The iPhone 4 is a slate smartphone designed and developed by Apple. It is the fourth generation of iPhone, and successor to the iPhone 3GS. It is particularly marketed for video calling, consumption of media such as books and periodicals, movies, music, and games, and for general web and e-mail access. It was announced on June 7, 2010 at the WWDC 2010 at the Moscone Center, San Francisco, and was released on June 24, 2010 in the United States, the United Kingdom, France, Germany and Japan.
The new design is more squared off, with a flatter back, creating a stronger shape in both your hand and eye. It’s not trying to hide the buttons, but rather showing off their careful placement and clean lines. I think the overarching themes here are power and superiority, rather than slickness. The glass on both sides, we found out in the closing video, is “almost as strong as sapphire crystal” and can deform pretty seriously without breaking. Good news to those of us afraid of exploding iPhones.
The iPhone 4 runs Apple’s iOS operating system, the same operating system as used on previous iPhones, the iPad, and the iPod Touch. It is primarily controlled by a user’s fingertips on the multi-touch display, which is sensitive to fingertip contact.
The display on the iPhone 4 is designed by Apple and is manufactured by LG, it features an LED backlit TFT LCD capacitive touchscreen with a pixel density of 326 pixels per inch (ppi) on a 3.5 in (8.9 cm) (960×640) display, each pixel is 78 micrometres in width. The display has a contrast ratio of 800:1. The screen is marketed by Apple as the “Retina Display”, based on the assertion that a display of approximately 300 ppi at a distance of 12 inches (305 mm) from one’s eye is the maximum amount of detail that the human retina can process. With the iPhone expected to be used at a distance of about 12 inches from the eyes, a higher resolution would allegedly have no effect on the image’s apparent quality as the maximum potential of the human eye has already been met.
The display has been the subject of some controversial criticism; focused primarily on Apple’s claims that the displays resolution exceeds the maximum amount of detail that the human retina can process. Raymond Soneira, president of DisplayMate Technologies, reported in an interview with Wired Magazine saying that the claims by Jobs’ are something of an exaggeration: “It is reasonably close to being a perfect display, but Steve pushed it a little too far”. Soneira continued to state that the resolution of the human retina is higher than claimed by Apple, working out to 477 ppi at 12 inches (305 mm) from the eyes.
The iPhone 4 features an additional front-facing VGA camera, and an improved (backslide-illuminated, big physical pixel size) 5 megapixel rear-facing camera integrated with an LED flash. The rear-facing camera is capable of recording HD video in 720p at 30 frames per second. Both cameras make use of the tap to focus feature, part of iOS 4, for photo and video recording. The rear-facing camera has a 5× digital zoom.
In contrast to what Steve Jobs announced at WWDC 2010, recent Federal Communications Commission documentation has shown that the iPhone 4 contains a Penta-Band 3G UMTS antenna, not a Quad-Band 3G UMTS radio, as advertised by Apple. According to the FCC documentation filed by Apple, the radio inside the device supports; 800, 850, 900, 1900, 2100. The 800 MHz frequency, which is most commonly used in Japanese mobile phones, is not advertised as being supported by Apple.
As with many other products manufactured by Apple, the iPhone 4 also uses the 30 pin dock connector as its only external data port.
However, Phil Plait, author of Bad Astronomy, whose career includes a collaboration with NASA regarding the camera on the Hubble Space Telescope, responded to the criticism by stating 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, the picture will look just fine.”
Processor and memory
The iPhone 4 is powered by the Apple A4 chip, which was designed by Intrinsity and, like all previous iPhone models, manufactured by Samsung. This system-on-a-chip is composed of a Cortex-A8 CPU integrated with a PowerVR SGX 535 GPU. The Apple A4 is also used in the iPad where it is clocked at its rated speed of 1 GHz. The clock speed in the iPhone 4 has not been disclosed . All previous models of the iPhone have underclocked the CPU, which typically extends battery life and lowers heat dissipation.
The iPhone 4 has 512 MB of eDRAM. The additional eDRAM supports increased performance and multi-tasking.
As usual, Apple isn’t fessing up about the RAM situation, though we have on very good authority that the iPhone 4 has 512MB onboard, a big step up from the 256MB in the previous model and the iPad. We would have liked to see it futureproofed with something like 1GB, but then again, Apple’s got to sell a new phone in a year. As far as internal storage goes, you can buy the new iPhone in either 16GB or 32GB capacity — fine for now, but since the company has just introduced 30FPS 720p video recording, you could find yourself outgrowing that number pretty quickly. It’s a little odd, in fact, that the company didn’t double down here and bump the capacity to 64GB, as it’s recently done with the iPod touch. In terms of wireless, the iPhone 4 is packed with an 802.11n WiFi radio, as well as a quad-band HSUPA chip and Bluetooth 2.1.
So how is Apple making this magic happen? Here’s a breakdown of just exactly what multitasking really means (and feels like) on the new iPhone (and the 3GS):
Fast app switching: You know how you can leave off in Mail halfway through writing a response and go back to exactly where you were? Well that happens everywhere now. When you leave the app, you go back in exactly the same place. And it happens quickly. Fast app switching is essentially like toggling between “paused” applications. This combined with Apple’s new app switcher (double tap the home button to bring up your most recently used apps) destroys that annoying iPhone feeling of going in and out and in and out. It just doesn’t exist anymore, provided all your apps are up to date, which is going to take some time. It’s amazing how much this single feature counts — it’s definitely one of the prime movers here, and it’s so simple it’s stupid. We would have liked to see options for “favorite” apps or some way to prioritize what you’re switching to, but once you get used to this system — which just puts whatever you’ve used most recently to the far left — it makes some sense.
Task completion: Basically, task completion lets an app do its thing even if you leave it. So if you’re uploading or downloading a picture in Evernote or Dropbox, or saving an article in the New York Times app, even if you navigate away, the job is done when you get back to the app. This accounts for a lot of what we think of as multitasking. Most of your apps are just idling — it’s only when you interact with them that it counts. We don’t know the boundaries for this API, though it seems to leave a lot of room for creative use. We know it’s not just big jobs, it’s little ones too — Colloquy uses this feature to keep you connected to your IRC host. To be honest, that kind of behavior is one thing we thought we wouldn’t see in iOS 4, and here it is. Hopefully Twitter app devs and other instant messaging clients will utilize the API in a similar manner.
Background audio and VoIP: These two are straightforward. The first allows for music playing apps to keep their stream running in the background (and even gives them little widget controls in the app switcher), and the second allows VoIP connections to stay active. That means you can stay on a Skype call and go check your mail, but it also means that the VoIP connection will be aware of incoming calls when you’re not actively using an app. Additionally, this API can be used to allow for recording even if you exit an app, as demonstrated effectively in the new version of Evernote.
Background GPS: Basically, GPS apps can keep running in the background… for obvious reasons. This one will drain your battery if you’re not docked — but who’s using a GPS app and not plugging that thing in? Okay, we might be a little guilty of that. Regardless, this will keep your navigation software afloat if you have to take a call, and apparently will let GPS-centric apps like FourSquare check in even if you’re not running it in the foreground.
Source : Mobile Crunch & Wikipedia