From: Johannes Wolf (mp2100_at_mail-gw.estec.esa.int)
Date: Fri Feb 06 2004 - 00:36:14 PST
Hi Calvin,
there is no heated discussion and therefore no fire you could put your fuel
in.
I was just unemotional trying to put some facts together and to explain my
personal experiences.
To make it clear: I never stated that the backlight4you solution is great or
the best, this is of course a solution with compromises and was the outcome
of a long and exhaustive search from the swiss/german backlight project.
And I have to admit - sorry - that I have not visited your webpages before.
There is another fact that I just realised: the two projects were running
nearly parallel in time.
just to comment on your points:
1) Of course the basic principle and construction of el BL remained
unchanged, but using different phosphors, different dielectrics, you end up
with different BL capacitance ...
and that is the very key to match the BL to the Newt BL driver circuit.
2) I do fully agree
3) I have to admit that they could have put such a picture on their website.
If you are interested I can send you pictures from my two Newts, one with
the replaced BL and the other with original BL. But I can tell you that the
differences are little.
4) This is what they experienced - the Newt LCDs readability is dependent on
the reflecting properties (incl. color) of the material used for the BL.
Since you want both - good readablility (contrast) at daylight and with BL
on, you have to take that into account. So it migt be the case that you have
a very good reflecting and bright background but a very low contrast.
5) Thats the point - if your BL is designed to have the same capacitance
like the original one, there is no problem with the driver at all. And I
would also prefer a white BL versus a green one.
6) If you tell me how to measure the intrinsic brightness of the BL I
probably can do that for you, no problem, what concerns the brightness
without driver mod, it is definitely less and not satisfactory. But the
point is here again: this BL was not primarily designed to have the same
capacitance. Due to the capacitance mismatch the driver needed a slight
mod...
Concerning the price: they launched a special series production and this has
its initial price - I was not directly involved in the project and so I can
believe what they say or not...
To lower the price there is for sure a certain production volume needed.
Cheers
Johannes
> -----Original Message-----
> From: newtontalk-bounce_at_newtontalk.net
> [mailto:newtontalk-bounce_at_newtontalk.net]On Behalf Of Calvin Grier
> Sent: Thursday, February 05, 2004 4:07 PM
> To: newtontalk_at_newtontalk.net
> Subject: Re: [NTLK] Need a new backlight
>
>
> I was going to try and stay out of this "discussion" because I
> did not want
> to throw fuel on the fire. However, I've just got to make some comments.
>
> 1) The technology of EL backlights has improved since Apple made theirs.
> Phosophor efficiencies and encapsulation techniques have improved
> as prices
> have come down. This has not in any way changed the basic electical
> construction of EL backlights, since they act more-or less like a
> capacitor
> in an electronic circuit. The electrical characteristics depend
> directly on
> the area of the EL lamp, and spacing between layers, and the dialectric
> between them. That hasn't changed very much since 1996.
>
> 2) Brighter is not always better. Imagine using your Newton in a dark room
> and turning on a very bright backlight. Looking straight on at a lamp as
> bright as a headlight is not going to be good for your
> night-vision. IF PBK
> has found a way to "dim" the EL backlight on a Newton so you can
> use it in a
> dark room, then maybe they don't have to worry about this issue.
>
> 3) If the new backlight is so great, why don't they show it?
> There's not one
> picture showing the backlight on their web page or in the installation
> manual. How about a side-by-side with an origianl Apple
> backlight? If you go
> to my web page, I show engineering drawings of our white EL backlight, and
> several pictures of the actual end-product we're selling for $29 US.
> www.adago.net (Side-note: our backlight was made to tighter
> tollerances than
> Apple's, and fits like a glove into the LCD module.) Here are a
> few links to
> EL pictures:
> www.adago.net/images/backlightcloseup.jpg
> www.adago.net/images/backlight1_big.jpg
>
> 4) There's one reason Apple decided on green when they made the Newton:
> GREEN phosphors are by-far the most efficient phosphors that can
> be used in
> an EL panel. (Just doing a little research on the web will tell you that.)
> The LCD is more-or-less color agnostic. I don't have data to back this up
> but it would be very easy to come up with some simple tests - using
> non-functional LCDs - to show if the LDC was preferentially transmitting
> red, green or blue. I might do that and post the results on the web.
>
> 5) I'll admit to never having attempted to reverse engineer the
> EL backlight
> circuit in the Newton. However, the white backlight I'm selling gives off
> 70% of the light of the original Apple backlight and uses the
> same amount of
> battery power. Our White EL backlight was designed to replicate the
> electrical properties of the Apple original so no other modifications are
> necessary. White is also more eye-pleasing - how many green paper
> notebooks
> have you ever purchased?
>
> 6) I'd really like to know what the intrinsic brightness of the PBK
> backlight is - when driven by a modified and unmodified Newton inverter. I
> wonder if they'd post that? :-)
>
>
> BTW, I still have some of the white backlights available for
> purchase at $29
> US. They aren't quite as bright as the original, but they have more
> "eye-appeal" and are a lot less expensive than other alternatives.
>
> --Calvin Grier
> www.adago.net
>
> --
> This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries
> List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html
> Official Newton FAQ: http://www.chuma.org/newton/faq/
>
-- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html Official Newton FAQ: http://www.chuma.org/newton/faq/
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