Improvements in and connected with the Production of Pictures or Representations in Natural Colours.
Year: 1899

page_text: Improvements in and connected with the Production of Pictures or
Representations in Natural Colours.
I, JAN SZCZEPANIK, of Ungargasse 12, Vienna III., Austria, Engineer, do
hereby declare the nature of this invention to be as follows;-
--
The invention relates to a method and apparatus for projecting pictures in
natural colours from a monochrome negative.
This method, which will be described in detail with reference to the accom
panying drawings, is based on the following:
---
If a plate e (hereinafter for shortness called a line-plate) provided with fine
transparent lines is placed between a matte sereena (Fig. 1), on which the image
of the object is to be projected, and an objective e, in which a diaphragm
provided with a square opening has been placed, then the image appears on the
matte screen in bands or lines which correspond to those of the line-plate.
If the line-plate is placed further from the matte screen, then the bands form-
ing the image appear broader and broader, until, in the case of a certain distance,
the lines or bands of light unite into one surface and give a sharp unbroken
image, which is, of course, less illuminated than an image projected without à
line-plate. If, instead of the diaphragm with the square opening (Fig. 2), a
diaphragm (Fig. 3) is inserted, the opening of which has the same height as
that of the diaphragm shown in Fig. 2, but has a less breadth, then the image
is less illuminated.
If, whilst the conditions are kept the same, a diaphragm is inserted which is
only one third open in the vertical direction (Fig. 4, 5, or 6), there are again
formed on the projected image black lines or bands, which are twice as broad as
the light ones.
Thus the width of the lines or bands of light is in direct proportion to the
height of the opening in the diaphragm, the distance of the line-plate from the
objective and from the matte screen remaining the same.
A consideration of Fig. 1, in which are shown the limiting rays corresponding
to the several diaphragms or diaphragın-openings shown in Figs. 4, 5, and 6,
will make the phenomena just described completely clear.
The transparent lines, or the line-plates themselves, may have any desired
positions (for example vertical or oblique); the diaphragm must be arranged
to correspond.
The line-plates instead of having straight transparent lines (Fig. 7) may be
provided with wavy or zig-zag lines (Figs. 8 or 9 respectively). As has been
stated, when a completely open diaphragm (Fig. 2) is used, a complete image is
obtained. Such an image can, however, also be produced by means of the three.
partly open diaphragms (Figs. 4, 5, and 6) if they are used one behind the other
in the manner hereinafter described.
Together with each separate diaphragm, a colour filter (1, 2 or 3) of the kind

page_text: =
The
used in three-colour printing is arranged in front of the objective, and in the
end a sharp negative is obtained, which, in consequence of the employment of
three diaphragms, exhibits three times as many lines as the line plate.
image, or picture will thus consist of successive groups of three lines each, of
which every first one is coloured correspondingly to the red colour-filter 1 every
second one to the yellow colour-filter 2, and every third one to the blue colour
filter 3.
The same result is attained if, instead of three diaphragms one behind another,
a single diaphragm (Fig. 10) is used, the opening of which is provided, succes-
sively as to height, with filters of like height for the red, yellow, and blue rays.
If a diapositive is produced from the negative that is obtained, a coloured
image, representation or picture can be projected by means of the apparatus
shown in Fig. 1. In this case a represents the diapositive, e as formerly, the line-
plate, the objective, & the diaphragm (with red, yellow, and blue plate). In
front of the diapositive a condenser f of known kind is arranged, and at b. the
coloured image representation, or picture is produced.
It is evident that the line-plate e must occupy exactly the same position in
relation to the diapositive, since otherwise it might come about that, for example,
the yellow rays impinged on the red filter. To remove this defect by adjusting the
line-plate is very difficult. Another device is therefore provided, by means of
which the correct adjustment can be effected without displacing the line-plate.
This device consists of a diaphragm which, as is shown in Fig. 11, possesses, in
addition to the filters for red, yellow, and blue (1, 2 and 3 respectively) already
provided, two other filters, one above and the other below this group of filters,
the upper one being for the blue colour and the lower one for the red colour. By
shifting such a diaphragm inside the objective vertically, the above-mentioned
defect can be removed, as this diaphragm permits of three different serial arrange-
ments of the colour-filters-namely red, yellow, blue (1, 2, 3)-yellow, blue,
red (2, 3, 1), and blue, red, yellow (3, 1, 2).
The shifting of the diaphragm may be effected by means of a screw or in any
other way.
As already stated an image or picture projected in the manner described
contains three times as many lines as correspond to the number of lines of the
line-plate, and each three successive lines appear in the three fundamental colours
(red, yellow, and blue). These lines are, however, so closely packed together that
the eye cannot distinguish them separately and thus the desired colour effect is
attained.
The image or picture is the better, the more closely the lines are packed
together on the plate e. The production of such closely lined plates, however, is,
on technical grounds, possible only within certain limits. On the other hand
the number of lines composing the image can be increased by further division
of the diaphragm: the opening in the diaphragm is divided, for example, into
six or nine parts, instead of three, so that two or three times as many groups
of lines (each consisting of three colour lines) appear as do in the case of the
tripartite diaphragm.
Fig. 12 shows by way of example one of the separate diaphragms to be used one
Behind another, the one shown being provided with a colour filter for yellow
rays.
A negative produced with such diaphragms thus contains six times as many
lines as correspond to the number of lines of the line-plate, and is, therefore, much
more accurate than a negative produced with the tripartite diaphragm.
If the line-plate is made of suitable thickness and provided at the back with
a layer sensitive to light, this plate can serve at the same time as a photographic
plate. Inversely, the photographic plate can be provided with transparent fine
lines on the side away from the light-sensitive layer. Such a plate also forms a
means of producing pictures or images in natural colours. When employing
such a photographic line-plate the distance of the light-sensitive layer from the

page_text: lined surface is always the same; the plate must, therefore, be kept exactly at
the same distance from the objective when projecting as when taking.
Dated this 12th day of April 1899.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.
Improvements in and connected with the Production of Pictures or
Representations in Natural Colours.
I, JAN SZCZEPANIK, of Ungargasse 12, Vienna III., Austria, Engineer, 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:-
This invention relates to a method and apparatus for projecting pictures or
representations in natural colours from a monochrome diapositive.
This method, which will be described in detail with reference to drawings filed
with my Provisional Specification, is based on the following:-
If a plate e (hereinafter for shortness called a line-plate) provided with fine
transparent lines is placed between a matte screen a (Fig. 1), on which the image
of the object b is to be projected, and an objective c, in which a diaphragm d
provided with a square opening has been placed, then the image appears on the
matte screen in bands or lines which correspond to those of the line-plate. If the
line-plate is moved further and further from the matte-screen, then the bands
forming the image become broader and broader, until when a certain distance is
reached, the lines or bands of light unite to form a sharp unbroken image, which
is, of course, less illuminated than an image projected without a line-plate. If,
instead of the diaphragm with the square opening (Fig. 2), a diaphragm (Fig. 3)
is inserted, the opening of which has the same height as that of the diaphragm
shown in Fig. 2, but has a less breadth, then again the image is less illuminated.
If, whilst the other conditions are kept the same, a diaphragm is inserted which
in the vertical direction is only one third open (Figs. 4, 5 or 6). there are again
formed on the projected image black lines or bands, which are twice as broad
as the light ones. Thus the width of the lines or bands of light is in direct
proportion to the height of the opening in the diaphragm if the distances of the
line-plate from the objective and the matte screen remain the same.
A consideration of Fig. 1, in which are shown the limiting rays corresponding
to the several diaphragms shown in Figs. 4, 5 and 6, will make the phenomena
just described completely clear.
The transparent lines, or the line-plates themselves, may have any desired
positions, (for example, vertical or oblique) if the diaphragm be arranged to
correspond. The line-plates instead of having straight transparent. lines (Fig. 7),
may be provided with wavy or zig-zag lines (Fig. 8 or 9 respectively).
As has been stated, when a completely. open diaphragm (Fig. 2) is used, a
complete image is obtained. A complete photographic image can also be produced
by means of the three partly open diaphragms (Figs. 4, 5 and 6) if they are
used one after another in the manner hereinafter described.
Together with each separate diaphragm, a colour filter (1, 2 or 3) of the kind
used in three-colour printing is arranged in front of the objective, and in the
end a sharp negative is obtained, which, in consequence of the employment of
the three diaphragms, exhibits three times as many lines as the line-plate. The

page_text: picture will thus consist of successive groups each composed of three lines which
on the negative are of course monochrome but in different shades correspondingly
to the red, yellow, and blue colour-filters, 1, 2 and 3 respectively.
The same result is attained if, instead of three diaphragms one after another,
a single diaphragm (Fig. 10) is used, the opening of which is provided with
filters of like height for the red, yellow, and blue rays, arranged one above
another.
If a diapositive or transparency (hereinafter called a diapositive) is produced
from the negative that is obtained, a coloured image, representation, or picture
can be projected by means of the apparatus shown in Fig. 1. In this case a
represents the diapositive, e (as formerly) the line-plate, the objective, a the
diaphragm (with red, yellow, and blue plate). In front of the diapositive a con-
denser of known kind is arranged, and at 6 the coloured image, representation.
or picture is produced. It is evident that the line-plate e must occupy exactly
the same position in relation to the diapositive as it did in relation to the negative
during taking, since otherwise it might come about that, for example, the yellow
rays impinged on the red filter. To remove this defect by adjusting the line-
plate is very difficult. Another device is therefore provided by means of which
the correct adjustment can be effected without displacing the line-plate. This
device consists of a diaphragm which, as is shown in Fig. 11, possesses, in addi-
tion to filters for red, yellow, and blue (1, 2, and 3 respectively) as shown in
Fig. 10, two other filters one above and the other below this group of filters, the
upper one being for the blue and the lower one for the red. By shifting such a
diaphragm inside the objective vertically, the defect hereinbefore mentioned can
be removed, as this diaphragm permits of three different serial arrangements of
the colour-filters-namely, red, yellow, blue (1, 2, 3): yellow. blue red (2,
3. 1), and blue, red, yellow (3, 1, 2). The shifting of the diaphragm may be
effected by means of a screw or in any other suitable way.
As already stated, an image or picture projected in the manner described con-
tains three times as many lines as there are in the line-plate, and each three
successive lines appear in the three fundamental colours (red, yellow, and blue,.
These lines are, however, so closely packed together.that the eye cannot distin-
guish them separately and thus the desired colour effect is attained.
The image or picture is the better the more closely the lines are packed
together on the plate e. The production of such closely lined plates, however, is
limited by commercial and technical considerations. On the other hand the
number of lines composing the image can be increased by further division of the
diaphragm; the opening in the diaphragm may be divided, for example, into six
or nine parts, instead of three; so that two or three times as many groups of
lines (each consisting of three-colour lines) appear as in the case of the tripartite
diaphragm. A single diaphragm having its opening divided into six parts is
provided with two groups of colour-filters one above the other and each such as
shown in Fig. 10; Fig. 12 shows by way of example one of three separate
diaphragms to be used one after another instead of a single diaphragm provided
with six colour-filters as just described, the diaphragm shown being provided
with two colour-filters for yellow rays: A negative produced with a single
diaphragm having six colour-filters or with three diaphragms of the kind
illustrated in Fig. 12, thus contains six times as many lines as there are in the
line-plate, and is, therefore, much more accurate than a negative produced with
the tripartite diaphragm.
If the line-plate is made of suitable thickness and provided at the back with
a layer sensitive to light, this plate can serve at the same time as a photographic
plate. Inversely, the photographic plate can be provided with fine transparent
lines on a dark ground on the side away from the light-sensitive layer. Such a
plate also forms a means of producing pictures or images in natural colours.
When employing such a photographic line-plate the distance of the light-sensitive
layer from the lined surface is always the same; the plate must, therefore, be

page_text: kept exactly at the same distance from the objective when projecting as when
taking.
Having now particularly described and ascertained the nature of the, said
invention and in what manner the same is to be performed I declare that what
I claim is.
1. For projecting pictures in natural colours, first producing a negative com-
posed of successive groups each of three lines of light corresponding to the three
fundamental colours, by means of a diaphragm which contains three colour-filters
for the three fundamental colours respectively, arranged one above another or by
means of three separate diaphragms provided respectively with three such colour-
filters and substituted for the aforesaid diaphragm, and a line-plate interposed
between the objective and the screen and provided with thin transparent lines,
then obtaining from the negative a diapositive and placing the said diapositive on
the side of the line plate away from the objective, and in exactly the same position
in relation to and at exactly the same distance from the objective as on taking,
so that on using a diaphragm of the kind mentioned with the appurtenant colour-
filters (1, 2, 3) the picture appears in the natural colours, since it is composed of
successive groups of three lines of light that are very close to one another and are
coloured in correspondence with the three filters.
2. A diaphragm for use as set forth in the preceding claim, which comprises in
addition to colour-filters for the three fundamental colours, and as extensions
thereof, two other colour-filters, one above and the other below the aforesaid
filters, so that any defect caused by inaccurate adjustment of the diapositive
on projecting, can be remedied by merely shifting the diaphragm up or down in
the objective.
3. A line-plate for use as set forth in Claim 1, one side of which is provided
with a layer sensitive to light, whilst the other side is provided with transparent
lines on a dark ground.
4. The production of pictures or representations in natural colours sub-
stantially as set forth.
ד
1
001
1
T
1000
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant..