U.S. patent number 3,779,770 [Application Number 05/246,701] was granted by the patent office on 1973-12-18 for a photographic film assemblage for a diffusion transfer film.
This patent grant is currently assigned to Polaroid Corporation. Invention is credited to William W. Alston, John J. Driscoll, Richard R. Wareham.
United States Patent |
3,779,770 |
Alston , et al. |
December 18, 1973 |
A PHOTOGRAPHIC FILM ASSEMBLAGE FOR A DIFFUSION TRANSFER FILM
Abstract
A photographic film assemblage including a container, a
plurality of self-developing film units within the container which
are adapted to be sequentially exposed and treated with a liquid
processing composition, and members associated with the container
so as to form an integral part of the assemblage for controlling
the distribution of the liquid processing composition during
treatment of a film unit. A photographic apparatus with which the
film assemblage is adapted to be used includes structure for
locating the distribution control members in operative association
with a film unit located in position for exposure and subsequent
treatment with the liquid processing composition.
Inventors: |
Alston; William W. (Somerville,
MA), Driscoll; John J. (Andover, MA), Wareham; Richard
R. (Marblehead, MA) |
Assignee: |
Polaroid Corporation
(Cambridge, MA)
|
Family
ID: |
22931836 |
Appl.
No.: |
05/246,701 |
Filed: |
April 24, 1972 |
Current U.S.
Class: |
396/365; 396/33;
396/582 |
Current CPC
Class: |
G03C
8/44 (20130101); G03D 9/02 (20130101); G03B
17/34 (20130101) |
Current International
Class: |
G03D
9/00 (20060101); G03C 8/00 (20060101); G03D
9/02 (20060101); G03B 17/32 (20060101); G03B
17/34 (20060101); G03C 8/44 (20060101); G03c
001/48 () |
Field of
Search: |
;96/76C,76R,29
;95/13 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Torchin; Norman G.
Assistant Examiner: Goodrou; John L.
Claims
What is claimed is:
1. A photographic film assemblage comprising:
a container;
at least one film unit within said container including an
image-forming area which is adapted to be treated with a liquid
processing composition; and
means associated with said container so as to form an integral part
of said assemblage for controlling the distribution of the liquid
processing composition during treatment of said one film unit by
applying a compressive pressure to a selective portion of said
image-forming area.
2. A photographic film assemblage as defined in claim 1 wherein
said means for controlling the distribution by applying said
compressive pressure to said selective portion of said
image-forming area includes at least one member for engaging one
side of said one film unit and means for urging said one side of
said one film unit into engagement with said one member.
3. A photographic film assemblage as defined in claim 2 wherein the
number of members for engaging said one side of said one film unit
is more than one.
4. A photographic film assemblage as defined in claim 2 further
including a plurality of film units disposed between said one film
unit and said means for urging said one film unit into engagement
with said one member.
5. A photographic film assemblage as defined in claim 1 wherein
said container includes a forward wall having a light-transmission
section therein through which said one film unit is adapted to be
exposed and a withdrawal slot at one end of said container through
which said one film unit is adapted to be extracted therefrom and
said distribution control means includes means integrally formed
with said forward wall for engaging one side of said one film unit
and means for urging said one film unit into engagement with said
film engaging means and for cooperating with said film engaging
means to apply said compressive pressure to said selective portion
of said image-forming area to effect uniform distribution of the
liquid processing composition during treatment of said one film
unit.
6. A photographic film assemblage as defined in claim 5 wherein
said means for engaging one side of said one film unit includes at
least one projection depending from said forward wall.
7. A photographic film assemblage as defined in claim 5 wherein
said means for engaging said one side of said one film unit
includes a plurality of projections depending from said forward
wall.
8. A photographic film assemblage as defined in claim 5 wherein
said means for engaging said one side of said one film unit
includes a portion of said forward wall bounded by at least one
recess integrally formed with said forward wall.
9. A photographic film assemblage as defined in claim 5 wherein
said forward wall includes a plurality of recesses formed therein
and said means for engaging said one side of said one film unit
includes a portion of said forward wall intermediate said plurality
of recesses.
10. A photographic film assemblage as defined in claim 5 wherein
said means for engaging said one side of said one film unit
includes a bearing surface intermediate a pair of openings in said
forward wall.
11. A photographic film assemblage as defined in claim 5 further
including a plurality of film units arranged in stacked relation
between said one film unit and said means for urging said one film
unit into engagement with said film engaging means.
12. A photographic film assemblage as defined in claim 1 wherein
each said film unit includes a photosensitive layer, a superposed
image-receiving layer, and a rupturable container having a liquid
processing composition therein which is adapted to be distributed
between predetermined layers of said film unit.
13. A photographic film assemblage comprising:
a container including a forward wall having a light-transmission
section therein and a withdrawal slot at one end of said
container;
a plurality of film units each including a photosensitive layer, a
superposed image-receiving layer, and a rupturable container having
a liquid processing composition therein which is adapted to be
distributed between predetermined layers of said film unit, said
film units being arranged in stacked relation within said container
with a forwardmost film unit located adjacent said forward wall in
position for exposure through said light-transmission section and
its container of processing composition located adjacent to and in
alignment with said withdrawal slot such that said forwardmost film
unit may be extracted from said container therethrough for
spreading of said liquid processing composition; and
means for controlling the distribution of said processing
composition during spreading including means integrally formed with
said forward wall adjacent said withdrawal slot for engaging a
selective portion of a surface of said forwardmost film adjacent
said forward wall.
14. A photographic film assemblage as defined in claim 13 further
including film support means for urging said stack of film units
towards said forward wall and for cooperating with said film
engaging means to apply a compressive pressure to said selective
portion of said forwardmost film unit to effect uniform
distribution of said liquid processing composition between said
predetermined layers.
15. A photographic film assemblage for use with photographic
apparatus of the type including pressure applying means for
spreading a liquid processing composition between superposed layers
of a film unit as the film unit is advanced relative to the
pressure applying means, said film assemblage comprising:
a container;
at least one film unit including a photosensitive layer, a
superposed image-receiving layer, and a rupturable container having
a liquid processing composition therein which is adapted to be
distributed between predetermined layers of said one film unit,
said one film unit being adapted to be advanced from said container
into operative association with the pressure applying means for
discharging said liquid from said rupturable container and
distributing said liquid as said film unit is advanced relative to
the pressure applying means; and
means associated with said container for controlling the
distribution of said liquid processing composition between said
predetermined layers, as it is distributed by the pressure applying
means, by applying a compressive pressure to a selective portion of
said one film unit.
16. A photographic film assemblage as defined in claim 15 wherein
said liquid processing composition is discharged from said
rupturable container in a mass which is spread along a wave front
traveling in a direction which is substantially parallel to the
direction of film unit advancement relative to the pressure
applying means and said distribution control means serves to retard
a portion of the wave front and cause a flow of liquid in a
direction transverse to the direction of film advancement.
17. A photographic film assemblage as defined in claim 15 wherein
the pressure applying means apply a first compressive pressure to
said one film unit to cause discharge of said liquid from said
rupturable container and subsequent distribution and said
distribution control means apply a second compressive pressure to
said one film unit in the path of said liquid wave front to effect
the uniform distribution of said liquid between said predetermined
layers of said film unit.
18. A photographic film assemblage as defined in claim 17 wherein
said container includes a forward wall having a light-transmission
section therein through which said one film unit is adapted to be
exposed and a withdrawal slot at one end of said container which is
adapted to be aligned with the pressure applying means of said
apparatus such that said one film unit may be advanced through said
slot into operative association with the pressure applying means
subsequent to exposure and said distribution control means include
means integrally formed with said forward wall adjacent to said
withdrawal slot for engaging one surface of said one film unit and
means cooperating with said film engaging means for urging said one
surface into engagement with said film engaging means to apply a
compressive pressure to said selective portion of said one film
unit to effect the uniform distribution of said liquid as it is
distributed by the pressure applying means.
19. A photographic film assemblage as defined in claim 18 wherein
said means integrally formed with said forward wall for engaging
said one surface of said one film unit includes at least one
projection depending from said forward wall.
20. A photographic film assemblage as defined in claim 18 wherein
said means integrally formed with said forward wall for engaging
said one surface of said one film unit includes a bearing surface
defined by at least one recess formed in said forward wall adjacent
said withdrawal slot.
21. A photographic film assemblage as defined in claim 18 further
including a plurality of film units disposed between said one film
unit and said means for urging said one film unit into engagement
with said film engaging means such that said one film unit is the
forwardmost film unit in the stack.
22. A photographic film assemblage as defined in claim 18 wherein
said forward wall is relatively flexible and is adapted to engage
and be restrained by structure within the photographic apparatus
for accurately locating said film engaging means in operative
relation with said one surface of said one film unit.
23. A photographic film assemblage as defined in claim 18 wherein
said one surface of said film unit includes a transparent sheet
through which actinic radiation is adapted to pass to expose said
photosensitive layer.
24. A photographic film assemblage as defined in claim 18 wherein
said means integrally formed with said forward wall for engaging
one surface of said one film unit is dimensioned to be narrower
than the width of said withdrawal slot.
25. A photographic film assemblage as defined in claim 15 wherein
said one film unit includes leading and trailing end margins and
lateral margins which cooperate to define the bounds of an image
forming area and said liquid is adapted to be discharged adjacent
said leading end margin and progressively advanced along a wave
front towards said trailing end longitudinal margin by the pressure
applying means and said distribution control means is adapted to
retard a selective portion of the wave front to cause a portion of
said liquid to flow towards said lateral margin to effect a more
uniform lateral distribution of said liquid between said
photosensitive and image-receiving elements.
26. A photographic film assemblage as defined in claim 25 wherein
said distribution control means engage and apply a compressive
pressure to selective portions of said image-forming area of said
film unit to retard a selective portion of the wave front.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of photography and, more
particularly, to photographic film assemblages and photographic
apparatus with which the assemblages are adapted to be used.
2. Description of the Prior Art
An important step in the processing of a self developing film unit
is the spreading of a liquid processing composition between and in
contact with an exposed photosensitive element and a superposed
image receiving element to initiate a diffusion transfer process.
In order to achieve an optimum quality positive print, it is
desirable that the processing fluid be spread such that it covers
the entire photoexposed area in a thin uniform layer.
A typical film unit includes a photosensitive element, an
image-receiving element which may be superposed on the
photosensitive element subsequent to exposure or may be transparent
and predisposed on the photosensitive element such that exposure
may be made through the image-receiving element, and a rupturable
pod or container of processing fluid located at one end of the two
elements.
In a typical self-developing photographic system, the film units
are arranged in stacked relation within a film container which is
adapted to be inserted into the receiving chamber of an appropriate
camera to locate the forwardmost film unit in the stack in position
for exposure.
Subsequent to exposure, the forwardmost film unit is extracted from
the film container and is advanced, pod first, between a pair of
pressure applying members mounted within the camera. The pressure
applying members exert a compressive force on the pod causing it to
rupture and discharge the fluid between the exposed photosensitive
element and the superposed image-receiving element. Continued
advancement of the film unit between the pressure applying members
results in the fluid being advanced along a liquid wave front
toward the trailing end of the film unit such that it is
progressively distributed over the photoexposed area of the film
unit.
The uniformity of the liquid layer is, to a large degree,
determined by the initial shape of the liquid wave front. In order
to uniformly spread the processing composition over a substantially
rectangular or square photoexposed area it is preferable that the
wave front be disposed in a substantially straight line which
extends outwardly to the lateral margins of the area and is
oriented in a direction that is normal to the direction of film
advancement between the pressure applying members.
There are several factors which effect the initial shape of the
wave front. One is a design of the pod and its rupture
characteristics. Another relates to the viscosity and amount of
liquid enclosed by the pod. The wave front shape is also influenced
by the velocity at which the film unit is advanced through the
pressure applying members, the amount of compressive pressure
exerted on the film unit, and the resistance to fluid flow at the
interfaces between the liquid and the superposed film unit
elements.
One of the most commonly observed spread shapes is a tongue shape
wherein the wave front progresses more rapidly at the central
portion of the photoexposed or image-forming area than out at the
lateral margins. This condition may be caused by an uneven
distribution of liquid upon initial discharge from the pod, i.e.,
more liquid being concentrated at the center of the film unit than
out at its edges. In the subsequent spreading of the tongue-shaped
wave front, it is possible that the corners of the image-forming
area at the trailing end of the film unit will be coated with a
layer of fluid of reduced depth or thickness, or not be coated at
all.
One method employed to compensate for a tongue-shaped wave front
has been to provide excess fluid in the pod. Another method has
been to equip the camera with spread control devices which serve to
modify the shape of the liquid wave front during spreading.
The spread control devices are designed to apply a second
compressive force to the central portion of the film unit in the
path of the mass of fluid discharged from the pod by the pressure
applying members. This serves to retard the central portion of the
wave front and cause a flow of liquid in a direction transverse to
the direction of film advancement. In this manner, the wave front
is modified such that it is substantially straight and is oriented
in a direction substantially normal to the parallel sides of the
rectangular or square image-forming area.
For example of cameras which are equipped with devices for
controlling the distribution of liquid processing composition,
reference may be had to U.S. Pat. No. 2,991,703, issued to V. K.
Eloranta on July 11, 1961, and U.S. Pat. No. 3,416,427, issued to
J. B. Murphy on Dec. 17, 1968, both of which are assigned to the
same assignee as the present invention.
SUMMARY OF THE INVENTION
The present invention relates to improvements in systems for
controlling the distribution of a liquid processing composition as
it is spread between the photosensitive element and the superposed
image-receiving element of a film unit.
More specifically, the present invention provides a film assemblage
which includes a container, a plurality of self developing film
units and structure associated with the container, such that it
forms an integral part of the assemblage, for controlling the
distribution of a liquid processing composition as a film unit is
advanced between pressure applying members mounted in a camera.
Also, photographic apparatus in the form of a camera is provided
which includes a housing, a chamber for receiving the film
container to locate one of the film units therein in position for
exposure, processing or pressure applying means, and means for
engaging the container to locate and maintain the distribution
control structure associated therewith in operative relation with
the film unit located in position for exposure and subsequent
treatment with the processing fluid.
After exposure, a film unit is advanced through a withdrawal slot
in the container and into engagement with the pressure applying
members which cause the film unit pod to rupture and discharge the
processing fluid between the superposed photosensitive and
image-receiving elements. By continuing to advance the film unit,
the pressure applying members spread the fluid toward the trailing
end of the film unit and towards the withdrawal slot through which
the film unit is being advanced.
In one embodiment, the distribution control members may include
projections located near the film container withdrawal slot such
that they extend into the path of travel of the film unit and
selectively apply compressive pressure to a central portion of the
film unit in the path of the advancing liquid front as the film
unit is being extracted from the container. In effect, the rapidly
advancing central portion of the liquid front is retarded which
causes the liquid to flow transversely of the direction of film
advancement thereby modifying the shape of the spread such that it
is substantially straight.
In other embodiments, the forward wall of the container includes
distribution control recesses, or is configured to have selective
sections thereof removed, such that a portion of the forward wall,
intermediate the recesses or removed sections, engages the central
portion of the film unit to selectively retard the wave front as
the film unit is advanced through the withdrawal slot.
In a preferred embodiment the film container is formed of a
thermoplastic material and includes relatively thin walls, one of
which supports the distribution control members. Advantageously,
the camera is provided with a receiving chamber which includes
surfaces for engaging and restraining any movement or distortion of
the film container walls, thereby serving to accurately locate the
distribution control members in operative association with a film
unit located in position for exposure and subsequent treatment with
the liquid processing composition.
A major advantage of incorporating the distribution control members
into the film container is that they may be specifically designed
to optimize the spreading characteristics of the particular type of
film stored therein. For example, the processing fluid pod
construction and rupture characteristics, and the viscosity and
amount of fluid contained therein may significantly differ in black
and white and color film units. When advanced through the same
pressure applying members, at the same velocity, the shape of the
liquid wave front may be significantly different for each type of
film unit and thereby require distribution control members which
vary in size, shape, disposition relative to the film unit, and the
amount of pressure applied thereto. If the distribution control
members are permanently mounted in a camera which is adapted to
accept more than one type of film unit, their design may be, at
best, a compromise.
Another significant advantage of mounting the distribution control
member in the film container relates to economics. Since the
control members are only utilized to process the number of film
units within the container and are then discarded, they may be
advantageously formed of a low cost plastic material. On the other
hand, when they are permanently mounted in the camera they are
generally formed of a metal to minimize the amount of wear on their
bearing surfaces in view of the significant number of film units to
be processed.
Also, by removing the distribution control member from the camera
housing, a saving of space is realized which may be utilized to
house structure for providing another function or reduce the
overall dimensions of the camera.
Therefore, it is an object of the present invention to provide a
photographic film assemblage including a container, a film unit
within the container which is adapted to be treated with a liquid
processing composition and means associated with the container to
form an integral part of the assemblage for controlling the
distribution of the processing composition during treatment of the
film unit.
Another object of the present invention is to provide a
photographic film assemblage which is adapted for use with
photographic apparatus of the type including pressure applying
means for spreading a liquid processing composition between
superposed elements of a film unit and the assemblage includes a
container having means for controlling the distribution of the
liquid processing composition as it is spread by the pressure
applying means.
It is yet another object of the present invention to provide
photographic apparatus adapted for use with a photographic film
assemblage of the type including a container, a plurality of film
units adapted to be sequentially exposed and treated with a liquid
processing composition, and means for controlling the distribution
of the processing composition during treatment of the film unit and
the apparatus includes a housing, means for receiving and
supporting the container to locate a film unit in position for
exposure, and means for locating the distribution control means in
operative association with the film unit located in position for
exposure.
Another object of the invention is to provide a system for
spreading a liquid processing composition between superposed
elements of a film unit which features photographic apparatus
including pressure applying members for spreading the processing
fluid and a film assemblage which includes a film container having
structure associated therewith for controlling the distribution of
fluid during spreading such that several different types of film
assemblages may be used with the same photographic apparatus and
each different assemblage may include distribution control members
which are designed to optimize the spreading characteristic of a
particular type of film unit contained therein.
Other objects of the invention will, in part, be obvious and will,
in part, appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the
invention, reference should be had to the following detailed
description taken in connection with the accompanying drawings
wherein:
FIG. 1 is an exploded perspective view of a photographic film
assemblage embodying the instant invention showing the construction
and location of various components of the assemblage;
FIG. 2 is a perspective view of a self-developing film unit;
FIG. 3 is an enlarged elevational view, partly in section, of a
portion of the film assemblage and camera showing a film unit in
operative association with a pair of pressure applying rollers
mounted in the camera and distribution control members located in
the film container;
FIG. 4 is an elevational view, partly in section, of a camera
having a film assemblage located at an operative position
therein;
FIG. 5 is an elevational view of a film unit showing the
progressive advancement of a liquid wave front, in dotted lines, to
illustrate the distribution of processing composition when
distribution control members are not utilized in the spread
system;
FIG. 6 is an elevational view of a film unit showing progressive
advancement of a liquid wave front, in dotted lines, showing the
modification of the shape of the wave front caused by the
distribution control members;
FIG. 7 is a perspective view of a first alternative embodiment of a
film container embodying the instant invention;
FIG. 8 is a perspective view of a second alternative embodiment of
a film container embodying the instant invention;
FIG. 9 is a perspective view of a third alternative embodiment of a
film container embodying the instant invention;
FIG. 9a is an elevational view of the film container of FIG. 9;
and
FIG. 9b is a perspective view of a section of the film container of
FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The components of a photographic film assemblage 10 embodying the
instant invention are shown in exploded fashion in FIG. 1 of the
drawings. They include a box-like film container 12 and its
contents, dark slide 14, a plurality of self-developing film units
16, a film support member 18, and preferably an electrical battery
20.
Film container 12 is preferably molded of an opaque thermoplastic
material, such as polystyrene, and includes relatively thin,
substantially planar walls. A forward wall 22 includes a generally
rectangular upstanding rib 24 which defines the bounds of a
generally rectangular light-transmitting section or exposure
aperture 26. Depending from three sides of forward wall 22 are a
pair of side walls 28 and a trailing end wall 30 which serve to
space a substantially planar rear wall 32 from forward wall 22.
The leading ends of forward wall 22, side walls 28, and rear wall
32 cooperated to define an elongated rectangular opening 34 at the
leading end of container 12 through which the contents may be
inserted. After insertion, a leading end wall 36 which is
preferably coupled to the leading end of rear wall 32 by integrally
formed flexible hinges 38, may be rotated 90.degree. and joined to
the leading ends of side walls 28, and rear wall 32 by any suitable
method such as ultrasonic welding.
It will be noted that when leading end wall 36 is located in its
closed position, its top edge 39 is spaced from the leading end of
forward wall 22 such that an elongated withdrawal slot 40 is formed
therebetween (see FIG. 3) through which dark slide 14 and film
units 16 may be sequentially extracted from container 12.
The contents of film container 12 are preferably arranged therein
in the stacked relation shown in FIG. 1. Battery 20 is
substantially flat and is positioned over the interior surface of
rear wall 32 such that two electrodes on the underside of the
battery (not shown) are aligned with a pair of tear-drop shaped
openings 42 in rear wall 32. When container 12 is operatively
positioned in a suitable camera, a pair of electrical contacts
mounted therein are adapted to extend through openings 42 for
coupling battery 20 to the camera's electrical system which may
include an automatic exposure control circuit, a flash mode
circuit, and electrically driven film advance and processing
mechanisms.
Positioned between the stack of film units 16 and battery 20 is the
film support member 18 which serves to spring bias the film units
16 towards the interior surface of forward wall 22. Preferably,
support member 18 includes a rectangular open support frame 44 for
engaging the peripheral margins of the rearwardmost film unit in
the stack, and a generally H-shaped center section 46 coupled to
support frame 44 and including four resilient legs 48 which bear
against battery 20 and provide an upward biasing force.
The film units 16 preferably include a rectangular or square
photosensitive image-forming area 50, which is surrounded by opaque
margins, and a rupturable pod 52, containing a liquid processing
composition, located at the leading end of the film unit outside of
the bounds of the image-forming area 50. A more detailed discussion
of the construction of film units 16 will appear hereinafter.
The film units 16 are arranged in stacked relation on top of
support frame 44 with their image-forming areas 50 facing towards
the exposure aperture 26 in container forward wall 22. Subsequent
to the removal of dark slide 14, the forwardmost film unit 16 bears
against the interior surface of forward 22 and is in position for
exposure to actinic radiation transmitted through exposure aperture
26.
It will be noted that the leading end of the forwardmost film unit
16, containing pod 52 is also aligned with withdrawal slot 40 at
the leading end of container 12. Subsequent to exposure, the
forwardmost film unit is adapted to be engaged by a film advancing
mechanism in the camera and moved out of container 12 through slot
40 for processing. Access for engaging the trailing end of the
forwardmost film unit to move it forwardly through slot 40 is
provided by an opening 53 located in forward wall 22 and the
trailing end wall 30 of container 12.
Dark slide 14 is formed of any suitable opaque material such as
cardboard, paper, or plastic and is initially positioned between
the forwardmost film unit 16 and the interior surface of forward
wall 22. It serves to light seal exposure aperture 26 and opening
53. Once film container 12 is located at its operative position
within a camera, it may be removed through withdrawal slot 40 in
the same manner as the forwardmost film unit 16.
In order to light seal withdrawal slot 40, container 12 is
preferably provided with an opaque flexible sheet 55 which is
secured at one end to exterior surface of leading end wall 36 and
is disposed in closing relation to slot 40. This sheet forms a
primary light seal for blocking light when container 12 is located
within a camera. A secondary light shield for blocking slot 40
prior to inserting container 12 into the camera may also be
provided in the form of an end cap member 58. Member 58 is coupled
to leading end wall 36 and includes an end cap 60 which is
initially positioned in closing relation to the primary light seal
55 and withdrawal slot 40 and may be pivoted to an open position in
response to inserting container 12 into the camera. For details as
to the construction and operation of end cap member 58, reference
may be had to the copending application of Nicholas Gold, Ser. No.
213,989, filed on Dec. 30, 1971, which is also assigned to the same
assignee as the present invention.
Referring now to FIGS. 2 and 3 of the drawing, a typical
self-developing film unit 16 generally includes a photosensitive
sheet or element 54 and a superposed, transparent image-receiving
sheet or element 56 which cooperate to form a laminate. The
laminate's structural integrity may also be enhanced or provided,
in whole or in part, by providing a binding member 61 which extends
around the edges of the laminate. The binding member 61 may take
the form of an opaque, pressure-sensitive adhesive tape which also
serves to provide lateral margins 62, and leading and trailing end
longitudinal margins 63 and 64 bordering the photosensitive
image-form area 50.
The rupturable pod 52 preferably comprises a rectangular blank of
fluid and air impervious sheet material folded longitudinally upon
itself to form two walls 65 which are sealed to one another along
their lateral end margins 66 and longitudinal margin 68 to form a
cavity in which a liquid processing composition 70 is retained. The
longitudinal seal 68 is made weaker than the lateral end seals 66
so as to become unsealed in response to hydraulic pressure
generated within the liquid 70 by the application of compressive
pressure to the walls 65 of the pod 52.
As best shown in FIG. 3, pod 52 is fixedly secured to the leading
ends of the superposed elements 54 and 56 such that the weaker
longitudinal seal 68 is positioned to effect an unidirectional
discharge of the fluid 70 between the photosensitive element 54 and
the image-receiving element 56 upon application of compressive
pressure to pod 52.
In use, film unit 16 is subjected to actinic radiation which is
directed through the transparent image-receiving element 56 to
photo-expose and form latent images in the underlying
photosensitive element 54. The film unit then may be advanced, pod
52 first, between a pair of juxtaposed cylindrical rollers 72 and
74 (see FIG. 3) which apply a compressive pressure to the walls 65
of pod 52 and induce a hydraulic pressure in fluid 70 thereby
causing seal 68 to rupture. The fluid 70 is discharged, in a mass,
between elements 54 and 56, at margin 63, and is spread between and
in contact therewith in a thin layer towards margin 64 by rollers
72 and 74, as film unit 16 is further advanced between the rollers,
thereby covering the photo-exposed area 50 with the liquid
processng composition 70. Processing composition 70 initiates a
diffusion transfer process which results in a positive print being
formed in the transparent image-receiving sheet 56.
At this point it may be well to explain that the description of
film unit 16, as including a photosensitive element 54 and an
image-receiving element 56 is an over simplification to aid in
illustrating the construction of the film units in the
drawings.
As disclosed in U.S. Pat. No. 3,415,644, issued to E. H. Land on
Dec. 10, 1968, the film unit generally includes an opaque bottom
sheet, a transparent top sheet, and a plurality of individual
layers of photographic materials located therebetween to form the
laminate. These layers include a photosensitive layer positioned
over the bottom sheet, and an image-receiving layer positioned
between the photosensitive layer and the top sheet. The term
"photosensitive layer" is meant to include one or more individual
photosensitive layers. Therefore, when it is stated that the
processing fluid 70 is spread between and in contact with elements
54 and 56, it will be understood that the fluid 70 may be spread
between any two predetermined adjacent layers in the film unit.
As noted earlier, it is desirable that the layer of processing
composition between elements 54 and 56 be of uniform thickness over
the entire image-forming area 50 to obtain an optimum quality
positive print. It was also noted that the uniformity of the liquid
layer is influenced by the initial shape of the wave front of the
mass of liquid as it is discharged from pod 52.
Different types of film units tend to have different initial wave
front shapes due to variances in their pod design, pod seal rupture
characteristics, the amount and viscosity of the liquid processing
composition enclosed by the pod, and the resistance to fluid flow
at the interface between the fluid and the superposed elements
forming the laminate.
A commonly observed wave front 76 is illustrated in FIG. 5. It is
tongue or bow-shaped, i.e., the liquid 70 initially tends to move
towards the trailing end of the film unit more rapidly at the
central portion of the photoexposed image-forming area 50 than out
at lateral margins 62 thereof. This is generally caused by more
fluid being concentrated at the center of pod 50 than out near the
end seals 66 and also by the influence of binding member 61 at the
lateral margins 62.
As the film unit 16 is advanced, the rollers 72 and 74
progressively spread the fluid 70 (as shown in dotted lines)
towards the trailing end margin 64 which may include an integrally
formed reservoir or trap for collecting and retaining excess fluid.
Because there is an uneven lateral distribution of fluid, the depth
or thickness of the layer may be reduced near the corners of the
image-forming area 50 at the trailing end of film unit 16.
In order to control the distribution of fluid 70 as it is spread by
a pair of pressure applying members mounted within a camera, film
assemblage 10 is provided with a distribution control device. Such
a device may take the form of one or more members which are adapted
to apply a second compressive force to the central portion of the
film unit 16 in the path of the liquid wave front 76. The added
pressure increases the resistance to fluid flow between elements 54
and 56 at the central portion of the film unit thereby selectively
retarding the center of the liquid wave front 76 and causing a flow
of fluid outwardly towards the lateral margins 62 of the film unit
to cause a more uniform lateral distribution.
In a preferred embodiment the distribution control device may
include one or more projections 78 depending from the interior
surface of film container forward wall 22 adjacent the withdrawal
slot 40 at the leading end of the container.
In the embodiment illustrated in FIGS. 1 and 3, three such
projections 78a, 78b, and 78c, are symmetrically disposed about a
longitudinal center line of the film container 12. Preferably,
projections 78 are formed of a thermoplastic material and are
integrally molded with the interior surface of forward wall 22. It
will be noted that projections 78 are tapered to increase in depth
in the direction of film advancement through withdrawal slot 40 to
provide a smooth transition surface between forward wall 22 and
withdrawal slot 40.
As best seen in FIG. 3, the projections 78 engage the surface of
the forwardmost film unit 16 which includes the image-receiving
element 56. This surface of the forwardmost film unit 16 is held in
engagement with projections 78 by the upward force of the spring
biased support member 18. After the forwardmost film unit 16 has
been exposed, it is advanced through withdrawal slot 40 and between
the rollers 72 and 74. When pod seal 68 ruptures, the liquid 70 is
discharged rearwardly (to the right as viewed in FIG. 3) towards
projections 78a-c.
It will be noted that projections 78 are aligned in a straight line
which is spaced from, but is substantially parallel to the axes of
rotation of rollers 72 and 74 such that the initial discharge of
liquid 70 occurs intermediate rollers 72 and 74 and the projections
78. While the projections 78 and support frame 18 cooperate to
apply a compressive pressure to pod 52 as it advances through slot
40, the amount of compressive pressure is not sufficient to cause
seal 68 to rupture. The initial discharge of liquid 70 is caused
solely by the compressive force applied to pod 52 by rollers 72 and
74.
Continued advancement of the film unit 16 (to the left as viewed in
FIG. 3) causes rollers 72 and 74 to spread the liquid 70 towards
the trailing end of the film unit. As best shown in FIG. 6,
projections 78a, 78b, and 78c modify the shape of the wave front 76
by applying a second compressive force to the central portion of
the film unit in the path of the wave front 76. This second
compressive force selectively increases the resistance to fluid
flow between elements 54 and 56 and retards the advancement of the
center portion of the wave front 76.
With rollers 72 and 74 applying the first compressive force behind
the mass of liquid 70, and projections 78a, 78b, and 78c applying
the second compressive force to the centtral portion of the fluid
flow path in front of the mass of liquid, a portion of the
concentration of fluid 70 at the center of the film unit seeks the
path of least resistance and tends to flow transversely of the
direction of film advancement toward the lateral margins 62 of the
film unit 16. Thus the distribution of liquid between the lateral
margins 62 becomes more uniform and the shape of the wave front 76
is modified such that it is substantially straight and normal to
margins 62.
In FIGS. 1 and 3, the distribution control device is shown to
include three separate projections 78a, 78b, and 78c. It must be
emphasized that this type of control device is suited for use with
a particular type of film unit. With another type of film unit
having different pod rupture characteristics or possibly including
a fluid having a different viscosity; the projections 78 may have
different spacing; they may or may not be symmetrically disposed
about the center line of the film container; the number of
projections may be increased or decreased to even include only one
elongated projection; or, the shape of the projections may be
substantially different. For an example of a film unit which
includes a rupturable pod that is subdivided into three separate
liquid bearing compartments, reference may be had to U.S. Pat. No.
3,621,768, issued to R. J. Chen on Nov. 23, 1971.
Also, the spacing between the bearing surfaces of projections 78
and the rollers 72 and 74 may vary. With one type of film unit, the
projections 78 may be set back from withdrawal slot 40 towards the
trailing end of the film container 12. With another, it may be
desirable to extend the length of forward wall 22 such that the
bearing surfaces of projections 78 extend forwardly (to the left as
viewed in FIG. 3) of the container leading end wall 36.
One alternative embodiment of the present invention, is shown in
FIG. 7. It will be noted that the interior surface of the forward
wall 22 of the film container 12 includes a pair of recesses 80
adjacent to side walls 28. By selectively elevating portions of
interior surface of container forward wall 22 near the withdrawal
slot 40, the area of contact between the top surface of the
forwardmost film unit 16, and the interior surface of forward wall
22 near withdrawal slot 40, is reduced to that portion 82 of
forward wall 22 intermediate recesses 80. Therefore, as the
forwardmost film unit 16 is advanced through slot 40, the interior
surface of portion 82 bears against the central portion of the film
unit 16 and, in cooperation with support member 18, applies the
second compressive force to the film unit image-forming area 50 for
controlling the distribution of processing composition 70.
Stated another way, container 12 includes a forward wall 22 having
a pair of recesses 80 therein which cooperate to define a bearing
surface 82 therebetween for selectively engaging a portion of a
film unit 16 as it is advanced through withdrawal slot 40 to
control the distribution of the liquid processing composition 70
during film processing operations.
Another alternative embodiment of the present invention is shown in
FIG. 8. The leading end of container forward wall 22 has two
triangular sections, near side walls 28 removed therefrom, which
define triangular openings or notches 200. Accordingly, that
portion of the interior surface of forward wall 22 which bears
against the top surface of the film unit 16 as it is advanced
through slot 40 is reduced to bearing surface 202 intermediate
openings 200. Operating in a manner similar to the embodiment shown
in FIG. 7, the film assemblage 10 includes a film container 12
having openings 200 therein which define a bearing surface 202
therebetween for cooperating with support plate 18 to control the
distribution of a liquid processing fluid as it is spread between
and in contact with the superposed elements 54 and 56 of the
forwardmost film unit 16.
Still another embodiment of the present invention is shown in FIGS.
9, 9a, and 9b. The interior surface of the leading end of container
forward wall 22 has a pair of triangular recesses or depression 300
molded therein to define a forward wall film bearing surface 302
therebetween. As best shown in FIG. 9a, forward wall 22 is
relatively thin, i.e., approximately 0.020 of an inch between its
interior and exterior surfaces. In a preferred embodiment, the
forward wall 22 is tapered in the regions designated 300 to reduce
in thickness from 0.020 of an inch near the lateral edges of
bearing surface 302 to a reduced thickness approximating 0.005 of
an inch near the side walls 28. It will be noted that recesses 300
preferably end short of the side walls 28 at 304 to facilitate
molding procedures and to enhance the structural stability of the
leading end of the film container 12.
With support member 18 urging the forwardmost film unit 16 against
the interior surface of container forward wall 22, the differential
in wall thickness between the centrally located bearing surface 302
and the edge recesses 300 causes a compressive pressure to be
selectively applied to the central portion of the film unit as it
is progressively extracted through withdrawal slot 40 during
processing operations. As noted earlier, by selectively applying a
second compressive pressure to the film unit in the path of the
advancing liquid wave front, the rapidly advancing center of the
wave front may be retarded thereby causing a flow of fluid toward
the lateral margins 62 of the film unit to achieve a more uniform
distribution of processing fluid.
Again, it may be well to point out that the film containers shown
in FIGS. 7, 8, and 9 are intended to be illustrative of embodiments
wherein the forward wall of the container includes recesses or
openings which define the bounds of distribution control means
therebetween. The number and location of the recesses or openings
will depend on the characteristics of the film units intended to be
packaged in these containers.
It will be noted, that while it is not shown in the drawings, each
of the film containers 12 shown in FIGS. 7, 8, and 9 preferably
includes a light sealing arrangement for withdrawal slot 40 similar
to the one shown in FIG. 1 at 55 and 58.
As noted earlier, film assemblage 10 is adapted to be inserted into
an appropriate photographic apparatus for sequentially exposing and
processing the film units 16 located within film container 12. Such
an apparatus may take the form of a compact, folding, single lens
reflex camera 84 shown in FIG. 4 in its extended and operative
position.
Camera 84 includes four housing sections 86, 88 90, and 92,
pivotally connected at pivots 87, 89, 91, and 93 for movement
between a compact folded position and the extended operative
position of FIG. 4, and a fifth housing section 94 pivotally
coupled to and extending forwardly (to the left as viewed in FIG.
4) of housing section 86. Enclosing the space between the extended
housing sections 86, 88, 90, and 92 to form the camera's exposure
chamber is a foldable opaque bellows or envelope 96.
Housing section 86 is a generally parallelepiped shaped structure
which includes an open-ended chamber 98 therein for receiving the
film assemblage 10. The open end 100 of chamber 98, through which
film container 12 is adapted to be inserted, is located near the
interface between housing sections 86 and 94. Access to opening 100
is provided by pivoting housing section 94 in a counterclockwise
direction (as viewed in FIG. 4) relative to housing section 86.
Chamber 98 is formed by a rear or bottom wall 102, a pair of inner
frame side walls 104 (only one of which is shown), a trailing end
wall 106, and a top or forward wall 108. Chamber wall 108 is
essentially a plate-like structure having a generally rectangular
opening 110 therein with which the exposure aperture 26 of film
container 12 is adapted to be aligned.
With housing section 94 located in the open position, film
container 12 is inserted through opening 100, trailing end first,
and is moved rearwardly (to the right as viewed in FIG. 4) into
chamber 98. It will be noted that camera 84 includes a pair of
brackets 112 (only one of which is shown) located near opening 100
for pivotally coupling housing section 92 to housing section 86.
Brackets 112 are located adjacent the path of travel of the film
container side walls 28 and engage and pivot the end cap 60 from
the closed to the open position such that it is out of alignment
with withdrawal slot 40.
Film container 12 is supported at its operative position within
chamber 98 by plate 108 which bears against the exterior surface of
forward wall 22, inner side walls 104 which bear against container
side walls 28, and a spring support member 114, mounted on the
interior surface of chamber wall 102, which bears against rear wall
32 of the film container 12.
When film container 12 is located at its operative position, the
exposure aperture 26 in the forward wall 22 of film container 12 is
aligned with aperture 110 in plate 108. Plate 108 serves to
position container 12 such that the forwardmost film unit 16 is
located at the camera's exposure plane (subsequent to removal of
dark slide 14). A pair of electrical contacts 116 (only one of
which is shown) extend through openings 42 in the rear wall 32 of
the container 12 and make electrical contact to the electrodes on
the underside of battery 20. Also, a film advancing mechanism (not
shown) mounted in housing section 86 extends through opening 53 in
the forward and trailing end walls of the film container 12 for
engaging and advancing the forwardmost film unit 16 through
withdrawal slot 40.
After film container 12 has been located at its operative position
within chamber 98, housing section 94 is pivoted to its closed
position thereby locating a pair of pressure applying members 118
and 120, mounted thereon, in operative relation with the film
container withdrawal slot 40. Pressure applying members 118 and 120
preferably take the form of a pair of cylindrical, juxtaposed
rollers having their axes of rotation substantially parallel to the
leading end wall 36 of a film container located in chamber 98 such
that the bite between the rollers is in a plane which includes
withdrawal slot 40 and the camera's exposure plane.
The forwardmost film unit 16 is adapted to be exposed by
image-bearing light transmitted through the aperture 110 in plate
108 and the exposure aperture 26 in the forward wall 22 of film
container 12.
Camera 84, being of the single lens reflex type, is adapted to
operate first in a viewing and focusing mode and then in an
exposure and processing mode.
The camera's optical system includes an objective lens mounted in
housing section 92; a planar mirror mounted on the interior surface
of housing section 88; a plate-like reflex member pivotally mounted
in housing section 86 at pivot 87 for movement between a viewing
and focusing position in which the reflex member rests atop plate
108 in covering relation to aperture 110 and an exposure position
in which it is positioned parallel with and adjacent to the planar
mirror mounted on housing section 88; and a reflex type viewing
device 122 mounted on housing section 90. The plate-like reflex
member includes a reflective focusing screen on its top side facing
housing sections 88 and 90 and a planar mirror on its underside
facing receiving chamber 98.
During the viewing and focusing mode of operation, light from the
objective lens is directed toward the mirror mounted on housing
section 88 which reflects it downwardly onto the focusing screen
covering aperture 110 to form an image of the scene to be
photographed. Light emanating from the image on the focusing screen
is directed back to the mirror mounted on housing section 88 which
reflects it into the viewing device 122. A second image of the
scene is formed by the viewing device 122 which may be viewed from
an eye station designated 124.
After adjusting the objective lens such that the image of the scene
is in sharp focus, the user actuates a button mounted on housing
section 92 to initiate the exposure and processing mode of
operation. A shutter behind the objective lens closes and an
entrance pupil for the viewing device 122 is blocked to render the
chamber, formed by the bellows 96, lighttight. The reflex member is
pivoted upwardly such that the planar mirror on the underside faces
the objective lens. The shutter is opened and light therefrom is
reflected by the mirror on the underside of the reflex member
through apertures 110 and 26 to cause exposure of photosensitive
element 54 of the forwardmost film unit 16 through its transparent
image-receiving element 56. After an appropriate exposure interval,
the shutter is closed and the reflex member is returned to its
viewing position. The shutter is then opened and the viewing device
entrance pupil is unblocked.
As the reflex member is being returned to the viewing position, the
film advance mechanism engages the exposed forwardmost film unit 16
and moves it through the withdrawal slot 40 into the bite of
rollers 118 and 120. At least one of the rollers is driven in a
direction to cause the film unit 16 to be advanced therebetween
towards the exterior of the camera 84 (to the left as viewed in
FIG. 4).
For a more detailed description of the camera's optical system and
modes of operation reference may be had to the copending
application of Peter F. Costa and Edward H. Coughlan, Ser. No.
141,554, filed on May 10, 1971, now U.S. Pat. No. 3,722,389 and
assigned to the same assignee as the present invention.
As pod 52 passes between rollers 118 and 120, they apply
compressive pressure to walls 65 of the pod causing the weaker seal
68 to rupture and discharge the mass of fluid 70 between the
photosensitive sheet 54 and the image-receiving sheet 56. As
described earlier, the distribution control projections 78a, 78b,
and 78c, located on the interior surface of container forward wall
22, (or the bearing surfaces such as 82, 202, or 302 of the several
alternative embodiments described) in cooperation with the support
member 18, apply a second compressive pressure to the central
portion of the film unit 16 in the path of the liquid wave front
76. The center section of the wave front 76 travelling in a
direction parallel to the direction of film advancement is thereby
retarded causing a flow of fluid in a direction transverse of the
direction of film advancement to more evenly distribute the layer
of fluid 70 within the laminate.
It was described earlier in the disclosure that the plastic walls
of film container 12 were relatively thin and therefore flexible.
It will be apparent to one skilled in the art that in order for the
distribution control members to function properly they must be
accurately positioned with respect to the forwardmost film unit
16.
In a preferred embodiment, the forwardmost film unit 16 is located
at the camera's exposure plane and is adapted to be moved in a film
exit plane into the bite of the rollers 118 and 120. Depending on
the design of the camera, the film exit plane may or may not
coincide with the exposure plane. Therefore, it is important to
accurately locate the distribution control projections 78 such that
they bear against the top surface of the forwardmost film unit 16
with the desired amount of pressure to effect uniform fluid
distribution as the film unit is advanced along the film exit
plane. Since the distribution control members are generally
integrally formed with the forward wall 22 of the film container
12, their location with respect to the forwardmost film unit 16
will, at best, be uncertain because of the flexibility of the
forward wall 22.
In order to accurately locate the distribution control members,
certain of the structural members forming chamber 98 are configured
to engage and dimensionally stabilize film container 12 when it is
located at its operative position therein. For example, that
portion 126 of the plate 108, which is positioned over the portion
128 of forward wall 22 between upstanding rib 24 and the leading
end of forward wall 22, provides a bearing surface which restrains
any upward bowing or distortion of forward wall portion 128. Also,
inner frame side walls 104 bear against container side wall 28 to
provide lateral support for the leading end of the container 12.
The rigidity of the container is also enhanced by a support surface
130, which may be integrally formed with the bottom wall 102 of
chamber 98 to bear against the leading end of the container rear
wall 32.
It will be understood that portion 126 of plate 108 may be suitably
configured to engage and restrain a film container having a
non-planar forward wall portion such as in the embodiment shown in
FIG. 7.
In this manner, the normally flexible walls of the container 12 are
restrained and dimensionally stabilized when the container is
located at its operative position within chamber 98 and camera 84
is provided with means for accurately locating distribution control
members, forming an integral part of a film assemblage, in relation
to a film unit located at an exposure position therein.
In summary, a novel system for uniformly spreading a liquid
processing composition within a self-developing film unit laminate
has been provided.
The system features a photographic film assemblage including a
container holding at least one film unit therein which is adapted
to be exposed and then treated with a liquid processing
composition, and means associated with the container, so as to form
an integral part of the assemblage, for controlling the
distribution of the liquid during treatment of the film unit.
The system also includes photographic apparatus, preferably a
camera, into which the film assemblage is adapted to be inserted to
locate the film unit at an exposure position therein. The camera is
provided with pressure applying means for spreading the liquid
processing composition between and in contact with superposed
elements of the film unit and means for engaging and dimensionally
stabilizing the container to accurately locate the distribution
control means in operative association with the film unit
positioned for exposure.
A major advantage of such a system is that several different types
of film assemblages, i.e., each having distribution control means
that are uniquely configured for the particular type of film unit
contained therein, may be utilized with the same camera.
The distribution control means may include one or more projections
(or a bearing surface defined by recesses or openings in the
forward wall of the container) integrally formed with the forward
wall of the container near the withdrawal slot
In operation, the distribution control means selectively apply a
compressive pressure to the central portion of the film unit to
retard the center of the liquid wave front of processing fluid
thereby causing a flow of fluid outwardly towards the lateral
margins of the film unit to achieve more uniform fluid
distribution.
Since certain changes may be made in the above photographic film
assemblage and photographic apparatus without departing from the
scope of the invention herein involved, it is intended that all
matter contained in the above description or shown in the
accompanying drawings shall be interpreted as illustrative and not
in a limiting sense.
* * * * *