Display technology for use in mobile devices and televisions
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AMOLED
(
active-matrix organic light-emitting diode
;
) is a type of
OLED
display device technology. OLED describes a specific type of thin-film-display technology in which
organic compounds
form the
electroluminescent
material, and
active matrix
refers to the technology behind the addressing of
pixels
.
Since 2007, AMOLED technology has been used in mobile phones, media players, TVs and digital cameras,
[1]
and it has continued to make progress toward low-power, low-cost, high resolution and large size (for example, 88-inch and
8K
resolution) applications.
[2]
[3]
[4]
[
neutrality
is
disputed
]
Design
[
edit
]
An AMOLED display consists of an
active matrix
of
OLED
pixels generating light (luminescence) upon electrical activation that have been deposited or integrated onto a
thin-film transistor
(TFT) array, which functions as a series of switches to control the current flowing to each individual
pixel
.
[5]
Typically, this
continuous current
flow is controlled by at least two TFTs at each pixel (to trigger the luminescence), with one TFT to start and stop the charging of a storage
capacitor
and the second to provide a
voltage
source at the level needed to create a constant current to the pixel, thereby eliminating the need for the very high currents required for
passive-matrix
OLED operation.
[6]
TFT
backplane
technology is crucial in the fabrication of AMOLED displays. In AMOLEDs, the two primary TFT backplane technologies,
polycrystalline silicon
(poly-Si) and
amorphous silicon
(a-Si), are currently used offering the potential for directly fabricating the active-matrix backplanes at low temperatures (below 150 °C) onto flexible plastic substrates for producing
flexible
AMOLED displays.
[7]
History
[
edit
]
AMOLED was developed in 2006.
Samsung SDI
was one of the main investors in the technology, and many other display companies were also developing it. One of the earliest consumer electronics products with an AMOLED display was the
BenQ-Siemens
S88 mobile handset
[8]
and, in 2007, the
iriver Clix 2
portable media player.
[9]
In 2008 it appeared on the
Nokia N85
followed by the Samsung i7110 - both
Nokia
and
Samsung Electronics
were early adopters of this technology on their smartphones.
[10]
Future development
[
edit
]
Manufacturers have developed in-cell touch panels, integrating the production of capacitive
sensor arrays
in the AMOLED module fabrication process. In-cell sensor AMOLED fabricators include
AU Optronics
and
Samsung
. Samsung has marketed its version of this technology as "Super AMOLED". Researchers at
DuPont
used computational fluid dynamics (CFD) software to optimize coating processes for a new solution-coated AMOLED display technology that is competitive in cost and performance with existing
chemical vapor deposition
(CVD) technology. Using custom modeling and analytic approaches, Samsung has developed short and long-range film-thickness control and uniformity that is commercially viable at large glass sizes.
[11]
Comparison to other display technologies
[
edit
]
Compared to other display technologies
, AMOLED screens have several advantages and disadvantages.
AMOLED displays can provide higher refresh rates than passive-matrix,
[
not specific enough to verify
]
often have response times less than a millisecond, and they consume significantly less
power
.
[12]
This advantage makes active-matrix OLEDs well-suited for portable electronics, where power consumption is critical to battery life.
The amount of power the display consumes varies significantly depending on the color and brightness shown. As an example, one old
QVGA
OLED display consumes 0.3 watts while showing white text on a black background, but more than 0.7 watts showing black text on a white background, while an
LCD
may consume only a constant 0.35 watts regardless of what is being shown on screen.
A new FHD+ or WQHD+ display will consume much more.
[13]
Because the black pixels turn completely off, AMOLED also has contrast ratios that are significantly higher than LCDs.
[14]
AMOLED displays may be difficult to view in direct sunlight compared with LCDs because of their reduced maximum brightness.
[15]
[
citation needed
]
Samsung's
Super AMOLED
technology addresses this issue by reducing the size of gaps between layers of the screen.
[16]
[17]
Additionally,
PenTile
technology is often used for a higher resolution display while requiring fewer subpixels than needed otherwise, sometimes resulting in a display less sharp and more grainy than a non-PenTile display with the same resolution.
The organic materials used in AMOLED displays are very prone to degradation over a relatively short period of time, resulting in color shifts as one color fades faster than another,
image persistence
, or
burn-in
.
[18]
[19]
Flagship smartphones sold in 2020 and 2021 used a Super AMOLED. Super AMOLED displays, such as the one on the
Samsung Galaxy S21+
/
S21 Ultra
and
Samsung Galaxy Note 20 Ultra
have often been compared to
IPS LCDs
, found in phones such as the
Xiaomi Mi 10T
,
Huawei Nova 5T
, and
Samsung Galaxy A20e
.
[20]
[21]
[22]
For example, according to
ABI Research
, the AMOLED display found in the
Motorola Moto X
draws just 92 mA during bright conditions and 68 mA while dim.
[23]
On the other hand, compared with the IPS, the yield rate of AMOLED is low; the cost is also higher.
Marketing terms
[
edit
]
Super AMOLED
[
edit
]
"Super AMOLED" is a marketing term created by
Samsung
for an AMOLED display with an integrated touch screen
digitizer
: the layer that detects touch is integrated into the display, rather than overlaid on top of it and cannot be separated from the display itself. The display technology itself is not improved. According to Samsung, Super AMOLED reflects one-fifth as much sunlight as the first generation AMOLED.
[24]
[25]
The generic term for this technology is
One Glass Solution
(OGS).
Comparison
[
edit
]
Below is a mapping table of marketing terms versus resolutions and sub-pixel types. Note how the pixel density relates to choices of sub-pixel type.
Future
[
edit
]
Future displays exhibited from 2011 to 2013 by Samsung have shown flexible, 3D, transparent Super AMOLED Plus displays using very high resolutions and in varying sizes for phones. These unreleased prototypes use a
polymer
as a substrate removing the need for glass cover, a metal backing, and touch matrix, combining them into one integrated layer.
[27]
So far, Samsung plans on branding the newer displays as Youm,
[28]
or y-octa.
[29]
Also planned for the future are 3D stereoscopic displays that use eye-tracking (via stereoscopic front-facing cameras) to provide full resolution 3D visuals.
See also
[
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]
References
[
edit
]
- ^
Lee, Hyunkoo; Park, Insun; Kwak, Jeonghun; Yoon, Do Y.; Kallmann, Changhee Lee (2010). "Improvement of electron injection in inverted bottom-emission blue phosphorescent organic light emitting diodes using zinc oxide nanoparticles".
Applied Physics Letters
.
96
(15): 153306.
Bibcode
:
2010ApPhL..96o3306L
.
doi
:
10.1063/1.3400224
.
- ^
Kim, Yang Wan; Kwak, Won Kyu; Lee, Jae Yong; Choi, Wong Sik; Lee, Ki Yong; Kim, Sung Chul; Yoo, Eui Jin (2009). "40 Inch FHD AM-OLED Display with IR Drop Compensation Pixel Circuit".
SID Symposium Digest of Technical Papers
.
40
: 85.
doi
:
10.1889/1.3256930
.
S2CID
110871831
.
- ^
Lee, Myung Ho; Seop, Song Myoung; Kim, Jong Soo; Hwang, Jung Ho; Shin, Hye Jin; Cho, Sang Kyun; Min, Kyoung Wook; Kwak, Won Kyu; Jung, Sun I; Kim, Chang Soo; Choi, Woong Sik; Kim, Sung Cheol; Yoo, Eu Jin (2009). "Development of 31-Inch Full-HD AMOLED TV Using LTPS-TFT and RGB FMM".
SID Symposium Digest of Technical Papers
.
40
: 802.
doi
:
10.1889/1.3256911
.
S2CID
110948118
.
- ^
Hamer, John W.; Arnold, Andrew D.; Boroson, Michael L.; Itoh, Masahiro; Hatwar, Tukaram K.; Helber, Margaret J.; Miwa, Koichi; Levey, Charles I.; Long, Michael; Ludwicki, John E.; Scheirer, David C.; Spindler, Jeffrey P.; Van Slyke, Steven A. (2008). "System design for a wide-color-gamut TV-sized AMOLED display".
Journal of the Society for Information Display
.
16
: 3.
doi
:
10.1889/1.2835033
.
S2CID
62669850
.
- ^
"Introduction to OLED Displays ? Design Guide for Active Matrix OLED (AMOLED) Displays"
(PDF)
. 4D Systems. 22 May 2008. Archived from
the original
(PDF)
on 5 July 2010
. Retrieved
6 September
2010
.
- ^
Lin, Chih-Lung; Chen, Yung-Chih (2007). "A Novel LTPS-TFT Pixel Circuit Compensating for TFT Threshold-Voltage Shift and OLED Degradation for AMOLED".
IEEE Electron Device Letters
.
28
(2): 129.
Bibcode
:
2007IEDL...28..129L
.
doi
:
10.1109/LED.2006.889523
.
S2CID
11194344
.
- ^
Sarma, Kalluri R.; Chanley, Charles; Dodd, Sonia R.; Roush, Jared; Schmidt, John; Srdanov, Gordana; Stevenson, Matthew; Wessel, Ralf; Innocenzo, Jeffrey; Yu, Gang; O'Regan, Marie B.; MacDonald, W. A.; Eveson, R.; Long, Ke; Gleskova, Helena; Wagner, Sigurd; Sturm, James C. (2003). "Active-matrix OLED using 150°C a-Si TFT backplane built on flexible plastic substrate (Proceedings Paper)".
SPIE Proceedings
.
5080
: 180.
doi
:
10.1117/12.497638
.
S2CID
12958469
.
"Archived copy"
(PDF)
. Archived from
the original
(PDF)
on 28 June 2011
. Retrieved
2010-09-06
.
{{
cite web
}}
: CS1 maint: archived copy as title (
link
)
- ^
"Active OLEDs close in on mobile phone market"
.
- ^
"Iriver clix2 Review"
.
www.anythingbutipod.com
. Archived from
the original
on 28 October 2007
. Retrieved
19 April
2022
.
- ^
"The Consumer Electronics Hall of Fame: Nokia N85 Cellphone"
. 13 December 2018.
- ^
Reid Chesterfield, Andrew Johnson, Charlie Lang, Matthew Stainer, and Jonathan Ziebarth, "
Solution-Coating Technology for AMOLED Displays
Archived
16 May 2011 at the
Wayback Machine
", Information Display Magazine, January 2011.
- ^
Suyko, Alan. "Oleds Ready For The Mainstream."
Electronics News
(2009): 20.
Associates Programs Source Plus
. Web. 9 Dec. 2011.
- ^
Dong, Mian; Choi, Yung-Seok Kevin; Zhong, Lin (2009). "Power modeling of graphical user interfaces on OLED displays".
Proceedings of the 46th Annual Design Automation Conference on ZZZ - DAC '09
. p. 652.
doi
:
10.1145/1629911.1630084
.
ISBN
9781605584973
.
S2CID
442526
.
- ^
"AMOLED vs LCD: differences explained"
.
Android Authority
. 8 February 2016.
Archived
from the original on 27 December 2016
. Retrieved
6 February
2017
.
- ^
Tim Carmody (10 November 2010).
"How Super AMOLED displays work"
.
Wired
.
Archived
from the original on 28 September 2012
. Retrieved
10 October
2012
.
- ^
"What Are The Benefits Of Using The Super AMOLED Display In My SGH-t959 (Vibrant) Phone?"
. Samsung. 15 July 2010. Archived from
the original
on 16 July 2011
. Retrieved
7 September
2010
.
- ^
"Big is beautiful"
. The Age. 12 August 2010. Archived from
the original
on 29 August 2010
. Retrieved
7 September
2010
.
- ^
Ashtiani, Shahin J.; Reza Chaji, G.; Nathan, Arokia (2007). "AMOLED Pixel Circuit With Electronic Compensation of Luminance Degradation".
Journal of Display Technology
.
38
(1): 36.
Bibcode
:
2007JDisT...3...36A
.
doi
:
10.1109/JDT.2006.890711
.
S2CID
44204246
.
- ^
US 7352345
, Chun-huai Li, "Driving apparatus and method for light emitting diode display", issued 2008-04-01
- ^
"AMOLED vs LCD: Which screen is best for your phone?"
.
digitaltrends.com
. 29 August 2014.
Archived
from the original on 29 March 2018
. Retrieved
6 May
2018
.
- ^
"Smartphone screens explained: display types, resolutions and more - AndroidPIT"
.
androidpit.com
.
Archived
from the original on 12 May 2015
. Retrieved
6 May
2018
.
- ^
"Nexus 4 Review: Not Exactly Perfect, But Close Enough For Me ? TechCrunch"
.
techcrunch.com
.
Archived
from the original on 7 February 2018
. Retrieved
6 May
2018
.
- ^
Google/Motorola Mobility Display a Bright Efficient Future
, ABI Research
- ^
"Samsung Smartphones | Technology"
. Samsung.com. 6 January 2012. Archived from
the original
on 27 June 2012
. Retrieved
10 October
2012
.
- ^
"Super AMOLED"
. Oled-info.com.
Archived
from the original on 9 October 2012
. Retrieved
10 October
2012
.
- ^
"HTC VIVE Focus Plus"
.
vive.com
.
Archived
from the original on 13 December 2017
. Retrieved
30 July
2021
.
- ^
"Samsung teases flexible, transparent display in concept video"
.
engadget.com
.
Archived
from the original on 11 October 2016
. Retrieved
6 May
2018
.
- ^
"Samsung names flexible OLED display series 'Youm', shows new prototype handheld device"
.
engadget.com
.
Archived
from the original on 16 February 2018
. Retrieved
6 May
2018
.
- ^
Kelly, Gordon.
"Samsung Report 'Confirms' Significant Galaxy S9 Design Changes"
.
forbes.com
.
Archived
from the original on 1 April 2018
. Retrieved
6 May
2018
.
External links
[
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]