JP6022412B2 - Lens device - Google Patents

Description

  The present invention relates to a lens apparatus.

  In a lens apparatus including a plurality of lens groups, for example, when zooming from the wide-angle end to the telephoto end, the two lens groups may be relatively moved along the optical axis. At this time, when the two lens groups are adjacent to each other, two cam grooves are provided in the direction along the optical axis so as to move the two lens groups along the optical axis in one cam mechanism. . Thus, the cam mechanism rotates about the optical axis, so that the two lens groups move relatively along the optical axis.

JP 2006-215394 A JP 2009-204890 A

  However, an optical group including a lens or the like may be provided between two lens groups that can move relative to each other along the optical axis. At this time, with one cam mechanism, the above-described optical group is fixed between the two cam grooves in a state where the two lens grooves are provided to move the two lens groups along the optical axis. It may be difficult to provide a mechanism for holding.

  An object of the present invention is to provide a lens apparatus that stably holds an optical group in a fixed state between two lens groups that move relative to each other along an optical axis.

According to a first aspect of the invention,
An object side lens group;
An object-side cam mechanism that engages the object-side lens group movably along the optical axis by rotating about the optical axis;
A fixed optical group that is fixed on the image plane side with respect to the object side lens group, and
A fixed optical holding unit that holds the fixed optical group on the image plane side with respect to the object-side cam mechanism;
An image surface side lens group disposed closer to the image surface than the fixed optical group;
Provided on the image plane side with respect to the fixed optical holding portion, and engaged with the image plane side lens group so that the image plane side lens group can be moved along the optical axis by rotating about the optical axis. An image plane side cam mechanism
A connecting member that connects the object side cam mechanism and the image plane side cam mechanism independently of each other from the fixed optical holding unit;
With
The object side cam mechanism and the image plane side cam mechanism are provided with a lens device that can be interlocked in the same circumferential direction by the connecting member.
According to a second aspect of the invention,
The object side cam mechanism is
An object side cam cylinder having a cam groove that is engaged with the object side lens group and inclined with respect to the optical axis;
An object side rectilinear cylinder having a rectilinear groove engaged with the object side lens group and provided in a direction along the optical axis;
With
The image plane side cam mechanism is
An image surface side cam cylinder having a cam groove that engages with the image surface side lens group and is provided at least partially inclined with respect to the optical axis;
An image surface side rectilinear cylinder having a rectilinear groove that is engaged with the image surface side lens group and provided in a direction along the optical axis;
With
The object side cam cylinder is provided inside the object side rectilinear cylinder,
The image plane side cam cylinder is provided outside the image plane side rectilinear cylinder,
The lens device according to the first aspect is provided in which the connecting member connects the object-side cam cylinder and the image plane-side cam cylinder to each other.
According to a third aspect of the invention,
The connecting member is
An object-side connecting portion connected in contact with one end on the image plane side of the object-side cam cylinder;
An image plane side coupling portion coupled to the outer periphery of the image plane side cam cylinder;
A relay section that extends between the object side coupling section and the image plane side coupling section and relays the object side coupling section and the image plane side coupling section;
A lens device according to the second aspect is provided.
According to a fourth aspect of the invention,
The lens device according to a third aspect is provided in which the image plane side coupling portion is coupled on both sides in the circumferential direction with the relay portion on the outer circumferential surface of the image plane side cam cylinder interposed therebetween.
According to a fifth aspect of the present invention,
The lens apparatus according to any one of the second to fourth aspects, further comprising a drive unit that rotates the object-side cam cylinder relative to the object-side rectilinear cylinder with the optical axis as an axis.
According to a sixth aspect of the present invention,
From the object side,
A first lens group;
A variator function for performing zooming, and a second lens group which is the object side lens group;
A third lens group which is the fixed optical group;
A compensator function for correcting the position of the image plane at the time of zooming, a fourth lens group that is the image plane side lens group;
A fifth lens group;
Consists of
When zooming from the wide-angle end to the telephoto end,
With the first lens group, the third lens group, and the fifth lens group fixed, the object-side cam mechanism and the image-side cam mechanism are rotated, so that the second lens group is The lens device according to any one of the first to fifth aspects is provided in which the fourth lens group moves along the optical axis while moving from the object side to the image plane side along the optical axis.
According to a seventh aspect of the present invention,
The first lens group has a focusing function;
When focusing
A lens device according to a sixth aspect in which only the first lens group moves along the optical axis is provided.
According to an eighth aspect of the present invention,
The lens device according to any one of the first to seventh aspects, in which the fixed optical group includes at least one of a lens and an iris.

  According to the present invention, it is possible to provide a lens device that stably holds an optical group in a fixed state between two lens groups that move relative to each other along the optical axis.

It is typical sectional drawing which shows the structure in the lens apparatus which concerns on one Embodiment of this invention. (A) is a perspective view which shows the external appearance structure in the lens apparatus which concerns on one Embodiment of this invention, (b) is the perspective view seen from the opposite side of (a). (A) is a perspective view which shows the internal structure in the lens apparatus which concerns on one Embodiment of this invention, (b) is the perspective view seen from the opposite side of (a). (A) is a perspective view which shows the 2nd cam cylinder which concerns on one Embodiment of this invention, (b) is a perspective view which shows the 4th cam cylinder which concerns on one Embodiment of this invention. (A) is a perspective view which shows the connection member which concerns on one Embodiment of this invention, (b) is a left view which shows a connection member, (c) is a top view which shows a connection member. (D) is a front view which shows a connection member. (A) is a perspective view which shows the iris which concerns on one Embodiment of this invention, (b) is a top view which shows an iris, (c) is a front view which shows an iris.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<One Embodiment of the Present Invention>
(1) Configuration of Lens Device A lens device according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing the configuration of the lens device according to the present embodiment.

  The lens device 10 of the present embodiment is configured to hold a fixed optical group provided between an object side lens group and an image plane side lens group that are movable relative to each other in a fixed state, specifically, An object-side lens group, an object-side cam mechanism that engages the object-side lens group so that the object-side lens group can move along the optical axis by rotating about the optical axis, and an image than the object-side lens group A fixed optical group fixed on the surface side, a fixed optical holding unit that holds the fixed optical group on the image plane side with respect to the object side cam mechanism, and an image plane side lens group disposed on the image plane side with respect to the fixed optical group And an image plane side that is provided on the image plane side of the fixed optical holding portion and engages with the image plane side lens group so as to be movable along the optical axis by rotating about the optical axis. The cam mechanism, the object-side cam mechanism, and the image-side cam mechanism can be Comprising a connecting member for connecting together al independently a. Further, the object side cam mechanism and the image plane side cam mechanism can be interlocked in the same circumferential direction by a connecting member. Details will be described below.

  Below, of the two lens groups that can move relative to each other, the lens group on the object side is the “object side lens group”, the lens group on the image side is the “image side lens group”, and is fixed between them. This optical group is called a “fixed optical group”.

  For example, as shown in FIG. 1, the lens device 10 is configured to be used in a monitoring camera or the like, and is sequentially moved from the object side along the first lens group G1 and the optical axis Z1 “object” A second lens group G2 that is a “side lens group”, a third lens group G3 that is a “fixed optical group”, and an “image plane” that is movable relative to the “object side lens group” along the optical axis. An example including the fourth lens group G4 and the fifth lens group G5 which are “side lens groups” will be described.

  In the upper side of FIG. 1, the first lens group G1 moves most toward the image plane (Simg) along the optical axis Z1, and the second lens group G2 moves closest to the object side along the optical axis Z1. In addition, it shows the time when the fourth lens group G4 has moved most toward the image plane Simg along the optical axis Z1. On the other hand, in the lower side of FIG. 1, the first lens group G1 moves most toward the object side along the optical axis Z1, the second lens group G2 moves most toward the image plane Simg along the optical axis Z1, and It shows a time when the fourth lens group G4 has moved to the most object side along the optical axis Z1.

  The first lens group G1 has, for example, a focusing function. Here, the “focusing function” refers to a function for focusing (focusing on) an object by moving the lens group along the optical axis Z1. A lens group having a focusing function is also referred to as a “focusing lens group”. In the present embodiment, for example, only the first lens group G1 is a focusing lens group.

  The first lens group G1 is provided, for example, at least one lens, a holding frame (not shown) that holds the lens, and an outer periphery of the holding frame that are arranged at equal intervals and project in the radial direction. Three cam followers G1a, and the cam followers G1a are configured to be held by the first cam mechanism 100 by engaging with a first cam mechanism 100 described later.

  The second lens group G2 is an “object-side lens group” that can move along the optical axis as described above, and has, for example, a variator function. Here, the “variator function” refers to a function of performing zooming by moving the lens group along the optical axis Z1. A lens group having a variator function is also referred to as a “variator lens group”. However, the second lens group G2 does not have a focusing function. That is, at the time of focusing, the second lens group G2 is fixed.

  The second lens group G2 includes, for example, one or more lenses, a holding frame G2f that holds the lens, and three cam followers that are arranged on the outer periphery of the holding frame G2f at regular intervals and project in the radial direction. G2a, and the cam follower G2a is configured to be held by the second cam mechanism 200 by engaging with a second cam mechanism 200 described later.

  The third lens group G3 is a “fixed optical group” as described above, and includes, for example, at least one of a lens and an iris (aperture stop). Here, the third lens group G3 includes, for example, an iris I1 and one or more lenses provided on the image plane Simg side with respect to the iris I1, and is held by a third optical holding unit 300 described later. Configured to

  The fourth lens group G4 is an “image surface side lens group” that can move relative to the “object side lens group” along the optical axis as described above, and has, for example, a compensator function. The “compensator function” herein refers to a function that corrects the position of the image plane by moving the lens group along the optical axis Z1 in conjunction with the variator lens group during zooming. A lens group having a compensator function is also referred to as a “compensator lens group”. However, the fourth lens group G4 does not have a focusing function. That is, the fourth lens group G4 is fixed during focusing.

  The fourth lens group G4 includes, for example, one or more lenses, a holding frame G4f that holds the lens, and three cam followers that are arranged on the outer periphery of the holding frame G4f at regular intervals and project in the radial direction. G4a, and the cam follower G4a is configured to be held by the fourth cam mechanism 400 by engaging with a fourth cam mechanism 400 described later. For example, the diameter of the lens of the fourth lens group G4 is smaller than the diameter of the lens of the second lens group G2 and the diameter of the lens of the third lens group G3.

  The fifth lens group G5 is a lens group that is fixed at the time of zooming, for example. Note that the fifth lens group G5 includes, for example, one or more lenses and is configured to be held by a fifth lens holding unit that also serves as a fourth rectilinear cylinder 440 described later.

  A solid-state imaging device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) is disposed at the position of the image plane Simg opposite to the object side in the optical axis Z1 direction.

(Object-side cam mechanism: second cam mechanism)
Next, referring to FIGS. 1 to 4, an object side cam mechanism (variator cam mechanism, V cam mechanism) that holds the second lens group G2 as the object side lens group movably in the direction of the optical axis Z1. The two-cam mechanism 200 will be described. FIG. 2A is a perspective view showing an external configuration of the lens apparatus according to the present embodiment, and FIG. 2B is a perspective view seen from the opposite side of FIG. FIG. 3A is a perspective view showing an internal configuration of the lens apparatus according to the present embodiment, and FIG. 3B is a perspective view seen from the opposite side of FIG. FIG. 4A is a perspective view showing the second cam cylinder according to the present embodiment, and FIG. 4B is a perspective view showing the fourth cam cylinder according to the present embodiment.

  As shown in FIG. 1, the second cam mechanism 200 that is an object side cam mechanism includes a second cam cylinder (object side cam cylinder) 220 and a second rectilinear cylinder (object) that engage with the second lens group G2. Side straight cylinder) 240.

  Here, in the lens device 10, for example, the second rectilinear cylinder 240 is fixed as a reference for the cam mechanism of each lens group. Inside the second rectilinear cylinder 240, a second cam cylinder 220 that is rotatable about the optical axis Z1 is provided.

  As shown in FIGS. 1, 2A and 2B, the second rectilinear cylinder 240 has a rectilinear groove 242 provided in a direction along the optical axis Z1. The cam follower G2a of the second lens group G2 is engaged with the rectilinear groove 242 of the second rectilinear cylinder 240.

  As shown in FIGS. 1, 3A, and 3B, the second cam barrel 220 has a cam groove 222 provided to be inclined with respect to the optical axis Z1. An opening that substantially coincides with the cam follower G2a is formed at a position where the cam groove 222 of the second cam cylinder 220 and the rectilinear groove 242 of the second rectilinear cylinder 240 overlap, and the cam follower G2a of the second lens group G2 engages with the opening. .

  As shown in FIG. 4A, the cam groove 222 of the second cam barrel 220 is provided to be inclined at a predetermined angle with respect to the optical axis Z1 from the wide-angle end 222w toward the telephoto end 222t. . By adjusting the angle at which the cam groove 222 is inclined with respect to the optical axis Z1, the straight travel distance in the direction of the optical axis Z1 of the second lens group G2 with respect to the rotational distance of the second cam cylinder 220 in the circumferential direction is set. Is done.

  As shown in FIGS. 1, 3 (a), and 3 (b), a drive unit 260, which will be described later, is provided on the image plane Simg side of the second cam cylinder 220 along the circumferential direction of the second cam cylinder 220. A gear (spur gear) 224 that transmits the driving force is provided. The gear 224 has through openings (not shown) provided uniformly along the circumferential direction, and positioning pins (not shown) of the second cam cylinder 220 are fitted into the through openings of the gear 224. Thereby, the gear 224 is fixed to the second cam cylinder 220. The gear 224 is fixed to the second cam cylinder 220 so that the normal of the surface on the image plane side of the gear 224 is along the optical axis Z1.

(Zooming drive)
As shown in FIG. 1, the second cam mechanism 200 includes a drive unit (zooming drive unit) 260 that is driven during zooming. The drive unit 260 of the second cam mechanism 200 is configured to rotate the second cam cylinder 220 relative to the second rectilinear cylinder 240 of the second cam mechanism 200 about the optical axis Z1. A main body (motor section) 262 that is a driving source for rotating the cam cylinder 220, a rotating shaft 264 rotated by the main body 262, and a gear (spur gear) that is provided on the rotating shaft 264 and rotates about the rotating shaft 264. 266.

  Further, for example, a play between the gear 266 of the driving unit 260 and the gear 224 of the second cam cylinder 220 is larger than the diameter of the gear 266 of the driving unit 260 and has a diameter equal to or greater than the thickness of the second rectilinear cylinder 240. A gear (play gear) 268 is provided. The gear 266 of the driving unit 260 is configured to mesh with the gear 224 of the second cam cylinder 220 via the idle gear 268. Thereby, the driving force of the drive unit 260 is transmitted to the second cam cylinder 220 with a large reduction ratio.

  As shown in FIGS. 2A and 2B, the main body 262 of the driving unit 260 is provided on the object side with respect to the third optical holding unit 300. Specifically, for example, the lens device 10 includes a flange portion 720 provided in contact with the outer periphery of the second rectilinear cylinder 240, and one end on the object side provided on the image plane Simg side of the flange portion 720 to the flange portion 720. A support plate 762 that contacts the other end of the support column 760 on the image plane Simg side and supports the main body 262 of the drive unit 260. The main body 262 of the drive unit 260 is fixed to the second rectilinear cylinder 240 via, for example, a support plate 762, a column 760, and a flange 720. An idle gear 268 is arranged on the support plate 762 so as to mesh with the gear 266 of the drive unit 260 and the gear 224 of the second cam cylinder 220 and rotate.

  As described above, the driving unit 260 of the second cam mechanism 200 rotates the gear 266 in a state where the main body 262 is fixed to the second rectilinear cylinder 240, thereby causing the second cam mechanism to be centered on the optical axis Z <b> 1. The second cam cylinder 220 is configured to rotate relative to the 200 second rectilinear cylinder 240.

(Position detector)
As shown in FIG. 2B, the second cam mechanism 200 further includes a position detector 280 that is a rotary encoder that detects the rotational position, rotational speed, and direction of the second cam cylinder 220. The position detector 280 includes, for example, a main body (detector) 282, a rotation shaft (not shown), and a gear (spur gear) 286. For example, a gap between the gear 286 of the position detector 280 and the gear 224 of the second cam cylinder 220 is larger than the diameter of the gear 286 of the position detector 280 and has a diameter equal to or greater than the thickness of the second rectilinear cylinder 240. A gear (play gear) 288 is provided. The gear 286 of the position detection unit 280 is configured to mesh with the gear 224 of the second cam cylinder 220 via the idle gear 288.

  In addition, the main body 282 of the position detection unit 280 is provided on the object side with respect to the third optical holding unit 300. Specifically, for example, the lens device 10 includes a support 764 provided on the image plane Simg side of the flange portion 720 and one end on the object side contacting the flange portion 720, and the other end of the support 764 on the image plane Simg side. And a support plate 766 that supports the main body 282 of the contact position detection unit 280. The main body 282 of the position detection unit 280 is fixed to the second rectilinear cylinder 240 via, for example, a support plate 766, a column 764, and a flange 720. An idle gear 288 is disposed on the support plate 766 so as to mesh with the gear 286 of the position detector 280 and the gear 224 of the second cam cylinder 220 and rotate.

  As described above, the position detection unit 280 rotates the second cam cylinder 220 by rotating the gear 286 by the rotation of the second cam cylinder 220 in a state where the main body 282 is fixed to the second rectilinear cylinder 240. It is configured to detect position, rotational speed and direction. Accordingly, the position of the second lens group G2 in the optical axis Z1 direction is detected based on the design information of the cam groove 222 of the second cam cylinder 220. The second cam mechanism 200 is interlocked with a later-described fourth cam mechanism 400, and based on the design information of the cam groove 422 of the fourth cam cylinder 420, together with the second lens group G2, the fourth lens group G4. The position in the direction of the optical axis Z1 can be detected.

(Fixed optical holder: third optical holder)
Next, the third optical holding unit 300 that is a fixed optical holding unit that holds the third lens group G3 as a fixed optical group will be described.

  As shown in FIG. 1, the third optical holding unit 300 is fitted and directly connected to the image plane Simg side of the second rectilinear cylinder 240, so that the second cam cylinder 220 is changed during zooming. Is rotated together with the second rectilinear cylinder 240 when it rotates. The third optical holding unit 300 is configured to hold the iris I1 on the object side and hold the lens so that the center overlaps the optical axis Z1.

  As shown in FIGS. 1 and 2B, the third optical holding unit 300 has an arc-shaped through-opening 302 along the circumferential direction. The through opening 302 is provided outside the third lens group G3. A connecting member 600 described later is inserted into the through opening 302. As viewed from the direction along the optical axis Z1, the angle at which the through-opening 302 spreads in the circumferential direction around the optical axis Z1 depends on the circumferential lengths of the cam groove 222 and the cam groove 422 and the movement range of the connecting member 600. For example, it is 103 °.

  Also, as shown in FIGS. 1, 2A and 2B, there is an idle gear 288 related to the gear 266 of the drive unit 260 between the second rectilinear cylinder 240 and the third optical holding unit 300. In addition, an opening (not shown) is provided so that the idle gear 288 related to the gear 286 of the position detector 280 meshes with the second cam cylinder 220.

(Iris)
Here, the iris I1 included in the third lens group G3 as the fixed optical group will be described with reference to FIG. FIG. 6A is a perspective view showing an iris according to the present embodiment, FIG. 6B is a top view showing the iris, and FIG. 6C is a front view showing the iris.

  As shown in FIGS. 6A to 6B, the iris I1 is configured to adjust the brightness by controlling the aperture diameter, and is provided along a direction perpendicular to the optical axis Z1. The diaphragm blade 320, a disk-shaped diaphragm support portion 340 that supports the plurality of diaphragm blades 320 so that the centers of the openings of the plurality of diaphragm blades 320 overlap the optical axis Z1, and a plurality of diaphragm support portions 340 An aperture drive unit (irismeter) 360 that is provided on the outer peripheral side of the aperture blade 320 and adjusts the aperture diameter around the optical axis Z1 by moving the plurality of aperture blades 320;

  As shown in FIG. 1, the support part 340 of the iris I1 is fixed to the third optical holding part 300 so that the centers of the openings of the plurality of aperture blades 320 overlap the optical axis Z1. Further, the aperture driving unit 360 is provided on the opposite side of the through-opening 302 of the third optical holding unit 300 when viewed from the direction along the optical axis Z1. A part of the aperture driving unit 360 is exposed to the outside of the third optical holding unit 300, and an external wiring (not shown) or the like is connected thereto.

(Image plane side cam mechanism: 4th cam mechanism)
Next, referring to FIGS. 1 to 4, an image surface side cam mechanism (compensator cam mechanism, C cam mechanism) that holds the fourth lens group G4 as the image surface side lens group movably in the direction along the optical axis Z1. The fourth cam mechanism 400 will be described.

  As shown in FIG. 1, the fourth cam mechanism 400, which is an image surface side cam mechanism, includes a fourth cam cylinder (image surface side cam cylinder) 420 and a fourth rectilinear cylinder that engage with the fourth lens group G4. (Image plane side rectilinear cylinder) 440 is provided. For example, since the diameter of the fourth lens group G4 is smaller than the diameter of the third lens group G3, the diameters of the fourth cam cylinder 420 and the fourth rectilinear cylinder 440 are the second cam cylinder 220 and the second rectilinear cylinder 240, respectively. Is smaller than the diameter.

  Here, the fourth rectilinear cylinder 440 is directly connected to the image plane Simg side of the third optical holding unit 300 by screws (not shown). A fourth cam cylinder 420 that is rotatable about the optical axis Z1 is provided outside the fourth rectilinear cylinder 440.

  As shown in FIG. 1, like the second cam mechanism 200, the fourth rectilinear cylinder 440 includes a rectilinear groove 442 provided in a direction along the optical axis Z1. The cam follower G4a of the fourth lens group G4 is engaged with the rectilinear groove 442 of the fourth rectilinear cylinder 440.

  As shown in FIGS. 1, 2A, and 2B, the fourth cam cylinder 420 has a cam groove 422 provided at least partially inclined with respect to the optical axis Z1. An opening that substantially coincides with the cam follower G4a is formed at a position where the cam groove 422 of the fourth cam cylinder 420 and the rectilinear groove 442 of the fourth rectilinear cylinder 440 overlap, and the cam follower G4a of the fourth lens group G4 engages with the opening.

  As shown in FIG. 4B, the cam groove 422 of the fourth cam barrel 420 has a curved curve that is convex toward the object side with respect to the optical axis Z1 from the wide-angle end 422w to the telephoto end 422t. Have. By adjusting the angle at which the cam groove 422 is tilted with respect to the optical axis Z1, the rectilinear distance in the direction of the optical axis Z1 of the fourth lens group G4 with respect to the rotational distance of the fourth cam cylinder 420 in the circumferential direction is set. The

(Connecting member)
Next, the connecting member 600 will be described with reference to FIGS. FIG.5 (a) is a perspective view which shows the connection member which concerns on this embodiment, (b) is a left view which shows a connection member, (c) is a top view which shows a connection member, (D) is a front view which shows a connection member.

  As shown in FIG. 1, the second cam mechanism 200 and the fourth cam mechanism 400 are connected to each other by a connecting member 600 independently of the third optical holding unit 300. Thus, the second cam mechanism 200 and the fourth cam mechanism 400 can be interlocked in the same circumferential direction by the connecting member 600.

  The connecting member 600 connects the second cam cylinder 220 provided inside the second rectilinear cylinder 240 and the fourth cam cylinder 420 provided outside the fourth rectilinear cylinder 440 to each other. That is, in the second cam mechanism 200, the inner second cam cylinder 220 rotates, and in the fourth cam mechanism 400, the outer fourth cam cylinder 420 rotates in the same circumferential direction as the second cam cylinder 220. Accordingly, the second cam mechanism 200 and the fourth cam mechanism 400 can be stably linked in a state where the third lens group G3 is fixed between the second cam mechanism 200 and the fourth cam mechanism 400.

  Specifically, the connecting member 600 has the following configuration.

  As shown in FIGS. 5A to 5D, the connecting member 600 is formed in, for example, a registration mark shape. Specifically, the connecting member 600 is in contact with one end on the image plane side of the second cam cylinder 220 and connected. The object side connecting portion 620, the image plane side connecting portion 660 connected to the outer periphery of the fourth cam cylinder 420, and the object side connecting portion 620 and the image plane side connecting portion 660. A long plate-shaped relay unit 640 that relays the connection unit 620 and the image plane side connection unit 660.

  The object-side coupling unit 620 is in contact with one end of the relay unit 640 on the object side and is bent perpendicular to the longitudinal direction of the relay unit 640. In addition, the object-side coupling unit 620 includes, for example, two recesses 622 (622a and 622b) provided symmetrically on both sides across a surface including a center line along the longitudinal direction of the relay unit 640, and the relay unit 640. A through-opening 624 that is located on a plane including the center line along the longitudinal direction and penetrates along the longitudinal direction of the relay portion 640.

  As shown in FIG. 3B, the object side connecting portion 620 is connected in contact with one end of the second cam cylinder 220 on the image plane side, for example, the image plane side surface of the gear 224. A positioning pin (not shown) provided on the gear 224 is fitted into the through-opening 624 of the object-side connecting portion 620. Thereby, the positional accuracy connected with respect to the 2nd cam cylinder 220 of the object side connection part 620 improves. In addition, screws (screws) (not shown) are fastened to the two recesses 622 from the connecting member 600 side to the second cam cylinder 220. Thereby, the object side connection part 620 is connected with the 2nd cam cylinder 220 so that the longitudinal direction of the relay part 640 may follow the optical axis Z1.

  As described above, when the object-side connecting portion 620 contacts one end of the second cam cylinder 220, the position of the connecting member 620 in the direction along the optical axis Z1 is determined.

  On the other hand, as shown in FIGS. 5A to 5D, the image plane side coupling portion 660 includes a first image plane side coupling portion 662 provided on both sides with the relay portion 640 interposed therebetween, and A second image plane side connecting portion 664 is provided. The first image plane side coupling portion 662 and the second image plane side coupling portion 664 are provided symmetrically with respect to the center line along the longitudinal direction of the relay portion 640, and the object side coupling portion 620 with respect to the relay portion 640. Is bent at a predetermined angle on the bent side. For example, the first image plane side coupling portion 662 and the second image plane side coupling portion 664 are relayed so as to be tangent to the outer periphery of the fourth cam cylinder 420 when viewed from the direction along the longitudinal direction of the relay portion 640. Bent with respect to portion 640.

  The first image plane side connecting portion 662 is provided at a position spaced apart from the plate portion 662c in contact with the relay portion 640 by a predetermined distance from the side of the plate portion 662c in contact with the relay portion 640, along the longitudinal direction of the relay portion 640. It has a long through-hole 662b and a bent part 662a provided on the opposite side of the relay part 640 from the through-opening 662b of the plate part 662c. For example, the bent portion 662a is bent from the plate portion 662c to the side opposite to the side where the object side connecting portion 620 is bent. A fold line between the bent portion 662 a and the plate portion 662 c is formed along the longitudinal direction of the relay portion 640.

  The second image plane side connecting portion 664 is configured symmetrically with the first image plane side connecting portion 662 with respect to the center line extending in the longitudinal direction of the relay portion 640, and is similar to the first image plane side connecting portion 662. , A plate portion 664c, a through opening 664b, and a bent portion 664a. Further, the distance between the through-opening 662b of the first image plane side connecting portion 662 and the through opening 664b of the second image plane side connecting portion 664 is longer than the width of the relay portion 640 in the short direction.

  Further, as shown in FIGS. 5A to 5D, the through-opening 642 is provided at the center between the first image plane side connecting portion 662 and the second image plane side connecting portion 664 of the relay portion 640. Is provided.

  As shown in FIG. 3B, the connecting member 600 is arranged so that the longitudinal direction of the relay portion 640 is along the optical axis Z1, and the image plane side connecting portion 660 is the outer periphery of the fourth cam cylinder 420. They are connected on both sides of the surface relay section 640. Thereby, when the rotational force of the 2nd cam cylinder 220 is transmitted to the relay part 640, it is suppressed that the longitudinal direction of the relay part 640 inclines with respect to the optical axis Z1. That is, the interlocking position between the second cam cylinder 220 and the fourth cam cylinder 420 is suppressed.

  Specifically, a positioning pin (not shown) provided on the fourth cam cylinder 420 is fitted into the through opening 642 of the relay portion 640. Thereby, the positional accuracy in at least the circumferential direction connected to the fourth cam cylinder 420 of the image plane side connecting portion 660 is improved. Further, the first image plane side connecting portion 662 and the second image plane side connecting portion 664 are in contact with the outer peripheral surface of the fourth cam cylinder 420. For example, in the through-opening 662b of the first image plane side connecting portion 662, two screws (not shown) are fastened to the fourth cam cylinder 420 from the connecting member 600 side, and the second image plane side One screw (not shown) is fastened to the through-opening 664 b of the connecting portion 664 from the connecting member 600 side to the fourth cam cylinder 420. Thereby, the image plane side connecting portion 660 is connected to the fourth cam cylinder 420.

  At this time, the distance between the through-opening 662b of the first image plane side connecting portion 662 and the through opening 664b of the second image plane side connecting portion 664 is longer than the width of the relay portion 640 in the short direction, thereby The side connecting portion 660 is fixed to the fourth cam cylinder 420 at two points farther from both ends of the relay portion 640 in the short direction. Accordingly, the fourth cam cylinder 420 can be stably rotated in synchronization with the second cam cylinder 220.

  Further, for example, the through-opening 662b is provided along the longitudinal direction of the relay portion 640, so that the assembly error when the second cam mechanism 200 to the fourth cam mechanism 400 are assembled is adjusted, and the image plane is adjusted. The side connection portion 660 is connected to the fourth cam cylinder 420. Thereby, the relative position of the fourth lens group G4 in the direction along the optical axis Z1 with respect to the second lens group G2 is adjusted.

  As shown in FIG. 2B, the relay part 640 of the connecting member 600 is inserted into the arcuate through opening 302 of the third optical holding part 300. The connecting member 600 connects the second cam cylinder 220 and the fourth cam cylinder 420 via the through opening 302. As a result, the connecting member 600 has the arcuate shape of the third optical holding unit 300 in a state where the second cam cylinder 220 and the fourth cam cylinder 420 are connected when the second cam cylinder 220 rotates during zooming. It rotates in the circumferential direction within the range of the through opening 302.

  Further, the second cam cylinder 220 and the fourth cam cylinder 420 are connected through the through opening 302 by one connecting member 600. Thereby, in the 3rd optical holding | maintenance part 300, the ratio for which the through-opening 302 which the connection member 600 penetrates can be made small. Therefore, the diaphragm drive unit 360 of the iris I1 can be exposed to the outside of the third optical holding unit 300 without the connecting member 600 interfering with the iris I1.

  Further, as shown in FIGS. 2A and 2B, for example, the cam follower G2a of the second lens group G2 and the cam follower G4a of the fourth lens group G4 are viewed from the direction along the optical axis Z1. As viewed, they are arranged in the same radial direction with respect to the optical axis Z1. That is, the rectilinear groove 242 of the second rectilinear cylinder 240 is disposed along the rectilinear groove 442 of the fourth rectilinear cylinder 440.

(Other configurations)
Next, another configuration of the lens apparatus 10 of the present embodiment will be described.

(First cam mechanism)
The first cam mechanism 100 that holds the first lens group G1 movably in the direction of the optical axis Z1 will be described with reference to FIGS.

  As shown in FIG. 1, the first cam mechanism 100 includes a first cam cylinder 120 and a first rectilinear cylinder 140 that engage with the first lens group G1. The first rectilinear cylinder 140 is directly connected to the object side of the second rectilinear cylinder 240. A first cam cylinder 120 that is rotatable about the optical axis Z1 is provided outside the first rectilinear cylinder 140.

  As shown in FIG. 1, like the second cam mechanism 200, the first rectilinear cylinder 140 has a rectilinear groove 142 provided in a direction along the optical axis Z1. The cam follower G1a of the first lens group G1 is engaged with the rectilinear groove 142 of the first rectilinear cylinder 140.

  As shown in FIGS. 1, 2A, and 2B, the first cam cylinder 120 has a cam groove 122 provided to be inclined with respect to the optical axis Z1. An opening that substantially coincides with the cam follower G1a is formed at a position where the cam groove 122 of the first cam cylinder 120 and the rectilinear groove 142 of the first rectilinear cylinder 140 overlap, and the cam follower G1a of the first lens group G1 engages with the opening.

  As shown in FIGS. 2A and 2B, the cam groove 122 of the first cam cylinder 120 is provided to be inclined at a predetermined angle with respect to the optical axis Z1. By adjusting the angle at which the cam groove 122 is inclined with respect to the optical axis Z1, the straight travel distance in the direction of the optical axis Z1 of the first lens group G1 with respect to the rotational distance of the first cam cylinder 120 in the circumferential direction is set. Is done. For example, the angle of the cam groove 122 of the first cam cylinder 120 with respect to the optical axis Z1 is larger than the angle of the cam groove 222 of the second cam cylinder 220 with respect to the optical axis Z1, and the optical axis of the cam groove 122 of the first cam cylinder 120 is. The length of Z1 is shorter than the length of the optical axis Z1 of the cam groove 222 of the second cam cylinder 220.

  Further, as shown in FIGS. 1, 2A, and 2B, on the image plane Simg side of the first cam cylinder 120, a drive, which will be described later, along the circumferential direction of the first cam cylinder 120. A gear (spur gear) 124 that transmits the driving force of the portion 160 is provided.

(Focusing drive)
As shown in FIG. 1, the first cam mechanism 100 is provided separately from the driving unit 260 as a zooming driving unit that is driven at the time of zooming, and is a driving unit (for focusing) that is driven at the time of focusing. Drive unit) 160. The drive unit 160 of the first cam mechanism 100 is configured to rotate the first cam cylinder 120 relative to the first rectilinear cylinder 140 of the first cam mechanism 100 about the optical axis Z1. A main body (motor section) 162 that is a drive source for rotating the cam cylinder 120, a rotating shaft 164 rotated by the main body 162, and a gear (spur gear) that is provided on the rotating shaft 164 and rotates around the rotating shaft 164. 166). The gear 166 of the drive unit 160 is configured to mesh with the gear 124 of the first cam cylinder 120. As a result, the driving force of the driving unit 160 is transmitted to the first cam cylinder 120.

  As shown in FIGS. 2A and 2B, the main body 162 of the driving unit 160 is provided on the image plane Simg side with respect to the first cam cylinder 120. Specifically, for example, the lens device 10 is provided on the object side of the flange portion 720 described above, and has one end on the image plane Simg side in contact with the flange portion 720 and the other end on the object side of the post 740 in contact with the drive. And a support plate 742 that supports the body portion 162 of the portion 160. The main body 162 of the drive unit 160 is fixed to the second rectilinear cylinder 240 via, for example, a support plate 742, a support column 740, and a flange portion 720.

  That is, the drive part 160 of the first cam mechanism 100 and the drive part 260 of the second cam mechanism 200 are fixed to the second rectilinear cylinder 240 via the same flange part 720. The drive unit 160 of the first cam mechanism 100 must be provided on the side close to the first cam cylinder 120 in order to rotate the first cam cylinder 120. On the other hand, the drive unit 260 of the second cam mechanism 200 may be closer to the object side or the image plane side than the third optical holding unit 300. However, the drive unit 260 of the second cam mechanism 200 is provided closer to the object side than the third optical holding unit 300, so that the drive unit 260 of the second cam mechanism 200 is brought closer to the drive unit 160 of the first cam mechanism 100, The first cam mechanism 100 can be fixed together with the driving unit 160. Accordingly, the flange portion 720 serving as a fulcrum for fixing the driving portion 260 and the gear 266 of the driving portion 260 serving as a power point for rotating the second cam mechanism 200 can be brought close to each other. Can be rotated stably. Further, the number of parts can be reduced as compared with the case where the driving unit 160 of the first cam mechanism 100 and the driving unit 260 of the second cam mechanism 200 are individually fixed.

  Further, the drive unit 160 of the first cam mechanism 100 has the same specifications as the drive unit 260 of the second cam mechanism 200, that is, the same rotational speed and torque. As a result, the same common component as the drive unit 260 of the second cam mechanism 200 can be used as the drive unit 160 of the first cam mechanism 100. Therefore, the manufacturing cost of the lens apparatus 10 can be reduced.

  As described above, the driving unit 160 of the first cam mechanism 100 rotates the gear 166 in a state where the main body 262 is fixed to the second rectilinear cylinder 240, thereby the first cam mechanism about the optical axis Z <b> 1. The first cam cylinder 120 is configured to rotate relative to the 100 first rectilinear cylinders 140.

(Position detector)
As shown in FIG. 2B, the first cam mechanism 100 further includes a position detector 180 that is a rotary encoder that detects the rotational position, rotational speed, and direction of the first cam cylinder 120. The position detector 180 includes, for example, a main body (detector) 182, a rotation shaft (not shown), and a gear (spur gear) 186. The gear 186 of the position detector 180 is configured to mesh with the gear 124 of the first cam cylinder 120.

  Further, the main body 182 of the position detection unit 180 is fixed to the second rectilinear cylinder 240 via the support plate 742, the column 740, and the flange 720, for example, in the same manner as the main body 162 of the drive unit 160.

  As described above, the position detection unit 180 rotates the first cam cylinder 120 when the gear 186 is rotated by the rotation of the first cam cylinder 120 in a state in which the main body 182 is fixed to the second rectilinear cylinder 240. It is configured to detect position, rotational speed and direction. Accordingly, the position of the first lens group G1 in the optical axis Z1 direction is detected based on the design information of the cam groove 122 of the first cam cylinder 120.

(Fifth lens holder)
A fifth lens holding unit that holds the fifth lens group G5 will be described with reference to FIGS.

  As shown in FIG. 1, for example, the fourth rectilinear cylinder 440 of the fourth cam mechanism 400 is configured to also serve as the fifth lens holding portion. Specifically, the fourth rectilinear cylinder 440 is configured to hold the fifth lens group G5 therein by being narrower on the object side than the rectilinear groove 442.

  As shown in FIGS. 1, 2 (a) and 2 (b), a mount connection portion (mount ring) 500 is provided on the outer periphery of the fourth rectilinear cylinder 440 on the image plane side. The mount connection unit 500 is configured to connect to, for example, a widely used C mount or CS mount.

  The diagonal length of the solid-state imaging device to which the lens device 10 of the present embodiment is connected is, for example, 8 mm (so-called 1/2 inch) or more and 11 mm (so-called 2/3 inch) or less. Moreover, the lens diameter of the largest lens (for example, lens L1) among zoom lenses is 50 mm or more and 100 mm or less, for example.

(2) Operation of Lens Device The operation of the lens device 10 according to the present embodiment will be described using FIG.

(zooming)
In the present embodiment, during zooming (variation) from the wide-angle end to the telephoto end, the second lens unit as the variator lens unit is fixed with the first lens unit G1, the third lens unit G3, and the fifth lens unit G5 fixed. The lens group G2 is moved along the optical axis Z1 from the object side to the image plane Simg side, and the fourth lens group G4 as a compensator lens group is moved along the optical axis Z1 so as to follow the second lens group G2. Let Accordingly, zooming of the zoom lens can be easily performed while maintaining the entire optical length. The “optical total length” refers to the distance from the lens surface closest to the object side to the image plane Simg.

  Specifically, when zooming from the wide-angle end to the telephoto end, the drive unit 260 of the second cam mechanism 200 looks at the object side from the image plane Simg side along the optical axis Z1, The two-cam cylinder 220 is rotated relative to the second rectilinear cylinder 240 in a clockwise direction.

  At this time, the rectilinear groove 242 of the second rectilinear cylinder 240 restricts the cam follower G2a from moving in the circumferential direction and guides it in the direction along the optical axis Z1. Further, when the second cam cylinder 220 rotates relative to the second rectilinear cylinder 240 in a clockwise direction, the cam groove 222 of the second cam cylinder 220 and the rectilinear groove 242 of the second rectilinear cylinder 240 overlap. Is moved to the image plane Simg side along the optical axis Z1. Thereby, the cam follower G2a of the second lens group G2 also moves along the optical axis Z1 together with the opening. In this way, the second lens group G2 slides monotonously in the second cam mechanism 200 from the object side to the image plane Simg side along the optical axis Z1. Here, “sliding monotonously” means sliding without returning to the opposite direction.

  Further, the fourth cam mechanism 400 is interlocked with the second cam mechanism 200 in the same circumferential direction while being connected to the second cam mechanism 200 by the connecting member 600. That is, the fourth cam cylinder 420 of the fourth cam mechanism 400, together with the second cam cylinder 220 of the second cam mechanism 200, looks at the object side from the image plane Simg side along the optical axis Z1, and is viewed as the fourth rectilinear cylinder 440. Rotate relative to clockwise.

  At this time, the rectilinear groove 442 of the fourth rectilinear cylinder 440 restricts the cam follower G4a from moving in the circumferential direction and guides it in the direction along the optical axis Z1. Further, when the fourth cam cylinder 420 is rotated relative to the fourth rectilinear cylinder 440 in a clockwise direction, the cam groove 422 of the fourth cam cylinder 420 and the rectilinear groove 442 of the fourth rectilinear cylinder 440 overlap each other. Is moved to the object side along the optical axis Z1, and then moved to the image plane Simg side. In other words, the opening moves so as to draw a convex locus on the object side. Accordingly, the cam follower G4a of the fourth lens group G4 moves along the optical axis Z1 together with the opening. In this manner, the fourth lens group G1 slides toward the image plane Simg after moving to the object side along the optical axis Z1 in the fourth cam mechanism 400.

  On the other hand, the first lens group G1, the third lens group G3, and the fifth lens group G5 are fixed as follows.

  The first lens group G1 maintains a fixed state because the driving unit 160 of the first cam mechanism 100 is stationary during zooming. The third lens group G3 is fixed to the third optical holder 300 connected to the second rectilinear cylinder 240 and the fourth rectilinear cylinder 440. In addition, the fifth lens group G5 is always fixed at the same position by the fifth holding portion that the fourth rectilinear cylinder 440 also serves.

  As described above, zooming (magnification) from the wide-angle end to the telephoto end of the lens device 10 is performed.

(Focusing)
In the present embodiment, when focusing (focusing), only the first lens group G1 as the focus lens group performs focusing from an object at infinity to an object at a short distance, for example, from the image plane Simg side along the optical axis Z1. Move to the object side. On the other hand, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are fixed. Thereby, even when the magnification is changed, the amount of extension of the focusing lens group is constant, and stable focusing can be performed. Note that the “feeding amount” of the lens refers to a moving distance for moving the lens back and forth in order to focus.

  Specifically, when performing focusing from an infinitely distant object to a close object, the driving unit 160 of the first cam mechanism 100 looks at the object side from the image plane Simg side along the optical axis Z1. The first cam cylinder 120 is rotated relative to the first rectilinear cylinder 140 counterclockwise.

  At this time, the rectilinear groove 142 of the first rectilinear cylinder 140 restricts the cam follower G1a from moving in the circumferential direction and guides the cam follower G1a in the direction along the optical axis Z1. Further, when the first cam cylinder 120 rotates relative to the first rectilinear cylinder 140 in the counterclockwise direction, the cam groove 122 of the first cam cylinder 120 and the rectilinear groove 142 of the first rectilinear cylinder 140 are formed. The opening formed at the overlapping position moves to the image plane Simg side along the optical axis Z1. Thereby, the cam follower G1a of the first lens group G1 moves along the optical axis Z1 together with the opening. In this way, the first lens group G1 monotonously slides in the first cam mechanism 100 from the object side to the image plane Simg side along the optical axis Z1.

  On the other hand, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are fixed.

  The second lens group G2 and the fourth lens group G4 maintain a fixed state because the driving unit 260 of the second cam mechanism 200 is stationary during focusing. The third lens group G3 is fixed to the third optical holder 300 connected to the second rectilinear cylinder 240 and the fourth rectilinear cylinder 440. In addition, the fifth lens group G5 is always fixed at the same position by the fifth holding portion that the fourth rectilinear cylinder 440 also serves.

  As described above, the focusing (focusing) of the lens apparatus 10 is performed.

(3) Effects of the present embodiment According to the present embodiment, one or more of the following effects are achieved.

(A) According to the present embodiment, the lens device 10 includes the second cam mechanism 200 as the object-side cam mechanism and the fourth cam mechanism 400 as the image plane-side cam mechanism as the third fixed optical holding unit. A connecting member 600 that is connected to each other independently from the optical holding unit 300 is provided. The second cam mechanism 200 and the fourth cam mechanism 400 can be interlocked in the same circumferential direction by the connecting member 600. Accordingly, the third lens group G3 can be stably held between the second lens group G2 and the fourth lens group G4.

  Here, as a comparative example, a case where one cam mechanism holds two lens groups that move relative to each other along the optical axis and a fixed optical group that is fixed between the two lens groups. Think. In the comparative example, for example, the cam mechanism has a cam cylinder and a rectilinear cylinder that engage with two lens groups. The cam barrel is provided with two cam grooves in the direction along the optical axis so as to move the two lens groups along the optical axis. In the comparative example, for example, a concave portion is provided between the two cam grooves of the cam mechanism in the direction perpendicular to the optical axis from the outer periphery, so that the fixed optical group is inserted into the concave portion of the cam barrel, and the straight advance cylinder It is possible to fix to.

  However, in order for the cam cylinder to rotate with the cam mechanism of the comparative example fixing the fixed optical group, it is necessary to provide a large recess in the cam cylinder. Specifically, the circumferential length of the recess in the cam cylinder is such a length that does not interfere with the fixed optical group when the cam cylinder rotates, and must be at least longer than the circumferential length of the cam groove. is there. For this reason, the overall rigidity of the cam mechanism is lowered, and there is a possibility that the cam groove machining accuracy (cam groove position accuracy) in the cam cylinder cannot be maintained. For example, when this cam mechanism is manufactured with low processing accuracy, there is a possibility that the relative positions of the two lens groups moving along the optical axis cannot be adjusted and are fixed.

  On the other hand, according to the present embodiment, the second cam mechanism 200 as the object side cam mechanism and the fourth cam mechanism 400 as the image plane side cam mechanism are provided separately. The second cam mechanism 200 and the fourth cam mechanism 400 are connected by a connecting member 600. The second cam mechanism 200 and the fourth cam mechanism 400 can be interlocked in the same circumferential direction by the connecting member 600. Accordingly, the rigidity of each of the second cam mechanism 200 and the fourth cam mechanism 400 is maintained, and the cam groove machining accuracy (cam groove position accuracy) in each of the second cam cylinder 220 and the fourth cam cylinder 420 is increased. Can be maintained. In this way, the lens device 10 that stably holds the third lens group G3 between the second lens group G2 and the fourth lens group G4 that move relative to each other along the optical axis Z1. Can be provided.

(B) According to this embodiment, the connecting member 600 includes the second cam cylinder 220 provided inside the second rectilinear cylinder 240 and the fourth cam cylinder provided outside the fourth rectilinear cylinder 440. 420 are connected to each other. That is, in the second cam mechanism 200, the inner second cam cylinder 220 rotates, and in the fourth cam mechanism 400, the outer fourth cam cylinder 420 rotates in the same circumferential direction as the second cam cylinder 220. Accordingly, the second cam mechanism 200 and the fourth cam mechanism 400 can be stably linked in a state where the third lens group G3 is fixed between the second cam mechanism 200 and the fourth cam mechanism 400.

  Here, as a comparative example, the connecting member connects the second cam cylinder provided outside the second rectilinear cylinder and the fourth cam cylinder provided outside the fourth rectilinear cylinder. think about. In this comparative example, since the second cam cylinder rotates outside the second rectilinear cylinder, the drive unit that rotates the second cam cylinder relative to the second rectilinear cylinder is fixed to the second rectilinear cylinder. May not be possible.

  As another comparative example, the connecting member connects the second cam cylinder provided inside the second rectilinear cylinder and the fourth cam cylinder provided inside the fourth rectilinear cylinder. Think about the case. In this comparative example, with respect to at least one of the cam cylinders, a connecting member must be connected to the inner cam cylinder in a state in which there is a rectilinear cylinder on the outer side, which may complicate the assembly process. . Further, in this comparative example, it is difficult for the connecting member to avoid the third lens group and connect the second cam cylinder and the fourth cam cylinder, and the connecting member may particularly interfere with the third lens group. There is sex.

  On the other hand, according to this embodiment, the second cam cylinder 220 is provided on the inner side of the second rectilinear cylinder 240, and conversely, the fourth cam cylinder 420 is on the outer side of the fourth rectilinear cylinder 440. Provided. The connecting member 600 connects the inner second cam cylinder 220 and the outer fourth cam cylinder 420 to each other across the third lens group G3. Thereby, the drive part 260 which rotates the 2nd cam cylinder 220 relatively with respect to the 2nd rectilinear cylinder 240 can be fixed to the 2nd rectilinear cylinder 240 located outside. Further, since the fourth cam cylinder 420 is provided outside the fourth rectilinear cylinder 440, the connecting member 600 can be easily connected to the fourth cam cylinder 420 when the lens device 10 is assembled. Further, the connecting member 600 can connect the second cam cylinder 220 and the fourth cam cylinder 420 while avoiding the third lens group G3, and the connection member 600 is particularly prevented from interfering with the third lens group G3. The Further, when the diameter of the fourth cam cylinder 420 is smaller than the diameter of the second cam cylinder 220 as in the present embodiment, the connecting member 600 avoids the third lens group G3 and the second cam cylinder 220 and the fourth cam cylinder 220. The cam cylinder 420 can be connected at a short distance. In this manner, the second cam mechanism 200 and the fourth cam mechanism 400 can be stably linked in a state where the third lens group G3 is fixed between the second cam mechanism 200 and the fourth cam mechanism 400. .

(C) According to the present embodiment, the connecting member 600 is connected to the outer periphery of the fourth cam cylinder 420 and the object side connecting portion 620 that contacts and is connected to one end of the second cam cylinder 220 on the image plane side. An image plane side connecting portion 660, a relay portion 640 extending between the object side connecting portion 620 and the image plane side connecting portion 660, and relaying between the object side connecting portion 620 and the image plane side connecting portion 660, Is provided. As a result, it is possible to connect the second cam cylinder 220 and the fourth cam cylinder 420 while avoiding the third lens group G3 as the fixed optical group. Further, the image plane side coupling portion 660 is coupled to the fourth cam barrel 420 while determining the position of the object side coupling portion 620 in the direction along the optical axis Z1 at one end of the second cam barrel 220 on the image plane side. The position can be adjusted to an appropriate position. That is, the relative position of the fourth lens group G4 in the direction along the optical axis Z1 with respect to the second lens group G2 can be adjusted to an appropriate position.

(D) According to the present embodiment, the image plane side connecting portion 660 is connected on both sides of the relay portion 640 on the outer peripheral surface of the fourth cam cylinder 420. Thereby, when the rotational force of the 2nd cam cylinder 220 is transmitted to the relay part 640, it is suppressed that the longitudinal direction of the relay part 640 inclines with respect to the optical axis Z1. That is, the interlocking position between the second cam cylinder 220 and the fourth cam cylinder 420 is suppressed.

(E) According to the present embodiment, the third optical holding unit 300 as the fixed optical holding unit has the arc-shaped through-opening 302 along the circumferential direction. The through opening 302 is provided outside the third lens group G3. The connecting member 600 connects the second cam mechanism 200 and the fourth cam mechanism 400 via the through opening 302. Thereby, the connecting member 600 is connected inside the outer periphery of the third optical holding unit 300, that is, inside the outer periphery of the first cam mechanism 100 that holds the largest first lens group G1. Therefore, the size of the lens apparatus 10 as a whole can be reduced.

(F) According to the present embodiment, since the second cam cylinder 220 and the fourth cam cylinder 420 connected to each other are rotated by the single drive section 260, a large load is applied to the drive section 260. Therefore, the drive unit 260 has the second cam relative to the second rectilinear cylinder 240 of the second cam mechanism 200 positioned on the object side instead of the fourth cam cylinder 420 positioned on the image plane side with the optical axis Z1 as an axis. The cylinder 220 is relatively rotated. As a result, the diameter of the second cam cylinder 220 located on the object side is larger than the diameter of the fourth cam cylinder 420 located on the image plane Simg side, and therefore the speed is reduced more than when the drive unit rotates the fourth cam cylinder. The ratio can be increased. That is, the torque applied to the drive unit 260 can be reduced, and the drive unit 260 can be reduced in size.

(G) According to the present embodiment, the variator lens group is in a state where the first lens group G1, the third lens group G3, and the fifth lens group G5 are fixed during zooming from the wide angle end to the telephoto end. The second lens group G2 is moved from the object side to the image plane Simg side along the optical axis Z1, and the fourth lens group G4, which is a compensator lens group, is moved along the optical axis Z1. Accordingly, zooming of the zoom lens can be easily performed while maintaining the entire optical length.

(H) According to this embodiment, the first lens group G1 has a focusing function, and only the first lens group G1 moves along the optical axis Z1 during focusing. On the other hand, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 are fixed. Thereby, even when the magnification is changed, the amount of extension of the focusing lens group is constant, and stable focusing can be performed.

<Other Embodiments of the Present Invention>
The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this.

  In the above-described embodiment, the case where the lens apparatus includes five lens groups has been described. However, the present invention is not limited to this. It is sufficient that the lens apparatus includes at least an “object-side lens group” and an “image-side lens group” that can move relative to each other, and a “fixed optical group” that is fixed therebetween. The number is not limited. The lens device may further include a lens or the like that has substantially no power. The “lens having substantially no power” refers to a lens or the like that does not have a power that has an influence on the optical performance of the zoom lens according to the present embodiment in principle.

  In the above-described embodiment, the case where the first lens group G1 is the focusing lens group has been described, but the present invention is not limited to this. The first lens group may be configured by a so-called front inner focus system in which a fixed group and a focusing lens group are configured.

  In the above embodiment, the mechanism for moving the first lens group G1 along the optical axis Z1 has been described as being the first cam mechanism 100 provided with the cam groove 122, but the present invention is not limited thereto. Is not to be done. The mechanism for moving the first lens group along the optical axis may be a helicoid mechanism having multiple threads.

  In the above-described embodiment, the case where the zoom lens is used for the surveillance camera has been described. However, the present invention is not limited to this. The zoom lens may be used in a video camera, an electronic still camera, or a broadcast camera.

  In the above-described embodiment, the case where the third lens group G3 as the fixed optical group includes the iris I1 and one or more lenses has been described, but the present invention is not limited to this. The fixed optical group may have only a lens or only an iris. The fixed optical group may have an optical filter that absorbs light in a specific wavelength range or an ND filter that reduces the amount of light.

  In the above-described embodiment, the case where the connecting member 600 connects the second cam mechanism 200 and the fourth cam mechanism 400 via the through opening 302 provided in the third optical holding unit 300 has been described. Is not limited to this. The connecting member may be connected to the third optical holding portion through a notch portion provided along the circumferential direction and notched from the outer peripheral side. That is, the outer side where the connecting member rotates may not be covered.

DESCRIPTION OF SYMBOLS 10 Lens apparatus 100 1st cam mechanism 120 1st cam cylinder 140 1st straight advance cylinder 200 2nd cam mechanism 220 2nd cam cylinder 240 2nd rectilinear advance cylinder 300 3rd optical holding part 320 Through-opening 400 4th cam mechanism 420 4th Cam cylinder 440 Fourth rectilinear cylinder 500 Mount connecting portion 600 Connecting member G1 First lens group G2 Second lens group G3 Third lens group I1 Iris G4 Fourth lens group G5 Fifth lens group

Claims (7)

An object side lens group;
An object-side cam mechanism that engages the object-side lens group movably along the optical axis by rotating about the optical axis;
A fixed optical group that is fixed on the image plane side with respect to the object side lens group, and
A fixed optical holding unit that holds the fixed optical group on the image plane side with respect to the object-side cam mechanism;
An image surface side lens group disposed closer to the image surface than the fixed optical group;
Provided on the image plane side with respect to the fixed optical holding portion, and engaged with the image plane side lens group so that the image plane side lens group can be moved along the optical axis by rotating about the optical axis. An image plane side cam mechanism
A connecting member that connects the object side cam mechanism and the image plane side cam mechanism independently of each other from the fixed optical holding unit;
With
The object side cam mechanism is
An object side cam cylinder having a cam groove that is engaged with the object side lens group and inclined with respect to the optical axis;
An object side rectilinear cylinder having a rectilinear groove engaged with the object side lens group and provided in a direction along the optical axis;
With
The image plane side cam mechanism is
An image surface side cam cylinder having a cam groove that engages with the image surface side lens group and is provided at least partially inclined with respect to the optical axis;
An image surface side rectilinear cylinder having a rectilinear groove that is engaged with the image surface side lens group and provided in a direction along the optical axis;
With
The object side cam cylinder is provided inside the object side rectilinear cylinder,
The image plane side cam cylinder is provided outside the image plane side rectilinear cylinder,
The connecting member connects the object-side cam cylinder and the image plane-side cam cylinder to each other,
The lens apparatus according to claim 1, wherein the object side cam mechanism and the image plane side cam mechanism can be interlocked in the same circumferential direction by the connecting member. The connecting member is
An object-side connecting portion connected in contact with one end on the image plane side of the object-side cam cylinder;
An image plane side coupling portion coupled to the outer periphery of the image plane side cam cylinder;
A relay section that extends between the object side coupling section and the image plane side coupling section and relays the object side coupling section and the image plane side coupling section;
The lens apparatus according to claim 1 , comprising: The lens apparatus according to claim 2 , wherein the image plane side coupling portion is coupled on both sides in the circumferential direction with the relay portion on the outer circumferential surface of the image plane side cam cylinder interposed therebetween. Lens apparatus according to any one of claims 1 to 3, further comprising a driving unit for relatively rotating the object side cam barrel with respect to the object side straight barrel to the optical axis as an axis. From the object side,
A first lens group;
A variator function for performing zooming, and a second lens group which is the object side lens group;
A third lens group which is the fixed optical group;
A compensator function for correcting the position of the image plane at the time of zooming, a fourth lens group that is the image plane side lens group;
A fifth lens group;
Consists of
When zooming from the wide-angle end to the telephoto end,
With the first lens group, the third lens group, and the fifth lens group fixed, the object-side cam mechanism and the image-side cam mechanism are rotated, so that the second lens group is while moving to the image side from the object side along the optical axis, the lens device according to any one of claims 1 to 4, wherein the fourth lens group is characterized in that moving along the optical axis. The first lens group has a focusing function;
When focusing
The lens apparatus according to claim 5 , wherein only the first lens group moves along the optical axis. The fixed optical unit includes a lens apparatus according to any one of claims 1 to 6, characterized in that it comprises a lens and at least one of the iris.

Images