Improvements in Photographic Films and Cartridges.
Year: 1899

page_text: Date of Application, 24th Oct., 1899-Accepted, 9th Dec., 1899
COMPLETE SPECIFICATION.
Improvements in Photographic Films and Cartridges.
A communication by ARTHUR WILLIAMS MCCURDY, of Washington, D.C., United
States of America.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., Agent for Foreign Patent
Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, 118, New Street, Birmingham, in the County of Warwick,
and 322, High Holborn, in the County of Middlesex, Civil 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:
套
This invention pertains to that class of photographic films or cartridges"
so-called, designed to be rolled into a compact coil or cylinder, and to be inserted
into and removed from cameras in daylight. The invention consists in a novel
construction of such films whereby the black paper commonly employed to
exclude light, and hitherto deemed essential, is dispensed with, and the film
as a whole is rendered capable of being directly immersed in the developing
and fixing baths, without injury to the bath or to the film.
Stated in another way, the invention consists in constructing the film with a
portion prepared and designed to receive an image or images when properly
exposed in a camera, and another portion designed to envelope or surround
the image-receiving portion and to exclude therefrom the actinic rays, or those
rays which might affect the sensitized film, the enveloping portion being devoid
of any agent, substance, or ingredient which, either in the baths or out of them,
might injure the film or its sensitized surface, or might give off anything
that would impair the quality or condition of the baths or either of them."
In the accompanying drawings,
Figure 1 is a perspective view of a "spool" with a "daylight film" of this
improved construction partially wound thereon;
Figure 2, a similar view, showing the light-excluding portions as made of
paper or like material, distinct from the body of the film, but suitably attached
thereto;
Figure 3, a view of like character showing the enveloping or light-excluding
portion coated, ground, or otherwise rendered opaque.
*
66
In the manufacture and use of so-called daylight films or cartridges, it is
the universal custom to provide a considerable length of black paper as a covering
or enveloping body, to exclude the light and prevent the sensitized film from
becoming fogged or light struck." A common plan is to extend the paper
along the back of the film throughout its entire length, and to a considerable
distance beyond each end; one end to be wound about the coiled or rolled
film a number of times, and to fill completely the space between the heads of the
spool so that no light may reach the film until the covering or enveloping portion
of the paper is unwound therefrom. This is done mainly after the cartridge or
roll is placed in the camera where it is properly protected.

page_text: Coverings of the class just noted have figures and marks printed on the back
to indicate what section of the film is being exposed, or to show where to cut
it to separate different exposures.
Another plan makes use only of the wrapping or enveloping paper section,
but like the first, employs the black paper.
Paper of the character referred to has to be specially prepared, and is expensive.
It is largely charged with dye stuff or pigment of one or another character,
which, if the paper be introduced into the developing or the fixing bath, is given
off and discolours and otherwise injuriously affects the bath. The composition
is such, also, that the paper is more or less hygroscopic, and either by gathering
moisture from the atmosphere and giving it to the sensitized coating of the film,
or by causing chemical or mechanical constituents of the paper to be given off to
the film, injuriously affects the latter.
Means have been contrived for developing or fixing films of the general class
here referred to, by which the ordinary dark room can be dispensed with though
the film itself is shielded from the light, and in the use of such apparatus it is
necessary or at least convenient to place the film and its jacket or covering in
a box or receptacle designed to receive the developing and fixing solutions, and
in which the jacket is liable to become wet with the liquid, or wholly immersed
therein. The injurious effects of the black paper, present in greater or less
degree under ordinary circumstances, become marked in this connection, and
it is for this reason primarily that it becomes desirable to dispense with it.
My correspondent has ascertained, by repeated experiments and working tests,
and has demonstrated in actual working, that black paper is not essential.
Celluloid prepared just as is the image-receiving surface, or ground or otherwise
rendered impervious to actinic rays, will, if wound in several layers about the
image-receiving portion of the film, effectually exclude all light rays that would
affect the latter. The light-excluding or enveloping sections may, therefore,
be mere extensions of the ordinary coated film, additional to the portion designed
to receive the images. So too it has been found that white paper, and papers
approximating white will likewise thoroughly protect the film.
Papers of this class contain no chemicals or substances of any kind, which,
being liberated either mechanically or by chemical action or reaction, will
injuriously affect the film, the developing bath, or the fixing bath, hence they
may be introduced into and immersed in the solutions with impunity, and
without any undesirable consequences.
My correspondent availing himself of this fact, and of the discovery that
both celluloid and light papers will adequately protect the film, makes or furnishes
the film with a protecting section of such material. In other words, he provides
the film with a covering or protecting sheet or section composed of material which
in the developing and fixing baths and out of them possesses only such ingredients
or components as are chemically inert under all ordinary conditions of storage,
exposure, development, or fixing of the film, or which being identical with
those of the image-receiving portion can give no injurious effect.
Turning again to the drawings, the embodiments of the invention there illus-
trated will be described.
Referring first to Figure 1, A indicates the body of a film, of celluloid or other
suitable material, having the image-receiving portion a coated with the usual
emulsion or preparation and sensitized to adapt it to receive the picture or
impression produced by the light transmitted by the lens of the camera. Formed
with and as extensions of the film, at the ends of the image-receiving portion,
are enveloping or light-excluding sections bb here represented as integral with
the intermediate section a. These sections 6 may be rendered opaque or semi-
opaque by pigment, colouring matter or dye, introduced into the celluloid in the
process of manufacture, and hence free from liability of being affected by the
baths or by the moisture of the atmosphere: or they may be ground, subjected
to the action of a sand blast, or in any other convenient manner made semi-

page_text: opaque. Thus prepared, or even without special preparation, other than such
as is given the image-receiving portion, the enveloping or light-excluding portion,
if made of moderate length so as to wind several times about the coiled film,
will effectually exclude the actinic rays, and protect the film from injury by light.
In Figure 2, the end sections are represented as formed of paper or like
material, which, however, will be free from any element or ingredient which shall
be capable of separation out of the paper, either chemically or mechanically,
under action of the atmosphere or of the baths, and at any temperature to which
it would otherwise be safe to subject the film.
Figure 3 shows the same construction as Figure 1, but indicates by surface
shading, the grinding, colouring or other treatment of the celluloid or like
material to render it impervious to actinic rays. It is found in practice that this
is not essential, and that the celluloid may be left untreated, or in other words,
that the emulsion or coating used on the body of the film, if carried over the
ends or enveloping sections, will answer all requirements. It is to be understood
that the enveloping portion will be provided at both ends of the film, and pointed
to facilitate threading into the spools.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is:-
-
1. A film for photographic purposes having an image-receiving section and
an enveloping or light-excluding section, the latter being free from any in-
gredient or constituent likely to affect injuriously the image-receiving section
under the conditions of storage or use, to which the film will under ordinary
circumstances be subjected.
2. A film for photographic purposes comprising an image-receiving section,
and an enveloping or light-excluding section, the latter being devoid of any
agents or ingredients which through chemical or mechanical action in the
solutions to which the film is subjected after exposure might injuriously affect
the solutions.
3. A film for photographic purposes comprising an image-receiving section,
and an enveloping or light-excluding section, the latter being devoid of any
agents or ingredients which through chemical or mechanical action in the
solutions to which the film is subjected after exposure might injuriously affect
the film.
4. A film for photographic purposes comprising an image-receiving section,
and an enveloping or light-excluding section, the latter being devoid of any
agents or constituents capable of injuriously affecting the image-receiving por-
tion under ordinary variations of atmospheric conditions.
5. A film for photographic purposes comprising an image-receiving portion
and a light-excluding enveloping portion integral therewith.
6. A cartridge film having the protecting end portions thereof made integral
with the image-receiving portions.
7. A cartridge film for photographic purposes having the portion which is
threaded into the spool made of a material free from any ingredient or constituent
likely to affect injuriously the image-receiving portion of the film under ordinary
conditions of storage, use, development or fixing.
Datod this ad day of flaiahar 1800
WM. P. THOMPSON & Co.,
Agents.