JP5412471B2 - Lens barrel and imaging device - Google Patents

Description

  The present invention relates to a lens barrel and an imaging apparatus that include a drive unit that drives a focus lens group.

  2. Description of the Related Art A lens barrel used in recent imaging apparatuses includes a drive unit that drives a focus lens group and a diaphragm mechanism unit that drives an aperture stop, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-276799, and a camera. Many have a configuration in which the position of the focus lens group and the aperture area of the aperture stop are changed in accordance with a command from the main body. In a fixed focus (single focus) lens, a retrofocus type lens, or the like, there is a medium aperture type in which an aperture stop is disposed between lens groups.

JP 2006-276799 A

  A lens barrel that includes a drive unit that drives the focus lens group and a diaphragm mechanism unit that drives the aperture stop has a complicated configuration, and therefore, the number of man-hours during assembly tends to increase.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lens barrel and an imaging apparatus that can simplify the assembly procedure.

A lens barrel according to the present invention is a lens barrel that holds an optical system member including a plurality of lenses with respect to a base portion having a bayonet claw that engages with a camera body, and is the most image of the optical system member. A focus lens group that includes one or a plurality of lenses disposed on the surface side, and that changes a focusing distance by moving in the optical axis direction with respect to the base portion; and the focus lens of the optical system member A fixed lens group comprising lenses other than the group, a focus lens group holding frame for holding the focus lens group, a fixed lens group holding frame for holding the fixed lens group and being fixed to the object side of the base, and the fixed Extending from the lens group holding frame toward the image plane side in parallel with the optical axis, guiding the focus lens group holding frame to move in the optical axis direction with respect to the fixed lens group holding frame, and A pair of sliding shaft for lifting, fixed to said fixed lens group holding frame, a driving unit for driving the focus lens group holding frame along the sliding shaft, and is fixed to the fixed lens group holding frame, brightness A pair of sliding shafts in a cantilever state in which the object side end is fixed to the fixed lens group holding frame and the image plane side end is a free end. It is characterized by. An imaging apparatus according to the present invention includes the lens barrel.

  ADVANTAGE OF THE INVENTION According to this invention, the lens barrel and imaging device which can simplify an assembly procedure can be provided.

It is a perspective view which shows the state which attached the lens-barrel to the camera main body. It is sectional drawing which shows the structure of an optical system member. FIG. 3 is an overall view of a lens barrel in a state where a rotation operation unit is located at a first position. FIG. 6 is an overall view of a lens barrel in a state where a rotation operation unit is located at a second position. It is sectional drawing of the lens barrel which shows a drive part. It is sectional drawing of a lens barrel in the state where a rotation operation part is located in the 1st position. It is sectional drawing of a lens barrel in the state where a rotation operation part is located in a 2nd position. It is a perspective view explaining the state by which engagement with the rotation operation part and the distance display part was cancelled | released. It is a perspective view explaining the state which the rotation operation part and the distance display part engaged. It is a perspective view explaining the structure of an encoder part. FIG. 6 is a partial cross-sectional view of a fixed lens group holding frame, a focus lens group holding frame, and a drive unit extracted from the same cross section as FIG. 5. It is a fragmentary sectional view by the plane containing the center of a pair of sliding shafts. It is the figure which looked at the focus lens group holding frame from the optical axis O direction rear side. It is a block diagram of the structure in connection with the focusing operation | movement of an imaging device. It is a flowchart of a focusing operation mode determination subroutine. It is a flowchart of an automatic focusing operation. It is a flowchart of a manual focusing operation. It is a flowchart of distance designation | designated focusing operation | movement.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings used for the following description, the scale of each component is made different in order to make each component recognizable on the drawing. It is not limited only to the quantity of the component described in (1), the shape of the component, the ratio of the size of the component, and the relative positional relationship of each component.

  As shown in FIG. 1, the imaging apparatus 1 according to the present embodiment is an imaging apparatus that includes a camera body 2 and a lens barrel 10. In the present embodiment, as an example, the imaging apparatus 1 has a form in which the camera body 2 and the lens barrel 10 can be separated. The camera body 2 and the lens barrel 10 are configured to be attachable / detachable by an attaching / detaching mechanism generally called a bayonet mount.

  In the imaging apparatus 1, the configuration that allows the camera body 2 and the lens barrel 10 to be detachable is not limited to the present embodiment, and the camera body 2 and the lens barrel 10 are, for example, a permanent magnet and a magnetic material. The structure which can be attached or detached by the mechanism using this may be sufficient. The imaging device 1 may have a configuration in which the camera body and the lens barrel are integrated.

  The lens barrel 10 holds an optical system member 11 composed of a plurality of lenses for forming a subject image. Although described later in detail, the lens barrel 10 includes a drive unit 15 that drives a focus lens group 11a, which is a part of lenses included in the optical system member 11, in the optical axis O direction.

  In the present embodiment, as an example, the imaging apparatus 1 includes an imaging element 9 disposed in the camera body 2 or the lens barrel 10, and electronically captures a subject image called a so-called electronic camera or digital camera. It has the structure which images and records. The imaging device 9 is configured to receive a photographic light beam incident from the optical system member 11 at a light receiving surface (pixel region) and output an electrical signal at a predetermined timing. For example, a charge coupled device such as a CCD And a back-illuminated CMOS (complementary metal oxide semiconductor) sensor.

  The imaging device 1 is configured to be capable of an automatic focusing operation (autofocus operation) for controlling the position of the focus lens group 11a in the direction of the optical axis O in order to focus on a subject, and the camera body 2 or the lens barrel. 10, an automatic focusing sensor unit used for the automatic focusing operation is disposed. In this embodiment, as an example, the imaging apparatus 1 detects the contrast value of the subject image based on the signal output from the imaging element 9 and adjusts the focus of the optical system member 11 so that the contrast value becomes the highest. The so-called contrast detection type automatic focusing operation is performed. Therefore, in the imaging device 1 of the present embodiment, the imaging device 9 also serves as an automatic focusing sensor unit.

  The imaging apparatus 1 may be configured to perform a so-called phase difference detection type automatic focusing operation. In this case, a sensor for detecting the phase difference of the subject image disposed in the camera body 2 or the lens barrel 10 is an automatic focusing sensor unit. The automatic focusing sensor unit may be another type of distance measuring sensor such as an infrared distance measuring sensor using the principle of triangulation.

  On the upper surface of the camera body 2, a release switch 3 for a user to input an instruction for an imaging operation, and a power switch 4 for a user to input instructions for a power-on operation and a power-off operation of the camera body 2. Is arranged.

  In the present embodiment, the release switch 3 is a push button type switch, and includes two first release switches 3a and 2b that are turned on according to two different stroke amounts (pressing amounts). It is comprised. Note that the release switch 3 is not limited to the form of a push button type switch, and may be a form constituted by another form of switch such as a touch sensor.

  When a so-called half-pressing operation is performed by pressing the release switch 3 to the middle of the full stroke amount, the first release switch 3a is turned on. The second release switch 3b is turned on. The imaging device 1 performs an imaging operation and stores an image when the second release switch 3b is turned on.

  The release switch 3 may be arranged at a position where the first release switch 3a and the second release switch 3b are separated. Further, the release switch 3 is not limited to a push button type switch, and may be configured by other types of switches such as a touch sensor.

  Although not shown, the camera body 2 is provided with a focusing mode switching operation unit 5 for inputting an instruction for switching the mode of the focusing operation of the imaging apparatus 1. When the user operates the focus mode switching operation unit 5, the focus operation mode of the imaging apparatus 1 includes an automatic focus operation mode for performing an automatic focus operation and a manual focus operation mode for performing a manual focus operation. Is selected. The operation of the imaging apparatus 1 in the automatic focusing operation mode and the manual focusing operation mode will be described later.

  The focus mode switching operation unit 5 is not limited to a button switch, and may be a touch sensor, a dial switch, or the like. Further, the camera body 2 may include an image display device, and the focus operation mode may be switched by selecting a menu displayed on the image display device via a button switch or a touch sensor. Further, the focus mode switching operation unit 5 may be arranged in the lens barrel 10.

  Although not shown in the drawings, the camera body 2 accommodates a storage unit for storing a battery storage unit for storing a primary battery or a secondary battery for supplying power to the imaging device 1 and a flash memory for storing an image. Is provided.

  In the present embodiment, the camera body 2 and the lens barrel 10 can be separated by an engagement mechanism generally called a bayonet mount. In the imaging apparatus 1, the configuration that enables the camera body 2 and the lens barrel 10 to be separated from each other is not limited to the present embodiment. For example, the configuration that is generally referred to as a screw mount using a screw mechanism is used. Also good. Further, the camera body 2 and the lens barrel 10 may be configured to be separable by a mechanism using a fitting or a magnet.

  Next, a detailed configuration of the lens barrel 10 will be described. First, the configuration of the optical system member 11 held by the lens barrel 10 will be described with reference to FIG. 2, the left direction is the object side and the right direction is the image plane side. In FIG. 2, I is an image plane.

  In the present embodiment, as an example, the optical system member 11 has a form of a so-called single focus lens in which the focal length is fixed to a predetermined value. The optical system member 11 includes a front lens group 11f having a negative refracting power and a rear lens group 11r having a positive refracting power arranged in order from the object side to the image side. The rear lens group 11r includes a sub lens group 11b having a positive refractive power and a focus lens group 11a having a positive refractive power. An aperture stop S is disposed between the front lens group 11f and the rear lens group 11r. The optical system member 11 may include other optical system elements such as a prism, a mirror, and a filter in addition to the lens and the aperture stop.

  The front lens group 11f includes, in order from the object side, a first negative meniscus lens 31 having a convex surface facing the object side, a second negative meniscus lens 32 having a convex surface facing the object side, a biconvex positive lens, It consists of a cemented lens 33 of a positive negative meniscus lens having a convex surface facing the object side, a biconcave negative lens 34, and a biconvex positive lens 35.

  The rear lens group 11r includes, in order from the object side, a cemented lens 36 of a biconcave negative lens and a biconvex positive lens, a biconvex positive lens 37, and a biconvex positive lens 38. Here, the sub lens group 11b includes a cemented lens 36 of a biconcave negative lens and a biconvex positive lens and a biconvex positive lens 37 on the object side in the rear lens group 11r.

  In the optical system member 11 of the present embodiment, the four surfaces of both the second negative meniscus lens Ln2 of the front lens group 11f and the both surfaces of the biconvex positive lens of the sub lens group 11b of the rear lens group 11r are: It is aspheric.

  In the optical system member 11 having the above-described configuration, the focus lens group 11a includes a biconvex positive lens 38 closest to the image plane. The focus distance of the optical system member 11 changes as the focus lens group 11a moves in the direction of the optical axis O with respect to other lenses. Here, the change in the focus distance means changing the distance to the subject to be focused.

  The focus lens group 11a may be configured by a plurality of lenses. Hereinafter, the optical system member 11 excluding the focus lens group 11a is referred to as a fixed lens group. That is, the fixed lens group includes a front lens group 11f, an aperture stop S, and a sub lens group 11b.

  The optical system member 11 of the present embodiment is a so-called retro optical system in which the front lens group 11f is fixed and the aperture stop S is arranged in the center. The optical system member 11 is, for example, a fish eye optical system. Or a pancake optical system.

  In addition to the optical system member 11, the lens barrel 10 includes a base unit 12, an index display frame 16, a distance display unit 18, a rotation operation unit 17, a fixed frame 14, a fixed lens group holding frame 40, and a focus lens group holding frame. 13 and the drive part 15 are comprised.

  As shown in FIGS. 3 and 4, the base 12 has a bayonet claw 12 a that engages with the camera body 2. The base 12 is fixed to the camera body 2 by the bayonet claws 12 a engaging the camera body 2.

  When the lens barrel 10 is viewed from the side (in a direction perpendicular to the optical axis O), the base unit 12, the index display frame 16, and the rotation operation unit 17 are partially exposed to the outer periphery of the lens barrel 10. It is arranged to do.

  As will be described in detail later, the rotation operation unit 17 rotates around the optical axis O by a force applied by the user. Further, as shown in FIGS. 3 and 4, the rotation operation unit 17 can move within a predetermined range in the direction of the optical axis O, and in a state where no external force is applied, either of the both ends of the movement range. It is selectively located on either side. Hereinafter, of the two positions where the rotation operation unit 17 is selectively positioned, the front side (object side) end of the movement range in the optical axis O direction is referred to as a first position, and the rear side of the movement range (image The end on the (surface side) shall be referred to as the second position.

  That is, FIG. 3 shows a state where the rotation operation unit 17 is located at the first position, and FIG. 4 shows a state where the rotation operation unit 17 is located at the second position. As shown in FIG. 4, when the rotation operation unit 17 is located at the second position, the distance display unit 18 is exposed on the outer periphery of the lens barrel 10. As shown in FIG. 3, when the rotation operation unit 17 is located at the first position, the distance display unit 18 is covered with the rotation operation unit 17 and hidden from the outer periphery of the lens barrel 10. .

  A distance scale 18a is provided in a region of the distance display unit 18 that is exposed when the rotation operation unit 17 is located at the second position. The distance scale 18a shows numerical values representing the distance from the shortest focusing distance of the optical system member 11 to infinity. The distance display unit 18 is a substantially cylindrical member that can be rotated around the optical axis O together with the rotation operation unit 17 when the rotation operation unit 17 is located at the second position, as will be described in detail later. It is.

  The index display frame 16 is a part of the exterior member of the lens barrel 10 whose position is fixed with respect to the base portion 12. The index display frame 16 is disposed in front of the rotation operation unit 17 in a state where the rotation operation unit 17 is located at the first position. The indicator display frame 16 is provided with a short linear indicator 16a substantially parallel to the optical axis O. The indicator 16a is for indicating the distance scale 18a provided in the distance display unit 18.

  In addition, the index display frame 16 is provided with depth-of-field indexes 16b on both sides in the circumferential direction substantially symmetrically with the index 16a interposed therebetween. The depth-of-field index 16b is for displaying the depth of field corresponding to the aperture value (F value) of the optical system member 11.

  When the rotation operation unit 17 is located at the second position, the distance display unit 18 rotates around the optical axis O with respect to the index display frame 16 as the rotation operation unit 17 rotates. That is, the distance scale 18a rotates relative to the index 16a around the optical axis O, and the numerical value of the distance scale 18a indicated by the index 16a changes.

  For example, in the state shown in FIG. 4, the combination of the index 16a and the distance scale 18a displays a numerical value of a distance of about 1.2 m. In the state shown in FIG. 4, when the aperture value of the aperture stop S is 5.6, the depth-of-field index 16b is focused on a subject whose distance is in the range of about 0.8 m to 3 m. Is displayed.

  Next, a detailed configuration inside the lens barrel 10 will be described using a cross-sectional view. Inside the lens barrel 10, an optical system member 11, a fixed frame 14, a fixed lens group holding frame 40, a focus lens group holding frame 13 and a driving unit 15 are disposed. FIG. 5 is a cross-sectional view of the lens barrel 10 by a plane including the rotation axis center of the stepping motor 15 c of the driving unit 15 and the optical axis O.

  A fixed frame 14 is fixed to the base portion 12. As shown in FIG. 5, the fixed frame 14 includes a substantially cylindrical first fixed frame 14 a and a second fixed frame 14 b. The first fixed frame 14a is fixed to the base portion 12 by a plurality of screws 14f. The second fixed frame 14b is fixed to the front side (object side) of the first fixed frame 14a with a plurality of screws. Note that a part or all of the base portion 12 and the fixed frame 14 may be integrally formed.

  The index display frame 16 described above is fixed to the front end of the second fixed frame 14b. That is, the index display frame 16 is fixed to the base unit 12 via the fixed frame 14. The rotation operation unit 17 and the distance display unit 18 are disposed on the outer peripheral portion of the fixed frame 14 so as to be slidable with respect to the fixed frame 14.

  Specifically, the rotation operation unit 17 of the present embodiment is exposed on the outer peripheral surface of the lens barrel 10 as shown in the cross-sectional views of FIGS. 6 and 7 and the perspective views of FIGS. A substantially cylindrical operation portion 17a having an uneven portion on the outer periphery so that the user's finger is involved, and a substantially cylindrical inner cylindrical portion 17b disposed with a predetermined gap inside the operation portion 17a. It has two substantially cylindrical parts. The inner cylindrical portion 17b is fitted to the outer peripheral portion of the first fixed frame 14a of the fixed frame 14 so as to be slidable in the optical axis O direction and the rotation direction around the optical axis O.

  In the illustrated embodiment, the operation portion 17a and the inner cylindrical portion 17b are separate members, and constitute the rotation operation portion 17 by being fixed by, for example, a screw or an adhesive, but the operation portion 17a. The inner cylindrical portion 17b may be integrally formed.

  As shown in FIGS. 6 and 7, on the inner peripheral surface of the operation portion 17a, a ridge portion 17c that protrudes radially inward and has a substantially triangular cross section is formed over the entire circumference in the circumferential direction. The convex portion 17c is directed forward along the optical axis O on the front side of the first inclined surface portion 17d, and the first inclined surface portion 17d formed so that the inner diameter decreases with increasing forward along the optical axis O. And a second inclined surface portion 17e formed so that the inner diameter increases.

  Moreover, the through-hole 14c is drilled in the location which opposes the protruding item | line part 17c of the 1st fixed frame 14a. A ball 14d is loosely fitted in the through hole 14c. The ball 14d can protrude outward from the outer peripheral surface of the fixed frame 14, and is urged outward in the radial direction by an urging member 14e that is a leaf spring. The urging member 14e and the ball 14d are disposed at a plurality of locations in the circumferential direction.

  When the rotation operation unit 17 is positioned at the first position, the ball 14d abuts on the first inclined surface portion 17d of the ridge portion 17c, and the rotation operation unit 17 is positioned at the second position. In that case, it abuts on the second inclined surface portion 17e of the ridge portion 17c. Since the ridge portion 17c has a substantially triangular cross section, the ball 14d is always in contact with either the first slope portion 17d or the second slope portion 17e regardless of the position of the rotation operation portion 17.

  Therefore, when the rotation operation unit 17 is positioned closer to the front of the movable range, the rotation operation unit 17 is urged forward by the ball 14d in contact with the first slope portion 17d, and the first operation is performed. In position, it is abutted against one end of the movable range and positioned.

  On the other hand, when the rotation operation unit 17 is located behind the movable range, the rotation operation unit 17 is urged rearward by the ball 14d in contact with the second inclined surface portion 17e, and the second operation At the position, it is positioned against the other end of the movable range.

  With the above configuration, when no external force is applied to the rotation operation unit 17, the position of the rotation operation unit 17 in the optical axis O direction is either the first position or the second position. For example, in the state where the rotation operation unit 17 is located at the first position, when the backward external force applied to the rotation operation unit 17 is weaker than the urging force generated by the urging member 14e and the ball 14d. If the external force disappears, the rotation operation unit 17 returns to the first position. Further, for example, in the state where the rotation operation unit 17 is located at the first position, if the backward external force applied to the rotation operation unit 17 is stronger than the urging force generated by the urging member 14e and the ball 14d, The rotation operation unit 17 moves to the second position.

  The lens barrel 10 includes a first encoder unit 21 that detects a rotation direction and an amount of rotation around the optical axis O of the rotation operation unit 17 when at least the rotation operation unit 17 is located at the first position. Is arranged. Further, the lens barrel 10 is provided with an operation unit position detection unit 22 that detects whether the rotation operation unit 17 is located in the first position or the second position in the optical axis O direction. .

  The first encoder unit 21 passes through a plurality of slits (notches) 17f provided at predetermined intervals in the circumferential direction in the rotation operation unit 17, or passes through a plurality of light shielding pieces provided at predetermined intervals in the circumferential direction. Are detected by the pair of photo interrupters 21a, and the rotation direction and the rotation amount of the rotation operation unit 17 are detected based on the output signals of the pair of photo interrupters 21a. The first encoder unit 21 of this embodiment has the same form as a so-called incremental rotary encoder.

  More specifically, in the present embodiment, the slit 17f is formed at the front end of the inner cylindrical portion 17b as shown in FIG. In other words, the slit 17f is a gap formed between a plurality of light shielding pieces extending from the front end portion of the inner cylindrical portion 17b to the front side and provided at a predetermined interval in the circumferential direction. As shown in FIGS. 6 and 7, the pair of photo interrupters 21a constituting the first encoder unit 21 is fixed to the second fixed frame 14b.

  The front end portion of the inner cylindrical portion 17b in which the slit 17f is formed is located within the detection range of the pair of photo interrupters 21a only when the rotation operation portion 17 is located at the first position. Therefore, the first encoder unit 21 of the present embodiment detects the rotation direction and the rotation amount around the optical axis O of the rotation operation unit 17 only when the rotation operation unit 17 is located at the first position. Can do.

  The form of the first encoder unit 21 can detect the rotation direction and the rotation amount around the optical axis O of the rotation operation unit 17 at least when the rotation operation unit 17 is located at the first position. There is no limitation to this embodiment. For example, the first encoder unit 21 may have a form of a magnetic rotary encoder.

  The operation unit position detection unit 22 includes a photo interrupter fixed to the first fixed frame 14a. When the rotation operation unit 17 is located at the second position, the operation unit position detection unit 22 is located at a position where the light shielding unit 17h that is a part of the rear end of the rotation operation unit 17 advances into the detection range. It is fixed.

  The form of the operation unit position detection unit 22 is not particularly limited as long as the position of the rotation operation unit 17 in the optical axis O direction can be detected. For example, the operation unit position detection unit 22 may be a magnetic sensor or the like.

  Further, the rotation operation portion 17 is provided with an engagement convex portion 17g constituting an engagement portion. When the rotation operation part 17 is located at the second position, the engagement convex part 17g engages with a distance display part 18 described later, and rotates the rotation operation part 17 and the distance display part 18 integrally. Is for.

  The engaging convex portion 17g is composed of a plurality of convex portions projecting radially outward on the outer peripheral surface of the inner cylindrical portion 17b. As shown in FIGS. 8 and 9, the plurality of convex portions constituting the engaging convex portion 17g are arranged at equal intervals in the circumferential direction with a certain gap therebetween. Further, the plurality of convex portions have a substantially V-shaped shape in which a part of the rear side becomes narrower toward the rear side when viewed from the radially outer side.

  The distance display unit 18 is slidably fitted around the optical axis O with respect to the outer peripheral portion of the second fixed frame 14b of the fixed frame 14 in a state where the rotation range around the optical axis O is restricted to a predetermined range. Match. The rear end portion of the distance display unit 18 extends between the operation unit 17a of the rotation operation unit 17 and the inner cylindrical unit 17b.

  The distance display unit 18 can rotate around the optical axis O only within a range in which the distance scale 18a is indicated by the index 16a. Therefore, when the rotation operation unit 17 is located at the second position, the distance scale 18a displays the numerical value of the distance from the shortest focusing distance to the infinity of the optical system member 11 in combination with the index 16a. .

  On the inner peripheral portion of the rear end portion of the distance display portion 18, one engagement pin 18b constituting the engagement portion is provided so as to protrude radially inward. In the present embodiment, the engagement pin 18b is a separate member from the distance display unit 18, and is fixed to the distance display unit 18 by press-fitting or adhesive. In addition, the form formed integrally with the distance display part 18 may be sufficient as the engagement pin 18b.

  Since the rear end portion of the distance display portion 18 extends between the operation portion 17a and the inner cylindrical portion 17b, the engagement pin 18b protrudes toward the inner cylindrical portion 17b. In other words, the engagement pin 18b of the distance display unit 18 and the engagement projection 17g of the rotation operation unit 17 protrude in directions facing each other.

  The outer diameter of the engagement pin 18b is smaller than the interval between the adjacent engagement projections 17g, and the engagement pin 18b has a shape that fits in a state of clearance fit between the adjacent engagement projections 17g. Have. Further, the engagement pin 18b has a cross-sectional shape in which the front side is substantially V-shaped when viewed from the radially inner side.

  As shown in FIGS. 6 and 8, when the rotation operation unit 17 is located at the first position, the engagement pin 18 b is on the rear side of the engagement projection 17 g of the rotation operation unit 17. Thus, even when the rotation operation unit 17 rotates around the optical axis O, the rotation operation unit 17 is disposed at a position where it does not interfere with the engagement convex portion 17g. As shown in FIGS. 7 and 9, when the rotation operation portion 17 is located at the second position, the engagement pin 18b is disposed at a position overlapping the engagement convex portion 17g in the circumferential direction. Has been.

  That is, when the rotation operation unit 17 is relatively moved from the first position to the second position, the engagement pin 18b is fitted between the adjacent engagement projections 17g. Conversely, when the rotation operation unit 17 is relatively moved from the second position to the first position, the engagement pin 18b and the engagement projection 17g are disengaged.

  Due to the engaging portion including the engaging convex portion 17g and the engaging pin 18b having the above-described configuration, the distance display portion 18 can be rotated when the rotation operating portion 17 is located at the second position. When the rotation operation unit 17 rotates around the optical axis O together with the unit 17 and the rotation operation unit 17 is positioned at the first position, even if the rotation operation unit 17 rotates around the optical axis O, the rotation operation unit 17 remains stopped without rotating. It becomes.

  As described above, the rotation range of the distance display unit 18 is limited to a range in which the combination of the distance scale 18a and the index 16a displays a numerical value of the distance from the shortest focusing distance of the optical system member 11 to infinity. . Therefore, when the rotation operation unit 17 is located at the second position and is engaged with the distance display unit 18, the rotation operation unit 17 can rotate only within the same rotation range as the distance display unit 18. . When the rotation operation unit 17 is located at the first position, the rotation operation unit 17 does not interfere with the distance display unit 18, so that the rotation range of the rotation operation unit 17 is not limited.

  As described above, the plurality of convex portions of the engaging convex portion 17g have a substantially V-shaped shape on the rear side when viewed from the outside in the radial direction, and the engaging pin 18b has the radial direction. Since the front side has a substantially V-shape when viewed from the inside, when the rotation operation unit 17 moves from the first position to the second position, the abbreviated shape provided on both of them. When the V-shaped parts follow each other, the distance display part 18 rotates slightly, and the engaging pin 18b and the engaging convex part 17g engage smoothly. For this reason, the operation of moving the rotation operation unit 17 in the optical axis O direction is not caught, and the rotation operation unit 17 can be moved quickly.

  The lens barrel 10 is provided with a second encoder unit 23 that detects an absolute rotational position around the optical axis O with respect to the base unit 12 of the distance display unit 18.

  As shown in FIG. 10, in the present embodiment, as an example, the second encoder unit 23 is configured to have a so-called absolute type rotary encoder. The second encoder section 23 includes a code pattern 23a having a predetermined number of bits made of a conductor and a contact part 23b made of a conductor that slides on the code pattern 23a.

  The code pattern 23 a is disposed on the outer peripheral portion of the second fixed frame 14 b of the fixed frame 14, and the contact portion 23 b is disposed on the inner peripheral portion of the distance display portion 18. In accordance with the rotational position of the distance display unit 18 around the optical axis O, the position of the code pattern 23a with which the contact unit 23b contacts changes. Although not shown, the second encoder section 23 has an electric circuit for detecting the contact state between the code pattern 23a and the contact section 23b. From this detection result, the optical axis of the distance display section 18 relative to the fixed frame 14 is shown. The absolute rotational position around O is calculated. Therefore, the second encoder unit 23 can detect an absolute rotational position around the optical axis O of the distance display unit 18 with respect to the base unit 12 to which the fixed frame 14 is fixed.

  The configuration of the second encoder unit 23 is not limited to the present embodiment as long as the absolute rotation position around the optical axis O of the distance display unit 18 with respect to the base unit 12 can be detected. Absent. For example, the second encoder unit 23 may be an optical or magnetic absolute rotary encoder, and may have a variable resistance whose electric resistance value changes according to the rotational position of the distance display unit 18 around the optical axis O. It may have a configuration similar to that of a so-called potentiometer.

  Next, a configuration for holding the optical system member 11 in the lens barrel 10 will be described. On the inner peripheral side of the fixed frame 14, the fixed lens group holding frame 40 to which the fixed lens group is fixed, the focus lens group holding frame 13 to which the focus lens group 11a is fixed, and the focus lens group 13 are driven in the direction of the optical axis O. A drive unit 15 is provided for this purpose.

  Although described in detail below, in the lens barrel 10, the focus lens group holding frame 13 and the driving unit 15 are supported by a fixed lens group holding frame 40. The fixed lens group holding frame 40 is fixed to the fixed frame 14 or the index display frame 16 fixed to the fixed frame 14. That is, in the present embodiment, the optical system member 11 is all held in the lens barrel 10 via the fixed lens group holding frame 40.

  FIG. 11 is a view in which the fixed lens group holding frame 40, the focus lens group holding frame 13, and the driving unit 15 are extracted from the same cross section as that of FIG. 12 is a cross-sectional view of the fixed lens group holding frame 40, the focus lens group holding frame 13, and the driving unit 15 in a plane including the center of a pair of sliding shafts provided on the fixed lens group holding frame 40. .

  The fixed lens group holding frame 40 includes a first frame 41 to which the first negative meniscus lens 31 and the second negative meniscus lens 32 are fixed, a cemented lens 33, a biconcave negative lens 34, and a biconvex positive lens 35. The second frame 42 to be fixed and the third frame 43 to which the cemented lens 36 and the biconvex positive lens 37 are fixed are fixed to each other. That is, the first frame 41 and the second frame 42 hold the front lens group 11f of the optical system member 11, and the third frame 43 holds the sub lens group 11b.

  In the present embodiment, the aperture stop S is incorporated in the stop mechanism unit 19. The aperture mechanism unit 19 includes a plurality of aperture blades for configuring the aperture stop S, and an electric motor that is a driving force generation source that drives the plurality of aperture blades to change the aperture area of the brightness aperture S. Configured. As the aperture area of the aperture stop S changes, the aperture value F of the lens barrel 10 changes. The aperture mechanism unit 19 is fixed to the fixed lens group holding frame 40.

  A front concave portion 42 a into which the rear end portion of the first frame 41 is fitted is provided at the front end portion of the second frame 42. The 1st frame 41 and the 2nd frame 42 are positioned by fitting in front side crevice 42a, and are fixed with a plurality of screws which are not illustrated.

  The diaphragm mechanism 19 is fixed to the rear end of the second frame 42 with a plurality of screws (not shown). The third frame 43 is fixed to the rear end portion of the second frame 42 by a plurality of screws 43 a on the rear side of the aperture mechanism unit 19.

  The focus lens group holding frame 13 holds the focus lens group 11a and is arranged on the rear side (image plane side) of the fixed lens group holding frame 40 so as to be movable in the optical axis O direction with respect to the fixed lens group holding frame 40. It is installed. As shown in FIG. 12, the fixed lens group holding frame 40 is provided with a pair of cylindrical sliding shafts 44 and 45 extending rearward substantially parallel to the optical axis O.

  The sliding shafts 44 and 45 are fixed to the fixed lens group holding frame 40 only at the front end portion, and are arranged in a so-called cantilever state where the rear end portion is a free end.

  In the present embodiment, as an example, the sliding shafts 44 and 45 are fixed by an adhesive in a state where the front end portions are fitted in the holes 42b and 42c formed in the region facing the rear side of the second frame 42. Has been. The sliding shafts 44 and 45 extend toward the rear side substantially parallel to the optical axis O on the radially outer side of the diaphragm mechanism 19 and the third frame 43 fixed to the rear side of the second frame 42. Yes. Further, the sliding shafts 44 and 45 are arranged at axially symmetric positions with the optical axis O as the symmetric axis.

  In the present embodiment, one sliding shaft 44 is longer than the other sliding shaft 45. In the second frame 42, the hole 42b into which the front end of one slide shaft 44 is fitted is more forward than the hole 42c into which the front end of the other slide shaft 45 is fitted. Is formed.

  The focus lens group holding frame 13 is disposed so as to slide along the pair of sliding shafts 44 and 45. The focus lens group holding frame 13 is provided with a through hole 13b and a groove 13d into which a pair of sliding shafts 44 and 45 are fitted with a predetermined gap inside.

  In the present embodiment, the through-hole 13b is 2 in a state of being separated by a predetermined distance in the optical axis O direction from the arm portion 13a extending toward the front side in the optical axis O direction on the outer periphery of the focus lens group holding frame 13. It is formed in the place. The pair of through holes 13b are formed on the same axis. One long sliding shaft 44 is fitted into the pair of through holes 13b with a predetermined gap.

  The groove portion 13d is formed in a convex portion 13c that protrudes radially outward from the outer peripheral portion of the focus lens group holding frame 13. As shown in FIG. 13, the groove 13 d has a concave shape that is recessed radially inward when viewed from the optical axis O direction. The groove portion 13d has a pair of planes whose side surfaces when viewed from the optical axis O direction are substantially parallel to a plane including the optical axis O and the central axis of the through-hole 13b and separated from the plane by a predetermined distance in both directions. It is constituted by. The separation distance between the pair of side surfaces of the groove portion 13d is set so that the other sliding shaft 45 having a short length is fitted with a predetermined gap therebetween.

  The focus lens group holding frame 13 is provided with an engaging portion 13e that engages with a nut 15b of the driving portion 15 described later. In the present embodiment, as shown in FIG. 11, the engaging portion 13 e is formed so as to protrude radially outward from the outer peripheral portion of the focus lens group holding frame 13. As shown in FIG. 13, the engaging portion 13 e is disposed adjacent to the through hole 13 b in the circumferential direction when viewed from the optical axis O direction.

  In the present embodiment as described above, the focus lens group holding frame 13 is guided by a pair of sliding shafts 44 and 45 extending rearward in a cantilevered manner from the fixed lens group holding frame 40, so that the fixed lens group It is supported so as to be movable relative to the holding frame 40 in the direction of the optical axis O. In the present embodiment, the guide for moving the focus lens group holding frame 13 in the direction of the optical axis O is mainly a pair of the longer sliding shaft 44 and a pair provided apart from each other in the direction of the optical axis O. The sliding of the other sliding shaft 45 having a shorter length and the groove 13d is mainly performed by one sliding shaft 44 of the focus lens group holding frame 13. It has the purpose of restricting rotation around.

  As in the present embodiment, the configuration in which the focus lens group holding frame 13 is guided and supported in the direction of the optical axis O by the pair of cantilevered slide shafts 44 and 55 supports both ends of the conventional slide shaft. The size can be reduced and the assembly is also easier than the configuration.

  The focus lens group holding frame 13 supported so as to be relatively movable in the optical axis O direction with respect to the fixed lens group holding frame 40 is driven in the optical axis O direction by the drive unit 15.

  Although the configuration of the drive unit 15 is not particularly limited, in the present embodiment, a stepping motor 15c having a rotation axis substantially parallel to the optical axis O, a screw 15a disposed around the rotation axis of the stepping motor 15c, And a nut 15b screwed into the screw 15a.

  The stepping motor 15 c is fixed to the fixed lens group holding frame 40 via the bracket portion 46. The main body of the stepping motor 15c is positioned on the front side of the aperture mechanism unit 19, and the rotating shaft and the screw 15a are held by the bracket unit 46 so as to extend toward the rear side.

  The bracket portion 46 has not only a configuration for fixing the main body of the stepping motor 15c to the fixed lens group holding frame 40, but also a bearing portion 46a that rotatably supports the tip end portion of the rotating shaft. Therefore, both ends of the rotating shaft of the stepping motor 15c and the screw 15a provided on the outer periphery of the rotating shaft are supported by the bearing portion inside the stepping motor 15c and the bearing portion 46a of the bracket portion 46. Thereby, the screw 15a can be rotated at high speed without swinging the rotating shaft.

  Although the nut 15b is not shown in detail, the rotation around the screw 15a is restricted. For this reason, the nut 15b moves in the direction of the optical axis O along with the rotation of the screw 15a. The drive unit 15 having the above-described configuration is disposed at a position where the nut 15b engages with the engagement unit 13e provided on the focus lens group holding frame 13.

  The drive unit 15 drives the focus lens group holding frame 13 in the direction of the optical axis O by rotating the screw 15a by the stepping motor 15c. The configuration of the drive unit 15 is not limited to the present embodiment, and may be another type such as a linear motor.

  As described above, in the lens barrel 10 of the present embodiment, all the optical system members 11, the focus lens group holding frame 13, and the driving unit 15 are supported by the fixed lens group holding frame 40. The fixed lens group holding frame 40 is fixed to the base portion 12 via the fixed frame 14. In other words, all the lenses constituting the optical system member 11, the mechanism unit for driving the aperture stop S, the diaphragm mechanism unit 19 as a driving force generation source, and the mechanism unit for driving the focus lens group 11a. The driving force generation source is supported by the fixed lens group holding frame 40.

  That is, in this embodiment, all the mechanical configurations for performing the focusing operation and the aperture value changing operation are assembled to the fixed lens group holding frame 40, and the fixed lens group holding frame 40 to which these are assembled is externally mounted. The focusing operation of the optical system member 11 and the changing operation of the aperture value can be performed simply by making an electrical connection to the optical system member 11.

  For this reason, when assembling the lens barrel 10, a fixed lens group holding frame 40 in which the optical system member 11, the aperture mechanism unit 19, the focus lens group holding frame 13 and the driving unit 15 are assembled in advance is prepared. If this is fixed in the fixed frame 14, the assembly procedure of the lens barrel 10 can be simplified.

  Next, the electrical configuration of the part related to the focusing operation of the imaging apparatus 1 will be described with reference to FIG.

  As described above, the camera body 2 is provided with the release switch 3, the power switch 4, the focus mode switching operation unit 5, and the image sensor 9 which is an automatic focusing sensor unit. The camera body 2 includes a camera body control unit 6, an image processing unit 7, a communication unit 8, an image display circuit 50, and an image display device 51.

  The camera body controller 6 includes an arithmetic device (CPU), a storage device (RAM), an input / output device, a power controller, and the like, and controls the operation of the camera body 2 based on a predetermined program. To do.

  The image processing unit 7 is an electronic circuit unit for performing image processing, and can calculate the contrast value of the subject image from the signal output from the image sensor 9. Note that the mounting form of the image processing unit 7 on the camera body 2 may be a hardware form in which computing hardware for image processing is mounted, or the computing device of the camera body control unit 6 may be a predetermined image. A software form that performs image processing based on a processing program may be used.

  The communication unit 8 is for communicating with the lens barrel control unit 24 via a communication unit 25 provided in the lens barrel 10 by wired communication or wireless communication. The image display circuit 50 is a circuit for displaying the subject image from the image sensor 9 on the image display device 51. For example, the image display device 51 displays the subject image during the focusing operation.

  As described above, the lens barrel 10 includes the drive unit 15, the operation unit position detection unit 22, the first encoder unit 21, and the second encoder unit 23. The lens barrel 10 is provided with a lens barrel control unit 24 and a communication unit 25.

  The lens barrel control unit 24 includes an arithmetic device, a storage device, an input / output device, and the like, and controls the operation of the lens barrel 10 based on a predetermined program. The communication unit 8 communicates with the camera body control unit 6 via the communication unit 8 provided in the camera body 2 by wired communication or wireless communication.

  Next, the operation of the imaging device 1 having the configuration described above will be described.

  In the imaging apparatus 1 of the present embodiment, when the camera body is in a power-on state, the camera body control unit 6 repeatedly performs the focusing operation mode determination subroutine shown in FIG. 15 at a predetermined cycle. The in-focus operation mode determination subroutine determines which one of the plurality of in-focus operation modes of the imaging apparatus 1 is selected by an instruction input from the user, and switches the in-focus operation mode of the imaging apparatus 1 according to the instruction input. Is for.

  Note that the focusing operation mode determination subroutine described below is appropriately incorporated into a main routine for the imaging apparatus 1 to perform a shooting operation. The main routine for the imaging apparatus 1 to perform a shooting operation is the same as that of a well-known technique, so that the description thereof is omitted.

  In the focus operation mode determination subroutine, first, in step S01, it is determined whether or not the focus operation mode selected by the user via the focus mode switching operation unit 5 is the automatic focus operation mode.

  As a result of the determination in step S01, when the automatic focusing operation mode is selected, the process proceeds to step S03, and the operation of the imaging apparatus 1 is switched so as to perform the automatic focusing operation. After step S03 is executed, the imaging apparatus 1 performs an automatic focusing operation shown in FIG.

  Although the timing at which the imaging apparatus 1 performs the automatic focusing operation is not particularly limited, in the present embodiment, as an example, when the first release switch 3a is turned on as shown in the flowchart of FIG. Assume that an automatic focusing operation is performed.

  When the imaging apparatus 1 performs an automatic focusing operation, the contrast value of the subject image is detected based on a signal output from the imaging element 9 that is a sensor unit for automatic focusing, and the focus is set so that the contrast value becomes the highest. The lens group holding frame 13 is driven.

  For example, in the case of the imaging apparatus 1 having a configuration in which the camera body 1 and the lens barrel 10 can be separated as in the present embodiment, based on a signal output from the imaging element 9 during the automatic focusing operation. The camera body control unit 6 issues a command to drive the focus lens group holding frame 13 in order to perform focus adjustment. In this case, the lens barrel control unit 24 of the lens barrel 10 moves the focus lens group holding frame 13 via the drive unit 15 in response to a command from the camera body control unit 6 input via the communication unit 25. To drive.

  Since the focusing operation mode determination subroutine is ended by executing step S03, in the imaging apparatus 1 of the present embodiment, when the automatic focusing operation mode is selected, the rotation operation unit 17 moves the first position and the first position. In any case, the automatic focusing operation is performed. Therefore, in the automatic focusing operation, even when the rotation operation unit 17 is located at the second position and the distance scale 18a is exposed to the outside, regardless of the distance value of the distance scale 18a indicated by the index 16a. First, the focus lens group holding frame 13 is driven to perform focus adjustment. In addition, here, even when the rotation operation unit 17 is located at the second position and the distance scale 18a is exposed to the outside, the focus is set regardless of the numerical value of the distance of the distance scale 18a indicated by the index 16a. The focus is adjusted by driving the lens group holding frame 13. However, as another embodiment, when the rotation operation unit 17 is located at the second position and the distance scale 18 a is exposed to the outside, an index is used. The focus lens group holding frame 13 may be driven to a position corresponding to this distance as indicated by the distance scale 18a indicated by 16a.

  On the other hand, if the result of determination in step S01 is that the automatic focusing operation mode has not been selected, the routine proceeds to step S02. In step S02, based on the output signal of the operation unit position detection unit 22, it is determined whether or not the rotation operation unit 17 is present at the first position.

  If it is determined in step S02 that the rotation operation unit 17 is present at the first position, the process proceeds to step S04, and the operation of the imaging apparatus 1 is performed so as to perform a manual focusing operation for focus adjustment. Switch.

  After step S04 is executed, the imaging apparatus 1 performs a manual focusing operation shown in FIG. When performing the manual focusing operation, the imaging device 1 holds the focus lens group according to the rotation direction and the rotation amount of the rotation operation unit 17 when the rotation of the rotation operation unit 17 is detected by the first encoder unit 21. The frame 13 is driven. In the manual focusing operation, the user can observe the in-focus state by observing the state of the subject image displayed on the image display device 51, and the rotation operation is performed based on the observation result. The unit 17 is operated. Of course, the user can observe the in-focus state by observing the state of the subject image displayed on the image display device 51 in the same manner during other in-focus operations.

  For example, when the lens barrel 10 is viewed from the rear, when it is detected that the rotation operation unit 17 is rotated in the clockwise direction, the imaging device 1 is a direction in which the focusing distance of the optical system member 11 is shortened. The focus lens group holding frame 13 is moved. Further, for example, when the lens barrel 10 is viewed from the rear, when the rotation operation unit 17 detects that the rotation operation unit 17 is rotated in the counterclockwise direction, the imaging apparatus 1 has a long focusing distance of the optical system member 11. The focus lens group holding frame 13 is moved in this direction.

  The moving distance and speed of the focus lens group holding frame 13 in the manual focusing operation are determined according to the rotation amount (rotation angle) and rotation speed (rotation angular velocity) of the rotation operation unit 17 detected by the first encoder unit 21. .

  The manual focusing operation shown in FIG. 17 is repeatedly executed until a focusing operation other than the manual focusing operation is selected by executing the focusing operation mode determination subroutine. That is, the manual focusing operation shown in FIG. 17 is performed until the automatic focusing operation mode is selected by the focusing mode switching operation unit 5 or the rotation operation unit 17 is moved from the first position to the second position. Repeatedly executed.

  On the other hand, if it is determined in step S02 that the rotation operation unit 17 does not exist in the first position, that is, if it is determined that the rotation operation unit 17 exists in the second position, the process proceeds to step S05. The operation of the imaging apparatus 1 is switched so as to perform a distance designation focusing operation for focus adjustment.

  After step S05 is executed, the imaging apparatus 1 performs a distance designation focusing operation shown in FIG. When the imaging apparatus 1 performs the distance designation focusing operation, the focus lens group holding frame 13 is positioned at a position corresponding to the distance numerical value of the distance scale 18a indicated by the index 16a calculated from the output signal of the second encoder unit 23. Drive.

  Specifically, in the distance designation focusing operation, first, in step S30, the lens barrel control unit 24 reads the output value of the second encoder unit 23. The output value of the second encoder unit 23 is a value representing an absolute rotational position around the optical axis O with respect to the base unit 12 of the distance display unit 18.

  Next, in step S31, the lens barrel control unit 24 calculates the numerical value of the distance of the distance scale 18a pointed to by the index 16a from the output value of the second encoder unit 23. The conversion from the output value of the second encoder unit 23 to the numerical value of the distance on the distance scale 18a indicated by the index 16a is performed based on, for example, a conversion table stored in advance by the lens barrel control unit 24.

  Next, in step S32, the lens barrel control unit 24 substantially matches the distance value of the distance scale 18a pointed to by the index 16a and the focusing distance of the optical system member 11 from the output value of the second encoder unit 23. The focus lens group holding frame 13 is moved in such a manner. For example, if the numerical value of the distance of the distance scale 18a pointed to by the index 16a is 3 m, the focus lens group holding frame 13 is moved so that the focusing distance of the optical system member 11 is 3 m.

  It is ideal that the distance value of the distance scale 18a pointed to by the index 16a matches the in-focus distance of the optical system member 11, but if the resolution of the second encoder unit 23 is low, they match. Since it is difficult to do so, the focus lens group holding frame 13 may be moved so that they approximate each other.

  Further, the lens barrel control unit 24 outputs the numerical value of the distance of the distance scale 18 a indicated by the calculated index 16 a to the camera body control unit 6 of the camera body 2 via the communication unit 25. The camera body control unit 6 determines an exposure value according to the received numerical value, or adds the numerical value to the captured image as metadata.

  The distance designation focusing operation shown in FIG. 18 is repeatedly executed until a focusing operation other than the distance designation focusing operation is selected by executing the focusing operation mode determination subroutine. That is, the distance designated focusing operation shown in FIG. 18 until the automatic focusing operation mode is selected by the focusing mode switching operation unit 5 or the rotation operation unit 17 is moved from the second position to the first position. Is executed repeatedly.

  Therefore, for example, when the lens barrel 10 is viewed from the rear, when it is detected that the rotation operation unit 17 has rotated in the clockwise direction, the focus lens is reduced in the direction in which the focusing distance of the optical system member 11 is shortened. The group holding frame 13 is moved. Further, for example, when the lens barrel 10 is viewed from the rear, when the rotation operation unit 17 detects that the rotation operation unit 17 is rotated in the counterclockwise direction, the imaging apparatus 1 has a long focusing distance of the optical system member 11. The focus lens group holding frame 13 is moved in this direction. That is, the imaging device 1 in a state where the distance designation focusing operation is selected operates in the same manner as the manual focusing operation.

  As described above, as described above, the imaging apparatus 1 according to the present embodiment is configured so that the user can operate the automatic focusing operation manually or manually by operating the focusing mode switching operation unit 5 or the rotation operation unit 17. It is possible to select a focusing operation.

  When the manual focus operation mode is selected by the focus mode switching operation unit 5 and the rotation operation unit 17 is located at the first position (subject side, front side), the rotation operation unit 17 is turned. By moving the lens, it is possible to perform a manual focusing operation in which the focus is adjusted based on the current position of the focus lens group 11a. In the manual focusing operation, since the rotation operation unit 17 and the distance display unit 18 are not engaged, the rotation operation unit 17 can rotate around the optical axis O without limitation. This kind of operation can perform finer focus adjustment than the distance-specific focusing operation using the distance scale, so it can be used for macro shooting or for shooting conditions that require more precise focus adjustment from the current focus adjustment state. Sometimes effective.

  On the other hand, when the manual focus operation mode is selected by the focus mode switching operation unit 5 and the rotation operation unit 17 is located at the second position (main body side, rear side), the distance scale is used. A distance designation focusing operation for manual focusing is possible. In the distance designation focusing operation, the user visually recognizes the distance scale 18a, the index 16a, and the depth-of-field index 16b exposed on the outer periphery of the lens barrel 10 and immediately confirms the subject distance to be focused. And can be set.

  During the distance designation focusing operation, the focus lens group holding frame 13 is forcibly driven to a position corresponding to the numerical value of the distance displayed by the distance scale 18a and the index 16a calculated from the output signal of the second encoder unit 23. . Accordingly, when it is desired to quickly adjust the distance visually confirmed distance or to focus on a previously known distance, the focus adjustment operation can be performed by manually setting the distance scale 18a to a predetermined focusing distance. It is possible to carry out a photographing method of photographing quickly without performing the above.

  As described above, in the imaging apparatus 1 of the present embodiment, although the focus adjustment is rough, the distance designation focusing operation that realizes quick shooting by specifying the focus distance and the depth of field, and the fine focus adjustment. It is possible to selectively execute a manual focusing operation that can be performed.

  Further, since switching between the distance designation focusing operation and the manual focusing operation can be performed only by moving the rotation operation unit 17 back and forth, first, the distance scale 18a is manually set with the rotation operation unit 17 in the second position. If the predetermined focusing distance is set, and then the rotation operation unit 17 is moved to the first position, it is possible to use more precise focus adjustment quickly from the predetermined focusing distance.

  When the rotation operation unit 17 is located at the first position, the rotation operation unit 17 and the distance display unit 18 are not engaged with each other. However, the distance display unit 18 does not rotate. That is, the focus distance set during the distance designated focus operation is not changed during the manual focus operation. Therefore, the following usage is also possible.

  For example, after the user rotates the distance display unit 18 so that the focusing distance is 3 meters during the distance designated focusing operation, the rotation operation unit 17 is moved to the first position, and the manual focusing operation is performed. Even if the focus adjustment is performed, the distance display unit 18 does not rotate. Therefore, when the user moves the rotation operation unit 17 to the second position and performs the distance specifying focusing operation thereafter, the focusing distance of the optical system member 11 returns to 3 meters. Therefore, if the in-focus distance is set to a desired value in advance during the distance-designated in-focus operation, the desired in-focus state can be quickly obtained simply by moving the rotary operation unit 17 backward from the state in which the manual in-focus operation is performed. Shooting with a focal length can be performed.

  Further, in the lens barrel 10 of the imaging apparatus 1 having the above-described configuration, the drive unit 15 is driven only by the focus lens group holding frame 13 that holds the focus lens group 11a, and the drive unit 15 is driven. The number of members to be reduced can be reduced and the weight can be reduced. Thereby, in this embodiment, the drive part 15 can be made small with a small output, and the lens barrel 10 can be miniaturized. Further, the focusing operation can be performed quickly, and the volume generated during the focusing operation can be suppressed.

  In the embodiment described above, the image sensor 9 is provided in the camera body 2, but the image sensor 9 may be provided in the lens barrel 10.

  The present invention is not limited to the imaging device described in the above-described embodiment, and can also be applied to an electronic device such as a mobile communication terminal having an imaging function.

1 imaging device,
2 Camera body,
3 Release switch,
3a First release switch,
3b Second release switch,
4 Power switch,
5 Focus mode switching operation section,
6 Camera body control unit (control unit),
7 Image processing unit,
8 Communication Department,
9 Image sensor (autofocus sensor unit)
10 Lens barrel,
11 Optical system members,
11a Focus lens group,
11b Sub lens group,
11f front lens group,
11r rear lens group,
12 base part,
12a Bayonet nails,
13 Focus lens group holding frame,
13a arm,
13b through hole,
13c convex part,
13d groove,
13e engaging part,
14 fixed frame,
14a first fixed frame,
14b second fixed frame,
14c through hole,
14d ball,
14e biasing member,
14f screw,
15 drive unit,
15a screw,
15b nut,
15c stepping motor (drive source, motor),
16 Indicator display frame,
16a indicator,
16b Depth of Field Index,
17 Rotation operation part,
17a operation unit,
17b inner cylindrical part,
17c ridge,
17d 1st slope part,
17e 2nd slope part,
17f slit,
17g engagement convex part (engagement part),
17h light shielding part,
18 Distance display section,
18a Distance scale,
18b engagement pin (engagement part),
19 Aperture mechanism,
21 1st encoder part,
21a Photo interrupter,
22 operation unit position detection unit,
23 second encoder section,
23a code pattern,
23b contact part,
24 lens barrel control unit (control unit),
25 communication unit 40 fixed lens group holding frame,
41 First frame,
42 Second frame,
42a front recess,
42b hole,
42c hole,
43 Third frame,
44 sliding shaft,
45 sliding shaft,
46 Bracket part,
46a Bearing part,
S Brightness stop.

Claims (7)

A lens barrel that holds an optical system member composed of a plurality of lenses with respect to a base portion having a bayonet claw that engages with a camera body ,
A focus lens group comprising one or a plurality of lenses arranged on the most image plane side of the optical system member, and changing a focusing distance by moving in the optical axis direction with respect to the base portion;
A fixed lens group comprising lenses other than the focus lens group of the optical system members,
A focus lens group holding frame for holding the focus lens group;
A fixed lens group holding frame that holds the fixed lens group and is fixed to the object side of the base ,
Extending from the fixed lens group holding frame toward the image plane parallel to the optical axis, guiding the focus lens group holding frame to move in the optical axis direction with respect to the fixed lens group holding frame, and A pair of sliding shafts to support,
A drive unit fixed to the fixed lens group holding frame and driving the focus lens group holding frame along the sliding axis; and
An aperture mechanism fixed to the fixed lens group holding frame and driving an aperture stop;
Comprising
The lens barrel according to claim 1, wherein the pair of sliding shafts are in a cantilever state in which an object side end portion is fixed to the fixed lens group holding frame and an image plane side end portion is a free end . 2. The lens barrel according to claim 1, wherein the focus lens group holding frame holds the focus lens group on an image plane side with respect to an image plane side end portion of the pair of sliding shafts . A fixed frame that covers an outer periphery of the fixed lens group holding frame and supports the fixed lens group holding frame to be fixed to the base portion;
In the fixed frame,
A rotation operation unit that is rotatable around the optical axis in the outer peripheral portion of the fixed frame and that is selectively movable in the optical axis direction to the first position or the second position;
An operation unit position detection unit for detecting whether the rotation operation unit is located at the first position or the second position;
A first encoder unit for detecting a rotation direction and a rotation amount of the rotation operation unit;
An index fixed to the outer periphery of the fixed frame;
A distance display unit that is disposed so as to be rotatable around an optical axis in an outer peripheral portion of the fixed frame, and has a distance scale that represents a distance by a combination with the indicator,
A second encoder for detecting a rotational position around the optical axis with respect to the base of the distance display;
When the rotation operation unit is located at the second position, the rotation operation unit and the distance display unit are engaged so that the rotation operation unit and the distance display unit rotate together, The rotation
An engagement portion that disengages the rotation operation portion and the distance display portion when the operation portion is located at the first position; and
A control unit is provided.
The lens barrel according to claim 1 or 2, wherein The operation unit position detection unit includes:
A photo interrupter disposed on the fixed frame;
A light-shielding unit that is provided in the rotation operation unit and is positioned within the detection range of the photo interrupter only when the rotation operation unit is located at either one of the first position or the second position; The lens barrel according to claim 3, comprising: The optical system member includes, in order from the object side to the image surface side, a front lens group having a negative refractive power and a rear lens group having a positive refractive power, and the rear lens group has a focus having at least a positive refractive power. The lens barrel according to claim 1, further comprising a lens group . The lens barrel according to claim 1, further comprising an automatic focusing sensor unit. An imaging apparatus comprising the lens barrel according to claim 1 and a sensor unit for automatic focusing.

Images