JP2017097135A - Lens device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem in which: an operation ring for performing a back focus adjustment is arranged at a position, in a rear end of a lens device, relatively close to a mount mounted to a camera, but a structural lug or the like from the camera becomes a hindering of an operation of the operation ring at the position close to the mount, and a back is difficult to be focused.SOLUTION: A lens device includes: back focus drive means for changing a back focus by moving a predetermined lens or lens group in a lens optical direction; diaphragm drive means for changing an aperture diameter of a diaphragm; a diaphragm operation ring for rotating substantially about a lens optical axis and rotatingly operating the diaphragm drive means; connection means for connecting the diaphragm operation ring and one of the diaphragm drive means and the back focus drive means; and connection switching means for switching a connection state between the diaphragm operation ring and the diaphragm drive means or the back focus drive means, by the connection means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens apparatus, and more particularly to a lens apparatus having a back focus mechanism and an adjustment method thereof.

  Patent Document 1 is a lens device for movie shooting. A technique is disclosed in which a lens apparatus having a back focus mechanism does not change the focus or aperture setting position even when an operation ring for adjusting the back focus is rotated.

Japanese Patent No. 4204890

  However, the conventional lens apparatus has the following problems. The focus, zoom, and aperture can be adjusted by rotating each operating ring that rotates around the lens optical axis by hand, or on the gear provided on the circumferential surface of the operating ring. This is done by operating the knob and lever of the operation unit engaged with the gear. For this reason, the operation ring is arranged at a position of the lens device that is easy to touch directly without any structure that hinders operation or attachment. On the other hand, the operation ring for adjusting the back focus is arranged in the optical axis direction of the lens device at a position closer to the mounting mount with the camera than the other operation rings.

  In a position close to the mount, there is a case where a projecting structure or cable from the camera attached to the mount is interposed around the operation ring and it is difficult to operate. In particular, in the lens apparatus and camera for movie shooting, the above-mentioned operation unit and shooting assisting member may be installed around the camera. Further, it becomes difficult to operate the operation ring, and it is difficult to adjust the back focus, which hinders shooting. There is a risk of coming.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lens device that is easy to operate, such as other focus, zoom, and aperture operations, for operations for back focus adjustment.

In order to achieve the above object, a lens apparatus according to the present invention includes:
Back focus driving means for changing the back focus by moving a predetermined lens or lens group in the direction of the lens optical axis, aperture driving means for changing the aperture diameter of the aperture, and rotating the lens optical axis about the center, A diaphragm operating ring for rotating the driving means, a coupling means coupled to one of the diaphragm operating ring and the diaphragm driving means or the back focus driving means, and a diaphragm operating ring and the diaphragm driving means or back focus driving by the coupling means. It has the connection switching means which switches a connection state with a means, It is characterized by the above-mentioned.

The lens device according to the present invention is
Zoom drive means for moving the zoom lens group in the direction of the lens optical axis, a zoom operation ring for rotating the lens optical axis about the center and rotating the zoom drive means, and a zoom operation ring and zoom drive means, or back focus drive And a connection switching unit that switches a connection between a zoom operation ring by the connection unit and a zoom driving unit or a back focus driving unit.

  Further objects and other features of the present invention will be made clear by the preferred embodiments described below with reference to the accompanying drawings.

  According to the present invention, it is possible to provide a lens device in which the back focus can be easily adjusted by performing the back focus operation using the aperture operation ring or the zoom operation ring.

It is the schematic showing the outline | summary of the apparatus relevant to the inside of the lens apparatus of this invention. It is the schematic showing the outline | summary of the apparatus relevant to the exterior surface of the lens apparatus of this invention. It is the schematic showing the outline | summary of the aperture unit of this invention. It is the schematic showing the rotation range of the aperture operation ring of this invention. It is the schematic diagram showing the outline | summary of the slide piece and peripheral structure of this invention. It is the schematic showing the outline | summary of the aperture connection switching mechanism of this invention. It is the schematic showing the outline | summary of the aperture connection switching mechanism of this invention. It is the schematic showing the outline | summary of the leaf | plate spring which urges | biases the aperture_rotation | rotation pin of this invention. It is the schematic showing the outline | summary of the aperture connection switching mechanism of this invention. It is the schematic showing the outline | summary of the switching knob of this invention. It is a schematic diagram showing the outline of back focus position fixation of the present invention. It is the schematic showing the outline | summary of the apparatus relevant to the inside of the lens apparatus of this invention. It is the schematic showing the outline | summary of the apparatus relevant to the exterior surface of the lens apparatus of this invention. It is an expanded view showing the outline | summary of the cam ring of this invention. It is the schematic showing the rotation range of the zoom operation ring of this invention. It is the schematic showing the outline | summary of the zoom connection switching mechanism of this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

[Example 1]
1 and 2 are schematic views showing an outline of a lens apparatus having the configuration of the present invention. FIG. 1 mainly shows the inside of the lens device, and FIG. 2 mainly shows the outline of the exterior surface of the lens device.

  The lens apparatus 100 includes a fixed focus lens group 1, a moving focus lens group 2, zoom lens groups 3A and 3B, an aperture unit 4, and a relay lens group 5. The moving focus lens group 2 is a lens group whose imaging position is variable, and the zoom lens groups 3A and 3B are lens groups whose focal length is variable. The light that has passed through these lens groups reaches an image sensor in a camera (not shown) attached to the mount 6 via the aperture unit 4 and the relay lens group 5.

  The lens barrel 100 of the lens apparatus 100 is provided with a focus operation ring 8, a zoom operation ring 9, and an aperture operation ring 10 that are rotatable about the lens optical axis. On the surface circumference of each operation ring, the focus operation ring 8 has a gear 11, the zoom operation ring 9 has a gear 12, and the aperture operation ring 10 has a gear 13. The gears 11, 12, and 13 are respectively engaged with gears of an operation unit (not shown) different from the lens device 100, and the gears of the operation unit are engaged with knobs and levers (not shown) provided on the operation unit. Each of the operation rings described above is rotated by operating.

  In addition, on each operation ring, an index indicating the lens to be driven and the state of the aperture is displayed on the surface circumference, the focus operation ring 8 has a focus index 14, and the zoom operation ring 9 has a zoom index 15. An aperture index 16 is displayed on the aperture operation ring 10. Further, the focus state can be visually recognized from the display position of the focus index 14 by the index reference line 17 displayed on the lens barrel 7. The index reference line 18 allows the zoom state to be visually recognized from the display position of the zoom index 15, and the aperture state can be visually recognized from the display position of the aperture index 16.

  The focus operation ring 8 is connected to the moving focus lens group 2 through a guide unit 19 via a screw feed mechanism (not shown). When the focus operation ring 8 is rotated, the focus is moved through the guide unit 19 and the screw feed mechanism. The lens group 2 is driven in the lens optical axis direction.

  The zoom operation ring 9 is engaged with the zoom lens groups 3A and 3B, the cam shaft 20, and a cam ring 21 provided on the inner diameter side of the lens barrel 7 so as to be rotatable about the lens optical axis. When the zoom operation ring 9 is rotated, the cam ring 21 is rotated via the cam shaft 20, and the zoom lens groups 3 </ b> A and 3 </ b> B are each driven in the optical axis direction along the locus of the cam groove provided in the cam ring 21. Is done.

  The aperture operation ring 10 is provided with a switching knob 22 for switching between an aperture operation and a back focus operation, and a slide piece 23 that can be moved in the lens optical axis direction together with the switching knob 22. The slide piece 23 and the aperture unit 4 are connected via a rotation pin 24 and a guide 25 when the aperture is switched to an aperture operation by switching between an aperture operation and a back focus operation, which will be described later. A plurality of aperture blades 26 and an aperture cam plate 27 are attached to the aperture unit 4.

  FIG. 3 is a schematic diagram showing an outline of the aperture blade 26 and the aperture cam plate 27.

  In FIG. 3, the diaphragm blades 26 are composed of six blades 26a, 26b, 26c, 26d, 26e, and 26f. The diaphragm blades 26a to 26f have guide pins 30a, 30b, 30c, 30d, 30e, and 30f, respectively, and engage with the cam grooves 31a, 31b, 31c, 31d, 31e, and 31f. In FIG. 3, as an example, the respective diaphragm blades are arranged at the position of “F2” which is the maximum aperture diameter.

  When the aperture operation ring 10 is rotated when switching to the aperture operation, the aperture cam plate 27 rotates via the slide piece 23, the rotation pin 24, and the guide 25, and the guide pin 30 follows the locus of the cam groove 31. It moves, and the position of the aperture blade 26 changes to change the aperture diameter. In FIG. 3, the aperture diameter of the aperture changes from the position of the maximum aperture diameter “F2” to the position of “F22” which is the minimum aperture diameter. Further, the aperture cam plate 27 is rotatable from the position “F2” to a back focus switching position described later. Although the number of aperture blades is 6 in FIG. 3, the number is not limited to this.

  The relay lens group 5 is connected to a rotary ring 28 and a rotary pin 29 included in the lens barrel 7 so as to be rotatable about the lens optical axis via a screw feed mechanism (not shown). When it rotates, it is driven in the direction of the optical axis of the lens via the rotating pin 29 and the screw feed mechanism. The rotating ring 28 moves in the lens optical axis direction while being engaged with the rotating pin 29 by switching between an aperture operation and a back focus operation, which will be described later. An index 32 is displayed on a part of the outer circumference of the rotating ring 28 and can be visually recognized from the display window 33 of the lens barrel 7. Further, an index reference line 34 is also displayed on the lens barrel 7 so that the state of the rotation position of the rotary ring 28 can be visually recognized from the display position of the index 32. By the way, the relay lens group 5 is a lens group that changes the back focus of the lens apparatus 100, and the back focus can be changed when the operation is switched to the back focus operation.

  Next, switching between the aperture operation and the back focus operation will be described in detail.

  FIG. 4 shows an outline of the rotation operation range of the aperture operation ring 10.

  The aperture operation ring 10 rotates from the angular position of “F2” that is the maximum aperture diameter to the angular position of “F22” that is the minimum aperture diameter when operating the aperture. At this time, the rotation pin 24 is in a state of being engaged with a straight groove 35 provided in the slide piece 23 parallel to the optical axis direction of the lens, and the angular position changes simultaneously with the slide piece 23 according to the rotation of the aperture operation ring 10. To do. Further, the aperture operation ring 10 rotates to an angular position for back focus switching, which is a position further rotated from the position “F2”, and at the same time, the angular positions of the slide piece 23 and the rotating pin 24 also change.

  By the way, since the locus of the cam groove 31 in FIG. 3 does not change in the radial direction from the position “F2” to the back focus switching position, the diameter of the guide pin 30 does not change even if the aperture cam plate 27 rotates. The direction position does not change. Accordingly, the aperture diameter of the aperture by the aperture blade 26 does not change, and the maximum aperture diameter is maintained from the position “F2” to the back focus switching position.

  Next, the slide frame 23 and the surrounding structure will be described with reference to the schematic diagram of FIG. The slide piece 23 is engaged with the diaphragm operating ring 10 via a guide 36 and is moved in the lens optical axis direction by the guide 36. The diaphragm operating ring 10 is provided with a long groove 37 extending in the lens optical axis direction, and the slide piece 23 is connected to the switching knob 22 via a connection pin 38 in the long groove 37. Further, a friction plate 39 is attached to the surface of the slide piece 23 so as to come into contact with the rotating ring 28 side during movement.

  FIG. 6 is a schematic diagram showing the states of the aperture and back focus components in the range in which the aperture operation from the position “F2” to the position “F22” in FIG. 4 is performed.

  In FIG. 6, the switching knob 22 is located at the position on the left side in the drawing farthest from the gear 13 in the aperture operation ring 10, that is, at the front end position in the lens optical axis direction, and slides with the connection pin 38 connected simultaneously. The frame 23 is also located at the front end. At this time, the rotation pin 24 is in a state of being fitted in the straight groove 35 of the slide piece 23, and the aperture diameter of the aperture changes due to the rotation operation of the aperture operation ring 10. The restricting plate 40 is a member that restricts the movement of the slide piece 23 in the lens optical axis direction. The restricting plate 40 has a substantially arc shape that is not shown around the lens optical axis except for the back focus switching position of FIG. Form the shape.

  Outside the back focus switching position, the slide piece 23 is blocked by the restricting plate 40 and cannot move from the front end in the lens optical axis direction to the rear side. Therefore, in the range of the aperture operation, the aperture operation ring 10 can only perform the aperture operation.

  A friction plate 41 is attached to the front surface of the rotating ring 28 in the lens optical axis direction. Further, an elastic member 42 is incorporated between the rotating ring 28 and the receiving plate 43. The elastic member 42 is configured by a member such as a compression spring or a leaf spring, and biases the rotary ring 28 forward in the lens optical axis direction. In the rotating ring 28, the friction plate 41 attached to the front surface is brought into contact with the contact plate 44 by the biased pressing force. At this time, the rotation of the rotating ring 28 is restricted by the frictional force between the friction plate 41 and the contact plate 44, and at the same time, the relay lens group 5 connected via the rotating ring 28 and the rotating pin 29 also moves in the lens optical axis direction. Due to the restriction, the back focus position is fixed.

  By the way, the contact plate 44 has a substantially arc shape (not shown) with the lens optical axis as the center, and is fixed at a position where the slide piece 23 does not come in contact with a range where the slide piece 23 rotates during the back focus operation described later. The friction plate 41 and the above-described friction plate 39 are made of a composite material formed of a resin or a metal sintered material. The friction coefficient of the surface is high, and a high frictional force is exerted by applying pressure to the contact surface. obtain. It should be noted that the surface of the friction plates 39 and 41 and the contact plate 44 may be finely toothed and the rotation may be restricted by a combination of meshing. is not.

  FIG. 7 is a schematic diagram showing the states of the aperture and back focus components at the back focus switching position of FIG. In addition, the same code | symbol is attached | subjected to the same part as the figure demonstrated previously.

  In FIG. 7, the switching knob 22 is located at the right side in the drawing closest to the gear portion 13 in the aperture operation ring 10, that is, at the rear end position in the lens optical axis direction, and connected at the same time. The slide piece 23 is also located at the rear end. At this time, the rotation pin 24 is separated from the straight groove 35 of the slide piece 23, and the aperture operation cannot be performed by the rotation operation of the aperture operation ring 10. When the slide piece 23 moves to the rear end, the friction plate 39 of the slide piece 23 comes into contact with the friction plate 41 of the rotating ring 28, and further, the rotating ring 28 is moved rearward in the lens optical axis direction against the pressing force of the elastic member 42. Move to. Then, the rotating ring 28 moves to a position where the friction plate 41 and the contact plate 44 are separated, and the rotation restriction of the rotating ring 28 is released.

  However, even if the rotary ring 28 moves, the connected state of the rotary ring 28 and the rotary pin 29 is maintained. Accordingly, the diaphragm operating ring 10 and the relay lens group 5 are connected by the frictional force between the friction plates 39 and 41, and the back focus operation can be performed by rotating the diaphragm operating ring 10. Since the restriction plate 40 does not have a shape that restricts the movement of the slide piece 23 at the back focus switching position, the slide piece 23 can be moved rearward. Further, as described above, the contact plate 44 is also fixed at a position where it does not contact within the range in which the slide piece 23 rotates for back focus.

  Incidentally, it is desirable that the operator can determine that the operation from the position “F2” to the back focus switching position in FIG. 4 is different from the purpose of the aperture operation performed during shooting. Further, when the slide piece 23 and the rotary pin 24 are separated at the back focus switching position, the position needs to be regulated so that the aperture diameter of the diaphragm does not change.

  FIG. 8 is a schematic diagram of a leaf spring 45 provided so that an operation from the position “F2” to the back focus switching position and a diaphragm operation can be discriminated.

  The leaf spring 45 is fixed to the inner wall surface of the lens barrel 7 and has a slope 46 and a V-groove 47. The slope 46 is in a position where it contacts when the rotating pin 24 reaches the position “F2”, and the V groove 47 is in a position where it contacts when the rotating pin 24 reaches the back focus switching position. Further, it has a substantially arc shape with the lens optical axis as the center.

  When the rotating pin 24 in contact with the inclined surface portion 46 rotates toward the back focus switching position, the leaf spring 45 is deformed by an elastic force, and a rotational force against the elastic force is required. When the operator applies a force necessary for rotation to the aperture operation ring 10 to rotate from the position “F2” and the rotation pin 24 reaches the back focus switching position, the rotation pin 24 is fitted into the V groove 47 and the rotation of the rotation pin 24 is restricted. Is done. Further, when returning from the back focus switching position to the position “F2”, it is rotated by applying a rotational force against the elastic force of the leaf spring 45 for removing the rotation pin 24 from the V groove 47.

  As described above, by providing the leaf spring, a difference occurs in the necessary rotational force between the aperture operation range and the other range so that the operator can discriminate, and the aperture opening diameter is regulated at the back focus switching position. .

  FIG. 9 is a schematic diagram showing a state in the middle of returning to the aperture operation by rotating the aperture operation ring 10 to a position other than the back focus switching position in FIG. 4 to finish the back focus operation. In addition, the same code | symbol is attached | subjected to the same part as the figure demonstrated previously.

  In FIG. 9, the switching knob 22 is in the middle position after returning from the moving position at the rear end in the lens optical axis direction to the front end for the diaphragm operation after the back focus operation performed in FIG. The connection pin 39 and the slide piece 23 are also located in the middle. When the slide piece 23 moves to the intermediate position, the friction plate 39 of the slide piece 23 and the friction plate 41 of the rotating ring 28 are separated. The rotating ring 28 is moved forward in the lens optical axis direction by the pressing force of the elastic member 42, and the friction plate 41 and the contact plate 44 come into contact with each other so that the rotation is restricted.

  As shown in FIG. 9, in the state where the slide piece 23 is in the intermediate position, the movement to the front side is restricted by the restriction plate 40, and it cannot move to the front end position except at the back focus switching position. Therefore, at the intermediate position, the straight groove 35 and the rotary pin 24 of the slide piece 23 are separated from each other, and the diaphragm operation cannot be performed yet. Therefore, after the back focus operation is completed, the operator rotates the aperture operation ring 10 to the back focus switching position with the switching knob 22 and the slide piece 23 being in the intermediate positions. At the back focus switching position, the restriction plate 40 is not regulated, and the slide piece 23 can move to the front end, so that the switching knob 22 is moved to the front end. Then, the rotation pin 24 engages with the straight groove 35 of the slide piece 23, and the aperture operation can be performed by rotating the aperture operation ring 10 to the range of the aperture operation.

  FIG. 10 is a schematic diagram of the switching knob 22 and shows the respective moving positions of FIGS. 6, 7 and 9.

  In FIG. 10, the switching knob 22 is located at the front end position in the lens optical axis direction for performing the diaphragm operation as in FIG. 6, and the index 48 displayed on the switching knob 22 is “IRIS” of the index 49 displayed on the diaphragm operating ring 10. ”. The switching knob 22 has a convex protrusion 50 on the side surface portion, and is fitted into a concave notch 51 provided in the diaphragm operating ring 10 to restrict the movement position. In FIG. 10, it fits in the notch 51a which is an aperture operation position.

  When the back focus operation of FIG. 7 is performed, the switching knob 22 moves to the rear end, and the protrusion 50 is fitted into the notch 51b to restrict the movement position. At this time, the index 48 is “FB” of the index 49. It matches the position of. Further, at the intermediate position in FIG. 9, the switching knob 22 moves in the middle, and the protrusion 50 fits into the notch 51 c to restrict the movement position. At this time, the index 48 matches the position “UNLOCK” of the index 49. By the way, the protrusion 50 is made of an elastically deformable material such as a resin, and when it is removed from the notch 51, the switch knob 22 moves due to elastic deformation.

  Here, the operating force required to release the notch 51 is set to be stronger than the force by which the slide knob 23 moves against the pressing force of the elastic member 42 in FIG. The position at the rear end is maintained. In FIG. 10, the movement of the switching knob 22 is restricted by the combination of the projection 50 and the notch 51, but other conventional positioning means using a ball plunger or a hook by a spring can be used instead. It is not limited.

  With the above-described configuration, it is possible to provide a lens apparatus that can adjust the back focus with the aperture having the maximum aperture diameter and that can be easily adjusted. In the embodiment, the back focus position is regulated by the frictional force. However, if it is desired to regulate the back focus position more firmly, fixing with screws as shown in FIG. 11 may be provided.

  FIG. 11 is a schematic diagram of a fixing screw that regulates the back focus position.

  The fixing screw 52 is screwed and coupled to a screw portion 53 provided on a part of the circumference of the rotary ring 28, and the head of the fixing screw 52 is provided on the lens barrel 7, and extends from a long groove 54 extending in the circumferential direction. It protrudes. The long groove 54 is set to have a wide width in consideration of the amount of movement of the fixing screw 52 along with the movement of the rotating ring 28 in the lens optical axis direction. When the fixing screw 52 is turned, the tip of the screw comes into contact with a part of the lens barrel 7 on the inner diameter side of the rotary ring 28, and the rotation of the rotary ring 28 and the movement in the lens optical axis direction are restricted by the tightening force of the screw. The The fixing screw 52 is disposed on the outer diameter circumference of the lens barrel 7 that is relatively unaffected by the protrusion from the camera and the photographing auxiliary member. For example, it is arranged on the upper surface of the lens barrel 7, or a plurality of arranged fixing screws on the outer circumference of the circumference instead of one place are selected and operated.

[Example 2]
12 and 13 are schematic views showing an outline of the second lens device having the configuration of the present invention. In addition, the same code | symbol is attached | subjected to the same part as the figure demonstrated previously, and description of each function is abbreviate | omitted.

  12 and 13, the main point of difference from the lens device of FIGS. 1 and 2 is that the zoom operation ring 55 is subjected to zoom operation and back focus operation instead of the switching knob 22 provided in the aperture operation ring 10. The switch knob 56 for switching is provided. FIG. 12 mainly shows the inside of the lens device, and FIG. 13 mainly shows the outline of the exterior surface of the lens device.

  Similarly to the lens device 100, the lens device 200 includes a fixed focus lens group 1, a moving focus lens group 2, zoom lens groups 3 </ b> A and 3 </ b> B, an aperture unit 57, and a relay lens group 5. The lens barrel 58 is provided with a focus operation ring 8, a zoom operation ring 55, and an aperture operation ring 59 that are rotatable about the lens optical axis. Each operation ring displays an index indicating the state of the lens to be driven and the diaphragm on the surface circumference. The index reference line 60 visually indicates the focus and zoom states, and the index reference line 18 visually confirms the aperture state. can do.

  The zoom operation ring 55 is provided with a switching knob 56 for switching between a zoom operation and a back focus operation, and a slide piece 61 that can move in the lens optical axis direction together with the switching knob 56. When the slide frame 61 and the zoom lens groups 3A and 3B are switched to a zoom operation by switching between a zoom operation and a back focus operation, which will be described later, the lens optical axis is centered on the inner diameter side of the cam shaft 62 and the lens barrel 58. It is connected by a cam ring 63 provided rotatably. When the zoom operation ring 55 is rotated, the cam ring 63 is rotated via the cam shaft 62, and the zoom lens groups 3A and 3B are each along the locus of the cam groove provided in the cam ring 63 in the optical axis direction. Driven.

  Further, a connecting guide 64 is attached to the slide piece 61 on the rear surface side in the lens optical axis direction. The connection guide 64 passes through the inner diameter side of the aperture operation ring 59 and contacts the aperture ring 28 when switching to the back focus described later.

  The aperture operation ring 59 engages with the rotation pin 65 and is connected to the aperture unit 57 via the guide 25. A plurality of aperture blades 26 and an aperture cam plate 66 are attached to the aperture unit 57. Unlike the aperture cam plate 27 of FIG. 3, the aperture cam plate 66 has only a cam trajectory that changes the aperture opening diameter, and therefore the aperture operation ring 59 performs only the aperture operation. The rotation pin 65 is disposed at a position where it does not come into contact with the connection guide 64 described above in the aperture operation range.

  FIG. 14 is a development view showing an outline of the cam locus of the cam ring 63.

  In FIG. 14, guide pins 67a and 67b are coupled to the zoom lens groups 3A and 3B, respectively, and are engaged with cam grooves 68a and 68b. In FIG. 14, as an example, a guide pin is disposed at the wide-angle end position where the focal length is the maximum wide-angle.

  In FIG. 14, the guide pins 67a and 67b extend along the locus of the cam grooves 68a and 68b from the wide-angle end position where the focal length is the maximum wide-angle to the telephoto end position where the focal length is the maximum telephoto. Move with. Furthermore, it is also possible to move from a wide-angle end position to a back focus switching position described later.

  Next, switching between the zoom operation and the back focus operation will be described in detail.

  FIG. 15 shows an outline of the rotation operation range of the zoom operation ring 55.

  When the zoom operation is performed, the zoom operation ring 55 rotates from the wide-angle end position where the focal length is the maximum wide-angle to the telephoto end position where the focal length is the maximum telephoto. At this time, the cam shaft 62 is engaged with a straight groove 69 provided in the slide piece 61 parallel to the lens optical axis direction, and the angular position changes simultaneously with the slide piece 61 according to the rotation of the zoom operation ring 55. To do. Further, the zoom operation ring 55 rotates to the back focus switching angular position that is further rotated from the wide-angle end position, and at the same time, the angular positions of the slide piece 61 and the cam shaft 62 also change.

  By the way, since the locus of the cam groove 31 in FIG. 14 does not change in the lens optical axis direction from the wide-angle end position to the back focus switching position, the guide pins 67a and 67b are rotated even if the cam ring 63 rotates. The position of the lens in the optical axis direction does not change. Accordingly, the positions of the zoom lens groups 3A and 3B do not change, and the maximum wide-angle focal length is maintained from the wide-angle end position to the back focus switching position.

  FIG. 16 is a schematic diagram showing the state of components of zoom and back focus in a range in which zoom operation is performed from the wide-angle end position where the focal length is the maximum wide-angle to the telephoto end position where the focal length is the maximum telephoto focal length in FIG. It is.

  In FIG. 16, the switching knob 56 is located at the position on the left side of the zoom operation ring 55 farthest from the gear 12 in the drawing, that is, the front end position in the lens optical axis direction. The connection pin 71 and the slide piece 61 connected to the switching knob 56 in the long groove 70 extending in the lens optical axis direction are also located at the front end. At this time, the cam shaft 62 is in a state of being fitted in the straight groove 69 of the slide piece 61, and the focal length is changed by the rotation operation of the zoom operation ring 55. A friction plate 39 is attached to the rear surface side of the coupling guide 64 in the lens optical axis direction.

  Further, the connection guide 64 is blocked by the restriction plate 40 except at the back focus switching position, and cannot move from the front end in the lens optical axis direction to the rear side. Accordingly, in the zoom operation range, the zoom operation ring 55 can only perform the zoom operation. In this state, as in the state of FIG. 6, the rotation ring 28 is restricted in rotation by the pressing force of the elastic member 42, and the back focus position is fixed.

  When the zoom operation ring 55 is rotated from this state to the back focus switching position in FIG. 15 and the switching knob 56 is moved to the rear end position, the zoom operation and the back focus operation are switched by the same action as in FIG. That is, the cam shaft 62 is separated from the straight groove 69 of the slide piece 61, the friction plate 39 of the coupling guide 64 and the friction plate 41 of the rotating ring 28 come into contact with each other, and the rotating ring 28 resists the pressing force of the elastic member 42. To move backwards. At this time, the zoom operation cannot be performed by the rotation operation of the zoom operation ring 55, but the connection state of the rotation ring 28 and the rotation pin 29 is maintained, so that the back focus operation can be performed instead.

  When the above-described back focus operation is finished, the switching knob 56 is moved from the rear end position to the front side. However, in a state where the zoom operation ring 55 is rotated from the back focus switching position, the connection guide 64 is blocked by the restricting plate 40 by the same action as in FIG. 9, and cannot move from the rear end to the front end position, but remains at the intermediate position. . At this time, the friction plate 39 and the friction plate 41 are separated, the rotary ring 28 moves in the front direction, the friction plate 41 and the contact plate 44 come into contact, and the rotation is restricted.

  Subsequently, when the zoom operation ring 55 is rotated to the back focus switching position, the restriction of the restriction plate 40 is eliminated, so that the connection guide 64 can be moved to the front end, and the switching knob 56 moves to the front end. Then, the cam shaft 62 is engaged with the straight groove 69 of the slide piece 61, and the zoom operation can be performed by rotating the zoom operation ring 55 to the zoom operation range. By the way, by providing a leaf spring similar to that in FIG. 8 in the range from the wide-angle end position to the back focus switching position in FIG. 15, it is possible to discriminate between the zoom operation range and the rotational force in other ranges. Is possible. Further, the state of the wide-angle end position at the back focus switching position can also be maintained. Furthermore, by providing the switching knob 56 with the same positioning means as in FIG. 10, the movement can be restricted at the zoom operation and back focus switching positions, and at an intermediate position between them.

  With the above-described configuration, it is possible to provide a lens device that can adjust the back focus at a maximum wide-angle focal length and that can be easily adjusted.

3A zoom lens group, 3B zoom lens group, 5 relay lens group, 7 lens barrel,
10 Aperture operation ring, 22 switching knob, 23 slide piece, 24 rotation pin,
26 Aperture blades, 27 Aperture cam plate, 28 rotary ring, 29 rotary pin,
30 guide pins, 31 cam grooves, 35 long grooves, 36 guides, 39 friction plates,
40 restricting plate, 41 friction plate, 42 elastic member, 44 contact plate, 45 leaf spring,
50 protrusion, 51 notch, 52 fixing screw, 55 zoom operation ring,
56 switching knob, 58 lens barrel, 61 slide frame, 62 camshaft, 63 cam ring,
64 Connecting guide, 67 Guide pin, 68 Cam groove, 69 Long groove

Claims (10)

  Back focus drive means for changing the back focus by moving a predetermined lens or lens group in the lens optical axis direction, aperture drive means for changing the aperture diameter of the aperture, and rotating about the lens optical axis, the aperture A diaphragm operating ring for rotating the driving means, a coupling means coupled to either the diaphragm operating ring and the diaphragm driving means, or the back focus driving means, the diaphragm operating ring and the diaphragm driving by the coupling means Or a connection switching means for switching a connection state with the back focus driving means.   2. The switching of connection and separation between the diaphragm operating ring and the diaphragm driving unit by the connection switching unit is performed at a rotational position of the diaphragm operating ring where the diaphragm is in a state of a maximum aperture diameter. Lens device.   When the diaphragm operating ring and the diaphragm driving means are separated by the connection switching means, the diaphragm holding means for maintaining the maximum aperture diameter, and the diaphragm operating ring and the back focus driving means are separated. The lens apparatus according to claim 2, further comprising back focus holding means for holding a back focus position.   The lens apparatus according to claim 3, wherein the connection switching unit includes an intermediate switching region in which the diaphragm operating ring is separated from both the diaphragm driving unit and the back focus driving unit.   Switching between connection and separation of the diaphragm operating ring and the diaphragm driving means by the connection switching means is performed at a maximum from a rotational position where the diaphragm has a maximum aperture diameter in a diaphragm operating range in which the diaphragm driving means is operated by the diaphragm operating ring. The lens apparatus according to claim 4, wherein the lens apparatus is performed at a further rotated position while maintaining the state of the aperture diameter.   Back focus driving means for changing the back focus by moving a predetermined lens or lens group in the lens optical axis direction, zoom driving means for moving the zoom lens group in the lens optical axis direction, and the lens optical axis as the center A zoom operation ring that rotates and rotates the zoom drive means, a connection means that connects the zoom operation ring and either the zoom drive means or the back focus drive means, and the zoom operation by the connection means A lens apparatus comprising: a connection switching unit that switches a connection between a ring and the zoom driving unit or the back focus driving unit.   The switching of connection and separation between the zoom operation ring and the zoom drive unit by the connection switching unit is performed at a rotation position of the zoom operation ring in which a zoom position is in a maximum wide-angle focal length state. 6. The lens device according to 6.   When the zoom operation ring and the zoom drive means are separated by the connection switching means, the zoom holding means for holding the maximum wide-angle focal length, and the zoom operation ring and the back focus drive means are separated. 8. The lens apparatus according to claim 7, further comprising back focus holding means for holding a back focus position in a state.   9. The lens apparatus according to claim 8, wherein the connection switching unit includes an intermediate switching region in which the zoom operation ring is separated from both the zoom driving unit and the back focus driving unit.   Switching between connection and separation of the zoom operation ring and the zoom driving means by the connection switching means is performed at a maximum from a rotational position that provides a maximum wide-angle focal length in a zoom operation range in which the zoom driving means is operated by the zoom operation ring. The lens apparatus according to claim 9, wherein the lens apparatus is performed at a further rotated position while maintaining a wide-angle focal length state.