(Hack) Modify cheap laptop for 3-D video

Conundrum, Mon Mar 19 2012, 07:36AM

Hi all.

It seems that many of the "cheap" laptops can be modified to do flicker glasses type 3-D.
The secret it seems is to replace the backlight LED strip driver with a homemade one.
This drives the LEDs with precisely adjusted pulses so that they are perfectly synchronised with the display refresh.
Then you need to modify the display slightly so that it can accept a marginally higher refresh than it was designed for.
Most panels will do this, but they need to be run at 30 degrees Celsius or above which requires a back heater.
The LED strips normally don't generate enough heat to make the panel warm at all, ironically the old CCFLs did but they couldn't be modified in this way due to phosphor persistence.
In addition the LED strip needs a discharge resistor (SERIOUSLY!) so that the capacitance is discharged.
Failing to do this will result in a blurred 3D effect

The glasses don't normally need modifying, but the exact code in the microcontroller will need to be set up so that they respond as if synchronised to the TV and the microcontroller needs to be connected to the LCD's clock signals via a buffer so that it correctly generates the sync pulses.

The other half of this hack is replacing the camera with a dual camera setup.
This requires modifying the cable to feed a miniature USB hub, which then drives a pair of cameras.
These MUST be different manufacturers ie Sweex and Phison or something, or it won't work.
Best tried before doing any soldering, to confirm that the cameras "play nice" and don't conflict.
Upon examining the cameras, they use an "EN" line which turns the camera on.
This output can be used for other stuff such as controlling the IR LED.
At least for turning 3-D on and off

Sounds feasible?
alternate idea *2, for non flicker glasses replace LED strip with TWO LED strips with alternating circular polarising filters, and remove the LCD's back polariser.
Not for the timid!!

-A