Camera.
Year: 1897

page_text: Date of Application, 12th Aug., 1897
Complete Specification Left, 18th Apr., 1898-Accepted, 18th June, 1898
I, EUGENE LOUIS DOYEN, M.D., of 5, Rue Cotta, Reims, (Marne), France, do
hereby declare the nature of this invention to be as follows;
This invention relates to a photographic camera in which the dark slide ordin-
arily employed during focusing, is dispensed with, and in which the rays from the
lens, for the purpose of focusing, are reflected twice by means of mirrors arranged
in the interior of the camera and are thrown on to a focusing screen without
having to pass through the dark chamber.
The light is allowed to penetrate this chamber only when taking the negative,
and after removing the shutter, so that the sensitised surface for exposure always
remains uncovered without interfering with the focusing.
In carrying out my invention, I arrange the focusing means in the interior of
the camera, and near the front part thereof, and I employ a lens with adjustable
focus. The rays entering the lens are directed on to a mirror which may be
connected to the shutter, and which shutter is carried by a partition forming the
front of the dark chamber. The rays reflected by this mirror fall on to a second
mirror depending from the top of the camera, and the rays, thus reflected by this
second mirror, are directed on to a focusing screen placed at a suitable angle in
the camera.
The image thrown on to the focusing screen may be viewed by first
lifting up a flap covering an aperture, in the top of the camera, and then looking
through a magnify-glass, advantageously arranged on the top of the camera.
Dated this 10th da
1907
An improved Photographic Camera.
I, EUGENE LOUIS DOYEN, M.D., of 5, Rue Cotta, Reims, (Marne), France, 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, reference being had to the accompanying drawings and to the letters
and figures marked thereon, that is to say:-
This invention relates to a photographic camera in which the focusing is effected
upon a fixed ground glass, well protected from light, after two successive reflec-
tions of the luminous rays, one of the reflecting mirrors being carried by the
obturator.
The size of photographic cameras for focusing by reflection on to a single mirror
is limited, owing to the ground glass having to occupy the same optical distance

page_text: from the objective as the sensitized surface. By the employment of two successive
reflections, I obtain a notable reduction in bulk.
The annexed drawing is a longitudinal axial section of my photographic camera.
My two mirrors, and my ground glass, conveniently placed and well protected
from light, are arranged in the following manner: The luminous rays which have
passed through the objective 1 fall first on to a first mirror 2, which is inclined at
about 75°; this mirror is very light being only 30 to 40 m/m in diameter, and is
directly carried by a rapid obturator 3. The reflected luminous rays fall on to a
second mirror 4 which throws them back on to the ground glass 5. Said second
mirror 4 is arranged vertically, or nearly so, according to the inclination which
it is desired to obtain for the ground glass, which is inclined at about 60° to the
horizontal. The focusing on to this ground glass 5 corresponds with the focusing
for the sensitized surface-plate or film as required--which is placed at the back
of the dark chamber and behind the obturator of plate 6. The focusing on to the
ground glass 5 is effected by means of a magnifying glass 7 which brings the image
to the distance of distinct vision, and in the focal plane of this glass 5. This
magnifying glass is mounted in a frame 8 which is connected to the lid 9 by a
hinge 10 provided with a spring 11 which tends to always increase the angle
formed between the frame 8 and cover 9. An opaque bellows 12 fixed around the
magnifying glass 7, and around the ground glass 5, protects them entirely from
the surrounding light and allows of focusing without a black head-covering, even
in a strong sun.
When out of use, the frame of the magnifying glass is folded against the lid 9
which is closed down on the apparatus; a hook 13 secures them in position.
Against this hook 13, the lower part of the frame 8 abuts, when the lid 9 is
open.
A small shutter 14, hinged to the frame 8 may, if desired, cover the magnifying
glass 7, and, when the sun is at one's back, will prevent the light, which might
enter through such magnifying glass 7, coming in through the ground glass 5
and, by reflection on the mirror 4, clouding the bottom of the sensitized plate at
the time of exposure.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:―
1, A photographic camera for focusing by double reflection, characterized by
the combination of the obturator mirror with a second fixed mirror, for the purpose
of obtaining, by means of these two successive reflections, a reduction in bulk,
substantially as described.
2, A photographic camera for focusing by double reflection, as above claimed,
characterized in that the obturator mirror is inclined at about 75° to the horizontal,
whilst the fixed mirror is vertical and is placed above the objective, for the purpose
of avoiding, in approaching as far as possible the normal incidence, the injurious
influence of the double reflection, substantially as described.
3, My improved photographic camera, substantially as hereinbefore described
and shown in the annexed drawing.
Dotod this 18th day of April 1808
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 5A, Market Street, Nottingham,
Agent for the Applicant.