MobileRead Forums - View Single Post

knc1 · 01-21-2017, 10:53 AM

This is an idea development thread, not a pre-packaged solution (no pun intended).

Consider:
This forum has had, and still has, posts by people who want changes to the Kindle's frontlight system to address various vision problems.

Also, user selected fonts (also a subject of visibility) is among our most widely used add-ins.

- - - - - -

It is the blue end of the spectrum, including Ultra-Violet, that is the most often cause of the problem.

To make a difficult vision situation worse, the front light system of the Kindles use a blue-white, LED, light source.
There have been posts here about changing the front light LEDs to ones operating at the red end of the spectrum.
At least I have usually answered that would be too technically difficult to be even worth trying.

But what if we tinted the outside of the front light layer of the display?
With a minimum of web searching, I find that the coating and/or dye materials are not hard to find.
For example:
http://www.phantomresearch.com/
Available in DIY quantities - at least if you consider 100 sunglass lens treatments: "DIY quantities".

Let me first address what seems to be a simple solution - wear specially treated eye protection when using a Kindle.

Consider first the light path(s) - an example of this can be easily seen from the "outside" of a person wearing sunglasses or from the outside of a tinted window.

The 'outside' light (to be reflected) travels through the coating, with selected losses -
That light is reflected (in varying amounts, all with losses) by the object to be viewed -
Then the light has to travel back through the coating, again with losses created by the tint of the dye or coating.
End result - you can't "see in" - either from the outside of sunglasses or the outside of the tinted window.

But that would be just great, when using the Kindle in unfavorable (to this user) conditions.

Now consider the front light, light path -

The light source is effectively the **inside** surface of the micro-etched front light display layer -
I.E: no 'first trip' through the outside surface of the front light display layer.
The light is reflected by the display (with varying losses) -
The light passes through the outside tint of the display, with losses.
I.E: This coating or dye would be selected to remove the UV and some amount of the blue from the LED sources.

Summary:
The troublesome part of the outside light (which is not easily controlled by the user - the Kindle does not have a button to adjust the sun) is reduced (about) twice.
The troublesome part of the 'inside' light is reduced once - the user can control this part of the light with the light level control of the front lighted Kindles and with the contrast range of the display itself.

With protective eye wear, all light has to pass through the filtering regardless of the source.

Properly selected 'filter' color - then we are affecting only the troublesome part of the spectrum to selective reduction.

But where am I going with this? One more consideration -

Why not use a UV sensitive, photochromic coating/dye?
(Photochromic - the technical term for what is widely known in the USA as "transitions lens (coating)" - a trademarked name.)

Now those products are not as easy to find, but for one (important) example:
http://www.qcrsolutions.com/Site/Pho...ions_Corp.html

Important when you consider how we are going to apply the coating to the Kindle display front light layer.

The first linked (non-photochromic) are heat cured.
This means somehow removing the front light layer from the display so that the heat applied during the process does not destroy the e-ink panel.

The careful reader will find that the photochromic dyes/coatings linked in the second example are available as UV (rather than heat) cure products.

Where the 'bath applied', 'heat cured', products give us the problem of how to protect the "inside" of the micro-etched layer during the application -
A UV cured product applied only to the outside (spray? spin coat?) could be cured 'in place' on the display assembly.

Which gives us a self-adjusting, blue/uv reduced, reflective display.
I.E: A good solution to the visibility problems of the Kindle display, not just for the vision handicapped but for everyone.

Comments and results from people with web-search time on their hands, etc.
web-search because there is probably a lot more information out there that could be included in this "thought project".

01-21-2017, 10:53 AM	#1
knc1 Going Viral Posts: 17,212 Karma: 18210809 Join Date: Feb 2012 Location: Central Texas Device: No K1, PW2, KV, KOA	Photochromic Kindle This is an idea development thread, not a pre-packaged solution (no pun intended). Consider: This forum has had, and still has, posts by people who want changes to the Kindle's frontlight system to address various vision problems. Also, user selected fonts (also a subject of visibility) is among our most widely used add-ins. - - - - - - It is the blue end of the spectrum, including Ultra-Violet, that is the most often cause of the problem. To make a difficult vision situation worse, the front light system of the Kindles use a blue-white, LED, light source. There have been posts here about changing the front light LEDs to ones operating at the red end of the spectrum. At least I have usually answered that would be too technically difficult to be even worth trying. But what if we tinted the outside of the front light layer of the display? With a minimum of web searching, I find that the coating and/or dye materials are not hard to find. For example: http://www.phantomresearch.com/ Available in DIY quantities - at least if you consider 100 sunglass lens treatments: "DIY quantities". Let me first address what seems to be a simple solution - wear specially treated eye protection when using a Kindle. Consider first the light path(s) - an example of this can be easily seen from the "outside" of a person wearing sunglasses or from the outside of a tinted window. The 'outside' light (to be reflected) travels through the coating, with selected losses - That light is reflected (in varying amounts, all with losses) by the object to be viewed - Then the light has to travel back through the coating, again with losses created by the tint of the dye or coating. End result - you can't "see in" - either from the outside of sunglasses or the outside of the tinted window. But that would be just great, when using the Kindle in unfavorable (to this user) conditions. Now consider the front light, light path - The light source is effectively the inside surface of the micro-etched front light display layer - I.E: no 'first trip' through the outside surface of the front light display layer. The light is reflected by the display (with varying losses) - The light passes through the outside tint of the display, with losses. I.E: This coating or dye would be selected to remove the UV and some amount of the blue from the LED sources. Summary: The troublesome part of the outside light (which is not easily controlled by the user - the Kindle does not have a button to adjust the sun) is reduced (about) twice. The troublesome part of the 'inside' light is reduced once - the user can control this part of the light with the light level control of the front lighted Kindles and with the contrast range of the display itself. With protective eye wear, all light has to pass through the filtering regardless of the source. Properly selected 'filter' color - then we are affecting only the troublesome part of the spectrum to selective reduction. But where am I going with this? One more consideration - Why not use a UV sensitive, photochromic coating/dye? (Photochromic - the technical term for what is widely known in the USA as "transitions lens (coating)" - a trademarked name.) Now those products are not as easy to find, but for one (important) example: http://www.qcrsolutions.com/Site/Pho...ions_Corp.html Important when you consider how we are going to apply the coating to the Kindle display front light layer. The first linked (non-photochromic) are heat cured. This means somehow removing the front light layer from the display so that the heat applied during the process does not destroy the e-ink panel. The careful reader will find that the photochromic dyes/coatings linked in the second example are available as UV (rather than heat) cure products. Where the 'bath applied', 'heat cured', products give us the problem of how to protect the "inside" of the micro-etched layer during the application - A UV cured product applied only to the outside (spray? spin coat?) could be cured 'in place' on the display assembly. Which gives us a self-adjusting, blue/uv reduced, reflective display. I.E: A good solution to the visibility problems of the Kindle display, not just for the vision handicapped but for everyone. Comments and results from people with web-search time on their hands, etc. web-search because there is probably a lot more information out there that could be included in this "thought project". Last edited by knc1; 01-21-2017 at 11:08 AM.