[Ronja] TX Head design question...

[ronjalist]

I honestly had no firm idea, but from a scrap & salvage point of view - 
perhaps after the optics, and wouldn't a 15 inch tft from a scrap laptop 
or similar do?

J.D. Bakker wrote:
>> Hi All,
>>    Just a quick question - Is there any reason why instead of forcing
>> the TX led to produce the pulses, a "shutter" cannot be employed instead ?
> 
> No fundamental reason, just practical ones. Sourcing shutter 
> film/foil which can reliably switch at 10MHz is likely challenging, 
> especially in the small quantities that the average Ronja builder 
> would need. Common LCD shutters max out at 100Hz-1kHz, so we'd need 
> four to five orders of magnitude better performance. If the shutter 
> were placed between LED and lens viewing angle and diffraction must 
> be accounted for, if the shutter is placed after the lens it needs to 
> be physically large (and diffraction is still an issue).
> 
> More here:
> 
> http://www.liquidcrystaltechnologies.com/tech_support/LCDShutterConsiderations.htm
> 
> Have you any suggestions for such a shutter?
> 
> JDB.