Results 1 to 4 of 4
  1.    #1  
    Just something I noticed after the latest Sprint update for the Treo. The keypad now flickers? Almost like a fluorescent light, which, I guess makes sense since it's a CCFL behind it...

    Anyone else notice any other new strange improvements?

    Sin,
    -Paul
  2. #2  
    Yeah,

    I'm not sure i'd call it an improvement, because at 'full' brightness it is still dimmer, and the flickering is annoying (at least to me). But it's because they pulse the light at different intervals in order to control the brightness of the keys.

    I wonder if the processor is in charge of controlling the pulsing, which would explain some performance issues in 1.12. (and I don't mean application loading slowness, at least for most apps)
  3.    #3  
    Ahhh, just notice that the keys are actually tied to the brightness of the screen now. Which, I think is an improvement. It allows for a more stealthy way to tooth folks in movie theaters and concerts ;-)

    Sin,
    -Paul
  4. CLB
    CLB is offline
    CLB's Avatar
    Posts
    11 Posts
    #4  
    Your prior ROM must not have dimmed the keyboard with the display. The newer ROM does.

    The keyboard is back lit with LED's, not ccfl. To dim the LED's Palm chose to PWM (pulse width modulate) them at full intensity as apposed to an analog adjustment of drive current. This gives better linearity and consistency from LED to LED.

    The LED's should be pulsed at a rate that is imperceptible to humans but as you "can see" the frequency choice is a little marginal.

    Readers digest version:
    The LED's always operate at full power but are driven at less than 100% duty ratio to reduce average output.

Posting Permissions