Different Display Technologies

[readit]

A question about the different Display Technologies on the market:

there are VGA, TFT, LCD, e-Ink and more out there; but when it comes to reading, it seems to make sense that a

• - non lit

• - 2 colours

screen brings the best experience on the long run, regarding daylight reading and battery life... Right or wrong in your opinion?

When I think back to the little electronic pocket games from the eighties (mario brothers etc), they where black/brownish and white, and very good visible in daylight..was this TFT?

The first Gameboy was like this as well, wasnt it?

So now we have experienced new magic devices for several hundred of $ with this old screen tec inside?

I would appreciate making a list together with you guys, which lists all display technologies which are capable of non-lit reading (probably there are some where you can switch of the backlight) maybe with some devices as example...

VGA is aways backlit,isnt it?

Confused...

[Dulin's Books]

VGA is an LCD specification not a display type.

TFT is a display component. Both LCD displays and Eink Displays have a TFT layer.

[delphin]

Many of the current readers use 800x600 resolution screens, which along with 1024x768, IS sometimes called SVGA resolution.

I think a little respect and curtasy is in order, because the original poster admitted being confused by all the options.

So here is some general information . . .

FIRST -

We can broadly devide displays into those that are LIGHT EMITTING and those that are non-light-emitting or PASSIVELY REFLECTING.

Examples of LIGHT EMITTING screen technologies include -

- BACKLIT LCD
- PLASMA
- OLED
- CRT

Examples of PASSIVELY REFLECTING screen technologies include -

- REFLECTIVE LCD (both passive and active matrix types)
- E-Ink


Many low cost readers and tablet devices are based on backlit LCD screens that are essentially the same as those used on Laptops, Netbooks, and PC's

Others like the Kindle, and Sony PRS-x50 devices are based on a "paper like" non-light-emitting reflective display called e-ink.

Some, like the Nook, come in BOTH flavors, with models that use Backlit TFT LCD screens AND other models that use passively reflecting 'paper like' E-Ink screens.

In fact at least one company has both a full sized LCD and a full sized E-Ink screen, SIDE BY SIDE ON THE SAME DEVICE.

A few like the Aluratek Libre claim that they are 'epaper' but are really just reflective LCD screens, not the costlier E-Ink technology.

As far as what works best goes . . .

This is all personal preference, and my own personal preferences change depending on what type of material I am reading or viewing.

Reflective screens are still only widely available in BLACK AND WHITE (16 level monochrome) and, despite recent advances, still have limited contrast. Well this is fine for printed text, it does NOT make for good viewing of photographs or complex multi-color illustrations.

So for daily news, magazines, travel guides, etc. I still prefer a nice backlit active matrix TFT LCD screen on a compact Android Tablet or Netbook PC.

For reading novels, short stories, or any mostly straight text based material, I greatly prefer the 'paper like' e-ink screens.

The LCD based reflective screens can routinely achieve contrast ratios that are even better than those available from electrophoretic e-ink devices, so they have some promise, but presently they are not as good as e-ink, because they are not yet well optimized for use in e-book reader devices.

In the LCD market, screens have mostly been optimized for only TWO situations.

1. Small, lower resolution screens for use in ultra long life low power devices like digital watches.

2. Larger, higher resolution TFT active matrix screens optimized for faster updates, used in higher power portable devices like laptops.

If the same ultra low power techniques used in the low power LCD screens used in clocks and digital watches were applied to larger E-Book high resolution screens, then by sacrificing a little on display update speed, you could have an LCD based E-Book reader screen that would compete on battery life with the e-ink screens.

But sadly, no one builds an LCD panel to these specs today, so the devices that do use reflective LCD's, like the Aluratek Libre, have to use a more power hungry TFT LCD technology that limits the battery life to about 24 hours.

So for now, the best two options are black and white reflective e-ink for text, and standard TFT backlit LCD screens for full color images and graphics.

[Dava]

It's too sad that no one are building the Low power LCD-screens anymore. The main reason I've not upgraded my Palm m500 for a modern E-bookreader is the lack of backlit-ability on the E-ink screens.

The B/W LCD on the Palm m500 are very good for e-book-reading, it's reflexive and sharp. The main problem is the low res. 160x160 and the small screen 3,8 inch.

I imagine that we will see the LCDs comeback soon.

[delphin]

Originally Posted by Dava

It's too sad that no one are building the Low power LCD-screens anymore. The main reason I've not upgraded my Palm m500 for a modern E-bookreader is the lack of backlit-ability on the E-ink screens.

The B/W LCD on the Palm m500 are very good for e-book-reading, it's reflexive and sharp. The main problem is the low res. 160x160 and the small screen 3,8 inch.

I imagine that we will see the LCDs comeback soon.

Before the mad rush to high quality backlit TFT screens, the reflective LCD did achieve quality that was at least on a par to the current e-ink screens.

Low power reflective LCD screens show a little more viewing angle sensitivity, so they are slightly less 'paper like', but on the other hand they have contrast ratios that are typically better than even the current 'Pearl' generation of e-ink (100:1 or better)

In the process of 'perfecting' full color backlit active matrix TFT LCD screens, it seems to have been forgotten that ultra low power high contrast reflective monochrome LCD screens would be a VERY good match for devices like E-Book Readers.

With low cost ultra low power LCD's we could see basic E-Book readers in the $49 range.

Such LCD screens would inexpensive to manufacture, but because they would compete with the costly e-ink, they would sell at premium prices compared to other similar LCD offerings.

So frankly, I am surprised that the LCD manufactures haven't caught on to this, with the recent popularity and high profit margins of e-ink devices.

Sooner or later, someone will wake up and figure out that reflective LCDs can easily compete on contrast and power IF you slow down the response time only slightly AND STILL BE AS FAST OR FASTER THAN E-INK.

This is contra intuitive though, since the manufactures of LCD devices have spent the last decade figuring how to reduce the response times (which are now in the low millisecond range).

They are obviously working on it. The LCD screen on the Aluratek Libre has great contrast, and is a lot faster and more responsive than e-ink, they just need to improve the battery life a bit, and I think we might start to see a lot more LCD devices.

[readit]

Wow guys, what a LOT of information, Thanks!

Found as well some display comparison sheets on wiki, and one interesting Term is the technical name for e-paper: "EPD" or "electrophoretic display" ...lovly, imagine the face of the shop staff having a customer asking for it

Comparison of display technology on Wiki (in General)

and , more important for the full-colour-fans, the

multi-touch Technology

Because yesterday I walked into a shop and compared the displays of 3 diffrent Androids, and the one with just a simple,older "Resistive touchscreen" was reeealy bad...it's the kind of devices which have that "milky" surface screen.

The thoughts you guys have about a renaissance of simple low power low price LCDs are worth watching, indeed!

I can imagine the chinese will hopon this probably and produce a lowlow priced one, which would fit into another thread here about "low cost eReaders for the 3rd world" (..hey, I would get one as well for 20 quid or bucks ..we always have to keep in mind that a mobile device can also quickly BREAK outside or while traveling,got stolen, etc )

[readit]

PS: and how funny and sad at the same time it is, that the "Aluratek Libre" mentioned by Dolphin above is really boldly writing "ePaper", despite not having it:

"(Feature) ePAPER Technology:
""Utilizing the latest in epaper display technology, the Libre provides a crisp black and white 5” screen with the same appearance and readibility of printed paper. With no backlight, reading on the Libre is like reading a book."

[delphin]

Originally Posted by readit

PS: and how funny and sad at the same time it is, that the "Aluratek Libre" mentioned by Dolphin above is really boldly writing "ePaper", despite not having it:

"(Feature) ePAPER Technology:
""Utilizing the latest in epaper display technology, the Libre provides a crisp black and white 5” screen with the same appearance and readibility of printed paper. With no backlight, reading on the Libre is like reading a book."

In fairness, ePaper is a poorly defined term, so most often now I see the electrophoretic screens like those in the Kindle and Sony reader devices called "e-ink" not "e-paper".

I don't think it's a problem calling ANY high contrast reflective viewing screen designed for paper like viewing - "ePaper" - as long as the specifications list the actual technology used, which Aluratek does do farther down in their specs for the Libre.

As far as the actual reading experience goes, if someone missed that little technical detail, then they are unlikely to feel victimized by the LCD screen on the AlurateK which has FASTER updates and BETTER CONTRAST than the much ballyhooed viziplex "Pearl".

As I said earlier, the only real downside to their current LCD ePaper design is that it has worse battery life, and a battery life spec is a battery life spec, no confusion there, and somehow I doubt anyone is buying the Libre vs the Kindle reader without checking on this data first.

In the future, I think we may well see these "ePaper" style reflective LCD screens with both high contrast AND several weeks of battery life, once the LCD panel manufactures realize that 100 millisecond or even 200 millisecond screen updates would be acceptable on an e-Book reader's screen as long as this slower update will also give you a few weeks of battery life (this is exactly the trade-off we accept on the current generation electrophoretic e-ink screens)

But I agree, these screens should be properly labeled so folks know what they are buying.

[Dulin's Books]

Originally Posted by delphin

In the future, I think we may well see these "ePaper" style reflective LCD screens with both high contrast AND several weeks of battery life, once the LCD panel manufactures realize that 100 millisecond or even 200 millisecond screen updates would be acceptable on an e-Book reader's screen as long as this slower update will also give you a few weeks of battery life (this is exactly the trade-off we accept on the current generation electrophoretic e-ink screens)

But I agree, these screens should be properly labeled so folks know what they are buying.

Electrowetting LCDs like those coming from LiquaVista(recently purchased by Samsung) will be the position that you describe, IMHO, having seen it in person and spoken with the head guy there.

as for the labeling- My opinion is that anything labeled as ePaper should be reflective and bi-stable or very close to bi-stable