JP6090132B2 - Zoom lens barrel - Google Patents

Description

  The present invention relates to a zoom lens barrel, and more particularly to a zoom lens barrel for a single lens reflex camera.

  The high magnification zoom lens barrel is desired to be able to cover a wide focal length from high angle to telephoto. In order to cover such a wide focal length, it is necessary to increase the extension amount of the lens, and in order to increase the extension amount of the lens, it is conceivable to stack a plurality of lenses. .

  As a zoom lens barrel in which a plurality of stages for extending a lens are stacked in this manner, for example, in Patent Document 1, as shown in FIGS. Zoom lens mirror having a 10-layer structure in which a lens barrel, an outer cylinder, a first-group lens sliding frame, a second cam cylinder, a zoom interlocking ring, a fixed cylinder, a focus cam cylinder, a rectilinear cylinder, and a first cam cylinder are arranged A cylinder is disclosed.

  In the zoom lens barrel described in the cited document 1, when the zoom operation ring is rotated, the zoom interlocking ring is moved in the optical axis direction with respect to the zoom operation ring while being rotated by the cam mechanism. , The rectilinear cylinder is moved in the optical axis direction with respect to the zoom interlocking ring, and the first cam cylinder rotates with respect to the rectilinear cylinder, whereby the zoom operation of the second to fourth lens groups is performed. .

JP 2010-44102 A

  Here, the high magnification zoom lens barrel is required to be compact in order to cover a wide focal length and to improve portability. However, when a plurality of stages for extending a lens, such as the zoom lens barrel described in the cited document 1, are stacked, the diameter of the lens barrel increases, and the problem of compactness cannot be achieved.

  Furthermore, when the lens is extended with many tubes stacked, the lens group is moved through the multiple tubes as described above, and when the lens is extended from the wide angle to the telephoto and when the lens is retracted from the telephoto to the wide angle. The difference in the feeding accuracy (that is, the difference in the feeding distance of the lens) becomes large.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a compact zoom lens barrel that can cover a wide focal length. Furthermore, an object of the present invention is to improve the feeding accuracy in a lens barrel configured by stacking many cylinders.

  The zoom lens barrel of the present invention is a zoom lens barrel having a plurality of lens groups, and is disposed on a fixed tube, a zoom ring disposed outside the fixed tube, and an inner side of the fixed tube, A lens feeding cylinder group that moves the plurality of lens groups in the optical axis direction when the zoom ring is rotated, and the lens feeding cylinder group includes an outer cylinder, a first sliding frame, and a second cam cylinder. And a second sliding frame, a focus cam cylinder, a rectilinear cylinder, and a first cam cylinder.

  In the present invention, it is preferable that the lens feeding cylinder group includes an outer cylinder, a first sliding frame, a second cam cylinder, a second sliding frame, a focus cam cylinder, a rectilinear cylinder, a first cylinder from the outside toward the inside. They are arranged in the order of cam cylinders.

  According to this invention of the said structure, it is comprised from the cylinder of 9 layers, and it can be set as a compact structure, covering a wide focal distance.

  In the present invention, it is preferable that the zoom lens barrel has first to fifth lens groups, the outer cylinder and the rectilinear cylinder are connected by a rectilinear cylinder interlocking piece, and the first cam cylinder is a rectilinear cylinder. On the other hand, movement in the optical axis direction is constrained, and when the zoom ring is rotated, the zoom ring is rotated with respect to the fixed cylinder, so that the rectilinear cylinder moves in the optical axis direction together with the outer cylinder without rotating. Then, the rotation of the zoom ring is transmitted to the first cam cylinder, and the first cam cylinder moves in the optical axis direction together with the outer cylinder and the rectilinear cylinder while rotating, and the third to fifth lens groups are moved relative to the rectilinear cylinder. When the first cam barrel rotates, the first cam barrel moves relative to the rectilinear barrel in the optical axis direction, whereby the third to fifth lens groups zoom in the optical axis direction.

  In the present invention, preferably, the second sliding frame rotates in the circumferential direction together with the second cam cylinder, and transmits the rotation to the first cam cylinder, whereby the rotation of the zoom ring causes the second cam to rotate. It is transmitted to the first cam cylinder via the cylinder and the second sliding frame.

  According to the present invention having the above-described configuration, the outer cylinder and the rectilinear cylinder move together in the optical axis direction, so that the lens is retracted from the wide angle to the telephoto and the lens is retracted from the telephoto to the wide angle as compared with the conventional case. It is possible to reduce the difference in feeding accuracy from the case of making it.

  In the present invention, preferably, when the zoom ring is rotated, the second sliding frame moves in the optical axis direction by rotating with respect to the rectilinear cylinder, and the focus cam cylinder is moved together with the second sliding frame. Moving in the optical axis direction, the second lens group zooms in the optical axis direction together with the focus cam barrel.

  In the present invention, preferably, the first lens group is fixed to the first sliding frame, and when the zoom ring is rotated, the rotation of the zoom ring is transmitted to the second cam cylinder, and the outer cylinder is the fixed cylinder. The first sliding frame is moved in the optical axis direction by rotating the second cam cylinder with respect to the outer cylinder without rotating with respect to the first lens. The group zooms in the direction of the optical axis.

  According to the present invention, it is possible to provide a compact zoom lens barrel while covering a wide focal length. Furthermore, according to the present invention, the feeding accuracy can be improved in a lens barrel configured by stacking many cylinders.

1 is a cross-sectional view of a surface passing through an optical axis at a wide angle of a zoom lens barrel according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a plane passing through the optical axis when the zoom lens barrel shown in FIG. FIG. 2 is a development view of a zoom ring in the zoom lens barrel shown in FIG. 1. FIG. 2 is a development view of a vertical groove cylinder in the zoom lens barrel shown in FIG. 1. FIG. 2 is a development view of an outer cylinder in the zoom lens barrel shown in FIG. 1. FIG. 3 is a development view of a first sliding frame in the zoom lens barrel shown in FIG. 1. FIG. 4 is a development view of a second cam barrel in the zoom lens barrel shown in FIG. 1. FIG. 4 is a development view of a second sliding frame in the zoom lens barrel shown in FIG. 1. FIG. 2 is a development view of a focus cam barrel in the zoom lens barrel shown in FIG. 1. FIG. 2 is a development view of a rectilinear cylinder 80 in the zoom lens barrel shown in FIG. 1. FIG. 2 is a development view of one cam barrel 90 in the zoom lens barrel shown in FIG. 1.

  Hereinafter, an embodiment of a zoom lens barrel of the present invention will be described with reference to the drawings. In the present embodiment, a zoom lens barrel having a five-lens group structure including an autofocus mechanism and a camera shake correction mechanism will be described.

(Constitution)
1 and 2 are cross-sectional views of a plane passing through the optical axis of a zoom lens barrel according to an embodiment of the present invention, respectively, showing cross-sections at wide angle and telephoto, respectively.
As shown in FIGS. 1 and 2, the inner focus zoom lens 1 includes a first lens group A disposed on the optical axis O, a second lens group B that is a focus lens group, a third lens group C, and a fourth lens group. It has a lens group D and a fifth lens group E. The fourth lens group D constitutes a correction lens group for correcting camera shake. The lenses in each lens group have substantially the same diameter, and smaller diameter lenses are used as they proceed from the first lens group A to the fifth lens group E. The first to fifth lens groups A to E are respectively held by first to fifth lens group frames 2, 3, 4, 5, and 6 formed in an annular shape.

  The zoom lens barrel 1 is provided with a first base tube 8 and a second base tube 9 in order from the mount 7. Further, a longitudinal groove cylinder 20 (fixed cylinder) is fixed to the center side in the radial direction of the first base cylinder 8.

  On the radially outer side of the longitudinal groove cylinder 20, the zoom ring 10 is rotatably provided in a state where movement in the optical axis direction is constrained. A focus ring 100 is rotatably provided on the radially outer side of the image forming side end of the second base tube 9.

  On the radially inner side of the longitudinal groove cylinder 20, the outer cylinder 30, the first sliding frame 40, the second cam cylinder 50, the second sliding frame 60, and the focus cam in order toward the radial center. A cylinder 70, a rectilinear cylinder 80, and a first cam cylinder 90 are arranged. The outer ring 30, the first sliding frame 40, the second cam cylinder 50, the second sliding frame 60, the focus cam cylinder 70, the rectilinear cylinder 80, and the first cam cylinder 90 rotate the zoom ring 10. And a lens feeding cylinder group for moving the first to fifth lens groups A to E in the optical axis direction.

  Further, on the inner side of the first cam cylinder 90, the second group sliding frame 110, the third group sliding frame 120, the fourth group sliding frame 130, and the fifth group are sequentially arranged from the objective side to the eyepiece side. A sliding frame 140 is provided. The second lens group frame 3, the third lens group frame 4, and the fifth lens group frame 6 are integrated with the second sliding frame 110, the third group sliding frame 120, and the fifth group sliding frame 140, respectively. It is fixed. The fourth group lens frame 5 is supported by the fourth group sliding frame 130 via a camera shake correction mechanism 150. A diaphragm mechanism 160 is attached to the objective side of the third group lens frame 4.

  Further, a focus gear ring 170 that can rotate around the optical axis and a focus gear ring 170 that rotates the focus gear ring 170 in the imaging-side space in the second base cylinder 9, for example, an ultrasonic motor. 180 are arranged. The focus gearing 170 and the focusing motor 180 are, for example, a distance measuring unit that measures the distance to the subject using infrared rays, and a control signal corresponding to the rotation angle of the focus gearing 170 to the focusing motor. Together with the sending control means, an autofocus mechanism is constituted. Based on the distance to the subject measured by the distance measuring means, the control means calculates the rotation angle of the focus gear ring 170 according to the moving distance of the second lens group B necessary for focusing.

  A focus interlocking plate 190 is connected to the focus gear ring 170. The focus interlocking plate 190 is inserted through an opening formed on the image forming side of the vertical groove cylinder 20 and extends in the optical axis direction inside the vertical groove cylinder 20 and outside the focus cam cylinder 70. A focus interlocking piece 191 is attached to the tip of the focus interlocking plate 30.

  Further, since manual focusing is performed, the rotation of the focus ring 100 can be transmitted to the focus gear ring 170 via the reduction gear of the focusing motor 180.

  The fourth lens group frame 5 that holds the fourth lens group D is held by a camera shake correction mechanism 150, and this camera shake correction mechanism detects the acceleration of the zoom lens barrel 1 by a gyro (not shown). The fourth lens group D is translated and rotated in a plane perpendicular to the optical axis according to the acceleration.

  3 to 11 show the zoom ring 10, the longitudinal groove cylinder 20, the outer cylinder 30, the first sliding frame 40, the second cam cylinder 50, and the second sliding frame in the zoom lens barrel 1 shown in FIG. 60 is a development view of the focus cam cylinder 70, the rectilinear cylinder 80, and the first cam cylinder 90. FIG. In each figure, the upper side is the subject side and the lower side is the imaging side.

  As shown in FIG. 3, the zoom ring 10 is formed with one second cam cylinder guide groove 11 and three outer cylinder cam grooves 12 on the inner surface side thereof. The second cam cylinder guide groove 11 extends in the optical axis direction, and the outer cylinder cam groove 12 is inclined in the circumferential direction with respect to the optical axis direction. In the second cam cylinder guide groove 11, a second cam cylinder interlocking piece which is planted on the outer peripheral surface of the second cam cylinder 50 and is inserted through the second cam cylinder piece insertion opening 22 formed in the longitudinal groove cylinder 20. The tip of 51 is engaged. Further, in the outer cylinder cam groove 12, an outer cylinder piece 31 that is planted on the outer peripheral surface of the outer cylinder 30 and is inserted through the outer cylinder piece rectilinear groove 21 of the vertical groove cylinder 20 is engaged.

  As shown in FIG. 4, in the longitudinal groove cylinder 20, three outer cylinder piece straight advance grooves 21 and one second cam cylinder piece insertion opening 22 are formed so as to penetrate the front and back. The outer cylinder piece rectilinear groove 21 extends in the optical axis direction, and the second cam cylinder piece insertion opening 22 is inclined in the circumferential direction with respect to the optical axis. The width of the second cam cylinder piece insertion opening 22 is larger than the diameter of the second cam cylinder interlocking piece 51 and is opposite to the outer cylinder cam groove 12 formed in the zoom ring 10 with respect to the optical axis direction. Inclined in the direction. An outer cylinder piece 31 planted on the outer peripheral surface of the outer cylinder 30 is inserted into the outer cylinder piece rectilinear groove 21, and a side surface of the outer cylinder piece 31 is in contact with an edge of the outer cylinder piece rectilinear groove 21. A second cam cylinder interlocking piece 51 inserted in the outer peripheral surface of the second cam cylinder 50 is inserted into the second cam cylinder piece insertion opening 22.

  As shown in FIG. 5, the outer cylinder 30 has three first sliding frame rectilinear grooves 32 formed on the inner peripheral surface thereof. The first sliding frame rectilinear groove 32 is engaged with the front end portion of the first group guide piece 41 planted on the outer peripheral surface of the first sliding frame 40. In addition, three outer cylinder tops 31 are planted on the edge of the outer peripheral surface of the outer cylinder 30 on the eyepiece side, and the protrusion 30A formed so as to protrude from the outer cylinder 30 to the eyepiece side is circular. Is formed, and the tip of the straight cylinder interlocking piece 33 planted on the outer peripheral surface of the straight cylinder 80 is engaged with this hole. The outer cylinder piece 31 is inserted through the outer cylinder piece rectilinear groove 21 of the vertical groove cylinder 20 as described above, and is engaged with the outer cylinder cam groove 12 of the zoom ring 10. Further, the tip of the straight cylinder interlocking piece 33 is implanted in the straight cylinder 80.

  As shown in FIG. 6, a first group guide piece 41 is planted at the edge of the outer peripheral surface of the first sliding frame 40 on the eyepiece side, and at the edge of the inner peripheral surface on the eyepiece side. The first group sliding piece 42 is implanted. As described above, the distal end portion of the first group guide piece 41 is engaged with the first sliding frame rectilinear groove 32 formed in the outer cylinder 30. Further, the front end portion of the first group sliding piece 42 is engaged with a first group cam groove 52 formed in the second cam cylinder 50.

  As shown in FIG. 7, the second cam cylinder 50 has three first group cam grooves 52 formed on the outer peripheral surface and three second sliding frame rectilinear grooves 53 formed on the inner peripheral surface. Yes. The first group cam groove 52 is inclined in the circumferential direction with respect to the optical axis, and the first group sliding piece 42 formed on the first sliding frame 40 is engaged therewith. The second sliding frame rectilinear groove 53 extends in the optical axis direction, and is engaged with a second sliding frame interlocking piece 61 planted on the outer peripheral surface of the second sliding frame 60. A second cam cylinder interlocking piece 51 is implanted toward the outer periphery in the radial direction at the eyepiece side end of the second cam cylinder. The second cam cylinder interlocking piece 51 is inserted through the second cam cylinder piece insertion opening 22 formed in the longitudinal groove cylinder 20 and the tip engages with the second cam cylinder guide groove 11 formed in the zoom ring 10. Yes.

  As shown in FIG. 8, the second sliding frame 60 has three second sliding frame interlocking pieces 61 planted on the outer peripheral surface, and three second groups on the inner peripheral surface. A frame 62 is planted. The second sliding frame interlocking piece 61 is engaged with a second sliding frame rectilinear groove 53 formed in the second cam cylinder 50. The second group piece 62 is formed in the first cam cylinder 90 through the second group focus groove 71 formed in the focus cam cylinder 70 and the second group frame guide groove 82 of the rectilinear cylinder 80. The second group rectilinear groove 91 is engaged.

  As shown in FIG. 9, the focus cam cylinder 70 includes three focus sliding frame guide grooves 72 formed on the object side edge and three second groups formed on the eyepiece side edge. A focus groove 71 and a focus interlocking coma groove 73 formed in the protruding portion 70A extending toward the eyepiece side are formed. The focus sliding frame guide groove 72 has a portion extending from one end to the intermediate portion in the circumferential direction, and a portion extending from the intermediate portion to the multi-end is curved toward the subject side. The focus sliding frame guide groove 72 abuts on the outer periphery of the second sliding frame 110 integrated with the second lens group frame 3. In the second group focus groove 71, a portion from one end to the middle portion extends in the circumferential direction, and a portion from the middle portion to the multi-end is curved toward the eyepiece side. A second group piece 62 formed on the second sliding frame 60 is inserted into the second group focus groove 71, and a side surface of the second group piece 62 is in contact with an edge of the second group focus groove 71. Yes. The focus interlocking coma groove 73 extends substantially in the optical axis direction, and a focus interlocking coma 191 attached to the tip of the focus interlocking plate 190 is engaged.

  As shown in FIG. 10, the straight cylinder 80 includes three focus sliding top cam grooves 81, three second group top guide grooves 82, three third group top guide grooves 83, and three. The first cam cylinder sliding piece guide groove 84 is formed. The focus sliding frame cam groove 81 is formed so as to be inclined in the circumferential direction with respect to the optical axis direction, and is implanted on the outer periphery of the second sliding frame 110 integrated with the second lens group frame 3. The focus sliding piece 201 is inserted. The second group frame guide groove 82 is formed so as to be inclined in the circumferential direction with respect to the optical axis direction, and the second group frame 62 formed in the second sliding frame 60 is inserted therethrough. The side surface of the group piece 62 is in contact with the edge of the second group piece guide groove 82. The third group frame guide groove 83 is formed so as to extend in the optical axis direction, and a third group frame 203 implanted on the outer periphery of the third lens group frame 4 is engaged. The first cam cylinder sliding piece guide groove 84 is formed so as to extend in the circumferential direction, and a first cam cylinder sliding piece 92 formed on the outer peripheral surface of the first cam cylinder 90 is engaged therewith. Further, a rectilinear cylinder interlocking piece 33 is planted on the outer peripheral surface of the rectilinear cylinder 80, and the tip of the rectilinear cylinder interlocking piece 33 is engaged with a hole formed in the protruding portion 30 </ b> A of the outer cylinder 30. In addition, a plurality of concave portions 80A are formed on the eyepiece side edge of the rectilinear cylinder, and the concave portions 80A are implanted on the outer periphery of the fourth group sliding frame 130 that supports the fourth lens group frame 5. The fourth group piece is fitted.

  As shown in FIG. 11, the first cam cylinder 90 includes a second group rectilinear groove 91 formed in three projecting portions 90 </ b> A projecting toward the subject side, and three first grooves formed on an edge portion on the subject side. A third group frame cam groove 93, three fourth group frame guide grooves 94 formed in the intermediate portion in the optical axis direction, and three fifth group frame guide grooves 95 formed in the edge on the eyepiece side are formed. Has been. The second group rectilinear groove 91 is formed so as to extend in the optical axis direction, and the second group piece 62 implanted in the second sliding frame 60 is engaged therewith. The third group coma cam groove 93 is formed so that a portion from one end to the middle portion extends in the circumferential direction, and a portion from the middle portion to the other end is formed to be inclined in the circumferential direction with respect to the optical axis direction. Yes. The third group frame cam groove 93 is inserted through the third group frame 203 that is planted on the outer periphery of the third lens group frame 4, and the side surface of the third group frame 203 abuts the edge of the third group frame cam groove 93. Touching. The fourth group frame guide groove 94 is formed so as to extend in the circumferential direction, and the fourth group frame 204 implanted in the outer periphery of the fourth lens group frame 5 is inserted therethrough. The fifth group frame guide groove 95 is formed so as to be inclined in the circumferential direction with respect to the optical axis direction, and is implanted on the outer periphery of the fifth group sliding frame 140 integrated with the fifth lens group frame 6. The fifth group frame 205 is engaged. In addition, a first cam cylinder sliding piece 92 is implanted in an intermediate portion of the first cam cylinder 90 in the optical axis direction. The first cam cylinder sliding piece 92 is engaged with a first cam cylinder sliding piece guide groove 84 formed in the rectilinear cylinder 80.

  The first lens group frame 2 is fixed to the distal end portion of the first sliding frame 40.

  A focus sliding piece 201 is planted on the outer periphery of the second group sliding frame 110 integrated with the second lens group frame 3, and the focus sliding piece 201 is formed on the straight cylinder 80. The moving frame cam groove 81 is inserted and engaged with a focus sliding frame guide groove 72 formed in the focus cam cylinder 70.

  A third group piece 203 is planted on the outer periphery of the third lens group frame 4, and the third group piece 203 is inserted through the third group piece cam groove 93 of the first cam cylinder 90, and the The third group frame guide groove 83 is engaged.

  A fourth group frame 204 is planted on the outer periphery of the fourth group sliding frame 130 that supports the fourth lens group frame 5, and the fourth group frame 204 is a fourth group frame guide of the first cam cylinder 90. The groove 94 is inserted and fitted into a recess 80 </ b> A formed in the rectilinear cylinder 80. Further, a fixed frame portion 210 extending toward the eyepiece side is formed at the rear portion of the fourth group sliding frame 130. A vertical groove 211 extending in the optical axis direction is formed in the fixed frame portion 210.

  A fifth group frame 205 is planted on the outer periphery of the fifth lens group frame 6, and the fifth group frame 205 is inserted through the fifth group frame guide groove 95 of the first cam cylinder 90, and the fourth lens group. The vertical frame 211 of the fixed frame part 210 connected to the frame 5 is engaged.

(Zoom operation)
The zoom lens barrel 1 described above is fixed to the camera body by the mount 7, whereby the vertical groove cylinder 20 fixed to the mount 7 is fixed to the camera body. During the zoom operation, the zoom ring 10 is rotated with respect to the camera body.

-First lens group-
When the zoom ring 10 is rotated, the outer cylinder piece 31 planted in the outer cylinder 30 passes through the outer cylinder piece rectilinear groove 21 formed in the longitudinal groove cylinder 20, and the outer cylinder formed in the zoom ring 10. Since it is engaged with the cam groove 12, the outer cylinder 30 is extended toward the subject side in the optical axis direction without rotating.

  Further, the second cam cylinder interlocking piece 51 of the second cam cylinder 50 is inserted through the second cam cylinder piece insertion opening 22 of the longitudinal groove cylinder 20 and engaged with the second cam cylinder guide groove 11 of the zoom ring 10. Yes. For this reason, when the zoom ring 10 is rotated, the second cam cylinder 50 is extended toward the subject side in the optical axis direction in a state in which the movement in the optical axis direction is restricted with respect to the outer cylinder 30 and the rectilinear cylinder 80, and Rotate around the optical axis.

  The first group guide piece 41 of the first sliding frame 40 engages with the first sliding frame rectilinear groove 32 of the outer cylinder 30 and also engages with the first group cam groove 52 of the second cam cylinder 50. ing. As a result, when the outer cylinder 30 is extended in the optical axis direction without rotating, and the second cam cylinder 50 is extended in the optical axis direction while rotating, the first sliding frame 40 does not rotate and the outer cylinder 30 is rotated. Is extended toward the subject in the optical axis direction. As described above, the outer cylinder 30 is extended in the optical axis direction, and is further extended with respect to the outer cylinder 30, whereby the first lens group A is moved in the optical axis direction.

-Second lens group-
Since the rectilinear cylinder interlocking piece 33 planted on the outer peripheral surface of the rectilinear cylinder 80 is engaged with a hole formed in the protruding portion 30A of the outer cylinder 30, the outer cylinder 30 is rotated by the rotation of the zoom ring 10. When it is drawn out in the optical axis direction, the rectilinear cylinder 80 is also drawn out toward the subject side in the optical axis direction without rotating in conjunction with the outer cylinder 30.

  In addition, since the second sliding frame interlocking piece 61 of the second sliding frame 60 is engaged with the second sliding frame rectilinear groove 53 of the second cam cylinder 50, when the second cam cylinder 50 rotates, The rotation of the two cam cylinder 50 is transmitted to the second sliding frame 60. Further, the second group piece 62 of the second sliding frame 60 is inserted through the second group piece guide groove 82 of the rectilinear cylinder 80. For this reason, when the second sliding frame 60 rotates with respect to the rectilinear cylinder 80, the second sliding frame 60 moves to the eyepiece side in the optical axis direction.

  Further, since the focus interlocking frame 191 is engaged with the focus interlocking frame groove 73 of the focus cam cylinder 70, the rotation of the focus cam cylinder is restricted to a predetermined angle range except during focusing. Further, since the second group frame 62 is inserted through the second group focus groove 71 of the focus cam cylinder 70, the focus cam cylinder 70 is interlocked with the second sliding frame 60 and does not rotate in the optical axis direction. Moved to the eyepiece side. Since the focus sliding piece 201 implanted on the outer periphery of the second lens group frame 3 is engaged with the focus sliding piece guide groove 72 of the focus cam cylinder 70, the focus cam cylinder 70 is moved in the optical axis direction. When moved to the eyepiece side, the second lens group B is also moved in the optical axis direction.

-Third lens group-
Further, the second group piece 62 formed on the second sliding frame 60 is engaged with the second group rectilinear groove 91 of the first cam cylinder 90, and the first cam cylinder formed on the first cam cylinder 90. The sliding piece 92 is engaged with a first cam cylinder sliding piece guide groove 84 formed in the rectilinear cylinder 80. Therefore, when the second sliding frame 60 rotates, the rotation is transmitted to the first cam cylinder 90, and the first cam cylinder 90 moves to the subject side in the optical axis direction together with the rectilinear cylinder 80 while rotating.

  The third group frame 203 formed on the outer periphery of the third lens group frame 4 is inserted into the third group frame cam groove 93 of the first cam cylinder 90 and engages with the third group frame guide groove 83 of the rectilinear cylinder 80. ing. For this reason, when the rectilinear cylinder 80 and the first cam cylinder 90 move toward the subject in the optical axis direction, the third lens group C moves along with the rectilinear cylinder 80 and the first cam cylinder 90 toward the subject in the optical axis direction. . Further, when the first cam cylinder 90 rotates with respect to the rectilinear cylinder 80, the third lens group C moves in the optical axis direction with respect to the rectilinear cylinder 80 and the first cam cylinder 90. In this way, the third lens group C moves to the subject side in the optical axis direction.

-Fourth lens group-
The fourth group frame 204 formed on the outer periphery of the fourth group sliding frame 130 that supports the fourth lens group frame 5 is inserted through the fourth group frame guide groove 94 of the first cam cylinder 90, and It fits into the recess 80A. For this reason, when the rectilinear cylinder 80 and the first cam cylinder 90 move to the subject side in the optical axis direction, the fourth lens group D fixed to the fourth lens group frame 5 does not rotate to the subject side in the optical axis direction. Moving.

-Fifth lens group-
The fifth group frame 205 formed on the outer periphery of the fifth lens group frame 6 passes through the fifth group frame guide groove 95 of the first cam cylinder 90 and is fixed to the rear portion of the fourth group sliding frame 130. The vertical groove 211 of the frame part 210 is engaged. Therefore, when the first cam cylinder 90 rotates and moves in the optical axis direction, the fifth lens group E moves in the optical axis direction with respect to the first cam cylinder 90. In this way, the fifth lens group E moves in the optical axis direction.

  As described above, by rotating the zoom ring 10, the first to fifth lens groups A to E move independently in the optical axis direction.

(Focus operation)
During manual focusing, when the focus ring 100 is rotated, the rotation is transmitted to the focus gear ring 170 via the reduction gear of the focusing motor 180. Further, during autofocusing, when a control signal corresponding to the distance from the control means to the subject is input to the focusing motor 180, the focusing motor 180 moves the focus gearing 170 by an angle corresponding to the distance to the subject. Rotate.

  When the focus gear ring 170 is rotated, the focus interlocking frame 191 planted on the focus interlocking plate 190 is engaged with the focus interlocking frame groove 73 formed in the focus cam cylinder 70, so that the focus cam cylinder 70 is It is rotated. Further, the focus sliding piece 201 implanted on the outer periphery of the second lens group frame 3 is inserted into the focus sliding piece cam groove 81 of the rectilinear cylinder 80 and engaged with the focus sliding piece guide groove 72 of the focus cam cylinder 70. Match. Therefore, when the focus cam cylinder 70 rotates, the focus cam cylinder 70 is moved in the optical axis direction with the second group frame 62 as a base point, and the second lens group B is moved in the optical axis direction together with the second group frame 62. Moving. Thereby, the focus operation is performed.

  As described above, the zoom lens barrel 1 of the present embodiment includes the longitudinal groove cylinder 20, the zoom ring 10 disposed outside the longitudinal groove cylinder 20, and the outer cylinder disposed in order from the outside toward the inside. 30, a first sliding frame 40, a second cam cylinder 50, a second sliding frame 60, a focus cam cylinder 70, a rectilinear cylinder 80, and a lens feeding cylinder group including a first cam cylinder 90. . That is, the zoom lens barrel 1 of the present embodiment is composed of nine layers of cylinders, and can be made compact while covering a wide focal length.

  Further, according to the present embodiment, the outer cylinder 30 and the rectilinear cylinder 80 are connected by the rectilinear cylinder interlocking piece 33. Therefore, when the zoom ring 10 is rotated, the outer cylinder 30 is moved in the optical axis direction by the cam mechanism, but the linear cylinder 80 is also moved in the optical axis direction integrally with the outer cylinder 30. Then, when the first cam cylinder 90 is rotated with respect to the rectilinear cylinder 80, the third to fifth lens groups C to E move in the optical axis direction. As described above, the outer cylinder 30 and the rectilinear cylinder 80 are integrally moved in the optical axis direction, so that the lens is extended from the wide angle to the telephoto and the lens is retracted from the telephoto to the wide angle as compared with the conventional case. The difference in feeding accuracy can be reduced.

  In the present embodiment, the case of the lens barrel having the first to fifth lens groups has been described. However, the present invention is not limited to this, and can be applied to a lens barrel having four lens groups, for example. It is. In other words, the present invention can be applied to any zoom lens barrel having a plurality of lens groups.

  In the present embodiment, in the lens feeding cylinder group, the outer cylinder 30, the first sliding frame 40, the second cam cylinder 50, the second sliding frame 60, the focus cam cylinder 70, and the rectilinear cylinder from the outside toward the inside. 80, the first cam cylinder 90 is arranged in the order described above, but the present invention is not limited to this, and the order of the cylinders may be changed.

DESCRIPTION OF SYMBOLS 1 Zoom lens barrel 2 1st lens group frame 3 2nd lens group frame 4 3rd lens group frame 5 4th lens group frame 6 5th lens group frame 7 Mount 8 1st base cylinder 9 2nd base cylinder 10 Zoom ring 11 Second cam cylinder guide groove 12 Outer cylinder cam groove 20 Vertical groove cylinder 21 Outer cylinder piece straight advance groove 22 Second cam cylinder piece insertion opening 30 Outer cylinder 31 Outer cylinder piece 32 First sliding frame straight advance groove 33 Straight advance cylinder interlocking piece 40 First sliding frame 41 First group guide piece 42 First group sliding piece 50 Second cam cylinder 51 Second cam cylinder interlocking piece 52 First group cam groove 53 Second sliding frame rectilinear groove 60 Second sliding Frame 61 Second sliding frame interlocking frame 62 Second group top 70 Focus cam cylinder 71 Second group focus groove 72 Focus sliding top guide groove 73 Focus interlocking top groove 80 Straight cylinder 80A Recess 81 Focus sliding top cam groove 82 Second Group frame guide groove 83 3rd group frame guide groove 84 1st cam cylinder sliding frame guide groove 90 1st cam cylinder 91 2nd group rectilinear groove 92 1st cam cylinder sliding frame 93 3rd group frame cam groove 94 4th group frame guide groove 95 5th Group frame guide groove 100 Focus ring 110 Second group sliding frame 120 Third group sliding frame 130 Fourth group sliding frame 140 Fifth group sliding frame 150 Camera shake correction mechanism 160 Aperture mechanism 170 Focus gear ring 180 For focusing Motor 190 Focus interlocking plate 191 Focus interlocking frame 201 Focus sliding frame 203 Third group frame 204 Fourth group frame 205 Fifth group frame 210 Fixed frame 211 Vertical groove

Claims (5)

A zoom lens barrel having a plurality of lens groups,
A fixed cylinder;
A zoom ring disposed outside the fixed cylinder;
A lens feeding cylinder group that is disposed inside the fixed cylinder and moves the plurality of lens groups in the optical axis direction when the zoom ring is rotated;
The lens feeding cylinder group includes an outer cylinder, a first sliding frame, a second cam cylinder, a second sliding frame, a focus cam cylinder, a rectilinear cylinder, which are arranged from the outside toward the inside . a first cam barrel, only including,
The zoom lens barrel has first to fifth lens groups,
The first cam cylinder is restrained from moving in the optical axis direction with respect to the rectilinear cylinder,
When the zoom ring is rotated,
When the zoom ring is rotated with respect to the fixed cylinder, the rectilinear cylinder moves in the optical axis direction together with the outer cylinder without rotating,
The rotation of the zoom ring is transmitted to the first cam cylinder, and the first cam cylinder moves in the optical axis direction together with the outer cylinder and the rectilinear cylinder while rotating,
The third to fifth lens groups move relative to the rectilinear cylinder in the optical axis direction by rotating the first cam cylinder with respect to the rectilinear cylinder,
Accordingly, the zoom lens barrel is characterized in that the third to fifth lens groups zoom in the optical axis direction . Before Symbol outer cylinder and the and the rectilinear barrel is connected by a straight barrel interlocking pieces, the zoom lens barrel according to claim 1, characterized in that. The second sliding frame rotates in the circumferential direction together with the second cam cylinder, and transmits the rotation to the first cam cylinder, whereby rotation of the zoom ring causes the second cam cylinder and the second cam cylinder to rotate. via two sliding frame, the first being transmitted to the cam barrel, a zoom lens barrel according to claim 1 or 2, characterized in that. When the zoom ring is rotated,
The second sliding frame moves in the optical axis direction by rotating with respect to the rectilinear cylinder,
The focus cam cylinder moves in the optical axis direction together with the second sliding frame;
The zoom lens barrel according to any one of claims 1 to 3, wherein the second lens group zooms together with the focus cam barrel in the optical axis direction. The first lens group is fixed to the first sliding frame,
When the zoom ring is rotated,
The rotation of the zoom ring is transmitted to the second cam cylinder, the outer cylinder moves in the optical axis direction without rotating with respect to the fixed cylinder, and the second cam cylinder further moves relative to the outer cylinder. by rotating, the first sliding frame is moved in the optical axis direction, thereby, the first lens group is moved for zooming in the optical axis direction, claim 1, wherein 4 of the 1 Zoom lens barrel described in the section.

Images