JP7077014B2 - Optical equipment - Google Patents

Description

The present invention relates to an optical device, and more particularly to an optical device such as a lens barrel mounted on an image pickup device such as a camera.

Generally, in an image pickup apparatus which is one of optical instruments, one in which an optical element such as a lens or a filter can be selectively inserted / removed or switched to the photographing optical axis is known. In particular, in consideration of the usability of the image pickup apparatus, various methods have been proposed in which the optical element is inserted / removed or switched electrically instead of manually.

For example, there is an image pickup device that switches a turret lens including a telelens and a wide lens with an actuator for switching drive in order to obtain a focal length beyond a continuous zoom region (Patent Document 1). Further, there is an image pickup device in which a specific lens group is guided by a straight-ahead cylinder and inserted into a photographing optical axis when the zoom lens barrel is driven to zoom to a predetermined region (Patent Document 2).

Japanese Unexamined Patent Publication No. 3-53230 Japanese Unexamined Patent Publication No. 2006-84728

However, in the image pickup apparatus described in Patent Document 1, a separate actuator is required for switching the lens, which increases the cost. Furthermore, it is necessary to secure a space for mounting the actuator, which increases the size of the lens barrel.

On the other hand, in the image pickup apparatus described in Patent Document 2, although it is not necessary to separately provide an actuator, the lens group is inserted and removed in the middle of the zoom region, so that the lens group is on the shooting optical axis only in a part of the zoom region. It will be placed. As a result, the lens group cannot be selectively inserted or removed over the entire zoom region.

Therefore, an object of the present invention is to provide an optical device that is low in cost, small in size, and capable of selectively using an optical element in the entire zoom region.

In order to achieve the above object, the optical device according to the present invention includes a zoom lens group that moves along the photographing optical axis to change the magnification of the imaging optical system, and a rotating cylinder that rotates about the photographing optical axis. In the optical device provided, a holding member that holds at least one optical element and a base member that movably holds the holding member in order to selectively position the optical element between the shooting optical axis and the outside of the shooting optical axis. The rotary cylinder is provided with a first cam groove for moving the zoom lens group from the wide-angle region to the telescopic region, and a second cam groove having a predetermined positional relationship with the first cam groove. The cam groove and the third cam groove that continuously connects the first cam groove and the second cam groove are formed, and further, the rotary cylinder is rotated to rotate the zoom lens group. When the zoom lens group is engaged with the third cam groove when the optics is moved between the first cam groove and the second cam groove, the holding member of the rotating cylinder It has a moving mechanism that moves in conjunction with rotation, and in the predetermined positional relationship, the second cam groove is formed symmetrically with respect to the first cam groove in the phase of the wide-angle region and the telescopic region. It is characterized by being in a state of being .

According to the present invention, the cost is low, the size is small, and the optical element can be selectively used in the entire zoom region.

It is sectional drawing which shows the structure of the example of the lens barrel which is one of the optical instruments by 1st Embodiment of this invention. It is a figure for demonstrating the switching mechanism for switching the switching lens group shown in FIG. 1. It is a figure for demonstrating the switching of the switching lens group shown in FIG. It is a figure which shows the structure of the cam cylinder shown in FIG. It is a figure for demonstrating the lock mechanism which prevents the switching of the switching lens group shown in FIG. 1. It is a figure for demonstrating the operation of the switching lens group shown in FIG. 1 (the 1). It is a figure for demonstrating the operation of the switching lens group shown in FIG. 1 (the 2). It is a figure for demonstrating the operation of the switching lens group shown in FIG. 1 (the 3). It is a figure for demonstrating the operation of the switching lens group shown in FIG. 1 (the 4). It is a figure for demonstrating the gap between the locking wall and a convex part shown in FIG. It is a figure which looked at the lens barrel shown in FIG. 1 from the side view. FIG. 1 is a cross-sectional view taken along the line CC shown in FIG. 11 (No. 1). FIG. 2 is a cross-sectional view taken along the line CC shown in FIG. 11 (No. 2). It is a figure which shows the lens switching mechanism used in the lens barrel according to the 2nd Embodiment of this invention from the front. It is a figure for demonstrating the operation of the lens switching mechanism shown in FIG. It is a figure for demonstrating the lock mechanism which prevents the switching of the switching lens group shown in FIG. 14.

Hereinafter, an example of an optical device according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a cross-sectional view showing the configuration of an example of a lens barrel, which is one of the optical instruments according to the first embodiment of the present invention. FIG. 1 (a) is a cross-sectional view showing a state in which the first switching lens is arranged on the photographing optical axis, and FIG. 1 (b) shows a state in which the second switching lens is arranged on the photographing optical axis. It is sectional drawing which shows.

The illustrated lens barrel is attached to, for example, a waterproof camera, which is one of the image pickup devices. Therefore, the lens barrel can be switched between a lens for underwater photography and a lens for land photography in order to correct the difference in optical characteristics between underwater and land. In the following description, the lens for underwater photography is referred to as a first switching lens 4a, and the lens for land photography is referred to as a second switching lens 4b.

The lens barrel includes a first lens group 1, a second lens group 2, a third lens group 3, and a switching lens group 4 in order from the front of the optical axis (subject side) as a lens group for photographing. An image pickup element 5 such as a CMOS image sensor is arranged after the group 5. The switching lens group 4 has first and second switching lenses 4a and 4b.

An optical image is formed on the image pickup element (imaging unit) 5 via a lens barrel, and the image pickup element 5 generates an image signal corresponding to the optical image.

As shown in the figure, the image pickup device 5 is held by the base member 6, and the fixing cylinder 7 is fixed to the base member 6 by screws (not shown). The cam cylinder (rotary cylinder) 11 is arranged inside the fixed cylinder 7, and the movement in the radial direction is regulated by the fixed cylinder 7, and the movement in the optical axis direction is regulated by the fixed cylinder 7 and the base member 6 to be rotatably held. Has been done.

The first lens group 1 is held by the fixed cylinder 7. Further, the second lens group 2 is held by the second lens holding frame 8, the third lens group 3 is held by the third lens holding frame 9, and the switching lens group 4 is held by the switching lens holding frame (holding member) 10. Held by. A pin-shaped portion 8a is formed on the second lens holding frame 8, and a pin-shaped member 9a is formed on the third lens holding frame 9. These pin-shaped portions 8a and 9a are engaged with cam grooves 12 and 13 formed on the inner circumference of the cam cylinder 11, respectively (see FIG. 8A described later).

The second lens holding frame 8 is restricted from going straight by a straight groove (not shown) formed in the fixed cylinder 7, and the third lens holding frame 9 is restricted from going straight by the second lens holding frame 8. When the cam cylinder 11 is rotationally driven by a zoom drive motor (not shown), the second lens holding frame 8 and the third lens holding frame 9 move along the optical axis along the trajectories of the cam grooves 12 and 13. (Magnification) is performed.

FIG. 2 is a diagram for explaining a switching mechanism for switching the switching lens group shown in FIG. 1. 2 (a) is an exploded perspective view, and FIG. 2 (b) is a front view. Further, FIG. 2 (c) is a cross-sectional view taken along the line AA shown in FIG. 2 (b).

The switching mechanism (moving mechanism) includes a switching lens holding frame 10. The switching lens holding frame 10 is provided with a positioning portion 10a having a through hole formed in a direction perpendicular to the optical axis. Further, the switching lens holding frame 10 is formed with a U-shaped steady rest portion 10b on the side opposite to the positioning portion 10a with the switching lens group 4 interposed therebetween.

Guide shafts 15a and 15b are slidably fitted to the positioning portion 10a and the steady rest portion 10b, respectively. The guide shafts 15a and 15b are supported by guide bearing portions 6a and 6b formed on the base member 6, respectively. The switching lens group 4 is movable along the guide axes 15a and 15b on a plane perpendicular to the optical axis.

Further, the switching lens holding frame 10 is formed with a rack portion 10c that always meshes with the idler gear 16 on the side of the positioning portion 10a. The idler gear 16 is rotatably supported by a gear shaft 17, and the gear shaft 17 is fixed to a gear shaft fixing portion 6c formed on the base member 6.

A roof portion 6d is formed on the base member 6, and a gear shaft through hole 6e is formed on the roof portion 6d coaxially with the gear shaft fixing portion 6c. The gear shaft 17 has a gear shaft protruding portion 17a that penetrates the gear shaft through hole 6e and projects toward the subject side from the roof portion 6d. The arm portion of the toggle spring 18 is locked to the gear shaft protruding portion 17a and the toggle spring hooking portion 10d formed on the switching lens holding frame 10, respectively. As a result, the direction of the urging force changes depending on the position of the switching lens group 4. Further, the toggle spring 18 is restricted from moving along the optical axis by the toggle spring cover 19 fixed to the base member 6 and the roof portion 6d so as not to fall off from the gear shaft 17.

FIG. 3 is a diagram for explaining switching of the switching lens group shown in FIG. 1. 3A is a front view showing a group of switching lenses when the first switching lens is arranged on the optical axis for photographing, and FIG. 3B is a front view showing the switching lens group when the first switching lens is arranged on the optical axis for photographing. It is a front view which shows the switching lens group at the time of arrangement.

In FIG. 3A, the switching lens holding frame 10 is urged upward in the figure by the toggle spring 18 and is in contact with the first mechanical stopper 6f. In FIG. 3B, the switching lens holding frame 10 is urged downward in the figure by the toggle spring 18 and is in contact with the second mechanical stopper 6g. In this way, even if any of the first and second switching lenses 4a and 4b is located on the photographing optical axis, the switching lens holding frame 10 is urged to the mechanical stopper by the toggle spring 18 to perform positioning.

FIG. 4 is a diagram showing the configuration of the cam cylinder shown in FIG. 1. 4 (a) is a perspective view of the cam cylinder, and FIG. 4 (b) is a view of the cam cylinder as viewed from the rear side.

The cam cylinder 11 is formed with an outer peripheral gear portion 11a and an internal tooth gear 11b. The outer peripheral gear portion 11a is always in mesh with a transmission gear (not shown), and the cam cylinder 11 is rotationally driven by obtaining a driving force from a zoom motor (not shown) via this transmission gear. The internal tooth gear 11b is formed so as to engage with the idler gear 16 to drive the switching lens holding frame 10 when the cam cylinder 11 is in a specific rotation phase. Further, cam grooves 12 and 13 are formed on the inner peripheral surface of the cam cylinder 11 (cam grooves 12 are not shown in FIG. 4). Then, the pin-shaped member 8a of the second lens holding frame 8 and the pin-shaped member 9a of the third lens holding frame 9 are engaged with the cam grooves 12 and 13, respectively.

In the cam cylinder 11, an arc-shaped locking wall 11c is provided on the image pickup surface side in a phase that does not overlap with the outer peripheral gear portion 11a when viewed from the direction of the optical axis for photographing. The locking wall 11c, together with the locking arms 10e-1 and 10e-2 (described later) provided on the switching lens holding frame 10, is a locking mechanism that prevents switching between the first switching lens 4a and the second switching lens 4b. To configure.

Further, in order to drive (reset) the cam cylinder 11 to a predetermined zoom position on the end surface of the cam cylinder 11 on the image pickup surface side, the light of the photo interrupter (not shown) held by the base member 6 is shielded from light. A light-shielding portion 11d is formed. When the cam cylinder 11 is rotated so that the zoom lens group (second lens group 2 and third lens group 3) reaches the super-telephoto end region in the first zoom drive region described later, the light-shielding portion 11d blocks the photo interrupter. do.

FIG. 5 is a diagram for explaining a locking mechanism for preventing switching of the switching lens group shown in FIG. 1. 5 (a) is a diagram showing a locking mechanism, and FIG. 5 (b) is a cross-sectional view taken along the line BB shown in FIG. 5 (a).

The locking mechanism is formed by an arc-shaped locking wall 11c provided on the cam cylinder 11 and a first locking arm 10e-1 and a second locking arm 10e-2 provided on the switching lens holding frame 10. It is composed. The first locking arm 10e-1 and the second locking arm 10e-2 are located along the driving direction of the switching lens group 4 from the position on the imaging surface side of the end surface of the locking wall 11c in the switching lens holding frame 10. It is formed so as to sandwich the lens.

Further, the tip portions of the first locking arm 10e-1 and the second locking arm 10e-2 are provided with convex portions 10f-1 and 10f-2 toward the subject side, respectively, and the first locking arm 10e-1 and the second locking arm 10e-2 are provided. The locking arm 10e-1 and the second locking arm 10e-2 are L-shaped. The convex portions 10f-1 and 10f-2 are formed so that their end faces protrude toward the subject side from the end faces of the locking wall 11c.

In a shooting state, for example, as shown in FIGS. 5A and 5B, in a state where the first switching lens 4a is located on the shooting optical axis, the convex portion 10f-1 is a locking wall 11c. It overlaps in the radial direction with respect to. Moreover, the convex portion 10f-1 is located radially outside the locking wall 11c.

It is assumed that a force equal to or greater than the urging force is applied to the switching lens group 4 in the direction opposite to the urging direction of the toggle spring (downward in FIGS. 5A and 5B). In this case, the inner peripheral surface 10g-1 of the convex portion 10f-1 comes into contact with the outer peripheral surface 11c-1 of the arcuate locking wall 11c, and the switching of the lens is prevented.

On the other hand, as will be described later, when the second switching lens 4b is located on the shooting optical axis, the convex portion 10f-2 overlaps the locking wall 11c in the radial direction, and the convex portion 10f-. 2 is located radially outside the locking wall 11c. When a force is applied upward in the figure, the inner peripheral surface 10g-2 of the convex portion 10f-2 abuts on 11c-1 to prevent the lens from switching.

6 to 9 are diagrams for explaining the operation of the switching lens group shown in FIG. 1. 6 (a) is a diagram showing the operation of the switching mechanism when the first switching lens is arranged on the photographing optical axis, and FIGS. 6 (b), 6 (c), and 7 (a). ) Is a diagram showing the operation of the switching mechanism when switching the switching lens located on the optical axis of photography. Further, FIG. 7B is a diagram showing the operation of the switching mechanism when the second switching lens is arranged on the photographing optical axis. Further, FIGS. 8 (a) to 8 (c), FIGS. 9 (a), and 9 (b) are shown in FIGS. 6 (a) to 6 (c), FIGS. 7 (a), and 7 (b), respectively. It is a figure which shows the position on the cam groove of the pin-shaped member of the 2nd lens holding frame, and the pin-shaped member of a 3rd lens holding frame in (b).

The cam grooves 12 and 13 are defined with first zoom drive regions 12a and 13a that zoom drive the imaging optical system from a wide-angle region for land use to a telephoto region. Further, the cam grooves 12 and 13 are defined with second zoom drive regions 12b and 13b for zooming the imaging optical system from the wide-angle region for underwater to the telephoto region. The cam grooves 12 and 13 have switching lens group moving regions 12c and 13c that continuously connect the two zoom drive regions.

The first zoom drive regions 12a and 13a and the second zoom drive regions 12b and 13b are formed substantially symmetrically with respect to the switching lens group moving regions 12c and 13c. These zoom drive regions are connected to the switching lens group moving regions 12c and 13c on the wide-angle side of each zoom drive region.

As described above, when connecting on the wide-angle side, it is assumed that the shooting frequency on the wide-angle side is high, and it is more convenient to start shooting from the wide-angle side after the switching operation of the switching lens group 4. This is because the switching time can be shortened.

During shooting, the pin-shaped members 8a and 9a engage with one of the first zoom drive regions 12a and 13a and the second zoom drive regions 12b and 13b to drive the zoom. It is assumed that the cam cylinder 11 is rotated so that the pin-shaped members 8a and 9a move from the first zoom drive regions 12a and 13a to the second zoom drive regions 12b and 13b or in the opposite direction. In this case, the switching lens group 4 is interlocked by the internal tooth gear 11b of the cam cylinder 11 to perform the switching operation while passing through the switching lens group moving regions 12c and 13c.

As shown in FIG. 6A, when the first switching lens 4a is arranged on the optical axis for photographing, the cam cylinder 11 is driven in a rotation range in which the internal tooth gear 11b and the idler gear 16 do not mesh with each other. .. Meanwhile, as shown in FIG. 8A, the second lens group 2 and the third lens group 3 are zoom-driven along the optical axis along the first zoom drive regions 12a and 13a. At this time, the locking wall 11c and the locking arm 10e-1 overlap in the radial direction in the entire area of the first zoom drive regions 12a and 13a. Moreover, the locking arm convex portion 10f-1 is located on the outer periphery of the locking wall 11c, and the locking mechanism operates.

As shown in FIGS. 6 (b) and 8 (b), the cam cylinder 11 moves the pin-shaped member 8a and the pin-shaped member 9a from the first zoom drive regions 12a and 13a to the switching lens group moving regions 12c and 13c. To rotate. Then, the internal tooth gear 11b starts meshing with the idler gear 16. Since the idler gear 16 and the rack portion 10b of the switching lens holding frame 10 are always in mesh with each other, the switching lens holding frame 10 starts moving along the guide shafts 13a and 13b as the idler gear 16 rotates.

In this way, when the internal tooth gear 11b begins to mesh with the idler gear 16, the locking wall 11c and the locking arm 10e-1 overlap in the radial direction, and the convex portion 10f-1 is arranged on the outer periphery of the locking wall 11c. The positional relationship is maintained, and the lock mechanism is still in an effective state.

Further, when the cam cylinder 11 is rotated to move the switching lens group 4, the locking wall 11c and the convex portion 10f-1 are in a positional relationship in which they do not overlap in the radial direction, and the lock is released (FIG. 6 (c)). And see FIG. 8 (c)). Then, before the switching lens group 4 moves and the meshing between the internal tooth gear 11b and the idler gear 16 is released, the convex portion 10f-2 radially overlaps with the locking wall 11c. Further, the convex portion 10f-2 is located on the outer peripheral side of the locking wall 11c, and the locking mechanism starts to work again (see FIGS. 7 (a) and 9 (a)).

After the locking wall 11c and the second locking arm 10e-2 are locked in the positional relationship in this way, the engagement between the idler gear 16 and the internal tooth gear 10c is released. After the switching operation is completed, by rotating the cam cylinder 11 in the same direction as before, the pin-shaped member 8a and the pin-shaped member 9a move from the second zoom drive regions 12c and 13c to the switching lens group moving region 12b. And 13b (see FIGS. 7 (b) and 9 (b)).

In this way, the switching operation of the switching lens group 4 can be performed in conjunction with the zoom motor through the cam cylinder 11 and the idler gear 16. Further, as described above, the cam grooves are connected substantially symmetrically to provide two zoom drive regions, and the switching lens group is switched in the connected regions. This makes it possible to use the switching lens group properly in the entire zoom drive range.

In the above-mentioned configuration in which the two cam grooves are not connected, when the lens is similarly switched on the wide-angle side, when the cam cylinder is rotated to the switching area on the wide-angle side, the first switching lens 4a to the first switching lens 4a are used. It can be switched to the switching lens 4b of 2. Then, the second switching lens 4b is switched to the first switching lens 4a. That is, it is necessary to alternately switch to different moving directions by the operation input from one direction. Therefore, it is necessary to incorporate a heart cam mechanism, a push lock mechanism, or the like, which complicates the configuration of the switching mechanism.

On the other hand, if the cam grooves are connected substantially symmetrically and two zoom drive regions are provided as in the first embodiment, the switching mechanism can be configured by a simple reciprocating switching mechanism using a gear and a rack.

Further, in the configuration in which the two cam grooves are not connected, it is necessary to perform a switching operation outside the zoom drive region, then stop the zoom motor once, rotate it in the reverse direction, and return it to the zoom drive region. On the other hand, in the first embodiment, such a reversing operation is not necessary, and the operation loss of the motor can be eliminated.

In FIG. 6A described above, the meshing range of the idler gear 16 and the internal tooth gear 11b in the rotation range of the cam cylinder 11 and the locking wall 11c and the first locking arm 10e-1 or the second locking arm 10e The effective range of the locking mechanism configured by -2 is shown. As shown in the figure, the movement of the switching lens holding frame 10 is restricted by the lock mechanism both after the gears start to mesh and before the gears are disengaged.

Next, the gap between the locking wall 11c and the convex portion 10f-1 or 10f-2 will be described.

FIG. 10 is a diagram for explaining the gap between the locking wall and the convex portion shown in FIG. 10 (a) is a diagram showing the switching mechanism when the idler gear and the internal tooth gear mesh with each other from the rear side, and FIG. 10 (b) shows the tooth tip circle of the idler gear and the tooth tip circle of the internal tooth gear. It is a figure.

As shown in FIG. 5B, the gap between the locking wall 11c constituting the locking mechanism and the locking arm convex portion 10f-1 is defined as ΔX. Further, the position of the tooth tip of the tooth 16a of the idler gear 16 that meshes with the internal tooth gear 11b as the second tooth on the tooth tip circle 20 of the idler gear 16 is defined as a point A. Further, the intersection of the tooth tip circle 20 of the idler gear 16 and the tooth tip circle 21 of the internal tooth gear 11b is defined as a point B (see FIG. 10B).

At this time, the gap ΔX between the locking wall 11c and the convex portion 10f-1 and the arc AB satisfy ΔX <arc AB. If ΔX <arc AB, it is possible to prevent a malfunction caused by the tooth 16a unintentionally engaging with the first tooth of the internal tooth gear 11b due to an external force.

FIG. 11 is a side view of the lens barrel shown in FIG. 1. 12 and 13 are cross-sectional views taken along the line CC shown in FIG. 12 (a), 12 (b), 13 (a), and 13 (b) are diagrams showing the operation when the first switching lens is arranged on the optical axis for photographing.

In order to establish the relationship of ΔX <arc AB, here, the tapered surfaces 11c-2, 11c-3, and 10h-1 are formed on both ends of the locking wall 11c and the convex portions 10f-1 and 10f-2, respectively. , And 10h-2 are formed.

In FIG. 12A, the locking wall 11c and the convex portion 10f-1 do not overlap in the radial direction, and the locking mechanism is not yet operating. In FIG. 12B, the tapered surface 11c-2 formed at the end of the locking wall 11c enters to a position where it radially overlaps the tapered surface 10h-1 of the convex portion 10f-1, and the locking mechanism is activated. Start working.

In FIG. 13A, the locking wall 11c and the convex portion 10f-1 are radially overlapped with each other to operate the locking mechanism, and the internal tooth gear 10b and the idler gear 16 are still in mesh with each other. .. When the switching operation proceeds to the position shown in FIG. 13B, the meshing between the internal tooth gear 10b and the idler gear 16 is released.

By forming the tapered surface in this way, it becomes possible to activate the locking mechanism from the time when the inner circumference 10g-1 of the convex portion is located radially inside the outer circumference 11c-1 of the locking wall. Therefore, the effective range of the lock mechanism and the meshing range of the gear can be overlapped with each other in a state where the radial gap between the locking wall 11c and the convex portion 10f-1 is narrowed. Then, the relationship of ΔX <arc AB can be maintained.

As described above, the effective range of the lock mechanism and the meshing range of the gear are partially overlapped, and the gap between the locking wall 11c and the convex portion 10f-1 or 10f-2 is defined in the above relationship. It is possible to prevent the biting of the gear and smoothly shift to the switching operation.

As described above, in the first embodiment of the present invention, the switching lens group is switched by the cam cylinder provided with the cam grooves connected substantially symmetrically, so that the switching lens group is switched at low cost and compactly, and the optics are optical over the entire zoom range. Elements can be selectively switched.

[Second Embodiment]
Subsequently, the lens barrel according to the second embodiment of the present invention will be described. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numbers, and the description thereof will be omitted.

In the lens switching mechanism according to the second embodiment, the configuration of the switching lens holding frame 10 for holding the switching lens group 4 and the support method for the switching lens holding frame 10 are different from those of the first embodiment.

FIG. 14 is a front view showing a lens switching mechanism used in the lens barrel according to the second embodiment of the present invention.

In the first embodiment described above, the switching lens holding frame 10 is held by the two guide shafts 15a and 15b so as to translate on a plane perpendicular to the optical axis (on a plane orthogonal to the optical axis). On the other hand, in the second embodiment, the switching lens holding frame 10 is rotatably held around a rotating shaft 22 arranged substantially parallel to the photographing optical axis.

FIG. 15 is a diagram for explaining the operation of the lens switching mechanism shown in FIG. 15 (a) is a diagram showing a state in which the first switching lens is positioned on the photographing optical axis from the rear side, and FIG. 15 (b) is a diagram showing the state in which the second switching lens is positioned on the photographing optical axis. It is a figure which shows the state which was made to have been made from the back side.

Similar to the first embodiment, when the first switching lens 4a is positioned on the photographing optical axis, the locking mechanism functions by the first locking arm 10e-1 and the locking wall 11c. Further, when the second switching lens 4b is positioned on the photographing optical axis, the locking mechanism functions by the second locking arm 10e-2 and the locking wall 11c.

The relationship between the lock mechanism and the meshing range of the gears during the switching operation is as shown in FIG. 8 (a). On the other hand, here, the idler gear 16 (relay transmission means) described in the first embodiment is not used.

As shown in FIGS. 15A and 15B, a switching gear portion 23 is provided in the switching lens holding frame 10, and the switching gear portion 23 is directly meshed with the internal tooth gear 11b to perform the first switching. The switching operation of the lens 4a and the second switching lens 4b is performed. This makes it possible to reduce the number of parts.

FIG. 16 is a diagram for explaining a locking mechanism for preventing switching of the switching lens group shown in FIG. 14. 16 (a) is a cross-sectional view, and FIG. 16 (b) is a diagram showing a tooth tip circle of the switching gear portion and the internal gear.

As shown in the figure, the gap ΔY of the locking mechanism composed of the locking wall 11c and the convex portions 10f-1 and 10f-2 has the same dimensions as ΔX in the first embodiment. Point C is the position of the tooth tip of the gear portion that meshes with the internal tooth gear 11b and the second tooth on the tooth tip circle 24 of the switching gear portion 23 shown in FIG. 16 (a). Further, the intersection of the tooth tip circle 24 of the gear portion 23 and the tooth tip circle 21 of the internal tooth gear 11b is defined as a point D (see FIG. 16B). At this time, the relationship is ΔY <arc CD. If ΔY <arc CD, it is possible to prevent malfunction caused by the internal tooth gear 11b and the tooth of the switching gear portion 23 that meshes with the second tooth unintentionally meshing with the first tooth due to an external force. ..

As described above, in the second embodiment of the present invention, the switching lens holding frame 10 is rotated around an axis substantially parallel to the optical axis for photographing, and a cam cylinder having a cam groove connected substantially symmetrically. Lens switching operation is performed by. As a result, the number of parts can be reduced, and as a result, a switching mechanism that is more advantageous in terms of cost can be configured.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

For example, in the embodiment, an example of switching between two switching lenses has been described, but the lens is not limited to the lens, and an optical element group such as a filter may be switched. Further, not only the switching of optical elements such as lenses, but also one optical element may be inserted and removed. Further, in the embodiment, the first zoom drive region 12a and the second zoom drive region 12b are connected on the wide-angle side, but the two zoom drive regions may be connected on the telephoto side.

4 Switching lens group 5 Imaging element 6 Base member 6a, 6b Guide bearing part 6c Gear shaft fixing part 6d Roof part 6e Gear shaft through hole 6f, 6g Mechanical stopper 7 Fixed cylinder 10 Switching lens holding frame

Claims (12)

In an optical device including a zoom lens group that moves along the shooting optical axis to change the magnification of the imaging optical system and a rotating cylinder that rotates about the shooting optical axis.
A holding member that holds at least one optical element and
A base member that movably holds the holding member in order to selectively position the optical element on the photographing optical axis and outside the photographing optical axis is provided.
The rotary cylinder has a first cam groove for moving the zoom lens group from the wide-angle region to the telephoto region.
With respect to the second cam groove having a predetermined positional relationship with respect to the first cam groove,
A third cam groove that continuously connects the first cam groove and the second cam groove is formed.
Further, when the rotary cylinder is rotated to move the zoom lens group between the first cam groove and the second cam groove, the zoom lens group engages with the third cam groove. It has a moving mechanism that moves the holding member in conjunction with the rotation of the rotary cylinder when the holding member is used.
The predetermined positional relationship is an optical instrument in which the second cam groove is formed so that the phases of the wide-angle region and the telephoto region are symmetrical with respect to the first cam groove . The optical device according to claim 1 , wherein the holding member is located inside the outer peripheral surface of the rotary cylinder. The holding member is axially supported by the base member so as to be movable in parallel on a plane orthogonal to the photographing optical axis.
The moving mechanism includes a rack portion formed on the holding member and a rack portion.
With an internal tooth gear partially formed on the rotary cylinder,
The optical device according to claim 1 or 2 , wherein the rack portion and the internal tooth gear are interlocked to move the holding member. The holding member is rotatably supported by the base member about an axis substantially parallel to the photographing optical axis.
The moving mechanism includes a gear portion formed on the holding member and a gear portion.
With an internal tooth gear partially formed on the rotary cylinder,
The optical device according to claim 1 or 2 , wherein the gear portion and the internal tooth gear are connected and driven to move the holding member. The optical device according to any one of claims 1 to 4 , wherein the wide-angle side of each of the first cam groove and the second cam groove is connected by the third cam groove. The optical device according to any one of claims 1 to 4 , wherein the telephoto side of each of the first cam groove and the second cam groove is connected by the third cam groove. The moving mechanism provides holding means for holding the holding member in each of a first photographing state in which the optical element is located on the photographing optical axis and a second photographing state in which the optical element is located outside the photographing optical axis. The optical device according to any one of claims 1 to 6 , wherein the optical instrument has. The optical device according to claim 7 , wherein the holding means holds the holding member by a toggle spring. The optical device is mounted on an image pickup apparatus having an image pickup unit that generates an image signal corresponding to an optical image, and is a lens barrel that forms an image of the optical image on the image pickup unit. 8. The optical device according to any one of 8. In an optical device including a zoom lens group that moves along the shooting optical axis to change the magnification of the imaging optical system and a rotating cylinder that rotates about the shooting optical axis.
A holding member that holds multiple optical elements and
A base member that movably holds the holding member in order to selectively position the optical element on the photographing optical axis and outside the photographing optical axis is provided.
The rotary cylinder has a first cam groove for moving the zoom lens group in a state where the first optical element among the plurality of optical elements is inserted in the photographing optical axis.
A second cam groove for moving the zoom lens group in a state where the second optical element of the plurality of optical elements is inserted in the photographing optical axis, and
A third cam groove that continuously connects the first cam groove and the second cam groove is formed.
Further, when the rotary cylinder is rotated to move the zoom lens group between the first cam groove and the second cam groove, the zoom lens group engages with the third cam groove. It has a moving mechanism that moves the holding member in conjunction with the rotation of the rotary cylinder when the holding member is used.
In the moving mechanism, when the zoom lens group enters the third cam groove from the first cam groove, the second optical element is inserted into the photographing optical axis and the first optical element is inserted. Depart from the shooting optical axis
When the zoom lens group enters the third cam groove from the second cam groove, the first optical element is inserted into the photographing optical axis and the second optical element is inserted from the photographing optical axis. An optical device characterized by being detached. The holding member is axially supported by the base member so as to be movable in parallel on a plane orthogonal to the photographing optical axis.
The moving mechanism includes a rack portion formed on the holding member and a rack portion.
With an internal tooth gear partially formed on the rotary cylinder,
The optical device according to claim 10, wherein the rack portion and the internal tooth gear are interlocked to move the holding member. The holding member is rotatably supported by the base member about an axis substantially parallel to the photographing optical axis.
The moving mechanism includes a gear portion formed on the holding member and a gear portion.
With an internal tooth gear partially formed on the rotary cylinder,
The optical device according to claim 10, wherein the gear portion and the internal tooth gear are connected and driven to move the holding member.

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