Fiber Optic Commutator
By Andy LaTorre
I'd like to throw out to MMD members, who are interested, an idea about roll scanning. My idea uses both simple electronics and mechanics. You see, I also considered CCD scanning but my understanding of that would require additional electronics and opics, I imagine. (My electronics experience is as follows: I can program in 8085 machine language and design interfaces and I can do some analog design - that's it.)
Let's call this idea a Mechanical Optical Scanner. Get some fiber optics cable (from where, at a reasonable price?) and connect each to a tracker bar position. Terminate the ends of the cables (65 or 88 cables, depending upon which roll frame one is scanning) to a cylindrical ring with each termination projecting into a, let's say, 4" diameter circle. Now, using a short 4-1/2" fiber optic cable bent into an "L" spin it on the short part of the "L" axis using a stepping motor. A small motor is all that is necessary because there will be hardly any load on it other than momentum of the rotating hub and fiber optic "L".
The long axis of the "L" will just miss each termination point of the fiber optics cable coming from the tracker bar. The short axis of the "L", rotating, will just "kiss" a single suitable high speed optical sensor.
Get the idea? The rotating "L" will make "contact" with each of the tracker bar holes through the optical cable. The optical sensor will read the amount of light present at the tracker bar hole and the stepper motor, because it steps in discrete (1.8 degree in some cases) units can be assured to be at the correct sensor. The electronics will keep track of all the positions and light readings. Of course, all this mechanical stuff will have to be placed in a light-proof box.
Now, for using it on different trackerbars: just remove the ring of cables and bring the motor assembly to the other roll frame with its ring of optical cables.
The problem of the varying densities of paper used might be solved by the use of one control, a potentiometer, which will set the sensivity of the optical sensor. This can be a comparator circuit.
This idea is an extension of my idea 18 years ago of a moving message display using only 7 LEDs (lights). It was great fun seeing a message suspended in mid air as the lights were rotated. I applied for a patent and was soundly taken by my lawyer. He strung me along with enough string to make it look like a lynching. What did I know? He did that stuff every day; I only attempted it once. I should have used all that string to lynch him. In the meanwhile others took up the idea (I don't claim to be the only one with the idea) and manufactured products with it.
I would pursue this Mechanical Optical Scanner idea if there was time available, but alas....
Andy LaTorre
Orgue Mecanique
POB 1479, Cullowhee, NC 28723
[ Andy, your device is quite novel, and I've not heard of it!
[ It is analogous to the rotating electric switch, also called
[ a commutator, so that's why I gave your subject the name,
[ "Fiber Optic Commutator".
[
[ The term "scanner" is more appropriate for the camera-style optical
[ device with "adjustable zoom" capability. -- Robbie |
(Message sent Fri 10 Jan 1997, 15:56:45 GMT, from time zone GMT-0500.) |
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