Wikipedia:Reference desk/Archives/Miscellaneous/2023 May 2

= May 2 =

LCD screen power usage
Does a an LCD screen use less electricity when in night mode (mostly black)? Also, my phone (TCL) has a selectable mode where the screen goes to B&W when battery level falls below a threshold; is this only to remind you, or does it also consume less energy without color? 136.56.52.157 (talk) 13:39, 2 May 2023 (UTC)
 * This seems to have some relevant data to answer your questions. -- Jayron 32 14:17, 2 May 2023 (UTC)
 * Thanks. Evidently, no savings with LCD, and about 3-9% for OLED. 136.56.52.157 (talk) 14:36, 2 May 2023 (UTC)
 * This depends on the actual technology. A pure LCD screen with no optimizations of any kind uses the same power regardless of brightness because it is a light with tiny LCD shutters in front of it. The light stays on, the same brightness, at all times. When it is darker, it is because the LCD shutters are closed. There are LCD screens that adjust the brightness of the light as well as using the LCDs. That technology would use less electricity if it was darkness implemented by lowering the brightness of the light. As far as going black and white, that is technology dependent as well. If it is a 4-light pixel and you turn off red, green, and blue, leaving only white (brightness), then you've essentially turned off 75% of the lights being used, but you will likely use more variance in the electricity going to the white lights, so it isn't going to be a 75% savings. 12.116.29.106 (talk) 18:33, 2 May 2023 (UTC)
 * Although The manual isn't specific, I suspect the B&W low-battery feature has some effect (as you describe). The screen is only specified as TFT LCD; I couldn't find anything in that WP article about power reduction in non-color mode (but that article induces brain-fog, so I'm not certain).  The model (Alcatel TCL A3 A509DL) originated in 2021, so it presumably has new-ish technology.  136.56.52.157 (talk) 21:33, 2 May 2023 (UTC)