Tuesday, June 9, 2009

Logitech QuickCam Pro 9000 Dissection Part 2

On last Thursday's episode of I Heart Robotics a QuickCam Pro 9000 was vivisected. However my attempts to learn how exactly the auto focus system worked were thwarted by screws that were glued in.

If you really want to remove those screws you can get them out by heating them gently with a clean soldering iron without solder on it. The heat should release the glue that holds them in. I suggest avoiding this if possible.

Finally got the screws out.

Then I figure out you can not take it apart from this direction.

This is where I realize I will need a special tool to remove the lens since its glued in.

Voila! Lens removed using custom Logitech Lens Adjustment Tool.

Why does this cover have latches and glue?! The permanent magnets for the auto focus motor hold it on just fine by itself.

Here is the linear drive motor exposed. It looks like they are using M8 threading for the lens mount, and the motor's displacement seems linearly proportional to the input voltage with a maximum of 3.3V. I think the auto focus uses contrast measurement so in theory you might be able to replace the lens with some sort of c-mount system and breakout the auto focus wires to drive the focus of an external lens.

Attempted to use "Component Cooler" to cool the CCD which in theory should improve its sensitivity.

I will admit that I did not really think this through. I couldn't really get it to work, and I quickly realized that I forgot what happens when you make something really cold in a room that has humidity. The entire circuit board ended up covered in condensation while it was running. Fortunately nothing fried and I had canned air to blow the water off.

If you look closely you can see where I lifted the trace for the auto focus connection.

Here is a photo taken from the web cam after the camera has been fully reassembled. The focus is a smidgen off but the camera is working again so it's time to build a high resolution stereovision system with it.

Also this means it should be possible to replace the lens with a wide angle or fisheye lens.

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