JP2013037176A - Lens barrel and method for controlling the same, and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a length between a guide shaft and a sliding portion of a holding frame to be shortened and to downsize a lens barrel.SOLUTION: A prism holding member 31 has sliding parts 31a, 31b engaging with a guide shaft 86 in a slidable manner, and a four-group bottom board 41 has sliding parts 41a, 41b engaging with the guide shaft 86 in a slidable manner. A length A between the sliding parts 31a, 31b and a length B between the sliding parts 41a, 41b in an optical axis Y direction are shorter than the maximum movable distance G in which the prism holding member 31 and the four-group bottom board 41 can move. When shifting from a SINK position to a WIDE position, a control part 100 starts to drive a stepping motor 43 after a prescribed time T1 has elapsed from the start of driving of a prism motor 32. Thereby, the prism holding member 31 is driven precedently and the four-group bottom board 41 is driven with a delay of a prescribed time T1. The moving speed of the four-group bottom board 41 is controlled to be equal to or less than that of the prism holding member 31.

Description

  The present invention relates to a lens barrel or the like in which a plurality of holding frames that hold an optical system are slidably supported on a guide shaft that extends in the optical axis direction.

  Conventionally, in some lens barrels, a plurality of holding frames that hold an optical system are slidably supported on a guide shaft that extends in the optical axis direction. In a zoom lens barrel provided in an imaging apparatus such as a silver salt camera, a digital camera, or a digital video camera, the lens moves to change the photographing magnification.

  In a lens barrel of a conventional imaging apparatus, when the same guide bar (guide shaft) is shared and a plurality of lens groups (or holding frames) are slidably held between a retracted position and a photographing position, Divide into areas. In addition, a plurality of lens groups are prevented from colliding by preventing the moving regions of the respective lens groups from overlapping.

  Further, in Patent Document 1, the same guide is provided so that two fitting portions of the sleeve-shaped portion with respect to the guide shaft provided in each of the two moving rings (holding frames) are sandwiched between the mating fitting portions. A technique for fitting the shaft is disclosed. The two fitting parts of the two groups of sleeve-shaped parts are alternately inserted into the guide shaft, and the length of the sleeve-shaped part connecting the two fitting parts is made sufficiently long to fit the two groups. The parts did not hit each other. That is, the length is configured such that the group on the object side can move the entire movable region while the group on the image side remains stopped at the end on the image side.

Japanese Patent No. 2776160

  However, the length of the sleeve-shaped portion that connects the two sliding portions that engage with the guide shaft to slidably support the holding frame that holds the lens group is long. The longer it is, the longer. If the sleeve-shaped part is long, the entire lens barrel is enlarged.

  In particular, in a lens barrel using an optical system in which the optical axis is bent rather than a straight line using a reflective optical system, a bent optical system, etc., the lens group arranged on the imaging surface side is retracted from the bent point. Need to secure space. That is, in a lens barrel that retracts the lens group closer to the subject than the bending optical system, the lens group closer to the image plane than the bending optical system is provided with a space for retracting the lens group and cam cylinder on the subject side. The amount of movement increases. Therefore, if the length of the sleeve-shaped portion corresponding to the amount of movement is secured and the fitting portions are alternately inserted, the length of the sleeve-shaped portion becomes too long and the lens barrel becomes large.

  In addition, when three or more lens groups are slidably supported on the guide shaft, and two sliding portions provided in one lens group are arranged in the three groups, the rotation around the guide shaft You have to divide the space into three and make three sleeves. Therefore, there exists a problem that the intensity | strength of each sleeve shape part falls compared with the time of 2 divisions.

  On the other hand, the sliding portions of the two lens groups are alternately sandwiched, and another third lens group is disposed on either side in the guide axis direction so as not to be sandwiched by the sliding portions of the other groups. It is possible. However, in such a case, there is a problem that the length of the sleeve-shaped portion of the third lens group cannot be increased unless the lens barrel is enlarged.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to reduce the length of the sliding portion of the holding frame relative to the guide shaft and to reduce the size of the lens barrel. It is in.

  In order to achieve the above object, the present invention includes a guide shaft extending in the direction of the optical axis, and a first sliding portion and a second sliding portion that are slidably engaged with the guide shaft, respectively. A first holding frame that holds the first optical system, and a third sliding portion and a fourth sliding portion that are slidably engaged with the guide shaft, respectively. A second holding frame that is disposed closer to the imaging surface than the holding frame and holds the second optical system, and a first driving unit that drives the first holding frame to move along the guide shaft. And second driving means for driving the second holding frame to move along the guide shaft, and control means for controlling the first driving means and the second driving means, The sliding portions are arranged in the order of the fourth sliding portion, the second sliding portion, the third sliding portion, and the first sliding portion from the side close to the imaging surface. Engaging with the guide shaft at a position, and the distance between the opposite end surfaces of the first sliding portion and the second sliding portion in a direction parallel to the guide shaft, and parallel to the guide shaft The distances between the end surfaces of the third sliding portion and the fourth sliding portion that are not opposite to each other in the direction are shorter than the maximum movable distance of the first holding frame, and the control means 1. When the second holding frame is moved between the retracted position and a predetermined photographing position, the third sliding part moves the second sliding part or the first sliding partway through the movement. The driving start timing and the moving speed of each of the first and second holding frames by the first and second driving means are controlled so as not to collide with any of the moving parts.

  According to the present invention, the lens barrel can be reduced in size by making it possible to shorten the length between the sliding portions of the holding frame and the guide shaft.

1 is a front view showing a state where a lens barrel according to an embodiment of the present invention is in a WIDE position, and a cross-sectional view passing through an optical axis thereof. It is sectional drawing which passes along the guide shaft in the state which has a lens-barrel in a WIDE position. It is a perspective view for demonstrating the drive mechanism of a 4th lens group. It is a perspective view of an aperture / shutter. It is a disassembled perspective view of a diaphragm and shutter. It is a front view which shows the state which has a lens-barrel in a TELE position, and sectional drawing which passes along the optical axis. It is sectional drawing which passes along the guide shaft in the state which has a lens-barrel in a TELE position. It is a front view showing a state where the lens barrel is in the SINK position, and a cross-sectional view passing through the optical axis. It is sectional drawing which passes along the guide shaft in the state which has a lens-barrel in a SINK position. It is an inner peripheral side expanded view of a fixed cylinder. It is the perspective view which decomposed | disassembled a cam cylinder and a part of mechanism which drives a prism. It is a top view which shows a holding member and a part of prism drive part which hold | maintain a prism. It is a figure for demonstrating the phase relationship of a prism carrier and a prism delay gear, and the charge amount of a torsion spring. It is sectional drawing which shows the relationship between a photo interrupter and a light-shielding plate. It is sectional drawing of the principal part cut | disconnected by the plane containing a guide shaft in the state which the prism holding member of the lens-barrel is moving to the imaging | photography position direction from a SINK position (storage position). It is a top view which shows a cam cylinder, a zoom motor, and a part of zoom gear train. It is a block diagram of the control mechanism of a digital camera. It is a flowchart which shows extension operation | movement of a lens-barrel. It is a flowchart which shows the retracting operation | movement of a lens-barrel.

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

  FIGS. 1A and 1B are a front view of a main part showing a state in which a lens barrel according to an embodiment of the present invention is in a WIDE position (wide-angle position), and a cross-sectional view of a main part thereof. . This lens barrel is provided in a digital camera which is an example of an imaging apparatus. FIG. 1A is viewed from the subject side in the optical axis X direction of the first lens group 10.

  FIG. 2 is a cross-sectional view of the main part of the lens barrel in a WIDE position (wide angle position) cut by a plane including a guide shaft. The lens barrel is configured as a zoom lens barrel in which the lens group moves in the optical axis direction to change the photographing magnification. Here, each lens group of the lens barrel moves between a retracted position (SINK position) and a photographable position (position from the WIDE position to the TELE position (telephoto position)).

  As shown in FIGS. 1 and 2, the digital camera includes a first lens group 10, a second lens group 20, a third lens group 30 including a prism 9, a fourth lens group 40, as a zoom lens barrel. A fifth lens group 50 and a sixth lens group 60 are provided. Furthermore, the optical filter 7, the image pickup device 8, the fixed cylinder 79, the cam cylinder 77, the rectilinear guide cylinder 78, the lens barrel base plate 71, the guide shaft 86 (FIG. 2), and the guide shaft 87 (FIG. 2) are provided.

  The first lens group 10 is constituted by these parts by holding the first group lens 1 in the first group barrel 11. The second lens group 20 is constituted by these parts by holding the second group lens 2 in the second group lens barrel 21. The first group barrel 11 and the second group barrel 21 are both held movably along the optical axis X by a cam barrel 77 and a rectilinear guide barrel 78. The light beams incident from the first group lens 1 and the second group lens 2 are bent by the prism 9 in the direction of the optical axis Y that intersects the optical axis X of the first group lens 1 and the second group lens 2 at an angle of about 90 °. Thus, the light is guided to the imaging plane of the image sensor 8. Between the prism 9 and the image sensor 8, the third group lens 3, the diaphragm / shutter 90 for controlling the amount of light to be photographed, the fourth group lens 4, and the fifth group lens 5, 6 are arranged in order from the prism 9 to the image sensor 8. The group lens 6 and the optical filter 7 are arranged along the optical axis Y.

  Both guide shafts 86 and 87 extend parallel to the direction of the optical axis Y. The third group lens 3 and the prism 9 correspond to the first optical system, and the fourth group lens 4 corresponds to the second optical system.

  As shown in FIG. 2, the prism 9 is held by a prism holding member 31 that is a first holding frame. The prism holding member 31 is provided with two sleeve-shaped sliding portions 31a and 31b on the guide shaft 86 side. It is done. The sliding portion 31a as the first sliding portion and the sliding portion 31b as the second sliding portion are slidably engaged with the guide shaft 86, respectively. The length between the two sliding portions 31a and 31b in the optical axis Y direction (the distance between the end faces not facing each other) is A. The prism holding member 31 has one sliding portion 31f on the guide shaft 87 side. The prism holding member 31 is pivotally supported by the guide shaft 86 and the guide shaft 87 so as to be movable along the optical axis Y by the action of the sliding portions 31a, 31b, and 31f.

  The third group lens 3 is integrated with the prism holding member 31 together with the prism 9 and is held so as to be movable along the optical axis Y. The third lens group 30 is configured by all these components. In the WIDE state, the prism holding member 31 abuts against the stopper portion 71c of the barrel base plate 71 at a position extended to the most object side in the optical axis Y direction (the side away from the imaging surface in the optical axis Y direction).

  The diaphragm / shutter 90 is fixed to the shutter base plate 92, and the fourth group base plate 41 and the shutter base plate 92, which are the second holding frame, are joined together by screws or the like to be integrated. The fourth group lens 4 is held by a fourth group lens holder 42 which is a member for holding the fourth group. The fourth group lens holder 42 is supported in the fourth group base plate 41 so as to be movable by a minute distance in a plane perpendicular to the optical axis Y, and constitutes the fourth lens group 40 as a whole unit. doing. The fourth group base plate 41 is disposed closer to the imaging surface than the prism holding member 31.

  The fourth lens group 40 moves back and forth along the optical axis Y by driving a stepping motor 43 (FIG. 1A) which is the second driving means, thereby performing a zooming operation. The fourth group lens holder 42 is controlled to move in a plane perpendicular to the optical axis Y by an actuator (not shown) and position detection means (not shown), so that an optical image stabilization operation is performed. Here, the diaphragm and the shutter are used together, and the optical image stabilization is performed in the fourth lens group 40. However, the configuration is not necessarily limited to this.

  Similar to the prism holding member 31, the fourth group base plate 41 has two sleeve-shaped sliding portions 41a and 41b on the guide shaft 86 side. Both the sliding portion 41 a that is the third sliding portion and the sliding portion 41 b that is the fourth sliding portion are slidably engaged with the guide shaft 86. The length between the two sliding portions 41a and 41b in the optical axis Y direction (the distance between the end faces that do not face each other) is B. The length B is the same as or substantially equal to the length A. Similar to the prism holding member 31, the fourth group base plate 41 has one sliding portion 41c on the guide shaft 87 side.

  The sliding portion 41a is always in a position sandwiched between the sliding portion 31a and the sliding portion 31b of the prism holding member 31 in the optical axis Y direction, and is a so-called misplacement. That is, the guide shaft 86 is engaged in the order of the sliding portion 41b, the sliding portion 31b, the sliding portion 41a, and the sliding portion 31a from the side close to the imaging surface in the optical axis Y direction. In the WIDE state of FIG. 2, the distance between the end surfaces of the sliding portion 31 a and the sliding portion 41 a opposite to the imaging surface is E, and this distance E is smaller than the length A.

  As shown in FIGS. 1 and 2, the fifth group lens 5 is held by a fifth group lens holder 51, and these parts constitute a fifth lens group 50. As shown in FIG. 2, the fifth lens group holder 51 is provided with two sleeve-shaped sliding portions 51d and 51e on the guide shaft 87 side, and one sliding portion 51c on the guide shaft 86 side. . The thickness of the portion where the sliding portion 51c is present in the optical axis Y direction is C. By the action of these sliding portions, the fifth group lens holder 51 is supported by guide shafts 86 and 87 so as to be movable along the optical axis Y direction. A light shielding plate 51 a is formed integrally with the fifth group lens holder 51, and the light shielding plate 51 a is for shielding the photo interrupter 49.

  The sixth group lens 6 is held by a sixth group lens holder 61, and the sixth lens group 60 is constituted by these components. The sixth group lens holder 61 is provided with two sleeve-shaped sliding portions 61a and 61b on the guide shaft 86 side, and the length between the two sliding portions 61a and 61b (the distance between the end faces that do not face each other) is D. It is. The sixth group lens holder 61 is provided with one sliding portion 61d on the guide shaft 87 side. By the action of these sliding portions, the sixth group lens holder 61 is supported by guide shafts 86 and 87 so as to be movable along the optical axis Y direction. By driving the stepping motor 62, the screw 62a is rotated, and the sixth lens group 60 is moved forward and backward along the optical axis Y, so that a zooming operation and a focusing operation are performed (FIG. 1A).

  The optical filter 7 has a low-pass filter function for cutting light with a high spatial frequency and a function for cutting infrared light. The lens barrel base plate 71 holds and fixes the two guide shafts 86 and 87 and the optical filter 7. As shown in FIG. 2, one side of the guide shafts 86 and 87 extends to a position overlapping the second group lens barrel 21 (FIG. 1B) in the cam barrel 77, and the opposite side holds the optical filter 7. Extends to position. The lens barrel base plate 71 holds a fixed cylinder 79 on the subject side in the direction of the optical axis X, and holds a gear train group which is driving equipment described later. The image sensor 8 is bonded and fixed to the sensor plate 81 (FIG. 1), and the sensor plate 81 is fixed to the lens barrel base plate 71.

  FIG. 3 is a perspective view for explaining a drive mechanism of the fourth lens group 40. As shown in FIG. 3, a gear 43 a is attached to the output shaft of the stepping motor 43. The gear 43a meshes with the gear 44a attached integrally with the screw 44b to rotate the screw 44b at a higher speed. Reference numeral 47 denotes a leaf spring that urges the screw 44b. A rack 46 attached to the fourth group base plate 41 is engaged with the screw 44b. The fourth group base plate 41 is movably supported along the optical axis Y by two guide shafts 86 and 87 parallel to the optical axis Y.

  Accordingly, the rotation of the screw 44b causes the rack 46 to move under the force in the optical axis Y direction, and the fourth lens including the fourth group base plate 41 and the fourth group lens holder 42 and the fourth group lens 4 together with the rack 46. The entire group 40 moves in the optical axis Y direction. Further, a fourth group cover 48 that covers the fourth group lens 4 and the fourth group lens holder 42 is provided. A photo interrupter 49 is attached and fixed to the fourth group cover 48. The fourth group cover 48 is fixedly attached to the fourth group base plate 41 with the fourth group lens holder 42 sandwiched therebetween, and both the fourth group cover 48 and the photo interrupter 49 move integrally with the fourth group base plate 41 in the optical axis Y direction. .

  FIG. 14 is a cross-sectional view showing the relationship between the photo interrupter 49 and the light shielding plate 51a. When the distance between the fourth lens group 40 and the fifth lens group 50 is reduced to a certain distance, as shown in FIG. 14A, the light of the LED in the photo interrupter 49 is sent to the light receiving sensor 49a by the light shielding plate 51a. Shaded to prevent entry. As a result, the photo interrupter 49 is configured to detect that the electrical output of the light receiving sensor 49a in the photo interrupter 49 is switched.

  As shown in FIG. 2, in the fifth group lens holder 51, an arm portion 51 b extends from a sleeve portion including sliding portions 51 d and 51 e that are supported by and slide on the guide shaft 87, and is attached to the lens barrel base plate 71. The arm portion 51b comes into contact with the formed stopper portion 71b. The tension spring 53 pulls between the lens barrel base plate 71 and the fifth group lens holder 51, and the fifth group lens holder 51 is offset by the tension spring 53 toward the side away from the imaging surface in the optical axis Y direction. Yes. At the time of photographing, the fifth group lens holder 51 is fixed by being shifted to the position shown in FIGS. 1 and 2 with the arm portion 51b abutting against the stopper portion 71b.

  The stepping motor 62 shown in FIG. 1A and the screw 62a integrally formed with the stepping motor 62 rotate integrally. A sixth group rack 63 attached to the sixth group lens holder 61 is engaged with the screw 62a. Accordingly, when the stepping motor 62 rotates, the sixth lens group 60 moves in the direction of the optical axis Y in the sixth lens group 60 in the same manner as the fourth lens group 40, so that the entire sixth lens group 60 moves along the optical axis Y. Move in the direction. A light shielding plate 61c is integrally attached to the sixth group lens holder 61 so that the switching position can be detected by the positional relationship with the photo interrupter 88 (FIG. 2).

  The length of the sleeve portion connecting the sliding portion 61a and the sliding portion 61b of the sixth group lens holder 61 that holds the sixth group lens 6 (distance between the end surfaces of the sliding portions 61a and 61b not facing each other) is shown in FIG. It is shown in In order to earn the length D, the sliding portions 61a and 61b are engaged and supported by a guide shaft 86 on the opposite side to the guide shaft 87 with which the sliding portions 51d and 51e of the fifth group base plate 51 are engaged. In this way, in order to make the length D of the six groups of sleeve portions as long as possible, the sleeve-shaped portion is provided on the side of the guide shaft 86 opposite to the one received by the adjacent five-group lens holder 51 in terms of arrangement. It is good to arrange. As a result, the guide shaft 86 on the same side as the sleeve of the fourth group base plate 41 is used as a shaft on which the sliding portions 61a and 61b of the sleeve-shaped portion are arranged.

  Next, the driving of the prism holding member 31 that moves the third lens group 30 including the prism 9 and the third group lens 3 will be described with reference to FIGS.

  FIG. 11 is a perspective view showing a part of a mechanism for driving the prism holding member 31. FIG. 12 is a plan view for explaining the prism holding member 31 that holds the prism 9 and the third group lens 3 and the driving unit thereof.

  A worm gear 32a (FIG. 12) is press-fitted into the motor shaft of the prism motor 32 which is the first driving means. The worm gear 32 a meshes with the inclined gear of the gear 33, the spur gear 33 b of the gear 33 meshes with the spur gear 34 a of the gear 34, and the spur gear 34 b of the gear 34 meshes with the prism 35.

  FIG. 13 is a diagram for explaining the phase relationship between the prism gear 35 and the prism delay gear 37 and the charge amount of the torsion spring 36.

  As shown in FIG. 11, a prism gear 35, a torsion spring 36, and a prism delay gear 37 are coaxially arranged in order from the subject side, and the prism delay gear 37 is rotatably supported on a shaft 35e of the prism gear 35. The The prism drive gear 38 meshes with the gear portion of the prism delay gear 37. As shown in FIG. 13, the prism gear 35 and the prism delay gear 37 are each provided with a latching portion 35b and a latching portion 37b extending in directions opposite to each other. It is arranged radially inward from 35b.

  As shown in FIG. 13, the torsion spring 36 includes a coil portion at the center and two arm portions 36a and 36b extending radially outward from both axial ends of the coil portion. The two arm portions 36 a and 36 b are hooked on the hook portions 37 b and 35 b of the prism delay gear 37 and the prism gear 35. When the torsion spring 36 is assembled, the two arm portions 36a and 36b are hooked on the hook portion 37b in a state where the hook portion 37b and the hook portion 35b are arranged in the same phase (see FIG. 13B). Stopped and precharged.

  In this state, when the prism gear 35 is rotated by freely rotating the prism delay gear 37, the prism gear 35, the prism delay gear 37, and the torsion spring 36 rotate integrally. On the other hand, when the prism gear 35 is rotated in a state where the rotation of the prism delay gear 37 is restricted, only the prism gear 35 is rotated while the torsion spring 36 is overcharged.

  As shown in FIG. 12, a rack gear 31c is formed in a range exceeding between the sliding portion 31a and the sliding portion 31b of the prism holding member 31 (see also FIG. 2), and this rack gear 31c is connected to the prism driving gear 38. Meshed. Further, the rack gear 31c is formed so as to extend longer than the length connecting the sliding portion 31a and the sliding portion 31b to the vicinity of the stopper portion 31g on the extension of the sleeve shape. For this reason, when the prism drive gear 38 rotates, the prism holding member 31 moves forward and backward along the optical axis Y together with the prism 9. A rib 71 a is formed integrally with the lens barrel base plate 71. The rib 71a is located between the back surface 31h and the guide shaft 86 with a gap between the back surface 31h opposite to the teeth of the rack gear 31c.

  Here, if the prism holding member 31 can move in the optical axis Y direction, the torsion spring 36 and the prism delay gear 37 rotate together with the prism gear 35 to advance and retract the prism holding member 31 in the optical axis Y direction. On the other hand, if the movement of the prism holding member 31 in the optical axis Y direction is restricted by hitting the stopper portion 71c of the barrel base plate 71 as in the WIDE state shown in FIG. 2, the prism delay gear 37 cannot be rotated. Therefore, the torsion spring 36 absorbs the rotation of the prism gear 35 while overcharging. Then, as shown in FIGS. 13A and 13C, the amount of rotation for the overcharge is also restricted by the collision between the stopper 35c of the prism gear 35 and the stopper 37c or the stopper 37d of the prism delay gear 37.

  In the shooting state such as the WIDE state, the state shown in FIG. In the SINK (collapsed) state, which will be described later, when the stopper portion 31g hits the stopper portion 71d (FIGS. 2 and 9) on the retracting side of the lens barrel base plate 71 on the imaging surface side in the optical axis Y direction, FIG. It will be in the state of (c). From the above description, the prism 9 can be driven by the prism motor 32.

  As shown in FIG. 12, a plurality of blades are provided as a pulse plate 32b integrally with the first stage worm gear 32a press-fitted into the prism motor 32. When the pulse plate 32b rotates, the blades of the pulse plate 32b may or may not shield the photo interrupter 39, thereby switching the electrical signal as in the mechanism of the photo interrupter 49 described above (FIG. 14). It can be detected. By detecting and counting this signal, it is possible to know how much the prism motor 32 has been rotated. The amount of movement of the prism 9 when the torsion spring 36 is not overcharged can be estimated from the rotation amount and the gear train reduction ratio.

  As shown in FIG. 2, light blocking plates 31d and 31e are attached to the prism holding member 31 to detect the switching positions of signals blocked by the photo interrupters 84 and 85 (see also FIG. 12). Can do. In the state of FIG. 2, since the prism holding member 31 abuts against the stopper portion 71c and the photo interrupter 84 is simultaneously shielded by the light shielding plate 31d, it can be detected that the prism holding member 31 is in the photographing position. The switching position where the photo interrupter 84 is shielded from light is used as a reference reset position, which is used as a reference for counting pulses detected by the photo interrupter 39.

  Next, the fixed cylinder 79, the cam cylinder 77, and the rectilinear guide cylinder 78 will be described.

  FIG. 10 is a development view of the inner circumference side of the fixed cylinder 79. FIG. 16 is a back view of the main part of the cam cylinder drive mechanism as seen from the image plane side in the optical axis X direction.

  As shown in FIG. 10, a plurality of cam grooves 79 a are formed in the inner peripheral portion of the fixed cylinder 79 at substantially equal intervals in the circumferential direction in which cam pins provided on the outer peripheral portion of the cam cylinder 77 are cam-engaged. Further, a notch 79b is formed at the rear end portion of the fixed cylinder 79, through which the prism holding member 31 that holds the prism 9 passes when moving forward and backward in the optical axis Y direction.

  The rectilinear guide cylinder 78 is disposed on the inner peripheral side of the cam cylinder 77 (FIG. 1B), can move in the direction of the optical axis X integrally with the cam cylinder 77, and cannot rotate due to the relationship with the fixed cylinder 79. It is possible. A first group cam groove and a second group cam groove (not shown) are formed in the inner peripheral portion of the cam cylinder 77. The first lens group 10 is disposed between the cam cylinder 77 and the rectilinear guide cylinder 78, and a cam pin 11a (FIG. 1B) provided on the outer peripheral portion of the first group lens barrel 11 of the first lens group 10. The cam cylinder 77 is cam-engaged with the first group cam groove.

  As shown in FIG. 16, a rectilinear groove 78c extending along the optical axis X direction is formed in the outer peripheral portion of the rectilinear guide tube 78, and the inner peripheral portion of the first group barrel 11 is formed in the rectilinear groove 78c. By engaging the convex portion 11b provided on the first lens barrel 11, the movement of the first group barrel 11 in the rotational direction is restricted.

  As shown in FIG. 16, the second lens group 20 is arranged on the inner peripheral side of the rectilinear guide tube 78, and a plurality of second lens groups 20 are arranged in the second group lens barrel 21 as in the first lens group 10. The provided cam pin 21 a is cam-engaged with the second group cam groove of the cam cylinder 77. Further, the straight guide tube 78 is provided with a through groove 78d in the optical axis X direction, and the engaging portion 21b provided at the base of the cam pin 21a of the second group barrel 21 is engaged with the through groove 78d. As a result, the movement of the second group barrel 21 in the rotational direction is restricted.

  When the cam barrel 77 is rotated, the convex portion 11b of the first group barrel 11 is moved straightly by the straight groove 78c of the straight guide barrel 78 by the cam action of the first group cam groove of the cam barrel 77 and the cam pin 11a of the first group barrel 11. Is slid in the direction of the optical axis X. While this sliding occurs, the first group barrel 11 advances and retreats along the optical axis X with respect to the cam barrel 77. Therefore, when the cam cylinder 77 advances and retreats along the optical axis X with respect to the fixed cylinder 79, the first group lens barrel 11 advances and retreats along the optical axis X with respect to the cam cylinder 77, and the first group lens 1 moves to the SINK position. Move between shooting positions. The second group lens 2 is also moved between the SINK position and the photographing position by the same operation.

  A gear portion 77 a that meshes with the drive gear 76 shown in FIG. 16 is formed on the outer peripheral portion of the cam barrel 77, and the drive force is transmitted from the drive gear 76, so that the cam barrel 77 is rotationally driven. At this time, the cam cylinder 77 advances and retreats along the optical axis X by the cam action of the cam groove 79 a of the fixed cylinder 79 and the cam pin of the cam cylinder 77.

  Next, the drive mechanism of the cam cylinder 77 will be described. As shown in FIG. 16, the zoom motor 72 is a drive source for moving the first lens group 10 and the second lens group 20. The zoom motor 72 is disposed with the motor axis line in the optical axis Y direction. A worm gear 72 a is press-fitted into the motor shaft of the zoom motor 72.

  The gear 73 meshes with the worm gear 72 a via the inclined gear, and the spur gear meshes with the gear 74. Another gear in the gear 74 meshes with the drive gear 76 via the idler gear 75, and the drive gear 76 meshes with the gear portion 77 a of the cam cylinder 77.

  As described above, when the gear train described above drives and rotates the zoom motor 72, the cam cylinder 77 can be rotationally driven by transmitting the driving force to the cam cylinder 77.

  When the zoom motor 72 is rotated in the extending direction of the cam cylinder 77, the cam pin of the cam cylinder 77 moves the cam groove 79a of the fixed cylinder 79 to the right in FIG. 10, and the cam cylinder 77 is extended in the optical axis X direction. Thus, a space for moving the prism holding member 31 to the photographing position side is formed.

  As shown in FIG. 16, a plurality of blades are provided as a pulse plate 72b integrally with a first stage worm gear 72a press-fitted into a zoom motor 72 of a zoom gear train. When the pulse plate 72b rotates, the blades of the pulse plate 72b may or may not shield the photo interrupter 83, so that the switching of electrical signals can be detected in the same manner as the mechanism of the photo interrupter 49 described above. The rotation amount of the zoom motor 72 can be measured by counting the number of times the blades of the pulse plate 72b have passed, and the rotation amount of the cam cylinder 77 is detected from the result and the reduction ratio of the gear train described above. Can do.

  The straight guide tube 78 is formed with a light shielding plate 78a. The photo interrupter 82 is shielded from light by the light shielding plate 78a when it is extended to the subject side in the optical axis X direction together with the linear guide cylinder 78 and the cam cylinder 77, so that it can be detected that the photo interrupter 82 has been extended to the photographing position. Similarly to the reset of the prism holding member 31, the switching position where the photo interrupter 82 is shielded from light is used as a reference reset position as a reference for counting pulses detected by the photo interrupter 83.

  4 is a perspective view of the diaphragm / shutter 90. FIG. 5 is an exploded perspective view of the diaphragm / shutter 90. As shown in FIG.

  As shown in FIGS. 4 and 5, the diaphragm / shutter 90 is provided with a plurality of blades 94, 95 that open and close the opening 96 a between the shutter base plate 92 and the cover 96 disposed on the fourth group base plate 41 side. ing. The cover 96 and the shutter base plate 92 are fixed to each other by screws 97.

  The stepping motor 91 is an actuator for opening and closing the plurality of blades 94, 95 of the diaphragm / shutter 90. The motor shaft of the stepping motor 91 has a lever 93 extending in a direction perpendicular to the axis of the motor shaft. It is attached. Shafts 93a and 93b are projected from both ends of the lever 93 in the extending direction.

  The shaft 93a is inserted into an arcuate hole 92a formed in the shutter base plate 92, an elongated hole 94a formed in the blade 94, and an arcuate hole 96a formed in the cover 96, and moves along the arcuate holes 92a and 96a. It is possible. The shaft 93b is inserted into an arcuate hole 92b formed in the shutter base plate 92, an elongated hole 95a formed in the blade 95, and an arcuate hole 96b formed in the cover 96, along the arcuate holes 92b and 96b. It is possible to move.

  When the lever 93 is rotated by driving the stepping motor 91, the blades 94 and 95 are rotated in opposite directions, and the blades 94 and 95 are reciprocated to open and close the opening 96a. Thereby, a diaphragm function for controlling the amount of photographing light is realized by adjusting a gap between the blades 94 and 95 that open and close the opening 96a, and the blades 94 and 95 are moved from the open state to the closed state. A shutter function is realized.

  FIGS. 6A and 6B are views showing a state in which the lens barrel is in the TELE position (telephoto position), and are a front view and a main part cross-sectional view of the main part viewed from the optical axis direction of the first lens group. It is. FIG. 7 is a view showing a state in which the lens barrel is in the TELE position (telephoto position), and is a cross-sectional view of the main part cut along a plane including the guide shafts 86 and 87.

  As shown in FIGS. 6 and 7, when the lens barrel is in the TELE position, the first lens group 10 moves forward along the optical axis X in the direction of the subject and the second lens group 20 moves along the optical axis. Retreats along the X direction and stops at a position approaching the prism 9. The fourth lens group 40 is moved toward the subject direction (the side away from the imaging surface) of the prism 9 along the optical axis Y direction by driving the stepping motor 43, and at a position close to the third lens group 30. Stop.

  Here, since the fifth lens group 50 has abutted against the stopper portion 71b from the WIDE position (wide angle position), it is fixed without moving. Therefore, the fourth lens group 40 moves away from the fifth lens group 50 by driving the stepping motor 43. Therefore, the photo interrupter 49 also moves with the fourth lens group 40. The light shielding plate 51a that has shielded the photo interrupter 49 does not move. Therefore, when the fourth lens group 40 starts to move from the WIDE position to the TELE position direction, the light shielding of the light receiving sensor 49a is released as shown in FIG.

  The timing of switching the light shielding is detected from the output of the photo interrupter 49, and the pulse at that time becomes the reset position for detecting the position of the fourth lens group 40 and counting the pulses. The section from the reset position to the TELE position is the section shown in FIG. 14C and is not shielded. The sixth lens group 60 is moved toward the image plane side of the image sensor 8 along the optical axis Y direction by driving of the stepping motor 62 and stops at a position close to the optical filter 7.

  FIGS. 8A and 8B are views showing a state in which the lens barrel is in the SINK position (storage position). FIG. 8B is a front view of the first lens group 10 viewed from the optical axis direction and a cross-sectional view of the main part thereof. is there. FIG. 9 is a view showing a state in which the lens barrel is in the SINK position (storage position), and is a cross-sectional view of a main part cut along a plane including the guide shafts 86 and 87.

  As shown in FIGS. 8 and 9, when the lens barrel is in the SINK position, the third lens group 30, the fourth lens group 40, the fifth lens group 50, and the sixth lens group 60 including the prism 9 are: It moves to the image sensor 8 side so as not to interfere with each other along the optical axis Y. Thus, a storage space is formed on the image plane side (opposite the subject side) in the first optical axis X direction of the second lens group 20 and the first lens group 10, and the first lens group 10 and the second lens group 20. Is stored there. When the lens barrel is in the SINK position, the cam pin of the cam barrel 77 is disposed at a position 79 c shown in FIG. 10 within the cam groove 79 a of the fixed barrel 79.

  At the SINK position, the fifth lens group 50 is pushed by the fourth lens group 40 toward the imaging surface in the optical axis Y direction and retracted to the SINK position. In the section from the WIDE position (wide angle position) to the SINK position (storage position), the photo interrupter 49 remains shielded by the light shielding plate 51a.

  Since the sixth lens group 60 is retracted to the SINK position and the photo interrupter 88 is shielded from light by the light shielding plate 61c of the sixth group lens holder 61, the switching signal can be detected from the output of the photo interrupter 88, and the SINK position Can be determined.

  At this time, the phase relationship between the prism gear 35 and the prism delay gear 37 is a phase relationship in which the torsion spring 36 is overcharged, as shown in FIG. In this state, the prism holding member 31 is urged in the retracting direction of the optical axis Y (on the image sensor 8 side) by the charging force of the torsion spring 36, but the retracting direction by the stopper portion 71 d on the retracting side of the barrel base plate 71. Movement to is restricted. Since the photo interrupter 85 is shielded from light by the light shielding plate 31e of the prism holding member 31, a switching signal can be detected from the output of the photo interrupter 85, and it can be determined that it is in the SINK position.

  At this time, the distance between the facing surfaces of the sliding portion 31a (at the SINK position) and the stopper portion 71c of the barrel base plate 71 is G, and the distance G is larger than the length A. Here, the distance G corresponds to the maximum distance (maximum movable distance) that the prism holding member 31 and the fourth group base plate 41 can move.

  FIG. 17 is a block diagram of the control mechanism of the digital camera. A photo interrupter 39, 49, 82 to 85, 88, a prism motor 32, a stepping motor 43, a stepping motor 62, a zoom motor 72, and a stepping motor 91 are connected to the control unit 100 as control means. Actuators and sensors other than these may be connected.

  Although not shown, the control unit 100 includes a CPU, a storage unit that stores a control program, a storage unit that stores various data, a timer, various interfaces, and the like. Signals indicating the detection results of the photo interrupters 39, 49, 82 to 85, 88 are supplied to the control unit 100. The control unit 100 controls the entire camera including the lens barrel. For example, the control unit 100 drives and controls the motors 32, 43, 62, 72, and 91 in accordance with the control program so as to perform operations according to user instructions, detection results of photo interrupters, and the like. Thereby, the operation of the component driven by each motor is controlled.

  Next, an operation sequence for extending the lens barrel from the SINK position to the WIDE position, which is a predetermined photographing enabled position, will be described.

  FIG. 18 is a flowchart showing the lens barrel feeding operation. This process is started when the digital camera is turned on.

  In order to extend the lens barrel to the WIDE position, the control unit 100 first starts driving the cam barrel 77 in the extension direction by the zoom motor 72 in step S100 of FIG. At this time, the cam pin of the cam cylinder 77 moves the cam groove 79a of the fixed cylinder 79 in the direction of the arrow Z1 in FIG. 10, and the first lens group 10 and the second lens group 20 are along the optical axis X in a section having a lift. To move in the feeding direction.

  By driving the zoom motor 72, the light shielding plate 78 a formed on the rectilinear guide cylinder 78 shown in FIG. 16 moves to the reset position where the photo interrupter 82 is shielded. The controller 100 determines whether or not the positions of the first lens group 10 and the second lens group 20 have been reset (step S101). When reset, the control unit 100 further drives the zoom motor 72 to move the first lens group 10 and the second lens group 20 to the WIDE position while counting pulses from the reset position.

  Eventually, the cam cylinder 77 is drawn out in the direction of the optical axis X to form a space in which the prism holding member 31 can move to the photographing position side, and the prism 9 can be drawn out. The control unit 100 determines whether or not the prism 9 can be extended (step S102), and when it becomes possible, starts driving the prism motor 32 (step S103). As a result, the prism gear 35 starts driving in the direction in which the prism holding member 31 is extended to the photographing position. However, since the torsion spring 36 is overcharged at the SINK position as shown in FIG. 13C, the prism delay gear 37 remains stopped. Therefore, the prism holding member 31 does not move from the retracted position.

  Then, as shown in FIG. 13B, when the phases of the latching portion 35b of the prism gear 35 and the latching portion 37b of the prism delay gear 37 coincide, the prism delay gear 37 starts to rotate together with the prism gear 35, The prism holding member 31 starts to move in the shooting position direction. The control unit 100 determines whether or not the cam cylinder 77 is extended and the first lens group 10 and the second lens group 20 have reached the WIDE position (step S104), and when it reaches, the driving of the zoom motor 72 is stopped. (Step S105).

  By the operation so far, the first lens group 10 and the second lens group 20 are arranged at the WIDE position and become ready for photographing. When the cam cylinder 77 reaches the WIDE position, the cam pin is positioned at a position 79d (FIG. 10) in the cam groove 79a of the fixed cylinder 79.

  FIG. 15 is a diagram showing a state in which the prism holding member 31 of the lens barrel moves from the SINK position (storage position) to the photographing position direction, and is a cross-sectional view of a main part cut along a plane including the guide shafts 86 and 87. is there. FIG. 15 shows a state where only the prism holding member 31 is moved from the SINK position without moving the fourth lens group 40 from the SINK position (storage position). The state shown in FIG. 15 is not actually passed through the control described later.

  The lengths A, B, D, the thickness C, and the distances E, G shown in FIGS. 2, 7, 9, and 15 are all dimensions in the optical axis Y direction. When the prism holding member 31 is moved without moving the fourth lens group 40, the distance between the opposed end surfaces of the sliding portion 31a and the stopper portion 71c in the optical axis Y direction is gradually reduced. As described above, since the A dimension is shorter than the G dimension, the sliding part 31b and the sliding part 41a collide when the end surfaces come close to the distance F as shown in FIG.

  In order to avoid this, in the present embodiment, the driving of the fourth group base plate 41 is started after the driving of the prism holding member 31 and before the sliding portion 31b and the sliding portion 41a collide.

  That is, in step S106 of FIG. 18, the control unit 100 determines whether or not a predetermined time T1 has elapsed from the start of driving of the prism motor 32. When the predetermined time T1 has elapsed, the control unit 100 starts driving the stepping motor 43 (step S107). As a result, the prism holding member 31 is driven in advance, and the fourth group base plate 41 is driven after a predetermined time T1 from the prism holding member 31. The predetermined time T1 is 120 ms as an example, but is not limited thereto, and is set to a value such that the fourth group ground plate 41 starts to be driven before the sliding portion 31b contacts the sliding portion 41a.

  Also, if the moving speed of the fourth group base plate 41 (fourth lens group 40) is too fast, it catches up with the prism holding member 31 before reaching the WIDE position, and the sliding portion 41b contacts the sliding portion 31b. It will collide from the side. In order to avoid this, the control unit 100 controls the moving speed of the fourth group base plate 41 to be equal to or lower than the moving speed of the prism holding member 31. That is, control is performed so that the fourth group base plate 41 does not catch up with the prism holding member 31 before reaching the WIDE position.

  Next, in step S108, the control unit 100 determines whether or not a predetermined time T2 (for example, 400 ms) has elapsed from the start of driving of the prism motor 32. If the predetermined time T2 has elapsed, the control unit 100 starts driving the stepping motor 62 in step S109.

  After the process of step S109, the control unit 100 executes the motor stop process of step S1000. Step S1000 includes the processes of steps S110 to S118. The processes of steps S110 to S112, the processes of steps S113 to S115, and the processes of steps S116 to S118 are executed in parallel.

  By driving the stepping motor 43, the light blocking plate 51a does not block the light receiving sensor 49a of the photo interrupter 49 where the fourth lens group 40 is eventually extended from the WIDE position shown in FIG. 14B. Move to the reset position. The control unit 100 determines whether or not the position of the fourth lens group 40 has been reset (step S113), and further drives the stepping motor 43 when the position is reset. Then, the control unit 100 performs control to move the fourth lens group 40 until the WIDE position is reached while counting pulses from the reset position (step S114). When the fourth lens group 40 reaches the WIDE position, the control unit 100 stops driving the stepping motor 43 (step S115).

  When the fourth group base plate 41 (fourth lens group 40) starts to move, the prism holding member 31 can continue to move because the distance until it collides with the fourth group base plate 41 increases. If the fourth group base plate 41 does not catch up with the prism holding member 31, and the distance between the sliding portion 41a of the fourth group base plate 41 and the stopper portion 71c is equal to or less than the distance obtained by subtracting the thickness of the sliding portion 41a from the A, the prism holding The member 31 can continue to move without fear of colliding with the fourth group base plate 41.

  When the prism holding member 31 reaches the photographing position, the prism holding member 31 comes into contact with the photographing stopper portion 71c and stops. At the same time as the prism holding member 31 stops, the prism delay gear 37 also stops. At the same time as the prism holding member 31 hits the stopper portion 71 c, the light shielding plate 31 d attached to the prism holding member 31 shields the photo interrupter 84. At this time, the position of the prism holding member 31 is reset.

  In step S1000, the control unit 100 determines whether or not the position of the prism holding member 31 has been reset (step S110). When the position of the prism holding member 31 is reset, the control unit 100 continues to drive the prism motor 32 while counting the pulses from the reset position until the prism holding member 31 reaches the WIDE position.

  The prism gear 35 continues to rotate in the direction in which the prism holding member 31 is extended to the photographing position, and the torsion spring 36 shown in FIG. 13A is overcharged. By overcharging the torsion spring 36, the prism holding member 31 is urged toward the photographing side stopper 71c by the action of the torsion spring 36, so that the position and posture of the prism holding member 31 are stabilized during photographing. There is.

  The controller 100 determines whether or not the prism holding member 31 has reached the WIDE position (step S111). When the WIDE position is reached, that is, when the torsion spring 36 reaches a predetermined overcharge state, the control unit 100 stops driving the prism motor 32 (step S112).

  Since the fifth lens group 50 is biased with respect to the fourth lens group 40 by the tension spring 53, the fifth lens group 50 starts to move together with the fourth lens group 40. Then, the fifth lens group 50 moves to a predetermined position on the optical axis Y by making the same movement as the fourth lens group 40 until the arm portion 51b hits the stopper portion 71b.

  After the arm portion 51b hits the stopper portion 71b, the fifth lens group 50 is fixed at the abutting position, and is separated from the fourth lens group 40 that continues to move. A section between the fixed position of the fifth lens group 50 and the position in the SINK state is a movable section of the sixth lens group 60.

  When the stepping motor 62 is driven, the sixth lens group 60 moves to a reset position where the light blocking plate 61c eventually blocks the photo interrupter 88. Then, the control unit 100 determines whether or not the position of the sixth lens group 60 has been reset (step S116). When the position of the sixth lens group 60 is reset, the control unit 100 further drives the stepping motor 62 to move the sixth lens group 60 to the WIDE position while counting pulses from the reset position.

  Then, the control unit 100 determines whether or not the sixth lens group 60 has reached the WIDE position (step S117). If the sixth lens group 60 has reached the WIDE position, the driving of the stepping motor 62 is stopped (step S118).

  When all the processes in steps S112, S115, and S118 are completed, the control unit 100 ends the lens barrel extension process in FIG. Thus, the feeding of the lens barrel to the WIDE position is completed.

  Next, an operation sequence for retracting the lens barrel from the WIDE position to the SINK position will be described.

  FIG. 19 is a flowchart showing the retracting operation of the lens barrel. This process is started when the digital camera is turned off.

  When the lens barrel is retracted from the WIDE position to the SINK position, in step S200, the control unit 100 moves the sixth lens group 60 in the direction of retracting to the image sensor 8 side along the optical axis Y direction. The driving of the stepping motor 62 is started. Next, in step S201, the control unit 100 starts driving the prism motor 32 in the retracting direction. Then, the prism gear 35 rotates in the direction in which the prism holding member 31 is moved to the retracted position.

  Then, the prism gear 35 rotates by the amount of overcharge of the torsion spring 36 described above, and the phase of the latching portion 35 b of the prism gear 35 and the latching portion 37 b of the prism delay gear 37 coincide. At this time, the prism delay gear 37 rotates integrally with the prism gear 35 and the torsion spring 36 in the direction to retract the prism holding member 31 to the retracted position, and the prism holding member 31 moves in the retracted direction. When the prism holding member 31 moves and moves away from the photographing-side stopper portion 71c, the light shielding plate 31d attached to the prism holding member 31 eventually does not block the photo interrupter 84. At this time, the position of the prism holding member 31 is reset.

  When the prism holding member 31 starts from the WIDE position (FIG. 2) and moves in the direction of the SINK position, if the prism holding member 31 moves by a distance obtained by subtracting the thickness of the sliding portion 31a from the distance E, It will interfere with the 4th group ground plane 41 which has stopped. That is, the sliding part 31a collides with the sliding part 41a. In order to avoid this, it is necessary to start the retraction of the fourth lens group 40 before the collision.

  Therefore, the control unit 100 determines whether or not a predetermined time T3 has elapsed from the start of driving of the prism motor 32 (step S202). When the predetermined time T3 has elapsed, the control unit 100 starts driving the stepping motor 43 (step S203). As a result, the prism holding member 31 is driven in the direction of the SINK position, and the fourth group base plate 41 is driven after a predetermined time T3 from the prism holding member 31. The predetermined time T1 is 120 ms as an example, but is not limited thereto, and is set to a value such that the fourth group ground plate 41 starts to be driven before the sliding portion 31a comes into contact with the sliding portion 41a.

  Also, if the moving speed of the prism holding member 31 is too fast, it catches up with the fourth group base plate 41 (fourth lens group 40) before reaching the SINK position, and eventually the sliding part 31a contacts the sliding part 41a. Colliding from the opposite side of the imaging surface. In order to avoid this, the control unit 100 controls the moving speed of the prism holding member 31 to be equal to or lower than the moving speed of the fourth group base plate 41. That is, control is performed so that the prism holding member 31 does not catch up with the fourth group base plate 41 before reaching the SINK position.

  During this time, the driving of the stepping motor 62 continues, so that the sixth lens group 60 eventually moves to a reset position where the light shielding plate 61c blocks the photo interrupter 88.

  After the process of step S203, the control unit 100 executes the motor stop process of step S2000. Step S2000 includes the processes of steps S204 to S212. The processes in steps S204 to S206, the processes in steps S207 to S209, and the processes in steps S210 to S212 are executed in parallel.

  In step S2000, the control unit 100 determines whether or not the position of the sixth lens group 60 has been reset (step S204). When the position of the sixth lens group 60 is reset, the control unit 100 further drives the stepping motor 62 to move the sixth lens group 60 to the SINK position while counting pulses from the reset position. Then, the control unit 100 determines whether or not the sixth lens group 60 has reached the SINK position (step S205). When the sixth lens group 60 has reached the SINK position, the driving of the stepping motor 62 is stopped (step S206).

  When the fourth lens group 40 is moved to the image plane side in the optical axis Y direction where the image pickup device 8 is located by driving the stepping motor 43, the fourth lens group 40 approaches the fifth lens group 50 and eventually the fifth lens group 50. The fourth lens group 40 abuts. At this time, the light receiving sensor 49a of the photo interrupter 49 is blocked by the light shielding plate 51a, and the position of the fourth lens group 40 is reset.

  The control unit 100 determines whether or not the position of the fourth lens group 40 has been reset (step S207). When the position of the fourth lens group 40 is reset, the control unit 100 further drives the stepping motor 43 so that the fourth lens group 40 is integrated with the fifth lens group 50 in the direction of the optical axis Y. Along the image sensor 8 side. Further, the control unit 100 moves the fourth lens group 40 to the SINK position while counting pulses from the reset position.

  Then, the control unit 100 determines whether or not the fourth lens group 40 has reached the SINK position (step S208). When the fourth lens group 40 has reached the SINK position, the driving of the stepping motor 43 is stopped (step S209).

  The controller 100 determines whether or not the position of the prism holding member 31 has been reset (step S210). When the position of the prism holding member 31 is reset, the control unit 100 continues to drive the prism motor 32 while counting the pulses from the reset position until the prism holding member 31 reaches the SINK position. Thereby, the prism gear 35 continues to rotate in the direction in which the prism holding member 31 is retracted to the SINK position. Then, the stopper portion 31g of the prism holding member 31 comes into contact with the retracting side stopper portion 71d and stops, and at the same time, the prism delay gear 37 also stops. The prism motor 32 continues to rotate in a direction to retract the prism holding member 31 to the retracted position while overcharging the torsion spring 36.

  The controller 100 determines whether or not the prism holding member 31 has reached the SINK position (step S211). When the SINK position is reached, that is, when the torsion spring 36 reaches a predetermined overcharge state, the control unit 100 stops driving the prism motor 32 (step S212).

  When the processes of steps S206, S209, and S212 are all completed, the control unit 100 advances the process to step S213.

  When the prism holding member 31 moves to the retracted position and a space that can be accommodated behind the cam cylinder 77 is formed, the control unit 100 moves the cam cylinder 77 of the zoom motor 72 in the retracting direction in step S213. Start driving. Then, the cam cylinder 77 starts to be retracted.

  By driving the zoom motor 72, the light shielding plate 78a formed on the straight guide cylinder 78 shown in FIG. 16 eventually moves to the reset position where the photo interrupter 82 is not shielded. At this time, the positions of the first lens group 10 and the second lens group 20 are reset. The control unit 100 determines whether or not the positions of the first lens group 10 and the second lens group 20 have been reset (step S214). When these positions are reset, the controller 100 further drives the zoom motor 72 to move the first lens group 10 and the second lens group 20 to the SINK position while counting pulses from the reset position.

  The zoom motor 72 continues to drive to retract the cam cylinder 77 to the storage position. Then, the cam cylinder 77 is accommodated in the SINK position from the position 79d to the position 79c in the direction of the arrow Z4 along the cam groove 79a of FIG. 10, and the first lens group 10 and the second lens group 20 are accommodated. The control unit 100 determines whether or not the first lens group 10 and the second lens group 20 are housed and are in the SINK position (step S215). And when it becomes a SINK position, the control part 100 stops the drive of the zoom motor 72 (step S216). This completes the lens barrel retracting process of FIG.

  By the way, the zooming operation is also controlled by the control unit 100. First, when the lens barrel is zoomed between the WIDE position and the TELE position, the first lens group 10 and the second lens group 20 are moved by driving the zoom motor 72 in the optical axis X direction. . In zooming the lens barrel from the WIDE position to the TELE position, the cam pin of the cam cylinder 77 moves the cam groove 79a of the fixed cylinder 79 to the position 79e in the arrow Z2 direction as shown in FIG.

  On the other hand, when zooming from the TELE position to the WIDE position, the cam cylinder 77 is moved in the direction of the arrow Z3 by the zoom motor 72 and moved to the position 79d in the reverse procedure (FIG. 10). Further, the prism holding member 31 is not moved, but the fourth lens group 40 is moved by the action of the stepping motor 42. At the same time, the sixth lens group 60 is moved to a focused position by the action of the stepping motor 62 in the same manner.

  Regarding the operations of the prism holding member 31 and the fourth group base plate 41 in the zooming operation between the WIDE position and the TELE position, the prism holding member 31 is stopped and only the fourth group base plate 41 is displaced in the optical axis Y direction. .

  By the way, according to the processing of FIG. 18 and FIG. 19, the prism holding member 31 precedes the fourth group base plate 41 in the movement between the SINK position and the WIDE position in any direction. However, the driving of the prism holding member 31 and the fourth group base plate 41 may be started simultaneously. Eventually, it is only necessary to prevent the sliding portion 41a from colliding with either the sliding portion 31b or the sliding portion 31a during the movement. The control unit 100 may control the drive start timing and the moving speed of the prism holding member 31 and the fourth group base plate 41 by the prism motor 32 and the stepping motor 43 as described above. In that case, the positions and speeds of the prism holding member 31 and the fourth group base plate 41 may be grasped, and the control unit 100 may determine the calculation and the like to control the movement of both.

  For example, when moving from the SINK position to the WIDE position and simultaneously starting the driving of the prism holding member 31 and the fourth group base plate 41, the control unit 100 determines the moving speed of the fourth group base plate 41 of the prism holding member 31. Control to make it slower than the moving speed.

  On the other hand, when the driving of the prism holding member 31 and the fourth group base plate 41 is started simultaneously when moving from the WIDE position to the SINK position, the control unit 100 determines the prism holding member with respect to the moving speed of the fourth group base plate 41. The moving speed of 31 is controlled to be low.

  According to the present embodiment, the length between the sliding portions 31a, 31b of the prism holding member 31 in the optical axis Y direction (A), the length between the sliding portions 41a, 41b of the fourth group base plate 41 (B). Can be shortened. Accordingly, the length between the sliding portions of the holding frame and the guide shaft can be shortened, and the lens barrel can be downsized.

  In the present embodiment, the prism holding member 31, the fourth group base plate 41, and the sixth group lens holder 61 are pivotally supported on the guide shaft 86 by two sliding portions. In this configuration, since the lengths A and B can be shortened, the length (D) between the sliding portions 61a and 61b of the sixth group lens holder 61 can be ensured to be long.

  The configuration of the present invention is not limited to that exemplified in the above embodiment, and the material, shape, dimensions, form, number, arrangement location, and the like can be changed as appropriate without departing from the scope of the present invention. It is.

  For example, in the above-described embodiment, the prism 9 is illustrated as the reflective optical element, but the present invention is not limited to this, and for example, a mirror or the like may be used. Moreover, it is not limited to the digital camera of an imaging device, A silver salt camera and a video camera are also included.

3 3 group lens 4 4 group lens 31 Prism holding member 31a, 31b sliding part 32 prism motor 41 4 group base plate 41a, 41b sliding part 43 4 group stepping motor 86 guide shaft 100 control part

Claims (9)

A guide shaft extending in the direction of the optical axis;
A first holding frame that has a first sliding portion and a second sliding portion that slidably engage with the guide shaft, respectively, and holds the first optical system;
Each has a third sliding portion and a fourth sliding portion that slidably engage with the guide shaft, and is disposed closer to the imaging surface than the first holding frame, and the second optical system A second holding frame to hold;
First driving means for driving the first holding frame to move along the guide shaft;
Second driving means for driving the second holding frame to move along the guide shaft;
Control means for controlling the first drive means and the second drive means,
The sliding portions are arranged in the order of the fourth sliding portion, the second sliding portion, the third sliding portion, and the first sliding portion from the side close to the imaging surface. Engaging the guide shaft,
A distance between end faces of the first sliding portion and the second sliding portion that are not opposite to each other in a direction parallel to the guide shaft, and the third sliding portion in a direction parallel to the guide shaft The distance between the end faces that do not face each other with the fourth sliding portion is shorter than the maximum movable distance of the first holding frame,
When the control means moves the first and second holding frames between the retracted position and a predetermined photographing enabled position, the third sliding part moves the second sliding partway through the movement. The drive start timing and the moving speed of each of the first and second holding frames by the first and second driving means are controlled so as not to collide with either the first part or the first sliding part. A lens barrel characterized by that.   When the first and second holding frames are moved from the retracted position to the predetermined photographing enabled position, the control means drives the first holding frame in advance and drives the third holding frame. 2. The lens barrel according to claim 1, wherein the lens barrel is controlled so as to start driving the second holding frame so that the sliding portion does not collide with the second sliding portion.   3. The control unit according to claim 2, wherein the control unit controls the moving speed of the second holding frame that starts driving later to be equal to or lower than the moving speed of the first holding frame. Lens barrel.   The control means starts driving the first and second holding frames simultaneously when moving the first and second holding frames from the retracted position to the predetermined photographing enabled position, and 2. The lens barrel according to claim 1, wherein the moving speed of the second holding frame is controlled to be lower than the moving speed of the first holding frame.   When the first and second holding frames are moved from the predetermined photographing enabled position to the retracted position, the control means drives the first holding frame in advance and drives the third holding frame. 2. The lens barrel according to claim 1, wherein the lens barrel is controlled to start driving the second holding frame so that the sliding portion does not collide with the first sliding portion.   The control means controls the moving speed of the first holding frame to be equal to or less than the moving speed of the second holding frame that starts driving later. The lens barrel described.   The control means starts driving the first and second holding frames simultaneously when moving the first and second holding frames from the predetermined photographing enabled position to the retracted position, and 2. The lens barrel according to claim 1, wherein the moving speed of the first holding frame is controlled to be lower than the moving speed of the second holding frame.   An image pickup apparatus comprising the lens barrel according to claim 1. A guide shaft extending in the direction of the optical axis;
A first holding frame that has a first sliding portion and a second sliding portion that slidably engage with the guide shaft, respectively, and holds the first optical system;
Each has a third sliding portion and a fourth sliding portion that slidably engage with the guide shaft, and is disposed closer to the imaging surface than the first holding frame, and the second optical system A second holding frame to hold;
First driving means for driving the first holding frame to move along the guide shaft;
Control of the lens barrel that moves the lens barrel having the second driving means for driving the second holding frame and moving the second holding frame along the guide shaft between the retracted position and a predetermined photographing position. A method,
The sliding portions are arranged in the order of the fourth sliding portion, the second sliding portion, the third sliding portion, and the first sliding portion from the side close to the imaging surface. Engaged with the guide shaft,
A distance between end faces of the first sliding portion and the second sliding portion that are not opposite to each other in a direction parallel to the guide shaft, and the third sliding portion in a direction parallel to the guide shaft The distance between the end faces that do not face each other with the fourth sliding portion is shorter than the maximum movable distance of the first holding frame,
When the first and second holding frames are moved between the retracted position and the predetermined photographing enabled position, the third sliding portion is moved to the second sliding portion or the middle during the movement. The drive start timing and the moving speed of each of the first and second holding frames by the first and second driving means are controlled so as not to collide with any of the first sliding portions. The lens barrel control method.

Images