Lens unit

Abstract

To provide a lens unit that performs eccentricity adjustment of a plastic lens, and that can reduce the positional deviation of the lens from an adjustment position.SOLUTION: A lens unit fixes and holds a lens that has been moved and adjusted in parallel with a receiving surface for positioning the lens in an optical axis direction, and the lens unit comprises: a lens holder that has the receiving surface and holds the lens; a press-hold member that is fixed with respect to the lens holder; and an elastic member that is arranged between the press-hold member and the lens and presses the lens against the lens holder. The lens holder has an opening into which a tool is inserted which is for pressing an outer peripheral surface of the lens to move and adjust the lens in parallel with the receiving surface. A position of the lens is fixed by the press-hold member and the elastic member.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a lens unit. [Background Art]

[0002] In recent years, as cameras have been required to have higher pixels and smaller sizes, eccentricity adjustment for adjusting the optical axis of a lens is sometimes performed. In addition, a plastic lens is sometimes used as the lens.

[0003] As a technique for adjusting eccentricity of and holding a lens, the technique disclosed in Patent Document 1 is known. In Patent Document 1, a lens holding member is provided with a holding claw, the lens is sandwiched between a receiving surface and the holding claw to be in a temporarily fixed state. After that, eccentricity adjustment is performed by pressing the side surface of the lens with an adjustment pin through a through hole, and then an adhesive is injected through an opening to fix the lens. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2007-065017 [Outline of the Invention] [Problem to be Solved by the Invention]

[0005] The technique of Patent Document 1 has a configuration in which the lens is adhesively fixed after eccentricity adjustment. However, some plastic lenses have low hydrophilicity, and adhesive fixing may result in poor adhesive strength. In such a case, adhesive peeling may occur in high or low temperature environments, and there is a risk that the lens will shift from the eccentricity-adjusted position. Further, if the biasing force of the holding claw is increased to eliminate adhesive fixing, the sliding load on the plastic lens increases during eccentricity adjustment, making fine position adjustment difficult.

[0006] The present invention provides a lens unit that can reduce positional displacement of a lens from an adjusted position in a configuration for adjusting the eccentricity of a plastic lens. [Means for solving the problem]

[0007] The lens unit of the present invention has a receiving surface that positions the lens in the optical axis direction, parallel to the optical axis. Eccentricity A lens unit for fixing and holding the adjusted lens, comprising a lens holder having the receiving surface and holding the lens, By screwing into the aforementioned lens holder A retaining member fixed to the lens holder, and a component positioned between the retaining member and the lens, which holds the lens relative to the lens holder. Favoring The lens holder comprises an elastic member, and the lens holder has an opening through which a tool is inserted for pressing the outer surface of the lens to adjust the lens to move parallel to the receiving surface. By pressing the outer surface of the lens with the tool, the lens is biased by the retaining member and the elastic member to allow it to slide, and the lens's eccentricity is adjusted. After the lens's eccentricity is adjusted, the retaining member is screwed into the lens holder to fix it in place. The pressing member and the elastic member Eccentric adjustment position The lens It is characterized by being fixed in place. [Effects of the Invention]

[0008] According to the present invention, in a configuration for adjusting the eccentricity of a plastic lens, a lens unit can be provided that can reduce the misalignment of the lens from the adjustment position. [Brief explanation of the drawing]

[0009] [Figure 1] Perspective view of the imaging device 100 of Embodiment 1 [Figure 2] Exploded perspective view of the imaging device 100 of Embodiment 1 [Figure 3] Exploded perspective view of the lens unit 20 of Embodiment 1 [Figure 4] Side cross-sectional view of the lens unit 20 of Embodiment 1 [Figure 5] Perspective view of the lens unit 20 of Embodiment 1 before eccentricity adjustment. [Figure 6] Perspective view of the lens unit 20 of Embodiment 1 after eccentricity adjustment. [Figure 7] Side cross-sectional view of the lens unit 20 of Embodiment 1 after eccentricity adjustment. [Figure 8] Exploded perspective view of the lens unit 20 of Embodiment 2 [Figure 9] Exploded perspective view of the lens unit 20 of Embodiment 3 [Figure 10] Side cross-sectional view of the lens unit 20 of Embodiment 3 [Figure 11] Exploded perspective view of the lens unit 20 of Embodiment 4 [Figure 12] Side cross-sectional view of the lens unit 20 of Embodiment 4 [Figure 13] Side cross-sectional view during eccentricity adjustment of the lens unit 20 of Embodiment 5 [Figure 14] Exploded perspective view of the lens unit 20 of Embodiment 6 [Figure 15] Side cross-sectional view of the lens unit 20 of Embodiment 6 [Figure 16] Exploded perspective view of the lens unit 20 of Embodiment 7 [Figure 17] Perspective view before eccentricity adjustment of the lens unit 20 of Embodiment 7 [Figure 18] Exploded perspective view of the lens unit 20 of Embodiment 8 [Figure 19] Perspective view before eccentricity adjustment of the lens unit 20 of Embodiment 8 [Figure 20] Perspective view after eccentricity adjustment of the lens unit 20 of Embodiment 8 MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0011] (Embodiment 1) Hereinafter, the lens unit in Embodiment 1 will be described with reference to FIG. 1 to FIG. 7.

[0012] FIG. 1 is a perspective view of the image pickup apparatus 100 according to Embodiment 1. FIG. 2 is an exploded perspective view of the image pickup apparatus 100 according to Embodiment 1. The image pickup apparatus 100 is configured of an image pickup lens unit 200 and an image pickup element unit 300.

[0013] The imaging lens unit 200 has a front housing member 50 and a rear housing member 51. The imaging lens unit 200 has an imaging optical system that includes a first lens group 1, a second lens group 2, and a third lens group 3, in order from the subject side, which is the side opposite to the side where the image sensor unit 300 is located.

[0014] The front housing member 50 is positioned on the subject side, and the rear housing member 51 is positioned on the imaging lens unit 200. The front housing member 50 is fixed to the rear housing member 51 with screws or the like.

[0015] The first lens group 1 is fixed to the front housing member 50 by heat crimping or the like. The second lens group 2 is held in the lens holder 24. The lens holder 24 is supported so as to be movable in the optical axis O direction of the imaging optical system by engaging with the guide bar 52. The lens holder 24 is also engaged with the guide bar 53, and its rotation around the guide bar 52 is restricted. The lens holder 24 also holds the 2-group rack 25. The 2-group rack 25 is engaged with the lead screw portion of the 2-group drive unit 56, which includes an actuator such as a stepping motor. When the lead screw portion is rotated by the 2-group drive unit 56, the lens holder 24 moves together with the 2-group rack 25 in the optical axis O direction of the imaging optical system. The lens unit 20 is composed of the lens holder 24, the 2-group rack 25, the second lens group 2, the retaining member 26, and the elastic member 27. Details of the lens unit 200 will be described later.

[0016] The third lens group 3 is held in the third lens group frame 31. The third lens group frame 31 is supported so as to be movable in the optical axis O direction by engaging with the guide bar 54. The third lens group frame 31 is also engaged with the guide bar 55, restricting its rotation around the guide bar 54. The third lens group frame 31 also holds the third group rack 32. The third group rack 32 is engaged with the lead screw portion of the third group drive unit 57, which includes an actuator such as a stepping motor. When the lead screw portion is rotated by the third group drive unit 57, the third lens group frame 31 moves together with the third group rack 32 in the optical axis O direction of the imaging optical system. Zooming and focusing of the imaging optical system are performed by the movement of the second lens group 2 and the third lens group 3 in the optical axis O direction of the imaging optical system. The guide bars 52, 53, 54, and 55 are sandwiched between the front housing member 50 and the rear housing member 51. Furthermore, the second group drive unit 56 and the third group drive unit 57 are fixed to the rear housing member 51 with screws or the like.

[0017] The image sensor unit 300 includes an image sensor 301 and an imaging substrate 302. The image sensor 301 is mounted on the imaging substrate 302. The imaging substrate 302 is fixed to the rear housing member 51 with screws or the like. However, the imaging substrate 302 may also be fixed to the rear housing member 51 via other members, and is not limited to this configuration. An image can be acquired when light focused by the imaging lens unit 200 is imaged onto the image sensor 301.

[0018] Figure 3 is an exploded perspective view of the lens unit 20 of Embodiment 1. Figure 4 is a side cross-sectional view of the lens unit 20 of Embodiment 1. The lens unit 20 includes a second lens group 2, a lens holder 24, a second group rack 25, a retaining member 26, and an elastic member 27.

[0019] The second lens group 2 consists of an adjustment lens 21, a lens 22, and a lens 23. Both lenses 22 and 23 are fixed to the lens holder 24 by heat scribing. However, the method of fixing lenses 22 and 23 may also be adhesive fixing or pressure fixing with a pressing member, and is not limited to this configuration.

[0020] The adjustment lens 21 is a plastic lens. The adjustment lens 21 is manufactured by molding. The surface of the adjustment lens 21 that contacts the lens holder 24 is the first surface 21a. The surface of the adjustment lens 21 that is located opposite the first surface 21a in the direction of the optical axis O is the second surface 21b. The portion connecting the first surface 21a and the second surface 21b of the adjustment lens 21 is the side surface 21c. The side surface 21c has a surface that is inclined in a direction away from the optical axis O as it moves from the second surface 21b toward the first surface 21a in the direction of the optical axis O. Note that the inclined surface of the side surface 21c does not need to be the entire surface of the side surface 21c, but may be partial. Alternatively, the side surface 21c may be parallel to the optical axis O. The adjustment lens 21 may also have protrusions from the gate marks due to molding.

[0021] The lens holder 24 is a member that holds the second lens group 2. The lens holder 24 is substantially cylindrical. The lens holder 24 has a receiving surface 24d for positioning the lens. The receiving surface 24d positions the lens in the direction of the optical axis. The lens holder 24 has three notches 24a that open in a direction perpendicular to the optical axis O. The notches 24a are for inserting a tool to press the outer circumferential surface of the adjustment lens 21 and adjust its movement parallel to the receiving surface 24d of the lens holder 24. The notches 24a are provided at three locations that divide the peripheral wall of the lens holder 24 into approximately three equal parts in the circumferential direction. The notches 24a open so as to penetrate in a direction perpendicular to the optical axis O. In other words, the notches 24a penetrate so that the adjustment lens 21 is visible when viewed from a direction perpendicular to the optical axis O. The side portion 21c (outer circumferential surface) of the adjustment lens 21 is exposed through the notch 24a even when the retaining member 26 is fixed to the lens holder 24. Note that there do not necessarily have to be three notches 24a; at least one notch 24a is sufficient.

[0022] The second group rack 25 transmits the driving force from the second group drive unit 56 to the second lens group 2. The second group rack 25 is engaged with the lead screw portion of the second group drive unit 56, which includes an actuator such as a stepping motor.

[0023] The retaining member 26 is a member for holding down the elastic member 27 and the adjustment lens 21. The retaining member 26 is in contact with the elastic member 27. The retaining member 26 is circular in shape.

[0024] The elastic member 27 is a component used to fix the adjustment lens 21. The elastic member 27 is circular in shape. The elastic member 27 is sandwiched and compressed between the retaining member 26 and the adjustment lens 21.

[0025] The lens holder 24 and the retaining member 26 have threaded portions, and the retaining member 26 is screwed into and fixed to the lens holder 24. Between the retaining member 26 and the lens holder 24 in the optical axis O direction, an elastic member 27 and an adjustment lens 21 are arranged in that order from the side of the retaining member 26. By screwing the retaining member 26 into and fixing it to the lens holder 24, the elastic member 27 is sandwiched and compressed between the retaining member 26 and the adjustment lens 21. As the elastic member 27 is compressed, the adjustment lens 21 is biased in the optical axis O direction relative to the lens holder 24 by the elastic member 27 and is held in the lens holder 24. Note that the fixing of the lens holder 24 and the retaining member 26 may be done by means of a snap fit, adhesive fixing, or screw fastening, and is not limited to this configuration.

[0026] Figure 5 is a perspective view of the lens unit 20 of Embodiment 1 before eccentricity adjustment. Figure 6 is a perspective view of the lens unit 20 of Embodiment 1 after eccentricity adjustment. Figure 7 is a side cross-sectional view of the lens unit 20 of Embodiment 1 after eccentricity adjustment.

[0027] The method for adjusting and holding the eccentricity of the adjustment lens 21 is described below.

[0028] When adjusting the eccentricity of the adjustment lens 21, an adjustment jig 500, such as a pin, is inserted into the notch 24a and pressed against the side portion 21c of the adjustment lens 21. The adjustment jig 500 may be configured to hold the adjustment lens 21 in suction, and there may be one or more adjustment jigs 500. While checking the image, the adjustment jig 500 is moved forward and backward to move the adjustment lens 21 to a desired position relative to the lens holder 24 in a direction perpendicular to the optical axis O. At this time, by pressing with the adjustment jig 500 from a direction perpendicular to the side portion 21c, the adjustment lens 21 is biased in the direction of the optical axis O relative to the lens holder 24. This prevents the adjustment lens 21 from lifting away from the lens holder 24.

[0029] Furthermore, during eccentricity adjustment, the adjustment lens 21 is not biased by the elastic member 27, so eccentricity adjustment can be performed smoothly in a direction perpendicular to the optical axis O. Alternatively, eccentricity adjustment may be performed with the retaining member 26 screwed into the lens holder 24 to a position where the elastic member 27 is not compressed. Or, the retaining member 26 may be screwed into the lens holder 24 to a position where the elastic member 27 is compressed to the extent that only sliding resistance sufficient for smooth eccentricity adjustment is generated, and eccentricity adjustment may be performed with the adjustment lens 21 biased. By performing eccentricity adjustment with the adjustment lens 21 lightly biased by the elastic member 27, it is possible to prevent the adjustment lens 21 from lifting away from the lens holder 24 regardless of the shape of the side portion 21c. With the eccentricity adjustment complete, the retaining member 26 is screwed into the lens holder 24. At this time, since the position of the adjustment lens 21 is restricted by the adjustment jig 500, the position of the adjustment lens 21 does not deviate from the desired position after eccentricity adjustment. The adjustment jig 500 restricts the position of the adjustment lens 21 until the retaining member 26 is fixed to the lens holder 24. This holds the adjustment lens 21 in the lens holder 24 at the desired position after eccentric adjustment. By removing the adjustment jig 500 after the adjustment lens 21 has been held, the eccentric adjustment and holding of the adjustment lens 21 are completed.

[0030] Furthermore, it is preferable that the coefficients of friction μ1 between the elastic member 27 and the retaining member 26, μ2 between the elastic member 27 and the adjustment lens 21, and μ6 between the adjustment lens 21 and the lens holder 24 are such that μ1 < μ6 or μ2 < μ6. This allows the elastic member 27 to slide and prevent the adjustment lens 21 from rotating even when a load is generated in the rotational direction of the optical axis O when the retaining member 26 is screwed into the lens holder 24. After the adjustment lens 21 is held in place, a light-shielding member or the like may be placed in the opening of the notch 24a to close the opening. By fixing the retaining member 26 to the lens holder 24 after the eccentric adjustment is complete, the adjustment lens 21 is held in the lens holder 24 while maintaining the desired eccentric position. In other words, since the adjustment lens 21 can be held by mechanical means rather than adhesive after the eccentric adjustment of the adjustment lens 21, positional displacement from the lens adjustment position can be reduced even in high and low temperature environments. Furthermore, since the adjustment lens 21 is held in the lens holder 24 by a biasing force in the direction of the optical axis O, it is not subjected to loads from a direction perpendicular to the optical axis O, and distortion of the optical surface is less likely to occur. In addition, since the elastic member 27 biases the surface of the adjustment lens 21 with a substantially uniform force, stress does not concentrate on the adjustment lens 21. Therefore, even when biased with the force necessary to hold the adjustment lens 21, the stress applied to the adjustment lens 21 is distributed, and distortion of the optical surface can be reduced.

[0031] According to this embodiment, a lens unit can be provided that can reduce positional deviation from the adjustment position when adjusting the eccentricity of the lens.

[0032] (Embodiment 2) The lens unit in Embodiment 2 will now be described with reference to Figure 8. In this embodiment, components common to Embodiment 1 are denoted by the same reference numerals as in Embodiment 1. Items common to Embodiment 1 will not be described. In Embodiment 1, the lens holder 24 was provided with a notch 24a, but in Embodiment 2, the lens holder 24 is provided with an opening 24b (through hole).

[0033] Figure 8 is an exploded perspective view of the lens unit 20 of Embodiment 2. The lens holder 24 is a member that holds the second lens group 2. The lens holder 24 is substantially cylindrical. The lens holder 24 has a receiving surface 24d for positioning the lenses. The lens holder 24 has three openings 24b (through holes) that open in a direction perpendicular to the optical axis O. The openings 24b are for inserting a tool to press the outer circumferential surface of the adjustment lens 21 and move the adjustment lens 21 parallel to the receiving surface 24d of the lens holder 24. The openings 24b are provided at three locations that divide the peripheral wall of the lens holder 24 into approximately three equal parts in the circumferential direction. The openings 24b penetrate the side surface of the lens holder 24. The openings 24b open in a direction perpendicular to the optical axis O. In other words, the openings 24b penetrate so that the adjustment lens 21 is visible when viewed from a direction perpendicular to the optical axis O. The outer surface of the adjustment lens 21 is exposed through the opening 24b even when the retaining member 26 is fixed to the lens holder 24. Note that there do not necessarily need to be three openings 24b; at least one opening 24b is sufficient.

[0034] Furthermore, the method for adjusting and holding the eccentricity is the same as in Embodiment 1.

[0035] According to this embodiment, similar to Embodiment 1, a lens unit is provided that can reduce positional deviation from the adjustment position when adjusting the eccentricity of the lens.

[0036] (Embodiment 3) The lens unit in Embodiment 3 will now be described with reference to Figures 9 to 10. In this embodiment, components common to Embodiment 1 are denoted by the same reference numerals as in Embodiment 1. Furthermore, components common to Embodiment 1 will not be described. The lens unit 20 of Embodiment 3 has a plate member 28.

[0037] Figure 9 is an exploded perspective view of the lens unit 20 of Embodiment 3. Figure 10 is a side cross-sectional view of the lens unit 20 of Embodiment 3.

[0038] The lens unit 20 includes a second lens group 2, a lens holder 24, a second group rack 25, a retaining member 26, an elastic member 27, and a plate member 28.

[0039] Between the retaining member 26 and the lens holder 24 in the optical axis O direction, an elastic member 27, a plate member 28, and an adjustment lens 21 are arranged in that order from the retaining member 26 side. When the retaining member 26 is screwed into the lens holder 24 and fixed, the elastic member 27 is sandwiched and compressed between the retaining member 26 and the plate member 28. As the elastic member 27 is compressed, the adjustment lens 21 is biased in the optical axis O direction relative to the lens holder 24 by the elastic member 27 together with the plate member 28, and is held in the lens holder 24.

[0040] Furthermore, the eccentricity adjustment and holding method is the same as in Embodiment 1. The coefficient of friction between the elastic member 27 and the retaining member is μ1, the coefficient of friction between the elastic member 27 and the plate member is μ3, the coefficient of friction between the plate member 28 and the adjustment lens is μ4, and the coefficient of friction between the adjustment lens 21 and the lens holder is μ6. In this case, it is preferable that μ1 < μ6, μ3 < μ6, or μ4 < μ6. This allows the elastic member 27 or the plate member 28 to slide and suppress the rotation of the adjustment lens 21 even when a load is generated in the rotational direction of the optical axis O when the retaining member 26 is screwed into the lens holder 24.

[0041] In this embodiment as well, the lens holder 24 may have an opening 24b instead of a notch 24a, similar to Embodiment 2.

[0042] According to this embodiment, similar to Embodiment 1, a lens unit can be provided that can reduce positional deviation from the adjustment position when adjusting the eccentricity of the lens. Furthermore, even if the elastic member 27 is made of a material that does not slide easily, the plate member 28 slides, so the rotation of the adjustment lens 21 can be suppressed.

[0043] (Embodiment 4) The lens unit in Embodiment 4 will now be described with reference to Figures 11 to 12. In this embodiment, components common to Embodiment 1 are denoted by the same reference numerals as in Embodiment 1. Components common to Embodiment 1 will not be described. The lens unit 20 of Embodiment 4 has a plate member 28, similar to Embodiment 3, and the plate member 28 also serves as a fixed aperture. The arrangement of the plate member 28 and the elastic member 27 differs from that of Embodiment 3.

[0044] Figure 11 is an exploded perspective view of the lens unit 20 of Embodiment 4. Figure 12 is a side cross-sectional view of the lens unit 20 of Embodiment 4.

[0045] The plate member 28 is a fixed aperture, shielding the adjustment lens 21 from unwanted light rays. Due to its light-shielding function, the inner diameter of the plate member 28 is smaller than that of the plate member 28 in Embodiment 3. Between the retaining member 26 and the lens holder 24 in the optical axis O direction, the plate member 28, elastic member 27, and adjustment lens 21 are arranged in that order from the retaining member 26 side. By screwing the retaining member 26 into the lens holder 24 and fixing it, the elastic member 27 is sandwiched and compressed between the plate member 28 and the adjustment lens 21. As the elastic member 27 is compressed, the adjustment lens 21 is biased in the optical axis O direction relative to the lens holder 24 by the elastic member 27 and is held in the lens holder 24.

[0046] Furthermore, the eccentricity adjustment and holding method is the same as in Embodiment 1. The coefficient of friction between the elastic member 27 and the adjustment lens is μ2, the coefficient of friction between the elastic member 27 and the plate member is μ3, the coefficient of friction between the plate member 28 and the retaining member is μ5, and the coefficient of friction between the adjustment lens 21 and the lens holder is μ6. In this case, it is preferable that μ2 < μ6, μ3 < μ6, or μ5 < μ6. This allows the elastic member 27 or the plate member 28 to slide and suppress the rotation of the adjustment lens 21 even when a load is generated in the rotational direction of the optical axis O when the retaining member 26 is screwed into the lens holder 24.

[0047] In this embodiment as well, the lens holder 24 may have an opening 24b instead of a notch 24a, similar to Embodiment 2.

[0048] According to this embodiment, similar to Embodiment 1, a lens unit can be provided that can reduce positional deviation from the adjustment position when adjusting the eccentricity of the lens. Also, similar to Embodiment 3, rotation of the adjustment lens 21 can be suppressed. Furthermore, since the plate member 28 also serves as a fixed aperture, the number of parts can be reduced.

[0049] (Embodiment 5) The lens unit in Embodiment 5 will now be described with reference to Figure 13. In this embodiment, components common to Embodiment 4 are denoted by the same reference numerals as in Embodiment 4. Furthermore, components common to Embodiment 4 will not be described. The lens unit 20 of Embodiment 5 differs from the lens unit 20 of Embodiment 4 in the shape of the adjustment lens 21.

[0050] Figure 13 is a side cross-sectional view of the lens unit 20 of Embodiment 5 during eccentricity adjustment.

[0051] The side portion 21c of the adjustment lens 21 has a stepped shape and has an edge portion 21d, which is the end of the stepped shape. The notch portion 24a is open in a direction perpendicular to the optical axis O. In other words, the notch portion 24a is through which the adjustment lens 21 is visible when viewed from a direction perpendicular to the optical axis O. The edge portion 21d of the adjustment lens 21 is exposed from the notch portion 24a even when the retaining member 26 is fixed to the lens holder 24. Note that the side portion 21c does not have to be stepped as long as it has an edge portion 21d. For example, the edge portion 21d may be provided by chamfering the connection portion between the second surface 21b of the adjustment lens 21 and the side portion 21c. The edge portion 21d may also have an R-chamfer.

[0052] The method for adjusting the eccentricity and holding the adjustment lens 21 is described below. When adjusting the eccentricity of the adjustment lens 21, an adjustment jig 500, such as a pin, is inserted into each of the three notches 24a and pressed against the edge portion 21d of the adjustment lens 21. At this time, the adjustment jig 500 presses against the edge portion 21d from a direction toward the lens holder 24, rather than from a direction perpendicular to the optical axis O. As a result, the adjustment lens 21 is biased toward the optical axis O relative to the lens holder 24, and it is possible to prevent the adjustment lens 21 from lifting away from the lens holder 24. Otherwise, the adjustment lens 21 is held in the lens holder 24 at the desired eccentric position by the same method as the eccentricity adjustment and holding method of Embodiment 1.

[0053] In this embodiment, as in Embodiment 1, the plate member 28 may not be present. Also, as in Embodiment 2, the lens holder 24 may have an opening 24b instead of a notch 24a. Furthermore, as in Embodiment 3, the plate member 28 may be positioned between the elastic member 27 and the adjustment lens 21.

[0054] According to this embodiment, similar to Embodiment 1, a lens unit can be provided that can reduce positional deviation from the adjustment position when adjusting the eccentricity of the lens. Also, similar to Embodiment 4, rotation of the adjustment lens 21 can be suppressed.

[0055] (Embodiment 6) The lens unit in Embodiment 6 will now be described with reference to Figures 14-15. In this embodiment, components common to Embodiment 4 are denoted by the same reference numerals as in Embodiment 4. Furthermore, components common to Embodiment 4 will not be described. The lens unit 20 of Embodiment 6 differs from the lens unit 20 of Embodiment 4 in the shape of the adjustment lens 21.

[0056] Figure 14 is an exploded perspective view of the lens unit 20 of Embodiment 6. Figure 15 is a side cross-sectional view of the lens unit 20 of Embodiment 6.

[0057] The adjustment lens 21 has three protrusions 21e. The side surfaces 21c of the three protrusions 21e are inclined in a direction away from the optical axis as you move from the second surface 21b toward the first surface 21a in the direction of the optical axis O. The lens surfaces other than the protrusions 21e are parallel to the optical axis O. Note that there do not necessarily have to be three protrusions 21e; ​​at least one or more protrusions 21e are sufficient. Also, the lens surfaces other than the protrusions 21e may be inclined with respect to the optical axis O. Furthermore, the side surfaces 21c of the protrusions 21e may be parallel to the optical axis O. Alternatively, as in Embodiment 5, the side surfaces 21c of the protrusions 21e may have an edge portion 21d.

[0058] The lens protrusion 21e is positioned in phase with the notch 24a in the rotational direction of the optical axis O. In other words, the lens protrusion 21e is positioned to correspond to the notch 24a. The notch 24a is open in a direction perpendicular to the optical axis O. In other words, the notch 24a is through which the adjustment lens 21 is visible when viewed from a direction perpendicular to the optical axis O. The lens protrusion 21e of the adjustment lens 21 is exposed from the notch 24a even when the retaining member 26 is fixed to the lens holder 24.

[0059] Furthermore, the method for adjusting and holding the eccentricity is the same as in Embodiment 1. Since the lens sides of the adjustment lens 21 other than the convex portion 21e do not need to be inclined, the adjustment lens 21 can be made smaller in the radial direction in areas other than the convex portion 21e. Moreover, since the convex portion 21e is located in the same phase as the notch portion 24a, the shape of the convex portion 21e does not affect the radial size of the lens holder 24. Therefore, by making the adjustment lens 21 smaller in the radial direction in areas other than the convex portion 21e, the lens holder 24 can be made smaller in the radial direction.

[0060] In this embodiment, as in Embodiment 1, the plate member 28 may not be present. Also, as in Embodiment 2, the lens holder 24 may have an opening 24b instead of a notch 24a. Furthermore, as in Embodiment 3, the plate member 28 may be positioned between the elastic member 27 and the adjustment lens 21.

[0061] According to this embodiment, similar to Embodiment 1, a lens unit can be provided that can reduce positional deviation from the adjustment position when adjusting the eccentricity of the lens. Also, similar to Embodiment 4, rotation of the adjustment lens 21 can be suppressed. Furthermore, the lens holder 24 can be made smaller in the radial direction.

[0062] (Embodiment 7) The lens unit in Embodiment 7 will now be described with reference to Figures 16-17. In this embodiment, components common to Embodiment 1 are denoted by the same reference numerals as in Embodiment 1. Furthermore, components common to Embodiment 1 will not be described. The lens unit 20 of Embodiment 7 differs from the lens unit 20 of Embodiment 1 in the shape of the adjustment lens 21.

[0063] Figure 16 is an exploded perspective view of the lens unit 20 of Embodiment 7. The adjustment lens 21 has three recesses 21f. The side portions 21c of the three recesses 21f are inclined in a direction away from the optical axis as you move from the second surface 21b toward the first surface 21a in the direction of the optical axis O. The lens sides other than the recesses 21f are parallel to the optical axis O. Note that there do not necessarily have to be three recesses 21f; at least one or more recesses 21f are sufficient. Also, the lens sides other than the recesses 21f may be inclined with respect to the optical axis O. Also, the side portions 21c of the recesses 21f may be parallel to the optical axis O. Furthermore, as in Embodiment 5, the side portions 21c of the recesses 21f may have edge portions 21d.

[0064] The lens recess 21f is positioned in phase with the notch 24a in the rotational direction of the optical axis O. In other words, the lens recess 21f is also provided at a position corresponding to the notch 24a. The notch 24a opens in a direction perpendicular to the optical axis O. In other words, the notch 24a penetrates so that the adjustment lens 21 is visible when viewed from a direction perpendicular to the optical axis O. The lens recess 21e of the adjustment lens 21 is exposed from the notch 24a even when the retaining member 26 is fixed to the lens holder 24.

[0065] Figure 17 is a perspective view of the lens unit 20 of Embodiment 7 before eccentricity adjustment.

[0066] The adjustment lens 21 is held in the lens holder 24 at the desired position after eccentric adjustment, in the same manner as the eccentric adjustment and holding method of Embodiment 1. At this time, the adjustment jig 500 is engaged with the recess 21f of the adjustment lens 21. Therefore, the adjustment lens 21 is restricted by the adjustment jig 500 in the rotational direction of the optical axis O, and thus the rotation of the adjustment lens 21 can be suppressed.

[0067] In this embodiment as well, the lens holder 24 may have an opening 24b instead of a notch 24a, similar to Embodiment 2. Furthermore, it may have a plate member 28, similar to Embodiment 3 or Embodiment 4.

[0068] According to this embodiment, similar to Embodiment 1, a lens unit can be provided that can reduce positional deviation from the adjustment position when adjusting the eccentricity of the lens. Furthermore, the rotation of the adjustment lens 21 can be suppressed by the engagement of the recess 21f of the adjustment lens 21 with the adjustment jig 500.

[0069] (Embodiment 8) The lens unit in Embodiment 8 will now be described with reference to Figures 18-20. In this embodiment, components common to Embodiment 1 are denoted by the same reference numerals as in Embodiment 1. Furthermore, components common to Embodiment 1 will not be described. Embodiment 8 has a retaining member 26 with a retaining member opening 26a.

[0070] Figure 18 is an exploded perspective view of the lens unit 20 of Embodiment 8.

[0071] The lens holder 24 has two notches 24a that open in a direction perpendicular to the optical axis O. The notches 24a open in a direction perpendicular to the optical axis O. In other words, the notches 24a penetrate so that the adjustment lens 21 is visible when viewed from a direction perpendicular to the optical axis O. The side portion 21c of the adjustment lens 21 is exposed through the notches 24a even when the retaining member 26 is fixed to the lens holder 24. Note that there are not necessarily two notches 24a; at least one or more notches 24a are sufficient.

[0072] The retaining member 26 has one retaining member opening 26a. The retaining member opening 26a is open in the direction of the optical axis O. The adjustment lens 21 is exposed through the retaining member opening 26a. Note that there may be more than one retaining member opening 26a.

[0073] Figure 19 is a perspective view of the lens unit 20 of Embodiment 8 before eccentricity adjustment.

[0074] Figure 20 is a perspective view of the lens unit 20 of Embodiment 8 after eccentricity adjustment.

[0075] The eccentricity adjustment is performed with the retaining member 26 screwed into the lens holder 24 to a position where the elastic member 27 is not compressed. Alternatively, the eccentricity adjustment may be performed with the adjustment lens 21 biased after screwing the retaining member 26 into the lens holder 24 to a position where the elastic member 27 is compressed to a degree that allows for sufficiently smooth eccentricity adjustment.

[0076] An adjustment jig 500, such as a pin, is inserted into the notch 24a and the retaining member opening 26a to press against the side portion 21c of the adjustment lens 21. This adjusts the eccentricity of the adjustment lens 21 in the same manner as in Embodiment 1. Once the eccentricity adjustment is complete, the retaining member 26 is screwed into the lens holder 24. At this time, the retaining member 26 rotates around the optical axis O as it is screwed in, but since the retaining member opening 26a extends in the direction of rotation, it does not interfere with the adjustment jig 500. Therefore, the position of the adjustment lens 21 can be restricted by the adjustment jig 500 while the retaining member 26 is screwed into the lens holder 24 and fixed. Otherwise, the adjustment lens 21 is held in the lens holder 24 at the desired eccentric position in the same manner as in Embodiment 1. Note that, as in Embodiment 1, the method of fixing the retaining member 26 and the lens holder 24 is not limited to screwing, and the opening shape of the retaining member opening 26a is not limited to the shape of this embodiment.

[0077] In this embodiment as well, the lens holder 24 may have an opening 24b instead of a notch 24a, similar to Embodiment 2. It may also have a plate member 28, similar to Embodiment 3 or Embodiment 4. Furthermore, similar to Embodiment 5, the side portion 21c of the adjustment lens 21 may have an edge portion 21d. Also, similar to Embodiment 6, the adjustment lens 21 may have a convex portion 21e. Alternatively, similar to Embodiment 7, the adjustment lens 21 may have a concave portion 21f.

[0078] According to this embodiment, similar to Embodiment 1, a lens unit is provided that can reduce positional deviation from the adjustment position when adjusting the eccentricity of the lens.

[0079] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. Furthermore, the invention is not limited to any configuration that takes design functionality into consideration. [Explanation of Symbols]

[0080] 1. First lens group 2. Second lens group 3. Third lens group 21 Adjustable lenses 21a Lens first surface 21b Lens second surface 21c Side part 21d edge 21e protrusion 21f recess 22, 23 lenses 24 Lens holder 24a Notch 24b opening 25 racks, 2 groups 26 Retaining member 26a Retaining member opening 27 Elastic members 28 Plate members 31 Third lens group frame 32 racks with 3 groups 50 Front housing member 51 Rear housing member 52, 53, 54, 55 Guide bars 56 Group 2 drive unit 57 3-group drive unit 200 imaging lens unit 300 Image Sensor Units 301 Image sensor 302 Imaging substrate 500 Adjustment Jig

Claims

1. A lens unit that fixes and holds the lens after it has been eccentrically adjusted parallel to a receiving surface that positions the lens in the optical axis direction, A lens holder having the aforementioned receiving surface and holding the lens, A retaining member that is fixed to the lens holder by being screwed into the lens holder, The system comprises an elastic member positioned between the retaining member and the lens, which biases the lens relative to the lens holder, The lens holder has an opening through which a tool is inserted for pressing the outer surface of the lens and adjusting the lens to move parallel to the receiving surface. A lens unit characterized in that the lens eccentricity is adjusted while the lens is biased by the retaining member and the elastic member so that it can slide by pressing the outer surface of the lens with the tool, and after the eccentricity adjustment of the lens, the retaining member is screwed into the lens holder and fixed, thereby fixing the lens in the position adjusted by the retaining member and the elastic member.

2. The lens unit according to claim 1, characterized in that the opening is a through hole or a notch.

3. The lens unit according to claim 1, characterized in that the opening is provided on the side surface of the lens holder.

4. A step of adjusting the eccentricity by pressing the outer surface of the lens parallel to the receiving surface of the lens holder through an opening provided in the lens holder that holds the lens, The process includes a step of fixing the retaining member to the lens holder by screwing it in, A method for fixing a lens unit, characterized in that, when the retaining member is fixed to the lens holder, the lens is biased against the lens holder by an elastic member positioned between the retaining member and the lens so that the lens can slide by pressing the outer surface of the lens against it, and the eccentricity of the lens is adjusted while the lens is biased against the lens holder by an elastic member positioned between the retaining member and the lens, and after the eccentricity of the lens is adjusted, the retaining member is screwed into the lens holder and fixed, thereby fixing the lens to the position adjusted by the retaining member and the elastic member.

Images