T3D Re: New 3D Display

[lunazzi <lunazzi@xxxxxxxxxxxxxx>]

(by a key managing error, a previous message was prematurely

sent, sorry).

Regarding two messages on the subject:

  > The only constraint is that the viewer's head must stay
within
  > a certain area in front of the screen. Move too far to
the left
  > or right and you lose the 3D effect. But Trayner says
most
  > people naturally sit in front of a display in the right
position.

  I wonder how long people can comfortably stay in the right
area.
  If there is a very sharp cutoff between left and right
viewing
  areas, then the most you could move your head to one side
or
  the other would be 1/2 the distance between your eyes.  I
like
  the idea of getting away from headgear.  The hologram is
just
  a compact way of making a large lens, of course; you could
do
  this part of the job other ways.

  John B
  ------------------------------

  Don't let the Hologram fool you, it is a version of ideas
that have come
  before us. The patent literature lists dozens of these
types of devices,
  same ideas used 30 years or more ago. It is nice that
people are thinking
  and manufacturing Stereoscopic devices, though.

  RM
------------------------------------------------------------

I can answer this question perfectly, because I think I am
the
inventor of the principle.  Please visit:

http://www.geocities.com/CapeCanaveral/Lab/6146/pub_imag.html

to see my french patent, started in 1989.

Of course, as RM says there are dozens of *this* type of
devices, but let me clarify that no one  can be considered
equal to another, if the patent is right, and which are the
differences.  I  discovered the possibility of projecting
*white light* images on a diffractive screen, usually named
"holographic screen", in 1987.  This is the same device
Gabor (the first inventor of holography) already patented
but using monochromatic light, and others made similar
patents but specific  for  computer or TV images.  I studied

during many days at the New York public library this
patents, and at the Paris patent office, in 1989, and
confirmed that no one applied this to white light.  It
happens that the  dispersion of wavelengths separates the
color composition, but it can be very reduced if the screen
is constructed appropriately, as specified in the patent.

The specific way to apply it to television is described in

http://www.geocities.com/CapeCanaveral/Lab/6146/prottv.html

in Portuguese language.  I showed it working in many
exhibits, in Brazil
and in many countries in Europe and also in USA (At
Rochester Institute
for  Imaging Science, and the screen at MIT) in 1990.
After showing  it to many people, I  understood  that it
will not be
considered, neither published in "New Scientist", or similar
magazines.

There is an adaptation in the case John mentioned, by
sampling the screen
in two, something I did not considered because I proposed
the projection
to come from  two separate projectors.

Now, answering John's question: I readily considered to be
very unpleasant
to stay with the head at fixed position, for more than 25
minutes (first time
you  see the phenomena) or for more than 10 minutes (when it
is not a
surprise anymore).  That is why I developed different new
systems.
There should be the possibility of  an automated system
follow a mark on the
observer's head, as in lenticular similar systems (useful
for  only one observer)
but it seems too complicated at this moment, although not
impossible. As you
already  guessed, it needs to move the lamps laterally in
opposite direction to the
observer head's movement.


JosČ
<lunazzi> at www.netword.com


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