Forma Is there any way, even in principle, of controlling the screen LEDs individually?

TheRealJohnAdams · 05-21-2020, 10:06 AM

I have unfortunately managed to get myself worked up about the Forma's uneven screen lighting. I don't care about the button-side light bar, but there is a darker spot on one side of the screen that really drives me nuts. It occurs to me that one solution might be to boost the LEDs that illuminate that spot (or dim the others) on an individual basis. If this is possible, it seems that one of three things might be accomplished, any of which would be an improvement over the current situation:

Even out the page lighting. (best)
Move the dark and light spots around periodically so it doesn't feel as though part of the screen has a permanent bruise. (second best)
Create a more mottled look, so at least the screen is consistently inconsistent. (still good)

Is there reason to believe that this might be possible? If there is, and nobody else has time to deal with it, I will look into doing it myself. I would appreciate any advice you might have.

pazos · 05-21-2020, 10:40 AM

Nope. Not possible at all. Leds are placed on the side of the screen, not behind it. The "band of suck" near the buttons is unfixable software-wise.

TheRealJohnAdams · 05-21-2020, 10:55 AM

Dang. I'm not doubting you, but how do you know?

pdurrant · 05-21-2020, 11:08 AM

E-Ink screens are opaque. All the lit ones use side (or bottom or top) LEDs with a light guide in front of the E-Ink screen.

TheRealJohnAdams · 05-21-2020, 11:43 AM

My original question was not worded as well as it might have been. I understand (in a general sense) how lit eInk works. IIRC, the Kobo Forma has 17 LEDs or something like that. My intuition was that the LEDs light different parts of the screen, probably with some overlap. If that's false, then obviously I am out of luck.

pdurrant · 05-21-2020, 11:47 AM

Quote:

Originally Posted by TheRealJohnAdams

My original question was not worded as well as it might have been. I understand (in a general sense) how lit eInk works. IIRC, the Kobo Forma has 17 LEDs or something like that. My intuition was that the LEDs light different parts of the screen, probably with some overlap. If that's false, then obviously I am out of luck.

Oh, I see. I very much doubt that the LEDs have individual drivers. I expect that they're all connected to one power source, either in parallel or series. Either way, you won't be able to adjust the brightness of individual LEDs.

I would expect that the light guide layer is more likely to be the cause of any brightness variation on the screen.

TheRealJohnAdams · 05-21-2020, 12:37 PM

Makes sense. Thanks. (I'm sure you're right about the light guide being the problem, by the way; I'm just looking for things that could potentially compensate for the problem. IMO the Kobo Forma would be genuinely perfect if not for the abysmal lighting, so I'm sort of desperate for a solution. I guess I just have to hope I'll get used to it.)

05-21-2020, 10:06 AM	#1
TheRealJohnAdams Enthusiast Posts: 29 Karma: 44914 Join Date: May 2020 Device: Kindle Oasis, Kobo Forma	Is there any way, even in principle, of controlling the screen LEDs individually? I have unfortunately managed to get myself worked up about the Forma's uneven screen lighting. I don't care about the button-side light bar, but there is a darker spot on one side of the screen that really drives me nuts. It occurs to me that one solution might be to boost the LEDs that illuminate that spot (or dim the others) on an individual basis. If this is possible, it seems that one of three things might be accomplished, any of which would be an improvement over the current situation: Even out the page lighting. (best) Move the dark and light spots around periodically so it doesn't feel as though part of the screen has a permanent bruise. (second best) Create a more mottled look, so at least the screen is consistently inconsistent. (still good) Is there reason to believe that this might be possible? If there is, and nobody else has time to deal with it, I will look into doing it myself. I would appreciate any advice you might have.

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05-21-2020, 10:40 AM	#2
pazos cosiñeiro Posts: 1,271 Karma: 2200049 Join Date: Apr 2014 Device: BQ Cervantes 4	Nope. Not possible at all. Leds are placed on the side of the screen, not behind it. The "band of suck" near the buttons is unfixable software-wise.

05-21-2020, 10:55 AM	#3
TheRealJohnAdams Enthusiast Posts: 29 Karma: 44914 Join Date: May 2020 Device: Kindle Oasis, Kobo Forma	Dang. I'm not doubting you, but how do you know?

05-21-2020, 11:08 AM	#4
pdurrant The Grand Mouse 高貴的老鼠 Posts: 71,515 Karma: 306214458 Join Date: Jul 2007 Location: Norfolk, England Device: Kindle Voyage	E-Ink screens are opaque. All the lit ones use side (or bottom or top) LEDs with a light guide in front of the E-Ink screen.

05-21-2020, 11:43 AM	#5
TheRealJohnAdams Enthusiast Posts: 29 Karma: 44914 Join Date: May 2020 Device: Kindle Oasis, Kobo Forma	My original question was not worded as well as it might have been. I understand (in a general sense) how lit eInk works. IIRC, the Kobo Forma has 17 LEDs or something like that. My intuition was that the LEDs light different parts of the screen, probably with some overlap. If that's false, then obviously I am out of luck.

05-21-2020, 12:37 PM	#7
TheRealJohnAdams Enthusiast Posts: 29 Karma: 44914 Join Date: May 2020 Device: Kindle Oasis, Kobo Forma	Makes sense. Thanks. (I'm sure you're right about the light guide being the problem, by the way; I'm just looking for things that could potentially compensate for the problem. IMO the Kobo Forma would be genuinely perfect if not for the abysmal lighting, so I'm sort of desperate for a solution. I guess I just have to hope I'll get used to it.)