JP2022115692A - Lens barrel, lens device, and imaging apparatus - Google Patents

Abstract

To provide a lens barrel having a simple configuration and advantageous for improvement of operability of tilt direction adjustment.SOLUTION: A lens barrel has: a stationary cylinder; a guide cylinder that is held with respect to the stationary cylinder immovably in an optical axis direction and rotatably around the optical axis, and has a plurality of guide grooves having guide grooves extending in the optical axis direction; a cam ring that has a plurality of cam grooves including cam grooves having inclination with respect to a surface orthogonal to the optical axis; and a lens holding frame that has a plurality of engagement parts engaging with the plurality of guide grooves and the plurality of cam grooves, and holds a lens. The cam ring has a state in which it is immovable in the optical axis direction and rotatable around the optical axis with respect to the guide cylinder, and a state in which it is non-rotatable around the optical axis with respect to the guide cylinder and rotatable integrally with the guide cylinder.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens barrel, a lens device, and an imaging device for optical equipment.

2. Description of the Related Art Conventionally, there has been provided a lens barrel capable of tilting a lens in all directions. In this type of lens barrel, the lens holding frame is tilted with respect to the fixed member by operating the operating member, thereby making it possible to adjust the tilt amount. Further, by rotating this fixing member around the optical axis, it is possible to adjust the tilting direction (Patent Document 1).

Japanese Patent No. 4462357

However, in the conventional technology as described above, the operation is complicated because the operation section to be rotated for adjusting the tilt amount and tilt direction is separate. In addition, since these are separate parts, the lens barrel becomes large and expensive, and the number of parts increases, which complicates the assembly work and increases the assembly cost.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a lens barrel that has a simple structure and is advantageous in improving the operability of tilt direction adjustment.

In order to achieve the above object, the lens barrel of the present invention includes a fixed barrel, and a fixed barrel that is held so as to be immovable in the optical axis direction and rotatable about the optical axis with respect to the fixed barrel, and extends in the optical axis direction. a guide cylinder having a plurality of guide grooves having existing guide grooves; a cam ring having a plurality of cam grooves including cam grooves inclined with respect to a plane orthogonal to the optical axis; the plurality of guide grooves and the a lens holding frame that holds a lens and has a plurality of engaging portions that engage with the plurality of cam grooves, wherein the cam ring is immovable in the optical axis direction with respect to the guide barrel; It is characterized by having a state of being rotatable about the optical axis and a state of being rotatable about the optical axis relative to the guide tube and being rotatable integrally with the guide tube.

According to the present invention, it is possible to provide a lens barrel that has a simple configuration and is advantageous in improving the operability of tilt direction adjustment.

4 is a cross-sectional view of the tilting mechanism of the lens barrel of Example 1. FIG. FIG. 4 is a side view (without tilt) of the tilting mechanism of the lens barrel of Example 1; FIG. 4 is a perspective view (without tilting) of the tilting mechanism of the lens barrel of Example 1; 4 is a developed view (without tilt) of the cam ring of the lens barrel of Example 1. FIG. FIG. 11 is a side view when the tilt amount is adjusted to the maximum; FIG. 11 is a perspective view when the tilt amount is adjusted to the maximum; FIG. 10 is an exploded view of the cam ring when the swing amount is adjusted to the maximum; FIG. 10 is a side view when the tilt amount is maximum and the tilt direction is adjusted; FIG. 10 is a perspective view when the tilt amount is maximum and the tilt direction is adjusted; FIG. 11 is a side view when the tilting amount is medium and the tilting direction is adjusted. FIG. 10 is a perspective view when the amount of tilting is medium and the direction of tilting is adjusted. 4 is an exploded view of the cam ring and the guide cylinder of Example 1. FIG. 4 is an exploded view of the cam ring and the guide cylinder of Example 1. FIG. FIG. 10 is an exploded view of a cam ring and a guide cylinder of Example 2; FIG. 10 is an exploded view of a cam ring and a guide cylinder of Example 3;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same reference numerals are given to the same members, and overlapping descriptions are omitted.
Also, in the explanation, "tilt" is sometimes expressed as "to beat", and "tilt" is sometimes expressed as "to beat", but these two words have the same meaning.

FIG. 1 shows a sectional view of a tilting mechanism which is a part of the lens barrel of this embodiment, FIG. 2 shows a side view, and FIG. 3 shows a perspective view. In both FIGS. 1 to 3, X indicates the optical axis of the lens barrel, and the left direction in the drawing indicates the object side and the right direction indicates the imaging surface side. A lens mount (not shown) is attached to the imaging surface side of the lens barrel. Also, the lens barrel can be attached to and detached from a camera body (not shown) via a lens mount. The camera body is a digital camera or a silver-salt film camera, and an imaging element such as a CMOS or film is arranged inside each perpendicular to the optical axis of the optical system of the lens barrel to be mounted. . The imaging plane mentioned above refers to an imaging element in a digital camera and a film in a silver-salt film camera.

Although a detailed description of the camera body is omitted, a digital camera is provided with various operation buttons such as a liquid crystal monitor, a viewfinder, and a shutter button for displaying an image drawn through a lens barrel or a photographed image. When the user operates the shutter button, exposure is started under predetermined conditions, and a photograph is taken.

In the present invention, the lens barrel is explained as an interchangeable lens that can be replaced with the camera body, but the present invention can also be applied to a digital still camera or a film camera in which the lens barrel and the camera body are integrated. be.

Next, the lens barrel will be described in detail with reference to the drawings.
The lens holding frame 3 has a hollow cylindrical shape, and holds a tilting lens (not shown) in the hollow interior. The lens holding frame 3 has four rollers (plurality of engaging portions) 42 to 45 fixed to its outer peripheral portion. The rollers 42 to 45 are arranged at intervals of 90° (equal angular intervals) around the optical axis.

A guide cylinder 2 is arranged on the outer diameter side of the lens holding frame 3, and a cam ring 1 is further arranged on the outer diameter side. A cam ring 1 is radially fitted with a guide cylinder 2, a bayonet groove 11 is formed in the cam ring 1, and a bayonet claw (not shown) is formed in the guide cylinder 2. As shown in FIG. By engaging the bayonet claws of the guide cylinder 2 with the bayonet grooves of the cam ring 1, the cam ring 1 is held so as to be immovable in the optical axis direction and rotatable about the optical axis X with respect to the guide cylinder 2. . The cam ring 1 is provided with four cam grooves 12 to 15, and the guide tube 2 is provided with a plurality of guide grooves 22 to 25 extending in the optical axis direction. The lens holding frame 3 is fixed to the lens holding frame 3 by inserting the rollers 42 to 45 into the four cam grooves 12 to 15 and the four guide grooves 22 to 25 so that the guide tube 2 and the cam ring are fixed. 1 is held without backlash.

FIG. 4 is a conceptual diagram in which the guide grooves of the guide cylinder 2 are projected onto the cam ring 1 of the first embodiment, which is developed in the circumferential direction around the optical axis. Description will be made with reference to FIGS. 1 to 4. FIG.

Cam grooves 12 to 15 are formed in the cam ring 1 . The cam grooves 12 to 15 are formed at 90° intervals (equal angular intervals) around the optical axis. The guide tube 2 also has guide grooves 22 to 25 formed at 90° intervals (equal angular intervals) around the optical axis. The roller 42 is inserted through the cam groove 12 and the guide groove 22 and fixed to the outer circumference of the lens holding frame 3 . Another roller 43 is inserted through the cam groove 13 and the guide groove 23 and fixed to the outer circumference of the lens holding frame 3 with a phase shifted by 90° around the optical axis. As for the other rollers, the roller 44 is inserted through the cam groove 14 and the guide groove 24, and the roller 45 is inserted through the cam groove 15 and the guide groove 25, and fixed to the outer circumference of the lens holding frame 3.

In FIG. 4, the vertical direction in the drawing indicates the direction of the optical axis, and the horizontal direction in the drawing indicates the circumferential direction of the developed view, which is the direction orthogonal to the optical axis. Phase 1 indicates a vertically downward direction (under gravity), phase 3 indicates a vertically upward direction (above gravity), phase 2 indicates a left direction when viewed from the imaging surface side, and phase 4 indicates a right direction when viewed from the imaging surface side. Each is equally divided by 90° (equal angular intervals). The cam groove 12 is inclined upward to the right with respect to the direction (plane) orthogonal to the optical axis, and the cam groove 14 is inclined downward to the right. The inclination angles of the cam grooves 12 and 14 with respect to the direction (plane) perpendicular to the optical axis are the same. That is, two cam grooves 12 and 14 that are not adjacent to each other among the four cam grooves are lead grooves having the same angle and opposite directions. On the other hand, of the four cam grooves, the other two cam grooves 13 and 15 that are not adjacent to each other are not lead grooves, but have a circumferential inclination angle of 0° (parallel) to the direction (plane) orthogonal to the optical axis. It has a groove. The cam grooves 12-15, the four rollers 42-45, and the guide grooves 22-25 and the rollers 42-45 are dimensioned so that there is almost no backlash.

The guide grooves 22 to 25 will be described with reference to FIG.
The guide grooves 22 and 24 are elongated holes extending in the optical axis direction. This is to prevent movement of the rollers 42, 44 along the cam grooves 12, 14 of the cam ring 1 in the optical axis direction. Further, the guide grooves 23 and 25 are long holes slightly extending in the optical axis direction. This is to absorb errors in part manufacturing and assembly, and to prevent multiple fittings.

Next, a procedure for adjusting the tilt amount will be described. 1 to 4 described above show the case where the lens holding frame 3 is held perpendicular to the optical axis and the amount of tilt is 0 in the tilting mechanism of the present invention. 5 and 6 show the state in which the cam ring 1 is rotated counterclockwise as viewed from the imaging surface side from this state, and the lens holding frame 3 is rotated with respect to the optical axis. Represents the most defeated state. FIG. 7 is a developed view of the cam ring 1 in this state, which corresponds to FIG.

5, 6 and 7, the roller 43 reaches the end of the cam groove 13 of the cam ring as the cam ring rotates. Therefore, the position of the roller 43 in the optical axis direction does not change from the position shown in FIG. This is the same for the rollers 45 as well.

Further, the roller 42 comes near the end of the cam groove 12 as the cam ring rotates. At this time, the roller 42 moves toward the object in the optical axis direction along the cam groove 12 inclined with respect to the direction orthogonal to the optical axis. On the other hand, the rollers 44 move along the optical axis toward the imaging plane side along the cam grooves 14 inclined with respect to the optical axis. The roller 42 moves toward the object side in the optical axis direction, and the roller 44 moves toward the imaging plane side in the optical axis direction. A straight line passing through falls with respect to the perpendicular to the optical axis. At this time, as described above, the positions of the rollers 43 and 45 in the optical axis direction have not changed. Therefore, the lens holding frame 3 tilts so as to rotate around the straight line connecting the rollers 43 and 45 as an axis. As shown in FIGS. 4 and 7, the cam groove 14 has a reverse inclination with respect to the circumferential direction with respect to the cam groove 12, and since it is a cam with the same amount of inclination, the rollers 42 and 44 move smoothly along the cam groove. move to When compared with FIG. 2 in the initial state, the object-side surface faces upward when the lens apparatus is placed so that the optical axis is horizontal. It can be seen from FIG. 5 that the lens holding frame 3 is tilted at an angle .theta.

On the other hand, if the cam ring 1 is rotated in the opposite direction, that is, clockwise when viewed from the imaging surface side, the lens holding frame 3 will tilt in the opposite direction, and when the lens device is placed so that the optical axis is horizontal, The side of the object faces downwards.

As described above, in the state shown in FIGS. 5 to 7, the roller 45 reaches the terminal end of the cam groove 15 formed as a circumferential groove of the cam ring 1, and the cam ring 1 is further rotated counterclockwise. However, the cam ring 1 and the guide cylinder 2 do not rotate relative to each other. Therefore, the lens holding frame 3 cannot be tilted any further with respect to the optical axis, and this state is the maximum amount of tilt.

At this time, focusing on the rollers 43 and 45 engaged with the cam grooves 13 and 15 formed as circumferential grooves, these two rollers do not move in the optical axis direction. That is, the lens holding frame 3 rotates, that is, falls down, about a straight line connecting the rollers 43 and 45 with the optical axis interposed therebetween. As a result, it is possible to change only the tilt amount without changing the position of the straight line connecting the rollers 43 and 45 of the lens holding frame 3 in the optical axis direction. The plurality of cam grooves 12 to 14 and the plurality of rollers 42 to 45 are configured so that the intersection of the plane including the plurality of rollers 42 to 45 and the optical axis does not move regardless of the rotational position of the cam ring 1 . Since the position of the straight line connecting the rollers 43 and 45 does not change in the optical axis direction, both optical axes are aligned when the optical axis direction of the inclined lens is inclined with respect to the optical axis direction of the lens device. , a more symmetrical optical effect can be obtained for tilting to either side. That is, various aberrations such as curvature of field are not deteriorated, which is advantageous in terms of optical performance and contributes to high image quality. In addition, since the focal position does not change, the user does not need to refocus, which contributes to operability.

Next, with reference to FIGS. 1 to 9, the adjustment of the direction of the rotation axis for tilting operation will be described.
As shown in FIG. 1, the guide tube 2 is radially fitted with the fixed tube 5 . A stationary roller 6 (see FIG. 1) is attached to the outer periphery of the fixed cylinder 5 . A circumferential groove 26 is provided in the inner diameter of the guide cylinder 2 , and the stationary roller 6 is fitted in the circumferential groove 26 . It is desirable that the fixed-position rollers 6 are provided at three or more locations on the outer periphery of the fixed cylinder 5 so as to be equally divided in the circumferential direction. The fixed-position rollers 6 hold the guide tube 2 immovable in the optical axis direction with respect to the fixed tube 5 and rotatable relative to the optical axis.

Referring to FIGS. 5 and 6, the roller 43 extends to the end of the cam groove 13 formed as a circumferential groove of the cam ring 1, thereby allowing the relative rotation between the cam ring 1 and the guide tube 2 to occur. is formed. The roller 45 is also the same. In this state, the amount of tilting of the lens holding frame 3 is the maximum, and the roller 44 is tilted closest to the imaging plane side, and the roller 46 is tilted closest to the object side, with the straight line connecting the rollers 43 and 45 as an axis. there is As shown in FIG. 5, the object-side surface of the lens held by the lens holding frame 3 faces upward. From this state, when the cam ring 1 is further rotated counterclockwise when viewed from the image pickup surface side, the ends of the cam grooves 13 and 15 formed as circumferential grooves of the cam ring 1 exert a rotational force on the rollers 43 and 45. to rotate the lens holding frame 3. The rollers 42 to 45 fixed to the lens holding frame 3 are engaged with the guide grooves 22 to 25 of the guide tube 2 , so that they transmit the rotational force to the guide tube 2 . The guide tube 2 is held relative to the fixed tube 5 so as to be immovable in the optical axis direction and relatively rotatable around the optical axis. As a result, the lens holding frame 3 and the guide tube 2 rotate integrally with respect to the fixed tube 5 as the cam ring 1 rotates. As a result, the tilting direction can be adjusted in an arbitrary direction while the tilting amount remains at the maximum state.

As an example, FIGS. 8 and 9 show the case where the direction of the tilting rotation axis becomes the vertical direction (the direction of gravity) as a result of adjusting the tilting direction. 5 and 6, the cam ring 1, the guide tube 2, and the lens holding frame 3 are rotated by 90 degrees. Rollers 43, 45, which are not movable in the direction of the optical axis by engaging cam grooves 13, 15 formed to extend in a plane perpendicular to the optical axis, are arranged vertically with respect to a plane perpendicular to the optical axis. Rollers 42 and 44 are arranged on the left and right sides to engage with the cam grooves 12 and 14 formed at an angle and move forward and backward in the direction of the optical axis. Since the roller 44 is moved toward the image pickup surface side in the optical axis direction and the roller 42 is moved toward the object side in the optical axis direction, the image pickup surface side surface of the lens held by the lens holding frame 3 is leftward when viewed from the image pickup surface side. It can be seen that it is tilted so as to face
Now that the tilting direction (direction of the rotation axis) has been adjusted, a method of adjusting the tilting amount again will be described with reference to FIGS.

The states shown in FIGS. 8 and 9 described above are states in which the tilting direction is the horizontal direction and the tilting amount is the maximum. From this state, the cam ring 1 is rotated in the opposite direction, that is, clockwise when viewed from the imaging surface side. Then, the guide cylinder 2, which has been rotating integrally with the cam ring 1, does not rotate, and only the cam ring 1 rotates clockwise. That is, the cam ring 1 rotates relative to the guide cylinder 2 . Then, the rollers 42 and 44 move along the cams of the cam grooves 12 and 14 in the optical axis direction. As a result, the tilting amount changes from the maximum tilting state toward the tilting state of zero.

For example, FIGS. 10 and 11 show the case where the cam ring 1 is rotated and stopped in the middle of returning to the state where the amount of tilt is zero. This state occurs when the tilt amount is moderate to the maximum tilt amount. The tilting direction remains horizontal, and the tilting amount is moderate. When the cam ring 1 is further rotated clockwise, the tilt amount becomes zero. When it is rotated as it is, the rollers 42 and 44 move along the cam grooves and the lens holding frame 3 falls in the opposite direction. Become. As the rollers 43 and 45 are rotated further, the rollers 43 and 45 reach the ends of the cam grooves 13 and 15 formed as circumferential grooves, and relative rotation between the cam ring 1 and the guide cylinder 2 becomes impossible. In this state, the tilt amount of the lens holding frame 3 is maximized. The tilting direction is the horizontal direction (the rotation axis is in the vertical direction), which is the opposite direction to the state shown in FIG. As the cam ring 1 is further rotated from there, the cam ring 1, the lens holding frame 3, and the guide tube 2 rotate together, and the rotation axis in the tilting direction changes from the vertical direction (the direction of gravity/vertical direction) to the horizontal direction. change by In other words, it is in the direction of returning to the state of FIGS.

As described above, the tilting amount can be adjusted by rotating the cam ring 1, and the tilting direction (the direction of the rotation axis) can be adjusted by rotating the cam ring 1 and the guide tube 2 integrally. Become.

In this embodiment, the rotational ends of the relative rotation of the cam ring 1 and the guide cylinder 2 are the end portions of the cam grooves 13 formed as circumferential grooves of the rollers 43 and the cam ring 1 and the circumferential grooves of the rollers 45 and the cam ring 1 . It is determined by the end portion of the cam groove 15 formed as . In the non-rotatable state, the rollers 43 and 45 transmit the rotational force of the cam ring 1 to the lens holding frame 3 and the guide tube 2 . However, instead of rollers, separate parts such as screws and pins may be used, or terminal portions of bayonet grooves and bayonet claws may be used.

In this embodiment, the guide cylinder 2 and the fixed cylinder 5 are connected by a fixed roller 6 so as to be immovable in the optical axis direction and relatively rotatable about the optical axis. A bayonet connection is also acceptable.

In this embodiment, the cam ring is rotated to adjust the tilt amount and tilt direction. , and the user operates the operation unit to perform the adjustment.

Furthermore, it is also possible to provide a drive section that electrically rotates the cam ring without mechanically connecting the cam rings, and to drive the drive section in accordance with an input drive command.

In this embodiment, the lens holding frame 3 is supported by four rollers equally spaced at 90 degrees around the optical axis, and when the cam ring 1 is rotated, the position of the lens holding frame 3 in the optical axis direction changes. It is configured to not However, in view of the gist of the present invention that the tilting amount and tilting direction of the lens holding frame 3 can be adjusted by rotating the cam ring 1, the present invention is not limited to this.

The four rollers 42 to 45 may not be arranged at equal intervals of 90°, and the inclinations of the cams may be different. It is sufficient that the plane formed by the four rollers 42 to 45 in the initial state and perpendicular to the optical axis is tilted by the rollers moving along the cam groove. At this time, smooth movement of the rollers is hindered if the flat surface is not maintained in the process of changing the tilting state. Therefore, it is necessary to consider the arrangement of the rollers and the inclination of the cam.

FIG. 12 shows an example in which the phases in which the rollers are arranged are not equally divided by 90° and the inclinations of the cams are different. Referring to FIG. 12, it can be seen that the cam grooves and the guide grooves, which are equally divided by 90° in FIG. 4, are not equally divided by 90°. Phase 2 approaches phase 1, and the cam groove 13 is not a circumferential groove but has an inclination. The inclination direction is the same as that of the cam groove 12 of phase 1, but the inclination angle is not as large as that of the cam groove 12. Further, phase 4 is approaching phase 3, and the cam groove 15 is not a circumferential groove but has an inclination. The direction of inclination is the same as that of the cam groove 14 of phase 3, but the inclination angle is not as large as that of the cam groove 14 . In other words, the inclinations of the cams of the cam grooves 12 to 15 should be appropriately set so that the four rollers form a flat surface even after the cam ring 1 rotates. With such a configuration, it is possible to keep the position of the lens holding frame 3 supported by the four rollers in the optical axis direction unchanged when the cam ring 1 is rotated. Preferably, the cam groove is designed so that the axis of rotation for tilting the lens holding frame 3 includes a point on the optical axis of the lens system. Thereby, when the optical axis of the lens to be tilted is tilted with respect to the optical axis of the lens device, a symmetrical optical effect can be obtained in tilting to both sides from a state in which both optical axes are aligned. , to achieve better operability for adjustment.

In addition, in the configuration of this embodiment, the position of one point on the optical axis of the lens held by the lens holding frame 3 in the direction of the optical axis of the lens device does not change when adjusting the tilt amount, but it is allowable. A configuration in which the position in the optical axis direction changes depending on the level may also be used. As an example of such a configuration, the configuration shown in FIG. 13 is illustrated. Referring to FIG. 13, the phases 1 to 4 are arranged at equal intervals of 90° around the optical axis. , phases 1, 2 and 4, the rollers 42, 43 and 45 change in the same direction in the optical axis direction. The amount of movement of the roller 42 of the phase 1 is the largest, and the amount of movement of the rollers 43 and 45 of the phases 2 and 4 is about half of that. In other words, if the inclinations of the cams of the cam grooves 12, 13, and 15 are appropriately set so that the amount of movement in the optical axis direction is such that the four rollers form a flat surface even after the cam ring 1 rotates. good. With such a configuration, when the cam ring 1 is rotated, it is possible to change the tilt while allowing the position of the lens holding frame 3 supported by the four rollers in the optical axis direction to change. .

In this embodiment, the lens holding frame 3 is held by the four rollers 42 to 45, but the number of rollers (cam grooves of the cam ring 1) of the lens holding frame 3 is not limited to four. , three or more conditions can be changed without departing from the spirit of the present invention. Another embodiment, which will be described later, is a configuration in which three rollers support the lens holding frame.

In the present embodiment, the tilt-adjustable lens barrel has been described as an example, but it is also applicable to a configuration for tilt adjustment, which is one of the optical adjustments in assembling the lens barrel. Specifically, in the assembly of the lens barrel, if the desired optical performance cannot be obtained due to part errors or assembly errors, the optical performance is monitored during assembly so that the desired optical performance can be obtained. Adjusting to tilt the lens holding frame. In the conventional structure, the lens holding frame is supported by a plurality of eccentric rollers arranged around the optical axis, and the lens holding frame is adjusted by rotating the eccentric rollers with a tool such as a screwdriver to adjust the position in the optical axis direction. We have realized the tilting adjustment of the frame, but we have the problem that fine adjustment is difficult. With the demand for smaller lens barrels, it is necessary to reduce the diameter of the eccentric rollers. becomes difficult. In addition, as the demand for higher image quality increases, finer adjustments are required, making the adjustment work difficult. Also, the eccentric rollers are arranged in two or three places in the circumferential direction around the optical axis, and it is necessary to rotate all the eccentric rollers to improve the optical performance. It is easy to work on the eccentric rollers on the upper side of the lens barrel, but the work on the eccentric rollers on the lower side has poor workability because it is necessary to look down from below and work with a screwdriver tool. there were.

In contrast to these complicated operations, in the present invention, it is only necessary to rotate the cam ring, so workability is good, optical adjustment can be performed with higher precision, and high-quality images can be obtained more easily. is possible.

A second embodiment of the embodiment will be described in detail below with reference to the accompanying drawings. In the description of this embodiment, the differences from the first embodiment will be explained, and the parts common to the first embodiment will be omitted.

FIG. 14 is a conceptual diagram in which the guide groove of the guide cylinder 2 is projected onto the cam ring 1 of the second embodiment, which is developed in the circumferential direction. It is a diagram corresponding to FIG. 4 in the first embodiment. Since other configurations are the same as those of the first embodiment, illustration thereof is omitted.

Referring to FIG. 14, there are three cam grooves 12-14, and corresponding three guide grooves 22-24. The three cam grooves and the three guide grooves are arranged at phases 1, 2, and 3 at equal intervals of 120° around the optical axis (equally angular intervals). By rotating the cam ring 1 as in the first embodiment, the lens holding frame 3 can be tilted with respect to the optical axis direction. The tilting direction is the direction from the phase 1 through the center of the optical axis toward the central phase of the phases 2 and 3 .

The cam grooves of phases 2 and 3 with respect to phase 1 have cams with opposite inclinations in the circumferential direction about the optical axis. For example, when the cam ring 1 is rotated to move leftward on the developed view of FIG. Move to the imaging plane side. By rotating the cam ring 1, the lens holding frame 3 can be tilted with respect to the optical axis.

The tangent of the angle of the cam groove 12 at phase 1 with respect to the plane perpendicular to the optical axis in the extending direction of the cam groove 12 is the optical axis in the extending direction of the cam grooves 13 and 15 at phases 2 and 3. -2 times the tangent of the angle to the plane perpendicular to In other words, when the cam ring is rotated by a predetermined amount, the roller 42 of phase 1 moves by 1, while the rollers 43 and 44 of phases 2 and 3 move by 1 on the optical axis. Move 0.5 in the opposite direction. The angle is the angle formed by the plane perpendicular to the optical axis when each cam groove is viewed from the outside in the radial direction centered on the optical axis.

As a result, the intersection of the plane formed by the three points of the rollers 42 to 44 and the optical axis does not change even if the cam ring is rotated. That is, it is possible to change only the tilted state without changing the position in the optical axis direction of the lens device at one point on the optical axis of the lens held by the lens holding frame 3 .

In this embodiment, the phases 2 and 3 are arranged at 120° intervals (equal angular intervals) with respect to the phase 1 where the rollers are arranged, but the intervals may not be 120°. For example, when phases 2 and 3 are arranged at intervals of 135° with respect to phase 1, the inclination of the cam is √2/2 (approximately 0.707) in the opposite direction to phase 1 and phases 2 and 3. You can set it.

Also, the positional relationship of phases 2 and 3 with respect to phase 1 need not be the same, and may be different. For example, if phase 2 is positioned at 120° relative to phase 1 and phase 3 at 135° relative to phase 1, then the tilt of the cam relative to phase 1 is 0.5 for phase 2 and 0.5 for phase 3. It should be set to √2/2 (approximately 0.707).

In other words, the tilt of the cam may be adjusted to the phase in which the rollers are arranged so that the intersection of the plane formed by the three rollers and the optical axis does not change even when the cam ring is rotated, and the combination is not limited to the above. .

A third embodiment of the embodiment will be described in detail below with reference to the accompanying drawings. In the description of this embodiment, the differences from the first and second embodiments will be explained, and the parts common to the first and second embodiments will be omitted.

FIG. 15 is a conceptual diagram in which the guide groove of the guide cylinder 2 is projected onto the cam ring 1 of the second embodiment, which is developed in the circumferential direction. It is a diagram corresponding to FIG. 4 in the first embodiment. Since other configurations are the same as those of the first embodiment, illustration thereof is omitted.

Referring to FIG. 15, there are three cam grooves 12 to 14, and corresponding three guide grooves 22 to 24 are provided. The three cam grooves and the three guide grooves are arranged in phases 1, 2, and 3 at equal intervals of 120° around the optical axis. By rotating the cam ring 1 as in the first embodiment, the lens holding frame 3 is tilted with respect to the optical axis. The tilting direction is the direction from the phase 1 through the center of the optical axis toward the central phase of the phases 2 and 3 .

The phase 1 cam groove 12 is a cam with an inclination, while the phase 2 and phase 3 are formed in a plane orthogonal to the optical axis, and the inclination angle with respect to the plane orthogonal to the optical axis is 0°. cam. For example, when the cam ring 1 is rotated to move leftward on the developed view of FIG. It does not move along the optical axis. By rotating the cam ring 1, the lens holding frame 3 can be tilted with respect to the optical axis.

Further, the point connecting the plane formed by the three points of the rollers 42 to 44 and the center of the optical axis changes as the cam ring rotates. That is, it is possible to tilt the lens holding frame 3 with respect to a plane orthogonal to the optical axis of the lens device while allowing a change in the position of the lens holding frame 3 in the optical axis direction.

In this embodiment, the phases 2 and 3 are arranged at intervals of 120° with respect to the phase 1 where the rollers are arranged, but the interval may not be 120°. Also, the positional relationship of phases 2 and 3 with respect to phase 1 need not be the same, and may be different.

A fourth embodiment of the embodiment will be described in detail below with reference to the accompanying drawings. The description of this embodiment will focus on the differences from the first embodiment, and will omit the parts common to the other embodiments described above.

In all of the above-described embodiments, the amount and direction of tilting of the lens holding frame 3 can be adjusted by a single operation of rotating the cam ring 1 . Specifically, by rotating the cam ring 1 and the guide tube 2 within a range in which the cam ring 1 and the guide tube 2 can rotate relative to each other, the tilting amount is adjusted, and the relative rotation between the cam ring 1 and the guide tube 2 becomes impossible, and the cam ring 1 and the guide tube 2 rotate together. In the range, it is configured to adjust the tilting direction.

However, when the cam ring 1 is rotated within the range in which the cam ring 1 and the guide tube 2 can relatively rotate, the cam ring 1 and the guide tube 2 do not rotate relatively, and the cam ring 1 and the guide tube 2 are integrated. There is a possibility that the guide tube 2 and the fixed tube 5 will rotate relative to each other. If this happens, the direction of the axis of rotation for tilting may change even though the amount of tilting is intended to be changed, resulting in extremely poor workability.

A configuration for preventing this will be described in this embodiment.
Referring to FIG. 1, a gap Y is formed between the cam ring 1 and the guide tube 2 in the optical axis direction.
Similarly, a gap Z is formed between the guide tube 2 and the fixed tube 5 in the optical axis direction. An urging member is added to this gap Y, and the urging force of the urging member urges the cam ring 1 against the guide tube 2 in the optical axis direction. Similarly, an urging member is added to the gap Z, and the urging force of the urging member urges the guide tube 2 with respect to the fixed tube 5 in the optical axis direction. By making a difference in this urging force, a difference in the rotational torque required to relatively rotate the cam ring 1 and the guide cylinder 2 and the rotational torque required to relatively rotate the guide cylinder 2 and the fixed cylinder 5 can also be achieved. It is possible to attach By setting the latter so that the torque is always greater than the former, it is possible to prevent the guide cylinder 2 from rotating together with the cam ring 1 within the range in which the cam ring 1 and the guide cylinder 2 can rotate relative to each other.

In other words, it is possible to prevent the tilting direction from changing when trying to adjust the tilting amount, thereby avoiding deterioration of operability.

In this embodiment, an urging member for urging in the optical axis direction is added as an example, but an urging member for urging in the radial direction may be added. Further, the above-described torque difference may be generated by applying greases having different viscosities to the respective sliding portions. Any configuration may be employed as long as the relative rotational torque between the guide tube 2 and the fixed tube 5 can be made larger than the relative rotational torque between the cam ring 1 and the guide tube 2 .

The shape of the cam groove formed in the cam ring and the shape of the guide groove formed in the guide cylinder are not limited to the shapes of the illustrated embodiments. All the guide grooves formed in the guide tube are elongated holes slightly extending in the direction of the optical axis in order to absorb part manufacturing errors and assembly errors and to prevent multiple fittings. . In addition, the shape of the guide groove is a shape that restricts the movement of the engaging roller in the circumferential direction (rotational direction about the optical axis) with respect to the guide cylinder. In addition, regardless of the tilt of the lens surface that changes due to the change in the position of the cam engaged with the cam groove in the optical axis direction due to the rotation of the cam barrel with respect to the guide barrel, the lens held in the lens holding frame is positioned at a predetermined position. It is preferable to configure the cam groove so that it does not change in the axial direction. The predetermined position of the lens includes, for example, the center of thickness on the optical axis of the lens, the surface vertex, the pupil position, and the like.

As described above, the configuration for achieving the object of the present invention has been described in Examples 1 to 4, but it is of course possible to apply other forms as long as they do not conflict with the object and configuration of the present invention. It is also possible to combine each configuration.

Reference Signs List 1 cam ring 2 guide tube 3 lens holding frame 5 fixed tube 12, 13, 14, 15 cam grooves 22, 23, 24, 25 guide groove 42 , 43, 44, 45...Rollers (engaging portions)

Claims (13)

a fixed barrel;
a guide cylinder held so as to be immovable in the optical axis direction and rotatable about the optical axis with respect to the fixed cylinder, and having a plurality of guide grooves having guide grooves extending in the optical axis direction;
a cam ring having a plurality of cam grooves including cam grooves inclined with respect to a plane orthogonal to the optical axis;
a lens holding frame having a plurality of engaging portions that engage with the plurality of guide grooves and the plurality of cam grooves and holding a lens;
has
The cam ring is configured to be immovable in the optical axis direction with respect to the guide tube and rotatable about the optical axis, and non-rotatable about the optical axis with respect to the guide tube and integral with the guide tube. a rotatable state;
A lens barrel characterized by: 2. The apparatus according to claim 1, wherein the engaging portion engaged with the guide groove extending in the direction of the optical axis engages with the cam groove inclined with respect to a direction perpendicular to the optical axis. Described lens barrel. 3. The lens according to claim 1, wherein the plurality of guide grooves are arranged around the optical axis at equal angular intervals, and the plurality of cam grooves are arranged around the optical axis at equal angular intervals. lens barrel. 4. The lens barrel according to any one of claims 1 to 3, wherein said plurality of guide grooves consist of four guide grooves, and said plurality of cam grooves consist of four cam grooves. 4. The lens barrel according to any one of claims 1 to 3, wherein said plurality of guide grooves consist of three guide grooves, and said plurality of cam grooves consist of three cam grooves. The plurality of cam grooves and the plurality of engaging portions are configured such that the intersection of the plane including the plurality of engaging portions and the optical axis does not move regardless of the rotational position of the cam ring. 6. A lens barrel according to any one of claims 1 to 5. 2. Two cam grooves that are not adjacent to each other among the four cam grooves are configured to have the same inclination angle in opposite directions with respect to a plane perpendicular to the optical axis. 5. The lens barrel according to 4. 8. The lens barrel according to claim 7, wherein the other two of the four cam grooves that are not adjacent to each other are parallel to a plane perpendicular to the optical axis. 6. The lens barrel according to claim 5, wherein at least one of said three cam grooves is inclined with respect to a plane orthogonal to said optical axis. the three cam grooves are inclined with respect to a plane perpendicular to the optical axis,
Inclinations of one of the three cam grooves and the other two cam grooves with respect to a plane perpendicular to the optical axis are opposite to each other.
10. The lens barrel according to claim 9, characterized in that: The rotational torque required for rotating the guide tube around the optical axis relative to the fixed tube is greater than the torque required for rotating the cam ring around the optical axis relative to the guide tube. 11. A lens barrel according to any one of claims 1 to 10, characterized in that the two are larger. A lens device comprising the lens barrel according to any one of claims 1 to 11. 13. An image pickup apparatus comprising: the lens apparatus according to claim 12; and an image sensor for taking an image formed by the lens apparatus.

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