Abstract:
There is described a camera incorporating a focal-plane shutter. The camera includes a lens, an image window having an aperture to bound a light coming through the lens in a plain perpendicular to an optical axis of the lens, a focal-plane shutter and a photometry sensor to receive the light reflected by the focal-plain shutter and detect an amount of the light reflected by the focal-plane shutter after coming through the lens. In the camera, the photometry sensor is located at an outside of the aperture and resides on a plane, which is parallel with the optical axis and includes a line which is parallel to a long-axis of the aperture and passes substantially a center of a short-axis of the aperture.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a camera incorporating a focal-plane shutter. 
     In certain conventional cameras, the photometry is achieved by measuring a light intensity reflected from the focal-plane shutter, using the photometry means. For instance, as shown in FIG.  30 ( a ), photometry means  1000  is disposed at substantially the lower center position of image window  1001 , or at the upper corner position of image window  1001  as shown in FIG.  30 ( b ). 
     Accordingly, the photometric region measured by the above photometry means is limited in an elliptical region covered by the aperture of the photometry means disposed at either the lower center position or the upper corner position. Therefore, the efficiency of the photometry means decreases at a rate of uncovered region in the image window, since the major axis of the elliptical region does not coincide with the longer axis of the image window. 
     Further, since the focal-plane shutter, incorporated in the above conventional cameras, is not integrally mounted with the photometry means and the dating means, the positioning process of the photometry means and the dating means relative to the image window should be performed after combining them with the image window. Therefore, readjustment of the photometry means and the dating means is necessary, after reassembling them into the camera, for instance, at the time of maintenance works. 
     In addition, in the above conventional cameras, error occurrences of the focal-plane shutter cannot be detected. 
     SUMMARY OF THE INVENTION 
     To overcome the abovementioned drawbacks in conventional cameras, the first object of the present invention is to provide a camera which makes it possible to perform a precise photometry, and the second object of the present invention is to provide a camera in which an assembling process is simplified and improved, the third object of the present invention is to provide a camera which makes it possible to detect an error of the focal-plane shutter. 
     Accordingly, to overcome the cited shortcomings, the abovementioned objects of the present invention can be attained by cameras described as follow. 
     (1) A camera, comprising a lens, an image window having an aperture to bound a light coming through the lens in a plain perpendicular to an optical axis of the lens, a focal-plane shutter and a photometry sensor to receive the light reflected by the focal-plane shutter and detect an amount of the light reflected by the focal-plane shutter after coming through the lens, wherein the photometry sensor is located at an outside of the aperture and resides on a plane, which is parallel with the optical axis and includes a line which is parallel to a long-axis of the aperture and passes substantially a center of a short-axis of the aperture. 
     (2) The camera of item  1 , wherein the photometry sensor is located outside a light path through which the light, entering from the lens, travels to the aperture. 
     (3) The camera of item  1 , further comprising a photometry aperture control to set a photometry range, the photometry aperture control is disposed in an optical path through which the light, reflected by the focal-plane shutter, travels to the photometry sensor. 
     (4) The camera of item  3 , further comprising a finder and a photometry range display, disposed in the finder, to display the photometry range set by the photometry aperture control. 
     (5) The camera of item  1 , further comprising a processor to obtain parameters in regard to an exposure control, based on an amount of the light detected by the photometry sensor. 
     (6) The camera of item  1 , wherein the photometry sensor is integrally arranged in a shutter unit which comprises the focal-plane shutter. 
     (7) The camera of item  1 , further comprising a date projector to project a date on a film loaded in the camera, the date projector is integrally arranged in a shutter unit which comprises the focal-plane shutter. 
     (8) The camera of item  1 , further comprising a X-switch signal sensor to detect a signal of a X-switch mounted in the focal-plane shutter and a controller to perform error jobs, when the X-switch signal sensor does not detect the signal within a predetermined time after activating a shutter release button. 
     (9) A camera, comprising a lens, a shutter unit comprising a focal-plane shutter and a photometry sensor to receive and detect an amount of a light reflected by the focal-plane shutter after coming through the lens, the photometry sensor is integrally arranged in the shutter unit. 
       (10 ) A camera, comprising a lens, a shutter unit comprising a focal-plane shutter and a date projector to project a date on a film loaded in the camera, the date projector is integrally arranged in the shutter unit. 
     (11) A camera, comprising a lens, a focal-plane shutter, a X-switch signal sensor to detect a signal of a X-switch and a controller to perform error jobs, when the X-switch signal sensor does not detect the signal within a predetermined time after activating a shutter release button. 
     Further, to overcome the abovementioned problems, other cameras, embodied in the present invention, will be described as follow: 
     (12) A camera, characterized in that said camera performs a photometry by means of a photometry means which receives a light coming through the lens and reflected by the focal-plane shutter, and the photometry means is arranged at substantially a center side position of a short-axis of the aperture, viewing from a photographic lens side. 
     According to the camera described in item  12 , the photometry efficiency can be improved by arranging the photometry means at substantially a center side position of a short-axis of the aperture, viewing from a photographic lens side, and by aligning a photometry region in a direction of the aperture. 
     (13) The camera of item  12 , characterized in that the camera further comprises a photometry aperture means to set a photometry range, and the photometry aperture means is disposed in an optical path through which the light, reflected by the focal-plane shutter, travels to the photometry means. 
     According to the camera described in item  13 , since a variable photometry can be achieved by varying the photometric region in an optical path, through which the light, reflected by the focal-plane shutter, enters into photometry means, it becomes possible for a photographer to select a suitable photometric region corresponding to the scene to be shot. 
     (14) The camera of item  13 , characterized in that the camera further comprises a photometry range display means, disposed in a finder, to display the photometry range set by the photometry aperture means. 
     According to the camera described in item  14 , since the photometric region is displayed on the photometric region display means disposed in the finder, it becomes possible for the photographer to easily select the desirable photometric region. 
     (15) A camera, characterized in that said camera performs a photometry by means of a photometry means which receives a light coming through a photographic lens and reflected by a focal-plane shutter, and a photometry means is integrally arranged in a focal-plane shutter unit which comprises the focal-plane shutter. 
     According to the camera described in item  15 , since the photometry means is integrally assembled with the focal-plane shutter unit, it is possible to adjust the relative position between the focal-plane shutter and the photometry means in a state of unit. Therefore, it becomes possible to detect failed units and to precisely assemble the units before assembling the focal-plane shutter unit in the camera body. 
     (16) A camera, characterized in that said camera performs a photometry by means of a photometry means which receives a light coming through a photographic lens and reflected by a focal-plane shutter, and a dating means is integrally arranged in a focal-plane shutter unit which comprises the focal-plane shutter. 
     According to the camera described in item  16 , since the dating means is integrally assembled with the focal-plane shutter unit, it is possible to adjust the relative position between the focal-plane shutter and the dating means in a state of unit. Therefore, the readjustment of the relative position between them is not necessarily when performing maintenance works. 
     (17) A camera, characterized in that said camera comprises a focal-plane shutter, a X-switch signal detecting means to detect a signal of a X-switch and a control means to perform error jobs, when the X-switch signal detecting means does not detect the signal of the X-switch within a predetermined time after activating a shutter release button. 
     According to the camera described in item  17 , in regard to the camera in which the X switch turns ON only when the succeeding shutter blind completely running through the aperture, it is possible to detect an error state caused by a certain malfunction, when the X switch does not turns ON within the predetermined time after the succeeding blind starts running. Thus, the photographer can easily perceive the error state of the camera, even when an image capturing becomes impossible due to a certain malfunction in the focal-plane shutter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: 
     FIG. 1 shows a front view of a camera; 
     FIG. 2 shows a top view of the camera; 
     FIG. 3 shows a bottom view of the camera; 
     FIG. 4 shows a rear view of the camera; 
     FIG. 5 shows a right-side view of the camera; 
     FIG. 6 shows a left-side view of the camera; 
     FIG. 7 shows internal structure of the camera, viewing from the front side; 
     FIG. 8 shows internal structure of the camera, viewing from the topside; 
     FIG. 9 shows an arrangement of a photometry means; 
     FIG. 10 shows variable photometric regions; 
     FIG. 11 shows a view displayed in the finder; 
     FIG. 12 shows another example of the view displayed in the finder; 
     FIG. 13 shows a perspective view of a photometry section and a shutter section; 
     FIG. 14 shows a rear view of the photometry section and the shutter section; 
     FIG. 15 shows a front view of a focal-plane shutter; 
     FIG. 16 shows a side view of a shutter charging section of the focal-plane shutter. 
     FIG. 17 shows a block-diagram of a control circuit of the camera; 
     FIG. 18 shows a timing-chart of the camera; 
     FIG. 19 shows a flow chart of the focal-plane shutter operation; 
     FIG. 20 shows a timing-chart of the focal-plane shutter operation; 
     FIG. 21 shows a flowchart of a main routine of the camera; 
     FIG. 22 shows an explanatory timing-chart for detecting a shutter charged state; 
     FIG. 23 also shows an explanatory timing-chart for detecting a shutter charged state; 
     FIG. 24 shows a flowchart of an initial operation sub-routine; 
     FIG. 25 shows a flowchart of a photometry sub-routine. 
     FIG. 26 shows a flowchart of a main ON-sleep sub-routine, which is performed after the photometry is finished and 15 second has passed since the main routine is activated; 
     FIG. 27 shows a flowchart of a real-exposure sub-routine; 
     FIG. 28 shows a flowchart of a shutter charging and film feeding sub-routine; 
     FIG. 29 shows a flowchart of a shutter drive sub-routine; and 
     FIG.  30 ( a ) and FIG.  30 ( b ) show an explanatory illustration of a photometry region in conventional cameras. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following, a camera, embodied in the present invention, will be described in detail, referring the drawings. 
     The camera, embodied in the present invention, is illustrated in FIGS. 1 through 8, specifically; FIG. 1 shows a front view of the camera, FIG. 2 shows a top view of the camera, FIG. 3 shows a bottom view of the camera, FIG. 4 shows a rear view of the camera, FIG. 5 shows a right-side view of the camera, FIG. 6 shows a left-side view of the camera, FIG. 7 shows internal structure of the camera, viewing from the front side and FIG. 8 shows internal structure of the camera viewing from the top side. 
     The camera specifications are indicated as follow. 
     Type of camera: 35 mm interchangeable lens camera with rangefinder and focal-plane shutter 
     AE method: aperture-priority automatic exposure method and manual shooting is possible 
     Lens mounting method: bayonet mount 
     Finder: inverted Galilean finder with real image rangefinder 
     Rangefinder: split image coincidence type rangefinder 
     Shutter: electronic-controlled vertical focal-plane shutter 
     Shutter speed: 16{fraction (1/4000)} sec in automatic mode and Bulb B-{fraction (1/400)} sec in manual mode 
     Photometry method: TTL stop-down metering method 
     Film sensitivity setting range: 25-5000 with automatic introduction of the DX code, 6-6400 in manual mode and exposure compensation is possible 
     Film feeding: automatic winding and rewinding, intermediate rewinding is possible and continuous shooting of 2.5 pictures per second at room temperature is possible 
     Now, the camera layout will be detailed in the following. 
     Metallic camera cover  10  and rear cover  11  enclose camera body  1 , to which rear cover  11  is attached, being capable of opening and closing. Rear cover  11  can be opened by lifting up rear cover opening lever  12  and rotate it in a clockwise direction. Film confirming window  13  is opened on the rear cover  11 . 
     Rings  14  for the carrying strap are attached to the both front-sides of camera cover  10  and lens mount  15  is equipped at the center of the camera. Lens detaching button  16  is located near one side of lens mount  15 , while lever  17  for switching the finder view frame is located near the other side of lens mount  15 . LED window  18  for the self-timer is located at a front-upper portion of camera cover  10 , as well as ranging window  20 , lighting window  21  and finder window  22 . While, viewfinder window  22  is attached to the rear side of camera cover  10 . 
     Main switch lever  30  and release button  31  are equipped on the topside of camera cover  10 , as well as shutter dial  32 , ISO/exposure compensation dial  33 , strobe attaching shoe  34 , film counter  35 , battery power display  36  and film-position indicator  37 . 
     On the right side of camera cover  10 , cable release socket  40  is disposed at the upper position of rear cover opening lever  12  and rewinding button  41  is disposed at the lower position of it. On the bottom side of camera cover  10 , battery cover  43  and tripod socket  44  are arranged. 
     Shutter section  50  is mounted in the center interior of camera cover  10 . Film winding room  45 , in which the reel winds the exposed film, and patrone housing  46 , in which a patrone is stored, are arranged at both side portions of shutter section  50 , as shown in FIG.  7 . Circuit boards  48 ,  49  are disposed at the front side of patrone housing  46  and at the lower side of shutter section  50 , respectively. 
     Shutter charging motor  51  is disposed at the lower position of shutter section  50  to drive shutter charging mechanism  52  which charges shutter blind  53  of electronic-controlled vertical focal-plane shutter  90 . 
     Film feeding motor  60  is disposed at the lower side of film winding room  45  to drive vertical gear train  61  arranged in vertical direction. Vertical gear train  61  is further geared with horizontal gear train  62  disposed at the upper side, which rotates the reel and the spool in the patrone to convey the film. Thus, the automatic winding and rewinding, as well as the intermediate rewinding are achieved in the abovementioned configurations. 
     Finder section  70  is mounted on the upper position of horizontal gear train  62 . Finder section  70  is the inverted Galilean finder with real image rangefinder, comprising prism  71 , lens  72 , view frame  73 , lens  74 , etc. Two batteries can be loaded in battery room  80  provided in the interior of film winding room  45 . 
     Next, the configuration of the photometry section will be detailed in the following, referring FIGS. 9 through 12. 
     In the camera, embodied in the present invention, the photometry is achieved by means of photometry means  91  which receives a light, coming through shooting lends  100  and reflected on focal-plane shutter  90 . 
     FIG. 9 shows an arrangement of the photometry means, FIG. 10 shows variable photometric regions, FIG. 11 shows a view displayed in the finder and FIG. 12 shows another example of the view displayed in the finder. 
     As shown in FIG. 9, photometry means  91  is arranged at substantially the center side position of the shorter-axis of image window  92 , viewing from the shooting lens side. Lens  93  is disposed in an optical path, through which the light reflected by focal-plane shutter  90  incidents on (enters into) photometry means  91 . Accordingly, it becomes possible to improve the efficiency of the photometry, since the longer direction of the photometric region coincides with that of image window  92  by arranging photometry means  91  at substantially the center side position of the shorter-axis of image window  92 , viewing from the shooting lens side. 
     Further, as shown in FIG. 10, lens  93  and photometry aperture  94  are disposed midway in optical path, through which the light reflected on focal-plane shutter  90  incidents on (enters into) photometry means  91 . Photometry aperture controlling means  95 , comprised of either mechanical or electronic structure, varies the aperture of photometry aperture  94 , when a user operates a switch-button, etc. In addition, since photometry means  91  is arranged at substantially the center side position of the shorter-axis of image window  92 , viewing from the shooting lens side, the efficiency of the photometry would be improved by positioning the longer direction of the photometric region on that of image window  92 . 
     As mentioned above, since the variable photometry can be achieved by varying the photometric region in an optical path, through which the light reflected by focal-plane shutter  90  incidents on (enters into) photometry means  91 , it becomes possible for a photographer to select the suitable photometric region corresponding to the scene to be shot. 
     Further, as shown in FIG.  11  and FIG. 12, photometric region display  96 , which displays the photometric region set by photometry aperture  94 , is equipped in the interior of the finder. In the embodiment shown in FIG. 11, liquid-crystal finder  97   a  is employed for displaying the photometric region depicted by the elliptical circles. While, in the embodiment shown in FIG. 12, liquid-crystal finder  97   a  is also employed for displaying average photometry  97   a   2 , weighted center photometry  97   a   3  and spot photometry  97   a   4 . 
     Accordingly, since the photometric region is displayed on photometric region display  96  equipped in the finder, it becomes possible for the photographer to easily select the desirable photometric region. 
     Next, the configuration of the photometry section and the shutter section will be detailed in the following, referring FIGS. 13 and 12. 
     In the camera, embodied in the present invention, the photometry is achieved by means of photometry means  91  which receives a light, coming through shooting lends  100  and reflected on focal-plane shutter  90 . FIG. 13 shows a perspective view of the photometry section and the shutter section and FIG. 14 shows a rear view of the photometry section and the shutter section. 
     As shown in FIG. 13, focal-plane shutter  90  is equipped in shutter base  111  of focal-plane shutter unit  110 . Prism  112  and photometry means  91  are mounted on mounting board  111   a  protruded from shutter base  111 . Prism  112  and photometry means  91  are integrally assembled with focal-plane shutter unit  110  so that photometry means  91  can conduct the photometry by receiving the light coming through shooting lends  100 , reflected on focal-plane shutter  90  and coming through prism  112 . 
     Accordingly, since prism  112  and photometry means  91  are integrally assembled with focal-plane shutter unit  110 , it is possible to adjust the relative position between focal-plane shutter  90  and photometry means  91  in a state of unit. Therefore, it becomes possible to detect failed units and to precisely assemble the units before assembling the unit in the camera body. 
     Further, as shown in FIG. 14, dating means  120  is integrally arranged at the film side of focal-plane shutter unit  110  comprising focal-plane shutter  90 . Projection windows  121 ,  122  of dating means  120  are formed on shutter base  111  of focal-plane shutter unit  110  to project date information on the standard size film through projection window  121  and on the panorama size film through projection window  122 . In addition, X switch S 3  is also arranged on shutter base  111  to detect the movement of the preceding shutter blind (the first blind) of focal-plane shutter  90 . 
     Accordingly, since dating means  120  is integrally assembled with focal-plane shutter unit  110 , it is possible to adjust the relative position between focal-plane shutter  90  and dating means  120  in a state of unit. Therefore, the readjustment of the relative position between them is not necessarily when performing maintenance works. 
     Next, the configuration of the shutter charging mechanism will be detailed in the following, referring FIGS. 15 and 16. 
     The shutter charging mechanism of the camera, embodied in the present invention, is structured as shown in FIG.  15  and FIG.  16 . FIG. 15 shows a front view of the focal-plane shutter and FIG. 16 shows the shutter charging section of the focal-plane shutter. 
     Focal-plane shutter  90 , equipped in focal-plane shutter unit  110 , comprises the preceding shutter blind (the first blind) and the succeeding shutter blind (the second blind). Each of the preceding and the succeeding shutter blinds, to which an electromagnet is attached, is set in a shutter charged state by means of shutter charging unit  140  described later. In the shutter charged state, the two blinds of the preceding and the succeeding shutter blinds cover shutter aperture. When exposing the film, at first, the preceding and the succeeding shutter blinds are electrically held by activating each of the electro-magnets. Next, shutter charging unit  140  releases the mechanical setting of the shutter charged state, and then, the preceding shutter blind covers the shutter aperture, while the succeeding shutter blind move to the standby position uncovering the shutter aperture, so as to make the preceding and the succeeding shutter blinds possible to run. Then, the exposure is started with running of the preceding shutter blind driven by the spring, by deactivating electro-magnet  138  serving for the preceding shutter blind. Finally, the exposure is finished with running of the succeeding shutter blind driven by the spring, by deactivating electro-magnet  139  serving for the succeeding shutter blind. 
     Shutter charging unit  140 , in which shutter charging mechanism  500  is assembled, is mounted on focal-plane shutter unit  110 . The reciprocating shutter setting method is employed for shutter charging mechanism  500 , in which shutter setting is achieved by converting the rotational movement of shutter charging motor  51 , located at the lower portion of shutter base  111 , to the reciprocal movement by means of shutter charging mechanism  500  comprising cams and gears. 
     In particular, the rotation of shutter charging motor  51  is transmitted to charge gear  149  through the reduction gear train including the first gear  142 ˜the seventh gear  148  rotatably arranged on supporting board  160 . Charging lever  150  is also rotatably interfitted into pivot axis  151  on supporting board  160 , and rotatable roller  152  is attached to charging lever  150 . Charge spring  153  forces charging lever  150  downward as shown by the arrow in FIG.  16  and roller  152  always touches cam  154  attached to gear  149 . 
     Accordingly, charging lever  150  reciprocates in the vertical direction with the rotation of cam  154  attached to gear  149 . When charging lever pin  155  moves upward, the preceding and the succeeding shutter blinds are set at shutter charged position. Further, the rotation of charging gear  149  is transmitted to detecting gear  156  through the seventh gear  148  to measure a revolution number of detecting board  157  stuck on detecting gear  156  by means of shutter charge reflector  158 . 
     Next, the control circuit of the camera will be detailed in the following, referring FIG.  17 . 
     FIG. 17 shows a block-diagram of the control circuit of the camera. The control circuit incorporates CPU  200  to which battery  81  supplies an electric power through power circuit  201 . Memory section  202 , including the rewritable EEP-ROM, etc., is coupled to CPU  200 . 
     Based on the data sent from switch group  203 , CPU  200  controls photometry section  204 , counter display section  205 , finder display section  206 , date projecting section  207  and shutter section  50 , and in addition, drives shutter charging motor  51  through motor driver  210  and film feeding motor  60  through motor driver  211 . Shutter charge reflector  158  and film feeding reflector detect the state of shutter charging operation and the state of film feeding operation, respectively. 
     Switch group  203  includes main switch S 0 , switch S 1  to detect the first position of release button  31 , switch S 2  to detect the second position of it and the rewinding switch, etc. 
     Next, the operation of the camera will be detailed in the following, referring FIGS. 18 through 20. 
     FIG. 18 shows a timing-chart of the camera, FIG. 19 shows a flow chart of the focal-plane shutter operation and FIG. 20 shows a timing-chart of the focal-plane shutter operation. 
     As shown in FIG. 18, when main switch S 0  turns ON, switches S 1  and S 2  are activated in a ready state for pushing release button  31 , the photometry section  204  performs the photometry operation at a predetermined time period and CPU  200  controls finder display section  206  to display in the finder. 
     When release button  31  is depressed for shooting, switch S 1  turns ON at the first stroke of the depression, and further, switch S 2  turns ON at the second stroke of the depression, whereby finder display section  206  is deactivated to erase the image displayed in the interior of the finder. 
     On the other hand, the power source for the shutter holding coil is activated to supply electric-current to electromagnets  138 ,  139 , whereby the preceding and succeeding shutter blinds are held at the shutter charged position. When the predetermined time has passed after activating electromagnets  138 ,  139 , shutter charging motor  51  rotates in normal direction to rotate charge gear  149  in shutter charging mechanism  500 , and shutter charge reflector  158  detects the rotation of detecting board  157  attached to detecting gear  156  linked to charge gear  149 . When shutter charging motor  51  starts to rotate, shutter charge reflector  158  detects the high reflective portion of detecting board  157  and outputs [H] (High level). While, when charging lever  150  moves to the lower position, shutter charge reflector  158  detects the low reflective portion of detecting board  157 , rotating according with movement of charging lever  150 , and outputs [L] (Low level). When the output level [L] of shutter charge reflector  158  is detected, CPU  200  turns the rotational direction of shutter charging motor  51  into the reverse direction and finally deactivates shutter charging motor  51  to stop charging lever  150 , comprising roller  152  contacting cam  154 , at the lower standby position and to release the shutter blinds from mechanical holding by shutter charging mechanism  500 . Whereby, the preceding shutter blind covers the shutter aperture, while the succeeding shutter blind move to the standby position uncovering the shutter aperture, so as to make the preceding and the succeeding shutter blinds possible to run, when deactivating electro-magnets  138 ,  139 . 
     When CPU  200  deactivates electromagnets  138 , serving for the preceding shutter blind, in the abovementioned state, the exposure is started with running of the preceding shutter blind driven by the spring so that the preceding shutter blind opens the aperture of the shutter and X switch S 3  turns ON when running of the preceding shutter blind is finished. Further, when a time period, predetermined depending on the shutter speed, has passed after the start of running of the preceding shutter blind, the succeeding shutter blind is driven by the spring so as to close the aperture of the shutter by deactivating electromagnet  139  serving for the succeeding shutter blind. 
     When X switch S 3  turns ON, CPU  200  outputs the trigger signal for initializing the strobe lighting and activates date projecting section  207  to project the date on the film. 
     When a waiting time for running of the succeeding shutter blind has passed, which is predetermined at longer time than the time being necessary for completing the running of the succeeding shutter blind, CPU  200  activates shutter charging motor  51  of shutter charging mechanism  500  to rotate charge gear  149  which moves charging lever  150  upward, so as to set the preceding and the succeeding shutter blinds at the shutter charged position. When charging lever  150  sets them at the shutter charged position, CPU  200  deactivates shutter charging motor  51 , and then drives film-feeding motor  60  to feed one frame of the film. When film feeding reflector  212  detects the completion of feeding one frame of the film, CPU  200  deactivates film-feeding motor  60  to finalize the film feeding. 
     Incidentally, when charging lever  150  sets the preceding and the succeeding shutter blinds at the shutter charged position, shutter charge reflector  158  detects the high reflective portion of detecting board  157  and outputs [H] (High level). Accordingly, the stopping process of shutter charging motor  51  is conducted on the basis of output level [H] of shutter charge reflector  158 . 
     In the abovementioned state, since two blinds of the preceding and the succeeding blinds cover the aperture of the shutter, no leakage of the light will occur. 
     Next, the operation of the focal-plane shutter will be detailed in the following, referring FIG.  19  and FIG.  20 . 
     In step a of FIG. 19, the power source for the shutter holding coil is activated to supply electric-current to electro-magnets  138 ,  139 , whereby the preceding and succeeding shutter blinds are held at the shutter charged position. In step b, shutter-charging motor  51  rotates in normal direction to move charging lever  150  of shutter-charging mechanism  500  from upper position to lower standby position enabling the running of the shutter blinds. In step c, when CPU  200  deactivates electromagnet  138 , the exposure is started with running of the preceding shutter blind driven by the spring, and in step d, timer  1  and timer  2  start to clock the time. Timer  1  clocks predetermined time period t 1  corresponding to the time until X switch S 3  turns ON, and timer  2  clocks shutter opening time t 2 . 
     In step e, either ON or OFF state of X switch S 3  is detected. In step f, when X switch S 3  turns ON, CPU  200  determines whether or not shutter opening time t 2  of timer  2  has passed, after activating the strobe trigger and the date projector (not shown in the drawings). In step g, when shutter opening time t 2  has passed, CPU  200  deactivates electro-magnet  139 , whereby the succeeding shutter blind is driven by the spring. When the waiting time for running of the succeeding shutter blind has passed in step h, shutter charging motor  51  rotates in normal direction to rotate charge gear  149  which moves charging lever  150  upward, so as to set the preceding and the succeeding shutter blinds at the shutter charged position in step i. 
     When X switch S 3  turns OFF in step e, CPU  200  determines whether or not predetermined time period t 1  has passed in step j. When not, CPU  200  determines whether or not shutter opening time t 2  of timer  2  has passed in step k. When CPU  200  determines that shutter opening time t 2  of timer  2  has passed in step k, CPU  200  deactivates electromagnet  139  and succeeding shutter blind is driven by the spring. Then, either ON or OFF state of X switch S 3  is detected in step m. When X switch S 3  turns OFF, in step n, CPU  200  determines whether or not X switch S 3  turns ON until the predetermined time t 1  of timer  1  has passed. If not, CPU  200  determines error state. 
     In case that X switch S 3  turns ON in step m, CPU  200  enters in step h after activating the strobe trigger and the date projector (not shown in the drawings), and when the waiting time for running of the succeeding shutter blind has passed, the aforementioned shutter charging operation is performed in step i. 
     Further, judgment of timer  1  is performed in step j, and when the predetermined time t 1 , corresponding to the time until X switch S 3  turns ON, has passed, judgment of timer  2  is performed in step o. When the shutter opening time of timer  2  has passed, after the succeeding shutter blind is driven by the spring, by deactivating electromagnet  139 , CPU  200  determines error state to stop operations and to conduct error jobs such as display of the warning, ban of rewinding, etc. 
     As mentioned above, CPU  200  makes judgments based on the states of X switch S 3  and timer  1 , namely, when X switch S 3  turns ON preceding to the time elapse of timer  1 , CPU  200  determines normal state of the shutter, while, when the predetermined time t 1  of timer  1  has passed before X switch S 3  turns ON, CPU  200  determines error state. 
     Shutter opening time t 2  of timer  2  is variable depending on the shutter speed and elapses either before or after X switch S 3  and predetermined time t 1  of timer  1  passes over. 
     Accordingly, the camera comprises a X switch signal detecting means for detecting X switch signal of focal-plane shutter  90  and a controlling means for performing error jobs when X switch S 3  does not turns ON within the predetermined time after depressing the shutter release button. The X switch signal detecting means and the controlling means are configured in CPU  200 . Since X switch S 3  turns ON only when the succeeding blind completely running through the aperture, it is possible to detect an error state caused by a certain malfunction, when X switch S 3  does not turns ON within the predetermined time after the succeeding blind starts running. Thus, the photographer can easily perceive the error state of the camera with the liquid-crystal display and/or the warning sound activated when the shooting becomes impossible due to a certain malfunction in focal-plane shutter  90 . 
     Next, the sequential operations of the camera will be detailed in the following, referring FIGS. 21 through 29. 
     FIG. 21 shows a flowchart of the main routine of the camera. 
     The main routine of the camera comprises the following steps of: step a 1 ; performing the initial operation when the main power switch turns ON, step a 2 ; determining either power ON or OFF, step a 3 ; turning each of power sources ON when determining power ON in step a 2 , step a 4 ; determining whether or not the status of rear cover  11  is changed to the closed state from the open state when power OFF in step a 2 , step a 5 ; determining whether or not the status of rear cover  11  is changed to the open state from the closed state when not in step a 4 , step a 6 ; determining either power ON or OFF when not in step a 5 , step a 3 ; turning each of power sources ON when determining power ON in step a 6 , step a 7 ; deactivating counter display section  205  of the liquid-crystal display when power OFF in step a 6 , step a 8 ; performing the rear cover closing processing, including, for instance, the judgment for automatic loading condition, etc., when determining that the status of rear cover  11  is changed to the closed state from the open state in step a 4 , and step a 9 ; performing the rear cover opening processing, including, for instance, the conversion of the counter display, etc., when determining that the status of rear cover  11  is changed to the open state from the closed state in step a 5 . 
     The main routine of the camera further comprises the following steps of: step a 10 ; determining whether or not one of push-switches is depressed when deactivating counter display section  205  of the liquid-crystal display in step a 7 , step a 11 ; continuing the action of determining whether or not one of push-switches is depressed until 500 ms elapses, step a 12 ; determining whether or not the rewinding switch turns ON when one of push-switches is depressed in step a 10  or when 500 ms elapses in step a 11 , step a 13 ; determining either power ON or OFF when not in step a 12 , step a 3 ; turning each of power sources ON when power ON in step a 13 , step a 14 ; performing the rewinding action when the rewinding switch turns ON in step a 12 , and performing error jobs when the rewinding action is failed, and step a 15 ; determining either power ON or OFF when the rewinding action is finished and entering into the main ON-sleep routine when power ON or entering into the sleep routine when power OFF as well as when power OFF in step a 13 . 
     The main routine of the camera further comprises the following steps of: step a 16 ; determining whether or not the camera enters into the communication mode for testing the camera with flag signals when each of power sources turns ON in step a 3 , step a 17 ; entering into the communication mode in which the camera is connected to, for instance, a Personal Computer to test its functions when determining that the camera enters into the communication mode in step a 16 , step a 18 ; determining either power ON or OFF when not in step a 16  or when the communication mode is finalized, step a 19 ; determining whether or not the camera enters into the test mode when power ON in step a 18 , step  20 ; performing the test mode when the camera enters into the test mode in step a 19 , and step a 21 ; performing the battery check when the test mode is finished, when power OFF in step a 18  or when not in step a 19 , and performing error jobs when the batteries are out of power as a result of the battery check. 
     The main routine of the camera further comprises the following steps of: step a 22 ; determining whether or not the shutter charging operation is already completed when the batteries are good as a result of the battery check in step a 21 , step a 23 ; performing the shutter charging operation and determining whether or not the shutter charging operation is normally completed when not in step a 22 , and step a 24 ; performing error jobs when the shutter charging operation is failed due to, for instance, a mechanical entrapment in the mechanism, etc., or determining whether or not the automatic loading condition is fulfilled when the shutter charging operation is normally completed or already completed in step a 22 . Incidentally, the automatic loading condition is to detect the film loading state by means of DX code, when the rear cover is closed. 
     Now, the shutter charging operation, performed in step a 23  when determining that the shutter charging operation is not completed in step a 22 , will be detailed in the following, referring FIG.  22  and FIG.  23 . 
     The embodiment of the camera shown in FIG. 22 comprises a shutter charge detecting means, including shutter charge reflector  158 , for detecting the state of shutter charging operation, and a shutter charge determining means, configured in CPU  200 , for determining the state of shutter charging operation based on the signals outputted from the shutter charge detecting means. When the shutter charge determining means determines that the shutter is in an incomplete charged state, the shutter charging operation, driven by shutter charging motor  51 , continues for longer time than the normal time period required for one routine of the shutter charge, after shutter charging motor  51  is driven, and CPU  200  bans the action to determine the state of shutter charging operation based on the signals outputted from the shutter charge detecting means within the predetermined time t 30 . 
     Since, in the incomplete charged state, the standby position of detecting board  157  linked to shutter charging motor  51  is uncertain relative to the position of shutter charge reflector  158 , after shutter charging motor  51  is driven, the shutter charging operation continues for longer time, namely, the predetermined time t 30 , than the normal time period required for one routine of the shutter charge. In addition, CPU  200  bans the determining action for the state of shutter charging operation, based on the signals outputted from the shutter charge detecting means, within the predetermined time t 30  to disable the braking action during the unstable current time t 30  at the starting period of shutter charging motor  51 . Therefore, it is possible to reduce the capacity of the RAM-memory for memorizing data of detecting the shutter charging operation and to simplify the program of it, since only the braking time after the motor current stabilizes is necessary to be memorized. 
     In another method shown in FIG. 23, when the shutter charge determining means determines that the shutter is in an incomplete charged state, CPU  200  stops shutter charging motor  51  based the second and later charge-completion decision made by the shutter charge determining means, after the first charging operation, initiating with the start of driving shutter charging motor  51 , is finished. 
     As mentioned above, when determining the incomplete charged state, CPU  200  does not stop shutter charging motor  51  at the first detecting point P 1  of the stopping position, but stops at the second detecting point P 1  of the stopping position, after the first charging operation, initiating with the start of driving shutter charging motor  51 , is finished. Since CPU  200  stops shutter charging motor  51  based the second and later charge-completion decision to ensure the necessary time period for stabilizing the shutter charging motor  51  at a constant revolution speed, the braking action is disabled during the drive-current fed to shutter charging motor  51  is unstable. Therefore, it is possible to reduce the capacity of the RAM-memory for memorizing data of detecting the shutter charging operation and to simplify the program of it, since only the braking time after the motor current stabilizes is necessary to be memorized. 
     Turning back to FIG. 21, the main routine of the camera further comprises the following steps of: step a 25 ; activating counter display section  205  of the liquid-crystal display and entering into the photometry sub-routine when not in step a 24 , step a 26 ; performing the automatic loading operation and determining whether or not the automatic loading operation is completed normally when determining that the automatic loading condition is fulfilled in step a 24 , and performing the error jobs when the automatic loading operation is failed, and step a 27 ; determining either power ON or OFF when determining that the automatic loading operation is completed normally in step a 26 , and entering into the photometry sub-routine when power ON or entering into the sleep sub-routine when power OFF. 
     FIG. 24 shows a flowchart of the initial operation sub-routine. 
     The initial operation sub-routine of the camera comprises the following steps of: step b 1 ; initializing the port, step b 2 ; banning interruptions, step b 3 ; initializing the RAM-memory, step b 4 ; determining whether or not entering into the communication mode, step b 5 ; entering into the communication mode when determining that entering into the communication mode in step b 4 , step b 6 ; determining either power ON or OFF when not in step b 4 , step b 7 ; determining whether or not entering into the test mode, and step b 8 ; performing the test mode when determining that entering into the test mode in step b 7 . 
     The initial operation sub-routine of the camera further comprises the following steps of: step b 9 ; displaying the bar symbol of [- -] on counter display section  205  of the liquid-crystal display after the test mode is completed or when power OFF in step b 6  or when not in step b 7 , step b 10 ; determining whether or not the main switch is turnover, step b 11 ; activating release button  31  in the state of power ON and determining whether or not switch S 2  turns ON when not in step b 10 , and step b 12 ; performing the battery check when determining that the main switch is turnover in step b 10  or when determining that switch S 2  turns ON in step b 11  and performing error jobs when the batteries are out of power as a result of the battery check. 
     The initial operation sub-routine of the camera further comprises the following steps of: step b 13 ; transferring data to the RAM-memory from the EEP-ROM when the batteries are good as a result of the battery check in step b 12 , step b 14 ; determining whether or not the shutter charging operation is already completed, step b 15 ; performing the shutter charging operation when not in step b 14  and determining whether or not the shutter charging operation is normally completed, and performing error jobs when the shutter charging operation is failed, step b 16 ; determining whether rear cover  11  is open or closed when determining that the shutter charging operation is normally completed in step b 15  or when determining that the shutter charging operation is already completed in step b 14 , step b 17 ; determining whether or not the camera is mid-course of shooting when determining that rear cover  11  is closed in step b 16 , step b 18 ; determining whether or not the camera is mid-course of rewinding when not in step b 17 , and&#39;step b 19 ; determining whether or not the automatic loading condition is fulfilled when not in step b 18 , and returning to the main routine when determining that the automatic loading condition is not fulfilled as well as when determining that rear cover  11  is open in step b 16 . 
     In step b 20 , when the camera is mid-course of shooting in step b 17 , CPU  200  reads the former value of the counter from the EEP-ROM. For instance, even if the battery is removed for changing to new one in the mid-course of shooting, the value of the counter is not in error, since the former value of the counter is read from the EEP-ROM. 
     Since the film rewinding sound sometimes makes noisy nuisance of other people depending on locations, the camera has a feature for allowing photographer to stop the film rewinding operation in the mid-course of it. In step b 18 , CPU  200  determines whether or not the film rewinding operation was stopped in the mid-course of it, before the battery change. In step b 21 , CPU  200  performs the continuation of the film rewinding operation when CPU  200  determines that the film rewinding operation was stopped in the mid-course of it, and returns to the main-routine when the film rewinding operation is completed or performs error jobs when the film rewinding operation is failed. When the photographer changes the battery while the film rewinding operation is stopped in the mid-course of it, the photographer would possibly forgot to activate the film rewinding operation again. To avoid the double exposure on the already exposed picture frame in the above case, CPU  200  determines whether or not the film rewinding operation was stopped in the mid-course of it, and automatically rewinds the film when CPU  200  determines that the film rewinding operation is in the mid-course of it. 
     Further, in step b 22 , CPU  200  performs the automatic loading operation when determining that the automatic loading condition is fulfilled in step b 19 , and determines whether or not the automatic loading operation is normally completed, and then, performs error jobs when the automatic loading is failed, or returns to the main routine when the automatic loading is completed normally. 
     FIG. 25 shows a flowchart of the photometry sub-routine. 
     The photometry sub-routine of the camera comprises the following steps of: step c 1 ; performing the battery check, and performing error jobs when the batteries are out of power as a result of the battery check, step c 2 ; starting the timer of 100 ms when the batteries are good as a result of the battery check in step c 1 , and step c 3 ; determining either the AE (Automatic Exposure) shooting mode or the manual shooting mode with a shutter speed set by the photographer by means of shutter dial  32 , and performing the dial check to read the IS 0  sensitivity and the exposure compensating information from ISO/exposure compensation dial  33 . When CPU  200  reads the instruction of the AE shooting mode, or the instruction of the shutter speed for the manual shooting, and/or the ISO sensitivity and the exposure compensating information from ISO/exposure compensation dial  33 , the value of the proper shutter speed for the AE shooting mode, or the value of the shutter speed set by the photographer and the value of the proper shutter speed is/are displayed in the interior of the finder. In case of the manual shooting, the value of the shutter speed set by the photographer is displayed by the constant lighting, while the value of the proper shutter speed is displayed by the periodical flashing of light. The timer of 100 ms set in step c 2  is also utilized for setting the flashing period of the light displayed in the finder. 
     In step c 3 , CPU  200  performs error jobs when the dial check value is abnormal due to, for instance, positioning errors of shutter dial  32  and/or ISO/exposure compensation dial  33  caused by mechanical entrapments, etc. In step c 4 , CPU  200  determines whether switch S 1  turns ON or OFF, when shutter dial  32  and ISO/exposure compensation dial  33  is set at the normal position and the instruction of the AE shooting mode or the shutter speed for the manual shooting, and/or the IS 0  sensitivity and the exposure compensating information are normally read into CPU  200 . 
     The photometry sub-routine of the camera further comprises the following steps of: step c 5 ; determining whether the rewinding switch turns ON or OFF when switch S 1  turns OFF in step c 4 , step c 6 ; performing the rewinding action when the rewinding switch turns ON in step c 5 , and performing error jobs when the rewinding action is failed, step c 7 ; determining either power ON or OFF when the rewinding action is normally completed in step c 6 , and entering into the main ON-sleep routine when power ON or entering into the sleep routine when power OFF, step c 8 ; determining either power ON or OFF when the rewinding switch turns OFF in step c 5 , and entering into the sleep routine when power OFF, step c 9 ; determining whether or not the status of rear cover  11  is changed to the closed state from the open state when power ON in step c 8 , step c 10 ; determining whether or not the status of rear cover  11  is changed to the open state from the closed state when not in step c 9 , and step c 11 ; determining whether or not 100 ms has passed when not in step c 10 , and returning to step c 3  when 100 ms has not passed. 
     The photometry sub-routine of the camera further comprises the following steps of: step c 12 ; performing the rear cover closing processing, including, for instance, the judgment for automatic loading condition, etc., when determining that the status of rear cover  11  is changed to the closed state from the open state in step c 9 , step c 13 ; performing the rear cover opening processing, including, for instance, the conversion of the counter display, etc., when determining that the status of rear cover  11  is changed to the open state from the closed state in step c 10 , step c 14 ; determining whether or not the photometry is the first time when determining that 100 ms has passed in step c 11 , step c 15 ; determining whether or not the AE lock mode is activated when not in step c 14 , step c 16 ; reading the digital photometry data after converting the analog photometry data to the digital photometry data when not in step c 15 , and step c 17 ; calculating the shutter speed based on the digital photometry data. 
     When CPU  200  determines that the photometry is the first time in step c 14 , CPU  200  enters step c 16  and reads the digital photometry data after converting the analog photometry data to the digital photometry data, and then, in step c 17 , calculates the shutter speed based on the digital photometry data. 
     The photometry sub-routine of the camera further comprises the following steps of: step c 18 ; determining whether or not the cable release is activated, and entering step c 32 , in which deactivating the liquid-crystal display in the finder and entering the real exposure sub-routine as shown in FIG. 27, when determining that the cable release is activated, step c 19 ; changing the contents displayed on the liquid-crystal display in the finder corresponding to the result of the shutter speed calculation performed in step c 17  when not in step c 18 , step c 20 ; determining whether or not  15  seconds have passed, and returning to step c 3  when determining that 15 seconds have not passed, and step  21 ; deactivating the liquid-crystal display in the finder and entering the routine after the photometry when determining that 15 seconds have passed in step c 20 . 
     When switch S 1  turns ON during the photometry operation described above, CPU  200  enters into the shutter operation mode, shifting-to step c 22  from step c 4 . 
     The photometry sub-routine of the camera further comprises the following steps of: step c 22 ; determining whether or not the automatic loading condition is fulfilled, step c 23 ; performing the automatic loading operation and determining whether or not the automatic loading operation is completed normally when determining that the automatic loading condition is fulfilled in step c 22 , and performing the error jobs when the automatic loading operation is failed, step c 24 ; determining either power ON or OFF when determining that the automatic loading operation is completed normally in step c 23 , and returning to step c 1  when power ON or entering into the sleep sub-routine when power OFF, step c 25 ; determining whether switch S 2  turns ON or OFF when not in step c 22 , step c 26 ; determining whether switch S 1  turns ON or OFF when determining that switch S 2  turns OFF in step c 25 , and entering step c 5  when determining that switch S 1  turns OFF or entering step c 27  when determining that switch S 1  turns ON, step c 27 ; entering step c 14  when switch S 2  does not turn ON and switch S 1  does not turn OFF until 100 ms has passed, step c 28 ; determining whether or not the photometry is the first time when determining that switch S 2  turns ON in step c 25 , step c 32 ; deactivating the liquid-crystal display in the finder when not in step c 28 , and entering step e 1  of the real exposure sub-routine shown in FIG. 27 after switch S 2  turns ON, step c 29 ; determining whether or not the camera is in the manual shooting mode when determining that the photometry is the first time in step c 28 , step c 31 ; calculating the shutter speed when determining that the camera is in the manual shooting mode in step c 29  and entering step c 32 , and step c 30 ; determining whether or not the camera is ready for flashing based on the charge completion signal of the strobe section when not in step c 29 , and entering step c 32  through step c 31  when determining that the camera is ready for flashing or returning to step c 26  when determining that the camera is not ready for flashing. 
     FIG. 26 shows a flowchart of the main ON-sleep sub-routine, which is performed after the photometry is finished and 15 second has passed since the main routine is activated. 
     The main ON-sleep sub-routine of the camera comprises the following steps of: step d 1 ; determining whether or not the status of rear cover  11  is changed to the closed state from the open state, step d 2 ; determining whether or not the status of rear cover  11  is changed to the open state from the closed state when not in step d 1 , step d 3 ; determining either power ON or OFF when not in step d 2 , step d 4 ; performing the rear cover closing processing, including, for instance, the judgment for automatic loading condition, etc., when determining that the status of rear cover  11  is changed to the closed state from the open state in step d 1 , step d 5 ; performing the rear cover opening processing, including, for instance, the conversion of the counter display, etc., when determining that the status of rear cover  11  is changed to the open state from the closed state in step d 2 , step d 6 ; entering into the sleep routine when power OFF in step d 3 , or determining whether or not one of push-switches is depressed when power ON in step d 3 , and step d 7 , d 8 ; continuing the action of determining whether or not one of push-switches is depressed until 500 ms elapses, when not in step d 6 . 
     The main ON-sleep sub-routine of the camera further comprises the following steps of: step d 9 ; determining whether switch S 1  turns ON or OFF, and entering into the photometry routine when determining that switch S 1  turns ON, step d 10 ; determining whether or not the cable release is activated when determining that switch S 1  turns OFF in step d 9 , and entering into the photometry routine when the cable release is activated, step d 11 ; determining whether the rewinding switch turns ON or OFF when not in step d 10 , and returning to step d 1  when determining that the rewinding switch turns OFF, step d 12 ; performing the rewinding action when determining that the rewinding switch turns ON in step d 11 , and determining whether or not the rewinding action is normally completed, and performing error jobs when the rewinding action is failed, and step d 13 ; determining either power ON or OFF when determining that the rewinding action is normally completed, and entering into the sleep routine when power OFF or entering into the main ON-sleep routine when power ON. 
     FIG. 27 shows a flowchart of the real-exposure sub-routine. 
     The real-exposure sub-routine of the camera comprises the following steps of: step e 1 ; determining whether or not the self-timer mode is activated when switch S 1  turns ON to enter the real-exposure mode, step e 2 ; flashing the liquid-crystal display to indicate the self-timer mode, step e 3 ; determining whether or not the self-timer switch turns ON or OFF during the self-timer mode, step e 4 ; determining either power ON or OFF when determining that the self-timer switch turns OFF, and entering into the sleep routine when power OFF or entering into the photometry routine, shown in FIG. 25, when power ON, step e 5 ; determining whether the rewinding switch turns ON or OFF when determining that the self-timer switch turns ON during the self-timer mode, step e 6 ; performing the rewinding action when determining that the rewinding switch turns ON in step e 5 , and determining whether or not the rewinding action is normally completed, and performing error jobs when the rewinding action is failed, step e 7 ; determining either power ON or OFF when determining that the rewinding action is normally completed, and entering into the main ON-sleep routine, shown in FIG. 26, when power ON or entering into the sleep routine when power OFF. 
     The real-exposure sub-routine of the camera further comprises the following steps of: step e 8 ; supplying electronic-current to the shutter coil when determining that the rewinding switch turns OFF or when not in step e 1 , step e 9 ; waiting 10 ms of the waiting time, step e 10 ; driving the shutter after the waiting time, step e 11 ; determining whether or not the shutter driving results in error, and performing error jobs when determining that the shutter driving results in error, step e 12 ; determining whether or not continuous shooting mode is activated when not in step e 11 , step e 13 ; performing the shutter charging operation when not in step e 12 , and then, determining whether or not the shutter charging operation is normally completed and performing error jobs when the shutter charging operation is failed, step e 14 ; performing the one-frame-film feeding operation, and then, determining whether or not the one-frame-film feeding operation is normally completed and performing error jobs when the one-frame-film feeding operation is failed, step e 15 ; determining whether or not the film tension of the final frame is detected, and entering step e 20  when determining that the film tension of the final frame is detected, and step e 16 ; waiting until switch S 2  turns OFF and the cable release is deactivated when not in step e 15 , and entering into the photometry sub-routine shown in FIG.  25 . 
     The real-exposure sub-routine of the camera further comprises the following steps of: step e 17 ; performing the shutter charging operation and the film feeding operation simultaneously when determining that continuous shooting mode is activated in step e 12 , step e 18 ; determining whether or not the shutter charging operation results in error and performing error jobs when determining that the shutter charging operation results in error, step e 19 ; determining whether or not the film tension of the final frame is detected when not in step e 18 , step e 20 ; performing the rewinding operation when determining that the film tension of the final frame is detected in step e 19 , and then, determining whether or not the rewinding operation is normally completed and performing error jobs when the rewinding operation is failed, step e 21 ; determining either power ON or OFF when determining that the rewinding operation is normally completed, and entering into the main ON-sleep routine shown in FIG. 26 when power ON or entering into the sleep routine when power OFF, step e 22 ; determining whether or not the film feeding operation results in error when not in step e 19 , and performing error jobs when determining that the film feeding operation results in error, step e 23 ; determining whether or not the automatic loading condition is fulfilled when not in step e 22 , step e 24 ; changing the value of the counter to [1] and entering step e 16  when determining that the automatic loading condition is fulfilled in step e 23 , step e 25 ; determining whether or not the value of the counter is [0] when not in step e 23 , step e 26 ; adding [1] to the value of the counter when not in step e 25 , step e 27 ; determining whether or not switch S 2  turns ON in the continuous shooting mode or whether or not the cable release is activated, and entering step e 16  when not, step e 28 ; determining whether or not the AE shooting mode is selected when determining that switch S 2  turns ON or the cable release is activated in step e 27 , and step e 29 ; performing the photometry and re-calculation of the shutter speed when determining that the AE shooting mode is selected in step e 28  and returning to step e 8 . 
     FIG. 28 shows a flowchart of the shutter charging and film feeding sub-routine performed in step e 17  shown in FIG.  27 . 
     The shutter charging and film feeding sub-routine of the camera comprises the following steps of: step f 1 ; confirming a shutter charging state by checking detecting board  157  stuck on detecting gear  156  by means of shutter charge reflector  158 , step f 2 ; determining whether or not charging lever  150  is positioned at a charge standby state, step f 25 ; turning the charge error flag to ON when not in step f 2 , and exiting this sub-routine to return to the real-exposure sub-routine, step f 3 ; initializing the flag for film-feeding when determining that charging lever  150  is positioned at a charge standby state in step f 2 , step f 4 ; initializing the RAM, step f 5 ; starting the 1 second timer, step f 6 ; rotating film feeding motor  60  in normal direction, step f 7 ; waiting 250 μs, step f 8 ; rotating shutter charging motor  51  in normal direction, step f 9 ; waiting 250 μs, and step f 10 ; confirming a film-feeding state. In the abovementioned flow, the starting time of film feeding motor  60  and that of shutter charging motor  51  are shifted 250 μs each other, in order to confirm the film-feeding state and the shutter charging state at an interval every 1 ms. 
     The shutter charging and film feeding sub-routine of the camera further comprises the following steps of: step f 11 ; further waiting 250 μs, step f 12 ; confirming a shutter charging state, step f 13 ; waiting 250 μs, and step f 14 ; determining whether or not the 1-second timer reaches to the timeout state. 
     In the above flowchart, both the confirming process of the shutter charging state and that of film feeding state are configured in the sub-routines, both of which finalize the processing within 250 μs. Therefore, the checking action for the shutter charging state and that for film feeding state is performed at an interval every 1 ms including waiting time of 250 μs inserted between two sub-routines mentioned above. 
     In both the confirming process of the shutter charging state and that of film feeding state, CPU  200  detects a present status of each process to perform a suitable processing corresponding to the detected status. Accordingly, CPU  200  sets a finalization flag when detecting completion of the film feeding or completion of the shutter charging at a certain time during repeatedly running through both sub-routines. 
     The shutter charging and film feeding sub-routine of the camera further comprises the following steps of: step f 14 ; determining whether or not the 1-second timer reaches to the timeout state after detecting completion of the film feeding operation and completion of the shutter charging operation, step f 15 ; determining whether or not the shutter charging operation is completed when not in step f 14 , and returning to step f 10  when determining that the shutter charging operation is not completed, step f 16 ; determining whether or not the film feeding operation is completed when determining that the shutter charging operation is completed in step f 15 , step f 17 ; stopping the 1-second timer when determining that the film feeding operation is completed in step f 16 , and exiting this sub-routine to return-to the real-exposure sub-routine. 
     For instance, when the film feeding operation is not completed in step f 16 , CPU  200  does not enter the shutter driving mode (shutter charge standby state), even if the shutter charging operation is completed in step f 15 . When both the film feeding operation and the shutter charging operation are completed within the predetermined time interval, CPU  200  stops the 1-second timer and exits the shutter charging and film feeding sub-routine to return to the real-exposure sub-routine. 
     Returning to the real-exposure sub-routine, the continuous shooting mode will be repeated, when the release button is still depressed to turn switch S 2  ON. 
     The shutter charging and film feeding sub-routine of the camera further comprises the following steps of: step f 18 ; stopping the 1-second timer when determining that the 1-second timer reaches to the timeout state in step f 14 , step f 19 ; determining whether or not the film feeding operation is completed, step f 20 ; determining whether or not the shutter charging operation is completed, when determining that the film feeding operation is completed in step f 19 , and exiting this sub-routine to return to the real-exposure sub-routine when determining that the shutter charging operation is completed, step f 21 ; stopping the film feeding motor  60  when not in step f 19 , step f 22 ; turning the film feeding error flag to ON, and entering step f 20 , step f 23 ; stopping shutter charging motor  51  when not in step f 20 , and step f 24 ; turning the shutter charging error flag to ON, and exiting this sub-routine to return to the real-exposure sub-routine. 
     FIG. 29 shows a flowchart of the shutter drive sub-routine performed in step e 10  shown in FIG.  27 . 
     The shutter drive sub-routine of the camera comprises the following steps of: step g 1 ; performing the shutter charge standby operation by rotating shutter charging motor  51  in normal direction, thereby, the preceding shutter blind and the succeeding shutter blind are electrically held, instead of the previous mechanical holding state, step g 2 ; determining whether or not the shutter charge standby operation is completed, step g 17 ; turning the shutter charge error flag to ON when not in step g 2 , and exiting this sub-routine to return to the real-exposure sub-routine, step g 3 ; allowing the preceding shutter blind to run by deactivating electro-magnet  138  serving for the preceding shutter blind when determining that the shutter charge standby operation is completed in step g 2 , step g 4 ; starting the specified time counter, step g 5 ; starting the shutter time counter which measures a shutter time corresponding to the real-exposure time, step g 6 ; determining whether or not X switch S 3  turns ON, step g 14 ; activating the trigger of the strobe and the date section (not shown in drawing) when determining that X switch S 3  turns ON in step g 6 , and then, determining whether or not the shutter time has passed, step g 15 ; allowing the succeeding shutter blind to run by deactivating electro-magnet  139  serving for the succeeding shutter blind when determining that the shutter time has passed in step g 15 , step g 16 ; waiting until the running time of the succeeding shutter blind has elapsed, and then, returning to the real-exposure sub-routine, step g 7 ; determining whether or not the specified time has passed when not in step g 6 , step g 8 ; turning the shutter drive error flag to ON when determining that the specified time has passed in step g 7 , step g 9 ; determining whether or not the shutter time has passed when not in step g 7 , and returning to step g 6  when determining that the shutter time has not passed, and step g 10 ; allowing the succeeding shutter blind to run when determining that the shutter time has passed in step g 9 . 
     As mentioned above, when the specified time has elapsed until X switch S 3  turns ON, CPU  200  determines that the preceding shutter blind did not open within the specified time interval and turns the shutter drive error flag to ON. 
     The shutter drive sub-routine of the camera further comprises the following steps of: step g 10 ; allowing the preceding shutter blind to run, step g 11 ; determining whether or not X switch S 3  turns ON, and entering step g 16  after activating the trigger of the strobe and the date section (not shown in drawing) when determining that X switch S 3  turns ON, step g 12 ; determining whether or not the specified time has passed when not in step g 11 , and step g 13 ; returning to step g 11  when not in step g 12 , or turning the shutter drive error flag to ON and entering step g 16  when determining that the specified time-has passed in step g 12 . 
     As mentioned above, when the exposure time is shorter than the specified time, CPU  200  allows the preceding shutter blind to run, and checks the ON status of X switch S 3  and the elapse of the specified time. Then, when the specified time has elapsed again until X switch S 3  turns ON even at this time, CPU  200  turns the shutter drive error flag to ON. After the succeeding shutter blind starts running, the shutter drive sub-routine is finalized when a sufficient time has passed to complete the running operation of the succeeding shutter blind. 
     According to the present invention, it becomes possible to improve the efficiency of the photometry, since the longer direction of the photometric region coincides with that of the image window by arranging the photometry means at substantially the center side position of the shorter-axis of the image window, viewing from the shooting lens side. 
     Further, according to the present invention, it becomes possible for a photographer to select the suitable photometric region corresponding to the scene to be shot, since the variable photometry can be achieved by varying the photometric region in an optical path, through which the light reflected by the focal-plane shutter incidents on (enters into) the photometry means. 
     Further, according to the present invention, it becomes possible for the photographer to easily select the desirable photometric region, since the photometric region is displayed on the photometric region display, which is equipped in the finder to display the photometric region set by the photometry aperture. 
     Further, according to the present invention, since the photometry means is integrally assembled with the focal-plane shutter unit, so as to adjust the relative position between the focal-plane shutter and the photometry means before assembling the unit in the camera body, it becomes possible to detect failed units and to precisely assemble the units. 
     Further, according to the present invention, since the dating means is integrally assembled with the focal-plane shutter unit, so as to adjust the relative position between the focal-plane shutter and the dating means in a state of unit, the readjustment of the relative position between them is not necessarily when performing maintenance works. 
     Furthermore, according to the present invention, since the X switch turns ON only when the succeeding blind completely running through the aperture, it is possible to detect an error state caused by a certain malfunction, when the X switch does not turns ON within the predetermined time after the succeeding blind starts running. Thus, the photographer can easily perceive the error state of the camera with the liquid-crystal display and/or the warning sound activated when the shooting becomes impossible.