OPTICAL APPARATUS AND IMAGE PICKUP APPARATUS

A lens apparatus comprises a fixed barrel, a movable barrel, a mechanism configured to move the movable barrel along an optical axis by rotation of the movable barrel around the optical axis, and an operating member disposed through the fixed barrel and rotationally operated. The operating member comprises a rotating shaft and an engaging portion eccentric from the rotating shaft. The rotating shaft is rotated with the operating member being rotationally operated, the engaging portion is engaged with a guide formed in the movable barrel along the optical axis. At least a part of the engaging portion is located outside the rotating shaft in a direction orthogonal to the rotating shaft. Rotation of the operating member causes the engaging portion to slide on the guide, the movable barrel to rotate around the optical axis, and the mechanism to move the movable barrel along the optical axis.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to an optical apparatus and an image pickup apparatus.

Description of the Related Art

Since the components of an optical apparatus such as a lens device have dimensional errors, the optical characteristics of the optical apparatus may deviate from the design values. For this reason, there is known a lens apparatus in which the position of the focus surface can be adjusted, for example, by adjusting the position of the movable final lens group in the optical axis direction (so-called flange back adjusting).

Japanese Patent No. 6415425 discloses a flange back adjusting mechanism in which rotation of a movable barrel about the optical axis is converted into movement in the optical axis direction of the movable barrel by a rotation linear motion converting mechanism such as a helicoid mechanism.

In the flange back adjusting mechanism disclosed in Japanese Patent No. 6415425, when the distance between the rotating shaft and the eccentric shaft of the operating portion is increased in order to increase the moving amount of the movable barrel in the optical axis direction, the operating portion is increased in size, and accordingly, the diameter of the circular hole portion of the fixed barrel through which the operating portion passes must be increased.

SUMMARY OF THE INVENTION

An aspect of embodiments provides, for example, an optical apparatus beneficial in small size and adjustment of optical characteristic thereof.

An aspect of embodiments provides an optical apparatus comprising: a fixed barrel; a movable barrel disposed inside the fixed barrel and holding an optical element; a mechanism configured to move the movable barrel along an optical axis by rotation of the movable barrel around the optical axis; and an operating member disposed through the fixed barrel and rotationally operated, wherein the operating member comprises a rotating shaft and an engaging portion eccentric from the rotating shaft, the rotating shaft being rotated with the operating member being rotationally operated, the engaging portion being engaged with a guide formed in the movable barrel along the optical axis; at least a part of the engaging portion is located outside the rotating shaft in a direction orthogonal to the rotating shaft; rotation of the operating member causes the engaging portion to slide on the guide, the movable barrel to rotate around the optical axis, and the mechanism to move the movable barrel along the optical axis.

DESCRIPTION OF THE EMBODIMENTS

EXAMPLE

A lens apparatus1(optical apparatus) according to an embodiment of the present disclosure will be described below.FIG.1is a cross-sectional view of the lens apparatus1according to an embodiment of the present disclosure.

The lens apparatus1is provided with a plurality of optical elements, and the plurality of optical elements comprises a first lens2a,a second lens2b,and a third lens2c.The first lens2aas a front fixing group is fixed to a front fixed barrel3, the second lens2bas an object to be adjusted by a flange back adjusting unit described later is fixed to a movable barrel5, and the third lens2cas a relay group is fixed to a rear fixed barrel6.

A lens mount7is provided at an end portion of the rear fixed barrel6, and is connected to a mount portion of an image pickup apparatus (not illustrated) at the time of photographing. A fixed barrel8is provided between the front fixed barrel3and the rear fixed barrel6. The fixed barrel8is provided with a flange back adjusting unit. The front fixed barrel3and the fixed barrel8are connected by a plurality of screws (not illustrated). The fixed barrel8and the rear fixed barrel6are connected by a plurality of screws10. The movable barrel5for holding the second lens2bis arranged inside the fixed barrel8.

The first lens2ais fixed to the front fixed barrel3by fastening a first pressing ring11ato screw portions formed on the front fixed barrel3. The second lens2bis fixed to the movable barrel5by fastening a second pressing ring11bto screw portions formed on the movable barrel5. The third lens2cis fixed to the rear fixed barrel6by fastening a third pressing ring11cto screw portions formed on the rear fixed barrel6. Although the lens apparatus1is not described in the embodiment, the lens apparatus1may be configured to be capable of focus adjustment, magnification, and light amount adjustment by a structure not illustrated.

Referring toFIGS.1and2, the flange back adjusting unit will be described.FIG.2is a perspective view of a flange back adjusting unit of the lens apparatus1. The flange back adjustment is performed by rotating an operating member9described later, and the operating member9is normally covered with a rubber cap12(second cap member) provided on a cover member13. The cover member13is provided on an outer peripheral surface of the fixed barrel8, and is provided so that the operating member9and a lock screw14(fixing member) are covered by fitting the rubber cap12to the cover member13. The operating member9and the lock screw14are not exposed to the external surface by the rubber cap12. The cover member13is made of resin or metal and is fixed to the outer peripheral surface of the fixed barrel8by two screws15. The rubber cap12is an elastic member such as rubber or resin, and is press-fitted and fixed to the cover member13. When the rubber cap12is removed, the operating member9and the lock screw14are exposed to the external surface.

Next, the movable barrel5, the fixed barrel8, the operating member9, and a cap member16(first cap member) will be described with reference toFIGS.3to5.FIG.3is an exploded perspective view illustrating a state in which the operating member9is inserted into the fixed barrel8.FIG.4is an enlarged view of a non-circular hole (hole) formed on the fixed barrel8.FIG.5is an enlarged cross-sectional view of the flange back adjusting unit.

The movable barrel5has a substantially cylindrical shape, and the second pressing ring11bfor fixing the second lens2bis screwed to an inner peripheral part, and a male helicoid screw part5bhaving a plurality of threads and a linear groove5a(guide portion) are formed along an optical axis direction H in an outer peripheral part.

A non-circular hole portion through which the operating member9penetrates is formed on the fixed barrel8so as to penetrate from the outer peripheral surface to an inner peripheral surface. The non-circular hole portion is formed of an arc portion8ahaving a partial arc and an escape portion8cconnected to the arc portion8a,and the overall shape thereof is substantially keyhole-shaped. A sliding surface8bis formed on a part of the circular arc surface of the arc portion8a,a rotating shaft portion9aof the operating member9is fitted to the sliding surface8b,the rotating shaft portion9aslides smoothly on the sliding surface8b,and the sliding surface8bsuppresses the falling of the rotating shaft portion9a.And the escape portion8cis formed so that an eccentric shaft portion9b(eccentric portion) of the operating member9can be inserted therethrough. The escape portion8cis formed along the optical axis direction H from the center of the rotating shaft portion9aof the arc portion8a.That is, the longitudinal direction of the non-circular hole portion is along the optical axis direction H. The non-circular hole portion is formed into the substantially keyhole-shaped by integrally forming the sliding surface8band the escape portion8c,so that the operating member9can be inserted into the fixed barrel8. In this manner, the operating member9is disposed so as to penetrate through the fixed barrel8and can be rotated.

The operating member9comprises the rotating shaft portion9aincluding a rotational axis A1for rotating operation, the eccentric shaft portion9bbeing eccentric from the rotational axis A1, a groove portion9c,a disk portion9d,and an engaging portion9e.Further, an arc groove9fis formed through the disk portion9d.The rotating shaft portion9ais coaxial with the rotational axis A1, and the eccentric shaft portion9bis parallel to the rotating shaft portion9aand protrudes eccentrically from the rotational axis A1. That is, the eccentric shaft portion9bextends in a direction closer to an optical axis O than the rotating shaft portion9a.And the engaging portion9eis formed at the distal end of the eccentric shaft portion9b.The engaging portion9eis engaged with the linear groove5aformed on the outer periphery of the movable barrel5along the optical axis O, and the engaging portion9eengaged with the linear groove5aincludes a spherical surface in contact with the linear groove5a,and is substantially spherical at least in a range in contact with the wall of the linear groove5a.And at least a part of the engaging portion9eis located outside the rotating shaft portion9ain the direction orthogonal to the rotational axis A1. Since a distance L2from the rotational axis A1to the outermost surface of the engaging portion9eis longer than a radius L1of the rotating shaft portion9a,the shape of the operating member9does not increase the size of the lens apparatus1, and it is possible to secure a larger amount of flange back adjustment than before.

The groove portion9cis a groove for rotating by inserting a tool such as a flat head screwdriver when adjusting the optical characteristic (when adjusting the flange back). The disk portion9dabuts on a plane portion8don the outer periphery of the fixed barrel8, and the operating member9is arranged on the fixed barrel8so as to be smoothly rotatable around the rotational axis A1orthogonal to the optical axis O.

After the eccentric shaft portion9bof the operating member9is inserted into the escape portion8cof the fixed barrel8, the cap member16is arranged in the non-circular hole portion. More specifically, the cap member16is inserted into the escape portion8c.The cap member16is fixed to the fixed barrel8by bonding with an adhesive, bonding with a double-sided tape, or press-fitting. The material of the cap member16is metal, resin or rubber. The cap member16is formed with an arc-shaped sliding surface16aon which the rotating shaft portion9aof the operating member9slides.

A female helicoid17is connected to the front fixed barrel3by a plurality of screws18. The female helicoid17is formed with a female helicoid screw part17ahaving a plurality of threads on an inner peripheral part. The male helicoid screw part5bof the movable barrel5is screwed to the female helicoid screw part17a,and the movable barrel5is moved along the optical axis O by the rotation of the movable barrel5around the optical axis O by a conversion mechanism (mechanism) for converting the rotational movement by a helicoid mechanism into linear movement. Although the conversion mechanism may be a cam mechanism or the helicoid mechanism.

FIG.6is an enlarged view of the operating member9assembled to the fixed barrel8. The arc groove9fhaving an arc of about 180° is formed in the disk portion9dso as to penetrate the disc portion9d.The lock screw14is inserted into the arc groove9fand screwed into a screw hole8e(refer toFIG.4) of the fixed barrel8.

The adjustment reference state in which the flange back adjustment section is positioned substantially at the center of the adjustment range is a state in which the rotational axis A1of the rotating shaft portion9aand the center axis A2of the eccentric shaft portion9bare most distant in the optical axis direction H (for example, refer toFIG.5). A groove portion14ais formed on a head portion of the lock screw14, and the groove portion14ais a groove for rotating the lock screw14by inserting a tool such as a flat head screwdriver. When the lock screw14is rotated toward the optical axis O, the disk portion9dof the operating member9is sandwiched between the plane portion8don the outer periphery of the fixed barrel8and the head portion of the lock screw14. The lock screw14is screwed into the screw hole8eformed on the fixed barrel8to fix the operating member9to the fixed barrel8so that the operating member9is rotationally operated.

Referring toFIGS.2,5, and6, a method of adjusting the flange back in the lens apparatus1having the above configuration will be described below.

First, the rubber cap12of the flange back adjusting unit is removed, and the exposed lock screw14is loosened by using a tool such as a flat head screwdriver. By loosening the lock screw14, the holding of the disk portion9dof the operating member9is released, so that the operating member9becomes rotatable.

Next, the groove portion9cof the operating member9is rotated by using a tool such as a minus driver. Since the rotating operation range is restricted by the contact between the lock screw14and the groove end of the arc groove9f,the rotating operation range is a range of about 90° in each of the clockwise and counterclockwise from the adjustment reference state. By rotating the operating member9, the engaging portion9eslides on the movable barrel5along the linear groove5aand rotates the movable barrel5around the optical axis O.

The rotation is converted into linear motion by the conversion mechanism of the helicoid mechanism, and the movable barrel5is moved along the optical axis O. Since the back focus is changed by moving the movable barrel5in the optical axis direction H, the flange back can be adjusted by rotating the operating member9as described above. After a flange back adjustment optical system (movable barrel5for holding the second lens2b) is adjusted to an appropriate position, the lock screw14is tightened to fix the adjustment position. Finally, the operation of the flange back adjustment is completed by fitting the rubber cap12of the flange back adjustment section.

As described above, the lens apparatus1can be configured to be small in size and space saving without increasing the size of the flange back adjusting unit even if the flange back adjusting amount of the movable barrel5is increased. Further, since the cap member16is provided in the escape portion8cof the non-circular hole portion of the fixed barrel8, a dust-proof and a drip-proof to the inside of the lens apparatus1are improved. Further, by providing the sliding surface16aon which the rotating shaft portion9aof the operating member9slides on the cap member16, the inclination of the operating member9in the optical axis direction H can be suppressed, and the accuracy at the time of adjusting the flange back can be improved. According to this embodiment, it is possible to provide an optical apparatus advantageous in terms of adjustment of optical characteristics and miniaturization.

Further, since the escape portion8cof the non-circular hole portion is formed along the optical axis direction H from the center of the rotating shaft portion9aof the operating member9, even if the operating member9falls toward the escape portion8cside, the engaging portion9eonly falls along the optical axis direction H. As a result, the rotating working force of the movable barrel5is hardly generated. Thus, since the amount of the flange back is hardly changed by the falling of the operating member9, stable adjustment is made possible when the amount of the flange back is adjusted by rotating the operating member9.

MODIFIED EXAMPLE

FIG.7is an enlarged cross-sectional view of a flange back adjusting unit according to a modification of the present embodiment.FIG.8is an enlarged view of a non-circular hole (hole) formed on a fixed barrel28of the modification. This modification will be described with reference toFIGS.7and8. It should be noted that the same components as those of the embodiment are denoted by the same reference numerals and the description thereof is omitted, and different components will be described.

When it is desired to further increase the flange back adjustment amount of the embodiment, the distance L2from the rotational axis A1to the outermost surface of an engaging portion29eof an eccentric shaft portion29b(eccentric portion) may be set larger than a distance L3from the rotational axis A1of an operating member29to an outer surface of a disk portion29d(flange portion). The relationship between the distance L2and the distance L3is L2>L3. That is, at least a part of the engaging portion29eis located outside the disk portion29dof the operating member29which does not penetrate the fixed barrel28in the direction orthogonal to the rotational axis A1. In such a configuration, an escape portion28cconnected to an arc portion28aconstituting the non-circular hole portion formed on the fixed barrel28for inserting the operating member29becomes large. As the size of the escape portion28cincreases, the size of a cap member26(first cap member) also increases, but the size of the flange back adjusting unit does not increase.

This is because the flange back adjusting unit can be formed without enlarging the rubber cap12and the cover member13. First, the cap member26is becomes large and protrudes from the outer surface of the disk portion29dof the operating member29in the optical axis direction H, but since a protruding portion26aof the cap member26is hidden by the rear fixed barrel6, there is little influence on the appearance. Since the cap member26is fixed to the fixed barrel28by adhesion by an adhesive, adhesion by a double-sided tape, or press-fitting, even if water or dust enters from a gap between the cover member13and the rear fixed barrel6, the water or the dust does not enter the inside of the fixed barrel28. According to this modification, it is possible to provide an optical apparatus advantageous in terms of adjustment of optical characteristics and miniaturization.

FIG.9is a schematic view illustrating a configuration example of a camera apparatus100(image pickup apparatus) using the lens apparatus1according to the embodiment of the present disclosure. The image pickup apparatus illustrated inFIG.9includes the lens apparatus1and the camera apparatus100including a camera body100ahaving an image pickup element100bfor capturing an image formed by the lens apparatus1. The image pickup apparatus may be configured such that the lens apparatus1is detachably mounted from the camera body100a(image pickup apparatus body) of the camera apparatus100.

Although preferred embodiments, modifications, and applications of the present disclosure have been described above, the present disclosure is not limited to these embodiments, modifications, and applications, and various modifications and modifications are possible within the scope of the present disclosure.

This application claims the benefit of Japanese Patent Application No. 2021-145089, filed Sep. 7, 2021 which is hereby incorporated by reference herein in its entirety.