Hitachi Displays has just announced a 4.5-inch IPS LCD panel that fits 1280 x 720 pixels within its frame, accounting for an eye-watering 329dpi density. That’s higher than you can get on the iPhone 4, but the fun doesn’t stop there. Hitachi’s new goodness also promises an 1,100:1 contrast ratio and 500 nits of brightness coming from an LED backlight.
Either the size isn’t as accurate or the guys who calculated the pixel density messed up. A 4.5-inch display with 1280×720 pixels has a PPI, not DPI, of 326. For a 329PPI display with 1280×720 pixels the size will have to be 4.46 inches or so. So is it a 4.46-inch 329PPI? Or is it a 4.5-inch 326PPI display? Yes, I know, I’m being picky. But I have a good reason.
326PPI is exactly the same pixel density as the 3.5-inch 960×640 Retina Display used in the iPhone 4. In my opinion, around 326PPI is the highest level of engineering that can be mass manufactured today. Engadget alludes to Hitachi’s new “Retina Display” as being better. Let’s see if that’s true.
The brightness figures are the same. And its been quite some time since all high-end mobile displays have gone LED backlights. But this here Hitachi LCD has a stated contrast ratio of 1100:1, higher than what Apple is reporting (800:1). But DisplayMate tests showed that Apple under-reports the specs, a rarity in this hyper-competitive market, and found that typical contrast ratios for the iPhone 4 were actually much higher, around 1117:1. That’s on par with Hitachi’s version. So, it seems we’ve got the same PPI, the same brightness, and the same contrast ratio.
There is one thing that will result in remarkably different experiences though.
The 1280×720 pixel format. A lot of smartphones shoot video at 1280×720 so there are a lot of content out there. Video quality suffers when you scale it. For instance if you have an iPhone 4 and you play back your 720p HD video footage, it’ll look good, but it won’t look as good as it should. The 1280×720 HD video is being scaled down to 960×640. On this Hitachi LCD, 1280×720 video footage can be played without any scaling. On this “Retina Display” from Hitachi, unscaled, pure, 1:1 720p HD will look absolutely fantastic!