bar code scaners

[jamilm9]

how does a bar code scanner make the wired pattern.

 

[thesk8nmidget]

most likely just a flat like diffraction type grating i would think.

but not for sure.

 

[360freak]

Optical pickups like a disc reader i think.

 

[rkcstr]

They are a laser scanning system (mirrors move the laser beam)... kinda like a mini laser show, but the reflection is picked back up for pattern recognition (the bar codes).  Some are simply a line, others are very complex patterns to allow for easily reading in a variety of orientations.

 

[rog8811]

The one I took apart has 3 long faces and 3 short faces on the rotating mirror all at different angles, the laser is reflected from the faces onto other angled mirrors which send the lines out of the front of the scanner.

Regards rog8811

 

[Ryo]

Probably spinning mirrors.. I have a barcode reader on my desk (standard straight light version) and it has a reflective mirror moving back and forth.

 

[Sefrez]

Yep, Just small cd like mirrors on a rod at an angle that spins.

Is this how the laser scanner things work to make those weird designs?

 

[Things]

I know at some toy stores, the barcode scanners ARE actually spirographs, they project one of the EXACT spirograph patterns!

 

[lamborgini8]

Theres one here at work that projects a cross before the scan and the usual line to read it.

That can't be done by any of what you said above.

 

[VillageIdiot]

I know at some toy stores, the barcode scanners ARE actually spirographs, they project one of the EXACT spirograph patterns!

I've seen that too. =D

 

[GooeyGus]

The one I took apart was just a diode pointed at a small mirror which was attached to a little electromagnet that went back and fourth when power was applied to it. It made a line.... pretty neat!

 

[laserwanabe]

I know they have those scanners in grocery stores that scan the things you buy. They usually have a hefty warning label on them, so what is the actual power of diodes used in the scanners?

 

[Things]

I'd say they would be <10mw

Possibly they could be 635nm diodes, but I kinda doubt it, the optical pickups on thise things are quite sensative!

 

[VillageIdiot]

I scanned my hand once on those things and it came up with $99. I couldn't do it again though D: I wanted to show my friend that my hand was worth a hundred bux.

 

[laserwanabe]

I scanned my hand once on those things and it came up with $99. I couldn't do it again though D: I wanted to show my friend that my hand was worth a hundred bux.

Haha i wonder how you pulled that off. Next time i see one im going to actually read the warning maybe it is mentioned.

 

[Things]

Actually now that I think of it, some older bar code scanners used HeNe's, they are typically around 635nm and about 10mw

I doubt the label will actually say its power, more or less, just a class.