Lurking Inside the iPad Is the Future of High-Def Displays
The appearance of indium gallium zinc oxide transistors in iPads shows that the display industry is poised to begin churning out a new breed of high-performance screens.
By Mike Orcutt on November 14, 2013
Case cracked: Teardown specialists who examined the latest iPads report that at least some are using a novel high-resolution display technology.
One of the most important innovations in Apple’s latest iPads lies behind the screen. In many of the tablets, the pixels in the display are controlled by transistors made of a material called indium gallium zinc oxide (IGZO), a promising replacement for the conventional amorphous silicon.
Displays featuring “backplanes” of IGZO transistors should make it possible for tablets and TVs to have much higher-resolution displays while consuming significantly less power. The technology has already cropped up in low volumes of high-end smartphones and televisions, but its appearance in iPads suggests we can expect IGZO to improve several more popular products over the next year.
Display makers are racing to produce screens with ever-higher resolution, including ones based on organic light-emitting diodes (OLEDs), which promise not only a better picture but also greater power efficiency and compatibility with flexible form factors. But the display makers have run up against the physical limits of amorphous silicon, because electrons don’t move through that material fast enough. If transistors can be made from a material with a higher degree of “electron mobility,” the transistors can be smaller, making it possible to pack more pixels into a given space.
The highest-resolution smartphone screens already feature an alternative material called low-temperature polysilicon (LTPS). But LTPS panels are relatively expensive to make, and the fabrication method has proved difficult to adapt to displays larger than those on phones. IGZO transistor arrays are cheaper to make, and the manufacturing method is more compatible with larger screens. Though electrons don’t move through IGZO as quickly as they do through LTPS, IGZO’s electron mobility is still 10 times better than amorphous silicon’s. This means IGZO can be used to efficiently run OLED pixels, which require more current than their LCD counterparts.
Not all of the latest iPads have IGZO displays; in fact, it’s not entirely clear how many of the tablets have the technology. Luke Koo, senior manager of a team in Seoul that tears down devices for the IHS research firm, says IGZO-based displays made by Sharp are in at least some iPad Minis. Jennifer Colgrove, the lead analyst at Touch Display Research, also says Sharp is supplying IGZO displays for Apple tablets, but she is unsure whether they are in the Mini, the larger iPad Air, or both. Another Apple supplier, LG Display, can now mass-produce IGZO panels and is making them for its 55-inch OLED TV, Colgrove says.
By analyzing the power consumption of the iPad Air, Raymond Soneira, the founder of DisplayMate Technologies, found something unusual: its display uses 57 percent less power than the previous generation of iPads. That tells him the display “simply can’t be amorphous silicon,” though it’s possible it uses LTPS and not IGZO.
Apple did not return messages seeking comment.
No matter how extensively the iPads are using IGZO, it’s clear the technology is finally gaining momentum after years of manufacturing challenges. Among other problems, it has been hard to produce transistors, which are made by depositing thin films of various materials, with the necessary uniformity.
Last month, however, semiconductor equipment maker Applied Materials announced the release of new manufacturing tools that the company claims will address the uniformity problem and other challenges. It says it is working with several unnamed companies to ramp up manufacturing capacity. The technology is compatible with glass panel sizes used in both tablets and televisions, says John Busch, general manager of a display group at Applied Materials.
Infographic: The IceCube Neutrino Observatory
Here's a look at the IceCube Neutrino Observatory located at the South Pole.
by Raoul Ranoa
November 21, 2013, 11:52 a.m.
Copyright © 2013, Los Angeles Times
en.wikipedia.org/wiki/Frederick_SangerFrederick Sanger, OM, CH, CBE, FRS, FAA /ˈsæŋər/ (13 August 1918 – 19 November 2013) was a British biochemist who won the Nobel Prize for Chemistry
Frederick Sanger, Father of DNA Sequencing, Dead at 95
Sanger is one of only three scientists to have been awarded two Nobel Prizes in the sciencesMolecular Biology at the University of Cambridge, UK. He was 95.
The chemist won the 1958 Nobel Prize for Chemistry for developing a method to determine the complete amino acid sequence of insulin. Twenty-two years later, the Nobel Committee awarded him the 1980 prize in Chemistry for discovering a way to determine the ordered sequence of DNA molecules. An adaptation of this method — known as Sanger sequencing — was used to sequence the human genome. He is only scientist to have won two Chemistry Nobels. Just two other scientists have been awarded two Nobel Prizes in the sciences: Marie Curie (Physics in 1903 and Chemistry in 1911) and John Bardeen (Physics in 1956 and 1972).
After the announcement of a draft human genome sequence in 2001, Sanger penned an essay for Nature Medicine on the history of DNA sequencing. “When we started working on DNA I don’t believe we were thinking about sequencing the entire human genome — perhaps in our wildest dreams but certainly not within the next 30 years,” Sanger wrote.
His archived lab notes were recently made available by the Wellcome Collection.
Update 12:53 p.m
The Medical Research Council (MRC) Laboratory for Molecular Biology (LMB), where Sanger spent much of his career, has posted an obituary encapsulating his professional life. It also notes that Sanger turned down a knighthood because he did not want to be called “Sir”.
Jeremy Farrar, the new director of the Wellcome Trust (which named its Sanger Institute after him), has issued a statement: “I am deeply saddened to learn of the death of Fred Sanger, one of the greatest scientists of any generation and the only Briton to have been honored with two Nobel Prizes. Fred can fairly be called the father of the genomic era: his work laid the foundations of humanity’s ability to read and understand the genetic code, which has revolutionized biology and is today contributing to transformative improvements in healthcare.”
Update 1:40 p.m.
J. Craig Venter — whose privately funded effort to sequence the human genome was criticized by Sanger for limiting access — has chimed in via Twitter.
One of the most important scientists of the 20th century! Fred Sanger has died. He twice changed the direction of the scientific world.Update 2:00 p.m.
— J. Craig Venter (@JCVenter) November 20, 2013
Science journalist and regular Nature contributor Ed Yong has a rather cryptic tribute on his blog: “CGCATTCCGTTTCGCGAAGATAGCGCGAACGGCGAACGC.” This tool will help translate.
Update 2:30 p.m.
University of Oxford neuroscientist and former MRC chief Colin Blakemore had this to say: “[H]e was a disarmingly modest man, who once said: ‘I was just a chap who messed about in his lab’. The journal Science rightly described him as ‘the most self-effacing person you could hope to meet’. Fred Sanger was a real hero of twentieth-century British science.”
Richard Henderson, former director of the LMB, said: “He was a superb hands-on scientist with outstanding judgment and skill, and an extremely modest yet encouraging way of interacting with his younger colleagues. I particularly remember one young scientist who had asked Fred for advice being told ‘I think you should try harder’. The example he set will continue to motivate young scientists even now he has gone.”
This article is reproduced with permission from the magazine Nature. The article was first published on November 20, 2013.
- 當代生物化學大師 桑格與世長辭 2013年11月20日 閻紀宇／綜合報導 有「基因體學之父」之稱的英國生物化學家桑格（Frederick Sanger），19日在英國劍橋於睡夢中病逝，享壽95歲。桑格曾經在1958年及1980年兩度榮膺諾貝爾化學獎，是至今唯一締造這項記錄的科學家。 桑格於1918年8月13日出生於英國格洛斯特郡，父親是一位醫生。他畢業於劍橋大學 聖約翰學院，原本打算研究醫學，後來對生物化學產生興趣，致力於蛋白質與DNA序列研究。 1955年，桑格將胰島素的胺基酸序列完整定序出來，同時證明蛋白質具有明確構造。他利用自己新發現的「桑格試劑」將胰島素降解成小片段，再與胰蛋白酶混 合，進行分析。這項研究讓他單獨得到1958年諾貝爾化學獎。 1975年，桑格研發出「鏈終止法」（chain termination method）來測定DNA序列，這種方法也稱做「雙去氧終止法」或是「桑格法」。兩年之後，他成功定序出Φ-X174噬菌體5000個鹼基的基因體序 列，這是科學家首次完成完整的基因體定序工作。 這項研究後來成為人類基因體計畫的關鍵，也讓桑格1980年再度獲得諾貝爾化學獎。諾貝爾獎歷史上，只有居禮夫人（Marie Curie）、鮑林（Linus Pauling）與巴丁（John Bardeen）與桑格曾經兩度獲獎，但只有桑格兩度拿下化學獎。 桑格於1982年退休，英國惠康信託基金會和醫學研究理事會於1993年為他成立了桑格中心（Sanger Centre），後來更名桑格研究院（Sanger Institute），是全球基因體研究的重鎮。 桑格對當代分子生物學貢獻厥偉，但謙沖為懷，風範深受科學界景仰。他經常說：「我只是一個在實驗室裡亂搞的傢伙。」但是英國醫學研究理事會前任執行長布萊 克莫爾說：「桑格是20世紀英國科學界真正的英雄。」 好文章請讓更多人看見！如果您喜愛「風傳媒」的文章，請按讚或分享：www.facebook.com/stormmedia