Photography – Self-developing camera – Including means to treat superimposed material
Reexamination Certificate
1999-08-20
2001-01-09
Rutledge, D. (Department: 2851)
Photography
Self-developing camera
Including means to treat superimposed material
Reexamination Certificate
active
06173120
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an instant photo film pack and an instant camera. More particularly, the present invention relates to an instant photo film pack and an instant camera in which developing solution of self-developing photo film units can be caused to spread adequately.
2. Description Related to the Prior Art
There is an instant photo film pack
4
as illustrated in
FIG. 13A. A
case
2
of the instant photo film pack
4
in a box shape contains plural self-developing photo film units
3
of a mono-sheet type. The case
2
is formed from plastic material and provided with opacity and dark color for shielding light. An exposure opening
2
a
is formed in the front wall of the case
2
, and opens for the exposure surface
3
a
of the photo film units
3
. A top end wall is provided with an exit slot
2
b
for exiting the photo film units
3
to the outside of the case
2
. The instant photo film pack
4
is for use with an instant camera, a printer and other optical instruments, and loaded in a pack chamber disposed in such optical instruments.
An advancing mechanism is incorporated in an optical instrument loadable with the instant photo film pack
4
, for example an instant camera, for advancing an exposed one of the photo film units
3
out of the case
2
and for spreading developing solution. The advancing mechanism is constituted by a claw member
7
and a pair of spreader rollers
8
. The claw member
7
moves upwards and enters a cutout
6
formed in the case
2
, and advances the one photo film unit
3
through an exit slot formed in the top of the case
2
. The spreader rollers
8
squeeze the one photo film unit
3
from the case
2
and rotate, so as to convey the one photo film unit
3
toward a camera exit slot, to spread developing solution to the photosensitive layer of the one photo film unit
3
.
U.S. Pat. No. 4,226,519 discloses a spreading control member, which is disposed at an exit slot of a case for contacting an advancing photo film unit for the purpose of raising precision in spreading developing solution to a photosensitive layer by controlling distribution of the developing solution on the photosensitive layer. A commonly assigned patent application U.S. Ser. No. 09/258,258 (corresponding to Japanese Patent Application No. 10-53855) suggests a spreading control plate
10
, disposed in an optical instrument loadable with the instant photo film pack
4
, and arranged between the exit slot
2
b
of the case
2
and the spreader rollers
8
.
The spreading control plate
10
being disposed above the spreader rollers
8
, resistance against the passage of the one photo film unit
3
toward the spreader rollers
8
is increased in the course of contact of the one photo film unit with the spreading control plate
10
. There occurs rotational moment with which the one photo film unit
3
starts rotating inside the case
2
, because one bottom corner of the one photo film unit
3
is pushed by the claw member
7
. Frictional resistance received by the one photo film unit
3
from the inside of the case
2
increases. It is likely that, in
FIG. 13B
, the one photo film unit
3
becomes curved convexly into the exposure opening
2
a.
If the one photo film unit
3
continues being advanced in such a curved state, a portion of the one photo film unit
3
pushed by the claw member
7
is pressed against the inside of the case
2
. In
FIG. 14
, there occurs an undeveloped portion
3
b
of the one photo film unit
3
where developing solution fails to be spread.
The above problems are remarkable according to the horizontally extending shape of the photo film units
3
, resistance applied to by the one photo film unit
3
, and lowness in rigidity of photo film units. It is to be noted that the rigidity of the photo film units becomes low also when humidity changes.
SUMMARY OF THE INVENTION
In view of the foregoing problems, an object of the present invention is to provide an instant photo film pack and an instant camera in which developing solution of self-developing photo film units can be caused to spread adequately.
In order to achieve the above and other objects and advantages of this invention, an instant photo film pack is loadable in a camera, and includes a box-shaped pack and plural stacked self-developing photo film units of a mono-sheet type contained therein. The pack includes an upper wall having an exposure opening for providing the photo film units with an exposure, and a front wall having an exit slot for exiting the photo film units. The photo film units have a developing solution pod for containing developing solution along an advancing edge thereof. A bottom edge of each one of the photo film units is pushed by an ejecting mechanism after the exposure to advance the advancing edge through the exit slot. Each one photo film unit is contacted by a spreading control member while moved to a pair of spreader rollers. The developing solution pod is squeezed and torn upon passage between the spreader rollers to spread the developing solution in each one photo film unit. The instant photo film pack is characterized in that the bottom edge of each one photo film unit comes to the exposure opening later than the advancing edge comes in contact with the spreading control member upon pushing of each one photo film unit inside the pack, so that the bottom edge is prevented from being deformed in contact with the ejecting mechanism.
According to one aspect of the present invention, a combination of an instant photo film pack and an optical instrument usable therewith is provided. The instant photo film pack includes a case, having a substantially box shape, having a small thickness, and having first and second walls disposed opposite to each other, for containing a stack of plural self-developing photo film units of a mono-sheet type. An exposure opening is formed in the first wall, for providing one of the photo film units directly behind the first wall with an exposure. An exit slot is formed in an end wall of the case disposed between the first and second walls, for exiting the one photo film unit being exposed. The optical instrument includes a pack chamber loadable with the instant photo film pack. An exposure station is disposed in a front wall of the pack chamber, the instant photo film pack being set behind the exposure station, the exposure station causing recording light to become incident into the exposure opening. An advancing mechanism advances the one photo film units being exposed in an advancing direction out of the case, and spreads developing solution on the one photo film unit. A spreading control member frictionally pushes the one photo film unit while the one photo film unit moves to an outside of the exit slot, for controlling a spread state of the developing solution. The photo film units, the exposure opening and the spreading control member satisfy a condition of:
D≦F
where D is a moving amount of the one photo film unit moving from the initial position to a position where the advancing edge of the one photo film unit contacts the spreading control member; and
F is a distance between an inner edge of the exposure opening positioned in reverse to the advancing direction, and a bottom edge of the one photo film unit directly behind the exposure opening, the bottom edge being positioned in reverse to the advancing direction. Orientation of the bottom edge is stabilized while the one photo film unit directly behind the exposure opening is advanced in the advancing direction.
By this construction, the developing solution of the self-developing photo film units can be caused to spread adequately, because the edge of the one photo film unit positioned on a side upstream in the advancing direction is prevented from deformation.
In a preferred embodiment, the optical instrument is an instant camera, the exposure station has a light-shielding tunnel for introducing object light to the exposure opening.
The advancing mechanism includes a claw member, disposed in the pack chamb
Fuji Photo Film Co. , Ltd.
Rutledge D.
Sughrue Mion Zinn Macpeak & Seas, PLLC
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