Cartridge sensing device

An apparatus for displaying the status of a film cartridge in a camera, the cartridge having a film exposure status indicator for identifying whether the cassette is fully unexposed, partially exposed, or fully exposed. The apparatus includes a blocking member which cooperates with the status indicator of the cartridge to prevent the loading of a fully exposed film cartridge, and a multiple state switching element which cooperates with the blocking member to sense the state of a loaded cartridge. An LCD provides user feedback as to the state of the camera depending on the state of the switching element.

CROSS-REFERENCE TO RELATED APPLICATION(S) 
Reference is made to commonly assigned applications Ser. No. 08/385219 
entitled: DOUBLE EXPOSURE PREVENTION APATUS, filed in the name of 
Robert L. Kuhn, Jr., and Ser. No. 08/386792, entitled: DOUBLE EXPOSURE 
PREVENTION APATUS FOR THRUST TYPE CARTRIDGES, filed in the names of J. 
David Cocca, Paul L. Taillie, and Beth A. O'Leary, each of which are 
assigned to the assignee of this application. 
FIELD OF THE INVENTION 
The invention relates generally to the field of photography, and in 
particular to cameras. More specifically, the invention relates to a 
device which provides user feedback for a camera using thrust type film 
cartridges. 
BACKGROUND OF THE INVENTION 
In thrust type 35 mm film manufacturers' cassettes, such as those 
manufactured by Eastman Kodak Co. and Fuji Film Photo Ltd., a leading 
portion of a film strip is thrust from the confines of a loaded film 
cassette onto a take-up spool rather than having to manually extract the 
protruding leading portion, as is common to other conventional 
non-thrusting film cassettes. This is particularly advantageous in that a 
protruding portion of the film is not required and that a user does not 
have to take the time to manually extend the leading portion of the film 
for cinching to a take-up spool prior to image capture. 
Another advantage realized using thrust type film cassettes is that a 
partially exposed film can be rewound into the cassette, and be extracted 
from the confines of the camera. The cassette can then be reloaded into a 
camera having a control system and associated logic for allowing the film 
strip to be thrust from the cassette and properly advanced to the next 
exposable frame prior to image capture. The features of rewinding a 
partially exposed film back into the cassette and for subsequent exposure 
of the previously unexposed film is referred to as mid-roll interrupt 
(MRI). 
In commonly assigned U.S. patent application 4,994,828, an apparatus is 
described for preventing a film cartridge having previously exposed film 
from being reloaded into a film loading chamber of a camera. A blocking 
member having an engageable end is spring biased into the loading chamber 
and cooperates with the film status indicator of a film cartridge to 
prevent the cartridge from being loaded in the film chamber if the 
cartridge contains exposed film. When the film cartridge, however, 
contains unexposed, or in the case of cameras having MRI logic, partially 
exposed film, the blocking member is pivoted out of the chamber and the 
cartridge can be loaded. 
In commonly assigned and concurrently filed U.S. application Ser. Nos. and 
08/385,291 and 08/386,792, a sensing member cooperates with the above 
described blocking member to prevent the double exposure of film contained 
in an unblocked film cassette and loaded in the film loading chamber. The 
sensing member senses the presence of a film cassette in the chamber and 
trips a resettable switch, which allows the unexposed film in the cassette 
to be loaded for exposure. The reloading of film is prevented, however, 
until the switch is reset and subsequently reopened. Though an efficient 
means for preventing double exposure is described by these references, 
particularly for thrusting type cartridges, there is no feedback provided 
to the user other than disablement of the camera, leading to possible 
confusion and dissatisfaction. 
There is a need for the user to understand the state of a camera, such as 
whether a cassette or cartridge and/or the film contained therein have 
been loaded, without recourse to opening the film loading chamber door, or 
first removing the film cartridge from the camera. 
SUMMARY OF THE INVENTION 
The present invention is directed to overcoming one or more of the problems 
set forth above. Briefly summarized, according to one aspect of the 
present invention, there is provided an apparatus for displaying the 
status of a film cartridge in a camera, the cartridge having a film 
exposure status indicator for identifying whether said cassette contains 
film which is fully unexposed, partially exposed, or fully exposed, said 
apparatus including a blocking member which cooperates with the status 
indicator of said cartridge to prevent the loading of a fully exposed film 
cartridge and allowing the loading of a fully unexposed film cartridge, 
characterized by: 
sensing means cooperating with the blocking member for sensing the state of 
a cartridge in the loading chamber; and 
display means cooperating with said sensing means for displaying status of 
the cartridge, depending on the state of said sensing means. 
According to another aspect of the invention, there is provided an 
apparatus for displaying the status of a film cartridge in a camera, said 
cartridge having a film exposure status indicator for identifying whether 
said cassette contains film which is fully unexposed, partially exposed, 
or fully exposed, said apparatus including a blocking member which 
cooperates with the status indicator of said cartridge to prevent the 
loading of a fully exposed film cartridge, is characterized by: 
a movable switching element which cooperates with the blocking member to 
move from a first position when no cartridge is present in said film 
loading chamber to a second position when a cartridge containing exposed 
film is blocked in said chamber, and to a third position when a cartridge 
is unblocked by said blocking member; and, 
a display device coupled to said switching element for displaying a 
visually perceivable indication as to the state of the camera loading 
chamber. 
An advantage provided by the present invention is that feedback as to the 
state of a camera, including a loaded thrust type film cartridge is 
readily available to a user having a camera according to the present 
invention. 
These and other aspects, objects, features and advantages of the present 
invention will be more clearly understood and appreciated from a review of 
the following Detailed Description of the Preferred Embodiments and 
appended Claims, and by reference to the accompanying Drawings.

DETAILED DESCRIPTION OF THE INVENTION 
The invention is disclosed as being embodied preferably in a still 
photographic camera. Because the features of this type of camera are 
generally well known, the description which follows is directed in 
particular to elements forming part of or cooperating directly with the 
disclosed embodiment. It is to be understood, however, that other elements 
not specifically shown or described may take various forms known to 
persons ordinarily skilled in the art. 
The Film Cassette 
Referring now to the drawings, FIG. 1 is an exploded perspective view of a 
film cassette 1 in accordance with a preferred embodiment of the 
invention. Generally, the film cassette 1 comprises a cassette shell 3, 
FIG. 2, constructed of carbon-black plastic material and made up of two 
mating shell halves 5 and 7, a similarly constructed light shielding door 
9 closed to prevent ambient light from entering the cassette interior 
through a film ingress/egress slot located between the two shell halves 
and opened to permit film movement into and out of the cassette interior 
via the film ingress/egress slot, a film spool 11, FIG. 2, supported for 
rotation inside the cassette shell in opposite film unwinding and winding 
directions to unwind a filmstrip 13 off a spool core 15 and to wind the 
filmstrip 13 onto the spool core, a spool lock 17 for engaging the spool 
core to prevent rotation of the film spool and out of engagement to 
release the film spool, and a cassette covering label 19. 
The spool core 15, as shown in FIGS. 1 and 5, has a toothed periphery 
consisting of successive symmetrical teeth 21 separated by interdental 
spaces 23, and the spool core also supports a pair of coaxial flanged 
disks 25 and 27 between which the filmstrip is stored in roll form. A 
trailing or inner end 29 of the filmstrip 13 is attached to the spool core 
15. 
The light shielding door 9, as shown in FIGS. 2-4 includes integral cam 
means 31 for pivoting the spool lock 17 in a locking position as the door 
is closed. When the spool lock 17 is in its locked position, not shown, an 
integral detent 33 of the spool lock is located in anyone of the 
interdental spaces between two adjacent teeth 21 of the spool core 15 in 
anyone of a number of rotational orientations equal to the number of 
interdental spaces. If the light-shielding door 9 is opened as shown in 
FIG. 3, its cam means 31 is retracted from the spool lock 17. As a result, 
forcible rotation of the film spool 11 in the film winding or unwinding 
direction will cause one of the two adjacent teeth 21 between which the 
detent 33 is located to eject the detent from the interdental space 23 
separating those two teeth. Thus, the spool lock 17 will be pivoted out of 
its locking position. 
The Film Exposure-Status Indicating Means Of The Film Cassette 
The shell half 5 at one of its ends has four icons in the form of 
respective cutouts 35, 37, 39, and 41 shown in FIG. 2. The cutout 35 is 
designed to effect an indication that the filmstrip 13 is fresh or 
unexposed. The cutout 37 is designed to effect an indication that the 
filmstrip 13 is partly exposed (and partly unexposed). The cutout 39 is 
designed to effect an indication that the filmstrip 13 is fully exposed. 
The cutout 41 is designed to effect an indication that the filmstrip 13 
has been processed in a film processing machine to develop the latent 
images on the exposed film. 
An indicator flag 43 is coaxially fixed to the spool core 15 at the 
remaining end of the spool opposite to the indicating status end of the 
cassette, as shown in FIGS. 1 and 5, to be rotated with the film spool 11 
in the film unwinding and film winding directions. Initially, the flag 43 
is secured with the film spool 11 in a rotational orientation that locates 
the flag immediately beneath the cutout 35 as shown in FIG. 3, to provide 
an indication that the filmstrip is fresh or unexposed. Conversely, when 
the flag 43 is secured with the film spool 11 in a rotational orientation 
that locates the flag immediately beneath the cut-out 37, it is visible to 
provide an indication that the filmstrip 13 is partly exposed (and partly 
unexposed). When the flag 43 is secured with the film spool 11 in a 
rotational orientation that locates the flag immediately beneath the 
cut-out 39, it is visible to provide an indication that the filmstrip is 
fully exposed. When the flag 43 is secured with the film spool 11 in a 
rotational orientation that locates the flag immediately beneath the 
cut-out 41, it is visible to provide an indication that the filmstrip 13 
has been processed. 
The film spool 11, as shown in FIGS. 1,3, 5 and 6 includes a plastic disk 
42 having a semi-circular configuration; that is, "c" shaped, including a 
central opening 28, and a pair of extreme ends 30 and 32. The spool core 
15 longitudinally extends through the central opening 28 of the disk 42 
and has a peripheral groove 34 in which the disk is seated to secure the 
disk and the spool core coaxially together. A registration stop 36 is 
fixed to the spool core 15 adjacent the peripheral groove 34, and has a 
pair of stop ends arranged to abut the extreme ends 30 and 32 of the disk 
to critically orient the disk 42 with respect to a key slot 38 of the 
spool core. 
A window 40 is provided in the shell half 7, FIG. 1. The window 40 is 
intended to provide status indication of the film 13 contained in the 
cassette 1 in cooperation with the disk 42, the spool core 11 and the 
indicator flag 43. When the disk 42 covers the entirety of the window 40, 
FIG. 3, the film contained within the cassette 1 is wholly unexposed. When 
a portion (approximately one half) of the window 40 is coveredby the disk 
42, there is partly exposed film contained in the cassette, corresponding 
to the indicator flag 43 being present in the cutout 37 at the other end 
of the cassette. Finally, when all of the film in the cassette is exposed, 
the disk 42 is not visible in the window 40. Additional details regarding 
the described cassette are found in commonly assigned U.S. Pat. No. 
5,296,887, issued to Zander, which is hereby incorporated by reference. 
DOUBLE EXPOSURE PREVENTION MEANS 
Referring now to FIGS. 7-9, a first embodiment is described which pertains 
to a double exposure prevention apparatus in accordance with the present 
invention. 
Referring specifically to FIG. 7, a film cassette 1 such as described above 
can be loaded endwise into a camera body 44 having a film loading chamber 
45, sized for receiving the film cassette and defined by an entry opening 
47. The chamber 45 includes a sidewall 51 having an aperture or slot 49 
through which protrudes a hook-shaped end 53 of a blocking member 55 which 
is pivotable about a support pin 59. The aperture 49 is preferably aligned 
with the window 40 of the status indicator end of a loaded cassette 1, so 
that the biased hook-shaped end 53 will engage the plastic disk 42 of a 
cassette containing fully unexposed film when the disk is present. 
According to this embodiment, a switch element 63, preferably made from a 
spring-like material, is mounted at one end to the camera body 44 adjacent 
to the support pin 59, and includes a protruding portion 64 which is 
biased in contact with a back surface 54 of the blocking member 55. A 
helical compression spring 57 normally biases the protruding portion 64 
into the back surface of the blocking member 55 and the hook-shaped end 53 
into the confines of the chamber 45. 
The switch element 63 extends across the aperture 49, and is also biased at 
its remaining end by the helical spring 57 into contact with a contact 
portion 62 of a first contact surface 65, mounted to the exterior of the 
sidewall 51. A contact portion 61 of a parallel second contact surface 66 
is also provided and is spaced from the first contact surface 65. 
The switch portion 63 and the first and second contact surfaces 65, 66 each 
provide electrical inputs to an interconnected controller 69, such as a 
microprocessor having logic for enabling a display device 71, FIG. 6. The 
display device 71 can be an icon, a light emitting device, such as a lamp, 
or in the case of the present embodiment an LCD array element capable of 
printing a plurality of messages, depending on the state of the apparatus. 
The display device 71 is only shown schematically according to FIGS. 7-9, 
though it can be disposed conveniently, such as on the exterior of the 
camera body 44, in a manner commonly known. 
The operation of the invention can now be described by FIGS. 7-9. Referring 
again specifically to FIG. 7, the film loading chamber 45 is shown in 
section prior to the loading of a film cassette 1. When no film cassette 1 
is present in the chamber 45, the blocking member 55 is fully biased into 
the interior of the chamber 45 through the sidewall aperture 49 by the 
spring forces supplied by switch element 63 and spring 57. The switch 
portion 63 is also normally biased in a first position into contact with 
the first contact surface 65, forming a closed electrical switch 
connection, sensed by the controller 69. 
Alternately, the switch element 63 can be used as a spring for 
simultaneously biasing the blocking member 55 and the switch element 63, 
eliminating the need for spring 57. Details relating to this particular 
arrangement are described in commonly assigned and concurrently filed U.S. 
patent application Ser. No. 08/385,291 filed by Robert L. Kuhn, Jr., which 
is incorporated by reference herein. 
According to the present embodiment, when the camera is powered, such as by 
a battery (not shown) or other power supply, the controller 69 is 
programmed to send a signal to the display device 71, in this case the 
LCD, conveniently positioned on the camera body 44, to display a message 
which is viewable to the user. Preferably, the controller 69 is programmed 
to enable the display device 71 after the film loading chamber door (not 
shown) covering the entry opening 47 is closed. A message such as "CHAMBER 
EMPTY" or "NO CARTRIDGE PRESENT", can then be displayed by the display 
device 71. 
Alternatively, any other graphic or icon-like characters can be displayed 
which are representative of this first state of the apparatus; for 
example, a light emitting element (not shown) can be substituted for the 
LCD in which a single light signal could be generated to indicate that the 
chamber is empty. 
FIG. 8 illustrates the sectional view of the above apparatus when a film 
cassette 1 has been loaded endwise, status indicator side first, an 
intermediate distance into the loading chamber 45. 
Prior to interfacing with the hook-shaped end 53 of the blocking member 55, 
the cassette 1 first engages an extending guide portion 67, see FIGS. 7 
and 8. This engagement slightly urges the blocking member 55, in a 
clockwise direction about the support pin 59, towards the exterior of the 
chamber 45. Preferably, the guide portion 67 is tapered in order to 
prevent the cassette 1 from binding prior to engagement with the 
hook-shaped end 53. The slight movement of the blocking member 55 allows 
the hook-shaped end 53 to be better aligned with the window 40, FIG. 3, of 
the loaded film cassette 1. 
In addition, the slight pivoting movement of the blocking member 55 due to 
the contact with the guide portion 67 is also preferably sufficient to 
overcome the biasing of the switch element 63. As seen, from the FIG., the 
switch element 63 is forced out of contact with the contact portion 62 of 
the first contact surface 65, causing an opening of the electrical 
connection between the switch and the contact portion 62, sensed by the 
controller 69. The controller 69 is programmed to transmit an input signal 
to the display device 71 which removes the first displayed message and 
while also initiating a timer circuit (not shown), described below. 
Still referring to FIG. 8, as the film cassette 1 continues to move endwise 
into the chamber, the hook-shaped end 53 of the blocking member 55 engages 
the status indicator end of the film cassette 1, which is shown only 
diagrammatically in the FIG. According to this embodiment, if the film 
contained within the cassette 1 has been previously exposed, either wholly 
or in part, then the blocking member 55 will not allow the film cassette 1 
to descend further into the chamber 45. The cassette 1 is effectively 
blocked in that the plastic disk 42, FIG. 3, is not present in the window 
40; therefore, the hook-shaped end 53 will pass unimpeded into the window 
40, sized for receiving the hook-shaped end, and will bind against the 
interior of the cassette shell. If, however, the film cassette 1 contains 
fresh or previously unexposed film, then the plastic disk 42, FIG. 3, will 
be present in the window 40 and will contact the hook-shaped end 53 of the 
blocking member 55. The contact between the plastic disk 42 and the 
hook-shaped end 53 is adequate to overcome the biasing force supplied by 
the spring 57, and the cassette urges the blocking member 55 out of the 
chamber 45 by pivoting about the support pin 59. The unblocked cassette 1 
can then be successfully loaded into the chamber 45. Additional details 
relating to the operation of the blocking member 55 relative to an 
exposed, fully exposed, or partially exposed film cassette 1 can be found 
in commonly assigned U.S. Pat. Nos. 4,994,828, 5,032,861 and U.S. Pat. No. 
5,049,913, the contents of which are hereby incorporated by reference. 
As noted above, the slight movement of the blocking member 55 is sufficient 
to break the contact of the switch element 63 with the first contact 
surface 65. This occurs whether the cassette 1 has exposed, partly 
exposed, or unexposed film contained therein. The breaking of the 
electrical connection between the cartridge presence sensor switch 63 and 
the contact surface 65 is sensed by the controller 69. In response, the 
controller 69 is programmed to send a signal to the display device 71 in 
order to provide a second message for viewing by the user. This second 
message may include such information as "NO INSERTION ALLOWED" or 
"PREVIOUSLY EXPOSED CARTRIDGE PRESENT" or a similar message, although any 
graphic or icon characters representative of the state of the camera and 
the cassette 1 can be used. Alternatively, a light emitting element (not 
shown) may be substituted as a display device for the LCD. 
As noted above, the controller 69 preferably includes a timing circuit 
which prevents the display of the second message by the display device 71 
until a predetermined period of time (e.g. 2-3 seconds) has elapsed. The 
timing circuit is provided to insure that the second message be displayed 
only if a cassette is blocked by the blocking member to avoid confusion to 
a user. 
Referring now to FIG. 9, a portion of an unblocked film cassette 1, 
containing an unexposed film, has descended vertically below the aperture 
49 into the loading chamber 45, causing the blocking member 55 to overcome 
the spring force supplied by the spring 57 and be fully urged out of the 
chamber. The length of travel of the blocking member 55 is sufficient to 
enable the rear surface 54 of the blocking member 55 to push the switch 
element 63 into biased contact with the contact portion 61 of the second 
contact surface 66, forming a second electrical connection sensed by the 
controller 69. The logic within the controller 69 provides another signal 
to the display device 71 for indicating a third message, representative of 
the state of the apparatus for viewing by the user. The third message may 
include such information as "INSERTION ALLOWED" or "CARTRIDGE LOADED", or 
may include alternatively, any graphic or icon characters which are 
representative. 
The film contained within the cassette 1 is now ready to be loaded into the 
camera. Preferably, the controller 69 senses the closing of the film 
chamber door (not shown), and the closed electrical connection between the 
switch element 63 and the second contact surface 66, indicating that a 
film cassette containing exposable film is present in the loading chamber. 
If both conditions are present, then the controller 69 enables the film to 
be loaded from the cassette. Reloading of film from the cassette 1 is 
prevented by the controller 69 until the switch member 63 has been reset 
into contact with the first contact surface 65 and subsequently forced by 
the blocking member 55 into contact with the second contact surface 66. 
This particular apparatus is described in the commonly assigned U.S. 
patent application Ser. Nos. 08/385,291 and 08/386792 entitled: DOUBLE 
EXPOSURE PREVENTION MEANS FOR CAMERAS USING THRUST TYPE CARTRIDGES, filed 
concurrently herewith and which are incorporated by reference. 
ALTERNATE EMBODIMENT OF A MULTIPLE STATE CARTRIDGE SENSING DEVICE 
Referring now to FIGS. 10(a)-10(c), an alternate embodiment of the present 
invention is herein described. Similar parts are labeled using the same 
reference numerals used in the preceding embodiment for clarity. 
A camera body 44 includes a loading chamber 45 having an entry opening 47 
for receiving a film cassette 1, in an endwise manner as previously 
described. The hook-shaped end 103 of a blocking member 101 is biased, 
FIG. 10(a), into the cavity of the chamber 45 which is pivotally mounted 
to the camera body 44 by means of a support pin 105. 
One end of a switch member 109 is mounted to the exterior of the sidewall 
51 of the chamber 45 adjacent the bottom of the chamber cavity and is 
sandwiched between a pair of contact surfaces 111 and 113, all being 
attached at one end to the exterior sidewall 51 of the chamber 45. 
According to this embodiment, the contact surfaces 111, 113 are separated 
by insulated spacers 117, 119, all attached to the sidewall 51 by a 
mounting screw 115. 
The remaining end of the switch member 109 is mounted to the rear of the 
blocking member 101 at a support 107 and biases the hook-shaped end 103 of 
the blocking member 101 into the chamber 45, as well as into contact with 
the first contact surface 111 in a normal position. Each of the contact 
surfaces 111, 113, as well as the switch member 109, are electrically 
attached to a controller 69 which is powered by a power supply (not 
shown). such as a battery. In the normal position, the switch element 109 
is biased into contact with the first contact surface 111, creating a 
first electrical connection which is sensed by the controller 69. The 
controller 69 is also attached to a display device 71, such as an LCD or 
other similar device, which is preferably visible on the exterior of the 
camera body. The connection between the switch member 109 and the first 
contact surface 111 is sensed by the controller 69 which in response sends 
an output signal activating the display device 71, and creating a first 
user message. In this case, a message such as "CARTRIDGE CHAMBER EMPTY", 
"LOAD CAMERA" or other suitable message representative of the first state 
of the apparatus is suitable. 
As a film cassette 1 is lowered into the chamber 45 through opening 47, 
FIG. 10(b), the bottom and side walls of the cassette shell contact the 
interior surface 106 causing the blocking member 101 to be urged slightly 
out of the chamber 45, though the blocking member is still biased by the 
switch member 109, which is supported by screw 115. The movement of the 
blocking member 101 due to the presence of the film cassette 1, however, 
is sufficient to cause the switch member 109 to be displaced out of 
contact with the first contact surface 111 due to the connection of the 
switch member at support 107. The breaking of the electrical connection 
between the switch element 109 and the contact surface 111 is sensed by 
the controller 69 which is programmed to cancel the display of the first 
message by the display device and start a timing circuit within the 
controller 69, as is described below. 
As the cassette 1 passes the aperture 49, FIG. 10(c), the hook-shaped end 
103 is urged fully out of the chamber 45. The movement of the blocking 
member 101 overcomes the spring force supplied by the switch member 109, 
causing the switch member to deflect until contact is made with the second 
contact surface 113. The contact between surface 113 and the switch member 
109 creates a second electrical connection which is sensed by the 
controller 69 which is programmed to send a signal to the display device 
71 to display a second message. In this case, a message such as "CARTRIDGE 
LOADED" OR "LOAD FILM" or any other message representative of this state 
of the camera can be displayed by the LCD. If the cassette 1 contains 
partly or fully exposed film then the hook-shaped end 53 will remain 
engaged with an aligned window 40, FIG. 2, of the cassette 1. The timing 
circuit of the controller 69 which is activated after the switch element 
109 is displaced from the first contact surface 107, thereafter causes the 
display of a separate message by the LCD 71 if contact between surface 113 
and switch portion 109 is not made within 2-3 seconds, or other reasonable 
period of time. This message can state "NO INSERTION PERMITTED" or 
"EXPOSED CARTRIDGE IN CHAMBER" or other message representative of the 
state of the apparatus. 
The logic of the controller 69 automatically causes the film contained 
within the cassette to be loaded within the camera after the film door 
(not shown) is closed and the load film flag has been set, due to the 
opening of the switch 63. 
In addition, after a film cassette 1 has loaded the film by thrusting the 
film leader (not shown) across the exposure gate (not shown) of the 
camera, the controller 69 can clear the film load flag which was set by 
the breaking of contact between the switch member 109 and the contact 
surface 111. At this stage, the film loading means (not shown) of the 
camera can not be reactivated until the switch member 109 has been 
reclosed and subsequently reopened, by a loaded film cassette. The 
controller 69 can be programmed to send a signal to the display device 71 
to send a fourth message after the film has been exposed and rewound in 
the film cassette 1. A message such as "UNLOAD CARTRIDGE" or "FILM 
EXPOSED", or any other message representative of the state of the camera 
is suitable. 
The invention has been described with reference to a preferred embodiment. 
However, it will be appreciated that variations and modifications can be 
effected by a person of ordinary skill in the art without departing from 
the scope of the invention. 
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TS LIST FOR FIGS. 1-10(c) 
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1 film cassette 
3 cassette shell 
5 shell half 
7 shell half 
9 light shielding door 
11 film spool 
13 filmstrip 
15 spool core 
17 spool lock 
19 covering label 
21 spool teeth 
23 interdental spaces 
25 spool disk 
27 spool disk 
28 central opening 
29 trailing film end 
30 extreme end 
31 camming means 
32 extreme end 
33 detent 
34 peripheral groove 
35 cutout 
36 registration stop 
37 cutout 
38 key slot 
39 cutout 
40 window 
41 cutout 
42 plastic disk 
43 indicator flag 
44 camera body 
45 loading chamber 
47 entry opening 
49 slot 
51 sidewall 
53 hook-shaped end 
54 rear surface 
55 blocking member 
59 support pin 
61 contact portion 
62 contact portion 
63 switch element 
64 mounting plate 
65 first contact surface 
66 second contact surface 
67 protruding portion 
69 controller 
71 display device 
101 blocking member 
103 hook-shaped end 
105 contour 
106 interior surface 
107 support 
109 switch member 
111 first contact surface 
113 second contact surface 
115 screw 
117 insulated spacer 
119 insulated spacer 
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