HTC One screen reviews: One comes with different display types

puremind · Mar 23, 2013

BarryH_GEG said:
Do you know what brightness settings each of the reviewer’s used when they tested battery life? I'm willing to bet it's not maximum brightness and that all the phones each of them test are set to some equivalent level that the reviewer applies consistently.

Yes, I read all of the testing protocols. Some measure at a fixed brightness, others at a 50%, others at maximum brightness.

As long as testers measure at a % point of maximum brightness (like in the GSM Arena test), a decrease in brightness will result in an increase in battery life.

Therefore this is a very comparable situation as the in Computerbase test:
100% brightness = 380cd/m²
50% brightness = 190cd/m²

Example with GDS Arena Video Test:
50% of 650cd/m² = 325 cd/m²
50% of 380cd/m² = 190 cd/m²

Instead of a 16% increase in battery performance, we can infer the 11% I was talking about. Of course this will depend on whether the videos displayed in both situations had the same overall average brightness levels. All I am saying is that it will have a form of impact. It can be more or less depending on the type of video material displayed on the web pages browsed, but it will have an impact and 15% more battery life for 50% decrease in brightness is a good estimate.

I mean do we even need to do calculations to have a feeling that increase screen brightness will negatively impact battery performance overall?

BarryH_GEG · Mar 23, 2013

The only thing that will prove your point is for someone to come forward with a display their One has that’s brightness is noticeably and drastically below other examples. Until that happens none of this is real and debating it further is kind of futile. I’m so confident in this that I’ll buy you a case for your One if you end up being right.

puremind · Mar 23, 2013

BarryH_GEG said:
Of course it is. Your assumption, based on a flawed comparative resulting in a flawed conclusion, is that each One built could have a display that varies from 382-647cd/m2 and therefore battery performance could vary accordingly. I'm saying there's most likely a single panel used on the One and the difference in brightness between any two panels is no more than 10+/-% due to manufacturing tolerances and that all One's will have similar battery life when used the same way. If you're right this thread will balloon in to 100+ pages and end up a sticky because the lucky winners of the "screen lottery" you're describing that draw 382cd/m2 displays will be up in arms. If I'm right this thread will die out fairly quickly as the deviation you're hypothesizing only exists on paper.

The observed range is 385cd/m² to 650cd/m², therefore the production tolerance is not +/-10%, it is 30%. 385* 1.3 * 1.3 = 650cd/m²

That a +/- 8% in battery performance.

But you are right on one thing, this depends on usage. That's what I am saying in my first post. To the extent that automatic brightness can be capped at a percentage of maximum brightness I would be very happy.

I know where I want to go with this...I want a custom rom to enable this feature, so I have to show why it matters

Why do you think I even open this thread in the first place? I don't want to constantly have to switch between custom brightness and automatic brightness or be in power saving mode all day...

puremind · Mar 23, 2013

BarryH_GEG said:
The only thing that will prove your point is for someone to come forward with a display their One has that’s brightness is noticeably and drastically below other examples. Until that happens none of this is real and debating it further is kind of futile. I’m so confident in this that I’ll buy you a case for your One if you end up being right.

Well, I will be sure to measure my HTC ones when I receive them. If I find different screen brightness with 2 different measurement devices under the same testing conditions, I will report on this? For now I can say for sure that the models I observed in the shops in Germany all had the 385cd/m² screen and very close brightness and color temperature. No wild fluctuation.

So if I do not manage to get my hands on a significantly brighter device, all this will mean (to me as a screen calibrator) is that HTC somehow paid reviewers to falsify their testing results on some reviews (doubtful) OR there are different screen versions (different hardware).

I honestly doubt it can be different calibration. At equal color temperature, the same screen can't be calibrated much brighter than it's native color temperature allows. Even assuming a different color temperature, you would have to put up with crazy cold color temperature to transform a 385cd/m² screen into a 650cd/m² screen to the point where it is not acceptable to the consumer and even then, you would barely scratch 450cd/m². There is only so much the pixels can do. Backlighting is the limiting factor mainly. I don't believe in a 70% jump in brightness achieved through calibration only.

What is more believable however is HTC capping backlighting in their devices to allow better battery tests, like Samsung does with their AMOLED displays...

Shasarak · Mar 23, 2013

BarryH_GEG said:
1. Reboot the phone twice to get a clean "last_kmsg" file
2. Use any file manager that gets you to the root directory
3. Navigate to the /proc folder
4. Find "last_kmsg"
5. Open it on the device or send it to a PC and open it as a text file. Your looking for "panel_id" and "panel_vendor." It's a long ass file so you're better off using an editor with a search feature to search on "panel."

Since there aren't many vendors making 1080P panels I'll bet all One's use the same panel type and it's probably from Renasis (Sharp) like the XZ and DNA.

[ 1.037509] c0 64 [TP] syn_get_version: panel_version: 3332
(snip)
[ 1.684877] c0 1 [DISP] mipi_command_samsung_init
[ 1.684907] c0 1 [DISP] m7_panel_init panel ID = PANEL_ID_M7_JDI_SAMSUNG_C2_2
[ 1.685182] c0 1 [DISP] m7_panel_init: PWM IC version A2
[ 1.685212] c0 1 [DISP] m7_panel_init

Anyone else want to post theirs?

If the screen is actually made by Samsung then some of the more rabid HTC fanboys won't be able to bring themselves to touch it .

omersak · Mar 23, 2013

As per this guy there are two:

https://twitter.com/fnoji/status/292594950397382657

JDI_SAMSUNG and SHARP_RENESAS. Apparently.

Now we wait.

BarryH_GEG · Mar 23, 2013

omersak said:
JDI_SAMSUNG.

Ironic. No?

puremind · Mar 23, 2013

omersak said:
As per this guy there are two:

https://twitter.com/fnoji/status/292594950397382657

JDI_SAMSUNG and SHARP_RENESAS. Apparently.

Now we wait.

That makes more sense to me. I will try and go to the shops next week to find out what that ID is on the one I saw previously. Based on previous experience with Sharp, I think mine are likely to be Samsung, too.

crucky · Mar 23, 2013

[ 1.666656] c1 1 Registering the dns_resolver key type
[ 1.666900] c1 1 mipi_m7_device_register
[ 1.667419] c1 1 [DISP] mipi_command_samsung_init
[ 1.667419] c1 1 [DISP] m7_panel_init panel ID = PANEL_ID_M7_JDI_SAMSUNG_C2_2
[ 1.667694] c0 1 [DISP] m7_panel_init: PWM IC version A2
[ 1.667724] c0 1 [DISP] m7_panel_init

My HTC One

o2 Germany WTF ? Samsung Panel in a HTC Nice one

I cant find panel_vendor in the last_kmsg file

omersak · Mar 23, 2013

Anyone know what this is and what it confirms regarding the screen towards the bottom?

jonstatt · Mar 23, 2013

Shasarak said:
[ 1.037509] c0 64 [TP] syn_get_version: panel_version: 3332
(snip)
[ 1.684877] c0 1 [DISP] mipi_command_samsung_init
[ 1.684907] c0 1 [DISP] m7_panel_init panel ID = PANEL_ID_M7_JDI_SAMSUNG_C2_2
[ 1.685182] c0 1 [DISP] m7_panel_init: PWM IC version A2
[ 1.685212] c0 1 [DISP] m7_panel_init

Anyone else want to post theirs?

If the screen is actually made by Samsung then some of the more rabid HTC fanboys won't be able to bring themselves to touch it .

Ugh...mine is Samsung too! You are not wrong about the HTC fanboys. In fact many Taiwanese will not be happy to hear it has a major Korean part! There is a lot of rivalry there!

omersak · Mar 23, 2013

jonstatt said:
Ugh...mine is Samsung too! You are not wrong about the HTC fanboys. In fact many Taiwanese will not be happy to hear it has a major Korean part! There is a lot of rivalry there!

JDI is Japanese Display Inc (Sony/Toshiba/Hitachi).. not sure how Samsung is there too. A sexpert on HTC panels needs to step in.

jonstatt · Mar 23, 2013

omersak said:
JDI is Japanese Display Inc (Sony/Toshiba/Hitachi).. not sure how Samsung is there too. A sexpert on HTC panels needs to step in.

I just googled JDI. Indeed you are absolutely right. But JDI has no link to Samsung. In fact they are absolute rivals. Looks like the phone has an identity crisis!

---------- Post added at 10:13 PM ---------- Previous post was at 10:07 PM ----------

crucky said:
My HTC One o2 Germany WTF ? Samsung Panel in a HTC Nice one I cant find panel_vendor in the last_kmsg file

The file is huge. The best thing is to copy it off the phone so you can search for it easily on your PC.

omersak · Mar 23, 2013

jonstatt said:
I just googled JDI. Indeed you are absolutely right. But JDI has no link to Samsung. In fact they are absolute rivals. Looks like the phone has an identity crisis!

I think the screen itself is JDI made and the 'Samsung' is.. something else.

For example, in the SHARP_RENESAS option, Sharp is the only one of the two who manufactures screens and Renesas is a semiconductor manufacturer who doesn't.

Again, we need an HTC expert to clear things out because it isn't displayed this way for other OEMS.

onlinejobwork · Mar 23, 2013

but how do I test or know which screen type I got? any apps from play store?

jonstatt · Mar 23, 2013

omersak said:
I think the screen itself is JDI made and the 'Samsung' is.. something else.

For example, in the SHARP_RENESAS option, Sharp is the only one of the two who manufactures screens and Renesas is a semiconductor manufacturer who doesn't.

Again, we need an HTC expert to clear things out because it isn't displayed this way for other OEMS.

Ah..you provided a clue. Renesas make the ICs for screen drivers/controllers. So this implies the JDI screen is powered by a Samsung screen driver/controller. Still a bit surprising to see anything with Samsung there but not quite as shocking as the screen itself!

omersak · Mar 23, 2013

onlinejobwork said:
but how do I test or know which screen type I got? any apps from play store?

Originally Posted by BarryH_GEG
1. Reboot the phone twice to get a clean "last_kmsg" file
2. Use any file manager that gets you to the root directory
3. Navigate to the /proc folder
4. Find "last_kmsg"
5. Open it on the device or send it to a PC and open it as a text file. Your looking for "panel_id" and "panel_vendor." It's a long ass file so you're better off using an editor with a search feature to search on "panel."

BarryH_GEG · Mar 23, 2013

omersak said:
JDI is Japanese Display Inc (Sony/Toshiba/Hitachi).. not sure how Samsung is there too. A sexpert on HTC panels needs to step in.

Renesas SP is a joint venture established by Renesas Electronics, Sharp Corporation and Powerchip Group in April 2008. It engages in the business of LCD Drivers that drive small and mid-sized LCD panels. As a top manufacturer in the display products market for mobile gadgets, it aims at making a significant contribution to the global display industry through continuous innovation, cost reduction and quick operations. It provides excellent sales support, quality designing and manufacturing skills and quality assurance system all over the world aiming to become a genuinely reliable company.

All these 1080P mobile displays are being made in a former Sharp plant the size of a football field that was dedicated to larger panels for use in TVs and was converted to small format displays and is now the largest physical plant dedicated to mobile devices in the world.