JP2013029713A - Imaging unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging unit capable of surely eliminating play between a lens frame and a nut by a spring and downsizing the imaging unit in the longitudinal direction of a guide rod.SOLUTION: The imaging unit includes: guide rods 36, 37; motors M1, M2 for rotating lead screws M1a, M2a; a driven nut 44 with a first pressed surface 44a screwed to the lead screw; lens frames 39, 47 with coil attachment sections 39b, 47b supported to be capable of being slid on the guide rods, nut receiving surface 39e1, 47e2 and second pressed surfaces 39h, 47h; and torsion springs S1, S2 having coil sections S1a, S2a fit into a coil attachment section, pressing the first pressed surface on one ends thereof S1b, S2b and pressing the second pressed surface by the other ends thereof S1c, S2c.

Description

  The present invention relates to an imaging unit including an imaging optical system and an imaging element.

  In recent years, portable electronic devices mainly for photographing such as digital still cameras and digital video cameras, and portable electronic devices having an incidental photographing function such as camera-equipped mobile phones and portable information terminals have been widely used. In this type of portable electronic device, it is widely performed to incorporate an imaging unit having a configuration in which an imaging element and an imaging optical system for guiding imaging light to the imaging element are housed in a hollow housing.

As a conventional technique of the imaging unit, for example, there is one disclosed in Patent Document 1. The imaging optical system of the imaging unit includes a guide rod extending in the longitudinal direction of the imaging unit, a lens frame that supports the lens and is slidably supported by the guide rod, a motor including a lead screw parallel to the guide rod, a lead The first and second nut members screwed into the screw, the nut supporting recess formed in the lens frame, in which the first nut member is loosely fitted, and the first nut member and the second nut member are separated from each other. A first coil spring that is biased in the direction, a second coil spring that is provided in a state of being contracted in the nut support recess, and that has one end abutting on the inner surface of the nut support recess and the other end abutting on the outer surface of the first nut member It is equipped with.
In this imaging unit, when the lead screw is rotated by the driving force of the motor, the first nut member slides in the axial direction of the lead screw. Therefore, the lens frame integrated with the first nut member via the second coil spring. Advances and retreats along the guide rod. Since the backlash is removed between the nut supporting recess (lens frame) and the first nut member by the second coil spring, the position of the lens can be accurately controlled by the motor.

JP 2003-295030 A

  However, in Patent Document 1, since the entire second coil spring is disposed in the nut support recess, it is necessary to form a nut support recess longer than the entire length (in a compressed state) of the second coil spring in the lens frame. Therefore, the lens frame is likely to be enlarged in the longitudinal direction of the guide rod, and it is difficult to downsize the imaging unit in the longitudinal direction of the guide rod.

  It is an object of the present invention to provide an imaging unit that can reliably remove a backlash between a lens frame and a nut by a spring, and that can downsize the imaging unit in the longitudinal direction of a guide rod.

  The imaging unit according to the present invention includes a guide rod that extends linearly, a lead screw that is parallel to the guide rod, a motor that rotates the lead screw around an axis, and a shaft that is screwed into the lead screw and orthogonal to the axis. A driven nut having a first pressed surface, a nut receiving surface that is slidably supported by the guide rod, and a surface opposite to the first pressed surface of the driven nut, and the axis. A lens frame having a second orthogonally pressed surface and supporting the driven nut in a non-rotatable manner and supporting a moving lens, a coil mounting portion formed on the lens frame, and its own coil portion The driven nut is brought into contact with the nut receiving surface by fitting into the mounting portion and pressing the first pressed surface in one direction in a direction parallel to the axis. A torsion spring that presses the second pressing surface in the direction parallel to the axis at the other end, an imaging optical system that includes the moving lens, and an imaging element that receives imaging light emitted from the imaging optical system; It is characterized by providing.

The lens frame has a pair of walls spaced apart in the axial direction, and one of the walls forms a nut support recess that constitutes the nut receiving surface, and the driven nut is disposed in the nut support recess. Also good.
Further, the coil mounting portion may be formed at a different location from the coil supporting recess, with the same position in the direction parallel to the coil supporting recess and the axis.

The imaging optical system bends the optical path of the imaging light extending along the optical axis of the moving lens, and the imaging element receives imaging light of the optical path bent by the imaging optical system. Good.
The imaging optical system includes a first reflecting surface that bends incident imaging light incident on the imaging unit in a direction perpendicular to the optical axis in the optical axis direction, and imaging light that travels along the optical axis. A second reflecting surface that is bent in a direction parallel to the incident photographing light and guided to the image sensor may be provided, and a central axis of the coil portion may be parallel to the incident photographing light.

  The coil mounting part extending in a direction orthogonal to the optical axis is projected from the lens frame, and a part of the coil part is seen at the distal end of the coil mounting part when viewed in the extending direction of the coil mounting part. A retaining portion that overlaps with the projection may be provided.

  Further, a rod insertion hole that penetrates the rod insertion portion and through which the guide rod is slidably inserted is formed in the rod insertion portion provided in the lens frame, and an axis of the rod insertion hole is formed on a side surface of the rod insertion portion. The coil mounting portion extending in a direction orthogonal to the direction may be provided.

  A communication hole that penetrates the coil attachment part in a direction parallel to the axis of the rod insertion hole and communicates with the through hole may be formed in the coil attachment part.

According to the present invention, since the backlash between the lens frame and the nut is removed by the torsion spring, the position of the lens frame (moving lens) can be accurately controlled by the motor.
Moreover, since the nut is pressed against the nut receiving surface formed on the lens frame at one end of the torsion spring, it is not necessary to form a concave portion (for arranging the nut) having a large longitudinal dimension of the guide rod in the lens frame. Therefore, the lens frame and the imaging unit can be downsized in the longitudinal direction of the guide rod.

It is the perspective view seen from the front diagonal upper part of the imaging 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 the perspective view seen from the 1st rod, the 2nd rod, the 2nd group lens frame, the 1st motor, the driven nut, and the torsion spring. It is the perspective view seen from the lower part of the 1st rod, the 2nd rod, the 2nd group lens frame, the 1st motor, the driven nut, and the torsion spring. It is the disassembled perspective view seen from the 2nd group lens frame and the lower part of a torsion spring. It is the perspective view seen from the 1st rod, the 2nd rod, the 3 group lens frame, the 2nd motor, the driven nut, and the torsion spring. It is the perspective view seen from the lower part of a 1st rod, a 2nd rod, a 3 group lens frame, a 2nd motor, a driven nut, and a torsion spring. It is the disassembled perspective view seen from the 3rd group lens frame and the lower part of a torsion spring.

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. 4). As shown in FIG. 4 and the like, the prism storage space 7 has a rectangular incident surface LP1-a that is long in the vertical direction orthogonal to the front-rear direction and a rectangular output surface that is long in the vertical direction orthogonal to the horizontal direction. A first prism LP1 including LP1-b is fitted and fixed. The front lens holding hole 8 is fitted and fixed with a lens L1 having a circular outer shape whose optical axis extends in the front-rear direction 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 FIG. 2, a front light-shielding mask 10 in which a lens escape hole 11 for avoiding the lens L1 is fixed is attached to the front surface (mask fixing surface) of the holder 4 in a fixed state. Since the four corners of the incident surface LP1-a are covered by the four corners, the four corners of the incident surface LP1-a are not exposed forward.

The lens L2 and the lens L3, both made of resin, are fitted in the right lens holding hole 9 of the holder 4 in a state where they are joined to each other (see FIG. 4).
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 lens L1, the first prism LP1, the lens L2, and the lens L3 described above are components of the first lens group LG1. The holder 4, the front light shielding mask 10, the first lens group LG <b> 1, and the right light shielding mask 13 are constituent elements of the first lens group block 3.

  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 having an incident surface LP2-a orthogonal to the left-right direction and an output surface LP2-b orthogonal to the front-rear direction. a faces the emission surface LP1-b in the left-right direction.

Both ends of a first rod 36 (guide rod) and a second rod 37 (guide rod), which are metal columnar members that extend linearly in the left-right direction, are arranged vertically on the inner surface of the right side wall of the housing 16 and the partition wall 19. They are fixed in a line.
The first rod 36 is provided with a substantially cylindrical rod insertion portion 39a (see FIGS. 5, 6, and 7) formed in the upper part of the second group lens frame 39 (lens frame) made of synthetic resin and extending in the left-right direction. An insertion hole 40 (rod insertion hole) penetrating in the direction is slidably fitted, and a rotation stop groove 41 formed at the lower end portion of the second group lens frame 39 is engaged with the second rod 37. 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 substantially cylindrical coil mounting portion 39b (see FIG. 6) extending forward is projected from the front surface of the rod insertion portion 39a, and a pair of retaining portions 39c are formed at the front end portion of the coil mounting portion 39b. Projecting upward and downward respectively. The coil attachment portion 39b is formed with a communication hole 39d that penetrates the coil attachment portion 39b in the left-right direction. The front end of the communication hole 39d is open, and the rear end of the communication hole 39d communicates with the insertion hole 40 inside the rod insertion part 39a. Further, a nut support recess 39e (see FIG. 7) having an open upper surface, front surface, and rear surface is formed at the upper end of the second group lens frame 39. As shown in the drawing, the nut supporting recess 39e has the same position in the left-right direction as the coil mounting part 39b, and the vertical position is different from the coil mounting part 39b. A rotation drive shaft insertion hole 39f having a circular cross section is formed as a through hole in the wall 39e1 positioned on the right side of the nut support recess 39e, and the rotation drive shaft insertion hole 39f is formed on the wall 39e2 positioned on the left side of the nut support recess 39e. And a rotational drive shaft escape recess 39g having a circular arc shape that is concentric with each other. Further, on the left side surface of the second group lens frame 39, a pressed surface 39h (second pressed surface), which is a plane located directly below the rod insertion portion 39a and orthogonal to the left-right direction, is formed.
A driven nut 44 having a female screw hole whose axis extends in the left-right direction is loosely fitted in the nut support recess 39e in a state where rotation around the axis is restricted. The plate thickness (left-right dimension) of the driven nut 44 is smaller than the left-right dimension of the nut support recess 39e. Further, a coil portion S1a of a torsion spring S1 having a circular coil portion S1a and end portions S1b and S1c extending from both ends of the coil portion S1a are fitted in the coil mounting portion 39b in a fixed state. (The central axis of the coil portion S1a extends in the front-rear direction). As shown in FIG. 5, when the coil part S1a is fitted to the coil attachment part 39b, the upper and lower retaining parts 39c overlap with the coil part S1a when viewed from the front, so that the coil part S1a is unexpectedly separated from the coil attachment part 39b. It will not drop out. The end portion S1b is elastically deformed and is in contact with the left side surface 44a (first pressed surface) of the driven nut 44 from the left side (the side surface 44a is a plane orthogonal to the left-right direction). It is energizing towards the right side. Therefore, the right side surface of the driven nut 44 is in contact with the left side surface (nut receiving surface) of the wall 39e1 located on the right side of the nut supporting recess 39e. Further, the end S1c is in elastic contact with the pressed surface 39h from the left side.
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 rotational drive shaft M1a (lead screw) that extends linearly toward the left. The rotational drive shaft M1a includes the rotational drive shaft insertion hole 39f, the female thread groove of the driven nut 44, and the rotation. The male screw groove formed in the vicinity of the tip end portion of the rotary drive shaft M1a is screwed into the female screw groove of the driven nut 44. The backlash between the driven nut 44 and the nut support recess 39e (the nut receiving surface which is the left side surface of the wall 39e1) is removed by the biasing force of the end S1b. 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.

Further, a synthetic resin third group lens frame 47 (lens frame) located on the right side of the second group lens frame 39 has a substantially cylindrical rod insertion portion 47a (FIGS. 8, 9, and 9) extending in the left-right direction at a lower portion thereof. 10), and an insertion hole 48 (rod insertion hole) penetrating the rod insertion portion 47 a in the left-right direction is slidably fitted to the second rod 37. Furthermore, since the rotation stop groove 49 formed at the upper end portion of the third group lens frame 47 is engaged with the first rod 36, the third group lens frame 47 extends along the first rod 36 and the second rod 37 ( It is slidable in the left-right direction (with the rotation restricted around the second rod 37). A third lens group LG3, which is composed of one lens L6 (moving lens) and is 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. Further, a substantially cylindrical coil mounting portion 47b extending forward is projected from the front surface of the rod insertion portion 47a, and a pair of retaining portions 47c are directed upward and downward at the front end portion of the coil mounting portion 47b. Each projectes. The coil attachment portion 47b is formed with a communication hole 47d penetrating the coil attachment portion 47b in the left-right direction. The front end of the communication hole 47d is open, and the rear end of the communication hole 47d communicates with the insertion hole 48 inside the rod insertion portion 47a. Further, a nut support recess 47e having a lower surface, a front surface, and a rear surface opened is formed at the lower end portion of the third group lens frame 47. As shown in the drawing, the nut supporting recess 47e has the same position in the left-right direction as the coil mounting portion 47b, and the vertical position is different from the coil mounting portion 47b. The pair of walls 47e1 and 47e2 positioned on the left and right sides of the nut support recess 47e are respectively formed with rotational drive shaft escape recesses 47f and 47g having concentric cross sections. Furthermore, a pressed surface 47h (second pressed surface), which is a plane orthogonal to the left-right direction, is formed on the right side surface of the protrusion protruding upward from the left end portion of the rod insertion portion 47a.
The driven nut 44 is loosely fitted in the nut supporting recess 47e in a state where the rotation around its own axis (left-right direction) is restricted. The plate thickness (left-right dimension) of the driven nut 44 is smaller than the left-right dimension of the nut support recess 47e. Further, the coil mounting portion 47b is fitted with a coil portion S2a of a torsion spring S2 having a circular coil portion S2a and end portions S2b and S2c extending from both ends of the coil portion S2a in a fixed state. (The central axis of the coil portion S2a extends in the front-rear direction). As shown in FIGS. 8 and 9, when the coil portion S2a is fitted to the coil mounting portion 47b, the upper and lower retaining portions 47c overlap with the coil portion S2a when viewed from the front, so that the coil portion S2a is overlapped with the coil mounting portion 47b. There is no sudden dropout. The end portion S2b is elastically deformed and is in contact with the right side surface 44a (first pressed surface) of the driven nut 44 from the right side (the side surface 44a is a plane perpendicular to the left-right direction). It is energizing towards the left side. Therefore, the left side surface of the driven nut 44 is in contact with the right side surface (nut receiving surface) of the wall 47e2 located on the left side of the nut support recess 47e. Further, the end portion S2c is in contact with the pressed surface 47h from the right side in a state of being elastically deformed.

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 the rotation drive shaft M2a (same specification as the rotation drive shaft M1a) is provided for the rotation drive shaft escape recess 47f and the driven nut 44. The female screw groove and the rotary drive shaft escape recess 47g are penetrated, and the male screw groove formed near the tip of the rotary drive shaft M2a (lead screw) is screwed into the female screw groove of the driven nut 44. The backlash between the driven nut 44 and the nut support recess 47e (the nut receiving surface that is the right side surface of the wall 47e2) is removed by the urging force of the end S2b. 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 housing 16, the first rod 36, the second rod 37, the second lens group LG2, the third lens group LG3, the second prism LP2, the first motor M1, the second motor M2, the torsion spring S1, and the like explained above. The torsion spring S2 is a component 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) fits into the communication hole 20 of the partition wall 19, and the lens L2 and the lens L3. Is coincident with the optical axes of the second lens group LG2 and the third lens group LG3.
The first lens group LG1, the second lens group LG2, the third lens group LG3, and the second prism LP2 described above are components of the imaging optical system (bending optical system), and the second lens group LG2 (lens L4). , L5) and the third lens group LG3 (lens L6) advance and retract along the first rod 36 and the second rod 37, the imaging optical system performs a zooming operation, and the third lens group LG3 advances and retracts. Performs focusing operation.

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 located in the front, reflected light (photographing light) of the subject traveling rearward passes through the lens L1 and then enters the first prism LP1 from the incident surface LP1-a. The light is reflected toward the right side while the traveling direction is changed by 90 ° toward the emission surface LP1-b by the inner surface (first reflection surface) of one prism LP1. Further, the reflected light that has exited 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, and then enters the inner surface (second reflection surface) of the second prism LP2. ) Is reflected forward while the traveling direction is converted by 90 ° toward the exit surface LP2-b, and after passing through the exposure hole 73 and the cover glass 70, the image is picked up (received) by the image pickup surface of the image pickup 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 backlash between the nut support recesses 39e and 47e (the second group lens frame 39 and the third group lens frame 47) and the driven nut 44 is removed by the torsion springs S1 and S2. Therefore, the position of the second group lens frame 39 and the third group lens frame 47 can be accurately controlled by the first motor M1 and the second motor M2.
Moreover, since the driven nut 44 is pressed by the end portions S1b and S2b, it is not necessary to increase the size of the nut support recesses 39e and 47e in the left-right direction. Furthermore, since the left and right positions of the nut supporting recesses 39e and 47e formed in the second group lens frame 39 and the third group lens frame 47 and the coil mounting portions 39b and 47b are the same, the left and right dimensions of the torsion springs S1 and S2 can be shortened. Therefore, the second group lens frame 39, the third group lens frame 47, and the imaging unit 1 can be downsized in the left-right direction.
Furthermore, when the second group lens frame 39 and the third group lens frame 47 made of synthetic resin are molded by using a mold, the portion for molding the insertion holes 40 and 48 of the mold is pulled out from the insertion holes 40 and 48. The portion of the mold for molding the coil mounting portions 39b, 47b (continuous with the portion for molding the insertion holes 40, 48) is pulled out from the coil mounting portions 39b, 47b using the communication holes 39d, 47d. Therefore, the productivity of the second group lens frame 39 and the third group lens frame 47 is good.

Although the present invention has been described using the present embodiment, the present invention can be implemented with various modifications.
For example, one of the retaining portions 39c and 47c may be omitted from the coil attachment portions 39b and 47b.
Further, at least one of the wall 39e2 and the wall 47e1 may be omitted. Furthermore, a wall 39e1 and a wall 47e2 that are not part of the nut support recess may be formed in the second group lens frame 39 and the third group lens frame 47 (the nut support recess 39e from the second group lens frame 39 and the third group lens frame 47). 47e may be omitted).
The first rod 36, the second rod 37, and the rotation drive shafts M1a, M2a do not have to be strictly parallel, and may be slightly inclined (for example, in a range of 1 to 2 °). Similarly, the communication holes 39d and 47d do not need to be strictly parallel to the axis of the insertion holes 40 and 48, and may be slightly inclined (for example, in a range of 1 to 2 °).
The coil mounting portions 39b and 47b do not need to be strictly orthogonal to the optical axes of the lenses L4, L5, and L6 (for example, the tilt angle may be in the range of about 88 ° to 92 °). The portions 39b and 47b do not need to be strictly orthogonal to the axes of the insertion holes 40 and 48 (for example, the inclination angle may be in the range of about 88 ° to 92 °).
Further, the end portions S1b, S1c, S2b, and S2c do not need to strictly press the side surface 44a and the pressed surfaces 39h and 47h in the left-right direction, and are slightly inclined with respect to the left-right direction (for example, a range of 1 to 2 °). ), The side surface 44a and the pressed surfaces 39h and 47h may be pressed.
Further, the first prism LP1 and the second prism LP2 may be replaced with mirrors.
Furthermore, the prism included in the imaging optical system (bending optical system) may be only the first prism LP1.

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 13 Right light-shielding mask 14 Opening 15 Main body module 16 Housing 17 Mounting recess 18 Storage recess 19 Partition 20 Communication hole 22 Positioning portion 23a 23b 23c Spacer 24 Positioning plane 25 Prism recess 27 Substrate support surface 28 Locking protrusion 30 First engagement recess 31 Second engagement recess 32 34 Engagement Protrusion 36 First rod (guide rod)
37 Second rod (guide rod)
39 2nd lens frame (lens frame)
39a Rod insertion portion 39b Coil mounting portion 39c Detachment portion 39d Communication hole 39e Nut support recess 39e1 Wall (nut receiving surface)
39e2 Wall 39f Rotation drive shaft insertion hole 39g Rotation drive shaft escape recess 39h Pressed surface (second pressed surface)
40 insertion hole (rod insertion hole)
41 Anti-rotation groove 42 Nut holding hole 44 Driven nut 44a Side surface (first pressed surface)
47 3 group lens frame (lens frame)
47a Rod insertion part 47b Coil attachment part 47c Stopping part 47d Communication hole 47e Nut support recess 47e1 Wall 47e2 Wall (nut receiving surface)
47f Rotation drive shaft escape recess 47g Rotation drive shaft escape recess 47h Pressed surface (second pressed surface)
48 Insertion hole (Rod insertion hole)
49 Rotation Stop Groove 50 Nut Holding Hole 65 Board Module 66 Circuit Board 67 Circular Hole 69 Image Sensor 70 Cover Glass 72 Packing 73 Exposing 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 engaging hole 84 85 86 pressing piece 84a 85a 86a pressing projection A optical axis B fixing screw L1 lens L2 lens L3 lens L4 lens L5 lens L6 lens (moving lens)
LG1 first lens group LG2 second lens group LG3 third lens group LP1 first prism LP1-a entrance surface LP1-b exit surface LP2 second prism LP2-a entrance surface LP2-b exit surface M1 first motor M1a rotational drive Shaft (lead screw)
M2 Second motor M2a Rotation drive shaft (lead screw)
S Spacer S1 Torsion spring S1a Coil part S1b S1c End S2 Torsion spring S2a Coil part S2b S2c End

Claims (8)

A linearly extending guide rod;
A lead screw parallel to the guide rod;
A motor for rotating the lead screw about its axis;
A driven nut having a first pressed surface perpendicular to the axis, screwed to the lead screw;
A nut receiving surface that is slidably supported by the guide rod and that a surface opposite to the first pressed surface of the driven nut contacts, and a second pressed surface that is orthogonal to the axis; And a lens frame that supports the driven nut in a non-rotatable manner and supports a moving lens;
A coil mounting portion formed on the lens frame;
The driven nut is brought into contact with the nut receiving surface by fitting its own coil portion to the coil mounting portion and pressing the first pressed surface in one direction in a direction parallel to the axis. A torsion spring that presses the second pressing surface at the end in a direction parallel to the axis;
An imaging optical system including the moving lens;
An image sensor for receiving imaging light emitted from the imaging optical system;
An imaging unit comprising: The imaging unit according to claim 1,
The lens frame has a pair of walls spaced apart in the axial direction, and one of the walls forms a nut support recess that constitutes the nut receiving surface,
An imaging unit in which the driven nut is disposed in the nut support recess. The imaging unit according to claim 2, wherein
An imaging unit in which the coil mounting recess is formed at a different location from the coil support recess, with the same position in the direction parallel to the coil support recess and the axis. The imaging unit according to any one of claims 1 to 3,
The imaging optical system bends the optical path of photographing light extending along the optical axis of the moving lens,
An imaging unit in which the imaging element receives imaging light of the optical path bent by the imaging optical system. The imaging unit according to claim 4, wherein
The imaging optical system includes a first reflecting surface that bends incident imaging light incident on the imaging unit in a direction perpendicular to the optical axis in the optical axis direction, and imaging light that travels along the optical axis. A second reflecting surface that is bent in a direction parallel to the incident photographing light and led to the image sensor;
An imaging unit in which a central axis of the coil portion is parallel to the incident photographing light. The imaging unit according to any one of claims 1 to 5,
Protruding the coil mounting portion extending in a direction perpendicular to the optical axis to the lens frame,
An imaging unit in which a retaining portion that overlaps a part of the coil portion when viewed in the extending direction of the coil attachment portion is provided at the distal end portion of the coil attachment portion. The imaging unit according to claim 6, wherein
A rod insertion hole that penetrates the rod insertion portion and through which the guide rod is slidably inserted is formed in the rod insertion portion provided in the lens frame,
An imaging unit in which the coil attachment portion extending in a direction perpendicular to the axis of the rod insertion hole is provided on the side surface of the rod insertion portion. The imaging unit according to claim 7, wherein
An imaging unit in which the coil attachment portion is formed with a communication hole that penetrates the coil attachment portion in a direction parallel to the axis of the rod insertion hole and communicates with the through hole.

Images