There is lit­tle doubt Apple is work­ing on a new iPhone (WSJ); it is dubbed the iPhone HD. Hon Hai Precision (Foxconn) will be man­u­fac­tur­ing it, like it has all pre­vi­ous iPhone mod­els. When is it com­ing? No one knows but it is expected to be announced on Tuesday, June 22nd. (There is also men­tion of a CDMA-based iPhone.)

The name iPhone HD might lead to spec­u­la­tions that we might see a 1280×720 pixel for­mat on a 3.5-inch dis­play. From a purely hard­ware point of view in order to prop­erly be called HD requires the dis­play to sport at least a 1280×720 pixel for­mat. Unfortunately the term HD has been defined that way. In real­ity HD is not solely depen­dent on the num­ber of pix­els. Resolution as it relates to dis­plays is a term that refers to pixel den­sity as in PPI (Pixels Per Inch). I do not know how we got to our cur­rent sit­u­a­tion where we equate 1920×1080 to res­o­lu­tion, but that is utterly incor­rect and I am not even being remotely picky. When peo­ple start say­ing that an apple is blue some­one has to become the idiot among the masses and start say­ing that an apple is red (or green). Hopefully over time the idiot will be proved right. So back to res­o­lu­tion: it is a term for pixel den­sity, not pixel for­mat. And res­o­lu­tion relates to deter­min­ing whether or not our eyes per­ceive HD-quality more so than pixel for­mat. (There is also the mat­ter of dis­tance from the viewer to the dis­play, but we won’t get into that dis­cus­sion here.)

Pixel Density: Some con­sider Apple’s dis­plays to have low res­o­lu­tion com­pared to its com­peti­tors espe­cially when it comes to note­book PCs. For instance, the high-end 13.3-inch MacBook Pro sports the same pixel for­mat as the low-end ver­sion at 1280×800; there are no other options for the dis­play. The cor­re­spond­ing pixel den­sity, or res­o­lu­tion, is 113.49 PPI. (I used a nifty PPI cal­cu­la­tor online.) Lenovo’s X300, a direct com­peti­tor to the high-end 13.3-inch and the MacBook Air has a 1440×900 pixel for­mat with a 127.68 PPI. Here’s another exam­ple: the 15.4-inch MacBook Pro has a 1440×900 pixel for­mat and a res­o­lu­tion of 110.27 PPI. Compare this to Dell’s Studio XPS 16 that has a 1920×1080 option on a 15.6-inch dis­play result­ing in a res­o­lu­tion of 141.21 PPI. These are big dif­fer­ences in res­o­lu­tion. But do note that Apple has been keen to keep the res­o­lu­tion at around 110 PPI for many of its dis­plays. For instance, the new 27-inch iMac sports a 108.79 PPI res­o­lu­tion. Apple has done that to pro­vide a con­sis­tent view­ing expe­ri­ence across its dis­plays. Two notable excep­tion are the 17-inch MacBook Pro with 133.19 PPI and the 164.83-PPI iPhone/iPod touch, which brings us to the topic at hand.

iPhone HD: If in fact the next-generation iPhone sports the HD suf­fix that would retroac­tively mean that cur­rent iPhones (first gen, 3G, 3GS) do not muster enough res­o­lu­tion (PPI) and there­fore is not HD class. So what is HD class? I do not know if there is a set def­i­n­i­tion any­where, so let’s look at other smart­phone man­u­fac­tur­ers and find out. Although there is no HD tags asso­ci­ated with Motorola’s Droid, I think it might be con­sid­ered the smart­phone with the best HD-class dis­play: a 3.7-inch TFT LCD with a 854×480 pixel for­mat and a 264.77 PPI res­o­lu­tion. That is an incred­i­bly high res­o­lu­tion! The dis­play on HTC’s HD/HD2 smart­phone is also highly regarded with a 4.3-inch LCD, a 800×480 pixel for­mat and a 216.97 PPI res­o­lu­tion. These are just two exam­ples but are exam­ples of two of the best in terms of dis­plays. Although the pixel for­mat is of inter­est pay more atten­tion to the PPI: they are well above 200 PPI. So it seems if Apple wants to play in the HD space it will need to equip the iPhone HD with at least a 200-PPI display.

600×400: Most likely Apple will keep the overal dimen­sions of the next iPhone intact. The dis­play size will prob­a­bly be unchanged at 3.5-inch. Keeping the same aspect ratio of the cur­rent iPhone at 3:2, a 3.5-inch dis­play with a 200-PPI res­o­lu­tion trans­lates to a pixel for­mat of at least 600×400. A pixel for­mat of 600×400 feels quite anti-climactic. I want it to be more. The com­pany is aware of the com­pe­ti­tion and it can­not lag too far behind but Apple is con­cerned more about the entire sys­tem, the entire user expe­ri­ence. The 600×400 pixel for­mat is sim­ply a guess as it relates to the 200 PPI min­i­mum require­ment that seems to be at play in the HD smart­phone game. Of this I am cer­tain: the view­ing expe­ri­ence on the iPhone HD will be thor­oughly HD.