LG announces 5.5in 2560x1440 smartphone display

[Roland00Address]

The screen door effect is essentially just an issue of PPI - it was an issue on 1st gen AMOLED Samsung Galaxy S phones too. On LCD's it was essentially 'solved' with "Retina"-class displays - 300+ PPI screens.

It's funny how he said IPS is susceptible to screen door effect when that's what OLED displays is notorious for due to pen-tile

I am not talking about seeing the individual pixels being a screen door.

I am talking about how a lcd screen functions. An lcd screen is essentially a white backlight which then puts a filter (aka a subpixel) on top of that white light to tint the color. Three individual subpixels change how much light shines through and blend together as 1 pixel.

The higher the resolution, the more backlight you need for each inch for the finer the "screen door" is the more light you need to shine through to overcome it.

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grkM3 gets what I am talking about

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The ipad 2 to 3 are very much the same tablet but one has double the ppi (four times the number of pixels), yet the ipad 3 gets worse battery life (8% less in anandtech test at 200 nits). The battery on the ipad 3 was increased by 70% (25 watt hour vs 42.5 watt hour) compared to the ipad 2 yet it has less battery life.

The soc on the ipad 2 and ipad 3 are of the same generation, the ipad cpu is the same but the gpu of the 3 is more beefy to cope with the higher resolution. That said you shouldn't be straining the gpu that much with a web browsing test.

The lost of battery of the 3 vs 2 is attributable to the higher dpi screen.

 

[MrX8503]

I am not talking about seeing the individual pixels being a screen door.

I am talking about how a lcd screen functions. An lcd screen is essentially a white backlight which then puts a filter (aka a subpixel) on top of that white light to tint the color. Three individual subpixels change how much light shines through and blend together as 1 pixel.

The higher the resolution, the more backlight you need for each inch for the finer the "screen door" is the more light you need to shine through to overcome it.

You know what's even funnier? How you say how its so funny and take the time to quote him and not read or comprehend what he is saying.

LCD back light light source is used to push through the screen like a screen door.

Oled makes its own light without a backlight and notice how the brightness of this hi res display is lower then today's lcds? Its because the pixels are a lot smaller and less room for that screen door backlight to push through and give you light

I know what he's saying. I don't see how screen door is relevant in a HiDPI LCD screen when OLED pentile screens had it much worse. This wasn't remedied until recently with 1080p, while we've haven't had screen door since the original iPhone 4.

OLED makes its own light, but do you know how pentile screens work? There are subpixels that makes one pixel, thus screen door.

 

[Roland00Address]

I know what he's saying. I don't see how screen door is relevant in a HiDPI LCD screen when OLED pentile screens had it much worse. This wasn't remedied until recently with 1080p, while we've haven't had screen door since the original iPhone 4.

OLED makes its own light, but do you know how pentile screens work? There are subpixels that makes one pixel, thus screen door.

No no no no no you do not know what I am saying.

Both LCD and OLED have subpixels

LCD screens work on the principle of having an original white light (a backlight) and each subpixel works as a filter. Each individual pixel can reduce some or all of their light. Since each subpixel works as a filter this is a reductive process, it subtracts light. Originally you have white, you subtract light to get blue, green, red, and/or black.

OLED screens work via the opposite principle, you originally have three, four (non rgb stripe which the samsung s3 and s4 use), or five subpixels (pentile, pen tile means penta latin for five and tile). These subpixels are either red, green, or blue. These subpixels combine by shining the light at different intensities, which blend together to get the desired color. Thus to get black you just keep all the subpixels active (thus you get true black allowing infinite contrast), to get white you blend all 3 subpixels together and to get color you vary the intensity of the subpixels. This is an additive process, it adds light

Because LCD screens work via filters on each individual subpixel, shrinking the subpixels (to get higher ppi) wastes efficiency, you need a stronger backlight to get the same end user brightness. It is a problem inherent with the technology. Thus there are diminishing returns about increasing ppi with lcd screens, eventually you will get a point you can't notice the increase in ppi yet at the same time even though you can't notice the increase in ppi you are getting less battery life due to the inherent technology.

OLED do not have this problem, increasing ppi does not decrease battery life instead it just makes the screen more expensive to produce. In fact increasing ppi is actually a good thing with OLED for with more pixels you can reduce the strain on the individual subpixels and increase the life expectancy (for the subpixels of OLED decay with time) while still keeping the same end user brightness.

Thus there is no point in comparing power consumption of Galaxy S3 or S4 screens and increase resolutions and then apply that knowledge to LG IPS LCD screens since those screens work via fundamentally different philosophies.

 

[MrX8503]

Dude, you can't see screen door since the original iPhone4, whereas you can see screendoor on OLED pentile screens for a long time. It wasn't until 1080p pentile came along it was fixed.

OLED do not have this problem, increasing ppi does not decrease battery life

No no no no no I never said otherwise.

 

[lopri]

@Roland00Address: Wow, you've just raised my knowledge on AMOLED technology by ten folds. Thank you for the explanation. Especially this bit;

pentile, pen tile means penta latin for five and tile

I had no clue where the name Pentile comes from and what exactly it meant prior.

 

[lopri]

Still, I think the biggest reason (AM)OLED is being developed is its flexibility (literally and figuratively) in potential future devices. What I've heard is the technology allows displays to be "printed" virtually everywhere including flexible materials. We also know that it allows techniques like "Active Display" that is not realistic on LCDs.