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[令和二年十月二十一日(2020/10/21)]
PC110 B/L用CCFL 調べ   [to English Note

PC110」への「VGA-TFT-LCD」の応用実験が、ほぼ一段落したので、今は「nFSTN-LCD」の改善にも留意している。

これの「バックライト(B/L)」から取り出した「拡散シート」や「レンズシート」が問題で、"表面の汚れ"が上手く取れず、強く拭うと"光が乱反射する傷”となって残るため、再利用が難しい。
だが、そうしたシート類を外してしまうと、更に"表示の明るさ"が減ってしまうわけだ。(図2[クリック])

それが補えないかと、"新品CCFL"を「eBay」経由で買ってみた。(110mm*2.6mm 4本$12.88+送料$5.99 手数料込み)
(国内で買うと、1本で同じ程の値段だから、どうしてもChina製はダイレクト購入にしたくなる。「Aliexpress」の方が品物は豊富で、安価なようだが、"支払い方法"が、私には不都合なので、そのルートは使っていない)
新しいCCFLで「バックライト」が明るければ、「nFSTN-LCD」に使うことを考えたが、調べたら殆ど変わらないので、交換は先送りする。

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+++ B/L輝度比較 +++

SOAR製1801で測った結果は、 9か所平均値 新品:約35μW、旧品:約39μWだった。(図4[クリック])

此の違いは、殆ど測定誤差によるもので、どちらも、およそ30〜50μWの光出力だろうと思う。(図3)
"液晶パネル"の「偏光板」を通すと、原理的に、1/2は減光するし、「カラーフィルタ」の「桟」による"マスク効果"(数値は不明)で更に減光するので、"前面光輝度"は、「バックライト輝度」の1/10〜1/20になるだろうと思う。

液晶表示の最前面の"表面輝度"は、せめて10μW程度あればと思うが、実はその数分の一しか期待出来そうにないということ。
そして、"新品CCFL"にしても、それほど輝度の向上は望めないようだ。

その点では、"LEDバックライト方式"の「TFT-LCD」の方が、"明るい画面"が得易いので、有利だと思う。(参考記事
それに、(CCFLインバータ用の)10V電源がそのまま使えるような"LEDバックライト"なら、更に好都合だろう。
だが、今は、「nFSTN-LCD」の"明るさ向上"がテーマだから、閑話休題。


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[2020/10/21)]
PC110 CCFL for BackLight, check

The application experiment of " VGA-TFT-LCD " to " PC110 " has almost finished, so now I am also paying attention to the improvement of the " nFSTN-LCD ".

The problem is the "diffusion sheet" and "lens sheet" taken out from the " backlight (B/L) " of this, and the "dirt on the surface" cannot be removed well. It is difficult to reuse because it remains as "diffusely reflected scratches".
However, if I remove such sheets, the "display brightness" will be further reduced. (Fig_2 [click])

I bought " new CCFL " via " eBay " to see if that could be compensated. (110mm * 2.6mm 4 pieces $ 12.88 + shipping fee $ 5.99 including handling fee)
(If I buy it in Japan, it's about the same price as one, so I definitely want to buy it directly from China. " Aliexpress " seems to have more items and is cheaper, but I don't use that route because "Payment method" is inconvenient for me)
If the "backlight" seems to be brighter with the new CCFL, I thought about using it for the " nFSTN-LCD ", but it's almost the same to old, so I'll postpone the replacement.

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+++ B/L brightness comparison +++

The result measured with SOAR 1801 was the average value of 9 locations : new product : about 3.5 μW, old product : about 3.9 μW.(Fig_4[click])

I think that this difference is almost by measurement error, and both have optical output of about 3 to 5 μW.(Fig_3)
In principle, when it is passed through the "polarizing plate" of the "liquid crystal panel", 1/2 is dimmed, and it is reduced to 1/3 by the "color filter". I think that the "surface light brightness" will be 1/10 to 1/20 of the "backlight brightness" because it will be further dimmed.

I think that the "surface brightness" should be at least about 1 μW, but it seems that only about 1/10 of that can be expected.
And even with a "new CCFL", it seems that the brightness cannot be improved so much.

In that respect, I think that the "LED backlight method" " TFT-LCD " is more advantageous because it makes it easier to obtain a "bright screen". ( Reference article )
Besides, an "LED backlight" that can use the 10V power supply (for CCFL inverter) as it is would be even more convenient.
However, now that the theme is "brightness improvement" of " nFSTN-LCD ", it is a quiet talk.


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