010 it’s worth noting that they are not the only company building MEMS based color displays.

Competition increases the possibility that we soon get a color eReader – Perhaps it will be the Kindle 4. Perhaps we get color screens as early as the Kindle 3 or the Nook 2 or the next Sony Reader.

What are MEMS?

Micro Electronic Mechanical Systems are really tiny machines that are made of three main components -

1. Microsensors - They perceive/sense the surroundings, gather this information, and then send it to the Microprocessor.
2. Microprocessor – This is the central data processing unit and is usually an integrated circuit.
3. Actuators – They execute commands from the Microprocessor.  

These three core elements of MEMS are tiny with each being 1 to 100 microns in size and the complete micromachine being pretty tiny – almost too tiny to see.

MEMS are already used in various everyday technologies like printers and air bag systems. You can find more information on MEMS at -

1. Wikipedia article on Microelectromechanical systems.  
2. MEMS Industry Group’s video introduction to MEMS at YouTube.

Could MEMS based display technologies be used with eReaders?

Yes.

Let’s start with the Digital MicroMirror Device made by Texas Instruments. It is an optical semiconductor that is the core of DLP projection technology. It’s used in TVs, HDTVs, the DLP Projector, and in head mounted displays.

Wikipedia describes how MEMS are a core part of the DMD -

A DMD chip has on its surface several hundred thousand microscopic mirrors arranged in a rectangular array which correspond to the pixels in the image to be displayed.

The mirrors can be individually rotated ±10-12°, to an on or off state. In the on state, light from the projector bulb is reflected into the lens making the pixel appear bright on the screen.

In the off state, the light is directed elsewhere (usually onto a heatsink), making the pixel appear dark.

Note that this produces grayscales. Color is produced in a DLP by various methods -

In a projector with a single DLP chip, colors are produced either by placing a color wheel between a white lamp and the DLP chip or by using individual light sources to produce the primary colors, LEDs or LASERs for example.

A three-chip DLP projector uses a prism to split light from the lamp, and each primary color of light is then routed to its own DLP chip, then recombined and routed out through the lens.

We’re basically talking about -

1. Using a micromachine based device to create grayscales from a light source. 
2. Then using a color wheel (or a prism and multiple MEMS based devices) to create color.

That’s pretty similar to what we need done for ereaders. We just assume the light source to be sunlight or an indoor light bulb and we can move on to using MEMS to create the eink and epaper.  

Companies doing interesting MEMS work that might be applicable to eReaders

Let’s start with a short note on Qualcomm.

Interferometric modulator display (iMoD) from Qualcomm

Qualcomm have already shown their 5.7″ color eReader based on Interferometric modulator display technology. Wikipedia provides some details -

In one state an iMoD subpixel reflects light at a specific wavelength and gives a pure, bright color at one intensity while in a second state it absorbs incident light and appears black to the viewer. When not being addressed, an iMoD display consumes very little power.

The wing of butterflies employ the same phenomena.

Basically, a number of these iMoD subpixels are grouped together to create a single RGB pixel. Since these are tiny and there are hundreds of thousands of these on an iMoD display you can get a pretty good range of intensity and color.

Wikipedia also has some history -

The iMoD was invented by Mark W. Miles, a MEMS researcher and founder of Etalon, Inc., and (co-founder) of Iridgim Display Corporation. Qualcomm took over the development of this technology after its acquisition of Iridigm in 2004, and subsequently formed Qualcomm MEMS Technologies (QMT).

QMT are bringing Mirasol displays to eReaders and a Mirasol display based eReader is supposed to arrive in the second half of 2010. Check this brief Qualcomm color Mirasol display article at DigiTimes for more details.

Not sure which company is making the eReader – hopefully we see Mirasol in Kindle 3 or Kindle 4.

Pixtronix and its Digital Micro Shutter (DMS) Displays

The second post at this thread on TMOS/DMS MEMS based displays includes an interview with Pixtronix founder Nesbitt Hagood. Here’s the key part -

The Digital Micro Shutter display has a similar architecture to that of a LCD panel, but it uses micro shutters instead of liquid crystals. And unlike LCDs, DMS displays do not need polarizers or color filters.

Pixtronix founder, CTO and president Nesbitt Hagood stresses that DMS displays have better light transmission efficiency than LCDs, hence lower power consumption.

They’re promising very low power consumption, 10% lower manufacturing costs (compared to LCDs), and the use of existing LCD infrastructure. Their two main claims are very impressive -

For a typical 2.5-inch display module, we are one quarter of the power consumption for TFT LCD or OLED displays currently available in the market. 

All this without sacrificing quality – We’re now demonstrating 18-bit color, 105% NTSC ratio, 170 viewing angle, high color saturation and high contrast ratio.

The interview is a very good read – even if we have no way of knowing how valid the claims are. At this point Pixtronix aren’t targeting eReaders – However, it’s a technology worth keeping an eye on.

Time Multiplexed Optical Shutter (TMOS) Displays from UniPixel

UniPixel sound very promising as they’ve signed an agreement with Samsung Electronics. From the first and fourth pages of the MEMS display technologies thread mentioned above -

UniPixel’s TMOS display technology is claimed to offer numerous advantages including -

- simplified production (TMOS consists of 6 layers and could be fabricated in as little as 12 steps vs. 128 for LCDs).

- with minor modifications, existing LCD plants could start mass producing TMOS displays soon.

- optical efficiency (TMOS allows >60% of light to pass from the backlight to the display surface while LCD allows only 5%).

- energy consumption (TMOS displays would use a tiny fraction of energy that LCDs and PDPs consume due to optical efficiency of TMOS and efficiencies inherent to LED or laser light sources).

- 1 microsecond pixel response time.

It almost sounds too good to be true.

The ability to be produced on existing LCD lines is a significant advantage – as is the better optical efficiency. Check out the UniPixel TMOS Specifications File (PDF). The good stuff starts at slide 9.

Will Texas Instruments jump in?

Texas Instruments have been talking about wanting to make the chips for eReaders. Given their expertise and experience with the Digital MicroMirror Device (they invented it in 1987) it’s not inconceivable they decide to also target eReader screens.

They might have something lined up or they might see how Qualcomm do with Mirasol and then make a move.

By 2011 we might have a dozen Color eReader options

If you look at the promises the three MEMS companies are making and what eInk and Liquavista are promising we suddenly have a plethora of color eReader screen technologies -

1. eInk is promising color by end 2010/early 2011. They use electrophoretic displays.
2. Qualcomm is promising iMoD Mirasol color screens by second half 2010.
3. Liquavista is promising color by end 2010/ early 2011. They use electrowetting and a LCD like manufacturing process.
4. UniPixel are promising TMOS based screens with much lower power consumption than LCDs.
5. Pixtronix are promising DMS displays that use 1/4th the power that LCDs use. 
6. Bridgestone have their QR-LPD color display technology. 
7. You then have a bunch of companies – Fujitsu, Opalux, Nemoptic, SiPix, and Kent Displays – that are all promising color eReaders (Fujitsu have already delivered, just not outside of Japan).

Check out my State of ePaper post from 2009 for lots of videos and details on the screen technologies not covered in detail in this post.

It certainly seems that one of Kindle 3 or Kindle 4 will be a color ereader. It also seems that mid to end 2011 will see a color ereader avalanche.

Filed under: Color Kindle Reader Tagged: | color ereader, color kindle