Photography – Self-developing camera – Including means to treat superimposed material
Reexamination Certificate
2001-04-12
2002-06-18
Rutledge, D (Department: 2851)
Photography
Self-developing camera
Including means to treat superimposed material
C396S527000, C396S038000
Reexamination Certificate
active
06408134
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an instant photo film pack that has plural instant photo film units with processing fluid pods and a case body for containing the instant photo film units. More particularly, the present invention relates to an instant photo film pack for preventing rupture of the processing fluid pod by excessive deformation of the case body.
2. Background Arts
An instant camera for use with an instant photo film pack (hereinafter referred to as film pack) is well-known. Japanese Laid-Open Patent Application (JP-A) No. 2000-81688 discloses a film pack having a box-shaped case body and plural instant photo film units (hereinafter referred to as film units) contained in the case. As shown in
FIGS. 10 and 11
, the case body, comprised of a case body
11
and a rear cover
12
, contains a film cover
14
, a plurality of film units
15
, a first resilient plate
16
and a second resilient plate
17
. All elements for comprising the film pack are formed from plastic material having light-tightness. The film unit
15
includes a processing fluid pod
15
b
, an exposure area
15
a
and a trap portion
15
c
, which are provided along an advancing direction of the film unit
15
in this order listed. The processing fluid pod
15
b
contains processing fluid for developing a latent image, recorded in the exposure area
15
a
, into a positive image. A surplus of processing fluid is accepted in the trap portion
15
b
. The processing fluid pod
15
b
and the trap portion
15
c
have a thickness larger than that of the exposure area
15
a.
An exposure opening
18
is formed through a front wall
11
a
of the case body
11
, and an ejection slit
19
is formed through an upper wall
11
b
. The film cover
14
and plural film units
15
are stacked in a stacking direction, and contained in the case body
11
through a rear opening formed in the rear side of the case body
11
. The rear opening is covered with the rear cover
12
. The exposure opening
18
is covered with the film cover
14
, which is ejected out of the case body through the ejection slit
19
when the film pack is loaded in the instant camera. After ejection of the film cover
14
, the first and second resilient plates
16
and
17
press the film units
15
toward the front wall
11
a
, so the exposure area
15
a
of the uppermost film unit
15
appears through the exposure opening
18
. A subject image is exposed in the exposure area
15
a
through the exposure opening
18
, and then the film unit
15
is advanced out of the instant camera through the ejection slit
19
. In ejecting the film unit
15
, the processing fluid pod
15
b
is ruptured to spread processing fluid over the whole exposure area
15
a
, so the positive image is developed in a few minutes.
The ejection slit
19
has a long and narrow opening, and has a size such that the film cover
14
or the film unit
15
is able to pass therethrough. The ejection slit
19
is covered with a resilient light-shielding flap
20
in a light-tight manner. The light-shielding flap
20
is partially stuck to the outer surface of the upper wall
11
b
, and is partially peeled off to open the ejection slit
19
when the film unit
15
is fed in the advancing direction.
As shown in
FIG. 12
, the ejection slit
19
has a width larger than the thickness of the film unit
15
, so there is a possibility that two or more film units
15
are advanced through the ejection slit
19
simultaneously. In order to prevent this, JP-A No. 2000-89353 discloses a film pack having plural guide projections
22
on an inside of a front wall
11
a
behind the ejection slit
19
, as shown in
FIGS. 12 and 13
. The guide projections
22
are disposed at certain intervals in the crosswise direction. The guide projection
22
is high in the stacking direction enough so that a top surface thereof is visible through the ejection slit
19
. Thereby, the film pack
15
is advanced without being caught by a front slit edge
19
a
. Moreover, in order to ensure to guide the film unit
15
toward the ejection slit
19
, each of the guide projections
22
has a taper inclined toward the front wall
11
a.
For keeping strength, the front wall
11
a
is required to be formed as thick as possible. In that case, however, since the front case
11
is formed from plastic material by injection molding, the front wall can have molding sink marks. Thus, plural grooves
11
c
are formed in the front wall
11
a
for preventing molding sink marks. Between the adjacent grooves
11
c
, ribs
11
d
are formed.
However, the exposure opening
18
is larger than the front wall
11
a
, and the upper wall
11
b
has a long ejection slit
19
. Thus, the front wall
11
a
does not have strength enough to resist an external force. As shown in
FIG. 14
, when a strong external force in the stacking direction is applied to the front wall
11
a
, the front wall
11
a
is curved inward such that the front slit edge
19
a
of the ejection slit
19
comes in contact with an opposite rear slit edge
19
b
. With stronger force, the front wall
11
a
is deformed such that the front slit edge
19
a
is located below the rear slit edge
19
b
, as shown in
FIGS. 15 and 16
. In that case, the film unit
15
is pressed by the front wall
11
a
, so the length L of the stacked film units
15
along the stacking direction becomes small. Then, the processing fluid pod
15
b
can be ruptured to spread processing fluid over the exposure area of unexposed film unit
15
, which then becomes useless.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of the present invention is to provide an instant photo film pack for preventing rupture of a processing fluid pod in an instant photo film unit, even when an external force is applied to a case body.
To achieve the above objects, an instant photo film pack of the present invention includes an exposure opening formed in a front wall of the film pack, an ejection slit formed in an upper wall of the film pack, at least one engaging projection which is provided on the front slit edge of the ejection slit and extended in the advancing direction, and an engaged portion which is provided in the rear slit edge of the ejection slit. The engaging projection has a shape of a triangular prism, and is provided on the middle of the front slit edge. The engaged portion is provided in the middle of the rear slit edge. When the front wall is deformed to close the ejection slit, the engaging projection presses the engaging portion. The engaged portion is depressed to be engaged with the engaging projection. Thus, it is possible to prevent further deformation of the front wall, which causes rupture of the processing fluid pod in the film unit.
In order to prevent the film unit from being scratched by the engaging projection, the front slit edge has a depression in the center with reference to the crosswise direction of the film unit. A slope is formed in the upper wall, to project the engaged portion toward inside of the case body, and the outer corner of the engaged portion is tapered off. On inside of the front wall behind the ejection slit, plural guide projections for guiding the film unit toward the ejection slit are arranged at certain intervals. A gap is formed between the engaging projection and the guide projection provided behind the engaging projection. When the front wall is deformed excessively, the engaged portion is fit into the gap.
When the engaged portion is depressed by the engaging projection, burrs are formed in the engaged portion. In order to ensure smooth movement of the stack of film units in the stacking direction, a regulating projection for regulating positions of the film units is provided on an inside of the upper wall. Instead of providing the regulating projection, an inner comer of the engaged portion may be tapered off.
REFERENCES:
patent: 6183144 (2001-02-01), Mizuno et al.
patent: 6195508 (2001-02-01), Katayama et al.
patent: 2000-081688 (2000-03-01), None
patent: 2000-089353 (2000-03-01), None
Takahashi Tomoyuki
Takatori Tetsuya
Fuji Photo Film Co. , Ltd.
Rutledge D
Sughrue & Mion, PLLC
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