DVD data recovery using 445 diode

[conundrum]

Hi all.

Looking at Powerful laser diode from DVD-RW burned gave me an idea.

I have been looking into recovering data from DVDRs that have failed due to old age, it seems that the dye is the root cause of this as over time it reflows around the damage so that the pits and lands become harder to resolve.
Typically by the time read errors are detected the disk is unrecoverable except by expensive data recovery companies, charging up to £200 a disk !

My plan is to obtain an old DVDRW drive, replace its existing red diode with a 445 blue and then modify the circuitry so that during reading the 445 gets its rated current, also attenuate the >150mW beam with an adjustable polariser stack so that the disk and optics are not damaged.

Does this sound feasible?

My reasoning is that the shorter wavelength ought to allow resolving of marginal pits, increasing the S/N ratio to the point that the disk can be read back intact.

-A

 

[eexe]

I think that multimode beam profile would not work reading compact discs :undecided: And I doubt if another wavelength would work reading it at all.

 

[Lotus_Darkrose]

There's a reason CD/DVD/Blu-Ray burners/readers contain the diode of the wavelength that's in them. Just like there's a reason the projector contains the 445 diodes. You can't just switch them up. It's like filling your flashlight up with gasoline. One thing can't always replace another.

 

[Gryphon]

The idea does sound reather feasible, but some what tricky to pull off. Your best bet would to use a HD DVD player, that way you get the shortest wavelength (405nm) for the tightest beam and the optics are already set up for the laser. Then i suppose it would just be a matter of getting it all programmed right.

I suggested a HD DVD player over a Blu ray player simply because they have focal points similar to that of regular dvds and cds. Blu ray players are set up to read a disk which has information written on it much closer to the surface of the disk (different focal length) when compared to regular dvds and cds

 

[rhd]

As mentioned in this thread, a 445 makes little sense on account of being multimode. You would want a 405nm, and blu-ray or HD-DVD drives would make the most sense as a starting point. If you've ever harvested a sled, you'll know why it is a much pleasanter thought to have a 405 already mounted in your drive, instead of trying to swap one in.

That said, I'm not sure the physics will work. DVDs use organic dyes, as do CDs. Blu-Rays and HD-DVDs use totally different inorganic dyes that are must more resistant to damage from light (like 405). I wouldn't be surprised if DVDs just couldn't handle intense lower wavelength light. You might damage them more.

 

[Cyparagon]

I think its worth a try (with a violet instead of a 445.)

 

[Cyparagon]

A shorter wavelength will offer a higher resolution and potentially a better chance of reading a bit. I think its worth a try (with a violet instead of a 445.) Maybe you can force a bluray drive to read with the violet instead of the red.

On the other hand, it seems too easy. It sounds simple to implement with software. Why hasn't it been done before?

 

[conundrum]

Update:-
Thanks to a helpful computer guy over here I now have a 20x DVD burner with a broken eject mechanism.
Took apart (curses, camera battery flat!) and the laser module has a nice easily removed clip lid to get to the guts.
Soldered wires to the two diode anodes so that it can be controlled out of the drive, and hopefully I can feed it extra current while reading.

Also this "mod" might enable me to fuse broken layer transitions back together on pressed DL DVDs as I have about 50 unplayable movies due to this :-( :-(

 

[sinner]

Well if it helps, i had once recovered a dvd which was scratched and old.. i cleaned it with some plain water and a mild surfactant which removed all the debris and buffed it just enough to remove the scratches.. idk what grit but it was a loose cotton felt type..
I dont claim this method to be the best working method.. if u have a dremel and a felt bob u could give it a shot.. try on some unwanted ones first!!