Toggle search
Toggle menu
5.1K
5.9K
229
48K
VR & AR Wiki
Toggle preferences menu
Toggle personal menu
Not logged in
Your IP address will be publicly visible if you make any edits.

AMOLED

From VR & AR Wiki
More actions

AMOLED (active-matrix organic light-emitting diode) is a type of OLED display in which every subpixel is switched and held by its own thin-film transistor (TFT) circuit, built on a backplane under the organic emitting layer. In a 2020 review of display technologies, Huang, Hsiang, Deng and Wu contrast it with passive-matrix driving: an active-matrix subpixel keeps emitting for the whole frame because a storage capacitor holds its drive voltage, while a passive-matrix subpixel is lit only while its row is addressed and must be driven proportionally brighter.[1] Low-temperature polycrystalline silicon (LTPS) transistors are widely used in mobile AMOLED panels, while metal-oxide transistors, which leak less, are used in large panels and low-frame-rate smartwatches, and hybrid LTPO circuits combine the two.[2]

Samsung AMOLED panels were used in several early consumer-era virtual reality headsets. The Oculus Rift DK2 used the complete Super AMOLED screen assembly of a Samsung Galaxy Note 3,[3] the Samsung Gear VR Innovator Edition used the Super AMOLED screen of the Galaxy Note 4 placed inside it,[4] and the HTC Vive and HTC Vive Pro used Samsung-made AMOLED panels.[5][6] Because each pixel's emission can be switched on and off within a fraction of a millisecond, these panels could be run in a pulsed, low-persistence mode that reduces the smearing seen during head movement.[7]

This article covers active-matrix OLED panels built with TFTs, as used in phones and in phone-class VR headsets. OLED technology in general is covered in the OLED article; OLED microdisplays on silicon wafers are covered in Micro-OLED.

Reviewed 6 October 2026. Every claim checked against its cited source (eight papers, iFixit and Road to VR teardowns, Samsung, Apple, Sony, EE Times, DPReview, OLED-Info, archived Abrash post). About review dates.

How it works

Active and passive matrix

An OLED subpixel emits light in proportion to the current passing through it, so the display needs a way to set and maintain that current for millions of subpixels arranged in rows and columns. In a passive-matrix design there is no storage element in the pixel: each row is turned on in sequence, and each subpixel emits only during its own row time. Huang et al. note that in a panel with N rows this means each subpixel is lit for only 1/N of the frame time, so its instantaneous luminance has to be N times higher than in an active-matrix panel to give the same average brightness.[1]

The active-matrix alternative places a small circuit at every subpixel. The basic version, described by Huang et al., uses two transistors and one capacitor (2T1C). A switching TFT opens for 1/N of the frame time, while that row is being addressed, and loads the data voltage onto the gate of a driving TFT; the switching TFT then closes and a storage capacitor holds the voltage, so the driving TFT keeps supplying current to the OLED for the rest of the frame.[1] The display can therefore drive each subpixel at a moderate current for a long time instead of a very high current for a short time.

Pixel compensation circuits

The current that reaches the OLED depends on the threshold voltage and carrier mobility of the driving transistor, and these vary from pixel to pixel. Fan, Lin and Liu describe threshold voltage shift and mobility variation as consequences of the crystallization process used to make LTPS transistors, and state that both variations lead to "significant non-uniform OLED current levels" and color distortion.[2]

Many compensating pixel circuits with more transistors than the 2T1C design have been proposed to correct this. A 1998 paper by Dawson and co-authors, among them C. W. Tang and S. Van Slyke, reported a polysilicon AMOLED pixel that drove the OLED with small constant currents and achieved excellent pixel-to-pixel current drive uniformity "despite the threshold voltage variation inherent in polysilicon transistors".[8] Later designs surveyed by Fan et al. range from a 3T1C circuit that uses the OLED's own capacitance for compensation to 4T2C and 7T1C circuits, each trading compensation of threshold voltage, mobility and supply-voltage (IR) drop against the number of transistors and control lines that fit in a high-resolution pixel.[2]

Color and optical stack

Full color can be produced in two ways. In an RGB OLED, red, green and blue organic materials are deposited into separate subpixels through a fine metal mask; in a white OLED (WOLED) design, every subpixel emits white light and a color filter selects the color. Writing about OLED microdisplays, Xiong and co-authors note that shadowing during deposition through the fine metal mask limits RGB resolution, while the color filters of a WOLED panel absorb about 70 percent of the emitted light.[9] The AMOLED panels of several headsets use the PenTile RGBG layout, which has twice as many green subpixels as red or blue; Zhao and co-authors note that the screen door effect is particularly common in headsets with PenTile OLED displays.[7] To stop ambient light reflecting off the metal electrodes, a circular polarizer is commonly laminated on top of an OLED panel.[1]

Backplane technologies

Three thin-film transistor technologies are used for AMOLED backplanes:

Backplane Characteristics reported in the literature Typical use
Low-temperature polycrystalline silicon (LTPS) High field-effect mobility and current-driving capability; threshold voltage and mobility vary because of the crystallization process; relatively high leakage current[2] Mativenga, Geng and Jang describe excimer-laser-annealed LTPS as having excellent performance and stability but a much higher process cost than oxide TFTs[10] Mobile AMOLED panels[2]
Metal oxide (for example indium gallium zinc oxide) Good uniformity and extremely low leakage current[2]; lower manufacturing cost, but run-to-run reproducibility and bias stability inferior to LTPS[10] Large AMOLED panels and smartwatches with low frame rates[2]
LTPO (LTPS and oxide combined) Uses both transistor types in the pixel circuit: LTPS for current drive, oxide as a low-leakage switch that keeps the storage capacitor from losing its data[2] Portable displays; Apple described the Apple Watch Series 5 display in 2019 as "the industry's only low-temperature polysilicon and oxide display (LTPO)"[11]

All three are thin-film transistor technologies. OLED microdisplays instead form the pixel circuits in a monocrystalline silicon wafer. Sony says this backplane is what lets its OLED microdisplays reach about 4,000 pixels per inch, and that they are used in applications "whose needs for ultra-compact, ultra-high-resolution products cannot be met with LTPS (low-temperature polycrystalline silicon) OLEDs".[12] That distinction separates glass-substrate AMOLED panels from the micro-OLED panels used in many newer headsets.

History

In 1987 C. W. Tang and S. A. VanSlyke of Eastman Kodak reported an efficient organic electroluminescent diode: a double-layer organic thin-film device that emitted green light with an external quantum efficiency of 1 percent, a luminous efficiency of 1.5 lm/W and brightness above 1,000 cd/m2 at a driving voltage below 10 V.[13] By 1998 a group that included Tang and Van Slyke was reporting polysilicon TFT active-matrix pixels for OLEDs, such as the compensated pixel described above.[8]

Kodak later formed SK Display Corp. with Sanyo Electric. EE Times reported in December 2001 that the joint venture, 66 percent owned by Sanyo and 34 percent by Kodak, would focus on active-matrix OLEDs and make 1-inch to 7-inch panels at Sanyo's Gifu works once production started in February 2002.[14] In March 2003 Kodak announced the EasyShare LS633, which DPReview called the "world's first digital camera with OLED display", with a 2.2-inch, 512 x 218 screen.[15] The trade site OLED-Info describes the LS633 as the first product with an AMOLED display.[16]

At Samsung, AMOLED development began at Samsung SDI. The company's history lists the development of a 260,000-color full-color AMOLED in 2003, a 17-inch AMOLED in 2004, and in 2007 a 31-inch AMOLED and the start of what it calls "production of the world's first AMOLED"; Samsung Mobile Display was launched in 2008.[17] Samsung Display was established on 1 July 2012 by merging Samsung Mobile Display with Samsung Electronics' LCD business and S-LCD Corporation.[18]

Super AMOLED and brand names

"AMOLED" is a generic technical term, but Samsung uses it in product branding. OLED-Info defines Super AMOLED as Samsung's name for mobile AMOLED displays with an integrated touch function: the touch sensor is built onto the display instead of being a separate layer, which OLED-Info says gives better visibility in direct sunlight than AMOLED panels with an external touch layer.[19] Samsung's newsroom states that the original Galaxy S of 2010 was "the world's first smartphone to be launched with a Super AMOLED display".[20] According to OLED-Info, Samsung's flagship phones moved to the "Dynamic AMOLED" name, while Super AMOLED remains in mid-range phones and secondary screens.[19]

Two early VR headsets used Super AMOLED phone panels. The Galaxy Note 3 panel inside the Oculus Rift DK2 was a 5.7-inch Super AMOLED, and iFixit found it still carried the phone's Synaptics touchscreen controller.[3] Samsung described the Galaxy Note 4 used with the first Gear VR as having a "5.7 inch Quad HD Super AMOLED (2560 x 1440)" display.[4]

Use in virtual reality

Persistence and judder

A head-mounted display moves with the head while the eyes stay fixed on objects in the virtual scene, so any image held still on the panel for a whole frame is smeared across the retina. Michael Abrash, then at Valve, explained this in a July 2013 post on judder. He defined full persistence as pixels being lit for the entire frame, "the case with many OLED and LCD displays, although it is by no means required for either technology", and argued that persistence "below roughly 2 ms" should "almost completely eliminate the smear component of judder"; he wrote that experimental prototypes confirmed this.[21]

In an active-matrix panel this is done by limiting each subpixel's emission to a short part of the frame. Huang et al. call the fraction of the frame during which light is emitted the duty ratio (DR) and give the resulting motion picture response time (MPRT) as roughly 0.8 x frame time x DR: a 60 fps display with a 10 percent duty ratio drops from about 13.3 ms to 1.33 ms. The cost is brightness; to keep the same average luminance at 10 percent duty, the pixels must be driven ten times brighter, with consequences for lifetime and efficiency.[1] For VR panels, the same review estimates that a peak luminance of 150 to 200 cd/m2 is adequate because the headset is dark inside, which corresponds to about 1,000 cd/m2 instantaneous luminance at a 15 to 20 percent duty ratio.[1]

Headsets with AMOLED panels

Oculus VR opened pre-orders for the DK2 on 19 March 2014 at US$350, with shipping expected in July. Road to VR listed its display as a low-persistence OLED at 960 x 1080 per eye, with refresh rates of 75, 72 or 60 Hz and persistence of 2 ms, 3 ms or full, and its reviewer found the image "substantially sharper in the DK2 when moving your head, mostly thanks to low-persistence".[22] iFixit's teardown found that Oculus ran the Note 3 panel at 75 Hz rather than the phone's stock 60 Hz.[3] Road to VR noted that every DK2 contained the Note 3's 1080p display, "including the touchscreen driver".[23] For the consumer Oculus Rift CV1, iFixit instead found two custom OLED panels of about 90 mm and roughly 456 ppi, not panels taken from a phone.[24]

Headset AMOLED panel as reported Source type
Oculus Rift DK2 (2014) One 5.7-inch Super AMOLED from the Samsung Galaxy Note 3, 960 x 1080 per eye, run at 75 Hz[3] Teardown
Samsung Gear VR Innovator Edition (2014) Uses the Galaxy Note 4's 5.7-inch Quad HD Super AMOLED (2560 x 1440)[4]; Oculus called it a "Quad HD low-persistence 5.7 inch 1440p AMOLED screen"[25] Manufacturer
HTC Vive (2016) Two Samsung AMOLED panels, 1080 x 1200 each, about 91.8 mm diagonal and about 447 ppi, 90 Hz[5] Teardown
HTC Vive Pro (2018) Two 1440 x 1600 Samsung AMS350MU04 AMOLED panels, believed to be the same as in the Samsung Odyssey[6] Teardown
Samsung Odyssey+ (2018) Two AMOLED panels, 1440 x 1600 each, 616 ppi, with a diffusing "Anti-SDE" layer[26] Press

Measured behavior

A 2022 study by researchers at the U.S. Food and Drug Administration measured the HTC Vive, Vive Pro and Vive Pro 2 with a photodiode. The Vive and Vive Pro, which the authors describe as using PenTile OLED panels at up to 90 Hz, both ran at a duty cycle of 17 percent "by modulating the OLED emission time", with rise and fall times of about 0.3 ms and 0.5 ms. The LCD-based Vive Pro 2 reached a 5 percent duty cycle at 120 Hz by switching its backlight. The authors concluded that keeping the emission duty cycle below 20 percent helps reduce motion blur, and that the higher pixel fill factor of the RGB LCD removed the screen door effect visible on the two OLED headsets.[7]

Samsung's Odyssey+ addressed the screen door effect with a layer that diffuses light from each pixel into the gaps around it; Samsung claimed this doubled "user-perceived resolution" to 1,233 ppi. Road to VR's Ben Lang wrote that the claim "sounds misleading": the diffuser may reduce the screen door effect, but as far as Road to VR could tell, it cannot increase the perceived sharpness of the display.[26] The later Vive Pro 2 switched to fast-switching RGB LCD panels.[7] The broader move of headsets between display types is covered in the OLED and Micro-OLED articles.

Research

Display makers have tried to push glass-substrate AMOLED to VR pixel densities. At SID Display Week 2018, Google and LG Display presented what they called the world's highest resolution OLED-on-glass panel: 18 megapixels at 1,443 ppi on a 4.3-inch diagonal. Vieri and co-authors explain that the design used a white OLED with color filters "for high density pixelization" and an n-type LTPS backplane "for faster response time than mobile phone displays", together with a custom high-bandwidth driver IC and a foveated pixel pipeline for VR and AR.[27] Road to VR's published specification lists a 17.6 µm pixel pitch, 120 Hz refresh, more than 15,000:1 contrast and 150 cd/m2 brightness at 20 percent duty.[28] At the same event Samsung Display showed a VR OLED display with a resolution of 1,200 ppi.[29] OLED-Info reported that Samsung Display also showed 3.5-inch 1440 x 1600 (616 ppi) and 3.2-inch 1824 x 1824 (806 ppi) VR AMOLED panels at 90 Hz.[30]

The density required is far above phone panels. Huang et al. estimate that eliminating the screen door effect across a 100 degree field of view needs about 6K x 6K resolution, or roughly 3,000 ppi on a 2-inch panel, and point to foveated rendering as a way to reduce that burden.[1] Backplane research continues on oxide and LTPO transistors, which trade the mobility of LTPS against uniformity, leakage and cost,[10][2] and on compensating pixel circuits that keep the OLED current uniform as resolution rises and the space available for each pixel shrinks.[2]

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Yuge Huang, En-Lin Hsiang, Ming-Yang Deng, Shin-Tson Wu (2020-06-18). "Mini-LED, Micro-LED and OLED displays: present status and future perspectives". Light: Science & Applications, vol. 9, article 105. https://doi.org/10.1038/s41377-020-0341-9. Retrieved 2026-10-06.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 Ching-Lin Fan, Wei-Yu Lin, Shih-Yang Liu (2023-09-18). "An Active-Matrix Organic Light-Emitting Diode Pixel Circuit Featuring Mobility Compensation for Portable Applications". Micromachines, vol. 14, no. 9, article 1785. https://doi.org/10.3390/mi14091785. Retrieved 2026-10-06.
  3. ↑ 3.0 3.1 3.2 3.3 "Oculus Rift Development Kit 2 Teardown". iFixit. 2014-07-31. https://www.ifixit.com/Teardown/Oculus+Rift+Development+Kit+2+Teardown/27613. Retrieved 2026-10-06.
  4. ↑ 4.0 4.1 4.2 "Samsung Introduces Gear VR Innovator Edition for the U.S. at Samsung Developer Conference". Samsung Mobile Press. Samsung Electronics. 2014-11-12. https://www.samsungmobilepress.com/articles/samsung-introduces-gear-vr-innovator-edition-for-the-u-s-at-samsung-developer-conference. Retrieved 2026-10-06.
  5. ↑ 5.0 5.1 "HTC Vive Teardown". iFixit. 2016-04-26. https://www.ifixit.com/Teardown/HTC+Vive+Teardown/62213. Retrieved 2026-10-06.
  6. ↑ 6.0 6.1 Ben Lang (2018-04-11). "Vive Pro Gets Detailed Teardown Confirming Samsung-made Displays". Road to VR. https://roadtovr.com/htc-vive-pro-disassembly-teardown-confirming-samsung-made-displays/. Retrieved 2026-10-06.
  7. ↑ 7.0 7.1 7.2 7.3 Chumin Zhao, Andrea S. Kim, Ryan Beams, Aldo Badano (2022-11-24). "Spatiotemporal image quality of virtual reality head mounted displays". Scientific Reports, vol. 12, article 20235. https://doi.org/10.1038/s41598-022-24345-9. Retrieved 2026-10-06.
  8. ↑ 8.0 8.1 R. M. A. Dawson, Z. Shen, D. A. Furst, S. Connor, J. Hsu, M. G. Kane, R. G. Stewart, A. Ipri, C. N. King, P. J. Green, R. Y. Flegal, S. Pearson, W. A. Barrow, E. Dickey, K. Ping, C. W. Tang, S. Van Slyke, F. Chen, J. Shi, J. C. Sturm, M. H. Lu (1998-05). "Design of an Improved Pixel for a Polysilicon Active-Matrix Organic LED Display". SID Symposium Digest of Technical Papers, vol. 29, no. 1, pp. 11-14. https://doi.org/10.1889/1.1833705. Retrieved 2026-10-06.
  9. ↑ Jianghao Xiong, En-Lin Hsiang, Ziqian He, Tao Zhan, Shin-Tson Wu (2021-10-25). "Augmented reality and virtual reality displays: emerging technologies and future perspectives". Light: Science & Applications, vol. 10, article 216. https://doi.org/10.1038/s41377-021-00658-8. Retrieved 2026-10-06.
  10. ↑ 10.0 10.1 10.2 Mallory Mativenga, Di Geng, Jin Jang (2014-06). "Invited Paper: Oxide Versus LTPS TFTs for Active-Matrix Displays". SID Symposium Digest of Technical Papers, vol. 45, no. 1, pp. 1-4. https://doi.org/10.1002/j.2168-0159.2014.tb00001.x. Retrieved 2026-10-06.
  11. ↑ "Apple unveils Apple Watch Series 5". Apple Newsroom. Apple. 2019-09-10. https://www.apple.com/newsroom/2019/09/apple-unveils-apple-watch-series-5/. Retrieved 2026-10-06.
  12. ↑ "OLED Microdisplay". Sony Semiconductor Solutions. Sony Semiconductor Solutions Corporation. https://www.sony-semicon.com/en/products/microdisplay/oled.html. Retrieved 2026-10-06.
  13. ↑ C. W. Tang, S. A. VanSlyke (1987-09-21). "Organic electroluminescent diodes". Applied Physics Letters, vol. 51, no. 12, pp. 913-915. https://doi.org/10.1063/1.98799. Retrieved 2026-10-06.
  14. ↑ Yoshiko Hara (2001-12-06). "Sanyo, Kodak ramp OLED production line". EE Times. https://www.eetimes.com/sanyo-kodak-ramp-oled-production-line/. Retrieved 2026-10-06.
  15. ↑ "Kodak LS633 First with OLED Display". DPReview. 2003-03-02. https://www.dpreview.com/articles/0923133050/kodakls633/. Retrieved 2026-10-06.
  16. ↑ "Kodak OLED technology". OLED-Info. https://www.oled-info.com/kodak-oled-technology. Retrieved 2026-10-06.
  17. ↑ "History". Samsung SDI. https://www.samsungsdi.com/about-sdi/history.html. Retrieved 2026-10-06.
  18. ↑ "[10 Year Anniversary] A Decade of Samsung Display's Historic Moments". Samsung Display Newsroom. 2022-07. https://global.samsungdisplay.com/30222/. Retrieved 2026-10-06.
  19. ↑ 19.0 19.1 "Super AMOLED: introduction and market status". OLED-Info. https://www.oled-info.com/super-amoled. Retrieved 2026-10-06.
  20. ↑ "How Samsung Galaxy Has Rewritten Smartphone History in 10 Innovative Technologies". Samsung Global Newsroom. Samsung Electronics. 2022-02-09. https://news.samsung.com/global/how-samsung-galaxy-has-rewritten-smartphone-history-in-10-innovative-technologies. Retrieved 2026-10-06.
  21. ↑ Michael Abrash (2013-07-26). "Down the VR rabbit hole: Fixing judder". Ramblings in Valve Time. Valve. https://web.archive.org/web/2016/http://blogs.valvesoftware.com/abrash/down-the-vr-rabbit-hole-fixing-judder/. Retrieved 2026-10-06.
  22. ↑ Ben Lang (2014-03-19). "GDC 2014: Oculus Rift Developer Kit 2 (DK2) Pre-orders Start Today for $350, Ships in July". Road to VR. https://roadtovr.com/oculus-rift-developer-kit-2-dk2-pre-order-release-date-specs-gdc-2014/. Retrieved 2026-10-06.
  23. ↑ Ben Lang (2014-07-31). "The Touchscreen from a Samsung Smartphone is Hidden Inside Every Oculus Rift DK2". Road to VR. https://www.roadtovr.com/samsung-galaxy-note-3-touchscreen-inside-oculus-rift-dk2/. Retrieved 2026-10-06.
  24. ↑ "Oculus Rift CV1 Teardown". iFixit. 2016-03-30. https://www.ifixit.com/Teardown/Oculus+Rift+CV1+Teardown/60612. Retrieved 2026-10-06.
  25. ↑ "Introducing the Samsung Gear VR Innovator Edition". Oculus Blog. Meta. 2014-09-03. https://www.meta.com/blog/introducing-the-samsung-gear-vr-innovator-edition/. Retrieved 2026-10-06.
  26. ↑ 26.0 26.1 Ben Lang (2018-10-23). "Samsung Odyssey+ Windows VR Headset Revealed with "Anti-SDE" Display". Road to VR. https://roadtovr.com/samsung-odyssey-plus-price-anti-sde-display/. Retrieved 2026-10-06.
  27. ↑ Carlin Vieri, Grace Lee, Nikhil Balram, Sang Hoon Jung, Joon Young Yang, Soo Young Yoon, In Byeong Kang (2018-05). "An 18 megapixel 4.3" 1443 ppi 120 Hz OLED display for wide field of view high acuity head mounted displays". Journal of the Society for Information Display, vol. 26, no. 5, pp. 314-324. https://doi.org/10.1002/jsid.658. Retrieved 2026-10-06.
  28. ↑ Scott Hayden (2018-05-22). "Google & LG Detail Next-Gen 1,443 PPI OLED VR Display, 'especially ideal for standalone AR/VR'". Road to VR. https://www.roadtovr.com/google-lg-detail-upcoming-1443-ppi-oled-vr-display/. Retrieved 2026-10-06.
  29. ↑ "Samsung Display Reveals Automotive OLED Display Solutions and Other Dazzling Technology at 'SID Display Week 2018'". Samsung Display. 2018-05-22. https://www.samsungdisplay.com/eng/media/news/detail/ssdsNews-180522.jsp. Retrieved 2026-10-06.
  30. ↑ Ron Mertens (2018-05-29). "Samsung Display unveils new VR AMOLED displays at SID 2018". OLED-Info. https://www.oled-info.com/samsung-display-unveils-new-vr-amoled-displays-sid-2018. Retrieved 2026-10-06.
Retrieved from "https://vrarwiki.com/index.php?title=AMOLED&oldid=47631"