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Quoth · 03-25-2024, 05:46 PM

The oled dots are light emitting. They are off when off.

LCD backlight is always on. If it's set too high then there is still slight light leakage through the polarised LCD panel.

Some very expensive Sony TVs have X Y array of LEDs or even R G B LEDs and turn them off on black areas of the screen.

BTW, white LEDs don't exist. They are blue, violet or near UV with phosphors. You can see the yellow phosphor on the "stick" filament type LED lamps and they light up when you shine UV on them. Also yellow visible on some other LED lamps.

The OLED do shift in colour. It's so gradual you may not notice and some systems count run time and compensate. Plasma panels and colour CRTs also shift but could be recalibrated.

LCD needs two optically perfect accurately spaced panes of glass. OLED can use any insulating substrate and the top layer is to keep out moisture. That then has another layer if a touch screen is needed.

So no mystery as to the OLED blacks. Also most people have the LCD brightness (backlight) far too high. The blacks on my LCD phones and monitors are as black as friend's OLED.

Also many LED and OLED TVs are LCD but LED or OLED backlights. The QLED TVs have LCD panels, pure blue backlight and so called "quantum" dots for red or green that change the blue light to red or green. The Black to White and greys of the polarised LCD thus vary the R, G and B (red and green frequency changing dots and clear squares for blue).

Marketing is driven by fashion, not reality.

Flat black tinted matt surfaces were on high end CRTs 40 years ago. Been on very few laptops.

Shiny screens are a fashion and also the absolute cheapest. The ereaders have expensive matt surfaces because the panels are x5 price of LCD or OLED and they are promoting the "paper" experience. There is a fashion for glossy paper photos since mid 1960s. They were matt before that and also glossy paper fancy books. Novels are printed on matt paper.

It's a shame all phones and laptops and monitors over the last 25 years are not matt. It's greed and fashion. Not any technical difficulty.

03-25-2024, 05:46 PM	#59
Quoth Still reading Posts: 14,509 Karma: 108666825 Join Date: Jun 2017 Location: Ireland Device: All 4 Kinds: epub eink, Kindle, android eink, NxtPaper	The oled dots are light emitting. They are off when off. LCD backlight is always on. If it's set too high then there is still slight light leakage through the polarised LCD panel. Some very expensive Sony TVs have X Y array of LEDs or even R G B LEDs and turn them off on black areas of the screen. BTW, white LEDs don't exist. They are blue, violet or near UV with phosphors. You can see the yellow phosphor on the "stick" filament type LED lamps and they light up when you shine UV on them. Also yellow visible on some other LED lamps. The OLED do shift in colour. It's so gradual you may not notice and some systems count run time and compensate. Plasma panels and colour CRTs also shift but could be recalibrated. LCD needs two optically perfect accurately spaced panes of glass. OLED can use any insulating substrate and the top layer is to keep out moisture. That then has another layer if a touch screen is needed. So no mystery as to the OLED blacks. Also most people have the LCD brightness (backlight) far too high. The blacks on my LCD phones and monitors are as black as friend's OLED. Also many LED and OLED TVs are LCD but LED or OLED backlights. The QLED TVs have LCD panels, pure blue backlight and so called "quantum" dots for red or green that change the blue light to red or green. The Black to White and greys of the polarised LCD thus vary the R, G and B (red and green frequency changing dots and clear squares for blue). Marketing is driven by fashion, not reality. Flat black tinted matt surfaces were on high end CRTs 40 years ago. Been on very few laptops. Shiny screens are a fashion and also the absolute cheapest. The ereaders have expensive matt surfaces because the panels are x5 price of LCD or OLED and they are promoting the "paper" experience. There is a fashion for glossy paper photos since mid 1960s. They were matt before that and also glossy paper fancy books. Novels are printed on matt paper. It's a shame all phones and laptops and monitors over the last 25 years are not matt. It's greed and fashion. Not any technical difficulty. Last edited by Quoth; 03-25-2024 at 05:52 PM.