A Method or System by means of which Pictures Projected upon a Screen from an Optical or Magic Lantern or Lanterns are Seen in Relief or with Stereoscopic Effect.
Year: 1891

page_text: Date of Application, 7th July, 1891
Complete Specification Left, 7th Apr., 1392-Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
A Method or System by means of which Pictures Projected upon a
Screen from an Optical or Magic Lantern or Lanterns are Seen
in Relief or with Stereoscopic Effect.
I, JOHN ANDERTON of :142 Suffolk Street Birmingham in the County of
Warwick Scientific Instrument Maker, do hereby declare the nature of this
invention to be as follows:-
Two views or pictures of an object are taken in the direction in which it would
be viewed by the two eyes, by photography or other means (as taken for the
stereoscope) and these pictures are placed in an optical or magic lantern with
two separate objectives or in two or more separate lanterns.
Into the optical system of each objective or lantern is introduced a Nichol's
prism, reflectors, plate of tourmaline, or any other material or apparatus that
will polarise the light, and these for simplicity say, two Nichol's prisins, are, so
placed that the light will emerge from one lantern polarised in a plane at, a
right angle.to that emerging from the other.
These two views so polarised are superposed upon a screen of ground glass,
or any other material that will not depolarise or elliptically polarise the enlarged
image or representation of the two views projected upon it.
"
The superposed views are viewed by the observer through a pair of analysers
of Nichol's prisms or any other substance or system capable of effecting same,
and these say Nichol's prisms are placed with their planes of polarisation at
right angles to each other. The one prism will permit the one picture that is
polarised in the same plane to reach say the right eye, and will prevent the
second picture from falling upon it; whilst the other prism having its plane
of polarisation at a right angle to the first, will permit the other picture ie the
one that is polarised in the same plane to reach the left eye, and will prevent
the second picture from falling upon it.
There is then (as the pictures are already superposed upon the screen and as
upon each eye a different picture or view falls upon corresponding portions of
the retina) all the conditions under which the effect of stereoscopic vision. is
produced and therefore the combined picture appears in relief, giving the
impression of actual solidity to the observer or observers.
"
4
By this method or system the colours of the pictures are not in any way
affected.
15 6th day of July A.D. 1891.
EDWARD J. PAYNE & SON,
104, Colmore Row, Birmingham, Agents for the Applicant.
COMPLETE SPECIFICATION.
A Method or System by means of which Pictures Projected upon a
Screen from an Optical or Magic Lantern or Lanterns are Seen
in Relief or with Stereoscopic Effect.
I, JOHN ANDERTON of 142 Suffolk Street Birmingham, in the' County of
Warwick, Scientific Instrument Maker, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
1
The object of my invention is to bring out in relief or stereoscopic effect pictures

page_text: projected upon a screen or such like, and this is effected by polarizing and
analyzing the projected images in the manner hereinafter set forth, or in any other
way possibly by the polarization of light.
One of two slides prepared from pictures taken by a stereoscope camera or
produced by other means is placed in one lantern of a Biunial or one of a pair of
optical lanterns and the other slide in the second lantern.
Into the optical system of each lantern or other arrangement for projecting
images upon the screen is introduced either between the condenser and objective or
before the objective or between the radiant and condenser or in any other position
but preferably between the lenses of an objective of a Petzval combination a
Nichol's prism plate of tourmaline, or any other material or apparatus that will
sufficiently polarize the light for the purpose intended.
Preferably a number of glass plates placed at the requisite angle for producing
polarization by refraction enclosed in a convenient case or frame will be used.--
These plates are so arranged in each lantern that the light from one will emerge
polarized in a plane at right angles to that emerging. from the other.
The images of the two slides or pictures so polarized arc projected and
superposed on a screen of ground glass, metal, or any other substance or material
that will not depolarize or elliptically or circularly polarise the images it receives.
Preferably a calico screen covered with dead silver paper.
These superposed images are viewed by the observer through a pair of analyzers
of any construction capable of effecting the requisite amount of analyzation and
these are set with their planes of polarization at right angles to each other.
One analyzer will permit the image of one of the pictures the one polarized in
the same plane to pass through to the eye whilst the second picture polarized in a
plane at right angles to it will not pass, with the second analyzer this order is
reversed, the image of the picture stopped by the first analyzer passing through it
whilst the other is stopped. Therefore upon cach cye of the observer the image
of a different picture falls, and as the two pictures are as nearly as possible super-
posed on the screen an image of one stereoscopic picture falls upon the retina of
one eye and an image of the second stereoscopic picture upon a corresponding
portion of the retina of the other eye.
The conditions being fulfilled under which stereoscopic vision of two pictures is
possible the one picture seen appears in relief.
Any number of observers each furnished with a pair of analyzers can see the
effect at one and the same time, and coloured pictures can be utilized as readily as
those in black and white.
The analyzers designed for this purpose are made of a number of thin glass
plates and the necessary polarization. is effected by refraction. These glass plates
are set at a proper angle in a mount resembling a very small opera glass or any
other form more convenient.
The plates are arranged at slightly varying angles to each other in the same
plane for if a number of plates be placed Hat one upon another, around the
principal image a number of fainter images are formed, and thereby the definition
or clearness of the principal one is impaired. By arranging the plates as described
a well defined picture is obtained.
Reference to the accompanying drawing shews one method of arrangement of the
plates and the positions they assume. In the sectional elevation shewn, A. A. is
the box or case for containing and holding the glass plates C. C. B. B. are strips
of metal or suitable material attached to the glass plates in order to give same
different angles in same plane. C. C are the glass plates seen on edge in position
in the box or case A. A. D. is the lens of objective of lantern, into which the
case of glass plates is introduced. E. E diaphragm.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I wish it to be understood
that I do not limit myself to the more precise details herein set forth as I may

page_text: sometimes vary the same to suit different requirements at the same time adhering
to the main principle of this my invention I declare that what I claim is,
The scientific arrangement of the several parts constituting an apparatus for
giving by polarization or partial polarization of the light a stereoscopic effect to
pictures and such like projected upon a screen or elsewhere and forming thereby
a method or system by means of which such pictures or other objects being so
projected from an optical or magic lantern or lanterns are seen in relief substan-
tially as herein more fully set forth and described.
Dated this 6th day of April A.D. 1892.
EDWARD J. PAYNE & SON,
104, Colmore Row, Birmingham, Agents for the Applicant.