JP6278735B2 - Eccentricity adjusting device, optical apparatus, and eccentricity adjusting method - Google Patents

Description

  The present invention relates to an eccentricity adjusting device, an optical apparatus, and an eccentricity adjusting method.

  In Patent Document 1, the first diameter portion of the cam pin is fitted into the circumferential groove, the second diameter portion of the cam pin is fitted into the guide groove and the cam groove, and is eccentric with respect to the first diameter portion. A lens moving device is proposed in which a cam pin rotates around the central axis of the second diameter portion. Thereby, the optical axis fall of an optical element can be adjusted.

Japanese Patent Laid-Open No. 02-113214

  However, the configuration of Patent Document 1 cannot adjust the parallel eccentricity of the lens. Here, “parallel decentering adjustment” adjusts the position of the optical axis of an optical element such as a lens within a plane orthogonal to the ideal optical axis (for example, to match the ideal optical axis) ( decenter). On the other hand, “optical axis tilt” refers to the tilt of the optical axis of the optical element with respect to the ideal optical axis. When the parallel eccentricity adjustment causes the optical axis to be tilted, the largest optical axis tilt amount needs to be within the allowable range in order to maintain the optical performance.

  An exemplary object of the present invention is to provide an eccentricity adjustment device, an optical apparatus, and an eccentricity adjustment method capable of performing parallel eccentricity adjustment of an optical element in a state where an optical axis tilt amount is suppressed within an allowable range. .

  An eccentricity adjusting device of the present invention is an eccentricity adjusting device that adjusts the parallel eccentricity of an optical element held by a holding member, and includes a guide member having a plurality of guide grooves, a cam member having a plurality of cam grooves, , Each having three eccentric rollers positioned at the intersection of the guide groove and the cam groove, each eccentric roller being inserted into the guide groove and the first cylindrical portion inserted into the cam groove A second cylindrical portion that is concentric with the first cylindrical portion; a third cylindrical portion that is eccentric with respect to the first cylindrical portion and the second cylindrical portion and is engaged with the holding member; The two eccentric rollers are composed of two first eccentric rollers and one second eccentric roller, and the first eccentric amount of the third cylindrical portion of the first eccentric roller is the first eccentric amount of the third cylindrical portion of the second eccentric roller. It is characterized by being larger than the second eccentric amount.

  According to the present invention, it is possible to provide an eccentricity adjustment device, an optical apparatus, and an eccentricity adjustment method capable of performing parallel eccentricity adjustment of an optical element in a state where an optical axis tilt amount is suppressed within an allowable range.

It is sectional drawing of the imaging system of this embodiment. It is a system block diagram of the imaging system shown in FIG. It is an expansion perspective view of an eccentric roller. It is a figure of the optical unit shown in FIG. It is a schematic enlarged view of the optical unit shown in FIG. 4 before adjustment with the eccentric roller of this embodiment. It is a schematic enlarged view of the optical unit shown in FIG. 4 after adjustment by the eccentric roller of this embodiment. It is a schematic enlarged view of the optical unit before adjustment by the eccentric roller of a comparative example. It is a schematic enlarged view of the optical unit after adjustment by the eccentric roller of the comparative example.

  FIG. 1 is a cross-sectional view of an imaging system (optical apparatus) that includes an interchangeable lens 200 and a camera body 500. The interchangeable lens (lens unit) 200 is an optical device configured to be detachable from the camera body 500. The camera body 500 is configured as a single-lens reflex camera (optical device) in the present embodiment, but may be configured as a mirrorless camera. The present invention is applicable not only to digital still cameras but also to digital video cameras and lens-integrated cameras.

  The interchangeable lens 200 has a photographing optical system that forms an optical image of a subject. The photographing optical system according to the present embodiment includes a first group lens 1, a second group lens 3, a third group lens 5, an anti-vibration lens 7, a focus lens 9, a fifth group lens 12, and an aperture unit 34.

  Reference numeral 2 denotes a first group lens barrel that holds the first group lens 1, 17 denotes a first group cylinder that fixes the first group lens barrel, 4 denotes a second group lens barrel that holds the second group lens 3, and 6 denotes a third group lens 5. This is a third group barrel (holding member). The image stabilizing lens 7 corrects image blur by moving in a direction perpendicular to the optical axis, and is held by the image stabilizing device 8. The vibration isolator 8 is fixed to the third group barrel 6.

  Reference numeral 10 denotes a focus lens barrel that holds the focus lens 9 and is moved in the optical axis direction by a guide mechanism and a drive mechanism provided in the fourth group lens barrel 11 to perform focus adjustment. Reference numeral 13 denotes a fifth group barrel that holds the fifth group lens 12. The diaphragm unit 34 adjusts the amount of light and is fixed to the third group barrel 6.

  Reference numeral 14 denotes a guide tube (guide member), which is provided with a plurality of guide grooves 14a (in this embodiment, parallel to the three optical axes in the circumferential direction) as shown in FIG. . When the cam ring 16 rotates in the third group barrel 6, the eccentric roller slides along the guide groove 14a and moves in the optical axis direction. It is assumed that the guide tube 14 is fixed. Further, the guide tube 14 is fitted to the cam ring 16 on the outer periphery thereof and slides with respect to the cam ring 16.

  A cam ring (cam member) 16 is rotatably fitted to the outer periphery of the guide cylinder 14. As shown in FIG. 4B, which will be described later, a plurality of cam grooves 16a (a total of 12 cam grooves 16 in the circumferential direction for each lens in the present embodiment) are provided in the circumferential direction of the cam ring 16. .

  Reference numeral 23 denotes a fixed barrel, which fixes the guide tube 14. Reference numeral 31 denotes a printed circuit board on which a lens driving IC, a microcomputer, and the like are arranged, and is fixed to the fixed barrel 23.

  27 is an external ring unit, and 32 is a mount. The mount 32 is screwed to the fixed barrel 23. The ring unit 27 is fixed between the fixed barrel 23 and the mount 32. Reference numeral 19 denotes a manual focus ring (MF) unit, which is supported so as to be rotatable about a fixed barrel 23. When the MF unit 19 is rotated, the rotation is detected by a sensor (not shown), and manual focus adjustment is performed according to the rotation amount.

  Reference numeral 33 denotes a contact block, which is connected to the printed circuit board 31 by wiring (not shown) (FPC or the like) and fixed to the mount 32 with screws. The interchangeable lens 200 is bayonet-fixed to the camera body 500 with a mount 32. When the interchangeable lens 200 is fixed to the camera body 500 with the mount 32, the printed circuit board 31 that controls the operation of each lens can communicate with the camera body 500 through the contact block 33.

  Reference numeral 600 denotes an imaging element mounted on the camera body 500, which is a photoelectric conversion element such as a CMOS or CCD that photoelectrically converts an optical image formed by the photographing optical system.

  FIG. 2 is a block diagram illustrating an electrical configuration of the imaging system.

  Reference numeral 501 denotes a camera CPU (camera control means) constituted by a microcomputer, which controls the operation of each unit in the camera body 500. The camera CPU 501 communicates with the lens CPU 201 (lens control means) of the interchangeable lens 200 via the electrical contacts 502 and 202 when the interchangeable lens 200 is mounted.

  Information (signals) transmitted from the camera CPU 501 to the lens CPU 201 includes drive amount information, parallel shake information, and out-of-focus information of the focus lens 9. Information (signal) transmitted from the lens CPU 201 to the camera CPU 501 includes imaging magnification information. The electrical contacts 502 and 202 include contacts for supplying power from the camera body 500 to the interchangeable lens 200.

  A power switch 503 that can be operated by the photographer is a switch for starting the camera CPU 501 and starting power supply to each actuator, sensor, and the like in the camera system.

  Reference numeral 504 denotes a release switch that can be operated by the photographer, and includes a first stroke switch SW1 and a second stroke switch SW2. A signal from the release switch 504 is input to the camera CPU 501. The camera CPU 501 enters a shooting preparation state in response to an ON signal input from the first stroke switch SW1. In the shooting preparation state, measurement of subject brightness by the photometry unit 505 and focus detection by the focus detection unit 506 are performed. The camera CPU 501 calculates the aperture value of the aperture unit 34, the exposure amount of the image sensor 600 (in shutter seconds), and the like based on the photometric result.

  Based on the focus detection result (defocus amount and defocus direction) by the focus detection unit 506, the camera CPU 501 drives the focus lens 9 and the focus lens barrel 10 to obtain the in-focus state (including the drive direction). ). Information on the driving amount (focus lens driving amount information) is transmitted to the lens CPU 201. The lens CPU 201 controls the operation of each component of the interchangeable lens 200.

  The camera CPU 501 controls image stabilization by the image stabilization device 8. When the ON signal from the second stroke switch SW2 is input, the camera CPU 501 transmits an aperture drive command to the lens CPU 201 to set an aperture value via the aperture unit 34. Further, the camera CPU 501 transmits an exposure start command to the exposure unit 507, causes the mirror (not shown) to be retracted and the shutter (not shown) to be opened, and exposes the imaging unit 508 including the imaging element 600.

  An image pickup signal from the image pickup unit 508 (image pickup element 600) is digitally converted by a signal processing unit in the camera CPU 501, subjected to various correction processes, and output as an image signal. An image signal (data) is recorded and stored in a recording medium such as a semiconductor memory such as a flash memory, a magnetic disk, or an optical disk in an image recording unit 509.

  Reference numeral 204 denotes an MF ring rotation detection unit, which includes the MF unit 19 and its rotation detection unit. Reference numeral 205 denotes a ZOOM ring rotation detection unit, which includes a manual zoom ring 35 and a sensor (not shown) that detects the rotation. Reference numeral 206 denotes an anti-vibration device drive unit, which includes a drive actuator of the anti-vibration device 8 that performs an anti-vibration operation and a drive circuit thereof.

  Reference numeral 209 denotes an AF driving unit that performs AF driving of the focus lens barrel 10 through an AF motor in accordance with focus lens driving amount information transmitted from the camera CPU 501. Reference numeral 208 denotes an electromagnetic aperture drive unit, which is controlled by the lens CPU 201 that has received an aperture drive command from the camera CPU 501 to operate the aperture unit 34 in an aperture state corresponding to a specified aperture value.

  Reference numeral 211 denotes an angular velocity sensor mounted on the interchangeable lens 200 and connected to the printed circuit board 31. The angular velocity sensor 211 outputs to the lens CPU 201 angular velocity signals indicating respective angular velocities of vertical (pitch direction) shake and lateral (yaw direction) shake, which are angular shakes of the camera system.

  The lens CPU 201 integrates the pitch velocity and yaw angular velocity signals from the angular velocity sensor 211 electrically or mechanically, and the pitch direction shake amount and the yaw direction shake amount, which are displacement amounts in the respective directions (summarizing them). (Also referred to as angular deflection). Further, the lens CPU 201 controls the image stabilization device driving unit 206 based on the combined displacement amount of the angle shake amount and the parallel shake amount to shift the moving group 700 of the image stabilization device 8 to perform the angle shake correction and the parallel shake correction. I do. Further, the lens CPU 201 controls the AF driving unit 209 based on the focus shift amount to drive the focus lens barrel 10 in the optical axis direction to perform focus adjustment.

  Energization of detection signals such as zoom, focus, and anti-vibration operations from the detection means to the lens CPU 201 and control signals from the lens CPU 201 to each actuator is performed by FPC.

  FIG. 3 is an enlarged perspective view of an eccentric roller (first eccentric roller) 40 used for adjusting the parallel eccentricity of the third group lens 5. In this embodiment, three eccentric rollers are provided in the circumferential direction at intervals of 120 degrees, and the three eccentric rollers are composed of two eccentric rollers 40 and one eccentric roller 50. Each eccentric roller is located at the intersection of the corresponding guide groove 14 a of the guide tube 14 and the corresponding cam groove 16 a of the cam ring 16. The parallel eccentricity adjustment of the third lens group 5 can be performed by the joint action of the guide groove 14a, the cam groove 16a, and the eccentric roller, thereby constituting an eccentricity adjusting device.

  In this embodiment, the parallel decentering adjustment of the third group lens 5 is performed. However, the optical element that is the target of the parallel decentering adjustment is not limited to the third group lens 5.

  Each eccentric roller has a first cylindrical part inserted into the cam groove 16a, a second cylindrical part inserted into the guide groove 14a and concentric with the first cylindrical part, the first cylindrical part and the second cylindrical part. And a third cylindrical portion engaged with the third group barrel 6 in an eccentric manner.

  The eccentric roller 40 shown in FIG. 3 is inserted into the first cylindrical portion 41 inserted into the cam groove 16a, the second cylindrical portion 42 inserted into the guide groove 14a, and the roller seat 6a which is a hole portion of the third group barrel 6. The third cylindrical portion 43 is provided. The first cylindrical portion 41 and the second cylindrical portion 42 are concentric cylinders, and the third cylindrical portion 43 is eccentric with respect to the first cylindrical portion 41 and the second cylindrical portion 42. The center is a hollow portion, and a screw 60 is inserted as will be described later.

  In the present embodiment, the first cylindrical portion 41 and the second cylindrical portion 42 have the same diameter as the first diameter portion, and the third cylindrical portion 43 has a diameter slightly larger than that of the second diameter portion. Good, but this is not essential. Moreover, although the 3rd cylindrical part 43 is rotatably inserted and engaged with the roller seat 6a of the 3rd group lens barrel 6, the engagement method is not ask | required.

  The first cylindrical portion 41 has two grooves 41a and one groove 41b.

  The two grooves 41a are, for example, a slot into which a not-shown flathead screwdriver is inserted. The eccentric roller 40 is rotated by a flat-blade screwdriver, and parallel eccentricity adjustment can be performed. This will be described later with reference to FIG. In addition, if it is a structure which engages with an external member and enables rotation of the eccentric roller 40, it is not limited to a groove | channel, A convex part etc. may be sufficient.

  The groove 41 b is a mark portion that provides a guide for the rotation angle of the eccentric roller 40. The mark portion is not limited to the groove shape, and may be a convex portion or a print. In the present embodiment, the rotation angle of the eccentric roller 40 is set in the range of 0 degrees to 90 degrees. An approximate rotation angle (for example, 30 degrees, 45 degrees, 60 degrees) can be grasped by the mark portion, and an angle exceeding 90 degrees is set (for example, 135 degrees is set instead of 45 degrees). ) Can be prevented.

  A stopper that restricts the rotation angle may be provided on the eccentric roller 40, and the rotation angle of the eccentric roller 40 may be mechanically restricted from 0 degrees to 90 degrees.

  The eccentric amount (first eccentric amount) of the third cylindrical portion 43 of the eccentric roller 40 is larger than the eccentric amount (second eccentric amount) of the third cylindrical portion of the eccentric roller 50. As described above, the first eccentric amount is the distance between the central axis of the third cylindrical portion 43 and the central axis of the first cylindrical portion 41 (second cylindrical portion 42). These central axes are parallel, and the distance between the central axes is an interval on a plane perpendicular to the central axes. The same applies to the second eccentric amount.

  As a result, 0 <(second eccentric amount) <(first eccentric amount). Preferably, the second eccentric amount is set to 1 / √2 times the first eccentric amount or a value in the vicinity thereof. That is, the second eccentric amount preferably has a value between 0.7 / √2 times the first eccentric amount and 1.3 / √2 times the first eccentric amount.

  FIG. 4A is a front view of the optical unit including the third group barrel 6, the cam ring 16, and the guide tube 14 as viewed from the optical axis direction. For convenience of explanation, the other groups are omitted. However, when optical adjustment is performed, parallel decentering adjustment is performed in the state where all the optical systems are assembled, and optical axis alignment is performed.

  FIG. 4B is a side view of the optical unit shown in FIG. 4C is a cross-sectional view taken along the line AA in FIG. 4A, and a cross section passing through the centers of the eccentric rollers 40 and 50 is cut. FIG. 4D is a schematic sectional view showing the relationship between the eccentric rollers 40 and 50 and the third group lens barrel 6 before adjusting the parallel eccentricity. For convenience of explanation, the eccentric amount of the eccentric rollers 40 and 50 is larger than the actual amount. It is the side view shown.

  Roller seats 6a are provided on the outer periphery of the third group barrel 6 at intervals of 120 degrees. Two of the three roller seats 6 a hold the eccentric roller 40, and the other one holds the eccentric roller 50 via screws 60.

  As shown in FIG. 4D, the first eccentric amount δA of the eccentric roller 40 and the second eccentric amount δB of the eccentric roller 50 are set to δA> δB. In the state before the eccentricity adjustment, the eccentric roller 40 and the eccentric roller 50 are incorporated so that the eccentric direction coincides with the optical axis direction (the guide groove 14 direction). It can be seen from the difference in the amount of eccentricity that in the initial state before the eccentricity adjustment, the third lens group 5 is inclined counterclockwise from the ideal optical axis indicated by the dotted line by θ1 as indicated by the alternate long and short dash line.

  FIGS. 5 and 6 are schematic enlarged views around the eccentric roller of the optical unit comprising the third group barrel 6, the cam ring 16 and the guide tube 14 in this embodiment, and the amount of eccentricity is exaggerated for convenience of explanation. This is shown schematically.

  FIG. 5 shows a state before the parallel eccentricity adjustment by the eccentric roller 40, and FIG. 6 shows a state after the parallel eccentricity adjustment by the eccentric roller 40. FIG. 5A and FIG. 6A are partially transparent front views as seen from the direction orthogonal to the optical axis. FIGS. 5B and 6B are partially transparent top views. FIG. 5C and FIG. 6C are partially transparent side views thereof. The x-axis is the optical axis direction, and the y-axis is the direction orthogonal to the optical axis.

  In this embodiment, eccentric rollers 40 and 50 having different eccentric amounts are used, and in the assembled state, as shown in FIG. 5C, an inclination of θ1 is generated in the third group lens 5 with respect to the ideal optical axis. . From there, by rotating the eccentric roller 40, the inclination of the third lens group 5 changes continuously, and the inclination direction is reversed to θ2 as shown in FIG. 6C.

  The eccentricity adjustment method of the present embodiment adjusts the parallel eccentricity of the third group lens 5 held by the third group lens barrel 6 using the eccentricity adjusting device, but is arranged before adjusting the parallel eccentricity of the third group lens 5. There is a feature.

  That is, before adjusting the parallel eccentricity of the third lens group 5, the optical axis of the third lens group 5 is inclined with respect to a predetermined axis (ideal optical axis) (only θ1 in FIG. 5C). When the roller 40 is rotated in a predetermined direction, the angle of the optical axis of the third group lens 5 with respect to the predetermined axis continuously decreases. When the eccentric roller 40 is further rotated in the predetermined direction after the optical axis of the third group lens 5 coincides with the predetermined axis, the angle of the optical axis of the third group lens 5 with respect to the predetermined axis is before adjusting the parallel eccentricity. Increases in the opposite direction. The angle of the optical axis of the third lens group 5 after the largest eccentric adjustment is θ2. That is, the optical axis tilt amount of the third lens group 5 changes from −θ1 to + θ2 when the θ2 direction is +. If the absolute value of θ1 and the absolute value of θ2 are within the allowable range, the optical axis tilt amount accompanying the parallel decentering of the third lens group 5 is within the allowable range. The absolute value of θ1 may be equal to the absolute value of θ2, or one of them may be larger.

(Comparative example)
7 and 8 are schematic enlarged views around the eccentric roller of the optical unit including the third group barrel 6, the cam ring 16, and the guide tube 14 as a comparative example. The comparative example also uses three eccentric rollers, but differs from the present embodiment in that the three eccentric rollers are composed of three eccentric rollers 40. 7 and 8 also schematically show the amount of eccentricity exaggerated for convenience of explanation.

  FIG. 7 shows a state before the parallel eccentricity adjustment by the eccentric roller 40, and FIG. 8 shows a state after the parallel eccentricity adjustment by the eccentric roller 40. FIGS. 7A and 8A are partially transparent front views as seen from the direction orthogonal to the optical axis. FIGS. 7B and 8B are partially transparent top views. FIGS. 7C and 8C are partially transparent side views.

  As shown in FIG. 7C, in the assembled state before the eccentricity adjustment, the inclination of the optical axis of the third lens unit 5 with respect to the ideal optical axis is substantially zero. 7 and 8, the eccentric adjustment is performed by rotating the eccentric rollers 40 at two locations. If the eccentric direction is the optical axis direction (the direction of the guide groove 14a), if the rotation angle for rotating the eccentric roller 41a with a flathead screwdriver or the like is θ, the roller seat 6a of the third group barrel 6 is only y = δAsinθ. Change. Thereby, the 3rd group lens 5 can be moved to a desired eccentric position.

  However, as shown in FIG. 8A, the roller seat 6a is displaced by x = δA (1-cos θ) in the optical axis direction. When the roller seat 6a changes by x in the optical axis direction, an inclination θ3 is generated in the third lens group 5. FIG. 8 shows a state in which the eccentric roller 40 is rotated by the same angle as in FIG. 6, and when the inclination of the third group lens 5 shown in FIG. 8C is θ3, | θ2 | <| θ3 | Further, assuming that the amount of eccentricity y = y1 necessary for the eccentricity adjustment, the amount of change x in the optical axis direction associated therewith is x = x1. The amount of eccentricity is set so that δA−δB <x1. This results in | θ1 | <| θ3 |.

  That is, in the comparative example, the optical axis tilt amount of the third group lens 5 changes from 0 to + θ3. Even if the absolute value of θ1 and the absolute value of θ2 are within the allowable range, an absolute value of θ3 larger than that may be outside the allowable range, and the optical performance may be deteriorated. For example, when the adjustment is performed in the Wide (wide-angle end) state, the change in tilt adversely affects the center resolution of the Tele (telephoto end).

  In this embodiment, the eccentric amount y = y1 necessary for the eccentric adjustment is described. However, the eccentric roller 40 has a groove 41b, and the rotation angle of the eccentric roller 40 can be recognized. Does not degrade performance or take time to adjust.

  As described above, when the eccentric roller 40 and the eccentric roller 50 having different eccentric amounts are used, the inclination of the third group lens 5 caused by the parallel eccentric adjustment can be suppressed to be small. Thereby, the optical performance can be further improved as compared with the case where the same eccentric rollers are used.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation and change are possible within the range of the summary.

  The present invention can be applied to an optical apparatus such as a lens barrel.

5 ... 3 group lens (optical element), 6 ... 3 group lens barrel (holding member), 14 ... guide tube (guide member), 14a ... guide groove, 16 ... cam ring (cam member), 16a ... cam groove, 40 ... Eccentric roller (first eccentric roller), 41 ... first cylindrical portion, 42 ... second cylindrical portion, 43 ... third cylindrical portion, 50 ... eccentric roller (second eccentric roller)

Claims (6)

An eccentricity adjusting device that adjusts the parallel eccentricity of the optical element held by the holding member,
A guide member having a plurality of guide grooves;
A cam member having a plurality of cam grooves;
Three eccentric rollers each located at the intersection of the guide groove and cam groove,
Have
Each eccentric roller includes a first cylindrical portion inserted into the cam groove, a second cylindrical portion inserted into the guide groove and concentric with the first cylindrical portion, the first cylindrical portion, and the second cylindrical portion. A third cylindrical portion that is eccentric with respect to the cylindrical portion and engaged with the holding member,
The three eccentric rollers include two first eccentric rollers and one second eccentric roller, and the first eccentric amount of the third cylindrical portion of the first eccentric roller is the third cylinder of the second eccentric roller. An eccentricity adjusting device characterized by being larger than the second eccentric amount of the part.   The eccentric adjustment device according to claim 1, wherein the first eccentric roller includes a mark portion that provides a guide for a rotation angle.   The eccentricity adjusting device according to claim 1, further comprising a stopper that regulates a rotation angle of the first eccentric roller.   4. The second eccentricity has a value between 0.7 / √2 times the first eccentricity and 1.3 / √2 times the first eccentricity. The eccentric adjustment apparatus of any one of these.   An optical apparatus comprising the eccentricity adjusting device according to any one of claims 1 to 4. An eccentricity adjustment method for adjusting parallel eccentricity of an optical element held by a holding member using the eccentricity adjustment device according to any one of claims 1 to 5,
Before adjusting the parallel eccentricity of the optical element, the optical axis of the optical element is inclined with respect to a predetermined axis, and the optical element is rotated when the first eccentric roller of the eccentricity adjusting device is rotated in a predetermined direction. The angle of the optical axis with respect to the predetermined axis is reduced, and when the first eccentric roller is further rotated in the predetermined direction after the optical axis of the optical element coincides with the predetermined axis, the optical element The eccentricity adjusting method, wherein the optical element is arranged so that an angle of an optical axis with respect to the predetermined axis is increased in a direction opposite to that before adjusting the parallel eccentricity.