Abstract:
In a first aspect of the present invention, a camera exposure control system is provided. The camera exposure control system has a shutter movable during an exposure period through a path of travel between a first position and a second position and a detector to sense the shutter and to generate a signal when the shutter is at a flash trigger position on the path of travel. A flash circuit is provided and receives the signal generated by the detector causing a flash of light to discharge when the signal is received. A stop is also provided. The stop is selectably movable from a location out of the path of travel of the shutter to a location in the path of travel of the shutter. The location of the stop determines whether the detector can sense the shutter during the exposure.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to photographic cameras and, in particular, to photographic cameras having flash illumination systems.  
         BACKGROUND OF THE INVENTION  
         [0002]    Conventional cameras capture images on a photosensitive element by exposing the photosensitive element to light from a scene. Such a photosensitive element is typically capable of recording useful images when exposed to light within a predetermined range. Thus, conventional cameras carefully meter exposures so that the light from the scene that strikes the photosensitive element is within the predefined range.  
           [0003]    Exposure metering is typically controlled by a shutter mechanism. The shutter mechanism exposes the photosensitive element to light from the scene for a period of time known as an exposure time. The exposure time needed for a useful image to form on the photosensitive element is generally inversely proportional to the amount of light in the scene. Accordingly, many cameras feature an exposure control system that monitors photographic conditions such as the ambient light in a scene and that causes the shutter mechanism to modify the exposure time in proportion to the amount of light in the scene. This optimizes the appearance of the image captured on the photographic element. Often cameras incorporate flash systems that emit a flash of light to provide supplemental illumination of the scene. The exposure control systems of certain flash cameras adapt the operation of the shutter mechanism to modify the exposure accordingly.  
           [0004]    It will be appreciated that such adaptive exposure control systems are complex and, accordingly, they can be challenging to design, manufacture and install in a camera. Thus, such exposure control systems are typically incorporated in more expensive point and shoot and single lens reflex cameras.  
           [0005]    A lower cost exposure control approach is to provide a camera that has a fixed exposure time that is calibrated so that the camera is likely to capture an acceptable image under a wide range of conditions including ambient light images and flash images. However, a disadvantage of this solution is that such cameras are not fully optimized to capture images at the extremes of these ranges.  
           [0006]    An example of such a camera is shown in JP 8-278, 529A which shows a camera with an exposure control system having a movable shutter and a camera body having various positions for receiving a stop that limits the path movement of the shutter blade during exposure. During camera manufacture, the stop is located at one of the positions. When the camera is recycled, the manufacturer can move the stop to shorten or extend the path of travel of the shutter. By shortening or extending the path of travel of the shutter, the exposure time is shortened or lengthened so that the same camera body can be used to accommodate the exposure needs of different film, flash, or lens arrangements. However, it is important to note that the location of the stop and therefore the exposure time is fixed until the next time the camera is recycled.  
           [0007]    Thus what is needed is a low cost camera exposure control system that adapts the exposure to optimize the appearance of captured images.  
           [0008]    One attempt to meet this need is JP 08-211,447 which shows a shutter mechanism that has a shutter that has a path of travel that is limited by a halt member. The halt member is movable to permit adjustment of the exposure. An opening in the cover permits a user to manually move the halt member. The biasing spring that propels the shutter is also connected to the halt member. As the halt member is moved, the amount of bias applied to the shutter changes. This changes the speed at which the shutter is moved during an exposure. This system requires that the user of the camera must make the determination as to which speed settings are appropriate for a particular photographic circumstance. However, this determination can be difficult for even advanced amateurs to make.  
           [0009]    This determination becomes even more difficult to make when such a speed control is implemented in a camera that also incorporates a flash system which the user can selectively enable and disable. This is because the presence or absence of flash illumination in a scene can significantly influence whether a particular speed setting is appropriate. Cameras having such user enabled flash systems are well known. One example of a camera having such a user enabled flash is shown in JP 11-282,060A. In this camera a flash illumination circuit is provided that discharges a flash of light when a switch is closed. The switch is a two contact switch that is controllably disabled by a user controlled insulator that is positioned between the two contacts. This prevents the contacts from engaging and disables the flash. In JP 11-282,060 A, a similar system is used. However in this system, the contacts are bent apart from each other to prevent them from engaging as the shutter blade makes contact with the switch. JP 11-64940 shows a flash illumination circuit having a switch with an on and off position wherein the illumination charge and discharge circuits are disabled by the switch. This circuit requires that the flash illumination circuit is electrically adapted to accommodate this disabling switch. While such cameras provide the ability to selectably enable and disable the flash, they do not optimize exposure conditions to reflect the condition of the flash.  
           [0010]    What is needed therefore is a low cost camera and camera exposure control system having a flash illumination system that can be enabled and disabled by a user and that automatically adjusts exposure characteristics to optimize the appearance of images captured in either flash or ambient light photography modes.  
         SUMMARY OF THE INVENTION  
         [0011]    In a first aspect of the present invention, a camera exposure control system is provided. The camera exposure control system has a shutter movable during an exposure period through a path of travel between a first position and a second position and a detector to sense the shutter and to generate a signal when the shutter is at a flash trigger position in the path of travel. A flash circuit is provided and receives the signal generated by the detector causing a flash of light to discharge when the signal is received. A stop is also provided. The stop is selectably movable from a location out of the path of travel of the shutter to a location in the path of travel of the shutter. The location of the stop determines whether the detector can sense the shutter during the exposure.  
           [0012]    In another aspect of the present invention, a camera is provided having a housing with an opening to admit light from a scene. An imaging gate is provided and positions an imaging surface to receive the light from the scene. A shutter is provided and is movable during an exposure period through a path of travel between a first position wherein the shutter blocks light from the scene from traveling to the imaging surface and a second position wherein the shutter permits light from the scene to travel to the imaging surface. A detector sense the shutter and generates a signal when the shutter is at a flash trigger position in the path of travel. A flash circuit receives the signal generated by the detector and causes a flash of light to discharge when the shutter electrically engages the contact. A stop is provided and is selectably movable from a location out of the path of travel of the shutter to a location in the path of travel of the shutter. The location of the stop determines whether the shutter can engage the contact during the exposure. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 a  shows an assembly view of a camera of the present invention.  
         [0014]    [0014]FIG. 1 b  shows a front view of an embodiment of an exposure control system in the embodiment of FIG. 1 a.    
         [0015]    [0015]FIG. 2 shows a front view of one embodiment of an exposure control system of the present invention.  
         [0016]    [0016]FIG. 3 shows a front perspective view of one embodiment of an exposure control system of the present invention.  
         [0017]    [0017]FIG. 4 shows a front view of the exposure control system of FIGS. 2 and 3 with the flash disabled.  
         [0018]    [0018]FIG. 5 shows an enlarged view of the exposure control system showing the first cover, base, and drive member in cross section and illustrating the interaction of the first cover, drive member, user control feature, pin, flash charging control switch.  
         [0019]    [0019]FIG. 6 shows a perspective view of the exposure control system illustrating the relationship between the control feature, drive member, pin and flash charging control switch.  
         [0020]    [0020]FIG. 7 shows a front view of an embodiment of an exposure control system with a pivotally mounted drive member in a flash disable position.  
         [0021]    [0021]FIG. 8 shows a front view of the embodiment of FIG. 7 with the drive member in the flash enable position.  
         [0022]    [0022]FIG. 9 shows a front view of an embodiment of on exposure control system having a slideable drive member with said slideable drive member in a flash enable position.  
         [0023]    [0023]FIG. 10 shows the embodiment of FIG. 9 with the drive member in a flash disable position.  
         [0024]    [0024]FIG. 11 shows a front view of another embodiment of the exposure control system having a stop positioned on a resilient support and a slidably movable drive member positioned in a flash enable position.  
         [0025]    [0025]FIG. 12 shows the embodiment of FIG. 11 with the drive member in a flash disable position.  
         [0026]    [0026]FIGS. 13 and 14 show another embodiment of the exposure control system having a contact positioned on the stop and the drive member in the flash disable position.  
         [0027]    [0027]FIG. 15 shows the embodiment of FIGS. 13 and 14 with the contact positioned on the stop and the drive member in the flash enable position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]    Turning now to FIGS. 1 a  and  1   b  what is shown is a diagram of an embodiment of camera  20  of the present invention. As shown in FIG. 1 a , camera  20  has a first cover  22  and a second cover  24 . A frame  26  is disposed between first cover  22  and second cover  24 . Frame  26  can be,a component that is separate from but joined to first cover  22 . Alternatively, frame  26  can be formed in whole or in part by features of first cover  22 . In the embodiment shown, camera  20  records images on a photographic element comprising a film  42  disposed at least partially in a film canister  40 . Frame  26  has a film canister holder  32  and a film supply reel area  34 . Disposed between film canister holder  32  and film supply reel area  34  is an image capture area  36 .  
         [0029]    In the embodiment of FIGS. 1 a  and  1   b , film canister holder  32  is adapted to receive a film canister  40  containing a length of film  42 . A length of film  42  is drawn from film canister  40 , across an image capture area  36  and wound about a film supply reel  38  that is disposed in film supply reel area  34 . During winding, winding mechanism  30  engages hub  44  and draws film  42  from supply reel  38  across image capture area  36  and into film canister  40 . It will be appreciated that other conventional methods can be used for moving film  42  between film canister holder  32  and film supply reel  38 .  
         [0030]    First cover  22  has light opening  48  aligned with image capture area  36 . A lens  52  is disposed in light opening  48  to focus light from a scene to form an image on film  42  during an exposure. An exposure control system  54  is positioned between lens  52  and image capture area  36 . In the embodiment shown in FIGS. 1 a  and  1   b , exposure control system  54  comprises a flash board  56  and shutter mechanism  60 . Shutter mechanism  60  has shutter blade  62  shown positioned in front of and blocking light from passing through a light passageway  58  that is aligned with lens  52  and image capture area  36  to pass light from a scene to film  42 . In the embodiment of FIGS. 1 a  and  1   b , flash board  56  is joined to camera frame  26  which acts as a base to support both flash board  56  and shutter mechanism  60 .  
         [0031]    [0031]FIGS. 2 and 3 show, respectively a front view and a front perspective view of an embodiment exposure control system  54 . In the embodiment shown, exposure control system  54  comprises a shutter mechanism, a flash system and a control system. The shutter mechanism  60  comprises a movable shutter blade  62  pivotally mounted to pivot  64 , a resilient member mounting  66  and a resilient member  68 . Resilient member  68  joins shutter blade  62  to resilient member mounting  66 . In the embodiment shown, shutter blade  62 , pivot  64 , resilient member mounting  66  and resilient member  68  are supported by an optional spacer  70 . Spacer  70  elevates shutter blade  62 , pivot  64 , and resilient member  68  above a top surface  72  of frame  26 . Spacer  70  defines passageway  74  which is aligned with image capture area  36 , light opening  48  and light passageway  58  to allow light from the scene to pass to film  42 .  
         [0032]    Shutter blade  62  is pivotally movable between a first position shown in FIG. 2 and a second position shown in FIG. 3. When shutter blade  62  is in the first position, shutter blade  62  blocks light from passing from the scene through passageway  74  to the film  42 . In the embodiment shown, shutter blade  62  is biased so that it normally remains in the first position between exposures. This bias is applied by resilient member  68  which draws shutter blade  62  into the first position. In the embodiment of FIGS. 2 and 3, the first position is defined by the position wherein resilient member  68  draws shutter blade  62  into engagement with stop  78  on spacer  70 . The bias applied by resilient member  68  holds shutter blade  62  in this position and prevents inadvertent exposure of film  42  to light.  
         [0033]    To capture an image on film  42 , shutter blade  62  is rapidly moved through an exposure cycle beginning with shutter blade  62  starting in the first position, travelling to the second position and ending in the first position. This requires that shutter blade  62  be driven against the bias provided by resilient member  68 . A variety of conventional mechanisms can be used to drive shutter blade  62  from the first position to the second position. An example of such a mechanism is an elastically deformable high-energy lever  80 . Between exposures, high-energy lever  80  is latched by a latch  82 . During film winding, a film winding mechanism  30  elastically deforms high-energy lever  80 . This stores potential energy in high-energy lever  80 . When a trigger button  84  is depressed, latch  82  releases the high-energy lever  80 . High-energy lever  80  has a latch drive surface  86  that applies the released energy to a shutter drive surface  88  on shutter blade  62 . The discharged stored potential energy is sufficient to drive shutter blade  62  to move rapidly from the first position to the second position.  
         [0034]    As is shown in FIG. 3, when shutter blade  62  reaches the second position, shutter blade  62  impacts a post  92  having a contact  94 . This impact exhausts the energy imparted on the shutter blade  62  by the high-energy lever  80 . The resilient member  68  then rapidly returns shutter blade  62  to the first position.  
         [0035]    It will be appreciated therefore that shutter mechanism  60  provides an exposure time that is defined by the amount of time required for shutter blade  62  to travel from the first position to the second position and to return to the first position. Thus, the position of post  92  has a significant impact upon the exposure time. Exposure time can be increased by positioning post  92  at a position that requires a greater degree of rotational movement of the shutter blade  62  during the exposure cycle. Similarly, exposure time can be decreased by positioning post  92  at a position that requires a lesser degree of rotational movement of shutter blade  62  during the exposure cycle.  
         [0036]    Exposure control system  54  further comprises a flash circuit having a flash capacitor  102 , a power supply  104 , a flash charging circuit  106 , a flash discharge circuit  108 , a flash charging control switch  110  and a flash tube  112 . Prior to a flash exposure, flash charging control switch  110  is depressed. Flash discharge circuit  108  is connected between flash capacitor  102  and power supply  104 . Flash charging circuit  106  is actuated by flash charging control switch  110 . In response to closure of flash charging control switch  110 , flash charging circuit  106  draws electrical power from power supply  104  and applies this power to flash capacitor  102 . This causes an electrical charge to be stored in flash capacitor  102 .  
         [0037]    Power supply  104  typically comprises a direct current battery cell providing a low voltage source. Flash charging circuit  106  operates to convert this low voltage into an output signal that is applied across flash capacitor  102  to store energy in flash capacitor  102  at a higher voltage level suitable for causing a discharge of light from the flash tube  112 . This higher voltage level can comprise a voltage of between  250  and  350  vdc while the low voltage is typically below 32 volts. In this regard, flash charging circuit  106  can comprise any known voltage step up circuit including but not limited to the so-called “press and hold” charging circuits and “one touch charging” circuits known to those skilled in the art. Examples of both “press and hold” and “one touch charging” circuits that can be usefully employed for this purpose are shown in commonly assigned and co-pending U.S. patent application Ser. No. 10/033,482 entitled CAMERA ELECTRONIC SYSTEM AND METHOD OF ASSEMBLING SAME, filed in the name of Douglas W. Constable on Dec. 27, 2002.  
         [0038]    Flash discharge circuit  108  defines an electrical circuit between flash capacitor  102  and flash tube  112 . Flash discharge circuit  108  is electrically connected in series with a detector  90 . Detector  90  is adapted to sense when shutter blade  62  is positioned at a flash trigger position in the path of travel and to generate a signal. In this regard detector  90  can comprise an electro-optical sensor, an electromechanical switch adapted to generate a signal when the shutter engages the switch. Detector  90  can also comprise an electromagnetic sensor that generates an electromagnetic field and senses shutter blade  62  by detecting changes in this electromagnetic field that occur as shutter blade  62  passes through the electromagnetic field. Other well known sensing systems can also be used for detector  90 .  
         [0039]    A particularly advantageous embodiment of detector  90  is shown. In this embodiment detector  90  comprises contact  94 . In the embodiment shown, contact  94  and shutter blade  62  are electronically wired in series with resilient member mounting  66 , resilient member  68  and leads  114 ,  116  and  118 . Each of contact  94 , shutter blade  62 , resilient member mounting  66 , and resilient member  68  are electrically conductive and electrically define a series electrical path between flash capacitor  102  and flash tube  112 . Contact  94  and shutter blade  62  are electrically isolated from each other except when shutter blade  62  is in a position wherein shutter blade  62  engages contact  94 . In the embodiment of FIGS.  2 - 4 , this occurs when shutter blade  62  reaches the second position. When shutter blade  62  is in the second position, shutter blade  62  electrically engages contact  94 . This generates a signal that causes flash discharge circuit  108  to apply the electrical energy stored in flash capacitor  102  across flash tube  112 . This releases energy stored in flash capacitor  102  and causes a flash of light to discharge from flash tube  112 . Accordingly, in the camera of FIG. 1, a flash of light is emitted from flash tube  112  in a manner that is synchronized with the action of shutter blade  62  during an exposure cycle.  
         [0040]    Camera exposure control system  54  further comprises a control system comprising stop  120 , and a drive member  122 . Stop  120  is selectively movable from a position out of the path of travel of shutter blade  62  to a position in the path of travel of shutter blade  62 . In the embodiment shown, drive member  122  comprises a dial rotatably mounted in mountings  124  that are joined to flash board  56  of camera exposure control system  54 . Stop  120  and drive member  122  are joined for common movement. A user control feature  126  is also joined to drive member  122  for common movement.  
         [0041]    When camera exposure control system  54  is joined to first cover  22 , user control feature  126  projects out of control opening  50  of first cover  22 . A user of camera  20  can use control feature  126  to define the pivotal position of drive member  122  to selectively locate stop  120  in the path of travel of shutter blade  62 . When stop  120  is outside the path of travel of shutter blade  62 , the shutter mechanism  60  operates as described above. However, when stop  120  is in the path of travel of shutter blade  62 , stop  120  blocks shutter blade  62  from reaching the second position. This has two effects. The first effect is that this prevents closure of the flash discharge circuit  108 . Because flash discharge circuit  108  cannot be closed, flash energy cannot be released from flash capacitor  102  and no flash of light is discharged from flash tube  112 . The second effect is that this limits the of path travel of shutter blade  62  and accordingly reduces exposure time. Thus, camera exposure control system  54  permits the user of camera  20  to selectively enable a flash and uses the user&#39;s action of selectively enabling the flash to automatically extend the exposure time. Conversely, this also has the effect of shortening the exposure time where the flash is disabled.  
         [0042]    It will be appreciated that the embodiment of the exposure control system shown in FIGS.  2 - 4  executes a flash exposure strategy that assumes that a user will enable the flash in low light conditions and disable the flash in higher light situations. Under this assumption, exposure control system  54  of FIGS.  2 - 4  optimizes the appearance of low light images by the expedients of providing artificial illumination and extending exposure time. Also under this assumption, exposure control system  54 , constructed in accordance with the embodiment of FIGS.  2 - 4 , optimizes the appearance of images of what are believed to be scenes having greater ambient light levels by limiting exposure time and thereby preventing overexposure.  
         [0043]    In one embodiment of the present invention, exposure control system  54  also features a pin  128  that is joined to drive member  122  proximate to flash charging control switch  110 . As shown in FIGS. 5 and 6, pin  128  is positioned on drive member  122  so that rotation of drive member  122  from the flash disable position to the flash enable position causes pin  128  to move from a first pin position (A) separated from the flash charging control switch  110 , through a second pin position (B) wherein pin  128  depresses flash charging control switch  110  and terminating in a third pin position (C) wherein pin  128  is separated from the flash charging control switch  110 . It will be appreciated that this motion accomplishes a one touch depression of flash charging control switch  110  which can be used to activate flash charging circuit  106  of the “one-touch” type. Alternatively, pin  128  and flash charging control switch  110  can be positioned so that pin  128  depresses flash charging control switch  110  and holds a flash charging control switch  110  in the depressed position when drive member  122  is in the flash enable position. In this way, a lower cost press and hold circuit can be used for camera flash charging circuit  106 . It will be appreciated that under either alternative, the action of moving drive member  122  from the flash disable position to the flash enable position advantageously performs both functions of starting the charging of the flash capacitor  102  and moving stop  120  out of the path of travel of shutter blade  62 .  
         [0044]    FIGS.  7 - 11  each show different embodiments of exposure control system  54  and describe how each can be used to implement the above described exposure control strategy.  
         [0045]    In the embodiment shown in FIGS. 7 and 8, drive member  122  is mounted to base  56  by way of pivot  130 . Drive member  122  is pivotally movable about pivot  130  between a flash enable position shown in FIG. 7 and a flash disable position shown in FIG. 8. As is shown in FIG. 7, stop  120  is mounted at one end of drive member  122  and user control  126  is positioned at the other end. When user control  126  is held in the flash enable position shown in FIG. 7, stop  120  is located outside of the path of travel of shutter blade  62 . As described above, this permits shutter blade  62  to engage contact  94  during an exposure cycle to cause a discharge of flash light. However, when user control  126  is moved to the flash disable position shown in FIG. 8, stop  120  is located in the path of travel of shutter blade  62 . This prevents shutter blade  62  from engaging contact  94  during an exposure cycle and prevents a discharge of flash light.  
         [0046]    Pin  128  is shown in the embodiment of FIGS. 7 and 8. Pin  128  is joined to drive member  122  so that pin  128  depresses flash charging control switch  110  as the drive member is moved from the flash disable position to the flash enable position. This initiates operation of flash charging circuit  106  so that charging of flash capacitor  102  can begin as the user intends to enable the flash.  
         [0047]    Another embodiment is shown in FIGS. 9 and 10. In this embodiment, drive member  122  is slidably mounted to flash board  56  between a flash enable position shown in FIG. 9 and a flash disable position shown in FIG. 10. As is shown in FIG. 9, stop  120  is mounted at one end of drive member  122  and user control  126  is positioned at the other. When user control  126  is held in the flash enable position shown in FIG. 9, stop  120  is located outside the path of travel of shutter blade  62 . As described above, this permits shutter blade  62  to engage contact  94  during an exposure cycle to cause a discharge of flash light. However, when user control  126  is moved to the flash disable position shown in Fig. 10, stop  120  is located in the path of travel of shutter blade  62 . This prevents shutter blade  62  from engaging contact  94  during an exposure cycle and prevents a discharge of flash light.  
         [0048]    Pin  128  is shown in the embodiment of FIGS. 9 and 10. Pin  128  is joined to drive member  122  so that pin  128  depresses flash charging control switch  110  as the drive member is moved from the flash disable position to the flash enable position. This initiates operation of flash charging circuit  106  so that charging of flash capacitor  102  can begin as the user intends to enable the flash.  
         [0049]    [0049]FIGS. 11 and 12 show still another embodiment of exposure control system  54 . In this embodiment stop  120  is located on a resilient support  134  that is resiliently biased into a position wherein resilient support  134  locates stop  120  in the path of travel of shutter blade  62 . In this embodiment, drive member  122  is slidably movable from a flash disable position shown in FIG. 11 to a flash enable position shown in FIG. 12. Drive member  122  is also formed from a resilient substrate. A deflection surface  136  is positioned in the path of slideable movement of drive member  122  so that as drive member  122  is moved from the flash disable position to the flash enable position, drive member  122  is deflected. As drive member  122  is further moved to the flash enable position, resilient support  134  is further deflected. At some point, resilient support  134  is deflected so that stop  120  is positioned outside the path of travel of shutter blade  62  as shutter blade  62  moves from the first position to the second position. It will be appreciated that as drive member  122  is withdrawn from the flash enable position to the flash disable position shown in FIG. 11, the degree of deflection of resilient support  134  decreases. This returns stop  120  to the path of travel of shutter blade  62 .  
         [0050]    It will be appreciated that the embodiments shown and described above can also be used to implement an alternative exposure control strategy in which exposure time is reduced when the flash is enabled and the exposure time is increased when the flash is disabled. This strategy reduces the possibility of over exposure when the flash is enabled and underexposure when the flash is disabled.  
         [0051]    In any of the above listed embodiments, this alternative strategy can be executed by locating detector  90  on stop  120  so that detector  90  can sense shutter blade  62  when stop  120  is located in the path of travel of shutter blade  62  but cannot sense shutter blade  62  when stop  90  is out of the path of travel of shutter blade  62 . An example of this is shown in FIG. 13 which depicts the exposure control system  54  of FIG. 2, adapted in this manner. As is shown in FIG. 13, contact  94  is positioned on stop  120  and is incorporated into flash discharge circuit  108  by an electrical connection with lead  118 . In this embodiment lead  118  is flexible. Sufficient extra length is provided in lead  116  to permit contact  94  to move from the position shown in FIG. 13 to the position shown in FIG. 14. It will be appreciated that when stop  120  is in the position shown in FIG. 13, both stop  120  and contact  94  are outside the path of travel of shutter blade  62  as it moves from the position shown in FIG. 13 to the position shown in FIG. 14. If an exposure is initiated with the stop  120  and contact  94  in this position, the force imparted by high energy lever  80  drives shutter blade  62  to travel from the first position to the second position. When shutter blade  62  reaches the second position, shutter blade  62  strikes the post  92  and is returned to the first position by biasing force applied by resilient member  68 . Because contact  94  does not engage shutter blade  62 , flash discharge circuit  108  is not closed during exposure and the flash is effectively disabled.  
         [0052]    However, if an exposure is initiated with stop  120  and contact  94  in the position shown in FIG. 15, the force imparted by high energy lever  80  drives shutter blade  62  from the first position to a position where shutter blade  62  strikes contact  94  and stop  120 . This has two effects. First, engagement of contact  94  with shutter blade  62  causes flash discharge circuit  108  to close. This, in turn, causes a flash of light to be discharged from flash tube  112 . Further, this has the effect of limiting the exposure time because shutter blade  62  cannot travel to the second position. In this way, the shutter time can be effectively limited when the flash is enabled.  
         [0053]    The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.  
       Parts List  
       [0054]    [0054] 20  camera  
         [0055]    [0055] 22  first cover  
         [0056]    [0056] 24  second cover  
         [0057]    [0057] 26  frame  
         [0058]    [0058] 30  winding mechanism  
         [0059]    [0059] 32  film canister holder  
         [0060]    [0060] 34  film supply reel area.  
         [0061]    [0061] 36  image capture area  
         [0062]    [0062] 38  film supply reel  
         [0063]    [0063] 40  film canister  
         [0064]    [0064] 42  film  
         [0065]    [0065] 44  hub  
         [0066]    [0066] 48  light opening  
         [0067]    [0067] 50  control opening  
         [0068]    [0068] 52  lens  
         [0069]    [0069] 54  exposure control system  
         [0070]    [0070] 56  flash board  
         [0071]    [0071] 58  light passageway  
         [0072]    [0072] 60  shutter mechanism  
         [0073]    [0073] 62  shutter blade  
         [0074]    [0074] 64  pivot  
         [0075]    [0075] 66  resilient member mounting  
         [0076]    [0076] 68  resilient member  
         [0077]    [0077] 70  spacer  
         [0078]    [0078] 72  top surface  
         [0079]    [0079] 74  passageway  
         [0080]    [0080] 78  stop  
         [0081]    [0081] 80  high energy lever  
         [0082]    [0082] 82  latch  
         [0083]    [0083] 84  trigger button  
         [0084]    [0084] 86  latch drive surface  
         [0085]    [0085] 88  shutter drive surface  
         [0086]    [0086] 90  detector  
         [0087]    [0087] 92  post  
         [0088]    [0088] 94  contact  
         [0089]    [0089] 100  flash circuit  
         [0090]    [0090] 102  flash capacitor  
         [0091]    [0091] 104  power supply  
         [0092]    [0092] 106  flash charging circuit  
         [0093]    [0093] 108  flash discharge circuit  
         [0094]    [0094] 110  flash charging control switch  
         [0095]    [0095] 112  flash tube  
         [0096]    [0096] 114  lead  
         [0097]    [0097] 116  lead  
         [0098]    [0098] 118  lead  
         [0099]    [0099] 120  stop  
         [0100]    [0100] 122  drive member  
         [0101]    [0101] 124  mounting  
         [0102]    [0102] 126  user control  
         [0103]    [0103] 128  pin  
         [0104]    [0104] 130  pivot  
         [0105]    [0105] 134  resilient support  
         [0106]    [0106] 136  deflection surface