LCD TV: Revizyonlar arasındaki fark

[kontrol edilmemiş revizyon][kontrol edilmemiş revizyon]
İçerik silindi İçerik eklendi
Ertly (mesaj | katkılar)
Değişiklik özeti yok
Değişiklik özeti yok
6. satır:
 
{{çeviri}}
 
 
{{about|Liquid crystal display (LCD) based televisions|LCD technology|Liquid crystal display}}
{{Refimprove|date=December 2010}}
 
[[Dosya:LCD generic tv.jpg|thumb|right|200px|AEkranın genericher LCDiki TV,tarafında withhoparlör speakersile ongenel eitherLCD side of the screenTV,.]]
'''Sıvı Kristal Ekran televizyonları''' ('''LCD TV''') olan televizyon]]ların kullanan Sıvı kristal ekran | LCD]] görüntüler üretmek için teknoloji. LCD televizyonlar ince ve katot ışınlı tüp | CRT]] daha hafiftir benzer ekran boyutu ve çok daha büyük boyutlarda mevcuttur. Üretim maliyetleri düştüğünde, özellikleri bu kombinasyon televizyon alıcıları için LCD'ler pratik yaptı.
'''Liquid-crystal display televisions''' ('''LCD TV''') are [[television set]]s that use [[Liquid crystal display|LCD]] technology to produce images. LCD televisions are thinner and lighter than [[cathode ray tube|CRTs]] of similar display size, and are available in much larger sizes. When manufacturing costs fell, this combination of features made LCDs practical for television receivers.
 
2007 yılında, LCD televizyon satışları aştı katot ışınlı tüp | CRT]] ilk kez dünya çapında tabanlı televizyonlar, {{kaynak belirtilmeli | tarih = Aralık 2010}} ve diğer teknolojilere göre kendi satış rakamlarını hızlandırıyor. LCD TV'ler hızla büyük ekran pazarında tek büyük rakipleri yerinden olan, plazma ekran paneli]] ve arka projeksiyon televizyon.]] LCD'ler farkla, en yaygın olarak üretilen ve satılan televizyon ekran tipi vardır.
In 2007, LCD televisions surpassed sales of [[cathode ray tube|CRT]]-based televisions worldwide for the first time,{{Citation needed|date=December 2010}} and their sales figures relative to other technologies are accelerating. LCD TVs are quickly displacing the only major competitors in the large-screen market, the [[plasma display panel]] and [[rear-projection television]]. LCDs are, by far, the most widely produced and sold television display type.
 
LCD'ler de dezavantajları bir çeşitlilik var. Ve Yüzey iletimli elektron yayan ekran | SED]], fakat {{olarak | Diğer teknolojiler organik ışık yayan diyot]] s (OLED), [FED] [Saha emisyon ekran] dahil olmak üzere, bu zayıflıkları ele | 2010 | lc = bunların}} hiçbiriyle yaygın girdiler.
LCDs also have a variety of disadvantages. Other technologies address these weaknesses, including [[organic light-emitting diode]]s (OLED), [[Field emission display|FED]] and [[Surface-conduction electron-emitter display|SED]], but {{as of|2010|lc=on}} none of these have entered widespread production.
 
== DescriptionAçıklama ==
{{Unreferenced section|date=JuneHaziram 2009}}
 
==== BasicTemel LCD conceptsconceptleri ====
{{Türkçe değil}}
[[Dosya:Home cinema 01.jpg|thumb|LCD television at home together with [[PlayStation 3]] and some other equipment]]
LCD televisions produced a black and colored image by selectively filtering a white light. The light is typically provided by a series of [[Cold cathode|cold cathode fluorescent lamp]]s (CCFLs) at the back of the screen, although some displays use white or colored [[LED]]s instead. Millions of individual LCD shutters, arranged in a grid, open and close to allow a metered amount of the white light through. Each shutter is paired with a colored filter to remove all but the red, green or blue (RGB) portion of the light from the original white source. Each shutter–filter pair forms a single ''sub-pixel''. The sub-pixels are so small that when the display is viewed from even a short distance, the individual colors blend together to produce a single spot of color, a ''[[pixel]]''. The shade of color is controlled by changing the relative intensity of the light passing through the sub-pixels.
Satır 32 ⟶ 34:
Several other variations and modifications have been used in order to improve performance in certain applications. In-Plane Switching displays (IPS and S-IPS) offer wider viewing angles and better color reproduction, but are more difficult to construct and have slightly slower response times. IPS displays are used primarily for [[computer monitors]]. Vertical Alignment (VA, S-PVA and MVA) offer higher [[contrast ratio]]s and good response times, but suffer from color shifting when viewed from the side. In general, all of these displays work in a similar fashion by controlling the polarization of the light source.
 
==== AddressingAdreslerin subSub-pixelsPikselliği ====
[[Dosya:TN display closeup 300X.jpg|thumb|right|A close-up (300×) view of a typical LCD display, clearly showing the sub-pixel structure. The "notch" at the lower left of each sub-pixel is the thin-film transistor. The associated capacitors and addressing lines are located around the shutter, in the dark areas.]]
 
Satır 41 ⟶ 43:
In order to attack these problems, modern LCDs use an [[active matrix]] design. Instead of powering both electrodes, one set, typically the front, is attached to a common ground. On the rear, each shutter is paired with a [[thin-film transistor]] that switches on in response to widely separated voltage levels, say 0 and +5 volts. A new addressing line, the ''gate line'', is added as a separate switch for the transistors. The rows and columns are addressed as before, but the transistors ensure that only the single shutter at the crossing point is addressed; any leaked field is too small to switch the surrounding transistors. When switched on, a constant and relatively high amount of charge flows from the ''source line'' through the transistor and into an associated [[capacitor]]. The capacitor is charged up until it holds the correct control voltage, slowly leaking this through the crystal to the common ground. The current is very fast and not suitable for fine control of the resulting store charge, so [[pulse code modulation]] is used to accurately control the overall flow. Not only does this allow for very accurate control over the shutters, since the capacitor can be filled or drained quickly, but the response time of the shutter is dramatically improved as well.
 
==== BuildingBir aDisplay displayüretme ====
A typical shutter assembly consists of a sandwich of several layers deposited on two thin glass sheets forming the front and back of the display. For smaller display sizes (under 30 inches), the glass sheets can be replaced with plastic.
 
Satır 50 ⟶ 52:
To produce a complete television, the shutter assembly is combined with control electronics and backlight. The backlight for small sets can be provided by a single lamp using a diffuser or frosted mirror to spread out the light, but for larger displays a single lamp is not bright enough and the rear surface is instead covered with a number of separate lamps. Achieving even lighting over the front of an entire display remains a challenge, and bright and dark spots are not uncommon.
 
== ComparisonKarşılaştırma ==
[[Dosya:Sony KDL-S19A10.jpg|thumb|A 19" [[Sony]] LCD TV]]
 
==== PackagingPaketşeme ====
In a CRT the electron beam is produced by heating a metal filament, which "boils" electrons off its surface. The electrons are then accelerated and focused in an [[electron gun]], and aimed at the proper location on the screen using [[electromagnet]]s. The majority of the power budget of a CRT goes into heating the filament, which is why the back of a CRT-based television is hot. Since the electrons are easily deflected by gas molecules, the entire tube has to be held in vacuum. The atmospheric force on the front face of the tube grows with the area, which requires ever-thicker glass. This limits practical CRTs to sizes around 30 inches; displays up to 40 inches were produced but weighed several hundred pounds, and televisions larger than this had to turn to other technologies like [[rear projection television|rear-projection]].
 
Satır 107 ⟶ 109:
In September 2009 [[Nanoco Group]] announced that it had signed a joint development agreement with a major Japanese electronics company under which it will design and develop quantum dots for use in LED backlights in LCD televisions.<ref>http://www.nanocogroup.com/content/Library/NewsandEvents/articles/Nanoco_Signs_Agreement_with_Major_Japanese_Electronics_Company/136.aspx</ref> [[Quantum dots]] are valued for displays, because they emit light in very specific [[Gaussian distribution]]s. This can result in a display that more accurately renders the colors that the human eye can perceive. [[Quantum dots]] also require very little power since they are not color filtered.
 
== HistoryTarihi ==
[[Dosya:2008Computex Press Center at TWTC Hall 1 time zones and LCD TV.jpg|thumb|An LCD TV hanging on a wall in the [[Taipei World Trade Center]] during the [[Computex Taipei]] show in 2008.]]
 
==== EarlyErken effortsÇabalar ====
{{Unreferenced section|date=June 2009}}
Passive matrix LCDs first became common in the 1980s for various portable computer roles. At the time they competed with plasma displays in the same market space. The LCDs had very slow refresh rates that blurred the screen even with scrolling text, but their light weight and low cost were major benefits. Screens using reflective LCDs required no internal light source, making them particularly well suited to laptop computers.
Satır 118 ⟶ 120:
Nevertheless, some experimentation with LCD televisions took place during this period. In 1988, Sharp Corporation introduced the first commercial LCD television, a 14" model. These were offered primarily as boutique items for discerning customers, and were not aimed at the general market. At the same time, plasma displays could easily offer the performance needed to make a high quality display, but suffered from low brightness and very high power consumption. However, a series of advances led to plasma displays outpacing LCDs in performance improvements, starting with Fujitsu's improved construction techniques in 1979, Hitachi's improved phosphors in 1984, and [[AT&T]]s elimination of the black areas between the sub-pixels in the mid-1980s. By the late 1980s, plasma displays were far in advance of LCDs.
 
==== High-definitiondefinitionlu çözünürlük ====
{{Unreferenced section|date=June 2009}}
It was the slow standardization of [[high definition television]] that first produced a market for new television technologies. In particular, the wider 16:9 [[aspect ratio]] of the new material was difficult to build using CRTs; ideally a CRT should be perfectly circular in order to best contain its internal vacuum, and as the aspect ratio becomes more rectangular it becomes more difficult to make the tubes. At the same time, the much higher resolutions these new formats offered were lost at smaller screen sizes, so CRTs faced the twin problems of becoming larger and more rectangular at the same time. LCDs of the era were still not able to cope with fast-moving images, especially at higher resolutions, and from the mid-1990s the plasma display was the only real offering in the high resolution space.
Satır 143 ⟶ 145:
* In January 2007, Sharp displayed a 108" LCD panel under the [[AQUOS]] brand name at [[International Consumer Electronics Show|CES]] in Las Vegas.<ref>[http://www.foxnews.com/story/0,2933,242431,00.html FOXNews.com - Sharp Unveils 108-Inch Flat-Panel TV - Science News | Science & Technology | Technology News<!-- Bot generated title -->]</ref>
 
==== RecentSon researchZamanda yapılan Araştırmalar ====
{{Unreferenced section|date=June 2009}}
Some manufacturers are also experimenting with extending color reproduction of LCD televisions. Although current LCD panels are able to deliver all [[sRGB]] colors using an appropriate combination of backlight's spectrum and optical filters, manufacturers want to display even more colors. One of the approaches is to use a fourth, or even fifth and sixth color in the optical color filter array. Another approach is to use two sets of suitably narrowband [[backlight]]s (e.g. [[LED]]s), with slightly differing colors, in combination with broadband optical filters in the panel, and alternating backlights each consecutive frame.
Fully using the extended color gamut will naturally require an appropriately captured material and some modifications to the distribution channel. Otherwise, the only use of the extra colors would be to let the looker boost the color saturation of the TV picture beyond what was intended by the producer, but avoiding the otherwise unavoidable loss of detail ("burnout") in saturated areas.
 
==== CompetingRekabet systemsSistemleri ====
In spite of LCD's current dominance of the television field, there are several other technologies being developed that address its shortcomings. Whereas LCDs produce an image by selectively blocking a backlight OLED, FED and SED all produce light directly on the front face of the display. In comparison to LCDs, all of these technologies offer better viewing angles, much higher brightness and contrast ratio (as much as 5,000,000:1), and better color saturation and accuracy, and use less than 1/10 as much power. In theory, they are less complex and less expensive to build.
 
Satır 155 ⟶ 157:
[[Samsung]] has been displaying OLED sets at 14.1, 31 and 40&nbsp;inch sizes for some time, and at the [[Society for Information Display|SID 2009]] trade show in [[San Antonio, Texas|San Antonio]] they announced that the 14.1 and 31&nbsp;inch sets are "production ready".<ref>[http://www.oled-display.net/smd-unveils-production-ready-oled-tvs-and-amoleds-at-sid-2009 "SMD unveils production ready OLED-TVs and AMOLEDs at SID 2009"]</ref>
 
== EnvironmentalÇevresel effectsEtkiler ==
{{Related|[[Electronic waste]]}}
The production of LCD screens uses [[nitrogen trifluoride]] (NF<sub>3</sub>) as an etching fluid during the production of the thin-film components. NF<sub>3</sub> is a potent [[greenhouse gas]], and its extensive [[half-life]] may make it a potentially harmful contributor to [[global warming]]. A report in ''Geophysical Research Letters'' suggested that its effects were theoretically much greater than better-known sources of greenhouse gasses like [[carbon dioxide]]. As NF<sub>3</sub> was not in widespread use at the time, it was not made part of the [[Kyoto Protocol]]s and has been deemed "the missing greenhouse gas".<ref name=nf3>[http://www.alternet.org/environment/95111/your_flat_screen_has_(greenhouse)_gas/ "NF<sub>3</sub> used in plasma and LCD screens"]</ref>
Satır 161 ⟶ 163:
Critics of the report point out that it assumes that all of the NF<sub>3</sub> produced would be released to the atmosphere. In reality, the vast majority of NF<sub>3</sub> is broken down during the cleaning processes; two earlier studies found that only 2% to 3% of the gas escapes destruction after its use.<ref name=natgas>Hannah Hoag, [http://www.nature.com/climate/2008/0808/full/climate.2008.72.html "The missing greenhouse gas"], ''Nature Reports Climate Change'', 10 July 2008</ref> Furthermore, the report failed to compare NF<sub>3</sub>'s effects with what it replaced, [[perfluorocarbon]], another powerful greenhouse gas, of which anywhere from 30% to 70% escapes to the atmosphere in typical use.<ref name=natgas/>
 
== SeeAyrıcı alsobak ==
*[[Ambilight]], Philips Electronics technology
*[[Comparison of display technology|Comparison of display technologies]]
Satır 171 ⟶ 173:
*[[TFT LCD|TFT-LCD]], a detailed discussion of LCD panels technology
 
== ReferencesKaynaklar ==
{{reflist}}
 
== ExternalDış linksBağlantılar ==
{{Commons category|LCD TVs}}
* [http://www.nytimes.com/2006/12/25/technology/25flat.html ''Plasma is better than LCD?''] according to [[Panasonic]] in 2006
"https://tr.wikipedia.org/wiki/LCD_TV" sayfasından alınmıştır