Method and apparatus for inspecting lens-fitted photo film unit

A lens-fitted photo film unit is pre-loaded with unexposed photo film, and includes a taking lens. A shutter device is disposed between the taking lens and the photo film, and cocked in response to a winding operation of the photo film. The shutter device has a shutter blade for opening/closing a photographic light path in response to an external releasing operation. A flash device has a flash emitter window, and emits flash light in response to operation of the shutter device. Before inspection of the lens-fitted photo film unit, a front of the flash emitter window or a periphery of a front of the light path is covered by use of a light-shielding member. The light-shielding member avoids entry of flash light emitted from the flash emitter window into the light path. The flash device is charged. The shutter mechanism is cocked. The shutter mechanism is released while the light-shielding member covers the front. An operation of opening/closing of the shutter mechanism is inspected in response to the releasing operation. An operation of flash emission of the flash device is inspected.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a method and an apparatus for inspecting a 
lens-fitted photo film unit. More particularly, the present invention 
relates to a method and an apparatus for inspecting a lens-fitted photo 
film unit incorporating an electronic flash device. 
2. Description Related to the Prior Art 
There is a lens-fitted photo film unit pre-loaded with photo film and 
incorporating a simple structure for taking exposures. In the lens-fitted 
photo film unit, the photo film is wound each time after one frame is 
exposed. The movement of the photo film in the winding operation is 
utilized for cocking a shutter mechanism, a one-frame advancement of the 
photo film and a rotation of a counter wheel by one step. The lens-fitted 
photo film unit incorporates an electronic flash device which emanates 
flash light in response to a releasing operation of the shutter mechanism, 
so that a photograph can be taken easily even indoors or at night. 
The prevalent types of the lens-fitted photo film unit are pre-loaded with 
a photo film cassette of the 135 type. Also there is a type of lens-fitted 
photo film unit pre-loaded with the photo film cassette of the IX240 type. 
In the photo film cassette of the IX240 type, the photo film has a train 
of perforations arranged therein. The photo film cassette includes a 
plastic cassette shell for containing a roll of the photo film. 
The photo film includes an effective exposure region and ineffective 
regions defined different from the effective exposure region. The 
effective exposure region is adapted to taking exposures in the 
lens-fitted photo film unit or a camera. The ineffective regions are 
determined as areas where exposures are inhibited. The perforations are 
arranged along an edge only of the effective exposure region of the photo 
film. The perforations are alternately arranged with two intervals being 
longer and shorter which are alternately repeated. One frame is exposed 
inside each of sections having the longer interval. Sections having the 
shorter interval are associated with intervals between the adjacent 
frames. The photo film for the photo film cassette does not have extra 
frames, but has the number of available frames determined for the photo 
film. The ineffective regions are used for development, and wound back 
into the cassette shell. 
In a manufacturing process of the lens-fitted photo film unit, performance 
of the shutter mechanism is inspected after loading of the photo film 
together with inspection of winding the photo film. For example, a shutter 
speed of the shutter mechanism is measured and evaluated for the 
inspection of the shutter mechanism. 
For the lens-fitted photo film unit with the flash device, it is 
conventionally general to inspect the shutter mechanism in a manner 
separate from inspection of the flash device. This is because a photo 
sensor of a reflection type for detecting movement of a shutter blade 
should be prevented from being affected by flash light of the flash 
device, and also because the ineffective region should be kept from being 
exposed by the flash light. However the inspecting manner of the shutter 
mechanism separate from the inspection of the flash device takes long 
time, is conspicuously slow in the manufacturing process, and is 
inconsistent to improvement of efficiency. 
SUMMARY OF THE INVENTION 
In view of the foregoing problems, an object of the present invention is to 
provide a method and an apparatus for inspecting a lens-fitted photo film 
unit, with efficiency heightened by simultaneously inspecting the shutter 
mechanism and the flash device. 
In order to achieve the above and other objects and advantages of this 
invention, a front of a flash emitter window or a periphery of a front of 
a photograph-taking light path is covered by use of a light-shielding 
member, the light-shielding member being adapted to avoiding entry of 
flash light emitted from the flash emitter window into the light path. The 
flash device is charged. The shutter mechanism is cocked. The shutter 
mechanism is released while the light-shielding member covers the front. 
An operation of opening/closing of the shutter mechanism is inspected in 
response to the releasing operation. An operation of flash emission of the 
flash device is inspected. 
In a preferred embodiment, the step of inspecting the shutter device 
includes steps of detecting existence of the shutter blade in the light 
path by use of a blade sensor through the taking lens, the blade sensor 
being shielded from the flash light by the light-shielding member. 
Acceptability of the opening/closing operation of the shutter device is 
evaluated in accordance with a signal from the blade sensor. 
The step of inspecting the flash device includes a step of evaluating 
acceptability of the flash emission operation of the flash device in 
accordance with the signal from the blade sensor and a signal from the 
flash light sensor. 
A shutter-open time is measured in response to the signal from the blade 
sensor, the shutter-open time being defined to begin upon retraction of 
the shutter blade from the light path and to end upon return of the 
shutter blade into the light path. The shutter-open time is evaluated with 
reference to a first predetermined range, and if the shutter-open time is 
detected within the first predetermined range, the shutter device being 
regarded as acceptable. 
An elapsed time is measured in response to the signal from the blade sensor 
and the signal from the flash light sensor, the elapsed time being defined 
to begin upon the retraction of the shutter blade from the light path and 
to end upon the flash emission of the flash device. The elapsed time is 
evaluated with reference to a second predetermined range, and if the 
elapsed time is detected within the second predetermined range, the flash 
device being regarded as acceptable. 
In accordance with the present invention, the shutter mechanism and the 
flash device can be simultaneously inspecting so that efficiency in 
manufacturing the lens-fitted photo film unit is heightened.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION 
In FIG. 1, a lens-fitted photo film unit 2 is constituted by a photo film 
housing 3 and an outer sheet member 4 of cardboard partially covering the 
housing 3. The housing 3 is pre-loaded with a photo film cassette, and 
includes structures for taking exposures. 
A top of the housing 3 has a shutter release button 6 and a counter window 
7. A front of the housing 3 has a viewfinder 8, a taking lens 9, a flash 
charge button 10 and a flash emitting window 11. There is a photo film 
winder wheel 12, which appears in a rear of the housing 3 in an operable 
manner for rotation each time after taking an exposure. A back surface of 
the outer sheet member 4 is coated with adhesive agent, to attach the 
outer sheet member 4 to cover the center of the housing 3 and portions 
about the shutter release button 6. The outer sheet member 4 has openings 
in which there appears the center of the shutter release button 6, the 
taking lens 9, the viewfinder 8, the counter window 7 and the like. 
In FIG. 2, the housing 3 is constituted by a photo film containing unit 15 
or main body, an exposure unit 16, an electronic flash device 17, a front 
cover 18, and a rear cover 19. The photo film containing unit 15 is loaded 
with a photo film cassette 14. The exposure unit 16 and the flash device 
17 are secured to the front of the photo film containing unit 15. The 
front cover 18 covers the front of the photo film containing unit 15. The 
rear cover 19 covers the rear of the photo film containing unit 15. All 
those are assembled and secured by use of engagement of hooks. 
The photo film cassette 14 is constituted by a cassette shell 21 and a 
photo film 22 contained in the cassette shell 22. The cassette shell 21 is 
formed from resin. A spool 23 is contained in the cassette shell 21 in a 
rotatable manner. A trailer of the photo film 22 is retained on the spool 
23. Also the cassette shell 21 incorporates a mechanism for advancing a 
leader of the photo film 22 externally upon rotation of the spool 23. A 
cassette shutter rod 25 is contained in a photo film passageway (not 
shown) through which the photo film 22 is passed into and out of the 
cassette shell 21. The cassette shutter rod 25 is externally rotated to 
open/close the photo film passageway. 
In FIG. 3, the photo film 22 includes a leader 22a, an effective region 22b 
and a trailer 22c. In the effective region 22b, there are perforations 27 
and 28 arranged along one lateral edge of the photo film 22. The great 
perforations 27 are relatively great. The small perforations 28 are 
smaller. The perforations 27 and 28 are arranged regularly in an alternate 
manner and at two intervals repeated alternately. Each of frames 29 is 
formed in a range of which beginning and ending positions are defined by 
one of the great perforations 27 and one of the small perforations 28. In 
the lens-fitted photo film unit 2, the photo film 22 is wound into the 
cassette shell 21 each time of taking an exposure. Consequently the 
beginning position of the one of the frames 29 is defined by one of the 
great perforations 27 as viewed in a direction of moving the photo film 
22. The ending position of the one of the frames 29 is defined by one of 
the small perforations 28. The number of pairs of the perforations 27 and 
28 is set equal to the number of the frames 29. 
An end of the trailer 22c is retained on the spool 23. An axial end of the 
spool 23 is engaged with the winder wheel 12. When the winder wheel 12 is 
operated to rotate the spool 23, the photo film 22 is wound about the 
spool 23. The leader 22a and the trailer 22c are regions unavailable for 
exposures, but will be utilized in a developing step. All the photo film 
22 including the leader 22a and the trailer 22c are pre-wound into the 
cassette shell 21 when unexposed. 
The photo film 22 is shaped by additionally working photo film adapted for 
use in an ordinary camera. The photo film 22 is distinct from the photo 
film for ordinary cameras for the reasons of the size of the great 
perforations 27 and existence of a small perforation 28a for initial 
cocking. The small perforation 28a is added in a range of the trailer 22c. 
In the photo film for ordinary cameras, there are one-size perforations 
including the small perforations 28 and such as would be defined by 
shortening the great perforations 27. The same photo film has no 
perforation 28a along the edge of the trailer 22c. 
In the center of the photo film containing unit 15, a light-shielding 
tunnel 31 is formed. The light-shielding tunnel 31 operates to cover a 
photographic light path between the exposure unit 16 and the photo film 
22. In the rear of the light-shielding tunnel 31 is formed an exposure 
aperture, which defines an exposure region to the photo film 22. Film 
rails 34 in FIG. 5 contact edges of the photo film 22 to guide it. In the 
front of the light-shielding tunnel 31, an opening 32 is formed to 
introduce a photographic object light from the taking lens 9 to the 
exposure aperture. In an upper position of the light-shielding tunnel 31, 
a wheel slot 33 is formed for causing a sprocket wheel in the exposure 
unit 16 to lie in contact with the photo film 22. 
There are a cassette containing chamber 35 and a roll containing chamber 36 
between which the light-shielding tunnel 31 lies. The cassette containing 
chamber 35 pre-contains the cassette shell 21. The roll containing chamber 
36 pre-contains a photo film roll 35 in which the photo film 22 is wound. 
On the top of the cassette containing chamber 35, the winder wheel 12 is 
mounted in a rotatable manner. A drive shaft is formed on a bottom of the 
winder wheel 12, and is engaged with the spool 23 of the cassette shell 
21. After each one exposure is taken, the winder wheel 12 is rotated in a 
counterclockwise direction in the drawing, to cause the spool 23 to wind 
the photo film 22, so that the photo film 22 is contained into the 
cassette shell 21. 
In FIG. 4, the exposure unit 16 in relation to the present invention 
includes a base portion 38, which is a resinous part and to which various 
parts are secured by way of a single unit. The exposure unit 16 is secured 
to the front of the light-shielding tunnel 31 in a detachable manner. 
Those parts include a shutter mechanism, a one-frame advance mechanism, a 
frame counter mechanism and the like. An objective lens 39a and an 
eyepiece lens 39b, combined as a finder lens, are supported on the top of 
the base portion 38 to constitute the viewfinder 8. 
In FIG. 5, a lens cover 40 is secured to the front of the base portion 38, 
and retains the taking lens 9. A shutter opening 95 is formed in the front 
of the base portion 38 for passing the object light. A shutter blade 96 is 
disposed at the shutter opening 95 in a swingable manner between the base 
portion 38 and the lens cover 40 to open/close the shutter opening 95. A 
return spring 97 biases the shutter blade 96 in a direction of closing the 
shutter opening 95. 
On the top of the base portion 38, there are formed shafts 43 and 44 and a 
receiving portion 45. A shutter drive lever 46 of the shutter mechanism, a 
first coil spring 47 and a frame counter wheel 48 are axially supported on 
the shaft 43, in the order listed. A second coil spring 49 and a retainer 
lever 50 are axially supported on the shaft 44 in this order. A cam member 
51 or rotating member is inserted in the receiving portion 45. All those 
parts in combination constitute the exposure unit 16 with the second coil 
spring 49, the retainer lever 50, the cam member 51, a sprocket wheel 54 
and the shutter blade 96. 
The receiving portion 45 consists of a through hole communicating 
downwards. A bottom end of a shaft 53 of the rotating member 51 protrudes 
from a bottom end of the receiving portion 45. The bottom end of the shaft 
53 is engaged with the sprocket wheel 54, which is supported to appear 
through the wheel slot 33 at the top of the light-shielding tunnel 31 
toward the photo film 22. The sprocket wheel 54 is constituted by a wheel 
portion and two pairs of teeth 54a and 54b protruded therefrom. The small 
teeth 54b are relatively small. The great teeth 54a are greater. A 
combination of one of the great teeth 54a and one of the small teeth 54b 
is positioned in a rotationally symmetrical manner from a combination of 
the other of the great teeth 54a and the other of the small teeth 54b. 
Each of the small teeth 54b is meshed with the one of the small 
perforations 28. Each of the great teeth 54a is meshed with the one of the 
great perforations 27. The sprocket wheel 54 is caused to make half a 
rotation in the counterclockwise direction by movement of the photo film 
22 toward the cassette shell 21 by one frame. 
The cam member 51 is one piece including a two-toothed gear 56, a wind 
block cam 57, a cocking cam 58, a bias cam 59 and the shaft 53, which are 
arranged downwards in the order listed. The two-toothed gear 56 is meshed 
with teeth 48a about the frame counter wheel 48. A top face of the frame 
counter wheel 48 has a scale with a series of numbers to indicate the 
number of available unexposed frames. The two-toothed gear 56 rotates the 
frame counter wheel 48 by one step when the two-toothed gear 56 makes half 
a rotation. A pair of notches 57a are formed in the periphery of the wind 
block cam 57 to open in opposite directions. When the wind block cam 57 
makes half a rotation, the retainer lever 50 becomes engaged with the 
notch 57a. The cocking cam 58 consists of a pair of wing-shaped 
projections directed in opposite directions, and when rotated, pushes the 
shutter drive lever 46 to cock the shutter mechanism. 
The bias cam 59 consists of a pair of projections extending symmetrically 
in opposite directions, and pushed by a spring 61 mounted on the top of 
the base portion 38. As the perforations in the photo film 22 are not 
consecutive one after another, there occurs a phenomenon in which neither 
of the sprocket teeth 54a and 54b is meshed with the perforations 27 and 
28. But the bias cam 59 is pushed by the spring 61 to rotate the sprocket 
wheel 54 up to a position where one of the small sprocket teeth 54b is 
engageable with one of the small perforations 28. The spring 61 consists 
of a flexed thin metal plate. 
The shutter drive lever 46 is rotatable between a cocked position disposed 
in a clockwise direction and a released position disposed in a 
counterclockwise direction. The first coil spring 47 biases the shutter 
drive lever 46 toward the released position. The shutter drive lever 46 is 
one piece including a push receiver 46a, a retainer projection 46b, a 
knocker end 46c and a spring receiver 46d. The push receiver 46a is pushed 
by the cocking cam 58 to rotate toward the cocked position. The retainer 
projection 46b is retained by the retainer lever 50 when in the cocked 
position. The knocker end 46c, when rotated from the cocked position to 
the released position, knocks and swings a protruded end 96a of the 
shutter blade 96, to open/close the shutter opening 95. The spring 
receiver 46d receives retention of a distal end of the first coil spring 
47. 
The retainer lever 50 is rotatable between a blocking position and a 
non-blocking position. The blocking position is located in the clockwise 
direction, and adapted to blocking movement of the photo film. The 
non-blocking position is located in the counterclockwise direction, and 
adapted to releasing movement of the photo film from being blocked. The 
retainer lever 50 is one piece including a retainer projection 50a, a 
driven end 50b, an engaging claw 50c and a lock claw 50d. The retainer 
projection 50a retains the retainer projection 46b of the shutter drive 
lever 46 in the cocked position. The driven end 50b is pushed toward the 
non-blocking position in response to depression of the shutter release 
button 6. The engaging claw 50c is meshed with the periphery of the taking 
lens 9. The lock claw 50d is engaged with the notch 57a of the wind block 
cam 57 to lock it. 
In FIG. 6, when the shutter mechanism of the exposure unit 16 stands 
cocked, the lock claw 50d of the retainer lever 50 is engaged with the 
notch 57a of the wind block cam 57 to block rotation of the wind block cam 
57. The retainer projection 50a is engaged with the retainer projection 
46b to keep the shutter drive lever 46 in the cocked position. As is not 
shown, the engaging claw 50c of the retainer lever 50 is meshed with the 
peripheral teeth of the taking lens 9 to block rotation of the taking lens 
9. 
When the shutter release button 6 is depressed in the blocked state, the 
driven end 50b of the retainer lever 50 is pushed in response to it. The 
retainer lever 50 is rotated toward the non-blocking position in the 
counterclockwise direction against the bias of the second coil spring 49. 
In FIG. 7, the shutter drive lever 46 is released from retention of the 
retainer lever 50, and is rotated toward the released position by the bias 
of the first coil spring 47, to knock the protruded end 96a of the shutter 
blade 96. The shutter blade 96 knocked at the protruded end 96a is swung 
against the return spring 97 to open the shutter opening 95, and then 
swung back by the return spring 97 to close the shutter opening 95. The 
retainer lever 50 is retained in the non-blocking position by the shutter 
drive lever 46 which has rotated to the released position. 
When the winder wheel 12 is rotated, the photo film 22 is moved in the 
arrow direction, to rotate the sprocket wheel 54 and the cam member 51 in 
the counterclockwise direction in mesh with the one great perforation 27. 
During the rotation, there occurs a section where the sprocket wheel 54 is 
not meshed with the photo film 22. However the spring 61 operates in the 
section to push the bias cam 59 to rotate the sprocket wheel 54. 
Accordingly the sprocket wheel 54 comes in mesh with succeeding ones of 
the perforations 27 and 28. 
A top plate 63 is mounted on a top of the base portion 38. The top plate 63 
has a hole 63a, which supports a top end of the shaft 43. There is a 
recess 63b, which supports a top end of the cam member 51. The entirety of 
the top plate 63 is formed from transparent plastic material. A reference 
numeral 64 designates a lens, which enlarges an image of the scale 
arranged on the top of the frame counter wheel 48. 
The flash device 17 includes a printed circuit board 66, the flash emitter 
window 11, a switch segment 68 and a synchro switch 69. The printed 
circuit board 66 has electric parts such as a main capacitor, and 
constitutes a flash circuit. The flash emitter window 11 is fitted on the 
printed circuit board 66, appears through the front cover 18, includes a 
flash discharge tube and a diffuser plate, and emits flash light. The 
switch segment 68 is disposed behind the flash charge button 10 and 
depressible. The synchro switch 69 is turned on in response to a releasing 
operation of the shutter mechanism. A dry battery 67 is mounted on the 
flash device 17 as a power source for the flash circuit. 
When the flash charge button 10 is depressed, the switch segment 68 pushed 
by it contacts the printed circuit board 66, to start a charging operation 
of the flash device 17. When the shutter release button 6 is depressed, 
the shutter mechanism incorporated in the exposure unit 16 is released. 
The shutter blade 96 being swung turns on the synchro switch 69. Thus 
flash light is emitted from the flash emitter window 11 to a photographic 
subject. 
The front cover 18 is removably mounted on the front of the photo film 
containing unit 15. The shutter release button 6 is disposed on the top of 
the front cover 18, and defined by the inside of three slits formed 
through the shutter release button 6 and connected in a channel shape. The 
shutter release button 6 is depressible with resiliency. Under the shutter 
release button 6 is formed a push arm 71, which, when the shutter release 
button 6 is depressed, pushes the driven end 50b of the retainer lever 50 
of the exposure unit 16 toward the non-blocking position. 
The rear cover 19 is secured to the rear of the photo film containing unit 
15, and keeps ambient light from entry to the inside of the photo film 
containing unit 15. There are bottom lids 73 and 74 formed integrally with 
the rear cover 19 for closing the bottoms of the chambers 35 and 36 
light-tightly. There are thin hinging portions being flexible and 
connecting the bottom lids 73 and 74 to the rear cover 19. The bottom lid 
73 is opened for removing the photo film cassette 14 from the lens-fitted 
photo film unit 2 after use for taking photographs. An inside of the rear 
cover 19 has a photo film support surface 19a, which is confronted with 
the exposure aperture and photo film rails. 
There is a cocking slot 76 formed in the rear cover 19 and adapted to cock 
the shutter mechanism of the exposure unit 16 externally in a forcible 
manner. In FIG. 8, a portion of the shutter drive lever 46 of the exposure 
unit 16 appears through the cocking slot 76. 
When the shutter mechanism does not stand cocked, a stick-shaped jig or 
tool 77 as a cocking operating unit is externally inserted through the 
cocking slot 76 to access the retainer projection 46b of the shutter drive 
lever 46. In FIG. 9, the shutter drive lever 46 is rotated against the 
first coil spring 47 toward the cocked position in the clockwise 
direction. Then the retainer lever 50 kept in the non-blocking position by 
contact of the shutter drive lever 46 is caused by the second coil spring 
49 to rotate toward the blocking position in the clockwise direction. Thus 
the retainer projection 50a of the retainer lever 50 enters a rotational 
path of the retainer projection 46b of the shutter drive lever 46, to 
cause the retainer lever 50 to retain the shutter drive lever 46 in the 
cocked position. It is possible to cock the shutter mechanism without 
winding the photo film 22. 
There is a shutter rotating mechanism, disposed between the top of the 
cassette containing chamber 35 to extend between the cassette containing 
chamber 35 and the light-shielding tunnel 31, for rotating the cassette 
shutter rod 25 of the cassette shell 21 to close it in response to an 
opening movement of the bottom lid 73. The shutter rotating mechanism is 
for example the same as that incorporated in the commercially sold model 
of the lens-fitted photo film unit 2 named "Fujicolor Quicksnap Super 
Slim" (trade name, manufactured by Fuji Photo Film Co., Ltd.). 
The lens-fitted photo film unit 2 is shipped with the shutter mechanism in 
the state of FIG. 8. The user, after purchasing the lens-fitted photo film 
unit 2, initially effects a pre-winding operation for the purpose of the 
shutter cocking. When the photo film 22 is moved in the arrow direction, 
the small perforation 28a moves to a position confronted with a succeeding 
one of the small sprocket teeth 54b of the sprocket wheel 54. Then the 
succeeding small sprocket tooth 54b is meshed with the small perforation 
28a by the bias of the spring 61. Operations of the shutter cocking, 
blocking of winding the photo film, and the frame counting are effected by 
the mesh of the photo film 22 and the sprocket wheel 54 and cooperation of 
the spring 61 and the bias cam 59. 
The lens-fitted photo film unit 2 is produced according to a flow 
illustrated in FIG. 10. A manufacture line for the lens-fitted photo film 
unit 2 includes an indexing circular table, on which the photo film 
containing unit 15 is placed and which rotates intermittently. A plurality 
of assembly stations are disposed on the periphery of the indexing table. 
When the indexing table is stopped with reference to the assembly 
stations, each of the parts are secured to the photo film containing unit 
15, until the lens-fitted photo film unit 2 is produced. 
In a first station defined in an initial position on the periphery of the 
indexing table, a pallet is supplied with the photo film containing unit 
15 of which a front is directed upwards. In a second station of the 
indexing table, the shutter rotating mechanism is mounted on the set 
position of the top and the side of the cassette containing chamber 35. 
In a third station, the exposure unit 16 is mounted on the front of the 
light-shielding tunnel 31 of the photo film containing unit 15. The winder 
wheel 12 is mounted on the top of the cassette containing chamber 35. 
Furthermore the flash device 17 is mounted on the front of the roll 
containing chamber 36. The battery 67 is also set on it. 
In a fourth station, the front cover 18 is mounted on the front of the 
photo film containing unit 15. A fifth station is disposed in a dark room, 
and adapted to changing orientation of the photo film containing unit 15 
to direct its front downwards. The photo film cassette 14 is inserted into 
the rear, inclusive of the cassette shell 21 and the photo film 22 in a 
roll form. In a sixth station, the rear cover 19 is secured to the rear of 
the photo film containing unit 15. Then the bottom lids 73 and 74 are 
closed, before completing the housing 3. 
The shutter mechanism shortly after assembling the housing 3 stands 
uncocked, namely has the shutter drive lever 46 disengaged from the 
retainer lever 50 as illustrated in FIG. 8. The sprocket wheel 54 is set 
in a state where the one small sprocket tooth 54b is protruded from the 
level of the photo film rails 34. The photo film 22 is loaded in the photo 
film containing unit 15 to confront the leader 22a with the exposure 
aperture. The one small sprocket tooth 54b of the sprocket wheel 54 is 
pushed by the photo film 22 and rotationally directed in reverse to the 
winding direction and against the spring 61. The one small sprocket tooth 
54b is contacting the photo film 22 inside the photo film rails 34. 
The lens-fitted photo film unit 2 is shipped with the shutter mechanism in 
the above-described state. 
The housing 3 after being completed is transferred to a seventh station by 
rotation of the indexing table. The seventh station is disposed in the 
darkroom, and adapted to inspection of the flash device 17 and the shutter 
mechanism incorporated in the exposure unit 16 in accordance with the flow 
depicted in FIG. 11. 
In FIG. 12, the housing 3 is positioned on a pallet 79 after adjustment of 
orientation for erection. In front of the taking lens 9 is positioned is a 
blade sensor 80, being a photo sensor for detecting a release operation of 
the shutter mechanism. A flash detector 82 is positioned in front of the 
flash emitter window 11 with a light-shielding structure. A plunger 83 as 
a release operating unit is positioned on the top of the shutter release 
button 6, and included in a solenoid for a moving structure. A plunger 84 
as a flash operating unit is positioned in front of the flash charge 
button 10, and included in a solenoid for a moving structure. The 
stick-shaped jig 77 is positioned in the rear of the housing 3 for the 
shutter cocking. 
The blade sensor 80, the flash detector 82, the charging solenoid, the 
releasing solenoid and the stick-shaped jig 77 are controlled by a 
microcomputer 86. The blade sensor 80 and the flash detector 82 send 
respective detecting signals to the microcomputer 86. 
In FIG. 12A, the flash detector 82 includes a base portion 88, a 
light-shielding sponge 89 and a flash light sensor 90 being a photo 
sensor. The base portion 88 is formed from metal or plastics. The 
light-shielding sponge 89 is formed from opaque material with resiliently 
compressible characteristic responsive to pressure, such as black sponge, 
for shielding light. The flash light sensor 90 is incorporated in the 
light-shielding sponge 89 for detecting flash light. The flash detector 82 
is movable by means of an air cylinder, a cam mechanism and the like. 
During the flash inspection, the light-shielding sponge 89 is pressed 
against the flash emitter window 11 and is deformed to cover the flash 
emitter window 11 to prevent flash light from exiting from the periphery 
of the flash emitter window 11. The flash light sensor 90, when detecting 
flash light, sends a detecting signal to the microcomputer 86. 
The blade sensor 80 includes a beam projector and a beam receiver. The beam 
projector projects a spot-shaped beam of infrared light to the taking lens 
9 along the optical axis of the taking lens 9 in a range below exposing 
the photo film 22. The beam receiver detects the infrared beam reflected 
by the shutter blade 96. The blade sensor 80, upon detecting the reflected 
infrared beam from the shutter blade 96, sends a detecting signal to the 
microcomputer 86. 
In FIG. 8, the stick-shaped jig 77 is driven by a drive mechanism 92 of the 
clocking operating unit under a control of the microcomputer 86, is 
inserted into the cocking slot 76 in the rear cover 19, and contacts the 
spring receiver 46d of the shutter drive lever 46. The drive mechanism 92 
further slides the stick-shaped jig 77 to rotate the cocking slot 76 
toward the cocked position. 
In FIG. 9, the shutter drive lever 46 is rotated toward the cocked position 
in the clockwise direction. The retainer lever 50, which is kept in the 
non-blocking position by the contact of the shutter drive lever 46, is 
caused by the second coil spring 49 to rotate toward the blocking position 
in the clockwise direction. Rotation of the retainer lever 50 causes the 
retainer projection 50a to enter the rotational path of the retainer 
projection 46b of the shutter drive lever 46, so that the retainer lever 
50 retains the shutter drive lever 46 in the cocked position. The shutter 
mechanism is forcibly cocked. Then the drive mechanism 92 retracts the 
stick-shaped jig 77 from the cocking slot 76. 
When the shutter cocking is finished with the stick-shaped jig 77, the 
microcomputer 86 drives the flash charging solenoid to protrude the 
plunger 84 in the arrow direction, to depress the flash charge button 10. 
The switch segment 68 behind the flash charge button 10 contacts the 
printed circuit board 66, so that a charging operation of the flash device 
17 is started. The flash device 17 incorporated in the housing 3 of the 
present embodiment is so structured that the charging operation is started 
in response to one-time depression of the flash charge button 10 in a 
short time. It is unnecessary to keep the flash charge button 10 depressed 
until the finish of the charging operation. The solenoid is driven only 
for a short time and stops from being driven before long. 
After a lapse of a predetermined duration defined for the flash charging, 
the microcomputer 86 drives the releasing solenoid to protrude the plunger 
83 to depress the shutter release button 6. The push arm 71 formed with 
the shutter release button 6 pushes the driven end 50b of the retainer 
lever 50 to rotate the retainer lever 50 toward the non-blocking position. 
The shutter drive lever 46 disengaged from the retainer lever 50 is 
rotated toward the released position by the bias of the first coil spring 
47. During the rotation the knocker end 46c knocks the protruded end 96a 
of the shutter blade 96. The shutter blade 96 is swung to open the light 
path from the taking lens 9 to the photo film 22. The shutter blade 96 
turns on the synchro switch 69 of the flash device 17, to cause the flash 
emitter window 11 to emit flash light. 
The blade sensor 80 applies an infrared beam to the taking lens 9 in a 
spotted manner at the same time as driving the charging solenoid. The 
blade sensor 80 detects the shutter blade 96 in a state prior to the 
shutter releasing operation, and sends a detecting signal to the 
microcomputer 86. Again the blade sensor 80 detects the shutter blade 96 
in a state following the shutter releasing operation, and sends a 
detecting signal to the microcomputer 86. 
The flash light sensor 90 of the flash detector 82 detects the flash light 
emitted from the flash emitter window 11, so that the flash detector 82 
sends the detecting signal to the microcomputer 86. The flash emitter 
window 11 is kept covered by the light-shielding sponge 89 of the flash 
detector 82. No flash light comes out of the light-shielding sponge 89 or 
affect the detection at the blade sensor 80, or exposes the photo film 22. 
As depicted in FIG. 13, the microcomputer 86 measures a shutter speed or 
shutter-open time T1, which is defined to lapse between the detecting 
signal received upon the beginning of the shutter release from the blade 
sensor 80 and that received upon the finish of the shutter release. Also 
the microcomputer 86 confirms existence of emitted flash light from the 
flash emitter window 11. Furthermore the microcomputer 86 measures an 
elapsed time T2 defined to lapse between the beginning of the shutter 
release and the beginning of the flash emission. The microcomputer 86 
evaluates the times T1 and T2 with reference to respective tolerable 
ranges by effecting an operation of comparison, to check acceptability of 
the housing 3. If the housing 3 is detected unacceptable, information of 
identifying the housing 3 is stored in a memory. 
For this operation, functions of the microcomputer 86 are schematically 
depicted in FIG. 13A. A first timer 100 incorporated in the microcomputer 
86 measures the shutter-open time T1 in response to the signal from the 
blade sensor 80. A first evaluator 102 evaluates the shutter-open time T1 
with reference to a first predetermined range. If the shutter-open time T1 
is detected within the first predetermined range, the shutter mechanism is 
regarded as acceptable. A second timer 104 measures the elapsed time T2 in 
response to the signal from the blade sensor 80 and the signal from the 
flash light sensor 90. A second evaluator 106 evaluates the elapsed time 
T2 with reference to a second predetermined range. If the elapsed time T2 
is detected within the second predetermined range, the flash device 17 is 
regarded as acceptable. 
When the inspection of the shutter mechanism and the flash device 17 is 
finished, the microcomputer 86 moves the blade sensor 80, the flash 
detector 82, the charging solenoid, the releasing solenoid and the 
stick-shaped jig 77 away from the housing 3. 
The housing 3 after the inspection in the seventh station is transferred to 
an eighth station by rotation of the indexing table. The housing 3 being 
unacceptable is removed from the indexing table during the transfer from 
the seventh station. The housing 3 is disassembled into parts, and reused 
as a component or recycled as a regenerated material. In the eighth 
station, the outer sheet member 4 is attached to the outside of the 
housing 3, packaged in a packaging, and shipped. 
In the above embodiment, the lens-fitted photo film unit is for use with 
the photo film cassette of the IX240 type. Alternatively a lens-fitted 
photo film unit may contain a 35 mm type of the photo film cassette. To 
shield flash light, the light-shielding sponge 89 is used. The 
light-shielding sponge 89 may be a member formed from any material with a 
light-shielding characteristic, for example rubber, plastics, or 
light-trapping fabric called plush; to contact the front face of the flash 
emitter window 11 without permeation of flash light. 
In the above embodiment, the front of the flash emitter window 11 is 
shielded. Alternatively, a wall-shaped shielding member may be fitted on 
the outside of the lens-fitted photo film unit 2 along a line between the 
taking lens and the flash emitter window 11. Furthermore, the front of the 
taking lens may be shielded from the outside by a member, which may 
incorporate the blade sensor 80, without using the light-shielding sponge 
89 at the flash emitter window 11. 
Although the present invention has been fully described by way of the 
preferred embodiments thereof with reference to the accompanying drawings, 
various changes and modifications will be apparent to those having skill 
in this field. Therefore, unless otherwise these changes and modifications 
depart from the scope of the present invention, they should be construed 
as included therein.