Apple Retina Display Technical details

 
 
Retina Display is a brand name used by Apple for liquid crystal displays which they claim to have a high enough pixel density that the human eye is unable to notice pixelation at a typical viewing distance. The term is used for several Apple products, including the iPhone, iPod Touch, iPad, and MacBook Pro.^[1] As the typical viewing distance would be different depending on each device's usage, the pixels per inch claimed as retina quality can be different for the smallest devices (326, iPhone and iPod Touch): greater than the mid-sized devices (264, iPad) and greater than the larger devices (220, MacBook Pro). The displays are manufactured by different suppliers. Currently, the iPad's display comes from the same suppliers Samsung use whilst Macbook Pro displays are mostly made by LG's suppliers, along with the iPhone and iPod Touch displays.^{[citation needed]} Apple has applied to register the term "Retina" as a trademark in regard to computers and mobile devices with the United States Patent and Trademark Office, Canadian Intellectual Property Office, and in Jamaica.^[3][4]

Contents 1 Technical information 1.1 Retina Display trigonometrical pixel density 2 Criticism 3 See also 4 References

Technical information

Apple markets the following devices as having retina displays.

Model	PPI (pixels per inch)	ppcm (pixels per cm)	Resolution	Typical Viewing Distance (in/cm)	Single Pixel Visual angle (arcminutes)
iPhone 4/4S and iPod Touch (4th generation)	326	128	960×640	10 inches (25 cm)	1.1
iPhone 5 and iPod Touch (5th generation)			1136×640
iPad (3rd generation)	264	104	2048×1536	15 inches (38 cm)	0.87
MacBook Pro (3rd generation)	220	87	2880×1800	20 inches (51 cm)	0.78

• For comparisons, see also: List of displays by pixel density

Retina Display trigonometrical pixel density

Retina Display's real measure unit is PPD: Pixel Per Degree. If a display's pixel density is more than 53 PPD (it's 57 ppd in case of iPhone 4's display) viewing it from its optimal distance, that is a Retina Display. 53 PPD pixel density means that there are 53 pixels visible in one degree angle. Any display's pixel density (from phone displays to huge projectors) can be described with this distance-independent universal parameter.

Criticism

According to Raymond Soneira, president of DisplayMate Technologies, the resolution of the actual human retina is higher than claimed by Apple, working out to 477 pixels per inch at 12 inches (305 mm) from the eye.Phil Plait of Bad Astronomy wrote a response saying that "if you have [better than 20/20] eyesight, then at one foot away the iPhone 4's pixels are resolved. The picture will look pixellated. If you have average eyesight [20/20 vision], the picture will look just fine," and concluded, "So in my opinion, what Jobs said was fine. Soneira, while technically correct, was being picky." Retinal neuroscientist Bryan Jones, using a similar but more detailed analysis, came to a similar conclusion on his blog, stating "...I’d find Apple’s claims stand up to what the human eye can perceive."

^{Via : Wikipedia}

Nokia India announces Lumia 510 as a “Diwali Gift”.To be priced less than 11000 INR.

Nokia seems to be in a mood of taking advantage of this festival season shopping in India to the Fullest. Vipul Mehrotra, Head, Smartphones, Nokia India has launched the cheapest Lumia yet Lumia 510 in India  and termed it as “Diwali Gift” to India. The definitive price is not yet known, but has been tipped by Nokia to be below 11000 INR at launch.
This is bit surprising because China was supposed to be the first country to get the device. But seems Nokia India has managed to get its hands on the device before any body else.
Wanna have a look at specs and hands-on video. Here you go,

• 4 “LCD screen,
• 5MP AF Camera, confirmed by Nokia India.
• 120.7×64.9×11.51(mm)
• 129(g)
• GSM-WCDMA-HSPA
• 800MHz MSM7227A + 256MB RAM
• Windows Phone 7.5/7.8

Every detail about ipad mini Released on 23 oct 12

The iPad Mini is here. It's a sleek, thin and light 7.9-inch tablet made of anodized aluminum and glass that follows the format reduction pioneered by Google and Amazon. This thing is really neat. Really light and thin at 0.68 pounds and 7.2 millimeters.
In a nutshell: it has better specs and it's thinner and lighter than the Amazon Kindle Fire HD and the Google Nexus 7, but much more expensive too.

The screen

The iPad Mini has a larger surface than the Nexus 7 or the Kindle Fire HD: 7.9 inches vs 7 inches. Remember that this size is diagonal, so the difference is quite substantial. The area of the iPad Mini is smaller than the regular iPad, but it's significantly larger than the panoramic Android 7-inch tablets. Here's a comparison:

In fact, the iPad mini's screen has 35% more real estate than the Nexus 7. According to Apple, that gives you a 50% larger surface to browse the web in portrait mode and 67% larger in landscape mode.
It's yet to be seen if the the size difference will affect consumers decision. My guess is yes, if consumers think the price is competitive enough. Are all the features and the thinner, lighter and prettier design worth the price differential with the Kindle Fire HD? $130 is a lot of money.
The pixel resolution is 1024 x 769 pixels. It's not as dense as the iPad 3 and 4, but at that size it will be much sharper than the previous generations.
One cool thing about the screen: it recognizes whether your thumb is resting on the display or actually using it. Clever.

Physical specifications

The iPad mini is an all anodized aluminum design, like the iPhone 5. The Google Nexus 7 is made of plastic, while the Kindle Fire HD has a rubberized back that is quite nice to grab. Like the iPhone too, it comes in black and white.
It's quite light and thin. It's comparable to a pad of paper, like Apple says: just 0.68 pounds and 7.2 millimeters thin. That's 53% lighter than the fourth-generation iPad. It compares very favorably to the Nexus 7 (0.75 pounds and 10.4 millimeters).

Connectivity

Some models come with LTE connectivity, like the Kindle Fire HD 8.9-inch. But that's much more expensive. The comparable regular Fire HD and the Nexus 7 only have Wi-Fi.
It naturally comes with 802.11a/b/g/n Wi-Fi and Bluetooth (like Amazon and Google's models).
Like all the latest iOS products, it uses a Lightning port too.

Guts

Basically, this is a reduced iPad 2. It uses the same dual-core A5 processor, and it probably comes with the same RAM as the old iPad: 512MB. Apple say it's basically the same (or better) guts but in a reduced package (an exception is the cameras and the Lightning port). Both the Fire HD and the Nexus 7 come with 1GB of RAM. We will have to wait to learn how much RAM it has, though. Perhaps this has been upgraded too.

Storage

Like all the iPads, it comes in 16GB, 32GB and 64GB flavors.

Battery life

Apple claims a 10 hour battery life surfing the web on Wi-Fi, watching video or listening to music, using its 16.3-watt-hour rechargeable lithium-polymer battery.
The Nexus 7 is rated by Google at 8 hours. Amazon says that their Fire HD has 11 hours.

Cameras

It has a FaceTime HD camera, which is better than the one in the iPad 2. It's comparable to the Nexus 7, which is 1.2 megapixels too. The iPad has a backside illuminated sensor and, like its older sibling, it supports Face detection.
Like the bigger iPad, it comes with a 5 megapixel camera on the back. This is something that neither the Nexus 7 nor the Kindle Fire HD have.

Price and availability

If you were hoping for a $250 starting point, brace yourself for disappointment. It starts at $329 for the Wi-Fi only version, with 16GB of storage. The 32GB and 64GB are $429 and $529. If you want the LTE connectivity, you will have to pay $130 more.
The Kindle Fire HD and the Nexus 7 don't have LTE support at any price point (if you want LTE on the Fire HD, you have to get the 8.9-inch model, which is the competition to the iPad 4 starting at $499 for the 32GB model). On the Wi-Fi front, however, both Android tablets have a much better price, specially the Fire HD, which is $199 for the 16GB model. The $199 Nexus 7 will only get you 8GB.
You can start pre-order this Friday, October 26, and receive the Wi-Fi version on Friday next week, November 2. The cellular versions will come first to the US, two weeks after that date. They will come later to the rest of the world (no announcement yet).
The iPad 2 remains at $399, by the way—the iPad 3 is gone, replaced by the 4th generation model at $499.

Via : Gizmodo

What Is Anodizing?

The lustrous patina that protects the backside of Apple's new iPad Mini isn't just some cheap shellac or sealant coat—it's actually "grown" on the metal itself in an electrochemical process known as anodization. Here's how.

Anodization takes a nonferrous metal...

Aluminum won't rust like iron and steel, but the metal is quite susceptible to corrosion. Its corrosion, or oxidation, produces a layer of aluminum oxide across the surface. Luckily, that aluminum oxide layer is actually quite durable, and it can act as a shell to protect the metal from degrading further.

...and coats it with an oxide layer...

The anodizing industrial process starts a controlled oxidation to create an engineered surface layer. It was pioneered in 1923, originally called as the Bengough-Stuart process as a means to seal Duralumin seaplane parts so they could resist corrosion. Today, it's used on products from roofing to cookware, along with plenty of consumer electronics.

...during an electrolytic process...

The anodizing process is simple. An electric current, as high as 300V DC (but normally only about 15-20V), passes through the metal. Then, the aluminum dips into an electrolytic acid bath, often composed of sulfuric acid. On the interior of the acid tank, a plate of lead (or 6063t6 alloy aluminum) acts as the cathode, or negative terminal. The charged aluminum acts as the anode, completing the circuit.
In the reaction, oxygen ions migrate from the electrolyte onto the surface of the anodizing aluminum. The ions build into a protective layer of oxide that is harder, more durable, and roughly 30-percent thicker than the pure aluminum below it.

...designed to protect the metal inside.

The anodized layer is highly ordered, and it contains nanopores 10-150 nanometers in diameter. These nanopores are essential in the anodizing process, as they allow oxygen to penetrate the aluminum surface and propagate the reaction. However, these pores also let water and air to penetrate the metal, causing corrosion—the exact thing anodization is meant to avoid.
So the outermost layer of oxide is typically filled in with dyes, or other corrosion inhibitors, before being sealed. The thickness of the oxide layer makes a difference too. Thicker layers can absorb dyes better, while thinner layers create a brilliant sheen.
Along with corrosion resistance, anodizing can provide cosmetic benefits, and help aluminum's ability to take a coat or primer or glue. But anodizing isn't a magic bullet of metal protection. The performance trade-offs include a harder aluminum that's more brittle. The anodized layer is less likely to crack through physical wear, but it's more likely to crack through thermal heat stress.

[Anodizing - Wikipedia - Milinc]

How Does Wi-Fi Work?

To mankind, Wi-Fi represents many things: Freedom of speech, access to information and the ability to keep in touch with both family members and strangers, near and far. But what does Wi-Fi stands for? Some will claim it’s shorthand for Wireless Fidelity, sort of like how people of New York call the region south of Houston Street “SoHo” and San Francisco calls South of Market “SoMa.”
But, that’s not true.
In 1999, the Wireless Ethernet Compatibility Alliance (not to be confused with the Rebel Alliance in Star Wars) wanted to set a standard for wireless connections. It was called IEEE 802.11, which didn’t exactly roll off the tongue. So, to be sure it would catch on, they needed to offer a brand identity to consumers. When given 10 options by consultancy Interbrand, the one they picked was Wi-Fi (check out the original press release).
That’s it. There’s no long, complicated, hard-to-pronounce terminology behind the curtain. Wi-Fi simply means Wi-Fi.

How It Works

Wi-Fi is a high-speed Internet and network connection without the use of cables or wires — you could use “wireless” as a solid synonym. The technology uses radio waves to transmit data between your computer and a router.
SEE ALSO: Hide Your Kids, Hide Your Wi-Fi: Mashable’s Favorite Wi-Fi Names It found early success in July 1999, when Apple built in Wi-Fi as an option on iBook computers, calling it AirPort. Other computer makers followed suit, and thus offered consistency to consumers.

Introduction of the Hotspot

Wi-Fi was most commonly used in the home, when people had many devices they wanted to put on the same network. This allowed for seamless file-sharing between computers and fewer cables to trip over. As laptops became more common, the need for an Internet connection that allowed for portability became more relevant.
SEE ALSO: Boingo and Google Offer Free Wi-Fi in 4,000 Locations Public hotspots were initially paid, at places like coffee shops and restaurants, and critics were skeptical of their longevity (and for good reason). Now, Wi-Fi is usually offered free as a service to customers in an airport or coffee shop, but hotspots are popping up even in less commerce-focused locations like subways, airplanes and phone booths.

Wi-Fi vs. 3G

Wi-Fi’s shortcoming is that it only works in close range because it’s dependent on radio waves. You must be in a hotspot to use it. But 3G, on the other hand, follows you. Devices like a Nook, Kindle or iPad are priced higher with 3G, plus, you pay a carrier like AT&T or Verizon for the service. Alternatively, 3G can be bought separately as a mobile hotspot — in this case, your mobile hotspot gets the Internet connection via 3G and in turn provides a connection to your other (multiple) devices via Wi-Fi.
Next time you walk into a coffee shop, keep in mind that your rhetoric reflects what kind of web user you are — asking if they offer free Internet will out you as a newbie, while requesting the “password for the wireless” is a small improvement. Next time, say you’re interested in their Wi-Fi, and say it like you know the term is short for nothing, especially not “Wireless Fidelity.” Want ultimate nerd cred? Ask about the IEEE 802.11 (but don’t blame me if you have to settle for a latte).

Via:Mashable