Question about the heat from screen

[peanuto]

Hi, my friends, I have one question about the heat from the screen.
Under native OS, after PMP, the screen can totally dim out.
I know that screen needs relative high voltage to drive, so it will generate heat when working.
After dim out, I suppose the screen display part is powered off, while the capacitance touch screen should be still alive(that's why we can still wake it up with touching).
But I still can feel it's quite warm on the screen. One can compare its temperature to that of a laptop and easily feel the difference.

My question is where the heat is from--
A. screen display part is actually not totally powered off(just show a black pic, for example) and the major heat is from this?
B. heat is (mainly) from the capacitance touch screen part?
C. from cpu and other ICs?

If A, do we have a method to totally power off the screen display part with touch screen part alive?
If B or we cannot totally power off the screen display part with touch screen part alive, can we totally power off the whole screen. And make use of the light sensor as an input member?
I noticed that in sqeezeplay, joggler is quite sensitive to the light sensor.
If C, it seems we have to improve the heat dissipation with some actions on hardware.

Any suggestions?
Thanks!

[gegs]

gforums' Plug'n'Pimp has a tool to switch off the screen; an excellent idea if you use the Joggler as an alarm clock. The touch screen remains active and the display will switch on again if you touch it. Is that what you meant in your post, or were you talking about Joggler's auto-dimming?

If I use the P'n'P tool to switch of the screen it definitely gets cooler, though not cold. I use it a lot.

[peanuto]

On the one side, I feel the temperature of joggler down when the screen dims out; on the other side, when comparing to laptop, I surprisingly found that the laptop screen seems have no temperature difference even after long time working. How can this be?

[Justblair]

I'm thinking that the heat that you are experiencing is coming from the motherboard of the Joggler and not the screen itself.

If you have the screen properly switched off, the next heat source comes from the motherboard/processor/memory of the Joggler. The Cooling on these things is fairly poor compared to other devices and unlike your laptop the whole unit is in one box.

[roobarb!]

I know that screen needs relative high voltage to drive, so it will generate heat when working.

One little point on this - the Joggler's backlight is LED and not cold cathode, so there are no high voltages within the device.

[peanuto]

oh thanks!