JP2012242424A - Lens unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens unit in which a plurality of lens elements can be bonded without using a lens supporting frame, which has a simple configuration as a whole, and whose lens elements can be easily molded.SOLUTION: The lens unit includes: a lens element L2 having a first lens part L2a, one of a reference reception part L3c and a reference projection L2c capable of fitting to the reference reception part, and an angle determination projection L2d; and a lens element L3 having a second lens part L3a, the other of the reference reception part and the reference projection to be fitted with the one of the reference reception part and the reference projection, and an angle determination reception part L3d to which the angle determination projection is fitted so that the optical axes A of the first and second lens parts coincide with each other while the first and second lens parts are separated from each other.

Description

  The present invention relates to a lens unit composed of a plurality of lens elements.

  When one lens unit is composed of a plurality of lens elements, each lens element is fitted into a common lens support frame, and the optical axes of the lens elements are aligned (eccentricity adjustment is performed). In general, the element is fixed to the lens support frame using an adhesive or the like. However, when the lens support frame is used, the lens unit becomes large, and the number of parts and the number of manufacturing steps increase, resulting in an increase in manufacturing cost.

Therefore, conventionally, a technique for unitizing a plurality of lens elements without using a lens support frame has been proposed.
In Patent Document 1, a lens unit is configured by joining two lens elements arranged in front and rear. The lens element on the front side is a concave part on the rear surface of the support part, a lens part that is a part through which the luminous flux is transmitted and the rear surface is a concave surface having a curved surface, a flange-like support part located on the outer peripheral side of the lens part A pair of recesses. The rear lens element is a lens part that is a part through which the luminous flux is transmitted and the front surface is a convex surface having a curved surface, a flange-like support part located on the outer peripheral side of the lens part, and a front projection of the support part And a contact surface located between the lens portion and the support portion.
The front and rear lens elements are adjusted by decentering the rear lens element by fitting the convex surface (front face) of the rear lens element to the concave face (rear face) of the front lens element. The abutment surface is brought into contact with the rear surface of the support portion of the front lens element, and a pair of protrusions are fitted into the pair of recesses to form a unit.

Japanese Examined Patent Publication No. 63-44204

However, in Patent Document 1, when the front and rear lens elements are unitized, a gap is formed between the support portion (the inner surface portion) of the front lens element and the support portion (the outer surface portion) of the rear lens element. The abutment surface must be formed on the rear lens element (apart from the support portion), so that the configuration is complicated.
Furthermore, high accuracy of decentration cannot be obtained unless the concave surface (rear surface) of the front lens element and the convex surface (front surface) of the rear lens element are accurately molded. However, it is easy to accurately mold the concave surface and the convex surface. Not. Moreover, in Patent Document 1, since the front and rear lens elements are aligned with each other, the flange-shaped support portion is further provided with a recess and a protrusion so as to be fitted. It was difficult to combine them.

  An object of the present invention is to provide a lens unit in which a plurality of lens elements can be joined to each other without using a lens support frame, and the overall configuration is simple, and each lens element can be easily molded.

  The lens unit of the present invention is a lens unit composed of a plurality of lens elements arranged in the optical axis direction, and one of the adjacent lens elements is positioned on the outer side of the first lens part and the first lens part. A reference receiving portion and one of reference protrusions that can be fitted to the reference receiving portion, and an angle determining protrusion positioned on the outer peripheral side of the first lens portion, and the other of the adjacent lens elements is the first Two lens parts, the other of the reference receiving part and the reference protrusion, which are located on the outer peripheral side of the second lens part and fitted to one of the reference receiving part and the reference protrusion, and the outer side of the second lens part In addition, the angle determining projection includes an angle determining receiving portion that allows the optical axes of the first lens portion and the second lens portion to coincide with each other by fitting the angle determining protrusion.

  The cross-sectional shape of the reference protrusion is a polygon, and the cross-sectional shape of the reference receiving portion is a shape including an arc surface that contacts each side of the polygon on at least a part of its peripheral surface, and determines the angle. The cross-sectional shape of the receiving portion is a shape having a pair of flat inner side surfaces that are symmetrical with respect to an imaginary straight line passing through the center of one of the reference receiving portion and the reference protrusion and the optical axis of the first lens portion, The cross-sectional shape of the angle determination protrusion may include a pair of contact portions that respectively contact the pair of flat inner side surfaces, and the virtual linear direction dimension may be shorter than the angle determination receiving portion.

  The reference receiving portion may be formed on the other lens element, and the reference receiving portion and the angle determination receiving portion on the side opposite to the optical axis may be opened on the outer peripheral surface of the other lens element.

  The entire reference protrusion may be positioned in the reference receiving portion, and the entire angle determination protrusion may be positioned in the angle determination receiving portion.

  Applying an adhesive to the clearance between the reference receiving portion and the reference protrusion, and the clearance between the angle determining reception portion and the angle determining protrusion, the reference receiving portion and the reference protrusion, and the angle determining reception portion and the angle determining protrusion. Each of these may be fixed.

  You may set the external shape of the said lens element so that one whole of the said adjacent lens element may be located in the other external shape line when it sees in the said optical axis direction.

  The reference receiving portion and the reference protrusion may be fitted in an interference fit state, and the angle determination receiving portion and the angle determination protrusion may be engaged in an interference fit state.

According to the present invention, one of the reference receiving portion and the reference projection formed on one lens element is fitted to the other of the reference receiving portion and the reference projection formed on the other lens element, and the other lens element If the angle determination protrusion formed on one lens element is fitted into the angle determination hole formed on the lens element, adjacent lens elements are joined together with the optical axes of the first lens portion and the second lens aligned. it can. That is, adjacent lens elements can be joined with high eccentricity accuracy without using a lens support frame.
Moreover, since it is not necessary to form a configuration for forming a gap in the optical axis direction between adjacent lens elements (a configuration corresponding to a contact surface in the prior art) in any lens element, the overall configuration is simple. It is.
Furthermore, since the decentering accuracy is not increased by the surface shapes of the first lens portion and the second lens portion (they are not brought into contact with each other), the first lens portion and the second lens portion can be easily molded.

It is the perspective view seen from the front diagonal upper part of the imaging unit carrying the lens unit of one embodiment of the present invention. It is the disassembled perspective view seen from the front diagonal upper direction of the imaging unit. It is a front view of an image pick-up unit which removed a cover member and a circuit board when an image pick-up optical system is in a wide end position. It is sectional drawing which follows the IV-IV arrow line of FIG. 1 when an imaging optical system exists in a tele end position. It is a perspective view of the separation state of two lenses which constitute a lens unit. It is a perspective view of the lens unit in a completed state. It is a right view of the lens unit in a completed state. It is a front view of the 1st lens group block of the image pick-up unit which removed the cover member and the circuit board, and its peripheral part. It is sectional drawing of the 1st lens group block which abbreviate | omits and shows a part of member along the IX-IX arrow line of FIG. It is a disassembled perspective view of the 1st lens group block which abbreviate | omitted the front lens, the front side light shielding mask, and the right side light shielding mask. It is a right view of the 1st lens group block which abbreviate | omits the right side light shielding mask. It is a left view of the lens unit of the 1st modification. It is a perspective view of the separation state of the lens unit of the 2nd modification. It is a perspective view of the lens unit in the completed state. FIG. 6 is a right side view of the lens unit in the completed state. It is a right view similar to FIG. 7 of a 3rd modification. It is a perspective view of the separation state of the lens unit of the 4th modification. FIG. 6 is a right side view of the lens unit in the completed state. It is a perspective view of the separation state of the lens unit of the 5th modification. FIG. 6 is a right side view of the lens unit in the completed state. It is a perspective view of the separation state of the lens unit of the 6th modification. FIG. 6 is a right side view of the lens unit in the completed state.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. In the following description, front and rear, left and right, and up and down directions are based on the arrow direction described in the figure.
As shown in FIGS. 1 and 2, the imaging unit 1 includes a first lens group block 3, a main body module 15, a substrate module 65, and a cover member 76 as large components.

The first lens group block 3 includes a holder 4 that is a molded product of synthetic resin. A pair of upper and lower ear pieces 5 having a through hole 6 project from the left end portion of the holder 4. In addition, a prism housing space 7 having an opening on the front and right sides is formed inside the holder 4, and a front lens holding hole 8 having an open left side is formed in the front opening of the prism housing space 7. In the right side opening of the prism storage space 7, a non-circular right lens holding hole 9 having upper and lower ends opened is formed (see FIG. 10). As shown in FIG. 4 and the like, a first prism LP1 having an entrance surface LP1-a orthogonal to the front-rear direction and an exit surface LP1-b orthogonal to the left-right direction is fitted and fixed in the prism storage space 7. It is. A lens L1 having the same cross-sectional shape as the front lens holding hole 8 and having an optical axis extending in the front-rear direction is fitted and fixed to the front lens holding hole 8 so as to face the incident surface LP1-a in the front-rear direction. .
As shown in FIG. 3, when the first lens group block 3 is viewed from the front, the four corners of the incident surface LP1-a of the first prism LP1 are located on the outer peripheral side of the lens L1. However, as shown in FIGS. 2 and 8, the front light-shielding mask 10 in which the lens escape hole 11 for avoiding the lens L <b> 1 is formed is attached to the front surface of the holder 4 in a fixed state. Covers the four corners of the incident surface LP1-a, so that the four corners of the incident surface LP1-a are not exposed forward.

A lens unit 12 including a lens L2 (one lens element) and a lens L3 (the other lens element) both made of resin is fitted in the right lens holding hole 9 of the holder 4 (see FIG. 10).
The outer shape of the lens L2 when viewed in the left-right direction is substantially the same as the cross-sectional shape of the right lens holding hole 9. That is, in order to reduce the thickness (front-rear dimension) of the imaging unit 1 (holder 4), the front and rear ends are non-circular. A lens portion L2a (first lens portion) having a substantially circular shape and a concave surface on the right side (exit side) is formed at the center of the lens L2. A pair of protrusions L2b protrude from the upper and lower sides of the lens portion L2a, and a reference protrusion L2c and an angle determining protrusion L2d, which are cylindrical members of the same shape, are directed to the right side of the upper and lower protrusions L2b. Projected to The central axes of the reference protrusion L2c and the angle determining protrusion L2d are both positioned on an imaginary straight line L that extends in the vertical direction through the center of the lens portion L2a (the position through which the optical axis A passes) (see FIG. 7).
The outer shape of the lens L3 when viewed in the left-right direction is substantially the same as that of the lens L2, and the central portion has the same side shape as the lens portion L2a (the shape when viewed in the left-right direction) and the left side surface ( A lens portion L3a (second lens portion) having a convex surface on the incident side is formed. A pair of protrusions L3b protrude from the upper and lower sides of the lens portion L3a. A reference hole L3c having a square cross section is formed as a through hole in the upper protrusion L3b. The length of each side of the reference hole L3c in the free state is slightly shorter than the diameter in the free state of the reference protrusion L2c (the tolerance between the reference protrusion L2c and the reference hole L3c is set to be shorter). An angle determining hole L3d (angle determining receiving portion) having a rectangular cross section which is long in the vertical direction is formed as a through hole in the lower protrusion L3b. The pair of flat inner side surfaces L3d1 that are the long sides of the angle determining hole L3d are symmetric (parallel) with respect to the virtual straight line L, and the length (vertical dimension) in the free state is larger than the diameter in the free state of the angle determining projection L2d. It is long (the tolerance of the angle determining projection L2d and the angle determining hole L3d is set to be longer), and the length (front-rear dimension) of the short side of the angle determining projection L3d in the free state is that in the free state of the angle determining projection L2d. It is slightly shorter than the diameter (the tolerance of the angle determining projection L2d and the angle determining hole L3d is set so as to be shorter).

As shown in FIGS. 5 to 7, the lens L2 and the lens L3 are configured such that the reference protrusion L2c and the angle determination protrusion L2d are fitted in the reference hole L3c and the angle determination hole L3d in an interference fit state, and the concave surface of the lens portion L2a and the lens In a state where the convex surfaces of the portion L3a are separated, the opposing surfaces (the portions located on the outer peripheral side of the lens portion L2a and the lens portion L3a) are brought into surface contact with each other. When the angle determining protrusion L2d is not fitted in the angle determining hole L3d, the reference protrusion L2c can rotate relative to the reference hole L3c around its own axis, but both front and rear end faces (contact portions) of the angle determining protrusion L2d ) Are in pressure contact with the pair of flat inner side surfaces L3d1 of the angle determining hole L3d, thereby restricting relative rotation of the reference protrusion L2c with respect to the reference hole L3c, so that the optical axis A of the lens L2 and the optical axis A of the lens L3 coincide. Further, by applying an adhesive (not shown) to the clearance formed between the reference protrusion L2c and the reference hole L3c and the clearance formed between the angle determination protrusion L2d and the angle determination hole L3d, the reference protrusion L2c is applied. The reference hole L3c, the angle determining projection L2d, and the angle determining hole L3d are firmly fixed.
The lens unit 12 integrated in this way is fitted in the right lens holding hole 9 while the upper and lower protrusions L2b and L3b are positioned in the open portions of the upper and lower ends of the right lens holding hole 9. The right side surface (exit side surface) of the lens L3 is located on the same plane as the right end surface of the holder 4 (the right end surface of the wall forming the right lens holding hole 9), and the lens portion L2a is the first prism. It faces the emission surface LP1-b of LP1 in the left-right direction (the optical axis direction of the lenses L2, L3).
Further, a right light-shielding mask 13 that covers the right side surface of the lens L3 is stuck to the right end surface of the holder 4 in a fixed state (see FIG. 2). However, since the opening 14 is formed in the right light-shielding mask 13, the inner peripheral side portion of the lens portion L3a is exposed to the right side from the outer peripheral edge portion.
The holder 4, the front light shielding mask 10, the lens unit 12, and the right light shielding mask 13 described above are the components of the first lens group block 3. The lens L1, the first prism LP1, the lens L2, and the lens L3 are components of the first lens group LG1.

  The main body module 15 includes a housing 16 made of synthetic resin. A mounting recess 17 is provided in the left end portion of the housing 16, and a storage recess 18 having a substantially rectangular cross section is formed on the front surface of a portion located on the right side of the mounting recess 17. A partition wall 19 is formed between the mounting recess 17 and the storage recess 18, and a communication hole 20 (see FIG. 3) for communicating the mounting recess 17 and the storage recess 18 at the center of the partition wall 19. (See FIG. 4). A positioning portion 22 having a substantially square shape in front view is projected forward from the right end portion of the bottom surface (rear surface) of the storage recess 18. Further, the positioning portion 22 includes three spacers 23a, 23b, and 23c protruding forward, and the front surfaces of the spacers 23a, 23b, and 23c are flat and perpendicular to the front-rear direction (thickness direction of the housing 16). A positioning plane 24 is formed. In addition, a prism recess 25 having openings on the front and left sides is provided in the positioning portion 22. Furthermore, substrate support surfaces 27 that are stepped backward from the front surface of the housing 16 and are orthogonal to the front-rear direction are formed at the front edge portion of the inner peripheral surface of the housing recess 18. Is provided with a locking projection 28 protruding forward. A first engagement recess 30 is formed at the front end of the central portion of the upper surface of the housing 16, which is one step lower than the peripheral portion (downward). The first engagement recess 30 is located on the left side of the first engagement recess 30. A second engaging recess 31 is formed at the same height as 30 and wider than the first engaging recess 30, and an engaging projection 32 projects from the second engaging recess 31. Further, a first engagement recess 30, a second engagement recess 31, and an engagement protrusion 32 having the same configuration are formed on the lower surface of the housing 16. The positional relationship between the first engaging recess 30, the second engaging recess 31, and the engaging protrusion 32 on the lower surface is the same as that on the upper surface, but the first engaging recess 30 and the second engaging recess 31 on the lower surface. The engaging protrusion 32 is displaced to the right as a whole with respect to the upper surface. Further, a pair of upper and lower engaging protrusions 34 project from the right side surface of the housing 16.

  The prism recess 25 is fitted and fixed with a second prism LP2 (exit-side prism) having an entrance surface LP2-a orthogonal to the left-right direction and an exit surface LP2-b orthogonal to the front-rear direction. The entrance surface LP2-a faces the exit surface LP1-b in the left-right direction.

Both the inner ends of the right side wall of the housing 16 and the partition wall 19 are fixed in a state where both ends of the first rod 36 and the second rod 37 which are metal cylindrical members linearly extending in the left-right direction are arranged vertically. .
The first rod 36 is fitted with an insertion hole 40 formed in the upper part of the second group lens frame 39 made of synthetic resin, and the second rod 37 is provided with a rotation stop groove formed in the lower end portion of the second group lens frame 39. 41 is engaged. Since the rotation stop groove 41 engages with the second rod 37 in this way, the rotation of the second group lens frame 39 around the first rod 36 is restricted, so that the second group lens frame 39 has the first rod 36 and the first rod 36. 2 is slidable in the left-right direction along the rod 37. The lens holding hole penetrating the second group lens frame 39 in the left-right direction is composed of two lenses L4 and L5, and the second lens group LG2 facing the exit surface LP1-b and the entrance surface LP2-a in the left-right direction. Is fixedly fitted. Further, a nut holding hole 42 whose left and right ends are open is formed at the upper end portion of the second group lens frame 39, and a driven nut 44 having a female screw hole whose axis extends in the left-right direction is formed in the nut holding hole 42. It is fitted and fixed in a state where the rotation around it is restricted. A first motor M1 made of a stepping motor is fixed to the upper portion of the housing recess 18. The first motor M1 includes a rotary drive shaft M1a that linearly extends to the left, and a male screw groove formed near the tip of the rotary drive shaft M1a is screwed into the female screw groove of the driven nut 44. . Accordingly, when the first motor M1 is operated to rotate the rotational drive shaft M1a forward and backward about its axis, the second group lens frame 39 (lenses L4 and L5) moves along the first rod 36 and the second rod 37. It moves linearly in the left-right direction between the tele end position shown in FIG. 4 and the wide end position shown in FIG.
The second rod 37 is fitted with an insertion hole 48 formed in the lower part of a synthetic resin third group lens frame 47 located on the right side of the second group lens frame 39, and the first rod 36 is fitted with a third group lens. Since the rotation stop groove 49 formed at the upper end of the frame 47 is engaged, the third group lens frame 47 is restricted in rotation along the first rod 36 and the second rod 37 (around the second rod 37). It can slide left and right. A third lens group LG3, which is composed of one lens L6 and concentric with the second lens group LG2, is fitted and fixed in a lens holding hole that penetrates the third group lens frame 47 in the left-right direction. A nut holding hole 50 having both left and right ends opened is formed at the lower end of 47, and the driven nut 44 is fitted and fixed in the nut holding hole 50 in a state where rotation around its own axis (left and right direction) is restricted. It is. Further, a second motor M2 having the same specification as that of the first motor M1 is fixed to the lower portion of the housing recess 18, and a male screw groove formed near the tip of the rotation drive shaft M2a (same specification as the rotation drive shaft M1a) is driven. The nut 44 is screwed into the female thread groove. Accordingly, when the second motor M2 is operated to rotate the rotational drive shaft M2a forward and backward about its axis, the third group lens frame 47 (third lens group LG3) moves along the first rod 36 and the second rod 37. 4 is moved linearly in the left-right direction between the tele end position shown in FIG. 4 and the wide end position shown in FIG.
The first lens group LG1, the second lens group LG2 (second group lens frame 39, driven nut 44), the third lens group LG3 (third group lens frame 47, driven nut 44), and the second prism LP2 described above are included. The second lens group LG2 (lenses L4 and L5) and the third lens group LG3 (lens L6) advance and retreat along the first rod 36 and the second rod 37, which are components of the imaging optical system (bending optical system). Thus, the imaging optical system performs a zooming operation, and performs a focusing operation by moving the third lens group LG3 back and forth.
Further, the housing 16, the first rod 36, the second rod 37, the imaging optical system, the first motor M 1, and the second motor M 2 are components of the main body module 15.

In the first lens group block 3 and the main body module 15, the portion located on the right side of the ear piece 5 of the holder 4 is fitted into the mounting recess 17, and the upper and lower ear pieces 5 and the upper and lower left end surfaces of the housing 16 (attachment) A pair of fixing screws B are inserted into the upper and lower through-holes 6 from the left side with the spacers S sandwiched between the concave portions 17 and the left end surfaces of the protrusions located on the upper and lower sides of the concave portion 17. These parts are integrated by screwing into a female screw hole formed in the left end surface of the housing 16.
When the first lens group block 3 and the main body module 15 are integrated, the right end portion of the holder 4 (the wall forming the right lens holding hole 9) is fitted into the communication hole 20 of the partition wall 19, and the lens unit 12 (lens L2, the optical axis A of the lens L3) coincides with the optical axes of the second lens group LG2 and the third lens group LG3.

The board module 65 includes a circuit board 66 made of a flat plate whose front shape is substantially the same as the housing recess 18 of the housing 16 and orthogonal to the front-rear direction. A printed circuit (not shown) is formed on the rear surface of the circuit board 66, and circular holes 67 are formed at two corners of the circuit board 66.
An imaging element 69 is fixed to the right end portion of the rear surface of the circuit board 66, and a plurality of terminals (not shown) provided on the imaging element 69 are connected to the printed circuit in a fixed state by soldering. An imaging surface (not shown) orthogonal to the front-rear direction is formed on the rear surface of the imaging element 69. Further, the imaging element 69 is provided with a cover glass 70 in a fixed state, which is a flat plate and covers the entire imaging surface on the incident side surface (rear surface in the drawing).
Further, a packing 72 made of an elastic material such as rubber whose front surface and left side surface are open is put on the rear surface (rear end portion) of the image sensor 69. Further, on the rear surface of the packing 72, an exposure hole (through hole) 73 for exposing the entire imaging surface rearward and three through holes for penetrating the spacers 23a, 23b, and 23c are formed. .
The circuit board 66, the image sensor 69, and the packing 72 described above are constituent elements of the board module 65.

The cover member 76, which is a press-formed product of a metal plate, includes a base portion 77 that is a flat plate portion orthogonal to the front-rear direction, a short engagement piece 78 that extends rearward from both upper and lower edges of the base portion 77, and a long length. A dimension engagement piece (elastic engagement piece) 79, and a pair of upper and lower side engagement pieces (elastic engagement pieces) 81 extending in the rear direction from the right edge of the base 77 and extending substantially rearward. Integrated. The base 77 has a substantially rectangular shape that is slightly larger than the circuit board 66, and includes a pressing piece 84, a pressing piece 85, and a pressing piece 86 that are both elastically deformable in the front-rear direction.
The pressing piece 84, the pressing piece 85, and the pressing piece 86 respectively include a pressing protrusion 84a, a pressing protrusion 85a, and a pressing protrusion 86a that protrude from the front to the rear (the pressing piece 84, the pressing piece 85, And the front surface of the portion corresponding to the pressing protrusion 84a, the pressing protrusion 85a, and the pressing protrusion 86a of the pressing piece 86 is recessed), the pressing piece 84, the pressing piece 85, and the pressing piece 86 are in a free state. It is located on the same plane as the other parts of the base 77.
The long engagement piece 79 and the side engagement piece 81 are respectively formed with an engagement hole 80 and an engagement hole 82 each having a square shape.

In order to assemble the board module 65 and the cover member 76 with respect to the main body module 15, first, the circuit board 66 holds the recesses by fitting the two circular holes 67 of the circuit board 66 into the two locking projections 28 of the housing 16. 18 is closed, and the peripheral portion of the rear surface of the circuit board 66 is brought into surface contact with the substrate support surface 27 (the front surface of the circuit board 66 and the front surface of the housing 16 are located on substantially the same plane). Then, the three spacers 23a, 23b, and 23c of the housing 16 pass through the three through holes of the packing 72 forward, and the positioning plane 24 is a flat rear surface of the cover glass 70 of the image sensor 69 (immediately after the image pickup surface). The surface is in contact with the outer peripheral side of the portion positioned, and a gap in the front-rear direction is formed between the cover glass 70 and the second prism LP2 (exit surface LP2-b). Further, the imaging surface of the imaging element 69 faces the exit surface LP2-b of the second prism LP2 in the front-rear direction through the exposure hole 73. Further, the rear surface of the packing 72 comes into contact with the front surface of the positioning portion 22.
Next, the base portion 77 of the cover member 76 is put on the front surface of the housing 16 from the front, and the upper and lower short engagement pieces 78 are engaged with the upper and lower first engagement recesses 30, respectively. By engaging the engagement holes 80 with the upper and lower engagement protrusions 32 and engaging the engagement holes 82 of the upper and lower side engagement pieces 81 with the upper and lower engagement protrusions 34, the cover member 76 is moved. Secure to the housing 16.
When the imaging unit 1 is assembled in this manner, the pressing piece 84, the pressing piece 85, and the pressing protrusion 84a, the pressing protrusion 85a, and the pressing protrusion 86a of the cover piece 76 are on the right side of the front surface of the circuit board 66. From the pressing piece 84, the pressing piece 85, and the pressing piece 86 that are elastically deformed slightly to the front, and are directed rearward to the front surface of the circuit board 66 (through the pressing protrusion 84a, the pressing protrusion 85a, and the pressing protrusion 86a). Since a pressing force (biasing force) is applied, the circuit board 66 and the image sensor 69 are pressed backward. Then, the integrated body of the circuit board 66 and the image sensor 69 is sandwiched from the front and rear by the positioning plane 24 of the three spacers 23a, 23b, and 23c of the housing 16, the pressing protrusion 84a, the pressing protrusion 85a, and the pressing protrusion 86a of the cover member 76. Therefore, the circuit board 66 and the imaging device 69 are accurately positioned in the front-rear direction with respect to the housing 16 and the second prism LP2 by the spacers 23a, 23b, 23c and the pressing protrusions 84a, 85a, 86a.

When the imaging unit 1 is directed to a subject positioned in front, reflected light (photographing light) of the subject passes through the lens L1 and then enters the first prism LP1 through the incident surface LP1-a, and the inner surface of the first prism LP1. Is reflected while the traveling direction is converted by 90 ° toward the exit surface LP1-b. Further, the reflected light that has exited from the exit surface LP1-b passes through the lenses L2 to L6 and then enters the inside of the second prism LP2 from the entrance surface LP2-a. The exit surface LP2-b is incident on the inner surface of the second prism LP2. The traveling direction is reflected by 90.degree. To the side, passes through the exposure hole 73 and the cover glass 70, and is imaged (received) by the imaging surface of the imaging element 69. When the external force or vibration is applied to the image pickup unit 1, the front and back positions of the image pickup element 69 (the image pickup surface thereof) are accurately held at the predetermined design position even when external force or vibration is applied as described above. In this case, the subject image can be picked up by the image pickup element 69 as a focused and unblurred image.
Further, the second lens group LG2 (lenses L4 and L5) and the third lens group LG3 (lens L6) are advanced and retracted along the first rod 36 and the second rod 37 using the first motor M1 and the second motor M2. Thus, if the image pickup optical system is zoomed and focused, the subject image can be picked up in a zoomed and focused state.

In the imaging unit 1 of the present embodiment described above, the lens unit 12 is configured by fitting the reference protrusion L2c to the reference hole L3c and fitting the angle determining protrusion L2d to the angle determining hole L3d. Therefore, a lens support frame for integrating the lens L2 and the lens L3 is not necessary.
Further, in both the lens L2 and the lens L3, a portion for forming a gap in the optical axis A direction between the lens portion L2a and the portion located on the outer peripheral side of the lens portion L3a (corresponding to the contact surface of the prior art) The configuration of the lens unit 12 is simple.
Further, since the lens portion L2a and the lens portion L3a are not used for eccentricity adjustment (they are not brought into contact with each other), the lens portion L2a and the lens portion L3a can be easily molded.
Further, since the longitudinal dimension (vertical dimension) of the angle determining hole L3d is longer than the diameter of the angle determining protrusion L2d, the angle determining protrusion L2d can be easily fitted into the angle determining hole L3d.
Further, since the reference protrusion L2c and the angle determining protrusion L2d are fitted into the reference hole L3c and the angle determining hole L3d in an interference fit state, it is possible to eliminate the play between both the holes and the shaft. And the lens L3 can be adjusted with high accuracy.

In this embodiment, in order to reduce the thickness (front-rear dimension) of the imaging unit 1, the front-rear dimensions of the lens L2 and the lens L3 are reduced. That is, by cutting off both front and rear ends of the lens L2 and the lens L3 linearly, the lens portion L2a and the front and rear ends of the lens portion L3a constitute part of the outer shape of the lens L2 and the lens L3 (front and rear ends). . However, the adhesive for fixing the lens L2 and the lens L3 is bonded to the clearance formed between the reference protrusion L2c and the reference hole L3c and the clearance formed between the angle determination protrusion L2d and the angle determination hole L3d. Since no adhesive is applied to the outer peripheral portions of the lens L2 and the lens L3, the adhesive adheres to the lens portion L2a and the lens portion L3a and is effectively transmitted through the lens portion L2a and the lens portion L3a. There is no light.
Furthermore, since the adhesive is applied to each clearance, it is possible to prevent the adhesive from flowing out to the lens portions L2a and L3a.
Further, since the outer peripheral surfaces of the reference protrusion L2c and the angle determining hole L2d and the inner peripheral surfaces of the reference hole L3c and the angle determining hole L3d are bonded, a strong adhesive force can be obtained.

Although the present invention has been described using the present embodiment, the present invention can be implemented with various modifications.
For example, the modification shown in FIG. 12 can be implemented.
The lens L3 of the lens unit 12A of this modification is the same as that in the above embodiment, but the lens L2A (one lens element) is smaller than the lens L2. Therefore, when the lens unit 12A is viewed in the direction of the optical axis A, the entire lens L2A is located within the outline of the lens L3. Therefore, when this lens unit 12A is fitted into the right lens holding hole 9 of the holder 4, only the outer peripheral surface of the lens L3 contacts the inner surface of the right lens holding hole 9, and the outer peripheral surface of the lens L2A is the right lens holding hole 9. Separate from the inner surface.
If the lens L2 and the lens L3 are designed to have substantially the same size, it can be predicted which of the lens L2 and the lens L3 interferes with the inner surface of the right lens holding hole 9 when the lens unit is fitted into the right lens holding hole 9. In addition, the influence of interference becomes more complicated. However, if the lens L2A is intentionally made smaller than the lens L3 so that only the lens L3 is brought into contact with the inner surface of the right lens holding hole 9, such a problem can be avoided.
The lens L3 may be smaller than the lens L2A, and only the lens L2A may be in contact with the inner surface of the right lens holding hole 9.

13 to 15 show another modification.
The lens L2B (one lens element) of this modification has the same configuration as the lens L2 except that the shape of the protrusion L2e is different from that of the protrusion L2b.
A pair of symmetrical support arms L3e project from the upper portion of the lens L3B (the other lens element), and the front end surfaces (opposing surfaces) of the support arms L3e move toward the lens portion L3a. The support inclined surface L3e1 is widened. Further, a support protrusion L3f protrudes from the inner surface of the space surrounded by the pair of support arms L3e and the lens portion 3a on the lens portion L3a side. On the other hand, a pair of symmetrically supporting arms L3g project from the lower portion of the lens L3B, and the tip surface (opposing surface) of each supporting arm L3g is the center of the lens portion L3a (position through which the optical axis A passes). It is a flat inner side face L3g1 that is located on both sides of the virtual straight line L that extends in the up-down direction and is parallel to the virtual straight line L.
When the reference protrusion L2c is fitted into a reference receiving portion (reference hole) constituted by the two support inclined surfaces L3e1 and the support protrusion L3f of the lens L3B, the three peripheral surfaces of the reference protrusion L2c have two support inclined surfaces L3e1. And the support protrusion L3f, respectively, and the reference receiving portion and the reference protrusion L2c are in an interference fit state. When the angle determination protrusion L2d is fitted into an angle determination receiving portion (angle determination hole) formed by the space on the optical axis A side of the two flat inner side surfaces L3g1 of the lens L3B and the support arm L3g, the circumference of the angle determination protrusion L2d The two front and rear portions (contact portions) of the surface are in pressure contact with the two flat inner side surfaces L3g1, respectively, and the angle determination receiving portion and the angle determination protrusion L2d are tightly fitted, and the optical axis A of the lens L2B and the optical axis A of the lens L3B Match. Furthermore, a clearance formed between the space formed by the outer peripheral surfaces of the two support arms L3e and the lens portion 3a and the reference protrusion L2c, and a space formed by the outer peripheral surfaces of the two support arms L3g and the lens portion 3a By applying an adhesive to the clearance formed between the angle determination protrusion L2d, the reference protrusion L2c and the lens L3B, and the angle determination protrusion L2d and the lens L3B are firmly fixed.
In the lens L3B of this modification, the portions of the reference receiving portion and the angle determining receiving portion opposite to the optical axis A are open on the outer peripheral surface of the lens L3B (the outer surfaces of the support arm L3e and the support arm L3g). That is, the lens L3B does not have a portion covering the upper side of the central portion of the reference receiving portion, and does not have a portion covering the lower side of the central portion of the angle determining receiving portion. Can be reduced.

The lens unit 12C of the modification of FIG. 16 is obtained by changing a part of the lens unit 12B.
The lens unit 12C includes a lens L3B (the other lens element) and a lens L3C (one lens element). The lens L3C has the same structure as the lens L3B except for the reference protrusion L2f and the angle determining protrusion L2g. The reference protrusion L2f has a shape obtained by linearly cutting off the upper end portion of the reference protrusion L2c, and the angle determining protrusion L2g has a shape obtained by linearly cutting the lower half of the angle determining protrusion L2d.
Therefore, when the lens L3B and the lens L3C are integrated, the entire reference projection L2f is located in the reference receiving portion constituted by the support inclined surface L3e1 and the support projection L3f, and the entire angle determining projection L2g is supported by the two flat inner side surfaces L3g1. Since it is located in the angle determination receiving part constituted by the space on the optical axis A side of the arm L3g, the vertical dimension of the lens unit 12C can be further reduced.

17 and 18 show another modification.
The reference protrusion L2h of the lens L2D (one lens element) of this modification has a substantially triangular prism shape. However, the three corners of the triangular prism are chamfered so as to be a cylindrical surface forming a part of a virtual cylindrical surface centered on the central axis of the triangular prism.
The cross-sectional shape of the reference hole L3h of the lens L3D (the other lens element) is a shape obtained by chamfering each vertex of a triangle whose phase in the rotation direction is shifted by 60 ° from the reference protrusion L2h. The angle determination hole L3i (angle determination receiving portion) of the lens L3D has the same shape as the angle determination hole L3d except that the cross-sectional shape of both upper and lower surfaces is an arc shape (a pair of flat inner side surfaces L3d1 are both sides of the virtual straight line L) And parallel to the virtual straight line L).
When the reference protrusion L2h is fitted into the reference hole L3h, the three cylindrical surfaces of the reference protrusion L2h are in pressure contact with the three inner surfaces of the reference hole L3h, respectively, so that the reference hole L3h and the reference protrusion L2h are tightly fitted. When the angle determination protrusion L2d is fitted into the angle determination hole L3i, the two front and rear positions (contact portions) of the angle determination protrusion L2d are in pressure contact with the two flat inner side surfaces L3d1 of the angle determination hole L3i, respectively. The determination protrusion L2d is in an interference fit state, and the optical axis A of the lens L2D and the optical axis A of the lens L3D coincide.

19 and 20 show another modification.
The reference protrusion L2i of the lens L2E (one lens element) of this modification has a substantially quadrangular prism shape. However, the four corners of the reference protrusion L2i are chamfered so as to form a cylindrical surface that forms a part of a virtual cylindrical surface centered on the central axis of the quadrangular prism.
The cross-sectional shape of the reference hole L3j of the lens L3E (the other lens element) is a shape obtained by chamfering each vertex of a quadrangle whose phase in the rotation direction is shifted by 45 ° from the reference protrusion L2i.
When the reference projection L2i is fitted into the reference hole L3j, the four cylindrical surfaces of the reference projection L2i are in pressure contact with the four inner surfaces of the reference hole L3j, respectively, so that the reference hole L3j and the reference projection L2i are in a tight fit state. When the angle determination protrusion L2d is fitted into the angle determination hole L3i, the two front and rear positions (contact portions) of the angle determination protrusion L2d are in pressure contact with the two flat inner side surfaces L3d1 of the angle determination hole L3i, respectively. The fixing projection L2d is in an interference fit state, and the optical axis A of the lens L2E and the optical axis A of the lens L3E coincide.

21 and 22 show another modification.
The reference protrusion L2j of the lens L2F (one lens element) of this modification has a substantially pentagonal prism shape. However, the five corners of the reference protrusion L2j are chamfered so as to be a cylindrical surface that forms a part of a virtual cylindrical surface centered on the central axis of the pentagonal prism.
The cross-sectional shape of the reference hole L3k of the lens L3F (the other lens element) is a shape obtained by chamfering each vertex of a pentagon whose phase in the rotation direction is shifted by 36 ° from the reference protrusion L2j.
When the reference protrusion L2j is fitted into the reference hole L3k, the five cylindrical surfaces of the reference protrusion L2j are in pressure contact with the five inner surfaces of the reference hole L3k, respectively, so that the reference hole L3k and the reference protrusion L2j are tightly fitted. When the angle determination protrusion L2d is fitted into the angle determination hole L3i, the two front and rear positions (contact portions) of the angle determination protrusion L2d are in pressure contact with the two flat inner side surfaces L3d1 of the angle determination hole L3i, respectively, and the reference hole L3h and the reference protrusion L2h is in an interference fit state, and the optical axis A of the lens L2F and the optical axis A of the lens L3F coincide.
The reference protrusion may be a columnar body having a hexagonal or more polygonal cross section, and the reference hole may be a hole having a hexagonal or more polygonal cross section corresponding thereto.

Further, in the above-described embodiment and each modification, the lens L2, L2A to L2F is formed on the lens L2, L2A to L2F side so that the lens L2, L2A to L2F is “the other lens element” in the claims. The lens L3, L3B to L3F may be “one lens element” in the claims by forming a reference protrusion and an angle determining protrusion on the lenses L3, L3B to L3F side. Further, the reference receiving portion and the angle determining projection may be provided on the “one lens element” side, and the reference protrusion and the angle determining receiving portion may be provided on the “other lens element” side.
Further, the present invention may be applied by setting one of adjacent lens elements among three or more lens elements arranged in the optical axis direction as “one lens element” and the other as “the other lens element”.

The lens unit to which the present invention is applied can also be applied to an optical device different from the imaging unit 1.
Further, the first prism LP1 and the second prism LP2 may be replaced with mirrors.
Further, only one prism may be included in the imaging optical system (bending optical system).

DESCRIPTION OF SYMBOLS 1 Imaging unit 3 1st lens group block 4 Holder 5 Ear piece 6 Through-hole 7 Prism storage space 8 Front lens holding hole 9 Right lens holding hole 10 Front light shielding mask 11 Lens escape hole 12 12A 12B 12C Lens unit 13 Right light shielding mask 14 Circular hole 15 Body module 16 Housing 17 Mounting recess 18 Storage recess 19 Bulkhead 20 Communication hole 22 Positioning portion 23a 23b 23c Spacer 24 Positioning plane 25 Prism recess 27 Substrate support surface 28 Locking projection 30 First engaging recess 31 Second Engaging recess 32 34 Engaging protrusion 36 1st rod 37 2nd rod 39 2nd group lens frame 40 Insertion hole 41 Rotation stop groove 42 Nut holding hole 44 Driven nut 47 3rd group lens frame 48 Insertion hole 49 Rotation stop groove 50 Nut holding Hole 65 Board module 66 Circuit board 67 Circular hole 6 The imaging device 70 cover glass 72 packing 73 exposure hole (through hole)
76 Cover member 77 Base 78 Short engagement piece 79 Long engagement piece (elastic engagement piece)
80 engagement hole 81 side engagement piece (elastic engagement piece)
82 Engagement hole 85 85 86 Pressing piece 84a 85a 86a Pressing protrusion A Optical axis B Fixing screw L Virtual straight line L1 Lens L2 L2A L2B L2C Lens L2a Lens part L2b Projection L2c Reference projection L2d Angle determination projection L2e Projection L2f Reference projection L2g Angle determining projection L2h Reference projection L2i Reference projection L2j Reference projection L3 L3B Lens L3a Lens portion L3b Projection L3c Reference hole L3d Angle determination hole L3d1 Flat inner side surface L3e Support arm L3e1 Support inclined surface L3f Support projection L3g Flat side inside support arm L3g1 L3h Reference hole L3i Angle determining hole L3j Reference hole L3k Reference hole L4 Lens L5 Lens L6 Lens LG1 First lens group LG2 Second lens group LG3 Third lens group LP1 First prism LP1-a Entrance surface LP1-b Outgoing surface LP2 First 2 prisms ( Morphism side prism)
LP2-a Incident surface LP2-b Outgoing surface M1 First motor M1a Rotation drive shaft M2 Second motor M2a Rotation drive shaft S Spacer

Claims (7)

A lens unit composed of a plurality of lens elements arranged in the optical axis direction,
One of the adjacent lens elements is a first lens part, a reference receiving part located on the outer peripheral side of the first lens part, one of the reference protrusions that can be fitted to the reference receiving part, and the first lens An angle determining protrusion located on the outer peripheral side of the part,
The other of the adjacent lens elements is a second lens part, the other of the reference receiving part and the reference protrusion that are located on the outer peripheral side of the second lens part and fits to one of the reference receiving part and the reference protrusion, An angle determination receiving portion that is positioned on the outer peripheral side of the second lens portion and that fits the angle determination protrusions so that the optical axes of the first lens portion and the second lens portion are aligned with each other. A lens unit characterized by that. The lens unit according to claim 1, wherein
The cross-sectional shape of the reference protrusion is a polygon,
The cross-sectional shape of the reference receiving portion is a shape including an arc surface that contacts each side of the polygon on at least a part of its peripheral surface,
The cross-sectional shape of the angle determination receiving portion is a shape having a pair of flat inner side surfaces that are symmetrical with respect to an imaginary straight line that passes through the center of one of the reference receiving portion and the reference protrusion and the optical axis of the first lens portion. Yes,
A lens unit in which the cross-sectional shape of the angle determination protrusion includes a pair of contact portions that contact the pair of flat inner side surfaces, respectively, and the virtual linear direction dimension is shorter than the angle determination receiving portion. The lens unit according to claim 1 or 2,
Forming the reference receiving portion on the other lens element;
A lens unit in which a portion opposite to the optical axis of the reference receiving portion and the angle determining receiving portion is opened on an outer peripheral surface of the other lens element. The lens unit according to claim 3,
A lens unit in which the entire reference protrusion is positioned in the reference receiving portion, and the entire angle determination protrusion is positioned in the angle receiving portion. The lens unit according to any one of claims 1 to 4,
Applying an adhesive to the clearance between the reference receiving portion and the reference protrusion, and the clearance between the angle determining reception portion and the angle determining protrusion, the reference receiving portion and the reference protrusion, and the angle determining reception portion and the angle determining protrusion. Each lens unit is fixed. The lens unit according to any one of claims 1 to 5,
A lens unit in which the outer shape of the lens element is set so that one of the adjacent lens elements is located within the other outer shape line when viewed in the optical axis direction. The lens unit according to any one of claims 1 to 6,
A lens unit in which the reference receiving portion and the reference protrusion are fitted in an interference fit state, and the angle determination receiving portion and the angle determination protrusion are engaged in an interference fit state.

Images