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???
04/30/09 03:40
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#164951 - silicone
Responding to: ???'s previous message
When I did build a solution maybe 10 years ago, I think I used silicone-based glue to glue the tiny mirrors onto the rim of the loudspeaker cones. The loudspeaker cone was mounted with rubber and a hard type that allowed me to remove much of the cone without getting stiffnes problems. But I have seen references where the mirror has been driven by the center of the cone too (should allow a smaller/cheaper speaker than I used), like in this link:
http://spt06.chez-alice.fr/00/scan1.htm

Richard: Remember that a x-y scanner with a reasonably number of scan lines either has to be very small, or has a very high-intensity laser because of the big length of the total sweep. And with a high-intensity laser, you will have two important problems:
1) there must be no reflective surface in the target zone, that can allow the light to reflect into the eyes of a viewer.
2) you must have a very good hardware watchdog system that will cut the laser output in case the modulation stops, or you may get a fire.

Using a rotating multi-facetted mirror combined with a linear deflector is the best way for building a x-y scanner, but you will get a stronger display by instead using separate X and Y modulation and vector-plot any information. The disadvantage would be that vector-plotted information changes in intensity with the complexity of the design, unless the LED instensity is adjusted to the drawing time.

When I originally built a solution, I had a very weak laser. I think I ended up with a laser diode from a CD reader (could have been from a low-speed CD writer). I have been thinking about building a new display using the much stronger laser diode from a high-speed DVD writer. But the dangers involved must not be ignored. I have been looking into using two secondary light sources with photo diodes controlling a hardware watchdog to make sure that if one of the mirrors stops moving, the laser gets instantly deactivated with no involvement of any processor.

List of 55 messages in thread
TopicAuthorDate
Circuit name for a "servo"            01/01/70 00:00      
   Something like that?            01/01/70 00:00      
   Specific vs General            01/01/70 00:00      
      Servo motor            01/01/70 00:00      
         Context            01/01/70 00:00      
            Equivalent is a strong word            01/01/70 00:00      
            yebbut            01/01/70 00:00      
            Yes, it's just another misnomer            01/01/70 00:00      
   To move data transfer between One proccessor to another one            01/01/70 00:00      
      I have never hear that            01/01/70 00:00      
         Typo ?            01/01/70 00:00      
   I misnamed what I want + info            01/01/70 00:00      
      Open-loop            01/01/70 00:00      
         I've got an old voice-coil FDD ...            01/01/70 00:00      
            Voice coils in HDD for quite some time            01/01/70 00:00      
      Look at commercial stuff for inspiration            01/01/70 00:00      
         Hinged mirror            01/01/70 00:00      
            What type of hinge            01/01/70 00:00      
               What Chico has is several angular options            01/01/70 00:00      
                  silicone            01/01/70 00:00      
                     That might work ...            01/01/70 00:00      
                        Precision relative to amount of modulation            01/01/70 00:00      
                           I don't quite see it            01/01/70 00:00      
                              At least two alternatives            01/01/70 00:00      
                                 There's another way ...            01/01/70 00:00      
                                    Rotating mirrors of limited use            01/01/70 00:00      
                                       Link about hazards            01/01/70 00:00      
                                          Safety First!            01/01/70 00:00      
                                             Today, rasters are hard for microcontrollers            01/01/70 00:00      
                                                Not necessarily! They don't have to be involved ... much.            01/01/70 00:00      
                                                   Easy first when all parts of the chain are easy            01/01/70 00:00      
                                                      It depends on how much you want to draw            01/01/70 00:00      
                                                         Still pushing rotating mirror, ignoring the problems            01/01/70 00:00      
                                                            Per, I think you've lost your way            01/01/70 00:00      
                                                               Stampede            01/01/70 00:00      
                                                                  One thing at a time            01/01/70 00:00      
                                                                     Finally noticing the lack of information from the OP?            01/01/70 00:00      
                                                                        GREAT links            01/01/70 00:00      
                                                                        It's about what people already are doing            01/01/70 00:00      
                                                                           Not DIY            01/01/70 00:00      
                                                                              Let's consider the commercial products.            01/01/70 00:00      
                                                                                 The man who rejected video uses video as his example...            01/01/70 00:00      
                                                                                    You mistake my viewpoint            01/01/70 00:00      
                                                                                       Chico might care            01/01/70 00:00      
                                                                                          The reason I don't care ...            01/01/70 00:00      
                                                                                             I wouldn't be surprised if Chico has a working projector            01/01/70 00:00      
                                                                                 Where ?            01/01/70 00:00      
                                                                                    8 angled mirrors...            01/01/70 00:00      
                                                                                       Ah.            01/01/70 00:00      
                                                plot rates            01/01/70 00:00      
                                                   Probably better than average, unless small angle            01/01/70 00:00      
                                                      In order to have high speed, you must have low mass            01/01/70 00:00      
         Homebuilt laser projector            01/01/70 00:00      
            EXCELLENT!            01/01/70 00:00      
               Yes, excellent            01/01/70 00:00      

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