Roll top-laptop

1. 1

CHAPTER 1
INTRODUCTION TO ROLLTOP LAPTOP
Laptops are continuously changing. From the compelling components, various
applications and thinner designs; to the memory storage, Wi-Fi capabilities and
television viewing; they’ve come a long way from the first bulky home computers,
and evolved into a fashionable trend.
Advancements in technology have led to more precise touch screens, longer range of
wireless connections, and more compact devices capable of streaming video and
audio while providing driving directions to any location within the network,
simultaneously.
German designer, Evgeny Orkin thinks he has found the answer with his Roll top
concept. “The main goal was to combine the laptop monitor and graphic tablet into
one gadget and avoid additional accessories,” he explains. He continued to say that
consumers have the option to buy a computer and a graphic tablet with a touchscreen
separately, but they are not able to use them as one laptop.
Notebooks and tablets already offer pretty convenient computing on-the-go
solutions, but Germany's Orkin Design proposes rolling up both devices into one
ultra-portable package. The Rolltop concept will take advantage of advances in
flexible OLED and touchscreen technologies to create a cylinder-shaped laptop
computer that can be rolled out to form a notebook, a tablet, or display monitor. The
concept has been floating around for a while, but has recently received a few tweaks
to the design. Although specifics are in short supply, read on for what we do know
Rather than carry around a notebook in a laptop bag, full to the brim with all manner
of cables, the Rolltop concept proposes bringing everything together in a flat panel
display that's wrapped around a central cylinder. The top of the column detaches and
acts as a power plug while the carry strap doubles as a power cord (presumably some
sort of battery technology is also included, although this has not been mentioned). The
central column also contains speakers, a camera, USB ports, and a LAN port.

2. 2

After unlocking the catch, the user would roll out the Rolltop display like a
mat and then either leave it flat for 17-inch tablet computing, or raise one end up for
something resembling a notebook. The lower part of the screen is then used for
keying on a virtual, onscreen keyboard while the upper part becomes a 13-inch
display for viewing content. A pull-out support at the back also allows the flattened
device to be used as a monitor-like display, and a stylus pen has been incorporated
into the body of the panel.
When rolled up, Rolltop will be 11 inches (28 cm) long and have a 3.26-inch (8.3-cm)
diameter – and that's about all we can tell you. As it's a concept designed to be built in
the future, some of the technology kinks are still being worked on, but Orkin has
stated its intention to see this design through to an actual, real-world product. There
are, of course, quite a number of technical hurdles to overcome before that happens
and unfortunately the designers do little to shed light on how such difficulties will be
dealt with, leaving us to speculate.
It requires no great stretch of the imagination to visualize the various technologies
already used in dual-screen notebooks, all-in-one computers and cutting edge tablets
being incorporated into the Rolltop. Recent developments in bendy screen technology
might also make this device a current possibility. However, details on how the
internal components like processors, memory, storage and graphics cards will be dealt
with have not been forthcoming, so it looks like we're just going to have to wait until
there is more substance to this project.

Fig.1.1 Rolltop Laptop Concept

3. 3

CHAPTER 2
INCONVENIENCE IN CARRYING LAPTOPS:
ORKIN says:
“The main problem is that the laptop has two levels – the level you can write on and
the level you look at. With two separate planes, the entire screen cannot be utilized
because the fold will hinder you,” Orkin says.
Another problem with modern day laptops is the many accessories and gadgets that
accompany them. Even with the smaller designs, big bags are required to carry
everything around, which can cause inconvenience and discomfort.
ORKIN’S idea:
Orkin thought of the roll-up laptop when working on his thesis for school. He was
interning at Schlagheck-Design in Germany under the direction of Julian Schlagheck,
who specializes in product design, print design and product development. He also
received guidance from Professor Peter Naumann of the University of Applied
Science in Munich, and Georg Trost, Former designer of Fujitsu-Siemens Computers.

Fig.2.1 Orkins Idea

The concept of the Rolltop may seem a bit futuristic to some, but as Orkin explains, the
technology is available and being produced, so a concept like this is neither
impossible or improbable.

4. 4

2.1 COMPONENTS:
Most of the components for the Rolltop already exist within the modern day designs
such as the main board, processor, memory (flash), working memory, etc.
“The Rolltop does not have a CD/DVD reader or Floppy disc because [they’re
obsolete]. Other components, such as the loudspeaker, Internet, web cam, USB ports
and power supply are based in the cylinder in which the screen would roll around,”
says Orkin.
Such a design would be perfect for students walking around campus grounds, business
professional that travel regularly and home consumers who just like to keep
themselves entertained when waiting to meet friends or relaxing in a coffee shop or at
home.
2.2 Bringing Rolltop To Market :
The Rolltop’s success hinges on the utilization of OLED Technology, or organic light
emitting diode. This technology would be the main component of the laptop’s
monitor. It is tough, flexible and energy saving. “All these qualitites are very
important to me,” explains Orkin. “Flexible to roll it, tough to draw on it, and energy
saving to have a smaller battery than what is already being implemented.”
For Orkin to develop and produce his Rolltop design, he needs the capacity of a big
company such as Panasonic, Samsung and Dell. He has had a lot of inquires and
believes it can be a huge success once it starts rolling.
2.3 BENEFITS OF ORKIN’S DESIGN ROLLTOP:
1.One, the Rolltop combines the laptop, monitor and graphic tables without any
problem (such as small display in monitor modus or fold on screen in graphic tablet
modus).
2. Secondly, the Rolltop is an all-in-one gadget that integrates the power supply, loud
speaker, laptop bag and mouse into one. You don’t have to carry extra accessories.
3. Lastly, due to the new available technology, the design is very compact and
possesses a completely new outlook.

5. 5


Fig.2.2 Benefits of Rolltop

With the one design model, Orkin hopes to catch the attention of major producers and
distributors. He is very confident that his concept would be very attractive to
consumers and sell big once it hits the market shelves.

CHAPTER 3
All-In-One Rolltop Laptop by Orkin:
This newly designed laptop uses flexible Oled display on the panel and keyboard.
 Uses flexible Oled display on the panel and keyboard
 It replaces the conventional physical keyboard so the 13" laptop transforms
into the graphics tablet with its 17" flatscreen
 Its a new concept in notebook design with a flexible display
 The Oled-Display technology has a multi touch screen
 All computer utilities from power supply thgough the holding belt to an
interactive pen are integrated into this rolltop
 The shutter also incorporates the system's hardware itself
 The wireless station can recharge the PC which provides two USB ports for
connecting peripherals.

6. 6


3.1 ROLLTOP DESIGN:

Fig.3.1 Rolltop Design


3.2 ORKIN NEW DESIGN ROLLTOP:
The future computer should come in the form of the proposed Orkin Design’s rolltop
– a conceptual computer that would have a screen rollable into bigger size, or just like
traditional newspaper which you could roll it up when not in use.

7. 7


Fig.3.2 New Design

The rolltop would come with a flexible OLED touchscreen display. Once it’s fully
rolled out, it’d serve as a 13-inch laptop/tablet, or a 17-inch dedicated computer
display. The device would also come with a detachable hub with power adapter, a
stylus and a couple of USB ports.
This conceptual device shouldn’t be too far from realistic, as OLED technology is
getting matured, making one of these flexible screens would not be too difficult in the
near future.
At this year’s CEATEC JAPAN 2009, the name derived from ‘Combined Exhibition
of Advanced Technologies’, held in Japan October 6 – 10, 2009, Denmark-based
Orkin Design and Japan’s Sony literally rolled-out its multi-touch laptop. These
laptops keep getting thinner and lighter, but as Jeremy Hsu commented on his posting
to popsci.com “some concept laptops take portable to a new level. Orkin Design's
Rolltop consists of an OLED display that can start as a rolled-up mat and deploy as a
multi-touch 17-inch laptop. My beastly HP laptop just shed a tear of envy.”
The Orkin laptop can also transform into a tablet PC operable with a stylus, or
become a standup flat screen display. A power adapter and other features fit with the
carrying canister that comes with a convenient holding strap.
While there really isn’t anything unique from a technology perspective (it does
however feature fabulous packaging), I was reminded and would think that it is only
made possible and constructed with the broad range of rare metals: rare earth magnets
in the voice coils, indium-tin-oxide in the OLED screens, tantalum in the capacitors,

8. 8

lithium in the batteries, beryllium in the connectors and wires (especially in this
model, I would think) etc.

3.3 PROVIDE EASE IN CARRYING :






As you will see in the picture, it is carried around with a strap over your shoulder and
can then be unfurled, making it available to many different configurations. From a flat
tablet to a traditional looking book style laptop.
Because the device as the flexible display it allows this new concept design growing
out of the traditional bookformed laptop into unfurling and convolving portable
computer. By virtue of the OLED-Display technology and a multi touch screen the
weight of the computer is said to be that of a mini-notebook size. A width of 13 inch
easily transforms into the graphics tablet, which with its 17-inch flat screen can be
also used as a primary monitor. So you can use it as a flexible laptop, a graphical
tablet, or even stand it up and you have a portable 17′ TV screen.

CHAPTER 4
STRUCTURE OF ROLLTOP:

Imagine a laptop so portable, you could roll it up like a yoga mat and carry it tucked
under your arm with an attached strap. Now you don’t have to imagine; this is the
concept behind the Rolltop laptop from Orkin Design.

9. 9

The Rolltop laptop incorporates energy-efficient flexible OLED technology and a
multi-touch screen.
As you unroll it, you get a laptop with a 13-inch screen. Flattened out, it
becomes a graphics tablet for use with the enclosed stylus pen. On the back the
Rolltop laptop is a stand that can be pulled out into a 17-inch display for viewing
videos. A webcam, loudspeaker and power/data supply are included in the core
cylinder.
Imagine if you could roll up your laptop like a newspaper and open it when required,
and what if you could turn your laptop into a primary monitor if you wanted to play
some awesome video games.
Well all these are possible with the cool new conceptual ROLL TOP Laptop concept,
which is being touted as a Future Designer Laptop. Orkin Design has unveiled this
cool new concept with the support of Schlagheck-Design and the device comes with a
flexible display which can be rolled and carried wherever you want. This goes beyond
the traditional book like laptops which are cumbersome to say the least.

Thanks to its OLED-Display technology and a multi touch screen, it can be used a
laptop while it weighs as much as mini notebook. It comes with a 13 inch screen
while being used a laptop and when being used as a monitor, you could get a cool 17
inches screen. Power supply, multi media integrated pen and even a holding belt are
integrated in the ROLL TOP and it certainly is an all-in-one gadget.

Fig.4.1 OLED

10. 10

CHAPTER 5
FUNCTIONS OF ROLLTOP:
While the world awaits the launch of the Apple Tablet, a German company is already
thinking about a much more distant future. The Orkin Design developed the prototype
of an ultraportable notebook with foldable screen. Called Rolltop, the device promises
to be the face of computers in the future
You could carry your laptop like a newspaper by rolling it up, and making sure that
you are not burdened by heavy laptop bags. While this is still a concept, we had
written about the cool Microsoft Courier Tablet which comes with dual screens. You
could also read about Cintiq, which allows you to write and draw better than with the
help of pen and paper.

Well wrapped. German company takes seriously the concept of portable computer and
develops a project that aims to be the notebook of the future. The fact that computers
are becoming smaller and more powerful, but still can not do much with them,
especially when it comes to mobility. Although small, all you can do, so far, is to raise
the lid, type in key properties and close the lid. The Rolltop it is still a laptop,
however, it goes much further.

11. 11

5.1 STYLE AND DESIGN:
With a focus on style, lightness and mobility, the prototype abuses of new
technologies in the field of flexible displays. According to the company developing
the project, Rolltop will have a multitouch screen OLED flexible 17-inch, if the User
use it as a tablet, or 13 inches if you use a notebook as "common”.

In this picture you can see that the screen is stuck in a bar and it is responsible for
storing all the hardware that the application requires. Because only one screen,
apparently the HD, battery, plates and connections were transported to the bar, so the
screen can stay thin and light. Unlike the prototype from Fujitsu, the computer of
tissue, which would allow the User only perform basic tasks - no DVDs, hard disk,
and webcam - the Rolltop includes tools that let more complete. On the hardware the
User can count on a webcam, speakers, three USB ports and energy supplier.

12. 12

CHAPTER 6
OLED (Organic Light Emiting Diode)
An organic light-emitting diode (OLED) is a light-emitting diode (LED) in
which the emissive electroluminescent layer is a film of organic compound which
emits light in response to an electric current. This layer of organic semiconductor is
situated between two electrodes; typically, at least one of these electrodes is
transparent. OLEDs are used to create digital displays in devices such
as television screens,computer monitors, portable systems such as mobile
phones, handheld game consoles and PDAs. A major area of research is the
development of white OLED devices for use in solid-state lighting applications.
[1][2][3]

There are two main families of OLED: those based on small molecules and those
employing polymers. Adding mobile ions to an OLED creates a light-emitting
electrochemical cell (LEC) which has a slightly different mode of operation. OLED
displays can use either passive-matrix (PMOLED) or active-matrix addressing
schemes. Active-matrix OLEDs (AMOLED) require a thin-film transistor backplane
to switch each individual pixel on or off, but allow for higher resolution and larger
display sizes.
An OLED display works without a backlight; thus, it can display deep black
levels and can be thinner and lighter than a liquid crystal display(LCD). In low
ambient light conditions (such as a dark room), an OLED screen can achieve a
higher contrast ratio than an LCD, regardless of whether the LCD uses cold cathode
fluorescent lamps or an LED backlight.
6.1 History
The first observations of electroluminescence in organic materials were in the
early 1950s by André Bernanose and co-workers at the Nancy-Université in France.
They applied high alternating voltages in air to materials such as acridine orange,
either deposited on or dissolved in cellulose or cellophane thin films. The proposed

13. 13

mechanism was either direct excitation of the dye molecules or excitation of
electrons.
In 1960, Martin Pope and some of his co -workers at New York
University developed ohmic dark-injecting electrode contacts to organic crystals.They
further described the necessary energetic requirements (work functions) for hole and
electron injecting electrode contacts. These contacts are the basis of charge injection
in all modern OLED devices. Pope's group also first observed direct current (DC)
electroluminescence under vacuum on a single pure crystal of anthracene and on
anthracene crystals doped with tetracene in 1963 using a small area silver electrode at
400 volts. The proposed mechanism was field-accelerated electron excitation of
molecular fluorescence.
Pope's group reported in 1965
[12]
that in the absence of an external electric field, the
electroluminescence in anthracene crystals is caused by the recombination of a
thermalized electron and hole, and that the conducting level of anthracene is higher in
energy than the exciton energy level. Also in 1965, W. Helfrich and W. G. Schneider
of the National Research Council in Canada produced double injection recombination
electroluminescence for the first time in an anthracene single crystal using hole and
electron injecting electrodes,
[13]
the forerunner of modern double injection devices. In
the same year, Dow Chemical researchers patented a method of preparing
electroluminescent cells using high voltage (500–1500 V) AC-driven (100–3000 Hz)
electrically insulated one millimetre thin layers of a melted phosphor consisting of
ground anthracene powder, tetracene, andgraphite powder.
[14]
Their proposed
mechanism involved electronic excitation at the contacts between the graphite
particles and the anthracene molecules.
Electroluminescence from polymer films was first observed by Roger Partridge at
the National Physical Laboratory in the United Kingdom. The device consisted of a
film of poly(N-vinylcarbazole) up to 2.2 micrometres thick located between two
charge injecting electrodes. The results of the project were patented in 1975
[15]
and
published in 1983.
The first diode device was reported at Eastman Kodak by Ching W. Tang and Steven
Van Slyke in 1987.
[20]
This device used a novel two-layer structure with separate hole

14. 14

transporting and electron transporting layers such that recombination and light
emission occurred in the middle of the organic layer; this resulted in a reduction in
operating voltage and improvements in efficiency that led to the current era of OLED
research and device production.
Research into polymer electroluminescence culminated in 1990 with J. H.
Burroughes et al. at the Cavendish Laboratory in Cambridge reporting a high
efficiency green light-emitting polymer based device using 100 nm thick films
of poly(p-phenylene vinylene).
[21]

Universal Display Corporation holds the majority of patents concerning the
commercialization of OLEDs.

6.2 Working Principples
A typical OLED is composed of a layer of organic materials situated between
two electrodes, the anode andcathode, all deposited on a substrate. The organic
molecules are electrically conductive as a result ofdelocalization of pi
electrons caused by conjugation over part or all of the molecule. These materials have
conductivity levels ranging from insulators to conductors, and are therefore
considered organic semiconductors. The highest occupied and lowest unoccupied
molecular orbitals (HOMO and LUMO) of organic semiconductors are analogous to
the valence and conduction bands of inorganic semiconductors.
Originally, the most basic polymer OLEDs consisted of a single organic layer. One
example was the first light-emitting device synthesised by J. H. Burroughes et al.,
which involved a single layer of poly(p-phenylene vinylene). However multilayer
OLEDs can be fabricated with two or more layers in order to improve device
efficiency. As well as conductive properties, different materials may be chosen to aid
charge injection at electrodes by providing a more gradual electronic profile,
[22]
or
block a charge from reaching the opposite electrode and being wasted.
[23]
Many
modern OLEDs incorporate a simple bilayer structure, consisting of a conductive
layer and an emissive layer. More recent developments in OLED architecture
improves quantum efficiency (up to 19%) by using a graded heterojunction.
[24]
In the

15. 15

graded heterojunction architecture, the composition of hole and electron-transport
materials varies continuously within the emissive layer with a dopant emitter. The
graded heterojunction architecture combines the benefits of both conventional
architectures by improving charge injection while simultaneously balancing charge
transport within the emissive region.
[25]

During operation, a voltage is applied across the OLED such that the anode is positive
with respect to the cathode. Anodes are picked based upon the quality of their optical
transparency, electrical conductivity, and chemical stability.
[26]
A current
of electrons flows through the device from cathode to anode, as electrons are injected
into the LUMO of the organic layer at the cathode and withdrawn from the HOMO at
the anode. This latter process may also be described as the injection of electron
holes into the HOMO. Electrostatic forces bring the electrons and the holes towards
each other and they recombine forming an exciton, a bound state of the electron and
hole. This happens closer to the emissive layer, because in organic semiconductors
holes are generally more mobile than electrons. The decay of this excited state results
in a relaxation of the energy levels of the electron, accompanied by emission
of radiation whose frequency is in the visible region. The frequency of this radiation
depends on the band gap of the material, in this case the difference in energy between
the HOMO and LUMO.
As electrons and holes are fermions with half integer spin, an exciton may either be in
a singlet state or a triplet state depending on how the spins of the electron and hole
have been combined. Statistically three triplet excitons will be formed for each singlet
exciton. Decay from triplet states (phosphorescence) is spin forbidden, increasing the
timescale of the transition and limiting the internal efficiency of fluorescent
devices. Phosphorescent organic light-emitting diodes make use of spin–orbit
interactions to facilitate intersystem crossing between singlet and triplet states, thus
obtaining emission from both singlet and triplet states and improving the internal
efficiency.
Indium tin oxide (ITO) is commonly used as the anode material. It is transparent to
visible light and has a high work function which promotes injection of holes into the
HOMO level of the organic layer. A typical conductive layer may consist

16. 16

of PEDOT:PSS
[27]
as the HOMO level of this material generally lies between the
workfunction of ITO and the HOMO of other commonly used polymers, reducing the
energy barriers for hole injection. Metals such as barium and calcium are often used
for the cathode as they have low work functionswhich promote injection of electrons
into the LUMO of the organic layer.
[28]
Such metals are reactive, so they require a
capping layer of aluminium to avoid degradation.

Experimental research has proven that the properties of the anode, specifically the
anode/hole transport layer (HTL) interface topography plays a major role in the
efficiency, performance, and lifetime of organic light emitting diodes. Imperfections
in the surface of the anode decrease anode-organic film interface adhesion, increase
electrical resistance, and allow for more frequent formation of non-emissive dark
spots in the OLED material adversely affecting lifetime. Mechanisms to decrease
anode roughness for ITO/glass substrates include the use of thin films and self-
assembled monolayers. Also, alternative substrates and anode materials are being
considered to increase OLED performance and lifetime. Possible examples include
single crystal

Fig.6.1 OLED Working

17. 17

sapphire substrates treated with gold (Au) film anodes yielding lower work functions,
operating voltages, electrical resistance values, and increasing lifetime of OLEDs.
[29]

Single carrier devices are typically used to study the kinetics and charge transport
mechanisms of an organic material and can be useful when trying to study energy
transfer processes. As current through the device is composed of only one type of
charge carrier, either electrons or holes, recombination does not occur and no light is
emitted. For example, electron only devices can be obtained by replacing ITO with a
lower work function metal which increases the energy barrier of hole injection.
Similarly, hole only devices can be made by using a cathode made solely of
aluminium, resulting in an energy barrier too large for efficient electron injection
6.3 Advantages
6.3.1 Lower cost in the future
OLEDs can be printed onto any suitable substrate by an inkjet printer or even
by screen printing,
[60]
theoretically making them cheaper to produce than LCD
or plasma displays. However, fabrication of the OLED substrate is more costly
than that of a TFT LCD, until mass production methods lower cost through
scalability. Roll-to-roll vapour-deposition methods for organic devices do
allow mass production of thousands of devices per minute for minimal cost,
although this technique also induces problems in that devices with multiple
layers can be challenging to make because of registration, lining up the
different printed layers to the required degree of accuracy.
6.3.2 Lightweight and flexible plastic substrates
OLED displays can be fabricated on flexible plastic substrates leading to the
possible fabrication of flexible organic light-emitting diodes for other new
applications, such as roll-up displays embedded in fabrics or clothing. As the
substrate used can be flexible such as polyethylene terephthalate (PET),
[61]
the
displays may be produced inexpensively. Further, plastic substrates are shatter
resistant, unlike glass displays used in LCD devices.
6.3.3 Wider viewing angles and improved brightness
OLEDs can enable a greater artificial contrast ratio (both dynamic range and
static, measured in purely dark conditions) and a wider viewing angle

18. 18

compared to LCDs because OLED pixels emit light directly. OLED pixel
colors appear correct and unshifted, even as the viewing angle approaches 90°
from normal.
6.3.4 Better power efficiency and thickness
LCDs filter the light emitted from a backlight, allowing a small fraction of
light through. So, they cannot show true black. However, an inactive OLED
element does not produce light or consume power, thus allowing true
blacks.
[62]
Dismissing the backlight also makes OLEDs lighter because some
substrates are not needed. This allows electronics potentially to be
manufactured more cheaply, but, first, a larger production scale is needed,
because OLEDs still somewhat are niche products.
[63]
When looking at top-
emitting OLEDs, thickness also plays a role when talking about index match
layers (IMLs). Emission intensity is enhanced when the IML thickness is 1.3–
2.5 nm. The refractive value and the matching of the optical IMLs property,
including the device structure parameters, also enhance the emission intensity
at these thicknesses.
[64]

6.3.4 Response time
OLEDs also have a much faster response time than an LCD. Using response
time compensation technologies, the fastest modern LCDs can reach as low
as 1ms response times for their fastest color transition and are capable
of refresh frequencies as high as 144 Hz (frame interpolation on modern
"240Hz" and "480Hz" LCD TVs is not a true increase in refresh frequency).
OLED response times are up to 1,000 times faster than LCD according to
LG,
[65]
putting conservative estimates at under 10μs (0.01ms), which in theory
could accommodate refresh frequencies approaching 100 kHz (100,000 Hz).
Due to their extremely fast response time, OLED displays can also be easily
designed to interpolate black frames, creating an effect similar to CRT flicker
in order to avoid the sample-and-hold behavior used on both LCDs and some
OLED displays that creates the perception of motion blur.

19. 19

6.4 Disadvantages
6.4.1 Lifespan
The biggest technical problem for OLEDs was the limited lifetime of the
organic materials. One 2008 technical report on an OLED TV panel found that
"After 1,000 hours the blue luminance degraded by 12%, the red by 7% and
the green by 8%."
[67]
In particular, blue OLEDs historically have had a
lifetime of around 14,000 hours to half original brightness (five years at 8
hours a day) when used for flat-panel displays. This is lower than the typical
lifetime of LCD, LED or PDP technology. Each currently is rated for about
25,000–40,000 hours to half brightness, depending on manufacturer and
model.
[68][69]
Degradation occurs because of the accumulation of nonradiative
recombination centers and luminescence quenchers in the emissive zone. It is
said that the chemical breakdown in the semiconductors occurs in four steps:
1) recombination of charge carriers through the absorption of UV light, 2)
hemolytic dissociation, 3) subsequent radical addition reactions that form π
radicals, and 4) disproportionation between two radicals resulting in hydrogen-
atom transfer reactions.
[70]
However, some manufacturers' displays aim to
increase the lifespan of OLED displays, pushing their expected life past that of
LCD displays by improving light outcoupling, thus achieving the same
brightness at a lower drive current.
[71][72]
In 2007, experimental OLEDs were
created which can sustain 400 cd/m
2
of luminance for over 198,000 hours for
green OLEDs and 62,000 hours for blue OLEDs.
[73]

6.4.2 Color balance
Additionally, as the OLED material used to produce blue light degrades
significantly more rapidly than the materials that produce other colors, blue
light output will decrease relative to the other colors of light. This variation in
the differential color output will change the color balance of the display and is
much more noticeable than a decrease in overall luminance.
[74]
This can be
avoided partially by adjusting color balance, but this may require advanced
control circuits and interaction with the user, which is unacceptable for some
users. More commonly, though, manufacturers optimize the size of the R, G
and B subpixels to reduce the current density through the subpixel in order to
equalize lifetime at full luminance. For example, a blue subpixel may be 100%

20. 20

larger than the green subpixel. The red subpixel may be 10% smaller than the
green.
6.4.3 Efficiency of blue OLEDs
Improvements to the efficiency and lifetime of blue OLEDs is vital to the
success of OLEDs as replacements for LCD technology. Considerable
research has been invested in developing blue OLEDs with high external
quantum efficiency as well as a deeper blue color.
[75][76]
External quantum
efficiency values of 20% and 19% have been reported for red (625 nm) and
green (530 nm) diodes, respectively.
[77][78]
However, blue diodes (430 nm)
have only been able to achieve maximum external quantum efficiencies in the
range of 4% to 6%.
[79]

6.4.4 Water damage
Water can instantly damage the organic materials of the displays. Therefore,
improved sealing processes are important for practical manufacturing. Water
damage especially may limit the longevity of more flexible displays.
[80]

6.4.5 Outdoor performance
As an emissive display technology, OLEDs rely completely upon converting
electricity to light, unlike most LCDs which are to some extent reflective. e-
paper leads the way in efficiency with ~ 33% ambient light reflectivity,
enabling the display to be used without any internal light source. The metallic
cathode in an OLED acts as a mirror, with reflectance approaching 80%,
leading to poor readability in bright ambient light such as outdoors. However,
with the proper application of a circular polarizer and antireflective coatings,
the diffuse reflectance can be reduced to less than 0.1%. With
10,000 fc incident illumination (typical test condition for simulating outdoor
illumination), that yields an approximate photopic contrast of 5:1. Recent
advances in OLED technologies, however, enable OLEDs to become actually
better than LCDs in bright sunlight. The Super AMOLED display in
the Galaxy S5, for example, was found to outperform all LCD displays on the
market in terms of brightness and reflectance.
[81]

6.4.6 Power consumption
While an OLED will consume around 40% of the power of an LCD displaying
an image that is primarily black, for the majority of images it will consume
60–80% of the power of an LCD. However, an OLED can use more than three

21. 21

times as much power to display an image with a white background, such as a
document or web site.
[82]
This can lead to reduced battery life in mobile
devices, when white backgrounds are used.

CHAPTER 7
CONCLUSION:
Besides leading to an extreme the concept of portable computer, the Rolltop
succeeded in reuniting two of the largest consumer dreams of geeks on call: netbooks,
objects of desire of any User who want to stay connected and up to date with new
technology and tablets, even more famous after rumors of the launch of Apple Tablet.
Thus, the folding notebook lets mobile fans delight in a notebook with touch-sensitive
keys or a tablet for photo editing or performing more complex tasks. To use one of
two devices, simply unroll the screen completely, in the case of the tablet, or bend it
90 degrees to enter text or surf the web with a 100% touchscreen notebook.
To close the package dreams of consumption, it also lets you view videos or
photos like a portable television. The screen has a support on the back. With this, you
can leave it up and watch a movie while waiting for an email from your boss.

References:
http://www.myrolltop.com/
http://www.gizmag.com/rolltop-laptop-concept-rolls-up-like-a-
mat/18230/
http://www.scribd.com/doc/139683103/dbsit-rolltop-laptop

* * * * * * * * * * * * * *