What do you get when you integrate Pixel Qi's stunning display technology into a standard netbook? A netbook that you can truly use under any lighting conditions. by Conrad H. Blickenstorfer
Just to make it clear right upfront: the SunBook we're reviewing here is not rugged. And if it looks suspiciously like a standard netbook, that's because it is. You're looking at a Samsung N145 Plus, a second gen entry-level netbook Samsung introduced late 2010. So what makes this a SunBook, and what does SunBook mean? It's a SunBook because Clover Systems of Laguna Niguel, California, retrofits this modest platform with one of the most remarkable LCD display innovations of recent history.
That would be the Pixel Qi (pronounced "chi") screen, a novel display design that absolutely guarantees perfect display viewability both indoors and outdoors, outdoor viewability that far transcends anything that's available on the market today. If, that is, you're willing to accept a compromise. And the compromise is that in bright, direct sunlight you're essentially looking at a black and white eReader screen similar to a Kindle screen (but really much better). How can that be? How does it work? And who should consider this?
This is also one of the instances where a picture tells more than a thousand words. So below is a sequence of video snaps that shows a SunBook being carried from shade into bright sunlight. See how the color goes from bright and vibrant, to muted, and then it's almost all black and white? And how the contrast and viewability never goes away?
So what you get here is a netbook with a display that you can always see and use, regardless of the lighting conditions. There's no need to hunt for shade, there's no need to try a different angle, there's no need for squinting. It simply always works. IF you can live with the fact that the color goes away. Which may be an issue, or it may not. It's not an issue for the millions of Kindle users, but the SunBook is a computer and not an eBook.
What are the LCD sunlight viewability challenges?
Let's first look at the problem at hand. Why do conventional LCD displays have such problems outdoors, and what solutions have been tried to fix that?
Any reader of RuggedPCReviews, and anyone using mobile computing equipment on the job, is familiar with the problem: screens become hard to read outdoors and in sunlight. And readers also know that the rugged industry has been searching for years to come up with display technologies that provide at least a degree of daylight/sunlight viewability. Why is this such a problem?
Overall, at this point, most standard LCDs are transmissive, which means that you have a backlight behind the LCD. This approach works great indoors because the ratio between the strength of the backlight and the reflected ambient light is very large. Outdoors, the ambient light is much stronger, and so the ratio between the strength of the backlight and the amount of reflected light is much smaller, which means there is much less contrast and the screen becomes unreadable.
In the past, notebook manufacturers tried different approaches to make the screens readable outdoors. One approach was to make screens reflective instead of transmissive. This way, the brighter the sunlight, the more readable the display became. This never caught on for two reasons. First, since you couldn't use a backlight, you needed a sidelight to make the screen viewable indoors. That just doesn't work with displays larger than those in a PDA (early Compaq iPAQ Pocket PCs used this approach). Second, even outdoors, the screens looked flat because the LCD background was greenish-brown, and not white.
Another approach was "transflective" screens. Transflective screens were part transmissive and part reflective by using sort of a half-silvered mirror behind the LCD layer. This was supposed to be the best of both worlds, but in reality while some light was reflected it cut the transmitted light, making the displays very dim in indoor lighting conditions. It was really just a compromise that didn't work very well. So that was abandoned.
Today, most outdoor displays use modified transmissive technology where optical coatings and polarizers reduce reflected ambient light to retain enough contrast to keep the display viewable. That can work remarkably well, but it still requires a strong backlight, which is bad for battery life, and even the strongest backlight is eventually no match for the sun.
How does the Pixel Qi screen work?
So how is Pixel Qi's technology different, how does it work, and if it's so good, why doesn't everyone use it? Good question. Here's some background:
Pixel Qi founder Mary Lou Jepsen has a Ph.D. in optics, worked at MIT, then Intel, co-founded MicroDisplay Corporation, and then co-founded the OLPC (One Laptop per Child) initiative. There the creation of an inexpensive display that worked under varying lighting conditions and used almost no power was a big priority. Jepsen then founded Pixel Qi in 2008 to bring the OLPC display and power management technologies to the commercial markets. Almost the entire team is PhDs in optical technologies, a veritable all-star cast. Their primary goal is to make LCD screens lower cost, higher resolution, easier to read and sunlight readable.
So what have they come up with? A better, different transflective display. The entire process is described in Pixel Qi's pending patent (US 2010/0020054 A1). The core of it is a display where pixels consist of a transmissive and a reflective part that have separate drivers. In essence, that allows them to have a "triple mode" display that can use one or both technologies, depending on the lighting situation. What are the three modes?
There's a transmissive mode with (in this Pixel Qi screen) standard netbook 1024 x 600 pixel resolution and 256k colors.
There's a transflective mode that still uses 1024 x 600 resolution but combines that with 64 grayscales. The backlight is still on, but the reflective subpixels now reflect ambient light, so the colors are desaturated.
Then there's a reflective mode where the resolution can triple to 3072 x 600 pixel, i.e it's three times as high horizontally. Why the tripling in reflective mode? Probably because the R, G, and B parts that make up one pixel in color mode are then used in black and white mode, and thus become separate pixels that can be separately controlled. Each pixel has 6-bit adjustment, which means 64 gray scales. When used as color pixels, 64 x 64 x 64 equals 262,144 shades of color, or 256k.
In terms of brightness, in transmissive mode the backlight can generate about 235 nits. That is barely more than the 180-200 nits your average notebook has. However, in reflective mode in sunlight, perceived brightness can be over a thousand nits.
Listening to Jepsen explain matters in a YouTube video (see here), she coyly states that theirs is simply a standard LCD with clever design, nothing special you know, just changing the layers with the six or seven masks on the bottom substrate and five or six masks on the top substrate, and the polarizers and retarders and the backlight films. They have about 20 patents on all this, but LCD manufacturing is a huge and hugely capital-intensive industry, and as much as getting one of the LCD manufacturers interested is almost impossible. Jepsen did manage to do that for the OLPC project and got a foot in the door, and it appears to be with CPT (Chunghwa Picture Tubes), the #2 mid-size LCD manufacturer worldwide. Picture Qi's design mantra is that their screens should require no process changes, no materials changes, and their displays should actually fit right into standard motherboards (which can be an issue as on most laptop motherboards you cannot totally turn off the backlight).
Jepsen claims that in reflective mode, their screen is a neutral white without the green tinge that's been plaguing earlier mirror-based designs, that it is nearly as reflective as an E Ink screen used in the Kindle and similar eBook readers, but that it has the transmission efficiency and color saturation of a regular LCD. And another vital advantage of Pixel Qi over E Ink technology is the much higher screen refresh rate that makes the Pixel Qi display suitable for full motion video whereas E Ink is not.
Where does Clover Systems fit in?
At first sight, Clover Systems seems an unlikely source for the SunBook. They've been around for 40 years, but their mission really lies in DVD and CD replicators and duplicators, and optical disc testing systems. So how did SunBook come about? Apparently, the Clover Systems principals, like millions who use notebooks, bemoaned the fact that standard consumer notebooks simply aren't usable in sunlight. They are portable and you can take them places, but you often really can't use them.
In 2010, they heard about Pixel Qi and felt the technology was exactly what they were looking for. They bought a Pixel Qi display kit and retrofitted it to a Samsung netbook. It worked great and they decided to try to sell them and see if there was a market for such a modified sunlight-viewable netbook. There was. Remember, one of Pixel Qi's goals was to make their screens drop-in replacements of standard displays. It's not always trivial, of course, and there is actually an entire forum dedicated to it at MAKE magazine, which specializes on do-it-yourself tech (see Pixel Qi forum).
As anyone who works with any technology knows, the difficult part is figuring out how it all works. Once you've done that, doing it again and improving it is much easier. Clover Systems has done it and they know how Pixel Qi screens work, and how to integrate them into netbooks and other technology. But why the Samsung N145 Plus with the 10.1-inch screen?
Now what about the Samsung N145 Plus?
My guess is that the Samsung N145 Plus was simply something Clover had at hand, or felt was a good match. The 10.1-inch screen size was a given as that is what Pixel Qi produces for now. Why? They had to go for something that had a chance to be produced in volume, and two years ago, a 10.1-inch netbook replacement display was a sound decision. At that point, netbooks sold by the tens of millions, and no one knew about the iPad yet.
And while Samsung conceived the N145 Plus as an entry-level netbook, it's actually a rather nice one. The 1.66GHz single-core Intel Atom N455 can handle DDR3 memory and is a decent performer. The device feels well-made and, unlike most netbooks, there isn't a lot of glitz and gloss. Except for a narrow glossy bezel around the display, everything is matte, as it should be. It comes with a rather powerful 48 watt-hour battery (and a 67 watt-hour battery is available as well). There's decent connectivity, a nice 5400rpm 250GB SATA hard disk, decent stereo speakers, and a pleasant keyboard.
The entry-level aspects show in the lack of Bluetooth and the first-gen netbook 1024 x 600 pixel resolution (though this is what Pixel Qi has for now anyway). The ever-important QWERTY part of the very nice keyboard is 93%-scale when there was room for a full 100%-scale layout. And while the N455 chip does a much better job at video than first gen N270-based netbooks, you still don't quite get full-speed 1080p video playback.
In terms of size and weight, the SunBook has a footprint of 10.4 x 7.4 inches and is about an inch thick (about 1.3 inches where the battery snaps in). Our tester weighed just 2.65 pounds. Below you can see what the device looks like from the top and all four sides:
Our testing procedure usually includes taking the device apart to see how well it is designed and made, but since this is not a rugged product where shock-mounting and sealing matter, we decided not to do it. Suffice it to say that the Samsung feels well-made, and at the time of this writing it received mostly 4 and 5 star ratings (5 being highest) at Amazon.
We did, however, run our standard benchmark suites, Passmark and CrystalMark, to show where performance fits in compared to similar size devices with other versions of the Atom processor and also compared to a much higher-end Core i5 device, the Fujitsu T580.
Clover Systems SunBook Benchmarks and Comparisons (PassMark 6.1, 32-bit version, 2 processes)
Processor Type: Intel
Intel Core i5
Thermal Design Power (TDP)
BatteryMon min draw
2D Graphics Mark
3D Graphics Mark
Benchmarks are notoriously unreliable and inconsistent, especially between processor platforms and operating systems. However, in our experience, the bottomline number is a pretty good representation of overall performance and usually matches well with subjective observation. That's the case here as well. The SunBook delivers standard Intel Atom-class netbook performance. However, neither benchmark shows the SunBook's much better video performance compared to the older Acer, and the vertical market Algiz machine from Handheld actually feels quickest of the Atom devices, but that's not reflected in the benchmarks that apparently had a problem recording the true speed of its very quick SSD.
What is indisputable is that no netbook comes close to Intel Core performance, but that's like dissing an econo-car for not matching a Corvette.
What's the impact of the Pixel Qi display on power draw?
When Jepsen and company worked on the OLPC computer project, reducing the power draw of the screen and screen illumination was a major thing. Initially they only got about 100 nits per watt, but then found ways to boost that to almost 200 nits per watt. That expertise came in handy when they designed the Pixel Qi screen. That's important because with low power systems such as netbooks, the screen backlight can easily become the major power drain.
To determine power draw, we installed PassMark's BatteryMon. With Windows Power Options set to Power Saver and the backlight set to minimum but WiFi on, we saw overall system power draws between 5.5 and 6 watts, good for well over eight hours of operation. Turning WiFi off brought that down to about 5 watts, good for over ten hours. With the backlight off completely and WiFi off as well, we saw as little as 4.5 watts and almost 11 hours. With backlight brightness all the way to the max, draw rose to a still very modest 7.6 watts, good for about 6.5 hours.
Going outside into direct sunshine with the backlight off completely yielded 5.4 watts and 9 hours of runtime. However, the backlight doesn't turn off automatically when you don't need it in the sun. If it's left on, draw will stay up at 7.5 watts or so, still almost nothing, but it can make a difference.
A minimum power draw of 4.5 watt is the lowest we ever witnessed on any device that came through the RuggedPCReview.com lab. Experienced manufacturers have long since learned how to use Intel Atom and Windows power conservation measures for very good battery life. Add the super-miserly Pixel Qi to the mix, and it gets better yet. And consider that the optional 67 watt-hour battery would extend battery life yet again. Even that, however, is only impressive in the Wintel world. The iPad, despite a bright display, gets ten hours from a comparatively much smaller 25 watt-hour battery.
What to expect from the display
After all is said and done, it all boils down to the special display properties of the Pixel Qi screen. Remember, this is all about making sure you can use your computer anywhere.
So how well does it work? Is even this new kind of transflective display a compromise, or is Pixel Qi on to something big? To figure that our we did comparison shots between a standard plain vanilla netbook (the Acer Aspire One we use around the lab) and the SunBook in a variety of very different lighting situations (also view the video).
Starting at the upper left, a) indoors the conventional transmissive display of the Acer remains more vibrant. That may be due to the Acer's high-gloss screen that makes the colors "pop," it may be due to whatever base LCD Pixel Qi had to work with, or it may be due to inherent issues with the Pixel Qi technology; b) is in bright daylight but in full shade. Here you can see the Pixel Qi display's middle mode where the colors become muted as you see a combination of reflective and transmissive image. The Acer can still power through the ambient light, but the reflections on the high-gloss screen surface make the display mirror-like.
In the second row left, the machines are in bright sunlight and partial shade. The standard netbook backlight is no longer strong enough to generate a viewable image, and then there's the gloss. The SunBook's display is muted, but offers full contrast and viewability. The final picture on the bottom right has the two machines directly facing the sun. The conventional display is totally washed out. The Pixel Qi display now works in full reflective mode with just a hint of color, and it offers superb contrast on a nearly white screen background.
But now let's take it a step farther and compare the SunBook with its Pixel Qi display to the absolute best current transmissive outdoor-viewable technology has to offer. Representing that technology is a big, top-of-the-line Getac X500 rugged notebook that we're currently testing at the lab. This seems like putting Muhammad Ali in a boxing ring with Mary Lou Retton in their respective primes, and indoors it does seem like a mismatch as the massively powerful 1,000 nits backlight of the Getac QuadraClear display yields a superb picture that the low-power Pixel Qi display cannot match. 1,000 nits and excellent reflection control also make the big Getac machine shine outdoors in the shade.
In full sunlight and partial shade the strong Getac backlight still offers a very good picture. But facing the sun directly reveals the physical limits of the transmissive display where even the latest in optical treatments and a backlight five times as strong as that of a standard notebook are no match for the sun.
Where is this all headed?
The above pictures really tell the story. If the object is to have a device that works indoors and also works outdoors even in the brightest sunshine, then the Pixel Qi even in its current state of development is an option. You can take the SunBook to the beach and work on it. The technology absolutely works, and Clover Systems' integration of the display into a standard netbook works. It doesn't look or feel like a retrofit, just like a netbook you can also use in the sun.
Two problems, though. One is the technology's switch from color indoors to black and white outdoors. Millions of Kindles are black and white, but not everyone will be ready to give up color in a computer. And color and color coding is an inherent part of most software. So that is an issue.
The other issue is price. Pixel Qi probably chose a netbook size display because they saw the largest possible market for that size. Problem is, none of the big manufacturers have so far picked up the Pixel Qi display, and without that sort of volume, it remains not exactly expensive, but expensive enough to remove it from the consideration of anyone who expects a netbook to cost no more than a couple hundred bucks or so. The SunBook, though, runs US$795, a very high price for a consumer netbook, albeit a total bargain for vertical markets that simply need sunlight viewability.
So that's the SunBook story. The product works, and it could well be exactly what a large number of field service operations and other outdoor service providers are looking for. For Pixel Qi, the situation is a bit tougher. They demonstrated that their display works, but in order to perfect the technology they need for someone to pick it up in mass production. There's no reason why it would not work with projected capacitive touch, so perhaps we'll see it in some tablets soon, but color might be the biggest challenge.
In our opinion, the Pixel Qi display would also lend itself for retrofitting into other existing and future rugged mobile computing hardware, including tablets. Anyone interested should check with Clover System for feasibility and opportunities. --