On 13/08/2019 18:11, Max Demian wrote:
On 13/08/2019 11:00, John Rumm wrote:
On 12/08/2019 22:30, wrote:
Steve Walker wrote:
Brilliant! (literally ;-) ) Thanks for posting this, all I need
now is a dead TV.

The last one I threw away had a failed backlight, so not much use
for this!

In the video it is noted that it is the diffuser and fresnel lens
in the screen is more use than a backlight (he replaces a backlight
that is inconvenient to power with a fairly generic LED strip).

Not all screens are edge lit though. Many of the ones I have
seen/repaired[1] have a backlight consisting of strips of LEDs mounted
on long thin PCBs, that point at the back of the screen panel, and are
arranged in a number of rows down the screen. These screens have lots
of diffusion layers, but not always a fresnel one.

Aren't there screens which have LEDs lighting a square of pixels so the
black areas of the screen don't have to be backlit at all? And dimly lit
areas have partly lit LEDs and the TFT elements adjusted to suit?

Yup, dynamic backlighting... the resolution is *very* coarse compared to
the actual pixel count though (unless you go OLED, in which case its 1:1)


--
Cheers,

John.

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