Benm
0
- Joined
- Aug 16, 2007
- Messages
- 7,896
- Points
- 113
If i'm not mistaken there is a tiny lens between the diode and combining cube in the sled. I'm not sure to what diameter/divergence this focuses the laser though.
Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers
Buy Site Supporter Role (remove some ads) | LPF Donations
Links below open in new window
FrozenGate by Avery
Cheapest RGV laser?
- Thread starter florian
- Start date
- Joined
- May 10, 2009
- Messages
- 379
- Points
- 28
The issue with leaving the red and br diodes uncollimated, pre cube, is that they will not have equal focal points. If you were to put a lens at the exit of the cube, the red diode would need the lens to be at a different distance than the br diode to have equal dot sizes at distance. This happens because of refraction, different wavelengths bend at different rates.
Benm: If I'm not mistaken their is a polarizing window between the diode and the cube, unfortunately I don't think it's a lens.
Benm: If I'm not mistaken their is a polarizing window between the diode and the cube, unfortunately I don't think it's a lens.
Last edited:
HIMNL9
0
- Joined
- May 26, 2009
- Messages
- 5,318
- Points
- 0
Not a lens, sorry ..... those are linear diffraction gratings (different lines-per-inches for different wavelenghts) ..... you can try with one of them, shine a laser beam through them and you get a line of dots in exit ..... i think they are used for "correct" and clean better the beams coming from the chips, before combine them, but i'm not 100% sure, about this .....
There's a lens in front of the reading chip, yes, it's usually a double-use element (i mean, one of the faces is a cylindrical lens, and the other is a negative concave face) ..... but they are normally molded with acrylate in strange shapes, and practically unusables .....
Benm
0
- Joined
- Aug 16, 2007
- Messages
- 7,896
- Points
- 113
I saw something between the diodes and the cube, so i assumed this must be a lens because the beam would be very wide without one. I looked it up and it seems to be a diffraction grating indeed (no idea of its purpose there).
If i have an intact sled i'll power up both diodes to see where the light actually goes
If i have an intact sled i'll power up both diodes to see where the light actually goes
If i have an intact sled i'll power up both diodes to see where the light actually goes
I just received my 2 first sleds today! I will play around with them and try to understand what is going on in it
- Joined
- May 10, 2009
- Messages
- 379
- Points
- 28
I just received my 2 first sleds today! I will play around with them and try to understand what is going on in it
If it helps to understand, here is the link to rog's page with a great description of the whole build process. Pocket white - It can be done
Benm
0
- Joined
- Aug 16, 2007
- Messages
- 7,896
- Points
- 113
Thats a great build, but it doesnt leave the blu and red diode in their original places. As this project needs low power but minimal costs as well, that would be prefereable if it could be done one way or another.
Re: Cheapest RBV laser?
There's a simple way to close the loop. Put an opto-interruptor sensor, or even a simple microswitch with a cam that activates the switch at one point in the revolution. The controller can keep track of the number of steps and then if the signal from the home sensor comes at a different point than it expects, simply zero the counter and go from there. If it gets out of sync, it will sync itself up within one rotation.
There's a simple way to close the loop. Put an opto-interruptor sensor, or even a simple microswitch with a cam that activates the switch at one point in the revolution. The controller can keep track of the number of steps and then if the signal from the home sensor comes at a different point than it expects, simply zero the counter and go from there. If it gets out of sync, it will sync itself up within one rotation.
