JP6929128B2 - Manufacturing method of lens barrel - Google Patents

Description

The present invention relates to a method of manufacturing lenses barrel.

Conventionally, a technique for adjusting a lens in a lens barrel has been proposed. In Patent Document 1, two groups are composed of a first lens fixed to a first lens holder and a second lens fixed to a second lens holder and having an facing surface facing an optical recording medium. A method of adjusting an objective lens for an optical pickup having a lens is disclosed. In Patent Document 1, the first lens holder and the second lens holder are brought into contact with each other on a contact surface substantially perpendicular to the optical axis, and the first lens and the second lens holder are rotated about an axis perpendicular to the contact surface. Adjust the relative tilt between the lenses. Further, the eccentricity of the first lens and the second lens is adjusted by moving the second lens holder relatively in parallel with the first lens holder in the contact surface. In Patent Document 2, a mechanism for adjusting the inclination of the first lens frame for holding the first lens group and a second lens frame for holding the second lens group are provided, and the second lens frame is of the second lens group. A lens barrel that is movable in the optical axis direction and that the first and second lens frames can be brought into contact with each other is disclosed.

Japanese Patent No. 3462997 Japanese Unexamined Patent Publication No. 2012-145873

In recent years, there has been a problem that it is difficult to prevent the lens from tilting so that the lens held by the moving ring and the lens fixed to the base holding the moving ring are parallel to each other. In the method of Patent Document 1, tilt adjustment and eccentricity adjustment are possible, but in order to adjust the distance between the two lenses, it is necessary to provide an adjustment mechanism inside the lens barrel, and as a result, the lens barrel becomes large. It ends up. Further, since the lens barrel of Patent Document 2 has a tilt adjusting mechanism, the size and weight of the lens barrel are increased.

An object of the present invention is to provide a method for manufacturing a lens barrel whose focus is adjusted while suppressing relative tilt of the lens.

A method of manufacturing a lens barrel as another aspect of the present invention is to hold a main plate, a first holding member for holding a first lens, and a second lens, and light the first lens. A method for manufacturing a lens barrel having a second holding member that is relatively movable along an axis, and a step of attaching the second holding member to the main plate so that it can be moved along the optical axis. And the first lens with respect to the second lens in a state where at least one of the second lens and the second holding member holds at least one of the first lens and the first holding member. The step of adjusting at least one of the position in the direction orthogonal to the optical axis and the position in the optical axis direction of the main plate with respect to the second lens, and the adjustment of the second lens and the second holding. Having at least one of the members holding at least one of the first lens and the first holding member , and having a step of fixing the first holding member to the main plate via an adhesive. It is a feature.

According to the present invention, it is possible to provide a method for manufacturing a lens barrel whose focus is adjusted while suppressing relative tilting of the lens.

It is the schematic of the image pickup apparatus provided with the lens barrel which concerns on embodiment of this invention. It is an exploded perspective view of a lens barrel. It is sectional drawing of the lens barrel in a telephoto shooting state. It is sectional drawing of the lens barrel in a wide-angle shooting state. It is sectional drawing of the lens barrel in a collapsed state. It is an exploded perspective view of the focus lens unit when viewed from the subject side. It is an exploded perspective view of the focus lens unit when viewed from the image plane side. It is a perspective view of the focus lens unit. It is a front view of the focus lens unit. It is a top view of the focus lens unit. It is sectional drawing of the focus lens unit at the time of optical adjustment. It is a rear view of the focus lens unit. It is a figure which shows the state before the focus motor is incorporated in 3 group cylinders. It is a figure which shows the state which the focus motor is incorporated in 3 group cylinders.

Hereinafter, examples of the present invention will be described in detail with reference to the drawings. In each figure, the same member is given the same reference number, and duplicate description is omitted.

FIG. 1 is a schematic view of an image pickup apparatus IA including a lens barrel LB according to an embodiment of the present invention. The lens barrel LB holds the imaging optical system IOS. The camera body CB holds the image sensor IE. The lens barrel LB may be integrally configured with the camera body CB, or may be configured to be detachably attached to the camera body CB. Further, the lens barrel LB may hold the image sensor IE.

The present invention includes not only a lens barrel and a lens-integrated camera that are detachably attached to a camera body, but also an imaging device such as a video camera and a surveillance camera, an observation device such as binoculars, and an image projection device such as a liquid crystal projector. It can also be applied to optical equipment.

FIG. 2 is an exploded perspective view of the lens barrel LB. FIG. 3 is a cross-sectional view of the lens barrel LB in the telephoto shooting state. FIG. 4 is a cross-sectional view of the lens barrel LB in the wide-angle shooting state. FIG. 5 is a cross-sectional view of the lens barrel LB in the retracted state.

The lens barrel LB of the present embodiment includes a 1st group lens 1, a 2nd group lens 2, a 3rd group lens 3, a 4th group lens 4, a 5th group lens 5, an optical filter 6, an image pickup element 7, and an aperture unit 8. When each lens group moves from the storage position shown in FIG. 5 to the wide shooting position shown in FIG. 4, the lens barrel LB becomes ready for shooting. Further, the photographing magnification can be changed by moving each lens group between the telephotographable position of FIG. 3 and the wide photographable position of FIG. 4 along the optical axis of the imaging optical system.

The group 1 lens holding frame 10 fixes the group 1 lens 1 with an adhesive. The adhesive is hidden by the veneer. A follower pin is provided inward at the end of the group 1 lens holding frame 10 on the image plane side.

The diaphragm unit 8 holds a diaphragm mechanism including a diaphragm blade, a blade drive ring, and a diaphragm motor. Three legs protruding toward the image plane are provided on the image plane side of the aperture unit 8, and follower pins protruding toward the outer periphery (diameterally outside) are provided at the tips of the legs.

The 2nd group lens holding frame 20 holds an optical image stabilization mechanism and a shutter mechanism for moving the 2nd group lens 2 and the 2nd group lens 2 in a plane orthogonal to the optical axis. The image plane side of the group 2 lens holding frame 20 is provided with three legs protruding toward the image plane side, and the tip of each leg is provided with a follower pin protruding toward the outer peripheral side (diameter outside). ..

The 5-group lens holding frame 50 fixes the 5-group lens 5. Three follower pins projecting outward in the radial direction are provided on the outer periphery of the group 5 lens holding frame 50. The light-shielding plate 55 closes the outside of the group 5 lens holding frame 50 and the inner circumference of the fixed cylinder 72, and is provided with three follower pins protruding outward in the radial direction on the outer circumference.

The image sensor 7 is held in the image sensor holding frame 71, and the subject image imaged by the image pickup optical system is photoelectrically converted and output as an image signal. A fixed cylinder 72 and a cover cylinder 73 are fixed to the image sensor holding frame 71.

A drive ring 74 is rotatably held on the outside of the fixed cylinder 72 with respect to the fixed cylinder 72. A gear (not shown) is provided on the outer circumference of the drive ring 74, and is rotationally driven by the zoom motor 79 via a reduction mechanism (not shown). A moving cam ring 75 is arranged on the inner circumference of the fixed cylinder 72. On the outer circumference of the moving cam ring 75, three follower pins (not shown) are provided at 120 ° equal parts, and three drive keys (not shown) are provided at 120 ° equal parts. The follower pin engages with the cam groove 72A provided on the inner circumference of the fixed cylinder 72. The drive key inserts a through cam groove 72B provided in the fixed cylinder 72 and engages with a drive groove (not shown) provided along the optical axis on the inner circumference of the drive ring 74. When the drive ring 74 is rotated by the zoom motor 79, rotational torque is transmitted to the moving cam ring 75 via the drive groove, and the moving cam ring 75 moves along the optical axis while rotating according to the trajectory of the cam groove 72A.

A cam cover cylinder 78 is arranged between the outer circumference of the moving cam ring 75 and the inner circumference of the fixed cylinder 72. The cam cover cylinder 78 is fixed to the moving cam ring 75 by a snap fit. A straight guide cylinder 76 is arranged on the inner circumference of the moving cam ring 75. A flange portion is provided along the outer peripheral direction at the end portion of the straight guide cylinder 76 on the subject side. The surface of the flange portion on the image plane side is in contact with the end face of the moving cam ring 75 on the subject side. At the end of the straight guide cylinder 76 on the image plane side, a straight guide plate 77 is fixed to the straight guide cylinder 76 by a snap fit. The straight guide plate 77 has a flat plate shape, and the surface on the subject side is in contact with the end surface on the image surface side of the moving cam ring 75.

A plurality of straight keys (not shown) extending to the outer circumference are provided on the outer circumference of the straight guide plate 77, and by engaging with the straight groove 72C provided on the inner circumference of the fixed cylinder 72, the straight guide plate 77 goes straight. The rotation of the guide plate 77 is regulated. Therefore, when the drive ring 74 is rotated by the zoom motor 79, the straight guide cylinder 76 and the straight guide plate 77 move along the optical axis together with the moving cam ring 75 without rotating.

Three cam grooves (not shown) are provided at 120 ° equal parts on the outer circumference of the moving cam ring 75, and three first cam grooves (not shown) and three second cams (not shown) are provided on the inner circumference. A groove and three third cam grooves are provided at 120 ° equal parts, respectively. The cam groove provided on the outer periphery engages with the follower pin of the group 1 lens holding frame 10. The first cam groove engages with the follower pin of the aperture unit 8, the second cam groove engages with the follower pin of the second group lens holding frame 20, and the third cam groove engages with the follower pin of the third group cylinder 30, which will be described later. Engage.

A straight-ahead key is provided on the outer periphery of the flange portion provided on the straight-ahead guide cylinder 76, and the first-group lens is held by engaging with a straight-ahead groove provided on the inner circumference of the first-group lens holding frame 10. The rotation of the frame 10 is regulated. The cylinder main body of the straight guide cylinder 76 is provided with three first straight through grooves and three second straight through grooves, each of which is divided into 120 ° equal parts. The first straight through groove is composed of a wall parallel to the line connecting the optical axis and the center of the first straight through groove, and engages with the straight guide portion provided at the base of the follower pin of the diaphragm unit 8. The rotation of the aperture unit 8 is regulated. Further, the first straight through groove regulates the rotation of the second group lens holding frame 20 by engaging with the straight guide portion provided at the base of the follower pin of the second group lens holding frame 20. The second straight through groove is composed of a wall parallel to the line connecting the optical axis and the center of the second straight through groove, and is engaged with the straight guide portion 30B provided at the root of the follower pin 30A of the third group cylinder 30. By matching, the rotation of the 3 group cylinder 30 is regulated.

On the inner circumference of the drive ring 74, three first cam grooves and three second cam grooves are provided at 120 ° equal parts.
The first cam groove engages with the follower pin of the 5th group lens holding frame 50. The second cam groove engages with the follower pin of the light shielding plate 55.

The fixed cylinder 72 is provided with three through straight grooves at 120 ° equal parts. A 5-group lens holding frame 50 and a light-shielding plate 55 are provided on the inner circumference of the fixed cylinder 72. The rotation of the 5th group lens holding frame 50 is restricted by engaging the straight guide portion at the base of the follower pin provided on the outer circumference of the 5th group lens holding frame 50 with the through straight groove of the fixed cylinder 72. A follower pin is provided on the outer circumference of the light-shielding plate 55, and the rotation of the light-shielding plate 55 is restricted by engaging the straight-ahead guide portion at the base of the follower pin with the straight-moving groove provided in the fixed cylinder 72.

Hereinafter, the configuration of the focus lens unit 300 including the third group lens 3 and the fourth group lens 4 will be described with reference to FIGS. 6 to 12. FIG. 6 is an exploded perspective view of the focus lens unit 300 when viewed from the subject side. FIG. 7 is an exploded perspective view of the focus lens unit 300 when viewed from the image plane side. FIG. 8 is a perspective view of the focus lens unit 300. FIG. 9 is a front view of the focus lens unit 300. FIG. 10 is a top view of the focus lens unit 300. FIG. 11 is a cross-sectional view of the focus lens unit 300 at the time of optical adjustment. FIG. 12 is a rear view of the focus lens unit 300.

The 3-group lens holder 31 as the first holding member holds the 3-group lens 3, and the 4-group lens holder 40 holds the 4-group lens 4. The 3rd group lens holder 31 is fixed to the 3rd group cylinder (base plate) 30 via an adhesive 35. The third group cylinder 30 fixes a focus motor 33 that supplies a driving force and a guide shaft 32 that movably supports the fourth group lens holder 40 along the optical axis. A sheet metal member is integrally attached to the focus motor 33. A flange portion (mechanical stopper) 33A is provided at the tip of the sheet metal member. A screw portion 33C is provided between the flange portion 33A and the focus motor 33. The screw portion 33C is rotated by energization from a circuit (not shown). The guide shaft 32 fits with the sleeve portions 40A and 40B of the 4-group lens holder 40 as a holding member, and guides the 4-group lens holder 40 in a straight line. A rack (contact member) 42 is attached to the 4th group lens holder 40. The rack 42 is screwed into the screw portion 33C and is offset in the optical axis direction and the radial direction by the spring 43. The 4th group lens holder 40 moves along the optical axis with respect to the 3rd group cylinder 30 by driving the focus motor 33 at the time of focusing, thereby focusing the subject image on the image plane of the image sensor 7.

On the image plane side of the three-group cylinder 30, three legs 30C protruding toward the image plane are provided. A follower pin 30A protruding from the outer periphery is provided at the tip of the leg 30C. As described above, the straight guide portion 30B provided at the base of the follower pin 30A regulates the rotation of the third group cylinder 30 by inserting the second straight through groove provided in the straight guide cylinder 76. There is.

As described above, in the present embodiment, when the zoom motor 79 is driven, the drive ring 74 rotates, and the moving cam ring 75 moves along the optical axis while rotating along with the rotation. The straight guide plate 77 and the straight guide cylinder 76 move along the optical axis together with the moving cam ring 75 without rotating. Further, the 1st group lens holding frame 10, the aperture unit 8, the 2nd group lens holding frame 20, the 3rd group cylinder 30, the 5th group lens holding frame 50, and the light shielding plate 55 do not rotate and follow the trajectory of their respective cam grooves. It moves along the optical axis.

Hereinafter, the optical adjustment of the focus lens unit 300 will be described. In the states of FIGS. 6 and 7, first, the 3rd group lens 3 and the 4th group lens 4 are press-fitted and fixed to the 3rd group lens holder 31 and the 4th group lens holder 40, respectively, and then bonded. In addition, it may be fixed by heat clamping or welding instead of adhesion. Next, the guide shaft 32 is pivotally supported by the sleeve portions 40A and 40B of the 4th group lens holder 40, and at the same time is press-fitted and fixed to the bearing portions 30E and 30F of the 3rd group cylinder 30. At the same time, the key 40C of the 4th group lens holder 40 is fitted between the grooves 30D of the 3rd group cylinder 30. By fitting the key 40C into the groove 30D, the 3rd group cylinder 30 and the 4th group lens holder 40 are restricted from relative rotation about the guide shaft 32.

Therefore, in FIG. 9, the 4th group lens holder 40 and the 3rd group cylinder 30 are fixed in position by the guide shaft 32 in the direction parallel to the paper surface, and can move in the direction perpendicular to the paper surface, that is, the optical axis direction. can. In the 4th group lens holder 40, the state X in which the sleeve portion 40A of the 4th group lens holder 40 collides with the bearing portion 30E of the 3rd group cylinder 30 and the sleeve portion 40B of the 4th group lens holder 40 are in the bearing portion 30F of the 3rd group cylinder 30. It can move along the optical axis with the colliding state Y.

After that, as shown in FIG. 11, the flat surface portion 4A provided on the subject side of the 4-group lens 4 is brought into contact with the flat surface portion 31A provided on the 3-group lens holder 31. In a state where the flat surface portion 4A and the flat surface portion 31A are in contact with each other, specifically, in a state where the 4-group lens 4 holds the 3-group lens holder 31, the tilting of the 3-group lens 3 and the 4-group lens 4 is caused by these members. It becomes constant within the range of the manufacturing error of the 3rd group lens holder 31 arranged between the lenses. Further, in this state, the optical eccentricity adjustment of the 3rd group lens 3 and the 4th group lens 4 is performed. Further, the guide shaft 32 adjusts the position of the 3-group cylinder 30 in the optical axis direction with respect to the 4-group lens 4, whose position is determined in the direction perpendicular to the optical axis. Adjusting the position of the 3rd group cylinder 30 in the optical axis direction means adjusting the position of the 3rd group lens holder 31 in the optical axis direction when the 3rd group cylinder 30 moves according to the cam locus. Therefore, the focus is adjusted by this adjustment.

After the adjustment, the group 3 lens holder 31 is solidified after filling the regions 35A, 35B, and 35C shown in FIG. 9 with the adhesive 35 in a state where the lens holder 31 is not in contact with the group tube 30 (floating in the air). As a result, it is fixed to the 3 group cylinder 30. In the present embodiment, as the adhesive 35, an adhesive that solidifies and cures by UV irradiation in the form of a liquid or gel for fixing two non-contact objects is used.

After bonding the 3rd group cylinder 30 and the 3rd group lens holder 31, the relative positional relationship between the 4th group lens 4 and the 3rd group lens holder 31 in the optical axis direction is changed so that the 4th group lens 4 and the 3rd group lens holder 31 are not in contact with each other. At this time, the rack 42 and the spring 43 are incorporated in the 4th group lens holder 40. After that, as shown in FIG. 13, the focus motor 33 is moved along the A direction while engaging the rack 42 with the screw portion 33C, and the key portion 33B of the focus motor 33 is sandwiched between the press-fitting portions 30H of the third group cylinder 30. Press-fit and fix in the state of being closed. At the same time, the key portion 33B is press-fitted and fixed while being sandwiched between the semicircular portion 30G shown in FIG. FIG. 14 shows a state in which the focus motor 33 is incorporated in the third group cylinder 30.

After that, the hatched areas 35D and 35E in FIG. 10 are filled with the adhesive 35 and then solidified to form the arms 33D and 33E extending from the sheet metal member attached to the focus motor 33 into the three-group cylinder 30. Adhere with the recessed part of. By adhesively fixing the focus motor 33, the screw for fixing the focus motor 33 can be eliminated, so that the deformation of the three-group cylinder 30 can be prevented. As a result, it is possible to prevent the orientation of the lens from changing due to the deformation of the three-group cylinder 30.

As shown in FIG. 10, the stopper surface 42A of the rack 42 is in contact with the inner circumference of the flange portion 33A of the focus motor 33, and the 4th group lens holder 40 is in a state Z where it cannot move to the subject side. Therefore, the movement range of the 4th group lens holder 40 in the optical axis direction is restricted from the state Z to the state X, and the 4th group lens 4 does not come into contact with the 3rd group lens holder 31. Therefore, the 4-group lens 4 will not be damaged or misaligned due to collision of parts after assembly.

As described above, the 3rd group lens 3 and the 4th group lens 4 are formed by aerial bonding of the 3rd group lens holder 31 to the 3rd group cylinder 30 in a state where the 4th group lens 4 and the 3rd group lens holder 31 are in contact with each other. Relative collapse of the lens can be suppressed.

Further, the space between the 3rd group lens holder 31 and the 3rd group cylinder 30 can be easily adjusted by filling the space between the 3rd group lens holder 31 and the 3rd group cylinder 30 with the adhesive 35 in a floating state, and it is necessary to mount the adjustment mechanism inside. It is advantageous for miniaturization because there is no such thing.

Further, after the adjustment adhesion, the 4th group lens holder 40 can move along the optical axis via the guide shaft 32 in a state where the 4th group lens 4 is prevented from coming into contact with the 3rd group lens holder 31.

In the present embodiment, the 3-group lens holder 31 is placed on the 4-group lens 4 for adjustment, but the present invention is not limited to this. For example, the 3-group lens 3 may be placed on the 4-group lens 4 for adjustment without providing the 3-group lens holder 31.

Further, in the present embodiment, the 4-group lens 4 moves along the optical axis by the guide shaft 32, but it may be configured to move along the optical axis by the cam groove with the follower pin as in the other groups. good.

Further, it is not the 4th group lens 4 that receives the 3rd group lens holder 31 at the time of adjustment, but the 4th group lens holder 40 may lift the 3rd group lens holder 31.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

3 Group 3 lens (first lens)
4 Group 4 lens (second lens)
30 3 group cylinder (base plate)
31 Group 3 lens holder (first holding member)
35 Adhesive 40 Group 4 lens holder (second holding member)

Claims (7)

A main plate, a first holding member that holds the first lens, and a second holding member that holds the second lens and is movable relative to the first lens along the optical axis. Is a method for manufacturing a lens barrel having,
A step of attaching the second holding member to the main plate so as to be movable along the optical axis,
The first lens with respect to the second lens, with at least one of the second lens and the second holding member holding at least one of the first lens and the first holding member. A step of adjusting at least one of the position in the direction orthogonal to the optical axis and the position in the optical axis direction of the main plate with respect to the second lens.
After the adjustment, at least one of the second lens and the second holding member holds at least one of the first lens and the first holding member, and the first one is held via an adhesive. A method for manufacturing a lens barrel, which comprises a step of fixing a holding member to the main plate. After the second lens is separated from the first holding member in the optical axis direction of the main plate, a step of providing a mechanical stopper for preventing the second lens from coming into contact with the first holding member is further added. The method for manufacturing a lens barrel according to claim 1, wherein the lens barrel is provided. It is characterized by further having a step of providing the second holding member with a contact member that comes into contact with the mechanical stopper attached to the main plate before the second lens comes into contact with the first holding member. The method for manufacturing a lens barrel according to claim 2. The method for manufacturing a lens barrel according to claim 3 , wherein the mechanical stopper and the contact member are attached after the first holding member is fixed to the main plate via the adhesive. It further has a motor that supplies a driving force for driving the second holding member.
The method for manufacturing a lens barrel according to any one of claims 2 to 4, wherein the mechanical stopper is a sheet metal attached to the motor. The method for manufacturing a lens barrel according to any one of claims 2 to 5, wherein the mechanical stopper is fixed to the main plate via an adhesive. The lens barrel according to any one of claims 1 to 6, further comprising a guide shaft fixed to the main plate and movably supporting the second holding member along the optical axis. Manufacturing method.

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