Patent Publication Number: US-10317056-B2

Title: Drive apparatus and illumination apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2016-086351 filed in Japan on Apr. 22, 2016. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a drive apparatus and an illumination apparatus. 
     2. Description of the Related Art 
     Conventionally, an illumination apparatus has been provided that is capable of changing the irradiation direction of a spotlight included in the illumination apparatus in any direction (see Japanese Patent Application Laid-open No. 2009-110717). Such an illumination apparatus (drive apparatus) rotatably and pivotally supports, for example, a lamp body thereof on one side of the lamp body by an arm extending from a support unit attached to a ceiling surface. In this case, the arm pivotally supported by the support unit is rotated thus changing the direction of the lamp body in the horizontal direction (panning direction), and the lamp body pivotally supported by the arm is rotated thus changing the direction of the lamp body in the vertical direction (tilting directions). 
     However, in the above-mentioned conventional technique, it is difficult to suppress troubles due to the weight of an operation target such as a light source or the lamp body in a state in which the operation target is capable of changing the direction thereof in an intended direction. For example, in the above-mentioned drive apparatus, the operation target is pivotally supported by the arm on the one side of the operation target and hence, there may be a case that the troubles due to the weight of the operation target are, for example, caused in a connection part between the operation target and the arm. 
     The present invention has been made under such circumstances, and it is an object of the present invention to provide a drive apparatus and an illumination apparatus that are capable of suppressing the troubles due to the weight of the operation target in a state in which the operation target is capable of changing the direction thereof in an intended direction. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least partially solve the problems in the conventional technology. 
     A drive apparatus according to an embodiment includes a support unit, an arm, an operation target and a bias part. The support unit includes an electrically-driven first driving source. The arm is supported by the support unit at one end part of the arm, and is, by the first driving source, rotatable about a first rotational axis that is along an extending direction of another end part of the arm extending from the one end part, the arm including an electrically-driven second driving source. The operation target is attached to the another end part side of the arm, and is, by the second driving source, rotatable about a second rotational axis intersecting with the extending direction. The bias part biases the operation target in a direction toward the arm along the second rotational axis. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating an illumination apparatus according to an embodiment; 
         FIG. 2  is a front view illustrating the illumination apparatus according to the embodiment; 
         FIG. 3  is a perspective view illustrating the essential part of a support unit in the illumination apparatus according to the embodiment; 
         FIG. 4  is a perspective view illustrating the inside of one end part of an arm in the illumination apparatus according to the embodiment; 
         FIG. 5  is a plan view illustrating an internal-gear part of the illumination apparatus according to the embodiment; 
         FIG. 6  is a perspective view illustrating the inside of the one end part of the arm in the illumination apparatus according to the embodiment; 
         FIG. 7  is a front view illustrating the inside of another end part of the arm in the illumination apparatus according to the embodiment; 
         FIG. 8  is a side view illustrating the essential part on the inside of the other end part of the arm in the illumination apparatus according to the embodiment; 
         FIG. 9  is a perspective view illustrating the essential part on the inside of the other end part of the arm in the illumination apparatus according to the embodiment; 
         FIG. 10  is a perspective view illustrating a pivotally supporting part of the illumination apparatus according to the embodiment; 
         FIG. 11  is a perspective view illustrating the relation between the pivotally supporting part and the other end part of the arm in the illumination apparatus according to embodiment; 
         FIG. 12  is a partially perspective view illustrating the arrangement of bearings in the illumination apparatus according to the embodiment. 
         FIG. 13  is a perspective view illustrating the relation between the pivotally supporting part and a light source unit in the illumination apparatus according to the embodiment; 
         FIG. 14  is a perspective view illustrating the light source unit of the illumination apparatus according to the embodiment; 
         FIG. 15  is a perspective view illustrating a zooming mechanism of the illumination apparatus according to the embodiment; 
         FIG. 16  is a perspective view illustrating a holding part of the illumination apparatus according to the embodiment; 
         FIG. 17  is a perspective view illustrating the essential part of the zooming mechanism in the illumination apparatus according to the embodiment; 
         FIG. 18  is a perspective view illustrating an alignment part of the illumination apparatus according to the embodiment; 
         FIG. 19  is a perspective view illustrating a rotational part of the illumination apparatus according to the embodiment; and 
         FIG. 20  is a partially perspective view illustrating the zooming mechanism of the illumination apparatus according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In an embodiment mentioned below, an illumination apparatus  1  is explained with reference to drawings as one example of a drive apparatus. For example, the illumination apparatus  1  has a light source unit  30  including a light source (not illustrated in the drawings), as an operation target. Here, the use of the drive apparatus is not limited to the embodiment explained below. Furthermore, it is necessary to consider that each of the drawings is a schematic drawing and hence, there may be a case that a dimensional relation between respective elements, or the dimensional ratio between the respective elements are different from actual dimensions. In the relation between the drawings also, there may be a case that the dimensional relations or the dimensional ratios illustrated in the respective drawings are different from each other. 
     Embodiment 
     First of all, the outline of the constitution of the illumination apparatus  1  is explained in conjunction with  FIG. 1  and  FIG. 2 .  FIG. 1  is a perspective view illustrating the illumination apparatus  1  as viewed from the light source unit  30  side of the illumination apparatus  1 .  FIG. 2  is a front view of the illumination apparatus  1 . 
     Hereinafter, the direction along the rotational axis (hereinafter, referred also to as “first rotational axis”) of an arm  20  mentioned below indicates a Y axis, and an X axis and a Z axis are orthogonal to each other in the plane orthogonal to the Y axis. For example, the X-axis is taken along the rotational axis (hereinafter, referred also to as “second rotational axis”) of the light source unit  30  at the attachment position (initial position) of the illumination apparatus  1 . 
     The illumination apparatus  1  has a support unit  10 , the arm  20 , and the light source unit  30 . As illustrated in  FIG. 2 , the light source unit  30  is arranged below the support unit  10  in the gravity direction (Y-axis negative direction), and arranged at the position such that the light source unit  30  overlaps with the support unit  10  as viewed in a plan view. 
     The support unit  10  is formed in a rectangular box shape. Here, the support unit  10  may be formed of any material, and may be, for example, formed of an aluminum material. The support unit  10  houses therein a power supply board (not illustrated in the drawings) that supplies power to elements such as a first motor  45 , a second motor  61 , or a light emitting part  33 , the elements being described later. Furthermore, the support unit  10  is attached to a predetermined object (structure) such as a ceiling through an engagement part (not illustrated in the drawings) arranged in the surface (upper surface in  FIG. 2 ) that faces in the Y-axis positive direction. For example, the support unit  10  is detachably attached to a rail (not illustrated in the drawings) arranged on a ceiling surface through the engagement part. 
     Hereinafter, the Y-axis positive direction indicates the upward direction, the Y-axis negative direction indicates the downward direction, and the direction orthogonal to the Y-axis indicates the horizontal direction. In this case, for example, the Y-axis negative direction assumes the gravity direction, and a plane orthogonal to the Y-axis assumes a horizontal plane. 
     As illustrated in  FIG. 3 , the support unit  10  forms a recessed portion  11  in the surface (the bottom surface of the support unit  10  in  FIG. 2 ) that faces in the Y-axis negative direction, the recessed portion  11  having an opening in the center thereof.  FIG. 3  is a perspective view illustrating the essential part of the support unit in the illumination apparatus according to the embodiment. In the support unit  10 , a first shaft  41  of a first rotational part  40  described later is inserted into the opening of the recessed portion  11 , and the recessed portion  11  attaches an internal-gear part  42  (see  FIG. 4 ) thereto with the use of screw members or the like. Due to such constitution, the arm  20  rotates about the center axis (first rotational axis) of the first shaft  41 , as will be specifically described later. 
     One end part  21  of the arm  20  is arranged close to the part in which the recessed portion  11  of the support unit  10  is formed. As illustrated in  FIG. 4 , in the one end part  21  of the arm  20 , the first rotational part  40  having the first motor  45  is arranged.  FIG. 4  is a perspective view illustrating the inside of the one end part of the arm in the illumination apparatus according to the embodiment. To be more specific,  FIG. 4  is a perspective view illustrating the internal-gear part  42  in a see-through manner except for a top cover  211  of the one end part  21  of the arm  20 . 
     The first rotational part  40  has the first shaft  41 , the internal-gear part  42 , and a first bracket  43 . 
     The internal-gear part  42  has a first cylindrical portion  421 , and a second cylindrical portion  422 . For example, the internal-gear part  42  is formed of a resin material or the like.  FIG. 5  is a plan view illustrating the internal-gear part of the illumination apparatus according to the embodiment. To be more specific,  FIG. 5  illustrates the plan view of the internal-gear part  42  as viewed from the second cylindrical portion  422  side (bottom side) of the internal-gear part  42 . Here, in  FIG. 5 , a restriction pin  433  of the first bracket  43  is illustrated in order to indicate a positional relation with a second projecting portion  426  of the internal-gear part  42 , as will be specifically described later. 
     The second cylindrical portion  422  is formed in such a manner that the second cylindrical portion  422  is larger in diameter than the first cylindrical portion  421 , and a surface of the second cylindrical portion  422  is opened, the surface being opposite to the part continuously extending to the first cylindrical portion  421 . The second cylindrical portion  422  has internal teeth  424  formed in the inner peripheral face thereof. In the example illustrated in  FIG. 5 , the internal teeth  424  are formed over the entire circumference of the inner peripheral face of the second cylindrical portion  422 . Furthermore, a first projecting portion  425  (see  FIG. 4 ) projects from the outer peripheral face of the first cylindrical portion  421  along the planar surface of the second cylindrical portion  422 . 
     As illustrated in  FIG. 5 , the inside of the first cylindrical portion  421  and the inside of the second cylindrical portion  422  are communicated with each other, and an insertion part  423  formed in a cylindrical shape is formed in the center portion of the first cylindrical portion  421  and the second cylindrical portion  422 . The first shaft  41  is inserted into the insertion part  423  of the internal-gear part  42 . In the top cover  211  of the one end part  21 , the part that overlaps with the recessed portion  11  of the support unit  10  is opened, and the first cylindrical portion  421  is attached to the recessed portion  11  with the use of screw members or the like. On the inside of the first cylindrical portion  421 , a reinforcing plate  427  (see  FIG. 4 ) formed in an annular shape is arranged, and both the first cylindrical portion  421  and the reinforcing plate  427  are attached to the recessed portion  11  with the use of screw members or the like. The reinforcing plate  427  is made of a metallic material or the like. Due to such constitution, the first shaft  41  is rotatably arranged on the inside of the opening of the recessed portion  11  and the insertion part  423  of the internal-gear part  42 . Furthermore, while the reinforcing plate  427  keeps the intended strength of the connection portion between the support unit  10  and the arm  20 , the arm  20  is hung from the support unit  10 . The illumination apparatus  1  may be provided with no reinforcing plate  427 . 
     Furthermore, the first bracket  43  is arranged on the second cylindrical portion  422  side of the internal-gear part  42 . As illustrated in  FIG. 6 , the first bracket  43  is provided with an insertion hole  430  into which a distal end portion  411  of the first shaft  41  is inserted. The distal end portion  411  of the first shaft  41  inserted into the first cylindrical portion  421  is inserted into the insertion hole  430 .  FIG. 6  is a perspective view illustrating the inside of the one end part of the arm in the illumination apparatus according to the embodiment. To be more specific,  FIG. 6  is a perspective view illustrating the inside of the one end part of the arm as viewed from a side opposite to the support unit  10  except for a housing part other than the top-cover  211  of the one end part  21  of the arm  20 . 
     For example, as illustrated in  FIG. 6 , the distal end portion  411  of the first shaft  41  is inserted into the insertion hole  430  provided to the first bracket  43  in such a state that the position of the first shaft  41  in the rotational direction is restricted. To be more specific, the distal end portion  411  of the first shaft  41  is provided with a pair of restriction pieces  412  projecting in directions away from each other. The distal end portion  411  having the pair of restriction pieces  412  is inserted into the insertion hole  430  of the first bracket  43  that is formed in a shape corresponding to the shape of the distal end portion  411  thus restricting the position of the first shaft  41  with respect to the first bracket  43  in the rotational direction. Due to such constitution, the first shaft  41  and the first bracket  43  rotate together with each other about the first rotational axis. Furthermore, the first bracket  43  is, for example, attached to the one end part  21  of the arm  20  with the use of screw members or the like, and the rotation of the first bracket  43  also causes the arm  20  to rotate about the first rotational axis. 
     As illustrated in  FIG. 4 , in the first bracket  43 , a first switch  44  is arranged at a position along the outer peripheral face of the second cylindrical portion  422  of the internal-gear part  42 . For example, the first switch  44  is arranged in such a manner that a lever  441  projects to the first cylindrical portion  421  side along the planar surface of the second cylindrical portion  422 . For example, the lever  441  of the first switch  44  is arranged in such a manner that the lever  441  projects to a position such that the lever  441  overlaps with the first projecting portion  425  of the internal-gear part  42  in the circumferential direction of the first cylindrical portion  421 . The first projecting portion  425  of the internal-gear part  42  rotates the lever  441  of the first switch  44  thus detecting the limit of the rotational angle set to stop the operation of the first motor  45 . This mechanism is used for motor control as described above. In the present embodiment, the first bracket  43 ; that is, the arm  20 , restricts the rotational angle thereof in the horizontal direction within the range of approximately 360° by the first switch  44  and the first projecting portion  425  of the internal-gear part  42 . 
     The first bracket  43  is provided with a raised part  431  arranged at a position such that the raised part  431  overlaps with the second cylindrical portion  422  of the internal-gear part  42 . The raised part  431  forms an insertion groove  432  therein. Furthermore, the first bracket  43  is provided with the restriction pin  433  arranged at a position such that the restriction pin  433  overlaps with the second cylindrical portion  422  of the internal-gear part  42 . The raised part  431  forms the insertion groove  432  therein. A distal end portion  434  of the restriction pin  433  is arranged in the insertion groove  432  of the raised part  431  in a horizontally movable manner. For example, as illustrated in  FIG. 5 , the restriction pin  433  is provided with an insertion hole  435 , and screw members or the like are threadedly engaged into the insertion hole  435  thus attaching the restriction pin  433  to the planar part of the first bracket  43 . The distal end portion  434  of the restriction pin  433  is capable of rotating about the insertion hole  435 . Due to such constitution, the distal end portion  434  of the restriction pin  433  is arranged in the insertion groove  432  of the raised part  431  in a horizontally movable manner. 
     Furthermore, the internal-gear part  42  has the second projecting portion  426  projecting from the outer peripheral face of the insertion part  423 . For example, the second projecting portion  426  is formed on the end portion on the second cylindrical portion  422  side of the insertion part  423  in a projecting manner toward the second cylindrical portion  422 . For example, the second projecting portion  426  of the internal-gear part  42  is arranged in such a manner that the second projecting portion  426  projects to a position such that the second projecting portion  426  overlaps with the distal end portion  434  of the restriction pin  433  in the circumferential direction of the insertion part  423 . Here, the second projecting portion  426  of the internal-gear part  42  is brought into contact with the distal end portion  434  of the restriction pin  433  thus restricting physically the rotation of the arm  20  about the first rotational axis. Furthermore, as illustrated in  FIG. 4 , the distal end portion  434  of the restriction pin  433  is horizontally movable in the insertion groove  432  of the raised part  431  and hence, the distal end portion  434  moves freely between both ends of the insertion groove  432  in the horizontal direction. In this manner, the second projecting portion  426 , the restriction pin  433 , and the raised part  431  are capable of restricting the rotation of the arm  20  about the first rotational axis within such an intended range as 360°. 
     The first rotational part  40  has the first motor  45  as an electrically-driven first driving source. As illustrated in  FIG. 4 , the first motor  45  is attached to the first bracket  43 . For example, a stepping motor is used for the first motor  45 , which is connected to a controller  50  (see  FIG. 7 ) through lead wires (not illustrated in the drawings) extending from the first motor  45 . As illustrated in  FIG. 6 , an output rotation shaft  451  of the first motor  45  is inserted into a through hole  436  formed in the planar part of the first bracket  43 , and projects to an opposite surface side (lower side in  FIG. 4 ) of the first bracket  43 . 
     Furthermore, a gear  452  is attached to the output rotation shaft  451  of the first motor  45 . The gear  452  attached to the output rotation shaft  451  of the first motor  45  is meshed with a large-diameter gear  453 . A small-diameter gear  455  (see  FIG. 4 ) is attached to a rotational shaft  454  to which the large-diameter gear  453  is attached. That is, the large-diameter gear  453  and the small-diameter gear  455  rotate about the rotational shaft  454 . Here, the large-diameter gear  453  and the small-diameter gear  455  may be integrally formed by molding. 
     Furthermore, in the rotational shaft  454 , one end portion opposite to the other end portion to which the large-diameter gear  453  is attached is inserted into a through hole (not illustrated in the drawings) formed in the planar part of the first bracket  43 , and projects to the other surface side (upper side in  FIG. 4 ) of the first bracket  43 . Accordingly, the small-diameter gear  455  is, as illustrated in  FIG. 4 , arranged on the planar part of the first bracket  43 . 
     The small-diameter gear  455  is meshed with the internal teeth  424  (see  FIG. 5 ) of the internal-gear part  42 . Furthermore, as mentioned above, the internal-gear part  42  is attached to the support unit  10 . Accordingly, the small-diameter gear  455  is moved along the internal teeth  424  depending on the output of the first motor  45 . Due to such constitution, the arm  20  is rotated about the first rotational axis by the output of the first motor  45 . 
     Next, the constitution on the inside of another end part  22  of the arm  20  is explained in conjunction with  FIG. 7  to  FIG. 9 .  FIG. 7  is a front view illustrating the inside of the other end part of the arm in the illumination apparatus according to the embodiment. To be more specific,  FIG. 7  is a front view illustrating the inside of the another end part  22  of the arm  20  except for the face opposite to an attachment face  221  of the another end part  22 .  FIG. 8  is a side view illustrating the essential part on the inside of the other end part of the arm in the illumination apparatus according to the embodiment. To be more specific,  FIG. 8  is a side view illustrating the inside of the another end part  22  of the arm  20  except for the side face continuously extending to an end portion of the attachment face  221  of the another end part  22 .  FIG. 9  is a perspective view illustrating the essential part on the inside of the other end part of the arm in the illumination apparatus according to the embodiment. To be more specific,  FIG. 9  is a perspective view illustrating the essential part on the inside of the another end part  22  of the arm  20 , except for an attachment gear part  63  described later, in such a state that a reinforcing plate  65  described later is illustrated in a see-through manner. 
     As illustrated in  FIG. 7 , the controller  50  and a second rotational part  60  are arranged on the inside of the another end part  22  of the arm  20 . In the example illustrated in  FIG. 7 , the controller  50  is a control board that controls the first motor  45  as the first driving source, and the second motor  61  (see  FIG. 8 ) as an electrically-driven second driving source described later. The controller  50  has a wireless communication function, such as Bluetooth (registered trademark), and may accept an instruction of driving the first motor  45  or the second motor  61  from the outside thereof by using the wireless communication function. Furthermore, the controller  50  may accept an instruction of controlling a light quantity of the light source unit  30  from the outside thereof by using the wireless communication function. As illustrated in  FIG. 7 , the controller  50  is arranged in the vicinity of the second motor  61  or the first motor  45  thus shortening wiring such as lead wires connected to the second motor  61  or the first motor  45 , and improving the assemblability of the illumination apparatus. Furthermore, the wiring such as the lead wire that connects the controller  50 , and the second motor  61  or the first motor  45  is shortened thus suppressing the effect of a noise. 
     As illustrated in  FIG. 8 , the second rotational part  60  has the second motor  61  as the second driving source. For example, a stepping motor is used for the second motor  61 , which is connected to the controller  50  (see  FIG. 7 ) through lead wires (not illustrated in the drawings) extending from the second motors  61 . Furthermore, the second motor  61  is attached to one side of a second bracket  611 , and an output rotation shaft  612  of the second motor  61  is inserted into a through hole formed in the second bracket  611 , and projects to the other side of the second bracket  611 . In the output rotation shaft  612  of the second motor  61 , a gear  613  is attached to a part of the output rotation shaft  612  that is projected to the other side of the second bracket  611 . 
     Furthermore, as illustrated in  FIG. 7 , the gear  613  attached to the output rotation shaft  612  of the second motor  61  is meshed with a large-diameter gear  62 . A small-diameter gear  622  is attached to a rotational shaft  621  to which the large-diameter gear  62  is attached. That is, the large-diameter gear  62  and the small-diameter gear  622  rotate about the rotational shaft  621 . Here, the large-diameter gear  62  and the small-diameter gear  622  may be integrally formed by molding. 
     As illustrated in  FIG. 8 , the small-diameter gear  613  is meshed with external teeth  633  formed in an arcuate portion  632  of the attachment gear part  63  described later. Due to such constitution, the driving force depending on the output of the second motor  61  is transmitted to the attachment gear part  63 . 
     As illustrated in  FIG. 7 , the attachment gear part  63  has a cylindrical portion  631  and the arcuate portion  632 . For example, the attachment gear part  63  is formed of a resin material or the like. The arcuate portion  632  is larger in diameter than the first cylindrical portion  421 , and continuously extends to a part of the outer peripheral face of the cylindrical portion  631 . Furthermore, the external teeth  633  are formed in a part of the outer peripheral face of the arcuate portion  632 . In the example illustrated in  FIG. 6  and  FIG. 7 , the external teeth  633  are formed in the range of 90° set as the central angle with respect to the outer peripheral face of the arcuate portion  632 . 
     Furthermore, as illustrated in  FIG. 9 , a large-diameter part  222  having a through hole in the center portion thereof is formed on the attachment face  221 . The large-diameter part  222  is formed in an annular shape as viewed in a plan view. A small-diameter part  223  that is smaller in diameter than the large-diameter part  222  is formed in a stacked manner on the large-diameter part  222  formed on the attachment face  221 . The small-diameter part  223  is formed in an annular shape as viewed in a plan view, and has a through hole that communicates with the through hole of the large-diameter part  222  in the center portion thereof. The attachment face  221  has a through hole passing through the center portion of the large-diameter part  222  and the small-diameter part  223 . The attachment gear part  63  inserts the small-diameter part  223  into the inside of the cylindrical portion  631  so as to be arranged in a stacked manner with the large-diameter part  222  formed on the attachment face  221 . Here, the rotation of the attachment gear part  63  also causes the light source unit  30  to rotate in the vertical direction, as will be specifically described later. 
     Here, the explanation is made with respect to the restriction of the rotation range of the attachment gear part  63  in conjunction with  FIG. 7 . End portions  636  and  637  have respective arcuate portions that are smaller in diameter than the arcuate portion  632 , and extend from the respective end portions  636  and  637  in the circumferential direction of the arcuate portion  632  of the attachment gear part  63 . Distal end portions  634  and  635  are formed on the respective distal ends of the end portions  636  and  637  in the respective extending directions thereof. In the example illustrated in  FIG. 7 , the distal end portions  634  and  635  are formed so that the angle formed by straight lines that connect the center of the attachment gear part  63  and the respective distal end portions  634  and  635  is set to 90°. 
     Furthermore, as illustrated in  FIG. 7 , a second switch  64  is arranged on the attachment face  221  at a position along the outer periphery of the large-diameter part  222 . For example, the second switch  64  has a lever  641  projecting to the small-diameter part  223  side along the planar surface of the large-diameter part  222 . For example, the lever  641  of the second switch  64  projects in such a manner that the distal end portion of the lever  641  is located between the distal end portion  634  and the distal end portion  635  of the arcuate portion  632  in the circumferential directions. Here, the distal end portion  634  ( 635 ) of the arcuate portion  632  rotates the lever  641  of the second switch  64  thus detecting the limit of the rotational angle set to stop the operation of the second motor  61 . This mechanism is used for motor control as described above. In the present embodiment, the attachment gear part  63  uses the distal end portions  634  and  635  of the arcuate portion  632  in cooperation with the second switch  64  to restrict the rotational angle of the light source unit  30  within 90° in the vertical direction. 
     Furthermore, as illustrated in  FIG. 9 , restriction pieces  224  and  225  are formed on the attachment face  221  along the outer periphery of the large-diameter part  222 , the restriction pieces  224  and  225  facing each other in an opposed manner in the circumferential direction of the large-diameter part  222 . For example, the restriction pieces  224  and  225  of the large-diameter part  222  are arranged so that the restriction pieces  224  and  225  overlap with the end portions  636  and  637  of the arcuate portion  632  in the circumferential direction of the arcuate portion  632 . Here, the restriction pieces  224  and  225  of the large-diameter part  222  are brought into contact with the respective end portions  636  and  637  of the arcuate portion  632  thus restricting physically the rotation of the attachment gear part  63  about the second rotational axis. 
     In the example illustrated in  FIG. 7 , when the attachment gear part  63  rotates clockwise about the second rotational axis, the end portion  636  of the arcuate portion  632  is brought into contact with the restriction piece  224  of the large-diameter part  222  thus restricting the clockwise rotation of the attachment gear part  63  about the second rotational axis. Furthermore, in the example illustrated in  FIG. 7 , when the attachment gear part  63  rotates counterclockwise about the second rotational axis, the end portion  637  of the arcuate portion  632  is brought into contact with the restriction piece  225  of the large-diameter part  222  thus restricting the counterclockwise rotation of the attachment gear part  63  about the second rotational axis. In this manner, the restriction pieces  224  and  225  of the large-diameter part  222 , and the end portions  636  and  637  of the arcuate portion  632  are capable of restricting the rotation of the attachment gear part  63  about the second rotational axis in an intended range. Here, as illustrated in  FIG. 9 , the large-diameter part  222  is provided with an insertion hole  226 , as will be specifically described later. 
     Furthermore, as illustrated in  FIG. 9 , a pivotally supporting part  68  is inserted into the through hole of the attachment face  221 . To be more specific, a cylindrical portion  681  of the pivotally supporting part  68  is inserted into the through hole of the attachment face  221 . Here, a sliding bearing  680  is arranged between the through hole of the attachment face  221  and the cylindrical portion  681  of the pivotally supporting part  68 . The sliding bearing  680  is capable of smoothly rotating the cylindrical portion  681  of the pivotally supporting part  68  with respect to the through hole of the attachment face  221 . 
     Furthermore, as illustrated in  FIG. 10 , in the cylindrical portion  681  of the pivotally supporting part  68 , a flange portion  683  that is larger in diameter than the cylindrical portion  681  continuously extends from the cylindrical portion  681 .  FIG. 10  is a perspective view illustrating the pivotally supporting part of the illumination apparatus according to the embodiment. The flange portion  683  of the pivotally supporting part  68  is larger in diameter than the through hole of the attachment face  221 . Accordingly, as illustrated in  FIG. 11 , the flange portion  683  of the pivotally supporting part  68  is brought into contact with the attachment face  221  from the outside of the attachment face  221 .  FIG. 11  is a perspective view illustrating the relation between the pivotally supporting part and the other end part of the arm in the illumination apparatus according to the embodiment. Furthermore, as illustrated in  FIG. 12 , the attachment face  221  has recessed portions  227  each of which is indented from the outside to the inside thereof, as will be specifically described later.  FIG. 12  is a partially perspective view illustrating the arrangement of bearings in the illumination apparatus according to the embodiment. 
     Furthermore, as illustrated in  FIG. 13 , the light source unit  30  is attached to the pivotally supporting part  68  by the flange portion  683 .  FIG. 13  is a perspective view illustrating the relation between the pivotally supporting part and the light source unit in the illumination apparatus according to the embodiment. To be more specific, a housing part  31  of the light source unit  30  is attached to the pivotally supporting part  68  with the use of screws  685  that are threadedly engaged into respective attachment holes  684  (see  FIG. 11 ) formed in the flange portion  683 . For example, the light source unit  30  is attached to the pivotally supporting part  68  with the use of the screws  685  that are threadedly engaged into the respective attachment holes  684  and respective attachment holes (not illustrated in the drawings) formed in the housing part  31 . 
     The cylindrical portion  681  of the pivotally supporting part  68  is provided with a plurality of attachment holes  682 , and attached to the attachment gear part  63  by a predetermined mechanism, such as screwing. In the example illustrated in  FIG. 9 , the cylindrical portion  681  is provided with eight attachment holes  682 , and attached to the attachment gear part  63  by threadedly engaging screws into four attachment holes  682  out of eight attachment holes  682 . Due to such constitution, the attachment gear part  63  holds the light source unit  30  with the pivotally supporting part  68  on the arm  20 . Here, the pivotally supporting part  68  and the attachment gear part  63  may be integrally formed. For example, the attachment gear parts  63  may be formed as a part of the pivotally supporting parts  68 . 
     As mentioned above, a load attributed to the weight of the light source unit  30  is applied to the attachment gear part  63  (see  FIG. 8 ) in the direction toward the light source unit  30  side (left side in  FIG. 8 ). Accordingly, in the illumination apparatus  1 , the insertion hole  226  (see  FIG. 12 ) is formed in the large-diameter part  222  at a position such that the insertion hole  226  overlaps with the attachment gear part  63 , and a bias part  66  is arranged in the insertion hole  226 . The bias part  66  has a spring member  660 , a shaft  661 , and a bearing  662 . For example, a coil spring is used for the spring member  660 . That is, the spring member  660  is arranged between the light source unit  30  and the arm  20 . 
     Furthermore, as illustrated in  FIG. 9 , the spring member  660  is arranged above the second rotational axis in the gravity direction (Y-axis negative direction). To be more specific, the spring member  660  is arranged above the cylindrical portion  681  of the pivotally supporting part  68  in the gravity direction (Y-axis negative direction). In this manner, the spring member  660  arranged in the insertion hole  226  biases the attachment gear part  63  in the direction away from the light source unit  30  thus biasing the light source unit  30  in the direction toward the arm  20  along the second rotational axis. 
     For example, the weight of the light source unit  30  causes the pivotally supporting part  68  and the attachment gear part  63  that are attached to the light source unit  30  to move to the light source unit  30  side and hence, there may be a case that wobbling is caused in the light source unit  30 . This may result in the breakage of the connection portion between the arm  20  and the light source unit  30 . Accordingly, in the illumination apparatus  1 , the spring member  660  is arranged between the light source unit  30  and the arm  20 ; that is, between the attachment gear part  63  to which the pivotally supporting part  68  is attached, and the attachment face  221 . Due to such constitution, the spring member  660  biases the attachment gear part  63  to which the pivotally supporting part  68  is attached thus suppressing the inclination of the light source unit  30  caused by the weight of the light source unit  30 , and ensuring the posture of the small-diameter gear  622  normally meshed with the external teeth  633 . 
     In this manner, the illumination apparatus  1  is capable of suppressing incomplete meshing of the small-diameter gear  622  with the external teeth  633  thus suppressing the breakage of the small-diameter gear  622 , the external teeth  633 , or the like, and the failure of a tilting mechanism. Accordingly, the illumination apparatus  1  is capable of suppressing troubles due to the weight of the light source unit  30 . The illumination apparatus  1  is constituted so that the light source unit  30  is located on the first rotational axis. For example, the illumination apparatus  1  is constituted so that the light source unit  30  is located on the first rotational axis even when the light source unit  30  rotates in either direction of rotation (clockwise or counterclockwise) in the horizontal direction depending on the output of the first motor  45 . Due to such constitution, the illumination apparatus  1  is capable of suppressing the inclination of the second rotational axis due to the weight of the light source unit  30  that is applied to the support unit  10  and the arm  20 . In this manner, the illumination apparatus  1  is capable of suppressing the inclination of the posture thereof due to the weight of the light source unit  30  that is applied to the arm  20  or the like. 
     Furthermore, the bearing  662  inserted into the shaft  661  is arranged between the attachment gear part  63  and the spring member  660 . The spring member  660  biases the shaft  661  to the attachment gear part  63  side. Due to such constitution, the bearing  662  is brought into contact with the attachment gear part  63 . Accordingly, when the light source unit  30  is rotated, the bearing  662  slides with respect to the attachment gear part  63  and hence, the light source unit  30  is capable of being rotated smoothly. 
     Furthermore, the reinforcing plate  65  is arranged between the attachment gear part  63  and the bearing  662 . The reinforcing plate  65  is attached to a part of the surface facing the large-diameter part  222  in the attachment gear part  63  with the use of attachment members  651 . To be more specific, the reinforcing plate  65  is arranged by the attachment members  651  at a position such that the reinforcing plate  65  overlaps with the insertion hole  226  in the attachment gear part  63  when the light source unit  30  is rotated. For example, the reinforcing plate  65  is attached to the attachment gear part  63  with the use of the attachment members  651  threadedly engaged with respective insertion holes  638  of the attachment gear part  63 . For example, the reinforcing plate  65  is made of a metallic material or the like. In this manner, the reinforcing plate  65  is arranged on the part of the attachment gear part  63  that is brought into contact with the bearing  662  thus reinforcing the attachment gear part  63  as a pivotally supporting part. The illumination apparatus  1  may be provided with no reinforcing plate  65 . 
     Furthermore, in order to bias the light source unit  30  by the spring member  660  arranged in the insertion hole  226  in the direction toward the arm  20  along the second rotational axis, as illustrated in  FIG. 11 , the flange portion  683  of the pivotally supporting part  68  is brought into contact with the attachment face  221  from the outside of the attachment face  221 . Accordingly, the flange portion  683  of the pivotally supporting part  68  slides with respect to the attachment face  221  when the light source unit  30  is rotated. As illustrated in  FIG. 12 , a plurality of recessed portions  227  each of which is indented from the outside to the inside thereof are formed in the attachment face  221 . To be more specific, three recessed portions  227  are formed in the attachment face  221 . Furthermore, sliding parts  69 - 1 ,  69 - 2 , and  69 - 3  are arranged on the respective recessed portions  227 . Here, when explaining without differentiating the sliding parts  69 - 1 ,  69 - 2 , and  69 - 3 , they are collectively referred to as “sliding part  69 ”. 
     One recessed portion  227  (lower side recessed portion  227  in  FIG. 12 ) out of the recessed portions  227  is located at a position opposite to the bias part  66  in the gravity direction (Y-axis negative direction) with respect to the second rotational axis as a center, and located between the light source unit  30  and the arm  20 . Accordingly, the sliding part  69 - 1  is arranged at a position opposite to the bias part  66  in the gravity direction with respect to the second rotational axis as a center, and arranged at a position between the light source unit  30  and the arm  20 . In this manner, the bias part  66  and the sliding part  69 - 1  are arranged with the second rotational axis interposed therebetween thus rotating smoothly the pivotally supporting part  68 . 
     Furthermore, the sliding parts  69 - 1 ,  69 - 2 , and  69 - 3  are arranged at equal intervals with respect to the second rotational axis as a center. In the example illustrated in  FIG. 12 , the sliding parts  69 - 1 ,  69 - 2 , and  69 - 3  are arranged at 120° intervals. In this manner, the sliding parts  69 - 1 ,  69 - 2 , and  69 - 3  are arranged at equal intervals thus rotating smoothly the pivotally supporting part  68 . 
     Hereinafter, the constitution of the light source unit  30  is explained. As illustrated in  FIG. 1  and  FIG. 2 , the light source unit  30  has the housing part  31 , a holding part  32 , the light emitting part  33 , and a heat radiation part  34 . Furthermore, the light emitting part  33  has, for example, a light emitting diode (LED) arranged on a board as a light source that constitutes an object to be changed in a direction thereof. That is, the light source unit  30  is a lamp body capable of changing an irradiation direction thereof. 
     The housing part  31  is formed in a hollow rectangular shape. As illustrated in  FIG. 13 , the pivotally supporting part  68  is attached to one surface (right side surface in  FIG. 2 ) of the housing part  31 . In this manner, the housing part  31  is attached to the pivotally supporting part  68 , and the light source unit  30  is rotated together with the pivotally supporting part  68  about the second rotational axis by the second motor  61 . For example, the light source unit  30  is rotated in the perpendicular direction (vertical direction) about the second rotational axis depending on the driving operation of the second motor  61 . 
     Next, the explanation is made with respect to the constitution on the inside of the housing part  31  of the light source unit  30  in conjunction with  FIG. 14 .  FIG. 14  is a perspective view illustrating the light source unit of the illumination apparatus according to the embodiment. To be more specific,  FIG. 14  is a perspective view illustrating the light source unit  30  except for the housing part  31 , in order to illustrate the constitution on the inside of the housing part  31 . As illustrated in  FIG. 14 , the heat radiation part  34  has a plurality of heat radiation fins  341 , and is attached to one surface of the holding part  32 , the one surface being opposite to the other surface of the holding part  32  that radiates light emitted from the light emitting part  33 . In the example illustrated in  FIG. 14 , the heat radiation part  34  is attached to the holding part  32  by an attachment mechanism, such as screwing. Here, The above-mentioned embodiment merely constitutes one example, and any attachment mechanism may be adopted as the attachment mechanism used for attaching the heat radiation part  34  to the holding part  32 . 
     Hereinafter, the constitution of a zooming mechanism is explained in conjunction with  FIG. 15  to  FIG. 20 .  FIG. 15  is a perspective view illustrating the zooming mechanism of the illumination apparatus according to the embodiment.  FIG. 16  is a perspective view illustrating the holding part of the illumination apparatus according to the embodiment.  FIG. 17  is a perspective view illustrating the essential part of the zooming mechanism in the illumination apparatus according to the embodiment.  FIG. 18  is a perspective view illustrating an alignment part of the illumination apparatus according to the embodiment.  FIG. 19  is a perspective view illustrating a rotational part of the illumination apparatus according to the embodiment.  FIG. 20  is a partially perspective view illustrating the zooming mechanism of the illumination apparatus according to the embodiment. 
     As illustrated in  FIG. 15 , the holding part  32  has a cylindrical part  321  and a bottom wall part  322 . As illustrated in  FIG. 14 , a reflection part  70  and an alignment part  80  are arranged on the inside of the cylindrical part  321 . A third motor  72  that rotates the reflection part  70  is arranged on the bottom wall part  322  of the holding part  32 . Furthermore, as illustrated in  FIG. 16 , a pair of restriction pieces  323  and  324  for moving the alignment part  80  back and forth along the axis of the cylindrical part  321  are provided to the inner peripheral face of the cylindrical part  321  in a projecting manner, as will be specifically described later. 
     As illustrated in  FIG. 17 , the reflection part  70  is arranged on the inside of the alignment part  80  in a rotatable manner with respect to the alignment part  80 . The reflection part  70  has a reflection surface  71 , the third motor  72 , and a third switch  73 . For example, the light emitting part  33  is arranged in the opening part of the reflection surface  71 , and the reflection surface  71  reflects light radiated from the light emitting part  33 . 
     An outer wall  74  is provided to the outer peripheral edge of the reflection surface  71  in a projecting manner toward the back side of the reflection surface  71 . In the example illustrated in  FIG. 17 , the outer wall  74  formed in a cylindrical shape is provided to the outer peripheral edge of the reflection surface  71  in a projecting manner toward the upper side of the reflection surface  71 . An inner wall  711  is provided to the reflection surface  71  in a projecting manner toward the back side of the reflection surface  71 . In the example illustrated in  FIG. 17 , the inner wall  711  formed in a cylindrical shape is provided to the reflection surface  71  in a projecting manner from the vicinity of the intermediate portion between the opening part and the outer peripheral edge in the reflection surface  71  toward the upper side of the reflection surface  71 . Furthermore, a gear part  712  is formed on a part of the outer peripheral face of the inner wall  711 . For example, the gear part  712  is formed in an extending manner over the range of 90° set as the central angle of the circular shape of the inner wall  711 . 
     The third motor  72  is attached to the bottom wall part  322  of the holding part  32 . For example, a geared motor is used for the third motor  72 . Here, not only the geared motor but also various kinds of motors, such as a DC motor, a DC brush-less motor, an AC motor, or a stepping motor, may be used for the third motor  72 . A gear  721  is attached to the output rotation shaft (not illustrated in the drawings) of the third motor  72 . The gear  721  attached to the output rotation shaft of the third motor  72  is meshed with a gear  722 . Furthermore, the gear  722  is meshed with the gear part  712  of the inner wall  711 . Due to such constitution, the reflection part  70  is rotated depending on the output of the third motor  72 . 
     A pair of projecting portions  741  and  742  projecting to the inside of the outer wall  74  are formed on the inner peripheral face of the outer wall  74 . Furthermore, the third switch  73  is attached to the bottom wall part  322  of the holding part  32 , and arranged at the position such that a lever  731  projects along the inner peripheral face of the outer wall  74 . To be more specific, the third switch  73  is arranged at the position such that the lever  731  overlaps with the projecting portions  741  and  742  in the circumferential direction of the outer wall  74 . Due to such constitution, either one of the projecting portions  741  and  742  of the outer wall  74  rotates the lever  731  of the third switch  73  thus detecting the limit of the rotational angle set to stop the operation of the third motor  72 . This mechanism is used for motor control as described above. In the present embodiment, the third switch  73  and the projecting portions  741  and  742  of the outer wall  74  restrict the rotational angle of the reflection part  70  within the range of approximately 90°. 
     Furthermore, as illustrated in  FIG. 18 , the alignment part  80  has a cylinder part  81  formed in a cylindrical shape, and a flange part  82  extending continuously to the cylinder part  81 . For example, an optical member (not illustrated in the drawings), such as a lens, is arranged on the flange part  82 . The cylinder part  81  of the alignment part  80  is provided with a plurality of guide grooves  811  and  812  each of which is formed in a projecting manner from the outer peripheral face of the cylinder part  81 . In the example illustrated in  FIG. 18 , two restriction grooves  811  and  812  are formed at 180° intervals along the outer periphery of the cylinder part  81 . That is, the pair of guide grooves  811  and  812  are formed in a projecting manner at respective positions opposite to each other with respect to the axis of the cylinder part  81  of the alignment part  80  as a center. 
     Here, the guide groove  811  ( 812 ) of the alignment part  80  is formed in such a shape that the restriction piece  323  ( 324 ) of the cylindrical part  321  of the holding part  32  is inserted into the guide groove  811  ( 812 ), and the restriction pieces  323  and  324  of the cylindrical part  321  are inserted into the respective guide grooves  811  and  812  of the alignment part  80 . For example, the restriction piece  323  of the cylindrical part  321  is inserted into the guide groove  811  of the alignment part  80 . Furthermore, for example, the restriction piece  324  of the cylindrical part  321  is inserted into the guide groove  812  of the alignment part  80 . Due to such constitution, the alignment part  80  is capable of moving back and forth along the axial direction of the cylindrical part  321  of the holding part  32  by way of the guide grooves  811  and  812 . 
     Projection portions  813  are formed in the inner peripheral face of the cylinder part  81  of the alignment part  80 . For example, three projection portions  813  are formed in the inner peripheral face of the cylinder part  81  of the alignment part  80  at equal intervals along the inner periphery of the cylinder part  81 . For example, three projection portions  813  are formed at 120° intervals along the inner periphery of the cylinder part  81 . In the example illustrated in  FIG. 18 , three projection portions  813  are formed on the upper end of the inner peripheral face of the cylinder part  81 . 
     Furthermore, a plurality of grooves  743  formed in a spiral manner are provided to the outer peripheral face of the outer wall  74  in the reflection part  70 . For example, three grooves  743  are formed in the outer peripheral face of the outer wall  74  in the reflection part  70  at equal intervals along the outer periphery of the outer wall  74 . For example, three grooves  743  are formed at 120° intervals along the outer periphery of outer wall  74 . 
     Here, the restriction pieces  323  and  324  of the holding part  32  are inserted into the respective guide grooves  811  and  812  thus restricting the rotation of the alignment part  80  about the axis of the cylinder part  81 . For example, in the case of  FIG. 20 , the alignment part  80  is movable in the direction (vertical direction) along the axis of the cylinder part  81 , and the rotation of the alignment part  80  about the axis extending in the vertical direction is restricted. On the other hand, the reflection part  70  rotates about the axis of the reflection part  70  along the vertical direction depending on the output of the third motor  72 . 
     Accordingly, the reflection part  70  rotates to change the position of the groove  743  in the reflection part  70  thus changing the position of the projection portion  813  in the axial direction while restricting the position of the projection portion  813  of the alignment part  80  in the rotational direction. Here, the alignment part  80  converts the rotation about the axis of the reflection part  70  into the movement in the axial direction. Due to such constitution, the alignment part  80  moves back and forth in the axial direction depending on the rotation of the reflection part  70  about the axis of the reflection part  70 . In this manner, the alignment part  80  moves in the axial direction thus changing the distance between the light emitting part  33  and the optical member arranged on the flange part  82  of the alignment part  80  to achieve a zoom function. 
     Here, in the present embodiment, three grooves  743  are formed in the reflection part  70  at 120° intervals in such a manner that the grooves  743  function only in a moving range of the alignment part  80  that moves back and forth in the axial direction. Furthermore, three projection portions  813  to be slidably engaged with the respective grooves  743  of the reflection part  70  are also formed on the alignment part  80  at 120° intervals. In this manner, three grooves  743  of the reflection part  70  correspond to respective three projection portions  813  of the alignment part  80  thus moving the alignment part  80  back and forth in a well-balanced manner due to a three-point supporting structure. Furthermore, the distal end portion of the projection portion  813  of the alignment part  80  may be formed in an elongated shape provided that the projection portion  813  can be slidably engaged with the groove  743  of the reflection part  70 . 
     As mentioned above, the illumination apparatus  1  is capable of rotating the arm  20  in the horizontal direction thus rotating an irradiation direction (irradiation axis) of the light source unit  30  in the horizontal direction in a state in which the tilting angle of the irradiation axis with respect to the vertical line is maintained. Although the rotating operation of the arm  20  in the horizontal direction depending on the first motor  45  and the rotating operation of the light source unit  30  in the vertical direction depending on the second motor  61  are individually explained, the controller is capable of controlling simultaneously the first motor  45 , the second motor  61 , and the third motor  72  depending on the operation of a remote controller by an operator. For example, the illumination apparatus  1  is capable of performing simultaneously the rotating operation of the arm  20  in the horizontal direction, and the rotating operation of the light source unit  30  in the vertical direction. 
     According to the present embodiment, the first motor  45  for rotating the arm  20  in the horizontal direction, and the second motor  61  for rotating the light source unit  30  in the vertical direction are arranged on the inside of the arm  20  to constitute the illumination apparatus  1 . 
     The present invention is not limited to the above-mentioned embodiment. The present invention includes a case of constituting the above-mentioned respective components optionally by combining them with each other. In addition, additional effects or modifications can easily be provided by those skilled in the art. Therefore, the more extensive aspect of the present invention is not limited to the above-mentioned embodiment, and various modifications can be made. 
     For example, the illumination apparatus  1  can be constituted as follows. The plurality of illumination apparatuses  1  are arranged on a ceiling or the like, and the respective illumination apparatuses  1  are connected with each other through wireless communication thus constituting the controller  50  so that the illumination apparatuses  1  can be simultaneously operated by remote control with one remote controller. Furthermore, the controller  50  is not limited to the remote controller using wireless communication, and an operation unit operated by the operator and the illumination apparatus  1  may be, for example, wiredly connected with each other. 
     Although the illumination apparatus  1  suspending from a ceiling is exemplified in the embodiment, the present invention is also applicable to an illumination apparatus suspending from a wall surface. Not only a stepping motor but also a DC motor, a DC brush-less motor, an AC motor, or the like is applicable to the first motor  45  and the second motor  61 . In this case also, the rotational angle (the amount of angular displacement) of the arm  20  in the horizontal direction, and the rotational angle (the amount of angular displacement) of the light source unit  30  in the vertical direction are made to coincide with each other or to coordinate with each other thus simplifying current control by the controller  50 . Furthermore, a light source is not limited to a light emitting element such as an LED, and may be any other light source such as a krypton bulb. 
     The drive apparatus may be used not only for changing the direction of the light source unit  30  including the light source provided to the illumination apparatus  1  according to the embodiment but also for changing the direction of any operation target. For example, the operation target may be a surveillance camera or the like. In this manner, the operation target is required to change the direction thereof to an intended direction, and any operation target may be used provided that the operation target is applicable to the drive apparatus. 
     According to one embodiment of the present invention, it is possible to suppress the troubles due to the weight of the operation target in a state in which the operation target is capable of changing the direction thereof in an intended direction. 
     Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.