Optical equipment

Abstract

To provide a compact optical apparatus having a plurality of driving means for driving a plurality of lens groups.SOLUTION: An optical apparatus includes: first and second holding members 104 and 106 that hold first and a second optical elements L4 and L6, respectively; first and a second guide members 153 and 155 that guide movement of the first and second holding members in an optical axis direction; and first and second driving means 151 and 152 that drive the first and second holding members. As viewed in the optical axis direction, when a first area AR1 to a third area AR3 are provided by dividing the optical apparatus into three in a circumferential direction around an optical axis, the first driving means and first guide means are arranged in the first area, the second driving means and third guide means are arranged in the second area, and a rotation stop member is arranged in the third area, the first driving means is arranged at a position closer to the rotation stop member than the first guide member, and the second driving means is arranged at a position closer to the rotation stop member than the second guide member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical apparatus that performs zooming, focusing, etc. by moving a plurality of lens groups. [Background technology]

[0002] In order to shorten the minimum imaging distance or improve image quality in close-up imaging, multiple lens groups may be moved during focusing. Patent Document 1 discloses an optical device in which multiple drive means (actuators) for moving each of the multiple lens groups are arranged on a line parallel to the optical axis. Patent Document 2 discloses an optical device in which multiple actuators for moving each of the multiple lens groups are arranged on the same circle centered on the optical axis in a plane perpendicular to the optical axis. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-284144 [Patent Document 2] WO16 / 051617 publication Summary of the Invention [Problem to be solved by the invention]

[0004] However, when multiple actuators are arranged side by side in the optical axis direction as in Patent Document 1, if the lens groups are spaced apart in the optical axis direction, the actuators must also be spaced apart in the optical axis direction, which hinders miniaturization of the optical device. Also, when multiple actuators are arranged in the circumferential direction as in Patent Document 2, if another fixed lens group is placed between the lens groups driven by these actuators, it becomes difficult to ensure a phase area for holding the fixed lens group.

[0005] The present invention provides a compact optical device having a plurality of actuators (driving means) that drive a plurality of lens groups. [Means for solving the problem]

[0006] An optical device according to one aspect of the present invention has a plurality of optical elements arranged in an optical axis direction, and includes a first guide member that guides movement in the optical axis direction of a first holding member that holds a first optical element among the plurality of optical elements, a second guide member that guides movement in the optical axis direction of a second holding member that holds a second optical element among the plurality of optical elements, a rotation stop member that prevents rotation of the first holding member about the first guide member and prevents rotation of the second holding member about the second guide member, first driving means that drives the first holding member in the optical axis direction, second driving means that drives the second holding member in the optical axis direction, and 1O Yo and and a base member for holding the driving means for the optical device. When the optical device is viewed along the optical axis, The third holding member for holding a third optical element among the plurality of optical elements is provided on the base member at three positions in the circumferential direction, and axes passing through the holding member and the optical axis are defined as a first axis, a second axis, and a third axis, respectively, and the distance between the first and second axes is defined as a second axis. The first area, Between the first and third axes The second area, Between the second and third axes The third area and When the first driving means and the first guide are Materials is disposed in the second region, and the second driving means and the 2 Guide Materials is disposed in the third region, and the rotation stop member is disposed in the third region, and when viewed along the optical axis, In the circumferential direction, The first driving means is arranged at a position closer to the rotation stop member than the first guide member, and the second driving means is arranged at a position closer to the rotation stop member than the second guide member. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce the size of an optical device having a plurality of driving means for driving a plurality of optical elements. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view of the interchangeable lens of the first embodiment as viewed from the optical axis direction. [Figure 2]FIG. 2 is a cross-sectional view of the interchangeable lens of the first embodiment at the wide-angle end. [Figure 3] FIG. 2 is a cross-sectional view of the interchangeable lens of the first embodiment at the telephoto end. [Figure 4] FIG. 1 is an exploded perspective view of an interchangeable lens according to a first embodiment. [Figure 5] FIG. 2 is a view of the interchangeable lens of the first embodiment as seen from the direction of the first axis. [Figure 6] FIG. 10 is a cross-sectional view of the interchangeable lens of the second embodiment as viewed from the optical axis direction. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Example]

[0010] 2 and 3 show the configuration of an interchangeable lens 100 serving as an optical apparatus (lens device) according to a first embodiment of the present invention. Fig. 2 shows a cross section of the interchangeable lens 100 at the wide-angle end, taken parallel to the optical axis, and Fig. 3 shows a cross section of the interchangeable lens 100 at the telephoto end, taken parallel to the optical axis. The interchangeable lens 100 is detachably attached to a camera body (not shown) serving as an imaging device equipped with an imaging element such as a CCD sensor or a CMOS sensor.

[0011] The interchangeable lens 100 has an imaging optical system made up of first to seventh lens groups L1 to L7 arranged in order from the subject side (front side). The imaging optical system focuses light from a subject (not shown) to form a subject image on an imaging element in the camera body. Focusing (focus adjustment) is performed by moving a floating lens group as the fourth lens group L4 and a focus lens group as the sixth lens group L6 in the optical axis direction, and zooming (variable magnification) is performed by moving the first to seventh lens groups L1 to L7 in the optical axis direction. Note that although an interchangeable lens will be described in this embodiment, the optical device may be a lens-integrated imaging device.

[0012] The lens mount 111 has a bayonet portion for detachably mounting on the camera body, and is fixed to the rear fixed barrel 112 with screws via an outer barrel 113. The outer barrel 113 is fixed by being sandwiched between the lens mount 111 and the rear fixed barrel 112. The front fixed barrel 115 is fixed to the rear fixed barrel 112 with screws. A zoom index and operation switches (not shown) are attached to the front fixed barrel 115. The guide barrel 116 is fixed to the rear fixed barrel 112 with screws.

[0013] The guide barrel 116 is formed with linear grooves that guide each lens group in the optical axis direction. The guide barrel 116 is also provided with cam grooves that engage with cam followers (not shown) that are fixed to the cam barrel 117 with screws. This causes the cam barrel 117 to move (linearly) in the optical axis direction while rotating around the optical axis during zooming. The cam barrel 117 is formed with a plurality of cam grooves that linearly move each lens group that moves during zooming.

[0014] The zoom operation barrel 118 is radially fitted into the guide barrel 116 and bayonet-engaged to be rotatable about the optical axis. Rotation of the zoom operation barrel 118 due to the user's zoom operation causes the linear movement barrel 122 to move linearly due to the linear movement guide action of a cam groove portion formed in the zoom operation barrel 118, a cam follower provided on the outside of the linear movement barrel 122, and the linear movement groove portion of the guide barrel 116. The cam follower of the linear movement barrel 122 also engages with the cam groove portion of the cam barrel 117, so that when the linear movement barrel 122 moves linearly, the cam barrel 117 rotates about the optical axis. At this time, the cam barrel 117, which is rotatable and linearly movable relative to the guide barrel 116, moves linearly while rotating due to the linear movement of the linear movement barrel 122.

[0015] When the cam barrel 117 rotates and moves straight relative to the guide barrel 116, rear group rollers 123, which are provided at three locations in the circumferential direction of the rear group unit (described later) centered on the optical axis, and seventh group rollers 124, which are provided at three locations in the circumferential direction of the seventh group unit (described later), engage with the straight groove portions of the guide barrel 116 and the cam groove portions of the cam barrel 117, causing the rear group unit and the seventh group unit to be driven separately in the optical axis direction.

[0016] In this way, in the interchangeable lens 100 of this embodiment, the rotation of the zoom operation tube 118 causes the linear movement tube 122 to move in a straight line (the first lens group L1 fixed to the linear movement tube 122 moves in the optical axis direction, as will be described later), and the rotation and linear movement of the cam tube 117 causes the second to seventh lens groups L2 to L7 to move in the optical axis direction.

[0017] The first lens retaining frame 101 holds the first lens group L1 and is fixed to the linear barrel 122 with screws. The first lens retaining ring 125 has a female screw formed on its inner periphery, and is fixed by screwing it into a male screw formed on the outer periphery of the linear barrel 122. The first lens retaining ring 125 serves to fix the first lens group L1.

[0018] The linear barrel 122 has a bayonet claw formed on its outer periphery for attaching a hood, and a screw formed on its inner periphery for attaching accessories such as a filter.

[0019] The second lens retaining frame 102 retains the second lens group L2 and constitutes a part of the vibration isolation unit 108. The vibration isolation unit 108 holds the second lens retaining frame 102 so that it can move in a direction perpendicular to the optical axis (hereinafter referred to as the shift direction), and reduces image blur by driving the second lens retaining frame 102 in the shift direction using a shift actuator made up of a magnet and a coil. The vibration isolation unit 108 is held in a manner that it is suspended from a guide cylinder 116 via rollers.

[0020] The third lens retaining frame 103 holds the third lens group L3 and is held by a rear group base 126 via three cam followers (129 in FIG. 5) arranged at three locations around the circumference of the third lens retaining frame 103. The third lens retaining frame 103 moves in the optical axis direction as the rear group base 126 moves straight forward during zooming. The third lens retaining frame 103 also holds an electromagnetic diaphragm unit 110 that is made up of a plurality of diaphragm blades and an diaphragm actuator that drives the diaphragm blades to open and close.

[0021] The fourth lens retaining frame 104 serving as a first retaining member retains the fourth lens group L4 serving as a first optical element, and is guided in a straight line by a guide bar 153 serving as a first guide member, whose front and rear ends are held by a rear group base 126 and a first rear group cover 127 fixed to the rear group base 126. The fourth lens group L4 (fourth lens retaining frame 104) moves in the optical axis direction as the rear group base 126 moves in the same direction during zooming, and also moves when driven in the optical axis direction relative to the rear group base 126 by a fourth lens drive motor unit 151 serving as first drive means.

[0022] The fourth lens retaining frame 104 is equipped with a scale for detecting its position in the optical axis direction. An optical sensor facing the scale is fixed to the rear group base 126 via a flexible printed circuit board (FPC). The scale and optical sensor constitute a position detecting means.

[0023] A fifth lens retaining frame 105 serving as a third retaining member retains a fifth lens group L5 serving as a third optical element, and is held by a rear group base 126 via three cam followers (retaining portions) 159 fixed at three locations in the circumferential direction of the fifth lens retaining frame 105. The fifth lens retaining frame 105 moves in the optical axis direction as the rear group base 126 moves straight during zooming.

[0024] The sixth lens holding frame 106 as a second holding member holds the sixth lens group L6 as a second optical element, and is guided in a straight line by a guide bar 155 as a second guide member whose front and rear ends are held by a rear group base 126 and a first rear group cover 127.

[0025] The motor unit drive base 135 is attached to the rear group base 126 so as to be movable in the optical axis direction, and is bayonet-engaged with the seventh group base 109 so as to be integrated only in the optical axis direction. The biasing force of the seventh group spring 136 attached to the seventh group base 109 removes backlash in the optical axis direction between the seventh group base 109 and the motor unit drive base 135.

[0026] The sixth lens holding frame 106 is driven in the optical axis direction relative to the motor unit drive base 135 by a sixth lens drive motor unit 152 serving as second drive means.

[0027] The seventh lens retaining frame 107 holds the seventh lens group L7 and is fixed by being screwed into the seventh group base 109. During zooming, the seventh lens retaining frame 107 is driven in the optical axis direction together with the seventh group base 109 by three cam followers provided on the seventh group base 109. The seventh group base 109 and the seventh lens retaining frame 107 form a seventh group unit.

[0028] In this embodiment, vibration-type linear motors using piezoelectric elements are used as the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152. The vibration-type linear motor is composed of a motor stator 130, a motor mover 131 that is excited by vibrations from the piezoelectric element and moves relative to the motor stator 130 in the optical axis direction, and a motor output section that moves together with the motor mover 131 in the optical axis direction. The motor stators 130 of the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152 are fixed to a motor unit drive base 135. The motor unit drive base 135, together with the rear group base 126, constitute a base member that holds the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152.

[0029] As shown in Fig. 1 and Fig. 4, which shows an exploded view of the rear group unit, the motor output sections of the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152 are engaged with arms 132, which are drive transmission members that transmit drive force from the motor output sections to the fourth lens retaining frame 104 or the sixth lens retaining frame 106. This enables the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152 to drive the fourth lens retaining member 104 and the sixth lens retaining member 106 in the optical axis direction. However, Figs. 1 and 4 only show the arm 132 provided for the sixth lens retaining frame 106.

[0030] It is also possible to use stepping motors as the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152, with arms engaged with lead screws provided in the motor output sections. When using stepping motors, it is also possible to eliminate the position detection means and perform open drive control.

[0031] The zoom operation tube 118 is provided with a groove that holds a movable element of a resistive linear sensor (potentiometer) 134, which is a zoom position detection means (not shown) that is fixed to the guide tube 116. The output of the resistive linear sensor 134 changes depending on the amount of rotation of the zoom operation tube 118, making it possible to detect the zoom position.

[0032] The focus operation tube 114 is sandwiched between the front fixed tube 115 and the rear fixed tube 112 so that it can rotate at a fixed position in the optical axis direction on the outer periphery of the front fixed tube 115. The amount and direction of rotation of the focus operation tube 114 is detected by a photodetector element provided on the front fixed tube 115 and a brightness scale provided on the inner periphery of the focus operation tube 114 so as to face the photodetector element.

[0033] The multipurpose operation barrel 121 is sandwiched between the rear fixed barrel 112 and the outer barrel 113 so as to be rotatable at a fixed position in the optical axis direction on the outer periphery of the rear fixed barrel 112. The amount and direction of rotation of the multipurpose operation barrel 121 are detected by a photodetector element provided on the rear fixed barrel 112 and a light / dark scale provided on the inner periphery of the multipurpose operation barrel 121 so as to face the photodetector element. The multipurpose operation barrel 121 and the rear fixed barrel 112 also have a click mechanism consisting of multiple grooves for providing a clicking sensation in response to user operation, and click pins biased by springs into the grooves.

[0034] A lens control unit (control board) 119 serving as control means controls the overall operation of the interchangeable lens 100, including focus drive control, aperture drive control, and vibration reduction control. When zooming, the lens control unit 119 controls the movement of the fourth lens group L4 and the sixth lens group L6 (that is, the drive of the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152) so that the focus position and various aberration amounts that fluctuate due to zooming are kept below certain values. The lens control unit 119 is fixed to the rear fixed barrel 112 with screws.

[0035] Next, the configuration of the rear group unit will be described in more detail with reference to Figures 1, 4, and 5. Figure 1 shows the rear group unit as seen from the optical axis direction (front side), and Figure 4 shows the rear group unit disassembled as described above. Figure 5 shows the rear group unit as seen from the direction of the first axis, which will be described later.

[0036] The third to sixth lens groups L3 to L6 are held on a rear group base 126 that moves straight during zooming, although only the fourth to sixth lens groups L4 to L6 are shown in FIG.

[0037] As described above, the fourth lens group L4 held by the fourth lens retaining frame 104 is a floating group, and is driven in the optical axis direction by the fourth lens drive motor unit 151. The sleeve portion 104a of the fourth lens retaining frame 104 is engaged (fitted) at two locations, front and rear, with the guide bar 153 so as to be movable in the optical axis direction, thereby preventing the fourth lens retaining frame 104 from being positioned in a direction perpendicular to the optical axis and from tilting relative to the optical axis. In addition, the U-shaped groove portion 104b of the fourth lens retaining frame 104 is engaged with the rotation stop bar 154, which serves as a first rotation stop member, so as to be movable in the optical axis direction. The front end of the rotation stop bar 154 is held by the rear group base 126, and the rear end is held by the second rear group cover 128 fixed to the rear group base 126.

[0038] The aforementioned arm 132, which is rotatably attached to the fourth lens retaining frame 104, is urged and engaged with the motor output portion of the fourth lens drive motor unit 151 by the urging force of an arm urging spring (urging means) 133, which is a torsion coil spring arranged around the rotation center axis of the arm 132. This removes engagement backlash between the arm 132 and the motor output portion. In addition, the urging force of the arm urging spring 133 urges the fourth lens retaining frame 104 in a direction that rotates it about the guide bar 153, causing the groove portion 104b to abut against the rotation stop bar 154. This removes rotational backlash in the fourth lens retaining frame 104.

[0039] The position of the fourth lens retaining frame 104 in the optical axis direction relative to the rear group base 126 is detected by reading a scale (not shown) fixed to the fourth lens retaining frame 104 with a fourth lens position sensor 157, which serves as a first position detection means, fixed to the rear group base 126.

[0040] As described above, the fifth lens retaining frame 105 is retained by the rear group base 126 via the three cam followers 159 fixed to the follower mounting portions 105a provided at three locations around the circumference of the fifth lens retaining frame 105.

[0041] As described above, the sixth lens group L6 held by the sixth lens retaining frame 106 is a focus group, and is driven in the optical axis direction by the sixth lens drive motor unit 152. The sleeve portion 106a of the sixth lens retaining frame 106 is engaged (fitted) at two locations, front and rear, with the guide bar 155 so as to be movable in the optical axis direction, thereby preventing the sixth lens retaining frame 106 from being positioned in a direction perpendicular to the optical axis and from tilting relative to the optical axis. Furthermore, the U-shaped groove portion 106b of the sixth lens retaining frame 106 is engaged with a rotation stop bar 156 serving as a second rotation stop member so as to be movable in the optical axis direction. The front end of the rotation stop bar 156 is held by the rear group base 126, and the rear end is held by the second rear group cover 128.

[0042] The arm 132, which is rotatably attached to the sixth lens retaining frame 106, is urged and engaged with the motor output portion of the sixth lens drive motor unit 152 by the urging force of a torsion arm urging spring 133 arranged around the rotation center axis of the arm 132. This removes engagement backlash between the arm 132 and the motor output portion. The urging force of the arm urging spring 133 also urges the sixth lens retaining frame 106 in a direction that rotates it about the guide bar 155, causing the U-shaped groove portion 106b to abut against the rotation stop bar 156. This removes rotational backlash in the sixth lens retaining frame 106.

[0043] The position of the sixth lens retaining frame 106 in the optical axis direction relative to the rear group base 126 is determined by the position of the motor unit drive base 135 in the optical axis direction relative to the rear group base 126 and the position of the motor mover 131 of the sixth lens drive motor unit 152 in the optical axis direction relative to the motor unit drive base 135. The position of the sixth lens retaining frame 106 in the optical axis direction relative to the rear group base 126 is detected by reading a scale (not shown) fixed to the sixth lens retaining frame 106 with a sixth lens position sensor 158 serving as second position detection means fixed to the rear group base 126.

[0044] In this embodiment, the fourth lens group L4 is a floating group, the sixth lens group L6 is a focusing group, and these lens groups move during focusing. However, one lens group may move for zooming and the other lens group may move for focusing. Also, in this embodiment, the sixth lens group L6 moves relative to the motor unit drive base 135. However, the motor unit drive base 135 may not be required.

[0045] Next, the arrangement of the components that make up the rear group unit will be described using Fig. 1. The first axis A1, second axis A2, and third axis A3 shown in Fig. 1 are straight lines that pass through the position of the optical axis AX and through the centers of three cam followers 159 that hold the fifth lens retaining frame 105 on the rear group base 126. The three cam followers 159 are arranged at intervals of approximately 120 degrees in the circumferential direction, and therefore the angle formed by adjacent axes in the circumferential direction of the first to third axes A1, A2, and A3 is also approximately 120 degrees.

[0046] In this embodiment, the phase of the three cam followers 159 for holding the fifth lens holding frame 105 to the rear group base 126 and the three rear group rollers (holding portions) 123 for holding the rear group base 126 (i.e., the rear group unit) to the guide tube (other member) 116 are arranged in the same phase, so when viewed in the optical axis direction, the first axis A1, the second axis A2 and the third axis A3 are also straight lines that pass through the optical axis AX and the centers of the three rear group rollers 123.

[0047] In the circumferential direction, the area between the first and second axes A1 and A2 is defined as a first area AR1, the area between the first and third axes A1 and A3 is defined as a second area AR2, and the area between the second and third axes A2 and A3 is defined as a third area AR3.

[0048] The first area AR1 is arranged with the fourth lens drive motor unit 151, the arm 132 provided on the fourth lens retaining frame 104, the arm biasing spring 133 that biases the arm 132, and the guide bar 153 that guides the fourth lens retaining frame 104. The guide bar 153 is arranged at a position farther from the first axis A1 than the fourth lens drive motor unit 151. Furthermore, the first area AR1 is arranged with a rotation stop bar 156 that prevents the rotation of the sixth lens retaining frame 106, close to the guide bar 153 (i.e., at a position farther from the first axis A1 than the fourth lens drive motor unit 151).

[0049] In the second area AR2, there are arranged the sixth lens drive motor unit 152, the rack 132 provided on the sixth lens retaining frame 106, the arm biasing spring 133 that biases the rack 132, and a guide bar 155 that guides the sixth lens retaining frame 106. The guide bar 155 is arranged at a position farther from the first axis A1 than the sixth lens drive motor unit 152. Furthermore, in the second area AR2, a rotation stop bar 154 that prevents rotation of the fourth lens retaining frame 104 is arranged close to the guide bar 155 (i.e., at a position farther from the first axis A1 than the sixth lens drive motor unit 152).

[0050] In this embodiment, the fourth and sixth lens groups L4 and L6, driven by the fourth and sixth lens drive motor units 151 and 152, respectively, are adjacent to each other in the optical axis direction, although the fifth lens group L5 is sandwiched between them. In this lens group arrangement, by arranging the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152 in the first area AR1 and the second area AR2, which are different areas in the circumferential direction, as described above, the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152 can be arranged in two areas that overlap each other over at least a partial range in the optical axis direction, as shown in Figures 1 and 5. This makes it possible to reduce the size of the rear group unit (i.e., the interchangeable lens 100) in the optical axis direction compared to when the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152 are arranged in two areas that do not overlap at all in the optical axis direction.

[0051] Furthermore, by arranging the lens drive motor unit and related parts (arm 132, arm biasing spring 133, and guide bars 153, 155) in each of the first area AR1 and the second area AR2, it becomes possible to arrange the follower mounting portion 105a, to which the cam follower 159 for holding the fifth lens holding frame 105 is attached, near the boundary between each area, and the follower mounting portion 105a can be secured without increasing the size of the interchangeable lens 100.

[0052] As described above, according to this embodiment, it is possible to reduce the size of the interchangeable lens 100 having the fourth and sixth lens drive motor units 151 and 152 that drive the fourth and sixth lens groups L4 and L6.

[0053] Furthermore, in this embodiment, the fourth lens drive motor unit 151 and its associated components, and the sixth lens drive motor unit 152 and its associated components are arranged line-symmetrically with respect to the first axis A1. "Line-symmetrical" here refers not only to a complete line-symmetrical arrangement, but also to an arrangement that can be considered to be approximately line-symmetric. FIG. 1 shows a moment M1 generated on the fourth lens retaining frame 104 by the biasing force of the arm biasing spring 133 that biases the arm 132 provided on the fourth lens retaining frame 104, and a moment M2 generated on the sixth lens retaining frame 106 by the biasing force of the arm biasing spring 133 that biases the arm 132 provided on the sixth lens retaining frame 106. Also shown are a reaction force F1 that the U-shaped groove portion 104b of the fourth lens retaining frame 104 receives from the moment M1, and a reaction force F2 that the U-shaped groove portion 106b of the sixth lens retaining frame 106 receives from the moment M6.

[0054] The direction of reaction force F1 is perpendicular to the line connecting the guide bar 153 and the U-groove 104b of the fourth lens retaining frame 104, and the direction of reaction force F2 is perpendicular to the line connecting the guide bar 155 and the U-groove 106b of the sixth lens retaining frame 106. Therefore, by arranging the arms 132 and arm biasing springs 133 associated with the fourth and sixth lens retaining frames 104, 104, and further the U-grooves 104b, 106b line-symmetrically with respect to the first axis A1, it is possible to make the reaction forces F1 and F2 point in the same direction. The "same direction" referred to here is not limited to completely the same (parallel) directions, but may be non-parallel directions that can be considered to be roughly the same direction.

[0055] If the biasing force of arm biasing spring 133 were smaller than the weight of the lens group and lens retaining frame, rattle would occur in the retention of the lens retaining frame, but because reaction forces F1 and F2 are directed in the same direction, there is no need to generate a strong biasing force in only one of arm biasing springs 133. This eliminates the need to use a large spring or to thicken the guide bar to ensure strength against a large load generated by a strong biasing force, making it possible to reduce the size of interchangeable lens 100. It is also possible to avoid the frictional force between the guide bar and lens retaining frame (sleeve portion and U-groove portion) increasing due to a large load, and there is no need to increase the drive force or size of the lens drive motor unit, making it possible to reduce the power consumption and size of interchangeable lens 100.

[0056] In order to align the directions of the reaction forces F1 and F2, it is preferable to bring the guide bar 153 for the fourth lens retaining frame 104 and the anti-rotation bar 156 for the sixth lens retaining frame 106 closer to each other, and to bring the guide bar 155 for the sixth lens retaining frame 106 and the anti-rotation bar 154 for the fourth lens retaining frame 104 closer to each other. Furthermore, it is more preferable to share one guide bar as the guide bar 153 for the fourth lens retaining frame 104 and the anti-rotation bar 156 for the sixth lens retaining frame 106, and to share another guide bar as the guide bar 155 for the sixth lens retaining frame 106 and the anti-rotation bar 154 for the fourth lens retaining frame 104.

[0057] Furthermore, in this embodiment, a flexible printed circuit board 160 serving as a first connecting member that connects the fourth and sixth lens drive motor units 151, 152 to the lens control unit 119 is disposed so as to extend in the optical axis direction near the first axis A1. Specifically, as shown in Figures 1 and 5, the connecting portion 151b of the fourth lens drive motor unit 151 and the connecting portion 152b of the sixth lens drive motor unit 152 each extend in the circumferential direction toward the flexible printed circuit board 160 disposed on the first axis A1 side and are connected to the flexible printed circuit board 160.

[0058] To enable such connections, in this embodiment, motor units of the same configuration are used as the fourth lens drive motor unit 151 and the sixth lens drive motor unit 152, and they are arranged with their front and back reversed. This eliminates the need to use separate motor units for the fourth and sixth lens drive motor units 151, 152. Furthermore, because the fourth and sixth lens drive motor units 151, 152 and the lens control unit 119 can be connected by a single flexible printed circuit board 160, it is possible to reduce the space required for connections and make it possible to miniaturize the interchangeable lens 100.

[0059] In this embodiment, a flexible printed circuit board 161 serving as a second connecting member connecting the fourth lens position sensor 157 and the sixth lens position sensor 158 to the lens control unit 119 is disposed in a third region AR3, which is a phase region on the opposite side of the first axis A1 in FIG. 1. Compared to the first and second regions AR1 and AR2 in which the fourth and sixth lens drive motor units 151 and 152 are disposed, the third region AR3 has more space. Therefore, by disposing the flexible printed circuit board 161 in the third region AR3, which is different from the first and second regions AR1 and AR2, a natural arrangement is possible. Moreover, because the fourth and sixth lens position sensors 157 and 158 can be connected using a single flexible printed circuit board 161, the space required for the connections can be reduced, enabling the interchangeable lens 100 to be made more compact.

[0060] The first to third axes A1, A2, A3 do not have to be straight lines passing through the centers of the three cam followers 159 for holding the fifth lens group L5. For example, in this embodiment, the three cam followers 159 and the three rear group rollers 123 are arranged in the same phase, but the three rear group rollers 123 may be arranged in a different phase from the three cam followers 159, and axes passing through the centers of the three rear group rollers 123 may be the first to third axes. Furthermore, instead of holding by cam followers, holding may be done using fixing members such as screws.

[0061] As a modification of the above embodiment, the connection portions 151b, 152b of the fourth and sixth lens drive motor units 151, 152 may extend circumferentially on the side opposite to the first axis A1. In this case, the connection portion 151b of the fourth lens drive motor unit 151 and the fourth lens position sensor 157 are connected to a flexible printed circuit board, which is then connected to the lens control unit 119. The connection portion 152b of the sixth lens drive motor unit 152 and the sixth lens position sensor 158 are connected to another flexible printed circuit board, which is then connected to the lens control unit 119. However, considering the effect that noise generated by driving the fourth and sixth lens drive motor units 151, 152 has on the signals from the fourth and sixth lens position sensors 157, 158, the connection in the above embodiment is preferable. [Example]

[0062] FIG. 6 shows a cross section of an interchangeable lens according to a second embodiment of the present invention, as viewed from the optical axis direction. Components of the interchangeable lens of this embodiment that are common to those of the first embodiment are assigned reference numerals in the 200s, with the last two digits of the reference numerals in the 100s being the same as those in the first embodiment. The first axis A21, second axis A22, and third axis A23 shown in FIG. 6 are straight lines that pass through the optical axis AX and the centers of three cam followers 259 for holding the fifth lens group, which is disposed between the fourth and sixth lens groups, on the rear group base 226. The three cam followers 259 are arranged at intervals of approximately 120 degrees in the circumferential direction, and therefore the angle formed by adjacent axes in the circumferential direction of the first to third axes A21, A22, and A23 is also approximately 120 degrees. The region sandwiched between the first and second axes A21 and A22 in the circumferential direction is defined as a first region AR21, No. 1 The area sandwiched between the first and third axes A21 and A23 is defined as a second area AR22, and the area sandwiched between the second and third axes A22 and A23 is defined as a third area AR23.

[0063] In this embodiment, the positional relationship between the fourth and sixth lens drive motor units and the guide bar is reversed compared to that in Embodiment 1. Specifically, in Embodiment 1, the guide bars 153 and 155 are disposed at positions farther from the first axis A1 than the fourth and sixth lens drive motor units 151 and 152 in the first and second regions AR1 and AR2, respectively. In contrast, in this embodiment, the fourth and sixth lens drive motor units 251 and 252 are disposed in the first and second regions AR21 and AR22, and the guide bars 253 and 255 are disposed at positions closer to the first axis A21 than the fourth and sixth lens drive motor units 251 and 252 in the first and second regions AR21 and AR22. In addition, the fourth lens position sensor 257 and the sixth lens position sensor 258 are also disposed near the first axis A21 in accordance with the positioning of the guide bars 253 and 255.

[0064] The front ends of guide bars 253, 254 that guide the fourth lens retaining frame 204 are held by the rear group base 226, and the rear ends are held by a rear group cover (not shown) fixed to the rear group base 226. A sleeve portion 204a of the fourth lens retaining frame 204 engages with the guide bar 253, and a U-shaped groove portion 204b engages with a rotation stop bar 254 arranged in the third area AR23.

[0065] Meanwhile, the front end of a guide bar 255 that guides the sixth lens retaining frame 206 is held by the rear group base 226, and the rear end is held by the rear group cover. The sleeve portion 206a of the sixth lens retaining frame 206 engages with the guide bar 255, and the U-shaped groove portion 206b engages with the rotation prevention bar 254, just like the U-shaped groove portion 204b of the fourth lens retaining frame 204. That is, in this embodiment, the rotation prevention bar 254, which is the same member (single member), is used as the first rotation prevention member and the second rotation prevention member.

[0066] Additionally, similarly to embodiment 1, an arm that engages with the motor moving part of the fourth lens drive motor unit 251 and an arm biasing spring that biases the arm are arranged in the first region AR21. Furthermore, an arm that engages with the motor moving part of the sixth lens drive motor unit 252 and an arm biasing spring that biases the arm are arranged in the second region AR22.

[0067] By arranging the lens drive motor unit and related parts (arm, arm biasing spring, and guide bars 253, 255) in each of the first area AR21 and the second area AR22 in this manner, it becomes possible to arrange the follower mounting portion a, to which the cam follower 259 for holding the fifth lens holding frame 205 is attached, near the boundary between each area, and it is possible to secure the follower mounting portion without increasing the size of the interchangeable lens.

[0068] In this embodiment as well, it is possible to reduce the size of an interchangeable lens having the fourth and sixth lens drive motor units 251 and 252 that drive the fourth and sixth lens groups.

[0069] In this embodiment, it is desirable to arrange the flexible printed circuit board 261, which connects the fourth lens position sensor 257, the sixth lens position sensor 258, and the lens control unit (not shown), near the first axis A21. It is also desirable to arrange the flexible printed circuit board 260, which connects the fourth and sixth drive motor units 251, 252 to the lens control unit, in the third area AR23, which is the phase area on the opposite side from the first axis A21. This enables a space-saving arrangement.

[0070] Furthermore, in the above embodiments, the motor units have been described as driving lenses as optical elements, but they may also drive optical elements other than lenses, such as apertures.

[0071] The embodiments described above are merely representative examples, and various modifications and alterations are possible to each embodiment when implementing the present invention. [Explanation of symbols]

[0072] 104 Fourth lens holder 105 5th lens holder 106 6th lens holder 126 rear group base 153,154,155,156 Guide bar 151 Fourth lens drive motor unit 152 6th lens drive motor unit 119 Lens control unit A1 First axis A2 Second axis A3 The third axis AR1 First Area AR2 Second Area AR3 The Third Region

Claims

1. An optical device having a plurality of optical elements arranged in an optical axis direction, a first guide member that guides movement of a first holding member that holds a first optical element among the plurality of optical elements in the optical axis direction; a second guide member configured to guide movement in the optical axis direction of a second holding member configured to hold a second optical element among the plurality of optical elements; a rotation stopper member that prevents the first holding member from rotating about the first guide member and that prevents the second holding member from rotating about the second guide member; a first driving means for driving the first holding member in the optical axis direction; a second driving means for driving the second holding member in the optical axis direction; a base member that holds the first and second driving means; When viewed along the optical axis, holding portions for holding a third holding member that holds a third optical element of the plurality of optical elements on the base member are provided at three locations in the circumferential direction, and axes passing through the holding portions and the optical axis are respectively defined as a first axis, a second axis, and a third axis, and a first region is defined between the first and second axes, a second region is defined between the first and third axes, and a third region is defined between the second and third axes, the first driving means and the first guide member are disposed in the first region, the second driving means and the second guide member are disposed in the second region, and the rotation stop member is disposed in the third region; When viewed along the optical axis, the first driving means is arranged at a position closer to the rotation stop member than the first guide member in the circumferential direction, and the second driving means is arranged at a position closer to the rotation stop member than the second guide member.

2. 2. The optical device according to claim 1, wherein, when viewed along the optical axis, the first driving means and the first guide member, and the second driving means and the second guide member are arranged symmetrically with respect to an axis connecting the optical axis and the rotation stop member.

3. a biasing means for biasing the first holding member and the second holding member so as to rotate around the first guide member and the second guide member, respectively; 3. The optical device according to claim 1, wherein, when viewed along the optical axis, the reaction force that the biased first holding member receives from the rotation stop member and the reaction force that the biased second holding member receives from the rotation stop member are directed in the same direction.

4. a first connecting member that connects the first driving means and the second driving means to a control means that controls the first driving means and the second driving means; a first position detecting means and a second position detecting means for detecting the positions of the first holding member and the second holding member, respectively; a second connecting member that connects the first position detecting means and the second position detecting means to the control means; 4. The optical device according to claim 1, wherein, when viewed along the optical axis, the second connecting member is arranged so as to intersect with the first axis, and the first connecting member is arranged in the third region.

5. 5. The optical device according to claim 1, which is detachable from the imaging device.

6. 6. The optical device according to claim 1, further comprising an image pickup element that receives light from the optical element.

Images