Author Topic: The negative-like "flash" when switching pages (Read 2300 times) Tweet

mlevin77 · « **on:** March 07, 2011, 09:57:12 am »

I just got a new Kindle DX and I want to make sure this is normal operation rather than a defect. When I switch from one page to another, the whole page "blinks" - it sort of turns negative (black->white and vice versa) before the new text comes up. It takes about a second so it's not a big deal but is this normal?

thanks in advance,

Mike

KBoards.com

intinst · « **Reply #1 on:** March 07, 2011, 10:12:52 am »

Yes, all e-ink devices do this.

mooshie78 · « **Reply #2 on:** March 07, 2011, 10:22:10 am »

Yep, that's normal. That's just how e-ink clears a screen to display a new one.

Bunny Hugger · « **Reply #3 on:** March 07, 2011, 01:05:33 pm »

You probably won't even notice it after a while

carl_h · « **Reply #4 on:** March 07, 2011, 04:00:42 pm »

I noticed it initially, but now I don't even think about it.

Xopher · « **Reply #5 on:** March 07, 2011, 04:12:20 pm »

Like other people have already said, this is normal. eInk does not use power while displaying a page. Supposedly, there is a screen on display at the factory that has been displaying the same page for 5+ years and has not been plugged in since it was loaded. This is why Kindles can go for weeks on a charge. It's all a part of the eInk technology.

pidgeon92 · « **Reply #6 on:** March 07, 2011, 07:30:47 pm »

Page 11 of the user manual describes the "flash" of the eink screen....

Quote

Kindle uses a high-resolution display technology called electronic paper. It works using ink just like books and newspapers, but it displays the ink particles electronically. The page flash you see when you turn the page is part of the ink placement process.

If you don't have the manual on your Kindle, you can either download it from your Kindle's archives, or get a PDF version here.

Raybrite · « **Reply #7 on:** March 07, 2011, 09:15:34 pm »

The flash is normal. It is like when you turn a page of a book and you blink your eyes. You can't read the turning.
Enjoy. Soon you will be wondering why the regular books don't flash. (LOL)
Ken

NogDog · « **Reply #8 on:** March 07, 2011, 11:21:03 pm »

To get geeky about it, each dot on the screen is a little 2-toned ball that is rotated electronically to display its white or black side (and perhaps a halfway position, I'm not sure). When the screen controller tells them to roll over to a new position when the image changes, there are always some small percentage that refuse to do so for some reason, which would result in some degree of a ghost image from the previous page. To avoid this ghosting, the controller tells them to all turn to the black side up, and then all to turn to the white side up (or vice versa) before then telling them each which way up for the new page, in order to get the screen background effectively all the same shade without any noticeable ghosting. So the "flashing" you see is a quick cycle of "Everybody, black side up! Now white side up! OK, now assume your positions for the next page!"

And yes, you likely won't even notice it after a few days of reading.

Morf · « **Reply #9 on:** March 08, 2011, 12:09:16 pm »

Sort of...

The black and white ball was an older implementation of e-ink. The current ones as in the Kindle replaces the ball with a clear dot containing black and white ink particles, and moves these to the top and bottom by means of an electric charge:

As you say, though, the negative image is there to push the pigment around so that more of it moves than would do with a normal screen change. Effectively it bounces all the ink particles bottom to top to bottom and then puts them where it wants them.

Makes you feel sorry for the ink particles!

Although it works in a completely different way, I like to think of it almost like an etch-a-sketch, and the flashes are like shaking it upside down above your head. Good job we don't have to do that every page turn!

SarahBarnard · « **Reply #10 on:** March 08, 2011, 12:56:09 pm »

Quote from: Raybrite on March 07, 2011, 09:15:34 pm

The flash is normal. It is like when you turn a page of a book and you blink your eyes. You can't read the turning.
Enjoy. Soon you will be wondering why the regular books don't flash. (LOL)
Ken

Paperbacks don't flash?

Morf · « **Reply #11 on:** March 08, 2011, 02:00:45 pm »

Quote from: SarahBarnard on March 08, 2011, 12:56:09 pm

Paperbacks don't flash?

Actually, I'd love to know if anybody has ever analysed how long it takes to turn the page in a paperback and compared that to the flash of a Kindle. I'd bet that the page turn takes longer, and yet it's somehow so natural to us that we don't even realise we do it.

Elk · « **Reply #12 on:** March 08, 2011, 08:01:27 pm »

I also bet physically turning a page takes longer.

And is more fun.

The flash is an attempt to make up for this.

SarahBarnard · « **Reply #13 on:** March 09, 2011, 02:21:08 am »

Quote from: Morf on March 08, 2011, 02:00:45 pm

Actually, I'd love to know if anybody has ever analysed how long it takes to turn the page in a paperback and compared that to the flash of a Kindle. I'd bet that the page turn takes longer, and yet it's somehow so natural to us that we don't even realise we do it.

and kindles don't *ever* give you a papercut...

NightGoat · « **Reply #14 on:** March 09, 2011, 04:12:03 am »

To be honest, I've never noticed this "negative flash" until mentioned here, and now it's all I see when changing pages.

Thank you NogDog and Morf for explaining the technical aspects of eInk.

We tend to take technology for granted and never really think about the genius that goes into getting these devices to work. I remember studying the process for laser printing for the A+ exam and saying to myself "There's no way that could actually work." But it does.

patrickt · « **Reply #15 on:** March 09, 2011, 04:43:34 am »

On my K3 it happens but it's much, much less than a second. It's fast enough that I have no way of measuring it. FWIW, I really hadn't noticed before so it obviously doesn't bother me.

4Katie · « **Reply #16 on:** March 09, 2011, 08:04:29 am »

Quote

So the "flashing" you see is a quick cycle of "Everybody, black side up! Now white side up! OK, now assume your positions for the next page!"

Sometimes when I have the volume up I can hear it.

mooshie78 · « **Reply #17 on:** March 09, 2011, 10:05:14 am »

Quote from: patrickt on March 09, 2011, 04:43:34 am

On my K3 it happens but it's much, much less than a second. It's fast enough that I have no way of measuring it. FWIW, I really hadn't noticed before so it obviously doesn't bother me.

Yeah, it's not so bad on the K3's pearl screen. It was much more noticeable on the K1 and K2, especially the former. Still didn't bother me much, but it was more like a full second or so on the K1. I learned to hit the button when I started reading the last line or so of the current page due the lag.

Tangiegirl · « **Reply #18 on:** March 09, 2011, 11:24:05 am »

Quote from: mooshie78 on March 09, 2011, 10:05:14 am

Yeah, it's not so bad on the K3's pearl screen. It was much more noticeable on the K1 and K2, especially the former. Still didn't bother me much, but it was more like a full second or so on the K1. I learned to hit the button when I started reading the last line or so of the current page due the lag.

I do the same thing....hit the button early on my K1. It's not necessary to do this with my K3. It changes pages VERY quickly. My K1 is my bubble bath buddy so I use both kindles daily. It always takes me a few page turns to remember to hit "next page" early when I switch back to the K1. K1's next page lag seems enormous now, compared to my K3. Though, it never bothered me when K1 was my only device.

KBoards.com