The story of the iPhone, continuing with the 2010 iPhone 4, which doubled cameras, quadrupled pixels, and brought considerable attention to antennas
Steve Jobs returned to the WWDC keynote stage on June 7, 2010. He'd introduced the iPad earlier in the year, and kicked things off with an update on how it, and the App Store had been doing. Then he turned his attention to iPhone, and after recapping Apple had done to date, he began on what would come next. It had over 100 new features. It has an all-new design, an all-new camera, and an all new screen resolution. It was hot. It was the iPhone 4
“iPhone 4 is the biggest leap since the original iPhone,” said Steve Jobs, Apple’s CEO. “FaceTime video calling sets a new standard for mobile communication, and our new Retina display is the highest resolution display ever in a phone, with text looking like it does on a fine printed page. We have been dreaming about both of these breakthroughs for decades.”
4 times the pixels, 2 times the face
The iPhone 4, codenamed N90/N92 and model iPhone3,1, for the first time, offered significant improvements to the display. Apple went with optical lamination and an inter-plane switching (ISP) panel with light-emitting diode (LED) backlighting that made images look as if they were painted just beneath the glass, and greatly improved the viewing angle. Moreover, instead of matching competing display sizes of the time, they leap-frogged over them. To boost pixel count yet maintain compatibility with existing apps, Apple doubled both horizontal and vertical counts, while keeping the physical size constant at 3.5-inches. They went from 480x320 to 960x640. That brought the density up from 163ppi to 326ppi, and Apple made the argument that, at that point, the pixels disappeared. They called it a Retina display.
It was part of a completely new design, although one that had not been kept a complete surprise (see below). Steve Jobs called it beautiful and it was, something akin to Braun and Leika, which Apple SVP of design, Jony Ive, held in the highest of esteem. It was flat, chemically-hardened glass (aluminosilicate) front and back, with a stainless steel band running around the sides, and it was 24% thinner than the iPhone 3GS. It would come in black and white, though the former far sooner than the latter (see below).
The cellular radio stayed pretty much the same, at least at first, though Apple did switch from mini to microSIM for the carrier card. Bluetooth stayed the same as well. The Wi-Fi radio went to 802.11 g/b/n, though only on the 2.4Mhz band. The kicker was, the stainless steel band around the iPhone was the antenna for all these radios. The top left contained Bluetooth, Wi-Fi, and aGPS, and the rest contained UMTS/HSPA. Steve Jobs said it had never been done before. Unfortunately, it hadn't been perfected yet either (see below). Dual mics were also added for noise cancelation and better noise quality.
Again, we had a full model number increase, which meant a full processor increase. In the case it was the custom-designed system-on-a-chip, Apple A4. It was still an ARM Cortex A8 processor, though clocked higher at 800Mhz, and the same PowerVR SGX535 graphics chip, but it would set the stage for some truly impressive work over the next few years. Storage options stayed the same at 16GB and 32GB, but RAM was increased to 512MB. Like every first generation Retina device, however, it was barely enough to support all those additional pixels. The battery was the sole exception. It jumped to 1420mAh, which meant that, even with Retina, Apple actually managed to increase useful battery life as well.
In addition to the previous accelerometer and compass, Apple added a 3-axis gyroscope to the iPhone 4, with pitch, roll, and yaw, as well as rotation around gravity. Working together they provided 6-axis motion detection. It was a huge leap forward when it came to precision control, especially for gaming.
Apple took the iPhone 4's rear camera to 5 megapixels and 720p video, but at the same 1.75 micro pixel size, and added a backside illuminated sensor (BSI) and LED flash. There was, however, one more thing. For the first time, Apple also added a front camera, VGA resolution, and while it was a boon to the profile pics and "selfies" that were growing in popularity, it also allowed Apple to launch FaceTime video calling.