A Retina Display will make its way into the iPad; I am 100% con­fi­dent. The ques­tion is: when? Only Apple knows, but since it is one of the most secre­tive com­pa­nies in the world, all of us out­side the core iPad dis­play team will need to guess.

Kevin Rose, founder of Digg:

I have it on good author­ity that Apple will be announc­ing the iPad 2 in the next “3-4 weeks”, pos­si­bly Tuesday February 1st. The iPad 2 will fea­ture a retina dis­play and front/back cameras.

There is an update cit­ing a another source that the iPad dis­play has a “higher dpi” but is not tech­ni­cally a Retina Display. Of course, that begs the ques­tion: what is a Retina Display? I answer the ques­tion in iPad 2.0 Gets Retina Display?:

A Retina Display isn’t a hard­ware spec­i­fi­ca­tion at all! It is sim­ply a dis­play that has a high-enough res­o­lu­tion when used at the typ­i­cal “usage dis­tance” that your eyes can­not dis­tin­guish indi­vid­ual pixels.

Of course, there is a hard­ware com­po­nent to the def­i­n­i­tion, but it isn’t a rigid hard­ware spec­i­fi­ca­tion. The source Rose is refer­ring to prob­a­bly is work­ing off a dif­fer­ent def­i­n­i­tion of Retina Display. I’d like to stick with my def­i­n­i­tion as I think it’s clos­est to what Steve Jobs was refer­ring to when he intro­duced the Retina Display on the iPhone 4. One com­ment before I move on: DPI? That’s for print­ers. For dis­plays it is PPI (Pixels Per Inch).

What would a Retina Display on the iPad look like?

Apple dou­bled the num­ber of pix­els ver­ti­cally and hor­i­zon­tally on the iPhone 4 com­pared to pre­vi­ous gen­er­a­tion iPhones: 480×320 → 960×640. And Apple will do pre­cisely that with the iPad 2.0: 1024×768 → 2048×1536. The result­ing res­o­lu­tion on the iPad 2.0 is 263PPI. That’s far from 300PPI, but you have to remem­ber the “usage distance.”

The num­ber of pix­els were dou­bled ver­ti­cally and hor­i­zon­tally mak­ing the new Retina Display able to dis­play every sin­gle pre­vi­ous app flaw­lessly, albeit with less clar­ity. Based on the assump­tion that the iPad has a far­ther usage dis­tance than the iPhone, the iPad 2′s 9.7-inch IPS LCD with a 2048×1536 pixel for­mat looks like it will qual­ify as a Retina Display. But is it tech­ni­cally fea­si­ble to man­u­fac­ture such a display?

On the LCD side cram­ming three mil­lion plus pix­els into a 4:3 9.7-inch LCD is quite pos­si­ble: LCD man­u­fac­tur­ers are hard at work per­fect­ing the dis­play as we speak, accord­ing to my sources. But even if the dis­play was pos­si­ble wouldn’t it require a pow­er­ful GPU, which might con­sume too much power in the next iPad?

Enter the SGX543 System on a Chip graph­ics. According to AppleInsider the SGX535 in the cur­rent iPad will be replaced by the SGX543, a dual core GPU with 1080p and OpenCL sup­port that offers twice the power of the SGX543. There is also spec­u­la­tion that it could be inte­grated into a SGX543MP2 with two SGX543 cores for a total of four. The qua­dru­pling in cores and graph­ics capa­bil­i­ties makes sense since the num­ber of pix­els also would quadru­ple in the iPad Retina Display. I’m not cer­tain about power require­ments but if the shift in CPUs from a high fre­quency sin­gle core to lower fre­quency mul­ti­ple cores is any indi­ca­tion power con­sump­tion shouldn’t increase much, if at all. It seems we have the LCD and the sil­i­con to back it up.

So, will the next iPad have a Retina Display? John Gruber is pretty sure that it won’t:

Rumors are ram­pant that the upcom­ing iPad 2 will fea­ture a higher-resolution retina dis­play. Long story short: No, it won’t.

Gruber cites his sources who say: “[...] it is too good to be true [...]” He does men­tion that the LCD in the iPad 2 will be opti­cally lam­i­nated to the cover glass, just like it is with the iPhone 4 bring­ing the LCD closer to the sur­face and improv­ing all sorts of things: reduced reflectance, improved bright­ness, view­ing angles, etc. The air gap will be elim­i­nated and gone will be the rit­ual of pulling your hair out when you notice that dust is stuck in there. Optical lam­i­na­tion of the LCD to the cover glass will also make the iPad 2 thinner.

DigiTimes says that the next iPad will cer­tainly sport a Retina Display:

[...] sources from upstream com­po­nent mak­ers pointed out that Apple is increas­ing iPad 2′s res­o­lu­tion to 2048 by 1536 and the new strat­egy is expected to widen the company’s tech­nol­ogy gap with its competitors.

DigiTimes has a spotty record when it comes to con­jec­tur­ing about future Apple prod­ucts, but it does have a lot of con­tacts within the com­po­nent sup­ply chain for Apple prod­ucts. As reported on MacRumors, there’s the “iPad 2 LCD Screen” that is being sold on GlobalDirectParts for US$218.19. That’s quite a bit more than the cur­rent iPad dis­play for just $63.35. Makes sense since the iPad Retina Display should pack four times the num­ber of pixels.

Avery Pennarun uses Moore’s Law to pre­dict when the iPad will fea­ture a Retina Display. An inter­est­ing analy­sis but his semi­con­duc­tor knowl­edge fails to over­come his lack of dis­play expertise:

Each of those suc­ces­sively higher res­o­lu­tion screens was a “new process” in semi­con­duc­tor speak. With each new process came a higher den­sity of imper­fec­tions per unit area, which is why smaller screens were the first to hit these crazy-high den­si­ties. We can assume that the biggest screens at “retina” den­sity as of the iPhone 4′s release – 960×640 in June 2010 – was the state of the art at the time. We can also assume that the iPad was the biggest you could go with the best process for that size at the time, 1024×768 in March 2010.

Back in 2005 I had the plea­sure of work­ing on Sony’s PCG-TR3AP, which was a 10.6-inch ultra­portable note­book PC. There were many other brands with 10.4-inch 4:3 LCDs that packed a 1024×768 pixel for­mat. Sony’s TR3AP fea­tured a 1280×768 pixel for­mat in a 10.6-inch LCD five years ago. Was 1024×768 in a 9.7-inch the best the LCD indus­try could do in 2010? Absolutely not. But, to get the $499 entry point it was prob­a­bly the best and only option.

We want to achieve 1024×768 times two = 2048×1536 = (2.13*960)x(2.40*640) = about 5x the phys­i­cal area of the iPhone 4.

Moore’s law says we get 2x every 18 months. So 5x is 2**2.32, ie. 2.32 dou­bling peri­ods, or 3.48 years.

By that cal­cu­la­tion, we can expect to see a double-resolution iPad 3.48 years from its orig­i­nal release date in March 2010, ie. Christmas 2013.

Christmas 2013? Nah. Interesting analy­sis, but Pennarun is wrong; 2048×1536 is pos­si­ble today, in 2011. But does that mean the next iPad will sport a Retina Display? I am not sure, but I will say this: I expect to see an iPad with a Retina Display announce­ment in 2011.

Oh, remem­ber Kevin Rose at the begin­ning of this arti­cle? He claimed the next iPad would sport a Retina Display. Well, now he claims it won’t. Nobody really knows but Apple. We’ll just have to wait and see. One thing that’s cool about Apple’s prod­uct announce­ments is the sus­pense and then the, “Surprise!!!”