Skimming a magazine in the barbers today and noticed a review for a LED LCD TV which headlined that it had a "224 LED Full Array" for back lighting. Does this imply that some LED LCD TVs do not have as many - or not in an array?
Anyone with any info or views?
Yes. It is my understanding (and I could be wrong) that all LCD TVs have some form of back lighting since the LCD does not emit light. This is usually a solid LED panel. Probably many LEDs but all turned on at once.
However there is a new breed of TVs where the back panel is active and the light in an area is turned down when that area of the picture is dark and up when it is light. The theory is that this improves the apparent contrast of the picture.
This is not an LED TV but is sometimes advertised as such.
Andrew
John presented the following explanation :
Some use something akin to a tiny strip light (correct name???), along the lower edge of the display, which is reflect up to create even back lit illumination. If these fail (not uncommon) you can still just about make out the characters in the display. The lighting tube is around
1/8" diameter.I suspect that now that LED illumination has progressed so far with brightness levels, that all they have done is replace the strip light with LED illumination.
Probably improves Dynamic Contrast localised to areas of the screen by ramping up the brightness of LED's close to where the programme material is bright.
Such a system (Samsung) is detailed here.
"Abstract: A backlight local dimming algorithm is proposed to achieve high static contrast more than
10000:1 on the LCD-TV which is mounted by an LEDarray backlight. On the dark region of the image, the backlight is dimmed to reduce light leakage and get deep dark. The proposed algorithm can avoid or significantly reduce such annoying local dimming artifacts as luminance decrease, nonuniformity and screen flicker in displaying video sequences."Get 'deep dark'. Yah...
many are now getting LED Back Lighting fir the LCD Panel.
I am trying to make sense of whether there is much variation in the deployment of the LEDs (eg 224 Array)
In theory, if you're going to alter backlight levels locally to improve the dark areas, they'd need to approximate to the pixel size to avoid unwanted effects?
Have something to add? Share your thoughts — no account required.
Ask the community — no account required