Abstract:
A light adjusting apparatus includes a first substrate, a second substrate, rotating-shaft member, light adjusting unit, and a drive unit. By moving the light adjusting unit by rotating the rotating-shaft member by the drive unit, the light adjusting unit is pivoted alternately to an opened position at which, the light adjusting unit is corresponding to the optical aperture, and a retracted position at which, the light adjusting unit is retracted from the optical aperture, and incident light which passes through the optical aperture is adjusted in the light adjusting apparatus. The light adjusting unit includes an optical element, and has an isolating unit which isolates a surface opposite each other the first substrate and the second substrate of the optical element, and the first substrate and the second substrate.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2010-271322 filed on Dec. 6, 2010; the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a light adjusting apparatus. 
         [0004]    2. Description of the Related Art 
         [0005]    In recent years, with improved high-quality performance of a portable equipment having an image pickup function and a small-size optical apparatus such as a micro video scope, with regard to optical elements such as a lens and an aperture, there has been increasing demand for an application of a focusing lens, a variable aperture, and an optical filter instead of a conventional fixed focusing lens and a fixed aperture stop, and further small-sizing (slimming) of such optical elements has been sought. 
         [0006]      FIG. 8  is an exploded perspective view showing an overall structure of a conventional diaphragm apparatus. In the diaphragm apparatus described in Patent Document 1, as shown in  FIG. 8 , a structure in which, an optical filter unit  15  and an equipment  20  thereof are installed integrally as an diaphragm apparatus  10 , has been proposed, and an adjustment of an amount of light is made possible by switching of an optical filter  16  by driving diaphragm blades  12  and  13  which are covered by a blade cover  14 . 
       CITATION LIST 
     Patent Literature 
       [0007]    Patent Document 1: Japanese Patent Application Laid-open Publication No. 2007-017594 
       SUMMARY OF THE INVENTION 
       [0008]    However, in the diaphragm apparatus described in Patent Document 1, the optical filter  16  is moved between the two diaphragm blades  12  and  13 . Therefore, at the time of driving the optical filter  16 , the optical filter  16  makes a contact with the upper and the lower diaphragm blades  12  and  13 . Accordingly, an optical thin film formed on the optical filter  16  comes off, and when the optical filter  16  is driven continuously, there is a possibility that an optical performance is degraded with the continuous driving. 
         [0009]    The present invention has been made in view of the abovementioned circumstances, and an object of the present invention is to provide a light adjusting apparatus in which, it is possible prevent damage to an optical thin film which has been formed on components such as an optical filter and a lens. 
         [0010]    To solve the abovementioned issues and to achieve the object, a light adjusting apparatus according to the present invention includes a first, substrate in which, an optical aperture is formed, and a second substrate in which, an optical aperture is formed, at least one rotating-shaft member which is rotatably installed on the first substrate and the second substrate, at least one light adjusting unit which is joined to the rotating shaft member, and a drive unit which moves the light adjusting unit, and by moving the light adjusting unit by rotating the rotating-shaft member by the drive unit, the light adjusting unit is pivoted alternately to an opened position at which, the light adjusting unit is corresponding to the optical aperture, and a retracted position at which, the light adjusting unit is retracted from the optical aperture, and incident light which passes through the optical aperture is adjusted in the light adjusting apparatus, and the light adjusting unit includes an optical element, and has an isolating unit which isolates a surface opposite each other the first substrate and the second substrate of the optical element, and the first substrate and the second substrate. 
         [0011]    In the light adjusting apparatus according to the present invention, it is preferable that the isolating unit is a frame member which holds the optical element from around, and has a protruding portion which protrudes in an optical axial direction. 
         [0012]    In the light adjusting apparatus according to the present invention, it is preferable that the frame member has a notch portion, and the optical element is joined to the frame member at the notch portion. 
         [0013]    In the light adjusting apparatus according to the present invention, it is preferable that a width of the notch portion is smaller than a diameter of the optical element, and the optical element is joined by an elastic force of the frame member. 
         [0014]    In the light adjusting apparatus according to the present invention, it is preferable that the isolating unit includes at least two protruding portions which hold locally, and the optical element is held by the protruding portion. 
         [0015]    In the light adjusting apparatus according to the present invention, it is preferable that the rotating-shaft member is formed by a circular cylindrical shaped magnet, and a drive source of the rotating-shaft member is an electromagnetic drive source which includes a yoke and a winding coil, and the circular cylindrical shaped magnet is rotated by the electromagnetic drive source. 
         [0016]    A light adjusting apparatus according to the present invention shows an effect that it is possible to prevent damage to an optical thin film which has been formed on components such as an optical filter and a lens. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is an exploded perspective view of a light adjusting apparatus according a first embodiment of the present invention; 
           [0018]      FIG. 2  is a perspective view showing the light adjusting apparatus according to the first embodiment, in an assembled state; 
           [0019]      FIG. 3  is a plan view describing a movement of the light adjusting apparatus according to the first embodiment; 
           [0020]      FIG. 4  is a plan view describing the movement of the light adjusting apparatus according to the first embodiment; 
           [0021]      FIG. 5A  and  FIG. 5B  are diagrams showing a structure of a light adjusting unit in the first embodiment, where,  FIG. 5A  is an exploded perspective view and  FIG. 5B  is a perspective view showing an assembled state; 
           [0022]      FIG. 6A  and  FIG. 6B  are diagrams showing a structure of a light adjusting unit in a second embodiment of the present invention, where,  FIG. 6A  is an exploded perspective view and  FIG. 6B  is a perspective view showing an assembled state; 
           [0023]      FIG. 7A  and  FIG. 7B  are diagrams showing a structure of a light adjusting unit in a third embodiment of the present invention, where,  FIG. 7A  is an exploded perspective view and  FIG. 7B  is a perspective view showing an assembled state; and 
           [0024]      FIG. 8  is an exploded perspective view showing an overall structure of a conventional diaphragm apparatus. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Exemplary embodiments of a light adjusting apparatus according to the present invention will be described below in detail by referring to the accompanying diagrams. However, the present invention is not restricted to the embodiments described below. 
       First Embodiment 
       [0026]    A light adjusting apparatus  900  according to a first embodiment of the present invention will be described below by referring to diagrams from  FIG. 1  to  FIG. 5 .  FIG. 1  is an exploded perspective view of the light adjusting apparatus  900 . In  FIG. 1 , an optical axial direction  801  of the light adjusting apparatus  900  is shown by an alternate long and short dashed line. The light adjusting apparatus  900  includes a substrate  101 , a substrate  201 , a light adjusting unit  300 , a spacer  401 , and an electromagnetic drive source  500  as a drive unit. An optical aperture  102  and a rotating-shaft hole  103  are formed in the substrate  101 , and an optical aperture  202  and a rotating-shaft hole  203  are formed in the substrate  201 . The light adjusting unit  300  includes a filter frame member  301  and an optical filter  302 , and a rotating-shaft member  303  which has a magnetic property. The spacer  401  is disposed between the substrate  101  and the substrate  201 , and creates a space for the light adjusting unit  300  to move. Moreover, the electromagnetic drive source  500  is a drive source which makes the light adjusting unit  300  turn, and has a winding coil portion  501  provided on a yoke member  502 . 
         [0027]      FIG. 2  is a perspective view showing the light adjusting apparatus  900  according to the first embodiment, in an assembled state. The rotating-shaft member  303  of the light adjusting unit  300  is supported by the rotating-shaft holes  103  and  203 . The light adjusting unit  300  is disposed between the substrate  101  and the substrate  201 . The electromagnetic drive source  500  is disposed on the substrate  101 . Front-end portions  502   a  and  502   b  of the yoke member  502  are disposed at positions opposite each other the rotating-shaft member  303  which has the magnetic property. Moreover, the light adjusting unit  300  moves by the rotating-shaft member  303  being rotated by the electromagnetic drive source  500 . 
         [0028]    An operation of the light adjusting apparatus  900  according to the first embodiment will be described below by using  FIG. 3  and  FIG. 4 . Here, the substrate  101  and the electromagnetic drive source  500  are omitted.  FIG. 3  and  FIG. 4  are plan views describing the operation of the light adjusting apparatus  900 . 
         [0029]      FIG. 3  shows a state in which, the light adjusting unit  300  is at a first stationary position (retracted position) of being retracted from the optical aperture  102 . At this time, the light adjusting unit  300  abuts with a curved surface portion  401   a  of the spacer  401 , and comes to rest at that position. 
         [0030]      FIG. 4  shows a state in which, the light adjusting unit  300  is at a second stationary position (opened position) overlapping with the optical aperture  102 . At this time, the light adjusting unit  300  abuts with a flat surface portion  401   b  of the spacer  401 , and comes to rest. At the second stationary position, light which is incident on the light adjusting apparatus  900  is adjusted by the optical filter  302 . In the light adjusting apparatus  900  according to the first embodiment, the rotating-shaft member  303  having a magnetic property is rotated by a magnetic force generated from the front-end portions  502   a  and  502   b,  by applying an electric current to the winding coil portion  501 . Accordingly, the light adjusting unit  300  is moved to the first stationary position and the second stationary position alternately. Moreover, in the first embodiment, although the spacer  401  is made to function as a stopper for stationary positions of the light adjusting unit  300 , a separate stopper member may be used. 
         [0031]    The light adjusting unit  300  in the first embodiment will be described below by using  FIG. 5A  and  FIG. 5B .  FIG. 5A  and  FIG. 5B  are diagrams showing a structure of the light adjusting unit  300 , where,  FIG. 5A  is an exploded perspective view of the light adjusting unit  300 , and  FIG. 5B  is a perspective view showing an assembled state of the light adjusting unit  300 .  FIG. 5B  shows a state in which, the optical filter  302  is fitted into a protective portion  304  of the filter frame member  301 . In  FIG. 5B , the optical axial direction  801 , when the optical filter  302  is disposed on the optical aperture  202 , is shown by an alternate long and short dashed line. The light adjusting unit  300  includes the filter frame member  301  joined to the rotating-shaft member  303  and the optical filter  302 . The protective portion  304  is formed integrally with the filter frame member  301 . The optical filter  302  is fitted into the protective member  304  of the filter frame member  301 , and the optical filter  302  is held by the protective portion  304 . As shown in  FIG. 5B , a height in the optical axial direction of the protective member  304  being more than a height of the optical filter  302 , a surface opposite each other the substrate  101  and the substrate  201  in the optical filter  302  is isolated from the substrate  101  and the substrate  201 . In the first embodiment, a method of joining the optical filter  302  and the filter frame member  301  is not specified in particular, and the optical filter  302  and the filter frame member  301  may be joined by using an adhesive etc. 
         [0032]    As shown in  FIG. 5B , in the first embodiment, the protective portion  304  holds around the optical filter  302 , and also the protective portion  304  is protruded in the optical axial direction more than the optical filter  302 . Accordingly, at the time of rotational movement of the light adjusting unit  300 , since the protective portion  304  abuts with the spacer  401 , the optical filter  302  does not abut with the spacer  401  directly. Moreover, when the light adjusting unit  300  undergoes rotational motion between the substrate  101  and the substrate  201 , since the protective portion  304  makes a contact with the substrates  101  and  201 , the optical filter  302  does not make a contact with the substrates  101  and  201 . Therefore, there is no breaking or chipping of the optical filter  302  due to an impact at the time of abutting. Furthermore, there is no degradation of an optical thin film which is formed on the optical filter  302 . 
       Second Embodiment 
       [0033]    A light adjusting apparatus according to a second embodiment of the present invention will be described below by using  FIG. 6A  and  FIG. 6B . The light adjusting apparatus according to the second embodiment differs from the light adjusting apparatus  900  according to the first embodiment at a point that a filter frame member  601  which replaces the filter frame member  301  in the first embodiment, is used in a light adjusting unit  320 , and the rest of the structure and a method of driving being similar as in the first embodiment, a description in detail thereof is omitted.  FIG. 6A  and  FIG. 6B  are diagrams showing a structure of the light adjusting unit  320 , where,  FIG. 6A  is an exploded perspective view and  FIG. 6B  is a perspective view showing an assembled state.  FIG. 6B  shows a state in which, the optical filter  302  is joined to the filter frame member  601 . In  FIG. 6B , the optical axial direction  801 , when the optical filter  302  is disposed on the optical aperture  202 , is shown by an alternate long and short dashed line. 
         [0034]    The light adjusting unit  320  includes the rotating-shaft member  303 , the optical filter  302 , and the filter frame member  601 . A height in an optical direction of the filter frame member  601  becomes more than the height of the optical filter  302 , and accordingly, the surface opposite each other the substrate  101  and the substrate  201  in the optical filter  302  is isolated from the substrate  101  and the substrate  201 . Moreover, notch portions  601   a  and  601   b  are formed in a front end of the filter frame member  601 . As shown in  FIG. 6B , the optical filter  302  is joined to the filter frame member  601  by being engaged with the notch portions  601   a  and  601   b,  and held. The optical filter  302  is fixed by an elastic force of the filter frame member  601  by forming a diameter of each of the notch portions  601   a  and  601   b  to be smaller than a diameter of the optical filter  302 . At this time, it is desirable that a material of the filter frame member  601  is a metal having a superior elasticity. Moreover, in the second embodiment, although the optical filter  302  and the filter frame member  601  are joined by the elastic force of the filter frame member  601 , a method such as using an adhesive may be used as another method of joining. 
         [0035]    In the second embodiment, the filter frame member  601  holds a part of a circumference of the optical filter  302 , and also, the filter frame member  601  is protruded along the optical axial direction  801  more than the optical filter  302 . Accordingly, at the time of rotating the light adjusting unit  320  to move, since the filter frame member  601  abuts with the spacer  401 , the optical filter  302  does not abut with the spacer  401  directly. Moreover, when the light adjusting unit  320  undergoes rotational motion between the substrate  101  and the substrate  201 , since the filter frame member  601  makes a contact with the substrates  101  and  201 , the optical filter  302  does not make a contact with the substrates  101  and  201 . Accordingly, there is no breaking or chipping of the optical filter  302  due to an impact at the time of abutting. Furthermore, there is no degradation of the optical thin film which is formed on the optical filter  302 . In the second embodiment, mainly the elastic force of the filter frame member  601  is used as a method of joining the optical filter  302  and the filter frame member  601 . Therefore, as joining is possible only engagement of the optical filter  302  with the notch portions of the filter frame member  601 , it is not necessary to use an adhesive etc., and assembling becomes easier. 
       Third Embodiment 
       [0036]    A light adjusting apparatus according to a third embodiment of the present invention will be described below by using  FIG. 7A  and  FIG. 7B . The light adjusting apparatus according to the third embodiment differs from the light adjusting apparatus  900  according to the first embodiment at a point that a filter frame member  701  which replaces the filter frame member  301  in the first embodiment, is used in a light adjusting unit  330 , and the rest of the structure and a method of driving being similar as in the first embodiment, a description in detail thereof is omitted.  FIG. 7A  and  FIG. 7B  are diagrams showing a structure of the light adjusting unit  330 , where,  FIG. 7A  is an exploded perspective view and  FIG. 7B  is a perspective view showing an assembled state.  FIG. 7B  shows a state in which, the optical filter  302  is joined to the filter frame member  701 . In  FIG. 7B , the optical axial direction  801 , when the optical filter  302  is disposed on the optical aperture  202 , is shown by an alternate long and short dashed line. 
         [0037]    In the third embodiment, the light adjusting unit  330  includes the rotating-shaft member  303 , the optical filter  302 , and the filter frame member  701 . Three protruding portions  701   a  are formed at an equiangular distance on the filter frame member  701 . The protruding portions  701   a  hold the optical filter  302  by holding locally the circumferential edge of the optical filter  302 . Moreover, a height in an optical axial direction of the protruding portion  701   a  becomes more than the height of the optical filter  302 , and accordingly, the surface opposite each other the substrate  101  and the substrate  201  in the optical filter  302  is isolated from the substrate  101  and the substrate  201 . In the third embodiment, a method of joining the optical filter  302  and the filter frame member  701  is bending the three protruding portions  701   a  in the optical axial direction after disposing the optical filter  302  on the filter frame member  701 . Thereafter, the optical filter  302  is held by the protruding portions  701   a.  Although three protruding portions are provided in the light adjusting unit  330  of the third embodiment, the number of protruding portions may be two or not less than four, provided that the optical filter  302  can be held. Moreover, in the third embodiment, although the optical filter  302  is fixed by being held by the protruding portions  701   a,  an adhesive may be used as another method of fixing. 
         [0038]    In the third embodiment, the protruding portions  701   a  hold the circumferential locations of the optical filter  302 , and also are protruded in an optical axial direction more than the optical filter  302 . Accordingly, at the time of rotating the light adjusting unit  330  to move, since the protruding portions  701   a  abut with the spacer  401 , the optical filter  302  does not abut with the spacer  401  directly. Moreover, when the light adjusting unit  330  undergoes rotational motion between the substrates  101  and the substrate  201 , since the protruding portions  701   a  make contact with the substrates  101  and  201 , the optical filter  302  does not make a contact with the substrates  101  and  201 . Accordingly, there is no breaking or chipping of the optical filter  302  due to an impact at the time of striking. Furthermore, there is no degradation of the optical thin film which is formed on the optical filter  302 . In the third embodiment, as a method of joining the optical filter  302  and the filter frame member  701 , the optical filter  302  is fixed by holding by the protruding portions  701   a.  Therefore, it is not necessary to use an adhesive etc., and assembling becomes easier. 
         [0039]    As it has been described above, the light adjusting apparatus according to the present invention is useful as a light adjusting apparatus in which, damage to the optical thin film which is formed on a component such as an optical filter and a lens is prevented, and the light adjusting unit is driven stably. 
       REFERENCE SIGNS LIST 
       [0040]      101  substrate 
         [0041]      102  optical aperture 
         [0042]      103  rotating-shaft hole 
         [0043]      201  substrate 
         [0044]      202  optical aperture 
         [0045]      203  rotating-shaft hole 
         [0046]      300  light adjusting unit 
         [0047]      301  filter frame member 
         [0048]      302  optical filter 
         [0049]      303  rotating-shaft member 
         [0050]      304  protective portion 
         [0051]      320  light adjusting unit 
         [0052]      330  light adjusting unit 
         [0053]      401  spacer 
         [0054]      401   a  curved surface portion 
         [0055]      401   b  flat surface portion 
         [0056]      500  electromagnetic drive source 
         [0057]      501  winding coil portion 
         [0058]      502  yoke member 
         [0059]      502   a  front-end portion 
         [0060]      502   b  front-end portion 
         [0061]      601  filter frame member 
         [0062]      601   a  notch portion 
         [0063]      601   b  notch portion 
         [0064]      701  filter frame member 
         [0065]      701   a  protruding portion 
         [0066]      801  optical axial direction 
         [0067]      900  light adjusting unit