Optical drives are somewhat passe in 2019, with most laptops and desktops no longer shipping with the hardware installed. The power of the cloud has begun to eliminate the need for physical media, but that doesn’t mean the technology is any less marvellous. [Leslie Wright] and [Samuel Goldwater] took a deep dive into what makes the PS3’s optical drive tick, back in the heyday of the Blu Ray era.
The teardown starts by examining the layout of the assembly, and the parts involved. This is followed by a deep dive into an exploration of the triple-laser diode itself, There are tips on how to safely extract the delicate parts, which are highly sensitive to electrostatic discharge, as well as exhaustive specifications and measurements of performance. There’s even a break down of the optical package, too, including a patent search to shed more light on the complicated inner workings of the hardware.
And if this lures you to dig deeper into Sam’s Laser FAQ, prepare to spend the rest of the week.
We’ve seen other optical teardowns before, too – like this look inside a stereo microscope. It’s quite technical stuff, and may fly over the heads over the optically inexperienced. However, for those in the know, it’s a great look at the technology used in a mass-produced console.
This post takes me back to when I got my first ps3 optical sled, and combined it with a dvd burner diode and terrible green laser pointer to make a full RGB laser projector (well, assuming you projected on a florescent surface…) on my middle school student’s budget. http://krazerlasers.com/lasers/rgb2/ It was like having the full whitelight argon ion laser I had always dreamed of, but costing only a few dollars, drawing literally less than 1/1000th the power, and no PCOAM needed for modulation either!
Amazing how far we have come in the last… 13 years… Now you can get 100mw singlemode RGB laser diode kits with combining optics and drivers on aliexpress for $50
“The power of the cloud has begun to eliminate the need for physical media”
Except for those concerned about all the issues the cloud presents.
I wouldn’t say that most consumers are concerned about the security and reliability issues of the cloud. That’s a HaD thing :)
Gaming and cloud streaming certainly has gotten a lot of noise.
Yes, the cloud is the opposite of the microcomputer revolution. Way back in the 19oos computers used to belong exclusively to corporate suits and the state. Then in the 70s and 80s we saw computers liberated for to the masses. Your files are YOUR files! But in recent times, amazingly, we’re being sold this bill of goods that oh, hey, owning hardware is like, hard, man, why not just abdicate and let big brother handle all that for you?
Cloud!
optical media are passe… blabla…
“The power of the cloud has begun to eliminate the need for physical media”
Let me rephrase that:
because internet is cheap, networks surrounds us and people are ignorantly sending their files to servers they never seen which are controlled by people they don’t know. Both are owned by other people who “promise” to keep everything safe but are only interested in making money. Yeah, you’re right, this does make all other media seem to be irrelevant.
Now don’t get me wrong, I don’t use optical dics, USB sticks are fine enough for data transport and archiving to optical disks is more complex than you might imagine. Using the cloud sounds nice… always have your files on any device, no need to carry media, sure… and then the internet can’t be reached (no reliable wifi network or no GSM signal).
No where’s my tinfoil hat?
I know a guy with 4 shelves full of USB 2.0 and USB 3.0 connected hard drives. He has them from 320 gig up to 4TB. Each of the drives has a twin so everything has two copies. They aren’t in a RAID or using anything fancy, just direct access to each drive. He’s starting to migrate and consolidate the contents of the smaller USB 2.0 drive to new, larger 3.0 drives.
That’s (my kind of) insane
CD/DVD/BRD optical drive systems are wonders of cost optimized mechatronics engineering. Especially the engineering of the optics portion has me wondering, as I don’t see a way for it to focus in Z. The lower slide is likely only for focusing different layers (as accuracy is less important for that task since the objective lens can correct within certain margins) so that means the objective lens must be able to move in Z, as well as radially, but I don’t see how in this design unless they did something really sneaky with the magnetization of the permanent magnets.
I believe the Z travel is actuated by a voice coil underneath the lens. It need to be fast enough to track any warp or wobble in the disc as it spins. It has fairly limited travel, I recall some cd/dvd rw drives that had a hard time tracking discs when adhesive labels were applied.
The four spring wire “beams” allow motion in tracking and focus direction and there are two sets of coils on the lens holder for this operation. It was quite obvious when I disassembled one to get the laser diode, but this was several years ago and I am not sure anymore about the exact arrangement of the coils and perm magnets.
It’s the same system these optical drives have used since the introduction of the audio CD.
One very interesting drive was one of the first DVD burners (or was it one of the first CD_RW drives?) which had a unique solution to the normal reading LASER being unsuitable for writing. Use two LASERs, two lenses, two focusing systems etc. To enable each LASER to reach the innermost part of the discs the whole shebang was mounted on a tiny rotary table that could spin 180 degrees really fast.
I happened to get one in a used tower some time after it was the hottest thing. I’d read a magazine (dead tree!) article on the drive when it was new. I thought it was pretty neat, but slow, and it’d make the tower shake a bit when it spun the LASER unit around or did fast seeks due to the weight of the sled. I built up a tower, put that drive in and sold it.
The only other thing I’ve had in odd disk drives that matched it for weird was a 1.44M NEC floppy drive that didn’t use a stepper and screw. It had a linear actuator that made a barely audible *eeep* as it went from track to track.
All the coils visible are “vertical” and would create a force in the horizontal plane (up down in the pictures). I don’t see a horizontal coil that would create a vertical movement. The lens seems to be solidly mounted to the beige lens carrier.
Of course, Sam was a regular for a long time in sci.electronics.repair and still pokes in occasionally.
Repairfaq.org has a lot of his stuff about repair. For a whike he did the repair column in Electronics Now, the final title for Radio Electronics. He was asked based on the repairfaq.
So this isn’t his first time writing about readers. He wrote about CD players , and CD drives, though maybe not DVD drives.
If yiu need to repair something, read the “FAQ”, it’s really like a short book.
A good percentage of everything I know about old lasers, I know from Sam’s Laser FAQ. And applying it to fix up / break a bunch of old HeNes.
https://www.youtube.com/watch?v=5bqujaldaCQ