Abstract:
An image sensing apparatus such as digital still camera and video camera having a lens barrel which is driven to extended-out and retracted-in positions. The apparatus comprises an external operation device externally operated by a user. When the image sensing apparatus is released from a disabled mode, the user is allowed to make a selection between cases where the optical system is positioned in the extended-out position and retracted-in position, through the operation device.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an image sensing device and a recording/reproduction device such as an electronic still camera and a video camera. 
     There have been proposed compact cameras using silver-salt films with a collapsible lens barrel. Compact cameras are designed to extend the barrel outwardly to a photographable position where the cameras are operable to take a picture when a power supply is turned-on, while retracting the barrel to a retracted position, or collapse position, when the power is turned-off, thus providing portability. FIG. 1 illustrates a perspective view showing a camera having such collapsible or retractable barrel, wherein the barrel is illustrated as retracted. In FIG. 1, reference numeral  60  denotes an operation lever for opening and closing a barrier (not shown). A user operates this operation lever  60  to open the barrier connected. 
     However, such cameras keep a collapsible barrel extended out during powered-on, so that the barrel is ready to be broken during the it is extended out. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in consideration of the aforementioned problem involved in the prior art. 
     An object of the present invention is to provide an image sensing apparatus comprising: 
     a driver device moving an image sensing optical system to image sensing and non image sensing regions; and 
     an external operation device that voluntarily selects a first mode in which the optical system is in the image sensing region or a second mode in which the optical system is positioned in the non image sensing region by an external operation, wherein the first mode and the second mode are different from an OFF mode. 
     The image sensing apparatus constructed above positions the optical system in the non image sensing region even when the apparatus is powered up, in a case where an electronic finder is being OFF&#39;ed, or images are being reproduced, for examples. In such cases, it does not matter that the optical system is in the non image sensing region, and placing the optical system in the non image sensing region can prevent it from being broken accidentally. 
     Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a conventional digital camera; 
     FIG. 2 is a block diagram showing an image sensing device of an embodiment according to the present invention; 
     FIGS. 3A and 3B are plan and front views respectively showing a lens barrier in the image sensing device illustrated in FIG. 2; 
     FIG. 4 is a view showing a lens barrel in the image sensing device illustrated in FIG. 2; 
     FIG. 5 is a view showing the lens barrel in the image sensing device illustrated in FIG. 2; 
     FIG. 6 is a view showing the lens barrel in the image sensing device illustrated in FIG. 2; 
     FIG. 7 is a view showing the lens barrel in the image sensing device illustrated in FIG. 2; 
     FIG. 8 is a view showing the lens barrel in the image sensing device illustrated in FIG. 2; 
     FIG. 9 is a view showing the lens barrel in the image sensing device illustrated in FIG. 2; 
     FIG. 10 is a view showing the lens barrel in the image sensing device illustrated in FIG. 2; 
     FIGS. 11A and 11B are plan and front views respectively showing a battery cover in the image sensing device illustrated in FIG. 2; 
     FIGS. 12A and 12B are plan and front views respectively showing a CF cover in the image sensing device illustrated in FIG. 2; 
     FIGS. 13A and 28B are a flow chart showing operation operated by a CPU of the image sensing device illustrated in FIG. 2; 
     FIG. 14 is a flow chart showing operation operated by a CPU of the image sensing device illustrated in FIG. 2; and 
     FIG. 15 is a flow chart showing operation operated by the CPU of the image sensing device illustrated in FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment according to the present invention will be described in detail below with reference to the accompanying drawings. 
     FIG. 2 is a block diagram showing an image sensing device of the embodiment. 
     In FIG. 2, reference numeral  101  denotes a housing (outer casing) covering the whole image sensing device; and  102   a , an electrically openable lens barrier placed inside the housing  101 . When a moving lens barrel (to be described later) is housed (collapsed), the lens barrier  102   a  is so positioned as to cover the front surface of the moving lens barrel. An actuator  102   b  is, e.g., a stepping motor and opens and closes the lens barrier  102   a . A detection switch  102   c  is, e.g., a leaf switch and detects “opening” and “closure” of the lens barrier  102   a.    
     A motor driver  103  drives the stepping motor as the actuator  102   b . The constructions of the lens barrier  102   a , the stepping motor as the actuator  102   b , the detection switch  102   c , and the like will be described in detail later. 
     A moving lens barrel  104   a  can be collapsed inside the housing  101  to a non image sensing position in a non image sensing mode and extended to an image sensing position outside the housing  101  in a sensing mode. This moving lens barrel  104   a  holds some photographing lenses. In this image sensing device, the moving lens barrel  104   a  moves to achieve a focusing function. An actuator  104   b  is, e.g., a stepping motor and moves the lens barrel  104   a . A detecting means  104   c  is, e.g., a photointerrupter and detects the reset position of the moving lens barrel  104   a.    
     A motor driver  105  drives the stepping motor of the actuator  104   b . An aperture/shutter  106   a  has both of an aperture function of adjusting the sensing light amount and a shutter function. An actuator  106   a   1  actually drives aperture blades. A motor driver  107  drives the actuator  106   a   1 . Reference numeral  108  denotes a fixed lens barrel for mounting a CCD or the like. This fixed lens barrel  108  holds fixed photographing lenses except for those held by the moving lens barrel  104   a . A photoelectric converting element or CCD  109  converts an optical image formed by the photographing lenses into an electrical signal. A driver  110  drives the CCD  109 . 
     An A/D converter  111  converts the electrical signal from the CCD  109  into a digital signal. An image signal processing IC  112  converts the digital signal from the A/D converter  111  into a signal of a format suited for display on an LCD (to be described below) or a signal of a format suited for recording on a recording medium inserted into a CF slot (recording medium slot to be described later). An LCD  113 , as an electronic view finder, displays the signal from the image signal processing IC  112 . This LCD  113  allows a user to observe live object images formed by the photographing lenses. A driver  114  drives the LCD  113 . 
     Reference numeral  115  denotes a CF slot (recording medium slot) into which a CF card (recording card) can be inserted. This CF slot  115  can record a signal processed by the image signal processing IC  112  on the recording medium. An LCD switch  116  can switch ON and OFF of the LCD  113  in a toggle manner. A REC/LOCK switch  117  can switch this image sensing device between a sensing mode (REC mode) and an operation stop mode (LOCK mode). When the switch is turned to REC mode, the image sensing device is powered on and ready to start an image sensing, while when it is turned to LOCK mode, the device is powered off. A release switch  118  allows to initiate image sensing operation when the REC/LOCK switch  117  is in the REC position. This release switch  118  has two stroke positions: the first position is referred to as a first release position, and the second position is as a second release position. When the switch  118  is at the first stroke position, AE (automatic-exposure) and AF (automatic-focusing) operations are enabled, while when the switch  118  is at the second stroke position, an image sensing is enabled. The switches  116 ,  117  and  118  are manually operated. The AF mechanism of this image sensing device is so-called hill climbing TVAF. 
     Reference numeral  119  denotes an optical finder through which a user can optically observe an object image;  120 , a battery box into which a battery for supplying power to the image sensing device can be inserted; and  121   a , a CF cover for covering the CF slot. This CF cover  121   a  has a lock mechanism and can be opened only when this lock mechanism is unlocked. A CF cover unlock detection switch  122  detects that the lock mechanism of the CF cover  121   a  is unlocked. It is possible by this switch to detect the possibility of the CF cover  121   a  being opened. 
     Reference numeral  123   a  denotes a battery cover for covering the battery box. This battery cover  123   a  has a lock mechanism and can be opened only when this lock mechanism is unlocked. A battery cover unlock detection switch  124  detects that the lock mechanism of the battery cover  123   a  is unlocked. It is possible by this switch to detect the possibility of the battery cover  123   a  being opened. 
     Reference numeral  126  denotes a manually operated switch by which a user switches a macro sensing region and a non-macro sensing region, thereby switching normal distance sensing (non-macro) and macro distance sensing (macro). A CPU  125  detects the states of the switches, controls the drivers and the A/D converter, checks the voltage of the battery in the battery box, detects a system error and the like of this image sensing device, and controls the image sensing device. 
     FIGS. 3A and 3B are plan and front views respectively showing details of the lens barrier unit including the lens barrier  102   a , the stepping motor as the actuator  102   b , and the detection switch  102   c.    
     The actuator  102   b  is a stepping motor having an output shaft into which a pinion gear  102   b   1  is pressed. The rotation of this stepping motor  102   b  is transmitted to a two-stage gear  102   d  and an output screw  102   e  formed by integrating a lead screw and a spur gear. The stepping motor  102   b , the two-stage gear  102   d , and the output screw  102   e  are mounted on a gear box  102   f  which is fixed to a barrier base  102   i . The tip of the output screw  102   e  is received by a bearing  102   i   1  of the barrier base  102   i.    
     The rotation of the output screw  102   e  is transmitted to a nut  102   g  engaging with the screw. This nut  102   g  engages with the slider  102   h  which is so caulked as to be movable in a direction A on the barrier base  102   i . The lens barrier  102   a  is rotatably caulked to a support portion  102   i   2  of the barrier base  102   i . This lens barrier  102   a  is engaged with the slider  102   h  by a bias spring  102   j  extended between a shaft  102   a   1  caulked to the lens barrier  102   a  and a slider  102   h . Accordingly, when the slider  102   h  moves in the direction A (FIG.  3 A), the lens barrier  102   a  rotates in a direction B (FIG. 3B) to open or close. 
     Leaf switches  102   c   1 ,  102   c   2 , and  102   c   3  detect opening and closure of the lens barrier  102   a . That is, a member  102   h   1  of the slider  102   h  which moves integrally with the lens barrier  102   a  pushes the leaf switch  102   c   2  and brings it into contact with the leaf switch  102   c   1 . Also, a member  102   h   2  pushes the leaf switch  102   c   2  and brings it into contact with the leaf switch  102   c   3 . In this manner opening or closure of the lens barrier  102   a  is detected. 
     FIGS. 4 to  10  are views showing details of the moving lens barrel  104   a , the iris (which also serves as a shutter)  106   a , and the fixed lens barrel  108 . FIG. 4 is a front view, FIGS. 5,  6 , and  7  are side views of the right side, and FIGS. 8,  9 , and  10  are sectional views of the central right side. 
     FIGS. 5 and 8 show the state in which the moving lens barrel  104   a  is at the collapsed (housed) position which is within “non image-sensing region”. FIGS. 6 and 9 show the state in which the moving lens barrel  104   a  is extended to an image sensing position which is within a “image-sensing region”. FIGS. 7 and 10 show the state in which the moving lens barrel  104   a  is in a reset position. 
     In FIGS. 8 and 9, reference numerals  127   a  to  127   d  denote photographing lenses:  127   a  is a G 1  lens (glass lens),  127   b  is a G 2  lens,  127   c  is a G 3 -G 4  cemented lens, and  127   d  is a G 5  lens. The G 1  lens  127   a  is caulked to the moving lens barrel  104   a . The G 2  lens  127   b , the G 3 -G 4  cemented lens  127   c , and the G 5  lens  127   d  are caulked to the fixed lens barrel  108  (FIG.  8 ). 
     In FIG. 4, reference numeral  128  denotes a main guide bar of the moving lens barrel  104   a ; and  129 , a sub-guide bar of the moving lens barrel  104   a  . The moving lens barrel  104   a  can move in the direction of optical axis while being guided by the main guide bar  128  and the sub-guide bar  129 . A lead screw  130  is an output shaft of a lens barrel driving stepping motor (not shown). In FIG. 6, nut  131  engages with this lead screw  130 . This nut  131  is clamped by a member  104   a   1  of the moving lens barrel  104   a , and the rotation of the nut  131  is regulated by the moving lens barrel  104   a . When the lens barrel driving stepping motor rotates in this state, in accordance with the direction of this rotation the moving lens barrel  104   a  moves step by step in the direction of optical axis along the main guide bar  128  and the sub-guide bar  129 . 
     Referring to FIGS. 5 to  7 , a photointerrupter  132  is attached to the fixed lens barrel  108 . A light-shielding plate  133  is attached to the moving lens barrel  104   a  and shields projected light from the photointerrupter  132  in accordance with the movement in the optical axis direction of the moving lens barrel  104   a . In the embodiment, the light from the photointerrupter  132  is not shielded when the moving lens barrel  104   a  is housed (collapsed), and is completely shielded when the lens barrel  104   a  is in the sensing region. That is, a switching point between non-light shielding and light shielding of the photointerrupter  132  exists between the position of housing (collapse) and the sensing region of the moving lens barrel  104   a . This switching point is the reset position of the moving lens barrel  104   a . At this switching point the moving lens barrel  104   a  is collapsed inside the housing (outer casing)  101  in front of the lens barrel. 
     In the image sensing device of the embodiment, the housing (collapse) position and the infinite and closest positions of the sensing region of the moving lens barrel  104   a  can be controlled by storing them as the numbers of steps of the stepping motor from the reset position in the CPU  125 . 
     FIGS. 11A and 11B illustrate plan and front views respectively showing details of the battery cover  123   a , the detection switch  124 , and their peripheral components. 
     Referring to FIG. 11A, the battery cover  123   a  can pivot in a direction C upon a shaft  123   a   1 . Referring to FIG. 11B, a slide button  123   c  is positioned outside the housing (outer casing)  101  and can slide in directions D and E. A locking member  123   b  is positioned inside the housing and moves integrally with the slide button  123   c . When the slide button  123   c  is slid in the direction D, a member  123   b   1  engages with a member  123   a   2  of the battery cover  123   a  to lock the pivot of the battery cover  123   a . The detection switch  124  can detect the position of the locking member  123   b  which moves integrally with the slide button  123   c . Since, therefore, the state of the slide button  123   c  which is slid to open the battery cover  123   a  can be detected, this image sensing device can detect the possibility of the battery cover  123   a  being opened, i.e., the possibility of the battery being removed. 
     FIGS. 12A and 12B illustrate plan and front views respectively showing details of the CF cover  121   a , the detection switch  122 , and their peripheral parts. 
     Referring to FIG. 12A, the CF cover  121   a  can pivot in a direction F upon a shaft  121   a   1 . Referring to FIG. 12B, a slide button  121   b  is positioned outside the housing (outer casing)  101  and can slide in directions G and H. A locking member  121   c  is positioned inside the housing and moves integrally with the slide button  121   b . When the slide button  121   b  is slid in the direction G, a member  121   b   1  engages with a member  121   a   2  of the CF cover  121   a  to lock the pivot of the CF cover  121   a . A detection switch  122  can detect the position of the locking member  121   c  which moves integrally with the slide button  121   b . Hence, the state of the slide button  121   b  which is slid to open the CF cover  121   a  can be detected, so this image sensing device can detect the possibility of the CF cover  121   a  being opened, i.e., the possibility of the CF being removed. 
     FIG. 13 is a flow chart for principally explaining the motions of the moving lens barrel  104   a  and the lens barrier  102   a  when the REC/LOCK switch  117  of this image sensing device is switched from the LOCK position to the REC (sensing) position. The motions are controlled by the CPU  125 . 
     The REC/LOCK switch  117  is switched from the LOCK position to the REC position (step S 100 ). The stepping motor as the actuator  102   b  rotates in a direction in which the lens barrier  102   a  opens (step S 101 ). This stepping motor rotates for five seconds until the leaf switches  102   c   3  and  102   c   2  of the detection switch  102   c  are turned on (detect the opening of the lens barrier  102   a ) (step S 102 ). 
     If the detection switch  102   c  is not turned on even after the stepping motor as the actuator  102   b  is driven for five seconds, the CPU  125  determines that a system error has occurred, and the actuator  102   b  rotates in a direction in which the lens barrier  102   a  closes (step S 104 ). 
     The stepping motor as the actuator  102   b  rotates for five seconds until the leaf switches  102   c   1  and  102   c   2  of the detection switch  102   c  are turned on (detect the closure of the lens barrier  102   a ) (step S 105 ). When the leaf switches  102   c   1  and  102   c   2  are turned on, the CPU  125  stops the system (step S 106 ). If the leaf switches  102   c   1  and  102   c   2  are not turned on (do not detect the closure of the lens barrier  102   a ) even after the five-second rotation, the CPU  125  determines that a system error has occurred and stops the system (step S 106 ). 
     If the leaf switches  102   c   3  and  102   c   2  of the detection switch  102   c  are turned on (detect the opening of the lens barrier  102   a , step S 103 ), the CPU  125  detects whether the LCD switch  116  is ON or OFF (step S 107 ). If the LCD switch  116  is OFF (i.e., the panel of the LCD  113  is OFF), a photographer is framing through the optical finder  119 . 
     The lens barrel driving stepping motor is driven in a direction in which the moving lens barrel  104   a  is extended (step S 108 ). This lens barrel driving stepping motor is driven for ten seconds until the reset position of the moving lens barrel  104   a  is detected (step S 110 ). If the reset position is detected within this ten-second driving (step S 110 ), the CPU  125  stops the moving lens barrel  104   a  by stopping the stepping motor (step S 111 ). If the reset position is not detected even after the ten-second driving, the CPU  125  determines that a system error has occurred and stops the system (step S 112 ). 
     In the above operation, the moving lens barrel  104   a  is stopped in the reset position in steps S 110  and S 111 . However, the moving lens barrel  104   a  can also be kept stopped in the housing (collapse) position or stopped before or behind the reset position by a predetermined distance, as long as the moving lens barrel  104   a  does not protrude from the outer casing. 
     If the LCD switch is ON (i.e., the panel of the LCD  113  is ON), it is highly likely that the photographer is framing on a live image on the LCD. 
     If this is the case, this live image needs to be focused to a certain degree. The lens barrel driving stepping motor is driven in the direction in which the moving lens barrel  104   a  is extended (step S 113 ). The lens barrel moving stepping motor is driven for ten seconds until the reset position of the moving lens barrel  104   a  is detected (step S 114 ). If the reset position is not detected even after this ten-second driving, the CPU  125  determines that a system error has occurred and stops the system (step S 115 ). 
     If the reset position is detected (step S 116 ), the CPU  125  detects whether the macro/non-macro sensing region switch  126  indicates macro (closest) or non-macro (normal distance) (step S 117 ). If macro is indicated, the CPU  125  extends the moving lens barrel  104   a  to a position where an object at infinity is focused, which is prestored as the number of stepping motor pulses from the reset position (step S 118 ). In this image sensing device, the closest distance is 10 cm. 
     When the first release of the release switch  118  is turned on (step S 161 ), the moving lens barrel  104   a  is driven to an in-focus position by hill climbing AF (step S 162 ). When the second release of the release switch  118  is turned on (step S 163 ), an image is sensed (step S 164 ). Steps  165  to S 168  are operations performed while the sensed image is recorded on the CF card (recording medium) in the CF slot (recording medium slot)  115  via the A/D converter  11  and the image signal processing IC  112 . 
     The lens barrel driving stepping motor is driven in a direction in which the moving lens barrel  104   a  is collapsed (step S 165 ). This lens barrel driving stepping motor is driven for ten seconds until the reset position of the moving lens barrel  104   a  is detected (step S 166 ). If the reset position is detected within this ten-second driving (step S 168 ), the CPU  125  extends the moving lens barrel  104   a  to the position where an object at the closest distance is focused, which is prestored as the number of stepping motor pulses from the reset position (step S 118 ). If the reset position is not detected even after the ten-second driving, the CPU  125  determines that a system error has occurred and stops the system (step S 167 ). 
     If non-macro is indicated, the CPU  125  extends the moving lens barrel  104   a  to a position where an object at infinity is focused, which is prestored as the number of stepping motor pulses from the reset position (step S 119 ). When the first release of the release switch  118  is turned on (step S 169 ), the moving lens barrel  104   a  is driven to an in-focus position by so-called hill climbing AF (step S 170 ). When the second release of the release switch  118  is turned on (step S 171 ), an image is sensed (step S 172 ). Steps S 173  to S 176  are operations performed while the sensed image is recorded on the CF card (recording medium) in the CF slot (recording medium slot)  115  via the A/D converter  11  and the image signal processing IC  112 . 
     The lens barrel driving stepping motor is driven in the direction in which the moving lens barrel  104   a  is collapsed (step S 173 ). This lens barrel driving stepping motor is driven for ten seconds until the reset position of the moving lens barrel  104   a  is detected (step S 174 ). If the reset position is detected within this ten-second driving (step S 176 ), the CPU  125  extends the moving lens barrel  104   a  to the position where an object at the closest distance is focused, which is prestored as the number of stepping motor pulses from the reset position (step S 119 ). If the reset position is not detected even after the ten-second driving, the CPU  125  determines that a system error has occurred and stops the system (step S 175 ). In this image sensing device, the collapsed position, reset position, infinity position, and closest position of the moving lens barrel  104   a  are arranged in this order from the image formation surface (CCD  109 ). 
     FIG. 14 is a flow chart for principally explaining the motions of the moving lens barrel  104   a  and the lens barrier  102   a  when the REC/LOCK switch  117  of the image sensing device is switched from the REC (sensing) position to the LOCK position. 
     The REC/LOCK switch  117  is switched from the REC position to the LOCK position (step S 121 ). The lens barrel driving stepping motor is driven in the direction in which the moving lens barrel  104   a  is collapsed (step S 122 ). This lens barrel driving stepping motor is driven in the collapsing direction for ten seconds until the reset position of the moving lens barrel is detected (step S 123 ). If the reset position is not detected even after this ten-second driving, the CPU  125  determines that a system error has occurred and stops the system (step S 124 ). 
     If the reset position is detected (step S 125 ), the CPU  125  collapses the moving lens barrel  104   a  to a housing (collapse) position which is prestored as the number of stepping motor pulses from the reset position (step S 126 ). The stepping motor as the actuator  102   b  rotates in the direction in which the lens barrier  102   a  closes (step S 127 ). This stepping motor rotates for five seconds until the leaf switches  102   c   1  and  102   c   2  of the detection switch  102   c  are turned on (detect the closure of the lens barrier  102   a ) (step S 128 ). If the detection switch  102   c  is turned on (step S 132 ), the CPU  125  terminates the system (step S 133 ). 
     If the detection switch  102   c  is not turned on even after the stepping motor as the actuator  102   b  is driven for five seconds, the CPU  125  determines that a system error has occurred, and the actuator  102   b  rotates in the direction in which the lens barrier  102   a  opens (step S 129 ). 
     The stepping motor as the actuator  102   b  rotates for five seconds until the leaf switches  102   c   3  and  102   c   2  of the detection switch  102   c  are turned on (detect the opening of the lens barrier  102   a ) (step S 130 ). If the detection switch  102   c  is turned on (step S 134 ), the CPU  125  stops the system (step S 131 ). If the leaf switches  102   c   1  and  102   c   2  are not turned on (do not detect the closure of the lens barrier  102   a ) even after this five-second rotation, the CPU  125  determines that a system error has occurred and stops the system (step S 131 ). 
     In this description, “termination” of the system means that the operation is ended after the system normally operates. “Stop” of the system means that the operation is unavoidably ended because the system cannot normally operate. 
     FIG. 15 is a flow chart for principally explaining the motions of the moving lens barrel  104   a  and the lens barrier  102   a  when the REC/LOCK switch  117  of this image sensing device is in the REC position and the detection switch  122  detects the possibility of the CF cover  121   a  being opened. 
     The detection switch  122  detects the possibility of the CF cover  121   a  being opened (step S 141 ). 
     The lens barrel driving stepping motor is driven in the direction in which the moving lens barrel  104   a  is collapsed (step S 142 ). This lens barrel driving stepping motor is driven in the collapsing direction for ten seconds until the reset position of the moving lens barrel is detected (step S 143 ). If the reset position is not detected even after this ten-second driving, the CPU  125  determines that a system error has occurred and stops the system (step S 144 ). 
     If the reset position is detected (step S 145 ), the CPU  125  collapses the moving lens barrel  104   a  to the housing (collapse) position which is prestored as the number of stepping motor pulses from the reset position (step S 146 ). The stepping motor as the actuator  102   b  rotates in the direction in which the lens barrier  102   a  closes (step S 147 ). This stepping motor rotates for five seconds until the leaf switches  102   c   1  and  102   c   2  of the detection switch  102   c  are turned on (detect the closure of the lens barrier  102   a ) (step S 148 ). If the detection switch  102   c  is turned on (step S 152 ), the CPU  125  terminates the system (step S 153 ). 
     If the detection switch  102   c  is not turned on even after the stepping motor as the actuator  102   b  is driven for five seconds, the CPU  125  determines that a system error has occurred, and the actuator  102   b  rotates in the direction in which the lens barrier  102   a  opens (step S 149 ). 
     The stepping motor as the actuator  102   b  rotates for five seconds until the leaf switches  102   c   3  and  102   c   2  of the detection switch  102   c  are turned on (detect the opening of the lens barrier  102   a ) (step S 150 ). If the detection switch  102   c  is turned on (step S 154 ), the CPU  125  stops the system (step S 151 ). If the leaf switches  102   c   1  and  102   c   2  are not turned on (do not detect the closure of the lens barrier  102   a ) even after this five-second rotation, the CPU  125  determines that a system error has occurred and stops the system (step S 151 ). 
     Operation is performed following essentially the same flow as shown in FIG. 15 when the detection switch  124  detects the possibility of the battery cover  123   a  being opened or when the CPU  125  detects a voltage drop of the power supply or some other system error. 
     The individual components shown in schematic or block form in the Drawings are all well-known in the camera arts and their specific construction and operation are not critical to the operation or best mode for carrying out the invention. 
     While the present invention has been described with respect to what is presently considered to be the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     The embodiments can be modified in various ways. 
     The present invention can be applied, for example, to a modification where a barrel is extended and retracted for altering a focal length of the camera. 
     Further, the embodiments described above, performs the extracting and retracting operations of the image sensing optical system (barrel) in response to the operation of the LCD switch  116 . The present invention is not limited to such switching by the LCD switch  116 . For example, the operations of the barrel may be triggered in response to operations on other external switches, for example to changing over image recording (sensing) and image reproducing during the apparatus is powered up. 
     The software and/or hardware configurations, for example, may be replaced or substituted in suitable manner. 
     Further, the present invention can be constituted of any combinations of the above described embodiments, as the occasions demand. Further, the present invention can be constituted of necessary components of any ones of the above described embodiments, as the occasions demands. 
     Further, the present invention can be applied to a device unit comprising the entire or partial structure of the claimed apparatus or embodied apparatus. Furthermore, the invention may be applied to a system wherein they are combined with another unit, or to a component comprised of an apparatus. 
     The present invention can be applied yet further to digital still cameras, video cameras, various types of cameras such as cameras using silver-salt films, any types of image sensing devices or optical devices except for cameras, and other types of devices. It can be further applied to a device which is applied to the cameras, optical devices and the other types of devices, or to any component comprising the cameras, the optical devices and the other types of devices.