Apple iPhone 4

IPhone 4 logo.svg
IPhone 4 in hand.jpg
Apple iPhone 4 (black UMTS/GSM model)
Developer Apple Inc.
Manufacturer Foxconn (UMTS/GSM model)
Pegatron (CDMA model)
Slogan This changes everything. Again.
Form factor Slate bar
Generation 4
Release date GSM model (black): 24 June 2010
CDMA model (black): 10 February 2011
GSM and CDMA models (white): 28 April 2011
Operating system iOS 4.3.3 (build 8J2) (GSM)
Released May 4, 2011; 43 days ago
iOS 4.2.8 (build 8E401) (CDMA)
Released May 4, 2011; 43 days ago
Power Built-in rechargeable Li-ion battery
3.7 V at 1420 mAh
CPU Apple A4 (ARM Cortex-A8)
GPU Apple A4 (PowerVR SGX 535)
Storage capacity 16 GB or 32 GB flash memory
Memory 512 MB eDRAM
Display 3.5-inch (89 mm) diagonal 1.5:1 aspect ratio widescreen
LED backlit IPS TFT LCD Retina display
640×960 resolution at 326 ppi (0.61 Megapixels)
800:1 contrast ratio (typical)
500 cd/m2 max brightness (typical)
Fingerprint-resistant oleophobic coating on front and back glass
Audio Single loudspeaker
3.5 mm TRRS
Frequency response: 20 Hz to 20 kHz
Input Multi-touch touchscreen display
Dual microphone
3-axis gyroscope
3-axis accelerometer
Digital compass
Proximity sensor
Ambient light sensor
Rear camera 5 MP back-side illuminated sensor
HD video (720p) at 30 fps
1.75 μm size pixels
5× digital zoom
Tap to focus video or still images
LED flash
Photo and video geotagging
Front camera 0.3 MP (VGA)
SD video (480p) at 30 fps
25.17 μm size pixels
Tap to focus video or still images
Photo and video geotagging
Connectivity Wi-Fi (802.11 b/g/n) (2.4 GHz only)
Bluetooth 2.1 + EDR
GSM model: Quad-band GSM/GPRS/EDGE
(800 850 900 1800 1900 MHz)
(800 850 900 1900 2100 MHz) (800 MHz not yet announced as supported by Apple)
CDMA model: Dual-band CDMA/EV-DO Rev. A (800 1900 MHz)
Hearing aid compatibility GSM
3G 850/1900 MHz M4, T4
2G 850 MHz M3, T3
2G 1900 MHz M2, T3
Online services App Store, iTunes Store, iBookstore, MobileMe
Dimensions 115.2 mm (4.54 in) (h)
58.66 mm (2.309 in) (w)
9.3 mm (0.37 in) (d)
Weight 137 g (4.8 oz)
Predecessor iPhone 3GS
Website Apple – iPhone

The iPhone 4 is a touchscreen smartphone developed by Apple. It is the fourth generation of iPhone, and successor to the iPhone 3GS. It is particularly marketed for video calling (marketed by Apple as FaceTime), 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 held 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 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 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.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”.

The latest operating system release is iOS 4.3.3 (for GSM) and 4.2.8 (for CDMA).


Prior to 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.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.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 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 prior to the raid when it was returned by Gizmodo. 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.

Taoviet Leak

Pictures and video of a second prototype were published on a Vietnamese website, Taoviet, on May 12, 2010. It was almost identical to the first, and used an A4 chip manufactured by Apple. The website purchased the prototype for $4,000. 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.


Steve Jobs, Apple CEO, holding a white iPhone 4. The white iPhone 4 would not be released until April 2011.

The iPhone 4 was made available for pre-order on 15 June 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. 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. Retail stores were also unable to complete pre-order transactions due to the servers crashing.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 has received in a single day for any device. Engadget reported that at 20:30 UTC, all iPhone 4 pre-order suppliers had sold out. 1.7 million iPhone 4s were sold in its first three days of availability.

The iPhone 4 has also been released through Orange in Tunisia and was available in eight cities at the launch. 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. The iPhone 4 was released in South Africa on September 22 on the Vodacom and MTN networks, in very limited quantities. 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.

The iPhone 4 was launched in India on 27 May 2011 by Aircel and Airtel. Aircel is releasing the 16GB iPhone 4 for Indian Rupee symbol.svg34,500 and the 32GB one for Indian Rupee symbol.svg40,990. The smartphone will be available on a contract basis from both the service providers.

On January 11, 2011, 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.The Verizon iPhone includes the ‘Personal Hotspot” feature which allows a user to use the iPhone as a wireless hotspot, with up to 5 devices connecting at one time. The February 3 presale of the iPhone 4 broke Verizon’s first day sales records for a single device.

On 24 June 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. On April 27 Apple announced that it would be releasing the white iPhone 4 model on April 28, 2011 for both GSM and CDMA. The release of the white iPhone 4 was carried out on April 28, and is still available for purchase today.


The display of 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) (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 is the maximum amount of detail that the human retina can perceive.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.

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.”


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 an improved (backside-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 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, 1900, and 2100 MHz. The 800 MHz frequency, which is most commonly used in Japanese mobile phones, is not advertised as being supported by Apple.[However, the 800 MHz band is a subset of the 850 MHz band, which probably explains why the device is advertised as Quad-Band. The chip-sets were manufactured by Skyworks Solutions and Infineon for GSM version.

As most of Apple’s mobile products, the iPhone 4 also uses the 30 pin dock connector as its only external data port.

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.

Processor and memory

The iPhone 4 is powered by the Apple A4 chip, which was designed by Intrinsity[citation needed] and, like all previous iPhone models, manufactured by Samsung.[44] 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.

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 previous 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.

As on previous models, all data is stored in flash memory, 16GB or 32GB, and not on the SIM. Unlike previous generations, the storage capacity is not printed on the back of the unit.


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. From the side, the metal structure most resembles the original iPhone, but from the rear, the plastic evokes the iPhone 3G and 3GS. The general layout of the device remains the same. The overall dimensions of the iPhone 4 have been reduced from its predecessor. It is 4.5 inches (110 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”. 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, however, 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 previous models.

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.


The iPhone 4 supports FaceTime, an embedded video calling application that is able to use either the front or back camera over a Wi-Fi connection to communicate with another iPhone 4, the fourth-generation iPod Touch, or any Mac computer running Mac OS X 10.6 Snow Leopard.



An iPhone 4 Bumper is a ring of rubber and plastic that surrounds the edge of the iPhone 4. The inner part is rubber with the external band made of plastic. The Bumper wraps around the edges of the device protecting the edges, and to a lesser extent, the screen. The Bumper does not cover the front or rear of the phone, though it does slightly raise the iPhone off whatever surface it is sitting on.

Additionally, the plastic band houses metallic buttons for the volume controls and sleep/wake button. The six holes in the Bumper enable access to the mute switch, dock connector, headphone jack, speaker, and microphones.The bumper also can be used to prevent the “antenna issue” that users face when holding the parts of the steel band where the antennas are, that could cause the phone’s signal to drop

Technical issues

Some users have reported a yellow discoloration of the screen, which was attributed to the glass lamination glue that was used. It did not have time to dry fully before the unit reached consumers due to the speed of manufacturing. Another issue reported by some users within days of the iPhone 4 release was that during calls the proximity sensor can be insensitive, so that facial contact with the touchscreen can end calls, mute calls, and dial other numbers


Shortly after the iPhone 4 was launched, some consumers reported that signal strength of the phone was reduced when touching the lower left edge of the phone, bridging one of the two locations which separates the two antennas, resulting in dropped calls in some areas with lower signal reception. In response, Apple issued a statement advising that customers should “avoid gripping [the phone] in the lower left corner” when making or receiving a call.
As a consequence of this problem, it was reported on July 2, 2010 that several iPhone 4 users were planning on suing Apple and AT&T for fraud by concealment, negligence, intentional misrepresentation and defective design. The legal challenge was started by California law firm Kershaw, Cutter and Ratinoff, who set up a website to recruit disenchanted iPhone 4 buyers for a lawsuit against Apple. Later that day, Apple issued another statement stating that it had discovered the cause of the “dramatic drop in bars”.Apple explained how the formula it used to calculate the number of bars to display was “wrong”. Apple promised to correct the issue and release a software update within a few weeks that would address the “mistake”, which had been present since the original iPhone. The New York Times commented that “the failure to detect this longstanding problem earlier is astonishing.”

Consumer Reports initially stated that the iPhone 4’s signal issues are not “unique, and may not be serious” and it continued to mention that signal loss is a problem that is faced by the entire smartphone industry. It has been such a problem that Apple made a formal apology. The next day, Consumer Reports altered their stance after encountering instances of dropped calls.Consumer Reports rejected Apple’s explanation after conducting tests in a controlled environment, and comparing the results against previous generations of iPhone. It sarcastically pointed out that using a piece of tape to cover the lower left antenna gap was one way to fix the problem, but recommended that consumers who “want an iPhone that works well without a masking-tape fix” purchase the iPhone 3GS instead. Consumer Reports also tested the iPhone 4 whilst it was wearing a Bumper, a frame-like cover manufactured by Apple that prevents direct contact with the antenna, reporting that it does fix the problem. CNN repeated Consumer Reports’ statement that a small amount of duct tape had proven an effective fix to the iPhone 4’s dropped call issue.

On 16 July 2010, at a press conference, Steve Jobs announced that Apple would provide all iPhone 4 owners with a free case to help solve the antenna issue and a refund to those users who had already purchased a Bumper. The free case offer would be valid until 30 September 2010, when Apple would reevaluate the situation.To get a free case, owners were able to apply via an app installed on the phone found in the App Store from 22 July 2010 to 30 September 2010. Jobs also announced that Apple could not produce enough Bumpers for all owners of the phone, but would source a supply and offer a range of cases. Additionally, Jobs cited figures from AppleCare which showed that only 0.55 percent of all iPhone 4 users have complained to the company about the issue, while the number of phones returned to Apple was 1.7 percent – 4.3 percentage points less than the number of iPhone 3GS models that were returned in the first month of the phone’s launch.

Consumer Reports noted that the solution was not permanent, though a good first step.However, because Jobs did not specify a time line for fixing the problem, and the offering for a free bumper only being a temporary solution, PC World decided to remove the iPhone 4 from its “Top 10 Cell Phones” chart and reassign it to a pending rating.

AnandTech researched iPhone 4 antenna and identified that its outer construction provides 5–9 dB (6.9–9 times) better sensitivity comparing to common internal antenna design of iPhone 3Gs (the phone keeps working connection with signal as low as −120/121 dB comparing to usual −113/115 dB).

Despite the negative media attention regarding the antenna issues, 72% of iPhone 4 users say that they are “very satisfied” with their iPhone 4 according to an August 2010 survey by ChangeWave Research.

Camera image fault

Reports about iPhone 4 cameras being rendered useless by a peculiar fault started to show up on the Internet in September 2010. Under certain lighting conditions the back camera produces a large green ‘halo’ in the center of the image. This renders many of these images to be of much lower quality than what the iPhone 3GS is capable of producing under similar lighting conditions. Reports started surfacing on forums and have since been picked up by major media sources

Critical reception

Reaction to the announcement

Media reaction to Steve Jobs’ announcement of the iPhone 4 was generally positive. The announcement included information that had not been covered by Gizmodo. Fox News commented that “seeing it in action is far more informative than staring at Gizmodo’s photos of a busted test unit”. Rhodri Marsden of The Independent said that “aside from the introduction of face-to-face video calling, it’s not a staggering feature set,” instead focusing on how the device is “more powerful than its predecessor, speedier, easier to use and will make previously laborious tasks seem like a cinch”.

CNET reacted to the announcement by explaining how it believes that iMovie for iOS was the “most exciting part of this year’s WWDC Keynote”. The article noted how the iPhone 4, unlike current cameras, can record HD content and then edit it from the same device, labeling it a “true mobile editing suite”.


Reviews of the iPhone 4 have been generally favorable. Walt Mossberg of The Wall Street Journal called the device “the best device in its class”. Engadget named it the “best smartphone on the market” in June 2010. CNET gave the iPhone 4 a rating of 8.6 out of 10, one of the highest ratings it has given any smartphone.TechRadar gave the device 4.5/5 stars.Consumer Reports said the signal problem was the reason they did not rate it a “recommended” model, although the other tests ranked it highest among smart phones.
Joshua Topolsky of Engadget described the device’s industrial design as being “more detailed and sophisticated” than its predecessor.

Timeline of iPhone models

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Jeffry is a Mechanical Engineer by education and an aspiring writer and blogger. After working hard for around 12 hours a day on his core job, he spends his remaining time in blogging and reading articles online. And he loves to make poor jokes, so be prepared.

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