Quote:
Originally Posted by BWinmill
I wonder why they haven't solved the problem of flicker with front/backlights. If I recall correctly, the intensity of an LED is related to the current passing through it. A simple approach involves using a potentiometer, which I understand isn't popular because it isn't software controlled. (Again if I recall correctly,) transistors can use voltage to control current as well, so it should be easy to design a software controlled way to control the intensity of a backlight using transistors.
Is there something that I'm missing?
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Probably because it requires extra hardware, whereas PWM is usually already implemented on the SOC (system on a chip). There are "Digital Potentiometers" available that would work (most home stereo systems that have remote volume control but no motorized volume knob use them).
Some systems do use this approach. I'm almost 100% sure my Galaxy Note 8.0 does (pointed a video camera at it, and adjusted the brightness - never caught any flicker). My Galaxy Note phone with it's OLED screen is a different story. Samsung seem to dim their OLED screens by adjusting the refresh rate.
The only time flicker ever bothered me was back in the days of the 60Hz CRTS. I can happily read on pretty much any LCD and have been since the Palm Pilot. Other people don't seem to be so lucky.