Flat-panel display

Source: Wikipedia, the free encyclopedia.

Information on two types of flat-panel display at the Zürich Hauptbahnhof railway station: an orange LED display (top right) and a LCD screen (bottom)

A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment.

Flat-panel displays are thin, lightweight, provide better linearity and are capable of higher resolution than typical consumer-grade TVs from earlier eras. They are usually less than 10 centimetres (3.9 in) thick. While the highest resolution for consumer-grade

4K
resolution.

In the 2010s, portable consumer electronics such as laptops, mobile phones, and portable cameras have used flat-panel displays since they consume less power and are lightweight. As of 2016, flat-panel displays have almost completely replaced CRT displays.

Most 2010s-era flat-panel displays use

capacitive touch screens
.

Flat-panel displays can be divided into two display device categories: volatile and static. The former requires that pixels be periodically electronically refreshed to retain their state (e.g.

e-ink technology
, and as such retain content even when power is removed.

History

The first engineering proposal for a flat-panel TV was by

heads up display and as an oscilloscope monitor, but conventional technologies overtook its development. Attempts to commercialize the system for home television use ran into continued problems and the system was never released commercially.[2][3][4]

patent battle. By the time the lawsuits were complete, with Aiken's patent applying in the US and Gabor's in the UK, the commercial aspects had long lapsed, and the two became friends.[5] Around this time,Clive Sinclair came across Gabor's work and began an ultimately unsuccessful decade-long effort to commercialize it.[6]

The

University of Illinois, according to The History of Plasma Display Panels.[7]

Liquid-crystal displays (LC displays, or LCDs)

The

dynamic scattering LCD that used standard discrete MOSFETs.[13]

The first

thin-film-transistor liquid-crystal display (TFT LCD).[15][16] Brody and Fang-Chen Luo demonstrated the first flat active-matrix liquid-crystal display (AM LCD) using TFTs in 1974.[12]

By 1982,

high-resolution and high-quality electronic visual display devices use TFT-based active-matrix displays.[21]

LED displays

The first usable LED display was developed by

digital display technology, replacing the Nixie tube for numeric displays and becoming the basis for later LED displays.[24]
In 1977, James P Mitchell prototyped and later demonstrated what was perhaps the earliest monochromatic flat-panel LED television display.

Hynix produced an organic EL driver capable of lighting in 4,096 colors.[26] In 2004, the Sony Qualia 005 was the first LED-backlit LCD.[27] The Sony XEL-1, released in 2007, was the first OLED television.[28]

Common types

Liquid-crystal display (LCD)

An LCD screen used as an information display for travellers

Field-effect LCDs are lightweight, compact, portable, cheap, more reliable, and easier on the eyes than CRT screens. LCD screens use a thin layer of liquid crystal, a liquid that exhibits crystalline properties. It is sandwiched between two glass plates carrying transparent electrodes. Two polarizing films are placed at each side of the LCD. By generating a controlled electric field between electrodes, various segments or pixels of the liquid crystal can be activated, causing changes in their polarizing properties. These polarizing properties depend on the alignment of the liquid-crystal layer and the specific field-effect used, being either

In-Plane Switching (IPS) or Vertical Alignment
(VA). Color is produced by applying appropriate color filters (red, green and blue) to the individual subpixels. LC displays are used in various electronics like watches, calculators, mobile phones, TVs, computer monitors and laptops screens etc.

LED-LCD

Most earlier large LCD screens were back-lit using a number of CCFL (cold-cathode fluorescent lamps). However, small pocket size devices almost always used LEDs as their illumination source. With the improvement of LEDs, almost all new displays are now equipped with

LED
backlight technology. The image is still generated by the LCD layer.

Plasma panel

A plasma display consists of two glass plates separated by a thin gap filled with a gas such as neon. Each of these plates has several parallel electrodes running across it. The electrodes on the two plates are at right angles to each other. A voltage applied between the two electrodes one on each plate causes a small segment of gas at the two electrodes to glow. The glow of gas segments is maintained by a lower voltage that is continuously applied to all electrodes. By 2010, consumer plasma displays had been discontinued by numerous manufacturers.

Electroluminescent panel

In an electroluminescent display (ELD), the image is created by applying electrical signals to the plates which make the phosphor glow.

Organic light-emitting diode

An OLED (organic light-emitting diode) 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.

Quantum-dot light-emitting diode

QLED or quantum dot LED is a flat panel display technology introduced by Samsung under this trademark. Other television set manufacturers such as Sony have used the same technology to enhance the backlighting of LCD TVs already in 2013.[29][30] Quantum dots create their own unique light when illuminated by a light source of shorter wavelength such as blue LEDs. This type of LED TV enhances the colour gamut of LCD panels, where the image is still generated by the LCD. In the view of Samsung, quantum dot displays for large-screen TVs are expected to become more popular than the OLED displays in the coming years; Firms like Nanoco and Nanosys compete to provide the QD materials. In the meantime, Samsung Galaxy devices such as smartphones are still equipped with OLED displays manufactured by Samsung as well. Samsung explains on their website that the QLED TV they produce can determine what part of the display needs more or less contrast. Samsung also announced a partnership with Microsoft that will promote the new Samsung QLED TV.

Volatile

movie trailers
.

Volatile displays require that pixels be periodically refreshed to retain their state, even for a static image. As such, a volatile screen needs electrical power, either from

wall socket) or a battery to maintain an image on the display or change the image. This refresh typically occurs many times a second. If this is not done, for example, if there is a power outage
, the pixels will gradually lose their coherent state, and the image will "fade" from the screen.

Examples

Further information:
Comparison CRT, LCD, Plasma

The following flat-display technologies have been commercialized in 1990s to 2010s:

Technologies that were extensively researched, but their commercialization was limited or has been ultimately abandoned:

Static

Amazon's Kindle Keyboard e-reader displaying a page of an e-book. The Kindle's image of the book's text will remain onscreen even if the battery runs out, as it is a static screen technology. Without power, however, the user cannot change to a new page.

Static flat-panel displays rely on materials whose color states are

e-book reader devices from Sony and iRex; anlabels; interferometric modulator displays
in a smartwatch).

See also

References

  1. ^ "Proposed Television Sets Would Feature Thin Screens." Popular Mechanics, November 1954, p. 111.
  2. ^ William Ross Aiken, "History of the Kaiser-Aiken, thin cathode ray tube", IEEE Transactions on Electron Devices, Volume 31 Issue 11 (November 1984), pp. 1605–1608.
  3. ^ "Flat Screen TV in 1958 – Popular Mechanics (Jan, 1958)".
  4. ^ "Geer Experimental Color CRT". www.earlytelevision.org.
  5. ^ Cobleigh, Jaimeson (30 October 1996). "Interview with William Ross Aiken" (PDF) (Interview). IEEE History Center'.
  6. ^ Adamson, Ian; Kennedy, Richard (1986). Sinclair and the 'sunrise' Technology. Penguin.
  7. ^ Plasma TV Science.org – The History of Plasma Display Panels
  8. ^ "1960 – Metal Oxide Semiconductor (MOS) Transistor Demonstrated". The Silicon Engine. Computer History Museum. Retrieved 29 July 2019.
  9. Atalla, M.; Kahng, D.
    (1960). "Silicon-silicon dioxide field induced surface devices". IRE-AIEE Solid State Device Research Conference.
  10. S2CID 51650159
    .
  11. ISBN 9781119247401
    .
  12. ^
    ISSN 1551-319X
    .
  13. ISBN 9789812389565
    .
  14. ISBN 981-238-956-3
    .
  15. ISSN 1064-8208
    .
  16. ISSN 0018-9383
    .
  17. ISSN 0026-8941
    .
  18. ISBN 9781119161356
    .
  19. ^ "ET-10". Epson. Archived from the original on 4 February 2020. Retrieved 29 July 2019.
  20. S2CID 20817375
    .
  21. ISBN 9783319000022
    .
  22. ISBN 9783540401506
    .
  23. ^ Borden, Howard C.; Pighini, Gerald P. (February 1969). "Solid-State Displays" (PDF). Hewlett-Packard Journal: 2–12.
  24. ^ "Hewlett-Packard 5082–7000". The Vintage Technology Association. Retrieved 15 August 2019.
  25. doi:10.1063/1.98799
    .
  26. ^ "History: 2000s". SK Hynix. Archived from the original on 6 August 2020. Retrieved 8 July 2019.
  27. ^ Wilkinson, Scott (19 November 2008). "Sony KDL-55XBR8 LCD TV". Sound & Vision. Retrieved 3 October 2019.
  28. ^ Sony XEL-1:The world's first OLED TV Archived 5 February 2016 at the Wayback Machine, OLED-Info.com (17 November 2008).
  29. ^ CES 2015 placing bets on new TV technologies. IEEE Spectrum, 7 January 2015. Retrieved 21 October 2017
  30. ^ LG leaps quantum dot rivals with new TV. CNET, 16 December 2014. Retrieved 21 October 2017
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