Patent Publication Number: US-2015086190-A1

Title: Light-quantity control apparatus and optical apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application No. PCT/JP2013/003579, filed on Jun. 6, 2013 which is hereby incorporated by reference herein in its entirety as if fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a light-quantity control apparatus and an optical apparatus having the light-quantity control apparatus. The light-quantity control apparatus is installed in an optical apparatus such as a digital camera, a video camera and an interchangeable lens. 
     2. Description of the Related Art 
     An optical apparatus such as a camera is necessary to have compactness. In particular, when a lens barrel for holding an image capturing lens protrudes from a camera body in its optical axis direction, it is necessary to reduce a length of the lens barrel in the optical axis direction as short as possible. Japanese Patent Laid-Open No. 2007-310412 discloses a camera having a so-called retractable lens barrel that protrudes from a camera body during a camera use time (image capturing) and is housed (retracted) to the camera body during a camera non-use time (carrying). In this camera, an aperture stop serving as the light-quantity control apparatus and a lens are arranged adjacently to each other in an optical axis direction. Therefore, the length of the lens barrel in the retracted state is reduced by inserting a part of the lenses into the aperture in the retracted state. 
     However, in the camera disclosed in Japanese Patent Laid-Open No. 2007-310412, the part of the lenses is inserted into the aperture formed by opening a stop blade more than its fully opened state. For this reason, a diameter of the fully opened aperture is required to be larger than an outer diameter of the lenses. This requires an increase in size of the stop blade forming the stop aperture and accordingly of an outer circumferential space into which the stop blade opened more than its fully opened state is to be retracted. This results in an increase in size of the light-quantity control apparatus, making it difficult to miniaturize the camera in which the light-quantity control apparatus is installed. 
     SUMMARY OF THE INVENTION 
     The present invention provides a light-quantity control apparatus that can be appropriately miniaturized. The present invention further provides an optical apparatus in which the light-quantity control apparatus is installed. 
     The present invention provides as an aspect thereof a light-quantity control apparatus. The light-quantity control apparatus includes a light-quantity control blade movable along a curved path preformed between a first optical member and a second optical member, and a blade driver configured to rotate the light-quantity control blade along the curved path. 
     The present invention provides as another aspect thereof a light-quantity control apparatus. The light-quantity control apparatus includes a light-quantity control blade movable along a curved path preformed between a first optical member and a second optical member, and a blade driver configured to rotate the light-quantity control blade along the curved path. The blade driver includes a rotating member configured to rotate the light-quantity control blade and a driver connected to an outer circumferential edge portion of the rotating member. 
     The present invention provides as another aspect thereof a light-quantity control apparatus provided with a light-passing aperture. The apparatus includes a base member, a light-quantity control blade including a light-quantity control portion to control quantity of light passing through the light-passing aperture and a supported portion rotatably supported with respect to the base member, and a rotating member rotating with respect to the base member to rotate the light-quantity control blade. When a direction orthogonal to an aperture plane of the light-passing aperture is defined as an optical axis direction, a concave space facing the light-passing aperture is formed more inside in a direction orthogonal to the optical axis direction than the light-quantity control blade, the rotating member includes gear tooth serving as a driving mechanism, and the gear tooth constitute part of a wall portion surrounding the concave space. 
     The present invention can realize a light-quantity control apparatus that can be appropriately miniaturized. In particular, a light-quantity control blade of the light-quantity control apparatus requires a smaller space in a radial direction when opened to its fully opened state. This configuration makes it possible to miniaturize the light-quantity control apparatus in the radial direction, which enables achieving miniaturization of an optical apparatus in which the light-quantity control apparatus is installed. 
     Other aspects of the present invention will become apparent from the following description and the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view illustrating an aperture stop apparatus that is Embodiment 1 of the present invention. 
         FIGS. 2A and 2B  are rear views illustrating the aperture stop apparatus of Embodiment 1 and an enlarged view of an anti-shake mechanism used in the aperture stop apparatus of Embodiment 4. 
         FIG. 3  is a side cross-sectional view illustrating the aperture stop apparatus of Embodiment 1. 
         FIGS. 4A and 4B  are explanatory diagrams illustrating operations of the aperture stop apparatus of Embodiment 1. 
         FIG. 5  is a perspective view illustrating the stop blade used in the aperture stop apparatus of Embodiment 1. 
         FIG. 6  is an exploded perspective view illustrating an aperture stop/shutter apparatus that is Embodiment 2 of the present invention. 
         FIGS. 7A and 7B  are rear perspective views illustrating the aperture stop/shutter apparatus of Embodiment 2. 
         FIG. 8  is a side cross-sectional view illustrating the aperture stop/shutter apparatus of Embodiment 2. 
         FIGS. 9A and 9B  are perspective views illustrating a stop blade and a shutter blade used in the aperture stop/shutter apparatus of Embodiment 2. 
         FIGS. 10A and 10B  are explanatory diagrams illustrating operations of the stop blade in Embodiment 2. 
         FIGS. 11A and 11B  are explanatory diagrams illustrating operations of the shutter blade in Embodiment 2. 
         FIG. 12  is an enlarged view of outer circumferential side in another variation of Embodiment 2. 
         FIG. 13  is an exploded perspective view illustrating an aperture stop apparatus that is Embodiment 3 of the present invention. 
         FIG. 14  is a perspective view illustrating an aperture stop apparatus in Embodiment 3. 
         FIGS. 15A and 15B  are internal structure views illustrating an aperture stop apparatus in Embodiment 3. 
         FIG. 16  is an arrangement view of a lens barrel illustrating an aperture stop apparatus in Embodiment 3. 
         FIG. 17  is a perspective view illustrating a stop blade used in an aperture stop apparatus in Embodiment 3. 
         FIGS. 18A ,  18 B and  18 C are explanatory diagrams illustrating operations of the aperture stop apparatus of Embodiment 3. 
         FIG. 19  is a perspective view illustrating an internal structure of an aperture stop apparatus in Embodiment 3. 
         FIG. 20  is an exploded perspective view illustrating an aperture stop apparatus that is Embodiment 4 of the present invention. 
         FIG. 21  is a perspective view illustrating an aperture stop apparatus in Embodiment 4. 
         FIGS. 22A and 22B  are side cross-sectional views illustrating the aperture stop apparatus of Embodiment 4. 
         FIG. 23  is a side cross-sectional view illustrating the aperture stop apparatus of the comparative example. 
         FIG. 24  is a rear view illustrating an anti-shake mechanism used in the aperture stop apparatus of Embodiment 4. 
         FIG. 25  is a perspective view illustrating the aperture stop blade of the light-quantity control mechanism used in the aperture stop apparatus of Embodiment 4. 
         FIGS. 26A and 26B  are explanatory diagrams illustrating operations of the stop blade used in the aperture stop apparatus of Embodiment 4. 
         FIGS. 27A and 27B  are front views illustrating the stop blade used in an aperture stop apparatus that is Embodiment 5 of the present invention. 
         FIGS. 28A and 28B  are block diagrams illustrating a configuration of a camera provided with the aperture stop apparatus of Embodiments 1 and 3, the aperture stop/shutter apparatus of Embodiment 2, and the aperture stop apparatus of Embodiments 5 and 6. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Exemplary embodiments of the present invention will hereinafter be described with reference to the accompanying drawings. 
     Embodiment 1 
       FIGS. 1 ,  2 A and  2 B illustrate an iris type aperture stop apparatus  110  as a light-quantity control apparatus that is Embodiment 1 of the present invention.  FIG. 2A  is a rear perspective view of the aperture stop apparatus  110 .  FIG. 2B  is an enlarged view of a connecting portion of a rotating member and a driver of the aperture stop apparatus  110 . In the drawings, reference numeral  101  denotes a base plate serving as a base member. A first fixed aperture  106  is formed at a diametric center portion of the base plate  101 . A mounted portion  101   a  is mounted on the base plate  101  at a position where gear tooth of the driver and gear tooth of the rotating member, both described later, engage with each other. At a circumferential edge portion of the mounted portion  101   a , a continuous curved surface shape of the base plate  101  is provided to connect the gear tooth, which will be described later, thereto so as to prevent the gear from, when being rotated, contacting with the base plate  101  near the mounted portion  101   a . In the following description, an axis that passes through an aperture plane  106   a  of the first fixed aperture  106  and is orthogonal to the aperture plane  106   a  is referred to as “an optical axis AX,” and a direction in which the optical axis AX extends is referred to as “an optical axis direction”. 
     In addition, a supporting hole portion (concave portion)  107  as a supporting portion is formed at each of a plurality of circumferential places of a ring portion surrounding the first fixed aperture  106  of the base plate  101 . A center axis BX of each supporting portion  107  has a tilt angle θB with respect to the optical axis direction (optical axis AX). 
     A driving ring  102  serves as a driving member. The driving ring  102  has a domical wall portion  102   a  formed in a domical shape concave toward the base plate  101  (first fixed aperture  106 ) (in other words, formed so as to have a shape concave toward one side in the optical axis direction from its outer circumferential side portion to its inner circumferential side portion). 
     A driven gear  102   b  is formed in a circumferential part of an outer circumferential side portion of the driving ring  102  than the domical wall portion  102   a . In the domical wall portion  102   a , a concave surface on a base plate ( 101 ) side and a convex surface (hereinafter, referred to as “a guide surface”)  102   c  on an opposite side thereto, and the driven gear  102   b  are respectively formed in a spherical surface shape. That is, in the end portion of the outer circumferential side portion along the curved surface shape of the domical wall portion  102   a  of the curved surface shape, a gear tooth of cover drive gear  102   b  which has a tilt with respect to the optical axis is established. A second fixed aperture  112  corresponding to a fully opened aperture is formed in a radially central part of the domical wall portion  102   a . A position of an aperture plane of the second fixed aperture  112  in the optical axis direction is distant from the base plate  101  (that is, the aperture plane  106   a  of the first fixed aperture  106 ) as compared to the outer circumferential portion of the domical wall portion  102   a  of the aperture-stop driving ring  102 . 
     The driver, which will be described later, is disposed on the mounted portion  101   a  provided at an outer circumferential edge portion of the base plate  101 . The disposition of the driver on the mounted portion  101   a  provided by recessing the outer circumferential edge portion of the base plate  101  enables miniaturizing the aperture stop apparatus  110  in the optical axis direction. Furthermore, providing the mounted portion  101   a  by recessing a curved portion of the base plate  101  enables miniaturizing the aperture stop apparatus  110  in a direction orthogonal to the optical axis direction. That is, the provision of the mounted portion  101   a  to a recess part of the outer circumferential edge portion of the base plate  101  results in the disposition of the mounted portion  101   a  on a first fixed aperture ( 106 ) side. This enables reducing a portion that protrudes from the outer circumferential edge portion of the base plate  101 , which makes it possible to miniaturize the entire aperture stop apparatus  110 . 
     In addition, a boss portion  108  is formed at each of a plurality of circumferential places of the stop guide surface  102   c  (circumferential places around the second fixed aperture  112 ) of the domical wall portion  102   a . A center axis CX of each boss portion  108  has a tilt angle θC with respect to the optical axis direction (optical axis AX) extending in a direction normal to the stop guide surface  102   c  and substantially intersects with the optical axis AX. 
     Reference numeral  103  denotes stop blades as a plurality of light-quantity control blades (light-blocking blades). Each stop blade  103  is constituted by a plate member bent along a lens surface. For instance, in this embodiment, each stop blade  103  is a bent thin plate member having a light-blocking property for forming, radially inside the first fixed aperture  106  of the base plate  101  and the second fixed aperture  112  of the driving ring  102 , a stop aperture (light-passing aperture) A whose circumference is a light-blocking area. 
     As illustrated in  FIG. 5 , each stop blade  103  includes a light-blocking portion  103   a  as a light-quantity control portion for forming the stop aperture A, a stop blade-supported portion  103   b  rotatably supported with respect to the base plate  101  and the driving ring (part of a blade driver)  102  and an intermediate portion  103   e  that connects the light-blocking portion  103   a  and the stop blade-supported portion  103   b . On the stop blade-supported portion  103   b , a boss portion (protruding portion)  103   c  is formed that is inserted into the supporting hole portion  107  formed on the base plate  101 . Each stop blade  103  is thus rotatable about the supporting hole portion  107  and the boss portion  103   c  with respect to the base plate  101  and the driving ring  102 . In addition, a direction of a stop blade-supported surface (abutted surface) of the stop blade-supported portion  103   b  provided with the boss portion  103   c  matches with a direction of a center axis (rotational axis) BX. 
     Each of the plurality of stop blades  103  is disposed so as to face the guide surface  102   c  of the domical wall portion  102   a  of the driving ring  102 . The light-blocking portion  103   a  is formed in a spherical surface shape (curved surface shape) having a curvature substantially the same as that of the guide surface  102   c  of the domical wall portion  102   a  of the driving ring  102 . For this reason, when each stop blade  103  is rotated, the light-blocking portion  103   a  is moved in a direction to advance and retract into and from a radially inside area of the second fixed aperture  112  (area facing the first and second fixed apertures  106  and  112 ), that is, a direction to change a size of the stop aperture A while moved along the guide surface  102   c , in other words, by being guided by the guide surface  2   c  to control quantity of light passing through the first and second fixed apertures  106  and  112 . The above advancing/retracting direction is hereinafter referred to as “a stop opening/closing direction.” Between the base plate  101  and the driving ring  102 , a step is provided such that the driving ring  102  is convex and the outer circumferential side portion is lower than the driving ring  102 . Since the driving ring  102  is convex, each stop blade  103  can be smoothly moved without caught by the outer circumferential portion. 
     Furthermore, on the light-blocking portion  103   a , a cam groove portion  103   d  is formed into which the boss portion  108  formed in the driving ring  2  is inserted and with which the boss portion  108  is engaged. When each light-blocking blade is manufactured by molding, press molding or the like, an angle of the abutted surface of the cam groove portion  103   d  has a certain value because a draft direction of a mold is fixed. The rotation of each light-quantity control blade  103  is restricted (limited) by the abutted surface of the cam groove portion  103   d  (rotation restricting portion) against which the boss portion  108  abuts, which enables more stable precision operations compared to a case where each light-quantity control blade  103  is rotated while supported at one point. The abutted surface of the cam groove portion  103   d  against which the boss portion  108  abuts serves as a restricting surface that restricts the rotation of each light-quantity control blade  103 . A direction of the restricting surface (abutted surface direction) matches with a direction indicated by symbol BX. As described above, the center axis CX of each boss portion  108  extends in a direction normal to the guide surface  102   c . This enables each boss portion  108  to more smoothly move in the cam groove portion  103   d , compared to a case where the center axis CX extends in the optical axis direction, which allows each boss portion  108  to rotate the light-blocking portion  103   a  (i.e., the stop blade  103 ) with good position accuracy. 
     Each light-quantity control blade of this embodiment described above is rotated on the spherical surface (curved surface) in order to effectively use a curved space between optical members. In a configuration for enabling this, a facing direction of the stop blade-supported surface (abutted surface) of the stop blade-supported portion  103   b  on which the above-described boss portion  103   c  is provided (a direction of the center axis BX of the rotation (rotational axis)) substantially intersects with a direction of the center axis BX of each supporting hole portion  107 . This means that the direction of the stop blade-supported surface of the stop blade-supported portion  103   b  and the direction of the restricting surface of the cam groove portion  103   d  serving as a rotation restring portion substantially intersect with each other. That is, each light-quantity control blade  103  of this embodiment is provided such that the direction of the stop blade-supported surface of the stop blade-supported portion  103   b  and the direction of the restricting surface of the cam groove portion  103   d  substantially intersect with each other with respect to the optical axis direction (AX direction). This means that the direction of the stop blade-supported surface of the stop blade-supported portion  103   b  and the direction of the restricting surface of the cam groove portion  103   d  intersect with each other or are the closest to each other at a point on an extension of the optical axis AX, the center axis BX and the center axis CX and that a spherical center of a spherical-shaped orbit on which each light-quantity control blade  103  is rotated is located near the point. Each light-quantity control blade  103  of this embodiment having such a configuration can be smoothly and stably opened and closed even though curved along the lens surface. In other words, each light-quantity control blade  103  in this embodiment can be smoothly and stably opened and closed and moreover requires a smaller installation space in the light-quantity control apparatus, which is highly advantageous for miniaturizing the light-quantity control apparatus. 
     On the other hand, when a tilt of the cam groove portion  103   d  is set to an inappropriate value, the cam groove portion  103   d  is likely to be caught by the boss portion  108  at the time of the rotation of the driving ring  102 . Setting the draft direction of the mold to a direction near a center of a range within which the cum is operated in order to set a section angle of the cam groove portion  103   d  to an optimum value makes it possible to minimize a difference between an angle of the cam groove portion  103   d  and that of the cum boss portion  108 . In addition, an increase in thickness of the intermediate portion  103   e  results in an improvement in strength of the stop blade  103 , which enables more accurate operation of the stop blade  103 . It is noted that an alternative configuration may be employed in which the light-blocking portion  103   a  is formed in the spherical surface shape and in which the guide surface  102   c  is formed not in the spherical surface shape, but in a truncated conical surface shape. 
     In a case where each stop blade  103  is to be formed by injection molding, a molten plastic is injected to a cavity from a sprue of the mold through a gate. The higher thickness of the intermediate portion  103   e  of each stop blade  103 , which is formed as a plastic-molded product, than that of the light-quantity control portion  103   a  results in an increase in strength of each stop blade  103 . In addition, presence of the gate provided near the stop blade-supported portion  103   b  having the higher thickness than that of the light-quantity control portion  103  lowers a possibility of breakage of a thin portion of each stop blade  103 . Moreover, presence of the gate provided on a back surface of the supporting boss portion  103   c  near the stop blade-supported portion  103   b  enables a smooth rotation operation of each stop blade  103 . 
     Of each stop blade  103 , the intermediate portion  103   e  and the stop blade-supported portion  103   b , namely, a portion on a stop blade-supported portion ( 103   b ) side than the light-blocking portion  103   a  has a tilt α in the optical axis direction with respect to the aperture plane  106   a  of the first fixed aperture  106  formed on the base plate  101  (such portion has the tilt α with respect also to the aperture plane of the second fixed aperture  112  formed in the driving ring  102  and of a third fixed aperture formed in a cover plate described later). The tilt α is an angle of certain degrees including 90°. Giving the tilt α to the intermediate portion  103   e  and the stop blade-supported portion  103   b  causes the light-blocking portion  103   a  to be located distant from the stop blade-supported portion  103   b  in the optical axis direction. A center axis of the boss portion  103   c  formed on the stop blade-supported portion  103   b  has a tilt with respect to the optical axis AX so as to match with the center axis BX of the supporting hole portion  107 . For this reason, each stop blade  103  can be smoothly rotated, compared to a case where the center axis BX of the supporting hole portion  107  extends in the optical axis direction. 
     It is noted that, in each stop blade  103 , the stop blade-supported portion  103   b  has a larger tilt in the optical axis direction with respect to the aperture plane  106   a  than that of the light-blocking portion  103   a . The entire part from the stop blade-supported portion  103   b  to the light-blocking portion  103   a  of each stop blade  103  may be formed in the spherical surface shape (curved surface shape). 
     Incidentally, a taper  103   f  is provided to each stop blade  103  such that each stop blade  103  becomes gradually thinner toward a ridgeline  103   g . The provision of the taper  103   f  to each stop blade  103  makes it possible to reduce a hump amount in a narrowly opened state. It is noted that the taper  103   f  may be provided on either of the outside or the inside of the curved surface shape of each stop blade  103 . 
     In  FIGS. 1 ,  2 A and  2 B, a cover plate (stop cover member)  104  forms a stop blade room for housing the driving ring  102  and each stop blade  103  between the cover plate  104  and the base plate  101 . On an inner circumferential portion of the cover plate  104 , a domical shape concave toward the base plate  101  is formed. On the cover plate  104  formed in the curved surface shape, a recess part is provided at a position corresponding to each mounted portion  101   a . This makes it easy to check the engagement of the gear tooth of the driving ring  102  with the gear tooth of the driver, which enables an improvement in assembly accuracy. This makes it easy to check the engagement of the gear tooth of the driving ring  102  with the gear tooth of the driver without removing the cover plate  104 . 
     An outer portion of the cover plate  104  is coupled with the base plate  101  by fixing means such as screws, and is thereby integrated with the base plate  101 . For this reason, the cover plate  104  can be treated also as the base member similarly to the base plate  101 . It is noted that a configuration in which a domical portion similar to the domical portion  104   a  is formed on the base plate  101  with an original position of the base plate  101  and that of the cover plate  104  exchanged allows each stop blade  103  to be rotated over the curved surface of the other side of the base plate  101 , each stop blade  103  can be smoothly moved in a space surrounded by the curved surfaces. 
     Reference numeral  105  denotes the driver including the actuator such as a stepping motor. A driving gear  105   a  to be engaged with the driven gear  102   b  of the driving ring  102  is fixed to the output shaft of the driver  105 . To the driving gear  105   a , a gear tooth  105   b  to be engaged with the driven gear  102   b  is provided. As illustrated in  FIG. 2B , the gear tooth of the driven gear  102   b  facing toward the base plate ( 101 ) side is engaged with the gear tooth  105   b  so as to cover the gear tooth  105   b  of the driving gear  105   a . That is, in the recess part of the base plate  101 , the rotating member  102  and the driver  105  face each other in the optical axis direction and are connected to each other. Since the driven gear  102   b  is formed in the spherical shape, the driving gear  105   a  and the driven gear  102   b  are each formed as a hypoid gear or a gear similar thereto. The driver  105  (stop driver) is provided so as to protrude in a direction opposite to a direction in which the domical shape of the cover plate  104  protrudes. This configuration in which the direction in which the domical shape of the cover plate  104  protrudes from the base member and the direction in which the driver  105  protrudes from the base member are opposite to each other enables, when the aperture stop apparatus  110  is installed in the optical apparatus such as the camera, effectively using a space in the optical apparatus (in particular, a space at a side opposite to a side on which the domical shape of the cover plate  104  is disposed), which enables miniaturizing the optical apparatus. 
     When the driver  105  is energized and thereby the driving gear  105   a  is rotated, as illustrated in  FIGS. 4A and 4B , a rotational force from the driver  105  is transmitted to the stop driving ring  102  through the driven gear  102   b  and rotates the stop driving ring  102  about the optical axis AX (around the light-passing aperture) with respect to the base plate  101 . With the rotation of the stop driving ring  102 , the boss portion  8  provided in the stop driving ring  102  moves in the cam groove portion  103   d  formed in the light-blocking portion  103   a  of each stop blade  3 . Therefore, each stop blade  103  is rotated in the stop opening/closing direction about the boss portion  103   c  and the supporting hole portion  107  into which the boss portion  103   c  is inserted. 
     Each stop blade  103  is movable along a curved path preformed between a lens  51  with a convex shape as a first optical member and a lens  53  with a concave shape as a second optical member  53 , both illustrated in  FIG. 3 . The blade driver that drives each stop blade  103  along the curved path includes the driving ring  102  as the rotating member that rotates each stop blade  103 , and the driver  105  connected to the outer circumferential edge portion of the driving ring  102 . That is, the blade driver rotates the driver  105  to thereby rotate the driving ring  102 . With the driving ring  102  rotated, each stop blade  103  is rotated. This configuration in which, at the time of the rotation of each stop blade  103 , the driver  105  is, at the outer circumferential portion of the driving ring  102 , connected to the end portion of the driving ring  102  in the optical axis direction (side opposite to an end portion side of the second fixed aperture  112 ) so as to transmit the rotational force is highly advantageous for miniaturizing the aperture stop apparatus  110  in the direction orthogonal to the optical axis direction. This configuration of the aperture stop apparatus  110  of this embodiment enables the miniaturization of the optical apparatus including the aperture stop apparatus  110  that drives each stop blade  103  between the two lenses to control quantity of light. In other words, the aperture stop apparatus  110  in this embodiment is capable of not only driving each stop blade  103  from the outer circumferential edge portion of the driving ring  102  to stably open and close each stop blade  103 , but also of rotating each stop blade  103  of the light-quantity control apparatus in the smaller installation space. This makes it easy to form a desired light-passing aperture and is, moreover, highly advantageous for miniaturizing the light-quantity control apparatus. 
     Although this embodiment described the case where (the center axis of) the supporting hole portion  107  formed on the base plate  101  and (the center axis of) the boss portion  108  formed on the driving ring  102  are tilted with respect to the optical axis direction, the supporting hole portion  107  and the boss portion  108  may be formed to extend in parallel with the optical axis direction as long as each stop blade  103  (stop blade-supported portion  103   b ) is rotated with respect to a virtual axis tilted with respect to the optical axis direction. 
     It is noted that although this embodiment described the configuration in which the boss portion  103   c  formed on the stop blade-supported portion  103   b  of each stop blade  103  so as to allow the stop blade  103  to be rotated thereabout is inserted into the supporting hole portion  107  of the base plate  101 , an alternative configuration may be employed in which a domical portion similar to the domical shape of the cover plate  104  is formed on the base plate  101  and thereon the boss portion inserted into the cam groove portion is formed and in which the driving ring  102  is rotatably disposed on an outer side of the fixed aperture of the domical portion and thereon the supporting boss portion is formed. In the case where the boss portion inserted into the cam groove portion is provided on the base plate  101 , the supporting boss portion formed on the driving ring  102  may be inserted into the hole portion formed on each stop blade  103 , and the boss portion formed on the base plate  101  may be inserted into the cam groove portion. In other words, although, in this embodiment, each stop blade  103  is rotated about the rotational axis at the base plate ( 101 ) side, each stop blade  103  may be rotated thereabout at a driving ring ( 102 ) side. As long as relative positions of the stop blade-supporting boss portion and the cam boss portion respectively inserted into the hole portion and the cam groove portion of each stop blade  103  are changeable, any one of the stop blade-supporting boss portion and the cam boss portion may be formed in the base plate  101  and the other thereof may be formed in the stop driving ring  102 . 
     Although this embodiment described the case where the boss portions  103   c  formed on the stop blades  103  and the boss portions  108  formed in the driving ring  102  are respectively inserted into the supporting hole portions  107  formed in the base plate  101  and the cam groove portions  103   d  formed in the stop blades  103 , a hole portion corresponding to the stop blade-supporting boss portion  107  and a boss portion corresponding to the boss portion  108  may be formed in each stop blade  3  to respectively insert the supporting boss portion formed in the base plate  101  into the hole portion of each stop blade  103  and the boss portion formed in each stop blade  103  into the cam groove portion formed in the driving ring  102 . 
     In the aperture stop apparatus  110  with the above-described configuration, the intermediate portion  103   e  and the stop blade-supported portion  103   b  of each stop blade  103 , which are described above, each have the tilt α in the optical axis direction. As a result, as illustrated in  FIG. 3 , a concave space S is formed that has, in the optical axis direction, a depth from the stop blade-supported portion ( 103   b ) side to a light-blocking portion ( 103   a ) side of each of the stop blades  103  inside the radial direction than each of the stop blades  103 . An end portion of the concave space S at the stop blade-supported portion ( 103   b ) side is opened in the first fixed aperture  106  formed in the base plate  101 . On the other hand, an end portion of the concave space S at the light-blocking portion ( 103   a ) side is closed in the second fixed aperture  112  formed in the driving ring  102  (and also in the stop aperture A and in the third fixed aperture  113  formed in the cover plate  104 ). In other words, the concave space S faces the first to third fixed apertures  106 ,  112  and  113 , and is located in the curved path that is the space between the lens  51  with the convex shape and the lens  53  with the concave shape. 
     The concave space S can be referred to also as a space whose outer circumference is surrounded by a surface of each of the stop blades  103 . However, in this embodiment, the surface of each of the stop blades  103  does not directly face the concave space S, which means that the domical wall portion  102   a  of the driving ring  102  surrounding the concave space S is located between the surface of each stop blade  103  and the concave space S. It is noted that the domical wall portion  102   a  is not necessarily required. As long as each stop blade  103  is stably guided by, for example, a rail radially extending in the radial direction, the surface of each stop blade  103  may directly face the concave space S without the domical wall portion  102   a  provided. 
     Embodiment 2 
     The present invention relates to a light-quantity control apparatus and an optical apparatus having the light-quantity control apparatus. The light-quantity control apparatus is installed in an optical apparatus such as a digital camera, a video camera and an interchangeable lens. 
     An optical apparatus such as a camera is necessary to have compactness. In particular, when a lens barrel for holding an image taking lens protrudes from a camera body in its optical axis direction, it is necessary to reduce a length of the lens barrel in the optical axis direction as short as possible. Japanese Patent Laid-Open No. 2004-184486 discloses a light-quantity control apparatus in which a plurality of stop blades for controlling a quantity of light by controlling a size of a light-passing aperture (stop aperture) and a driving ring for opening/closing the stop blades are arranged between a base plate and a partition plate, and in which a shutter blade for opening/closing the light-passing aperture (shutter aperture) is arranged between the partition plate and a cover plate. In this manner, a light-quantity control apparatus having an aperture stop function and a shutter function is implemented using a single base plate. Therefore, a camera can be miniaturized in an optical axis direction, compared to a case where the aperture stop apparatus and the shutter apparatus are separately provided. 
     In the light-quantity control apparatus disclosed in Japanese Patent Laid-Open No. 2004-184486, it is also necessary to provide a thickness of the base plate in the optical axis direction, a space for moving the stop blade, and a space for moving the shutter blade. Therefore, miniaturization is restricted. 
     This embodiment provides a light-quantity control blade of a light-quantity control apparatus including a stop blade and a shutter blade and enabling miniaturization in an optical axis direction while achieving downsizing in a radial direction, and also provides the optical apparatus using the light-quantity control blade. 
     A light-quantity control apparatus of this embodiment includes a base member; a stop blade including a stop portion to control quantity of light passing through a light-passing aperture and a supported portion rotatably supported with respect to the base member; and a shutter blade including a shutter portion to block light through the light-passing aperture and a supported portion rotatably supported with respect to the base member. When a direction orthogonal to an aperture plane of the light-passing aperture is defined as an optical axis direction and a direction orthogonal to the optical axis direction is defined as a radial direction, the supported portions have tilts toward the same side in the optical axis direction with respect to the aperture plane so as to locate the stop portion and the shutter portion distant from the respective supported portions of the stop blade and the shutter blade in the optical axis direction so that a concave space facing the light-passing aperture is formed more inside in the radial direction than the stop blade and the shutter blade. 
     The light-quantity control apparatus of this embodiment is mountable on an optical apparatus including an optical system in which the light-quantity control apparatus and a lens are disposed in the optical axis direction, and allowing at least a part of the lens to be inserted into the concave space in the light-quantity control apparatus. 
     According to this embodiment, it is possible to form the concave space, into which the lens can be inserted, in a radially inner area than the stop and shutter blades without opening the stop and shutter blades to their fully opened states in the light-quantity control apparatus including the stop and shutter blades. That is, it is possible to insert the lens inside in the optical axis direction while preventing a size increase of the light-quantity control apparatus in the radial direction. Therefore, downsizing of the optical apparatus on which the light-quantity control apparatus is mounted can be achieved. 
     The supported portions of the stop blade and the shutter blade are supported rotatably about an axis tilted with respect to the optical axis direction so that these blades can be rotated more smoothly. 
     Embodiment 2 will hereinafter be described with reference to the accompanying drawings. 
       FIGS. 6 ,  7 A and  7 B illustrate an iris type aperture stop/shutter apparatus  10  as a light-quantity control apparatus that is Embodiment 2 of the present invention. In these drawings, a base plate  1  as a base member formed in a ring shape has an opening  6  formed in an inner circumferential part thereof. In the following description, an axis passing through a center of the aperture stop/shutter apparatus  10  and orthogonal to an opening plane of the opening  6  formed in the base plate  1  and an aperture plane of each fixed aperture described below is referred to as “an optical axis AX,” and a direction where the optical axis AX extends is referred to as “an optical axis direction.” In addition, a direction orthogonal to the optical axis direction is referred to as “a radial direction.” 
     A stop blade-supporting boss portion (protruding portion)  7  as a stop blade-supporting portion is formed at each of a plurality of circumferential places of a ring portion surrounding the opening  6  of the base plate  1 . A center axis BX of each stop blade-supporting boss portion  7  has a tilt angle θB with respect to the optical axis direction (optical axis AX). 
     A stop driving ring  2  serves as a driving member. The stop driving ring  2  has a domical wall portion  2   a  formed in a domical shape concave toward the base plate  1  (opening  6 ) (in other words, convex toward an opposite side to the base plate  1 ). A first fixed aperture  12  as a light-passing aperture is formed in an innermost circumferential portion (diametric center portion) of the domical wall portion  2   a . In addition, a driven gear  2   b  is formed in a circumferential part of an outer circumferential side portion of the aperture-stop driving ring  2  than the domical wall portion  2   a . In the domical wall portion  2   a , a concave surface on a base plate ( 1 ) side and a convex surface (hereinafter, referred to as “a stop guide surface”)  2   c  on an opposite side thereto are respectively formed in a curved surface shape (for example, a spherical surface shape). A position of the aperture plane of the first fixed aperture  12  in the optical axis direction is distant from the base plate  1  (that is, the opening plane of the opening  6 ) as compared to an outer circumferential edge of the domical wall portion  2   a  of the aperture-stop driving ring  2 . That is, in the aperture-stop driving ring  2 , the domical wall portion  2   a  is formed so as to protrude in a direction distant from the base plate  1  in the optical axis direction. 
     In addition, a cam boss portion  8  is formed at each of a plurality of circumferential places of the stop guide surface  2   c  (circumferential places around the first fixed aperture  12 ) of the domical wall portion  2   a . A center axis CX of each cam boss portion  8  has a tilt angle θC with respect to the optical axis direction (optical axis AX) extending in a direction normal to the stop guide surface  2   c.    
     Reference numeral  3  denotes a stop blade serving as a light-blocking blade. In this embodiment, a plurality of the stop blades  3 , specifically six stop blades  3 , are provided. Each stop blade  3  is a thin plate member having a light-blocking property for forming, radially inside the first fixed aperture  12  formed in the stop driving ring  2 , a stop aperture A whose circumference is a light-blocking area. 
     As illustrated in  FIG. 9A  in detail, each stop blade  3  includes a stop portion  3   a  as a light-blocking portion for forming a stop aperture A and a stop blade-supported portion  3   b  having a hole portion  3   c  into which the stop blade-supporting boss portion  7  of the base plate  1  is inserted. The stop blade-supported portion  3   b  (that is, the stop blade  3 ) is supported with respect to the base plate  1 , by insertion of the stop blade-supporting boss portion  7  into the hole portion  3   c , rotatably about the stop blade-supporting boss portion  7 . In addition, the stop blade  3  has an intermediate portion  3   e  that connects the stop portion  3   a  and the stop blade-supported portion  3   b.    
     Each stop blade  3  is disposed so as to face (or extend along) the stop guide surface  2   c  of the domical wall portion  2   a  of the stop driving ring  2 . The stop portion  3   a  is formed in a spherical surface shape (a curved surface shape) having a curvature substantially the same as that of the stop guide surface  2   c  of the domical wall portion  2   a . For this reason, when the stop blade  3  is rotated, the stop portion  3   a  is rotated in a direction to advance and retract into and from an radially inside area of the first fixing aperture  12  (area facing the first fixed aperture  12 ), that is, a direction to change a size of the stop aperture A while the stop portion  3   a  is rotated along the stop guide surface  2   c , in other words, by being guided by the stop guide surface  2   c . The above advancing/retracting direction is hereinafter referred to as “a stop opening/closing direction.” 
     The intermediate portion  3   e  and the stop blade-supported portion  3   b  of each stop blade  3 , that is, at least a stop blade-supported portion ( 3   b ) side part than the stop portion  3   a  has a tilt α toward the optical axis direction with respect to the aperture plane (indicated as “P” in  FIG. 9A ) of the opening  6  of the base plate  1 . This tilt α corresponds to a tilt with respect to the aperture plane of the first fixed aperture  12  formed in the stop driving ring  2  and to a tilt with respect to the aperture plane of a second fixed aperture formed in a stop cover plate described below. Furthermore, since each aperture plane is formed along the radial direction, the tilt α can also be referred to as a tilt with respect to the radial direction. 
     The tilt α is set to be equal to or lower than 90°. Giving the tilt α to the intermediate portion  3   e  and the stop blade-supported portion  3   b  causes the stop portion  3   a  to be located distant from the stop blade-supported portion  3   b  in the optical axis direction. In addition, a center axis of the hole portion  3   c  formed in the stop blade-supported portion  3   b  has a tilt with respect to the optical axis AX so as to match the center axis BX of the stop blade-supporting boss portion  7 . Therefore, the stop blade  3  can smoothly rotate, compared to a case where the center axis of the stop blade-supporting boss portion  7  extends in the optical axis direction. 
     It is noted that, in each stop blade  3 , the tilt of the stop blade-supported portion  3   b  toward the optical axis direction with respect to the aperture plane (radial direction) P is larger than that of the stop portion  3   a . In other words, the tilt of the stop portion  3   a  toward the optical axis direction with respect to the aperture plane P is smaller than that of the stop blade-supported portion  3   b . In addition, the entire stop blade  3  from the stop blade-supported portion  3   b  to the stop portion  3   a  may be formed in a spherical surface shape (a curved surface shape). 
     Furthermore, each stop blade  3  has a cam groove portion  3   d  into which the cam boss portion  8  formed in the stop driving ring  2  is inserted and with which the cam boss portion  8  is engaged. As described above, the center axis CX of the cam boss portion  8  extends in the direction normal to the stop guide surface  2   c . For this reason, compared to a case where the center axis of the cam boss portion  8  extends in the optical axis direction, the cam boss portion  8  can smoothly move in the cam groove portion  3   d , and the stop portion  3   a  (i.e., the stop blade  3 ) can be rotated in the stop opening/closing direction with good position accuracy. It is noted that the stop portion  3   a  is formed in a spherical surface shape and the stop guide surface  2   c  may be formed in a truncated conical surface shape instead of the curved surface shape. 
     In  FIGS. 6 and 7A , a stop cover plate (stop cover member)  4  is disposed on an opposite side to the base plate  1  with respect to the stop driving ring  2  and the stop blades  3  to form a stop blade room for housing the stop blades  3  between the stop cover plate  4  and the stop driving ring  2  (domical wall portion  2   a ). The stop cover plate  4  includes a domical wall portion  4   a  having a domical shape concave toward the base plate side (opening  6  side), in other words, convex toward the opposite side to the base plate  1 , and a ring portion formed in an outer circumferential portion of the domical wall portion  4   a . The domical wall portion  4   a  is formed in a spherical surface shape or a curved surface shape having approximately the same curvature as that of the domical wall portion  2   a  of the stop driving ring  2 . 
     A second fixed aperture  13  as a light-passing aperture is formed in an innermost circumferential portion (diametric center portion) of the domical wall portion  4   a . An aperture plane of the second fixed aperture  13  is located distant from the base plate  1  (opening  6 ) in the optical axis direction relative to an outer circumferential edge of the domical wall portion  4   a . That is, in the stop cover plate  4 , the domical wall portion  4   a  is formed so as to protrude in a direction distant from the base plate  1  in the optical axis direction. 
     The ring portion of the stop cover plate  4  is coupled with the base plate  1  using screws, and thereby the stop cover plate  4  is integrated with the base plate  1 . For this reason, similar to the base plate  1 , the stop cover plate  4  may also serve as a base member. 
     It is noted that the stop cover plate  4  may be omitted by forming a domical wall portion similar to the domical wall portion  4   a  of the stop cover plate  4  in the base plate  1  and forming a fixed aperture in the domical wall portion of the base plate. 
     Reference numeral  5  denotes a stop driver including an actuator such as a stepping motor. A driving gear  5   a  meshing with the driven gear  2   b  of the stop driving ring  2  is fixed to an output shaft of the stepping motor as illustrated I  FIG. 7B . The stop driver  5  is fixed (installed) to the base plate  1  via a motor base plate  11  and the stop cover plate  4 . The stop driver  5  is disposed at one place in an outer circumferential portion of the base member including the base plate  1  and the stop cover plate  4  than the domical wall portion  4   a . In other words, the stop driver  5  is disposed so as to protrude from its surrounding portions in a same direction as that where the domical wall portion  4   a  protrudes with respect to its surrounding portions. 
     In this manner, the domical wall portion  4   a  and the stop driver  5  have the same protruding direction from the base member. Thereby, as in a case where the aperture stop/shutter apparatus  10  is mounted on an optical apparatus such as a camera as described in Embodiment 4 below, it is possible to effectively use a space inside the optical apparatus (particularly, a space on an opposite side to that where the domical wall portion  4   a  and the stop driver  5  are arranged), which enables miniaturizing the optical apparatus. 
     When the stop driver  5  is energized and thereby the driving gear  5   a  is rotated, as illustrated in  FIGS. 10A and 10B , a rotational force from the stop driver  5  is transmitted to the stop driving ring  2  through the driving gear  5   a  and the driven gear  2   b  and rotates the stop driving ring  2  about the optical axis AX (around the light-passing aperture) with respect to the base plate  1 . With the rotation of the stop driving ring  2 , the cam boss portion  8  provided in the stop driving ring  2  moves in the cam groove portion  3   d  formed in the stop portion  3   a  of each stop blade  3 . Therefore, each stop blade  3  is rotated in the stop opening/closing direction about the stop blade-supporting boss portion  7  inserted into the hole portion  3   c  of the stop blade-supported portion  3   b . In this manner, the rotation of the stop portions  3   a  of the stop blades  3  (only one stop blade  3  is illustrated in  FIGS. 10A and 10B ) in the stop opening/closing direction changes a diameter of the stop aperture A formed by the stop portions  3   a , which increases and decreases (controls) a quantity of light passing through the stop aperture A. 
     It is noted that, although this embodiment described the case where (the center axis of) the stop blade-supporting boss portion  7  formed in the base plate  1  and (the center axis of) the cam boss portion  8  formed in the stop driving ring  2  are tilted with respect to the optical axis direction, the stop blade-supporting boss portion  7  and the cam boss portion  8  may be formed to extend in parallel with the optical axis direction as long as the stop blade  3  (stop blade-supported portion  3   b ) is rotated with respect to a virtual axis tilted with respect to the optical axis direction. 
     Moreover, a domical wall portion similar to the domical wall portion  4   a  of the stop cover plate  4  may be formed in the base plate  1 , and a fixed aperture may be formed in the domical wall portion. In addition, a cam boss portion may be formed in an inner surface (concave surface) of the domical wall portion, and a stop blade-supporting boss portion may be formed in the rotatable stop driving ring  2 . In this case, the stop blade-supporting boss portion formed in the stop driving ring  2  is inserted into the hole portion  3   c  formed in the stop blade  3 , and the cam boss portion formed in the domical wall portion of the base plate  1  is inserted into the cam groove portion  3   d . Also in such a configuration, rotating the stop driving ring  2  can rotate the stop blade  3  in the stop opening/closing direction. In this manner, as long as relative positions of the stop blade-supporting boss portion and the cam boss portion respectively inserted into the hole portion  3   c  and the cam groove portion  3   d  of the stop blade  3  are changeable, any one of the stop blade-supporting boss portion and the cam boss portion may be formed in the base plate  1  and the other thereof may be formed in the stop driving ring  2 . Even when the stop driving ring  2  directly supports the stop blade-supported portion  3   b  of the stop blade  3  in this manner, it is common that the stop blade-supported portion  3   b  is rotatably supported with respect to the base plate  1 . 
     Although this embodiment described the case where the stop blade-supporting boss portion  7  formed in the base plate  1  and the cam boss portion  8  formed in the stop driving ring  2  are respectively inserted into the hole portion  3   c  and the cam groove portion  3   d  formed in the stop blade  3 , a boss portion corresponding to the stop blade-supporting boss portion and a boss portion corresponding to the cam boss portion  8  may be formed in the stop blade  3  to insert them into a hole portion formed in the base plate  1  and a cam groove portion formed in the stop driving ring  2 . 
     Furthermore, in  FIG. 6 , reference numerals  21  and  22  denote two shutter blades  21  and  22 , which are disposed on an opposite side to the stop blades  3  with respect to the base plate  1  (and the stop driving ring  2 ). Similar to the stop blade  3 , the shutter blade  21  and the shutter blade  22  are each formed as a thin flat plate member having a light-blocking property. 
     Reference numeral  23  denotes a shutter cover plate (shutter cover member), which is disposed on an opposite side to the base plate  1  and the stop driving ring  2  with respect to the shutter blades  21  and  22 . The shutter cover plate  23  is fixed to the base plate  1  to form a shutter blade room for housing the shutter blades  21  and  22  between the shutter cover plate  23  and the stop driving ring  2  (domical wall portion  2   a ). The shutter cover plate  23  includes a domical wall portion  23   a  having a domical shape convex toward the base plate  1  side (opening  6  side), in other words, concave toward the opposite side to the base plate  1 , and a ring portion formed in an outer circumferential portion of the domical wall portion  23   a . The domical wall portion  23   a  is formed in a spherical surface shape (a curved surface shape) having approximately the same curvature as that of the domical wall portion  2   a  of the stop driving ring  2 . 
     A third fixed aperture  28  as a light-passing aperture is formed in an innermost circumferential portion (diametric center portion) of the domical wall portion  23   a . In the optical axis direction, the aperture plane of the third fixed aperture  28  is located distant from the base plate  1  (opening  6 ) relative to an outer circumferential edge portion (ring portion) of the domical wall portion  23   a . That is, in the shutter cover plate  23 , the domical wall portion  23   a  is formed so as to protrude in a direction distant from the base plate  1  in the optical axis direction. 
     The shutter cover plate  23  is integrated with the base plate  1  by bonding the ring portion of the shutter cover plate  23  to the base plate  1 . Thus, similar to the base plate  1  and the stop cover plate  4 , the shutter cover plate  23  can be treated as a base member. 
     As illustrated in  FIG. 9B  in detail, the shutter blade  21  includes shutter portion  21   a  as a light-blocking portion and a shutter blade-supported portion  21   b . The shutter portion  21   a  advances and retracts into and from an area facing the third fixed aperture  28  of the shutter cover plate  23  to open and close the third fixed aperture  28 . Closing the third fixed aperture  28  blocks the light passing through the third fixed aperture  28  (and the first and second apertures  12  and  13 ). 
     A hole portion  21   c  is formed in the shutter blade-supported portion  21   b , and a shutter blade-supporting boss portion  26  formed in the base plate  1  is inserted into the hole portion  21   c . As a result, the shutter blade-supported portion  21   b  (i.e., shutter blade  21 ) is supported with respect to the base plate  1  rotatably about the shutter blade-supporting boss portion  26 . In addition, a hole portion  21   d  into which a shutter driving pin described below is inserted and which engages therewith is formed in the shutter blade  21 . 
     The other shutter blade  22  is formed similarly to the shutter blade  21 . As illustrated in  FIGS. 11A and 11B , the shutter blade  22  includes a shutter portion  22   a , a shutter blade-supported portion  22   b  having a hole portion  22   c  into which the supporting boss portion is inserted, and a hole portion  22   d  into which the shutter driving pin is inserted. In  FIGS. 11A and 11B , the shutter blades  21  and  22  are illustrated in a state of removing the shutter cover plate  23 . 
     The shutter blades  21  and  22  are disposed to face (or extend along) a concave surface  2   e  of the domical wall portion  2   a  of the stop driving ring  2  and a convex surface  23   c  of the domical wall portion  23   a  of the shutter cover plate  23 . The shutter blades  21  and are each formed in a curved surface shape (for example, a spherical surface shape) having approximately the same curvature as those of the concave surface  2   e  and the convex surface  23   c . Therefore, when the shutter blades  21  and  22  are rotated, the shutter portions  21   a  and  22   a  are rotated in a direction to open or close the third fixed aperture  28  (the direction is hereinafter referred to as “a shutter opening/closing direction”) along the concave surface  2   e  of the domical wall portion  2   a  of the stop driving ring  2  and the convex surface  23   c  of the domical wall portion  23   a  of the shutter cover plate  23  while the shutter portions  21   a  and  22   a  are guided by the concave surface  2   e  and the convex surface  23   c . The concave surface  2   e  and the convex surface  23   c  are hereinafter collectively referred to as “a shutter guide surface.” 
     A portion of the shutter blades  21  and  22  closer to the supported portions  21   b  and  22   b  than the shutter portions  21   a  and  22   a  has a tilt β toward the optical axis direction with respect to the aperture plane P described above. This tilt β is set to be equal to or smaller than 90°. Giving the tilt β to the shutter blade-supported portions  21   b  and  22   b  causes the shutter portions  21   a  and  22   a  to be located distant from the shutter blade-supported portions  21   b  and  22   b  in the optical axis direction. It is noted that, in the shutter blades  21  and  22 , the tilt β of the shutter blade-supported portions  21   b  and  22   b  toward the optical axis direction with respect to the aperture plane P is larger than that of the shutter portions  21   a  and  22   a  with respect to the aperture plane P. In other words, the tilt of the shutter portions  21   a  and  22   a  toward the optical axis direction with respect to the aperture plane P is smaller than that of the shutter blade-supported portions  21   b  and  22   b.    
     Reference numeral  24  denotes a shutter driver  24  which rotates the shutter blades  21  and  22  in the shutter opening/closing direction. Reference numeral  25  denotes a fixing member  25  which fixes the shutter driver  24  to the base plate  1 . The shutter driver  24  includes a positively magnetized magnet, a stator yoke wound around the magnet, a coil for exciting the stator yoke and others. The shutter driver  24  reciprocatingly rotates the magnet between two positions by energization of the coil. 
     In this embodiment, the shutter driver  24  and the fixing member  25  are installed to a surface of the base plate  1  on an opposite side to that where the shutter blade-supporting boss portions  26  and  27  that support the shutter blade-supported portions  21   b  and  22   b  of the shutter blades  21  and  22  are provided (a same side surface to which the stop driver  5  is fixed). 
     A shutter driving pin  24   a  is integrally formed in the magnet of the shutter driver  24 . The shutter driving pin  24   a  penetrates through a hole portion formed in the base plate  1  and is inserted into driving hole portions  21   d  and  22   d  of the shutter blades  21  and  22  to engage therewith. Therefore, when the shutter driving pin  24   a  is rotated by energization of the coil, the shutter blades  21  and  22  are rotated in the shutter opening/closing direction about the shutter blade-supporting boss portions  26  and  27  as illustrated in  FIGS. 11A and 11B . 
     The shutter blades  21  and  22  (at least the shutter portions  21   a  and  22   b ) are each formed in a spherical surface shape (curved surface shape) having a curvature approximately the same as that of the guide surfaces  2   e  and  23   c  of the domical wall portion  2   a  of the stop driving ring  2  and the domical wall portion  23   a  of the shutter cover plate  23 . For this reason, the shutter blades  21  and  22  are rotated in the shutter opening/closing direction along the guide surfaces  2   e  and  23   c  while the shutter blades  21  and  22  are guided by the guide surfaces  2   e  and  23   c.    
     As illustrated in  FIGS. 6 and 9B , a center axis DX of the shutter driving pin  24   a  has a tilt θD extending in a direction normal to the domical wall portion  23   a  (guide surface  2   e ) with respect to the optical axis direction (optical axis AX). In addition, center axes of the driving hole portions  21   d  and  22   d  engaging with the shutter driving pin  24   a  in the shutter blades  21  and  22  each have a tilt with respect to the optical axis AX so as to match the center axis DX of the shutter driving pin  24   a . In addition, as illustrated in  FIG. 7B , the shutter blade-supporting boss portions  26  and  27  each have a tilt θE with respect to the optical axis direction (optical axis AX), and, as illustrated in  FIG. 9B , center axes of the hole portions  21   c  and  22   c  engaging with the shutter blade-supporting boss portions  26  and  27  each have a tilt with respect to the optical axis AX so as to match center axes EX of the shutter blade-supporting boss portions  26  and  27 . Therefore, it is possible to more smoothly and rapidly rotate the shutter blades  21  and  22  to perform a shutter operation, compared to a case where the center axes of the shutter driving pin  24   a  and the shutter blade-supporting boss portions  26  and  27  extend in the optical axis direction. 
     As in the configuration applied to the stop blade  103  in Embodiment 1, an outer circumferential portion that drives the shutter blades  21  and  22  in this embodiment can be provided with a step to prevent the shutter blades  21  and  22  from being caught.  FIG. 12  illustrates an enlarged view of the outer circumferential side portion provided with the step as a variation of the aperture stop/shutter apparatus  10  described in this embodiment. In order to have the step between the base plate  1  and an outer circumferential side portion of the driving ring  2 , a step portion  1   h  is provided on an inner circumferential side end portion of the base plate  1 , and a step portion  2   h  is provided on an outer circumferential side end portion of the driving ring  2 . The driving ring  2  is arranged on the step portion  1   h  of the base plate  1  such that the shutter blades  21  and  22  are prevented from touching. The step portions  1   h  and  2   h  are shaped smaller toward an outside in a direction along movement of the shutter blades  21  and  22  such that a curvature of the driving ring  2  is smaller than a curvature of the base plate  1 . This prevents the shutter blade  22  from being caught at the outer circumferential portion, thereby achieving smooth movement. 
     This embodiment described the configuration that enables the light-quantity control apparatus on which the stop blade and the shutter blades are mounted to be downsized in the radial direction so as to achieve smooth movement. This embodiment may have the configuration of the stop blade  103  described in Embodiment 1 so as to form portions of the shutter blades  21  and  22  such that they have different thicknesses with thicker portions closer to the supported portions, which is a center of rotation. The thicker portions, which are thicker than the light-quantity controller and provided to other than the light-quantity controller, enable the shutter blades  21  and  22  as the light-quantity control blades to have improved strength. This enables an accurate operation of the shutter blades  21  and  22 . Similarly to the stop blade, the light-quantity controller is formed in a spherical surface shape, and the guide surfaces for the shutter blades may be formed in a truncated conical surface shape instead of a spherical surface shape. 
     The light-quantity control blades are arranged so as to move in a space formed between any pair of the stop cover member  4 , the driving ring  2  and the shutter cover plate  23  that each have a convex shape toward an identical direction. This arrangement facilitates movement of the light-quantity control blades that are contributive to downsizing. 
     It is noted that, although this embodiment described the case where the shutter blade-supporting boss portions  26  and  27  formed in the base plate  1  are inserted into the hole portions  21   c  and  22   c  formed in the shutter blades  21  and  22 , a shutter blade-supporting boss portion may be installed in the shutter cover plate  4 . In addition, boss portions corresponding to the shutter blade-supporting boss portions  26  and  27  may be formed in the shutter blades  21  and  22  to insert them into the hole portion formed in the base plate  1 . 
     As described above, in the aperture stop/shutter apparatus  10  of this embodiment, the stop and shutter blade-supported portions  3   b ,  21   b  and  22   b  of the stop and shutter blades  3 ,  21  and  22  have tilts α and β toward the same one side in the optical axis direction with respect to the aperture plane P such that the stop and shutter portions  3   a ,  21   a  and  22   a  are located distant from the stop- and shutter blade-supported portions  3   b ,  21   b  and  22   b  in the optical axis direction, as illustrated in  FIG. 3 . In addition, the stop the driving ring  2  and the shutter cover plate  23  each have a shape (domical wall portions  2   a  and  23   a ) concave toward the one side. As a result, a concave space S facing the first to third fixed apertures (light-passing apertures)  12 ,  13  and  28  is formed inside in the radial direction than the stop blades  3 , the stop the driving ring  2 , the shutter cover plate  23  and the shutter blades  21  and  22  as illustrated in  FIG. 8 . 
     In practice, this concave space S is formed in a radially inside of the shutter cover plate  23  having the third fixed aperture  28  as a space having a depth in the optical axis direction toward the first and second fixed apertures  12  and  13  formed in the stop the driving ring  2  and the stop cover plate  4 . The concave space S on its fixed aperture ( 12 ,  13 ,  28 ) side opens toward the first to third fixed apertures  12 ,  13  and  28  (that is, faces the first to third fixed apertures  12 ,  13  and  28 ), and the concave space S on an opposite side thereto opens toward an outside of the aperture stop/shutter apparatus  10  in the optical axis direction with its inner diameter increasing toward the opposite side. 
     As illustrated in  FIG. 8 , at least part of the lens  51  can be inserted into the concave space S. That is, according to this embodiment, it is possible to form the concave space S, into which at least part of the lens  51  can be inserted, in a radially inner area than the stop and shutter blades  3 ,  21  and  22  without opening the stop and shutter blades  21  and  22  up to their fully opened state. 
     In this embodiment, one of the stop blades  3  and the shutter blades  21  and  22  (the stop blades  3  in this embodiment) is disposed on an opposite side to the concave space S in the optical axis direction relative to the other one (the shutter blades  21  and  22  in this embodiment), and the stop blades  3  are disposed so as to be convex from the base plate  1  toward the opposite side to the concave space S. Such disposition of the stop blades  3  makes it possible to arrange convex surfaces of the stop blades  3  (the domical wall portion  4   a  of the stop cover plate  4 ) and a concave surface of a lens  53 , which is disposed on an opposite side to the lens  51  with respect to the aperture stop/shutter apparatus  10 , to be close to each other, as illustrated in  FIG. 8 . Thereby, it is possible to arrange the stop blades  3  and the shutter blades  21  and  22  in a narrow space between a convex surface of the lens  51  and the concave surface of the lens  53 . 
     Furthermore, in this embodiment, the shutter blades  21  and  22 , the base plate  1 , and the stop blades  3  are arranged in this order in a concave direction of the concave space S (depth direction toward the first to third fixed apertures  12 ,  13 , and  28 ). In other words, the stop blades  3  are disposed on a convex side where the aperture stop/shutter apparatus  10  is convex toward the optical axis direction, and the shutter blades  21  and  22  are disposed on a concave side where the aperture stop/shutter apparatus  10  is concave. The reason of that is as follows. Since the number of the stop blades  3  (six in this embodiment) is greater than the number of the shutter blades  21  and  22  (two in this embodiment), the number of the stop blade-supporting boss portions  7  formed in the base plate  1  and the number of the cam boss portions  8  formed in the stop the driving ring  2  increase accordingly. When such boss portions are formed in the wall portion having a domical shape, they are easily formed on its convex surface than a case where they are formed on its concave surface because a mold structure is simplified, which can improve productivity. 
     However, in comparison, the shutter blades, the base plate, and the stop blades may be arranged in this order in an opposite direction to the concave direction of the concave space, that is, the stop blades may be disposed on the concave side where the aperture stop/shutter apparatus  10  is concave toward the optical axis direction, and the shutter blades  21  and  22  are disposed on the convex side. 
     Embodiment 3 
     An optical apparatus such as a camera is necessary to have compactness. In particular, when a lens barrel for holding an image capturing lens protrudes from a camera body in its optical axis direction, it is necessary to reduce a length of the lens barrel in the optical axis direction as short as possible. 
     Japanese Patent Laid-Open No. 2008-203576 discloses a light-quantity control apparatus that includes a base portion thicker than a blade portion and in which the blade portion and the base portion overlap with each other during a fully opened state, for the purpose of miniaturization. In the light-quantity control apparatus, the blade portion and the base portion thicker than the blade portion overlap with each other in an optical axis direction, which reduces a drive load of the light-quantity control apparatus. 
     However, the light-quantity control apparatus disclosed in Japanese Patent Laid-Open No. 2008-203576 requires providing a light-quantity control blade on a cam member and, moreover, a rotating member on the light-quantity control blade for driving the light-quantity control blade. 
     For this reason, the following light-quantity control apparatuses are required. 
     (1) A light-quantity control apparatus including a base member provided with an aperture portion; a light-quantity control blade that is mounted, from one surface side of the base member, on a blade supporting portion located at an outer circumferential edge portion of the aperture portion and that is rotatably provided in a circumferential direction; and a blade driving member engaged with the light-quantity control blade from the other surface side of the base member and configured to drive the light-quantity control blade. A blade engaging portion between the light-quantity control blade and the blade driving member is disposed on a side of the aperture portion than the blade supporting portion. 
     (2) A light-quantity control apparatus including a base member provided with an aperture portion; a light-quantity control blade that includes a light-quantity control portion for forming a light-passing aperture to control quantity of light passing through the aperture portion and a supported portion rotatably supported by a blade supporting portion provided to the base member; a blade driving member that includes a blade engaging portion engaged with the light-quantity control blade, is rotatably supported by the base member in a circumferential direction of the light-passing aperture and rotates to rotate the light-quantity control blade through the blade engaging portion; and a driver configured to rotate the blade driving member. When a direction orthogonal to an aperture plane of the light-passing aperture is defined as an optical axis direction, the light-quantity control blade has a shape in which the light-quantity control portion is located distant from the supported portion on one side in the optical axis direction such that a concave space having a depth toward the light-passing aperture more inside in a direction orthogonal to the optical axis direction than the light-quantity control blade is formed, the base member and the blade driving member are disposed at a side of the concave space than the light-quantity control blade, and the blade driving member is fixed to the base member from, of the optical axis direction, a direction opposite to a direction in which the light-quantity control blade is fixed to the base member such that the blade engaging portion is disposed on a side of the aperture portion than the blade supporting portion of the base member. 
     The light-quantity control apparatuses described in (1) and (2) are capable of opening and closing the light-quantity control blade with a simplified structure. This contributes to miniaturization of the optical apparatus in which any one of them is installed. 
     Next, referring to  FIGS. 13 ,  16  and  19 , description will be made of an iris type aperture stop apparatus  210  as a light-quantity control apparatus that is Embodiment 3 of the present invention. In the drawings, reference numeral  201  denotes a base plate as a base member. At a diametric center portion of the base plate  201 , a fixed aperture  201   a  is formed. In the following description, an axis that passes through a center of an aperture plane of the fixed aperture  201   a  (which is also an aperture plane of a stop aperture that is a light-passing aperture) and is orthogonal to the aperture plane is referred to as “an optical axis AX”, and a direction in which the optical axis AX extends is referred to as “an optical axis direction.” A direction orthogonal to the optical axis direction (a direction along the aperture plane of the stop aperture) is referred to as “a direction orthogonal to the optical axis direction” or “a radial direction. 
     “In  FIGS. 13 and 16 , on a side more left than the base plate  201  (one side in the optical axis direction and one surface side of the base plate  201 ), a plurality of stop blades  203  each serving as a light-quantity control blade. In the following description, the left side in  FIGS. 13 and 16 , and a side corresponding thereto in other drawings are each referred to as “a front side.” On the other hand, in  FIG. 13 , on a side more right than each stop blade  203  and the base plate  201  (the other side in the optical axis direction and the other surface side of the base plate  1 ), a driving ring  202  as a blade driving member is illustrated. In the following description, the right side in  FIGS. 13 and 16 , and a side corresponding thereto in the other drawings are each referred to as “a rear side.” 
     As readily illustrated especially in a section of  FIG. 16 , in an outer circumferential portion of the base plate  201 , a ring-shaped flange portion  201   c  to fix the aperture stop apparatus  210  to an inside of a lens barrel of a camera is formed. The flange portion  201   c  is formed as a wall portion extending from an inner side to an outer side in the direction orthogonal to the optical axis direction. In addition, more inside in the direction orthogonal to the optical axis direction than the flange portion  201   c  on the front side of the base plate  201  (one surface side) and around the fixed aperture (aperture portion)  201   a , a blade guide portion  201   b  is formed so as to protrude toward the front side than the flange portion  201   c . A further front end of an outer circumferential surface (front surface) of the blade guide portion  201   b  is formed as a curved surface (part of a spherical surface) located more inside in the direction orthogonal to the optical axis direction. 
     An inner circumferential surface of the blade guide portion  201   b  (which can be referred to also as an inner circumferential surface of the base plate  201 ) is formed as a cylindrical surface parallel to the optical axis direction. However, at each of a plurality of circumferential places of the cylindrical surface, a driving ring supporting convex portion  201   f  described later is formed. In addition, at each of a plurality of circumferential places of the outer circumferential surface of the blade guide portion  201   b  (a blade guide surface at a base member side), a supporting boss portion (protruding portion)  201   e  as a blade supporting portion having a convex shape. In the following description, the outer circumferential surface of the blade guide portion  201   b  is referred to as “a blade guide surface” of the base plate  201 . As illustrated in  FIG. 19 , a center axis BX of each supporting boss portion  201   e  extends in a direction normal to the blade guide surface of the base plate  201  and has a tilt θ1 with respect to the optical axis direction (optical axis AX). 
     On an outer circumferential portion of the driving ring  202 , a flange portion  202   d  to position the driving ring  202  with respect to the base plate  201  in the optical axis direction, in other words, to position the driving ring  202  in a direction of a surface different from the surface on which each supporting boss portion  201   e  is formed, that is, at a rear surface side (the other surface side) of the base plate  201  is formed. The flange portion  202   d  is formed as a wall portion extending from the inner side to the outer side in the direction orthogonal to the optical axis direction. A front surface of the flange portion  202   d  abuts against a driving ring positioning surface  201   d  formed on an inner circumferential portion of the flange portion  201   c  of the base plate  201  by one step deeper than a rear end surface of the flange portion  201   c . It is noted that, on the front surface of the flange portion  202   d  of the driving ring  202 , a protruding portion  202   d ′ is formed to reduce a rotational resistance of the driving ring  202  caused by the abutment against the driving ring positioning surface  201   d  of the base plate  201 . On the other hand, on a rear surface of the flange portion  202   d  of the driving ring  202 , a protruding portion  202   d ″ is formed to reduce the rotational resistance of the driving ring  202  caused by the abutment against a rear cover plate  207  described later. 
     In addition, more inside than the flange portion  202   d  of the driving ring  202  in the direction orthogonal to the optical axis direction, a cylindrical portion  202   c  extending from the flange portion  202   d  toward the front side (optical axis direction). Furthermore, a blade guide portion  202   b  is formed on the front side of the cylindrical portion  202   c , and a fixed aperture  202   a  forming a fully opened aperture is formed on an inner circumferential portion of a front end of the blade guide portion  202   b . In the optical axis direction, the aperture plane of the fixed aperture  202   a  is located on the front side than the fixed aperture (aperture portion)  201   a  of the base plate  201 . An aperture diameter of the fixed aperture  202   a  is smaller than that of the fixed aperture  201   a . The stop aperture (light-passing aperture) formed by each stop blade  203  is adjusted within an aperture diameter smaller than that of the fixed aperture  202   a.    
     A further front end of an outer circumferential surface (front surface) of the blade guide portion  202   b  than a boundary between the outer circumferential surface and that of the cylindrical portion  202   c  as a rear end is formed as the curved surface (part of a spherical surface) located more inside in the direction orthogonal to the optical axis direction. On the other hand, a portion of the inner circumferential surface of the blade guide portion  202   b  close to the cylindrical portion  202   c  is formed as a curved surface similar to the outer circumferential surface of the blade guide portion  202   b , and a portion of the inner circumferential surface of the blade guide portion  202   b  close to the fixed aperture  202   a  is formed as a plane tilted so as to make a thickness of the blade guide portion  202   b  become thinner as being closer to the fixed aperture  202   a.    
     In this manner, the blade guide portion  202   b  of the driving ring  202  is formed so as to have a domical shape convex toward the front side. Inside the cylindrical portion  202   c  and the blade guide portion  202   b  in the direction orthogonal to the optical axis direction, a concave space S is formed that is opened at the rear end of the driving ring  202  and is concave so as to have a depth toward one side continuing up to the inner circumferential surface of the blade guide portion  202   b  in the optical axis direction. A front end of the concave space S faces the fixed aperture  202   a  (that is, the concave space S is opened in the fixed aperture  202   a ). 
     In addition, at each of a plurality of circumferential places of the outer circumferential surface of the blade guide portion  202   b  (the blade guide surface at a driving ring ( 202 ) side), a boss portion (protruding portion)  202   e  as the blade engaging portion having the convex shape is formed. In the following description, the outer circumferential surface of the blade guide portion  202   b  is referred to as “a blade guide surface” of the driving ring  202 . As illustrated in  FIGS. 16 and 19 , when the driving ring  202  is fixed to the base plate  201 , each boss portion  202   e  of the driving ring  202  is located at the front side (one side in the optical axis direction) than each supporting boss portion  201   e  of the base plate  201 . 
     A center axis CX of each boss portion  202   e  has a tilt θ2 with respect to the optical axis direction (optical axis AX), and extends in a direction normal to the blade guide surface of the driving ring  202  in this embodiment. An edge portion of the protruding portion of each boss portion  202   e  is provided more inside in the direction orthogonal to the optical axis direction than the outer diameter (the inner diameter of the base plate  1 ) of the fixed aperture  201   a  so as not to contact with the fixed aperture  201   a . Therefore, the blade guide surface and each boss portion  202   e  of the blade guide portion  202   b  of the driving ring  202  are formed so as to have a diameter within a range equal to or less than the outer diameter of the fixed aperture  201   a  and equal to or more than an outer diameter of the fixed aperture  202   a . This simplified structure makes it possible to dispose the driving ring  202 , which is a member that drives each stop blade  203  to change the light-passing aperture, on the rear side (the other side) of each stop blade  203 . The structure enables fixing the driving ring  202  with use of at least two rear-side positioning portions to allow the driving ring  202  to drive each of the stop blades  203 . This makes it easy to assemble the driving ring  202 . 
     In addition, when driving ring  202  is fixed to the base plate  201 , the blade guide surface of the base plate  201  and the blade guide surface of the driving ring  202  are respectively arranged on the outer side and the inner side in the direction orthogonal to the optical axis direction so as to be located along a continuous curved surface (virtual curved surface). In this embodiment, when symbol R1 represents a curvature radius of the blade guide surface of the base plate  201 , and symbol R2 denotes a curvature radius of the blade guide surface of the driving ring  202 , R1 and R2 satisfy a relation of R2&gt;R1. In other words, from the blade guide surface of the base plate  201  to the blade guide surface of the driving ring  202 , an overall curvature becomes smaller toward the fixed aperture  202   a  of the driving ring  202 . This enables each stop blade  203  to be smoothly rotated when they are rotated being sliding to or approaching the blade guide portion  202   b  of the driving ring  202 . 
     In addition, as described above, while each supporting boss portion  201   e  of the base plate  201  and each cam boss portion  202   e  of the driving ring  202  protrude in a direction tilted toward the outer side in the direction orthogonal to the optical axis direction, the tilt θ1 of each supporting boss portion  201   e  and the tilt θ2 of each boss portion  202   e  satisfy a relation of θ1&gt;θ2 in accordance with the above-described relation of R2&gt;R1. 
     The driving ring  202  is positioned with respect to the base plate  201  in the direction orthogonal to the optical axis direction and rotatably supported around the optical axis AX (that is, in the circumferential direction of the light-passing aperture) by the abutment of the outer circumferential surface of the cylindrical portion  202   c  of the driving ring  202  against the driving ring supporting convex portions  201   f  formed at the plurality of circumferential places of the base plate  201  (the blade guide portion  201   b ). 
     Furthermore, as illustrated in  FIG. 13 , at part of the circumferential places of the flange portion  202   d  of the driving ring  202 , a driven gear  202   f  is formed. 
     Each of the stop blades  203  is, as illustrated in  FIG. 16 , disposed so as to face (be located along) the blade guide surfaces of the base plate  201  and the driving ring  202 . Each stop blade  203  is a thin plate member having a light-blocking property for forming, inside the fixed aperture  202   a  of the driving ring  202 , the stop aperture as the light-passing aperture whose circumference is a light-blocking area. 
       FIG. 17  illustrates details of the shape of each stop blade  203 . Each stop blade  203  includes a light-blocking portion  203   a  as a light-quantity control portion for forming the stop aperture; a stop blade-supported portion  203   b  rotatably supported by the base plate  201 ; and an intermediate portion  203   e  to connect the light-blocking portion  203   a  and the stop blade-supported portion  203   b  to each other. A hole portion (concave portion)  203   c  into which the supporting boss portion  201   e  formed on the base plate  201  is inserted is formed in the stop blade-supported portion  203   b . Each stop blade  203  is rotatable about the supporting boss portion  201   e  and the hole portion  203   c  with respect to the base plate  201  (and the driving ring  202 ). 
     Each light-blocking portion  203   a  is formed in the curved surface shape (spherical surface shape) having a curvature approximately the same as that of the blade guide surface of the driving ring  202 . For this reason, at the time of the rotation of each stop blade  203 , each light-blocking portion  203   a  is moved in a direction to advance and retract into and from a radially inside area of the fixed aperture  202   a  of the driving ring  202 , being sliding to or approaching the blade guide surface of the driving ring  202 , that is, being guided by the blade guide surface. The movement of the light-blocking portion  203   a  of each of the stop blades  203  in this manner changes a size of the stop aperture (stop aperture diameter) formed by the light-blocking portions  203   a . Thereby, quantity of light passing through the stop aperture is controlled. In the following description, a rotation direction of each stop blade  203  for increasing and decreasing the stop aperture diameter is referred to also as “an opening/closing direction” of each stop blade  203 . 
     In addition, the intermediate portion  203   e  and the stop blade-supported portion  203   b  of each stop blade  203 , that is, at least a portion on a stop blade-supported portion ( 203   b ) side than the light-blocking portion  203   a  has a tilt α with respect to the aperture plane (the direction orthogonal to the optical axis direction)  206   a  of the stop aperture in the optical axis direction. The tilt α is an angle of certain degrees including 90°. Giving the tilt α to the intermediate portion  203   e  and the stop blade-supported portion  203   b  causes the light-blocking portion  203   a  to be located distant from the stop blade-supported portion  203   b  in the optical axis direction. In each stop blade  203  of this embodiment, while the light-blocking portion  203   a  has the tilt with respect to the aperture plane  206   a , the intermediate portion  203   e  and the stop blade-supported portion  203   b  each has a larger tilt with respect to the aperture plane  206   a  of the stop aperture in the optical axis direction than that of the light-blocking portion  203   a . It is noted that the tilts corresponding to when the light-blocking portion  203   a , the intermediate portion  203   e  and the stop blade-supported portion  203   b  each have the curved surface shape can each be considered as a tilt of a tangent to the portions. 
     In addition, on each light-blocking portion  203   a , a cam groove portion (concave portion)  203   d  as an engaged portion into which the boss portion  202   e  formed on the driving ring  202  is inserted so as to be engaged therewith. As described above, the center axis CX of each boss portion  202   e  extends in the direction normal to the blade guide surface of the driving ring  202 . For this reason, compared to a case where the center axis CX of each boss portion  202   e  extends in the optical axis direction, each boss portion  202   e  can smoothly move in the cam groove portion  203   d , and each light-blocking portion  203   a  (that is, each stop blade  203 ) can be rotated in the opening/closing direction with good positioning accuracy. The provision of the blade guide surface not only to the driving ring  202   a , but also to the base plate  201  enables even the stop blade-supported portion  203   b  of each stop blade  203  to be smoothly rotated. It is noted that the blade guide surface of the driving ring  202   a  (and the base plate  201 ) may be formed not in the spherical surface shape, but in a truncated conical surface shape. 
     Furthermore, the center axis BX of each supporting boss portion  201   e  inserted into the hole portion  203   c  formed in the stop blade-supported portion  203   b  extends in the direction normal to the blade guide surface of the base plate  201 . For this reason, each stop blade  203  can be smoothly rotated, compared to a case where the center axis BX of each supporting boss portion  201   e  extends in the optical axis direction. It is noted that the direction in which each supporting boss portion  201   e  is tilted with respect to the optical axis direction and the direction in which each boss portion  202   e  is tilted with respect to the optical axis direction are not necessarily required to be the direction normal to the blade guide surface of the base plate  201  and the direction normal to the blade guide surface of the driving ring  202 , respectively. 
     It is also noted that an entire part of each stop blade  203  from the stop blade-supported portion  203   b  to the light-blocking portion  203   a  may be formed in the curved surface shape (spherical surface shape). 
     Similarly to the aperture stop apparatus of this embodiment, in a case where the driving ring  202   a  has the domical shape, and each stop blade  203  is disposed along an outer surface of the domical shape, a configuration is possible in which the driving ring  202  and each stop blade are fixed to the base plate  201  in this order from the same side (front side) in the optical axis direction (hereinafter, referred to as “a comparative example”). However, in the comparative example, it is necessary to provide a portion to position the driving ring  202  in the optical axis direction and in the direction orthogonal to the optical axis direction, on the outer side of the base plate  201  in the direction orthogonal to the optical axis direction than each supporting boss portion provided on the side (front side). Otherwise, it is necessary to provide a portion extending toward the inner side in the direction orthogonal to the optical axis direction than an outer circumference (outer edge) of the portion on which each boss portion serving as the cam of the driving ring  202   a  is provided, in order to position the driving ring  202   a  in the optical axis direction and in the direction orthogonal to the optical axis direction at a side (rear side) opposite to the side (front side) on which each boss portion serving as the cam of the driving ring  202   a  is provided. This results in an increase in size of the aperture stop apparatus in the optical axis direction and the direction orthogonal to the optical axis direction (radial direction) and in a decrease in diameter and depth of the concave space. 
     In contrast to this, in this embodiment, in the optical axis direction, the driving ring  202  is fixed to the base plate  201  from a direction (the rear side, which is the other surface side) opposite to the direction (from the front side, which is one surface side) in which each stop blade  203  is fixed to the base plate  201 . This makes it possible to use the driving ring positioning surface  201   d , which is a portion of the base plate  201  provided on the side (rear side) opposite to the side (front side) on which each supporting boss portion  201   e  is provided, for the positioning of the driving ring  202  with respect to the base plate  201  in the optical axis direction. Furthermore, in this embodiment, the driving ring supporting convex portion  201   f  provided in the direction orthogonal to the optical axis direction on the inner side (inner circumferential surface) of the blade guide portion  201   b , which is a portion of the base plate  201  on which each supporting boss portion  201   e  is provided, abuts against the outer circumferential surface of the cylindrical portion  202   a , which is a portion extending backward from (outermost circumferential portion of) the blade guide portion  202   b , which is a portion of the driving ring  202  on which each boss portion  202   e  is provided. This makes it possible to position the driving ring  202  with respect to the base plate  201  in the optical axis direction. 
     For this reason, according to this embodiment, it is not necessary to provide the portion to position the driving ring  202  in the optical axis direction and in the direction orthogonal to the optical axis direction, on the outer side of the base plate  201  in the direction orthogonal to the optical axis direction than each supporting boss portion  201   e . This enables miniaturizing the base plate  201 . Moreover, it is not necessary to form, on the base plate  201 , a portion extending toward the inner side in the direction orthogonal to the optical axis direction than an outer edge of the blade guide surface on which each cam boss portion  202   e  of the driving ring  202  is provided, in order to position the driving ring  202  in the optical axis direction and in the direction orthogonal to the optical axis direction at a portion opposite to the side on which each boss portion  202   e  of the driving ring  202  is provided. This enables miniaturizing the base plate  201 . 
     In addition, a portion at which each stop blade  203  and the driving ring  202  are engaged with each other is located on a fixed aperture ( 201   a ) side than each supporting boss portion  201   e  (an outer side in the direction orthogonal to the optical axis direction than the fixed aperture  202   a ), which enables rotating each stop blade  203  with the simplified structure. Therefore, particularly in a case where the stop blades forming the concave space are used similarly to this embodiment, it is possible to, compared to the comparative example, increase a diameter and a depth of the concave space S while reducing the size of the aperture stop apparatus in the optical axis direction and in the direction orthogonal to the optical axis direction (radial direction). 
     A front cover plate (first cover member)  204  is disposed on the front side than the base plate  201  and forms a stop blade room for housing each stop blade  203  between the front cover plate  204 , and the base plate  201  and the driving ring  202  (the blade guide portion  202   b ). On an inner circumferential portion of the front cover plate  204 , a domical portion (blade cover portion)  204   b  having a domical shape convex toward the front side is formed. The domical portion  204   b  has a curved surface shape (spherical surface shape) with a curvature approximately the same as that of the blade guide surface of the driving ring  202 . On a front end of the domical portion  204   b , a fixed aperture  204   a  is formed whose diameter is larger than that of the fixed aperture  202   a  of the driving ring  202  and smaller than that of the fixed aperture  201   a  of the base plate  201 . The front cover plate  204  is, at its outer circumferential portion, coupled with the base plate  201  using screws, and thereby the front cover plate  204  is integrated with the base plate  201 . The front cover plate  204  may be fixed to the base plate  201  not by using the screws, but by thermal calking. 
     Reference numeral  205  denotes a driver including an actuator such as a stepping motor. A driving gear  205   a  engaged with the driven gear  202   f  of the driving ring  202  is fixed to an output shaft of the driver  205 . The driver  205  is fixed to the base plate  201  through a motor base plate  205   b . Specifically, the driver  205  is fixed to the flange portion  201   c  of the base plate  201  by screws  206  across a flange portion located on the outer side of the front cover plate  204  in the direction orthogonal to the optical axis direction than the domical portion  204   b . That is, the driver  205  is provided so as to protrude in the same direction as that in which the blade guide portion  202   b  of the driving ring  202 , each stop blade  203  and the domical portion  204   b  of the front cover plate  204  protrude toward a circumferential portion thereof (hereinafter, referred to as “a domical portion protruding direction”), from the circumferential portion. The disposition of the driver  205  in the domical portion protruding direction than the base plate  201  enables, when the aperture stop apparatus  210  is installed in the optical apparatus such as the camera similarly to Embodiment 4 described later, effectively using a space in the optical apparatus (in particular, a space opposite to the domical portion protruding direction with respect to the aperture stop apparatus  210 ). This enables miniaturizing the optical apparatus. 
     A rear cover plate (second cover member)  207  is disposed on the rear side than the base plate  201  and is fixed to the flange portion  201   c  of the base plate  201  by using the screws so as to cover a rear surface of each of the flange portion  201   c  of the base plate  201  and the flange portion  202   d  of the driving ring  202 . On an inner circumferential portion of the rear cover plate  207 , a fixed aperture  207   a  having an inner diameter approximately the same as the inner diameter of the flange portion  202   d  of the driving ring  202 . The fixed aperture  207   a  serves as a rear end aperture of the concave space S. In addition, the rear cover plate  207  abuts against the protruding portion  202   d ″ formed on the rear surface of the flange portion  202   d  of the driving ring  202  to retain the driving ring  202  forward with respect to the base plate  201  (prevent the driving ring  202  from dropping off rearward from the base plate  201 ). The rear cover plate  207  may be fixed to the base plate  201  not by the screws, but by the thermal calking. 
       FIG. 14  illustrates the aperture stop apparatus  210  with the above-described configuration that has been assembled.  FIGS. 15A and 15B  illustrate the base plate  201  to which the driving ring  202  and the driver  205  are fixed, as viewed from the front side and the rear side, respectively. 
     Furthermore,  FIGS. 18A ,  18 B and  18 C illustrate an operation of the aperture stop apparatus  210  of this embodiment.  FIG. 18A  illustrates the operation of the aperture stop apparatus  210 , and  FIGS. 18B and 18C  illustrate one stop blade  203  being rotated, as viewed from the front side and the rear side of the aperture stop apparatus  210 , respectively. 
     When the driver  205  is energized and thereby the driving gear  205   a  is rotated, a rotational force from the driver  205  is transmitted to the stop driving ring  202  through the driven gear  202   f  and rotates the stop driving ring  202  about the optical axis AX with respect to the base plate  201 . With the rotation of the stop driving ring  202 , each cam boss portion  202   e  provided in the stop driving ring  202  moves in the cam groove portion  203   d  formed in the light-blocking portion  203   a  of each stop blade  203 . Therefore, each stop blade  203  is rotated in the opening/closing direction about the supporting boss portion  201   e  inserted into the hole portion  203   c  of the stop blade-supported portion  203   b . The rotation of each of the stop blades  203  in this manner changes the size of the stop aperture A formed by the light-blocking portions  203   a  of the stop blades  203 . Thereby, quantity of the light passing through the stop aperture is controlled. 
     It is noted that although this embodiment described the case where each supporting boss portion  201   e  formed on the base plate  201  and each cam boss portion  202   e  formed on the driving ring  202  are respectively inserted into the hole portion  203   c  and the cam groove portion  203   d  both formed on each stop blade  203 , boss portions corresponding to the supporting boss portions  201   e  and boss portions corresponding to the cam boss portions  202   e  may be formed on each stop blade  203  and may be respectively inserted into the hole portions  203   c  formed on the base plate  201  and the cam groove portions  203   d  formed on the driving ring  202 . 
     It is also noted that although this embodiment described the case where the blade guide portion  202   b  of the driving ring  202  is formed in the curved surface shape (spherical surface shape) continuous in the circumferential direction, the blade guide portion  202   b  may be formed in a plurality of radially rails extending in the direction orthogonal to the optical axis direction. 
     It is moreover noted that this embodiment described the case where the driving ring  202   a  has the domical shape and each stop blade  203  is disposed along the outer surface of the domical shape, each boss portion formed on the driving ring and each supporting boss portion formed on the base plate may have an approximately the same height by using flat-shaped stop blades. In this configuration, it is enough that each supporting boss portion of the base plate and each boss portion of the driving ring are formed so as to extend in the optical axis direction, the supporting boss portion of the hole portion of each stop blade-supported portion of the base plate is inserted from the optical axis direction, and each boss portion of the driving ring is inserted into the hole portion of each stop blade from the optical axis direction. In this configuration, the stop blades are disposed so as to overlap with one another over the base plate and the driving ring in the optical axis direction and are supported by the base plate and the driving ring at the two points on one surface side in the optical axis direction. This enables the stop blades to be stably rotated in the direction orthogonal to the optical axis direction. 
     It is noted that the light-quantity control apparatuses described in (1) and (2) above may have the following alternative configurations. 
     (3) A light-quantity control apparatus according to (1), in which the blade driving member is fixed to the base member from, of an optical axis direction, a direction opposite to a direction in which the light-quantity control blade is fixed to the base member. 
     (4) A light-quantity control apparatus according to (1) or (3), in which the light-quantity control blade has a shape in which the light-quantity control portion is located distant from the supported portion at one side in the optical axis direction such that a concave space having a depth toward the aperture portion more inside in a direction orthogonal to the optical axis direction than the light-quantity control blade is formed. 
     (5) A light-quantity control apparatus according to (2), in which the blade driving member abuts against a portion of the base member opposite to a side on which the blade supporting portion is provided and is thereby positioned with respect to the base member. 
     (6) A light-quantity control apparatus according to (2) or (5), in which, in a direction orthogonal to the optical axis direction, the blade driving member is positioned with respect to the base member by abutment of a portion extending in the optical axis direction from a portion of the blade driving member on which the blade engaging portion is provided against an inner side of a portion of the base member on which the blade supporting portion is provided. 
     (7) A light-quantity control apparatus according to any one of (2), (5) and (6), in which the blade driving member is fixed to the base member such that the blade engaging portion is located on the one side than the blade supporting portion. 
     (8) A light-quantity control apparatus according to (7), in which: at least the light-quantity control portion of the light-quantity control blade has a curved surface shape; the base member and the blade driving member are each a surface on which the light-quantity control blade is rotated being sliding or approaching and respectively have a base-member-side blade guide surface and a driving-member-side blade guide surface, both of which has a curved surface shape; the base-member-side blade guide surface and the driving-member-side blade guide surface are respectively disposed on an outer side and an inner side in the direction orthogonal to the optical axis direction; and a curvature radius of the driving-member-side blade guide surface is larger than a curvature radius of the base-member-side blade guide surface. 
     (9) A light-quantity control apparatus according to any one of (4) to (8), in which: of the light-quantity control blade, the supported portion and an engaged portion with which the blade engaging portion is engaged each has a tilt with respect to the aperture plane in the optical axis direction; one of the supported portion and the blade supporting portion is formed as a protruding portion inserted into a concave portion of the other; one of the engaged portion and the blade engaging portion is formed as a protruding portion inserted into a concave portion of the other; and each of the protruding portions is formed so as to be tilted with respect to the optical axis direction. 
     (10) A light-quantity control apparatus according to any one of (1) to (9), in which the blade engaging portion between the light-quantity control blade and the blade driving member are constituted by an engaging portion provided on the blade driving member and an engaged portion of the light-quantity control blade; and the engaging portion provided on the blade driving member is constituted by a protruding portion provided on an inner side of the aperture portion. 
     Embodiment 4 
       FIG. 28A  illustrates a camera (video camera or still camera) as an optical apparatus on which the light-quantity control apparatus (aperture stop apparatuses  110  or  210  or aperture stop/shutter apparatus  10 ) described in Embodiments 1 to 3 is mounted. Reference numeral  50  denotes a camera body (optical apparatus body), and reference numerals  51  and  53  denote a plurality of lenses included in an image pickup optical system. The image pickup optical system is housed in a lens barrel of the camera body  50 . Reference numeral  52  denotes an image sensor that includes a CCD sensor and a CMOS sensor and photoelectrically converts an object image formed through the image pickup optical system. 
     Reference numeral  54  denotes a controller that includes a CPU and controls operations of the driver ( 105 ,  5 ,  205 ) of the light-quantity control apparatus ( 110 ,  10 ,  210 ) and the image sensor  52 . 
     In such a camera, as illustrated in  FIGS. 3 ,  8  and  16 , at least part of the lens  51  (convex surface) arranged adjacently to the light-quantity control apparatus in the optical axis direction can be inserted into the concave space S of the light-quantity control apparatus ( 110 ,  10 ,  210 ).  FIGS. 3 ,  8  and  16  illustrate that an opening into the concave space S for the lens  51  opens toward an image plane side, and the lens  51  (and a lens holder  52  holding the lens  51  in  FIG. 8 ) arranged adjacently to the light-quantity control apparatus and closer to the image plane side than the light-quantity control apparatus is inserted into the concave space S. 
     The opening into the concave space S for a lens may open toward an object side so as to allow the lens  53  arranged adjacently to the light-quantity control apparatus and closer to the object side than the light-quantity control apparatus to be inserted into the concave space S. 
     Such an arrangement enables the image pickup optical system of the camera to be downsized in the optical axis direction, in particular. 
     A size (inner diameter) of the back-end aperture as the opening into the concave space S for the lens  51  basically depends on a circle passing through the supported portions (supporting boss portion) of the stop blades and does not depend on the size of the stop aperture formed by the stop blades. Thus, when the stop aperture is narrowed down, the lens can be inserted into the concave space S without opening the stop aperture to a fully-opened aperture diameter or beyond that. This eliminates the need for increasing a maximum diameter of the stop aperture in accordance with the outer diameter of the lens  51 , thereby preventing a size of the light-quantity control apparatus having an inner space in which the lens can be inserted from increasing in the direction (radial direction) orthogonal to the optical axis. 
       FIGS. 3 ,  8  and  16  illustrate that a convex surface (domical shape surface) on the object side of the cover plate ( 104 ,  4 ,  204 ) of the light-quantity control apparatus ( 110 ,  10 ,  210 ) and a concave surface on the image plane side of the lens  53  disposed closer to the object side than the convex surface are close to each other. Thereby, it is possible to arrange the stop blades  103  and  3  and the shutter blades  21  and  22  in a narrow space between the convex surface on the object side of the lens  51  and the concave surface on the image plane side of the lens  53 . 
     As illustrated with arrows in  FIGS. 3 and 8 , while the light-quantity control apparatus ( 110 ,  10 ,  210 ) is close to the lenses  51  and  53  on both sides thereof, the lens barrel holding the image pickup optical system may be housed (retracted) in the camera body. 
     The light-quantity control apparatus ( 110 ,  10 ,  210 ) can be mounted not only on the camera illustrated in  FIG. 28A  but also on any other optical apparatus such as an interchangeable lens. 
     Embodiment 5 
     An optical apparatus such as a camera is necessary to have compactness. In particular, when a lens barrel for holding an image taking lens protrudes from a camera body in its optical axis direction, it is necessary to reduce a length of the lens barrel in the optical axis direction as short as possible. Some image taking lens includes a light-quantity control apparatus (aperture stop apparatus or aperture stop/shutter apparatus) that controls quantity of light reaching at an image plane, and an optical image stabilizing apparatus that shifts a correcting lens in a direction orthogonal to the optical axis to reduce image blur due to hand shake. 
     Japanese Patent Laid-open No. 2007-94074 discloses a light-quantity control apparatus in which a light-quantity control blade including a protruding portion having a curved surface shape (spherical surface shape) slides in a direction orthogonal to an optical axis direction so as to change a size of an opening through which light passes. The protruding portion included in the light-quantity control blade forms a concave space (semispherical space) in which a lens is housed. This enables the image taking lens (lens barrel) to have a shorter length in the optical axis direction. 
     In the apparatus disclosed in Japanese Patent Laid-open No. 2007-94074, the light-quantity control blade is retracted in the direction orthogonal to the optical axis direction, facilitating downsizing in the optical axis direction. However, a retraction space for the light-quantity control blade is necessary to have a thickness larger than that of the light-quantity control blade including the protruding portion, which makes it difficult to provide other drivers. 
     Thus, light-quantity control apparatuses described below are required. 
     (1) A light-quantity control apparatus includes a light-quantity control blade movable along a curved path formed between a first optical member and a second optical member, and an apparatus body including a blade driver configured to drive the light-quantity control blade along the curved path. The apparatus body is provided with a shake correction unit. 
     (2) A light-quantity control apparatus includes a base member; a light-quantity control blade including a light-quantity controller to form a light-passing aperture and a supported portion rotatably supported by the base member; a rotational driving member rotatably supported in a circumferential direction of the light-passing aperture by the base member and configured to rotate to rotate the light-quantity control blade; a blade driver configured to rotate the rotational driving member; and a shake correction driver configured to shift, when a direction orthogonal to an aperture plane of the light-passing aperture is defined as an optical axis direction, an optical material that shifts with respect to the base member in the direction orthogonal to the optical axis direction to reduce image blur. The light-quantity control blade has such a shape that the light-quantity controller is located distant from the supported portion in the optical axis direction so as to form a concave space having a depth from the light-quantity control blade toward the light-passing aperture. The blade driver and the shake correction driver are arranged at positions different from each other in a plane orthogonal to the optical axis direction and on a side opposite with respect to the base member in the optical axis direction to a side on which the light-quantity control blade is arranged. At least part of the optical material is disposed inside the concave space and configured to shift inside the concave space. 
     According to the light-quantity control apparatus described in each of (1) and (2), applying a light-quantity control blade having a curved surface shape and providing an shake correction unit suitable for the light-quantity control blade can achieve downsizing in the optical axis direction, a light-quantity control function and an shake correction function. This can thus achieve downsizing of an optical apparatus on which the light-quantity control apparatus is mounted. 
       FIGS. 20 and 21  illustrate an aperture stop apparatus  310  as a light-quantity control image stabilizing apparatus in Embodiment 5 of the present invention. This aperture stop apparatus  310  includes an iris aperture stop mechanism and a shake correction mechanism (optical image stabilizing mechanism). In  FIGS. 20 and 21 , reference numeral  301  denotes a base plate as a ring shaped base member in which central portion an opening  306  is formed. Hereinafter, the optical axis AX is defined as an axis that passes centers of an opening plane of the opening  306  and aperture planes of fixed apertures and a stop aperture described later and is orthogonal to the planes. A direction in which the optical axis AX extends is defined as an optical axis direction. In addition, the radial direction is defined as a direction orthogonal to the optical axis direction. In  FIGS. 20 and 21 , a left side (one side in the optical axis direction, a side on one surface of the base plate  301 ) is referred to as a “front side”, and a right side (the other side in the optical axis direction, a side on the other surface of the base plate  301 ) is referred to as a “rear side”. 
     The base plate  301  has a ring portion that surrounds the opening  306  and on which stop blade-supporting boss portions (protruding portions)  307  as blade support portions are formed at a plurality of positions in a circumferential direction. A center axis BX of each stop blade-supporting boss portion  307  has a tilt angle θB with respect to the optical axis direction (optical axis AX). 
     Reference numeral  302  denotes a stop driving ring as a rotational driving member. The stop driving ring  302  includes a domical wall portion  302   a  formed in a domical shape that is concave toward the base plate  301  (opening  306 ) (in other words, convex toward an opposite side to the base plate  301 ). The domical wall portion  302   a  has a fixed aperture  312  formed on its innermost circumferential portion (diametric center portion). The stop driving ring  302  has a driven gear  302   b  formed on part of its outer circumferential side portion than the domical wall portion  302   a , the part being along the circumferential direction. A concave surface of the domical wall portion  302   a  closer to the base plate  301 , and a convex surface (hereinafter, referred to as a stop guide surface)  302   c  opposite to the concave surface are each formed in a curved surface shape (for example, a spherical surface shape). An aperture plane of the fixed aperture  312  is located more distant from the base plate  301  (opening plane of the opening  306 ) in the optical axis direction than an outer circumference edge of the domical wall portion  302   a  of the stop driving ring  302 . In other words, the domical wall portion  302   a  of the stop driving ring  302  is formed so as to protrude in a direction distant from the base plate  301  in the optical axis direction (that is, so as to have a shape that is concave toward one side in the optical axis direction from the outer circumferential side portion of the stop driving ring  302  to its inner circumferential side). 
     The stop guide surface  302   c  of the domical wall portion  302   a  has boss portions (protruding portions)  308  as convex blade-engaging members formed at a plurality of positions (a plurality of positions around the fixed aperture  312 ) in the circumferential direction. A center axis CX of each boss portion  308  has a tilt angle θC with respect to the optical axis direction (optical axis AX) so as to extend in a direction normal to the stop guide surface  302   c.    
     Reference numeral  303  denotes a stop blade as a light-quantity control blade and is one of a plurality (six) of light-quantity control blades provided in this embodiment. The stop blade  303  is a thin plate member having a light-blocking property to form a stop aperture A as a light-passing aperture around which light is blocked at an inner position along a direction orthogonal to the optical axis direction than the fixed aperture  312  formed on the stop driving ring  302 . 
     As illustrated in detail in  FIG. 25 , the stop blade  303  includes a stop portion  303   a  as a light-quantity controller to form the stop aperture A, and a supported portion  303   c  provided with a hole portion  303   c  into which the stop blade-supporting boss portion  307  of the base plate  301  is inserted. A supported portion  303   b  (that is, the stop blade  303 ) is supported rotatably about the stop blade-supporting boss portion  307  by the base plate  301  when the stop blade-supporting boss portion  307  is inserted in the hole portion  303   c . The stop blade  303  further includes an intermediate portion  303   e  connecting the stop portion  303   a  and the supported portion  303   b.    
     Each stop blade  303  is disposed to face (or extend along) the stop guide surface  302   c  of the domical wall portion  302   a  of the stop driving ring  302 . The stop portion  303   a  is formed in a curved surface shape (for example, a spherical surface shape) having approximately the same curvature as that of the stop guide surface  302   c  of the domical wall portion  302   a . Therefore, when the stop blade  303  is rotated, the stop portion  303   a  is rotated in a direction to advance and retract in an inside region (a region facing the fixed aperture  312 ) in a direction orthogonal to the optical axis direction of the fixed aperture  312  along the stop guide surface  302   c  while the stop portion  303   a  is guided by the stop guide surface  302   c . This changes a size of the stop aperture. Hereinafter, a direction of the rotation of the stop blade  303  is referred to as a stop opening/closing direction. 
     The intermediate portion  303   e  and the supported portion  303   b  of each stop blade  303 , that is, at least part of the stop blade  303  closer to the supported portion  303   b  than the stop portion  303   a  has a tilt α in the optical axis direction with respect to the opening plane (denoted by reference numeral  306   a  in  FIG. 25 ) of the opening  306  of the base plate  1 . Since this tilt α corresponds to a tilt with respect to the aperture plane of the fixed aperture  312  formed on the stop driving ring  302 , an aperture plane of a fixed aperture formed on a stop cover plate described later, and an aperture plane of the stop aperture A, and each aperture plane is aligned along the direction orthogonal to the optical axis direction, the tilt is with respect to the radial direction. 
     The tilt α is set to be equal to or smaller than 90°. Giving the tilt α to the intermediate portion  303   e  and the supported portion  303   b  causes the stop portion  303   a  to be located distant from the supported portion  303   b  in the optical axis direction. In addition, a center axis of the hole portion  303   c  formed on the supported portion  303   b  has a tilt with respect to the optical axis AX so as to match a center axis BX of the stop blade-supporting boss portion  307 . Therefore, it is possible to more smoothly rotate the stop blade  303  compared to a case where the center axis of the stop blade-supporting boss portion  307  extends in the optical axis direction. 
     In this embodiment, the stop portion  303   a  has a tilt (tilt of a tangent line of the stop portion  303   a  in the curved surface shape) with respect to the opening plane  306   a . The intermediate portion  303   e  and the supported portion  303   b  have larger tilts in the optical axis direction with respect to the opening plane  306   a  (the radial direction) than the stop portion  303   a . In other words, the stop portion  303   a  has a smaller tilt in the optical axis direction with respect to the opening plane  306   a  than the tilt of the supported portion  303   b . The entire stop blade  303  from the supported portion  303   b  to the stop portion  303   a  may be formed in a curved surface shape (for example, a spherical surface shape). 
     In addition, a cam groove  303   d  in which the cam boss portion  308  formed on the stop driving ring  302  is inserted and which engages therewith is formed in the stop blade  303 . As described above, the center axis CX of the cam boss portion  308  extends in the direction normal to the stop guide surface  302   c . Thus, the cam boss portion  308  can move more smoothly in the cam groove  303   d  compared to a case where the center axis of the cam boss portion  308  extends in the optical axis direction, so as to accurately rotate the stop portion  303   a  (that is, the stop blade  303 ) in the stop opening/closing direction. The stop portion  303   a  is formed in a curved surface shape (for example, a spherical surface shape), and the stop guide surface  302   c  may be formed in a truncated conical surface shape instead of a curved surface shape. 
     In  FIG. 20  and In  FIG. 21 , reference numeral  304  denotes a stop cover plate (stop cover member) that is disposed on an opposite side to the base plate  301  with respect to the stop driving ring  302  and the stop blade  303  and forms a stop blade room to house the stop blade  303  between the stop cover plate  304  and the stop driving ring  302  (domical wall portion  302   a ). The stop cover plate  304  includes a domical wall portion  304   a  formed in a domical shape that is concave toward the base plate  301  (opening  306 ) (in other words, convex toward an opposite side to the base plate  301 ), and a ring portion formed on an outer circumference of the domical wall portion  304   a . The domical wall portion  304   a  is formed in a curved surface shape (for example, a spherical surface shape) having approximately the same curvature as that of the domical wall portion  302   a  of the stop driving ring  302 . An apparatus body of the aperture stop apparatus  310  includes the base plate  301  and the stop driving ring  302  and houses the stop blade  303  at least. 
     A fixed aperture  313  is formed in an innermost circumferential portion (center portion in a direction orthogonal to the optical axis direction) of the domical wall portion  304   a . In the optical axis direction, an aperture plane of the fixed aperture  313  is located distant from the base plate  301  (opening  306 ) relative to an outer circumferential edge portion (ring portion) of the domical wall portion  304   a . That is, the domical wall portion  304   a  of the stop cover plate  304  is formed so as to protrude in a direction distant from the base plate  301  in the optical axis direction. 
     The stop cover plate  304  is integrated with the base plate  301  by connecting the ring portion of the stop cover plate  304  to the base plate  301  by a screw. Thus, similarly to the base plate  301 , the stop cover plate  304  can be treated as a base member. 
     Reference numeral  305  denotes a stop driver (blade driver) including an actuator such as a stepping motor. A driving gear  305   a  meshing with the driven gear  302   b  of the stop driving ring  302  is fixed to an output shaft of the stop driver as illustrated in FIG.  26 A. The stop driver  305  is fixed (installed) to the base plate  301  via a motor base plate  305   b . The stop driver  305  is disposed on a plane orthogonal to the optical axis direction on an opposite side to the stop cover plate  304  with respect to the base member as the base plate  301 . In other words, the stop driver  305  is disposed so as to protrude in an opposite direction to a convex shape of the stop cover plate  304 . 
     When the stop driver  305  is energized and thereby the driving gear  305   a  is rotated, as illustrated in  FIGS. 26A and 26B , a rotational force from the stop driver  305  is transmitted to the stop driving ring  302  through the driven gear  302   b  and the driving gear  305   a  and rotates the stop driving ring  302  about the optical axis AX (around the light-passing aperture) with respect to the base plate  301 . With the rotation of the stop driving ring  302 , the cam boss portion  308  provided in the stop driving ring  302  moves in the cam groove  303   d  formed in the stop portion  303   a  of each stop blade  303 . Therefore, each stop blade  303  is rotated in the stop opening/closing direction about the stop blade-supporting boss portion  307  inserted into the hole portion  303   c  of the supported portion  303   b . In this manner, the rotation of the stop portion  303   a  of the stop blades  303  (only one stop blade  303  is illustrated in  FIGS. 26A and 26B ) in the stop opening/closing direction changes a diameter of the stop aperture A formed by the stop portions  303   a , which increases and decreases (controls) a quantity of light passing through the stop aperture A. 
     It is noted that, although this embodiment described the case where (the center axis BX of) the stop blade-supporting boss portion  307  formed in the base plate  301  and (the center axis CX of) the cam boss portion  308  formed in the stop driving ring  302  are tilted with respect to the optical axis direction, the stop blade-supporting boss portion  307  and the cam boss portion  308  may be formed to extend in parallel with the optical axis direction as long as the stop blade  303  (supported portion  303   b ) is rotated with respect to a virtual axis tilted with respect to the optical axis direction. 
     Moreover, a domical wall portion similar to the domical wall portion  304   a  of the stop cover plate  304  may be formed in the base plate  301 , and a fixed aperture may be formed in the domical wall portion. In addition, a cam boss portion to be inserted into the cam groove may be formed in an inner surface (concave surface) of the domical wall portion, and a stop blade-supporting boss portion may be formed in the rotatable stop driving ring  2 . In this case, the stop blade-supporting boss portion formed in the stop driving ring  302  is inserted into the hole portion  303   c  formed in the stop blade  303 , and the cam boss portion formed in the domical wall portion of the base plate  301  is inserted into the cam groove  303   d . Also in such a configuration, rotating the stop driving ring  302  can rotate the stop blade  303  in the stop opening/closing direction. 
     In this manner, as long as relative positions of the stop blade-supporting boss portion and the cam boss portion respectively inserted into the hole portion  303   c  and the cam groove  303   d  of the stop blade  303  are changeable, any one of the stop blade-supporting boss portion and the cam boss portion may be formed in the base plate  301  and the other thereof may be formed in the stop driving ring  302 . Even when the stop driving ring  302  directly supports the stop blade-supported portion  303   b  of the stop blade  303  in this manner, it is common that the stop blade-supported portion  303   b  is rotatably supported with respect to the base plate  301 . 
     Although this embodiment described the case where the stop blade-supporting boss portion  307  formed in the base plate  301  and the cam boss portion  308  formed in the stop driving ring  302  are respectively inserted into the hole portion  303   c  and the cam groove  303   d  formed in the stop blade  303 , a boss portion corresponding to the stop blade-supporting boss portion  307  and a boss portion corresponding to the boss portion  308  may be formed in the stop blade  303  to insert them into a hole portion formed in the base plate  301  and a cam groove formed in the stop driving ring  302 . 
     In the aperture stop apparatus  310  in this embodiment including the shake correction mechanism, as described above, the stop blade  303  has such a shape that the stop portion  303   a  is located distant from the supported portion  303   b  in the optical axis direction. Thus, as illustrated in  FIG. 22A  and  FIG. 22B  of an enlarged view of part of  FIG. 22A , when a space between a concave lens  353  as the first optical member and a correcting lens  351  as the second optical member described later and a shift frame  327  is referred to as a concave space SA, a curved path through which the stop blade  303  moves is formed in the concave space SA. An opening is formed across the circumferential direction at end portions of the first and second optical members, and the stop blade  303  driven by the stop driver moves in the concave space SA in the opening. A concave shake correction space Sa having a depth from the opening  306  of the base plate  301  toward the stop aperture (light-passing aperture) A and the fixed apertures  312  and  313  is formed more inside in the direction orthogonal to the optical axis direction than the stop blade  303 . 
     In practice, the shake correction space Sa is formed more inside in the direction orthogonal to the optical axis direction than the stop driving ring  302 . An opening (back-end opening) on the base plate  301  side of the shake correction space Sa is connected with an inner space of the opening  306  of the base plate  301 . The shake correction space Sa has a convex shape toward a front side thereof and houses at least part (in this embodiment, a convex surface on the front side) of the correcting lens  351  described later that is disposed inside the opening  306  of the base plate  301 . The shake correction space Sa is included in the concave space SA that houses at least part of the correcting lens  351 . 
     Next, with reference to  FIGS. 20 and 24 , a description will be made of the shake correction mechanism of the aperture stop apparatus  310  in this embodiment, and an electric system (image stabilizing system) provided to an optical apparatus on which the aperture stop apparatus  310  is mounted to operate the shake correction mechanism.  FIG. 24  illustrates the aperture stop apparatus  310  when viewed from a right side (rear side) in  FIG. 20 . 
     First, a description will be made of an optical shake correction mechanism. Hereinafter, shake correction is also referred to as image stabilization. Reference numeral  327  denotes a shift frame holding the correcting lens  351  as an image stabilizing optical element and disposed movable in a pitch (vertical) direction and a yaw (horizontal) direction that are orthogonal to the optical axis direction on an opposite side to the stop driving ring  302  and the stop blades  303  with respect to the base plate  301 . A pitch magnet  321   p  and a yaw magnet  321   y  are attached to the shift frame  327  with their phases being 90° different from each other around the optical axis AX. Reference numeral  322   p  denotes a pitch coil, and reference numeral  322   y  denotes a yaw coil. The pitch and yaw coils  322   p  and  322   y  are attached at positions different from that of the stop driver  305  around the optical axis AX in a plane orthogonal to the optical axis direction on an opposite side to a surface of the base plate  301  on which the stop driving ring  302  and the stop blade  303  are disposed, that is, the surface to which the stop driver  305  is attached. The pitch and yaw coils  322   p  and  322   y  are attached at such positions that their phases are 90° different from each other. As illustrated in  FIG. 24 , the shift frame  327  is disposed such that the pitch magnet  321   p  and the yaw magnet  321   y  respectively face the pitch coil  322   p  and the yaw coil  322   y  in the optical axis direction. The pitch magnet  321   p , the yaw magnet  321   y  and the stop driver  305  are connected with a flexible substrate  328 . 
     Three balls  325  are disposed between the base plate  301  and the shift frame  327 . Two tension springs  326  connect the base plate  301  and the shift frame  327 . These tension springs  326  exert a spring force that pushes the shift frame  327  toward the base plate  301 . This spring force pushes the shift frame  327  to the base plate  301  via the balls  325 . The balls  325  roll to guide the shift frame  327  when the shift frame  327  is shifted in the pitch direction and the yaw direction with respect to the base plate  301 . 
     Next, a description will be made of the image stabilizing system. Reference numerals  318   p  and  318   y  respectively denote a pitch shake sensor and a yaw shake sensor to detect a shake of the optical apparatus in the pitch direction and the yaw direction, and the sensors each include a gyro element that detects a rotation angle acceleration. Signals output from these shake sensors  318   p  and  318   y  are input to a CPU  354  as a controller. The CPU  354  provides integration and filter processing on the signals output from the shake sensors  318   p  and  318   y  depending on a shake of the optical apparatus so as to produce a correction signal for shifting the correcting lens  351  in a direction to reduce (correct) image blur due to the shake. The correction signal is input to an image stabilizing driver  356 . The image stabilizing driver  356  energizes the pitch and yaw coils  322   p  and  322   y  in response to the correction signal. This generates a thrust force as an electromagnetic force between the pitch and yaw coils  322   p  and  322   y  and the pitch and yaw magnets  321   p  and  321   y  that shifts the correcting lens  351  together with the shift frame  327  in the pitch direction and the yaw direction so as to reduce the image blur. 
     As described above (as illustrated in  FIG. 22 ), the correcting lens  351  held by the shift frame  327  is disposed in the opening  306  of the base plate  301  and in the shake correction space Sa. The operation of the image stabilizing system shifts the correcting lens  351  in the pitch direction and the yaw direction in the opening  306  of the base plate  301  and in the shake correction space Sa. 
     A diameter and depth of the shake correction space Sa is fixed irrespective of whether the stop blades  303  are open or closed. In practice, the driving ring is between the stop blades  303  and the shake correction space Sa, and the diameter of the shake correction space Sa basically depends on a diameter of a circle passing through the supported portion  303   b  (stop blade-supporting boss portion  307 ) of each stop blade  303 , and does not depend on a size of the stop aperture A formed by the stop blades  303 . The depth of the shake correction space Sa, as illustrated in  FIG. 25  depends on the tilt α of the portion from the supported portion  303   b  to the intermediate portion of each stop blade  303  with respect to the opening plane  306   a  in the optical axis direction, and does not depend on the size of the stop aperture A. Thus, when the stop aperture A is narrowed down, (a front face of) the correcting lens  351  can be inserted into the concave space Sa without opening the stop aperture A to a fully opened aperture diameter or beyond that. Therefore, a shiftable amount (maximum shift amount) of the correcting lens  351  can be fixed irrespective of whether the stop blades  303  are open or closed (irrespective of the size of the stop aperture), and thereby the correcting lens  351  can be sufficiently shifted for a favorable image stabilization. 
     The shake correction space Sa is a space large extending from an end portion of a convex portion of the correcting lens  351  in a direction intersecting with the optical axis direction, preventing the correcting lens  351  and the shift frame  327  from contacting with the stop blades  303  when they are shifted. 
     Moreover, a description will be made of a case where the concave lens  353  having a concave surface facing the stop blades  303  is disposed on a front side (stop blade  303  side) of the aperture stop apparatus  310  of the optical apparatus on which the aperture stop apparatus  310  is mounted as illustrated in  FIG. 22 . In this case, the concave lens  353  and the correcting lens  351  can be arranged sufficiently close to each other in the optical axis direction although the stop cover plate  304 , the stop blades  303  and the driving ring  302  are arranged therebetween. This achieves downsizing of the optical apparatus in the optical axis direction. This can also provide a large move range of one of the concave lens  353  and the correcting lens  351  (the aperture stop apparatus  310 ) relative to the other in an optical operation such as a magnification-varying operation. A length from the front face of the concave lens  353  to the correcting lens  351  in the optical axis direction is denoted by L. 
       FIG. 23  illustrates an aperture stop apparatus  310 ′ in a comparative example. A driving ring  302 ′ in this comparative example is shaped such that a fixed aperture is formed in a center of a circular plate whose front and back faces are approximately flat. A stop blade  303 ′ and a stop cover plate  304 ′ are also formed flat. In this comparative example, it is obvious from  FIG. 23  that the driving ring  302 ′ prevents the concave lens  353  from becoming sufficiently close to the correcting lens  351 . Thus, the length from the front face of the concave lens  353  to the correcting lens  351  in the optical axis direction is a length L′ longer than the length L in  FIG. 22 . This makes it difficult to achieve downsizing in the optical axis direction of an optical apparatus on which the aperture stop apparatus  310 ′ in the comparative example is mounted, and also restricts the move range of one of the concave lens  353  and the correcting lens  351  (the aperture stop apparatus  310 ′) relative to the other. 
     As described above, in this embodiment, the shake correction space Sa is formed to have a size enough to allow the correcting lens  351  to shift therein with no need to largely open the stop blades  303 . This enables the concave lens  353  adjacent to the aperture stop apparatus  310  in the optical axis direction to become close to the correcting lens  351  in the shake correction space Sa. Therefore, this embodiment provides an aperture stop apparatus that includes a light-quantity control mechanism and a shake correction mechanism (optical image stabilizing mechanism) and achieves miniaturization of an optical apparatus on which the aperture stop apparatus is mounted in an optical axis direction and downsizing thereof in a direction orthogonal to the optical axis direction. 
     It is noted that, although this embodiment described the case where a lens (the correcting lens  351 ) is used as the image stabilizing optical element, any optical element other than the lens may be used. 
     The light-quantity control apparatus described in (1) and (2) may be configured as follows. 
     (3) A light-quantity control apparatus according to (1), in which the curved path is formed between a concave portion of the first optical member and a convex portion of the second optical member, and a shake correction space between an end portion of the convex portion and the light-quantity control blade is formed on an aperture side of the curved path where the light-quantity control blade is supported. 
     (4) A light-quantity control apparatus according to (3), in which the shake correction space is a space largely expanding from the end portion of the convex portion in a direction intersecting with the optical axis direction. 
     (5) A light-quantity control apparatus according to any one of (1), (3) and (4), in which the shake correction unit includes a shake correction driver configured to shift at least one of the first and second optical members in a direction different from the optical axis direction. 
     (6) A light-quantity control apparatus according to (5), in which the blade driver includes a stop driver, and the stop driver and the shake correction driver are disposed at positions different from each other in a plane orthogonal to the optical axis direction in the apparatus body. 
     (7) A light-quantity control apparatus according to (6), in which the apparatus body includes a base member on which the light-quantity control blade and the blade driver are mounted, and the shake correction driver is disposed on an opposite side to a side of the base member on which the light-quantity control blade is disposed. 
     (8) A light-quantity control apparatus according to (7), in which: the light-quantity control blade includes a light-quantity controller to form a light-passing aperture, and a supported portion rotatably supported by the base member, and has such a shape that the light-quantity controller is located distant from the supported portion in the optical axis direction so as to form a concave space having a depth from the light-quantity control blade toward the light-passing aperture; and at least part of an optical material is disposed inside the concave space and configured to shift inside the concave space. 
     (9) A light-quantity control apparatus according to (2), in which a shiftable amount of the optical material that is shifted by the shake correction driver is fixed irrespective of a size of the light-passing aperture. 
     (10) A light-quantity control apparatus according to (2) or (9), in which the supported portion of the light-quantity control blade has a larger tilt with respect to the aperture plane in the optical axis direction than that of the light-quantity controller of the light-quantity control blade. 
     (11) A light-quantity control apparatus according to any one of (2), (9) and (10), in which the supported portion of the light-quantity control blade has a tilt with respect to the aperture plane in the optical axis direction, and the supported portion rotates around an axis titled with respect to the optical axis direction. 
     (12) A light-quantity control apparatus according to any one of (2), (9) and (11), in which the base member includes a fixed aperture, and the blade driver and the shake correction driver are disposed in a circumferential edge portion of the fixed aperture of the base member. 
     Embodiment 6 
       FIGS. 27A and 27B  illustrate a light-quantity control mechanism in an aperture stop apparatus in Embodiment 6 of the present invention. In  FIGS. 27A and 27B , components common to the present embodiment and Embodiment 5 are denoted by the same reference numerals as those in Embodiment 5, and a description thereof will be omitted. Although Embodiment 5 described the case where the size of the stop aperture formed by the plurality of stop blades  303  is changed so as to control the quantity of light, the quantity of light is controlled by rotating a single stop blade  343  in this embodiment. 
     The stop blade  343  includes a stop portion  343   a  to form a stop aperture (light-passing aperture), a supported portion  343   b  rotatably supported with respect to the base plate  301  and the driving ring  302 , and an intermediate portion connecting the stop portion  343   a  and the supported portion  343   b . A hole portion (concave portion)  343   c  into which the stop blade-supporting boss portion  307  formed in the base plate  301  is inserted is formed in the supported portion  343   b . The stop blade  343  is rotatable about the supporting boss portion  307  and the hole portion  343   c  with respect to the base plate  301  and the driving ring  302 . 
     In addition, a cam groove  343   d  in which the boss portion  308  provided to the driving ring  302  is inserted and that engages therewith is formed in the stop blade  343 . Thus, as illustrated in  FIGS. 27A and 27B , rotation of the driving ring  302  moves the boss portion  308  along the cam groove  343   d  and rotates the stop blade  343 . The stop blade  343  is rotated between a position at which the stop portion  343   a  covers fixed apertures (only the fixed aperture  312  of the driving ring  302  is illustrated in  FIG. 27A ) formed in the base plate  301  and the driving ring  302  as illustrated in  FIG. 27A  and a position at which the stop portion  343   a  is completely retracted from a region facing the fixed aperture as illustrated in  FIG. 27B . In this manner, the quantity of light passing through the fixed apertures is controlled. 
     The stop portion  343   a  is formed in a spherical surface shape (curved surface shape) having approximately the same curvature as that of the guide surface  302   c  of the domical wall portion  302   a  of the driving ring  302 . Thus, the rotation of the stop blade  343  moves the stop portion  343   a  along the guide surface  302   c.    
     In this embodiment as well, the supported portion  343   b  (and the intermediate portion) of the stop blade  343  has a tilt with respect to an opening plane of an opening of the base plate  301  in the optical axis direction. Thus a concave space having a depth from a supported portion ( 343   b ) side to a stop portion ( 343   a ) side in the optical axis direction and facing the fixed apertures is formed more inside than the stop blade  343  in the radial direction. 
     The light-quantity controller may rotate a single ND blade (light-quantity control blade) formed as an ND filter instead of the stop blade  343  so as to control the quantity of light. The ND filter is formed by, for example, mixing light-absorbing organic dye or pigment into a substrate, applying with light-absorbing organic dye or pigment, or depositing an evaporated film of metal and metallic compound. The ND filter having a curved surface shape is, however, preferably formed by mixing light-absorbing organic dye or pigment in a resin substrate. 
     Embodiment 7 
       FIG. 28B  illustrates a camera (video camera or still camera) as an optical apparatus on which the aperture stop apparatus  310  described in Embodiments 5 and 6 is mounted. Reference numeral  350  denotes a camera body (optical apparatus body). Reference numeral  351  denotes the correcting lens described above, and reference numeral  353  denotes the concave lens described above. The aperture stop apparatus  310  including the concave lens  353  and the correcting lens  351 , and other illustrated lenses are included in an image pickup optical system. The image pickup optical system is housed in a lens barrel of the camera body  350 . Reference numeral  352  denotes an image sensor. Reference numeral  354  denotes the CPU described above that controls operations of the aperture stop apparatus  310  (the stop driver  305  and the coils  322   p  and  322   y  included in the image stabilizing driver) and the image sensor  352 . The aperture stop apparatus  310  may have a shutter function. 
     The lens barrel housing the image pickup optical system may be configured to be housed (retractable) in the camera body. When the lens barrel is retracted, the concave lens  353  is located close to the correcting lens  351  so as to achieve miniaturization of the camera in a retracted state as illustrated in  FIG. 22A . 
     The aperture stop apparatus  310  is mountable not only on the camera illustrated in  FIG. 28B  but also on any other optical apparatus such as an interchangeable lens. 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2012-128808, filed on Jun. 6, 2012, No. 2012-274970, filed on Dec. 17, 2012, No. 2012-285712, filed on Dec. 27, 2012, No. 2012-286350, filed on Dec. 27, 2012, and No. 2013-1553, filed on Jan. 9, 2013, which are hereby incorporated by reference herein in their entirety.