The iPhone 4 runs Apple's iOS operating system, the same operating system as used on prior iPhones, the iPad, and the iPod Touch. It is mainly controlled by a user's fingertips on the multi-touch display, which is sensitive to fingertip contact. When released the iPhone 4 used iOS 4.[citation needed] The latest version available is iOS 6 (September 2012).[8]
The most noticeable difference between the iPhone 4 and its predecessors is the new design, which incorporates an uninsulated stainless steel frame that acts as the device's antenna. The internal components of the device are situated between two panels of chemically strengthened aluminosilicate glass.[9] It has an Apple A4 processor and 512 MB of eDRAM, twice that of its predecessor and four times that of the original iPhone. Its 3.5-inch (89 mm) LED backlit liquid crystal display with a 960×640 pixel resolution is marketed as the "Retina display".
In October 2011, the iPhone 4S was announced, which retains the same form factor but includes some upgrades such as the A5 processor, Siri, and an improved camera.[10]
Prototypes
Before the official unveiling of the iPhone 4 on June 7, 2010, two prototypes were brought to the attention of the media, breaching Apple's normally secretive development process. Many of the speculations regarding technical specifications proved accurate.
Gizmodo leak
On April 19, 2010, gadget website Gizmodo reported that they had purchased an iPhone prototype for $5000, and furthermore, had conducted a product teardown of the device. The prototype is reported to have been lost by an Apple employee, Gray Powell, in Redwood City, California.[11] Shortly after Gizmodo published detailed information about the prototype, Apple's legal associates formally requested for the phone to be returned to Apple, and Gizmodo responded with the intent to cooperate.[12]
On April 22, officers from the Rapid Enforcement Allied Computer Team (REACT) task force of the California HTTAP Program raided the home of Jason Chen, the Gizmodo editor responsible for reviewing the prototype, seizing all of his computers and hard drives.[13] The Electronic Frontier Foundation criticized the raid as violating journalist source protection laws that forbid the seizure of journalist computers as well as the suspicion that Apple had used its influence as a member of the steering committee which is charged with direction and oversight of the California REACT task force to push police into action in a way that would not normally be conducted for this type of incident. Apple had already received the iPhone prototype before the raid when it was returned by Gizmodo.[14] The District Attorney has stated that the investigation has been suspended, and discontinued searching through the Gizmodo editor's belongings as they determine whether the shield laws are applicable, and cautioned that no charges have been issued at this point.[15][16]
Taoviet leak
Pictures and video of a second prototype were published on a Vietnamese website, Taoviet, on May 12, 2010.[17] It was almost identical to the first, and used an A4 chip manufactured by Apple.[18] The website purchased the prototype for $4,000.[19] DigiTimes reported that the screen resolution of the new phone was 960-by-640, which was confirmed by Apple at the iPhone 4's official announcement.
Release
The iPhone 4 was made available for pre-order on June 15, 2010. Customers attempting to pre-order the iPhone 4 reported problems with the pre-order process on the U.S. and U.K. online Apple Stores which crashed due to the surge in traffic.[20] The same issue was reported with AT&T and SoftBank, Apple's exclusive partners in the United States and Japan respectively, who suspended advance sales of the iPhone 4 as demand threatened to exceed supply.[21] Retail stores were also unable to complete pre-order transactions due to the servers crashing.[22]
Apple and its partner carriers received 600,000 pre-orders for the iPhone 4 in the first 24 hours, the largest number of pre-orders Apple had received in a single day for any device up to that point.[23] Engadget reported that at 20:30 UTC, all iPhone 4 pre-order suppliers had sold out.[24] 1.7 million iPhone 4s were sold in its first three days of availability.[25]
The iPhone 4 has also been released through Orange in Tunisia and was available in eight cities at the launch.[26] In South Korea, it was released by KT on September 10. In Israel, it was released, too, on September 24, through Cellcom, Pelephone and Orange. It was launched in Thailand on September 23 by AIS, DTAC and True Move, and in Malaysia on September 26 in Kuala Lumpur, and nationwide on September 27 according to the website of Maxis.[27]
The iPhone 4 was released in South Africa on September 22 on the Vodacom and MTN networks, in very limited quantities.[28] The iPhone 4 was launched in Vietnam on September 30 by VinaPhone and Viettel, at first in 3 major cities: Hanoi, Ho Chi Minh city and Da Nang, and then all over the country by the end of October.[29][30]
The iPhone 4 was launched in India on May 27, 2011 by Aircel and Airtel. Aircel is releasing the 16 GB iPhone 4 for INR34,500 and the 32 GB one for INR40,990. The smartphone will be available via contract from both service providers.[31]
On January 11, 2011, Verizon Wireless (Verizon) announced during a media event that it had reached an agreement with Apple and would begin selling a CDMA iPhone 4 in the United States, ending Apple's exclusivity agreement with AT&T. The Verizon iPhone went on sale on February 10 and pre orders began on February 3.[32][33][34] The Verizon iPhone includes the 'Personal Hotspot" feature which allows a user to use the iPhone as a wireless hotspot, with up to five devices connecting at one time. The February 3 presale of the iPhone 4 broke Verizon's first day sales records for a single device.[35]
On June 24, 2010, Apple issued a statement that the white iPhone 4 models were proving more "challenging to manufacture" than expected, and initially pushed the release date back to the second half of July. There was a lot of speculation surrounding the delay of the white iPhone 4. Among the most popular rumors are those concerning the phone's internal camera being adversely affected by light leaking in due to the semi-translucent glass and the white paint. Other sources report that the problem relates to Apple's inability to match the white color of the front face plate with that of the home button.[36] On April 27, Apple announced that it would be releasing the white iPhone 4 model on April 28, 2011, for both GSM and CDMA.[37] The release of the white iPhone 4 was carried out on April 28, and is still available for purchase.[38][39]
During Apple's official unveiling of the iPhone 4S on October 4, 2011, it was announced that Sprint would begin carrying the reconfigured CDMA iPhone 4 and the iPhone 4S in the U.S. on October 14.[40][41]
he display of the iPhone 4 is manufactured by LG under an exclusive contract with Apple. 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) (diagonally measured), 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, or 57 arcseconds per pixel[42] is the maximum amount of detail that the human retina can perceive.[43] 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.
This claim has been disputed. Raymond Soneira, president of DisplayMate Technologies, said in an interview with Wired magazine, 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 stated 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, or 36 arcseconds per pixel.[44]
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"
Camera
The iPhone 4 is the first iPhone model to have two cameras. The LED flash for the rear-facing camera (top) and the forward-facing camera (bottom, left of speaker) are not present in older models.
The iPhone 4 features an additional front-facing VGA camera, and a backside-illuminated 5 megapixel rear-facing camera with a 3.85 mm f/2.8 lens[47][1] and 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.[48] The rear-facing camera has a 5× digital zoom.
Connectivity
In contrast to Steve Jobs' announcement 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 iPhone 4 supports 800, 850, 900, 1,900, and 2,100 MHz. The 800 MHz frequency, which is most commonly used in Japanese mobile phones, is not advertised as being supported by Apple.[49] However, the 800 MHz band is a subset of the 850 MHz band, which probably explains why the device is advertised as quad-band.[citation needed] The chip-sets were manufactured by Skyworks Solutions[50] and Infineon for GSM version.
As with most of Apple's mobile products, the iPhone 4 also uses the 30 pin dock connector as its only external data port.
The iPhone 4 is the first generation of iPhone to have a second microphone used for noise cancellation. It is located on the top of the unit near the headphone jack; the main microphone is on the bottom left.[51]
Gyroscope and accelerometer
The iPhone 4 introduces a gyroscopic sensor that detects 3-axis angular acceleration around the X, Y and Z axes, enabling precise calculation of yaw, pitch, and roll. The gyroscope complements the accelerometer, a sensor that has been present since the original iPhone, which detects the device's acceleration, shake, vibration shock, or fall by detecting linear acceleration along one of three axes (X, Y and Z). The combined data from the accelerometer and the gyroscope provides detailed and precise information about the device's 6-axis movement in space. The 3 axes of the gyroscope combined with the 3 axes of the accelerometer enable the device to recognize approximately how far, fast, and in which direction it has moved in space.[52]
Processor and memory
The iPhone 4 is powered by the Apple A4 chip, which was designed by Intrinsity[53] and, like all prior iPhone models, manufactured by Samsung.[54] This system-on-a-chip is composed of an ARM Cortex-A8 CPU integrated with a PowerVR SGX 535 GPU.[55] 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 prior 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.[56]
Storage and Micro-SIM
The iPhone 4 uses a Micro-SIM card on iPhone 4 devices running on a GSM network, which is positioned in an ejectable tray, located on the right side of the device. On a CDMA network, however, the phone connects to the network using an ESN. All prior models have used regular Mini-SIM cards. Depending on the operator, Micro-SIM cards may not be available for all networks globally. As a technical workaround it is possible to trim a Mini-SIM card with a knife or scissors so that it fits into the Micro-SIM tray.[57]
As on prior models, all data is stored in flash memory, 8, 16 or 32 GB, and not on the SIM. Unlike prior generations, the storage capacity is not printed on the back of the unit.
Design
The iPhone 4 is constructed of glass faces and a metal rim.
The iPhone 4 features a redesigned structure, designed by Jonathan Ive. Most notably, the bulges of the back panel as well as the band between the front and back are gone and have been replaced with flattened surfaces. The redesign reflects the utilitarianism and uniformity of existing Apple products, such as the iPad and the iMac. The overall dimensions of the iPhone 4 have been reduced from its predecessor.[58]
It is 4.53 inches (115 mm) high, 2.31 inches (59 mm) wide, and 0.37 inches (9.4 mm) deep, compared to the iPhone 3GS, which is 4.55 inches (116 mm) high, 2.44 inches (62 mm) wide, and 0.48 inches (12 mm) deep; making the iPhone 4.24% thinner than its predecessor, the iPhone 3GS. Steve Jobs claims that it is "the thinnest smartphone on the planet".[58] The reduced size of the device is primarily due to the externally placed antenna.
The iPhone 4 is structured around a stainless steel frame that wraps around the edge of the phone, acting both as the primary structure for the device and as the iPhone 4's antennas. This metal band features two slits on the GSM version of the phone, one at the lower left, and one at the top (and a fake slit along the lower right, to cosmetically mirror the one at the lower left) that divide the band into two antenna sections: the left section of the band serves as the Bluetooth, Wi-Fi, and GPS antenna, and the right and lower sections of the band act as the antenna for GSM and UMTS connectivity.
On the CDMA version of the phone there are four slits in the metal band. Two at the top (on the left and right) and two at the bottom. This divides the metal band into four different segments, which like the GSM version of the phone, serves as different antennas for connectivity. The top portion of the band (divided by the top left and right slits) is for connecting to the CDMA network. The left portion of the metal band is for Bluetooth, Wi-Fi, and GPS just like the GSM version. The right side is not an antenna, but serves to cosmetically mirror the left side and also to create a similar look to the GSM version of the phone.
The internal components are situated between two panels of aluminosilicate glass, described by Apple as being "chemically strengthened to be 20 times stiffer and 30 times harder than plastic," theoretically allowing it to be more scratch resistant and durable than the prior models.[9]
In fall 2010, pentalobular screws started to replace the Philips screws used in post-repair units in the US and in production units in Japan.
Source: Wikipedia.
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