Abstract:
An optical member driving device of the present disclosure includes an optical member for changing an optical path, the optical member having a parallel flat plate shape; a driving mechanism having a movable portion controlled to move in a direction orthogonal to a surface of the optical member by a drive signal, the driving mechanisms being disposed outside the optical member; a connecting member rotatably connecting an end of the optical member and the movable portion of the driving mechanism on two axes orthogonal to each other at a surface center of the optical member; a support portion disposed between the end of the optical member and the movable portion of the driving mechanism, the support portion rotatably pivoting the connecting member; and a controller configured to control the movable portion of the driving mechanism.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to an optical member driving device for moving a position of an image to be projected for display, and a projection image display apparatus that uses the same. 
         [0003]    2. Description of the Related Art 
         [0004]    PTL 1 discloses an image moving device that moves a display position of a projector which projects and displays an image. This image moving device includes piezoelectric devices that hold four corners of parallel flat plate glass, between a fixed pixel type display device for optically modulating an image, and a quadrangular parallel flat plate glass for moving an image position. The image moving device applies a voltage to these four piezoelectric devices to move an image. 
       CITATION LIST 
     Patent Literature 
       [0000]    
       
         PTL 1: Unexamined Japanese Patent Publication No. 2007-206567 
       
     
       SUMMARY 
       [0006]    The image moving device described in PTL 1 has a structure in which the four piezoelectric devices that support the four corners of the parallel flat plate glass are provided between the fixed pixel type display device that optically modulates an image, and the quadrangular parallel flat plate glass that moves an image position 
         [0007]    The piezoelectric devices operate as actuators for moving the parallel flat plate glass, and an elongation amount of each of the piezoelectric devices is proportional to a thickness of each of the piezoelectric devices. 
         [0008]    In a case where image movement of ½ pixel of the display device is achieved by the projector shown in PTL 1, piezoelectric devices each having 10 times or larger thickness than a thickness of the display device are required, and there is a problem that it is difficult to dispose such piezoelectric devices in a projector having an optical component disposed in a narrow space. 
         [0009]    In order to solve this problem, it is conceivable that an outer shape of the parallel flat plate glass is made larger than an outer shape of the display device, and piezoelectric devices having increased thicknesses are mounted on the parallel flat plate glass located outside the outer shape of the display device. 
         [0010]    However, in this configuration, a position at which the piezoelectric devices drive the parallel flat plate glass becomes far from the center of the parallel flat plate glass, and therefore a rotational moment for driving the parallel flat plate glass with the piezoelectric devices significantly increases. This causes a problem that the elongation amount of each of the piezoelectric devices for moving the parallel flat plate glass is required to be further increased. 
         [0011]    The present disclosure provides an optical member driving device and a projection image display apparatus each enabling suppression of increase in a rotational moment of actuators for driving a parallel flat plate glass, and suppression of increase in elongation amounts of the actuators, even in a case where the actuators are disposed at positions distant from the center of the parallel flat plate glass. 
         [0012]    An optical member driving device of the present disclosure includes an optical member for changing an optical path, the optical member having a parallel flat plate shape; a driving mechanism having a movable portion controlled to move in a direction orthogonal to a surface of the optical member by a drive signal, the driving mechanisms being disposed outside the optical member; a connecting member rotatably connecting an end of the optical member and the movable portion of the driving mechanism on two axes orthogonal to each other at a surface center of the optical member; a support portion disposed between the end of the optical member and the movable portion of the driving mechanism, the support portion rotatably pivoting the connecting member; and a controller configured to control the movable portion of the driving mechanism. 
         [0013]    The optical member driving device of the present disclosure is capable of suppressing increase in a rotational moment of the driving mechanism, and is effective for suppressing an amount of movement of the movable portion of the driving mechanism. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0014]      FIG. 1  is a diagram showing a structure of an optical member driving device of a first exemplary embodiment; 
           [0015]      FIG. 2  is a plan view of a parallel flat plate glass used in the optical member driving device of the first exemplary embodiment; 
           [0016]      FIG. 3  is a block diagram showing an electrical configuration of the optical member driving device of the first exemplary embodiment; 
           [0017]      FIG. 4  is a schematic diagram of an actuator used in the optical member driving device of the first exemplary embodiment; 
           [0018]      FIG. 5A  to  FIG. 5C  are diagrams for illustrating a principle of the optical member driving device of the first exemplary embodiment; 
           [0019]      FIG. 6A  and  FIG. 6B  are diagrams showing operation of the optical member driving device of the first exemplary embodiment; 
           [0020]      FIG. 7  is a diagram for illustrating a principle of changing an optical path by the parallel flat plate glass; 
           [0021]      FIG. 8  is a diagram showing a direction of tilt drive of the parallel flat plate glass; 
           [0022]      FIG. 9  is a diagram for illustrating a principle of outputting an input light beam at a plurality of positions by the parallel flat plate glass; 
           [0023]      FIG. 10A  and  FIG. 10B  are diagrams for illustrating position shift of the parallel flat plate glass; 
           [0024]      FIG. 11  is a diagram for illustrating initial adjustment of the actuators; 
           [0025]      FIG. 12A  and  FIG. 12B  are diagrams showing a principle and operation of an optical member driving device of a second exemplary embodiment; 
           [0026]      FIG. 13  is a diagram showing a projection image display apparatus to which an optical member driving device is applied; and 
           [0027]      FIG. 14  is a diagram for illustrating a configuration of a phosphor wheel used in the projection image display apparatus. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    Hereinafter, exemplary embodiments are described in detail with reference to the drawings appropriately. However, excessively detailed description may be omitted. For example, detailed description of matters that are already well known, or redundant description for substantially the same configuration may be omitted. This is to avoid making the following description unnecessarily redundant, and to facilitate the understanding by a person skilled in the art. 
         [0029]    The attached drawings and the following description are provided in order that a person skilled in the art sufficiently understands the present disclosure, and are not intended to limit the subject matter recited in the scope of the claims. 
       First Exemplary Embodiment 
       [0030]    Hereinafter, with reference to  FIG. 1  to  FIG. 11 , a first exemplary embodiment is described. 
       [1-1. Configuration] 
       [0031]      FIG. 1  is a schematic perspective view showing a structure of optical member driving device  1111 . 
         [0032]    Optical member driving device  1111  includes parallel flat plate glass  1000 , four connecting members  110   a ,  110   b ,  110   c  and  110   d , and actuator A 101   a , actuator B 101   b , actuator C 101   c , and actuator D 101   d  serving as four driving mechanisms. To ends of parallel flat plate glass  1000 , respective first ends of connecting members  110   a  to  110   d  are rotatably connected through linking portions  106   a ,  106   b ,  106   c  and  106   d . Respective second ends of connecting members  110   a  to  110   d  are rotatably connected to movable portions  107   a ,  107   b ,  107   c  and  107   d  of actuator A 101   a  to actuator D 101   d  through linking portions  116   a ,  116   b ,  116   c  and  116   d . Movable portions  107   a  to  107   d  are provided with four position sensors  102   a ,  102   b ,  102   c  and  102   d , respectively. 
         [0033]    Connecting members  110   a  to  110   d  are rotatably supported at central positions by support portions  109   a ,  109   b ,  109   c  and  109   d  through hinges  108   a ,  108   b ,  108   c  and  108   d , respectively. 
         [0034]      FIG. 2  is a plan view of parallel flat plate glass  1000 . Linking portions  106   a  to  106   d  shown in  FIG. 1  are rotatably connected at central ends EA, EB, EC and ED of respective sides, on A-C axis and B-D axis orthogonal to each other at surface center O of parallel flat plate glass  1000 . Movable portions  107   a  to  107   d  of actuator A 101   a  to actuator D 101   d  vertically move, so that ends EA, EB, EC and ED of parallel flat plate glass  1000  vertically move through connecting members  110   a  to  110   d , respectively. Parallel flat plate glass  1000  is formed in a quadrangle in this exemplary embodiment, but may be formed in a circle. 
         [0035]      FIG. 3  is a block diagram showing a circuit configuration of optical member driving device  1111 . Four actuators A 101   a  to D 101   d  are driven by drive circuits  104   a ,  104   b ,  104   c  and  104   d  controlled by control signals of single microcomputer  105 . 
         [0036]    Actuator A 101   a  to actuator D 101   d  are driven by drive signal currents from drive circuits  104   a  to  104   d  such that movable portions  107   a  to  107   d  advance/retreat in a uniaxial direction. Position detection circuits  103   a ,  103   b ,  103   c  and  103   d  detect position sensors  102   a  to  102   d  provided in movable portions  107   a  to  107   d , thereby detecting positions of movable portions  107   a  to  107   d.    
         [0037]    Then, respective detection outputs of position detection circuit  103   a  to  103   d  are input to microcomputer  105 . Microcomputer  105  always monitors the respective positions of movable portions  107   a  to  107   d  of actuator A 101   a  to actuator D 101   d  based on these detection signals, and servo-controls actuator A 101   a  to actuator D 101   d.    
         [0038]    Actuator A 101   a  to actuator D 101   d  are sometimes simply referred to as actuators  101 , movable portions  107   a  to  107   d  are sometimes simply referred to as movable portions  107 , position sensors  102   a  to  102   d  are sometimes simply referred to as position sensors  102 , connecting members  110   a  to  110   d  are sometimes simply referred to as connecting members  110 , linking portions  106   a  to  106   d  are sometimes simply referred to as linking portions  106 , linking portions  116   a  to  116   d  are sometimes simply referred to as linking portions  116 , support portion  109   a  to  109   d  are sometimes simply referred to as support portions  109 , and hinges  108   a  to  108   d  are sometimes simply referred to as hinges  108 . 
         [0039]    In this exemplary embodiment, as each actuator  101 , a voice coil motor (VCM) is used.  FIG. 4  shows an example of a structure of the VCM, in which permanent magnets having different magnetic poles (N-pole permanent magnets  1012  and S-pole permanent magnets  1013 ) are disposed so as to face each other at a constant distance in square-shaped yoke  1011 , and movable portion  107  is disposed between permanent magnets  1012  and  1013  disposed so as to face each other. 
         [0040]    Movable portion  107  is formed with guide window  1070 , yoke  1011  is inserted into guide window  1070 , and coil  1014  provided in movable portion  107  is disposed between permanent magnets  1012  and  1013  disposed so as to face each other. When a drive signal current flows through coil  1014 , movable portion  107  moves in a uniaxial direction along an arrow shown in  FIG. 4 . 
         [0041]    Driving force of this movable portion  107  is generated in a positive direction or a negative direction from a reference position, according to magnitude of a signal current flowing through coil  1014 . Position detection circuits  103   a  to  103   d  shown in  FIG. 3  detect position sensors  102   a  to  102   d  mounted on movable portions  107   a  to  107   d , respectively, thereby detecting an amount of movement of each movable portion  107 . A slight clearance is generated between movable portion  107  mounted with coil  1014  and permanent magnets  1012  and  1013 . 
         [0042]    Accordingly, when force in a perpendicular direction to the uniaxial direction in which movable portion  107  is driven by the drive signal current is applied to movable portion  107 , movable portion  107  is displaced by an allowable distance of the slight clearance. A magnet having large mass is fixed as the voice coil motor, and a weight of coil  1014  mounted on movable portion  107  is reduced, thereby enabling reduction in moment. 
         [0043]    Next, relation among parallel flat plate glass  1000 , connecting member  110 , actuators  101 , and support portion  109  is described in detail with reference to  FIG. 5A  to  FIG. 5C ,  FIG. 6A , and  FIG. 6B . While  FIG. 5A  to  FIG. 5C ,  FIG. 6A , and  FIG. 6B  each illustrate members disposed on the A-C axis shown in  FIG. 2 , relation among members disposed on B-D axis are similar to relation among the members disposed on A-C axis. 
         [0044]    As shown in  FIG. 5A , when a configuration in which the ends of parallel flat plate glass  1000  are directly driven by actuators  101  without connecting members  110  employed, an optical component larger than parallel flat plate glass  1000 , for example, a prism or the like cannot be disposed on a side close to actuators  101 . That is, a size of parallel flat plate glass  1000  restricts a space for disposing the optical member such as the prism located on the side close to actuators  101 , upon which input light beam Li is incident. 
         [0045]    As shown in  FIG. 5B , when a configuration, in which arms  207  are provided so as to extend integrally from parallel flat plate glass  1000 , and actuators  101  drive tips of arms  207 , is employed, the optical component larger than parallel flat plate glass  1000  can be disposed on the side close to actuators  101 . However, a position in which each actuator  101  drives parallel flat plate glass  1000  is far from surface center O of parallel flat plate glass  1000 . 
         [0046]    An moment that acts on each actuator  101  is a total of a rotational moment for rotating parallel flat plate glass  1000 , and a rotational moment for rotating arms  207  connecting parallel flat plate glass  1000  and movable portions  107  of actuators  101 , and a rotational moment by mass of movable portions  107  of actuators  101 . Each rotational moment increases in proportion to a square of a distance from surface center O of parallel flat plate glass  1000 . 
         [0047]    For example, when a position at which each actuator  101  drives is three times distance r from surface center O of parallel flat plate glass  1000  to the end of parallel flat plate glass  1000 , a rotational moment by movable portions  107  of actuators  101  becomes 9 times. Furthermore, the rotational moment for rotating arms  207  is added, and a total rotational moment largely increases, thereby causing a situation in which a rotational speed enabling drive reduces. 
         [0048]    As shown in  FIG. 5C , in optical member driving device  1111  of this exemplary embodiment, central parts of connecting members  110  are rotatably supported through hinges  108  by support portions  109 , the first ends of connecting members  110  are rotatably connected to parallel flat plate glass  1000  through linking portions  106 , and the second ends of connecting members  110  are rotatably connected to movable portions  107  of actuators  101  through linking portions  116 . 
         [0049]    Support portions  109  rotatably support connecting members  110  with hinges  108  having axes (not shown) as rotation centers. Horizontal distances between parallel flat plate glass  1000  and connecting members  110 , and horizontal distances between movable portions  107  of actuators  101  and connecting members  110  are changed by rotation of connecting members  110 , and therefore linking portions  106  and linking portions  116  are configured by flat springs (not shown) or the like so as to absorb changed amounts of the horizontal distances. 
         [0050]    In connection by connecting members  110  and support portions  109  of  FIG. 5C , connecting members  110  and support portions  109  configure levers. A position at which each support portion  109  supports connecting member  110  is a fulcrum of the lever, a position at which each actuator  101  is connected to connecting member  110  is a point of effort of the lever, and a position at which each connecting member  110  is connected to parallel flat plate glass  1000  is a point of load of the lever. 
         [0051]    In connection by connecting members  110  and support portions  109  of  FIG. 5C , distances from the fulcrums of the levers to the points of effort are equal to distances from the fulcrums to the points of load, and therefore force having the same magnitude as force applied to each point of effort and having an opposite direction to the force applied to each point of effort is applied to the point of load. That is, a connection case of  FIG. 5C  is different from a direct connection case of  FIG. 5A , in which actuators  101  are directly mounted on parallel flat plate glass  1000 , in that displacement directions are opposite, but the connection case of  FIG. 5C  is equivalent to the direct connection case of  FIG. 5A  in acting force and an displacement amount. That is, it is possible to achieve a structure in which the rotational moment is increased by a rotational moment of connecting members  110 , but is substantially the same rotational moment as the rotational moment in the direction connection case of  FIG. 5A , and a component larger than parallel flat plate glass  1000 , for example, a prism can be disposed on the side close to actuators  101  of parallel flat plate glass  1000 . 
         [0052]      FIG. 6A  and  FIG. 6B  each show movement during operation of actuators  101 . As shown in  FIG. 6A , when movable portion  107   a  of left actuator A 101   a  moves in a contraction direction, and movable portion  107   c  of right actuator C 101   c  moves in an extension direction by the same amount as movable portion  107   a  of left actuator A 101   a , parallel flat plate glass  1000  rotates about surface center O clockwise. 
         [0053]    As shown in  FIG. 6B , when movable portion  107   a  of left actuator A 101   a  moves in the extension direction, and movable portion  107   c  of right actuator C 101   c  moves in the contraction direction by the same amount as movable portion  107   a  of left actuator A 101   a , parallel flat plate glass  1000  rotates about surface center O counterclockwise. 
       [1-2. Operation] 
       [0054]    Operation of optical member driving device  1111  configured as described above is hereinafter described. 
         [0055]    As shown in  FIG. 7 , when the surface of parallel flat plate glass  1000  is orthogonal to input light beam Li, input light beam Li advances straight without being refracted on an interface between parallel flat plate glass  1000  and air. Input light beam Li passes through parallel flat plate glass  1000  without being refracted, and parallel flat plate glass  1000  is a parallel flat surface, and has an interface orthogonal to a light beam also on an interface with air, and therefore input light beam Li advances straight without being refracted. Therefore, in a case where input light beam Li is image light, an image does not move. 
         [0056]    On the other hand, when parallel flat plate glass  1000  is not orthogonal to input light beam Li as shown by a broken line of  FIG. 7 , input light beam Li is refracted on the interface between parallel flat plate glass  1000  and air. Input light beam Li that is refracted and incident upon parallel flat plate glass  1000  passes through parallel flat plate glass  1000 , and the interface with air is not orthogonal to the interface with the light beam, and therefore input light beam Li is refracted. 
         [0057]    An angle, at which the input light beam is refracted when the input light beam is incident upon parallel flat plate glass  1000 , is equal to an angle, at which the input light beam is refracted when the input light beam emits from parallel flat plate glass  1000 . Therefore, when input light beam Li is image light, image light of output light beam Lo moves parallel to a tilt direction of parallel flat plate glass  1000 . As a result, a display position of an image output and projected from parallel flat plate glass  1000  moves. 
         [0058]    For example, while movable portion  107   b  of actuator B 101   b  and movable portion  107   d  of actuator D 101   d  are not displaced, movable portion  107   a  of actuator A 101   a  is displaced upward and movable portion  107   c  of actuator C 101   c  is displaced downward from a state shown in  FIG. 5C , so that parallel flat plate glass  1000  can be displaced about B-D axis as shown in  FIG. 6B . 
         [0059]    By utilization of such a principle, optical member driving device  1111  can rotate parallel flat plate glass  1000  with actuators  101 . 
         [0060]      FIG. 8  and  FIG. 9  are diagrams for illustrating such control of actuators  101 . 
         [0061]    As shown in  FIG. 8 , A-C axis and B-D axis intersect with each other at surface center O on the same plane. Operation of moving pixels by vertically moving ends EA and EC on A-C axis and vertically moving ends EB and ED on B-D axis, in a state where this intersection is held at a fixed position is described with reference to  FIG. 9 . 
         [0062]    In  FIG. 9 , each broken arrow shows a case where input light beam Li is incident perpendicular to parallel flat plate glass  1000 , namely, output light beam Lo at a horizontal position of parallel flat plate glass  1000 . When input light beam Li is image light, output light beam Lo is displayed at position Pf shown in (e) of  FIG. 9 , as a pixel. For convenience, this state is referred to as a reference state. 
         [0063]    Position Pa shown in (e) of  FIG. 9  is a position at which a pixel is displayed when parallel flat plate glass  1000  is in a state shown in (a) of  FIG. 9  (first state). That is, in this state, actuator C 101   c  moves end EC upward, and actuator A  101   a  moves end EA downward by the same amount as end EC. With this movement, actuator D 101   d  moves end ED downward, and actuator B 101   b  moves end EB upward by the same amount as end ED, so that the pixel can be displayed at position Pa shown in (e) of  FIG. 9 . 
         [0064]    Position Pb shown in (e) of  FIG. 9  is a position at which the pixel is displayed when parallel flat plate glass  1000  is in a state shown in (b) of  FIG. 9  (second state). That is, in this state, actuator C 101   c  moves end EC upward, and actuator A 101   a  moves end EA downward by the same amount as end EC. With this movement, actuator D 101   d  moves end ED upward, and actuator B 101   b  moves end EB downward by the same amount as end ED, so that the pixel can be displayed at position Pb shown in (e) of  FIG. 9 . 
         [0065]    Position Pc shown in (e) of  FIG. 9  is a position at which the pixel is displayed when parallel flat plate glass  1000  is in a state shown in (c) of FIG.  9  (third state). That is, in this state, actuator C 101   c  moves end EC downward, and actuator A 101   a  moves end EA upward by the same amount as end EC. With this movement, actuator D 101   d  moves end ED upward, and actuator B 101   b  moves end EB downward by the same amount as end ED, so that pixel c can be displayed at position Pc shown in (e) of  FIG. 9 . 
         [0066]    Position Pd shown in (e) of  FIG. 9  is a position at which the pixel is displayed when parallel flat plate glass  1000  is in a state shown in (d) of  FIG. 9  (fourth state). That is, in this state, actuator C 101   c  moves end EC downward, and actuator A 101   a  moves end EA upward by the same amount as end EC. With this movement, actuator D 101   d  moves end ED downward, and actuator B 101   b  moves end EB upward by the same amount as end ED, so that the pixel can be displayed at position Pd shown in (e) of  FIG. 9 . 
         [0067]    At timing of the first to fourth states shown in (a) to (d) of  FIG. 9 , image light is input to parallel flat plate glass  1000 , so that pixels can be displayed at different four positions Pa to Pd shown in (e) of  FIG. 9 . 
         [0068]    Even when displacement amounts of movable portions  107  of actuators  101  (hereinafter, simply referred to as “actuator displacement amounts”) are controlled to the same displacement amount as a target, errors are caused by limitation of accuracy of position sensors  102 . 
         [0069]    In a case where actuator A 101   a  and actuator C 101   c  are driven while actuator B 101   b  and actuator D 101   d  are not displaced as shown in  FIG. 10A , an amount of downward displacement of actuator A 101   a  and an amount of upward displacement of actuator C 101   c  are equal to each other in a normal state. In this case, center O of parallel flat plate glass  1000  is not displaced before/after actuator A 101   a  and actuator C 101   c  are driven. 
         [0070]    However, as shown in  FIG. 10B , the amount of upward displacement of actuator C 101   c  is sometimes greater than the amount of downward displacement of actuator A 101   a  due to the above factor. That is, displacement amounts of end EA and end EC of parallel flat plate glass  1000  are sometimes different. In this case, surface center O of parallel flat plate glass  1000  is displaced before/after actuator A 101   a  and actuator C 101   c  are driven. 
         [0071]    In such a situation, positions of movable portions  107   b  and  107   d  of actuator B 101   b  and actuator D 101   d  mounted on parallel flat plate glass  1000 , which are determined by difference between the displacement amounts of actuator A 101   a  and actuator C 101   c , are different from original positions. 
         [0072]    Therefore, microcomputer  105  generates large driving force to four actuators  101 , to control parallel flat plate glass  1000  to move to an original position, thereby generating high distortion stress in parallel flat plate glass  1000 . 
         [0073]    As shown in  FIG. 3 , the device of the present disclosure is configured such that single microcomputer  105  controls the four actuators. Accordingly, as shown in  FIG. 10B , microcomputer  105  can detect and correct stationary and large drive outputs to actuators  101 , which are generated in a case where the displacement amounts of actuator A 101   a  and actuator C 101   c  are different. 
         [0074]      FIG. 11  shows an example of a process flowchart of control position error correction control by microcomputer  105  of optical member driving device  1111  of the present disclosure. 
         [0075]    In a case where a point where A-C axis and B-D axis intersect, shown in  FIG. 2  and  FIG. 8 , namely, a position of surface center O of parallel flat plate glass  1000  located when A-C axis and B-D axis are not tilted coincides with a position of surface center O of parallel flat plate glass  1000  located when A-C axis and B-D axis are tilted, it is possible to prevent distortion stress applied to parallel flat plate glass  1000 . Herein, A-C axis is a virtual line that connects end EA and end EC supporting parallel flat plate glass  1000 . Similarly, B-D axis is a virtual line that connects end EB and end ED supporting parallel flat plate glass  1000 . 
         [0076]    In order that the above points where A-C axis and B-D axis intersect coincide with each other, microcomputer  105  performs the following initial adjustment before normal drive described in  FIG. 9 . 
         [0077]    Hereinafter, the above adjustment is described along the process flowchart of  FIG. 11 . In this description, positions of actuators  101  means positions of movable portions  107  of actuators  101  detected by position sensors  102 . 
         [0078]    When a power source is turned on (Step S 1 ), positioning servo gains of actuators  101  are set to be small (Step S 2 ). Consequently, excessive driving force is not generated in each actuator  101 , even when a reference position of each actuator  101  (position at which displacement of actuator  101  is 0), and the gain are different, and position shift of an intersection of A-C axis and B-D axis occurs. Herein, positioning servo of each actuator  101  means servo-control for moving movable portion  107  of each actuator  101  to a target position. 
       [Origin Adjustment] 
       [0079]    Displacement of all of actuators  101  is set to 0 (“reference position”) (Step S 3 ). Next, in Step S 4 , adjustment is performed such that the points where A-C axis and B-D axis intersect coincide with each other (hereinafter referred to as “origin adjustment”). This origin adjustment is adjustment for positioning ends EA, EB, EC and ED of parallel flat plate glass  1000  on the same plane. 
         [0080]    Target positions of all of actuators  101  are set to reference positions in Step S 3 . At this time, errors sometimes occur in the respective reference positions of actuators  101  due to fluctuation in respective mounting positions of actuators  101  or the like, and end EA, EB, EC and ED of parallel flat plate glass  1000  are not sometimes present on the same plane. 
         [0081]    Therefore, a target position of actuator D 101   d  is adjusted, and a position at which it can be determined that driving force of actuator D 101   d  is minimum, namely, position shift of the intersection of A-C axis and B-D axis is minimum, is reset as the reference position of actuator D 101   d  (Step S 4 ). By this operation, the reference positions of all of actuators  101  are located on the same plane. Although actuator D 101   d  is adjusted in Step S 4 , any one of actuator A 101   a  to D 101   d  may be adjusted. 
       [A-C Axis Gain Adjustment] 
       [0082]    The target position of actuator D 101   d  is set to a plus (+) direction maximum value, and a target position of actuator B 101   b  is set to a minus (−) direction maximum value (Step S 5 ). 
         [0083]    However, actual amounts of movement of actuator D 101   d  and actuator B 101   b  differ depending on a sensitivity difference between position sensor  102   d  and position sensor  102   b  that detect amounts of movement from the reference positions of actuator D 101   d  and actuator B 101   b.    
         [0084]    Therefore, subsequent to Step S 5 , the displacement amount of actuator D 101   d  is adjusted (this is defined as A-C axis gain adjustment) such that surface center O of parallel flat plate glass  1000  is not displaced by displacement of actuator B 101   b  and actuator D 101   d , namely, actual displacement amounts of actuator D 101   d  and actuator B 101   b  coincide. The adjustment is performed by multiplying the displacement amount of actuator D 101   d  by a coefficient (this coefficient is defined as a gain correction value) such that displacement directions of actuator D 101   d  and actuator B 101   b  are opposite, and absolute values of the displacement amounts are the same. 
         [0085]    When surface center O of parallel flat plate glass  1000  is not displaced by the displacement of actuator B 101   b  and actuator D 101   d , force acting on each of actuator A 101   a  and actuator C 101   c  is eliminated. By utilization of this, a gain correction value of actuator D 101   d  is detected. 
         [0086]    Specifically, a gain value of actuator D 101   d  is adjusted, thereby detecting a gain value in which a difference between driving force values of actuator A 101   a  and actuator C 101   c  before and after the target position of actuator D 101   d  is set to the + direction maximum value, and the target position of actuator B 101   b  is set to the − direction maximum value is minimum. 
         [0087]    During regular operation, this gain value is always applied as the gain correction value of actuator D 101   d  (Step S 6 ). Thereafter, the target positions of actuator D 101   d  and actuator B 101   b  are set to the reference positions (Step S 7 ). 
       [B-D Axis Gain Adjustment] 
       [0088]    A target position of actuator A 101   a  is set to a plus (+) direction maximum value, and a target position of actuator C 101   c  is set to a minus (−) direction maximum value (Step S 8 ). 
         [0089]    However, actual amounts of movement of actuator A 101   a  and actuator C 101   c  differ depending on a sensitivity difference between position sensor  102   a  and position sensor  102   c  that detect amounts of movement from the reference positions of actuator A 101   a  and actuator C 101   c.    
         [0090]    Therefore, subsequent to Step S 8 , the displacement amount of actuator C 101   c  is adjusted (this is defined as B-D axis gain adjustment) such that surface center O of parallel flat plate glass  1000  is not displaced by displacement of actuator A 101   a  and actuator C 101   c , namely, actual displacement amounts of actuator A 101   a  and actuator C 101   c  coincide. The adjustment is performed by multiply the displacement amount of actuator C 101   c  by a coefficient (this coefficient is defined as a gain correction value) such that displacement directions of actuator A 101   a  and actuator C 101   c  are opposite, and absolute values of the displacement amounts are the same. 
         [0091]    When surface center O of parallel flat plate glass  1000  is not displaced by the displacement of actuator A 101   a  and actuator C 101   c , force acting on each of actuator D 101   d  and actuator B 101   b  is eliminated. By utilization of this, a gain correction value of actuator C 101   c  is detected. 
         [0092]    Specifically, a gain value of actuator C 101   c  is adjusted, thereby detecting a gain value, in which a difference between driving force values of actuator B 101   b  and actuator D 101   d  before and after the target position of actuator A 101   a  is set to the + direction maximum value, and the target position of actuator C 101   c  is set to the − direction maximum value is minimum. 
         [0093]    During regular operation, this gain value is always applied as the gain correction value of actuator C 101   c  (Step S 9 ). 
         [0094]    When B-D axis gain adjustment is terminated, positioning servo gain values are set to regular values (Step S 10 ). Thereafter, the process transfers to regular operation described in  FIG. 9  (Step S 11 ). 
         [0095]    Microcomputer  105  performs such adjustment, so that the above points where A-C axis and B-D axis intersect always are controlled to coincide at predetermined positions during regular operation. 
       [1-3. Effects and the Like] 
       [0096]    Thus, in optical member driving device  1111 , it is possible to achieve a structure in which rotation of parallel flat plate glass  1000  is achieved with a rotational moment obtained by increase in only the rotational moment of connecting members  110 , which is substantially equal to the rotational moment in a case of the direct connection shown in  FIG. 6A , and a component larger than parallel flat plate glass  1000 , for example, a prism can be disposed on the side close to actuators  101  of parallel flat plate glass  1000 . 
       Second Exemplary Embodiment 
       [0097]      FIG. 12A  and  FIG. 12B  each show a configuration in which a ratio of a distance of a fulcrum of each lever configured from connecting member  110  and support portion  109  and a point of effort, to a distance between the fulcrum and a point of load is changed to 1:3 from 1:1 shown in  FIG. 5C ,  FIG. 6A , and  FIG. 6B .  FIG. 12A  corresponds to  FIG. 6A , and  FIG. 12B  corresponds to  FIG. 6B . According to this configuration, each end of parallel flat plate glass  1000  moves by three times a displacement amount of actuator  101 . Conversely, a displacement amount of each actuator  101  for moving the end of parallel flat plate glass  1000  by the same amount as the case shown in each of  FIG. 5C ,  FIG. 6A , and  FIG. 6B  is only ⅓. 
         [0098]    That is, the displacement amount is equivalent to the displacement amount in a case where a position of ⅓ of distance r from surface center O of parallel flat plate glass  1000  to each end is driven by actuator  101 , and therefore increase in a rotational moment by mass of movable portions  107  of actuators  101  is 1/9. On the other hand, driving force required for each actuator  101  is three times. 
       Other Exemplary Embodiments 
       [0099]    A case where a ratio of a distance of a fulcrum of each lever configured from connecting member  110  and support portion  109  and a point of effort, to a distance between the fulcrum and a point of load is 1:3, and a case where the ratio is 1:1 are described. However, this ratio is adjustable in consideration of an increased amount of a rotational moment by movable portions  107  of actuators  101 , and driving force of each actuator  101 . 
         [0100]    The ratio of the distance of the fulcrum of each lever configured from connecting member  110  and support portion  109  and the point of effort, to a distance between the fulcrum and the point of load may be adjusted in a range of 1:3 to 3:1, and a case where this ratio is 1:1 is an optimum condition. 
         [0101]    Support portions  109  are configured so as to support connecting members  110  from ground, but are not limited to this configuration. Support portions  109  may be configured so as to support connecting members  110  from a top surface, or may be configured so as to support connecting members  110  from side surfaces. 
         [0102]    In the above exemplary embodiments, actuators  101  are used as driving mechanisms. However, the present disclosure is not limited to this, and driving mechanisms that continuously generate power, such as motors and engines, may be used. 
       Application Example 
       [0103]    The optical member driving device of the present disclosure is applicable to a projection image display apparatus.  FIG. 13  and  FIG. 14  are diagrams for illustrating a configuration of an optical system of a projection image display apparatus using optical member driving device  1111  of the present disclosure. 
         [0104]    For the following description, a XYZ rectangular coordinate system shown in the drawing is employed in  FIG. 13 . Now, illumination optical system  3000  of projection image display apparatus is described. 
         [0105]    Laser light sources  301  are blue semiconductor lasers, and are configured by a plurality of semiconductor lasers in order to achieve a high luminance lighting apparatus. Respective laser beams emitted from laser light sources  301  are collimated by corresponding collimator lenses  302 . The light beams emitted from collimator lenses  302  are substantially parallel light beams. Whole luminous flux is condensed by condenser lens  303  to pass through diffuser  304 , and thereafter is substantially collimated by lens  305  again. The laser luminous flux collimated by lens  305  is incident upon dichroic mirror  306  disposed at about 45 degrees with respect to an optical axis. 
         [0106]    Diffuser  304  is a glass flat plate, and is formed with a diffusion surface having fine unevenness. Dichroic mirror  306  has a property to reflect light in a wavelength region of a blue semiconductor laser, and to transmit light in other wavelength region. 
         [0107]    The laser beams incident upon dichroic mirror  306  from a + X-direction in the drawing are reflected on dichroic mirror  306  to be emitted in a −Z-direction in the drawing. Thereafter, the laser beams are condensed by condenser lenses  307  and  308  to excite a phosphor formed on phosphor wheel  3001 . 
         [0108]    Phosphor wheel  3001  is configured by motor  3011  and base material  3012  as shown in  FIG. 14 . Base material  3012  is formed with first phosphor  3013 , second phosphor  3014 , and opening  3015  on circumference in which distances from the rotation center of the phosphor wheel are equal. A phosphor formation surface of the base material is mirror-finished, and reflects light. 
         [0109]    In a case where light beams condensed on phosphor wheel  3001  are condensed on phosphor  3013 , fluorescence corresponding to phosphor  3013  is emitted. Herein, a red phosphor is used as phosphor  3013 , and is excited by light beams of the blue semiconductor lasers to emit red light. 
         [0110]    In a case where light beams condensed on phosphor wheel  3001  are condensed on phosphor  3014 , fluorescence corresponding to phosphor  3014  is emitted. Herein, a green phosphor is used as phosphor  3014 , and is excited by light beams of the blue semiconductor lasers to emit green light beams. 
         [0111]    Furthermore, in a case where light beams condensed on phosphor wheel  3001  are condensed on opening  3015 , light beams of the blue semiconductor lasers are transmitted. 
         [0112]    The red light beams and the green light beams obtained by phosphor wheel  3001  are reflected from phosphor wheel  3001 . These red light beams and green light beams are collimated by condenser lenses  308  and  307  to be transmitted through dichroic mirror  306 , and are condensed by condenser lens  317  to be incident upon rod integrator  318 . 
         [0113]    On the other hand, blue light beams of the blue semiconductor lasers that are transmitted through opening  3015  advance along a route from lens  309  to lens  316  through lens  310 , mirror  311 , lens  312 , mirror  313 , lens  314 , and mirror  315 , are reflected by dichroic mirror  306 , and are condensed by condenser lens  317  to be incident upon rod integrator  318 . Lenses  312 ,  314  and  316  function as relay lenses. 
         [0114]    Light beams emitted from rod integrator  318  pass through lenses  330 ,  331  and  332 , and are incident upon total reflection prism  335  including a pair of prisms  333  and  334 , and incident light beams are modulated by using a video signal in DMD (Digital Mirror Device)  336  being an optical modulator element, to be emitted as image light. Lenses  330 ,  331  and  332  each have a function of imaging light in an emission surface of rod integrator  318  on DMD  336 . 
         [0115]    The image light beams emitted from DMD  336  are incident upon optical member driving device  1111 . Optical member driving device  1111  is schematically shown in  FIG. 13 , and the optical member driving device described in each of the first and second exemplary embodiments can be used. Light beams emitted from optical member driving device  1111  are incident upon project lens  337 , and light beams emitted from project lens  337  are magnified and projected on a screen (not shown). 
         [0116]    Thus, the projection image display apparatus can display a plurality of different images while shifting display positions of the images in one frame period of an input image, and can perform wobbling display for improving resolution of display image in an equivalent manner, by use of a function of moving a display position of image light of optical member driving device  1111 . Additionally, the projection image display apparatus is applicable to a system that shifts and displays the same images, and erases an area where no image is present between a display pixel and a display pixel, to smoothly display the image, in one frame period for an input image, or is applicable to shake prevention for detecting shake of an image generated by vibration of a projector, and correcting the shake, or the like. 
         [0117]    Since the embodiments described above are merely examples of the technology in the present disclosure, it is understood that various modifications, replacements, additions, omissions, and the like can be performed in the scope of the claims or in an equivalent scope thereof. 
         [0118]    The present disclosure is applicable to an optical member driving device that moves a display position of a projection image of a projection image display apparatus such as a projector.