Abstract:
A battery pack includes structures which prevent it from being improperly loaded in a battery loading device. The batter pack includes a battery cell, a casing for housing the battery cell, and output terminals for outputting the power of the battery cell. The bottom surface of the battery pack includes a discriminating recess formed in the bottom surface and control recesses formed at the intersection of its bottom and front surfaces. These recesses are sized and shaped to accept corresponding projections on selected battery loading devices so that the battery pack may be loaded onto these battery loading devices. However, the recesses do not accept the corresponding projections on other battery loading devices, thereby preventing the battery packs from being assembled to these other battery loading devices.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a battery pack, having housed therein a charging type battery cell used e.g., as a power source of an electronic equipment, a battery device on which is loaded the battery pack etc, and to an external equipment having the battery device on which is loaded the battery pack etc. This invention also relates to a power supply device for outputting the power furnished from e.g., an external power source. 
     2. Description of Prior Art 
     There has hitherto been known a battery pack having therein a battery cell used as a power source for an electronic equipment. This sort of the battery pack is detachably loaded on a battery loading device provided on the main body portion of the electronic equipment. 
     The battery pack is made up of a battery cell for supplying the power, a casing having this battery cell housed therein, and an output terminal connected to a connection terminal on the battery loading device. The battery cell provided in the battery pack is chargeable, such that, on power depletion, it is charged through the output terminal. The battery casing has guide grooves on both lateral sides thereof engaging with the battery loading device. The output terminal is arranged adjacent to the bottom surface of the casing so that its one end faces a longitudinal lateral side thereof. 
     The battery loading device includes a loading section for loading the battery pack and a terminal for connection to the output terminal of the battery pack. The loading section is formed with a setting surface slightly larger in area than the outer size of the battery pack and on which the bottom surface of the battery pack is set. On the surfaces of the loading section facing both lateral sides of the battery pack are formed guide projections engaged in the guide grooves formed in the battery pack. The terminal section is arranged on the inner rim of the loading section for facing the output terminal of the loaded battery pack. On loading the battery pack on the loading section, the terminal section is connected to the output terminal of the battery pack to permit the power to be supplied. 
     With the above-described structure of the battery loading device, the operation of loading the battery pack on the loading section of the battery loading device is hereinafter explained. When loading the battery pack on the loading section of the battery loading device, the respective guide projections on the loading section are engaged in the respective guide recesses with the bottom surface of the battery pack substantially parallel to the setting surface of the loading section. When loaded on the battery loading device, the battery pack furnishes the power from the battery cell to an electronic equipment provided with the battery loading device through the output terminal connected to the terminal section in the loading section. 
     When a battery pack is loaded on the battery loading device, the battery pack occasionally is introduced and loaded with its bottom surface tilted relative to a setting surface of a loading section of the battery loading device. 
     When the battery pack is loaded on the loading section of the battery loading device, the bottom surface of the battery pack may be loaded with the bottom surface of the battery pack being tilted relative to the setting surface of the loading section of the battery loading device in the lengthwise direction of the battery pack or with the bottom surface of the battery pack being tilted relative to the setting surface of the loading section of the battery loading device in the width-wise direction. The former and latter cases are referred to below as the battery pack being loaded with a tilt in the longitudinal direction and as the battery pack being loaded with a tilt in the width-wise direction, respectively. 
     If a battery pack  401  is loaded with a tilt in the longitudinal direction relative to the loading section, by having one end in the inserting direction of the battery pack into the loading section of a battery loading device  402  proximate to the setting surface of the loading section, as shown in FIG. 1, mistaken loading is restricted by a guide recess  405  formed on both width-wise sides and by a guide projection  411  of the battery loading device  402 . 
     However, if the battery pack  401  is inserted with its bottom surface tilted in the width-wise direction relative to the setting surface of the battery loading device  402  and thrust with a larger force, a guide grove  409  may ride over the guide projection  413  formed on the loading section in an imperfect loading of the battery pack on the loading pack. 
     If the battery pack  401  is inserted with a tilt relative to the setting surface and loaded in a non-optimum position on the loading section, there is a risk of the battery pack  401  inadvertently descending from the loading section to destroy the battery pack  401 . 
     That is, if, with the conventional battery loading device, the battery pack  401  is erroneously loaded with a width-wise tilt on the setting surface of the battery loading device  402 , there is no restricting means for positively prohibiting the battery pack  401  from being loaded with a tilt in the width-wise direction, thus possibly leading to loading of the battery pack with a tilt in the width-wise direction. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a battery pack which is positively prohibited from being loaded with a tilt on the loading section of the battery loading device to protect the output terminal and the connection terminal against possible destruction, and a battery loading device on which is loaded a power supply member exemplified by the battery pack. 
     It is another object of the present invention to provide an electronic equipment in which a power supply member is positively prohibited from being loaded with a tilt to protect the output terminal and the connection terminal against possible destruction. 
     It is yet another object of the present invention to provide a power supply device which is positively prohibited from being loaded with a tilt on the battery loading device to prevent destruction of the output terminal and the connection terminal against possible destruction. 
     In view of the above objects, the present invention provides a battery pack having plural engagement recesses at corners of first and second surfaces of the casing for opening in the first and second surfaces. At least one of the engagement recesses has a bent form such that an opening thereof in the first surface has a portion perpendicular to the second surface and a portion parallel to the second surface. 
     When loading the battery pack on the battery loading device, the plural engagement recesses of the casing are engaged by projections of the battery loading device, whereby the second surface of the casing is correctly oriented relative to the battery loading device. 
     A battery loading device according to the present invention includes plural engagement recesses at corners of first and second surfaces of the casing for opening in the first and second surfaces so as to be engaged by the battery loading device. At least one of the engagement recesses has a bent form such that an opening thereof in the first surface has a portion perpendicular to the second surface and a portion parallel to the second surface. 
     When loading the power supply device on the battery loading device, the plural engagement recesses of the casing are engaged by plural projections of the battery loading device so that the second surface of the casing is correctly oriented relative to the battery loading device. 
     An electronic equipment according to the present invention includes a plurality of projections provided substantially on a centerline of the second surface perpendicular to said first surface, and a plurality of engagement projections formed at corners of said first and second surfaces for engaging with the power supplying member. At least one of the engagement projections has a bent shape as cast on the first surface. The bent shape is made up of a portion perpendicular to the second surface and a portion parallel to the second surface. 
     With the electronic equipment, when a power supplying member is loaded on the battery loading device, the engagement projections are engaged with the power supplying member, whereby the power supplying member is oriented correctly relative to the battery loading device. 
     The battery pack of the present invention can be positively prevented from being erroneously loaded on the inappropriate battery loading device. 
     With the battery loading device of the present invention, a power supply member inappropriate for the device can be positively prohibited from being erroneously loaded thereon. 
     The power supply device of the present invention can be positively prohibited from being erroneously loaded on a battery loading device inappropriate for the power supply device. 
     Also, with the electronic equipment of the present invention, a power supply member inappropriate for the equipment can be positively prohibited from being erroneously loaded thereon. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view showing the state in which a conventional battery pack is loaded on a conventional battery loading device with a tilt in the longitudinal direction. 
     FIG. 2 is a side view showing the state in which a conventional battery pack is loaded on a conventional battery loading device with a tilt in the width-wise direction. 
     FIG. 3 is a perspective view showing a video camera apparatus having a battery loading mechanism according to the present invention. 
     FIG. 4 is a perspective view showing a first battery pack provided on the battery loading mechanism. 
     FIG. 5 is a perspective view looking from the bottom side of the first battery pack. 
     FIG. 6 is a perspective view showing a first battery loading device provided on the battery loading mechanism. 
     FIG. 7 is a perspective view showing a terminal section provided on the battery loading mechanism. 
     FIG. 8 is a front view showing the terminal section. 
     FIG. 9 is a perspective view showing a connection terminal of the terminal section. 
     FIG. 10 is a side view looking from the side of the terminal section, and showing the state in which, when the first battery pack is loaded on the first battery loading device, the first battery pack is loaded with a tilt in the longitudinal direction. 
     FIG. 11 is a side view showing the state in which, when the first battery pack is loaded on the first battery loading device, the first battery pack is loaded with a tilt in the longitudinal direction. 
     FIG. 12 is a side view looking from the side of the terminal section, and showing the state in which, when the first battery pack is loaded on the first battery loading device, the first battery pack is loaded with a tilt in the width-wise direction. 
     FIG. 13 is a side view showing the state in which, when the first battery pack is loaded on the first battery loading device, the first battery pack is loaded with a tilt in the width-wise direction. 
     FIGS. 14A,  14 B are perspective views showing a discrimination recess and a discrimination projection. 
     FIGS. 15A,  15 B are perspective views showing a modified discrimination recess and a modified discrimination projection. 
     FIGS. 16A to  16 D are perspective views showing other modified discrimination recess and another modified discrimination projections. 
     FIGS. 17A to  17 C are perspective views showing still other modified discrimination recess and still another modified discrimination projections. 
     FIG. 18 is a perspective view looking from the bottom side and showing a second battery pack. 
     FIG. 19 is a perspective view looking from the bottom side and showing a third battery pack. 
     FIG. 20 is a perspective view showing a battery plate. 
     FIG. 21 is a perspective view looking from the bottom side and showing the battery plate. 
     FIG. 22 is a perspective view showing a second battery pack. 
     FIG. 23 is a perspective view looking from the bottom side and showing the second battery pack. 
     FIG. 24 is a perspective view showing a second battery loading device. 
     FIG. 25 is a perspective view showing a third battery loading device. 
     FIG. 26 is a perspective view showing a fourth battery loading device. 
     FIG. 27 is a perspective view showing a first illumination device. 
     FIG. 28 is a perspective view showing a fifth battery loading device. 
     FIG. 29 is a perspective view showing a second illumination device. 
     FIG. 30 is a perspective view showing a sixth battery loading device. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, a battery pack and a battery loading device having a battery loading mechanism for loading the battery pack according to the present invention will be explained in detail. It is noted that a battery pack  5  and a battery loading device  6 , provided on the battery loading mechanism, are applied to a video camera apparatus  1 , as shown for example in FIG.  3 . 
     The battery pack  5  may be of a high capacity type, a standard capacity type or of a low capacity type, depending on the size of the charging capacity of the battery cell. The battery pack  5  may also be of the plate type adapted to be supplied with the power from an external power source. There are different battery loading devices associated with these different sorts of battery packs. 
     Referring first to FIGS. 4 and 5, the first battery pack  5 , used as a high capacity type, includes a battery cell, not shown, a casing  19 , housing therein the battery cell, and plural output terminals  21  to  23  connected to the battery cell. 
     The first battery pack  5  includes a casing  19  formed of, for example, a synthetic resin material. Referring to FIGS. 4 and 5, the casing  19  has guide grooves  26 ,  26  on both its width-wise lateral sides for guiding the casing as to the loading direction to a first battery loading device  6 . The guide grooves  26 ,  26  on both lateral sides of the casing  19  are opened at one end thereof on the bottom surface  24  of the casing  19  and are arrayed side-by-side in the longitudinal direction of the casing  19 , as shown in FIG.  5 . 
     On a front surface  20  of the casing  19  in the loading direction to the first battery loading device  6 , there are provided a first output terminal  21  and a second output terminal  22  on both width-wise lateral sides of the casing  19 . At a width-wise mid portion of the front surface of the casing  19 , there is provided a third output terminal  23 . The first and second output terminals  21 ,  22  furnish the power through the battery loading device  6  to a main body portion of the video camera apparatus  1 . The third output terminal  23  outputs information signals, such as residual power of the battery cell, to the main body portion of the video camera apparatus  1 . The outwardly directed ends of the output terminals  21  to  23  are positioned in substantially rectangular recesses formed in the front surface  20  of the casing  19 . Thus, these ends of the output terminals are prohibited from being destroyed due to abutment against portions other than the connection terminals of the battery loading device. 
     The casing  19  of the first battery pack  5  is provided with a pair of control recesses  28 ,  29  as shown in FIG. 5 for regulating the tilt in the width-wise direction of the bottom surface  24  of the casing  19  with respect to the first battery loading device  6  when the casing  19  is loaded on the appropriate first battery loading device  6 . These control recesses  28 ,  29  are formed line-symmetrically in the front surface  20  with respect to a width-wise mid line, not shown, in the inserting direction into the first battery loading device  6 . 
     These control recesses  28 ,  29  are each provided with a first portion extending at right angles to the bottom surface  24  of the casing  19  and a second portion extending at right angles to the first portion, and hence are substantially L-shaped in cross-section, as shown in FIG.  5 . 
     The first battery pack  5  also includes, at a mid portion in the bottom surface  24  of the casing  19 , a substantially rectangular discrimination recess  30  for discriminating whether or not the battery loading device is an appropriate battery loading device, for battery pack  5 . 
     The discrimination recess  30 , thus located substantially on the width-wise centerline of the casing  19 , is formed from the mid position of the bottom surface  24  of the casing  19  towards the front surface  20 , as shown in FIG.  5 . In the bottom surface in the discrimination recess  30 , a substantially rectangular discrimination groove  32  is formed on substantially the width-wise centerline of the casing  19  between the longitudinal ends of the discrimination recess  30 , as shown in FIG.  5 . Thus, the inside of the discrimination recess  30  is formed with steps on both width-wise sides thereof, as shown in FIG.  5 . This discrimination recess  30  has a size W 0  in a direction parallel to the width of the bottom surface  24 . 
     The first battery pack  5  also includes a first guide groove  34 , adjacent to the third output terminal  23 , as shown in FIG.  5 . The first guide groove  34  is formed parallel to the longitudinal direction of the casing  19  for guiding the loading direction to the first battery pack  5 . This first guide groove  34  has its one end opened in the front surface  20  of the casing  19 , while having its other end extended in continuation to the discrimination recess  30 . Adjacent to the front surface  20  of the casing  19 , there is formed in the first guide groove  34  a step  35  having a different depth, that is a different size in the direction perpendicular to the bottom surface  24  of the casing  19 . 
     In the bottom surface  24  of the casing  19 , there is formed a second guide groove  36 , at an opposite side of the third output terminal  23  with respect to the first guide groove  34 , as shown in FIG.  5 . This second guide groove  36  is formed parallel to the longitudinal direction of the casing  19  and has its one end opened in the front surface  20  of the casing  19 . 
     In both width-wise lateral sides of the casing  19 , there are formed control grooves  37 ,  37 , adjacent to the first and second output terminals  21 ,  22 , so as to be opened in the front surface  20  substantially parallel to the bottom surface  24 . These control grooves  37 ,  37  serve for regulating the tilt in the width-wise direction of the bottom surface  24  with respect to the first battery loading device  6 . 
     In the bottom surface  24  of the casing  19 , there are formed a first lock recess  38  and a second lock recess  39  engaged by the first battery loading device  6  when the casing is loaded on the first battery loading device  6 . The first lock recess  38  is substantially rectangular in profile and is located substantially on the width-wise centerline of the casing  19  adjacent to the discrimination recess  30 . The second lock recess  39 , slightly larger in size that the first lock recess  38 , is substantially rectangular in profile and is formed in the back side in the loading direction on substantially the width-wise centerline of the casing  19 . 
     As shown in FIG. 6, the first battery loading device  6  includes a loading section  43  having a setting surface  45  on which to set the bottom surface  24  of the battery pack  5 , and a terminal section  44  to which are connected the respective output terminals  21  to  23  of the first battery pack  5 . The loading section  43  is slightly larger in size than the bottom surface  24  of the first battery pack  5 , and is formed with guide projections  47 ,  47  engageable with the guide grooves  26 ,  26  of the first battery pack  5 . The guide projections  47  are formed on the inner lateral sides in the width-wise direction of the battery loading device  6  adjacent to the setting surface  45 . 
     When the first battery pack is loaded in position, the loading section  43  sets the bottom surface  24  of the casing  19  parallel to the setting surface  45 , by the guide projections  47 ,  47  engaging in the guide grooves  26 ,  26  of the casing  19 , as the loading section  43  holds the first battery pack  5 . 
     The terminal section  44  is arranged on an abutment surface  46  facing the front surface  20  of the loaded first battery pack  5 , as shown in FIGS. 6 and 7. With the terminal section  44 , a first connection terminal  51  and a second connection terminal  52 , connectable respectively to the first and second output terminals  21 ,  22  of the first battery pack  5 , are provided on both sides along the width-wise direction of the loading section  43 , as shown in FIGS. 6 and 8. Also, with the terminal section  44 , a third connection terminal  53 , connectable to the third output terminal  23  of the first battery pack  5 , is located at a mid portion along the width-wise direction of the loading section  43 . 
     The first to third connection terminals  51  to  53  are formed on the abutment surface  46  parallel to the bottom surface  24  of the first battery pack  5  and to the longitudinal direction of the first battery pack  5 , as shown in FIGS. 6 and 7. Each of the first to third connection terminals  51  to  53  is provided with a terminal plate  55 , adapted for insertion into each of the first to third output terminals  21  to  23  of the first battery pack  5 , and with a protection member  56  for protecting the terminal plate  55 . 
     The terminal plate  55  has its major surface substantially parallel to the setting surface of the loading section  43 , while having its proximal end supported by the abutment surface  46  of the loading section  43 . The terminal plate  55  is fractionated by having a cut-out  57  formed at its distal end so that the distal end is elastically flexible in the width-wise direction. 
     The protection member  56  is a substantially semi-tubular substrate bent at a mid portion along the longitudinal direction of the substrate, with the terminal plate  55  in-between, as shown in FIG.  9 . The distal end of the terminal plate  55  is elastically flexible protruded from the folded distal end to both width-wise lateral sides of the protection member  56 . 
     When the connection terminals  51  to  53  are inserted into the output terminals  21  to  23  of the first battery pack  5 , the distal ends of the terminal plates  55  are elastically flexed in the width-wise direction to establish the electrical connection by the terminal plates  55  positively compressing against the output terminals. 
     The connection terminals  51  to  53  are improved in tenacity against the thrusting force from the height-wise direction of the first battery pack  5 , corresponding to the depth-wise direction of the loading section  43 , when the bottom surface  24  of the first battery pack  5  is erroneously abutted thereon during loading of the first battery pack  5  on the loading section  43 . Thus, the terminal plates  55  may be safeguarded against inadvertent destruction. 
     On the terminal section  44 , a cover member  60  for protecting the first to third connection terminals  51  to  53  is mounted for rotation in the direction indicated by arrows a 1  and a 2  in FIG. 7 relative to the loading section  43 . 
     The cover member  60  is formed of, for example, a synthetic resin material, and includes a substantially rectangular protective piece  61  and supporting pieces  62 ,  62  for supporting the protective piece  61 , as shown in FIGS. 7 and 8. The protective piece  61  of the cover member  60  has, on its surface facing the setting surface  45  of the loading section  43 , a surface section  63  inclined along the thickness direction. When the first battery pack  5  is inserted into the loading section  43 , the casing  19  is abutted against the protective piece  61 , as the casing is inserted, so that the cover member  60  is rotated easily in the direction indicated by arrow a 2  in FIG.  7 . The cover member  60  has the supporting pieces  62 ,  62  rotatably supported on the abutment surface  46  of the loading section  43  through a rotary pivot shaft, not shown. On the outer periphery of the rotary pivot shaft of the cover member  60 , there is mounted a torsion coil spring, not shown. This torsion coil spring has it one end retained by the abutment surface  46  of the loading section  43 , while having its other end retained by the supporting pieces  62 ,  62  of the cover member  60 . Thus, the cover member  60  is biased by the spring force of the torsion coil spring for rotation in the direction indicated by arrow a 1  in FIG.  7  and is thereby moved to a position overlying the first to third connection terminals  51  to  53 . 
     Thus, through the cover member  60 , the connection terminals  51  to  53  are covered when the first battery pack  5  is not loaded on the loading section  43 , so that the connection terminals  51  to  53  are positively protected against possible destruction. 
     Also, the loading section  43  of the first battery loading device  6  is formed as one with a pair of control projections  65 ,  66  astride the abutment surface  46  and the setting surface  45  substantially exactly spaced with respect to the width-wise centerline. These control projections  65 ,  66 , engageable with the control recesses  28 ,  29  of the first battery pack  5 , are provided adjacent to the first and second connection terminals  51 ,  52 , as shown in FIGS. 7 and 8. 
     These control projections  65 ,  66  are each provided with a first portion, perpendicular to the setting surface  45 , and a second portion perpendicular to the first portion, and the hence are each formed to a substantially L-shaped cross-section. These control projections  65 ,  66  restrict the bottom surface  24  of the first battery pack  5  from assuming a state inclined obliquely relative to the setting surface  45  of the loading section  43 . The control projections  65 ,  66  are configured so that the height H 1  thereof in a direction perpendicular to the setting surface  45  will be larger than the height H 0  of the outer periphery of the connection terminals  51  to  53 . 
     The loading section  43  of the first battery loading device  6  is formed as one with a first guide projection  68  adjacent to the third connection terminal  53  astride the abutment surface  46  and the setting surface  45  for guiding the insertion of the first battery pack  5 . The first guide projection  68  is formed so as to be parallel to the longitudinal direction of the setting surface  45  at a position engageable in the first guide groove  34  in the bottom surface  24  of the loaded first battery pack  5 . 
     The control projections  65 ,  66  are of a height larger than the connection terminals  51  to  53 , and hence are protruded to a height level higher than the connection terminals  51  to  53 , as shown in FIGS. 7 and 8. Thus, the control projections  65 ,  66  prohibit the outer periphery of the casing  19  from erroneously abutting against the connection terminals  51  to  53 , when the first battery pack  5  is inserted from the direction perpendicular to the setting surface  45  to prevent possible destruction of the connection terminals  51  to  53 . Also, the control projections  65 , 66 , having the substantially L-shaped cross-section, exhibit sufficient toughness. 
     Meanwhile, the connection terminals  51  to  53  can be protected if the control projections  65 ,  66  and the first guide projection  68  are of a height level substantially equal to that of the outer periphery of the connection terminals  51  to  53 . 
     The loading section  43  is also formed as one with a second guide projection  70  astride the abutment surface  46  and the setting surface  45 , parallel to the longitudinal direction of the setting surface  45  as shown in FIGS. 6 to  8  for guiding the loading direction of the first battery pack  5 . This second guide projection  70  is engageable with the second guide groove  36  of the first battery pack  5  to guide the loading direction. 
     The loading section  43  of the first battery loading device  6  is formed on both width-wise lateral sides as one with control pawls  72 ,  72  adapted for engaging with control grooves  37 ,  37 . These control pawls  72 ,  72  are parallel to the setting surface  45 , while extending parallel to the longitudinal direction of the first battery pack  5  when assembled to the first battery loading device  6 . 
     The loading section  43  of the first battery loading device  6  is formed substantially centrally of the setting surface  45  with a discrimination projection  73  engageable with the discrimination recess  30  of the first battery pack  5 . This discrimination projection  73  is formed substantially in a rectangular profile. The distal end of the discrimination projection  73  is formed as one with a discrimination lug  74  engageable in the discrimination groove  32  of the discrimination recess  30 . This discrimination projection  73  has a size W 1  in a direction parallel to the width-wise direction of the setting surface  45  smaller than the width W 0  of the discrimination recess  30  of the first battery pack  5 , so that the projection  73  can be inserted into the discrimination recess  30 . The discrimination projection  73  also is formed at a distance L 1  from the abutment surface  46  in the direction perpendicular to the abutment surface  46 , as shown in FIG.  6 . 
     The loading section  43  of the first battery loading device  6  is provided with a lock mechanism  75  adapted for holding the first battery pack  5  when the battery pack  5  is loaded in position. This lock mechanism  75  includes a substantially flat-plate-shaped lock member  76  engageable with the first battery pack  5 , an operating lever  77  for causing the movement of the lock member  76  relative to the setting surface  45 , and a coil spring, not shown, for biasing the operating lever  77  in a direction of engaging with the first lock recess  38  of the first battery pack. 
     The lock member  76  is formed on its major surface with an upstanding lock pawl  79  engageable with the first lock recess  38  of the first battery pack  5 . An opening  80  through which the lock pawl  79  of the lock member  76  protrudes above the setting surface  45  is formed substantially centrally of the loading section  43 . 
     The operating lever  77  has its distal end engaged with the lock member  76 , while having its other end formed as one with an operating piece  81  adapted for performing a thrusting operation. The setting surface  45  if formed with an operating recess  82  positioned so as to correspond to the back side of the first battery pack  5  where loaded in the loading section  43 . In the operating recess  82  is formed the protuberant operating piece  81 . Movement of the lock member  76  moves operating lever  77 , pushing  81  outwardly into the operating recess  82 . 
     When the battery pack  5  is loaded in the loading section  43 , the lock pawl  79  of the lock member  76  is engaged in the first lock recess  38  to disable the movement of the first battery pack  5  from the loading section  43 . In this locked position, the operating piece  81  of the operating lever  77  protrudes into the operating recess  82 , as the lock pawl  79  of the lock member  76  protrudes from the opening  80 . 
     Also, when dismounting the first battery pack  5  loaded on the loading section  43 , the lock pawl  79  is disengaged from the lock recess  38  by thrusting the operating piece  81  of the operating lever  77  inwardly causing the lock pawl  79  to become disengaged from the first lock recess  38 . The first battery pack  5 , is thus rendered movable in the loading section  43  and may be dismounted therefrom. 
     The above-described lock mechanism  75  is configured so that the lock pawl  79  of the lock member  76  is engageable in the first lock recess  38  of the first battery pack  5 . Alternatively, the lock pawl  79  may be configured to be engageable in the second lock recess  39  by design change of the loading section  43 . 
     The operation of loading the above-described first battery pack  5  on the first battery loading device  6  is explained with reference to the drawings. 
     First, if the first battery pack  5  is improperly loaded into the loading section  43  of the first battery loading device  6 , with the bottom surface  24  of the casing  19  being tilted in the direction indicated by arrow b in FIG. 11 corresponding to the longitudinal direction of the bottom surface  24 , as shown in FIGS. 10 and 11, the bottom surface  24  of the casing  19  will be abutted against the guide projections  47 , whilst the front surface  20  of the casing  19  will be abutted against the control projections  65 ,  66 . This disables insertion of the battery pack. Moreover, the output terminals  51  to  53  and the connection terminals  21  to  23  are positively prohibited from abutting against optional portions. Therefore, the output terminals  51  to  53  and the connection terminals  21  to  23  are positively safeguarded against possible destruction. 
     The first battery pack  5  is loaded satisfactorily on the first battery loading device  6 , by the guide projections  47  of the loading section  43  being inserted into the respective guide grooves  26  of the casing  19 . Specifically, the state of longitudinal tilting of the bottom surface  24  of the casing  19  relative to the setting surface  45  of the loading section  43  is positively controlled, as indicated by arrow b in FIG. 11, so that longitudinal direction of the bottom surface  24  is parallel to the setting surface  45 . 
     If the first battery pack  5  is loaded on the first battery loading device  6 , by applying an extremely large force as the bottom surface  24  of the casing  19  is tilted, and if a large external pressure for detaching the first battery pack  5  is applied, the output terminals  51  to  53  and the connection terminals  21  to  23  are positively safeguarded against possible destruction, since the large external force is applied to the substantially L-shaped control projections  65 ,  66  of higher tenacity. 
     If, when the first battery pack  5  is to be loaded in the loading section  43  of the first battery loading device  6 , as shown in FIGS. 12 and 13, it is loaded improperly, with the bottom surface  24  of the casing  19  being tilted in the direction indicated by arrow c in FIG. 12 corresponding to the width-wise direction of the bottom surface  24 , at least one of the control pawls  72 ,  72  is not inserted into the corresponding control groove, with the bottom surface  24  of the casing then abutting against the control pawl  72  and with the front surface  20  of the casing  19  abutting against the control projections. The first battery pack is thus prevented from loading on the first battery loading device  6 , such that the output terminals  51  to  53  or the connection terminals  21  to  23  are positively prohibited from abutting against other than the intended portions. This positively prohibits destruction of the output terminals  51  to  53  or the connection terminals  21  to  23 . 
     The control projections  65 ,  66  of the loading section  43  are inserted into the control recesses  28 ,  29  of the casing  19 , whereby the state of tilt in the width-wise direction of the bottom surface  24  of the casing  19  relative to the setting surface  45  of the loading section  43  is positively controlled, with the width-wise direction of the bottom surface  24  being substantially parallel to the setting surface  45  to permit the first battery pack  5  to be loaded satisfactorily on the first battery loading device  6 . 
     Also, when the first battery pack  5  is loaded in the loading section  43  of the first battery loading device  6 , the control pawls  72 ,  72  of the loading section  43  are engaged in the control grooves  37 ,  37  of the casing  19 , whereby the state of tilt in the width-wise direction of the bottom surface  24  of the casing  19  relative to the setting surface  45  of the loading section  43  is positively controlled, with the width-wise direction of the bottom surface  24  being rendered substantially parallel to the setting surface  45 , to permit the first battery pack  5  to be satisfactorily loaded on the first battery loading device  6 . 
     Thus, when the first battery pack  5  is loaded in the loading section  43  of the first battery loading device  6 , the first battery pack  5  is rendered substantially parallel to the setting surface  45  of the loading section  43 . Stated differently, when the first battery pack  5  is loaded in the loading section  43  of the first battery pack  5 , the first battery pack  5  is positively prevented from being loaded in an improper orientation in the loading section  43 , with the bottom surface  24  of the casing  19  tilted in the longitudinal direction or in the width-wise direction relative to the setting surface  45 . 
     When the first battery pack  5  is loaded in the loading section  43  of the first battery loading device  6 , with the bottom surface  24  of the casing  19  being set on the setting surface  45 , the discrimination projection  73  of the setting surface  43  is inserted into the discrimination recess  30  in the bottom surface  24 , at the same time as the discrimination lug  74  is inserted into the discrimination groove  32 , whereby it is assured that the first battery pack  5  is suited to the first battery loading device battery loading device  6  checks whether or not the first battery pack  5  is appropriate for the first battery loading device  6  based on whether or not the discrimination projection  73  of the setting surface  45  can be inserted into the discrimination recess  30  in the bottom surface  24 , that is, based on the relative position between the discrimination recess  30  and the discrimination projection  73 , and also based on whether or not the discrimination lug  74  can be inserted into the discrimination groove  32 . 
     Although the discrimination recess  30  and the discrimination projection  73  are discriminated from each other based on their positions in the longitudinal direction of the bottom surface  24  of the casing  19 , they may also be discriminated from each other based on their positions in the width-wise direction of the bottom surface  24 . 
     The first battery pack  5  and the first battery loading device  6  are formed so that the control recesses  28 ,  29  and the control projections  65 ,  66  have substantially the same L-shaped cross-section, These recesses or projections may, of course, be configured as control recesses  85  or control projections  86  of substantially the same T-shaped cross-section, as shown in FIGS. 14A and 14B, or as control recesses  88  or control projections  89  of substantially the same Y-shaped cross-section, as shown in FIGS. 15A and 15B. 
     With the first battery pack  5  and the first battery loading device  6 , described above, the control recesses  28 ,  29  and the control projections  65 ,  66 , mating with each other, are of the same profile. Alternatively, the control projections may be shaped to be engaged in portions of the grooves defining control recess  91 , as shown in FIGS. 16A to  16 D. For example control projections  92  to  94  may in the control recess  91 , as shown in FIGS. 16A to  16 D. That is, the battery pack having the control recess  91  can be loaded on three sorts of the battery loading device, that is on the battery loading devices having the control projections  92  to  94 . 
     Alternatively, control projections engageable with portions of the substantially T-shaped control recess  96 , as shown in FIGS. 17A to  17 E may also be used. The control recess  96  may be formed with plural control recesses that may be engaged by control projections  97 ,  98 , as shown in FIGS. 17A to  17 C. That is, the battery pack having the control recess  96  may be loaded on two sorts of the battery loading device having the control projection  97  or  98 . 
     In the above-described first battery pack  5  and the first battery loading device  6 , the control recesses  28 ,  29  and the control projections  65 ,  66  are formed line-symmetrically with respect to substantially the centerline in the width-wise direction of the bottom surface  24 . Of course, these recesses or projections may also be formed to the same profile at corresponding unequal positions from the width-wise centerline of the bottom surface  24 . 
     With the battery loading device according to the present invention, in which the state of tilt in the width-wise direction of the first battery pack  5  relative to the setting surface  45  of the loading section  43  of the first battery loading device  6  can be controlled positively, the bottom surface  24  of the first battery pack  5  can be positively prohibited from being inserted with a tilt in the width-wise direction relative to the setting surface  45  of the loading section  43 . Thus, with the present battery loading device, it is possible to prevent possible destruction of the output terminals  21  to  23  and the connection terminals  51  to  53  of the first battery pack  5  and the first battery loading device  6 . 
     Referring to the drawings, modifications of the battery pack and the battery loading device according to the present invention will be explained in detail. Meanwhile, in the following description of the modifications of the battery pack and the battery loading device, parts of components which are the same as those of the first embodiment are depicted by the same reference symbols and are oat explained specifically. 
     Referring to FIG. 18, the second battery pack  7  is of the standard charging capacity, and is of a thickness smaller than the first battery pack  5 . 
     The second battery pack  7  includes a casing  101 , housing a battery cell in its inside, and first to third output terminals  105  to  107  provided on a front surface  103  of the casing  101  and which are connected to the battery cell. The casing  101  is formed with guide grooves  109 , 109  for guiding the insertion direction into the battery loading device. 
     In the front surface  103  of the casing  101  of the second battery pack  7 , there are formed control recesses as shown in FIG. 18 111 ,  112  for controlling the state of tilt of the bottom surface  104  in the width-wise direction relative to the battery loading device. 
     At a mid portion of the bottom surface  104  of the casing  1 O 1  of the second battery pack  7 , there is formed a discrimination recess  113  for discriminating whether or not the battery loading device is appropriate for loading battery pack  7 . In the bottom surface of the discrimination recess  113  is formed a substantially rectangular groove  115  on substantially the centerline in the width-wise direction of the casing  101 , whilst a step is formed on each side of the recess in the width-wise direction of the bottom surface  104 . This discrimination recess  113  has a width W 0  along the width of the bottom surface  104 . 
     In the discrimination recess  113 , essential to the second battery pack  7 , there is formed as one a discrimination lug  116  projecting parallel to the longitudinal direction from the opening edge of the recess  113  which is parallel to the front surface  103 . 
     In the bottom surface  104  of the casing  101 , there are formed a first guide groove  118  and a second guide groove  119 , adjacent to the third output terminal  107 , for guiding the loading direction to the battery loading device. In both lateral sides in the width-wise direction of the casing  101  are formed control grooves  120 ,  120  for controlling the tilt in the width-wise direction of the bottom surface  104  relative to the battery loading device. The grooves  120 ,  120  are opened in the front surface  103  and are substantially parallel to the bottom surface  104 . 
     In the bottom surface  104  of the casing  101  are formed a first lock recess  121  and a second lock recess  122  which are engaged by the battery loading device when the casing  101  is loaded thereon. 
     A third battery pack  9 , shown in FIG. 19 is of a low charging capacity, and is of a smaller thickness than the second battery pack  7 , as the standard type battery pack. 
     The third battery pack  9  includes a casing  124 , housing a battery cell therein, and first to third output terminals  128  to  130 , provided on a front surface  126  of the casing  124  and which are connected to the battery cell. In both lateral sues in the width-wise direction of the casing  124  are formed guide grooves  132 , 132  for guiding the loading direction of the casing relative to the battery loading device. 
     In the front surface  126  of the casing  124  of the third battery pack  9 , there are formed control recesses  134 ,  135 , symmetrically positioned relative to substantially the centerline in the width-wise direction, as shown in FIG. 19, for controlling the state of tilt in the width-wise direction of the bottom surface  127  relative to the battery loading device when loading the casing on the appropriate battery loading device. 
     At a mid portion of the bottom surface  127  of the casing  124  of the third battery pack  9  is formed a discrimination recess  137 , as shown in FIG. 19, for discriminating whether or not the battery loading device is appropriate for the casing  124 . In the bottom surface of the discrimination recess  137  is formed a discriminating groove  138 , substantially rectangular in profile, substantially on the centerline in the width-wise direction of the casing  124 . On both sides of the recess in the width-wise direction of the bottom surface  127  are formed steps. The discriminating recess  137  has a width W 0  parallel to the width-wise direction of the bottom surface  127 . 
     In the discriminating recess  137 , essential to the third battery pack  9 , there is formed a discriminating lug  139  projecting from the opening edge of the recess, which is parallel to the front surface  126 , in a direction parallel to the longitudinal direction of the casing  124 . In the distal end in the longitudinal direction of the discriminating lug  139  is formed a discriminating recess  140 . 
     The casing  124  is formed with a first guide groove  142  and second guide groove  143 , adjacent to the third output terminal  130 , for guiding the loading of the casing relative to the battery loading device. In both lateral sides along the width of the casing  124  are formed control grooves  144 ,  144  for controlling the tilt in the width-wise direction of the bottom surface  127  relative to the battery loading device. The control grooves  144 ,  144  are opened on the front surface  126  and are substantially parallel to the bottom surface  127 . 
     In the bottom surface  127  of the casing  124  are also formed a first lock recess  146  and a second lock recess  147  which are engaged by the battery loading device when the casing is loaded thereon. 
     A battery plate used for connection to a further external power source, such as an AC power source for household use, is now explained by referring to the drawings. Referring to FIGS. 20 and 21, the battery plate  11  is of a substantially rectangular plate shape and includes a connection terminal section  148  for connection to a variety of external power sources, a casing  149  provided with the connection terminal section  148  and first to third output terminals  153  to  155  connected to the connection terminal section  148 . 
     The connection terminal section  148  includes a wiring card for connection to an AC adapter; not shown. In both lateral sides in the width-wise direction of the casing  149  are formed guide grooves  157  for guiding the casing as it is loaded on the battery loading device. 
     In a front surface  150  of the casing  149  of the battery plate  11 , there are formed control recesses  160 , 161  symmetrically positioned relative to substantially the centerline in the width-wise direction thereof, as shown in FIG.  21 . The control recesses  160 ,  161  are used for controlling the state of tilt in the width-wise direction of the bottom surface  151  relative to the battery loading device when loading the casing on the appropriate battery loading device. 
     At a mid portion of the bottom surface  151  of the casing  149  of the battery plate  11 , there is formed a discriminating recess  163  for discriminating whether the casing is appropriate for loading the battery loading device. In the bottom surface of the discriminating recess  163  is formed a substantially rectangular discriminating groove  165  on substantially the centerline in the width-wise direction of the casing  149 . On one side of recess  163  in the width-wise direction of the bottom surface  151  is formed a step. The discriminating recess  163  has a size W 2  parallel to the width of the bottom surface  151  which is smaller than the width W 0  of each of the discriminating recesses  30 ,  113 ,  137  of the above-described battery packs  5 ,  7 ,  9 . 
     In the bottom surface  151  of the casing  149  are formed a first guide groove  167  and a second guide groove  168 , adjacent to the third output terminal  155 , for guiding the casing as it is loaded on the battery loading device. The first guide groove  167 , which is planar and contiguous to the step in the discriminating recess  163 , has a profile different from that of the first guide grooves  30 ,  113 ,  137  of the above-described battery packs  5 ,  7 ,  9 . 
     In both lateral sides in the width-wise direction of the casing  149  are formed control grooves  169 ,  169  for controlling the tilt in the width-wise direction of the bottom surface  151  relative to the battery loading device. The control grooves are opened on the front surface  150  and are substantially parallel to the bottom surface  151 . 
     In the bottom surface  151  of the casing  149  are formed a first lack recess  171  and a second lock recess  172 , engaged by the battery loading device on loading the casing thereon. 
     The battery plate  11 , constructed as described above, is loaded on an appropriate battery loading device, and is connected via an AC adapter to an external power source or a large-sized battery, to supply the power from the external power source directly to the main body portion of the device. 
     A fourth battery pack  12  is configured substantially similarly to the first battery pack  5 , and has a casing  175  with a bottom surface  177 . Referring to FIGS. 22 and 23, fourth battery pack  12  has a longitudinal length which is smaller from the front surface side than that of the first battery pack  5  shown in FIGS. 4 and 5, as indicated by a broken line shown in FIG.  4 . 
     This fourth battery pack  12  has a casing  175 , housing therein the battery cell, and first to third output terminals  181  to  183 , which are provided on the front surface  176  of the casing  175  and which are connected to the battery cell. On both lateral sides in the width-wise direction of the casing  175  are formed guide grooves  185  for guiding the casing  175  as it is loaded on the battery loading device. 
     In the front surface  176  of the casing  175  of the second battery pack  12  are formed control recesses  187 ,  188  for controlling the state of tilt in the width-wise direction of the bottom surface  177  relative to the battery loading device when loading the casing on the appropriate battery loading device. The control recesses  187 ,  188  are of substantially T-shaped cross-section and of substantially L-shaped cross-section, respectively. 
     In a mid portion of the bottom surface  177  of the casing  175  of the fourth battery pack  12 , there is formed a discriminating recess  190  for discriminating whether or not the battery loading device is appropriate for loading the casing  175 . In the bottom surface of the discriminating recess  190  is formed a substantially rectangular discriminating groove  191 , substantially on the centerline in the width-wise direction of the casing  175 . On both sides of the recess  190  in the width-wise direction of the bottom surface are formed steps. The discriminating recess  190  has a width W 0  parallel to the width of the bottom surface  177 . 
     Adjacent to the third output terminal  183  on the bottom surface  177  of the casing  175 , there are formed a first guide groove  193  and a second guide groove  194  for guiding the casing as it is loaded on the battery loading device. In the bottom surface  177  of the casing  175  is formed a discriminating groove  195  adjacent to the first guide groove  193  for discrimination from the first battery pack  5 . In both lateral sides in the width-wise direction of the casing  175  are formed control grooves  196 ,  196  for controlling the tilt in the width-wise direction of the bottom surface  177  relative to the battery loading device. The grooves  196 ,  196  are opened in the front surface  176  and are extended substantially parallel to the bottom surface  177 . 
     In the bottom surface  177  of the casing  175 , there are formed a first lock recess  197  and a second lack recess  198  engaged by the battery loading device on loading the casing on the battery loading device. The second lock recess  198  is formed so that it is opened in the back surface of the casing  175 . 
     A second battery loading device  8 , on which can be loaded the above-described first to fourth battery packs  5 ,  7 ,  9  and  12 , is now explained by referring to the drawings. 
     Referring to FIG. 24, the second battery loading device  8  includes a loading section  201 , having a setting surface  204  on which to set the battery packs  5 ,  7 ,  9  and  12 , and a terminal section  202  to which are connected output terminals  21 ,  22 ,  23 ,  105 ,  106 ,  107 ,  128 ,  129 ,  130 ,  181 ,  182  and  183  of the battery packs  5 ,  7 ,  9  and  12 , respectively. 
     On both lateral sides in the width-wise direction of the setting surface  204  of the loading section  201 , there are formed guide projections  207  adjacent to the setting surface  204  and engageable in the guide grooves  26 ,  109 ,  132 ,  185  of the battery packs  5 ,  7 ,  9 ,  12 . 
     The terminal section  202  is provided on an abutment surface  205  of the battery loading device adapted to face the front surfaces  20 ,  103 ,  126 ,  176  of the battery packs  5 ,  7 ,  9  and  12 , when the battery packs are loaded thereon. The terminal section  202  is provided with first, second and third connection terminals  211 ,  212  and  213 , which are connectable to the output terminals  21  to  23 ,  105  to  107 ,  128  to  130  and  181  to  183  of the battery packs  5 ,  7 ,  9  and  12 . On the terminal section  202 , a cover member  215  for projecting the connection terminals  211  to  213  is mounted for rotation with respect to the loading section  201 , as shown in FIG.  24 . 
     The loading section  201  of the second battery loading device  8  is formed as one with a pair of control projections  217 ,  218  line-symmetrically with respect to substantially the centerline in the width-wise direction of the setting surface  204 , as shown in FIG.  24 . These control projections  217 , 218  are provided astride the abutment surface  205  and the setting surface  204  so as to be engagable with the control recesses  28 ,  29 ,  111 ,  112 ,  134 ,  135 ,  187 ,  188  of the battery packs  5 ,  7 ,  9  and  12 . These control projections  217 ,  218  are of a height level in a direction perpendicular to the setting surface  204  higher than the outer peripheral parts of the connection terminals  211  to  213  to prevent possible destruction of these connection terminals  211  to  213 . 
     The loading section  201  of the second battery loading device  8  is formed as one with a first guide projection  220  adapted for guiding the battery packs  5 ,  7 ,  9  and  12  The first guide projection  220  is provided astride the abutment surface  245  and the setting surface  204 . Adjacent to the third connection terminal  213  and extending parallel to the longitudinal direction of the setting surface  204 . On the first guide projection  220  is formed a step, projected in a direction perpendicular to the setting surface  204 , integrally connected to the abutment surface  205 . This step has a height level in a direction perpendicular to the setting surface  204  slightly higher than the control projections  217 , 218  to prevent possible destruction of the connection terminals  211  to  213 . 
     The loading section  201  of the second battery loading device  8  is formed as one with a second guide projection  222 , astride the setting surface  204  and the abutment surface  205 , for guiding the loading direction of the battery packs  5 ,  7 ,  9 ,  12 . The loading section  201  of the second battery loading device  8  is also formed on both lateral sides in the width-wise direction thereof as one with control pawls  224 ,  224  engageable in the control grooves  37 ,  120 ,  132  and  196  of the battery packs  5 ,  7 ,  9  and  12 . The control pawls  224 ,  224  are parallel to the setting surface  204 , while being parallel to the longitudinal direction of the setting surface  204 . At a mid portion of the setting surface  204  of the loading section  201  of the second battery loading device  8  is integrally formed a discriminating projection  226  engageable in the discriminating recesses  30 ,  113 ,  137 ,  194  of the battery packs  5 ,  7 ,  9  and  12 . 
     The discriminating projection  226  is of a width W 3  parallel to the width of the setting surface  204  which is larger than the width W 1  of the discriminating projection  73  of the first battery loading device  6 . This discriminating projection  226  is slightly smaller than the width W 0  of the discriminating recesses  30 ,  113 ,  137 ,  190  of the battery packs  5 ,  7 ,  9  and  12  and hence can be inserted into the discriminating recesses  30 ,  113 ,  137 ,  190 . The discriminating projection  226  is formed at a position spaced a distance L 2  larger than the distance L 1  of the discriminating projection  73  of the first battery loading device  6  in a direction perpendicular to the abutment surface  205 , as shown in FIG.  24 . 
     The loading section  201  of the second battery loading device  8  is provided with a lock mechanism  228  for holding the loaded battery packs  5 ,  7 ,  9  and  12 . The lock mechanism  228  includes a lock member  230 , having a lock pawl  232  for engaging with lock recesses  38 ,  121 ,  146 ,  197  of the battery packs  5 ,  7 ,  9  and  12 , and an operating piece  231  for actuating this lock member  230 . The lock pawl  232  is movably passed through an opening  234  formed in the setting surface  204 . 
     If the first to fourth battery packs  5 ,  7 ,  9  and  12  are loaded on the above-described second battery loading device  8 , the battery packs are verified to be appropriate and loaded if the discriminating projection  226  is passed through the discriminating recesses  30 ,  113 ,  137 ,  190 . If the, battery plate  11 , verified to be inappropriate, is loaded on the second battery loading device  8 , the step of the first guide projection  220  presses against the planar surface of the first guide groove  167  of the battery plate  11  to render insertion of the battery plate  11  impossible. Also, since the width W 2  of the discriminating recess  163  of the battery plate  11  is smaller than the width W 3  of the discriminating projection  226 , the discriminating projection  226  cannot be inserted into the discriminating recess  163 . This verifies that the battery plate  11  is inappropriate and renders the insertion of the battery plate  11  impossible. Therefore, only the battery plate  11  is verified to be non-loadable on the second battery loading device  8 . 
     A third battery loading device, on which can be loaded the battery packs  5 ,  7 ,  9  and  12  and the battery plate  11 , is now explained by referring to the drawings. 
     Referring to FIG. 25, the third battery loading device  10  includes a loading section  238 , having a setting surface  241  on which to set the battery packs  5 ,  7 ,  9  and  12  and the battery plate  11 , and a terminal section  239 , to which are connected the output terminals  21  to  23 ,  105  to  107 ,  128  to  130 ,  181  to  183  and  153  to  155 . 
     On both width-wise lateral sides of the setting surface  241  of the loading section  239  are formed guide projections  244 , adjacent to the setting surface  241 , for engaging in the guide grooves  26 ,  109 ,  132 ,  185  and  157  of the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 . 
     The terminal section  239  is arranged on an abutment surface  242  adapted to face the front surfaces  20 ,  103 ,  126  and  176  of the battery packs  5 ,  7 ,  9 ,  12  and the front surface  150  of the battery plate  11 , and includes first, second and third connection terminals  246  to  248 , to which are connected output terminals  21  to  23 ,  105  to  107 ,  128  to  130 ;  181  to  183  and  153  to  155  of the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 . In the terminal section  239 , a cover member  250  for projecting the connection terminals  246  to  248  is arranged for rotation with respect to the loading section  239 , as shown in FIG.  25 . 
     The loading section  238  of the third battery loading device  10  is formed as one with a pair of control projections  252 ,  253  line-symmetrically with respect to substantially the width-wise centerline of the setting surface  241 , as shown in FIG.  25 . The control projections  252 ,  253  are formed astride the abutment surface  242  and the setting surface  241  so as to be engageable in the control recesses  28 ,  29 ,  111 ,  112 ,  134 ,  135 ,  187 ,  188 ,  160 ,  161  of the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 . These control projections  252 ,  253  are of a height level in a direction perpendicular to the setting surface  241  slightly higher than the outer periphery of the connection terminals  246  to  248  to prevent destruction of the connection terminals  246  to  248 . 
     The loading section  238  of the third battery loading device  10  is formed as one with a first guide projection  255 , astride the setting surface  241  and the abutment surface  242 , adjacent to the third-connection terminal  248 , for guiding the loading of the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 . 
     The loading section  238  of the third battery loading device  10  is formed as one with a second guide projection  256  extending parallel to the longitudinal direction of the setting surface  242  astride the setting surface  241  and the abutment surface  241 , as shown in FIG.  25 . The second guide projection  256  is adapted for guiding the loading direction of the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 . On both lateral sides in the width-wise direction of the loading section  238  of the third battery loading device  10  are integrally formed control pawls  257 ,  257  engageable control grooves  37 ,  120 ,  132 ,  196 ,  169  of the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 . The control pawls  257 ,  257  are formed parallel to the setting surface  241  and to the longitudinal direction of the setting surface  241 . Meanwhile, there is not formed, at a mid portion of the setting surface  241  of the loading section  238  of the third battery loading device  10 , a discriminating projection engageable in the discriminating recesses  30 ,  113 ,  137 ,  190 ,  163  of the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 . Thus, the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11  can be set on the setting surface  241  of the third battery loading device  10 . 
     The loading section  238  of the third battery loading device  10  is provided with a lack mechanism  260  for holding the loaded battery packs  5 ,  7 ,  9 ,  12  and the loaded battery plate  11 . The lock mechanism  260  includes a lock member  262  having a lock pawl  264  engageable in first lock recesses  38 ,  121 ,  146 ,  197 ,  171  formed in the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 , and an operating piece  263  for activating the lock member  262 . The lock pawl  264  is movably passed through an opening  265  formed in the setting surface  241 . 
     The above-described third battery loading device  10  is not formed with discriminating projections adapted for insertion into the discriminating recesses  30 , 113 , 137 , 190 ,  163 , so that, when the battery packs  5 ,  7 ,  9 , l  2  and the battery plate  11  are loaded thereon, these are loaded thereon as being appropriate. Moreover, since there is no step formed on the first guide projection  255  of the third battery loading device  10 , it is inserted into the first guide groove  167  of the battery plate  11  so that the battery plate  11  is loaded as being appropriate. 
     A fourth battery loading device  13 , on which can be loaded only the above-described fourth battery pack  12 , is explained by referring to FIG.  26 . 
     The fourth battery loading device  13  includes a loading section  268 , having a setting surface  271  on which to set the fourth battery pack  12 , and a terminal section  269  to which are connectable the respective output terminals  181  to  183  of the fourth battery pack  12 . 
     The loading section  268  is formed with guide projections  275 , adjacent to both lateral sides in the width-wise direction of the setting surface  271 , engageable in the respective guide grooves  185  of the fourth battery pack  12 . 
     The terminal section  269  is provided on an abutment surface  272  adapted to face the front surface  176  of the fourth battery pack  12 , when the battery pack is loaded thereon, and includes first to third connection terminals  277  to  279  which are connectable to the output terminals  181  to  183  of the fourth battery pack l 2 . A cover member  282  for projecting the connection terminals  277  to  279  is rotationally mounted on the terminal section  269  for rotation relative to the loading section  268 , as shown in FIG.  26 . 
     The loading section  268  of the fourth battery loading device  13  is formed as one with a pair of control projections  285 ,  286 , astride the abutment surface  272  and the setting surface  271 , adapted for engagement in the control recesses  187 ,  188  of the fourth battery pack  12 . These control projections  285 ,  286  are of a height level in a direction perpendicular to the setting surface  271  higher than the outer periphery of the connection terminals  277  to  279  to prevent destruction of the connection terminals  277  to  279 . 
     The loading section  268  of the fourth battery loading device  13  is formed with a first guide projection  288 , astride the abutment surface  272  and the setting surface  271 , adjacent to the third connection terminal  279 , for guiding the loading of the fourth battery pack  12  in a direction parallel to the longitudinal direction of the setting surface  271 . The first guide projection  288  is formed with a step integrally connected to the abutment surface  272  and extending in a direction perpendicular to the setting surface  271 . This step has a height level slightly higher than the control projections  285 ,  286  to prevent possible destruction of the connection terminals  277  to  279 . 
     On both lateral sides in the width-wise direction of the loading section  268  of the fourth battery loading device  13 , there are integrally formed control pawls  290 ,  290  engageable in the control grooves  196 , 196  of the fourth battery pack  12 . The control pawls  290 ,  290  are parallel to the setting surface  271  and to the longitudinal direction of the setting surface  271 . At a mid portion of the setting surface  271 , the loading section  268  of the fourth battery loading device  13  is formed as one with a discriminating projection  291  engageable in a discriminating recess  190  of the fourth battery pack  12 . 
     The discriminating projection  291  has a width W 0  larger than the width W 1  of the  8  discriminating projection  73  of the first battery loading device  6 . The discriminating projection  291  is formed at a site spaced a distance L 2  larger than the distance L 1  of the discriminating projection  73  of the first battery loading device  6 , as shown in FIG.  26 . 
     The loading section  268  of the fourth battery loading device  13  is provided with a lock mechanism  293  for holding the loaded fourth battery pack  12 . The lock mechanism  293  includes a lock member  295  having a lock pawl  298  engageable in a lock hole  197  of the fourth battery pack  12 , and an operating piece  296  for activating the lock member  295 . The lock pawl  298  is movably passed through an opening  299  formed in the setting surface  281 . 
     If the fourth battery pack  12  is loaded on the above-described fourth battery loading device  13 , the discriminating projection  291  will be inserted into the discriminating recess  190 , whereby only the fourth battery pack  12  will be verified to be appropriate and loaded. 
     If the first to third battery packs  5 ,  7  and  9  and the battery plate  11 , verified to be inappropriate, are loaded erroneously, the control projection  286  will be pressed against the front surfaces  20 ,  103 ,  126 ,  150  of the casings  19 ,  101 ,  124 ,  149  to prevent the insertion of the battery packs  5 ,  7  and  9  or the battery plate  11 , whereby the first to third battery packs  5 ,  7  and  9  and the battery plate  11  will be verified to be inappropriate and cannot be loaded. 
     Finally, the first battery loading device  6  permits the loading only of the first battery pack  5  and the battery pack  11 , whilst the second to fourth battery packs  7 ,  9 ,  12  are verified to be inappropriate. If the first battery pack  5  and the battery plate  11  are loaded an the first battery loading device  8  the discriminating projection  73  and the discrimination lug  74  will be inserted into the discriminating recesses  30 ,  163 , so that the first battery pack  5  and the battery plate  11  will be verified to be appropriate and loaded. 
     If the second battery pack  7 , verified to be inappropriate, is loaded on the first battery loading device  6 , the discrimination lug  74  of the discriminating projection  73  abuts the discriminating projection  116  of the discriminating recess  113  to demonstrate that it cannot be inserted. Therefore, the second battery pack  7  is verified to be inappropriate and non-loadable. If the third battery pack  9 , verified to be inappropriate, is loaded on the first battery loading device  6 , the discrimination lug  74  of the discriminating projection  73  abuts the discriminating projection  139  of the discriminating recess  137  to demonstrate the non-loadability, so that the third battery pack  9  is verified to be inappropriate and non-insertable. 
     The battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11  are configured to be loaded on a variety of battery loading devices provided an the video camera apparatus  1 . Alternatively, the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11  may be loaded on an illumination device mounted on the video camera apparatus  1 . This illumination device, on which the battery packs  5 ,  7 ,  9 ,  12  and the battery plate  11 , may be loaded now explained by referring to the drawings. 
     Referring to FIGS. 27 and 28, a first illumination device  15  includes an illumination unit  301  for illuminating an object, a changeover switch  302  for switching the operating state of the illumination unit  301 , a loading unit  303  on which the first and second battery packs  5 ,  7  can be loaded and a terminal unit  304  to which may be connected output terminals  21  to  23  and  105  to  107  of the battery packs  5  and  7 . 
     The loading unit  303  is provided with guide projections  309  shown in FIG. 28, which are engageable with guide grooves  26 ,  109  of the battery packs  5 ,  7 . The guide projections  309  are provided on both lateral sides in the width-wise direction of the setting surface  306  in adjacency to the setting surface  306 . 
     The terminal unit  304  is provided on an abutment surface  307  may be connected surfaces  20 ,  103  of the loaded battery packs  5 ,  7 , and includes first to third connection terminals  311  to  313  to which output terminals of the battery packs  5 ,  7 , may be connected. A cover member  315  for projecting the connection terminals  311  to  313  is mounted for rotation relative to the loading unit  303 , as shown in FIG.  28 . 
     The loading unit  303  of the first illumination device  15  is provided with a pair of control projections  316 ,  317 , line-symmetrically relative to substantially the centerline in the width-wise direction of the setting surface  306 , as shown in FIG.  28 . The control projections  316 ,  317  are formed as one with the loading unit  303  astride the abutment surface  307  and the setting surface  346  so as to be engageable with the control recesses  28 ,  29 ,  111 ,  112  of the battery packs  5 ,  7 . The control projections  316 ,  317  are of a height level in a direction perpendicular to the setting surface  306  higher than the outer periphery of the connection terminals  311  to  313  to prevent destruction of the connection terminals  311  as one. 
     The loading unit  303  of the first illumination device  15  is formed as one with a first guide projection  319  for guiding the loading of the battery packs  5 ,  7  in a direction parallel to the longitudinal direction of the setting surface  306 . The first guide projection  319  is formed astride the abutment  367  surface and the setting surface  306  and adjacent to the third connection terminal  313 . A step projecting in a direction perpendicular to the setting surface  306  is provided on the first guide projection  319  and is integrally connected to the abutment surface  307 . This step has a height level in a direction perpendicular to the setting surface  306  slightly higher than the control projections  316 ,  317  to prevent the destruction of the connection terminals  311  to  313 . 
     The loading unit  303  of the first illumination device  15  is formed as one with a second guide projection  321  extending parallel to the longitudinal direction of the setting surface  346 , as shown in FIG.  28 . The second guide projection  321  is formed astride the setting surface  306  and the abutment surface  307  for guiding the loading of the battery packs  5 ,  7 . The loading unit  303  of the first illumination device  15  is formed as one with control pawls  323 ,  323  on both width-wise lateral sides for engaging the control grooves  37 ,  120  of the battery packs  5 ,  7 . The control pawls  323 ,  323  are parallel to the setting surface  306  and to the longitudinal direction of the setting surface  306 . At a mid portion of the setting surface  306  of the loading unit  303  of the first illumination device  15  is integrally formed a discriminating projection  325  engageable in the discriminating recesses  30 ,  113  of the battery packs  5 ,  7 . The distal end of the discriminating projection  325  is formed with a discriminating lug  326 . 
     This discriminating projection  325  is of a width W 3  larger than the width W 1  of the discrimination projection  73  of the first battery loading device  6 , The discriminating projection  325  is formed at a position spaced a distance L 2  larger than the distance L 1  of the discriminating projection  73  of the battery loading device  6  in a direction perpendicular to the abutment surface  307 . 
     The loading unit  303  of the first illumination device  15  is provided with a lock mechanism  328  for holding the loaded battery packs  5 ,  7 . The lock mechanism  328  includes a lock member  330  having a lock pawl  332  engageable in the first lock holes  38 ,  121  of the battery packs  5 ,  7  and an operating piece  331  for activating the lock member  330 . The lock pawl  332  is movably passed through the opening  333  formed in the setting surface  306 . 
     If the first, second or fourth battery packs  5 ,  7 ,  12  are loaded on the loading unit  303  of the first illumination device  15 , the discriminating projection  325  will be inserted into the discriminating recesses  30 ,  113 ,  190  to demonstrate that the first, second and fourth battery packs are verified to be appropriate and loaded. 
     If the third battery pack  9 , verified to be inappropriate, is erroneously loaded on the loading unit  303  of the first illumination device  15 , the discriminating lug  326  of the discriminating projection  325  will be pressed against the discriminating recess  140  of the discriminating projection  139  in the discriminating recess  137  and demonstrates that it cannot be inserted. Thus, the third battery pack  9  is verified to be inappropriate and non-loadable. 
     If the battery plate  11 , verified to be inappropriate, is erroneously loaded an the loading unit  303  of the first illumination device  15 , the step on the first guide projection  319  will abut the planar surface of the first guide groove  167  of the battery plate  11 , and thus demonstrates that it cannot be inserted. Moreover, since the width W 2  of the discriminating recess  163  of the battery plate  11  is smaller than the width W 3  of the discriminating projection  325 , the discriminating projection  325  cannot be inserted into the discriminating recess  163 . Thus, the battery plate  11  is verified to be inappropriate and non-loadable. 
     Therefore, the loading unit  303  of the first illumination device  15  is configured so that the high capacity type first battery pack  5  and the standard type second and fourth battery packs  7 ,  12  can be loaded thereon. Since the illumination unit  341  of the first illumination device  15  consumes much power, the third battery pack  9  having a lower charging capacity and the battery plate  11  are verified to be inappropriate. 
     Referring to the drawings, a second illumination device  17 , having a larger illumination volume than that of the above-described first illumination device  15 , is now explained. 
     As shown in FIGS. 29 and 30, the second illumination device  17  includes an illumination unit  336  for illuminating an object, a changeover switch  337  for changing over the operating state of the illumination unit  336 , a loading section  338  on which the first battery pack  5  may be removably loaded, and a terminal unit  339  to which the output terminals  21  to  23  of the first battery pack  5 , may be connected. 
     On both lateral sides in the width-wise direction of the setting surface  34  and adjacent thereto, there are formed guide projections  344  engageable in the guide grooves  26  of the first battery parallel to the longitudinal direction of the setting surface  341 . The first guide projection  355  is provided astride the abutment surface  342  and the setting surface  341  and adjacent to the third connection terminal  348 . This first guide projection  355  is formed with a step protruding in a direction perpendicular to the setting surface  341  and integrally connected to the abutment surface  342 . This step has a height level in a direction perpendicular to the setting surface  341  slightly higher than the control projections  352 ,  353  to prevent possible destruction of the connection terminals  346  to  348 . 
     The loading section  338  of the second illumination device  17  is formed as one with a second guide projection  357  extending parallel to the longitudinal direction of the setting surface  341 . The second guide projection  357  is formed astride the setting surface  341  and the abutment surface  342  for guiding the loading of the first battery pack  5 . On both width-wise lateral sides of the loading section  338  of the second illumination device  17  are formed protruding control pawls  358 ,  358  engageable in the control groove  37  of the first battery pack  5 . The control panel  358 ,  358  are parallel to the setting surface  341  and to the longitudinal direction of the setting surface. At a mid portion of the setting surface  341  of the loading section  338  of the second illumination device  17  is integrally formed a discriminating projection  360  engageable in the discriminating recess  30  of the first battery pack  5 . The distal end of the discriminating projection  360  is formed with a discriminating lug  361 . 
     The discriminating projection  360  has a width W 3  larger than the width W 1  of pack  5 . 
     The terminal unit  339  is arranged on the abutment surface  342  adapted to face the front surface  20  of the loaded first battery pack  5 , and includes first to third connection terminals  346  to  348  to which the output terminals  21  to  23  of the first battery pack  5 , may be connected. The terminal unit  339  is also provide with a cover member  350  for projecting the connection terminals  346  to  348 . The cover member is adapted for rotation relative to the loading section  338 , as shown in FIG.  30 . 
     The loading section  338  of the second illumination device  17  is formed as one with a pair of control projections  352 ,  353  line-symmetrically with respect to substantially the centerline in the width-wise direction of the setting surface  341 . The control projections  352 ,  353  are formed astride the abutment surface  342  and the setting surface  341  so as to be engagable in the control recesses  28 ,  29  of the first battery pack  5 . These control projections  352 ,  353  are of a height level in the direction perpendicular to the setting surface  341  higher than the outer periphery of the connection terminals  346  to  348  to prevent possible destruction of the connection terminals  346  to  348 . 
     The loading section  338  of the second illumination device  17  is formed as one with a first guide projection  355  for guiding the loading of the first battery pack  5  the discrimination projection  73  of the first battery loading device  6 . The discriminating projection  360  is formed at a position spaced a distance L 1  smaller than the distance L 2  of the discriminating projection  325  of the first illumination device  15  in a direction perpendicular to the abutment surface  342 . 
     The loading section  338  of the second illumination device  17  is provided with a lock mechanism  363  for holding the loaded first battery pack  5 . The lock mechanism  363  includes a lock member  364  having a lock pawl  366  engageable in the first lock hole  30  of the first battery pack  5 , and an operating piece  365  for activating the lock member  364 . The lock pawl  366  is movably passed through an opening  368  formed in the setting surface  341 . 
     If the first or second battery pack  5  or  12  is loaded on the loading section  338  of the above-described second illumination device  17 , the discriminating projection  360  will be inserted into the discriminating recesses  30 ,  190  to demonstrate that the first and second battery packs  5 ,  12  are appropriate for the loading section  338  to permit the battery pack  5  or  12  to be loaded in position. 
     If the second battery pack  7 , verified to be inappropriate, is loaded on the loading section  338  of the second illumination device  17 , the discriminating lug  361  of the discriminating projection  360  will be pressed against the discriminating projection  116  of the discriminating recess  113  to prevent the insertion. Thus, the second battery pack  7  is verified to be inappropriate and non-loadable. On the other hand, if the third battery pack  9 , verified to be inappropriate, is loaded on the second illumination device  17 , the discriminating lug  361  of the discriminating projection  360  will be pressed against the discriminating projection  139  of the discriminating recess  137  to prevent the insertion. Thus, the third battery pack  9  is verified to be inappropriate and non-loadable. Also, if the battery plate  11 , verified to be inappropriate, is loaded on the loading section  338  of the second illumination device  17 , the step on the first guide projection  355  will be pressed against the planar surface of the first guide groove  167  to prevent the insertion. Moreover, since the width W 2  of the discriminating recess  163  of the battery plate  11  is smaller than the width W 3  of the discriminating projection  360 , the discriminating projection  360  cannot be inserted into the discriminating recess  163 . Thus, the battery plate  11  is verified to be inappropriate and non-loadable. Therefore, the high capacity type first and fourth battery packs  5 ,  12  can be loaded on the loading section  338  of the second illumination device  17 . 
     With the battery loading mechanism according to the present invention, the discriminating recesses  30 ,  113 ,  137 ,  190  of the battery packs  5 ,  7 ,  9 ,  11 , discriminating grooves  32 ,  115 ,  138 ,  191  in the discriminating recesses  30 ,  113 ,  137 ,  190 , discriminating  116 ,  139 , discriminating recess  140 , discriminating projections  73 ,  226 ,  291 ,  325 ,  360  and the discriminating projections  74 ,  326  and  321  of these discriminating projections  73 ,  226 ,  291 ,  325 ,  360  are used for discrimination, so that it is possible to set various shapes conforming to plural specifications. Since it suffices in this battery loading mechanism to suitably modify only the shape of the discriminating recesses and the discriminating projections, it is unnecessary to manufacture new metal molds for different battery packs having different specifications rendering possible to reduce the manufacturing cost of metal molds. 
     It should be noted that, although the battery pack according to the present invention includes a battery cell having a chargeable secondary battery, this is merely illustrative since the battery pack can be configured to exchangeably hold primary dry batteries. Moreover, although the battery loading device according to the present invention is configured for being loaded on a video camera or an illumination device, it may also be mounted on an electronic equipment such as a charging device used for charging the battery pack.