Improvements in Kinematographs, Kinetoscopes, Zoetropes, and such like Instruments.
Year: 1898

page_text: Improvements in Kinematographs, Kinetoscopes, Zoetropes, and
such like Instruments.
I, WILLIAM STROUD, Yorkshire College, Leeds, in the County of York, Professor
of Physics, do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in instruments by which a succession of
objects or pictures are presented to the eye or exhibited upon a screen, which
instruments receive such names as kinematographs, kinetoscopes, zoetropes. In
some of its forms it is also suitable for the production of a series of photographs to
be exhibited in such like instruments.
In what follows I shall use the word " pictures " instead of pictures or
objects" for the sake of brevity.
My improvements consist in a method or methods of, and apparatus for, the
production of images of the pictures viewed, which images will blend or dissolve
one into the other without the occultations which take place in instruments now
commonly in use.
.
This I accomplish by causing the pictures and also optical appliances consisting
either of reflectors or lenses or combinations of these, to move continuously with
uniform or approximately uniform velocities, the relative positions and velocities of
the pictures and the optical appliances being such that the optical images or virtual
images of those details of the pictures which represent stationary objects remain
stationary or approximately so.
The motions of the pictures and optical appliances may be either rectilinear or
rotatory.
One manner of carrying my invention into effect for the construction of an
improved kinetoscope or zoetrope is as follows:-
On the external cylindrical surface of a drum capable of rotation about its axis I
mount a number of plane mirrors and on another drum surrounding the first drum
co-axially and moving with it I mount an equal number of pictures, which pictures
may have the details varied as is customary in zoetropes in order to exhil it objects
in motion. The distance of the pictures from the axis is double that of the mirrors
from the axis. An observer whose eye is suitably placed for observing the
reflections of the pictures in the mirrors will then see the pictures as if they were
stationary, or nearly so, but one picture will succeed another in his field of view as
the drum is rotated. Having thus produced a stationary or approximately.
stationary virtual image changing in details with the succession of pictures, it may
be viewed directly or through a lens, or a real image corresponding to the virtual
one at the axis may be produced upon a screen by means of a convex lens or
concave mirror or a system of lenses and mirrors in a manner similar to that in use
in optical lanterns.

page_text: Instead of having a limited number of pictures mounted on the larger drum a
series of pictures produced or mounted upon a strip, or so connected as to form a
strip, may be passed in succession to produce a like effect.
In place of plane mirrors I may sometimes use a number of concave or convex
mirrors making suitable changes in the relative distances of the mirrors or pictures
from the axis, so as to cause the virtual images to lie, as before, at, or approximately
at, the axis of the drum. It will be evident also that when concave mirrors are
used the pictures may be placed on the outside of the inner drum and the mirrors
on the inside of the outer drum, in which case a real magnified image of the pictures
would be formed at the axis of the drum. In each case the mirrors may be suitably
placed relatively to the pictures in the direction of the axis, to enable the observer
to view them conveniently and stationary reflecting mirrors or prisms may be used
to project the beam of light forming the image in any desired direction.
My invention may also be carried into effect by means of refracting lenses instead
of reflecting mirrors. In one manner of doing so the succession of pictures is
mounted or caused to pass upon the surface of a drum and a number of convex
lenses in corresponding angular positions are mounted on an outer drum co-axial
with the first, the arrangement being such that a magnified virtual image is formed
at the axis of the drums and a real image of this virtual image may be formed by a
suitable stationary optical system.
When the pictures are transparencies it will be convenient to mount within the
picture drum and rotating with it a number of mirrors corresponding in angular.
magnitude to the pictures so placed as to reflect beams of light through the pictures
and thence through the lenses, which beams will be stationary relatively to the
pictures while they are being exhibited.
To facilitate the application of my invention to the exhibition of a series of pictures
formed upon or mounted to constitute a strip it may be convenient to shift the picture
drum axially with reference to the lense drum so as to facilitate the winding of the
strip on and off.
A stationary double reflector (or a series of double reflectors fixed to the drum
and rotating with it) may be mounted to reflect the light which passes through the
pictures so as to pass through the lenses. By such means the instrument may
sometimes be made more convenient in form and the stationary image may be formed
in other positions than at the axis of the drum.
When an image is to be formed upon a screen I may mount the picture drum
and the lens drum side by side on the same axis and may mount within the drums
a double reflector (as for example a right angled prism with a portion of its
hypotenusal face opposite the picture and another portion of that face opposite the
corresponding lens) to transmit the beam which has passed inwards from the
picture outwards through the lens, and the radius of the picture-drum may further
be made larger than the radius of the lens drum in order that the image on the
screen may be made stationary as a whole or the radii of the two drums may be
made equal and a double reflector be so placed behind the picture and lens that the
picture is situated-optically-at the principal focus of the lens. A stationary
image would in this case be formed at an infinite distance and a stationary convex
Jense or system of lenses may then be used for the production of an image on a
screen at a finite distance.
Dated this 24th day of Wa 1000

page_text: Improvements in Kinematographs, Kinetoscopes, Zoetropes, and
such like Instruments.
I, WILLIAM STROUD, Yorkshire College, Leeds, in the County of York, Professor
of Physics, 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 :-
My invention relates to improvements in instruments by which a succession of
objects or pictures are presented to the eye or exhibited upon a screen, which
instruments receive such names as kinematographs, kinetoscopes, zoetropes. In
some of its forms it is also suitable for the production of a series of photographs to
be exhibited in such like instruments.
In what follows I use the word "pictures" instead of "pictures or objects" for
the sake of brevity.
pro-
My improvements consist in a method or methods of, and apparatus for, the
duction of images of the pictures viewed, which images will blend or dissolve one
with the other without the occultatious which take place in instruments now
commonly in use.
This I accomplish by causing the pictures and also optical appliances consisting
either of reflectors or lenses or combinations of these, to move continuously with
uniform or approximately uniform velocities, the relative positions and velocities of
the pictures and the optical appliances being such that the optical images or virtual
images of those details of the pictures which represent stationary objects remain
stationary or approximately so.
The motions of the pictures and optical appliances may be either rectilinear or
rotatory.
In order that the nature of my improvements and the manner in which the same
may be performed, may be more clearly and fully understood, I now describe them
with reference to the accompanying drawings and to the letters and marks thereon.
In the various figures the same letters are used to indicate the same or like parts
where such occur.
Figures 1 & 2 represent respectively plan and elevation of an instrument of the
zoetrope type.
M, M,...M" are a number of strips of plane mirror arranged equidistantly on the
external surface of a cylindrical drum "d."
"
P P P represent an equal number of pictures arranged equidistantly on the
internal surface of a drum "D" in a manner similar to that customary in zoetropes.
The radius of the drum D" is double that of the drum "d" so that the images
of P, in M₁, of P₂ in M... and of Pn in M are formed at the axis of rotation O of
the instrument and are therefore stationary, except for an angular rotation about
the axis of the instrument which rotation is small in amount for one picture
during the time it is visible from a given point. In what follows I shall neglect this
rotation and speak of such images as stationary.
The succession of stationary images may be viewed by an eye placed at E, or a
stationary optical system of lenses may be employed for projecting the succession
of stationary images on a screen as described below in connection with Figure 3.
In this and in subsequent illustrations transparencies suitably illuminated may in
every case take the place of opaque pictures. Such a series of transparencies may
be in a continuous strip as in the ordinary kinematograph provided the condition is
satisfied that "n" of these pictures shall equal in length the periphery of the
drum "D" on which the pictures rest, where there are
" 22 mirrors on the
drum
"
d."

page_text: Figure 3 represents a plan of an instrument in which convex lenses are employed
to produce stationary images. A number of lenses L, L... L" of the same focal
length "f" are mounted equidistantly on the cylindrical surface of a drum of
radius "R" (called the lens drum) and an equal number of pictures are mounted
equidistantly on the cylindrical surface of a concentric drum of radius in such a
manner that virtual images of the pictures are formed by the lenses at the axis of
R (R)
rotation. This condition is fulfilled if
1
1
1
R
r
R
or f
1
?"
Figure 4 represents a case where the stationary images are not necessarily
coincident with the axis of rotation of the drums. Here "d" represents the lens
drum and "D" the picture drum. "" carries a series of lenses L, L..... L" and
'D" carries a corresponding series of pictures P₁ P₂ P. P and they rotate
together about the same axis 00. A and B are reflectors (mirrors or prisms) which
are fixed independently and do not rotate with the drum.
If R-
1
-
focal length of each
radius of lens drum, ? radius of picture drum, f=
convex lens and S optical distance between a lens and the corresponding picture,
we shall get a stationary image whose distance from the lens is
then if
RS
S "
1
J R
or
fr
R r" R 7"
A special case arises when R =r; here S = f, the image is at an
infinite distance and the rays from any point of the picture emerge from the corre-
sponding lens as a parallel beam which does not rotate as the drum rotates.
Figures 5 and 6 represent plan and elevation of a similar case to Figure 4 and
shows an arrangement whereby the pictures and lenses may have rectilinear instead
of rotatory motion.
The lenses are mounted in a continuous chain which passes over the pulleys p
and while the pictures are rolled from one drum D on to another drum D¹.
A and B are two reflectors as in Figure 4.
V S
If now the velocities of the pictures and lenses are arranged so that
where "V" is the linear velocity of the picture strip, "V1" that of lenses, "S" the
optical distance between a picture and its corresponding lens and "f" the focal
length of the lenses, then the image we get will be stationary. The distance
between the centres of adjacent pictures must bear to the distance between the
centres of the corresponding lenses the ratio V/V¹.
Figure 7 represents a somewhat similar arrangement to Figure 4.
"d" is the
lens drum, "D" the picture drum and A and B two fixed mirrors or equivalent
reflecting prisms, or a fixed double reflecting prism of the shape illustrated in the
figure.
Figure 8 represents an arrangement in which cencave lenses are used. "d" is a
drum which serves the double purpose of lens drum and picture drum, pivoted on
an axis o.
.
Lenses L₁ L. L' each having a focal length equal to the diameter of the drum
are mounted all round the periphery. A series of pictures of such a size that when
wrapped on the drum the centre of each picture coincides with the centre of a lens,
is causedto move in contact with the drum in the manner indicated in the drawing.
True centring is secured by pins on the drum engaging in holes in the margin of the
picture strip (as is customary in kinematographs) or by other suitable means. The
rotation of the drum "d" may in some cases be produced by winding the strip on
to the drum "D" off the drum D¹.
In this last case I have represented the arrangements necessary for projecting a
succession of transparencies on a screen as in the ordinary kinematograph. S is
the source of light enclosed in a lantern of which C is the condenser "" is a fixed
lens or system of lenses so arranged that O the axis of the drum and the screen on
which the image is to be projected are optically conjugate to one another. A
similar method may also be adopted in the cases represented by the Figures 1, 2, 3, 4,

page_text: 5, 6, and 7. In cases 3 and 7 however it will be convenient to use a stationary
reflector inclined at about 45° to the plane of the picture as it passes, so that
the axis of the lantern may be roughly parallel to the axis of rotation of the
drum.
Any one of these instruments above described can also be used conversely for the
production of a series of photographic pictures of the kind required for observation
or exhibition by means of these instruments, by the substitution of sensitive
photographic plates or films for the pictures, the film being suitably protected from
extraneous light.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same may be performed, I declare that what I
claim is :-
1. The use in kinematographs, kinetoscopes, and similar instruments, of a series
of continuously moving mirrors or lenses or a combination of mirrors and lenses so
disposed with reference to a series of continuously moving pictures, that stationary
images of these pictures are produced, in such a manner that the images succeed
one another without the occultations usual in such instruments, and which images
may be observed directly by the eye or after projection on a screen, all substantially
as described.
2. An improved zoetrope consisting of a drum around the interior of which a
series of pictures is placed while at a radius of about half the radius of the drum
plane mirrors are placed in a series equidistantly round the axis, by reflection in
which mirrors the pictures are seen in succession as if situated at the axis of the
drum, all substantially as described.
3. An improved zoetrope substantially as described with reference to Figures 1
and 2.
4. An improved kinematograph or kinetoscope, substantially as described with
reference to Figure 3.
5. An improved kinematograph or kinetoscope, substantially as described with
reference to Figure 4.
6. An improved kinematograph or kinetoscope, substantially as described with
reference to Figures 5 and 6.
7. An improved kinematograph or kinetoscope, substantially as described with
reference to Figure 7.
8. An improved kinematograph or kinetoscope, substantially as described with
reference to Figure 8.
11
0011
D1000
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Patent Agents.