JP7380325B2 - Optical system drive device - Google Patents

Description

The present invention relates to an optical system drive device that moves optical elements such as lenses in the optical axis direction.

In optical equipment such as imaging devices, when optical elements such as lenses are movable in the optical axis direction, it is desirable to configure the optical system drive device as compactly as possible in order to downsize the optical equipment and increase flexibility in component layout. I have a request. Furthermore, in this type of optical system drive device, it is required to improve the workability of assembling each component during the manufacturing process. In particular, when a plurality of optical elements that move in the optical axis direction are provided, the mechanism for supporting and driving each optical element tends to become complicated, so the above requirements become stronger.

For example, as in Patent Document 1, in a viewfinder device that is installed in an imaging device and has an adjustable diopter, an operation member (such as a dial) for adjusting the diopter is provided on the rear surface of the exterior of the imaging device. Accordingly, the movable lens constituting the finder optical system is moved in the optical axis direction. A guide mechanism that movably guides the movable lens in the optical axis direction and a transmission mechanism that transmits the operating force of the operating member to the movable lens are required to have a space-saving and easy-to-manufacture structure.

Japanese Patent Application Publication No. 2004-205980

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical system drive device that has a compact and simple structure, has excellent productivity, and is capable of moving a plurality of optical elements in the optical axis direction.

The present invention provides an optical system drive device that moves a first movable optical element and a second movable optical element in the optical axis direction in response to the operation of an operating means, in which the first movable optical element is moved in the optical axis direction. A first guide member that movably guides the second movable optical element and a second guide member that movably guides the second movable optical element in the optical axis direction are arranged spaced apart in a direction perpendicular to the optical axis. Between the first guide member and the second guide member in the vertical direction, the first movable optical element and the second movable optical element are respectively moved along predetermined trajectories in the optical axis direction in response to the operation of the operating means. The first movable optical element and the second movable optical element have a common optical axis, and the first movable optical element and the second movable optical element share a common optical axis. The first guide member and the second guide member are located on the axis and have different positions in the optical axis direction, and each of the first guide member and the second guide member is a shaft member that extends in the optical axis direction. The length and the length of the second guide member in the optical axis direction are at least partially located in the same range in the optical axis direction, and a part of the drive member is located in the same range as the central axis of the first guide member and the second guide member. It is characterized in that it is arranged close to the optical axes of the first movable optical element and the second movable optical element to a position overlapping with an imaginary line connecting the central axis of the guide member.

According to the present invention, it is possible to obtain an optical system drive device that has a small and simple structure, has excellent productivity, and is capable of moving a plurality of optical elements in the optical axis direction.

FIG. 3 is a front perspective view of the finder block in an exploded state. FIG. 3 is a rear perspective view of the finder block in an exploded state. FIG. 3 is a front view of a movable lens and a drive mechanism that constitute the finder block. FIG. 3 is a rear view of the movable lens and the drive mechanism. FIG. 3 is a top view of a movable lens and a drive mechanism. It is a side view of a movable lens and a drive mechanism. FIG. 3 is a rear view of a finder block including a diopter adjustment dial. 8 is a sectional view taken along line VIII-VIII in FIG. 7. FIG. FIG. 6 is a diagram showing the relationship between rotation of a cam member and movement of a movable lens.

Embodiments to which the present invention is applied will be described below with reference to the drawings. The present embodiment is applied to a finder block 10 that constitutes a finder of an imaging device (camera) as an example of an optical system driving device. The finder block 10 is assembled into a main body (not shown) of an imaging device after assembling various parts to be described later into the state shown in FIGS. 7 and 8. The direction along the optical axis OX (see FIGS. 3 to 6 and 8) of the optical system of the finder block 10 is defined as the optical axis direction. Front and back, left and right, and up and down indicated by arrows in each figure mean each direction with respect to the imaging device in which the finder block 10 is mounted. The front-rear direction coincides with the optical axis direction of the finder block 10.

The optical system constituting the finder block 10 is a part of the eyepiece side of the finder optical system in the imaging device, and the finder block 10 has a diopter adjustment function that can be operated by the user. When applying the present invention to a finder optical system with a diopter adjustment function, there are two types: a reflex type that guides the subject light from the photographing optical system to the eyepiece optical system via a reflector, and a reflex type that guides the subject light from the photographing optical system to the eyepiece optical system without using a reflector. It can be applied to any non-reflex type (direct view type) finder that directly observes the subject using an independent finder optical system.

1 and 2 show the main parts of the finder block 10 in an exploded state. The finder block 10 has a case 11 that serves as a base (supporting member) for assembling each component, and is constructed by assembling lenses, which are optical elements, and other components to the case 11. As shown in FIG. 7, the finder block 10 includes a back cover 12 attached to the rear of the case 11, and a diopter adjustment dial 13 rotatably supported with respect to the back cover 12. The back cover 12 constitutes a part of the exterior on the back side of the imaging device when the finder block 10 is attached to the imaging device. The diopter adjustment dial 13 is located on the back side of the imaging device and can be rotated by the user.

As shown in FIG. 8, the optical system in the finder block 10 includes, in order from the front in the optical axis direction, a front fixed lens L1, a front movable lens L2, a rear movable lens L3, and a rear fixed lens L4. As shown in FIGS. 1 to 4, each lens L1 to L4 has a substantially rectangular outer shape when viewed from the front (or rear view) along the optical axis OX, with the longitudinal direction facing the left and right direction and the short It has an oblong shape with the hand facing up and down. In the following explanations regarding each lens L1 to L4, "side surface" means the edges on both sides facing in the left-right direction, "top surface" means the edge facing upward, and "bottom surface" means the edge facing downward. means.

The front fixed lens L1 and the rear fixed lens L4 are fixed lenses that are fixedly supported with respect to the case 11, and the front movable lens L2 and the rear movable lens L3 are movable relative to the case 11 in the optical axis direction. It is a supported movable lens. In response to a rotational operation of the diopter adjustment dial 13, the front movable lens L2 and the rear movable lens L3 each move along predetermined trajectories in the optical axis direction, thereby performing diopter adjustment.

The case 11 has an accommodation space 14 inside that accommodates each of the lenses L1 to L4. The case 11 has a box-like shape that penetrates in the optical axis direction, and has left and right walls surrounding each lens, and upper and lower walls as a basic structure, but the upper and lower walls are partially open, and the rear Each of the lenses L1 to L3, except for the fixed lens L4, is assembled into the case 11 from above and below.

More specifically, as shown in FIG. 1, the upper surface side of the case 11 is formed with a first opening 15 located furthest forward in the optical axis direction, and a second opening 16 that comes into contact with and separates from the rear of the first opening 15. has been done. The front fixed lens L1 is inserted into the housing space 14 from above to below through the first opening 15. The front movable lens L2 is inserted into the housing space 14 from above to below through the second opening 16. That is, in the accommodation space 14, the space below the first opening 15 is an area that accommodates the front fixed lens L1, and the space below the second opening 16 is an area that accommodates the front movable lens L2.

As shown in FIG. 2, a third opening 17 is formed on the lower surface side of the case 11. The third opening 17 is formed behind the second opening 16 in the optical axis direction, and the rear movable lens L3 is inserted into the accommodation space 14 from below to above through the third opening 17. That is, the space above the third opening 17 in the accommodation space 14 is an area that accommodates the rear movable lens L3. A rear end accommodating portion 18 that opens rearward is formed on the rear end side of the case 11. The rear end accommodating portion 18 constitutes the rear end portion of the accommodating space 14, and the rear fixed lens L4 is assembled to the rear end accommodating portion 18 from the rear.

The case 11 further includes a side support portion 19 on the right side of the housing space 14 . The side support portion 19 is a portion that collectively supports components related to supporting and driving each of the movable lenses L2 and L3, such as the main guide shafts 23 and 28, the camshaft member 40, and the transmission member 55, which will be described later. be.

As shown in FIGS. 1 and 8, a plurality of ribs 20 are provided on the periphery (left and right side surfaces and lower surface) of the front fixed lens L1. The front fixed lens L1 inserted into the accommodation space 14 through the first opening 15 has a plurality of ribs 20 fitted into a plurality of recesses 11a formed on the inside of the case 11 (left and right side surfaces and bottom surface). The axial position is determined. Further, the fitting between the recess 11a and the rib 20 restricts the movement of the front fixed lens L1 in the left-right direction and downward, and the position is determined.

As shown in FIGS. 1, 3 to 6, a first arm 21 and a second arm 22 are provided that protrude left and right from the front movable lens L2. The first arm 21 protrudes from the right side surface of the front movable lens L2, and the second arm 22 protrudes from the left side surface of the front movable lens L2. The first arm 21 and the second arm 22 each protrude from a portion of the left and right side surfaces of the front movable lens L2 that is closer to the upper surface of the front movable lens L2. The first arm 21 is formed with a guide hole 21a that penetrates in the optical axis direction. The second arm 22 is formed with an elongated rotation regulating groove 22a that penetrates in the optical axis direction and is open toward the left.

As shown in FIGS. 1 and 8, a support hole 11b penetrating in the optical axis direction is formed in the side support portion 19 on the right side of the case 11. As shown in FIGS. Two support holes 11b are provided at different positions in the optical axis direction, and the first arm 21 is arranged between the two support holes 11b. A main guide shaft 23 extending in the optical axis direction is inserted into the support hole 11b and the guide hole 21a. The main guide shaft 23 is a cylindrical member with a uniform cross-sectional shape along the optical axis direction, and has a large diameter head 23a at the rear end in the optical axis direction. The main guide shaft 23 is inserted until the head 23a comes into contact with the bottom surface of the recess 11c (see FIGS. 2 and 8) formed on the rear side of the side support portion 19. The main guide shaft 23 is fixedly supported in each support hole 11b. The guide hole 21a of the first arm 21 is supported slidably in the optical axis direction with respect to the main guide shaft 23, which is fixedly supported.

As shown in FIGS. 1 and 8, a support hole 11d penetrating in the optical axis direction is formed on the left side of the case 11. Two support holes 11d are provided at different positions in the optical axis direction, and the second arm 22 is arranged between the two support holes 11d. A sub-guide shaft 24 extending in the optical axis direction is inserted into the support hole 11d and the rotation regulating groove 22a. The sub-guide shaft 24 is a cylindrical member with a uniform cross-sectional shape along the optical axis direction, and has a large-diameter head 24a at the rear end portion in the optical axis direction. The sub-guide shaft 24 is inserted until the head 24a comes into contact with the bottom surface of a rearward-facing recess 11e (see FIG. 8) formed in the case 11. The sub-guide shaft 24 is fixedly supported in each support hole 11d. The rotation regulating groove 22a of the second arm 22 is slidably supported in the optical axis direction with respect to the fixedly supported sub-guide shaft 24.

The guide hole 21a has a cylindrical inner peripheral surface surrounding the main guide shaft 23, and the movement of the first arm 21 in all directions perpendicular to the optical axis OX is limited by the main guide shaft 23. That is, the first arm 21 is linearly guided so as to move only in the optical axis direction with respect to the main guide shaft 23. The rotation regulating groove 22a has a length in the horizontal direction larger than a width in the vertical direction. Position changes in the directions are allowed. Therefore, the front movable lens L2 is guided in a straight line in the optical axis direction by the main guide shaft 23, and its rotation about the axis (main guide shaft 23) parallel to the optical axis OX is restricted by the sub guide shaft 24. Supported by

The first arm 21 is provided with a cylindrical portion 21b that protrudes forward, and a guide hole 21a is formed in the center of the cylindrical portion 21b. A coil spring 25 is attached that surrounds the cylindrical portion 21b and has its axis directed in the optical axis direction. The coil spring 25 is a compression spring, and when the front movable lens L2 is assembled in the case 11, one end of the coil spring 25 is in contact with the first arm 21, and the other end of the coil spring 25 is in contact with the inner surface of the case 11 (lateral support part). 19 front wall). The coil spring 25 urges the front movable lens L2 toward the rear in the optical axis direction.

As shown in FIGS. 2 to 6, a first arm 26 and a second arm 27 are provided that protrude left and right from the rear movable lens L3. The first arm 26 protrudes from the right side surface of the rear movable lens L3, and the second arm 27 protrudes from the left side surface of the rear movable lens L3. The first arm 26 and the second arm 27 each protrude from a lower portion of the left and right side surfaces of the rear movable lens L3 that is close to the lower surface of the rear movable lens L3. A guide hole 26a is formed in the first arm 26 and extends in the optical axis direction. The second arm 27 is formed with an elongated rotation regulating groove 27a that penetrates in the optical axis direction and is open toward the left.

As shown in FIG. 2, a support hole 11f penetrating in the optical axis direction is formed in the side support portion 19 on the right side of the case 11 below the above-mentioned support hole 11b. Although only one support hole 11f is shown in FIG. 2, two support holes 11f are provided at different positions in the optical axis direction, and the first arm 26 is provided between the two support holes 11f. is placed. A main guide shaft 28 extending in the optical axis direction is inserted into the support hole 11f and the guide hole 26a. The main guide shaft 28 is a cylindrical member with a uniform cross-sectional shape along the optical axis direction, and has a large diameter head 28a at the rear end in the optical axis direction. The main guide shaft 28 is inserted until the head 28a comes into contact with the bottom of the recess 11g (see FIG. 2) formed on the rear side of the side support part 19. The main guide shaft 28 is fixedly supported in each support hole 11f. The guide hole 26a of the first arm 26 is supported slidably in the optical axis direction with respect to the main guide shaft 28, which is fixedly supported.

As shown in FIG. 2, on the left side of the case 11, a support hole 11h is formed below the above-mentioned support hole 11d and penetrates in the optical axis direction. Although only one support hole 11h is shown in FIG. 2, two support holes 11h are provided at different positions in the optical axis direction, and the second arm 27 is provided between the two support holes 11h. is placed. A sub-guide shaft 29 extending in the optical axis direction is inserted into the support hole 11h and the rotation regulating groove 27a. The sub-guide shaft 29 is a cylindrical member with a uniform cross-sectional shape along the optical axis direction, and has a large-diameter head 29a at the rear end in the optical axis direction. The sub-guide shaft 29 is inserted until the head 29a comes into contact with the bottom surface of a rearward-facing recess (not shown) formed in the case 11. The sub-guide shaft 29 is fixedly supported in each support hole 11h. The rotation regulating groove 27a of the second arm 27 is slidably supported in the optical axis direction with respect to the fixedly supported sub-guide shaft 29.

The guide hole 26a has a cylindrical inner peripheral surface surrounding the main guide shaft 28, and the movement of the first arm 26 in all directions perpendicular to the optical axis OX is limited by the main guide shaft 28. In other words, the first arm 26 is linearly guided so as to move only in the optical axis direction with respect to the main guide shaft 28. The rotation regulating groove 27a has a length in the horizontal direction larger than a width in the vertical direction. Position changes in the directions are allowed. Therefore, the rear movable lens L3 is guided straight in the optical axis direction by the main guide shaft 28, and its rotation about the axis (main guide shaft 28) parallel to the optical axis OX is restricted by the sub guide shaft 29. Supported by

The first arm 26 is provided with a cylindrical portion 26b that protrudes rearward, and a guide hole 26a is formed in the center of the cylindrical portion 26b. A coil spring 30 is attached to surround the cylindrical portion 26b and have its axis directed in the optical axis direction. The coil spring 30 is a compression spring, and when the rear movable lens L3 is assembled into the case 11, one end of the coil spring 30 is in contact with the first arm 26, and the other end of the coil spring 30 is in contact with the inner surface of the case 11 (lateral support part). 19 rear wall). The coil spring 30 urges the rear movable lens L3 forward in the optical axis direction.

As shown in FIG. 2, a plurality of ribs 31 are provided on the periphery (left and right side surfaces, upper surface, and lower surface) of the rear fixed lens L4. The rear fixed lens L4 inserted into the rear end accommodating portion 18 from the rear is positioned in the optical axis direction by fitting the plurality of ribs 31 into the plurality of recesses 11i formed in the case 11. Furthermore, the fitting between the recess 11i and the rib 31 restricts the movement of the front and back fixed lens L4 in the left-right direction and the up-down direction, and the position is determined. Further, the fitting protrusions 32 on the rear fixed lens L4 side fit into the plurality of fitting holes 11j formed in the case 11, and the rear fixed lens L4 moves backward from the rear end accommodating part 18 (falls off). ) are regulated.

The lenses L1 to L4 are assembled to the case 11 as follows. The front fixed lens L1 and the front movable lens L2 are inserted into the accommodation space 14 from above through the corresponding first opening 15 and second opening 16, respectively. By fitting the rib 20 into the recess 11a, the position of the front fixed lens L1 in the optical axis direction is determined. Further, the front fixed lens L1 is surrounded by the wall surface of the case 11 except for the upper surface of the case 11 where the first opening 15 is formed, and movement of the front fixed lens L1 in the left-right direction and downward direction is restricted.

After inserting the front fixed lens L1 and the front movable lens L2 into the housing space 14, the upper cover 33 (see FIG. 1) is attached to the upper surface side of the case 11. Three positioning protrusions 11k and two screw holes 11m are formed on the upper surface of the case 11. The upper cover 33 has three positioning holes 33a corresponding to the positioning projections 11k and two screw insertion holes 33b corresponding to the screw holes 11m. The position of the upper cover 33 is determined by inserting the corresponding positioning protrusion 11k into each positioning hole 33a. Then, the upper cover 33 is fixed to the case 11 by screwing the screws 34 into the screw holes 11m through the respective screw insertion holes 33b.

The upper cover 33 attached to the case 11 covers the first opening 15 and the second opening 16. A protrusion 35 (see FIG. 1) provided on the upper surface side of the front fixed lens L1 comes into contact with the upper cover 33, thereby restricting upward movement of the front fixed lens L1 (falling off from the first opening 15). That is, the front fixed lens L1 is surrounded by each wall of the case 11 and the upper cover 33, and is fixedly supported.

After inserting the front movable lens L2 into the housing space 14, the main guide shaft 23 and the sub guide shaft 24 are inserted from behind in the optical axis direction and attached to the case 11. The main guide shaft 23 is inserted into the guide hole 21a, and the sub guide shaft 24 is inserted into the rotation regulating groove 22a. The front movable lens L2 is not directly restricted in position by the case 11, but is supported so as to be movable in the optical axis direction via the main guide shaft 23 and the sub guide shaft 24.

The rear movable lens L3 is inserted into the accommodation space 14 from below through the third opening 17. After inserting the rear movable lens L3 into the housing space 14, the main guide shaft 28 and the sub guide shaft 29 are inserted from behind in the optical axis direction and attached to the case 11. The main guide shaft 28 is inserted into the guide hole 26a, and the sub guide shaft 29 is inserted into the rotation regulating groove 27a. The rear movable lens L3 is not directly restricted in position by the case 11, but is supported via the main guide shaft 28 and the sub guide shaft 29 so as to be movable in the optical axis direction.

After inserting the rear movable lens L3 into the housing space 14, a lower cover 36 (see FIG. 2) is attached to the lower surface side of the case 11. The lower surface of the case 11 is formed with four positioning protrusions 11n and two screw holes 11p. The lower cover 36 has four positioning holes 36a corresponding to the positioning projections 11n and two screw insertion holes 36b corresponding to the screw holes 11p. The position of the lower cover 36 is determined by inserting the corresponding positioning protrusion 11n into each positioning hole 36a. The lower cover 36 is fixed to the case 11 by screwing the screws 37 into the screw holes 11p through the respective screw insertion holes 36b.

The movement of the rear movable lens L3 in the direction perpendicular to the optical axis OX is restricted by the main guide shaft 28 and the sub guide shaft 29. Therefore, unlike the upper cover 33 that is involved in supporting the front fixed lens L1, the lower cover 36 does not directly support the rear movable lens L3. However, as shown in FIG. 2, the rear edge portion of the third opening 17 in the case 11 (the boundary portion with the rear end accommodating portion 18) has a narrow bridge shape. Therefore, the strength of the case 11 around the third opening 17 can be improved by attaching the lower cover 36 configured to fit also to the bridge portion. Further, from the viewpoint of light shielding properties and dustproof properties, it is preferable to cover the third opening 17 with the lower cover 36 instead of leaving it open.

The rear fixed lens L4 is assembled to the rear end accommodating portion 18 from the rear in the optical axis direction. Furthermore, as shown in FIG. 8, a rear cover 38 is attached to the rear part of the case 11. The rear cover 38 supports the cover glass G, and when the rear cover 38 is attached, the rear of the rear fixed lens L4 is covered by the cover glass G. Further, a sealing member (not shown) is sandwiched between the rear cover 38 and the cover glass G, so that the rear surface side of the finder block 10 has a dust-proof and drip-proof structure.

When assembled into the case 11, only the rear fixed lens L4 is inserted in the optical axis direction, and the other lenses L1, L2, and L3 are assembled into the case 11 in a direction perpendicular to the optical axis OX. Therefore, compared to a configuration in which a plurality of lenses are sequentially assembled in the optical axis direction, the finder block 10 of this embodiment has a higher degree of freedom in the order in which the lenses L1 to L4 are assembled to the case 11.

As shown in FIGS. 3 to 6, two main guide shafts 23, 28 and two sub guide shafts 24, 29 that support the front movable lens L2 and the rear movable lens L3 support the front movable lens L2 and the rear movable lens L3. They are arranged on the left and right sides of the screen. The main guide shaft 23 and the main guide shaft 28 are located on the right side of the front movable lens L2 and the rear movable lens L3, and are spaced apart in the vertical direction with the main guide shaft 23 at the top and the main guide shaft 28 at the bottom. It is placed with a space between. The sub guide shaft 24 and the sub guide shaft 29 are located on the left side of the front movable lens L2 and the rear movable lens L3, and are spaced apart in the vertical direction with the sub guide shaft 24 at the top and the sub guide shaft 29 at the bottom. It is placed with a space between. In this way, by arranging the four guide shafts near the four corners of the horizontally long rectangular front movable lens L2 and rear movable lens L3, the front movable lens L2 and rear movable lens The lens L3 can be guided in a straight line with high accuracy and stability.

For example, the larger the support length of the guide holes 21a, 26a in the optical axis direction by the main guide shafts 23, 28, the less likely the front movable lens L2 and the rear movable lens L3 will be tilted with respect to the optical axis OX, and the higher the precision of the lens. support can be achieved. By arranging the main guide shaft 23 and the main guide shaft 28 at different positions in the vertical direction, the lengths of the main guide shafts 23 and 28 and the support length for the guide holes 21a and 26a can be set without interfering with each other. This makes it possible to achieve a structure with excellent support accuracy for the front movable lens L2 and the rear movable lens L3. Furthermore, compared to a configuration in which the main guide shaft 23 and the main guide shaft 28 are arranged side by side in the optical axis direction, the guide mechanism for guiding the two movable lenses L2 and L3 can be made more compact in the optical axis direction.

More specifically, as shown in FIGS. 5 and 6, more than half of the lengths of the main guide shaft 23 and the main guide shaft 28 are located in the same range in the optical axis direction. Furthermore, the first arm 21 of the front movable lens L2 and the first arm 26 of the rear movable lens L3 are partially located at the same position in the optical axis direction. However, since the main guide shaft 23 and the main guide shaft 28 are provided apart from each other in the vertical direction, the main guide shaft 23 and the main guide shaft 28, and the first arm 21 and the first arm 26 interfere with each other. It can be accommodated within a limited space in the optical axis direction.

Similar effects can be obtained with the sub guide shafts 24, 29 and the second arms 22, 27. As shown in FIG. 5, by making their positions different in the vertical direction, the sub guide shaft 24 and the sub guide shaft 29 can have more than half of their respective lengths located in the same range in the optical axis direction. , it is possible to realize compactness in the optical axis direction while increasing the support accuracy of the front movable lens L2 and the rear movable lens L3.

The finder block 10 includes a camshaft member 40 as a drive member that moves the front movable lens L2 and the rear movable lens L3 in the optical axis direction in response to a rotational operation of the diopter adjustment dial 13. As shown in FIG. 1, the camshaft member 40 has at its center a shaft hole 41 with a circular cross section that penetrates in the optical axis direction, and has a cylindrical tube portion 42 surrounding the shaft hole 41. A transmitted gear 43 having a larger diameter than the cylindrical portion 42 is provided near the center of the cylindrical portion 42 in the optical axis direction. The transmitted gear 43 is a spur gear provided with a plurality of teeth facing parallel to the axis.

The camshaft member 40 is further provided with a front cam portion 44 and a rear cam portion 45 on both sides (front and rear) in the optical axis direction with the transmitted gear 43 interposed therebetween. A front cam portion 44 provided on one side (front side) in the optical axis direction with respect to the transmitted gear 43 has an end cam 44a facing forward. A rear cam portion 45 provided on the other side (rear side) in the optical axis direction with respect to the transmitted gear 43 has an end cam 45a facing rearward.

As shown in FIGS. 1 and 2, a cam accommodating portion 50 for accommodating the camshaft member 40 is formed in the side support portion 19 of the case 11. As shown in FIGS. The cam accommodating portion 50 has front and rear walls 50a where the front and rear ends of the cylindrical portion 42 face each other, and a shaft support hole 50b is formed in each of the front and rear walls 50a.

The camshaft member 40 is inserted between the front and rear walls 50a of the cam accommodating portion 50. As shown in FIG. 1, the cam accommodating portion 50 is open toward the right side opposite to the accommodating space 14 that accommodates each lens L1 to L4, and the cam shaft member 40 is inserted into the cam accommodating portion 50 from the right side. inserted. The camshaft member 40 inserted into the cam accommodating portion 50 has front and rear end surfaces of the cylindrical portion 42 facing the front and rear walls 50a, and movement in the optical axis direction is restricted.

A support shaft 52 extending in the optical axis direction is inserted into the shaft support hole 50b of the cam housing portion 50 and the shaft hole 41 of the camshaft member 40. The support shaft 52 is a cylindrical member with a uniform cross-sectional shape along the optical axis direction, and has a large-diameter head 52a at the rear end in the optical axis direction. Insert the support shaft 52 until the head 52a abuts the rear wall 50a. The support shaft 52 is fixedly supported in each shaft support hole 50b. The camshaft member 40 is rotatably supported around a support shaft 52 that is fixedly supported.

The support shaft 52 and the camshaft member 40 attached to the side support part 19 of the case 11 are located between the main guide shaft 23 and the main guide shaft 28 in the vertical direction, as shown in FIGS. 3 and 4. ing. More specifically, the main guide shaft 23 and the main guide shaft 28 are located at substantially the same position in the left-right direction, and are spaced apart from each other in the vertical direction. A virtual line P0 connecting the central axis of the main guide shaft 23 and the central axis of the main guide shaft 28 is shown in FIGS. 3 and 4. The virtual line P0 extends generally in the vertical direction.

The support shaft 52 is located between the main guide shaft 23 and the main guide shaft 28 (approximately in the middle) in the vertical direction, and is located to the right (movable lens L2, It is located away from the right side of L3). As shown in FIGS. 3 and 4, the length of an imaginary line P1 connecting the central axes of the main guide shaft 23 and the support shaft 52, and the imaginary line P2 connecting the central axes of the main guide shaft 28 and the support shaft 52, respectively. The lengths of are almost equal. In other words, the distance from the central axis of the main guide shaft 23 to the rotation center of the camshaft member 40 is approximately equal to the distance from the central axis of the main guide shaft 28 to the rotation center of the camshaft member 40. The main guide shaft 23, the main guide shaft 28, and the support shaft 52 are arranged at the vertices of a triangle (isosceles triangle whose base is the virtual line P0) formed with the virtual lines P0, P1, and P2 as sides. has been done.

As shown in FIGS. 5 and 6, substantially the entire position of the support shaft 52 in the optical axis direction is included in the same range as the main guide shafts 23 and 28. Therefore, like the main guide shafts 23 and 28, the support shaft 52 is housed in space efficiently in the optical axis direction.

A camshaft member 40 supported by a support shaft 52 is located between the main guide shaft 23 and the main guide shaft 28 which are spaced apart in the vertical direction. As shown in FIGS. 3 and 4, the camshaft member 40 is disposed close to the movable lenses L2, L3 (optical axis OX) to a position where a portion thereof overlaps with the virtual line P0, and the camshaft member 40 is arranged close to the movable lenses L2, L3 (optical axis OX) and The space between the guide shafts 28 is effectively used as an area for arranging the camshaft member 40. In other words, by reducing the amount of rightward offset of the support shaft 52 with respect to the main guide shaft 23 and the main guide shaft 28, the camshaft member 40 is placed between the main guide shaft 23 and the main guide shaft 28 in the vertical direction. I'm trying to fit some of it in. Since the main guide shaft 23 and the main guide shaft 28 are spaced apart in the vertical direction to a position close to the upper and lower surfaces of the substantially rectangular movable lenses L2 and L3, the main guide shaft 23 and the main guide shaft 28 can be moved without interfering with each other. , it is possible to arrange the camshaft member 40 closer to the optical axis OX of the optical system in the left-right direction.

Note that by increasing the distance between the main guide shaft 23 and the main guide shaft 28 in the vertical direction, it is possible to move the camshaft member 40 even closer to the optical axis OX in the left-right direction. However, in a configuration in which the main guide shaft 23 is located above the upper surface of the movable lenses L2, L3, or the main guide shaft 28 is located below the bottom surface of the movable lenses L2, L3, the guide mechanism is As a result, the size of the finder block 10 as a whole increases in the vertical direction. In this embodiment, the finder block 10 is made smaller in the vertical direction by housing the guide mechanism between the upper and lower surfaces of the movable lenses L2 and L3. In addition, the camshaft member 40 is arranged to enter between the main guide shafts 23 and 28, so that the horizontal dimension of the finder block 10 is also minimized.

The first arm 21 of the front movable lens L2 is provided with a cam follower 53 that protrudes diagonally downward to the right approximately along the imaginary line P1 (see FIG. 3). The cam follower 53 protrudes to a position in front of the front cam portion 44 in the radial direction about the main guide shaft 23, and the end cam 44a and the cam follower 53 face each other in the optical axis direction. The first arm 21 is biased rearward by a coil spring 25, and this biasing force maintains the state in which the cam follower 53 is in contact with the end cam 44a.

The first arm 26 of the rear movable lens L3 is provided with a cam follower 54 that protrudes diagonally upward to the right approximately along the imaginary line P2 (see FIG. 4). The cam follower 54 protrudes to the rear of the rear cam portion 45 in the radial direction about the main guide shaft 28, and the end cam 45a and the cam follower 54 face each other in the optical axis direction. The first arm 26 is urged forward by a coil spring 30, and this urging force maintains the state in which the cam follower 54 is in contact with the end cam 45a.

The end cam 44a and the end cam 45a each change the amount of protrusion in the optical axis direction as they advance in the rotational direction of the camshaft member 40. FIG. 9 schematically shows a movement trajectory L2z of the front movable lens L2 and a movement trajectory L3z of the rear movable lens L3, which correspond to the developed shapes of the end cam 44a and the end cam 45a. In the portions of FIG. 9 showing the movement trajectories L2z and L3z, the vertical axis represents the rotation angle of the camshaft member 40, and the horizontal axis represents the position in the optical axis direction.

At the first rotation end M1 of the camshaft member 40, the cam follower 53 contacts the area of the end cam 44a that projects the least amount forward, and the cam follower 53 contacts the area of the end cam 45a that projects the least amount backward. 54 comes into contact. Therefore, at the first rotation end M1, within the operating range controlled by the camshaft member 40, the front movable lens L2 is positioned furthest back in the optical axis direction, and the rear movable lens L3 is positioned furthest forward in the optical axis direction. The distance between the front movable lens L2 and the rear movable lens L3 in the optical axis direction is minimized.

When the cam shaft member 40 is rotated from the first rotation end M1 toward the second rotation end M2, the cam follower 53 is gradually moved forward in the optical axis direction by the end cam 44a against the urging force of the coil spring 25. The cam follower 54 is gradually pushed and moved backward in the optical axis direction by the end cam 45a against the biasing force of the coil spring 30, and the distance between the front movable lens L2 and the rear movable lens L3 in the optical axis direction increases. do. Note that the inclination of the camshaft member 40 (support shaft 52) with respect to the central axis is set so that the end cam 44a is larger than the end cam 45a, and the inclination in the optical axis direction per unit rotation angle of the camshaft member 40 is The amount of movement of the front movable lens L2 is larger than that of the rear movable lens L3.

At the second rotation end M2, within the operating range controlled by the camshaft member 40, the front movable lens L2 is located furthest forward in the optical axis direction, and the rear movable lens L3 is located furthest rearward in the optical axis direction. , the distance between the front movable lens L2 and the rear movable lens L3 in the optical axis direction becomes maximum. Movement of the front movable lens L2 and the rear movable lens L3 in a direction further apart from this maximum distance in the optical axis direction is restricted by the case 11.

When the camshaft member 40 is rotated from the second rotation end M2 toward the first rotation end M1, the cam followers 53 and 54 are moved by the urging force of the coil springs 25 and 30, contrary to the above operation. Following the end cams 44a and 45a, the front movable lens L2 and the rear movable lens L3 move toward each other in the optical axis direction.

The diopter adjustment in the optical system of the finder block 10 is performed by the above-described relative movement of the front movable lens L2 and the rear movable lens L3 in the optical axis direction. The operation of the camshaft member 40 for adjusting the diopter is performed by transmitting rotational force from the diopter adjustment dial 13 via the transmission member 55.

As shown in FIG. 3, the transmission gear 55a of the transmission member 55 meshes with the transmission gear 43 of the camshaft member 40. A forwardly protruding cylindrical shaft portion 55b provided on the transmission member 55 is inserted into a shaft hole 56 formed in the side support portion 19 of the case 11 (diagonally above the cam housing portion 50). Due to the relationship between the shaft portion 55b and the shaft hole 56, the transmission member 55 is supported so as to be rotatable about an axis facing in the optical axis direction. That is, the camshaft member 40 and the transmission member 55 rotate about mutually parallel axes, and the rotation of the transmission member 55 is transmitted to the camshaft member 40 via the transmission gear 55a and the transmitted gear 43.

As shown in FIG. 8, the transmission member 55 is provided coaxially with the diopter adjustment dial 13, and the diopter adjustment dial 13 and the transmission member 55 are fastened and fixed by a fastening screw 57. The transmission member 55 is formed with a screw hole 55c into which the fastening screw 57 is screwed, and the diopter adjustment dial 13 is formed with a screw insertion hole 13a that communicates with the screw hole 55c. The fastening screw 57 inserted from the rear into the screw insertion hole 13a is screwed into the screw hole 55c, and with the head 57a on the rear end side in contact with the bottom surface of the recess 13b on the back side of the diopter adjustment dial 13. When the fastening screw 57 is tightened, the diopter adjustment dial 13 is fixed to the transmission member 55. The diopter adjustment dial 13 is rotatably supported by the back cover 12 via a support bush 58, and the diopter adjustment dial 13 and the transmission member 55 rotate integrally.

As shown in FIGS. 3 and 4, the transmission member 55 is located at approximately the same position as the main guide shaft 23 in the vertical direction, and is located to the right of the main guide shaft 23b. The shaft portion 55b, which is the rotation center of the transmission member 55, is located above and to the right of the support shaft 52, which is the rotation center of the camshaft member 40, and the shaft portion 55b is located on an extension of the imaginary line P2. There is. In other words, the three shaft members, the shaft portion 55b, the support shaft 52, and the main guide shaft 28, are generally aligned in a straight line when viewed from the front (back). The shaft portion 55b and the main guide shaft 23 are located at substantially the same position in the vertical direction, and the shaft portion 55b is spaced apart to the right with respect to the main guide shaft 23. The support shaft 52 is located between the shaft portion 55b and the main guide shaft 23 (substantially in the middle) in the left-right direction, and is located below the main guide shaft 23 and the shaft portion 55b.

That is, with respect to the support shaft 52 that pivotally supports the camshaft member 40, the main guide shaft 23 is disposed diagonally above the left, the main guide shaft 28 is disposed diagonally below the left, and the shaft portion 55b is disposed diagonally above the right. Then, the front movable lens L2 and the rear movable lens L3 are moved in the optical axis direction in a triangular space when viewed from the front (back), connecting the central axes of the main guide shaft 23, the main guide shaft 28, and the shaft portion 55b. A guide mechanism that can support the diopter and a drive mechanism that transmits operating force (driving force) from the diopter adjustment dial 13 to the front movable lens L2 and the rear movable lens L3 are disposed. As shown in FIGS. 3 and 4, a portion of the camshaft member 40 is arranged in a positional relationship that overlaps the main guide shafts 23, 28 and the shaft portion 55b in the left-right direction, so that the above-mentioned triangular space is , the width occupied in the left-right direction is kept small, and the size of the finder block 10 in the left-right direction is realized. Furthermore, since the components of the guide mechanism and the drive mechanism are arranged so as to fit within the vertical dimensions of the front movable lens L2 and the rear movable lens L3, it is possible to suppress the enlargement of the finder block 10 in the vertical direction. . For example, even if the diopter adjustment dial 13 in the drive mechanism is located further away from the optical axis OX than the camshaft member 40, as shown in FIGS. 7 and 8, it can be moved closer to the optical system in the horizontal and vertical directions. placement has been achieved.

The transmission member 55 is further formed with a locking uneven portion 55d located behind the transmission gear 55a. The locking uneven portions 55d are gear-shaped uneven portions arranged in the rotational direction of the transmission member 55, and the pitch of the unevenness in the rotational direction is set to be equal to that of the transmission gear 55a. By providing the locking uneven portions 55d at the same fine pitch as the transmission gear 55a, it becomes possible to finely adjust the diopter position by engagement with a click spring 59d, which will be described later.

As shown in FIG. 1, the finder block 10 is provided with a click member 59. As shown in FIG. The click member 59 has a flat base plate 59a, and two positioning holes 59b and one screw insertion hole 59c are formed through the base plate 59a. The base plate 59a is supported in an overlapping manner on the upper side of the above-mentioned upper cover 33, and its position with respect to the case 11 is determined by fitting positioning protrusions 11k into each positioning hole 59b. The screw 34 is inserted into the screw insertion hole 59c and the screw insertion hole 33b, and the click member 59 is fixed to the case 11 in a state where it is tightened together with the upper cover 33.

A click spring 59d, which is a cantilever-shaped elastic engagement portion, extends rightward from the base plate 59a. The click spring 59d can be elastically deformed in the vertical direction using the connection point to the base plate 59a as a fulcrum. The tip portion of the click spring 59d engages with the concave shape of the locking concavo-convex portion 55d of the transmission member 55 from above. Due to this engagement, the rotation of the transmission member 55 and the diopter adjustment dial 13 is lightly stopped (click-stopped), and the position in the rotational direction is stabilized. When the transmission member 55 rotates, the click spring 59d is elastically deformed upward and overcomes the convex shape of the locking uneven portion 55d.

The finder block 10 configured as described above operates as follows. When the user rotates the diopter adjustment dial 13, the transmission member 55 fastened and fixed to the diopter adjustment dial 13 rotates about the shaft portion 55b. Rotation is transmitted from the transmission gear 55a of the transmission member 55 to the transmitted gear 43, and the camshaft member 40 rotates about the support shaft 52. Since no other gear is interposed between the transmission gear 55a and the transmitted gear 43, the rotation direction of the camshaft member 40 is opposite to the rotation direction of the transmission member 55. When the camshaft member 40 rotates, the rotational force is converted into a moving force in the optical axis direction due to the relationship between the end cam 44a of the front cam part 44 and the cam follower 53, and the front movable lens L2 moves straight in the optical axis direction. Due to the relationship between the end cam 45a of the rear cam portion 45 and the cam follower 54, the rotational force is converted into a moving force in the optical axis direction, and the rear movable lens L3 moves straight in the optical axis direction. The respective movement trajectories of the front movable lens L2 and the rear movable lens L3 at this time are as described above with reference to FIG.

The rotation operation of the diopter adjustment dial 13 is performed stepwise by a click feeling obtained by the engagement of the click spring 59d and the locking uneven portion 55d. When the user stops the rotational operation, the diopter adjustment dial 13 is lightly locked, and the adjusted positions of the front movable lens L2 and the rear movable lens L3 are maintained.

The finder block 10 of this embodiment described above includes the main guide shaft 23, which is the first and second guide members that guide the two movable optical elements, the front movable lens L2 and the rear movable lens L3, in a straight line in the optical axis direction. 28 are spaced apart in the vertical direction (direction perpendicular to the optical axis OX), and the front movable lens L2 and the rear movable lens L3 are moved in the optical axis direction by operation of the diopter adjustment dial 13, which is an operating means. A camshaft member 40, which is a common driving member that moves along a predetermined trajectory, is arranged between the main guide shaft 23 and the main guide shaft 28 in the vertical direction. With this configuration, a guide mechanism that guides the movement of the front movable lens L2 and the rear movable lens L3, and a drive mechanism that applies a moving force in the optical axis direction to the front movable lens L2 and the rear movable lens L3 can be provided with space efficiency. This allows the finder block 10 to be made smaller. Further, since the two movable lenses L2 and L3 are driven by the common camshaft member 40, the number of parts is small, and the effects of reducing manufacturing costs and weight can be obtained.

As described above, by arranging the main guide shaft 23 and the main guide shaft 28 at different positions in the vertical direction, each movable lens in the optical axis direction is prevented from increasing in size in the optical axis direction. It is possible to ensure a long support length of L2 and L3 (guide holes 21a and 26a) and perform highly accurate guiding.

The auxiliary guide shaft 24 and the auxiliary guide shaft 29 are arranged on the left side of each of the oblong movable lenses L2 and L3, which is opposite to the right side where the main guide shaft 23 and the main guide shaft 28 are provided. . Therefore, the distance from the main guide shafts 23, 28 to the sub guide shafts 24, 29 is large, and the effect of suppressing rotation on each movable lens L2, L3 is increased, contributing to improvement in the support accuracy of each movable lens L2, L3. Furthermore, since the sub-guide shaft 24 and the sub-guide shaft 29 are arranged at different positions in the vertical direction, similar to the main guide shaft 23 and the main guide shaft 28, the large size of the finder block 10 in the optical axis direction The effect of increasing the support length of each movable lens L2, L3 (rotation regulating grooves 22a, 27a) in the optical axis direction can be obtained while preventing the rotation from occurring.

A camshaft member 40 is arranged between the main guide shaft 23 and the main guide shaft 28 so as to be approximately equidistant from the respective main guide shafts 23 and 28. As a result, the length of the cam follower 53 extending from the first arm 21 guided by the main guide shaft 23 and the length of the cam follower 54 extending from the first arm 26 guided by the main guide shaft 28 are approximately equal. It has become. As a result, the load acts on the drive system of the front movable lens L2 and the drive system of the rear movable lens L3 in a well-balanced manner, and the two movable lenses L2 and L3 can be efficiently and smoothly driven. Further, the lengths of both the cam followers 53 and 54 are made compact to ensure rigidity, and highly accurate lens driving with few errors can be realized.

The camshaft member 40 has a front cam portion 44 and a rear cam portion 45 distributed before and after a transmitted gear 43 to which rotation from a transmission member 55 is transmitted. As a result, the power transmission path for the front movable lens L2 located at the front in the optical axis direction and the power transmission path for the rear movable lens L3 located at the rear in the optical axis direction are each configured to be simple and have excellent drive efficiency. can do. Specifically, a simple-shaped cam follower 53 that extends linearly (along the imaginary line P1) in the direction connecting the main guide shaft 23 and the support shaft 52, and a cam follower 53 that has a simple shape and extends linearly in the direction that connects the main guide shaft 28 and the support shaft 52. Power transmission to each of the movable lenses L2 and L3 can be realized by the simple-shaped cam follower 54 that extends to the target (along the virtual line P2). In addition, since the cam followers 53 and 54, which are the destinations of driving force, are arranged on both sides of the transmitted gear 43 to which rotation is input to the camshaft member 40, the load applied to the camshaft member 40 is lightened. By equalizing it in the axial direction, it is possible to improve the driving accuracy and power transmission efficiency of each movable lens L2, L3 by the camshaft member 40.

Not only the camshaft member 40 but also the transmission member 55 and the diopter adjustment dial 13 are arranged close to the optical axis OX of the optical system, contributing to miniaturization of the finder block 10 as a whole. Specifically, as shown in FIGS. 3 and 4, the transmission member 55 is located at a position to the right of the main guide shaft 23 without significantly protruding upward from the upper surface of each movable lens L2, L3. . Furthermore, by shifting the position of the shaft portion 55b upward relative to the support shaft 52 that pivotally supports the camshaft member 40, the transmission member 55 is placed closer to the main guide shaft 23 in the left-right direction.

As described above, in the finder block 10 of this embodiment, each component responsible for supporting and driving each movable lens L2, L3 is attached to the side of each movable lens L2, L3 (each movable lens L2 having a rectangular shape, The area along one side of the outer shape of L3 is concentrated and arranged in a space-efficient manner. In order to realize this arrangement, a side support portion 19 is formed on the right side of the case 11 to support the main guide shafts 23 and 28, the camshaft member 40, the transmission member 55, and the like. From the movable lenses L2, L3, first arms 21, 26 that enter the side support portion 19 protrude laterally, and are more horizontal than the fixed lenses L1, L4 located before and after the movable lenses L2, L3. is increasing in size.

Under such conditions, in order to make the case 11 as compact as possible and to improve the ease of assembling each lens L1 to L4, a part of the case 11 is opened vertically and the first opening 15 and the second opening are opened. An opening 16 and a third opening 17 are formed so that the lenses L1 to L3 can be inserted into the housing space 14 of the case 11 from above and below.

First, by forming the openings 15, 16, and 17 for lens assembly on the upper and lower surfaces of the case 11, there are no restrictions on the left and right structural parts of the case 11, such as the side support parts 19, and the movable lenses L2 and L3 are supported. and configurations optimized to support drive components, including space-efficient placement of the components described above. Further, there is no need to form a large opening at the front end or rear end of the case 11 through which the movable lenses L2, L3 having the first arms 21, 26 and the second arms 22, 27 projecting laterally. , the front and rear portions of the case 11 can be reduced to the minimum size necessary to support the fixed lenses L1 and L4. Further, since the portion for accommodating the first arms 21, 26 and the second arms 22, 27 is provided only in the middle portion of the case 11 in the optical axis direction, the case 11 can be made smaller and have higher rigidity.

The side support part 19 in the case 11 is used for inserting and accommodating components for supporting and driving the movable lenses L2 and L3 in the optical axis direction (main guide shafts 23 and 28, support shaft 52, and transmission member 55). It has a structure that allows assembly by either insertion (camshaft member 40) from the side opposite to the space 14. Therefore, each member other than the lenses L1 to L4 can be easily and reliably assembled to the case 11.

The camshaft member 40 has end cams 44a and 45a facing forward and backward in the optical axis direction, and the cam accommodating portion 50 is open on the right side of the side support portion 19. Therefore, after each movable lens L2, L3 having each cam follower 53, 54 is assembled into the case 11, the cam shaft member 40 can be easily inserted into the cam accommodating portion 50 from the side. By inserting the cam shaft member 40 into the cam accommodating portion 50, each cam follower 53, 54 comes into contact with and faces each end cam 44a, 45a, and can be assembled easily without requiring complicated adjustment. , the camshaft member 40 and each movable lens L2, L3 can be linked.

Further, the click member 59 (click spring 59d) that elastically engages with the locking uneven portion 55d of the transmission member 55 is fixed together with the upper cover 33 that covers the first opening 15 of the case 11. Thereby, the mechanism for clicking and stopping the diopter adjustment dial 13 can be made simple and has excellent assembly workability.

Although the present invention has been described above based on the illustrated embodiments, the present invention is not limited to the above-described embodiments, and modifications and improvements can be made within the gist of the invention.

For example, in the embodiment described above, the cam surface provided on the camshaft member 40 is composed of end cams 44a and 45a. By using the end cams 44a and 45a that are open toward the front and rear, work efficiency is improved when the camshaft member 40 is assembled into the cam accommodating portion 50 and brought into linkage (contact) with each of the cam followers 53 and 54. It has the advantage of being good. However, instead of the end cam, it is also possible to use a cam groove or lead groove that has side surfaces (cam surface, lead surface) on both sides in the optical axis direction as the power transmission structure (movement control section) provided in the drive member. It is.

In the embodiment described above, the transmission member 55 is arranged on the side (to the right) of the upper main guide shaft 23. With this arrangement, the diopter adjustment dial 13, which rotates coaxially with the transmission member 55, is located above the vertical center of the optical system of the finder block 10 (see FIG. 7). In a single-lens reflex camera, the finder block 10 is located at the upper center of the camera body, so if the diopter adjustment dial 13 is placed in this position, the operation of the diopter adjustment dial 13 will be less restricted by the camera body, and the operability of the diopter adjustment dial 13 will be easier. will improve. However, if there is no problem with the operability of the diopter adjustment dial 13, it is also possible to arrange the transmission member 55 on the side (right side) of the lower main guide shaft 28. In terms of space efficiency in the finder block 10 and workability during manufacturing, the same effects as in the embodiment described above can be obtained even when the transmission member 55 is arranged on the side of the lower main guide shaft 28.

The above embodiment has a structure in which the diopter adjustment dial 13 and the transmission member 55, which are formed as separate members, are coupled with the fastening screw 57, but the portion corresponding to the diopter adjustment dial 13 and the transmission member 55 are formed as a single member. It is also possible to form In other words, the diopter adjustment dial itself may include a portion corresponding to the transmission gear 55a and the locking uneven portion 55d. In this case, the content explained as the arrangement of the transmission member 55 in the above embodiment shall be read as the arrangement of the diopter adjustment dial.

Although the present invention is suitable for driving rectangular lenses such as the movable lenses L2 and L3 in the above embodiment, it is also applicable to driving optical elements having shapes other than rectangular shapes. For example, the movable optical element may be a D-cut lens whose left and right sides are not planar but convex.

At least one of the two movable optical elements to be driven in the present invention may be an optical element other than a lens. For example, an optical filter, a field frame, or the like may be driven.

10: Finder block (optical system drive device)
11: Case (supporting member)
12: Rear cover 13: Diopter adjustment dial (operation means)
14: Accommodation space 15: First opening 16: Second opening (opening)
17: Third opening (opening)
18 : Rear end storage part 19 : Side support part 21 : First arm 22 : Second arm 23 : Main guide shaft (first guide member)
24: Sub-guide shaft 25: Coil spring 26: First arm 27: Second arm 28: Main guide shaft (second guide member)
29: Sub-guide shaft 30: Coil spring 32: Fitting protrusion 33: Upper cover (cover)
36: Lower cover (cover)
38: Rear cover 40: Camshaft member (drive member)
43: Transmitted gear (transmitted part)
44: Front cam section (first movement control section)
44a: End cam 45: Rear cam section (second movement control section)
45a: End cam 50: Cam housing portion 52: Support shaft 53: Cam follower (first cam follower)
54: Cam follower (second cam follower)
55 : Transmission member 55a : Transmission gear 55d : Locking uneven part 57 : Fastening screw 59 : Click member 59d : Click spring (elastic engagement part)
G: Cover glass L1: Front fixed lens L2: Front movable lens (first movable optical element)
L3: Rear movable lens (second movable optical element)
L4: Rear fixed lens OX: Optical axis

Claims (10)

An optical system drive device that moves the first movable optical element and the second movable optical element in the optical axis direction according to the operation of the operating means,
a first guide member that movably guides the first movable optical element in the optical axis direction; a second guide member that movably guides the second movable optical element in the optical axis direction; spaced apart in the direction perpendicular to the optical axis,
between the first guide member and the second guide member in a direction perpendicular to the optical axis, the first movable optical element and the second movable optical element are respectively operated by the operating means; disposing a driving member that moves along a predetermined trajectory in the optical axis direction ;
The optical axis is common to the first movable optical element and the second movable optical element,
The first movable optical element and the second movable optical element are located on the optical axis and have different positions in the optical axis direction,
The first guide member and the second guide member are each shaft members extending in the optical axis direction,
The length of the first guide member in the optical axis direction and the length of the second guide member in the optical axis direction are at least partially located in the same range in the optical axis direction,
The first movable optical element and the second movable optical element move until a portion of the drive member overlaps with an imaginary line connecting the central axis of the first guide member and the central axis of the second guide member. An optical system driving device, characterized in that the optical system driving device is arranged close to the optical axis of an optical element . The driving member is rotatable about an axis facing in the optical axis direction,
a transmitted portion to which force in a rotational direction is transmitted from the operating means;
a first movement control section that is provided on one side in the optical axis direction with respect to the transmitted section and moves the first movable optical element in the optical axis direction by the rotation;
a second movement control section that is provided on the other side in the optical axis direction with respect to the transmitted section and moves the second movable optical element in the optical axis direction by the rotation;
The optical system driving device according to claim 1, further comprising: The distance from the central axis of the first guide member to the rotation center of the drive member is approximately equal to the distance from the central axis of the second guide member to the rotation center of the drive member . The optical system drive device according to claim 2, characterized in that: The first movement control unit and the second movement control unit each have a cam surface that changes the position in the optical axis direction as the drive member advances in the rotation direction ,
A first cam follower provided on the side of the first movable optical element extends in a direction connecting the central axis of the first guide member and the rotation center of the drive member to control the first movement. contacting the cam surface of the part;
A second cam follower provided on the side of the second movable optical element extends in a direction connecting the central axis of the second guide member and the rotation center of the drive member to control the second movement. The optical system driving device according to claim 3, wherein the optical system driving device contacts the cam surface of the portion. Each of the first movable optical element and the second movable optical element is a lens having a substantially rectangular outer shape surrounding the optical axis,
5. The first guide member, the second guide member, and the drive member are arranged in a region along one side of the outer shape of the lens, according to any one of claims 1 to 4. optical system drive device. an accommodation space that accommodates the first movable optical element and the second movable optical element therein; and the first guide member, the second guide member, and the drive member provided on the side of the accommodation space. a support member having a lateral support part that supports the
The support member opens in a direction different from that of the side support portion, and allows the first movable optical element and the second movable optical element to be inserted into the accommodation space in a direction perpendicular to the optical axis. The optical system drive device according to any one of claims 1 to 5, having an opening. The support member has two openings that open in opposite directions in a direction perpendicular to the optical axis, and the first movable optical element can be inserted through one of the openings, and the first movable optical element can be inserted through the other opening. 7. The optical system driving device according to claim 6, wherein the second movable optical element can be inserted through the opening. The optical system according to claim 6 or 7, further comprising a cover that covers the opening in a state in which the first movable optical element and the second movable optical element are accommodated inside the accommodation space. Drive device. The operating means is rotatable about an axis facing in the optical axis direction, and the operating means or a transmission member that rotates together with the operating means and transmits rotation to the drive member is arranged in the rotation direction. It has a plurality of locking uneven parts,
9. The optical system driving device according to claim 8, wherein an elastic engagement portion that elastically engages with the plurality of locking uneven portions is supported by the support member together with the cover. The operating means is rotatable about an axis facing in the optical axis direction, and the operating means or a transmission member that rotates together with the operating means and transmits rotation to the driving member is configured to rotate along the optical axis. The optical system driving device according to any one of claims 1 to 9, wherein the optical system driving device is located at substantially the same position as the first guide member or the second guide member in a vertical direction.

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