Improvements in or relating to Photographic Cameras.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Photographic Cameras.
I, FREDERIC EUGENE IVES, of 2750 North Eleventh Street, in the City of Phila-
delphia, State of Pennsylvania, United States of America, and of 119 Shaftesbury
Avenue, in the County of London, Photographer, do hereby declare the nature of
this Invention to be as follows:-
The object of this Invention is to provide a convenient means of making succes-
sive exposures through different color screens or by the action of different groups
of spectrum rays, upon different sections of the same photographic sensitive plate,
or upon several plates occupying the same plane. Photographic negatives such
as are made by this means, constitute the chromogram or color record necessary
for carrying out the method of colour photography which is now known as the
photochromoscope system, and are similar to those made by a single exposure in a
camera such as that described in the Specification of Letters Patent No. 3784 of
1895, granted to me, but the arrangement according to my present Invention is
intended for use in cases such for example as portraiture where it is desirable to
use lenses of a character specially adapted for this class of work. According to
my Invention I arrange the sensitized plate or plates on which the chromogram
sections are to be produced with a colour screen opposite each plate or portion of
the plate on which the respective chromogram sections are to be produced and I
provide means whereby the plate or plates and screens can be successively moved
into position to receive the light passing through the lens. The movement may
be effected by hand or by mechanism such as clockwork which can be set so as
to give the requisite time of exposure for each individual chromogram section and
the length of exposure as a whole in accordance with the varying conditions as to
light.
I do not limit myself to particular details but a convenient way of carrying
out my Invention is to mount the various color-screens in a frame which is free
to slide in guides at the back of the exposure opening, together with the dark
slide containing the plate, film, or other sensitised surface to be exposed. This
frame is provided with an arm or projection whose movement may be arrested by
a series of stops which are successively released by hand or mechanically, for
example, by a spring or other motor. When a motor is provided the stops may
be withdrawn from the path of the arm by levers operated by a disc carrying
tappets, crank pins or the like which latter are preferably adjustable so as to
enable the time exposures through the-various coloured screens to be varied in
relation to each other, according to requirements. The motor may also be pro-
vided with a brake or other device for enabling its speed to be varied so as to
admit of the exposures through the various coloured screens to be varied all in the
same proportion.
or
There being three coloured screens in the frame the sequence of operations is
as follows: The frame being in front of, and suitably connected to
formed in part with, the dark slide with say the No. 1 colour screen at the back of

page_text: the exposure opening and the shutter closed, the first operation is to open, either
by hand or mechanically, the lens shutter whereby the image is taken through the
No. 1 colour screen, then, after a predetermined interval, the frame and dark
slide are released so that the No. 2 colour screen and respective section of sensitized
surface are presented to the exposure opening and then, after another pre-determined
interval, the frame and dark slide are again released so that the No. 3 colour screen
and respective section of sensitized surface are presented to the exposure opening,
the lens shutter finally closing after this last named section has been sufficiently
exposed.
If desired the lens shutter may be closed and opened each time the colour
screens are changed.
Although I have mentioned colour screens as being used in front of each plato
or portion of the plate I do not limit myself to this as it will be evident that I can.
use any arrangement whereby the requisite records of colour sensation can be
obtained in the respective chromogram sections.
The chromograms are usually made stereoscopic which, with the apparatus
hereinbefore described, involves the use of a pair of lenses and the production of
two images behind each colour screen. Ordinarily these images have to be cut
apart and transposed but I overcome this necessity by placing in front of each
lens an inverting prism by which each image is reversed right and left.
Dated this 6th day of February 1897.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
арте башса.
I, FREDERIC EUGENE IVES, of 2750 North Eleventh Street, in the City of Phila-
delphia, State of Pennsylvania, United States of America, and of 119 Shaftesbury
Avenue, in the County of London, Photographer, 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: —
The cbject of this invention is to provide a convenient means of making succes-
sive exposures through different colour screens or by the action of different groups
of spectrum rays, upon different sections of the same photographic sensitive plate,
or upon several plates occupying the same plane. Photographic negatives such as
are made by this means constitute the chromogram or colour record necessary for
carrying out the method of colour photography which is now known as the photo-
chromoscope system, and are similar to those made by a single exposure in a
camera such as described in the Specification of Letters Patent No. 3784 of 1895
granted to me, but the arrangement according to my present invention is intended
for use in cases such for example as portraiture where it is desirable to use lenses
of a character specially adapted for this class of work.
According to this invention I arrange the sensitized plate or plates, on which
the chromogram sections are to be produced, with a colour screen opposite each
plate or portion of the plate on which the respective chromogram sections are to be
produced, and I provide means whereby the plate or plates and screens can be
successively moved into position to receive the light passing through the lens.
The movement may be effected by hand, or by mechanism such as clockwork which
can be set so as to give the requisite time of exposure for each individual chromo-
gram section, and the length of exposure as a whole, in accordance with the varying
conditions as to light,

page_text: I will describe the invention by reference to the accompanying drawings, in
which I have, as an example, represented one form of my improved apparatus as
applied to a stereoscopic camera.
Figure 1 is a side elevation of this camera.
Figure 2 a plan of a portion of Figure 1.
Figure 3 is a back elevation of the camera, with a portion of the dark-slide
broken away to shew the colour screen and
Figure 4 is a vertical section on the line 4-4 of Figure 3.
Like letters of reference indicate like parts throughout the drawings.
In carrying out my invention as shewn in the drawings, I mount the various
colour screens a, a³, a³ in a frame A, which, together with the dark-slide B, con-
taining the plate, film, or other sensitized surface to be exposed, is free to slide in
guides C in the camera body C2, at the back of the exposure opening or open-
ings C and lenses D. The frame A may be engaged with the dark slide B by
means of projections, or plates, a, so as to prevent any independent movement of
these two parts, and it is provided with an arm, or projection, as, which projects
through a slot in the side of the camera, body C. The descent of the arm a
and consequently that of the frame A and dark slide B is periodically arrested by
a series of stops e, e, e³, which are successively removed from the path of the
The stops e e e are formed upon, or secured to, a lever E pivotted at e
to the side of the camera body, the said stops being of different length so that when
the camera is ready for operation, the stops e e³ project into the path of the arm a³,
the stop e, more than the stop e, and the stop e³ more than the stop e³.
arm a
The lever E is provided with an rm e on which are formed ratchet teeth e6
with which engages a pawl f pivotted on the lower end of a lever F. The lever F
is pivotted to the side of the camera body C³, and is operated on by a spring f³
which tends always to move the lower end of the lever towards, or retain it in
contact with, a stop f³. At its upper end the lever F is adapted to be operated on
by a series of tappet pins 9, 92, 93, inserted in any desired positions in a disc G
rotated in the direction indicated by the arrow z by a clockwork, or other, motor
contained in the casing G². The disc G may be rotated at any desired speed, but
for convenience it may be assumed to rotate once in a minute, under which
circumstances the space between any two adjacent holes 9 of the series of sixty
holes shewn in Figure 1, will represent a second of time.
H is a flap shutter, the pivot, or spindle, h, of which extends through the side of
the camera body C2, where it is provided with a small pulley, h2, to which is
attached one end of a cord ³ whose opposite end is attached to the lever F so that
when the lever F is in its normal position, the cord h³ holds open the shutter H, and
when the lever F is moved by the tappet pins 9 g g³ for effecting the release of
the frame A, the shutter H, by its own weight, falls and closes the exposure
opening, the cord at this time being wound to a slight extent upon the pulley ha.
Jis a sliding shutter which may be raised and lowered by hand by means of
a rod the upper end of which is adapted, when the shutter J is raised and in its
closed position, to project into the path of the vane or flyer 95, or other moving
part, of the motor in the casing G³, so as to prevent the operation of the motor.
When the rod j is lowered the shutter J is opened and simultaneously therewith
the motor G2 is started.
K are two springs which are secured to the back of the camera body C³, and
which are caused, by means of the screws k, to bear with more, or less, pressure
upon the dark slide B and thereby more, or less, retard the descent of the said dark-
slide and colour screens according to requirements.
In Figure I have represented my improved apparatus as set and ready for
making a series of exposures, the tappet pins 99³ ³ being inserted in respectively
the tenth, seventeenth and twenty-third of the holes g counting from the zero, or
starting point, 6. When the apparatus as thus set, is started, assuming the disc G,
to rotate once in a minute, the sequence of operations is as follows:-
The shutter J is opened so that light is allowed to pass through the colour

page_text: screen a, to the part of the sensitized surface immediately at its rear, this exposure
continuing for ten seconds at which time the tappet pin 9 operates on the lever F
so as to allow the flap shutter H to close, and at the same time withdraws the stop e
from beneath the arm a³ so that the frame A and dark-slide B drop until arrested
by the arm a³ reaching the stop ea³, at which juncture the colour screen a³ and the
part of the sensitized surface at the rear thereof are immediately opposite the
exposure opening C³. When the tappet pin 9 leaves the lever F the said lever is
pushed over to the stop f3 by the spring f2 so that the flap shutter H is again
opened to allow the light to pass through the colour screen a, and the pawl f
engages with the second of the ratchet teeth es all as shewn in Figure 4; this
second exposure continues for seven seconds when the shutter H is again closed by
the tappet pin g acting on the lever F, as before described with reference to the
tappet pin 9, and the stop is withdrawn from beneath the arm a5, so that the
frame A and dark-slide B descend until arrested by the arm a³ reaching the stop e³
at which time the colour screen a³ and the part of the sensitized surface at the rear
thereof are immediately opposite the exposure opening C³. When the tappet pin ga
leaves the lever F the flap shutter H is again opened for making the exposure
through the colour screen a³, and the pawl f engages with the third of the ratchet
teeth e, this third exposure being terminated when, at the expiration of six
seconds, the tappet ping engages with the lever F by which operation the flap
shutter H is shut and the arm a is released for the third and last time.
third release of the arm a³ the frame A and dark slide B are allowed to descend
until the arm reaches the end of the slot c in the camera body C², the said arm in
this position being opposite to a downward extension of the stop e³ so as to lock
the lever E in the position to which it was last moved, by which means the lever
is caused to constitute a stop against which the pawl f abuts when the lever F is
released by the tappet pin g³ and the flap shutter consequently prevented from
opening at this stage the rod j may be raised so as to close the sliding shutter J
and stop the motor in the casing G³.
At this
The length of the various exposures before described can be varied by inserting
the tappet pins g, g², g³ in those of the holes g at a distance apart corresponding
with the desired times of exposure. To enable the exposures to be varied all in
the same proportion I may provide an adjustable brake or equivalent device for
more, or less, retarding the speed of the motor.
The chromograms are usually made stereoscopic which, as herein before described
and shewn in the accompanying drawings, involves the use of a pair of lenses D
and the production of two images behind each of the colour screens a a² a³.
Ordinarily these images have to be cut apart and transposed but I overcome this
necessity by placing in front of each lens, as shewn in Figures 1 and 2, a prism L
by which each image is reversed right and left; the prisms L may conveniently be
supported by frames & secured to the lens mounts.
The before described apparatus may be varied in many ways without departing
from the essential features of the invention for example although I have mentioned
colour screens as being used in front of each sensitized surface, or portion of the
sensitized surface, any other arrangement whereby the requisite records of colour
sensation can be obtained in the respective chromogram sections, may be employed.
To avoid unnecessary complication I wish it understood that the term "colour
filters" employed in the claims is intended to include all devices whereby records
of different colour sensations may be obtained as previously described, and that the
term series of sensitized surfaces" is intended to include a sensitized surface the
different portions of which are successively exposed in the camera.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. In a photographic camera the combination with a series of sensitized surfaces
capable of being adjusted in their own plane so as to bring different sensitized
surfaces opposite the exposure opening, of a series of colour filters moveable with

page_text: the said sensitized surfaces whereby records of different colour sensations may be
obtained on the said sensitized surfaces substantially as herein before described.
2. In a photographic camera the combination with colour filters moveable
therein of motor mechanism for intermittently presenting or controlling the pre-
sentation of different colour filters to the exposure opening substantially as
hereinbefore described.
3. In a photographic camera the combination with colour filters and motor
mechanism for intermittently presenting, or controlling the presentation of,
different colour filters to the exposure opening, of devices for enabling the periods
of exposure of the different parts to be varied either independently of each other
or all in the same proportion substantially as herein before described.
4. The combination with a stereoscopic camera of two prisms one situated in
front of each of the lenses substantially as and for the purpose hereinbefore
described with reference to the accompanying drawings.
5. The combination and arrangement of parts constituting the photographic
camera substantially as hereinbefore described and illustrated in the accompanying
drawings.
Dated this 0th 1.
CN100%
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.