Narrow-Bandwidth Television Association

G'day all.

Whilst I've been thinking a lot about my solid state iconoscope camera project and the possibility of DIY iconoscope tubes having the right equipment handy and I've had an interesting idea flashing in my head and I wonder if it might work.

I was pondering on the possibility of making a vacuumless iconoscope type camera tube which instead of having a cathode ray gun scanning its beam across the photosensitive mosaic target inside a vacuumed tube, there will be a laser scanning its beam across across a photosensitive mosaic target made of material that will discharge to the laser beam hitting it converting the image projected on it into electrical impulses in the same fashion as the traditional iconoscope. This idea will eliminate the need of a vacuum in the tube and also eliminate the need of horizontal/vertical deflection coils. Of course I am guessing there will still be keystone trapezoidal distortion due to the 30 degree offset of the laser beam and it requiring variable horizontal scanning width from top to bottom. I have made a diagram of the tube to visually represent this idea which can be seen below.

Anyways those who read this thread I would love to hear your opinions of this idea and if it can work any knowledge you can provide to make it practical as my knowledge of designing the circuitry is very limited.

How do you change the image (=light) into electricity using a laser (=light)? I think I'm not understanding something in your idea.

Basically cathode ray beam in a traditional iconoscope doesn't convert light to electricity but charges up the photosensitive plate's silver capacitively charged bead like elements and then the image focused on the plate causes each element to discharge in accordance to the light levels it picks up from the image which on scanning progressively outputs varying voltages into a video signal. I figured why not have a photosensitive plate with capacitive elements that can be charged up by a scanning laser beam instead of a cathode ray beam and with an image focused on the plate the elements being discharged to voltage levels on scanning making the video signal just like in the traditional iconoscope.

The operation of an iconoscope can be better explained on Wikipedia http://en.wikipedia.org/wiki/Iconoscope which corrected my initial mistaken understanding that the beam discharges the elements instead of charging them first to be discharged by the image focused on it.

Hi Troy

Just thinking a little different scanning part you need rotating mirrors pretty the laser nbtv tv idea i made a while back with a very high speed one for the line scan if you are using perhaps a polygon i used a 8 sided one in that project /

I have not got to it yet but that could be pretty much a flying spot scanner as well if you are brave enough to be scanned by a laser ..point a head amp at it and you have a camera .

I know say a photo were scanned by a laser with my laser scanner that would work now using your idea of a camera lens projecting a subject to a mirror and the laser is scanning the image off that mirror and say again a head amp is close just picking up the varying light levels ? it would be interesting if that would work ? you would have to angle the laser so its not just projecting back out the lens .....
Don't know
I wonder if you had a sort of feed back system where the head amp feed the video right back to the laser doing the scanning if the lasers angled right it would scan and project the scanned image to a screen on the same device maybe perhaps better SSTV idea than a NBTV movement .